File: | src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Transforms/IPO/AttributorAttributes.cpp |
Warning: | line 5899, column 9 Value stored to 'HasChanged' is never read |
Press '?' to see keyboard shortcuts
Keyboard shortcuts:
1 | //===- AttributorAttributes.cpp - Attributes for Attributor deduction -----===// |
2 | // |
3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
4 | // See https://llvm.org/LICENSE.txt for license information. |
5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
6 | // |
7 | //===----------------------------------------------------------------------===// |
8 | // |
9 | // See the Attributor.h file comment and the class descriptions in that file for |
10 | // more information. |
11 | // |
12 | //===----------------------------------------------------------------------===// |
13 | |
14 | #include "llvm/Transforms/IPO/Attributor.h" |
15 | |
16 | #include "llvm/ADT/APInt.h" |
17 | #include "llvm/ADT/SCCIterator.h" |
18 | #include "llvm/ADT/SmallPtrSet.h" |
19 | #include "llvm/ADT/Statistic.h" |
20 | #include "llvm/Analysis/AliasAnalysis.h" |
21 | #include "llvm/Analysis/AssumeBundleQueries.h" |
22 | #include "llvm/Analysis/AssumptionCache.h" |
23 | #include "llvm/Analysis/CaptureTracking.h" |
24 | #include "llvm/Analysis/InstructionSimplify.h" |
25 | #include "llvm/Analysis/LazyValueInfo.h" |
26 | #include "llvm/Analysis/MemoryBuiltins.h" |
27 | #include "llvm/Analysis/OptimizationRemarkEmitter.h" |
28 | #include "llvm/Analysis/ScalarEvolution.h" |
29 | #include "llvm/Analysis/TargetTransformInfo.h" |
30 | #include "llvm/Analysis/ValueTracking.h" |
31 | #include "llvm/IR/Constants.h" |
32 | #include "llvm/IR/IRBuilder.h" |
33 | #include "llvm/IR/Instruction.h" |
34 | #include "llvm/IR/Instructions.h" |
35 | #include "llvm/IR/IntrinsicInst.h" |
36 | #include "llvm/IR/NoFolder.h" |
37 | #include "llvm/Support/Alignment.h" |
38 | #include "llvm/Support/Casting.h" |
39 | #include "llvm/Support/CommandLine.h" |
40 | #include "llvm/Support/ErrorHandling.h" |
41 | #include "llvm/Support/FileSystem.h" |
42 | #include "llvm/Support/raw_ostream.h" |
43 | #include "llvm/Transforms/IPO/ArgumentPromotion.h" |
44 | #include "llvm/Transforms/Utils/Local.h" |
45 | #include <cassert> |
46 | |
47 | using namespace llvm; |
48 | |
49 | #define DEBUG_TYPE"attributor" "attributor" |
50 | |
51 | static cl::opt<bool> ManifestInternal( |
52 | "attributor-manifest-internal", cl::Hidden, |
53 | cl::desc("Manifest Attributor internal string attributes."), |
54 | cl::init(false)); |
55 | |
56 | static cl::opt<int> MaxHeapToStackSize("max-heap-to-stack-size", cl::init(128), |
57 | cl::Hidden); |
58 | |
59 | template <> |
60 | unsigned llvm::PotentialConstantIntValuesState::MaxPotentialValues = 0; |
61 | |
62 | static cl::opt<unsigned, true> MaxPotentialValues( |
63 | "attributor-max-potential-values", cl::Hidden, |
64 | cl::desc("Maximum number of potential values to be " |
65 | "tracked for each position."), |
66 | cl::location(llvm::PotentialConstantIntValuesState::MaxPotentialValues), |
67 | cl::init(7)); |
68 | |
69 | STATISTIC(NumAAs, "Number of abstract attributes created")static llvm::Statistic NumAAs = {"attributor", "NumAAs", "Number of abstract attributes created" }; |
70 | |
71 | // Some helper macros to deal with statistics tracking. |
72 | // |
73 | // Usage: |
74 | // For simple IR attribute tracking overload trackStatistics in the abstract |
75 | // attribute and choose the right STATS_DECLTRACK_********* macro, |
76 | // e.g.,: |
77 | // void trackStatistics() const override { |
78 | // STATS_DECLTRACK_ARG_ATTR(returned) |
79 | // } |
80 | // If there is a single "increment" side one can use the macro |
81 | // STATS_DECLTRACK with a custom message. If there are multiple increment |
82 | // sides, STATS_DECL and STATS_TRACK can also be used separately. |
83 | // |
84 | #define BUILD_STAT_MSG_IR_ATTR(TYPE, NAME)("Number of " "TYPE" " marked '" "NAME" "'") \ |
85 | ("Number of " #TYPE " marked '" #NAME "'") |
86 | #define BUILD_STAT_NAME(NAME, TYPE)NumIRTYPE_NAME NumIR##TYPE##_##NAME |
87 | #define STATS_DECL_(NAME, MSG)static llvm::Statistic NAME = {"attributor", "NAME", MSG}; STATISTIC(NAME, MSG)static llvm::Statistic NAME = {"attributor", "NAME", MSG}; |
88 | #define STATS_DECL(NAME, TYPE, MSG)static llvm::Statistic NumIRTYPE_NAME = {"attributor", "NumIRTYPE_NAME" , MSG};; \ |
89 | STATS_DECL_(BUILD_STAT_NAME(NAME, TYPE), MSG)static llvm::Statistic NumIRTYPE_NAME = {"attributor", "NumIRTYPE_NAME" , MSG};; |
90 | #define STATS_TRACK(NAME, TYPE)++(NumIRTYPE_NAME); ++(BUILD_STAT_NAME(NAME, TYPE)NumIRTYPE_NAME); |
91 | #define STATS_DECLTRACK(NAME, TYPE, MSG){ static llvm::Statistic NumIRTYPE_NAME = {"attributor", "NumIRTYPE_NAME" , MSG};; ++(NumIRTYPE_NAME); } \ |
92 | { \ |
93 | STATS_DECL(NAME, TYPE, MSG)static llvm::Statistic NumIRTYPE_NAME = {"attributor", "NumIRTYPE_NAME" , MSG};; \ |
94 | STATS_TRACK(NAME, TYPE)++(NumIRTYPE_NAME); \ |
95 | } |
96 | #define STATS_DECLTRACK_ARG_ATTR(NAME){ static llvm::Statistic NumIRArguments_NAME = {"attributor", "NumIRArguments_NAME", ("Number of " "arguments" " marked '" "NAME" "'")};; ++(NumIRArguments_NAME); } \ |
97 | STATS_DECLTRACK(NAME, Arguments, BUILD_STAT_MSG_IR_ATTR(arguments, NAME)){ static llvm::Statistic NumIRArguments_NAME = {"attributor", "NumIRArguments_NAME", ("Number of " "arguments" " marked '" "NAME" "'")};; ++(NumIRArguments_NAME); } |
98 | #define STATS_DECLTRACK_CSARG_ATTR(NAME){ static llvm::Statistic NumIRCSArguments_NAME = {"attributor" , "NumIRCSArguments_NAME", ("Number of " "call site arguments" " marked '" "NAME" "'")};; ++(NumIRCSArguments_NAME); } \ |
99 | STATS_DECLTRACK(NAME, CSArguments, \{ static llvm::Statistic NumIRCSArguments_NAME = {"attributor" , "NumIRCSArguments_NAME", ("Number of " "call site arguments" " marked '" "NAME" "'")};; ++(NumIRCSArguments_NAME); } |
100 | BUILD_STAT_MSG_IR_ATTR(call site arguments, NAME)){ static llvm::Statistic NumIRCSArguments_NAME = {"attributor" , "NumIRCSArguments_NAME", ("Number of " "call site arguments" " marked '" "NAME" "'")};; ++(NumIRCSArguments_NAME); } |
101 | #define STATS_DECLTRACK_FN_ATTR(NAME){ static llvm::Statistic NumIRFunction_NAME = {"attributor", "NumIRFunction_NAME" , ("Number of " "functions" " marked '" "NAME" "'")};; ++(NumIRFunction_NAME ); } \ |
102 | STATS_DECLTRACK(NAME, Function, BUILD_STAT_MSG_IR_ATTR(functions, NAME)){ static llvm::Statistic NumIRFunction_NAME = {"attributor", "NumIRFunction_NAME" , ("Number of " "functions" " marked '" "NAME" "'")};; ++(NumIRFunction_NAME ); } |
103 | #define STATS_DECLTRACK_CS_ATTR(NAME){ static llvm::Statistic NumIRCS_NAME = {"attributor", "NumIRCS_NAME" , ("Number of " "call site" " marked '" "NAME" "'")};; ++(NumIRCS_NAME ); } \ |
104 | STATS_DECLTRACK(NAME, CS, BUILD_STAT_MSG_IR_ATTR(call site, NAME)){ static llvm::Statistic NumIRCS_NAME = {"attributor", "NumIRCS_NAME" , ("Number of " "call site" " marked '" "NAME" "'")};; ++(NumIRCS_NAME ); } |
105 | #define STATS_DECLTRACK_FNRET_ATTR(NAME){ static llvm::Statistic NumIRFunctionReturn_NAME = {"attributor" , "NumIRFunctionReturn_NAME", ("Number of " "function returns" " marked '" "NAME" "'")};; ++(NumIRFunctionReturn_NAME); } \ |
106 | STATS_DECLTRACK(NAME, FunctionReturn, \{ static llvm::Statistic NumIRFunctionReturn_NAME = {"attributor" , "NumIRFunctionReturn_NAME", ("Number of " "function returns" " marked '" "NAME" "'")};; ++(NumIRFunctionReturn_NAME); } |
107 | BUILD_STAT_MSG_IR_ATTR(function returns, NAME)){ static llvm::Statistic NumIRFunctionReturn_NAME = {"attributor" , "NumIRFunctionReturn_NAME", ("Number of " "function returns" " marked '" "NAME" "'")};; ++(NumIRFunctionReturn_NAME); } |
108 | #define STATS_DECLTRACK_CSRET_ATTR(NAME){ static llvm::Statistic NumIRCSReturn_NAME = {"attributor", "NumIRCSReturn_NAME" , ("Number of " "call site returns" " marked '" "NAME" "'")}; ; ++(NumIRCSReturn_NAME); } \ |
109 | STATS_DECLTRACK(NAME, CSReturn, \{ static llvm::Statistic NumIRCSReturn_NAME = {"attributor", "NumIRCSReturn_NAME" , ("Number of " "call site returns" " marked '" "NAME" "'")}; ; ++(NumIRCSReturn_NAME); } |
110 | BUILD_STAT_MSG_IR_ATTR(call site returns, NAME)){ static llvm::Statistic NumIRCSReturn_NAME = {"attributor", "NumIRCSReturn_NAME" , ("Number of " "call site returns" " marked '" "NAME" "'")}; ; ++(NumIRCSReturn_NAME); } |
111 | #define STATS_DECLTRACK_FLOATING_ATTR(NAME){ static llvm::Statistic NumIRFloating_NAME = {"attributor", "NumIRFloating_NAME" , ("Number of floating values known to be '" "NAME" "'")};; ++ (NumIRFloating_NAME); } \ |
112 | STATS_DECLTRACK(NAME, Floating, \{ static llvm::Statistic NumIRFloating_NAME = {"attributor", "NumIRFloating_NAME" , ("Number of floating values known to be '" #NAME "'")};; ++ (NumIRFloating_NAME); } |
113 | ("Number of floating values known to be '" #NAME "'")){ static llvm::Statistic NumIRFloating_NAME = {"attributor", "NumIRFloating_NAME" , ("Number of floating values known to be '" #NAME "'")};; ++ (NumIRFloating_NAME); } |
114 | |
115 | // Specialization of the operator<< for abstract attributes subclasses. This |
116 | // disambiguates situations where multiple operators are applicable. |
117 | namespace llvm { |
118 | #define PIPE_OPERATOR(CLASS) \ |
119 | raw_ostream &operator<<(raw_ostream &OS, const CLASS &AA) { \ |
120 | return OS << static_cast<const AbstractAttribute &>(AA); \ |
121 | } |
122 | |
123 | PIPE_OPERATOR(AAIsDead) |
124 | PIPE_OPERATOR(AANoUnwind) |
125 | PIPE_OPERATOR(AANoSync) |
126 | PIPE_OPERATOR(AANoRecurse) |
127 | PIPE_OPERATOR(AAWillReturn) |
128 | PIPE_OPERATOR(AANoReturn) |
129 | PIPE_OPERATOR(AAReturnedValues) |
130 | PIPE_OPERATOR(AANonNull) |
131 | PIPE_OPERATOR(AANoAlias) |
132 | PIPE_OPERATOR(AADereferenceable) |
133 | PIPE_OPERATOR(AAAlign) |
134 | PIPE_OPERATOR(AANoCapture) |
135 | PIPE_OPERATOR(AAValueSimplify) |
136 | PIPE_OPERATOR(AANoFree) |
137 | PIPE_OPERATOR(AAHeapToStack) |
138 | PIPE_OPERATOR(AAReachability) |
139 | PIPE_OPERATOR(AAMemoryBehavior) |
140 | PIPE_OPERATOR(AAMemoryLocation) |
141 | PIPE_OPERATOR(AAValueConstantRange) |
142 | PIPE_OPERATOR(AAPrivatizablePtr) |
143 | PIPE_OPERATOR(AAUndefinedBehavior) |
144 | PIPE_OPERATOR(AAPotentialValues) |
145 | PIPE_OPERATOR(AANoUndef) |
146 | PIPE_OPERATOR(AACallEdges) |
147 | PIPE_OPERATOR(AAFunctionReachability) |
148 | PIPE_OPERATOR(AAPointerInfo) |
149 | |
150 | #undef PIPE_OPERATOR |
151 | |
152 | template <> |
153 | ChangeStatus clampStateAndIndicateChange<DerefState>(DerefState &S, |
154 | const DerefState &R) { |
155 | ChangeStatus CS0 = |
156 | clampStateAndIndicateChange(S.DerefBytesState, R.DerefBytesState); |
157 | ChangeStatus CS1 = clampStateAndIndicateChange(S.GlobalState, R.GlobalState); |
158 | return CS0 | CS1; |
159 | } |
160 | |
161 | } // namespace llvm |
162 | |
163 | /// Get pointer operand of memory accessing instruction. If \p I is |
164 | /// not a memory accessing instruction, return nullptr. If \p AllowVolatile, |
165 | /// is set to false and the instruction is volatile, return nullptr. |
166 | static const Value *getPointerOperand(const Instruction *I, |
167 | bool AllowVolatile) { |
168 | if (!AllowVolatile && I->isVolatile()) |
169 | return nullptr; |
170 | |
171 | if (auto *LI = dyn_cast<LoadInst>(I)) { |
172 | return LI->getPointerOperand(); |
173 | } |
174 | |
175 | if (auto *SI = dyn_cast<StoreInst>(I)) { |
176 | return SI->getPointerOperand(); |
177 | } |
178 | |
179 | if (auto *CXI = dyn_cast<AtomicCmpXchgInst>(I)) { |
180 | return CXI->getPointerOperand(); |
181 | } |
182 | |
183 | if (auto *RMWI = dyn_cast<AtomicRMWInst>(I)) { |
184 | return RMWI->getPointerOperand(); |
185 | } |
186 | |
187 | return nullptr; |
188 | } |
189 | |
190 | /// Helper function to create a pointer of type \p ResTy, based on \p Ptr, and |
191 | /// advanced by \p Offset bytes. To aid later analysis the method tries to build |
192 | /// getelement pointer instructions that traverse the natural type of \p Ptr if |
193 | /// possible. If that fails, the remaining offset is adjusted byte-wise, hence |
194 | /// through a cast to i8*. |
195 | /// |
196 | /// TODO: This could probably live somewhere more prominantly if it doesn't |
197 | /// already exist. |
198 | static Value *constructPointer(Type *ResTy, Type *PtrElemTy, Value *Ptr, |
199 | int64_t Offset, IRBuilder<NoFolder> &IRB, |
200 | const DataLayout &DL) { |
201 | assert(Offset >= 0 && "Negative offset not supported yet!")((void)0); |
202 | LLVM_DEBUG(dbgs() << "Construct pointer: " << *Ptr << " + " << Offsetdo { } while (false) |
203 | << "-bytes as " << *ResTy << "\n")do { } while (false); |
204 | |
205 | if (Offset) { |
206 | SmallVector<Value *, 4> Indices; |
207 | std::string GEPName = Ptr->getName().str() + ".0"; |
208 | |
209 | // Add 0 index to look through the pointer. |
210 | assert((uint64_t)Offset < DL.getTypeAllocSize(PtrElemTy) &&((void)0) |
211 | "Offset out of bounds")((void)0); |
212 | Indices.push_back(Constant::getNullValue(IRB.getInt32Ty())); |
213 | |
214 | Type *Ty = PtrElemTy; |
215 | do { |
216 | auto *STy = dyn_cast<StructType>(Ty); |
217 | if (!STy) |
218 | // Non-aggregate type, we cast and make byte-wise progress now. |
219 | break; |
220 | |
221 | const StructLayout *SL = DL.getStructLayout(STy); |
222 | if (int64_t(SL->getSizeInBytes()) < Offset) |
223 | break; |
224 | |
225 | uint64_t Idx = SL->getElementContainingOffset(Offset); |
226 | assert(Idx < STy->getNumElements() && "Offset calculation error!")((void)0); |
227 | uint64_t Rem = Offset - SL->getElementOffset(Idx); |
228 | Ty = STy->getElementType(Idx); |
229 | |
230 | LLVM_DEBUG(errs() << "Ty: " << *Ty << " Offset: " << Offsetdo { } while (false) |
231 | << " Idx: " << Idx << " Rem: " << Rem << "\n")do { } while (false); |
232 | |
233 | GEPName += "." + std::to_string(Idx); |
234 | Indices.push_back(ConstantInt::get(IRB.getInt32Ty(), Idx)); |
235 | Offset = Rem; |
236 | } while (Offset); |
237 | |
238 | // Create a GEP for the indices collected above. |
239 | Ptr = IRB.CreateGEP(PtrElemTy, Ptr, Indices, GEPName); |
240 | |
241 | // If an offset is left we use byte-wise adjustment. |
242 | if (Offset) { |
243 | Ptr = IRB.CreateBitCast(Ptr, IRB.getInt8PtrTy()); |
244 | Ptr = IRB.CreateGEP(IRB.getInt8Ty(), Ptr, IRB.getInt32(Offset), |
245 | GEPName + ".b" + Twine(Offset)); |
246 | } |
247 | } |
248 | |
249 | // Ensure the result has the requested type. |
250 | Ptr = IRB.CreateBitOrPointerCast(Ptr, ResTy, Ptr->getName() + ".cast"); |
251 | |
252 | LLVM_DEBUG(dbgs() << "Constructed pointer: " << *Ptr << "\n")do { } while (false); |
253 | return Ptr; |
254 | } |
255 | |
256 | /// Recursively visit all values that might become \p IRP at some point. This |
257 | /// will be done by looking through cast instructions, selects, phis, and calls |
258 | /// with the "returned" attribute. Once we cannot look through the value any |
259 | /// further, the callback \p VisitValueCB is invoked and passed the current |
260 | /// value, the \p State, and a flag to indicate if we stripped anything. |
261 | /// Stripped means that we unpacked the value associated with \p IRP at least |
262 | /// once. Note that the value used for the callback may still be the value |
263 | /// associated with \p IRP (due to PHIs). To limit how much effort is invested, |
264 | /// we will never visit more values than specified by \p MaxValues. |
265 | template <typename StateTy> |
266 | static bool genericValueTraversal( |
267 | Attributor &A, IRPosition IRP, const AbstractAttribute &QueryingAA, |
268 | StateTy &State, |
269 | function_ref<bool(Value &, const Instruction *, StateTy &, bool)> |
270 | VisitValueCB, |
271 | const Instruction *CtxI, bool UseValueSimplify = true, int MaxValues = 16, |
272 | function_ref<Value *(Value *)> StripCB = nullptr) { |
273 | |
274 | const AAIsDead *LivenessAA = nullptr; |
275 | if (IRP.getAnchorScope()) |
276 | LivenessAA = &A.getAAFor<AAIsDead>( |
277 | QueryingAA, |
278 | IRPosition::function(*IRP.getAnchorScope(), IRP.getCallBaseContext()), |
279 | DepClassTy::NONE); |
280 | bool AnyDead = false; |
281 | |
282 | Value *InitialV = &IRP.getAssociatedValue(); |
283 | using Item = std::pair<Value *, const Instruction *>; |
284 | SmallSet<Item, 16> Visited; |
285 | SmallVector<Item, 16> Worklist; |
286 | Worklist.push_back({InitialV, CtxI}); |
287 | |
288 | int Iteration = 0; |
289 | do { |
290 | Item I = Worklist.pop_back_val(); |
291 | Value *V = I.first; |
292 | CtxI = I.second; |
293 | if (StripCB) |
294 | V = StripCB(V); |
295 | |
296 | // Check if we should process the current value. To prevent endless |
297 | // recursion keep a record of the values we followed! |
298 | if (!Visited.insert(I).second) |
299 | continue; |
300 | |
301 | // Make sure we limit the compile time for complex expressions. |
302 | if (Iteration++ >= MaxValues) |
303 | return false; |
304 | |
305 | // Explicitly look through calls with a "returned" attribute if we do |
306 | // not have a pointer as stripPointerCasts only works on them. |
307 | Value *NewV = nullptr; |
308 | if (V->getType()->isPointerTy()) { |
309 | NewV = V->stripPointerCasts(); |
310 | } else { |
311 | auto *CB = dyn_cast<CallBase>(V); |
312 | if (CB && CB->getCalledFunction()) { |
313 | for (Argument &Arg : CB->getCalledFunction()->args()) |
314 | if (Arg.hasReturnedAttr()) { |
315 | NewV = CB->getArgOperand(Arg.getArgNo()); |
316 | break; |
317 | } |
318 | } |
319 | } |
320 | if (NewV && NewV != V) { |
321 | Worklist.push_back({NewV, CtxI}); |
322 | continue; |
323 | } |
324 | |
325 | // Look through select instructions, visit assumed potential values. |
326 | if (auto *SI = dyn_cast<SelectInst>(V)) { |
327 | bool UsedAssumedInformation = false; |
328 | Optional<Constant *> C = A.getAssumedConstant( |
329 | *SI->getCondition(), QueryingAA, UsedAssumedInformation); |
330 | bool NoValueYet = !C.hasValue(); |
331 | if (NoValueYet || isa_and_nonnull<UndefValue>(*C)) |
332 | continue; |
333 | if (auto *CI = dyn_cast_or_null<ConstantInt>(*C)) { |
334 | if (CI->isZero()) |
335 | Worklist.push_back({SI->getFalseValue(), CtxI}); |
336 | else |
337 | Worklist.push_back({SI->getTrueValue(), CtxI}); |
338 | continue; |
339 | } |
340 | // We could not simplify the condition, assume both values.( |
341 | Worklist.push_back({SI->getTrueValue(), CtxI}); |
342 | Worklist.push_back({SI->getFalseValue(), CtxI}); |
343 | continue; |
344 | } |
345 | |
346 | // Look through phi nodes, visit all live operands. |
347 | if (auto *PHI = dyn_cast<PHINode>(V)) { |
348 | assert(LivenessAA &&((void)0) |
349 | "Expected liveness in the presence of instructions!")((void)0); |
350 | for (unsigned u = 0, e = PHI->getNumIncomingValues(); u < e; u++) { |
351 | BasicBlock *IncomingBB = PHI->getIncomingBlock(u); |
352 | bool UsedAssumedInformation = false; |
353 | if (A.isAssumedDead(*IncomingBB->getTerminator(), &QueryingAA, |
354 | LivenessAA, UsedAssumedInformation, |
355 | /* CheckBBLivenessOnly */ true)) { |
356 | AnyDead = true; |
357 | continue; |
358 | } |
359 | Worklist.push_back( |
360 | {PHI->getIncomingValue(u), IncomingBB->getTerminator()}); |
361 | } |
362 | continue; |
363 | } |
364 | |
365 | if (UseValueSimplify && !isa<Constant>(V)) { |
366 | bool UsedAssumedInformation = false; |
367 | Optional<Value *> SimpleV = |
368 | A.getAssumedSimplified(*V, QueryingAA, UsedAssumedInformation); |
369 | if (!SimpleV.hasValue()) |
370 | continue; |
371 | if (!SimpleV.getValue()) |
372 | return false; |
373 | Value *NewV = SimpleV.getValue(); |
374 | if (NewV != V) { |
375 | Worklist.push_back({NewV, CtxI}); |
376 | continue; |
377 | } |
378 | } |
379 | |
380 | // Once a leaf is reached we inform the user through the callback. |
381 | if (!VisitValueCB(*V, CtxI, State, Iteration > 1)) |
382 | return false; |
383 | } while (!Worklist.empty()); |
384 | |
385 | // If we actually used liveness information so we have to record a dependence. |
386 | if (AnyDead) |
387 | A.recordDependence(*LivenessAA, QueryingAA, DepClassTy::OPTIONAL); |
388 | |
389 | // All values have been visited. |
390 | return true; |
391 | } |
392 | |
393 | bool AA::getAssumedUnderlyingObjects(Attributor &A, const Value &Ptr, |
394 | SmallVectorImpl<Value *> &Objects, |
395 | const AbstractAttribute &QueryingAA, |
396 | const Instruction *CtxI) { |
397 | auto StripCB = [&](Value *V) { return getUnderlyingObject(V); }; |
398 | SmallPtrSet<Value *, 8> SeenObjects; |
399 | auto VisitValueCB = [&SeenObjects](Value &Val, const Instruction *, |
400 | SmallVectorImpl<Value *> &Objects, |
401 | bool) -> bool { |
402 | if (SeenObjects.insert(&Val).second) |
403 | Objects.push_back(&Val); |
404 | return true; |
405 | }; |
406 | if (!genericValueTraversal<decltype(Objects)>( |
407 | A, IRPosition::value(Ptr), QueryingAA, Objects, VisitValueCB, CtxI, |
408 | true, 32, StripCB)) |
409 | return false; |
410 | return true; |
411 | } |
412 | |
413 | const Value *stripAndAccumulateMinimalOffsets( |
414 | Attributor &A, const AbstractAttribute &QueryingAA, const Value *Val, |
415 | const DataLayout &DL, APInt &Offset, bool AllowNonInbounds, |
416 | bool UseAssumed = false) { |
417 | |
418 | auto AttributorAnalysis = [&](Value &V, APInt &ROffset) -> bool { |
419 | const IRPosition &Pos = IRPosition::value(V); |
420 | // Only track dependence if we are going to use the assumed info. |
421 | const AAValueConstantRange &ValueConstantRangeAA = |
422 | A.getAAFor<AAValueConstantRange>(QueryingAA, Pos, |
423 | UseAssumed ? DepClassTy::OPTIONAL |
424 | : DepClassTy::NONE); |
425 | ConstantRange Range = UseAssumed ? ValueConstantRangeAA.getAssumed() |
426 | : ValueConstantRangeAA.getKnown(); |
427 | // We can only use the lower part of the range because the upper part can |
428 | // be higher than what the value can really be. |
429 | ROffset = Range.getSignedMin(); |
430 | return true; |
431 | }; |
432 | |
433 | return Val->stripAndAccumulateConstantOffsets(DL, Offset, AllowNonInbounds, |
434 | AttributorAnalysis); |
435 | } |
436 | |
437 | static const Value *getMinimalBaseOfAccsesPointerOperand( |
438 | Attributor &A, const AbstractAttribute &QueryingAA, const Instruction *I, |
439 | int64_t &BytesOffset, const DataLayout &DL, bool AllowNonInbounds = false) { |
440 | const Value *Ptr = getPointerOperand(I, /* AllowVolatile */ false); |
441 | if (!Ptr) |
442 | return nullptr; |
443 | APInt OffsetAPInt(DL.getIndexTypeSizeInBits(Ptr->getType()), 0); |
444 | const Value *Base = stripAndAccumulateMinimalOffsets( |
445 | A, QueryingAA, Ptr, DL, OffsetAPInt, AllowNonInbounds); |
446 | |
447 | BytesOffset = OffsetAPInt.getSExtValue(); |
448 | return Base; |
449 | } |
450 | |
451 | static const Value * |
452 | getBasePointerOfAccessPointerOperand(const Instruction *I, int64_t &BytesOffset, |
453 | const DataLayout &DL, |
454 | bool AllowNonInbounds = false) { |
455 | const Value *Ptr = getPointerOperand(I, /* AllowVolatile */ false); |
456 | if (!Ptr) |
457 | return nullptr; |
458 | |
459 | return GetPointerBaseWithConstantOffset(Ptr, BytesOffset, DL, |
460 | AllowNonInbounds); |
461 | } |
462 | |
463 | /// Clamp the information known for all returned values of a function |
464 | /// (identified by \p QueryingAA) into \p S. |
465 | template <typename AAType, typename StateType = typename AAType::StateType> |
466 | static void clampReturnedValueStates( |
467 | Attributor &A, const AAType &QueryingAA, StateType &S, |
468 | const IRPosition::CallBaseContext *CBContext = nullptr) { |
469 | LLVM_DEBUG(dbgs() << "[Attributor] Clamp return value states for "do { } while (false) |
470 | << QueryingAA << " into " << S << "\n")do { } while (false); |
471 | |
472 | assert((QueryingAA.getIRPosition().getPositionKind() ==((void)0) |
473 | IRPosition::IRP_RETURNED ||((void)0) |
474 | QueryingAA.getIRPosition().getPositionKind() ==((void)0) |
475 | IRPosition::IRP_CALL_SITE_RETURNED) &&((void)0) |
476 | "Can only clamp returned value states for a function returned or call "((void)0) |
477 | "site returned position!")((void)0); |
478 | |
479 | // Use an optional state as there might not be any return values and we want |
480 | // to join (IntegerState::operator&) the state of all there are. |
481 | Optional<StateType> T; |
482 | |
483 | // Callback for each possibly returned value. |
484 | auto CheckReturnValue = [&](Value &RV) -> bool { |
485 | const IRPosition &RVPos = IRPosition::value(RV, CBContext); |
486 | const AAType &AA = |
487 | A.getAAFor<AAType>(QueryingAA, RVPos, DepClassTy::REQUIRED); |
488 | LLVM_DEBUG(dbgs() << "[Attributor] RV: " << RV << " AA: " << AA.getAsStr()do { } while (false) |
489 | << " @ " << RVPos << "\n")do { } while (false); |
490 | const StateType &AAS = AA.getState(); |
491 | if (T.hasValue()) |
492 | *T &= AAS; |
493 | else |
494 | T = AAS; |
495 | LLVM_DEBUG(dbgs() << "[Attributor] AA State: " << AAS << " RV State: " << Tdo { } while (false) |
496 | << "\n")do { } while (false); |
497 | return T->isValidState(); |
498 | }; |
499 | |
500 | if (!A.checkForAllReturnedValues(CheckReturnValue, QueryingAA)) |
501 | S.indicatePessimisticFixpoint(); |
502 | else if (T.hasValue()) |
503 | S ^= *T; |
504 | } |
505 | |
506 | /// Helper class for generic deduction: return value -> returned position. |
507 | template <typename AAType, typename BaseType, |
508 | typename StateType = typename BaseType::StateType, |
509 | bool PropagateCallBaseContext = false> |
510 | struct AAReturnedFromReturnedValues : public BaseType { |
511 | AAReturnedFromReturnedValues(const IRPosition &IRP, Attributor &A) |
512 | : BaseType(IRP, A) {} |
513 | |
514 | /// See AbstractAttribute::updateImpl(...). |
515 | ChangeStatus updateImpl(Attributor &A) override { |
516 | StateType S(StateType::getBestState(this->getState())); |
517 | clampReturnedValueStates<AAType, StateType>( |
518 | A, *this, S, |
519 | PropagateCallBaseContext ? this->getCallBaseContext() : nullptr); |
520 | // TODO: If we know we visited all returned values, thus no are assumed |
521 | // dead, we can take the known information from the state T. |
522 | return clampStateAndIndicateChange<StateType>(this->getState(), S); |
523 | } |
524 | }; |
525 | |
526 | /// Clamp the information known at all call sites for a given argument |
527 | /// (identified by \p QueryingAA) into \p S. |
528 | template <typename AAType, typename StateType = typename AAType::StateType> |
529 | static void clampCallSiteArgumentStates(Attributor &A, const AAType &QueryingAA, |
530 | StateType &S) { |
531 | LLVM_DEBUG(dbgs() << "[Attributor] Clamp call site argument states for "do { } while (false) |
532 | << QueryingAA << " into " << S << "\n")do { } while (false); |
533 | |
534 | assert(QueryingAA.getIRPosition().getPositionKind() ==((void)0) |
535 | IRPosition::IRP_ARGUMENT &&((void)0) |
536 | "Can only clamp call site argument states for an argument position!")((void)0); |
537 | |
538 | // Use an optional state as there might not be any return values and we want |
539 | // to join (IntegerState::operator&) the state of all there are. |
540 | Optional<StateType> T; |
541 | |
542 | // The argument number which is also the call site argument number. |
543 | unsigned ArgNo = QueryingAA.getIRPosition().getCallSiteArgNo(); |
544 | |
545 | auto CallSiteCheck = [&](AbstractCallSite ACS) { |
546 | const IRPosition &ACSArgPos = IRPosition::callsite_argument(ACS, ArgNo); |
547 | // Check if a coresponding argument was found or if it is on not associated |
548 | // (which can happen for callback calls). |
549 | if (ACSArgPos.getPositionKind() == IRPosition::IRP_INVALID) |
550 | return false; |
551 | |
552 | const AAType &AA = |
553 | A.getAAFor<AAType>(QueryingAA, ACSArgPos, DepClassTy::REQUIRED); |
554 | LLVM_DEBUG(dbgs() << "[Attributor] ACS: " << *ACS.getInstruction()do { } while (false) |
555 | << " AA: " << AA.getAsStr() << " @" << ACSArgPos << "\n")do { } while (false); |
556 | const StateType &AAS = AA.getState(); |
557 | if (T.hasValue()) |
558 | *T &= AAS; |
559 | else |
560 | T = AAS; |
561 | LLVM_DEBUG(dbgs() << "[Attributor] AA State: " << AAS << " CSA State: " << Tdo { } while (false) |
562 | << "\n")do { } while (false); |
563 | return T->isValidState(); |
564 | }; |
565 | |
566 | bool AllCallSitesKnown; |
567 | if (!A.checkForAllCallSites(CallSiteCheck, QueryingAA, true, |
568 | AllCallSitesKnown)) |
569 | S.indicatePessimisticFixpoint(); |
570 | else if (T.hasValue()) |
571 | S ^= *T; |
572 | } |
573 | |
574 | /// This function is the bridge between argument position and the call base |
575 | /// context. |
576 | template <typename AAType, typename BaseType, |
577 | typename StateType = typename AAType::StateType> |
578 | bool getArgumentStateFromCallBaseContext(Attributor &A, |
579 | BaseType &QueryingAttribute, |
580 | IRPosition &Pos, StateType &State) { |
581 | assert((Pos.getPositionKind() == IRPosition::IRP_ARGUMENT) &&((void)0) |
582 | "Expected an 'argument' position !")((void)0); |
583 | const CallBase *CBContext = Pos.getCallBaseContext(); |
584 | if (!CBContext) |
585 | return false; |
586 | |
587 | int ArgNo = Pos.getCallSiteArgNo(); |
588 | assert(ArgNo >= 0 && "Invalid Arg No!")((void)0); |
589 | |
590 | const auto &AA = A.getAAFor<AAType>( |
591 | QueryingAttribute, IRPosition::callsite_argument(*CBContext, ArgNo), |
592 | DepClassTy::REQUIRED); |
593 | const StateType &CBArgumentState = |
594 | static_cast<const StateType &>(AA.getState()); |
595 | |
596 | LLVM_DEBUG(dbgs() << "[Attributor] Briding Call site context to argument"do { } while (false) |
597 | << "Position:" << Pos << "CB Arg state:" << CBArgumentStatedo { } while (false) |
598 | << "\n")do { } while (false); |
599 | |
600 | // NOTE: If we want to do call site grouping it should happen here. |
601 | State ^= CBArgumentState; |
602 | return true; |
603 | } |
604 | |
605 | /// Helper class for generic deduction: call site argument -> argument position. |
606 | template <typename AAType, typename BaseType, |
607 | typename StateType = typename AAType::StateType, |
608 | bool BridgeCallBaseContext = false> |
609 | struct AAArgumentFromCallSiteArguments : public BaseType { |
610 | AAArgumentFromCallSiteArguments(const IRPosition &IRP, Attributor &A) |
611 | : BaseType(IRP, A) {} |
612 | |
613 | /// See AbstractAttribute::updateImpl(...). |
614 | ChangeStatus updateImpl(Attributor &A) override { |
615 | StateType S = StateType::getBestState(this->getState()); |
616 | |
617 | if (BridgeCallBaseContext) { |
618 | bool Success = |
619 | getArgumentStateFromCallBaseContext<AAType, BaseType, StateType>( |
620 | A, *this, this->getIRPosition(), S); |
621 | if (Success) |
622 | return clampStateAndIndicateChange<StateType>(this->getState(), S); |
623 | } |
624 | clampCallSiteArgumentStates<AAType, StateType>(A, *this, S); |
625 | |
626 | // TODO: If we know we visited all incoming values, thus no are assumed |
627 | // dead, we can take the known information from the state T. |
628 | return clampStateAndIndicateChange<StateType>(this->getState(), S); |
629 | } |
630 | }; |
631 | |
632 | /// Helper class for generic replication: function returned -> cs returned. |
633 | template <typename AAType, typename BaseType, |
634 | typename StateType = typename BaseType::StateType, |
635 | bool IntroduceCallBaseContext = false> |
636 | struct AACallSiteReturnedFromReturned : public BaseType { |
637 | AACallSiteReturnedFromReturned(const IRPosition &IRP, Attributor &A) |
638 | : BaseType(IRP, A) {} |
639 | |
640 | /// See AbstractAttribute::updateImpl(...). |
641 | ChangeStatus updateImpl(Attributor &A) override { |
642 | assert(this->getIRPosition().getPositionKind() ==((void)0) |
643 | IRPosition::IRP_CALL_SITE_RETURNED &&((void)0) |
644 | "Can only wrap function returned positions for call site returned "((void)0) |
645 | "positions!")((void)0); |
646 | auto &S = this->getState(); |
647 | |
648 | const Function *AssociatedFunction = |
649 | this->getIRPosition().getAssociatedFunction(); |
650 | if (!AssociatedFunction) |
651 | return S.indicatePessimisticFixpoint(); |
652 | |
653 | CallBase &CBContext = static_cast<CallBase &>(this->getAnchorValue()); |
654 | if (IntroduceCallBaseContext) |
655 | LLVM_DEBUG(dbgs() << "[Attributor] Introducing call base context:"do { } while (false) |
656 | << CBContext << "\n")do { } while (false); |
657 | |
658 | IRPosition FnPos = IRPosition::returned( |
659 | *AssociatedFunction, IntroduceCallBaseContext ? &CBContext : nullptr); |
660 | const AAType &AA = A.getAAFor<AAType>(*this, FnPos, DepClassTy::REQUIRED); |
661 | return clampStateAndIndicateChange(S, AA.getState()); |
662 | } |
663 | }; |
664 | |
665 | /// Helper function to accumulate uses. |
666 | template <class AAType, typename StateType = typename AAType::StateType> |
667 | static void followUsesInContext(AAType &AA, Attributor &A, |
668 | MustBeExecutedContextExplorer &Explorer, |
669 | const Instruction *CtxI, |
670 | SetVector<const Use *> &Uses, |
671 | StateType &State) { |
672 | auto EIt = Explorer.begin(CtxI), EEnd = Explorer.end(CtxI); |
673 | for (unsigned u = 0; u < Uses.size(); ++u) { |
674 | const Use *U = Uses[u]; |
675 | if (const Instruction *UserI = dyn_cast<Instruction>(U->getUser())) { |
676 | bool Found = Explorer.findInContextOf(UserI, EIt, EEnd); |
677 | if (Found && AA.followUseInMBEC(A, U, UserI, State)) |
678 | for (const Use &Us : UserI->uses()) |
679 | Uses.insert(&Us); |
680 | } |
681 | } |
682 | } |
683 | |
684 | /// Use the must-be-executed-context around \p I to add information into \p S. |
685 | /// The AAType class is required to have `followUseInMBEC` method with the |
686 | /// following signature and behaviour: |
687 | /// |
688 | /// bool followUseInMBEC(Attributor &A, const Use *U, const Instruction *I) |
689 | /// U - Underlying use. |
690 | /// I - The user of the \p U. |
691 | /// Returns true if the value should be tracked transitively. |
692 | /// |
693 | template <class AAType, typename StateType = typename AAType::StateType> |
694 | static void followUsesInMBEC(AAType &AA, Attributor &A, StateType &S, |
695 | Instruction &CtxI) { |
696 | |
697 | // Container for (transitive) uses of the associated value. |
698 | SetVector<const Use *> Uses; |
699 | for (const Use &U : AA.getIRPosition().getAssociatedValue().uses()) |
700 | Uses.insert(&U); |
701 | |
702 | MustBeExecutedContextExplorer &Explorer = |
703 | A.getInfoCache().getMustBeExecutedContextExplorer(); |
704 | |
705 | followUsesInContext<AAType>(AA, A, Explorer, &CtxI, Uses, S); |
706 | |
707 | if (S.isAtFixpoint()) |
708 | return; |
709 | |
710 | SmallVector<const BranchInst *, 4> BrInsts; |
711 | auto Pred = [&](const Instruction *I) { |
712 | if (const BranchInst *Br = dyn_cast<BranchInst>(I)) |
713 | if (Br->isConditional()) |
714 | BrInsts.push_back(Br); |
715 | return true; |
716 | }; |
717 | |
718 | // Here, accumulate conditional branch instructions in the context. We |
719 | // explore the child paths and collect the known states. The disjunction of |
720 | // those states can be merged to its own state. Let ParentState_i be a state |
721 | // to indicate the known information for an i-th branch instruction in the |
722 | // context. ChildStates are created for its successors respectively. |
723 | // |
724 | // ParentS_1 = ChildS_{1, 1} /\ ChildS_{1, 2} /\ ... /\ ChildS_{1, n_1} |
725 | // ParentS_2 = ChildS_{2, 1} /\ ChildS_{2, 2} /\ ... /\ ChildS_{2, n_2} |
726 | // ... |
727 | // ParentS_m = ChildS_{m, 1} /\ ChildS_{m, 2} /\ ... /\ ChildS_{m, n_m} |
728 | // |
729 | // Known State |= ParentS_1 \/ ParentS_2 \/... \/ ParentS_m |
730 | // |
731 | // FIXME: Currently, recursive branches are not handled. For example, we |
732 | // can't deduce that ptr must be dereferenced in below function. |
733 | // |
734 | // void f(int a, int c, int *ptr) { |
735 | // if(a) |
736 | // if (b) { |
737 | // *ptr = 0; |
738 | // } else { |
739 | // *ptr = 1; |
740 | // } |
741 | // else { |
742 | // if (b) { |
743 | // *ptr = 0; |
744 | // } else { |
745 | // *ptr = 1; |
746 | // } |
747 | // } |
748 | // } |
749 | |
750 | Explorer.checkForAllContext(&CtxI, Pred); |
751 | for (const BranchInst *Br : BrInsts) { |
752 | StateType ParentState; |
753 | |
754 | // The known state of the parent state is a conjunction of children's |
755 | // known states so it is initialized with a best state. |
756 | ParentState.indicateOptimisticFixpoint(); |
757 | |
758 | for (const BasicBlock *BB : Br->successors()) { |
759 | StateType ChildState; |
760 | |
761 | size_t BeforeSize = Uses.size(); |
762 | followUsesInContext(AA, A, Explorer, &BB->front(), Uses, ChildState); |
763 | |
764 | // Erase uses which only appear in the child. |
765 | for (auto It = Uses.begin() + BeforeSize; It != Uses.end();) |
766 | It = Uses.erase(It); |
767 | |
768 | ParentState &= ChildState; |
769 | } |
770 | |
771 | // Use only known state. |
772 | S += ParentState; |
773 | } |
774 | } |
775 | |
776 | /// ------------------------ PointerInfo --------------------------------------- |
777 | |
778 | namespace llvm { |
779 | namespace AA { |
780 | namespace PointerInfo { |
781 | |
782 | /// An access kind description as used by AAPointerInfo. |
783 | struct OffsetAndSize; |
784 | |
785 | struct State; |
786 | |
787 | } // namespace PointerInfo |
788 | } // namespace AA |
789 | |
790 | /// Helper for AA::PointerInfo::Acccess DenseMap/Set usage. |
791 | template <> |
792 | struct DenseMapInfo<AAPointerInfo::Access> : DenseMapInfo<Instruction *> { |
793 | using Access = AAPointerInfo::Access; |
794 | static inline Access getEmptyKey(); |
795 | static inline Access getTombstoneKey(); |
796 | static unsigned getHashValue(const Access &A); |
797 | static bool isEqual(const Access &LHS, const Access &RHS); |
798 | }; |
799 | |
800 | /// Helper that allows OffsetAndSize as a key in a DenseMap. |
801 | template <> |
802 | struct DenseMapInfo<AA::PointerInfo ::OffsetAndSize> |
803 | : DenseMapInfo<std::pair<int64_t, int64_t>> {}; |
804 | |
805 | /// Helper for AA::PointerInfo::Acccess DenseMap/Set usage ignoring everythign |
806 | /// but the instruction |
807 | struct AccessAsInstructionInfo : DenseMapInfo<Instruction *> { |
808 | using Base = DenseMapInfo<Instruction *>; |
809 | using Access = AAPointerInfo::Access; |
810 | static inline Access getEmptyKey(); |
811 | static inline Access getTombstoneKey(); |
812 | static unsigned getHashValue(const Access &A); |
813 | static bool isEqual(const Access &LHS, const Access &RHS); |
814 | }; |
815 | |
816 | } // namespace llvm |
817 | |
818 | /// Helper to represent an access offset and size, with logic to deal with |
819 | /// uncertainty and check for overlapping accesses. |
820 | struct AA::PointerInfo::OffsetAndSize : public std::pair<int64_t, int64_t> { |
821 | using BaseTy = std::pair<int64_t, int64_t>; |
822 | OffsetAndSize(int64_t Offset, int64_t Size) : BaseTy(Offset, Size) {} |
823 | OffsetAndSize(const BaseTy &P) : BaseTy(P) {} |
824 | int64_t getOffset() const { return first; } |
825 | int64_t getSize() const { return second; } |
826 | static OffsetAndSize getUnknown() { return OffsetAndSize(Unknown, Unknown); } |
827 | |
828 | /// Return true if this offset and size pair might describe an address that |
829 | /// overlaps with \p OAS. |
830 | bool mayOverlap(const OffsetAndSize &OAS) const { |
831 | // Any unknown value and we are giving up -> overlap. |
832 | if (OAS.getOffset() == OffsetAndSize::Unknown || |
833 | OAS.getSize() == OffsetAndSize::Unknown || |
834 | getOffset() == OffsetAndSize::Unknown || |
835 | getSize() == OffsetAndSize::Unknown) |
836 | return true; |
837 | |
838 | // Check if one offset point is in the other interval [offset, offset+size]. |
839 | return OAS.getOffset() + OAS.getSize() > getOffset() && |
840 | OAS.getOffset() < getOffset() + getSize(); |
841 | } |
842 | |
843 | /// Constant used to represent unknown offset or sizes. |
844 | static constexpr int64_t Unknown = 1 << 31; |
845 | }; |
846 | |
847 | /// Implementation of the DenseMapInfo. |
848 | /// |
849 | ///{ |
850 | inline llvm::AccessAsInstructionInfo::Access |
851 | llvm::AccessAsInstructionInfo::getEmptyKey() { |
852 | return Access(Base::getEmptyKey(), nullptr, AAPointerInfo::AK_READ, nullptr); |
853 | } |
854 | inline llvm::AccessAsInstructionInfo::Access |
855 | llvm::AccessAsInstructionInfo::getTombstoneKey() { |
856 | return Access(Base::getTombstoneKey(), nullptr, AAPointerInfo::AK_READ, |
857 | nullptr); |
858 | } |
859 | unsigned llvm::AccessAsInstructionInfo::getHashValue( |
860 | const llvm::AccessAsInstructionInfo::Access &A) { |
861 | return Base::getHashValue(A.getRemoteInst()); |
862 | } |
863 | bool llvm::AccessAsInstructionInfo::isEqual( |
864 | const llvm::AccessAsInstructionInfo::Access &LHS, |
865 | const llvm::AccessAsInstructionInfo::Access &RHS) { |
866 | return LHS.getRemoteInst() == RHS.getRemoteInst(); |
867 | } |
868 | inline llvm::DenseMapInfo<AAPointerInfo::Access>::Access |
869 | llvm::DenseMapInfo<AAPointerInfo::Access>::getEmptyKey() { |
870 | return AAPointerInfo::Access(nullptr, nullptr, AAPointerInfo::AK_READ, |
871 | nullptr); |
872 | } |
873 | inline llvm::DenseMapInfo<AAPointerInfo::Access>::Access |
874 | llvm::DenseMapInfo<AAPointerInfo::Access>::getTombstoneKey() { |
875 | return AAPointerInfo::Access(nullptr, nullptr, AAPointerInfo::AK_WRITE, |
876 | nullptr); |
877 | } |
878 | |
879 | unsigned llvm::DenseMapInfo<AAPointerInfo::Access>::getHashValue( |
880 | const llvm::DenseMapInfo<AAPointerInfo::Access>::Access &A) { |
881 | return detail::combineHashValue( |
882 | DenseMapInfo<Instruction *>::getHashValue(A.getRemoteInst()), |
883 | (A.isWrittenValueYetUndetermined() |
884 | ? ~0 |
885 | : DenseMapInfo<Value *>::getHashValue(A.getWrittenValue()))) + |
886 | A.getKind(); |
887 | } |
888 | |
889 | bool llvm::DenseMapInfo<AAPointerInfo::Access>::isEqual( |
890 | const llvm::DenseMapInfo<AAPointerInfo::Access>::Access &LHS, |
891 | const llvm::DenseMapInfo<AAPointerInfo::Access>::Access &RHS) { |
892 | return LHS == RHS; |
893 | } |
894 | ///} |
895 | |
896 | /// A type to track pointer/struct usage and accesses for AAPointerInfo. |
897 | struct AA::PointerInfo::State : public AbstractState { |
898 | |
899 | /// Return the best possible representable state. |
900 | static State getBestState(const State &SIS) { return State(); } |
901 | |
902 | /// Return the worst possible representable state. |
903 | static State getWorstState(const State &SIS) { |
904 | State R; |
905 | R.indicatePessimisticFixpoint(); |
906 | return R; |
907 | } |
908 | |
909 | State() {} |
910 | State(const State &SIS) : AccessBins(SIS.AccessBins) {} |
911 | State(State &&SIS) : AccessBins(std::move(SIS.AccessBins)) {} |
912 | |
913 | const State &getAssumed() const { return *this; } |
914 | |
915 | /// See AbstractState::isValidState(). |
916 | bool isValidState() const override { return BS.isValidState(); } |
917 | |
918 | /// See AbstractState::isAtFixpoint(). |
919 | bool isAtFixpoint() const override { return BS.isAtFixpoint(); } |
920 | |
921 | /// See AbstractState::indicateOptimisticFixpoint(). |
922 | ChangeStatus indicateOptimisticFixpoint() override { |
923 | BS.indicateOptimisticFixpoint(); |
924 | return ChangeStatus::UNCHANGED; |
925 | } |
926 | |
927 | /// See AbstractState::indicatePessimisticFixpoint(). |
928 | ChangeStatus indicatePessimisticFixpoint() override { |
929 | BS.indicatePessimisticFixpoint(); |
930 | return ChangeStatus::CHANGED; |
931 | } |
932 | |
933 | State &operator=(const State &R) { |
934 | if (this == &R) |
935 | return *this; |
936 | BS = R.BS; |
937 | AccessBins = R.AccessBins; |
938 | return *this; |
939 | } |
940 | |
941 | State &operator=(State &&R) { |
942 | if (this == &R) |
943 | return *this; |
944 | std::swap(BS, R.BS); |
945 | std::swap(AccessBins, R.AccessBins); |
946 | return *this; |
947 | } |
948 | |
949 | bool operator==(const State &R) const { |
950 | if (BS != R.BS) |
951 | return false; |
952 | if (AccessBins.size() != R.AccessBins.size()) |
953 | return false; |
954 | auto It = begin(), RIt = R.begin(), E = end(); |
955 | while (It != E) { |
956 | if (It->getFirst() != RIt->getFirst()) |
957 | return false; |
958 | auto &Accs = It->getSecond(); |
959 | auto &RAccs = RIt->getSecond(); |
960 | if (Accs.size() != RAccs.size()) |
961 | return false; |
962 | auto AccIt = Accs.begin(), RAccIt = RAccs.begin(), AccE = Accs.end(); |
963 | while (AccIt != AccE) { |
964 | if (*AccIt != *RAccIt) |
965 | return false; |
966 | ++AccIt; |
967 | ++RAccIt; |
968 | } |
969 | ++It; |
970 | ++RIt; |
971 | } |
972 | return true; |
973 | } |
974 | bool operator!=(const State &R) const { return !(*this == R); } |
975 | |
976 | /// We store accesses in a set with the instruction as key. |
977 | using Accesses = DenseSet<AAPointerInfo::Access, AccessAsInstructionInfo>; |
978 | |
979 | /// We store all accesses in bins denoted by their offset and size. |
980 | using AccessBinsTy = DenseMap<OffsetAndSize, Accesses>; |
981 | |
982 | AccessBinsTy::const_iterator begin() const { return AccessBins.begin(); } |
983 | AccessBinsTy::const_iterator end() const { return AccessBins.end(); } |
984 | |
985 | protected: |
986 | /// The bins with all the accesses for the associated pointer. |
987 | DenseMap<OffsetAndSize, Accesses> AccessBins; |
988 | |
989 | /// Add a new access to the state at offset \p Offset and with size \p Size. |
990 | /// The access is associated with \p I, writes \p Content (if anything), and |
991 | /// is of kind \p Kind. |
992 | /// \Returns CHANGED, if the state changed, UNCHANGED otherwise. |
993 | ChangeStatus addAccess(int64_t Offset, int64_t Size, Instruction &I, |
994 | Optional<Value *> Content, |
995 | AAPointerInfo::AccessKind Kind, Type *Ty, |
996 | Instruction *RemoteI = nullptr, |
997 | Accesses *BinPtr = nullptr) { |
998 | OffsetAndSize Key{Offset, Size}; |
999 | Accesses &Bin = BinPtr ? *BinPtr : AccessBins[Key]; |
1000 | AAPointerInfo::Access Acc(&I, RemoteI ? RemoteI : &I, Content, Kind, Ty); |
1001 | // Check if we have an access for this instruction in this bin, if not, |
1002 | // simply add it. |
1003 | auto It = Bin.find(Acc); |
1004 | if (It == Bin.end()) { |
1005 | Bin.insert(Acc); |
1006 | return ChangeStatus::CHANGED; |
1007 | } |
1008 | // If the existing access is the same as then new one, nothing changed. |
1009 | AAPointerInfo::Access Before = *It; |
1010 | // The new one will be combined with the existing one. |
1011 | *It &= Acc; |
1012 | return *It == Before ? ChangeStatus::UNCHANGED : ChangeStatus::CHANGED; |
1013 | } |
1014 | |
1015 | /// See AAPointerInfo::forallInterferingAccesses. |
1016 | bool forallInterferingAccesses( |
1017 | Instruction &I, |
1018 | function_ref<bool(const AAPointerInfo::Access &, bool)> CB) const { |
1019 | if (!isValidState()) |
1020 | return false; |
1021 | // First find the offset and size of I. |
1022 | OffsetAndSize OAS(-1, -1); |
1023 | for (auto &It : AccessBins) { |
1024 | for (auto &Access : It.getSecond()) { |
1025 | if (Access.getRemoteInst() == &I) { |
1026 | OAS = It.getFirst(); |
1027 | break; |
1028 | } |
1029 | } |
1030 | if (OAS.getSize() != -1) |
1031 | break; |
1032 | } |
1033 | if (OAS.getSize() == -1) |
1034 | return true; |
1035 | |
1036 | // Now that we have an offset and size, find all overlapping ones and use |
1037 | // the callback on the accesses. |
1038 | for (auto &It : AccessBins) { |
1039 | OffsetAndSize ItOAS = It.getFirst(); |
1040 | if (!OAS.mayOverlap(ItOAS)) |
1041 | continue; |
1042 | for (auto &Access : It.getSecond()) |
1043 | if (!CB(Access, OAS == ItOAS)) |
1044 | return false; |
1045 | } |
1046 | return true; |
1047 | } |
1048 | |
1049 | private: |
1050 | /// State to track fixpoint and validity. |
1051 | BooleanState BS; |
1052 | }; |
1053 | |
1054 | struct AAPointerInfoImpl |
1055 | : public StateWrapper<AA::PointerInfo::State, AAPointerInfo> { |
1056 | using BaseTy = StateWrapper<AA::PointerInfo::State, AAPointerInfo>; |
1057 | AAPointerInfoImpl(const IRPosition &IRP, Attributor &A) : BaseTy(IRP) {} |
1058 | |
1059 | /// See AbstractAttribute::initialize(...). |
1060 | void initialize(Attributor &A) override { AAPointerInfo::initialize(A); } |
1061 | |
1062 | /// See AbstractAttribute::getAsStr(). |
1063 | const std::string getAsStr() const override { |
1064 | return std::string("PointerInfo ") + |
1065 | (isValidState() ? (std::string("#") + |
1066 | std::to_string(AccessBins.size()) + " bins") |
1067 | : "<invalid>"); |
1068 | } |
1069 | |
1070 | /// See AbstractAttribute::manifest(...). |
1071 | ChangeStatus manifest(Attributor &A) override { |
1072 | return AAPointerInfo::manifest(A); |
1073 | } |
1074 | |
1075 | bool forallInterferingAccesses( |
1076 | LoadInst &LI, function_ref<bool(const AAPointerInfo::Access &, bool)> CB) |
1077 | const override { |
1078 | return State::forallInterferingAccesses(LI, CB); |
1079 | } |
1080 | bool forallInterferingAccesses( |
1081 | StoreInst &SI, function_ref<bool(const AAPointerInfo::Access &, bool)> CB) |
1082 | const override { |
1083 | return State::forallInterferingAccesses(SI, CB); |
1084 | } |
1085 | |
1086 | ChangeStatus translateAndAddCalleeState(Attributor &A, |
1087 | const AAPointerInfo &CalleeAA, |
1088 | int64_t CallArgOffset, CallBase &CB) { |
1089 | using namespace AA::PointerInfo; |
1090 | if (!CalleeAA.getState().isValidState() || !isValidState()) |
1091 | return indicatePessimisticFixpoint(); |
1092 | |
1093 | const auto &CalleeImplAA = static_cast<const AAPointerInfoImpl &>(CalleeAA); |
1094 | bool IsByval = CalleeImplAA.getAssociatedArgument()->hasByValAttr(); |
1095 | |
1096 | // Combine the accesses bin by bin. |
1097 | ChangeStatus Changed = ChangeStatus::UNCHANGED; |
1098 | for (auto &It : CalleeImplAA.getState()) { |
1099 | OffsetAndSize OAS = OffsetAndSize::getUnknown(); |
1100 | if (CallArgOffset != OffsetAndSize::Unknown) |
1101 | OAS = OffsetAndSize(It.first.getOffset() + CallArgOffset, |
1102 | It.first.getSize()); |
1103 | Accesses &Bin = AccessBins[OAS]; |
1104 | for (const AAPointerInfo::Access &RAcc : It.second) { |
1105 | if (IsByval && !RAcc.isRead()) |
1106 | continue; |
1107 | bool UsedAssumedInformation = false; |
1108 | Optional<Value *> Content = A.translateArgumentToCallSiteContent( |
1109 | RAcc.getContent(), CB, *this, UsedAssumedInformation); |
1110 | AccessKind AK = |
1111 | AccessKind(RAcc.getKind() & (IsByval ? AccessKind::AK_READ |
1112 | : AccessKind::AK_READ_WRITE)); |
1113 | Changed = |
1114 | Changed | addAccess(OAS.getOffset(), OAS.getSize(), CB, Content, AK, |
1115 | RAcc.getType(), RAcc.getRemoteInst(), &Bin); |
1116 | } |
1117 | } |
1118 | return Changed; |
1119 | } |
1120 | |
1121 | /// Statistic tracking for all AAPointerInfo implementations. |
1122 | /// See AbstractAttribute::trackStatistics(). |
1123 | void trackPointerInfoStatistics(const IRPosition &IRP) const {} |
1124 | }; |
1125 | |
1126 | struct AAPointerInfoFloating : public AAPointerInfoImpl { |
1127 | using AccessKind = AAPointerInfo::AccessKind; |
1128 | AAPointerInfoFloating(const IRPosition &IRP, Attributor &A) |
1129 | : AAPointerInfoImpl(IRP, A) {} |
1130 | |
1131 | /// See AbstractAttribute::initialize(...). |
1132 | void initialize(Attributor &A) override { AAPointerInfoImpl::initialize(A); } |
1133 | |
1134 | /// Deal with an access and signal if it was handled successfully. |
1135 | bool handleAccess(Attributor &A, Instruction &I, Value &Ptr, |
1136 | Optional<Value *> Content, AccessKind Kind, int64_t Offset, |
1137 | ChangeStatus &Changed, Type *Ty, |
1138 | int64_t Size = AA::PointerInfo::OffsetAndSize::Unknown) { |
1139 | using namespace AA::PointerInfo; |
1140 | // No need to find a size if one is given or the offset is unknown. |
1141 | if (Offset != OffsetAndSize::Unknown && Size == OffsetAndSize::Unknown && |
1142 | Ty) { |
1143 | const DataLayout &DL = A.getDataLayout(); |
1144 | TypeSize AccessSize = DL.getTypeStoreSize(Ty); |
1145 | if (!AccessSize.isScalable()) |
1146 | Size = AccessSize.getFixedSize(); |
1147 | } |
1148 | Changed = Changed | addAccess(Offset, Size, I, Content, Kind, Ty); |
1149 | return true; |
1150 | }; |
1151 | |
1152 | /// Helper struct, will support ranges eventually. |
1153 | struct OffsetInfo { |
1154 | int64_t Offset = AA::PointerInfo::OffsetAndSize::Unknown; |
1155 | |
1156 | bool operator==(const OffsetInfo &OI) const { return Offset == OI.Offset; } |
1157 | }; |
1158 | |
1159 | /// See AbstractAttribute::updateImpl(...). |
1160 | ChangeStatus updateImpl(Attributor &A) override { |
1161 | using namespace AA::PointerInfo; |
1162 | State S = getState(); |
1163 | ChangeStatus Changed = ChangeStatus::UNCHANGED; |
1164 | Value &AssociatedValue = getAssociatedValue(); |
1165 | |
1166 | const DataLayout &DL = A.getDataLayout(); |
1167 | DenseMap<Value *, OffsetInfo> OffsetInfoMap; |
1168 | OffsetInfoMap[&AssociatedValue] = OffsetInfo{0}; |
1169 | |
1170 | auto HandlePassthroughUser = [&](Value *Usr, OffsetInfo &PtrOI, |
1171 | bool &Follow) { |
1172 | OffsetInfo &UsrOI = OffsetInfoMap[Usr]; |
1173 | UsrOI = PtrOI; |
1174 | Follow = true; |
1175 | return true; |
1176 | }; |
1177 | |
1178 | auto UsePred = [&](const Use &U, bool &Follow) -> bool { |
1179 | Value *CurPtr = U.get(); |
1180 | User *Usr = U.getUser(); |
1181 | LLVM_DEBUG(dbgs() << "[AAPointerInfo] Analyze " << *CurPtr << " in "do { } while (false) |
1182 | << *Usr << "\n")do { } while (false); |
1183 | |
1184 | OffsetInfo &PtrOI = OffsetInfoMap[CurPtr]; |
1185 | |
1186 | if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Usr)) { |
1187 | if (CE->isCast()) |
1188 | return HandlePassthroughUser(Usr, PtrOI, Follow); |
1189 | if (CE->isCompare()) |
1190 | return true; |
1191 | if (!CE->isGEPWithNoNotionalOverIndexing()) { |
1192 | LLVM_DEBUG(dbgs() << "[AAPointerInfo] Unhandled constant user " << *CEdo { } while (false) |
1193 | << "\n")do { } while (false); |
1194 | return false; |
1195 | } |
1196 | } |
1197 | if (auto *GEP = dyn_cast<GEPOperator>(Usr)) { |
1198 | OffsetInfo &UsrOI = OffsetInfoMap[Usr]; |
1199 | UsrOI = PtrOI; |
1200 | |
1201 | // TODO: Use range information. |
1202 | if (PtrOI.Offset == OffsetAndSize::Unknown || |
1203 | !GEP->hasAllConstantIndices()) { |
1204 | UsrOI.Offset = OffsetAndSize::Unknown; |
1205 | Follow = true; |
1206 | return true; |
1207 | } |
1208 | |
1209 | SmallVector<Value *, 8> Indices; |
1210 | for (Use &Idx : llvm::make_range(GEP->idx_begin(), GEP->idx_end())) { |
1211 | if (auto *CIdx = dyn_cast<ConstantInt>(Idx)) { |
1212 | Indices.push_back(CIdx); |
1213 | continue; |
1214 | } |
1215 | |
1216 | LLVM_DEBUG(dbgs() << "[AAPointerInfo] Non constant GEP index " << *GEPdo { } while (false) |
1217 | << " : " << *Idx << "\n")do { } while (false); |
1218 | return false; |
1219 | } |
1220 | UsrOI.Offset = PtrOI.Offset + |
1221 | DL.getIndexedOffsetInType( |
1222 | CurPtr->getType()->getPointerElementType(), Indices); |
1223 | Follow = true; |
1224 | return true; |
1225 | } |
1226 | if (isa<CastInst>(Usr) || isa<SelectInst>(Usr)) |
1227 | return HandlePassthroughUser(Usr, PtrOI, Follow); |
1228 | |
1229 | // For PHIs we need to take care of the recurrence explicitly as the value |
1230 | // might change while we iterate through a loop. For now, we give up if |
1231 | // the PHI is not invariant. |
1232 | if (isa<PHINode>(Usr)) { |
1233 | // Check if the PHI is invariant (so far). |
1234 | OffsetInfo &UsrOI = OffsetInfoMap[Usr]; |
1235 | if (UsrOI == PtrOI) |
1236 | return true; |
1237 | |
1238 | // Check if the PHI operand has already an unknown offset as we can't |
1239 | // improve on that anymore. |
1240 | if (PtrOI.Offset == OffsetAndSize::Unknown) { |
1241 | UsrOI = PtrOI; |
1242 | Follow = true; |
1243 | return true; |
1244 | } |
1245 | |
1246 | // Check if the PHI operand is not dependent on the PHI itself. |
1247 | APInt Offset(DL.getIndexTypeSizeInBits(AssociatedValue.getType()), 0); |
1248 | if (&AssociatedValue == CurPtr->stripAndAccumulateConstantOffsets( |
1249 | DL, Offset, /* AllowNonInbounds */ true)) { |
1250 | if (Offset != PtrOI.Offset) { |
1251 | LLVM_DEBUG(dbgs()do { } while (false) |
1252 | << "[AAPointerInfo] PHI operand pointer offset mismatch "do { } while (false) |
1253 | << *CurPtr << " in " << *Usr << "\n")do { } while (false); |
1254 | return false; |
1255 | } |
1256 | return HandlePassthroughUser(Usr, PtrOI, Follow); |
1257 | } |
1258 | |
1259 | // TODO: Approximate in case we know the direction of the recurrence. |
1260 | LLVM_DEBUG(dbgs() << "[AAPointerInfo] PHI operand is too complex "do { } while (false) |
1261 | << *CurPtr << " in " << *Usr << "\n")do { } while (false); |
1262 | UsrOI = PtrOI; |
1263 | UsrOI.Offset = OffsetAndSize::Unknown; |
1264 | Follow = true; |
1265 | return true; |
1266 | } |
1267 | |
1268 | if (auto *LoadI = dyn_cast<LoadInst>(Usr)) |
1269 | return handleAccess(A, *LoadI, *CurPtr, /* Content */ nullptr, |
1270 | AccessKind::AK_READ, PtrOI.Offset, Changed, |
1271 | LoadI->getType()); |
1272 | if (auto *StoreI = dyn_cast<StoreInst>(Usr)) { |
1273 | if (StoreI->getValueOperand() == CurPtr) { |
1274 | LLVM_DEBUG(dbgs() << "[AAPointerInfo] Escaping use in store "do { } while (false) |
1275 | << *StoreI << "\n")do { } while (false); |
1276 | return false; |
1277 | } |
1278 | bool UsedAssumedInformation = false; |
1279 | Optional<Value *> Content = A.getAssumedSimplified( |
1280 | *StoreI->getValueOperand(), *this, UsedAssumedInformation); |
1281 | return handleAccess(A, *StoreI, *CurPtr, Content, AccessKind::AK_WRITE, |
1282 | PtrOI.Offset, Changed, |
1283 | StoreI->getValueOperand()->getType()); |
1284 | } |
1285 | if (auto *CB = dyn_cast<CallBase>(Usr)) { |
1286 | if (CB->isLifetimeStartOrEnd()) |
1287 | return true; |
1288 | if (CB->isArgOperand(&U)) { |
1289 | unsigned ArgNo = CB->getArgOperandNo(&U); |
1290 | const auto &CSArgPI = A.getAAFor<AAPointerInfo>( |
1291 | *this, IRPosition::callsite_argument(*CB, ArgNo), |
1292 | DepClassTy::REQUIRED); |
1293 | Changed = translateAndAddCalleeState(A, CSArgPI, PtrOI.Offset, *CB) | |
1294 | Changed; |
1295 | return true; |
1296 | } |
1297 | LLVM_DEBUG(dbgs() << "[AAPointerInfo] Call user not handled " << *CBdo { } while (false) |
1298 | << "\n")do { } while (false); |
1299 | // TODO: Allow some call uses |
1300 | return false; |
1301 | } |
1302 | |
1303 | LLVM_DEBUG(dbgs() << "[AAPointerInfo] User not handled " << *Usr << "\n")do { } while (false); |
1304 | return false; |
1305 | }; |
1306 | if (!A.checkForAllUses(UsePred, *this, AssociatedValue, |
1307 | /* CheckBBLivenessOnly */ true)) |
1308 | return indicatePessimisticFixpoint(); |
1309 | |
1310 | LLVM_DEBUG({do { } while (false) |
1311 | dbgs() << "Accesses by bin after update:\n";do { } while (false) |
1312 | for (auto &It : AccessBins) {do { } while (false) |
1313 | dbgs() << "[" << It.first.getOffset() << "-"do { } while (false) |
1314 | << It.first.getOffset() + It.first.getSize()do { } while (false) |
1315 | << "] : " << It.getSecond().size() << "\n";do { } while (false) |
1316 | for (auto &Acc : It.getSecond()) {do { } while (false) |
1317 | dbgs() << " - " << Acc.getKind() << " - " << *Acc.getLocalInst()do { } while (false) |
1318 | << "\n";do { } while (false) |
1319 | if (Acc.getLocalInst() != Acc.getRemoteInst())do { } while (false) |
1320 | dbgs() << " --> "do { } while (false) |
1321 | << *Acc.getRemoteInst() << "\n";do { } while (false) |
1322 | if (!Acc.isWrittenValueYetUndetermined())do { } while (false) |
1323 | dbgs() << " - " << Acc.getWrittenValue() << "\n";do { } while (false) |
1324 | }do { } while (false) |
1325 | }do { } while (false) |
1326 | })do { } while (false); |
1327 | |
1328 | return Changed; |
1329 | } |
1330 | |
1331 | /// See AbstractAttribute::trackStatistics() |
1332 | void trackStatistics() const override { |
1333 | AAPointerInfoImpl::trackPointerInfoStatistics(getIRPosition()); |
1334 | } |
1335 | }; |
1336 | |
1337 | struct AAPointerInfoReturned final : AAPointerInfoImpl { |
1338 | AAPointerInfoReturned(const IRPosition &IRP, Attributor &A) |
1339 | : AAPointerInfoImpl(IRP, A) {} |
1340 | |
1341 | /// See AbstractAttribute::updateImpl(...). |
1342 | ChangeStatus updateImpl(Attributor &A) override { |
1343 | return indicatePessimisticFixpoint(); |
1344 | } |
1345 | |
1346 | /// See AbstractAttribute::trackStatistics() |
1347 | void trackStatistics() const override { |
1348 | AAPointerInfoImpl::trackPointerInfoStatistics(getIRPosition()); |
1349 | } |
1350 | }; |
1351 | |
1352 | struct AAPointerInfoArgument final : AAPointerInfoFloating { |
1353 | AAPointerInfoArgument(const IRPosition &IRP, Attributor &A) |
1354 | : AAPointerInfoFloating(IRP, A) {} |
1355 | |
1356 | /// See AbstractAttribute::initialize(...). |
1357 | void initialize(Attributor &A) override { |
1358 | AAPointerInfoFloating::initialize(A); |
1359 | if (getAnchorScope()->isDeclaration()) |
1360 | indicatePessimisticFixpoint(); |
1361 | } |
1362 | |
1363 | /// See AbstractAttribute::trackStatistics() |
1364 | void trackStatistics() const override { |
1365 | AAPointerInfoImpl::trackPointerInfoStatistics(getIRPosition()); |
1366 | } |
1367 | }; |
1368 | |
1369 | struct AAPointerInfoCallSiteArgument final : AAPointerInfoFloating { |
1370 | AAPointerInfoCallSiteArgument(const IRPosition &IRP, Attributor &A) |
1371 | : AAPointerInfoFloating(IRP, A) {} |
1372 | |
1373 | /// See AbstractAttribute::updateImpl(...). |
1374 | ChangeStatus updateImpl(Attributor &A) override { |
1375 | using namespace AA::PointerInfo; |
1376 | // We handle memory intrinsics explicitly, at least the first (= |
1377 | // destination) and second (=source) arguments as we know how they are |
1378 | // accessed. |
1379 | if (auto *MI = dyn_cast_or_null<MemIntrinsic>(getCtxI())) { |
1380 | ConstantInt *Length = dyn_cast<ConstantInt>(MI->getLength()); |
1381 | int64_t LengthVal = OffsetAndSize::Unknown; |
1382 | if (Length) |
1383 | LengthVal = Length->getSExtValue(); |
1384 | Value &Ptr = getAssociatedValue(); |
1385 | unsigned ArgNo = getIRPosition().getCallSiteArgNo(); |
1386 | ChangeStatus Changed; |
1387 | if (ArgNo == 0) { |
1388 | handleAccess(A, *MI, Ptr, nullptr, AccessKind::AK_WRITE, 0, Changed, |
1389 | nullptr, LengthVal); |
1390 | } else if (ArgNo == 1) { |
1391 | handleAccess(A, *MI, Ptr, nullptr, AccessKind::AK_READ, 0, Changed, |
1392 | nullptr, LengthVal); |
1393 | } else { |
1394 | LLVM_DEBUG(dbgs() << "[AAPointerInfo] Unhandled memory intrinsic "do { } while (false) |
1395 | << *MI << "\n")do { } while (false); |
1396 | return indicatePessimisticFixpoint(); |
1397 | } |
1398 | return Changed; |
1399 | } |
1400 | |
1401 | // TODO: Once we have call site specific value information we can provide |
1402 | // call site specific liveness information and then it makes |
1403 | // sense to specialize attributes for call sites arguments instead of |
1404 | // redirecting requests to the callee argument. |
1405 | Argument *Arg = getAssociatedArgument(); |
1406 | if (!Arg) |
1407 | return indicatePessimisticFixpoint(); |
1408 | const IRPosition &ArgPos = IRPosition::argument(*Arg); |
1409 | auto &ArgAA = |
1410 | A.getAAFor<AAPointerInfo>(*this, ArgPos, DepClassTy::REQUIRED); |
1411 | return translateAndAddCalleeState(A, ArgAA, 0, *cast<CallBase>(getCtxI())); |
1412 | } |
1413 | |
1414 | /// See AbstractAttribute::trackStatistics() |
1415 | void trackStatistics() const override { |
1416 | AAPointerInfoImpl::trackPointerInfoStatistics(getIRPosition()); |
1417 | } |
1418 | }; |
1419 | |
1420 | struct AAPointerInfoCallSiteReturned final : AAPointerInfoFloating { |
1421 | AAPointerInfoCallSiteReturned(const IRPosition &IRP, Attributor &A) |
1422 | : AAPointerInfoFloating(IRP, A) {} |
1423 | |
1424 | /// See AbstractAttribute::trackStatistics() |
1425 | void trackStatistics() const override { |
1426 | AAPointerInfoImpl::trackPointerInfoStatistics(getIRPosition()); |
1427 | } |
1428 | }; |
1429 | |
1430 | /// -----------------------NoUnwind Function Attribute-------------------------- |
1431 | |
1432 | struct AANoUnwindImpl : AANoUnwind { |
1433 | AANoUnwindImpl(const IRPosition &IRP, Attributor &A) : AANoUnwind(IRP, A) {} |
1434 | |
1435 | const std::string getAsStr() const override { |
1436 | return getAssumed() ? "nounwind" : "may-unwind"; |
1437 | } |
1438 | |
1439 | /// See AbstractAttribute::updateImpl(...). |
1440 | ChangeStatus updateImpl(Attributor &A) override { |
1441 | auto Opcodes = { |
1442 | (unsigned)Instruction::Invoke, (unsigned)Instruction::CallBr, |
1443 | (unsigned)Instruction::Call, (unsigned)Instruction::CleanupRet, |
1444 | (unsigned)Instruction::CatchSwitch, (unsigned)Instruction::Resume}; |
1445 | |
1446 | auto CheckForNoUnwind = [&](Instruction &I) { |
1447 | if (!I.mayThrow()) |
1448 | return true; |
1449 | |
1450 | if (const auto *CB = dyn_cast<CallBase>(&I)) { |
1451 | const auto &NoUnwindAA = A.getAAFor<AANoUnwind>( |
1452 | *this, IRPosition::callsite_function(*CB), DepClassTy::REQUIRED); |
1453 | return NoUnwindAA.isAssumedNoUnwind(); |
1454 | } |
1455 | return false; |
1456 | }; |
1457 | |
1458 | bool UsedAssumedInformation = false; |
1459 | if (!A.checkForAllInstructions(CheckForNoUnwind, *this, Opcodes, |
1460 | UsedAssumedInformation)) |
1461 | return indicatePessimisticFixpoint(); |
1462 | |
1463 | return ChangeStatus::UNCHANGED; |
1464 | } |
1465 | }; |
1466 | |
1467 | struct AANoUnwindFunction final : public AANoUnwindImpl { |
1468 | AANoUnwindFunction(const IRPosition &IRP, Attributor &A) |
1469 | : AANoUnwindImpl(IRP, A) {} |
1470 | |
1471 | /// See AbstractAttribute::trackStatistics() |
1472 | void trackStatistics() const override { STATS_DECLTRACK_FN_ATTR(nounwind){ static llvm::Statistic NumIRFunction_nounwind = {"attributor" , "NumIRFunction_nounwind", ("Number of " "functions" " marked '" "nounwind" "'")};; ++(NumIRFunction_nounwind); } } |
1473 | }; |
1474 | |
1475 | /// NoUnwind attribute deduction for a call sites. |
1476 | struct AANoUnwindCallSite final : AANoUnwindImpl { |
1477 | AANoUnwindCallSite(const IRPosition &IRP, Attributor &A) |
1478 | : AANoUnwindImpl(IRP, A) {} |
1479 | |
1480 | /// See AbstractAttribute::initialize(...). |
1481 | void initialize(Attributor &A) override { |
1482 | AANoUnwindImpl::initialize(A); |
1483 | Function *F = getAssociatedFunction(); |
1484 | if (!F || F->isDeclaration()) |
1485 | indicatePessimisticFixpoint(); |
1486 | } |
1487 | |
1488 | /// See AbstractAttribute::updateImpl(...). |
1489 | ChangeStatus updateImpl(Attributor &A) override { |
1490 | // TODO: Once we have call site specific value information we can provide |
1491 | // call site specific liveness information and then it makes |
1492 | // sense to specialize attributes for call sites arguments instead of |
1493 | // redirecting requests to the callee argument. |
1494 | Function *F = getAssociatedFunction(); |
1495 | const IRPosition &FnPos = IRPosition::function(*F); |
1496 | auto &FnAA = A.getAAFor<AANoUnwind>(*this, FnPos, DepClassTy::REQUIRED); |
1497 | return clampStateAndIndicateChange(getState(), FnAA.getState()); |
1498 | } |
1499 | |
1500 | /// See AbstractAttribute::trackStatistics() |
1501 | void trackStatistics() const override { STATS_DECLTRACK_CS_ATTR(nounwind){ static llvm::Statistic NumIRCS_nounwind = {"attributor", "NumIRCS_nounwind" , ("Number of " "call site" " marked '" "nounwind" "'")};; ++ (NumIRCS_nounwind); }; } |
1502 | }; |
1503 | |
1504 | /// --------------------- Function Return Values ------------------------------- |
1505 | |
1506 | /// "Attribute" that collects all potential returned values and the return |
1507 | /// instructions that they arise from. |
1508 | /// |
1509 | /// If there is a unique returned value R, the manifest method will: |
1510 | /// - mark R with the "returned" attribute, if R is an argument. |
1511 | class AAReturnedValuesImpl : public AAReturnedValues, public AbstractState { |
1512 | |
1513 | /// Mapping of values potentially returned by the associated function to the |
1514 | /// return instructions that might return them. |
1515 | MapVector<Value *, SmallSetVector<ReturnInst *, 4>> ReturnedValues; |
1516 | |
1517 | /// State flags |
1518 | /// |
1519 | ///{ |
1520 | bool IsFixed = false; |
1521 | bool IsValidState = true; |
1522 | ///} |
1523 | |
1524 | public: |
1525 | AAReturnedValuesImpl(const IRPosition &IRP, Attributor &A) |
1526 | : AAReturnedValues(IRP, A) {} |
1527 | |
1528 | /// See AbstractAttribute::initialize(...). |
1529 | void initialize(Attributor &A) override { |
1530 | // Reset the state. |
1531 | IsFixed = false; |
1532 | IsValidState = true; |
1533 | ReturnedValues.clear(); |
1534 | |
1535 | Function *F = getAssociatedFunction(); |
1536 | if (!F || F->isDeclaration()) { |
1537 | indicatePessimisticFixpoint(); |
1538 | return; |
1539 | } |
1540 | assert(!F->getReturnType()->isVoidTy() &&((void)0) |
1541 | "Did not expect a void return type!")((void)0); |
1542 | |
1543 | // The map from instruction opcodes to those instructions in the function. |
1544 | auto &OpcodeInstMap = A.getInfoCache().getOpcodeInstMapForFunction(*F); |
1545 | |
1546 | // Look through all arguments, if one is marked as returned we are done. |
1547 | for (Argument &Arg : F->args()) { |
1548 | if (Arg.hasReturnedAttr()) { |
1549 | auto &ReturnInstSet = ReturnedValues[&Arg]; |
1550 | if (auto *Insts = OpcodeInstMap.lookup(Instruction::Ret)) |
1551 | for (Instruction *RI : *Insts) |
1552 | ReturnInstSet.insert(cast<ReturnInst>(RI)); |
1553 | |
1554 | indicateOptimisticFixpoint(); |
1555 | return; |
1556 | } |
1557 | } |
1558 | |
1559 | if (!A.isFunctionIPOAmendable(*F)) |
1560 | indicatePessimisticFixpoint(); |
1561 | } |
1562 | |
1563 | /// See AbstractAttribute::manifest(...). |
1564 | ChangeStatus manifest(Attributor &A) override; |
1565 | |
1566 | /// See AbstractAttribute::getState(...). |
1567 | AbstractState &getState() override { return *this; } |
1568 | |
1569 | /// See AbstractAttribute::getState(...). |
1570 | const AbstractState &getState() const override { return *this; } |
1571 | |
1572 | /// See AbstractAttribute::updateImpl(Attributor &A). |
1573 | ChangeStatus updateImpl(Attributor &A) override; |
1574 | |
1575 | llvm::iterator_range<iterator> returned_values() override { |
1576 | return llvm::make_range(ReturnedValues.begin(), ReturnedValues.end()); |
1577 | } |
1578 | |
1579 | llvm::iterator_range<const_iterator> returned_values() const override { |
1580 | return llvm::make_range(ReturnedValues.begin(), ReturnedValues.end()); |
1581 | } |
1582 | |
1583 | /// Return the number of potential return values, -1 if unknown. |
1584 | size_t getNumReturnValues() const override { |
1585 | return isValidState() ? ReturnedValues.size() : -1; |
1586 | } |
1587 | |
1588 | /// Return an assumed unique return value if a single candidate is found. If |
1589 | /// there cannot be one, return a nullptr. If it is not clear yet, return the |
1590 | /// Optional::NoneType. |
1591 | Optional<Value *> getAssumedUniqueReturnValue(Attributor &A) const; |
1592 | |
1593 | /// See AbstractState::checkForAllReturnedValues(...). |
1594 | bool checkForAllReturnedValuesAndReturnInsts( |
1595 | function_ref<bool(Value &, const SmallSetVector<ReturnInst *, 4> &)> Pred) |
1596 | const override; |
1597 | |
1598 | /// Pretty print the attribute similar to the IR representation. |
1599 | const std::string getAsStr() const override; |
1600 | |
1601 | /// See AbstractState::isAtFixpoint(). |
1602 | bool isAtFixpoint() const override { return IsFixed; } |
1603 | |
1604 | /// See AbstractState::isValidState(). |
1605 | bool isValidState() const override { return IsValidState; } |
1606 | |
1607 | /// See AbstractState::indicateOptimisticFixpoint(...). |
1608 | ChangeStatus indicateOptimisticFixpoint() override { |
1609 | IsFixed = true; |
1610 | return ChangeStatus::UNCHANGED; |
1611 | } |
1612 | |
1613 | ChangeStatus indicatePessimisticFixpoint() override { |
1614 | IsFixed = true; |
1615 | IsValidState = false; |
1616 | return ChangeStatus::CHANGED; |
1617 | } |
1618 | }; |
1619 | |
1620 | ChangeStatus AAReturnedValuesImpl::manifest(Attributor &A) { |
1621 | ChangeStatus Changed = ChangeStatus::UNCHANGED; |
1622 | |
1623 | // Bookkeeping. |
1624 | assert(isValidState())((void)0); |
1625 | STATS_DECLTRACK(KnownReturnValues, FunctionReturn,{ static llvm::Statistic NumIRFunctionReturn_KnownReturnValues = {"attributor", "NumIRFunctionReturn_KnownReturnValues", "Number of function with known return values" };; ++(NumIRFunctionReturn_KnownReturnValues); } |
1626 | "Number of function with known return values"){ static llvm::Statistic NumIRFunctionReturn_KnownReturnValues = {"attributor", "NumIRFunctionReturn_KnownReturnValues", "Number of function with known return values" };; ++(NumIRFunctionReturn_KnownReturnValues); }; |
1627 | |
1628 | // Check if we have an assumed unique return value that we could manifest. |
1629 | Optional<Value *> UniqueRV = getAssumedUniqueReturnValue(A); |
1630 | |
1631 | if (!UniqueRV.hasValue() || !UniqueRV.getValue()) |
1632 | return Changed; |
1633 | |
1634 | // Bookkeeping. |
1635 | STATS_DECLTRACK(UniqueReturnValue, FunctionReturn,{ static llvm::Statistic NumIRFunctionReturn_UniqueReturnValue = {"attributor", "NumIRFunctionReturn_UniqueReturnValue", "Number of function with unique return" };; ++(NumIRFunctionReturn_UniqueReturnValue); } |
1636 | "Number of function with unique return"){ static llvm::Statistic NumIRFunctionReturn_UniqueReturnValue = {"attributor", "NumIRFunctionReturn_UniqueReturnValue", "Number of function with unique return" };; ++(NumIRFunctionReturn_UniqueReturnValue); }; |
1637 | // If the assumed unique return value is an argument, annotate it. |
1638 | if (auto *UniqueRVArg = dyn_cast<Argument>(UniqueRV.getValue())) { |
1639 | if (UniqueRVArg->getType()->canLosslesslyBitCastTo( |
1640 | getAssociatedFunction()->getReturnType())) { |
1641 | getIRPosition() = IRPosition::argument(*UniqueRVArg); |
1642 | Changed = IRAttribute::manifest(A); |
1643 | } |
1644 | } |
1645 | return Changed; |
1646 | } |
1647 | |
1648 | const std::string AAReturnedValuesImpl::getAsStr() const { |
1649 | return (isAtFixpoint() ? "returns(#" : "may-return(#") + |
1650 | (isValidState() ? std::to_string(getNumReturnValues()) : "?") + ")"; |
1651 | } |
1652 | |
1653 | Optional<Value *> |
1654 | AAReturnedValuesImpl::getAssumedUniqueReturnValue(Attributor &A) const { |
1655 | // If checkForAllReturnedValues provides a unique value, ignoring potential |
1656 | // undef values that can also be present, it is assumed to be the actual |
1657 | // return value and forwarded to the caller of this method. If there are |
1658 | // multiple, a nullptr is returned indicating there cannot be a unique |
1659 | // returned value. |
1660 | Optional<Value *> UniqueRV; |
1661 | Type *Ty = getAssociatedFunction()->getReturnType(); |
1662 | |
1663 | auto Pred = [&](Value &RV) -> bool { |
1664 | UniqueRV = AA::combineOptionalValuesInAAValueLatice(UniqueRV, &RV, Ty); |
1665 | return UniqueRV != Optional<Value *>(nullptr); |
1666 | }; |
1667 | |
1668 | if (!A.checkForAllReturnedValues(Pred, *this)) |
1669 | UniqueRV = nullptr; |
1670 | |
1671 | return UniqueRV; |
1672 | } |
1673 | |
1674 | bool AAReturnedValuesImpl::checkForAllReturnedValuesAndReturnInsts( |
1675 | function_ref<bool(Value &, const SmallSetVector<ReturnInst *, 4> &)> Pred) |
1676 | const { |
1677 | if (!isValidState()) |
1678 | return false; |
1679 | |
1680 | // Check all returned values but ignore call sites as long as we have not |
1681 | // encountered an overdefined one during an update. |
1682 | for (auto &It : ReturnedValues) { |
1683 | Value *RV = It.first; |
1684 | if (!Pred(*RV, It.second)) |
1685 | return false; |
1686 | } |
1687 | |
1688 | return true; |
1689 | } |
1690 | |
1691 | ChangeStatus AAReturnedValuesImpl::updateImpl(Attributor &A) { |
1692 | ChangeStatus Changed = ChangeStatus::UNCHANGED; |
1693 | |
1694 | auto ReturnValueCB = [&](Value &V, const Instruction *CtxI, ReturnInst &Ret, |
1695 | bool) -> bool { |
1696 | bool UsedAssumedInformation = false; |
1697 | Optional<Value *> SimpleRetVal = |
1698 | A.getAssumedSimplified(V, *this, UsedAssumedInformation); |
1699 | if (!SimpleRetVal.hasValue()) |
1700 | return true; |
1701 | if (!SimpleRetVal.getValue()) |
1702 | return false; |
1703 | Value *RetVal = *SimpleRetVal; |
1704 | assert(AA::isValidInScope(*RetVal, Ret.getFunction()) &&((void)0) |
1705 | "Assumed returned value should be valid in function scope!")((void)0); |
1706 | if (ReturnedValues[RetVal].insert(&Ret)) |
1707 | Changed = ChangeStatus::CHANGED; |
1708 | return true; |
1709 | }; |
1710 | |
1711 | auto ReturnInstCB = [&](Instruction &I) { |
1712 | ReturnInst &Ret = cast<ReturnInst>(I); |
1713 | return genericValueTraversal<ReturnInst>( |
1714 | A, IRPosition::value(*Ret.getReturnValue()), *this, Ret, ReturnValueCB, |
1715 | &I); |
1716 | }; |
1717 | |
1718 | // Discover returned values from all live returned instructions in the |
1719 | // associated function. |
1720 | bool UsedAssumedInformation = false; |
1721 | if (!A.checkForAllInstructions(ReturnInstCB, *this, {Instruction::Ret}, |
1722 | UsedAssumedInformation)) |
1723 | return indicatePessimisticFixpoint(); |
1724 | return Changed; |
1725 | } |
1726 | |
1727 | struct AAReturnedValuesFunction final : public AAReturnedValuesImpl { |
1728 | AAReturnedValuesFunction(const IRPosition &IRP, Attributor &A) |
1729 | : AAReturnedValuesImpl(IRP, A) {} |
1730 | |
1731 | /// See AbstractAttribute::trackStatistics() |
1732 | void trackStatistics() const override { STATS_DECLTRACK_ARG_ATTR(returned){ static llvm::Statistic NumIRArguments_returned = {"attributor" , "NumIRArguments_returned", ("Number of " "arguments" " marked '" "returned" "'")};; ++(NumIRArguments_returned); } } |
1733 | }; |
1734 | |
1735 | /// Returned values information for a call sites. |
1736 | struct AAReturnedValuesCallSite final : AAReturnedValuesImpl { |
1737 | AAReturnedValuesCallSite(const IRPosition &IRP, Attributor &A) |
1738 | : AAReturnedValuesImpl(IRP, A) {} |
1739 | |
1740 | /// See AbstractAttribute::initialize(...). |
1741 | void initialize(Attributor &A) override { |
1742 | // TODO: Once we have call site specific value information we can provide |
1743 | // call site specific liveness information and then it makes |
1744 | // sense to specialize attributes for call sites instead of |
1745 | // redirecting requests to the callee. |
1746 | llvm_unreachable("Abstract attributes for returned values are not "__builtin_unreachable() |
1747 | "supported for call sites yet!")__builtin_unreachable(); |
1748 | } |
1749 | |
1750 | /// See AbstractAttribute::updateImpl(...). |
1751 | ChangeStatus updateImpl(Attributor &A) override { |
1752 | return indicatePessimisticFixpoint(); |
1753 | } |
1754 | |
1755 | /// See AbstractAttribute::trackStatistics() |
1756 | void trackStatistics() const override {} |
1757 | }; |
1758 | |
1759 | /// ------------------------ NoSync Function Attribute ------------------------- |
1760 | |
1761 | struct AANoSyncImpl : AANoSync { |
1762 | AANoSyncImpl(const IRPosition &IRP, Attributor &A) : AANoSync(IRP, A) {} |
1763 | |
1764 | const std::string getAsStr() const override { |
1765 | return getAssumed() ? "nosync" : "may-sync"; |
1766 | } |
1767 | |
1768 | /// See AbstractAttribute::updateImpl(...). |
1769 | ChangeStatus updateImpl(Attributor &A) override; |
1770 | |
1771 | /// Helper function used to determine whether an instruction is non-relaxed |
1772 | /// atomic. In other words, if an atomic instruction does not have unordered |
1773 | /// or monotonic ordering |
1774 | static bool isNonRelaxedAtomic(Instruction *I); |
1775 | |
1776 | /// Helper function specific for intrinsics which are potentially volatile |
1777 | static bool isNoSyncIntrinsic(Instruction *I); |
1778 | }; |
1779 | |
1780 | bool AANoSyncImpl::isNonRelaxedAtomic(Instruction *I) { |
1781 | if (!I->isAtomic()) |
1782 | return false; |
1783 | |
1784 | if (auto *FI = dyn_cast<FenceInst>(I)) |
1785 | // All legal orderings for fence are stronger than monotonic. |
1786 | return FI->getSyncScopeID() != SyncScope::SingleThread; |
1787 | else if (auto *AI = dyn_cast<AtomicCmpXchgInst>(I)) { |
1788 | // Unordered is not a legal ordering for cmpxchg. |
1789 | return (AI->getSuccessOrdering() != AtomicOrdering::Monotonic || |
1790 | AI->getFailureOrdering() != AtomicOrdering::Monotonic); |
1791 | } |
1792 | |
1793 | AtomicOrdering Ordering; |
1794 | switch (I->getOpcode()) { |
1795 | case Instruction::AtomicRMW: |
1796 | Ordering = cast<AtomicRMWInst>(I)->getOrdering(); |
1797 | break; |
1798 | case Instruction::Store: |
1799 | Ordering = cast<StoreInst>(I)->getOrdering(); |
1800 | break; |
1801 | case Instruction::Load: |
1802 | Ordering = cast<LoadInst>(I)->getOrdering(); |
1803 | break; |
1804 | default: |
1805 | llvm_unreachable(__builtin_unreachable() |
1806 | "New atomic operations need to be known in the attributor.")__builtin_unreachable(); |
1807 | } |
1808 | |
1809 | return (Ordering != AtomicOrdering::Unordered && |
1810 | Ordering != AtomicOrdering::Monotonic); |
1811 | } |
1812 | |
1813 | /// Return true if this intrinsic is nosync. This is only used for intrinsics |
1814 | /// which would be nosync except that they have a volatile flag. All other |
1815 | /// intrinsics are simply annotated with the nosync attribute in Intrinsics.td. |
1816 | bool AANoSyncImpl::isNoSyncIntrinsic(Instruction *I) { |
1817 | if (auto *MI = dyn_cast<MemIntrinsic>(I)) |
1818 | return !MI->isVolatile(); |
1819 | return false; |
1820 | } |
1821 | |
1822 | ChangeStatus AANoSyncImpl::updateImpl(Attributor &A) { |
1823 | |
1824 | auto CheckRWInstForNoSync = [&](Instruction &I) { |
1825 | /// We are looking for volatile instructions or Non-Relaxed atomics. |
1826 | |
1827 | if (const auto *CB = dyn_cast<CallBase>(&I)) { |
1828 | if (CB->hasFnAttr(Attribute::NoSync)) |
1829 | return true; |
1830 | |
1831 | if (isNoSyncIntrinsic(&I)) |
1832 | return true; |
1833 | |
1834 | const auto &NoSyncAA = A.getAAFor<AANoSync>( |
1835 | *this, IRPosition::callsite_function(*CB), DepClassTy::REQUIRED); |
1836 | return NoSyncAA.isAssumedNoSync(); |
1837 | } |
1838 | |
1839 | if (!I.isVolatile() && !isNonRelaxedAtomic(&I)) |
1840 | return true; |
1841 | |
1842 | return false; |
1843 | }; |
1844 | |
1845 | auto CheckForNoSync = [&](Instruction &I) { |
1846 | // At this point we handled all read/write effects and they are all |
1847 | // nosync, so they can be skipped. |
1848 | if (I.mayReadOrWriteMemory()) |
1849 | return true; |
1850 | |
1851 | // non-convergent and readnone imply nosync. |
1852 | return !cast<CallBase>(I).isConvergent(); |
1853 | }; |
1854 | |
1855 | bool UsedAssumedInformation = false; |
1856 | if (!A.checkForAllReadWriteInstructions(CheckRWInstForNoSync, *this, |
1857 | UsedAssumedInformation) || |
1858 | !A.checkForAllCallLikeInstructions(CheckForNoSync, *this, |
1859 | UsedAssumedInformation)) |
1860 | return indicatePessimisticFixpoint(); |
1861 | |
1862 | return ChangeStatus::UNCHANGED; |
1863 | } |
1864 | |
1865 | struct AANoSyncFunction final : public AANoSyncImpl { |
1866 | AANoSyncFunction(const IRPosition &IRP, Attributor &A) |
1867 | : AANoSyncImpl(IRP, A) {} |
1868 | |
1869 | /// See AbstractAttribute::trackStatistics() |
1870 | void trackStatistics() const override { STATS_DECLTRACK_FN_ATTR(nosync){ static llvm::Statistic NumIRFunction_nosync = {"attributor" , "NumIRFunction_nosync", ("Number of " "functions" " marked '" "nosync" "'")};; ++(NumIRFunction_nosync); } } |
1871 | }; |
1872 | |
1873 | /// NoSync attribute deduction for a call sites. |
1874 | struct AANoSyncCallSite final : AANoSyncImpl { |
1875 | AANoSyncCallSite(const IRPosition &IRP, Attributor &A) |
1876 | : AANoSyncImpl(IRP, A) {} |
1877 | |
1878 | /// See AbstractAttribute::initialize(...). |
1879 | void initialize(Attributor &A) override { |
1880 | AANoSyncImpl::initialize(A); |
1881 | Function *F = getAssociatedFunction(); |
1882 | if (!F || F->isDeclaration()) |
1883 | indicatePessimisticFixpoint(); |
1884 | } |
1885 | |
1886 | /// See AbstractAttribute::updateImpl(...). |
1887 | ChangeStatus updateImpl(Attributor &A) override { |
1888 | // TODO: Once we have call site specific value information we can provide |
1889 | // call site specific liveness information and then it makes |
1890 | // sense to specialize attributes for call sites arguments instead of |
1891 | // redirecting requests to the callee argument. |
1892 | Function *F = getAssociatedFunction(); |
1893 | const IRPosition &FnPos = IRPosition::function(*F); |
1894 | auto &FnAA = A.getAAFor<AANoSync>(*this, FnPos, DepClassTy::REQUIRED); |
1895 | return clampStateAndIndicateChange(getState(), FnAA.getState()); |
1896 | } |
1897 | |
1898 | /// See AbstractAttribute::trackStatistics() |
1899 | void trackStatistics() const override { STATS_DECLTRACK_CS_ATTR(nosync){ static llvm::Statistic NumIRCS_nosync = {"attributor", "NumIRCS_nosync" , ("Number of " "call site" " marked '" "nosync" "'")};; ++(NumIRCS_nosync ); }; } |
1900 | }; |
1901 | |
1902 | /// ------------------------ No-Free Attributes ---------------------------- |
1903 | |
1904 | struct AANoFreeImpl : public AANoFree { |
1905 | AANoFreeImpl(const IRPosition &IRP, Attributor &A) : AANoFree(IRP, A) {} |
1906 | |
1907 | /// See AbstractAttribute::updateImpl(...). |
1908 | ChangeStatus updateImpl(Attributor &A) override { |
1909 | auto CheckForNoFree = [&](Instruction &I) { |
1910 | const auto &CB = cast<CallBase>(I); |
1911 | if (CB.hasFnAttr(Attribute::NoFree)) |
1912 | return true; |
1913 | |
1914 | const auto &NoFreeAA = A.getAAFor<AANoFree>( |
1915 | *this, IRPosition::callsite_function(CB), DepClassTy::REQUIRED); |
1916 | return NoFreeAA.isAssumedNoFree(); |
1917 | }; |
1918 | |
1919 | bool UsedAssumedInformation = false; |
1920 | if (!A.checkForAllCallLikeInstructions(CheckForNoFree, *this, |
1921 | UsedAssumedInformation)) |
1922 | return indicatePessimisticFixpoint(); |
1923 | return ChangeStatus::UNCHANGED; |
1924 | } |
1925 | |
1926 | /// See AbstractAttribute::getAsStr(). |
1927 | const std::string getAsStr() const override { |
1928 | return getAssumed() ? "nofree" : "may-free"; |
1929 | } |
1930 | }; |
1931 | |
1932 | struct AANoFreeFunction final : public AANoFreeImpl { |
1933 | AANoFreeFunction(const IRPosition &IRP, Attributor &A) |
1934 | : AANoFreeImpl(IRP, A) {} |
1935 | |
1936 | /// See AbstractAttribute::trackStatistics() |
1937 | void trackStatistics() const override { STATS_DECLTRACK_FN_ATTR(nofree){ static llvm::Statistic NumIRFunction_nofree = {"attributor" , "NumIRFunction_nofree", ("Number of " "functions" " marked '" "nofree" "'")};; ++(NumIRFunction_nofree); } } |
1938 | }; |
1939 | |
1940 | /// NoFree attribute deduction for a call sites. |
1941 | struct AANoFreeCallSite final : AANoFreeImpl { |
1942 | AANoFreeCallSite(const IRPosition &IRP, Attributor &A) |
1943 | : AANoFreeImpl(IRP, A) {} |
1944 | |
1945 | /// See AbstractAttribute::initialize(...). |
1946 | void initialize(Attributor &A) override { |
1947 | AANoFreeImpl::initialize(A); |
1948 | Function *F = getAssociatedFunction(); |
1949 | if (!F || F->isDeclaration()) |
1950 | indicatePessimisticFixpoint(); |
1951 | } |
1952 | |
1953 | /// See AbstractAttribute::updateImpl(...). |
1954 | ChangeStatus updateImpl(Attributor &A) override { |
1955 | // TODO: Once we have call site specific value information we can provide |
1956 | // call site specific liveness information and then it makes |
1957 | // sense to specialize attributes for call sites arguments instead of |
1958 | // redirecting requests to the callee argument. |
1959 | Function *F = getAssociatedFunction(); |
1960 | const IRPosition &FnPos = IRPosition::function(*F); |
1961 | auto &FnAA = A.getAAFor<AANoFree>(*this, FnPos, DepClassTy::REQUIRED); |
1962 | return clampStateAndIndicateChange(getState(), FnAA.getState()); |
1963 | } |
1964 | |
1965 | /// See AbstractAttribute::trackStatistics() |
1966 | void trackStatistics() const override { STATS_DECLTRACK_CS_ATTR(nofree){ static llvm::Statistic NumIRCS_nofree = {"attributor", "NumIRCS_nofree" , ("Number of " "call site" " marked '" "nofree" "'")};; ++(NumIRCS_nofree ); }; } |
1967 | }; |
1968 | |
1969 | /// NoFree attribute for floating values. |
1970 | struct AANoFreeFloating : AANoFreeImpl { |
1971 | AANoFreeFloating(const IRPosition &IRP, Attributor &A) |
1972 | : AANoFreeImpl(IRP, A) {} |
1973 | |
1974 | /// See AbstractAttribute::trackStatistics() |
1975 | void trackStatistics() const override{STATS_DECLTRACK_FLOATING_ATTR(nofree){ static llvm::Statistic NumIRFloating_nofree = {"attributor" , "NumIRFloating_nofree", ("Number of floating values known to be '" "nofree" "'")};; ++(NumIRFloating_nofree); }} |
1976 | |
1977 | /// See Abstract Attribute::updateImpl(...). |
1978 | ChangeStatus updateImpl(Attributor &A) override { |
1979 | const IRPosition &IRP = getIRPosition(); |
1980 | |
1981 | const auto &NoFreeAA = A.getAAFor<AANoFree>( |
1982 | *this, IRPosition::function_scope(IRP), DepClassTy::OPTIONAL); |
1983 | if (NoFreeAA.isAssumedNoFree()) |
1984 | return ChangeStatus::UNCHANGED; |
1985 | |
1986 | Value &AssociatedValue = getIRPosition().getAssociatedValue(); |
1987 | auto Pred = [&](const Use &U, bool &Follow) -> bool { |
1988 | Instruction *UserI = cast<Instruction>(U.getUser()); |
1989 | if (auto *CB = dyn_cast<CallBase>(UserI)) { |
1990 | if (CB->isBundleOperand(&U)) |
1991 | return false; |
1992 | if (!CB->isArgOperand(&U)) |
1993 | return true; |
1994 | unsigned ArgNo = CB->getArgOperandNo(&U); |
1995 | |
1996 | const auto &NoFreeArg = A.getAAFor<AANoFree>( |
1997 | *this, IRPosition::callsite_argument(*CB, ArgNo), |
1998 | DepClassTy::REQUIRED); |
1999 | return NoFreeArg.isAssumedNoFree(); |
2000 | } |
2001 | |
2002 | if (isa<GetElementPtrInst>(UserI) || isa<BitCastInst>(UserI) || |
2003 | isa<PHINode>(UserI) || isa<SelectInst>(UserI)) { |
2004 | Follow = true; |
2005 | return true; |
2006 | } |
2007 | if (isa<StoreInst>(UserI) || isa<LoadInst>(UserI) || |
2008 | isa<ReturnInst>(UserI)) |
2009 | return true; |
2010 | |
2011 | // Unknown user. |
2012 | return false; |
2013 | }; |
2014 | if (!A.checkForAllUses(Pred, *this, AssociatedValue)) |
2015 | return indicatePessimisticFixpoint(); |
2016 | |
2017 | return ChangeStatus::UNCHANGED; |
2018 | } |
2019 | }; |
2020 | |
2021 | /// NoFree attribute for a call site argument. |
2022 | struct AANoFreeArgument final : AANoFreeFloating { |
2023 | AANoFreeArgument(const IRPosition &IRP, Attributor &A) |
2024 | : AANoFreeFloating(IRP, A) {} |
2025 | |
2026 | /// See AbstractAttribute::trackStatistics() |
2027 | void trackStatistics() const override { STATS_DECLTRACK_ARG_ATTR(nofree){ static llvm::Statistic NumIRArguments_nofree = {"attributor" , "NumIRArguments_nofree", ("Number of " "arguments" " marked '" "nofree" "'")};; ++(NumIRArguments_nofree); } } |
2028 | }; |
2029 | |
2030 | /// NoFree attribute for call site arguments. |
2031 | struct AANoFreeCallSiteArgument final : AANoFreeFloating { |
2032 | AANoFreeCallSiteArgument(const IRPosition &IRP, Attributor &A) |
2033 | : AANoFreeFloating(IRP, A) {} |
2034 | |
2035 | /// See AbstractAttribute::updateImpl(...). |
2036 | ChangeStatus updateImpl(Attributor &A) override { |
2037 | // TODO: Once we have call site specific value information we can provide |
2038 | // call site specific liveness information and then it makes |
2039 | // sense to specialize attributes for call sites arguments instead of |
2040 | // redirecting requests to the callee argument. |
2041 | Argument *Arg = getAssociatedArgument(); |
2042 | if (!Arg) |
2043 | return indicatePessimisticFixpoint(); |
2044 | const IRPosition &ArgPos = IRPosition::argument(*Arg); |
2045 | auto &ArgAA = A.getAAFor<AANoFree>(*this, ArgPos, DepClassTy::REQUIRED); |
2046 | return clampStateAndIndicateChange(getState(), ArgAA.getState()); |
2047 | } |
2048 | |
2049 | /// See AbstractAttribute::trackStatistics() |
2050 | void trackStatistics() const override{STATS_DECLTRACK_CSARG_ATTR(nofree){ static llvm::Statistic NumIRCSArguments_nofree = {"attributor" , "NumIRCSArguments_nofree", ("Number of " "call site arguments" " marked '" "nofree" "'")};; ++(NumIRCSArguments_nofree); }}; |
2051 | }; |
2052 | |
2053 | /// NoFree attribute for function return value. |
2054 | struct AANoFreeReturned final : AANoFreeFloating { |
2055 | AANoFreeReturned(const IRPosition &IRP, Attributor &A) |
2056 | : AANoFreeFloating(IRP, A) { |
2057 | llvm_unreachable("NoFree is not applicable to function returns!")__builtin_unreachable(); |
2058 | } |
2059 | |
2060 | /// See AbstractAttribute::initialize(...). |
2061 | void initialize(Attributor &A) override { |
2062 | llvm_unreachable("NoFree is not applicable to function returns!")__builtin_unreachable(); |
2063 | } |
2064 | |
2065 | /// See AbstractAttribute::updateImpl(...). |
2066 | ChangeStatus updateImpl(Attributor &A) override { |
2067 | llvm_unreachable("NoFree is not applicable to function returns!")__builtin_unreachable(); |
2068 | } |
2069 | |
2070 | /// See AbstractAttribute::trackStatistics() |
2071 | void trackStatistics() const override {} |
2072 | }; |
2073 | |
2074 | /// NoFree attribute deduction for a call site return value. |
2075 | struct AANoFreeCallSiteReturned final : AANoFreeFloating { |
2076 | AANoFreeCallSiteReturned(const IRPosition &IRP, Attributor &A) |
2077 | : AANoFreeFloating(IRP, A) {} |
2078 | |
2079 | ChangeStatus manifest(Attributor &A) override { |
2080 | return ChangeStatus::UNCHANGED; |
2081 | } |
2082 | /// See AbstractAttribute::trackStatistics() |
2083 | void trackStatistics() const override { STATS_DECLTRACK_CSRET_ATTR(nofree){ static llvm::Statistic NumIRCSReturn_nofree = {"attributor" , "NumIRCSReturn_nofree", ("Number of " "call site returns" " marked '" "nofree" "'")};; ++(NumIRCSReturn_nofree); } } |
2084 | }; |
2085 | |
2086 | /// ------------------------ NonNull Argument Attribute ------------------------ |
2087 | static int64_t getKnownNonNullAndDerefBytesForUse( |
2088 | Attributor &A, const AbstractAttribute &QueryingAA, Value &AssociatedValue, |
2089 | const Use *U, const Instruction *I, bool &IsNonNull, bool &TrackUse) { |
2090 | TrackUse = false; |
2091 | |
2092 | const Value *UseV = U->get(); |
2093 | if (!UseV->getType()->isPointerTy()) |
2094 | return 0; |
2095 | |
2096 | // We need to follow common pointer manipulation uses to the accesses they |
2097 | // feed into. We can try to be smart to avoid looking through things we do not |
2098 | // like for now, e.g., non-inbounds GEPs. |
2099 | if (isa<CastInst>(I)) { |
2100 | TrackUse = true; |
2101 | return 0; |
2102 | } |
2103 | |
2104 | if (isa<GetElementPtrInst>(I)) { |
2105 | TrackUse = true; |
2106 | return 0; |
2107 | } |
2108 | |
2109 | Type *PtrTy = UseV->getType(); |
2110 | const Function *F = I->getFunction(); |
2111 | bool NullPointerIsDefined = |
2112 | F ? llvm::NullPointerIsDefined(F, PtrTy->getPointerAddressSpace()) : true; |
2113 | const DataLayout &DL = A.getInfoCache().getDL(); |
2114 | if (const auto *CB = dyn_cast<CallBase>(I)) { |
2115 | if (CB->isBundleOperand(U)) { |
2116 | if (RetainedKnowledge RK = getKnowledgeFromUse( |
2117 | U, {Attribute::NonNull, Attribute::Dereferenceable})) { |
2118 | IsNonNull |= |
2119 | (RK.AttrKind == Attribute::NonNull || !NullPointerIsDefined); |
2120 | return RK.ArgValue; |
2121 | } |
2122 | return 0; |
2123 | } |
2124 | |
2125 | if (CB->isCallee(U)) { |
2126 | IsNonNull |= !NullPointerIsDefined; |
2127 | return 0; |
2128 | } |
2129 | |
2130 | unsigned ArgNo = CB->getArgOperandNo(U); |
2131 | IRPosition IRP = IRPosition::callsite_argument(*CB, ArgNo); |
2132 | // As long as we only use known information there is no need to track |
2133 | // dependences here. |
2134 | auto &DerefAA = |
2135 | A.getAAFor<AADereferenceable>(QueryingAA, IRP, DepClassTy::NONE); |
2136 | IsNonNull |= DerefAA.isKnownNonNull(); |
2137 | return DerefAA.getKnownDereferenceableBytes(); |
2138 | } |
2139 | |
2140 | int64_t Offset; |
2141 | const Value *Base = |
2142 | getMinimalBaseOfAccsesPointerOperand(A, QueryingAA, I, Offset, DL); |
2143 | if (Base) { |
2144 | if (Base == &AssociatedValue && |
2145 | getPointerOperand(I, /* AllowVolatile */ false) == UseV) { |
2146 | int64_t DerefBytes = |
2147 | (int64_t)DL.getTypeStoreSize(PtrTy->getPointerElementType()) + Offset; |
2148 | |
2149 | IsNonNull |= !NullPointerIsDefined; |
2150 | return std::max(int64_t(0), DerefBytes); |
2151 | } |
2152 | } |
2153 | |
2154 | /// Corner case when an offset is 0. |
2155 | Base = getBasePointerOfAccessPointerOperand(I, Offset, DL, |
2156 | /*AllowNonInbounds*/ true); |
2157 | if (Base) { |
2158 | if (Offset == 0 && Base == &AssociatedValue && |
2159 | getPointerOperand(I, /* AllowVolatile */ false) == UseV) { |
2160 | int64_t DerefBytes = |
2161 | (int64_t)DL.getTypeStoreSize(PtrTy->getPointerElementType()); |
2162 | IsNonNull |= !NullPointerIsDefined; |
2163 | return std::max(int64_t(0), DerefBytes); |
2164 | } |
2165 | } |
2166 | |
2167 | return 0; |
2168 | } |
2169 | |
2170 | struct AANonNullImpl : AANonNull { |
2171 | AANonNullImpl(const IRPosition &IRP, Attributor &A) |
2172 | : AANonNull(IRP, A), |
2173 | NullIsDefined(NullPointerIsDefined( |
2174 | getAnchorScope(), |
2175 | getAssociatedValue().getType()->getPointerAddressSpace())) {} |
2176 | |
2177 | /// See AbstractAttribute::initialize(...). |
2178 | void initialize(Attributor &A) override { |
2179 | Value &V = getAssociatedValue(); |
2180 | if (!NullIsDefined && |
2181 | hasAttr({Attribute::NonNull, Attribute::Dereferenceable}, |
2182 | /* IgnoreSubsumingPositions */ false, &A)) { |
2183 | indicateOptimisticFixpoint(); |
2184 | return; |
2185 | } |
2186 | |
2187 | if (isa<ConstantPointerNull>(V)) { |
2188 | indicatePessimisticFixpoint(); |
2189 | return; |
2190 | } |
2191 | |
2192 | AANonNull::initialize(A); |
2193 | |
2194 | bool CanBeNull, CanBeFreed; |
2195 | if (V.getPointerDereferenceableBytes(A.getDataLayout(), CanBeNull, |
2196 | CanBeFreed)) { |
2197 | if (!CanBeNull) { |
2198 | indicateOptimisticFixpoint(); |
2199 | return; |
2200 | } |
2201 | } |
2202 | |
2203 | if (isa<GlobalValue>(&getAssociatedValue())) { |
2204 | indicatePessimisticFixpoint(); |
2205 | return; |
2206 | } |
2207 | |
2208 | if (Instruction *CtxI = getCtxI()) |
2209 | followUsesInMBEC(*this, A, getState(), *CtxI); |
2210 | } |
2211 | |
2212 | /// See followUsesInMBEC |
2213 | bool followUseInMBEC(Attributor &A, const Use *U, const Instruction *I, |
2214 | AANonNull::StateType &State) { |
2215 | bool IsNonNull = false; |
2216 | bool TrackUse = false; |
2217 | getKnownNonNullAndDerefBytesForUse(A, *this, getAssociatedValue(), U, I, |
2218 | IsNonNull, TrackUse); |
2219 | State.setKnown(IsNonNull); |
2220 | return TrackUse; |
2221 | } |
2222 | |
2223 | /// See AbstractAttribute::getAsStr(). |
2224 | const std::string getAsStr() const override { |
2225 | return getAssumed() ? "nonnull" : "may-null"; |
2226 | } |
2227 | |
2228 | /// Flag to determine if the underlying value can be null and still allow |
2229 | /// valid accesses. |
2230 | const bool NullIsDefined; |
2231 | }; |
2232 | |
2233 | /// NonNull attribute for a floating value. |
2234 | struct AANonNullFloating : public AANonNullImpl { |
2235 | AANonNullFloating(const IRPosition &IRP, Attributor &A) |
2236 | : AANonNullImpl(IRP, A) {} |
2237 | |
2238 | /// See AbstractAttribute::updateImpl(...). |
2239 | ChangeStatus updateImpl(Attributor &A) override { |
2240 | const DataLayout &DL = A.getDataLayout(); |
2241 | |
2242 | DominatorTree *DT = nullptr; |
2243 | AssumptionCache *AC = nullptr; |
2244 | InformationCache &InfoCache = A.getInfoCache(); |
2245 | if (const Function *Fn = getAnchorScope()) { |
2246 | DT = InfoCache.getAnalysisResultForFunction<DominatorTreeAnalysis>(*Fn); |
2247 | AC = InfoCache.getAnalysisResultForFunction<AssumptionAnalysis>(*Fn); |
2248 | } |
2249 | |
2250 | auto VisitValueCB = [&](Value &V, const Instruction *CtxI, |
2251 | AANonNull::StateType &T, bool Stripped) -> bool { |
2252 | const auto &AA = A.getAAFor<AANonNull>(*this, IRPosition::value(V), |
2253 | DepClassTy::REQUIRED); |
2254 | if (!Stripped && this == &AA) { |
2255 | if (!isKnownNonZero(&V, DL, 0, AC, CtxI, DT)) |
2256 | T.indicatePessimisticFixpoint(); |
2257 | } else { |
2258 | // Use abstract attribute information. |
2259 | const AANonNull::StateType &NS = AA.getState(); |
2260 | T ^= NS; |
2261 | } |
2262 | return T.isValidState(); |
2263 | }; |
2264 | |
2265 | StateType T; |
2266 | if (!genericValueTraversal<StateType>(A, getIRPosition(), *this, T, |
2267 | VisitValueCB, getCtxI())) |
2268 | return indicatePessimisticFixpoint(); |
2269 | |
2270 | return clampStateAndIndicateChange(getState(), T); |
2271 | } |
2272 | |
2273 | /// See AbstractAttribute::trackStatistics() |
2274 | void trackStatistics() const override { STATS_DECLTRACK_FNRET_ATTR(nonnull){ static llvm::Statistic NumIRFunctionReturn_nonnull = {"attributor" , "NumIRFunctionReturn_nonnull", ("Number of " "function returns" " marked '" "nonnull" "'")};; ++(NumIRFunctionReturn_nonnull ); } } |
2275 | }; |
2276 | |
2277 | /// NonNull attribute for function return value. |
2278 | struct AANonNullReturned final |
2279 | : AAReturnedFromReturnedValues<AANonNull, AANonNull> { |
2280 | AANonNullReturned(const IRPosition &IRP, Attributor &A) |
2281 | : AAReturnedFromReturnedValues<AANonNull, AANonNull>(IRP, A) {} |
2282 | |
2283 | /// See AbstractAttribute::getAsStr(). |
2284 | const std::string getAsStr() const override { |
2285 | return getAssumed() ? "nonnull" : "may-null"; |
2286 | } |
2287 | |
2288 | /// See AbstractAttribute::trackStatistics() |
2289 | void trackStatistics() const override { STATS_DECLTRACK_FNRET_ATTR(nonnull){ static llvm::Statistic NumIRFunctionReturn_nonnull = {"attributor" , "NumIRFunctionReturn_nonnull", ("Number of " "function returns" " marked '" "nonnull" "'")};; ++(NumIRFunctionReturn_nonnull ); } } |
2290 | }; |
2291 | |
2292 | /// NonNull attribute for function argument. |
2293 | struct AANonNullArgument final |
2294 | : AAArgumentFromCallSiteArguments<AANonNull, AANonNullImpl> { |
2295 | AANonNullArgument(const IRPosition &IRP, Attributor &A) |
2296 | : AAArgumentFromCallSiteArguments<AANonNull, AANonNullImpl>(IRP, A) {} |
2297 | |
2298 | /// See AbstractAttribute::trackStatistics() |
2299 | void trackStatistics() const override { STATS_DECLTRACK_ARG_ATTR(nonnull){ static llvm::Statistic NumIRArguments_nonnull = {"attributor" , "NumIRArguments_nonnull", ("Number of " "arguments" " marked '" "nonnull" "'")};; ++(NumIRArguments_nonnull); } } |
2300 | }; |
2301 | |
2302 | struct AANonNullCallSiteArgument final : AANonNullFloating { |
2303 | AANonNullCallSiteArgument(const IRPosition &IRP, Attributor &A) |
2304 | : AANonNullFloating(IRP, A) {} |
2305 | |
2306 | /// See AbstractAttribute::trackStatistics() |
2307 | void trackStatistics() const override { STATS_DECLTRACK_CSARG_ATTR(nonnull){ static llvm::Statistic NumIRCSArguments_nonnull = {"attributor" , "NumIRCSArguments_nonnull", ("Number of " "call site arguments" " marked '" "nonnull" "'")};; ++(NumIRCSArguments_nonnull); } } |
2308 | }; |
2309 | |
2310 | /// NonNull attribute for a call site return position. |
2311 | struct AANonNullCallSiteReturned final |
2312 | : AACallSiteReturnedFromReturned<AANonNull, AANonNullImpl> { |
2313 | AANonNullCallSiteReturned(const IRPosition &IRP, Attributor &A) |
2314 | : AACallSiteReturnedFromReturned<AANonNull, AANonNullImpl>(IRP, A) {} |
2315 | |
2316 | /// See AbstractAttribute::trackStatistics() |
2317 | void trackStatistics() const override { STATS_DECLTRACK_CSRET_ATTR(nonnull){ static llvm::Statistic NumIRCSReturn_nonnull = {"attributor" , "NumIRCSReturn_nonnull", ("Number of " "call site returns" " marked '" "nonnull" "'")};; ++(NumIRCSReturn_nonnull); } } |
2318 | }; |
2319 | |
2320 | /// ------------------------ No-Recurse Attributes ---------------------------- |
2321 | |
2322 | struct AANoRecurseImpl : public AANoRecurse { |
2323 | AANoRecurseImpl(const IRPosition &IRP, Attributor &A) : AANoRecurse(IRP, A) {} |
2324 | |
2325 | /// See AbstractAttribute::getAsStr() |
2326 | const std::string getAsStr() const override { |
2327 | return getAssumed() ? "norecurse" : "may-recurse"; |
2328 | } |
2329 | }; |
2330 | |
2331 | struct AANoRecurseFunction final : AANoRecurseImpl { |
2332 | AANoRecurseFunction(const IRPosition &IRP, Attributor &A) |
2333 | : AANoRecurseImpl(IRP, A) {} |
2334 | |
2335 | /// See AbstractAttribute::initialize(...). |
2336 | void initialize(Attributor &A) override { |
2337 | AANoRecurseImpl::initialize(A); |
2338 | if (const Function *F = getAnchorScope()) |
2339 | if (A.getInfoCache().getSccSize(*F) != 1) |
2340 | indicatePessimisticFixpoint(); |
2341 | } |
2342 | |
2343 | /// See AbstractAttribute::updateImpl(...). |
2344 | ChangeStatus updateImpl(Attributor &A) override { |
2345 | |
2346 | // If all live call sites are known to be no-recurse, we are as well. |
2347 | auto CallSitePred = [&](AbstractCallSite ACS) { |
2348 | const auto &NoRecurseAA = A.getAAFor<AANoRecurse>( |
2349 | *this, IRPosition::function(*ACS.getInstruction()->getFunction()), |
2350 | DepClassTy::NONE); |
2351 | return NoRecurseAA.isKnownNoRecurse(); |
2352 | }; |
2353 | bool AllCallSitesKnown; |
2354 | if (A.checkForAllCallSites(CallSitePred, *this, true, AllCallSitesKnown)) { |
2355 | // If we know all call sites and all are known no-recurse, we are done. |
2356 | // If all known call sites, which might not be all that exist, are known |
2357 | // to be no-recurse, we are not done but we can continue to assume |
2358 | // no-recurse. If one of the call sites we have not visited will become |
2359 | // live, another update is triggered. |
2360 | if (AllCallSitesKnown) |
2361 | indicateOptimisticFixpoint(); |
2362 | return ChangeStatus::UNCHANGED; |
2363 | } |
2364 | |
2365 | // If the above check does not hold anymore we look at the calls. |
2366 | auto CheckForNoRecurse = [&](Instruction &I) { |
2367 | const auto &CB = cast<CallBase>(I); |
2368 | if (CB.hasFnAttr(Attribute::NoRecurse)) |
2369 | return true; |
2370 | |
2371 | const auto &NoRecurseAA = A.getAAFor<AANoRecurse>( |
2372 | *this, IRPosition::callsite_function(CB), DepClassTy::REQUIRED); |
2373 | if (!NoRecurseAA.isAssumedNoRecurse()) |
2374 | return false; |
2375 | |
2376 | // Recursion to the same function |
2377 | if (CB.getCalledFunction() == getAnchorScope()) |
2378 | return false; |
2379 | |
2380 | return true; |
2381 | }; |
2382 | |
2383 | bool UsedAssumedInformation = false; |
2384 | if (!A.checkForAllCallLikeInstructions(CheckForNoRecurse, *this, |
2385 | UsedAssumedInformation)) |
2386 | return indicatePessimisticFixpoint(); |
2387 | return ChangeStatus::UNCHANGED; |
2388 | } |
2389 | |
2390 | void trackStatistics() const override { STATS_DECLTRACK_FN_ATTR(norecurse){ static llvm::Statistic NumIRFunction_norecurse = {"attributor" , "NumIRFunction_norecurse", ("Number of " "functions" " marked '" "norecurse" "'")};; ++(NumIRFunction_norecurse); } } |
2391 | }; |
2392 | |
2393 | /// NoRecurse attribute deduction for a call sites. |
2394 | struct AANoRecurseCallSite final : AANoRecurseImpl { |
2395 | AANoRecurseCallSite(const IRPosition &IRP, Attributor &A) |
2396 | : AANoRecurseImpl(IRP, A) {} |
2397 | |
2398 | /// See AbstractAttribute::initialize(...). |
2399 | void initialize(Attributor &A) override { |
2400 | AANoRecurseImpl::initialize(A); |
2401 | Function *F = getAssociatedFunction(); |
2402 | if (!F || F->isDeclaration()) |
2403 | indicatePessimisticFixpoint(); |
2404 | } |
2405 | |
2406 | /// See AbstractAttribute::updateImpl(...). |
2407 | ChangeStatus updateImpl(Attributor &A) override { |
2408 | // TODO: Once we have call site specific value information we can provide |
2409 | // call site specific liveness information and then it makes |
2410 | // sense to specialize attributes for call sites arguments instead of |
2411 | // redirecting requests to the callee argument. |
2412 | Function *F = getAssociatedFunction(); |
2413 | const IRPosition &FnPos = IRPosition::function(*F); |
2414 | auto &FnAA = A.getAAFor<AANoRecurse>(*this, FnPos, DepClassTy::REQUIRED); |
2415 | return clampStateAndIndicateChange(getState(), FnAA.getState()); |
2416 | } |
2417 | |
2418 | /// See AbstractAttribute::trackStatistics() |
2419 | void trackStatistics() const override { STATS_DECLTRACK_CS_ATTR(norecurse){ static llvm::Statistic NumIRCS_norecurse = {"attributor", "NumIRCS_norecurse" , ("Number of " "call site" " marked '" "norecurse" "'")};; ++ (NumIRCS_norecurse); }; } |
2420 | }; |
2421 | |
2422 | /// -------------------- Undefined-Behavior Attributes ------------------------ |
2423 | |
2424 | struct AAUndefinedBehaviorImpl : public AAUndefinedBehavior { |
2425 | AAUndefinedBehaviorImpl(const IRPosition &IRP, Attributor &A) |
2426 | : AAUndefinedBehavior(IRP, A) {} |
2427 | |
2428 | /// See AbstractAttribute::updateImpl(...). |
2429 | // through a pointer (i.e. also branches etc.) |
2430 | ChangeStatus updateImpl(Attributor &A) override { |
2431 | const size_t UBPrevSize = KnownUBInsts.size(); |
2432 | const size_t NoUBPrevSize = AssumedNoUBInsts.size(); |
2433 | |
2434 | auto InspectMemAccessInstForUB = [&](Instruction &I) { |
2435 | // Skip instructions that are already saved. |
2436 | if (AssumedNoUBInsts.count(&I) || KnownUBInsts.count(&I)) |
2437 | return true; |
2438 | |
2439 | // If we reach here, we know we have an instruction |
2440 | // that accesses memory through a pointer operand, |
2441 | // for which getPointerOperand() should give it to us. |
2442 | Value *PtrOp = |
2443 | const_cast<Value *>(getPointerOperand(&I, /* AllowVolatile */ true)); |
2444 | assert(PtrOp &&((void)0) |
2445 | "Expected pointer operand of memory accessing instruction")((void)0); |
2446 | |
2447 | // Either we stopped and the appropriate action was taken, |
2448 | // or we got back a simplified value to continue. |
2449 | Optional<Value *> SimplifiedPtrOp = stopOnUndefOrAssumed(A, PtrOp, &I); |
2450 | if (!SimplifiedPtrOp.hasValue() || !SimplifiedPtrOp.getValue()) |
2451 | return true; |
2452 | const Value *PtrOpVal = SimplifiedPtrOp.getValue(); |
2453 | |
2454 | // A memory access through a pointer is considered UB |
2455 | // only if the pointer has constant null value. |
2456 | // TODO: Expand it to not only check constant values. |
2457 | if (!isa<ConstantPointerNull>(PtrOpVal)) { |
2458 | AssumedNoUBInsts.insert(&I); |
2459 | return true; |
2460 | } |
2461 | const Type *PtrTy = PtrOpVal->getType(); |
2462 | |
2463 | // Because we only consider instructions inside functions, |
2464 | // assume that a parent function exists. |
2465 | const Function *F = I.getFunction(); |
2466 | |
2467 | // A memory access using constant null pointer is only considered UB |
2468 | // if null pointer is _not_ defined for the target platform. |
2469 | if (llvm::NullPointerIsDefined(F, PtrTy->getPointerAddressSpace())) |
2470 | AssumedNoUBInsts.insert(&I); |
2471 | else |
2472 | KnownUBInsts.insert(&I); |
2473 | return true; |
2474 | }; |
2475 | |
2476 | auto InspectBrInstForUB = [&](Instruction &I) { |
2477 | // A conditional branch instruction is considered UB if it has `undef` |
2478 | // condition. |
2479 | |
2480 | // Skip instructions that are already saved. |
2481 | if (AssumedNoUBInsts.count(&I) || KnownUBInsts.count(&I)) |
2482 | return true; |
2483 | |
2484 | // We know we have a branch instruction. |
2485 | auto *BrInst = cast<BranchInst>(&I); |
2486 | |
2487 | // Unconditional branches are never considered UB. |
2488 | if (BrInst->isUnconditional()) |
2489 | return true; |
2490 | |
2491 | // Either we stopped and the appropriate action was taken, |
2492 | // or we got back a simplified value to continue. |
2493 | Optional<Value *> SimplifiedCond = |
2494 | stopOnUndefOrAssumed(A, BrInst->getCondition(), BrInst); |
2495 | if (!SimplifiedCond.hasValue() || !SimplifiedCond.getValue()) |
2496 | return true; |
2497 | AssumedNoUBInsts.insert(&I); |
2498 | return true; |
2499 | }; |
2500 | |
2501 | auto InspectCallSiteForUB = [&](Instruction &I) { |
2502 | // Check whether a callsite always cause UB or not |
2503 | |
2504 | // Skip instructions that are already saved. |
2505 | if (AssumedNoUBInsts.count(&I) || KnownUBInsts.count(&I)) |
2506 | return true; |
2507 | |
2508 | // Check nonnull and noundef argument attribute violation for each |
2509 | // callsite. |
2510 | CallBase &CB = cast<CallBase>(I); |
2511 | Function *Callee = CB.getCalledFunction(); |
2512 | if (!Callee) |
2513 | return true; |
2514 | for (unsigned idx = 0; idx < CB.getNumArgOperands(); idx++) { |
2515 | // If current argument is known to be simplified to null pointer and the |
2516 | // corresponding argument position is known to have nonnull attribute, |
2517 | // the argument is poison. Furthermore, if the argument is poison and |
2518 | // the position is known to have noundef attriubte, this callsite is |
2519 | // considered UB. |
2520 | if (idx >= Callee->arg_size()) |
2521 | break; |
2522 | Value *ArgVal = CB.getArgOperand(idx); |
2523 | if (!ArgVal) |
2524 | continue; |
2525 | // Here, we handle three cases. |
2526 | // (1) Not having a value means it is dead. (we can replace the value |
2527 | // with undef) |
2528 | // (2) Simplified to undef. The argument violate noundef attriubte. |
2529 | // (3) Simplified to null pointer where known to be nonnull. |
2530 | // The argument is a poison value and violate noundef attribute. |
2531 | IRPosition CalleeArgumentIRP = IRPosition::callsite_argument(CB, idx); |
2532 | auto &NoUndefAA = |
2533 | A.getAAFor<AANoUndef>(*this, CalleeArgumentIRP, DepClassTy::NONE); |
2534 | if (!NoUndefAA.isKnownNoUndef()) |
2535 | continue; |
2536 | bool UsedAssumedInformation = false; |
2537 | Optional<Value *> SimplifiedVal = A.getAssumedSimplified( |
2538 | IRPosition::value(*ArgVal), *this, UsedAssumedInformation); |
2539 | if (UsedAssumedInformation) |
2540 | continue; |
2541 | if (SimplifiedVal.hasValue() && !SimplifiedVal.getValue()) |
2542 | return true; |
2543 | if (!SimplifiedVal.hasValue() || |
2544 | isa<UndefValue>(*SimplifiedVal.getValue())) { |
2545 | KnownUBInsts.insert(&I); |
2546 | continue; |
2547 | } |
2548 | if (!ArgVal->getType()->isPointerTy() || |
2549 | !isa<ConstantPointerNull>(*SimplifiedVal.getValue())) |
2550 | continue; |
2551 | auto &NonNullAA = |
2552 | A.getAAFor<AANonNull>(*this, CalleeArgumentIRP, DepClassTy::NONE); |
2553 | if (NonNullAA.isKnownNonNull()) |
2554 | KnownUBInsts.insert(&I); |
2555 | } |
2556 | return true; |
2557 | }; |
2558 | |
2559 | auto InspectReturnInstForUB = |
2560 | [&](Value &V, const SmallSetVector<ReturnInst *, 4> RetInsts) { |
2561 | // Check if a return instruction always cause UB or not |
2562 | // Note: It is guaranteed that the returned position of the anchor |
2563 | // scope has noundef attribute when this is called. |
2564 | // We also ensure the return position is not "assumed dead" |
2565 | // because the returned value was then potentially simplified to |
2566 | // `undef` in AAReturnedValues without removing the `noundef` |
2567 | // attribute yet. |
2568 | |
2569 | // When the returned position has noundef attriubte, UB occur in the |
2570 | // following cases. |
2571 | // (1) Returned value is known to be undef. |
2572 | // (2) The value is known to be a null pointer and the returned |
2573 | // position has nonnull attribute (because the returned value is |
2574 | // poison). |
2575 | bool FoundUB = false; |
2576 | if (isa<UndefValue>(V)) { |
2577 | FoundUB = true; |
2578 | } else { |
2579 | if (isa<ConstantPointerNull>(V)) { |
2580 | auto &NonNullAA = A.getAAFor<AANonNull>( |
2581 | *this, IRPosition::returned(*getAnchorScope()), |
2582 | DepClassTy::NONE); |
2583 | if (NonNullAA.isKnownNonNull()) |
2584 | FoundUB = true; |
2585 | } |
2586 | } |
2587 | |
2588 | if (FoundUB) |
2589 | for (ReturnInst *RI : RetInsts) |
2590 | KnownUBInsts.insert(RI); |
2591 | return true; |
2592 | }; |
2593 | |
2594 | bool UsedAssumedInformation = false; |
2595 | A.checkForAllInstructions(InspectMemAccessInstForUB, *this, |
2596 | {Instruction::Load, Instruction::Store, |
2597 | Instruction::AtomicCmpXchg, |
2598 | Instruction::AtomicRMW}, |
2599 | UsedAssumedInformation, |
2600 | /* CheckBBLivenessOnly */ true); |
2601 | A.checkForAllInstructions(InspectBrInstForUB, *this, {Instruction::Br}, |
2602 | UsedAssumedInformation, |
2603 | /* CheckBBLivenessOnly */ true); |
2604 | A.checkForAllCallLikeInstructions(InspectCallSiteForUB, *this, |
2605 | UsedAssumedInformation); |
2606 | |
2607 | // If the returned position of the anchor scope has noundef attriubte, check |
2608 | // all returned instructions. |
2609 | if (!getAnchorScope()->getReturnType()->isVoidTy()) { |
2610 | const IRPosition &ReturnIRP = IRPosition::returned(*getAnchorScope()); |
2611 | if (!A.isAssumedDead(ReturnIRP, this, nullptr, UsedAssumedInformation)) { |
2612 | auto &RetPosNoUndefAA = |
2613 | A.getAAFor<AANoUndef>(*this, ReturnIRP, DepClassTy::NONE); |
2614 | if (RetPosNoUndefAA.isKnownNoUndef()) |
2615 | A.checkForAllReturnedValuesAndReturnInsts(InspectReturnInstForUB, |
2616 | *this); |
2617 | } |
2618 | } |
2619 | |
2620 | if (NoUBPrevSize != AssumedNoUBInsts.size() || |
2621 | UBPrevSize != KnownUBInsts.size()) |
2622 | return ChangeStatus::CHANGED; |
2623 | return ChangeStatus::UNCHANGED; |
2624 | } |
2625 | |
2626 | bool isKnownToCauseUB(Instruction *I) const override { |
2627 | return KnownUBInsts.count(I); |
2628 | } |
2629 | |
2630 | bool isAssumedToCauseUB(Instruction *I) const override { |
2631 | // In simple words, if an instruction is not in the assumed to _not_ |
2632 | // cause UB, then it is assumed UB (that includes those |
2633 | // in the KnownUBInsts set). The rest is boilerplate |
2634 | // is to ensure that it is one of the instructions we test |
2635 | // for UB. |
2636 | |
2637 | switch (I->getOpcode()) { |
2638 | case Instruction::Load: |
2639 | case Instruction::Store: |
2640 | case Instruction::AtomicCmpXchg: |
2641 | case Instruction::AtomicRMW: |
2642 | return !AssumedNoUBInsts.count(I); |
2643 | case Instruction::Br: { |
2644 | auto BrInst = cast<BranchInst>(I); |
2645 | if (BrInst->isUnconditional()) |
2646 | return false; |
2647 | return !AssumedNoUBInsts.count(I); |
2648 | } break; |
2649 | default: |
2650 | return false; |
2651 | } |
2652 | return false; |
2653 | } |
2654 | |
2655 | ChangeStatus manifest(Attributor &A) override { |
2656 | if (KnownUBInsts.empty()) |
2657 | return ChangeStatus::UNCHANGED; |
2658 | for (Instruction *I : KnownUBInsts) |
2659 | A.changeToUnreachableAfterManifest(I); |
2660 | return ChangeStatus::CHANGED; |
2661 | } |
2662 | |
2663 | /// See AbstractAttribute::getAsStr() |
2664 | const std::string getAsStr() const override { |
2665 | return getAssumed() ? "undefined-behavior" : "no-ub"; |
2666 | } |
2667 | |
2668 | /// Note: The correctness of this analysis depends on the fact that the |
2669 | /// following 2 sets will stop changing after some point. |
2670 | /// "Change" here means that their size changes. |
2671 | /// The size of each set is monotonically increasing |
2672 | /// (we only add items to them) and it is upper bounded by the number of |
2673 | /// instructions in the processed function (we can never save more |
2674 | /// elements in either set than this number). Hence, at some point, |
2675 | /// they will stop increasing. |
2676 | /// Consequently, at some point, both sets will have stopped |
2677 | /// changing, effectively making the analysis reach a fixpoint. |
2678 | |
2679 | /// Note: These 2 sets are disjoint and an instruction can be considered |
2680 | /// one of 3 things: |
2681 | /// 1) Known to cause UB (AAUndefinedBehavior could prove it) and put it in |
2682 | /// the KnownUBInsts set. |
2683 | /// 2) Assumed to cause UB (in every updateImpl, AAUndefinedBehavior |
2684 | /// has a reason to assume it). |
2685 | /// 3) Assumed to not cause UB. very other instruction - AAUndefinedBehavior |
2686 | /// could not find a reason to assume or prove that it can cause UB, |
2687 | /// hence it assumes it doesn't. We have a set for these instructions |
2688 | /// so that we don't reprocess them in every update. |
2689 | /// Note however that instructions in this set may cause UB. |
2690 | |
2691 | protected: |
2692 | /// A set of all live instructions _known_ to cause UB. |
2693 | SmallPtrSet<Instruction *, 8> KnownUBInsts; |
2694 | |
2695 | private: |
2696 | /// A set of all the (live) instructions that are assumed to _not_ cause UB. |
2697 | SmallPtrSet<Instruction *, 8> AssumedNoUBInsts; |
2698 | |
2699 | // Should be called on updates in which if we're processing an instruction |
2700 | // \p I that depends on a value \p V, one of the following has to happen: |
2701 | // - If the value is assumed, then stop. |
2702 | // - If the value is known but undef, then consider it UB. |
2703 | // - Otherwise, do specific processing with the simplified value. |
2704 | // We return None in the first 2 cases to signify that an appropriate |
2705 | // action was taken and the caller should stop. |
2706 | // Otherwise, we return the simplified value that the caller should |
2707 | // use for specific processing. |
2708 | Optional<Value *> stopOnUndefOrAssumed(Attributor &A, Value *V, |
2709 | Instruction *I) { |
2710 | bool UsedAssumedInformation = false; |
2711 | Optional<Value *> SimplifiedV = A.getAssumedSimplified( |
2712 | IRPosition::value(*V), *this, UsedAssumedInformation); |
2713 | if (!UsedAssumedInformation) { |
2714 | // Don't depend on assumed values. |
2715 | if (!SimplifiedV.hasValue()) { |
2716 | // If it is known (which we tested above) but it doesn't have a value, |
2717 | // then we can assume `undef` and hence the instruction is UB. |
2718 | KnownUBInsts.insert(I); |
2719 | return llvm::None; |
2720 | } |
2721 | if (!SimplifiedV.getValue()) |
2722 | return nullptr; |
2723 | V = *SimplifiedV; |
2724 | } |
2725 | if (isa<UndefValue>(V)) { |
2726 | KnownUBInsts.insert(I); |
2727 | return llvm::None; |
2728 | } |
2729 | return V; |
2730 | } |
2731 | }; |
2732 | |
2733 | struct AAUndefinedBehaviorFunction final : AAUndefinedBehaviorImpl { |
2734 | AAUndefinedBehaviorFunction(const IRPosition &IRP, Attributor &A) |
2735 | : AAUndefinedBehaviorImpl(IRP, A) {} |
2736 | |
2737 | /// See AbstractAttribute::trackStatistics() |
2738 | void trackStatistics() const override { |
2739 | STATS_DECL(UndefinedBehaviorInstruction, Instruction,static llvm::Statistic NumIRInstruction_UndefinedBehaviorInstruction = {"attributor", "NumIRInstruction_UndefinedBehaviorInstruction" , "Number of instructions known to have UB"};; |
2740 | "Number of instructions known to have UB")static llvm::Statistic NumIRInstruction_UndefinedBehaviorInstruction = {"attributor", "NumIRInstruction_UndefinedBehaviorInstruction" , "Number of instructions known to have UB"};;; |
2741 | BUILD_STAT_NAME(UndefinedBehaviorInstruction, Instruction)NumIRInstruction_UndefinedBehaviorInstruction += |
2742 | KnownUBInsts.size(); |
2743 | } |
2744 | }; |
2745 | |
2746 | /// ------------------------ Will-Return Attributes ---------------------------- |
2747 | |
2748 | // Helper function that checks whether a function has any cycle which we don't |
2749 | // know if it is bounded or not. |
2750 | // Loops with maximum trip count are considered bounded, any other cycle not. |
2751 | static bool mayContainUnboundedCycle(Function &F, Attributor &A) { |
2752 | ScalarEvolution *SE = |
2753 | A.getInfoCache().getAnalysisResultForFunction<ScalarEvolutionAnalysis>(F); |
2754 | LoopInfo *LI = A.getInfoCache().getAnalysisResultForFunction<LoopAnalysis>(F); |
2755 | // If either SCEV or LoopInfo is not available for the function then we assume |
2756 | // any cycle to be unbounded cycle. |
2757 | // We use scc_iterator which uses Tarjan algorithm to find all the maximal |
2758 | // SCCs.To detect if there's a cycle, we only need to find the maximal ones. |
2759 | if (!SE || !LI) { |
2760 | for (scc_iterator<Function *> SCCI = scc_begin(&F); !SCCI.isAtEnd(); ++SCCI) |
2761 | if (SCCI.hasCycle()) |
2762 | return true; |
2763 | return false; |
2764 | } |
2765 | |
2766 | // If there's irreducible control, the function may contain non-loop cycles. |
2767 | if (mayContainIrreducibleControl(F, LI)) |
2768 | return true; |
2769 | |
2770 | // Any loop that does not have a max trip count is considered unbounded cycle. |
2771 | for (auto *L : LI->getLoopsInPreorder()) { |
2772 | if (!SE->getSmallConstantMaxTripCount(L)) |
2773 | return true; |
2774 | } |
2775 | return false; |
2776 | } |
2777 | |
2778 | struct AAWillReturnImpl : public AAWillReturn { |
2779 | AAWillReturnImpl(const IRPosition &IRP, Attributor &A) |
2780 | : AAWillReturn(IRP, A) {} |
2781 | |
2782 | /// See AbstractAttribute::initialize(...). |
2783 | void initialize(Attributor &A) override { |
2784 | AAWillReturn::initialize(A); |
2785 | |
2786 | if (isImpliedByMustprogressAndReadonly(A, /* KnownOnly */ true)) { |
2787 | indicateOptimisticFixpoint(); |
2788 | return; |
2789 | } |
2790 | } |
2791 | |
2792 | /// Check for `mustprogress` and `readonly` as they imply `willreturn`. |
2793 | bool isImpliedByMustprogressAndReadonly(Attributor &A, bool KnownOnly) { |
2794 | // Check for `mustprogress` in the scope and the associated function which |
2795 | // might be different if this is a call site. |
2796 | if ((!getAnchorScope() || !getAnchorScope()->mustProgress()) && |
2797 | (!getAssociatedFunction() || !getAssociatedFunction()->mustProgress())) |
2798 | return false; |
2799 | |
2800 | const auto &MemAA = |
2801 | A.getAAFor<AAMemoryBehavior>(*this, getIRPosition(), DepClassTy::NONE); |
2802 | if (!MemAA.isAssumedReadOnly()) |
2803 | return false; |
2804 | if (KnownOnly && !MemAA.isKnownReadOnly()) |
2805 | return false; |
2806 | if (!MemAA.isKnownReadOnly()) |
2807 | A.recordDependence(MemAA, *this, DepClassTy::OPTIONAL); |
2808 | |
2809 | return true; |
2810 | } |
2811 | |
2812 | /// See AbstractAttribute::updateImpl(...). |
2813 | ChangeStatus updateImpl(Attributor &A) override { |
2814 | if (isImpliedByMustprogressAndReadonly(A, /* KnownOnly */ false)) |
2815 | return ChangeStatus::UNCHANGED; |
2816 | |
2817 | auto CheckForWillReturn = [&](Instruction &I) { |
2818 | IRPosition IPos = IRPosition::callsite_function(cast<CallBase>(I)); |
2819 | const auto &WillReturnAA = |
2820 | A.getAAFor<AAWillReturn>(*this, IPos, DepClassTy::REQUIRED); |
2821 | if (WillReturnAA.isKnownWillReturn()) |
2822 | return true; |
2823 | if (!WillReturnAA.isAssumedWillReturn()) |
2824 | return false; |
2825 | const auto &NoRecurseAA = |
2826 | A.getAAFor<AANoRecurse>(*this, IPos, DepClassTy::REQUIRED); |
2827 | return NoRecurseAA.isAssumedNoRecurse(); |
2828 | }; |
2829 | |
2830 | bool UsedAssumedInformation = false; |
2831 | if (!A.checkForAllCallLikeInstructions(CheckForWillReturn, *this, |
2832 | UsedAssumedInformation)) |
2833 | return indicatePessimisticFixpoint(); |
2834 | |
2835 | return ChangeStatus::UNCHANGED; |
2836 | } |
2837 | |
2838 | /// See AbstractAttribute::getAsStr() |
2839 | const std::string getAsStr() const override { |
2840 | return getAssumed() ? "willreturn" : "may-noreturn"; |
2841 | } |
2842 | }; |
2843 | |
2844 | struct AAWillReturnFunction final : AAWillReturnImpl { |
2845 | AAWillReturnFunction(const IRPosition &IRP, Attributor &A) |
2846 | : AAWillReturnImpl(IRP, A) {} |
2847 | |
2848 | /// See AbstractAttribute::initialize(...). |
2849 | void initialize(Attributor &A) override { |
2850 | AAWillReturnImpl::initialize(A); |
2851 | |
2852 | Function *F = getAnchorScope(); |
2853 | if (!F || F->isDeclaration() || mayContainUnboundedCycle(*F, A)) |
2854 | indicatePessimisticFixpoint(); |
2855 | } |
2856 | |
2857 | /// See AbstractAttribute::trackStatistics() |
2858 | void trackStatistics() const override { STATS_DECLTRACK_FN_ATTR(willreturn){ static llvm::Statistic NumIRFunction_willreturn = {"attributor" , "NumIRFunction_willreturn", ("Number of " "functions" " marked '" "willreturn" "'")};; ++(NumIRFunction_willreturn); } } |
2859 | }; |
2860 | |
2861 | /// WillReturn attribute deduction for a call sites. |
2862 | struct AAWillReturnCallSite final : AAWillReturnImpl { |
2863 | AAWillReturnCallSite(const IRPosition &IRP, Attributor &A) |
2864 | : AAWillReturnImpl(IRP, A) {} |
2865 | |
2866 | /// See AbstractAttribute::initialize(...). |
2867 | void initialize(Attributor &A) override { |
2868 | AAWillReturnImpl::initialize(A); |
2869 | Function *F = getAssociatedFunction(); |
2870 | if (!F || !A.isFunctionIPOAmendable(*F)) |
2871 | indicatePessimisticFixpoint(); |
2872 | } |
2873 | |
2874 | /// See AbstractAttribute::updateImpl(...). |
2875 | ChangeStatus updateImpl(Attributor &A) override { |
2876 | if (isImpliedByMustprogressAndReadonly(A, /* KnownOnly */ false)) |
2877 | return ChangeStatus::UNCHANGED; |
2878 | |
2879 | // TODO: Once we have call site specific value information we can provide |
2880 | // call site specific liveness information and then it makes |
2881 | // sense to specialize attributes for call sites arguments instead of |
2882 | // redirecting requests to the callee argument. |
2883 | Function *F = getAssociatedFunction(); |
2884 | const IRPosition &FnPos = IRPosition::function(*F); |
2885 | auto &FnAA = A.getAAFor<AAWillReturn>(*this, FnPos, DepClassTy::REQUIRED); |
2886 | return clampStateAndIndicateChange(getState(), FnAA.getState()); |
2887 | } |
2888 | |
2889 | /// See AbstractAttribute::trackStatistics() |
2890 | void trackStatistics() const override { STATS_DECLTRACK_CS_ATTR(willreturn){ static llvm::Statistic NumIRCS_willreturn = {"attributor", "NumIRCS_willreturn" , ("Number of " "call site" " marked '" "willreturn" "'")};; ++ (NumIRCS_willreturn); }; } |
2891 | }; |
2892 | |
2893 | /// -------------------AAReachability Attribute-------------------------- |
2894 | |
2895 | struct AAReachabilityImpl : AAReachability { |
2896 | AAReachabilityImpl(const IRPosition &IRP, Attributor &A) |
2897 | : AAReachability(IRP, A) {} |
2898 | |
2899 | const std::string getAsStr() const override { |
2900 | // TODO: Return the number of reachable queries. |
2901 | return "reachable"; |
2902 | } |
2903 | |
2904 | /// See AbstractAttribute::updateImpl(...). |
2905 | ChangeStatus updateImpl(Attributor &A) override { |
2906 | return ChangeStatus::UNCHANGED; |
2907 | } |
2908 | }; |
2909 | |
2910 | struct AAReachabilityFunction final : public AAReachabilityImpl { |
2911 | AAReachabilityFunction(const IRPosition &IRP, Attributor &A) |
2912 | : AAReachabilityImpl(IRP, A) {} |
2913 | |
2914 | /// See AbstractAttribute::trackStatistics() |
2915 | void trackStatistics() const override { STATS_DECLTRACK_FN_ATTR(reachable){ static llvm::Statistic NumIRFunction_reachable = {"attributor" , "NumIRFunction_reachable", ("Number of " "functions" " marked '" "reachable" "'")};; ++(NumIRFunction_reachable); }; } |
2916 | }; |
2917 | |
2918 | /// ------------------------ NoAlias Argument Attribute ------------------------ |
2919 | |
2920 | struct AANoAliasImpl : AANoAlias { |
2921 | AANoAliasImpl(const IRPosition &IRP, Attributor &A) : AANoAlias(IRP, A) { |
2922 | assert(getAssociatedType()->isPointerTy() &&((void)0) |
2923 | "Noalias is a pointer attribute")((void)0); |
2924 | } |
2925 | |
2926 | const std::string getAsStr() const override { |
2927 | return getAssumed() ? "noalias" : "may-alias"; |
2928 | } |
2929 | }; |
2930 | |
2931 | /// NoAlias attribute for a floating value. |
2932 | struct AANoAliasFloating final : AANoAliasImpl { |
2933 | AANoAliasFloating(const IRPosition &IRP, Attributor &A) |
2934 | : AANoAliasImpl(IRP, A) {} |
2935 | |
2936 | /// See AbstractAttribute::initialize(...). |
2937 | void initialize(Attributor &A) override { |
2938 | AANoAliasImpl::initialize(A); |
2939 | Value *Val = &getAssociatedValue(); |
2940 | do { |
2941 | CastInst *CI = dyn_cast<CastInst>(Val); |
2942 | if (!CI) |
2943 | break; |
2944 | Value *Base = CI->getOperand(0); |
2945 | if (!Base->hasOneUse()) |
2946 | break; |
2947 | Val = Base; |
2948 | } while (true); |
2949 | |
2950 | if (!Val->getType()->isPointerTy()) { |
2951 | indicatePessimisticFixpoint(); |
2952 | return; |
2953 | } |
2954 | |
2955 | if (isa<AllocaInst>(Val)) |
2956 | indicateOptimisticFixpoint(); |
2957 | else if (isa<ConstantPointerNull>(Val) && |
2958 | !NullPointerIsDefined(getAnchorScope(), |
2959 | Val->getType()->getPointerAddressSpace())) |
2960 | indicateOptimisticFixpoint(); |
2961 | else if (Val != &getAssociatedValue()) { |
2962 | const auto &ValNoAliasAA = A.getAAFor<AANoAlias>( |
2963 | *this, IRPosition::value(*Val), DepClassTy::OPTIONAL); |
2964 | if (ValNoAliasAA.isKnownNoAlias()) |
2965 | indicateOptimisticFixpoint(); |
2966 | } |
2967 | } |
2968 | |
2969 | /// See AbstractAttribute::updateImpl(...). |
2970 | ChangeStatus updateImpl(Attributor &A) override { |
2971 | // TODO: Implement this. |
2972 | return indicatePessimisticFixpoint(); |
2973 | } |
2974 | |
2975 | /// See AbstractAttribute::trackStatistics() |
2976 | void trackStatistics() const override { |
2977 | STATS_DECLTRACK_FLOATING_ATTR(noalias){ static llvm::Statistic NumIRFloating_noalias = {"attributor" , "NumIRFloating_noalias", ("Number of floating values known to be '" "noalias" "'")};; ++(NumIRFloating_noalias); } |
2978 | } |
2979 | }; |
2980 | |
2981 | /// NoAlias attribute for an argument. |
2982 | struct AANoAliasArgument final |
2983 | : AAArgumentFromCallSiteArguments<AANoAlias, AANoAliasImpl> { |
2984 | using Base = AAArgumentFromCallSiteArguments<AANoAlias, AANoAliasImpl>; |
2985 | AANoAliasArgument(const IRPosition &IRP, Attributor &A) : Base(IRP, A) {} |
2986 | |
2987 | /// See AbstractAttribute::initialize(...). |
2988 | void initialize(Attributor &A) override { |
2989 | Base::initialize(A); |
2990 | // See callsite argument attribute and callee argument attribute. |
2991 | if (hasAttr({Attribute::ByVal})) |
2992 | indicateOptimisticFixpoint(); |
2993 | } |
2994 | |
2995 | /// See AbstractAttribute::update(...). |
2996 | ChangeStatus updateImpl(Attributor &A) override { |
2997 | // We have to make sure no-alias on the argument does not break |
2998 | // synchronization when this is a callback argument, see also [1] below. |
2999 | // If synchronization cannot be affected, we delegate to the base updateImpl |
3000 | // function, otherwise we give up for now. |
3001 | |
3002 | // If the function is no-sync, no-alias cannot break synchronization. |
3003 | const auto &NoSyncAA = |
3004 | A.getAAFor<AANoSync>(*this, IRPosition::function_scope(getIRPosition()), |
3005 | DepClassTy::OPTIONAL); |
3006 | if (NoSyncAA.isAssumedNoSync()) |
3007 | return Base::updateImpl(A); |
3008 | |
3009 | // If the argument is read-only, no-alias cannot break synchronization. |
3010 | const auto &MemBehaviorAA = A.getAAFor<AAMemoryBehavior>( |
3011 | *this, getIRPosition(), DepClassTy::OPTIONAL); |
3012 | if (MemBehaviorAA.isAssumedReadOnly()) |
3013 | return Base::updateImpl(A); |
3014 | |
3015 | // If the argument is never passed through callbacks, no-alias cannot break |
3016 | // synchronization. |
3017 | bool AllCallSitesKnown; |
3018 | if (A.checkForAllCallSites( |
3019 | [](AbstractCallSite ACS) { return !ACS.isCallbackCall(); }, *this, |
3020 | true, AllCallSitesKnown)) |
3021 | return Base::updateImpl(A); |
3022 | |
3023 | // TODO: add no-alias but make sure it doesn't break synchronization by |
3024 | // introducing fake uses. See: |
3025 | // [1] Compiler Optimizations for OpenMP, J. Doerfert and H. Finkel, |
3026 | // International Workshop on OpenMP 2018, |
3027 | // http://compilers.cs.uni-saarland.de/people/doerfert/par_opt18.pdf |
3028 | |
3029 | return indicatePessimisticFixpoint(); |
3030 | } |
3031 | |
3032 | /// See AbstractAttribute::trackStatistics() |
3033 | void trackStatistics() const override { STATS_DECLTRACK_ARG_ATTR(noalias){ static llvm::Statistic NumIRArguments_noalias = {"attributor" , "NumIRArguments_noalias", ("Number of " "arguments" " marked '" "noalias" "'")};; ++(NumIRArguments_noalias); } } |
3034 | }; |
3035 | |
3036 | struct AANoAliasCallSiteArgument final : AANoAliasImpl { |
3037 | AANoAliasCallSiteArgument(const IRPosition &IRP, Attributor &A) |
3038 | : AANoAliasImpl(IRP, A) {} |
3039 | |
3040 | /// See AbstractAttribute::initialize(...). |
3041 | void initialize(Attributor &A) override { |
3042 | // See callsite argument attribute and callee argument attribute. |
3043 | const auto &CB = cast<CallBase>(getAnchorValue()); |
3044 | if (CB.paramHasAttr(getCallSiteArgNo(), Attribute::NoAlias)) |
3045 | indicateOptimisticFixpoint(); |
3046 | Value &Val = getAssociatedValue(); |
3047 | if (isa<ConstantPointerNull>(Val) && |
3048 | !NullPointerIsDefined(getAnchorScope(), |
3049 | Val.getType()->getPointerAddressSpace())) |
3050 | indicateOptimisticFixpoint(); |
3051 | } |
3052 | |
3053 | /// Determine if the underlying value may alias with the call site argument |
3054 | /// \p OtherArgNo of \p ICS (= the underlying call site). |
3055 | bool mayAliasWithArgument(Attributor &A, AAResults *&AAR, |
3056 | const AAMemoryBehavior &MemBehaviorAA, |
3057 | const CallBase &CB, unsigned OtherArgNo) { |
3058 | // We do not need to worry about aliasing with the underlying IRP. |
3059 | if (this->getCalleeArgNo() == (int)OtherArgNo) |
3060 | return false; |
3061 | |
3062 | // If it is not a pointer or pointer vector we do not alias. |
3063 | const Value *ArgOp = CB.getArgOperand(OtherArgNo); |
3064 | if (!ArgOp->getType()->isPtrOrPtrVectorTy()) |
3065 | return false; |
3066 | |
3067 | auto &CBArgMemBehaviorAA = A.getAAFor<AAMemoryBehavior>( |
3068 | *this, IRPosition::callsite_argument(CB, OtherArgNo), DepClassTy::NONE); |
3069 | |
3070 | // If the argument is readnone, there is no read-write aliasing. |
3071 | if (CBArgMemBehaviorAA.isAssumedReadNone()) { |
3072 | A.recordDependence(CBArgMemBehaviorAA, *this, DepClassTy::OPTIONAL); |
3073 | return false; |
3074 | } |
3075 | |
3076 | // If the argument is readonly and the underlying value is readonly, there |
3077 | // is no read-write aliasing. |
3078 | bool IsReadOnly = MemBehaviorAA.isAssumedReadOnly(); |
3079 | if (CBArgMemBehaviorAA.isAssumedReadOnly() && IsReadOnly) { |
3080 | A.recordDependence(MemBehaviorAA, *this, DepClassTy::OPTIONAL); |
3081 | A.recordDependence(CBArgMemBehaviorAA, *this, DepClassTy::OPTIONAL); |
3082 | return false; |
3083 | } |
3084 | |
3085 | // We have to utilize actual alias analysis queries so we need the object. |
3086 | if (!AAR) |
3087 | AAR = A.getInfoCache().getAAResultsForFunction(*getAnchorScope()); |
3088 | |
3089 | // Try to rule it out at the call site. |
3090 | bool IsAliasing = !AAR || !AAR->isNoAlias(&getAssociatedValue(), ArgOp); |
3091 | LLVM_DEBUG(dbgs() << "[NoAliasCSArg] Check alias between "do { } while (false) |
3092 | "callsite arguments: "do { } while (false) |
3093 | << getAssociatedValue() << " " << *ArgOp << " => "do { } while (false) |
3094 | << (IsAliasing ? "" : "no-") << "alias \n")do { } while (false); |
3095 | |
3096 | return IsAliasing; |
3097 | } |
3098 | |
3099 | bool |
3100 | isKnownNoAliasDueToNoAliasPreservation(Attributor &A, AAResults *&AAR, |
3101 | const AAMemoryBehavior &MemBehaviorAA, |
3102 | const AANoAlias &NoAliasAA) { |
3103 | // We can deduce "noalias" if the following conditions hold. |
3104 | // (i) Associated value is assumed to be noalias in the definition. |
3105 | // (ii) Associated value is assumed to be no-capture in all the uses |
3106 | // possibly executed before this callsite. |
3107 | // (iii) There is no other pointer argument which could alias with the |
3108 | // value. |
3109 | |
3110 | bool AssociatedValueIsNoAliasAtDef = NoAliasAA.isAssumedNoAlias(); |
3111 | if (!AssociatedValueIsNoAliasAtDef) { |
3112 | LLVM_DEBUG(dbgs() << "[AANoAlias] " << getAssociatedValue()do { } while (false) |
3113 | << " is not no-alias at the definition\n")do { } while (false); |
3114 | return false; |
3115 | } |
3116 | |
3117 | A.recordDependence(NoAliasAA, *this, DepClassTy::OPTIONAL); |
3118 | |
3119 | const IRPosition &VIRP = IRPosition::value(getAssociatedValue()); |
3120 | const Function *ScopeFn = VIRP.getAnchorScope(); |
3121 | auto &NoCaptureAA = A.getAAFor<AANoCapture>(*this, VIRP, DepClassTy::NONE); |
3122 | // Check whether the value is captured in the scope using AANoCapture. |
3123 | // Look at CFG and check only uses possibly executed before this |
3124 | // callsite. |
3125 | auto UsePred = [&](const Use &U, bool &Follow) -> bool { |
3126 | Instruction *UserI = cast<Instruction>(U.getUser()); |
3127 | |
3128 | // If UserI is the curr instruction and there is a single potential use of |
3129 | // the value in UserI we allow the use. |
3130 | // TODO: We should inspect the operands and allow those that cannot alias |
3131 | // with the value. |
3132 | if (UserI == getCtxI() && UserI->getNumOperands() == 1) |
3133 | return true; |
3134 | |
3135 | if (ScopeFn) { |
3136 | const auto &ReachabilityAA = A.getAAFor<AAReachability>( |
3137 | *this, IRPosition::function(*ScopeFn), DepClassTy::OPTIONAL); |
3138 | |
3139 | if (!ReachabilityAA.isAssumedReachable(A, *UserI, *getCtxI())) |
3140 | return true; |
3141 | |
3142 | if (auto *CB = dyn_cast<CallBase>(UserI)) { |
3143 | if (CB->isArgOperand(&U)) { |
3144 | |
3145 | unsigned ArgNo = CB->getArgOperandNo(&U); |
3146 | |
3147 | const auto &NoCaptureAA = A.getAAFor<AANoCapture>( |
3148 | *this, IRPosition::callsite_argument(*CB, ArgNo), |
3149 | DepClassTy::OPTIONAL); |
3150 | |
3151 | if (NoCaptureAA.isAssumedNoCapture()) |
3152 | return true; |
3153 | } |
3154 | } |
3155 | } |
3156 | |
3157 | // For cases which can potentially have more users |
3158 | if (isa<GetElementPtrInst>(U) || isa<BitCastInst>(U) || isa<PHINode>(U) || |
3159 | isa<SelectInst>(U)) { |
3160 | Follow = true; |
3161 | return true; |
3162 | } |
3163 | |
3164 | LLVM_DEBUG(dbgs() << "[AANoAliasCSArg] Unknown user: " << *U << "\n")do { } while (false); |
3165 | return false; |
3166 | }; |
3167 | |
3168 | if (!NoCaptureAA.isAssumedNoCaptureMaybeReturned()) { |
3169 | if (!A.checkForAllUses(UsePred, *this, getAssociatedValue())) { |
3170 | LLVM_DEBUG(do { } while (false) |
3171 | dbgs() << "[AANoAliasCSArg] " << getAssociatedValue()do { } while (false) |
3172 | << " cannot be noalias as it is potentially captured\n")do { } while (false); |
3173 | return false; |
3174 | } |
3175 | } |
3176 | A.recordDependence(NoCaptureAA, *this, DepClassTy::OPTIONAL); |
3177 | |
3178 | // Check there is no other pointer argument which could alias with the |
3179 | // value passed at this call site. |
3180 | // TODO: AbstractCallSite |
3181 | const auto &CB = cast<CallBase>(getAnchorValue()); |
3182 | for (unsigned OtherArgNo = 0; OtherArgNo < CB.getNumArgOperands(); |
3183 | OtherArgNo++) |
3184 | if (mayAliasWithArgument(A, AAR, MemBehaviorAA, CB, OtherArgNo)) |
3185 | return false; |
3186 | |
3187 | return true; |
3188 | } |
3189 | |
3190 | /// See AbstractAttribute::updateImpl(...). |
3191 | ChangeStatus updateImpl(Attributor &A) override { |
3192 | // If the argument is readnone we are done as there are no accesses via the |
3193 | // argument. |
3194 | auto &MemBehaviorAA = |
3195 | A.getAAFor<AAMemoryBehavior>(*this, getIRPosition(), DepClassTy::NONE); |
3196 | if (MemBehaviorAA.isAssumedReadNone()) { |
3197 | A.recordDependence(MemBehaviorAA, *this, DepClassTy::OPTIONAL); |
3198 | return ChangeStatus::UNCHANGED; |
3199 | } |
3200 | |
3201 | const IRPosition &VIRP = IRPosition::value(getAssociatedValue()); |
3202 | const auto &NoAliasAA = |
3203 | A.getAAFor<AANoAlias>(*this, VIRP, DepClassTy::NONE); |
3204 | |
3205 | AAResults *AAR = nullptr; |
3206 | if (isKnownNoAliasDueToNoAliasPreservation(A, AAR, MemBehaviorAA, |
3207 | NoAliasAA)) { |
3208 | LLVM_DEBUG(do { } while (false) |
3209 | dbgs() << "[AANoAlias] No-Alias deduced via no-alias preservation\n")do { } while (false); |
3210 | return ChangeStatus::UNCHANGED; |
3211 | } |
3212 | |
3213 | return indicatePessimisticFixpoint(); |
3214 | } |
3215 | |
3216 | /// See AbstractAttribute::trackStatistics() |
3217 | void trackStatistics() const override { STATS_DECLTRACK_CSARG_ATTR(noalias){ static llvm::Statistic NumIRCSArguments_noalias = {"attributor" , "NumIRCSArguments_noalias", ("Number of " "call site arguments" " marked '" "noalias" "'")};; ++(NumIRCSArguments_noalias); } } |
3218 | }; |
3219 | |
3220 | /// NoAlias attribute for function return value. |
3221 | struct AANoAliasReturned final : AANoAliasImpl { |
3222 | AANoAliasReturned(const IRPosition &IRP, Attributor &A) |
3223 | : AANoAliasImpl(IRP, A) {} |
3224 | |
3225 | /// See AbstractAttribute::initialize(...). |
3226 | void initialize(Attributor &A) override { |
3227 | AANoAliasImpl::initialize(A); |
3228 | Function *F = getAssociatedFunction(); |
3229 | if (!F || F->isDeclaration()) |
3230 | indicatePessimisticFixpoint(); |
3231 | } |
3232 | |
3233 | /// See AbstractAttribute::updateImpl(...). |
3234 | virtual ChangeStatus updateImpl(Attributor &A) override { |
3235 | |
3236 | auto CheckReturnValue = [&](Value &RV) -> bool { |
3237 | if (Constant *C = dyn_cast<Constant>(&RV)) |
3238 | if (C->isNullValue() || isa<UndefValue>(C)) |
3239 | return true; |
3240 | |
3241 | /// For now, we can only deduce noalias if we have call sites. |
3242 | /// FIXME: add more support. |
3243 | if (!isa<CallBase>(&RV)) |
3244 | return false; |
3245 | |
3246 | const IRPosition &RVPos = IRPosition::value(RV); |
3247 | const auto &NoAliasAA = |
3248 | A.getAAFor<AANoAlias>(*this, RVPos, DepClassTy::REQUIRED); |
3249 | if (!NoAliasAA.isAssumedNoAlias()) |
3250 | return false; |
3251 | |
3252 | const auto &NoCaptureAA = |
3253 | A.getAAFor<AANoCapture>(*this, RVPos, DepClassTy::REQUIRED); |
3254 | return NoCaptureAA.isAssumedNoCaptureMaybeReturned(); |
3255 | }; |
3256 | |
3257 | if (!A.checkForAllReturnedValues(CheckReturnValue, *this)) |
3258 | return indicatePessimisticFixpoint(); |
3259 | |
3260 | return ChangeStatus::UNCHANGED; |
3261 | } |
3262 | |
3263 | /// See AbstractAttribute::trackStatistics() |
3264 | void trackStatistics() const override { STATS_DECLTRACK_FNRET_ATTR(noalias){ static llvm::Statistic NumIRFunctionReturn_noalias = {"attributor" , "NumIRFunctionReturn_noalias", ("Number of " "function returns" " marked '" "noalias" "'")};; ++(NumIRFunctionReturn_noalias ); } } |
3265 | }; |
3266 | |
3267 | /// NoAlias attribute deduction for a call site return value. |
3268 | struct AANoAliasCallSiteReturned final : AANoAliasImpl { |
3269 | AANoAliasCallSiteReturned(const IRPosition &IRP, Attributor &A) |
3270 | : AANoAliasImpl(IRP, A) {} |
3271 | |
3272 | /// See AbstractAttribute::initialize(...). |
3273 | void initialize(Attributor &A) override { |
3274 | AANoAliasImpl::initialize(A); |
3275 | Function *F = getAssociatedFunction(); |
3276 | if (!F || F->isDeclaration()) |
3277 | indicatePessimisticFixpoint(); |
3278 | } |
3279 | |
3280 | /// See AbstractAttribute::updateImpl(...). |
3281 | ChangeStatus updateImpl(Attributor &A) override { |
3282 | // TODO: Once we have call site specific value information we can provide |
3283 | // call site specific liveness information and then it makes |
3284 | // sense to specialize attributes for call sites arguments instead of |
3285 | // redirecting requests to the callee argument. |
3286 | Function *F = getAssociatedFunction(); |
3287 | const IRPosition &FnPos = IRPosition::returned(*F); |
3288 | auto &FnAA = A.getAAFor<AANoAlias>(*this, FnPos, DepClassTy::REQUIRED); |
3289 | return clampStateAndIndicateChange(getState(), FnAA.getState()); |
3290 | } |
3291 | |
3292 | /// See AbstractAttribute::trackStatistics() |
3293 | void trackStatistics() const override { STATS_DECLTRACK_CSRET_ATTR(noalias){ static llvm::Statistic NumIRCSReturn_noalias = {"attributor" , "NumIRCSReturn_noalias", ("Number of " "call site returns" " marked '" "noalias" "'")};; ++(NumIRCSReturn_noalias); }; } |
3294 | }; |
3295 | |
3296 | /// -------------------AAIsDead Function Attribute----------------------- |
3297 | |
3298 | struct AAIsDeadValueImpl : public AAIsDead { |
3299 | AAIsDeadValueImpl(const IRPosition &IRP, Attributor &A) : AAIsDead(IRP, A) {} |
3300 | |
3301 | /// See AAIsDead::isAssumedDead(). |
3302 | bool isAssumedDead() const override { return isAssumed(IS_DEAD); } |
3303 | |
3304 | /// See AAIsDead::isKnownDead(). |
3305 | bool isKnownDead() const override { return isKnown(IS_DEAD); } |
3306 | |
3307 | /// See AAIsDead::isAssumedDead(BasicBlock *). |
3308 | bool isAssumedDead(const BasicBlock *BB) const override { return false; } |
3309 | |
3310 | /// See AAIsDead::isKnownDead(BasicBlock *). |
3311 | bool isKnownDead(const BasicBlock *BB) const override { return false; } |
3312 | |
3313 | /// See AAIsDead::isAssumedDead(Instruction *I). |
3314 | bool isAssumedDead(const Instruction *I) const override { |
3315 | return I == getCtxI() && isAssumedDead(); |
3316 | } |
3317 | |
3318 | /// See AAIsDead::isKnownDead(Instruction *I). |
3319 | bool isKnownDead(const Instruction *I) const override { |
3320 | return isAssumedDead(I) && isKnownDead(); |
3321 | } |
3322 | |
3323 | /// See AbstractAttribute::getAsStr(). |
3324 | const std::string getAsStr() const override { |
3325 | return isAssumedDead() ? "assumed-dead" : "assumed-live"; |
3326 | } |
3327 | |
3328 | /// Check if all uses are assumed dead. |
3329 | bool areAllUsesAssumedDead(Attributor &A, Value &V) { |
3330 | // Callers might not check the type, void has no uses. |
3331 | if (V.getType()->isVoidTy()) |
3332 | return true; |
3333 | |
3334 | // If we replace a value with a constant there are no uses left afterwards. |
3335 | if (!isa<Constant>(V)) { |
3336 | bool UsedAssumedInformation = false; |
3337 | Optional<Constant *> C = |
3338 | A.getAssumedConstant(V, *this, UsedAssumedInformation); |
3339 | if (!C.hasValue() || *C) |
3340 | return true; |
3341 | } |
3342 | |
3343 | auto UsePred = [&](const Use &U, bool &Follow) { return false; }; |
3344 | // Explicitly set the dependence class to required because we want a long |
3345 | // chain of N dependent instructions to be considered live as soon as one is |
3346 | // without going through N update cycles. This is not required for |
3347 | // correctness. |
3348 | return A.checkForAllUses(UsePred, *this, V, /* CheckBBLivenessOnly */ false, |
3349 | DepClassTy::REQUIRED); |
3350 | } |
3351 | |
3352 | /// Determine if \p I is assumed to be side-effect free. |
3353 | bool isAssumedSideEffectFree(Attributor &A, Instruction *I) { |
3354 | if (!I || wouldInstructionBeTriviallyDead(I)) |
3355 | return true; |
3356 | |
3357 | auto *CB = dyn_cast<CallBase>(I); |
3358 | if (!CB || isa<IntrinsicInst>(CB)) |
3359 | return false; |
3360 | |
3361 | const IRPosition &CallIRP = IRPosition::callsite_function(*CB); |
3362 | const auto &NoUnwindAA = |
3363 | A.getAndUpdateAAFor<AANoUnwind>(*this, CallIRP, DepClassTy::NONE); |
3364 | if (!NoUnwindAA.isAssumedNoUnwind()) |
3365 | return false; |
3366 | if (!NoUnwindAA.isKnownNoUnwind()) |
3367 | A.recordDependence(NoUnwindAA, *this, DepClassTy::OPTIONAL); |
3368 | |
3369 | const auto &MemBehaviorAA = |
3370 | A.getAndUpdateAAFor<AAMemoryBehavior>(*this, CallIRP, DepClassTy::NONE); |
3371 | if (MemBehaviorAA.isAssumedReadOnly()) { |
3372 | if (!MemBehaviorAA.isKnownReadOnly()) |
3373 | A.recordDependence(MemBehaviorAA, *this, DepClassTy::OPTIONAL); |
3374 | return true; |
3375 | } |
3376 | return false; |
3377 | } |
3378 | }; |
3379 | |
3380 | struct AAIsDeadFloating : public AAIsDeadValueImpl { |
3381 | AAIsDeadFloating(const IRPosition &IRP, Attributor &A) |
3382 | : AAIsDeadValueImpl(IRP, A) {} |
3383 | |
3384 | /// See AbstractAttribute::initialize(...). |
3385 | void initialize(Attributor &A) override { |
3386 | if (isa<UndefValue>(getAssociatedValue())) { |
3387 | indicatePessimisticFixpoint(); |
3388 | return; |
3389 | } |
3390 | |
3391 | Instruction *I = dyn_cast<Instruction>(&getAssociatedValue()); |
3392 | if (!isAssumedSideEffectFree(A, I)) { |
3393 | if (!isa_and_nonnull<StoreInst>(I)) |
3394 | indicatePessimisticFixpoint(); |
3395 | else |
3396 | removeAssumedBits(HAS_NO_EFFECT); |
3397 | } |
3398 | } |
3399 | |
3400 | bool isDeadStore(Attributor &A, StoreInst &SI) { |
3401 | bool UsedAssumedInformation = false; |
3402 | SmallSetVector<Value *, 4> PotentialCopies; |
3403 | if (!AA::getPotentialCopiesOfStoredValue(A, SI, PotentialCopies, *this, |
3404 | UsedAssumedInformation)) |
3405 | return false; |
3406 | return llvm::all_of(PotentialCopies, [&](Value *V) { |
3407 | return A.isAssumedDead(IRPosition::value(*V), this, nullptr, |
3408 | UsedAssumedInformation); |
3409 | }); |
3410 | } |
3411 | |
3412 | /// See AbstractAttribute::updateImpl(...). |
3413 | ChangeStatus updateImpl(Attributor &A) override { |
3414 | Instruction *I = dyn_cast<Instruction>(&getAssociatedValue()); |
3415 | if (auto *SI = dyn_cast_or_null<StoreInst>(I)) { |
3416 | if (!isDeadStore(A, *SI)) |
3417 | return indicatePessimisticFixpoint(); |
3418 | } else { |
3419 | if (!isAssumedSideEffectFree(A, I)) |
3420 | return indicatePessimisticFixpoint(); |
3421 | if (!areAllUsesAssumedDead(A, getAssociatedValue())) |
3422 | return indicatePessimisticFixpoint(); |
3423 | } |
3424 | return ChangeStatus::UNCHANGED; |
3425 | } |
3426 | |
3427 | /// See AbstractAttribute::manifest(...). |
3428 | ChangeStatus manifest(Attributor &A) override { |
3429 | Value &V = getAssociatedValue(); |
3430 | if (auto *I = dyn_cast<Instruction>(&V)) { |
3431 | // If we get here we basically know the users are all dead. We check if |
3432 | // isAssumedSideEffectFree returns true here again because it might not be |
3433 | // the case and only the users are dead but the instruction (=call) is |
3434 | // still needed. |
3435 | if (isa<StoreInst>(I) || |
3436 | (isAssumedSideEffectFree(A, I) && !isa<InvokeInst>(I))) { |
3437 | A.deleteAfterManifest(*I); |
3438 | return ChangeStatus::CHANGED; |
3439 | } |
3440 | } |
3441 | if (V.use_empty()) |
3442 | return ChangeStatus::UNCHANGED; |
3443 | |
3444 | bool UsedAssumedInformation = false; |
3445 | Optional<Constant *> C = |
3446 | A.getAssumedConstant(V, *this, UsedAssumedInformation); |
3447 | if (C.hasValue() && C.getValue()) |
3448 | return ChangeStatus::UNCHANGED; |
3449 | |
3450 | // Replace the value with undef as it is dead but keep droppable uses around |
3451 | // as they provide information we don't want to give up on just yet. |
3452 | UndefValue &UV = *UndefValue::get(V.getType()); |
3453 | bool AnyChange = |
3454 | A.changeValueAfterManifest(V, UV, /* ChangeDropppable */ false); |
3455 | return AnyChange ? ChangeStatus::CHANGED : ChangeStatus::UNCHANGED; |
3456 | } |
3457 | |
3458 | /// See AbstractAttribute::trackStatistics() |
3459 | void trackStatistics() const override { |
3460 | STATS_DECLTRACK_FLOATING_ATTR(IsDead){ static llvm::Statistic NumIRFloating_IsDead = {"attributor" , "NumIRFloating_IsDead", ("Number of floating values known to be '" "IsDead" "'")};; ++(NumIRFloating_IsDead); } |
3461 | } |
3462 | }; |
3463 | |
3464 | struct AAIsDeadArgument : public AAIsDeadFloating { |
3465 | AAIsDeadArgument(const IRPosition &IRP, Attributor &A) |
3466 | : AAIsDeadFloating(IRP, A) {} |
3467 | |
3468 | /// See AbstractAttribute::initialize(...). |
3469 | void initialize(Attributor &A) override { |
3470 | if (!A.isFunctionIPOAmendable(*getAnchorScope())) |
3471 | indicatePessimisticFixpoint(); |
3472 | } |
3473 | |
3474 | /// See AbstractAttribute::manifest(...). |
3475 | ChangeStatus manifest(Attributor &A) override { |
3476 | ChangeStatus Changed = AAIsDeadFloating::manifest(A); |
3477 | Argument &Arg = *getAssociatedArgument(); |
3478 | if (A.isValidFunctionSignatureRewrite(Arg, /* ReplacementTypes */ {})) |
3479 | if (A.registerFunctionSignatureRewrite( |
3480 | Arg, /* ReplacementTypes */ {}, |
3481 | Attributor::ArgumentReplacementInfo::CalleeRepairCBTy{}, |
3482 | Attributor::ArgumentReplacementInfo::ACSRepairCBTy{})) { |
3483 | Arg.dropDroppableUses(); |
3484 | return ChangeStatus::CHANGED; |
3485 | } |
3486 | return Changed; |
3487 | } |
3488 | |
3489 | /// See AbstractAttribute::trackStatistics() |
3490 | void trackStatistics() const override { STATS_DECLTRACK_ARG_ATTR(IsDead){ static llvm::Statistic NumIRArguments_IsDead = {"attributor" , "NumIRArguments_IsDead", ("Number of " "arguments" " marked '" "IsDead" "'")};; ++(NumIRArguments_IsDead); } } |
3491 | }; |
3492 | |
3493 | struct AAIsDeadCallSiteArgument : public AAIsDeadValueImpl { |
3494 | AAIsDeadCallSiteArgument(const IRPosition &IRP, Attributor &A) |
3495 | : AAIsDeadValueImpl(IRP, A) {} |
3496 | |
3497 | /// See AbstractAttribute::initialize(...). |
3498 | void initialize(Attributor &A) override { |
3499 | if (isa<UndefValue>(getAssociatedValue())) |
3500 | indicatePessimisticFixpoint(); |
3501 | } |
3502 | |
3503 | /// See AbstractAttribute::updateImpl(...). |
3504 | ChangeStatus updateImpl(Attributor &A) override { |
3505 | // TODO: Once we have call site specific value information we can provide |
3506 | // call site specific liveness information and then it makes |
3507 | // sense to specialize attributes for call sites arguments instead of |
3508 | // redirecting requests to the callee argument. |
3509 | Argument *Arg = getAssociatedArgument(); |
3510 | if (!Arg) |
3511 | return indicatePessimisticFixpoint(); |
3512 | const IRPosition &ArgPos = IRPosition::argument(*Arg); |
3513 | auto &ArgAA = A.getAAFor<AAIsDead>(*this, ArgPos, DepClassTy::REQUIRED); |
3514 | return clampStateAndIndicateChange(getState(), ArgAA.getState()); |
3515 | } |
3516 | |
3517 | /// See AbstractAttribute::manifest(...). |
3518 | ChangeStatus manifest(Attributor &A) override { |
3519 | CallBase &CB = cast<CallBase>(getAnchorValue()); |
3520 | Use &U = CB.getArgOperandUse(getCallSiteArgNo()); |
3521 | assert(!isa<UndefValue>(U.get()) &&((void)0) |
3522 | "Expected undef values to be filtered out!")((void)0); |
3523 | UndefValue &UV = *UndefValue::get(U->getType()); |
3524 | if (A.changeUseAfterManifest(U, UV)) |
3525 | return ChangeStatus::CHANGED; |
3526 | return ChangeStatus::UNCHANGED; |
3527 | } |
3528 | |
3529 | /// See AbstractAttribute::trackStatistics() |
3530 | void trackStatistics() const override { STATS_DECLTRACK_CSARG_ATTR(IsDead){ static llvm::Statistic NumIRCSArguments_IsDead = {"attributor" , "NumIRCSArguments_IsDead", ("Number of " "call site arguments" " marked '" "IsDead" "'")};; ++(NumIRCSArguments_IsDead); } } |
3531 | }; |
3532 | |
3533 | struct AAIsDeadCallSiteReturned : public AAIsDeadFloating { |
3534 | AAIsDeadCallSiteReturned(const IRPosition &IRP, Attributor &A) |
3535 | : AAIsDeadFloating(IRP, A), IsAssumedSideEffectFree(true) {} |
3536 | |
3537 | /// See AAIsDead::isAssumedDead(). |
3538 | bool isAssumedDead() const override { |
3539 | return AAIsDeadFloating::isAssumedDead() && IsAssumedSideEffectFree; |
3540 | } |
3541 | |
3542 | /// See AbstractAttribute::initialize(...). |
3543 | void initialize(Attributor &A) override { |
3544 | if (isa<UndefValue>(getAssociatedValue())) { |
3545 | indicatePessimisticFixpoint(); |
3546 | return; |
3547 | } |
3548 | |
3549 | // We track this separately as a secondary state. |
3550 | IsAssumedSideEffectFree = isAssumedSideEffectFree(A, getCtxI()); |
3551 | } |
3552 | |
3553 | /// See AbstractAttribute::updateImpl(...). |
3554 | ChangeStatus updateImpl(Attributor &A) override { |
3555 | ChangeStatus Changed = ChangeStatus::UNCHANGED; |
3556 | if (IsAssumedSideEffectFree && !isAssumedSideEffectFree(A, getCtxI())) { |
3557 | IsAssumedSideEffectFree = false; |
3558 | Changed = ChangeStatus::CHANGED; |
3559 | } |
3560 | if (!areAllUsesAssumedDead(A, getAssociatedValue())) |
3561 | return indicatePessimisticFixpoint(); |
3562 | return Changed; |
3563 | } |
3564 | |
3565 | /// See AbstractAttribute::trackStatistics() |
3566 | void trackStatistics() const override { |
3567 | if (IsAssumedSideEffectFree) |
3568 | STATS_DECLTRACK_CSRET_ATTR(IsDead){ static llvm::Statistic NumIRCSReturn_IsDead = {"attributor" , "NumIRCSReturn_IsDead", ("Number of " "call site returns" " marked '" "IsDead" "'")};; ++(NumIRCSReturn_IsDead); } |
3569 | else |
3570 | STATS_DECLTRACK_CSRET_ATTR(UnusedResult){ static llvm::Statistic NumIRCSReturn_UnusedResult = {"attributor" , "NumIRCSReturn_UnusedResult", ("Number of " "call site returns" " marked '" "UnusedResult" "'")};; ++(NumIRCSReturn_UnusedResult ); } |
3571 | } |
3572 | |
3573 | /// See AbstractAttribute::getAsStr(). |
3574 | const std::string getAsStr() const override { |
3575 | return isAssumedDead() |
3576 | ? "assumed-dead" |
3577 | : (getAssumed() ? "assumed-dead-users" : "assumed-live"); |
3578 | } |
3579 | |
3580 | private: |
3581 | bool IsAssumedSideEffectFree; |
3582 | }; |
3583 | |
3584 | struct AAIsDeadReturned : public AAIsDeadValueImpl { |
3585 | AAIsDeadReturned(const IRPosition &IRP, Attributor &A) |
3586 | : AAIsDeadValueImpl(IRP, A) {} |
3587 | |
3588 | /// See AbstractAttribute::updateImpl(...). |
3589 | ChangeStatus updateImpl(Attributor &A) override { |
3590 | |
3591 | bool UsedAssumedInformation = false; |
3592 | A.checkForAllInstructions([](Instruction &) { return true; }, *this, |
3593 | {Instruction::Ret}, UsedAssumedInformation); |
3594 | |
3595 | auto PredForCallSite = [&](AbstractCallSite ACS) { |
3596 | if (ACS.isCallbackCall() || !ACS.getInstruction()) |
3597 | return false; |
3598 | return areAllUsesAssumedDead(A, *ACS.getInstruction()); |
3599 | }; |
3600 | |
3601 | bool AllCallSitesKnown; |
3602 | if (!A.checkForAllCallSites(PredForCallSite, *this, true, |
3603 | AllCallSitesKnown)) |
3604 | return indicatePessimisticFixpoint(); |
3605 | |
3606 | return ChangeStatus::UNCHANGED; |
3607 | } |
3608 | |
3609 | /// See AbstractAttribute::manifest(...). |
3610 | ChangeStatus manifest(Attributor &A) override { |
3611 | // TODO: Rewrite the signature to return void? |
3612 | bool AnyChange = false; |
3613 | UndefValue &UV = *UndefValue::get(getAssociatedFunction()->getReturnType()); |
3614 | auto RetInstPred = [&](Instruction &I) { |
3615 | ReturnInst &RI = cast<ReturnInst>(I); |
3616 | if (!isa<UndefValue>(RI.getReturnValue())) |
3617 | AnyChange |= A.changeUseAfterManifest(RI.getOperandUse(0), UV); |
3618 | return true; |
3619 | }; |
3620 | bool UsedAssumedInformation = false; |
3621 | A.checkForAllInstructions(RetInstPred, *this, {Instruction::Ret}, |
3622 | UsedAssumedInformation); |
3623 | return AnyChange ? ChangeStatus::CHANGED : ChangeStatus::UNCHANGED; |
3624 | } |
3625 | |
3626 | /// See AbstractAttribute::trackStatistics() |
3627 | void trackStatistics() const override { STATS_DECLTRACK_FNRET_ATTR(IsDead){ static llvm::Statistic NumIRFunctionReturn_IsDead = {"attributor" , "NumIRFunctionReturn_IsDead", ("Number of " "function returns" " marked '" "IsDead" "'")};; ++(NumIRFunctionReturn_IsDead); } } |
3628 | }; |
3629 | |
3630 | struct AAIsDeadFunction : public AAIsDead { |
3631 | AAIsDeadFunction(const IRPosition &IRP, Attributor &A) : AAIsDead(IRP, A) {} |
3632 | |
3633 | /// See AbstractAttribute::initialize(...). |
3634 | void initialize(Attributor &A) override { |
3635 | const Function *F = getAnchorScope(); |
3636 | if (F && !F->isDeclaration()) { |
3637 | // We only want to compute liveness once. If the function is not part of |
3638 | // the SCC, skip it. |
3639 | if (A.isRunOn(*const_cast<Function *>(F))) { |
3640 | ToBeExploredFrom.insert(&F->getEntryBlock().front()); |
3641 | assumeLive(A, F->getEntryBlock()); |
3642 | } else { |
3643 | indicatePessimisticFixpoint(); |
3644 | } |
3645 | } |
3646 | } |
3647 | |
3648 | /// See AbstractAttribute::getAsStr(). |
3649 | const std::string getAsStr() const override { |
3650 | return "Live[#BB " + std::to_string(AssumedLiveBlocks.size()) + "/" + |
3651 | std::to_string(getAnchorScope()->size()) + "][#TBEP " + |
3652 | std::to_string(ToBeExploredFrom.size()) + "][#KDE " + |
3653 | std::to_string(KnownDeadEnds.size()) + "]"; |
3654 | } |
3655 | |
3656 | /// See AbstractAttribute::manifest(...). |
3657 | ChangeStatus manifest(Attributor &A) override { |
3658 | assert(getState().isValidState() &&((void)0) |
3659 | "Attempted to manifest an invalid state!")((void)0); |
3660 | |
3661 | ChangeStatus HasChanged = ChangeStatus::UNCHANGED; |
3662 | Function &F = *getAnchorScope(); |
3663 | |
3664 | if (AssumedLiveBlocks.empty()) { |
3665 | A.deleteAfterManifest(F); |
3666 | return ChangeStatus::CHANGED; |
3667 | } |
3668 | |
3669 | // Flag to determine if we can change an invoke to a call assuming the |
3670 | // callee is nounwind. This is not possible if the personality of the |
3671 | // function allows to catch asynchronous exceptions. |
3672 | bool Invoke2CallAllowed = !mayCatchAsynchronousExceptions(F); |
3673 | |
3674 | KnownDeadEnds.set_union(ToBeExploredFrom); |
3675 | for (const Instruction *DeadEndI : KnownDeadEnds) { |
3676 | auto *CB = dyn_cast<CallBase>(DeadEndI); |
3677 | if (!CB) |
3678 | continue; |
3679 | const auto &NoReturnAA = A.getAndUpdateAAFor<AANoReturn>( |
3680 | *this, IRPosition::callsite_function(*CB), DepClassTy::OPTIONAL); |
3681 | bool MayReturn = !NoReturnAA.isAssumedNoReturn(); |
3682 | if (MayReturn && (!Invoke2CallAllowed || !isa<InvokeInst>(CB))) |
3683 | continue; |
3684 | |
3685 | if (auto *II = dyn_cast<InvokeInst>(DeadEndI)) |
3686 | A.registerInvokeWithDeadSuccessor(const_cast<InvokeInst &>(*II)); |
3687 | else |
3688 | A.changeToUnreachableAfterManifest( |
3689 | const_cast<Instruction *>(DeadEndI->getNextNode())); |
3690 | HasChanged = ChangeStatus::CHANGED; |
3691 | } |
3692 | |
3693 | STATS_DECL(AAIsDead, BasicBlock, "Number of dead basic blocks deleted.")static llvm::Statistic NumIRBasicBlock_AAIsDead = {"attributor" , "NumIRBasicBlock_AAIsDead", "Number of dead basic blocks deleted." };;; |
3694 | for (BasicBlock &BB : F) |
3695 | if (!AssumedLiveBlocks.count(&BB)) { |
3696 | A.deleteAfterManifest(BB); |
3697 | ++BUILD_STAT_NAME(AAIsDead, BasicBlock)NumIRBasicBlock_AAIsDead; |
3698 | } |
3699 | |
3700 | return HasChanged; |
3701 | } |
3702 | |
3703 | /// See AbstractAttribute::updateImpl(...). |
3704 | ChangeStatus updateImpl(Attributor &A) override; |
3705 | |
3706 | bool isEdgeDead(const BasicBlock *From, const BasicBlock *To) const override { |
3707 | return !AssumedLiveEdges.count(std::make_pair(From, To)); |
3708 | } |
3709 | |
3710 | /// See AbstractAttribute::trackStatistics() |
3711 | void trackStatistics() const override {} |
3712 | |
3713 | /// Returns true if the function is assumed dead. |
3714 | bool isAssumedDead() const override { return false; } |
3715 | |
3716 | /// See AAIsDead::isKnownDead(). |
3717 | bool isKnownDead() const override { return false; } |
3718 | |
3719 | /// See AAIsDead::isAssumedDead(BasicBlock *). |
3720 | bool isAssumedDead(const BasicBlock *BB) const override { |
3721 | assert(BB->getParent() == getAnchorScope() &&((void)0) |
3722 | "BB must be in the same anchor scope function.")((void)0); |
3723 | |
3724 | if (!getAssumed()) |
3725 | return false; |
3726 | return !AssumedLiveBlocks.count(BB); |
3727 | } |
3728 | |
3729 | /// See AAIsDead::isKnownDead(BasicBlock *). |
3730 | bool isKnownDead(const BasicBlock *BB) const override { |
3731 | return getKnown() && isAssumedDead(BB); |
3732 | } |
3733 | |
3734 | /// See AAIsDead::isAssumed(Instruction *I). |
3735 | bool isAssumedDead(const Instruction *I) const override { |
3736 | assert(I->getParent()->getParent() == getAnchorScope() &&((void)0) |
3737 | "Instruction must be in the same anchor scope function.")((void)0); |
3738 | |
3739 | if (!getAssumed()) |
3740 | return false; |
3741 | |
3742 | // If it is not in AssumedLiveBlocks then it for sure dead. |
3743 | // Otherwise, it can still be after noreturn call in a live block. |
3744 | if (!AssumedLiveBlocks.count(I->getParent())) |
3745 | return true; |
3746 | |
3747 | // If it is not after a liveness barrier it is live. |
3748 | const Instruction *PrevI = I->getPrevNode(); |
3749 | while (PrevI) { |
3750 | if (KnownDeadEnds.count(PrevI) || ToBeExploredFrom.count(PrevI)) |
3751 | return true; |
3752 | PrevI = PrevI->getPrevNode(); |
3753 | } |
3754 | return false; |
3755 | } |
3756 | |
3757 | /// See AAIsDead::isKnownDead(Instruction *I). |
3758 | bool isKnownDead(const Instruction *I) const override { |
3759 | return getKnown() && isAssumedDead(I); |
3760 | } |
3761 | |
3762 | /// Assume \p BB is (partially) live now and indicate to the Attributor \p A |
3763 | /// that internal function called from \p BB should now be looked at. |
3764 | bool assumeLive(Attributor &A, const BasicBlock &BB) { |
3765 | if (!AssumedLiveBlocks.insert(&BB).second) |
3766 | return false; |
3767 | |
3768 | // We assume that all of BB is (probably) live now and if there are calls to |
3769 | // internal functions we will assume that those are now live as well. This |
3770 | // is a performance optimization for blocks with calls to a lot of internal |
3771 | // functions. It can however cause dead functions to be treated as live. |
3772 | for (const Instruction &I : BB) |
3773 | if (const auto *CB = dyn_cast<CallBase>(&I)) |
3774 | if (const Function *F = CB->getCalledFunction()) |
3775 | if (F->hasLocalLinkage()) |
3776 | A.markLiveInternalFunction(*F); |
3777 | return true; |
3778 | } |
3779 | |
3780 | /// Collection of instructions that need to be explored again, e.g., we |
3781 | /// did assume they do not transfer control to (one of their) successors. |
3782 | SmallSetVector<const Instruction *, 8> ToBeExploredFrom; |
3783 | |
3784 | /// Collection of instructions that are known to not transfer control. |
3785 | SmallSetVector<const Instruction *, 8> KnownDeadEnds; |
3786 | |
3787 | /// Collection of all assumed live edges |
3788 | DenseSet<std::pair<const BasicBlock *, const BasicBlock *>> AssumedLiveEdges; |
3789 | |
3790 | /// Collection of all assumed live BasicBlocks. |
3791 | DenseSet<const BasicBlock *> AssumedLiveBlocks; |
3792 | }; |
3793 | |
3794 | static bool |
3795 | identifyAliveSuccessors(Attributor &A, const CallBase &CB, |
3796 | AbstractAttribute &AA, |
3797 | SmallVectorImpl<const Instruction *> &AliveSuccessors) { |
3798 | const IRPosition &IPos = IRPosition::callsite_function(CB); |
3799 | |
3800 | const auto &NoReturnAA = |
3801 | A.getAndUpdateAAFor<AANoReturn>(AA, IPos, DepClassTy::OPTIONAL); |
3802 | if (NoReturnAA.isAssumedNoReturn()) |
3803 | return !NoReturnAA.isKnownNoReturn(); |
3804 | if (CB.isTerminator()) |
3805 | AliveSuccessors.push_back(&CB.getSuccessor(0)->front()); |
3806 | else |
3807 | AliveSuccessors.push_back(CB.getNextNode()); |
3808 | return false; |
3809 | } |
3810 | |
3811 | static bool |
3812 | identifyAliveSuccessors(Attributor &A, const InvokeInst &II, |
3813 | AbstractAttribute &AA, |
3814 | SmallVectorImpl<const Instruction *> &AliveSuccessors) { |
3815 | bool UsedAssumedInformation = |
3816 | identifyAliveSuccessors(A, cast<CallBase>(II), AA, AliveSuccessors); |
3817 | |
3818 | // First, determine if we can change an invoke to a call assuming the |
3819 | // callee is nounwind. This is not possible if the personality of the |
3820 | // function allows to catch asynchronous exceptions. |
3821 | if (AAIsDeadFunction::mayCatchAsynchronousExceptions(*II.getFunction())) { |
3822 | AliveSuccessors.push_back(&II.getUnwindDest()->front()); |
3823 | } else { |
3824 | const IRPosition &IPos = IRPosition::callsite_function(II); |
3825 | const auto &AANoUnw = |
3826 | A.getAndUpdateAAFor<AANoUnwind>(AA, IPos, DepClassTy::OPTIONAL); |
3827 | if (AANoUnw.isAssumedNoUnwind()) { |
3828 | UsedAssumedInformation |= !AANoUnw.isKnownNoUnwind(); |
3829 | } else { |
3830 | AliveSuccessors.push_back(&II.getUnwindDest()->front()); |
3831 | } |
3832 | } |
3833 | return UsedAssumedInformation; |
3834 | } |
3835 | |
3836 | static bool |
3837 | identifyAliveSuccessors(Attributor &A, const BranchInst &BI, |
3838 | AbstractAttribute &AA, |
3839 | SmallVectorImpl<const Instruction *> &AliveSuccessors) { |
3840 | bool UsedAssumedInformation = false; |
3841 | if (BI.getNumSuccessors() == 1) { |
3842 | AliveSuccessors.push_back(&BI.getSuccessor(0)->front()); |
3843 | } else { |
3844 | Optional<Constant *> C = |
3845 | A.getAssumedConstant(*BI.getCondition(), AA, UsedAssumedInformation); |
3846 | if (!C.hasValue() || isa_and_nonnull<UndefValue>(C.getValue())) { |
3847 | // No value yet, assume both edges are dead. |
3848 | } else if (isa_and_nonnull<ConstantInt>(*C)) { |
3849 | const BasicBlock *SuccBB = |
3850 | BI.getSuccessor(1 - cast<ConstantInt>(*C)->getValue().getZExtValue()); |
3851 | AliveSuccessors.push_back(&SuccBB->front()); |
3852 | } else { |
3853 | AliveSuccessors.push_back(&BI.getSuccessor(0)->front()); |
3854 | AliveSuccessors.push_back(&BI.getSuccessor(1)->front()); |
3855 | UsedAssumedInformation = false; |
3856 | } |
3857 | } |
3858 | return UsedAssumedInformation; |
3859 | } |
3860 | |
3861 | static bool |
3862 | identifyAliveSuccessors(Attributor &A, const SwitchInst &SI, |
3863 | AbstractAttribute &AA, |
3864 | SmallVectorImpl<const Instruction *> &AliveSuccessors) { |
3865 | bool UsedAssumedInformation = false; |
3866 | Optional<Constant *> C = |
3867 | A.getAssumedConstant(*SI.getCondition(), AA, UsedAssumedInformation); |
3868 | if (!C.hasValue() || isa_and_nonnull<UndefValue>(C.getValue())) { |
3869 | // No value yet, assume all edges are dead. |
3870 | } else if (isa_and_nonnull<ConstantInt>(C.getValue())) { |
3871 | for (auto &CaseIt : SI.cases()) { |
3872 | if (CaseIt.getCaseValue() == C.getValue()) { |
3873 | AliveSuccessors.push_back(&CaseIt.getCaseSuccessor()->front()); |
3874 | return UsedAssumedInformation; |
3875 | } |
3876 | } |
3877 | AliveSuccessors.push_back(&SI.getDefaultDest()->front()); |
3878 | return UsedAssumedInformation; |
3879 | } else { |
3880 | for (const BasicBlock *SuccBB : successors(SI.getParent())) |
3881 | AliveSuccessors.push_back(&SuccBB->front()); |
3882 | } |
3883 | return UsedAssumedInformation; |
3884 | } |
3885 | |
3886 | ChangeStatus AAIsDeadFunction::updateImpl(Attributor &A) { |
3887 | ChangeStatus Change = ChangeStatus::UNCHANGED; |
3888 | |
3889 | LLVM_DEBUG(dbgs() << "[AAIsDead] Live [" << AssumedLiveBlocks.size() << "/"do { } while (false) |
3890 | << getAnchorScope()->size() << "] BBs and "do { } while (false) |
3891 | << ToBeExploredFrom.size() << " exploration points and "do { } while (false) |
3892 | << KnownDeadEnds.size() << " known dead ends\n")do { } while (false); |
3893 | |
3894 | // Copy and clear the list of instructions we need to explore from. It is |
3895 | // refilled with instructions the next update has to look at. |
3896 | SmallVector<const Instruction *, 8> Worklist(ToBeExploredFrom.begin(), |
3897 | ToBeExploredFrom.end()); |
3898 | decltype(ToBeExploredFrom) NewToBeExploredFrom; |
3899 | |
3900 | SmallVector<const Instruction *, 8> AliveSuccessors; |
3901 | while (!Worklist.empty()) { |
3902 | const Instruction *I = Worklist.pop_back_val(); |
3903 | LLVM_DEBUG(dbgs() << "[AAIsDead] Exploration inst: " << *I << "\n")do { } while (false); |
3904 | |
3905 | // Fast forward for uninteresting instructions. We could look for UB here |
3906 | // though. |
3907 | while (!I->isTerminator() && !isa<CallBase>(I)) |
3908 | I = I->getNextNode(); |
3909 | |
3910 | AliveSuccessors.clear(); |
3911 | |
3912 | bool UsedAssumedInformation = false; |
3913 | switch (I->getOpcode()) { |
3914 | // TODO: look for (assumed) UB to backwards propagate "deadness". |
3915 | default: |
3916 | assert(I->isTerminator() &&((void)0) |
3917 | "Expected non-terminators to be handled already!")((void)0); |
3918 | for (const BasicBlock *SuccBB : successors(I->getParent())) |
3919 | AliveSuccessors.push_back(&SuccBB->front()); |
3920 | break; |
3921 | case Instruction::Call: |
3922 | UsedAssumedInformation = identifyAliveSuccessors(A, cast<CallInst>(*I), |
3923 | *this, AliveSuccessors); |
3924 | break; |
3925 | case Instruction::Invoke: |
3926 | UsedAssumedInformation = identifyAliveSuccessors(A, cast<InvokeInst>(*I), |
3927 | *this, AliveSuccessors); |
3928 | break; |
3929 | case Instruction::Br: |
3930 | UsedAssumedInformation = identifyAliveSuccessors(A, cast<BranchInst>(*I), |
3931 | *this, AliveSuccessors); |
3932 | break; |
3933 | case Instruction::Switch: |
3934 | UsedAssumedInformation = identifyAliveSuccessors(A, cast<SwitchInst>(*I), |
3935 | *this, AliveSuccessors); |
3936 | break; |
3937 | } |
3938 | |
3939 | if (UsedAssumedInformation) { |
3940 | NewToBeExploredFrom.insert(I); |
3941 | } else if (AliveSuccessors.empty() || |
3942 | (I->isTerminator() && |
3943 | AliveSuccessors.size() < I->getNumSuccessors())) { |
3944 | if (KnownDeadEnds.insert(I)) |
3945 | Change = ChangeStatus::CHANGED; |
3946 | } |
3947 | |
3948 | LLVM_DEBUG(dbgs() << "[AAIsDead] #AliveSuccessors: "do { } while (false) |
3949 | << AliveSuccessors.size() << " UsedAssumedInformation: "do { } while (false) |
3950 | << UsedAssumedInformation << "\n")do { } while (false); |
3951 | |
3952 | for (const Instruction *AliveSuccessor : AliveSuccessors) { |
3953 | if (!I->isTerminator()) { |
3954 | assert(AliveSuccessors.size() == 1 &&((void)0) |
3955 | "Non-terminator expected to have a single successor!")((void)0); |
3956 | Worklist.push_back(AliveSuccessor); |
3957 | } else { |
3958 | // record the assumed live edge |
3959 | auto Edge = std::make_pair(I->getParent(), AliveSuccessor->getParent()); |
3960 | if (AssumedLiveEdges.insert(Edge).second) |
3961 | Change = ChangeStatus::CHANGED; |
3962 | if (assumeLive(A, *AliveSuccessor->getParent())) |
3963 | Worklist.push_back(AliveSuccessor); |
3964 | } |
3965 | } |
3966 | } |
3967 | |
3968 | // Check if the content of ToBeExploredFrom changed, ignore the order. |
3969 | if (NewToBeExploredFrom.size() != ToBeExploredFrom.size() || |
3970 | llvm::any_of(NewToBeExploredFrom, [&](const Instruction *I) { |
3971 | return !ToBeExploredFrom.count(I); |
3972 | })) { |
3973 | Change = ChangeStatus::CHANGED; |
3974 | ToBeExploredFrom = std::move(NewToBeExploredFrom); |
3975 | } |
3976 | |
3977 | // If we know everything is live there is no need to query for liveness. |
3978 | // Instead, indicating a pessimistic fixpoint will cause the state to be |
3979 | // "invalid" and all queries to be answered conservatively without lookups. |
3980 | // To be in this state we have to (1) finished the exploration and (3) not |
3981 | // discovered any non-trivial dead end and (2) not ruled unreachable code |
3982 | // dead. |
3983 | if (ToBeExploredFrom.empty() && |
3984 | getAnchorScope()->size() == AssumedLiveBlocks.size() && |
3985 | llvm::all_of(KnownDeadEnds, [](const Instruction *DeadEndI) { |
3986 | return DeadEndI->isTerminator() && DeadEndI->getNumSuccessors() == 0; |
3987 | })) |
3988 | return indicatePessimisticFixpoint(); |
3989 | return Change; |
3990 | } |
3991 | |
3992 | /// Liveness information for a call sites. |
3993 | struct AAIsDeadCallSite final : AAIsDeadFunction { |
3994 | AAIsDeadCallSite(const IRPosition &IRP, Attributor &A) |
3995 | : AAIsDeadFunction(IRP, A) {} |
3996 | |
3997 | /// See AbstractAttribute::initialize(...). |
3998 | void initialize(Attributor &A) override { |
3999 | // TODO: Once we have call site specific value information we can provide |
4000 | // call site specific liveness information and then it makes |
4001 | // sense to specialize attributes for call sites instead of |
4002 | // redirecting requests to the callee. |
4003 | llvm_unreachable("Abstract attributes for liveness are not "__builtin_unreachable() |
4004 | "supported for call sites yet!")__builtin_unreachable(); |
4005 | } |
4006 | |
4007 | /// See AbstractAttribute::updateImpl(...). |
4008 | ChangeStatus updateImpl(Attributor &A) override { |
4009 | return indicatePessimisticFixpoint(); |
4010 | } |
4011 | |
4012 | /// See AbstractAttribute::trackStatistics() |
4013 | void trackStatistics() const override {} |
4014 | }; |
4015 | |
4016 | /// -------------------- Dereferenceable Argument Attribute -------------------- |
4017 | |
4018 | struct AADereferenceableImpl : AADereferenceable { |
4019 | AADereferenceableImpl(const IRPosition &IRP, Attributor &A) |
4020 | : AADereferenceable(IRP, A) {} |
4021 | using StateType = DerefState; |
4022 | |
4023 | /// See AbstractAttribute::initialize(...). |
4024 | void initialize(Attributor &A) override { |
4025 | SmallVector<Attribute, 4> Attrs; |
4026 | getAttrs({Attribute::Dereferenceable, Attribute::DereferenceableOrNull}, |
4027 | Attrs, /* IgnoreSubsumingPositions */ false, &A); |
4028 | for (const Attribute &Attr : Attrs) |
4029 | takeKnownDerefBytesMaximum(Attr.getValueAsInt()); |
4030 | |
4031 | const IRPosition &IRP = this->getIRPosition(); |
4032 | NonNullAA = &A.getAAFor<AANonNull>(*this, IRP, DepClassTy::NONE); |
4033 | |
4034 | bool CanBeNull, CanBeFreed; |
4035 | takeKnownDerefBytesMaximum( |
4036 | IRP.getAssociatedValue().getPointerDereferenceableBytes( |
4037 | A.getDataLayout(), CanBeNull, CanBeFreed)); |
4038 | |
4039 | bool IsFnInterface = IRP.isFnInterfaceKind(); |
4040 | Function *FnScope = IRP.getAnchorScope(); |
4041 | if (IsFnInterface && (!FnScope || !A.isFunctionIPOAmendable(*FnScope))) { |
4042 | indicatePessimisticFixpoint(); |
4043 | return; |
4044 | } |
4045 | |
4046 | if (Instruction *CtxI = getCtxI()) |
4047 | followUsesInMBEC(*this, A, getState(), *CtxI); |
4048 | } |
4049 | |
4050 | /// See AbstractAttribute::getState() |
4051 | /// { |
4052 | StateType &getState() override { return *this; } |
4053 | const StateType &getState() const override { return *this; } |
4054 | /// } |
4055 | |
4056 | /// Helper function for collecting accessed bytes in must-be-executed-context |
4057 | void addAccessedBytesForUse(Attributor &A, const Use *U, const Instruction *I, |
4058 | DerefState &State) { |
4059 | const Value *UseV = U->get(); |
4060 | if (!UseV->getType()->isPointerTy()) |
4061 | return; |
4062 | |
4063 | Type *PtrTy = UseV->getType(); |
4064 | const DataLayout &DL = A.getDataLayout(); |
4065 | int64_t Offset; |
4066 | if (const Value *Base = getBasePointerOfAccessPointerOperand( |
4067 | I, Offset, DL, /*AllowNonInbounds*/ true)) { |
4068 | if (Base == &getAssociatedValue() && |
4069 | getPointerOperand(I, /* AllowVolatile */ false) == UseV) { |
4070 | uint64_t Size = DL.getTypeStoreSize(PtrTy->getPointerElementType()); |
4071 | State.addAccessedBytes(Offset, Size); |
4072 | } |
4073 | } |
4074 | } |
4075 | |
4076 | /// See followUsesInMBEC |
4077 | bool followUseInMBEC(Attributor &A, const Use *U, const Instruction *I, |
4078 | AADereferenceable::StateType &State) { |
4079 | bool IsNonNull = false; |
4080 | bool TrackUse = false; |
4081 | int64_t DerefBytes = getKnownNonNullAndDerefBytesForUse( |
4082 | A, *this, getAssociatedValue(), U, I, IsNonNull, TrackUse); |
4083 | LLVM_DEBUG(dbgs() << "[AADereferenceable] Deref bytes: " << DerefBytesdo { } while (false) |
4084 | << " for instruction " << *I << "\n")do { } while (false); |
4085 | |
4086 | addAccessedBytesForUse(A, U, I, State); |
4087 | State.takeKnownDerefBytesMaximum(DerefBytes); |
4088 | return TrackUse; |
4089 | } |
4090 | |
4091 | /// See AbstractAttribute::manifest(...). |
4092 | ChangeStatus manifest(Attributor &A) override { |
4093 | ChangeStatus Change = AADereferenceable::manifest(A); |
4094 | if (isAssumedNonNull() && hasAttr(Attribute::DereferenceableOrNull)) { |
4095 | removeAttrs({Attribute::DereferenceableOrNull}); |
4096 | return ChangeStatus::CHANGED; |
4097 | } |
4098 | return Change; |
4099 | } |
4100 | |
4101 | void getDeducedAttributes(LLVMContext &Ctx, |
4102 | SmallVectorImpl<Attribute> &Attrs) const override { |
4103 | // TODO: Add *_globally support |
4104 | if (isAssumedNonNull()) |
4105 | Attrs.emplace_back(Attribute::getWithDereferenceableBytes( |
4106 | Ctx, getAssumedDereferenceableBytes())); |
4107 | else |
4108 | Attrs.emplace_back(Attribute::getWithDereferenceableOrNullBytes( |
4109 | Ctx, getAssumedDereferenceableBytes())); |
4110 | } |
4111 | |
4112 | /// See AbstractAttribute::getAsStr(). |
4113 | const std::string getAsStr() const override { |
4114 | if (!getAssumedDereferenceableBytes()) |
4115 | return "unknown-dereferenceable"; |
4116 | return std::string("dereferenceable") + |
4117 | (isAssumedNonNull() ? "" : "_or_null") + |
4118 | (isAssumedGlobal() ? "_globally" : "") + "<" + |
4119 | std::to_string(getKnownDereferenceableBytes()) + "-" + |
4120 | std::to_string(getAssumedDereferenceableBytes()) + ">"; |
4121 | } |
4122 | }; |
4123 | |
4124 | /// Dereferenceable attribute for a floating value. |
4125 | struct AADereferenceableFloating : AADereferenceableImpl { |
4126 | AADereferenceableFloating(const IRPosition &IRP, Attributor &A) |
4127 | : AADereferenceableImpl(IRP, A) {} |
4128 | |
4129 | /// See AbstractAttribute::updateImpl(...). |
4130 | ChangeStatus updateImpl(Attributor &A) override { |
4131 | const DataLayout &DL = A.getDataLayout(); |
4132 | |
4133 | auto VisitValueCB = [&](const Value &V, const Instruction *, DerefState &T, |
4134 | bool Stripped) -> bool { |
4135 | unsigned IdxWidth = |
4136 | DL.getIndexSizeInBits(V.getType()->getPointerAddressSpace()); |
4137 | APInt Offset(IdxWidth, 0); |
4138 | const Value *Base = |
4139 | stripAndAccumulateMinimalOffsets(A, *this, &V, DL, Offset, false); |
4140 | |
4141 | const auto &AA = A.getAAFor<AADereferenceable>( |
4142 | *this, IRPosition::value(*Base), DepClassTy::REQUIRED); |
4143 | int64_t DerefBytes = 0; |
4144 | if (!Stripped && this == &AA) { |
4145 | // Use IR information if we did not strip anything. |
4146 | // TODO: track globally. |
4147 | bool CanBeNull, CanBeFreed; |
4148 | DerefBytes = |
4149 | Base->getPointerDereferenceableBytes(DL, CanBeNull, CanBeFreed); |
4150 | T.GlobalState.indicatePessimisticFixpoint(); |
4151 | } else { |
4152 | const DerefState &DS = AA.getState(); |
4153 | DerefBytes = DS.DerefBytesState.getAssumed(); |
4154 | T.GlobalState &= DS.GlobalState; |
4155 | } |
4156 | |
4157 | // For now we do not try to "increase" dereferenceability due to negative |
4158 | // indices as we first have to come up with code to deal with loops and |
4159 | // for overflows of the dereferenceable bytes. |
4160 | int64_t OffsetSExt = Offset.getSExtValue(); |
4161 | if (OffsetSExt < 0) |
4162 | OffsetSExt = 0; |
4163 | |
4164 | T.takeAssumedDerefBytesMinimum( |
4165 | std::max(int64_t(0), DerefBytes - OffsetSExt)); |
4166 | |
4167 | if (this == &AA) { |
4168 | if (!Stripped) { |
4169 | // If nothing was stripped IR information is all we got. |
4170 | T.takeKnownDerefBytesMaximum( |
4171 | std::max(int64_t(0), DerefBytes - OffsetSExt)); |
4172 | T.indicatePessimisticFixpoint(); |
4173 | } else if (OffsetSExt > 0) { |
4174 | // If something was stripped but there is circular reasoning we look |
4175 | // for the offset. If it is positive we basically decrease the |
4176 | // dereferenceable bytes in a circluar loop now, which will simply |
4177 | // drive them down to the known value in a very slow way which we |
4178 | // can accelerate. |
4179 | T.indicatePessimisticFixpoint(); |
4180 | } |
4181 | } |
4182 | |
4183 | return T.isValidState(); |
4184 | }; |
4185 | |
4186 | DerefState T; |
4187 | if (!genericValueTraversal<DerefState>(A, getIRPosition(), *this, T, |
4188 | VisitValueCB, getCtxI())) |
4189 | return indicatePessimisticFixpoint(); |
4190 | |
4191 | return clampStateAndIndicateChange(getState(), T); |
4192 | } |
4193 | |
4194 | /// See AbstractAttribute::trackStatistics() |
4195 | void trackStatistics() const override { |
4196 | STATS_DECLTRACK_FLOATING_ATTR(dereferenceable){ static llvm::Statistic NumIRFloating_dereferenceable = {"attributor" , "NumIRFloating_dereferenceable", ("Number of floating values known to be '" "dereferenceable" "'")};; ++(NumIRFloating_dereferenceable); } |
4197 | } |
4198 | }; |
4199 | |
4200 | /// Dereferenceable attribute for a return value. |
4201 | struct AADereferenceableReturned final |
4202 | : AAReturnedFromReturnedValues<AADereferenceable, AADereferenceableImpl> { |
4203 | AADereferenceableReturned(const IRPosition &IRP, Attributor &A) |
4204 | : AAReturnedFromReturnedValues<AADereferenceable, AADereferenceableImpl>( |
4205 | IRP, A) {} |
4206 | |
4207 | /// See AbstractAttribute::trackStatistics() |
4208 | void trackStatistics() const override { |
4209 | STATS_DECLTRACK_FNRET_ATTR(dereferenceable){ static llvm::Statistic NumIRFunctionReturn_dereferenceable = {"attributor", "NumIRFunctionReturn_dereferenceable", ("Number of " "function returns" " marked '" "dereferenceable" "'")};; ++( NumIRFunctionReturn_dereferenceable); } |
4210 | } |
4211 | }; |
4212 | |
4213 | /// Dereferenceable attribute for an argument |
4214 | struct AADereferenceableArgument final |
4215 | : AAArgumentFromCallSiteArguments<AADereferenceable, |
4216 | AADereferenceableImpl> { |
4217 | using Base = |
4218 | AAArgumentFromCallSiteArguments<AADereferenceable, AADereferenceableImpl>; |
4219 | AADereferenceableArgument(const IRPosition &IRP, Attributor &A) |
4220 | : Base(IRP, A) {} |
4221 | |
4222 | /// See AbstractAttribute::trackStatistics() |
4223 | void trackStatistics() const override { |
4224 | STATS_DECLTRACK_ARG_ATTR(dereferenceable){ static llvm::Statistic NumIRArguments_dereferenceable = {"attributor" , "NumIRArguments_dereferenceable", ("Number of " "arguments" " marked '" "dereferenceable" "'")};; ++(NumIRArguments_dereferenceable ); } |
4225 | } |
4226 | }; |
4227 | |
4228 | /// Dereferenceable attribute for a call site argument. |
4229 | struct AADereferenceableCallSiteArgument final : AADereferenceableFloating { |
4230 | AADereferenceableCallSiteArgument(const IRPosition &IRP, Attributor &A) |
4231 | : AADereferenceableFloating(IRP, A) {} |
4232 | |
4233 | /// See AbstractAttribute::trackStatistics() |
4234 | void trackStatistics() const override { |
4235 | STATS_DECLTRACK_CSARG_ATTR(dereferenceable){ static llvm::Statistic NumIRCSArguments_dereferenceable = { "attributor", "NumIRCSArguments_dereferenceable", ("Number of " "call site arguments" " marked '" "dereferenceable" "'")};; ++ (NumIRCSArguments_dereferenceable); } |
4236 | } |
4237 | }; |
4238 | |
4239 | /// Dereferenceable attribute deduction for a call site return value. |
4240 | struct AADereferenceableCallSiteReturned final |
4241 | : AACallSiteReturnedFromReturned<AADereferenceable, AADereferenceableImpl> { |
4242 | using Base = |
4243 | AACallSiteReturnedFromReturned<AADereferenceable, AADereferenceableImpl>; |
4244 | AADereferenceableCallSiteReturned(const IRPosition &IRP, Attributor &A) |
4245 | : Base(IRP, A) {} |
4246 | |
4247 | /// See AbstractAttribute::trackStatistics() |
4248 | void trackStatistics() const override { |
4249 | STATS_DECLTRACK_CS_ATTR(dereferenceable){ static llvm::Statistic NumIRCS_dereferenceable = {"attributor" , "NumIRCS_dereferenceable", ("Number of " "call site" " marked '" "dereferenceable" "'")};; ++(NumIRCS_dereferenceable); }; |
4250 | } |
4251 | }; |
4252 | |
4253 | // ------------------------ Align Argument Attribute ------------------------ |
4254 | |
4255 | static unsigned getKnownAlignForUse(Attributor &A, AAAlign &QueryingAA, |
4256 | Value &AssociatedValue, const Use *U, |
4257 | const Instruction *I, bool &TrackUse) { |
4258 | // We need to follow common pointer manipulation uses to the accesses they |
4259 | // feed into. |
4260 | if (isa<CastInst>(I)) { |
4261 | // Follow all but ptr2int casts. |
4262 | TrackUse = !isa<PtrToIntInst>(I); |
4263 | return 0; |
4264 | } |
4265 | if (auto *GEP = dyn_cast<GetElementPtrInst>(I)) { |
4266 | if (GEP->hasAllConstantIndices()) |
4267 | TrackUse = true; |
4268 | return 0; |
4269 | } |
4270 | |
4271 | MaybeAlign MA; |
4272 | if (const auto *CB = dyn_cast<CallBase>(I)) { |
4273 | if (CB->isBundleOperand(U) || CB->isCallee(U)) |
4274 | return 0; |
4275 | |
4276 | unsigned ArgNo = CB->getArgOperandNo(U); |
4277 | IRPosition IRP = IRPosition::callsite_argument(*CB, ArgNo); |
4278 | // As long as we only use known information there is no need to track |
4279 | // dependences here. |
4280 | auto &AlignAA = A.getAAFor<AAAlign>(QueryingAA, IRP, DepClassTy::NONE); |
4281 | MA = MaybeAlign(AlignAA.getKnownAlign()); |
4282 | } |
4283 | |
4284 | const DataLayout &DL = A.getDataLayout(); |
4285 | const Value *UseV = U->get(); |
4286 | if (auto *SI = dyn_cast<StoreInst>(I)) { |
4287 | if (SI->getPointerOperand() == UseV) |
4288 | MA = SI->getAlign(); |
4289 | } else if (auto *LI = dyn_cast<LoadInst>(I)) { |
4290 | if (LI->getPointerOperand() == UseV) |
4291 | MA = LI->getAlign(); |
4292 | } |
4293 | |
4294 | if (!MA || *MA <= QueryingAA.getKnownAlign()) |
4295 | return 0; |
4296 | |
4297 | unsigned Alignment = MA->value(); |
4298 | int64_t Offset; |
4299 | |
4300 | if (const Value *Base = GetPointerBaseWithConstantOffset(UseV, Offset, DL)) { |
4301 | if (Base == &AssociatedValue) { |
4302 | // BasePointerAddr + Offset = Alignment * Q for some integer Q. |
4303 | // So we can say that the maximum power of two which is a divisor of |
4304 | // gcd(Offset, Alignment) is an alignment. |
4305 | |
4306 | uint32_t gcd = |
4307 | greatestCommonDivisor(uint32_t(abs((int32_t)Offset)), Alignment); |
4308 | Alignment = llvm::PowerOf2Floor(gcd); |
4309 | } |
4310 | } |
4311 | |
4312 | return Alignment; |
4313 | } |
4314 | |
4315 | struct AAAlignImpl : AAAlign { |
4316 | AAAlignImpl(const IRPosition &IRP, Attributor &A) : AAAlign(IRP, A) {} |
4317 | |
4318 | /// See AbstractAttribute::initialize(...). |
4319 | void initialize(Attributor &A) override { |
4320 | SmallVector<Attribute, 4> Attrs; |
4321 | getAttrs({Attribute::Alignment}, Attrs); |
4322 | for (const Attribute &Attr : Attrs) |
4323 | takeKnownMaximum(Attr.getValueAsInt()); |
4324 | |
4325 | Value &V = getAssociatedValue(); |
4326 | // TODO: This is a HACK to avoid getPointerAlignment to introduce a ptr2int |
4327 | // use of the function pointer. This was caused by D73131. We want to |
4328 | // avoid this for function pointers especially because we iterate |
4329 | // their uses and int2ptr is not handled. It is not a correctness |
4330 | // problem though! |
4331 | if (!V.getType()->getPointerElementType()->isFunctionTy()) |
4332 | takeKnownMaximum(V.getPointerAlignment(A.getDataLayout()).value()); |
4333 | |
4334 | if (getIRPosition().isFnInterfaceKind() && |
4335 | (!getAnchorScope() || |
4336 | !A.isFunctionIPOAmendable(*getAssociatedFunction()))) { |
4337 | indicatePessimisticFixpoint(); |
4338 | return; |
4339 | } |
4340 | |
4341 | if (Instruction *CtxI = getCtxI()) |
4342 | followUsesInMBEC(*this, A, getState(), *CtxI); |
4343 | } |
4344 | |
4345 | /// See AbstractAttribute::manifest(...). |
4346 | ChangeStatus manifest(Attributor &A) override { |
4347 | ChangeStatus LoadStoreChanged = ChangeStatus::UNCHANGED; |
4348 | |
4349 | // Check for users that allow alignment annotations. |
4350 | Value &AssociatedValue = getAssociatedValue(); |
4351 | for (const Use &U : AssociatedValue.uses()) { |
4352 | if (auto *SI = dyn_cast<StoreInst>(U.getUser())) { |
4353 | if (SI->getPointerOperand() == &AssociatedValue) |
4354 | if (SI->getAlignment() < getAssumedAlign()) { |
4355 | STATS_DECLTRACK(AAAlign, Store,{ static llvm::Statistic NumIRStore_AAAlign = {"attributor", "NumIRStore_AAAlign" , "Number of times alignment added to a store"};; ++(NumIRStore_AAAlign ); } |
4356 | "Number of times alignment added to a store"){ static llvm::Statistic NumIRStore_AAAlign = {"attributor", "NumIRStore_AAAlign" , "Number of times alignment added to a store"};; ++(NumIRStore_AAAlign ); }; |
4357 | SI->setAlignment(Align(getAssumedAlign())); |
4358 | LoadStoreChanged = ChangeStatus::CHANGED; |
4359 | } |
4360 | } else if (auto *LI = dyn_cast<LoadInst>(U.getUser())) { |
4361 | if (LI->getPointerOperand() == &AssociatedValue) |
4362 | if (LI->getAlignment() < getAssumedAlign()) { |
4363 | LI->setAlignment(Align(getAssumedAlign())); |
4364 | STATS_DECLTRACK(AAAlign, Load,{ static llvm::Statistic NumIRLoad_AAAlign = {"attributor", "NumIRLoad_AAAlign" , "Number of times alignment added to a load"};; ++(NumIRLoad_AAAlign ); } |
4365 | "Number of times alignment added to a load"){ static llvm::Statistic NumIRLoad_AAAlign = {"attributor", "NumIRLoad_AAAlign" , "Number of times alignment added to a load"};; ++(NumIRLoad_AAAlign ); }; |
4366 | LoadStoreChanged = ChangeStatus::CHANGED; |
4367 | } |
4368 | } |
4369 | } |
4370 | |
4371 | ChangeStatus Changed = AAAlign::manifest(A); |
4372 | |
4373 | Align InheritAlign = |
4374 | getAssociatedValue().getPointerAlignment(A.getDataLayout()); |
4375 | if (InheritAlign >= getAssumedAlign()) |
4376 | return LoadStoreChanged; |
4377 | return Changed | LoadStoreChanged; |
4378 | } |
4379 | |
4380 | // TODO: Provide a helper to determine the implied ABI alignment and check in |
4381 | // the existing manifest method and a new one for AAAlignImpl that value |
4382 | // to avoid making the alignment explicit if it did not improve. |
4383 | |
4384 | /// See AbstractAttribute::getDeducedAttributes |
4385 | virtual void |
4386 | getDeducedAttributes(LLVMContext &Ctx, |
4387 | SmallVectorImpl<Attribute> &Attrs) const override { |
4388 | if (getAssumedAlign() > 1) |
4389 | Attrs.emplace_back( |
4390 | Attribute::getWithAlignment(Ctx, Align(getAssumedAlign()))); |
4391 | } |
4392 | |
4393 | /// See followUsesInMBEC |
4394 | bool followUseInMBEC(Attributor &A, const Use *U, const Instruction *I, |
4395 | AAAlign::StateType &State) { |
4396 | bool TrackUse = false; |
4397 | |
4398 | unsigned int KnownAlign = |
4399 | getKnownAlignForUse(A, *this, getAssociatedValue(), U, I, TrackUse); |
4400 | State.takeKnownMaximum(KnownAlign); |
4401 | |
4402 | return TrackUse; |
4403 | } |
4404 | |
4405 | /// See AbstractAttribute::getAsStr(). |
4406 | const std::string getAsStr() const override { |
4407 | return getAssumedAlign() ? ("align<" + std::to_string(getKnownAlign()) + |
4408 | "-" + std::to_string(getAssumedAlign()) + ">") |
4409 | : "unknown-align"; |
4410 | } |
4411 | }; |
4412 | |
4413 | /// Align attribute for a floating value. |
4414 | struct AAAlignFloating : AAAlignImpl { |
4415 | AAAlignFloating(const IRPosition &IRP, Attributor &A) : AAAlignImpl(IRP, A) {} |
4416 | |
4417 | /// See AbstractAttribute::updateImpl(...). |
4418 | ChangeStatus updateImpl(Attributor &A) override { |
4419 | const DataLayout &DL = A.getDataLayout(); |
4420 | |
4421 | auto VisitValueCB = [&](Value &V, const Instruction *, |
4422 | AAAlign::StateType &T, bool Stripped) -> bool { |
4423 | const auto &AA = A.getAAFor<AAAlign>(*this, IRPosition::value(V), |
4424 | DepClassTy::REQUIRED); |
4425 | if (!Stripped && this == &AA) { |
4426 | int64_t Offset; |
4427 | unsigned Alignment = 1; |
4428 | if (const Value *Base = |
4429 | GetPointerBaseWithConstantOffset(&V, Offset, DL)) { |
4430 | Align PA = Base->getPointerAlignment(DL); |
4431 | // BasePointerAddr + Offset = Alignment * Q for some integer Q. |
4432 | // So we can say that the maximum power of two which is a divisor of |
4433 | // gcd(Offset, Alignment) is an alignment. |
4434 | |
4435 | uint32_t gcd = greatestCommonDivisor(uint32_t(abs((int32_t)Offset)), |
4436 | uint32_t(PA.value())); |
4437 | Alignment = llvm::PowerOf2Floor(gcd); |
4438 | } else { |
4439 | Alignment = V.getPointerAlignment(DL).value(); |
4440 | } |
4441 | // Use only IR information if we did not strip anything. |
4442 | T.takeKnownMaximum(Alignment); |
4443 | T.indicatePessimisticFixpoint(); |
4444 | } else { |
4445 | // Use abstract attribute information. |
4446 | const AAAlign::StateType &DS = AA.getState(); |
4447 | T ^= DS; |
4448 | } |
4449 | return T.isValidState(); |
4450 | }; |
4451 | |
4452 | StateType T; |
4453 | if (!genericValueTraversal<StateType>(A, getIRPosition(), *this, T, |
4454 | VisitValueCB, getCtxI())) |
4455 | return indicatePessimisticFixpoint(); |
4456 | |
4457 | // TODO: If we know we visited all incoming values, thus no are assumed |
4458 | // dead, we can take the known information from the state T. |
4459 | return clampStateAndIndicateChange(getState(), T); |
4460 | } |
4461 | |
4462 | /// See AbstractAttribute::trackStatistics() |
4463 | void trackStatistics() const override { STATS_DECLTRACK_FLOATING_ATTR(align){ static llvm::Statistic NumIRFloating_align = {"attributor", "NumIRFloating_align", ("Number of floating values known to be '" "align" "'")};; ++(NumIRFloating_align); } } |
4464 | }; |
4465 | |
4466 | /// Align attribute for function return value. |
4467 | struct AAAlignReturned final |
4468 | : AAReturnedFromReturnedValues<AAAlign, AAAlignImpl> { |
4469 | using Base = AAReturnedFromReturnedValues<AAAlign, AAAlignImpl>; |
4470 | AAAlignReturned(const IRPosition &IRP, Attributor &A) : Base(IRP, A) {} |
4471 | |
4472 | /// See AbstractAttribute::initialize(...). |
4473 | void initialize(Attributor &A) override { |
4474 | Base::initialize(A); |
4475 | Function *F = getAssociatedFunction(); |
4476 | if (!F || F->isDeclaration()) |
4477 | indicatePessimisticFixpoint(); |
4478 | } |
4479 | |
4480 | /// See AbstractAttribute::trackStatistics() |
4481 | void trackStatistics() const override { STATS_DECLTRACK_FNRET_ATTR(aligned){ static llvm::Statistic NumIRFunctionReturn_aligned = {"attributor" , "NumIRFunctionReturn_aligned", ("Number of " "function returns" " marked '" "aligned" "'")};; ++(NumIRFunctionReturn_aligned ); } } |
4482 | }; |
4483 | |
4484 | /// Align attribute for function argument. |
4485 | struct AAAlignArgument final |
4486 | : AAArgumentFromCallSiteArguments<AAAlign, AAAlignImpl> { |
4487 | using Base = AAArgumentFromCallSiteArguments<AAAlign, AAAlignImpl>; |
4488 | AAAlignArgument(const IRPosition &IRP, Attributor &A) : Base(IRP, A) {} |
4489 | |
4490 | /// See AbstractAttribute::manifest(...). |
4491 | ChangeStatus manifest(Attributor &A) override { |
4492 | // If the associated argument is involved in a must-tail call we give up |
4493 | // because we would need to keep the argument alignments of caller and |
4494 | // callee in-sync. Just does not seem worth the trouble right now. |
4495 | if (A.getInfoCache().isInvolvedInMustTailCall(*getAssociatedArgument())) |
4496 | return ChangeStatus::UNCHANGED; |
4497 | return Base::manifest(A); |
4498 | } |
4499 | |
4500 | /// See AbstractAttribute::trackStatistics() |
4501 | void trackStatistics() const override { STATS_DECLTRACK_ARG_ATTR(aligned){ static llvm::Statistic NumIRArguments_aligned = {"attributor" , "NumIRArguments_aligned", ("Number of " "arguments" " marked '" "aligned" "'")};; ++(NumIRArguments_aligned); } } |
4502 | }; |
4503 | |
4504 | struct AAAlignCallSiteArgument final : AAAlignFloating { |
4505 | AAAlignCallSiteArgument(const IRPosition &IRP, Attributor &A) |
4506 | : AAAlignFloating(IRP, A) {} |
4507 | |
4508 | /// See AbstractAttribute::manifest(...). |
4509 | ChangeStatus manifest(Attributor &A) override { |
4510 | // If the associated argument is involved in a must-tail call we give up |
4511 | // because we would need to keep the argument alignments of caller and |
4512 | // callee in-sync. Just does not seem worth the trouble right now. |
4513 | if (Argument *Arg = getAssociatedArgument()) |
4514 | if (A.getInfoCache().isInvolvedInMustTailCall(*Arg)) |
4515 | return ChangeStatus::UNCHANGED; |
4516 | ChangeStatus Changed = AAAlignImpl::manifest(A); |
4517 | Align InheritAlign = |
4518 | getAssociatedValue().getPointerAlignment(A.getDataLayout()); |
4519 | if (InheritAlign >= getAssumedAlign()) |
4520 | Changed = ChangeStatus::UNCHANGED; |
4521 | return Changed; |
4522 | } |
4523 | |
4524 | /// See AbstractAttribute::updateImpl(Attributor &A). |
4525 | ChangeStatus updateImpl(Attributor &A) override { |
4526 | ChangeStatus Changed = AAAlignFloating::updateImpl(A); |
4527 | if (Argument *Arg = getAssociatedArgument()) { |
4528 | // We only take known information from the argument |
4529 | // so we do not need to track a dependence. |
4530 | const auto &ArgAlignAA = A.getAAFor<AAAlign>( |
4531 | *this, IRPosition::argument(*Arg), DepClassTy::NONE); |
4532 | takeKnownMaximum(ArgAlignAA.getKnownAlign()); |
4533 | } |
4534 | return Changed; |
4535 | } |
4536 | |
4537 | /// See AbstractAttribute::trackStatistics() |
4538 | void trackStatistics() const override { STATS_DECLTRACK_CSARG_ATTR(aligned){ static llvm::Statistic NumIRCSArguments_aligned = {"attributor" , "NumIRCSArguments_aligned", ("Number of " "call site arguments" " marked '" "aligned" "'")};; ++(NumIRCSArguments_aligned); } } |
4539 | }; |
4540 | |
4541 | /// Align attribute deduction for a call site return value. |
4542 | struct AAAlignCallSiteReturned final |
4543 | : AACallSiteReturnedFromReturned<AAAlign, AAAlignImpl> { |
4544 | using Base = AACallSiteReturnedFromReturned<AAAlign, AAAlignImpl>; |
4545 | AAAlignCallSiteReturned(const IRPosition &IRP, Attributor &A) |
4546 | : Base(IRP, A) {} |
4547 | |
4548 | /// See AbstractAttribute::initialize(...). |
4549 | void initialize(Attributor &A) override { |
4550 | Base::initialize(A); |
4551 | Function *F = getAssociatedFunction(); |
4552 | if (!F || F->isDeclaration()) |
4553 | indicatePessimisticFixpoint(); |
4554 | } |
4555 | |
4556 | /// See AbstractAttribute::trackStatistics() |
4557 | void trackStatistics() const override { STATS_DECLTRACK_CS_ATTR(align){ static llvm::Statistic NumIRCS_align = {"attributor", "NumIRCS_align" , ("Number of " "call site" " marked '" "align" "'")};; ++(NumIRCS_align ); }; } |
4558 | }; |
4559 | |
4560 | /// ------------------ Function No-Return Attribute ---------------------------- |
4561 | struct AANoReturnImpl : public AANoReturn { |
4562 | AANoReturnImpl(const IRPosition &IRP, Attributor &A) : AANoReturn(IRP, A) {} |
4563 | |
4564 | /// See AbstractAttribute::initialize(...). |
4565 | void initialize(Attributor &A) override { |
4566 | AANoReturn::initialize(A); |
4567 | Function *F = getAssociatedFunction(); |
4568 | if (!F || F->isDeclaration()) |
4569 | indicatePessimisticFixpoint(); |
4570 | } |
4571 | |
4572 | /// See AbstractAttribute::getAsStr(). |
4573 | const std::string getAsStr() const override { |
4574 | return getAssumed() ? "noreturn" : "may-return"; |
4575 | } |
4576 | |
4577 | /// See AbstractAttribute::updateImpl(Attributor &A). |
4578 | virtual ChangeStatus updateImpl(Attributor &A) override { |
4579 | auto CheckForNoReturn = [](Instruction &) { return false; }; |
4580 | bool UsedAssumedInformation = false; |
4581 | if (!A.checkForAllInstructions(CheckForNoReturn, *this, |
4582 | {(unsigned)Instruction::Ret}, |
4583 | UsedAssumedInformation)) |
4584 | return indicatePessimisticFixpoint(); |
4585 | return ChangeStatus::UNCHANGED; |
4586 | } |
4587 | }; |
4588 | |
4589 | struct AANoReturnFunction final : AANoReturnImpl { |
4590 | AANoReturnFunction(const IRPosition &IRP, Attributor &A) |
4591 | : AANoReturnImpl(IRP, A) {} |
4592 | |
4593 | /// See AbstractAttribute::trackStatistics() |
4594 | void trackStatistics() const override { STATS_DECLTRACK_FN_ATTR(noreturn){ static llvm::Statistic NumIRFunction_noreturn = {"attributor" , "NumIRFunction_noreturn", ("Number of " "functions" " marked '" "noreturn" "'")};; ++(NumIRFunction_noreturn); } } |
4595 | }; |
4596 | |
4597 | /// NoReturn attribute deduction for a call sites. |
4598 | struct AANoReturnCallSite final : AANoReturnImpl { |
4599 | AANoReturnCallSite(const IRPosition &IRP, Attributor &A) |
4600 | : AANoReturnImpl(IRP, A) {} |
4601 | |
4602 | /// See AbstractAttribute::initialize(...). |
4603 | void initialize(Attributor &A) override { |
4604 | AANoReturnImpl::initialize(A); |
4605 | if (Function *F = getAssociatedFunction()) { |
4606 | const IRPosition &FnPos = IRPosition::function(*F); |
4607 | auto &FnAA = A.getAAFor<AANoReturn>(*this, FnPos, DepClassTy::REQUIRED); |
4608 | if (!FnAA.isAssumedNoReturn()) |
4609 | indicatePessimisticFixpoint(); |
4610 | } |
4611 | } |
4612 | |
4613 | /// See AbstractAttribute::updateImpl(...). |
4614 | ChangeStatus updateImpl(Attributor &A) override { |
4615 | // TODO: Once we have call site specific value information we can provide |
4616 | // call site specific liveness information and then it makes |
4617 | // sense to specialize attributes for call sites arguments instead of |
4618 | // redirecting requests to the callee argument. |
4619 | Function *F = getAssociatedFunction(); |
4620 | const IRPosition &FnPos = IRPosition::function(*F); |
4621 | auto &FnAA = A.getAAFor<AANoReturn>(*this, FnPos, DepClassTy::REQUIRED); |
4622 | return clampStateAndIndicateChange(getState(), FnAA.getState()); |
4623 | } |
4624 | |
4625 | /// See AbstractAttribute::trackStatistics() |
4626 | void trackStatistics() const override { STATS_DECLTRACK_CS_ATTR(noreturn){ static llvm::Statistic NumIRCS_noreturn = {"attributor", "NumIRCS_noreturn" , ("Number of " "call site" " marked '" "noreturn" "'")};; ++ (NumIRCS_noreturn); }; } |
4627 | }; |
4628 | |
4629 | /// ----------------------- Variable Capturing --------------------------------- |
4630 | |
4631 | /// A class to hold the state of for no-capture attributes. |
4632 | struct AANoCaptureImpl : public AANoCapture { |
4633 | AANoCaptureImpl(const IRPosition &IRP, Attributor &A) : AANoCapture(IRP, A) {} |
4634 | |
4635 | /// See AbstractAttribute::initialize(...). |
4636 | void initialize(Attributor &A) override { |
4637 | if (hasAttr(getAttrKind(), /* IgnoreSubsumingPositions */ true)) { |
4638 | indicateOptimisticFixpoint(); |
4639 | return; |
4640 | } |
4641 | Function *AnchorScope = getAnchorScope(); |
4642 | if (isFnInterfaceKind() && |
4643 | (!AnchorScope || !A.isFunctionIPOAmendable(*AnchorScope))) { |
4644 | indicatePessimisticFixpoint(); |
4645 | return; |
4646 | } |
4647 | |
4648 | // You cannot "capture" null in the default address space. |
4649 | if (isa<ConstantPointerNull>(getAssociatedValue()) && |
4650 | getAssociatedValue().getType()->getPointerAddressSpace() == 0) { |
4651 | indicateOptimisticFixpoint(); |
4652 | return; |
4653 | } |
4654 | |
4655 | const Function *F = |
4656 | isArgumentPosition() ? getAssociatedFunction() : AnchorScope; |
4657 | |
4658 | // Check what state the associated function can actually capture. |
4659 | if (F) |
4660 | determineFunctionCaptureCapabilities(getIRPosition(), *F, *this); |
4661 | else |
4662 | indicatePessimisticFixpoint(); |
4663 | } |
4664 | |
4665 | /// See AbstractAttribute::updateImpl(...). |
4666 | ChangeStatus updateImpl(Attributor &A) override; |
4667 | |
4668 | /// see AbstractAttribute::isAssumedNoCaptureMaybeReturned(...). |
4669 | virtual void |
4670 | getDeducedAttributes(LLVMContext &Ctx, |
4671 | SmallVectorImpl<Attribute> &Attrs) const override { |
4672 | if (!isAssumedNoCaptureMaybeReturned()) |
4673 | return; |
4674 | |
4675 | if (isArgumentPosition()) { |
4676 | if (isAssumedNoCapture()) |
4677 | Attrs.emplace_back(Attribute::get(Ctx, Attribute::NoCapture)); |
4678 | else if (ManifestInternal) |
4679 | Attrs.emplace_back(Attribute::get(Ctx, "no-capture-maybe-returned")); |
4680 | } |
4681 | } |
4682 | |
4683 | /// Set the NOT_CAPTURED_IN_MEM and NOT_CAPTURED_IN_RET bits in \p Known |
4684 | /// depending on the ability of the function associated with \p IRP to capture |
4685 | /// state in memory and through "returning/throwing", respectively. |
4686 | static void determineFunctionCaptureCapabilities(const IRPosition &IRP, |
4687 | const Function &F, |
4688 | BitIntegerState &State) { |
4689 | // TODO: Once we have memory behavior attributes we should use them here. |
4690 | |
4691 | // If we know we cannot communicate or write to memory, we do not care about |
4692 | // ptr2int anymore. |
4693 | if (F.onlyReadsMemory() && F.doesNotThrow() && |
4694 | F.getReturnType()->isVoidTy()) { |
4695 | State.addKnownBits(NO_CAPTURE); |
4696 | return; |
4697 | } |
4698 | |
4699 | // A function cannot capture state in memory if it only reads memory, it can |
4700 | // however return/throw state and the state might be influenced by the |
4701 | // pointer value, e.g., loading from a returned pointer might reveal a bit. |
4702 | if (F.onlyReadsMemory()) |
4703 | State.addKnownBits(NOT_CAPTURED_IN_MEM); |
4704 | |
4705 | // A function cannot communicate state back if it does not through |
4706 | // exceptions and doesn not return values. |
4707 | if (F.doesNotThrow() && F.getReturnType()->isVoidTy()) |
4708 | State.addKnownBits(NOT_CAPTURED_IN_RET); |
4709 | |
4710 | // Check existing "returned" attributes. |
4711 | int ArgNo = IRP.getCalleeArgNo(); |
4712 | if (F.doesNotThrow() && ArgNo >= 0) { |
4713 | for (unsigned u = 0, e = F.arg_size(); u < e; ++u) |
4714 | if (F.hasParamAttribute(u, Attribute::Returned)) { |
4715 | if (u == unsigned(ArgNo)) |
4716 | State.removeAssumedBits(NOT_CAPTURED_IN_RET); |
4717 | else if (F.onlyReadsMemory()) |
4718 | State.addKnownBits(NO_CAPTURE); |
4719 | else |
4720 | State.addKnownBits(NOT_CAPTURED_IN_RET); |
4721 | break; |
4722 | } |
4723 | } |
4724 | } |
4725 | |
4726 | /// See AbstractState::getAsStr(). |
4727 | const std::string getAsStr() const override { |
4728 | if (isKnownNoCapture()) |
4729 | return "known not-captured"; |
4730 | if (isAssumedNoCapture()) |
4731 | return "assumed not-captured"; |
4732 | if (isKnownNoCaptureMaybeReturned()) |
4733 | return "known not-captured-maybe-returned"; |
4734 | if (isAssumedNoCaptureMaybeReturned()) |
4735 | return "assumed not-captured-maybe-returned"; |
4736 | return "assumed-captured"; |
4737 | } |
4738 | }; |
4739 | |
4740 | /// Attributor-aware capture tracker. |
4741 | struct AACaptureUseTracker final : public CaptureTracker { |
4742 | |
4743 | /// Create a capture tracker that can lookup in-flight abstract attributes |
4744 | /// through the Attributor \p A. |
4745 | /// |
4746 | /// If a use leads to a potential capture, \p CapturedInMemory is set and the |
4747 | /// search is stopped. If a use leads to a return instruction, |
4748 | /// \p CommunicatedBack is set to true and \p CapturedInMemory is not changed. |
4749 | /// If a use leads to a ptr2int which may capture the value, |
4750 | /// \p CapturedInInteger is set. If a use is found that is currently assumed |
4751 | /// "no-capture-maybe-returned", the user is added to the \p PotentialCopies |
4752 | /// set. All values in \p PotentialCopies are later tracked as well. For every |
4753 | /// explored use we decrement \p RemainingUsesToExplore. Once it reaches 0, |
4754 | /// the search is stopped with \p CapturedInMemory and \p CapturedInInteger |
4755 | /// conservatively set to true. |
4756 | AACaptureUseTracker(Attributor &A, AANoCapture &NoCaptureAA, |
4757 | const AAIsDead &IsDeadAA, AANoCapture::StateType &State, |
4758 | SmallSetVector<Value *, 4> &PotentialCopies, |
4759 | unsigned &RemainingUsesToExplore) |
4760 | : A(A), NoCaptureAA(NoCaptureAA), IsDeadAA(IsDeadAA), State(State), |
4761 | PotentialCopies(PotentialCopies), |
4762 | RemainingUsesToExplore(RemainingUsesToExplore) {} |
4763 | |
4764 | /// Determine if \p V maybe captured. *Also updates the state!* |
4765 | bool valueMayBeCaptured(const Value *V) { |
4766 | if (V->getType()->isPointerTy()) { |
4767 | PointerMayBeCaptured(V, this); |
4768 | } else { |
4769 | State.indicatePessimisticFixpoint(); |
4770 | } |
4771 | return State.isAssumed(AANoCapture::NO_CAPTURE_MAYBE_RETURNED); |
4772 | } |
4773 | |
4774 | /// See CaptureTracker::tooManyUses(). |
4775 | void tooManyUses() override { |
4776 | State.removeAssumedBits(AANoCapture::NO_CAPTURE); |
4777 | } |
4778 | |
4779 | bool isDereferenceableOrNull(Value *O, const DataLayout &DL) override { |
4780 | if (CaptureTracker::isDereferenceableOrNull(O, DL)) |
4781 | return true; |
4782 | const auto &DerefAA = A.getAAFor<AADereferenceable>( |
4783 | NoCaptureAA, IRPosition::value(*O), DepClassTy::OPTIONAL); |
4784 | return DerefAA.getAssumedDereferenceableBytes(); |
4785 | } |
4786 | |
4787 | /// See CaptureTracker::captured(...). |
4788 | bool captured(const Use *U) override { |
4789 | Instruction *UInst = cast<Instruction>(U->getUser()); |
4790 | LLVM_DEBUG(dbgs() << "Check use: " << *U->get() << " in " << *UInstdo { } while (false) |
4791 | << "\n")do { } while (false); |
4792 | |
4793 | // Because we may reuse the tracker multiple times we keep track of the |
4794 | // number of explored uses ourselves as well. |
4795 | if (RemainingUsesToExplore-- == 0) { |
4796 | LLVM_DEBUG(dbgs() << " - too many uses to explore!\n")do { } while (false); |
4797 | return isCapturedIn(/* Memory */ true, /* Integer */ true, |
4798 | /* Return */ true); |
4799 | } |
4800 | |
4801 | // Deal with ptr2int by following uses. |
4802 | if (isa<PtrToIntInst>(UInst)) { |
4803 | LLVM_DEBUG(dbgs() << " - ptr2int assume the worst!\n")do { } while (false); |
4804 | return valueMayBeCaptured(UInst); |
4805 | } |
4806 | |
4807 | // For stores we check if we can follow the value through memory or not. |
4808 | if (auto *SI = dyn_cast<StoreInst>(UInst)) { |
4809 | if (SI->isVolatile()) |
4810 | return isCapturedIn(/* Memory */ true, /* Integer */ false, |
4811 | /* Return */ false); |
4812 | bool UsedAssumedInformation = false; |
4813 | if (!AA::getPotentialCopiesOfStoredValue( |
4814 | A, *SI, PotentialCopies, NoCaptureAA, UsedAssumedInformation)) |
4815 | return isCapturedIn(/* Memory */ true, /* Integer */ false, |
4816 | /* Return */ false); |
4817 | // Not captured directly, potential copies will be checked. |
4818 | return isCapturedIn(/* Memory */ false, /* Integer */ false, |
4819 | /* Return */ false); |
4820 | } |
4821 | |
4822 | // Explicitly catch return instructions. |
4823 | if (isa<ReturnInst>(UInst)) { |
4824 | if (UInst->getFunction() == NoCaptureAA.getAnchorScope()) |
4825 | return isCapturedIn(/* Memory */ false, /* Integer */ false, |
4826 | /* Return */ true); |
4827 | return isCapturedIn(/* Memory */ true, /* Integer */ true, |
4828 | /* Return */ true); |
4829 | } |
4830 | |
4831 | // For now we only use special logic for call sites. However, the tracker |
4832 | // itself knows about a lot of other non-capturing cases already. |
4833 | auto *CB = dyn_cast<CallBase>(UInst); |
4834 | if (!CB || !CB->isArgOperand(U)) |
4835 | return isCapturedIn(/* Memory */ true, /* Integer */ true, |
4836 | /* Return */ true); |
4837 | |
4838 | unsigned ArgNo = CB->getArgOperandNo(U); |
4839 | const IRPosition &CSArgPos = IRPosition::callsite_argument(*CB, ArgNo); |
4840 | // If we have a abstract no-capture attribute for the argument we can use |
4841 | // it to justify a non-capture attribute here. This allows recursion! |
4842 | auto &ArgNoCaptureAA = |
4843 | A.getAAFor<AANoCapture>(NoCaptureAA, CSArgPos, DepClassTy::REQUIRED); |
4844 | if (ArgNoCaptureAA.isAssumedNoCapture()) |
4845 | return isCapturedIn(/* Memory */ false, /* Integer */ false, |
4846 | /* Return */ false); |
4847 | if (ArgNoCaptureAA.isAssumedNoCaptureMaybeReturned()) { |
4848 | addPotentialCopy(*CB); |
4849 | return isCapturedIn(/* Memory */ false, /* Integer */ false, |
4850 | /* Return */ false); |
4851 | } |
4852 | |
4853 | // Lastly, we could not find a reason no-capture can be assumed so we don't. |
4854 | return isCapturedIn(/* Memory */ true, /* Integer */ true, |
4855 | /* Return */ true); |
4856 | } |
4857 | |
4858 | /// Register \p CS as potential copy of the value we are checking. |
4859 | void addPotentialCopy(CallBase &CB) { PotentialCopies.insert(&CB); } |
4860 | |
4861 | /// See CaptureTracker::shouldExplore(...). |
4862 | bool shouldExplore(const Use *U) override { |
4863 | // Check liveness and ignore droppable users. |
4864 | bool UsedAssumedInformation = false; |
4865 | return !U->getUser()->isDroppable() && |
4866 | !A.isAssumedDead(*U, &NoCaptureAA, &IsDeadAA, |
4867 | UsedAssumedInformation); |
4868 | } |
4869 | |
4870 | /// Update the state according to \p CapturedInMem, \p CapturedInInt, and |
4871 | /// \p CapturedInRet, then return the appropriate value for use in the |
4872 | /// CaptureTracker::captured() interface. |
4873 | bool isCapturedIn(bool CapturedInMem, bool CapturedInInt, |
4874 | bool CapturedInRet) { |
4875 | LLVM_DEBUG(dbgs() << " - captures [Mem " << CapturedInMem << "|Int "do { } while (false) |
4876 | << CapturedInInt << "|Ret " << CapturedInRet << "]\n")do { } while (false); |
4877 | if (CapturedInMem) |
4878 | State.removeAssumedBits(AANoCapture::NOT_CAPTURED_IN_MEM); |
4879 | if (CapturedInInt) |
4880 | State.removeAssumedBits(AANoCapture::NOT_CAPTURED_IN_INT); |
4881 | if (CapturedInRet) |
4882 | State.removeAssumedBits(AANoCapture::NOT_CAPTURED_IN_RET); |
4883 | return !State.isAssumed(AANoCapture::NO_CAPTURE_MAYBE_RETURNED); |
4884 | } |
4885 | |
4886 | private: |
4887 | /// The attributor providing in-flight abstract attributes. |
4888 | Attributor &A; |
4889 | |
4890 | /// The abstract attribute currently updated. |
4891 | AANoCapture &NoCaptureAA; |
4892 | |
4893 | /// The abstract liveness state. |
4894 | const AAIsDead &IsDeadAA; |
4895 | |
4896 | /// The state currently updated. |
4897 | AANoCapture::StateType &State; |
4898 | |
4899 | /// Set of potential copies of the tracked value. |
4900 | SmallSetVector<Value *, 4> &PotentialCopies; |
4901 | |
4902 | /// Global counter to limit the number of explored uses. |
4903 | unsigned &RemainingUsesToExplore; |
4904 | }; |
4905 | |
4906 | ChangeStatus AANoCaptureImpl::updateImpl(Attributor &A) { |
4907 | const IRPosition &IRP = getIRPosition(); |
4908 | Value *V = isArgumentPosition() ? IRP.getAssociatedArgument() |
4909 | : &IRP.getAssociatedValue(); |
4910 | if (!V) |
4911 | return indicatePessimisticFixpoint(); |
4912 | |
4913 | const Function *F = |
4914 | isArgumentPosition() ? IRP.getAssociatedFunction() : IRP.getAnchorScope(); |
4915 | assert(F && "Expected a function!")((void)0); |
4916 | const IRPosition &FnPos = IRPosition::function(*F); |
4917 | const auto &IsDeadAA = A.getAAFor<AAIsDead>(*this, FnPos, DepClassTy::NONE); |
4918 | |
4919 | AANoCapture::StateType T; |
4920 | |
4921 | // Readonly means we cannot capture through memory. |
4922 | const auto &FnMemAA = |
4923 | A.getAAFor<AAMemoryBehavior>(*this, FnPos, DepClassTy::NONE); |
4924 | if (FnMemAA.isAssumedReadOnly()) { |
4925 | T.addKnownBits(NOT_CAPTURED_IN_MEM); |
4926 | if (FnMemAA.isKnownReadOnly()) |
4927 | addKnownBits(NOT_CAPTURED_IN_MEM); |
4928 | else |
4929 | A.recordDependence(FnMemAA, *this, DepClassTy::OPTIONAL); |
4930 | } |
4931 | |
4932 | // Make sure all returned values are different than the underlying value. |
4933 | // TODO: we could do this in a more sophisticated way inside |
4934 | // AAReturnedValues, e.g., track all values that escape through returns |
4935 | // directly somehow. |
4936 | auto CheckReturnedArgs = [&](const AAReturnedValues &RVAA) { |
4937 | bool SeenConstant = false; |
4938 | for (auto &It : RVAA.returned_values()) { |
4939 | if (isa<Constant>(It.first)) { |
4940 | if (SeenConstant) |
4941 | return false; |
4942 | SeenConstant = true; |
4943 | } else if (!isa<Argument>(It.first) || |
4944 | It.first == getAssociatedArgument()) |
4945 | return false; |
4946 | } |
4947 | return true; |
4948 | }; |
4949 | |
4950 | const auto &NoUnwindAA = |
4951 | A.getAAFor<AANoUnwind>(*this, FnPos, DepClassTy::OPTIONAL); |
4952 | if (NoUnwindAA.isAssumedNoUnwind()) { |
4953 | bool IsVoidTy = F->getReturnType()->isVoidTy(); |
4954 | const AAReturnedValues *RVAA = |
4955 | IsVoidTy ? nullptr |
4956 | : &A.getAAFor<AAReturnedValues>(*this, FnPos, |
4957 | |
4958 | DepClassTy::OPTIONAL); |
4959 | if (IsVoidTy || CheckReturnedArgs(*RVAA)) { |
4960 | T.addKnownBits(NOT_CAPTURED_IN_RET); |
4961 | if (T.isKnown(NOT_CAPTURED_IN_MEM)) |
4962 | return ChangeStatus::UNCHANGED; |
4963 | if (NoUnwindAA.isKnownNoUnwind() && |
4964 | (IsVoidTy || RVAA->getState().isAtFixpoint())) { |
4965 | addKnownBits(NOT_CAPTURED_IN_RET); |
4966 | if (isKnown(NOT_CAPTURED_IN_MEM)) |
4967 | return indicateOptimisticFixpoint(); |
4968 | } |
4969 | } |
4970 | } |
4971 | |
4972 | // Use the CaptureTracker interface and logic with the specialized tracker, |
4973 | // defined in AACaptureUseTracker, that can look at in-flight abstract |
4974 | // attributes and directly updates the assumed state. |
4975 | SmallSetVector<Value *, 4> PotentialCopies; |
4976 | unsigned RemainingUsesToExplore = |
4977 | getDefaultMaxUsesToExploreForCaptureTracking(); |
4978 | AACaptureUseTracker Tracker(A, *this, IsDeadAA, T, PotentialCopies, |
4979 | RemainingUsesToExplore); |
4980 | |
4981 | // Check all potential copies of the associated value until we can assume |
4982 | // none will be captured or we have to assume at least one might be. |
4983 | unsigned Idx = 0; |
4984 | PotentialCopies.insert(V); |
4985 | while (T.isAssumed(NO_CAPTURE_MAYBE_RETURNED) && Idx < PotentialCopies.size()) |
4986 | Tracker.valueMayBeCaptured(PotentialCopies[Idx++]); |
4987 | |
4988 | AANoCapture::StateType &S = getState(); |
4989 | auto Assumed = S.getAssumed(); |
4990 | S.intersectAssumedBits(T.getAssumed()); |
4991 | if (!isAssumedNoCaptureMaybeReturned()) |
4992 | return indicatePessimisticFixpoint(); |
4993 | return Assumed == S.getAssumed() ? ChangeStatus::UNCHANGED |
4994 | : ChangeStatus::CHANGED; |
4995 | } |
4996 | |
4997 | /// NoCapture attribute for function arguments. |
4998 | struct AANoCaptureArgument final : AANoCaptureImpl { |
4999 | AANoCaptureArgument(const IRPosition &IRP, Attributor &A) |
5000 | : AANoCaptureImpl(IRP, A) {} |
5001 | |
5002 | /// See AbstractAttribute::trackStatistics() |
5003 | void trackStatistics() const override { STATS_DECLTRACK_ARG_ATTR(nocapture){ static llvm::Statistic NumIRArguments_nocapture = {"attributor" , "NumIRArguments_nocapture", ("Number of " "arguments" " marked '" "nocapture" "'")};; ++(NumIRArguments_nocapture); } } |
5004 | }; |
5005 | |
5006 | /// NoCapture attribute for call site arguments. |
5007 | struct AANoCaptureCallSiteArgument final : AANoCaptureImpl { |
5008 | AANoCaptureCallSiteArgument(const IRPosition &IRP, Attributor &A) |
5009 | : AANoCaptureImpl(IRP, A) {} |
5010 | |
5011 | /// See AbstractAttribute::initialize(...). |
5012 | void initialize(Attributor &A) override { |
5013 | if (Argument *Arg = getAssociatedArgument()) |
5014 | if (Arg->hasByValAttr()) |
5015 | indicateOptimisticFixpoint(); |
5016 | AANoCaptureImpl::initialize(A); |
5017 | } |
5018 | |
5019 | /// See AbstractAttribute::updateImpl(...). |
5020 | ChangeStatus updateImpl(Attributor &A) override { |
5021 | // TODO: Once we have call site specific value information we can provide |
5022 | // call site specific liveness information and then it makes |
5023 | // sense to specialize attributes for call sites arguments instead of |
5024 | // redirecting requests to the callee argument. |
5025 | Argument *Arg = getAssociatedArgument(); |
5026 | if (!Arg) |
5027 | return indicatePessimisticFixpoint(); |
5028 | const IRPosition &ArgPos = IRPosition::argument(*Arg); |
5029 | auto &ArgAA = A.getAAFor<AANoCapture>(*this, ArgPos, DepClassTy::REQUIRED); |
5030 | return clampStateAndIndicateChange(getState(), ArgAA.getState()); |
5031 | } |
5032 | |
5033 | /// See AbstractAttribute::trackStatistics() |
5034 | void trackStatistics() const override{STATS_DECLTRACK_CSARG_ATTR(nocapture){ static llvm::Statistic NumIRCSArguments_nocapture = {"attributor" , "NumIRCSArguments_nocapture", ("Number of " "call site arguments" " marked '" "nocapture" "'")};; ++(NumIRCSArguments_nocapture ); }}; |
5035 | }; |
5036 | |
5037 | /// NoCapture attribute for floating values. |
5038 | struct AANoCaptureFloating final : AANoCaptureImpl { |
5039 | AANoCaptureFloating(const IRPosition &IRP, Attributor &A) |
5040 | : AANoCaptureImpl(IRP, A) {} |
5041 | |
5042 | /// See AbstractAttribute::trackStatistics() |
5043 | void trackStatistics() const override { |
5044 | STATS_DECLTRACK_FLOATING_ATTR(nocapture){ static llvm::Statistic NumIRFloating_nocapture = {"attributor" , "NumIRFloating_nocapture", ("Number of floating values known to be '" "nocapture" "'")};; ++(NumIRFloating_nocapture); } |
5045 | } |
5046 | }; |
5047 | |
5048 | /// NoCapture attribute for function return value. |
5049 | struct AANoCaptureReturned final : AANoCaptureImpl { |
5050 | AANoCaptureReturned(const IRPosition &IRP, Attributor &A) |
5051 | : AANoCaptureImpl(IRP, A) { |
5052 | llvm_unreachable("NoCapture is not applicable to function returns!")__builtin_unreachable(); |
5053 | } |
5054 | |
5055 | /// See AbstractAttribute::initialize(...). |
5056 | void initialize(Attributor &A) override { |
5057 | llvm_unreachable("NoCapture is not applicable to function returns!")__builtin_unreachable(); |
5058 | } |
5059 | |
5060 | /// See AbstractAttribute::updateImpl(...). |
5061 | ChangeStatus updateImpl(Attributor &A) override { |
5062 | llvm_unreachable("NoCapture is not applicable to function returns!")__builtin_unreachable(); |
5063 | } |
5064 | |
5065 | /// See AbstractAttribute::trackStatistics() |
5066 | void trackStatistics() const override {} |
5067 | }; |
5068 | |
5069 | /// NoCapture attribute deduction for a call site return value. |
5070 | struct AANoCaptureCallSiteReturned final : AANoCaptureImpl { |
5071 | AANoCaptureCallSiteReturned(const IRPosition &IRP, Attributor &A) |
5072 | : AANoCaptureImpl(IRP, A) {} |
5073 | |
5074 | /// See AbstractAttribute::initialize(...). |
5075 | void initialize(Attributor &A) override { |
5076 | const Function *F = getAnchorScope(); |
5077 | // Check what state the associated function can actually capture. |
5078 | determineFunctionCaptureCapabilities(getIRPosition(), *F, *this); |
5079 | } |
5080 | |
5081 | /// See AbstractAttribute::trackStatistics() |
5082 | void trackStatistics() const override { |
5083 | STATS_DECLTRACK_CSRET_ATTR(nocapture){ static llvm::Statistic NumIRCSReturn_nocapture = {"attributor" , "NumIRCSReturn_nocapture", ("Number of " "call site returns" " marked '" "nocapture" "'")};; ++(NumIRCSReturn_nocapture); } |
5084 | } |
5085 | }; |
5086 | |
5087 | /// ------------------ Value Simplify Attribute ---------------------------- |
5088 | |
5089 | bool ValueSimplifyStateType::unionAssumed(Optional<Value *> Other) { |
5090 | // FIXME: Add a typecast support. |
5091 | SimplifiedAssociatedValue = AA::combineOptionalValuesInAAValueLatice( |
5092 | SimplifiedAssociatedValue, Other, Ty); |
5093 | if (SimplifiedAssociatedValue == Optional<Value *>(nullptr)) |
5094 | return false; |
5095 | |
5096 | LLVM_DEBUG({do { } while (false) |
5097 | if (SimplifiedAssociatedValue.hasValue())do { } while (false) |
5098 | dbgs() << "[ValueSimplify] is assumed to be "do { } while (false) |
5099 | << **SimplifiedAssociatedValue << "\n";do { } while (false) |
5100 | elsedo { } while (false) |
5101 | dbgs() << "[ValueSimplify] is assumed to be <none>\n";do { } while (false) |
5102 | })do { } while (false); |
5103 | return true; |
5104 | } |
5105 | |
5106 | struct AAValueSimplifyImpl : AAValueSimplify { |
5107 | AAValueSimplifyImpl(const IRPosition &IRP, Attributor &A) |
5108 | : AAValueSimplify(IRP, A) {} |
5109 | |
5110 | /// See AbstractAttribute::initialize(...). |
5111 | void initialize(Attributor &A) override { |
5112 | if (getAssociatedValue().getType()->isVoidTy()) |
5113 | indicatePessimisticFixpoint(); |
5114 | if (A.hasSimplificationCallback(getIRPosition())) |
5115 | indicatePessimisticFixpoint(); |
5116 | } |
5117 | |
5118 | /// See AbstractAttribute::getAsStr(). |
5119 | const std::string getAsStr() const override { |
5120 | LLVM_DEBUG({do { } while (false) |
5121 | errs() << "SAV: " << SimplifiedAssociatedValue << " ";do { } while (false) |
5122 | if (SimplifiedAssociatedValue && *SimplifiedAssociatedValue)do { } while (false) |
5123 | errs() << "SAV: " << **SimplifiedAssociatedValue << " ";do { } while (false) |
5124 | })do { } while (false); |
5125 | return isValidState() ? (isAtFixpoint() ? "simplified" : "maybe-simple") |
5126 | : "not-simple"; |
5127 | } |
5128 | |
5129 | /// See AbstractAttribute::trackStatistics() |
5130 | void trackStatistics() const override {} |
5131 | |
5132 | /// See AAValueSimplify::getAssumedSimplifiedValue() |
5133 | Optional<Value *> getAssumedSimplifiedValue(Attributor &A) const override { |
5134 | return SimplifiedAssociatedValue; |
5135 | } |
5136 | |
5137 | /// Return a value we can use as replacement for the associated one, or |
5138 | /// nullptr if we don't have one that makes sense. |
5139 | Value *getReplacementValue(Attributor &A) const { |
5140 | Value *NewV; |
5141 | NewV = SimplifiedAssociatedValue.hasValue() |
5142 | ? SimplifiedAssociatedValue.getValue() |
5143 | : UndefValue::get(getAssociatedType()); |
5144 | if (!NewV) |
5145 | return nullptr; |
5146 | NewV = AA::getWithType(*NewV, *getAssociatedType()); |
5147 | if (!NewV || NewV == &getAssociatedValue()) |
5148 | return nullptr; |
5149 | const Instruction *CtxI = getCtxI(); |
5150 | if (CtxI && !AA::isValidAtPosition(*NewV, *CtxI, A.getInfoCache())) |
5151 | return nullptr; |
5152 | if (!CtxI && !AA::isValidInScope(*NewV, getAnchorScope())) |
5153 | return nullptr; |
5154 | return NewV; |
5155 | } |
5156 | |
5157 | /// Helper function for querying AAValueSimplify and updating candicate. |
5158 | /// \param IRP The value position we are trying to unify with SimplifiedValue |
5159 | bool checkAndUpdate(Attributor &A, const AbstractAttribute &QueryingAA, |
5160 | const IRPosition &IRP, bool Simplify = true) { |
5161 | bool UsedAssumedInformation = false; |
5162 | Optional<Value *> QueryingValueSimplified = &IRP.getAssociatedValue(); |
5163 | if (Simplify) |
5164 | QueryingValueSimplified = |
5165 | A.getAssumedSimplified(IRP, QueryingAA, UsedAssumedInformation); |
5166 | return unionAssumed(QueryingValueSimplified); |
5167 | } |
5168 | |
5169 | /// Returns a candidate is found or not |
5170 | template <typename AAType> bool askSimplifiedValueFor(Attributor &A) { |
5171 | if (!getAssociatedValue().getType()->isIntegerTy()) |
5172 | return false; |
5173 | |
5174 | // This will also pass the call base context. |
5175 | const auto &AA = |
5176 | A.getAAFor<AAType>(*this, getIRPosition(), DepClassTy::NONE); |
5177 | |
5178 | Optional<ConstantInt *> COpt = AA.getAssumedConstantInt(A); |
5179 | |
5180 | if (!COpt.hasValue()) { |
5181 | SimplifiedAssociatedValue = llvm::None; |
5182 | A.recordDependence(AA, *this, DepClassTy::OPTIONAL); |
5183 | return true; |
5184 | } |
5185 | if (auto *C = COpt.getValue()) { |
5186 | SimplifiedAssociatedValue = C; |
5187 | A.recordDependence(AA, *this, DepClassTy::OPTIONAL); |
5188 | return true; |
5189 | } |
5190 | return false; |
5191 | } |
5192 | |
5193 | bool askSimplifiedValueForOtherAAs(Attributor &A) { |
5194 | if (askSimplifiedValueFor<AAValueConstantRange>(A)) |
5195 | return true; |
5196 | if (askSimplifiedValueFor<AAPotentialValues>(A)) |
5197 | return true; |
5198 | return false; |
5199 | } |
5200 | |
5201 | /// See AbstractAttribute::manifest(...). |
5202 | ChangeStatus manifest(Attributor &A) override { |
5203 | ChangeStatus Changed = ChangeStatus::UNCHANGED; |
5204 | if (getAssociatedValue().user_empty()) |
5205 | return Changed; |
5206 | |
5207 | if (auto *NewV = getReplacementValue(A)) { |
5208 | LLVM_DEBUG(dbgs() << "[ValueSimplify] " << getAssociatedValue() << " -> "do { } while (false) |
5209 | << *NewV << " :: " << *this << "\n")do { } while (false); |
5210 | if (A.changeValueAfterManifest(getAssociatedValue(), *NewV)) |
5211 | Changed = ChangeStatus::CHANGED; |
5212 | } |
5213 | |
5214 | return Changed | AAValueSimplify::manifest(A); |
5215 | } |
5216 | |
5217 | /// See AbstractState::indicatePessimisticFixpoint(...). |
5218 | ChangeStatus indicatePessimisticFixpoint() override { |
5219 | SimplifiedAssociatedValue = &getAssociatedValue(); |
5220 | return AAValueSimplify::indicatePessimisticFixpoint(); |
5221 | } |
5222 | |
5223 | static bool handleLoad(Attributor &A, const AbstractAttribute &AA, |
5224 | LoadInst &L, function_ref<bool(Value &)> Union) { |
5225 | auto UnionWrapper = [&](Value &V, Value &Obj) { |
5226 | if (isa<AllocaInst>(Obj)) |
5227 | return Union(V); |
5228 | if (!AA::isDynamicallyUnique(A, AA, V)) |
5229 | return false; |
5230 | if (!AA::isValidAtPosition(V, L, A.getInfoCache())) |
5231 | return false; |
5232 | return Union(V); |
5233 | }; |
5234 | |
5235 | Value &Ptr = *L.getPointerOperand(); |
5236 | SmallVector<Value *, 8> Objects; |
5237 | if (!AA::getAssumedUnderlyingObjects(A, Ptr, Objects, AA, &L)) |
5238 | return false; |
5239 | |
5240 | for (Value *Obj : Objects) { |
5241 | LLVM_DEBUG(dbgs() << "Visit underlying object " << *Obj << "\n")do { } while (false); |
5242 | if (isa<UndefValue>(Obj)) |
5243 | continue; |
5244 | if (isa<ConstantPointerNull>(Obj)) { |
5245 | // A null pointer access can be undefined but any offset from null may |
5246 | // be OK. We do not try to optimize the latter. |
5247 | bool UsedAssumedInformation = false; |
5248 | if (!NullPointerIsDefined(L.getFunction(), |
5249 | Ptr.getType()->getPointerAddressSpace()) && |
5250 | A.getAssumedSimplified(Ptr, AA, UsedAssumedInformation) == Obj) |
5251 | continue; |
5252 | return false; |
5253 | } |
5254 | if (!isa<AllocaInst>(Obj) && !isa<GlobalVariable>(Obj)) |
5255 | return false; |
5256 | Constant *InitialVal = AA::getInitialValueForObj(*Obj, *L.getType()); |
5257 | if (!InitialVal || !Union(*InitialVal)) |
5258 | return false; |
5259 | |
5260 | LLVM_DEBUG(dbgs() << "Underlying object amenable to load-store "do { } while (false) |
5261 | "propagation, checking accesses next.\n")do { } while (false); |
5262 | |
5263 | auto CheckAccess = [&](const AAPointerInfo::Access &Acc, bool IsExact) { |
5264 | LLVM_DEBUG(dbgs() << " - visit access " << Acc << "\n")do { } while (false); |
5265 | if (!Acc.isWrite()) |
5266 | return true; |
5267 | if (Acc.isWrittenValueYetUndetermined()) |
5268 | return true; |
5269 | Value *Content = Acc.getWrittenValue(); |
5270 | if (!Content) |
5271 | return false; |
5272 | Value *CastedContent = |
5273 | AA::getWithType(*Content, *AA.getAssociatedType()); |
5274 | if (!CastedContent) |
5275 | return false; |
5276 | if (IsExact) |
5277 | return UnionWrapper(*CastedContent, *Obj); |
5278 | if (auto *C = dyn_cast<Constant>(CastedContent)) |
5279 | if (C->isNullValue() || C->isAllOnesValue() || isa<UndefValue>(C)) |
5280 | return UnionWrapper(*CastedContent, *Obj); |
5281 | return false; |
5282 | }; |
5283 | |
5284 | auto &PI = A.getAAFor<AAPointerInfo>(AA, IRPosition::value(*Obj), |
5285 | DepClassTy::REQUIRED); |
5286 | if (!PI.forallInterferingAccesses(L, CheckAccess)) |
5287 | return false; |
5288 | } |
5289 | return true; |
5290 | } |
5291 | }; |
5292 | |
5293 | struct AAValueSimplifyArgument final : AAValueSimplifyImpl { |
5294 | AAValueSimplifyArgument(const IRPosition &IRP, Attributor &A) |
5295 | : AAValueSimplifyImpl(IRP, A) {} |
5296 | |
5297 | void initialize(Attributor &A) override { |
5298 | AAValueSimplifyImpl::initialize(A); |
5299 | if (!getAnchorScope() || getAnchorScope()->isDeclaration()) |
5300 | indicatePessimisticFixpoint(); |
5301 | if (hasAttr({Attribute::InAlloca, Attribute::Preallocated, |
5302 | Attribute::StructRet, Attribute::Nest, Attribute::ByVal}, |
5303 | /* IgnoreSubsumingPositions */ true)) |
5304 | indicatePessimisticFixpoint(); |
5305 | |
5306 | // FIXME: This is a hack to prevent us from propagating function poiner in |
5307 | // the new pass manager CGSCC pass as it creates call edges the |
5308 | // CallGraphUpdater cannot handle yet. |
5309 | Value &V = getAssociatedValue(); |
5310 | if (V.getType()->isPointerTy() && |
5311 | V.getType()->getPointerElementType()->isFunctionTy() && |
5312 | !A.isModulePass()) |
5313 | indicatePessimisticFixpoint(); |
5314 | } |
5315 | |
5316 | /// See AbstractAttribute::updateImpl(...). |
5317 | ChangeStatus updateImpl(Attributor &A) override { |
5318 | // Byval is only replacable if it is readonly otherwise we would write into |
5319 | // the replaced value and not the copy that byval creates implicitly. |
5320 | Argument *Arg = getAssociatedArgument(); |
5321 | if (Arg->hasByValAttr()) { |
5322 | // TODO: We probably need to verify synchronization is not an issue, e.g., |
5323 | // there is no race by not copying a constant byval. |
5324 | const auto &MemAA = A.getAAFor<AAMemoryBehavior>(*this, getIRPosition(), |
5325 | DepClassTy::REQUIRED); |
5326 | if (!MemAA.isAssumedReadOnly()) |
5327 | return indicatePessimisticFixpoint(); |
5328 | } |
5329 | |
5330 | auto Before = SimplifiedAssociatedValue; |
5331 | |
5332 | auto PredForCallSite = [&](AbstractCallSite ACS) { |
5333 | const IRPosition &ACSArgPos = |
5334 | IRPosition::callsite_argument(ACS, getCallSiteArgNo()); |
5335 | // Check if a coresponding argument was found or if it is on not |
5336 | // associated (which can happen for callback calls). |
5337 | if (ACSArgPos.getPositionKind() == IRPosition::IRP_INVALID) |
5338 | return false; |
5339 | |
5340 | // Simplify the argument operand explicitly and check if the result is |
5341 | // valid in the current scope. This avoids refering to simplified values |
5342 | // in other functions, e.g., we don't want to say a an argument in a |
5343 | // static function is actually an argument in a different function. |
5344 | bool UsedAssumedInformation = false; |
5345 | Optional<Constant *> SimpleArgOp = |
5346 | A.getAssumedConstant(ACSArgPos, *this, UsedAssumedInformation); |
5347 | if (!SimpleArgOp.hasValue()) |
5348 | return true; |
5349 | if (!SimpleArgOp.getValue()) |
5350 | return false; |
5351 | if (!AA::isDynamicallyUnique(A, *this, **SimpleArgOp)) |
5352 | return false; |
5353 | return unionAssumed(*SimpleArgOp); |
5354 | }; |
5355 | |
5356 | // Generate a answer specific to a call site context. |
5357 | bool Success; |
5358 | bool AllCallSitesKnown; |
5359 | if (hasCallBaseContext() && |
5360 | getCallBaseContext()->getCalledFunction() == Arg->getParent()) |
5361 | Success = PredForCallSite( |
5362 | AbstractCallSite(&getCallBaseContext()->getCalledOperandUse())); |
5363 | else |
5364 | Success = A.checkForAllCallSites(PredForCallSite, *this, true, |
5365 | AllCallSitesKnown); |
5366 | |
5367 | if (!Success) |
5368 | if (!askSimplifiedValueForOtherAAs(A)) |
5369 | return indicatePessimisticFixpoint(); |
5370 | |
5371 | // If a candicate was found in this update, return CHANGED. |
5372 | return Before == SimplifiedAssociatedValue ? ChangeStatus::UNCHANGED |
5373 | : ChangeStatus ::CHANGED; |
5374 | } |
5375 | |
5376 | /// See AbstractAttribute::trackStatistics() |
5377 | void trackStatistics() const override { |
5378 | STATS_DECLTRACK_ARG_ATTR(value_simplify){ static llvm::Statistic NumIRArguments_value_simplify = {"attributor" , "NumIRArguments_value_simplify", ("Number of " "arguments" " marked '" "value_simplify" "'")};; ++(NumIRArguments_value_simplify); } |
5379 | } |
5380 | }; |
5381 | |
5382 | struct AAValueSimplifyReturned : AAValueSimplifyImpl { |
5383 | AAValueSimplifyReturned(const IRPosition &IRP, Attributor &A) |
5384 | : AAValueSimplifyImpl(IRP, A) {} |
5385 | |
5386 | /// See AAValueSimplify::getAssumedSimplifiedValue() |
5387 | Optional<Value *> getAssumedSimplifiedValue(Attributor &A) const override { |
5388 | if (!isValidState()) |
5389 | return nullptr; |
5390 | return SimplifiedAssociatedValue; |
5391 | } |
5392 | |
5393 | /// See AbstractAttribute::updateImpl(...). |
5394 | ChangeStatus updateImpl(Attributor &A) override { |
5395 | auto Before = SimplifiedAssociatedValue; |
5396 | |
5397 | auto PredForReturned = [&](Value &V) { |
5398 | return checkAndUpdate(A, *this, |
5399 | IRPosition::value(V, getCallBaseContext())); |
5400 | }; |
5401 | |
5402 | if (!A.checkForAllReturnedValues(PredForReturned, *this)) |
5403 | if (!askSimplifiedValueForOtherAAs(A)) |
5404 | return indicatePessimisticFixpoint(); |
5405 | |
5406 | // If a candicate was found in this update, return CHANGED. |
5407 | return Before == SimplifiedAssociatedValue ? ChangeStatus::UNCHANGED |
5408 | : ChangeStatus ::CHANGED; |
5409 | } |
5410 | |
5411 | ChangeStatus manifest(Attributor &A) override { |
5412 | ChangeStatus Changed = ChangeStatus::UNCHANGED; |
5413 | |
5414 | if (auto *NewV = getReplacementValue(A)) { |
5415 | auto PredForReturned = |
5416 | [&](Value &, const SmallSetVector<ReturnInst *, 4> &RetInsts) { |
5417 | for (ReturnInst *RI : RetInsts) { |
5418 | Value *ReturnedVal = RI->getReturnValue(); |
5419 | if (ReturnedVal == NewV || isa<UndefValue>(ReturnedVal)) |
5420 | return true; |
5421 | assert(RI->getFunction() == getAnchorScope() &&((void)0) |
5422 | "ReturnInst in wrong function!")((void)0); |
5423 | LLVM_DEBUG(dbgs()do { } while (false) |
5424 | << "[ValueSimplify] " << *ReturnedVal << " -> "do { } while (false) |
5425 | << *NewV << " in " << *RI << " :: " << *this << "\n")do { } while (false); |
5426 | if (A.changeUseAfterManifest(RI->getOperandUse(0), *NewV)) |
5427 | Changed = ChangeStatus::CHANGED; |
5428 | } |
5429 | return true; |
5430 | }; |
5431 | A.checkForAllReturnedValuesAndReturnInsts(PredForReturned, *this); |
5432 | } |
5433 | |
5434 | return Changed | AAValueSimplify::manifest(A); |
5435 | } |
5436 | |
5437 | /// See AbstractAttribute::trackStatistics() |
5438 | void trackStatistics() const override { |
5439 | STATS_DECLTRACK_FNRET_ATTR(value_simplify){ static llvm::Statistic NumIRFunctionReturn_value_simplify = {"attributor", "NumIRFunctionReturn_value_simplify", ("Number of " "function returns" " marked '" "value_simplify" "'")};; ++(NumIRFunctionReturn_value_simplify ); } |
5440 | } |
5441 | }; |
5442 | |
5443 | struct AAValueSimplifyFloating : AAValueSimplifyImpl { |
5444 | AAValueSimplifyFloating(const IRPosition &IRP, Attributor &A) |
5445 | : AAValueSimplifyImpl(IRP, A) {} |
5446 | |
5447 | /// See AbstractAttribute::initialize(...). |
5448 | void initialize(Attributor &A) override { |
5449 | AAValueSimplifyImpl::initialize(A); |
5450 | Value &V = getAnchorValue(); |
5451 | |
5452 | // TODO: add other stuffs |
5453 | if (isa<Constant>(V)) |
5454 | indicatePessimisticFixpoint(); |
5455 | } |
5456 | |
5457 | /// Check if \p Cmp is a comparison we can simplify. |
5458 | /// |
5459 | /// We handle multiple cases, one in which at least one operand is an |
5460 | /// (assumed) nullptr. If so, try to simplify it using AANonNull on the other |
5461 | /// operand. Return true if successful, in that case SimplifiedAssociatedValue |
5462 | /// will be updated. |
5463 | bool handleCmp(Attributor &A, CmpInst &Cmp) { |
5464 | auto Union = [&](Value &V) { |
5465 | SimplifiedAssociatedValue = AA::combineOptionalValuesInAAValueLatice( |
5466 | SimplifiedAssociatedValue, &V, V.getType()); |
5467 | return SimplifiedAssociatedValue != Optional<Value *>(nullptr); |
5468 | }; |
5469 | |
5470 | Value *LHS = Cmp.getOperand(0); |
5471 | Value *RHS = Cmp.getOperand(1); |
5472 | |
5473 | // Simplify the operands first. |
5474 | bool UsedAssumedInformation = false; |
5475 | const auto &SimplifiedLHS = |
5476 | A.getAssumedSimplified(IRPosition::value(*LHS, getCallBaseContext()), |
5477 | *this, UsedAssumedInformation); |
5478 | if (!SimplifiedLHS.hasValue()) |
5479 | return true; |
5480 | if (!SimplifiedLHS.getValue()) |
5481 | return false; |
5482 | LHS = *SimplifiedLHS; |
5483 | |
5484 | const auto &SimplifiedRHS = |
5485 | A.getAssumedSimplified(IRPosition::value(*RHS, getCallBaseContext()), |
5486 | *this, UsedAssumedInformation); |
5487 | if (!SimplifiedRHS.hasValue()) |
5488 | return true; |
5489 | if (!SimplifiedRHS.getValue()) |
5490 | return false; |
5491 | RHS = *SimplifiedRHS; |
5492 | |
5493 | LLVMContext &Ctx = Cmp.getContext(); |
5494 | // Handle the trivial case first in which we don't even need to think about |
5495 | // null or non-null. |
5496 | if (LHS == RHS && (Cmp.isTrueWhenEqual() || Cmp.isFalseWhenEqual())) { |
5497 | Constant *NewVal = |
5498 | ConstantInt::get(Type::getInt1Ty(Ctx), Cmp.isTrueWhenEqual()); |
5499 | if (!Union(*NewVal)) |
5500 | return false; |
5501 | if (!UsedAssumedInformation) |
5502 | indicateOptimisticFixpoint(); |
5503 | return true; |
5504 | } |
5505 | |
5506 | // From now on we only handle equalities (==, !=). |
5507 | ICmpInst *ICmp = dyn_cast<ICmpInst>(&Cmp); |
5508 | if (!ICmp || !ICmp->isEquality()) |
5509 | return false; |
5510 | |
5511 | bool LHSIsNull = isa<ConstantPointerNull>(LHS); |
5512 | bool RHSIsNull = isa<ConstantPointerNull>(RHS); |
5513 | if (!LHSIsNull && !RHSIsNull) |
5514 | return false; |
5515 | |
5516 | // Left is the nullptr ==/!= non-nullptr case. We'll use AANonNull on the |
5517 | // non-nullptr operand and if we assume it's non-null we can conclude the |
5518 | // result of the comparison. |
5519 | assert((LHSIsNull || RHSIsNull) &&((void)0) |
5520 | "Expected nullptr versus non-nullptr comparison at this point")((void)0); |
5521 | |
5522 | // The index is the operand that we assume is not null. |
5523 | unsigned PtrIdx = LHSIsNull; |
5524 | auto &PtrNonNullAA = A.getAAFor<AANonNull>( |
5525 | *this, IRPosition::value(*ICmp->getOperand(PtrIdx)), |
5526 | DepClassTy::REQUIRED); |
5527 | if (!PtrNonNullAA.isAssumedNonNull()) |
5528 | return false; |
5529 | UsedAssumedInformation |= !PtrNonNullAA.isKnownNonNull(); |
5530 | |
5531 | // The new value depends on the predicate, true for != and false for ==. |
5532 | Constant *NewVal = ConstantInt::get( |
5533 | Type::getInt1Ty(Ctx), ICmp->getPredicate() == CmpInst::ICMP_NE); |
5534 | if (!Union(*NewVal)) |
5535 | return false; |
5536 | |
5537 | if (!UsedAssumedInformation) |
5538 | indicateOptimisticFixpoint(); |
5539 | |
5540 | return true; |
5541 | } |
5542 | |
5543 | bool updateWithLoad(Attributor &A, LoadInst &L) { |
5544 | auto Union = [&](Value &V) { |
5545 | SimplifiedAssociatedValue = AA::combineOptionalValuesInAAValueLatice( |
5546 | SimplifiedAssociatedValue, &V, L.getType()); |
5547 | return SimplifiedAssociatedValue != Optional<Value *>(nullptr); |
5548 | }; |
5549 | return handleLoad(A, *this, L, Union); |
5550 | } |
5551 | |
5552 | /// Use the generic, non-optimistic InstSimplfy functionality if we managed to |
5553 | /// simplify any operand of the instruction \p I. Return true if successful, |
5554 | /// in that case SimplifiedAssociatedValue will be updated. |
5555 | bool handleGenericInst(Attributor &A, Instruction &I) { |
5556 | bool SomeSimplified = false; |
5557 | bool UsedAssumedInformation = false; |
5558 | |
5559 | SmallVector<Value *, 8> NewOps(I.getNumOperands()); |
5560 | int Idx = 0; |
5561 | for (Value *Op : I.operands()) { |
5562 | const auto &SimplifiedOp = |
5563 | A.getAssumedSimplified(IRPosition::value(*Op, getCallBaseContext()), |
5564 | *this, UsedAssumedInformation); |
5565 | // If we are not sure about any operand we are not sure about the entire |
5566 | // instruction, we'll wait. |
5567 | if (!SimplifiedOp.hasValue()) |
5568 | return true; |
5569 | |
5570 | if (SimplifiedOp.getValue()) |
5571 | NewOps[Idx] = SimplifiedOp.getValue(); |
5572 | else |
5573 | NewOps[Idx] = Op; |
5574 | |
5575 | SomeSimplified |= (NewOps[Idx] != Op); |
5576 | ++Idx; |
5577 | } |
5578 | |
5579 | // We won't bother with the InstSimplify interface if we didn't simplify any |
5580 | // operand ourselves. |
5581 | if (!SomeSimplified) |
5582 | return false; |
5583 | |
5584 | InformationCache &InfoCache = A.getInfoCache(); |
5585 | Function *F = I.getFunction(); |
5586 | const auto *DT = |
5587 | InfoCache.getAnalysisResultForFunction<DominatorTreeAnalysis>(*F); |
5588 | const auto *TLI = A.getInfoCache().getTargetLibraryInfoForFunction(*F); |
5589 | auto *AC = InfoCache.getAnalysisResultForFunction<AssumptionAnalysis>(*F); |
5590 | OptimizationRemarkEmitter *ORE = nullptr; |
5591 | |
5592 | const DataLayout &DL = I.getModule()->getDataLayout(); |
5593 | SimplifyQuery Q(DL, TLI, DT, AC, &I); |
5594 | if (Value *SimplifiedI = |
5595 | SimplifyInstructionWithOperands(&I, NewOps, Q, ORE)) { |
5596 | SimplifiedAssociatedValue = AA::combineOptionalValuesInAAValueLatice( |
5597 | SimplifiedAssociatedValue, SimplifiedI, I.getType()); |
5598 | return SimplifiedAssociatedValue != Optional<Value *>(nullptr); |
5599 | } |
5600 | return false; |
5601 | } |
5602 | |
5603 | /// See AbstractAttribute::updateImpl(...). |
5604 | ChangeStatus updateImpl(Attributor &A) override { |
5605 | auto Before = SimplifiedAssociatedValue; |
5606 | |
5607 | auto VisitValueCB = [&](Value &V, const Instruction *CtxI, bool &, |
5608 | bool Stripped) -> bool { |
5609 | auto &AA = A.getAAFor<AAValueSimplify>( |
5610 | *this, IRPosition::value(V, getCallBaseContext()), |
5611 | DepClassTy::REQUIRED); |
5612 | if (!Stripped && this == &AA) { |
5613 | |
5614 | if (auto *I = dyn_cast<Instruction>(&V)) { |
5615 | if (auto *LI = dyn_cast<LoadInst>(&V)) |
5616 | if (updateWithLoad(A, *LI)) |
5617 | return true; |
5618 | if (auto *Cmp = dyn_cast<CmpInst>(&V)) |
5619 | if (handleCmp(A, *Cmp)) |
5620 | return true; |
5621 | if (handleGenericInst(A, *I)) |
5622 | return true; |
5623 | } |
5624 | // TODO: Look the instruction and check recursively. |
5625 | |
5626 | LLVM_DEBUG(dbgs() << "[ValueSimplify] Can't be stripped more : " << Vdo { } while (false) |
5627 | << "\n")do { } while (false); |
5628 | return false; |
5629 | } |
5630 | return checkAndUpdate(A, *this, |
5631 | IRPosition::value(V, getCallBaseContext())); |
5632 | }; |
5633 | |
5634 | bool Dummy = false; |
5635 | if (!genericValueTraversal<bool>(A, getIRPosition(), *this, Dummy, |
5636 | VisitValueCB, getCtxI(), |
5637 | /* UseValueSimplify */ false)) |
5638 | if (!askSimplifiedValueForOtherAAs(A)) |
5639 | return indicatePessimisticFixpoint(); |
5640 | |
5641 | // If a candicate was found in this update, return CHANGED. |
5642 | return Before == SimplifiedAssociatedValue ? ChangeStatus::UNCHANGED |
5643 | : ChangeStatus ::CHANGED; |
5644 | } |
5645 | |
5646 | /// See AbstractAttribute::trackStatistics() |
5647 | void trackStatistics() const override { |
5648 | STATS_DECLTRACK_FLOATING_ATTR(value_simplify){ static llvm::Statistic NumIRFloating_value_simplify = {"attributor" , "NumIRFloating_value_simplify", ("Number of floating values known to be '" "value_simplify" "'")};; ++(NumIRFloating_value_simplify); } |
5649 | } |
5650 | }; |
5651 | |
5652 | struct AAValueSimplifyFunction : AAValueSimplifyImpl { |
5653 | AAValueSimplifyFunction(const IRPosition &IRP, Attributor &A) |
5654 | : AAValueSimplifyImpl(IRP, A) {} |
5655 | |
5656 | /// See AbstractAttribute::initialize(...). |
5657 | void initialize(Attributor &A) override { |
5658 | SimplifiedAssociatedValue = nullptr; |
5659 | indicateOptimisticFixpoint(); |
5660 | } |
5661 | /// See AbstractAttribute::initialize(...). |
5662 | ChangeStatus updateImpl(Attributor &A) override { |
5663 | llvm_unreachable(__builtin_unreachable() |
5664 | "AAValueSimplify(Function|CallSite)::updateImpl will not be called")__builtin_unreachable(); |
5665 | } |
5666 | /// See AbstractAttribute::trackStatistics() |
5667 | void trackStatistics() const override { |
5668 | STATS_DECLTRACK_FN_ATTR(value_simplify){ static llvm::Statistic NumIRFunction_value_simplify = {"attributor" , "NumIRFunction_value_simplify", ("Number of " "functions" " marked '" "value_simplify" "'")};; ++(NumIRFunction_value_simplify); } |
5669 | } |
5670 | }; |
5671 | |
5672 | struct AAValueSimplifyCallSite : AAValueSimplifyFunction { |
5673 | AAValueSimplifyCallSite(const IRPosition &IRP, Attributor &A) |
5674 | : AAValueSimplifyFunction(IRP, A) {} |
5675 | /// See AbstractAttribute::trackStatistics() |
5676 | void trackStatistics() const override { |
5677 | STATS_DECLTRACK_CS_ATTR(value_simplify){ static llvm::Statistic NumIRCS_value_simplify = {"attributor" , "NumIRCS_value_simplify", ("Number of " "call site" " marked '" "value_simplify" "'")};; ++(NumIRCS_value_simplify); } |
5678 | } |
5679 | }; |
5680 | |
5681 | struct AAValueSimplifyCallSiteReturned : AAValueSimplifyImpl { |
5682 | AAValueSimplifyCallSiteReturned(const IRPosition &IRP, Attributor &A) |
5683 | : AAValueSimplifyImpl(IRP, A) {} |
5684 | |
5685 | void initialize(Attributor &A) override { |
5686 | AAValueSimplifyImpl::initialize(A); |
5687 | if (!getAssociatedFunction()) |
5688 | indicatePessimisticFixpoint(); |
5689 | } |
5690 | |
5691 | /// See AbstractAttribute::updateImpl(...). |
5692 | ChangeStatus updateImpl(Attributor &A) override { |
5693 | auto Before = SimplifiedAssociatedValue; |
5694 | auto &RetAA = A.getAAFor<AAReturnedValues>( |
5695 | *this, IRPosition::function(*getAssociatedFunction()), |
5696 | DepClassTy::REQUIRED); |
5697 | auto PredForReturned = |
5698 | [&](Value &RetVal, const SmallSetVector<ReturnInst *, 4> &RetInsts) { |
5699 | bool UsedAssumedInformation = false; |
5700 | Optional<Value *> CSRetVal = A.translateArgumentToCallSiteContent( |
5701 | &RetVal, *cast<CallBase>(getCtxI()), *this, |
5702 | UsedAssumedInformation); |
5703 | SimplifiedAssociatedValue = AA::combineOptionalValuesInAAValueLatice( |
5704 | SimplifiedAssociatedValue, CSRetVal, getAssociatedType()); |
5705 | return SimplifiedAssociatedValue != Optional<Value *>(nullptr); |
5706 | }; |
5707 | if (!RetAA.checkForAllReturnedValuesAndReturnInsts(PredForReturned)) |
5708 | if (!askSimplifiedValueForOtherAAs(A)) |
5709 | return indicatePessimisticFixpoint(); |
5710 | return Before == SimplifiedAssociatedValue ? ChangeStatus::UNCHANGED |
5711 | : ChangeStatus ::CHANGED; |
5712 | } |
5713 | |
5714 | void trackStatistics() const override { |
5715 | STATS_DECLTRACK_CSRET_ATTR(value_simplify){ static llvm::Statistic NumIRCSReturn_value_simplify = {"attributor" , "NumIRCSReturn_value_simplify", ("Number of " "call site returns" " marked '" "value_simplify" "'")};; ++(NumIRCSReturn_value_simplify ); } |
5716 | } |
5717 | }; |
5718 | |
5719 | struct AAValueSimplifyCallSiteArgument : AAValueSimplifyFloating { |
5720 | AAValueSimplifyCallSiteArgument(const IRPosition &IRP, Attributor &A) |
5721 | : AAValueSimplifyFloating(IRP, A) {} |
5722 | |
5723 | /// See AbstractAttribute::manifest(...). |
5724 | ChangeStatus manifest(Attributor &A) override { |
5725 | ChangeStatus Changed = ChangeStatus::UNCHANGED; |
5726 | |
5727 | if (auto *NewV = getReplacementValue(A)) { |
5728 | Use &U = cast<CallBase>(&getAnchorValue()) |
5729 | ->getArgOperandUse(getCallSiteArgNo()); |
5730 | if (A.changeUseAfterManifest(U, *NewV)) |
5731 | Changed = ChangeStatus::CHANGED; |
5732 | } |
5733 | |
5734 | return Changed | AAValueSimplify::manifest(A); |
5735 | } |
5736 | |
5737 | void trackStatistics() const override { |
5738 | STATS_DECLTRACK_CSARG_ATTR(value_simplify){ static llvm::Statistic NumIRCSArguments_value_simplify = {"attributor" , "NumIRCSArguments_value_simplify", ("Number of " "call site arguments" " marked '" "value_simplify" "'")};; ++(NumIRCSArguments_value_simplify ); } |
5739 | } |
5740 | }; |
5741 | |
5742 | /// ----------------------- Heap-To-Stack Conversion --------------------------- |
5743 | struct AAHeapToStackFunction final : public AAHeapToStack { |
5744 | |
5745 | struct AllocationInfo { |
5746 | /// The call that allocates the memory. |
5747 | CallBase *const CB; |
5748 | |
5749 | /// The kind of allocation. |
5750 | const enum class AllocationKind { |
5751 | MALLOC, |
5752 | CALLOC, |
5753 | ALIGNED_ALLOC, |
5754 | } Kind; |
5755 | |
5756 | /// The library function id for the allocation. |
5757 | LibFunc LibraryFunctionId = NotLibFunc; |
5758 | |
5759 | /// The status wrt. a rewrite. |
5760 | enum { |
5761 | STACK_DUE_TO_USE, |
5762 | STACK_DUE_TO_FREE, |
5763 | INVALID, |
5764 | } Status = STACK_DUE_TO_USE; |
5765 | |
5766 | /// Flag to indicate if we encountered a use that might free this allocation |
5767 | /// but which is not in the deallocation infos. |
5768 | bool HasPotentiallyFreeingUnknownUses = false; |
5769 | |
5770 | /// The set of free calls that use this allocation. |
5771 | SmallPtrSet<CallBase *, 1> PotentialFreeCalls{}; |
5772 | }; |
5773 | |
5774 | struct DeallocationInfo { |
5775 | /// The call that deallocates the memory. |
5776 | CallBase *const CB; |
5777 | |
5778 | /// Flag to indicate if we don't know all objects this deallocation might |
5779 | /// free. |
5780 | bool MightFreeUnknownObjects = false; |
5781 | |
5782 | /// The set of allocation calls that are potentially freed. |
5783 | SmallPtrSet<CallBase *, 1> PotentialAllocationCalls{}; |
5784 | }; |
5785 | |
5786 | AAHeapToStackFunction(const IRPosition &IRP, Attributor &A) |
5787 | : AAHeapToStack(IRP, A) {} |
5788 | |
5789 | ~AAHeapToStackFunction() { |
5790 | // Ensure we call the destructor so we release any memory allocated in the |
5791 | // sets. |
5792 | for (auto &It : AllocationInfos) |
5793 | It.getSecond()->~AllocationInfo(); |
5794 | for (auto &It : DeallocationInfos) |
5795 | It.getSecond()->~DeallocationInfo(); |
5796 | } |
5797 | |
5798 | void initialize(Attributor &A) override { |
5799 | AAHeapToStack::initialize(A); |
5800 | |
5801 | const Function *F = getAnchorScope(); |
5802 | const auto *TLI = A.getInfoCache().getTargetLibraryInfoForFunction(*F); |
5803 | |
5804 | auto AllocationIdentifierCB = [&](Instruction &I) { |
5805 | CallBase *CB = dyn_cast<CallBase>(&I); |
5806 | if (!CB) |
5807 | return true; |
5808 | if (isFreeCall(CB, TLI)) { |
5809 | DeallocationInfos[CB] = new (A.Allocator) DeallocationInfo{CB}; |
5810 | return true; |
5811 | } |
5812 | bool IsMalloc = isMallocLikeFn(CB, TLI); |
5813 | bool IsAlignedAllocLike = !IsMalloc && isAlignedAllocLikeFn(CB, TLI); |
5814 | bool IsCalloc = |
5815 | !IsMalloc && !IsAlignedAllocLike && isCallocLikeFn(CB, TLI); |
5816 | if (!IsMalloc && !IsAlignedAllocLike && !IsCalloc) |
5817 | return true; |
5818 | auto Kind = |
5819 | IsMalloc ? AllocationInfo::AllocationKind::MALLOC |
5820 | : (IsCalloc ? AllocationInfo::AllocationKind::CALLOC |
5821 | : AllocationInfo::AllocationKind::ALIGNED_ALLOC); |
5822 | |
5823 | AllocationInfo *AI = new (A.Allocator) AllocationInfo{CB, Kind}; |
5824 | AllocationInfos[CB] = AI; |
5825 | TLI->getLibFunc(*CB, AI->LibraryFunctionId); |
5826 | return true; |
5827 | }; |
5828 | |
5829 | bool UsedAssumedInformation = false; |
5830 | bool Success = A.checkForAllCallLikeInstructions( |
5831 | AllocationIdentifierCB, *this, UsedAssumedInformation, |
5832 | /* CheckBBLivenessOnly */ false, |
5833 | /* CheckPotentiallyDead */ true); |
5834 | (void)Success; |
5835 | assert(Success && "Did not expect the call base visit callback to fail!")((void)0); |
5836 | } |
5837 | |
5838 | const std::string getAsStr() const override { |
5839 | unsigned NumH2SMallocs = 0, NumInvalidMallocs = 0; |
5840 | for (const auto &It : AllocationInfos) { |
5841 | if (It.second->Status == AllocationInfo::INVALID) |
5842 | ++NumInvalidMallocs; |
5843 | else |
5844 | ++NumH2SMallocs; |
5845 | } |
5846 | return "[H2S] Mallocs Good/Bad: " + std::to_string(NumH2SMallocs) + "/" + |
5847 | std::to_string(NumInvalidMallocs); |
5848 | } |
5849 | |
5850 | /// See AbstractAttribute::trackStatistics(). |
5851 | void trackStatistics() const override { |
5852 | STATS_DECL(static llvm::Statistic NumIRFunction_MallocCalls = {"attributor" , "NumIRFunction_MallocCalls", "Number of malloc/calloc/aligned_alloc calls converted to allocas" };; |
5853 | MallocCalls, Function,static llvm::Statistic NumIRFunction_MallocCalls = {"attributor" , "NumIRFunction_MallocCalls", "Number of malloc/calloc/aligned_alloc calls converted to allocas" };; |
5854 | "Number of malloc/calloc/aligned_alloc calls converted to allocas")static llvm::Statistic NumIRFunction_MallocCalls = {"attributor" , "NumIRFunction_MallocCalls", "Number of malloc/calloc/aligned_alloc calls converted to allocas" };;; |
5855 | for (auto &It : AllocationInfos) |
5856 | if (It.second->Status != AllocationInfo::INVALID) |
5857 | ++BUILD_STAT_NAME(MallocCalls, Function)NumIRFunction_MallocCalls; |
5858 | } |
5859 | |
5860 | bool isAssumedHeapToStack(const CallBase &CB) const override { |
5861 | if (isValidState()) |
5862 | if (AllocationInfo *AI = AllocationInfos.lookup(&CB)) |
5863 | return AI->Status != AllocationInfo::INVALID; |
5864 | return false; |
5865 | } |
5866 | |
5867 | bool isAssumedHeapToStackRemovedFree(CallBase &CB) const override { |
5868 | if (!isValidState()) |
5869 | return false; |
5870 | |
5871 | for (auto &It : AllocationInfos) { |
5872 | AllocationInfo &AI = *It.second; |
5873 | if (AI.Status == AllocationInfo::INVALID) |
5874 | continue; |
5875 | |
5876 | if (AI.PotentialFreeCalls.count(&CB)) |
5877 | return true; |
5878 | } |
5879 | |
5880 | return false; |
5881 | } |
5882 | |
5883 | ChangeStatus manifest(Attributor &A) override { |
5884 | assert(getState().isValidState() &&((void)0) |
5885 | "Attempted to manifest an invalid state!")((void)0); |
5886 | |
5887 | ChangeStatus HasChanged = ChangeStatus::UNCHANGED; |
5888 | Function *F = getAnchorScope(); |
5889 | const auto *TLI = A.getInfoCache().getTargetLibraryInfoForFunction(*F); |
5890 | |
5891 | for (auto &It : AllocationInfos) { |
5892 | AllocationInfo &AI = *It.second; |
5893 | if (AI.Status == AllocationInfo::INVALID) |
5894 | continue; |
5895 | |
5896 | for (CallBase *FreeCall : AI.PotentialFreeCalls) { |
5897 | LLVM_DEBUG(dbgs() << "H2S: Removing free call: " << *FreeCall << "\n")do { } while (false); |
5898 | A.deleteAfterManifest(*FreeCall); |
5899 | HasChanged = ChangeStatus::CHANGED; |
Value stored to 'HasChanged' is never read | |
5900 | } |
5901 | |
5902 | LLVM_DEBUG(dbgs() << "H2S: Removing malloc-like call: " << *AI.CBdo { } while (false) |
5903 | << "\n")do { } while (false); |
5904 | |
5905 | auto Remark = [&](OptimizationRemark OR) { |
5906 | LibFunc IsAllocShared; |
5907 | if (TLI->getLibFunc(*AI.CB, IsAllocShared)) |
5908 | if (IsAllocShared == LibFunc___kmpc_alloc_shared) |
5909 | return OR << "Moving globalized variable to the stack."; |
5910 | return OR << "Moving memory allocation from the heap to the stack."; |
5911 | }; |
5912 | if (AI.LibraryFunctionId == LibFunc___kmpc_alloc_shared) |
5913 | A.emitRemark<OptimizationRemark>(AI.CB, "OMP110", Remark); |
5914 | else |
5915 | A.emitRemark<OptimizationRemark>(AI.CB, "HeapToStack", Remark); |
5916 | |
5917 | Value *Size; |
5918 | Optional<APInt> SizeAPI = getSize(A, *this, AI); |
5919 | if (SizeAPI.hasValue()) { |
5920 | Size = ConstantInt::get(AI.CB->getContext(), *SizeAPI); |
5921 | } else if (AI.Kind == AllocationInfo::AllocationKind::CALLOC) { |
5922 | auto *Num = AI.CB->getOperand(0); |
5923 | auto *SizeT = AI.CB->getOperand(1); |
5924 | IRBuilder<> B(AI.CB); |
5925 | Size = B.CreateMul(Num, SizeT, "h2s.calloc.size"); |
5926 | } else if (AI.Kind == AllocationInfo::AllocationKind::ALIGNED_ALLOC) { |
5927 | Size = AI.CB->getOperand(1); |
5928 | } else { |
5929 | Size = AI.CB->getOperand(0); |
5930 | } |
5931 | |
5932 | Align Alignment(1); |
5933 | if (AI.Kind == AllocationInfo::AllocationKind::ALIGNED_ALLOC) { |
5934 | Optional<APInt> AlignmentAPI = |
5935 | getAPInt(A, *this, *AI.CB->getArgOperand(0)); |
5936 | assert(AlignmentAPI.hasValue() &&((void)0) |
5937 | "Expected an alignment during manifest!")((void)0); |
5938 | Alignment = |
5939 | max(Alignment, MaybeAlign(AlignmentAPI.getValue().getZExtValue())); |
5940 | } |
5941 | |
5942 | unsigned AS = cast<PointerType>(AI.CB->getType())->getAddressSpace(); |
5943 | Instruction *Alloca = |
5944 | new AllocaInst(Type::getInt8Ty(F->getContext()), AS, Size, Alignment, |
5945 | "", AI.CB->getNextNode()); |
5946 | |
5947 | if (Alloca->getType() != AI.CB->getType()) |
5948 | Alloca = new BitCastInst(Alloca, AI.CB->getType(), "malloc_bc", |
5949 | Alloca->getNextNode()); |
5950 | |
5951 | A.changeValueAfterManifest(*AI.CB, *Alloca); |
5952 | |
5953 | if (auto *II = dyn_cast<InvokeInst>(AI.CB)) { |
5954 | auto *NBB = II->getNormalDest(); |
5955 | BranchInst::Create(NBB, AI.CB->getParent()); |
5956 | A.deleteAfterManifest(*AI.CB); |
5957 | } else { |
5958 | A.deleteAfterManifest(*AI.CB); |
5959 | } |
5960 | |
5961 | // Zero out the allocated memory if it was a calloc. |
5962 | if (AI.Kind == AllocationInfo::AllocationKind::CALLOC) { |
5963 | auto *BI = new BitCastInst(Alloca, AI.CB->getType(), "calloc_bc", |
5964 | Alloca->getNextNode()); |
5965 | Value *Ops[] = { |
5966 | BI, ConstantInt::get(F->getContext(), APInt(8, 0, false)), Size, |
5967 | ConstantInt::get(Type::getInt1Ty(F->getContext()), false)}; |
5968 | |
5969 | Type *Tys[] = {BI->getType(), AI.CB->getOperand(0)->getType()}; |
5970 | Module *M = F->getParent(); |
5971 | Function *Fn = Intrinsic::getDeclaration(M, Intrinsic::memset, Tys); |
5972 | CallInst::Create(Fn, Ops, "", BI->getNextNode()); |
5973 | } |
5974 | HasChanged = ChangeStatus::CHANGED; |
5975 | } |
5976 | |
5977 | return HasChanged; |
5978 | } |
5979 | |
5980 | Optional<APInt> getAPInt(Attributor &A, const AbstractAttribute &AA, |
5981 | Value &V) { |
5982 | bool UsedAssumedInformation = false; |
5983 | Optional<Constant *> SimpleV = |
5984 | A.getAssumedConstant(V, AA, UsedAssumedInformation); |
5985 | if (!SimpleV.hasValue()) |
5986 | return APInt(64, 0); |
5987 | if (auto *CI = dyn_cast_or_null<ConstantInt>(SimpleV.getValue())) |
5988 | return CI->getValue(); |
5989 | return llvm::None; |
5990 | } |
5991 | |
5992 | Optional<APInt> getSize(Attributor &A, const AbstractAttribute &AA, |
5993 | AllocationInfo &AI) { |
5994 | |
5995 | if (AI.Kind == AllocationInfo::AllocationKind::MALLOC) |
5996 | return getAPInt(A, AA, *AI.CB->getArgOperand(0)); |
5997 | |
5998 | if (AI.Kind == AllocationInfo::AllocationKind::ALIGNED_ALLOC) |
5999 | // Only if the alignment is also constant we return a size. |
6000 | return getAPInt(A, AA, *AI.CB->getArgOperand(0)).hasValue() |
6001 | ? getAPInt(A, AA, *AI.CB->getArgOperand(1)) |
6002 | : llvm::None; |
6003 | |
6004 | assert(AI.Kind == AllocationInfo::AllocationKind::CALLOC &&((void)0) |
6005 | "Expected only callocs are left")((void)0); |
6006 | Optional<APInt> Num = getAPInt(A, AA, *AI.CB->getArgOperand(0)); |
6007 | Optional<APInt> Size = getAPInt(A, AA, *AI.CB->getArgOperand(1)); |
6008 | if (!Num.hasValue() || !Size.hasValue()) |
6009 | return llvm::None; |
6010 | bool Overflow = false; |
6011 | Size = Size.getValue().umul_ov(Num.getValue(), Overflow); |
6012 | return Overflow ? llvm::None : Size; |
6013 | } |
6014 | |
6015 | /// Collection of all malloc-like calls in a function with associated |
6016 | /// information. |
6017 | DenseMap<CallBase *, AllocationInfo *> AllocationInfos; |
6018 | |
6019 | /// Collection of all free-like calls in a function with associated |
6020 | /// information. |
6021 | DenseMap<CallBase *, DeallocationInfo *> DeallocationInfos; |
6022 | |
6023 | ChangeStatus updateImpl(Attributor &A) override; |
6024 | }; |
6025 | |
6026 | ChangeStatus AAHeapToStackFunction::updateImpl(Attributor &A) { |
6027 | ChangeStatus Changed = ChangeStatus::UNCHANGED; |
6028 | const Function *F = getAnchorScope(); |
6029 | |
6030 | const auto &LivenessAA = |
6031 | A.getAAFor<AAIsDead>(*this, IRPosition::function(*F), DepClassTy::NONE); |
6032 | |
6033 | MustBeExecutedContextExplorer &Explorer = |
6034 | A.getInfoCache().getMustBeExecutedContextExplorer(); |
6035 | |
6036 | bool StackIsAccessibleByOtherThreads = |
6037 | A.getInfoCache().stackIsAccessibleByOtherThreads(); |
6038 | |
6039 | // Flag to ensure we update our deallocation information at most once per |
6040 | // updateImpl call and only if we use the free check reasoning. |
6041 | bool HasUpdatedFrees = false; |
6042 | |
6043 | auto UpdateFrees = [&]() { |
6044 | HasUpdatedFrees = true; |
6045 | |
6046 | for (auto &It : DeallocationInfos) { |
6047 | DeallocationInfo &DI = *It.second; |
6048 | // For now we cannot use deallocations that have unknown inputs, skip |
6049 | // them. |
6050 | if (DI.MightFreeUnknownObjects) |
6051 | continue; |
6052 | |
6053 | // No need to analyze dead calls, ignore them instead. |
6054 | bool UsedAssumedInformation = false; |
6055 | if (A.isAssumedDead(*DI.CB, this, &LivenessAA, UsedAssumedInformation, |
6056 | /* CheckBBLivenessOnly */ true)) |
6057 | continue; |
6058 | |
6059 | // Use the optimistic version to get the freed objects, ignoring dead |
6060 | // branches etc. |
6061 | SmallVector<Value *, 8> Objects; |
6062 | if (!AA::getAssumedUnderlyingObjects(A, *DI.CB->getArgOperand(0), Objects, |
6063 | *this, DI.CB)) { |
6064 | LLVM_DEBUG(do { } while (false) |
6065 | dbgs()do { } while (false) |
6066 | << "[H2S] Unexpected failure in getAssumedUnderlyingObjects!\n")do { } while (false); |
6067 | DI.MightFreeUnknownObjects = true; |
6068 | continue; |
6069 | } |
6070 | |
6071 | // Check each object explicitly. |
6072 | for (auto *Obj : Objects) { |
6073 | // Free of null and undef can be ignored as no-ops (or UB in the latter |
6074 | // case). |
6075 | if (isa<ConstantPointerNull>(Obj) || isa<UndefValue>(Obj)) |
6076 | continue; |
6077 | |
6078 | CallBase *ObjCB = dyn_cast<CallBase>(Obj); |
6079 | if (!ObjCB) { |
6080 | LLVM_DEBUG(dbgs()do { } while (false) |
6081 | << "[H2S] Free of a non-call object: " << *Obj << "\n")do { } while (false); |
6082 | DI.MightFreeUnknownObjects = true; |
6083 | continue; |
6084 | } |
6085 | |
6086 | AllocationInfo *AI = AllocationInfos.lookup(ObjCB); |
6087 | if (!AI) { |
6088 | LLVM_DEBUG(dbgs() << "[H2S] Free of a non-allocation object: " << *Objdo { } while (false) |
6089 | << "\n")do { } while (false); |
6090 | DI.MightFreeUnknownObjects = true; |
6091 | continue; |
6092 | } |
6093 | |
6094 | DI.PotentialAllocationCalls.insert(ObjCB); |
6095 | } |
6096 | } |
6097 | }; |
6098 | |
6099 | auto FreeCheck = [&](AllocationInfo &AI) { |
6100 | // If the stack is not accessible by other threads, the "must-free" logic |
6101 | // doesn't apply as the pointer could be shared and needs to be places in |
6102 | // "shareable" memory. |
6103 | if (!StackIsAccessibleByOtherThreads) { |
6104 | auto &NoSyncAA = |
6105 | A.getAAFor<AANoSync>(*this, getIRPosition(), DepClassTy::OPTIONAL); |
6106 | if (!NoSyncAA.isAssumedNoSync()) { |
6107 | LLVM_DEBUG(do { } while (false) |
6108 | dbgs() << "[H2S] found an escaping use, stack is not accessible by "do { } while (false) |
6109 | "other threads and function is not nosync:\n")do { } while (false); |
6110 | return false; |
6111 | } |
6112 | } |
6113 | if (!HasUpdatedFrees) |
6114 | UpdateFrees(); |
6115 | |
6116 | // TODO: Allow multi exit functions that have different free calls. |
6117 | if (AI.PotentialFreeCalls.size() != 1) { |
6118 | LLVM_DEBUG(dbgs() << "[H2S] did not find one free call but "do { } while (false) |
6119 | << AI.PotentialFreeCalls.size() << "\n")do { } while (false); |
6120 | return false; |
6121 | } |
6122 | CallBase *UniqueFree = *AI.PotentialFreeCalls.begin(); |
6123 | DeallocationInfo *DI = DeallocationInfos.lookup(UniqueFree); |
6124 | if (!DI) { |
6125 | LLVM_DEBUG(do { } while (false) |
6126 | dbgs() << "[H2S] unique free call was not known as deallocation call "do { } while (false) |
6127 | << *UniqueFree << "\n")do { } while (false); |
6128 | return false; |
6129 | } |
6130 | if (DI->MightFreeUnknownObjects) { |
6131 | LLVM_DEBUG(do { } while (false) |
6132 | dbgs() << "[H2S] unique free call might free unknown allocations\n")do { } while (false); |
6133 | return false; |
6134 | } |
6135 | if (DI->PotentialAllocationCalls.size() > 1) { |
6136 | LLVM_DEBUG(dbgs() << "[H2S] unique free call might free "do { } while (false) |
6137 | << DI->PotentialAllocationCalls.size()do { } while (false) |
6138 | << " different allocations\n")do { } while (false); |
6139 | return false; |
6140 | } |
6141 | if (*DI->PotentialAllocationCalls.begin() != AI.CB) { |
6142 | LLVM_DEBUG(do { } while (false) |
6143 | dbgs()do { } while (false) |
6144 | << "[H2S] unique free call not known to free this allocation but "do { } while (false) |
6145 | << **DI->PotentialAllocationCalls.begin() << "\n")do { } while (false); |
6146 | return false; |
6147 | } |
6148 | Instruction *CtxI = isa<InvokeInst>(AI.CB) ? AI.CB : AI.CB->getNextNode(); |
6149 | if (!Explorer.findInContextOf(UniqueFree, CtxI)) { |
6150 | LLVM_DEBUG(do { } while (false) |
6151 | dbgs()do { } while (false) |
6152 | << "[H2S] unique free call might not be executed with the allocation "do { } while (false) |
6153 | << *UniqueFree << "\n")do { } while (false); |
6154 | return false; |
6155 | } |
6156 | return true; |
6157 | }; |
6158 | |
6159 | auto UsesCheck = [&](AllocationInfo &AI) { |
6160 | bool ValidUsesOnly = true; |
6161 | |
6162 | auto Pred = [&](const Use &U, bool &Follow) -> bool { |
6163 | Instruction *UserI = cast<Instruction>(U.getUser()); |
6164 | if (isa<LoadInst>(UserI)) |
6165 | return true; |
6166 | if (auto *SI = dyn_cast<StoreInst>(UserI)) { |
6167 | if (SI->getValueOperand() == U.get()) { |
6168 | LLVM_DEBUG(dbgs()do { } while (false) |
6169 | << "[H2S] escaping store to memory: " << *UserI << "\n")do { } while (false); |
6170 | ValidUsesOnly = false; |
6171 | } else { |
6172 | // A store into the malloc'ed memory is fine. |
6173 | } |
6174 | return true; |
6175 | } |
6176 | if (auto *CB = dyn_cast<CallBase>(UserI)) { |
6177 | if (!CB->isArgOperand(&U) || CB->isLifetimeStartOrEnd()) |
6178 | return true; |
6179 | if (DeallocationInfos.count(CB)) { |
6180 | AI.PotentialFreeCalls.insert(CB); |
6181 | return true; |
6182 | } |
6183 | |
6184 | unsigned ArgNo = CB->getArgOperandNo(&U); |
6185 | |
6186 | const auto &NoCaptureAA = A.getAAFor<AANoCapture>( |
6187 | *this, IRPosition::callsite_argument(*CB, ArgNo), |
6188 | DepClassTy::OPTIONAL); |
6189 | |
6190 | // If a call site argument use is nofree, we are fine. |
6191 | const auto &ArgNoFreeAA = A.getAAFor<AANoFree>( |
6192 | *this, IRPosition::callsite_argument(*CB, ArgNo), |
6193 | DepClassTy::OPTIONAL); |
6194 | |
6195 | bool MaybeCaptured = !NoCaptureAA.isAssumedNoCapture(); |
6196 | bool MaybeFreed = !ArgNoFreeAA.isAssumedNoFree(); |
6197 | if (MaybeCaptured || |
6198 | (AI.LibraryFunctionId != LibFunc___kmpc_alloc_shared && |
6199 | MaybeFreed)) { |
6200 | AI.HasPotentiallyFreeingUnknownUses |= MaybeFreed; |
6201 | |
6202 | // Emit a missed remark if this is missed OpenMP globalization. |
6203 | auto Remark = [&](OptimizationRemarkMissed ORM) { |
6204 | return ORM |
6205 | << "Could not move globalized variable to the stack. " |
6206 | "Variable is potentially captured in call. Mark " |
6207 | "parameter as `__attribute__((noescape))` to override."; |
6208 | }; |
6209 | |
6210 | if (ValidUsesOnly && |
6211 | AI.LibraryFunctionId == LibFunc___kmpc_alloc_shared) |
6212 | A.emitRemark<OptimizationRemarkMissed>(AI.CB, "OMP113", Remark); |
6213 | |
6214 | LLVM_DEBUG(dbgs() << "[H2S] Bad user: " << *UserI << "\n")do { } while (false); |
6215 | ValidUsesOnly = false; |
6216 | } |
6217 | return true; |
6218 | } |
6219 | |
6220 | if (isa<GetElementPtrInst>(UserI) || isa<BitCastInst>(UserI) || |
6221 | isa<PHINode>(UserI) || isa<SelectInst>(UserI)) { |
6222 | Follow = true; |
6223 | return true; |
6224 | } |
6225 | // Unknown user for which we can not track uses further (in a way that |
6226 | // makes sense). |
6227 | LLVM_DEBUG(dbgs() << "[H2S] Unknown user: " << *UserI << "\n")do { } while (false); |
6228 | ValidUsesOnly = false; |
6229 | return true; |
6230 | }; |
6231 | if (!A.checkForAllUses(Pred, *this, *AI.CB)) |
6232 | return false; |
6233 | return ValidUsesOnly; |
6234 | }; |
6235 | |
6236 | // The actual update starts here. We look at all allocations and depending on |
6237 | // their status perform the appropriate check(s). |
6238 | for (auto &It : AllocationInfos) { |
6239 | AllocationInfo &AI = *It.second; |
6240 | if (AI.Status == AllocationInfo::INVALID) |
6241 | continue; |
6242 | |
6243 | if (MaxHeapToStackSize == -1) { |
6244 | if (AI.Kind == AllocationInfo::AllocationKind::ALIGNED_ALLOC) |
6245 | if (!getAPInt(A, *this, *AI.CB->getArgOperand(0)).hasValue()) { |
6246 | LLVM_DEBUG(dbgs() << "[H2S] Unknown allocation alignment: " << *AI.CBdo { } while (false) |
6247 | << "\n")do { } while (false); |
6248 | AI.Status = AllocationInfo::INVALID; |
6249 | Changed = ChangeStatus::CHANGED; |
6250 | continue; |
6251 | } |
6252 | } else { |
6253 | Optional<APInt> Size = getSize(A, *this, AI); |
6254 | if (!Size.hasValue() || Size.getValue().ugt(MaxHeapToStackSize)) { |
6255 | LLVM_DEBUG({do { } while (false) |
6256 | if (!Size.hasValue())do { } while (false) |
6257 | dbgs() << "[H2S] Unknown allocation size (or alignment): " << *AI.CBdo { } while (false) |
6258 | << "\n";do { } while (false) |
6259 | elsedo { } while (false) |
6260 | dbgs() << "[H2S] Allocation size too large: " << *AI.CB << " vs. "do { } while (false) |
6261 | << MaxHeapToStackSize << "\n";do { } while (false) |
6262 | })do { } while (false); |
6263 | |
6264 | AI.Status = AllocationInfo::INVALID; |
6265 | Changed = ChangeStatus::CHANGED; |
6266 | continue; |
6267 | } |
6268 | } |
6269 | |
6270 | switch (AI.Status) { |
6271 | case AllocationInfo::STACK_DUE_TO_USE: |
6272 | if (UsesCheck(AI)) |
6273 | continue; |
6274 | AI.Status = AllocationInfo::STACK_DUE_TO_FREE; |
6275 | LLVM_FALLTHROUGH[[gnu::fallthrough]]; |
6276 | case AllocationInfo::STACK_DUE_TO_FREE: |
6277 | if (FreeCheck(AI)) |
6278 | continue; |
6279 | AI.Status = AllocationInfo::INVALID; |
6280 | Changed = ChangeStatus::CHANGED; |
6281 | continue; |
6282 | case AllocationInfo::INVALID: |
6283 | llvm_unreachable("Invalid allocations should never reach this point!")__builtin_unreachable(); |
6284 | }; |
6285 | } |
6286 | |
6287 | return Changed; |
6288 | } |
6289 | |
6290 | /// ----------------------- Privatizable Pointers ------------------------------ |
6291 | struct AAPrivatizablePtrImpl : public AAPrivatizablePtr { |
6292 | AAPrivatizablePtrImpl(const IRPosition &IRP, Attributor &A) |
6293 | : AAPrivatizablePtr(IRP, A), PrivatizableType(llvm::None) {} |
6294 | |
6295 | ChangeStatus indicatePessimisticFixpoint() override { |
6296 | AAPrivatizablePtr::indicatePessimisticFixpoint(); |
6297 | PrivatizableType = nullptr; |
6298 | return ChangeStatus::CHANGED; |
6299 | } |
6300 | |
6301 | /// Identify the type we can chose for a private copy of the underlying |
6302 | /// argument. None means it is not clear yet, nullptr means there is none. |
6303 | virtual Optional<Type *> identifyPrivatizableType(Attributor &A) = 0; |
6304 | |
6305 | /// Return a privatizable type that encloses both T0 and T1. |
6306 | /// TODO: This is merely a stub for now as we should manage a mapping as well. |
6307 | Optional<Type *> combineTypes(Optional<Type *> T0, Optional<Type *> T1) { |
6308 | if (!T0.hasValue()) |
6309 | return T1; |
6310 | if (!T1.hasValue()) |
6311 | return T0; |
6312 | if (T0 == T1) |
6313 | return T0; |
6314 | return nullptr; |
6315 | } |
6316 | |
6317 | Optional<Type *> getPrivatizableType() const override { |
6318 | return PrivatizableType; |
6319 | } |
6320 | |
6321 | const std::string getAsStr() const override { |
6322 | return isAssumedPrivatizablePtr() ? "[priv]" : "[no-priv]"; |
6323 | } |
6324 | |
6325 | protected: |
6326 | Optional<Type *> PrivatizableType; |
6327 | }; |
6328 | |
6329 | // TODO: Do this for call site arguments (probably also other values) as well. |
6330 | |
6331 | struct AAPrivatizablePtrArgument final : public AAPrivatizablePtrImpl { |
6332 | AAPrivatizablePtrArgument(const IRPosition &IRP, Attributor &A) |
6333 | : AAPrivatizablePtrImpl(IRP, A) {} |
6334 | |
6335 | /// See AAPrivatizablePtrImpl::identifyPrivatizableType(...) |
6336 | Optional<Type *> identifyPrivatizableType(Attributor &A) override { |
6337 | // If this is a byval argument and we know all the call sites (so we can |
6338 | // rewrite them), there is no need to check them explicitly. |
6339 | bool AllCallSitesKnown; |
6340 | if (getIRPosition().hasAttr(Attribute::ByVal) && |
6341 | A.checkForAllCallSites([](AbstractCallSite ACS) { return true; }, *this, |
6342 | true, AllCallSitesKnown)) |
6343 | return getAssociatedValue().getType()->getPointerElementType(); |
6344 | |
6345 | Optional<Type *> Ty; |
6346 | unsigned ArgNo = getIRPosition().getCallSiteArgNo(); |
6347 | |
6348 | // Make sure the associated call site argument has the same type at all call |
6349 | // sites and it is an allocation we know is safe to privatize, for now that |
6350 | // means we only allow alloca instructions. |
6351 | // TODO: We can additionally analyze the accesses in the callee to create |
6352 | // the type from that information instead. That is a little more |
6353 | // involved and will be done in a follow up patch. |
6354 | auto CallSiteCheck = [&](AbstractCallSite ACS) { |
6355 | IRPosition ACSArgPos = IRPosition::callsite_argument(ACS, ArgNo); |
6356 | // Check if a coresponding argument was found or if it is one not |
6357 | // associated (which can happen for callback calls). |
6358 | if (ACSArgPos.getPositionKind() == IRPosition::IRP_INVALID) |
6359 | return false; |
6360 | |
6361 | // Check that all call sites agree on a type. |
6362 | auto &PrivCSArgAA = |
6363 | A.getAAFor<AAPrivatizablePtr>(*this, ACSArgPos, DepClassTy::REQUIRED); |
6364 | Optional<Type *> CSTy = PrivCSArgAA.getPrivatizableType(); |
6365 | |
6366 | LLVM_DEBUG({do { } while (false) |
6367 | dbgs() << "[AAPrivatizablePtr] ACSPos: " << ACSArgPos << ", CSTy: ";do { } while (false) |
6368 | if (CSTy.hasValue() && CSTy.getValue())do { } while (false) |
6369 | CSTy.getValue()->print(dbgs());do { } while (false) |
6370 | else if (CSTy.hasValue())do { } while (false) |
6371 | dbgs() << "<nullptr>";do { } while (false) |
6372 | elsedo { } while (false) |
6373 | dbgs() << "<none>";do { } while (false) |
6374 | })do { } while (false); |
6375 | |
6376 | Ty = combineTypes(Ty, CSTy); |
6377 | |
6378 | LLVM_DEBUG({do { } while (false) |
6379 | dbgs() << " : New Type: ";do { } while (false) |
6380 | if (Ty.hasValue() && Ty.getValue())do { } while (false) |
6381 | Ty.getValue()->print(dbgs());do { } while (false) |
6382 | else if (Ty.hasValue())do { } while (false) |
6383 | dbgs() << "<nullptr>";do { } while (false) |
6384 | elsedo { } while (false) |
6385 | dbgs() << "<none>";do { } while (false) |
6386 | dbgs() << "\n";do { } while (false) |
6387 | })do { } while (false); |
6388 | |
6389 | return !Ty.hasValue() || Ty.getValue(); |
6390 | }; |
6391 | |
6392 | if (!A.checkForAllCallSites(CallSiteCheck, *this, true, AllCallSitesKnown)) |
6393 | return nullptr; |
6394 | return Ty; |
6395 | } |
6396 | |
6397 | /// See AbstractAttribute::updateImpl(...). |
6398 | ChangeStatus updateImpl(Attributor &A) override { |
6399 | PrivatizableType = identifyPrivatizableType(A); |
6400 | if (!PrivatizableType.hasValue()) |
6401 | return ChangeStatus::UNCHANGED; |
6402 | if (!PrivatizableType.getValue()) |
6403 | return indicatePessimisticFixpoint(); |
6404 | |
6405 | // The dependence is optional so we don't give up once we give up on the |
6406 | // alignment. |
6407 | A.getAAFor<AAAlign>(*this, IRPosition::value(getAssociatedValue()), |
6408 | DepClassTy::OPTIONAL); |
6409 | |
6410 | // Avoid arguments with padding for now. |
6411 | if (!getIRPosition().hasAttr(Attribute::ByVal) && |
6412 | !ArgumentPromotionPass::isDenselyPacked(PrivatizableType.getValue(), |
6413 | A.getInfoCache().getDL())) { |
6414 | LLVM_DEBUG(dbgs() << "[AAPrivatizablePtr] Padding detected\n")do { } while (false); |
6415 | return indicatePessimisticFixpoint(); |
6416 | } |
6417 | |
6418 | // Verify callee and caller agree on how the promoted argument would be |
6419 | // passed. |
6420 | // TODO: The use of the ArgumentPromotion interface here is ugly, we need a |
6421 | // specialized form of TargetTransformInfo::areFunctionArgsABICompatible |
6422 | // which doesn't require the arguments ArgumentPromotion wanted to pass. |
6423 | Function &Fn = *getIRPosition().getAnchorScope(); |
6424 | SmallPtrSet<Argument *, 1> ArgsToPromote, Dummy; |
6425 | ArgsToPromote.insert(getAssociatedArgument()); |
6426 | const auto *TTI = |
6427 | A.getInfoCache().getAnalysisResultForFunction<TargetIRAnalysis>(Fn); |
6428 | if (!TTI || |
6429 | !ArgumentPromotionPass::areFunctionArgsABICompatible( |
6430 | Fn, *TTI, ArgsToPromote, Dummy) || |
6431 | ArgsToPromote.empty()) { |
6432 | LLVM_DEBUG(do { } while (false) |
6433 | dbgs() << "[AAPrivatizablePtr] ABI incompatibility detected for "do { } while (false) |
6434 | << Fn.getName() << "\n")do { } while (false); |
6435 | return indicatePessimisticFixpoint(); |
6436 | } |
6437 | |
6438 | // Collect the types that will replace the privatizable type in the function |
6439 | // signature. |
6440 | SmallVector<Type *, 16> ReplacementTypes; |
6441 | identifyReplacementTypes(PrivatizableType.getValue(), ReplacementTypes); |
6442 | |
6443 | // Register a rewrite of the argument. |
6444 | Argument *Arg = getAssociatedArgument(); |
6445 | if (!A.isValidFunctionSignatureRewrite(*Arg, ReplacementTypes)) { |
6446 | LLVM_DEBUG(dbgs() << "[AAPrivatizablePtr] Rewrite not valid\n")do { } while (false); |
6447 | return indicatePessimisticFixpoint(); |
6448 | } |
6449 | |
6450 | unsigned ArgNo = Arg->getArgNo(); |
6451 | |
6452 | // Helper to check if for the given call site the associated argument is |
6453 | // passed to a callback where the privatization would be different. |
6454 | auto IsCompatiblePrivArgOfCallback = [&](CallBase &CB) { |
6455 | SmallVector<const Use *, 4> CallbackUses; |
6456 | AbstractCallSite::getCallbackUses(CB, CallbackUses); |
6457 | for (const Use *U : CallbackUses) { |
6458 | AbstractCallSite CBACS(U); |
6459 | assert(CBACS && CBACS.isCallbackCall())((void)0); |
6460 | for (Argument &CBArg : CBACS.getCalledFunction()->args()) { |
6461 | int CBArgNo = CBACS.getCallArgOperandNo(CBArg); |
6462 | |
6463 | LLVM_DEBUG({do { } while (false) |
6464 | dbgs()do { } while (false) |
6465 | << "[AAPrivatizablePtr] Argument " << *Argdo { } while (false) |
6466 | << "check if can be privatized in the context of its parent ("do { } while (false) |
6467 | << Arg->getParent()->getName()do { } while (false) |
6468 | << ")\n[AAPrivatizablePtr] because it is an argument in a "do { } while (false) |
6469 | "callback ("do { } while (false) |
6470 | << CBArgNo << "@" << CBACS.getCalledFunction()->getName()do { } while (false) |
6471 | << ")\n[AAPrivatizablePtr] " << CBArg << " : "do { } while (false) |
6472 | << CBACS.getCallArgOperand(CBArg) << " vs "do { } while (false) |
6473 | << CB.getArgOperand(ArgNo) << "\n"do { } while (false) |
6474 | << "[AAPrivatizablePtr] " << CBArg << " : "do { } while (false) |
6475 | << CBACS.getCallArgOperandNo(CBArg) << " vs " << ArgNo << "\n";do { } while (false) |
6476 | })do { } while (false); |
6477 | |
6478 | if (CBArgNo != int(ArgNo)) |
6479 | continue; |
6480 | const auto &CBArgPrivAA = A.getAAFor<AAPrivatizablePtr>( |
6481 | *this, IRPosition::argument(CBArg), DepClassTy::REQUIRED); |
6482 | if (CBArgPrivAA.isValidState()) { |
6483 | auto CBArgPrivTy = CBArgPrivAA.getPrivatizableType(); |
6484 | if (!CBArgPrivTy.hasValue()) |
6485 | continue; |
6486 | if (CBArgPrivTy.getValue() == PrivatizableType) |
6487 | continue; |
6488 | } |
6489 | |
6490 | LLVM_DEBUG({do { } while (false) |
6491 | dbgs() << "[AAPrivatizablePtr] Argument " << *Argdo { } while (false) |
6492 | << " cannot be privatized in the context of its parent ("do { } while (false) |
6493 | << Arg->getParent()->getName()do { } while (false) |
6494 | << ")\n[AAPrivatizablePtr] because it is an argument in a "do { } while (false) |
6495 | "callback ("do { } while (false) |
6496 | << CBArgNo << "@" << CBACS.getCalledFunction()->getName()do { } while (false) |
6497 | << ").\n[AAPrivatizablePtr] for which the argument "do { } while (false) |
6498 | "privatization is not compatible.\n";do { } while (false) |
6499 | })do { } while (false); |
6500 | return false; |
6501 | } |
6502 | } |
6503 | return true; |
6504 | }; |
6505 | |
6506 | // Helper to check if for the given call site the associated argument is |
6507 | // passed to a direct call where the privatization would be different. |
6508 | auto IsCompatiblePrivArgOfDirectCS = [&](AbstractCallSite ACS) { |
6509 | CallBase *DC = cast<CallBase>(ACS.getInstruction()); |
6510 | int DCArgNo = ACS.getCallArgOperandNo(ArgNo); |
6511 | assert(DCArgNo >= 0 && unsigned(DCArgNo) < DC->getNumArgOperands() &&((void)0) |
6512 | "Expected a direct call operand for callback call operand")((void)0); |
6513 | |
6514 | LLVM_DEBUG({do { } while (false) |
6515 | dbgs() << "[AAPrivatizablePtr] Argument " << *Argdo { } while (false) |
6516 | << " check if be privatized in the context of its parent ("do { } while (false) |
6517 | << Arg->getParent()->getName()do { } while (false) |
6518 | << ")\n[AAPrivatizablePtr] because it is an argument in a "do { } while (false) |
6519 | "direct call of ("do { } while (false) |
6520 | << DCArgNo << "@" << DC->getCalledFunction()->getName()do { } while (false) |
6521 | << ").\n";do { } while (false) |
6522 | })do { } while (false); |
6523 | |
6524 | Function *DCCallee = DC->getCalledFunction(); |
6525 | if (unsigned(DCArgNo) < DCCallee->arg_size()) { |
6526 | const auto &DCArgPrivAA = A.getAAFor<AAPrivatizablePtr>( |
6527 | *this, IRPosition::argument(*DCCallee->getArg(DCArgNo)), |
6528 | DepClassTy::REQUIRED); |
6529 | if (DCArgPrivAA.isValidState()) { |
6530 | auto DCArgPrivTy = DCArgPrivAA.getPrivatizableType(); |
6531 | if (!DCArgPrivTy.hasValue()) |
6532 | return true; |
6533 | if (DCArgPrivTy.getValue() == PrivatizableType) |
6534 | return true; |
6535 | } |
6536 | } |
6537 | |
6538 | LLVM_DEBUG({do { } while (false) |
6539 | dbgs() << "[AAPrivatizablePtr] Argument " << *Argdo { } while (false) |
6540 | << " cannot be privatized in the context of its parent ("do { } while (false) |
6541 | << Arg->getParent()->getName()do { } while (false) |
6542 | << ")\n[AAPrivatizablePtr] because it is an argument in a "do { } while (false) |
6543 | "direct call of ("do { } while (false) |
6544 | << ACS.getInstruction()->getCalledFunction()->getName()do { } while (false) |
6545 | << ").\n[AAPrivatizablePtr] for which the argument "do { } while (false) |
6546 | "privatization is not compatible.\n";do { } while (false) |
6547 | })do { } while (false); |
6548 | return false; |
6549 | }; |
6550 | |
6551 | // Helper to check if the associated argument is used at the given abstract |
6552 | // call site in a way that is incompatible with the privatization assumed |
6553 | // here. |
6554 | auto IsCompatiblePrivArgOfOtherCallSite = [&](AbstractCallSite ACS) { |
6555 | if (ACS.isDirectCall()) |
6556 | return IsCompatiblePrivArgOfCallback(*ACS.getInstruction()); |
6557 | if (ACS.isCallbackCall()) |
6558 | return IsCompatiblePrivArgOfDirectCS(ACS); |
6559 | return false; |
6560 | }; |
6561 | |
6562 | bool AllCallSitesKnown; |
6563 | if (!A.checkForAllCallSites(IsCompatiblePrivArgOfOtherCallSite, *this, true, |
6564 | AllCallSitesKnown)) |
6565 | return indicatePessimisticFixpoint(); |
6566 | |
6567 | return ChangeStatus::UNCHANGED; |
6568 | } |
6569 | |
6570 | /// Given a type to private \p PrivType, collect the constituates (which are |
6571 | /// used) in \p ReplacementTypes. |
6572 | static void |
6573 | identifyReplacementTypes(Type *PrivType, |
6574 | SmallVectorImpl<Type *> &ReplacementTypes) { |
6575 | // TODO: For now we expand the privatization type to the fullest which can |
6576 | // lead to dead arguments that need to be removed later. |
6577 | assert(PrivType && "Expected privatizable type!")((void)0); |
6578 | |
6579 | // Traverse the type, extract constituate types on the outermost level. |
6580 | if (auto *PrivStructType = dyn_cast<StructType>(PrivType)) { |
6581 | for (unsigned u = 0, e = PrivStructType->getNumElements(); u < e; u++) |
6582 | ReplacementTypes.push_back(PrivStructType->getElementType(u)); |
6583 | } else if (auto *PrivArrayType = dyn_cast<ArrayType>(PrivType)) { |
6584 | ReplacementTypes.append(PrivArrayType->getNumElements(), |
6585 | PrivArrayType->getElementType()); |
6586 | } else { |
6587 | ReplacementTypes.push_back(PrivType); |
6588 | } |
6589 | } |
6590 | |
6591 | /// Initialize \p Base according to the type \p PrivType at position \p IP. |
6592 | /// The values needed are taken from the arguments of \p F starting at |
6593 | /// position \p ArgNo. |
6594 | static void createInitialization(Type *PrivType, Value &Base, Function &F, |
6595 | unsigned ArgNo, Instruction &IP) { |
6596 | assert(PrivType && "Expected privatizable type!")((void)0); |
6597 | |
6598 | IRBuilder<NoFolder> IRB(&IP); |
6599 | const DataLayout &DL = F.getParent()->getDataLayout(); |
6600 | |
6601 | // Traverse the type, build GEPs and stores. |
6602 | if (auto *PrivStructType = dyn_cast<StructType>(PrivType)) { |
6603 | const StructLayout *PrivStructLayout = DL.getStructLayout(PrivStructType); |
6604 | for (unsigned u = 0, e = PrivStructType->getNumElements(); u < e; u++) { |
6605 | Type *PointeeTy = PrivStructType->getElementType(u)->getPointerTo(); |
6606 | Value *Ptr = |
6607 | constructPointer(PointeeTy, PrivType, &Base, |
6608 | PrivStructLayout->getElementOffset(u), IRB, DL); |
6609 | new StoreInst(F.getArg(ArgNo + u), Ptr, &IP); |
6610 | } |
6611 | } else if (auto *PrivArrayType = dyn_cast<ArrayType>(PrivType)) { |
6612 | Type *PointeeTy = PrivArrayType->getElementType(); |
6613 | Type *PointeePtrTy = PointeeTy->getPointerTo(); |
6614 | uint64_t PointeeTySize = DL.getTypeStoreSize(PointeeTy); |
6615 | for (unsigned u = 0, e = PrivArrayType->getNumElements(); u < e; u++) { |
6616 | Value *Ptr = constructPointer(PointeePtrTy, PrivType, &Base, |
6617 | u * PointeeTySize, IRB, DL); |
6618 | new StoreInst(F.getArg(ArgNo + u), Ptr, &IP); |
6619 | } |
6620 | } else { |
6621 | new StoreInst(F.getArg(ArgNo), &Base, &IP); |
6622 | } |
6623 | } |
6624 | |
6625 | /// Extract values from \p Base according to the type \p PrivType at the |
6626 | /// call position \p ACS. The values are appended to \p ReplacementValues. |
6627 | void createReplacementValues(Align Alignment, Type *PrivType, |
6628 | AbstractCallSite ACS, Value *Base, |
6629 | SmallVectorImpl<Value *> &ReplacementValues) { |
6630 | assert(Base && "Expected base value!")((void)0); |
6631 | assert(PrivType && "Expected privatizable type!")((void)0); |
6632 | Instruction *IP = ACS.getInstruction(); |
6633 | |
6634 | IRBuilder<NoFolder> IRB(IP); |
6635 | const DataLayout &DL = IP->getModule()->getDataLayout(); |
6636 | |
6637 | if (Base->getType()->getPointerElementType() != PrivType) |
6638 | Base = BitCastInst::CreateBitOrPointerCast(Base, PrivType->getPointerTo(), |
6639 | "", ACS.getInstruction()); |
6640 | |
6641 | // Traverse the type, build GEPs and loads. |
6642 | if (auto *PrivStructType = dyn_cast<StructType>(PrivType)) { |
6643 | const StructLayout *PrivStructLayout = DL.getStructLayout(PrivStructType); |
6644 | for (unsigned u = 0, e = PrivStructType->getNumElements(); u < e; u++) { |
6645 | Type *PointeeTy = PrivStructType->getElementType(u); |
6646 | Value *Ptr = |
6647 | constructPointer(PointeeTy->getPointerTo(), PrivType, Base, |
6648 | PrivStructLayout->getElementOffset(u), IRB, DL); |
6649 | LoadInst *L = new LoadInst(PointeeTy, Ptr, "", IP); |
6650 | L->setAlignment(Alignment); |
6651 | ReplacementValues.push_back(L); |
6652 | } |
6653 | } else if (auto *PrivArrayType = dyn_cast<ArrayType>(PrivType)) { |
6654 | Type *PointeeTy = PrivArrayType->getElementType(); |
6655 | uint64_t PointeeTySize = DL.getTypeStoreSize(PointeeTy); |
6656 | Type *PointeePtrTy = PointeeTy->getPointerTo(); |
6657 | for (unsigned u = 0, e = PrivArrayType->getNumElements(); u < e; u++) { |
6658 | Value *Ptr = constructPointer(PointeePtrTy, PrivType, Base, |
6659 | u * PointeeTySize, IRB, DL); |
6660 | LoadInst *L = new LoadInst(PointeeTy, Ptr, "", IP); |
6661 | L->setAlignment(Alignment); |
6662 | ReplacementValues.push_back(L); |
6663 | } |
6664 | } else { |
6665 | LoadInst *L = new LoadInst(PrivType, Base, "", IP); |
6666 | L->setAlignment(Alignment); |
6667 | ReplacementValues.push_back(L); |
6668 | } |
6669 | } |
6670 | |
6671 | /// See AbstractAttribute::manifest(...) |
6672 | ChangeStatus manifest(Attributor &A) override { |
6673 | if (!PrivatizableType.hasValue()) |
6674 | return ChangeStatus::UNCHANGED; |
6675 | assert(PrivatizableType.getValue() && "Expected privatizable type!")((void)0); |
6676 | |
6677 | // Collect all tail calls in the function as we cannot allow new allocas to |
6678 | // escape into tail recursion. |
6679 | // TODO: Be smarter about new allocas escaping into tail calls. |
6680 | SmallVector<CallInst *, 16> TailCalls; |
6681 | bool UsedAssumedInformation = false; |
6682 | if (!A.checkForAllInstructions( |
6683 | [&](Instruction &I) { |
6684 | CallInst &CI = cast<CallInst>(I); |
6685 | if (CI.isTailCall()) |
6686 | TailCalls.push_back(&CI); |
6687 | return true; |
6688 | }, |
6689 | *this, {Instruction::Call}, UsedAssumedInformation)) |
6690 | return ChangeStatus::UNCHANGED; |
6691 | |
6692 | Argument *Arg = getAssociatedArgument(); |
6693 | // Query AAAlign attribute for alignment of associated argument to |
6694 | // determine the best alignment of loads. |
6695 | const auto &AlignAA = |
6696 | A.getAAFor<AAAlign>(*this, IRPosition::value(*Arg), DepClassTy::NONE); |
6697 | |
6698 | // Callback to repair the associated function. A new alloca is placed at the |
6699 | // beginning and initialized with the values passed through arguments. The |
6700 | // new alloca replaces the use of the old pointer argument. |
6701 | Attributor::ArgumentReplacementInfo::CalleeRepairCBTy FnRepairCB = |
6702 | [=](const Attributor::ArgumentReplacementInfo &ARI, |
6703 | Function &ReplacementFn, Function::arg_iterator ArgIt) { |
6704 | BasicBlock &EntryBB = ReplacementFn.getEntryBlock(); |
6705 | Instruction *IP = &*EntryBB.getFirstInsertionPt(); |
6706 | Instruction *AI = new AllocaInst(PrivatizableType.getValue(), 0, |
6707 | Arg->getName() + ".priv", IP); |
6708 | createInitialization(PrivatizableType.getValue(), *AI, ReplacementFn, |
6709 | ArgIt->getArgNo(), *IP); |
6710 | |
6711 | if (AI->getType() != Arg->getType()) |
6712 | AI = |
6713 | BitCastInst::CreateBitOrPointerCast(AI, Arg->getType(), "", IP); |
6714 | Arg->replaceAllUsesWith(AI); |
6715 | |
6716 | for (CallInst *CI : TailCalls) |
6717 | CI->setTailCall(false); |
6718 | }; |
6719 | |
6720 | // Callback to repair a call site of the associated function. The elements |
6721 | // of the privatizable type are loaded prior to the call and passed to the |
6722 | // new function version. |
6723 | Attributor::ArgumentReplacementInfo::ACSRepairCBTy ACSRepairCB = |
6724 | [=, &AlignAA](const Attributor::ArgumentReplacementInfo &ARI, |
6725 | AbstractCallSite ACS, |
6726 | SmallVectorImpl<Value *> &NewArgOperands) { |
6727 | // When no alignment is specified for the load instruction, |
6728 | // natural alignment is assumed. |
6729 | createReplacementValues( |
6730 | assumeAligned(AlignAA.getAssumedAlign()), |
6731 | PrivatizableType.getValue(), ACS, |
6732 | ACS.getCallArgOperand(ARI.getReplacedArg().getArgNo()), |
6733 | NewArgOperands); |
6734 | }; |
6735 | |
6736 | // Collect the types that will replace the privatizable type in the function |
6737 | // signature. |
6738 | SmallVector<Type *, 16> ReplacementTypes; |
6739 | identifyReplacementTypes(PrivatizableType.getValue(), ReplacementTypes); |
6740 | |
6741 | // Register a rewrite of the argument. |
6742 | if (A.registerFunctionSignatureRewrite(*Arg, ReplacementTypes, |
6743 | std::move(FnRepairCB), |
6744 | std::move(ACSRepairCB))) |
6745 | return ChangeStatus::CHANGED; |
6746 | return ChangeStatus::UNCHANGED; |
6747 | } |
6748 | |
6749 | /// See AbstractAttribute::trackStatistics() |
6750 | void trackStatistics() const override { |
6751 | STATS_DECLTRACK_ARG_ATTR(privatizable_ptr){ static llvm::Statistic NumIRArguments_privatizable_ptr = {"attributor" , "NumIRArguments_privatizable_ptr", ("Number of " "arguments" " marked '" "privatizable_ptr" "'")};; ++(NumIRArguments_privatizable_ptr ); }; |
6752 | } |
6753 | }; |
6754 | |
6755 | struct AAPrivatizablePtrFloating : public AAPrivatizablePtrImpl { |
6756 | AAPrivatizablePtrFloating(const IRPosition &IRP, Attributor &A) |
6757 | : AAPrivatizablePtrImpl(IRP, A) {} |
6758 | |
6759 | /// See AbstractAttribute::initialize(...). |
6760 | virtual void initialize(Attributor &A) override { |
6761 | // TODO: We can privatize more than arguments. |
6762 | indicatePessimisticFixpoint(); |
6763 | } |
6764 | |
6765 | ChangeStatus updateImpl(Attributor &A) override { |
6766 | llvm_unreachable("AAPrivatizablePtr(Floating|Returned|CallSiteReturned)::"__builtin_unreachable() |
6767 | "updateImpl will not be called")__builtin_unreachable(); |
6768 | } |
6769 | |
6770 | /// See AAPrivatizablePtrImpl::identifyPrivatizableType(...) |
6771 | Optional<Type *> identifyPrivatizableType(Attributor &A) override { |
6772 | Value *Obj = getUnderlyingObject(&getAssociatedValue()); |
6773 | if (!Obj) { |
6774 | LLVM_DEBUG(dbgs() << "[AAPrivatizablePtr] No underlying object found!\n")do { } while (false); |
6775 | return nullptr; |
6776 | } |
6777 | |
6778 | if (auto *AI = dyn_cast<AllocaInst>(Obj)) |
6779 | if (auto *CI = dyn_cast<ConstantInt>(AI->getArraySize())) |
6780 | if (CI->isOne()) |
6781 | return Obj->getType()->getPointerElementType(); |
6782 | if (auto *Arg = dyn_cast<Argument>(Obj)) { |
6783 | auto &PrivArgAA = A.getAAFor<AAPrivatizablePtr>( |
6784 | *this, IRPosition::argument(*Arg), DepClassTy::REQUIRED); |
6785 | if (PrivArgAA.isAssumedPrivatizablePtr()) |
6786 | return Obj->getType()->getPointerElementType(); |
6787 | } |
6788 | |
6789 | LLVM_DEBUG(dbgs() << "[AAPrivatizablePtr] Underlying object neither valid "do { } while (false) |
6790 | "alloca nor privatizable argument: "do { } while (false) |
6791 | << *Obj << "!\n")do { } while (false); |
6792 | return nullptr; |
6793 | } |
6794 | |
6795 | /// See AbstractAttribute::trackStatistics() |
6796 | void trackStatistics() const override { |
6797 | STATS_DECLTRACK_FLOATING_ATTR(privatizable_ptr){ static llvm::Statistic NumIRFloating_privatizable_ptr = {"attributor" , "NumIRFloating_privatizable_ptr", ("Number of floating values known to be '" "privatizable_ptr" "'")};; ++(NumIRFloating_privatizable_ptr ); }; |
6798 | } |
6799 | }; |
6800 | |
6801 | struct AAPrivatizablePtrCallSiteArgument final |
6802 | : public AAPrivatizablePtrFloating { |
6803 | AAPrivatizablePtrCallSiteArgument(const IRPosition &IRP, Attributor &A) |
6804 | : AAPrivatizablePtrFloating(IRP, A) {} |
6805 | |
6806 | /// See AbstractAttribute::initialize(...). |
6807 | void initialize(Attributor &A) override { |
6808 | if (getIRPosition().hasAttr(Attribute::ByVal)) |
6809 | indicateOptimisticFixpoint(); |
6810 | } |
6811 | |
6812 | /// See AbstractAttribute::updateImpl(...). |
6813 | ChangeStatus updateImpl(Attributor &A) override { |
6814 | PrivatizableType = identifyPrivatizableType(A); |
6815 | if (!PrivatizableType.hasValue()) |
6816 | return ChangeStatus::UNCHANGED; |
6817 | if (!PrivatizableType.getValue()) |
6818 | return indicatePessimisticFixpoint(); |
6819 | |
6820 | const IRPosition &IRP = getIRPosition(); |
6821 | auto &NoCaptureAA = |
6822 | A.getAAFor<AANoCapture>(*this, IRP, DepClassTy::REQUIRED); |
6823 | if (!NoCaptureAA.isAssumedNoCapture()) { |
6824 | LLVM_DEBUG(dbgs() << "[AAPrivatizablePtr] pointer might be captured!\n")do { } while (false); |
6825 | return indicatePessimisticFixpoint(); |
6826 | } |
6827 | |
6828 | auto &NoAliasAA = A.getAAFor<AANoAlias>(*this, IRP, DepClassTy::REQUIRED); |
6829 | if (!NoAliasAA.isAssumedNoAlias()) { |
6830 | LLVM_DEBUG(dbgs() << "[AAPrivatizablePtr] pointer might alias!\n")do { } while (false); |
6831 | return indicatePessimisticFixpoint(); |
6832 | } |
6833 | |
6834 | const auto &MemBehaviorAA = |
6835 | A.getAAFor<AAMemoryBehavior>(*this, IRP, DepClassTy::REQUIRED); |
6836 | if (!MemBehaviorAA.isAssumedReadOnly()) { |
6837 | LLVM_DEBUG(dbgs() << "[AAPrivatizablePtr] pointer is written!\n")do { } while (false); |
6838 | return indicatePessimisticFixpoint(); |
6839 | } |
6840 | |
6841 | return ChangeStatus::UNCHANGED; |
6842 | } |
6843 | |
6844 | /// See AbstractAttribute::trackStatistics() |
6845 | void trackStatistics() const override { |
6846 | STATS_DECLTRACK_CSARG_ATTR(privatizable_ptr){ static llvm::Statistic NumIRCSArguments_privatizable_ptr = { "attributor", "NumIRCSArguments_privatizable_ptr", ("Number of " "call site arguments" " marked '" "privatizable_ptr" "'")};; ++(NumIRCSArguments_privatizable_ptr); }; |
6847 | } |
6848 | }; |
6849 | |
6850 | struct AAPrivatizablePtrCallSiteReturned final |
6851 | : public AAPrivatizablePtrFloating { |
6852 | AAPrivatizablePtrCallSiteReturned(const IRPosition &IRP, Attributor &A) |
6853 | : AAPrivatizablePtrFloating(IRP, A) {} |
6854 | |
6855 | /// See AbstractAttribute::initialize(...). |
6856 | void initialize(Attributor &A) override { |
6857 | // TODO: We can privatize more than arguments. |
6858 | indicatePessimisticFixpoint(); |
6859 | } |
6860 | |
6861 | /// See AbstractAttribute::trackStatistics() |
6862 | void trackStatistics() const override { |
6863 | STATS_DECLTRACK_CSRET_ATTR(privatizable_ptr){ static llvm::Statistic NumIRCSReturn_privatizable_ptr = {"attributor" , "NumIRCSReturn_privatizable_ptr", ("Number of " "call site returns" " marked '" "privatizable_ptr" "'")};; ++(NumIRCSReturn_privatizable_ptr ); }; |
6864 | } |
6865 | }; |
6866 | |
6867 | struct AAPrivatizablePtrReturned final : public AAPrivatizablePtrFloating { |
6868 | AAPrivatizablePtrReturned(const IRPosition &IRP, Attributor &A) |
6869 | : AAPrivatizablePtrFloating(IRP, A) {} |
6870 | |
6871 | /// See AbstractAttribute::initialize(...). |
6872 | void initialize(Attributor &A) override { |
6873 | // TODO: We can privatize more than arguments. |
6874 | indicatePessimisticFixpoint(); |
6875 | } |
6876 | |
6877 | /// See AbstractAttribute::trackStatistics() |
6878 | void trackStatistics() const override { |
6879 | STATS_DECLTRACK_FNRET_ATTR(privatizable_ptr){ static llvm::Statistic NumIRFunctionReturn_privatizable_ptr = {"attributor", "NumIRFunctionReturn_privatizable_ptr", ("Number of " "function returns" " marked '" "privatizable_ptr" "'")};; ++ (NumIRFunctionReturn_privatizable_ptr); }; |
6880 | } |
6881 | }; |
6882 | |
6883 | /// -------------------- Memory Behavior Attributes ---------------------------- |
6884 | /// Includes read-none, read-only, and write-only. |
6885 | /// ---------------------------------------------------------------------------- |
6886 | struct AAMemoryBehaviorImpl : public AAMemoryBehavior { |
6887 | AAMemoryBehaviorImpl(const IRPosition &IRP, Attributor &A) |
6888 | : AAMemoryBehavior(IRP, A) {} |
6889 | |
6890 | /// See AbstractAttribute::initialize(...). |
6891 | void initialize(Attributor &A) override { |
6892 | intersectAssumedBits(BEST_STATE); |
6893 | getKnownStateFromValue(getIRPosition(), getState()); |
6894 | AAMemoryBehavior::initialize(A); |
6895 | } |
6896 | |
6897 | /// Return the memory behavior information encoded in the IR for \p IRP. |
6898 | static void getKnownStateFromValue(const IRPosition &IRP, |
6899 | BitIntegerState &State, |
6900 | bool IgnoreSubsumingPositions = false) { |
6901 | SmallVector<Attribute, 2> Attrs; |
6902 | IRP.getAttrs(AttrKinds, Attrs, IgnoreSubsumingPositions); |
6903 | for (const Attribute &Attr : Attrs) { |
6904 | switch (Attr.getKindAsEnum()) { |
6905 | case Attribute::ReadNone: |
6906 | State.addKnownBits(NO_ACCESSES); |
6907 | break; |
6908 | case Attribute::ReadOnly: |
6909 | State.addKnownBits(NO_WRITES); |
6910 | break; |
6911 | case Attribute::WriteOnly: |
6912 | State.addKnownBits(NO_READS); |
6913 | break; |
6914 | default: |
6915 | llvm_unreachable("Unexpected attribute!")__builtin_unreachable(); |
6916 | } |
6917 | } |
6918 | |
6919 | if (auto *I = dyn_cast<Instruction>(&IRP.getAnchorValue())) { |
6920 | if (!I->mayReadFromMemory()) |
6921 | State.addKnownBits(NO_READS); |
6922 | if (!I->mayWriteToMemory()) |
6923 | State.addKnownBits(NO_WRITES); |
6924 | } |
6925 | } |
6926 | |
6927 | /// See AbstractAttribute::getDeducedAttributes(...). |
6928 | void getDeducedAttributes(LLVMContext &Ctx, |
6929 | SmallVectorImpl<Attribute> &Attrs) const override { |
6930 | assert(Attrs.size() == 0)((void)0); |
6931 | if (isAssumedReadNone()) |
6932 | Attrs.push_back(Attribute::get(Ctx, Attribute::ReadNone)); |
6933 | else if (isAssumedReadOnly()) |
6934 | Attrs.push_back(Attribute::get(Ctx, Attribute::ReadOnly)); |
6935 | else if (isAssumedWriteOnly()) |
6936 | Attrs.push_back(Attribute::get(Ctx, Attribute::WriteOnly)); |
6937 | assert(Attrs.size() <= 1)((void)0); |
6938 | } |
6939 | |
6940 | /// See AbstractAttribute::manifest(...). |
6941 | ChangeStatus manifest(Attributor &A) override { |
6942 | if (hasAttr(Attribute::ReadNone, /* IgnoreSubsumingPositions */ true)) |
6943 | return ChangeStatus::UNCHANGED; |
6944 | |
6945 | const IRPosition &IRP = getIRPosition(); |
6946 | |
6947 | // Check if we would improve the existing attributes first. |
6948 | SmallVector<Attribute, 4> DeducedAttrs; |
6949 | getDeducedAttributes(IRP.getAnchorValue().getContext(), DeducedAttrs); |
6950 | if (llvm::all_of(DeducedAttrs, [&](const Attribute &Attr) { |
6951 | return IRP.hasAttr(Attr.getKindAsEnum(), |
6952 | /* IgnoreSubsumingPositions */ true); |
6953 | })) |
6954 | return ChangeStatus::UNCHANGED; |
6955 | |
6956 | // Clear existing attributes. |
6957 | IRP.removeAttrs(AttrKinds); |
6958 | |
6959 | // Use the generic manifest method. |
6960 | return IRAttribute::manifest(A); |
6961 | } |
6962 | |
6963 | /// See AbstractState::getAsStr(). |
6964 | const std::string getAsStr() const override { |
6965 | if (isAssumedReadNone()) |
6966 | return "readnone"; |
6967 | if (isAssumedReadOnly()) |
6968 | return "readonly"; |
6969 | if (isAssumedWriteOnly()) |
6970 | return "writeonly"; |
6971 | return "may-read/write"; |
6972 | } |
6973 | |
6974 | /// The set of IR attributes AAMemoryBehavior deals with. |
6975 | static const Attribute::AttrKind AttrKinds[3]; |
6976 | }; |
6977 | |
6978 | const Attribute::AttrKind AAMemoryBehaviorImpl::AttrKinds[] = { |
6979 | Attribute::ReadNone, Attribute::ReadOnly, Attribute::WriteOnly}; |
6980 | |
6981 | /// Memory behavior attribute for a floating value. |
6982 | struct AAMemoryBehaviorFloating : AAMemoryBehaviorImpl { |
6983 | AAMemoryBehaviorFloating(const IRPosition &IRP, Attributor &A) |
6984 | : AAMemoryBehaviorImpl(IRP, A) {} |
6985 | |
6986 | /// See AbstractAttribute::updateImpl(...). |
6987 | ChangeStatus updateImpl(Attributor &A) override; |
6988 | |
6989 | /// See AbstractAttribute::trackStatistics() |
6990 | void trackStatistics() const override { |
6991 | if (isAssumedReadNone()) |
6992 | STATS_DECLTRACK_FLOATING_ATTR(readnone){ static llvm::Statistic NumIRFloating_readnone = {"attributor" , "NumIRFloating_readnone", ("Number of floating values known to be '" "readnone" "'")};; ++(NumIRFloating_readnone); } |
6993 | else if (isAssumedReadOnly()) |
6994 | STATS_DECLTRACK_FLOATING_ATTR(readonly){ static llvm::Statistic NumIRFloating_readonly = {"attributor" , "NumIRFloating_readonly", ("Number of floating values known to be '" "readonly" "'")};; ++(NumIRFloating_readonly); } |
6995 | else if (isAssumedWriteOnly()) |
6996 | STATS_DECLTRACK_FLOATING_ATTR(writeonly){ static llvm::Statistic NumIRFloating_writeonly = {"attributor" , "NumIRFloating_writeonly", ("Number of floating values known to be '" "writeonly" "'")};; ++(NumIRFloating_writeonly); } |
6997 | } |
6998 | |
6999 | private: |
7000 | /// Return true if users of \p UserI might access the underlying |
7001 | /// variable/location described by \p U and should therefore be analyzed. |
7002 | bool followUsersOfUseIn(Attributor &A, const Use &U, |
7003 | const Instruction *UserI); |
7004 | |
7005 | /// Update the state according to the effect of use \p U in \p UserI. |
7006 | void analyzeUseIn(Attributor &A, const Use &U, const Instruction *UserI); |
7007 | }; |
7008 | |
7009 | /// Memory behavior attribute for function argument. |
7010 | struct AAMemoryBehaviorArgument : AAMemoryBehaviorFloating { |
7011 | AAMemoryBehaviorArgument(const IRPosition &IRP, Attributor &A) |
7012 | : AAMemoryBehaviorFloating(IRP, A) {} |
7013 | |
7014 | /// See AbstractAttribute::initialize(...). |
7015 | void initialize(Attributor &A) override { |
7016 | intersectAssumedBits(BEST_STATE); |
7017 | const IRPosition &IRP = getIRPosition(); |
7018 | // TODO: Make IgnoreSubsumingPositions a property of an IRAttribute so we |
7019 | // can query it when we use has/getAttr. That would allow us to reuse the |
7020 | // initialize of the base class here. |
7021 | bool HasByVal = |
7022 | IRP.hasAttr({Attribute::ByVal}, /* IgnoreSubsumingPositions */ true); |
7023 | getKnownStateFromValue(IRP, getState(), |
7024 | /* IgnoreSubsumingPositions */ HasByVal); |
7025 | |
7026 | // Initialize the use vector with all direct uses of the associated value. |
7027 | Argument *Arg = getAssociatedArgument(); |
7028 | if (!Arg || !A.isFunctionIPOAmendable(*(Arg->getParent()))) |
7029 | indicatePessimisticFixpoint(); |
7030 | } |
7031 | |
7032 | ChangeStatus manifest(Attributor &A) override { |
7033 | // TODO: Pointer arguments are not supported on vectors of pointers yet. |
7034 | if (!getAssociatedValue().getType()->isPointerTy()) |
7035 | return ChangeStatus::UNCHANGED; |
7036 | |
7037 | // TODO: From readattrs.ll: "inalloca parameters are always |
7038 | // considered written" |
7039 | if (hasAttr({Attribute::InAlloca, Attribute::Preallocated})) { |
7040 | removeKnownBits(NO_WRITES); |
7041 | removeAssumedBits(NO_WRITES); |
7042 | } |
7043 | return AAMemoryBehaviorFloating::manifest(A); |
7044 | } |
7045 | |
7046 | /// See AbstractAttribute::trackStatistics() |
7047 | void trackStatistics() const override { |
7048 | if (isAssumedReadNone()) |
7049 | STATS_DECLTRACK_ARG_ATTR(readnone){ static llvm::Statistic NumIRArguments_readnone = {"attributor" , "NumIRArguments_readnone", ("Number of " "arguments" " marked '" "readnone" "'")};; ++(NumIRArguments_readnone); } |
7050 | else if (isAssumedReadOnly()) |
7051 | STATS_DECLTRACK_ARG_ATTR(readonly){ static llvm::Statistic NumIRArguments_readonly = {"attributor" , "NumIRArguments_readonly", ("Number of " "arguments" " marked '" "readonly" "'")};; ++(NumIRArguments_readonly); } |
7052 | else if (isAssumedWriteOnly()) |
7053 | STATS_DECLTRACK_ARG_ATTR(writeonly){ static llvm::Statistic NumIRArguments_writeonly = {"attributor" , "NumIRArguments_writeonly", ("Number of " "arguments" " marked '" "writeonly" "'")};; ++(NumIRArguments_writeonly); } |
7054 | } |
7055 | }; |
7056 | |
7057 | struct AAMemoryBehaviorCallSiteArgument final : AAMemoryBehaviorArgument { |
7058 | AAMemoryBehaviorCallSiteArgument(const IRPosition &IRP, Attributor &A) |
7059 | : AAMemoryBehaviorArgument(IRP, A) {} |
7060 | |
7061 | /// See AbstractAttribute::initialize(...). |
7062 | void initialize(Attributor &A) override { |
7063 | // If we don't have an associated attribute this is either a variadic call |
7064 | // or an indirect call, either way, nothing to do here. |
7065 | Argument *Arg = getAssociatedArgument(); |
7066 | if (!Arg) { |
7067 | indicatePessimisticFixpoint(); |
7068 | return; |
7069 | } |
7070 | if (Arg->hasByValAttr()) { |
7071 | addKnownBits(NO_WRITES); |
7072 | removeKnownBits(NO_READS); |
7073 | removeAssumedBits(NO_READS); |
7074 | } |
7075 | AAMemoryBehaviorArgument::initialize(A); |
7076 | if (getAssociatedFunction()->isDeclaration()) |
7077 | indicatePessimisticFixpoint(); |
7078 | } |
7079 | |
7080 | /// See AbstractAttribute::updateImpl(...). |
7081 | ChangeStatus updateImpl(Attributor &A) override { |
7082 | // TODO: Once we have call site specific value information we can provide |
7083 | // call site specific liveness liveness information and then it makes |
7084 | // sense to specialize attributes for call sites arguments instead of |
7085 | // redirecting requests to the callee argument. |
7086 | Argument *Arg = getAssociatedArgument(); |
7087 | const IRPosition &ArgPos = IRPosition::argument(*Arg); |
7088 | auto &ArgAA = |
7089 | A.getAAFor<AAMemoryBehavior>(*this, ArgPos, DepClassTy::REQUIRED); |
7090 | return clampStateAndIndicateChange(getState(), ArgAA.getState()); |
7091 | } |
7092 | |
7093 | /// See AbstractAttribute::trackStatistics() |
7094 | void trackStatistics() const override { |
7095 | if (isAssumedReadNone()) |
7096 | STATS_DECLTRACK_CSARG_ATTR(readnone){ static llvm::Statistic NumIRCSArguments_readnone = {"attributor" , "NumIRCSArguments_readnone", ("Number of " "call site arguments" " marked '" "readnone" "'")};; ++(NumIRCSArguments_readnone) ; } |
7097 | else if (isAssumedReadOnly()) |
7098 | STATS_DECLTRACK_CSARG_ATTR(readonly){ static llvm::Statistic NumIRCSArguments_readonly = {"attributor" , "NumIRCSArguments_readonly", ("Number of " "call site arguments" " marked '" "readonly" "'")};; ++(NumIRCSArguments_readonly) ; } |
7099 | else if (isAssumedWriteOnly()) |
7100 | STATS_DECLTRACK_CSARG_ATTR(writeonly){ static llvm::Statistic NumIRCSArguments_writeonly = {"attributor" , "NumIRCSArguments_writeonly", ("Number of " "call site arguments" " marked '" "writeonly" "'")};; ++(NumIRCSArguments_writeonly ); } |
7101 | } |
7102 | }; |
7103 | |
7104 | /// Memory behavior attribute for a call site return position. |
7105 | struct AAMemoryBehaviorCallSiteReturned final : AAMemoryBehaviorFloating { |
7106 | AAMemoryBehaviorCallSiteReturned(const IRPosition &IRP, Attributor &A) |
7107 | : AAMemoryBehaviorFloating(IRP, A) {} |
7108 | |
7109 | /// See AbstractAttribute::initialize(...). |
7110 | void initialize(Attributor &A) override { |
7111 | AAMemoryBehaviorImpl::initialize(A); |
7112 | Function *F = getAssociatedFunction(); |
7113 | if (!F || F->isDeclaration()) |
7114 | indicatePessimisticFixpoint(); |
7115 | } |
7116 | |
7117 | /// See AbstractAttribute::manifest(...). |
7118 | ChangeStatus manifest(Attributor &A) override { |
7119 | // We do not annotate returned values. |
7120 | return ChangeStatus::UNCHANGED; |
7121 | } |
7122 | |
7123 | /// See AbstractAttribute::trackStatistics() |
7124 | void trackStatistics() const override {} |
7125 | }; |
7126 | |
7127 | /// An AA to represent the memory behavior function attributes. |
7128 | struct AAMemoryBehaviorFunction final : public AAMemoryBehaviorImpl { |
7129 | AAMemoryBehaviorFunction(const IRPosition &IRP, Attributor &A) |
7130 | : AAMemoryBehaviorImpl(IRP, A) {} |
7131 | |
7132 | /// See AbstractAttribute::updateImpl(Attributor &A). |
7133 | virtual ChangeStatus updateImpl(Attributor &A) override; |
7134 | |
7135 | /// See AbstractAttribute::manifest(...). |
7136 | ChangeStatus manifest(Attributor &A) override { |
7137 | Function &F = cast<Function>(getAnchorValue()); |
7138 | if (isAssumedReadNone()) { |
7139 | F.removeFnAttr(Attribute::ArgMemOnly); |
7140 | F.removeFnAttr(Attribute::InaccessibleMemOnly); |
7141 | F.removeFnAttr(Attribute::InaccessibleMemOrArgMemOnly); |
7142 | } |
7143 | return AAMemoryBehaviorImpl::manifest(A); |
7144 | } |
7145 | |
7146 | /// See AbstractAttribute::trackStatistics() |
7147 | void trackStatistics() const override { |
7148 | if (isAssumedReadNone()) |
7149 | STATS_DECLTRACK_FN_ATTR(readnone){ static llvm::Statistic NumIRFunction_readnone = {"attributor" , "NumIRFunction_readnone", ("Number of " "functions" " marked '" "readnone" "'")};; ++(NumIRFunction_readnone); } |
7150 | else if (isAssumedReadOnly()) |
7151 | STATS_DECLTRACK_FN_ATTR(readonly){ static llvm::Statistic NumIRFunction_readonly = {"attributor" , "NumIRFunction_readonly", ("Number of " "functions" " marked '" "readonly" "'")};; ++(NumIRFunction_readonly); } |
7152 | else if (isAssumedWriteOnly()) |
7153 | STATS_DECLTRACK_FN_ATTR(writeonly){ static llvm::Statistic NumIRFunction_writeonly = {"attributor" , "NumIRFunction_writeonly", ("Number of " "functions" " marked '" "writeonly" "'")};; ++(NumIRFunction_writeonly); } |
7154 | } |
7155 | }; |
7156 | |
7157 | /// AAMemoryBehavior attribute for call sites. |
7158 | struct AAMemoryBehaviorCallSite final : AAMemoryBehaviorImpl { |
7159 | AAMemoryBehaviorCallSite(const IRPosition &IRP, Attributor &A) |
7160 | : AAMemoryBehaviorImpl(IRP, A) {} |
7161 | |
7162 | /// See AbstractAttribute::initialize(...). |
7163 | void initialize(Attributor &A) override { |
7164 | AAMemoryBehaviorImpl::initialize(A); |
7165 | Function *F = getAssociatedFunction(); |
7166 | if (!F || F->isDeclaration()) |
7167 | indicatePessimisticFixpoint(); |
7168 | } |
7169 | |
7170 | /// See AbstractAttribute::updateImpl(...). |
7171 | ChangeStatus updateImpl(Attributor &A) override { |
7172 | // TODO: Once we have call site specific value information we can provide |
7173 | // call site specific liveness liveness information and then it makes |
7174 | // sense to specialize attributes for call sites arguments instead of |
7175 | // redirecting requests to the callee argument. |
7176 | Function *F = getAssociatedFunction(); |
7177 | const IRPosition &FnPos = IRPosition::function(*F); |
7178 | auto &FnAA = |
7179 | A.getAAFor<AAMemoryBehavior>(*this, FnPos, DepClassTy::REQUIRED); |
7180 | return clampStateAndIndicateChange(getState(), FnAA.getState()); |
7181 | } |
7182 | |
7183 | /// See AbstractAttribute::trackStatistics() |
7184 | void trackStatistics() const override { |
7185 | if (isAssumedReadNone()) |
7186 | STATS_DECLTRACK_CS_ATTR(readnone){ static llvm::Statistic NumIRCS_readnone = {"attributor", "NumIRCS_readnone" , ("Number of " "call site" " marked '" "readnone" "'")};; ++ (NumIRCS_readnone); } |
7187 | else if (isAssumedReadOnly()) |
7188 | STATS_DECLTRACK_CS_ATTR(readonly){ static llvm::Statistic NumIRCS_readonly = {"attributor", "NumIRCS_readonly" , ("Number of " "call site" " marked '" "readonly" "'")};; ++ (NumIRCS_readonly); } |
7189 | else if (isAssumedWriteOnly()) |
7190 | STATS_DECLTRACK_CS_ATTR(writeonly){ static llvm::Statistic NumIRCS_writeonly = {"attributor", "NumIRCS_writeonly" , ("Number of " "call site" " marked '" "writeonly" "'")};; ++ (NumIRCS_writeonly); } |
7191 | } |
7192 | }; |
7193 | |
7194 | ChangeStatus AAMemoryBehaviorFunction::updateImpl(Attributor &A) { |
7195 | |
7196 | // The current assumed state used to determine a change. |
7197 | auto AssumedState = getAssumed(); |
7198 | |
7199 | auto CheckRWInst = [&](Instruction &I) { |
7200 | // If the instruction has an own memory behavior state, use it to restrict |
7201 | // the local state. No further analysis is required as the other memory |
7202 | // state is as optimistic as it gets. |
7203 | if (const auto *CB = dyn_cast<CallBase>(&I)) { |
7204 | const auto &MemBehaviorAA = A.getAAFor<AAMemoryBehavior>( |
7205 | *this, IRPosition::callsite_function(*CB), DepClassTy::REQUIRED); |
7206 | intersectAssumedBits(MemBehaviorAA.getAssumed()); |
7207 | return !isAtFixpoint(); |
7208 | } |
7209 | |
7210 | // Remove access kind modifiers if necessary. |
7211 | if (I.mayReadFromMemory()) |
7212 | removeAssumedBits(NO_READS); |
7213 | if (I.mayWriteToMemory()) |
7214 | removeAssumedBits(NO_WRITES); |
7215 | return !isAtFixpoint(); |
7216 | }; |
7217 | |
7218 | bool UsedAssumedInformation = false; |
7219 | if (!A.checkForAllReadWriteInstructions(CheckRWInst, *this, |
7220 | UsedAssumedInformation)) |
7221 | return indicatePessimisticFixpoint(); |
7222 | |
7223 | return (AssumedState != getAssumed()) ? ChangeStatus::CHANGED |
7224 | : ChangeStatus::UNCHANGED; |
7225 | } |
7226 | |
7227 | ChangeStatus AAMemoryBehaviorFloating::updateImpl(Attributor &A) { |
7228 | |
7229 | const IRPosition &IRP = getIRPosition(); |
7230 | const IRPosition &FnPos = IRPosition::function_scope(IRP); |
7231 | AAMemoryBehavior::StateType &S = getState(); |
7232 | |
7233 | // First, check the function scope. We take the known information and we avoid |
7234 | // work if the assumed information implies the current assumed information for |
7235 | // this attribute. This is a valid for all but byval arguments. |
7236 | Argument *Arg = IRP.getAssociatedArgument(); |
7237 | AAMemoryBehavior::base_t FnMemAssumedState = |
7238 | AAMemoryBehavior::StateType::getWorstState(); |
7239 | if (!Arg || !Arg->hasByValAttr()) { |
7240 | const auto &FnMemAA = |
7241 | A.getAAFor<AAMemoryBehavior>(*this, FnPos, DepClassTy::OPTIONAL); |
7242 | FnMemAssumedState = FnMemAA.getAssumed(); |
7243 | S.addKnownBits(FnMemAA.getKnown()); |
7244 | if ((S.getAssumed() & FnMemAA.getAssumed()) == S.getAssumed()) |
7245 | return ChangeStatus::UNCHANGED; |
7246 | } |
7247 | |
7248 | // The current assumed state used to determine a change. |
7249 | auto AssumedState = S.getAssumed(); |
7250 | |
7251 | // Make sure the value is not captured (except through "return"), if |
7252 | // it is, any information derived would be irrelevant anyway as we cannot |
7253 | // check the potential aliases introduced by the capture. However, no need |
7254 | // to fall back to anythign less optimistic than the function state. |
7255 | const auto &ArgNoCaptureAA = |
7256 | A.getAAFor<AANoCapture>(*this, IRP, DepClassTy::OPTIONAL); |
7257 | if (!ArgNoCaptureAA.isAssumedNoCaptureMaybeReturned()) { |
7258 | S.intersectAssumedBits(FnMemAssumedState); |
7259 | return (AssumedState != getAssumed()) ? ChangeStatus::CHANGED |
7260 | : ChangeStatus::UNCHANGED; |
7261 | } |
7262 | |
7263 | // Visit and expand uses until all are analyzed or a fixpoint is reached. |
7264 | auto UsePred = [&](const Use &U, bool &Follow) -> bool { |
7265 | Instruction *UserI = cast<Instruction>(U.getUser()); |
7266 | LLVM_DEBUG(dbgs() << "[AAMemoryBehavior] Use: " << *U << " in " << *UserIdo { } while (false) |
7267 | << " \n")do { } while (false); |
7268 | |
7269 | // Droppable users, e.g., llvm::assume does not actually perform any action. |
7270 | if (UserI->isDroppable()) |
7271 | return true; |
7272 | |
7273 | // Check if the users of UserI should also be visited. |
7274 | Follow = followUsersOfUseIn(A, U, UserI); |
7275 | |
7276 | // If UserI might touch memory we analyze the use in detail. |
7277 | if (UserI->mayReadOrWriteMemory()) |
7278 | analyzeUseIn(A, U, UserI); |
7279 | |
7280 | return !isAtFixpoint(); |
7281 | }; |
7282 | |
7283 | if (!A.checkForAllUses(UsePred, *this, getAssociatedValue())) |
7284 | return indicatePessimisticFixpoint(); |
7285 | |
7286 | return (AssumedState != getAssumed()) ? ChangeStatus::CHANGED |
7287 | : ChangeStatus::UNCHANGED; |
7288 | } |
7289 | |
7290 | bool AAMemoryBehaviorFloating::followUsersOfUseIn(Attributor &A, const Use &U, |
7291 | const Instruction *UserI) { |
7292 | // The loaded value is unrelated to the pointer argument, no need to |
7293 | // follow the users of the load. |
7294 | if (isa<LoadInst>(UserI)) |
7295 | return false; |
7296 | |
7297 | // By default we follow all uses assuming UserI might leak information on U, |
7298 | // we have special handling for call sites operands though. |
7299 | const auto *CB = dyn_cast<CallBase>(UserI); |
7300 | if (!CB || !CB->isArgOperand(&U)) |
7301 | return true; |
7302 | |
7303 | // If the use is a call argument known not to be captured, the users of |
7304 | // the call do not need to be visited because they have to be unrelated to |
7305 | // the input. Note that this check is not trivial even though we disallow |
7306 | // general capturing of the underlying argument. The reason is that the |
7307 | // call might the argument "through return", which we allow and for which we |
7308 | // need to check call users. |
7309 | if (U.get()->getType()->isPointerTy()) { |
7310 | unsigned ArgNo = CB->getArgOperandNo(&U); |
7311 | const auto &ArgNoCaptureAA = A.getAAFor<AANoCapture>( |
7312 | *this, IRPosition::callsite_argument(*CB, ArgNo), DepClassTy::OPTIONAL); |
7313 | return !ArgNoCaptureAA.isAssumedNoCapture(); |
7314 | } |
7315 | |
7316 | return true; |
7317 | } |
7318 | |
7319 | void AAMemoryBehaviorFloating::analyzeUseIn(Attributor &A, const Use &U, |
7320 | const Instruction *UserI) { |
7321 | assert(UserI->mayReadOrWriteMemory())((void)0); |
7322 | |
7323 | switch (UserI->getOpcode()) { |
7324 | default: |
7325 | // TODO: Handle all atomics and other side-effect operations we know of. |
7326 | break; |
7327 | case Instruction::Load: |
7328 | // Loads cause the NO_READS property to disappear. |
7329 | removeAssumedBits(NO_READS); |
7330 | return; |
7331 | |
7332 | case Instruction::Store: |
7333 | // Stores cause the NO_WRITES property to disappear if the use is the |
7334 | // pointer operand. Note that we do assume that capturing was taken care of |
7335 | // somewhere else. |
7336 | if (cast<StoreInst>(UserI)->getPointerOperand() == U.get()) |
7337 | removeAssumedBits(NO_WRITES); |
7338 | return; |
7339 | |
7340 | case Instruction::Call: |
7341 | case Instruction::CallBr: |
7342 | case Instruction::Invoke: { |
7343 | // For call sites we look at the argument memory behavior attribute (this |
7344 | // could be recursive!) in order to restrict our own state. |
7345 | const auto *CB = cast<CallBase>(UserI); |
7346 | |
7347 | // Give up on operand bundles. |
7348 | if (CB->isBundleOperand(&U)) { |
7349 | indicatePessimisticFixpoint(); |
7350 | return; |
7351 | } |
7352 | |
7353 | // Calling a function does read the function pointer, maybe write it if the |
7354 | // function is self-modifying. |
7355 | if (CB->isCallee(&U)) { |
7356 | removeAssumedBits(NO_READS); |
7357 | break; |
7358 | } |
7359 | |
7360 | // Adjust the possible access behavior based on the information on the |
7361 | // argument. |
7362 | IRPosition Pos; |
7363 | if (U.get()->getType()->isPointerTy()) |
7364 | Pos = IRPosition::callsite_argument(*CB, CB->getArgOperandNo(&U)); |
7365 | else |
7366 | Pos = IRPosition::callsite_function(*CB); |
7367 | const auto &MemBehaviorAA = |
7368 | A.getAAFor<AAMemoryBehavior>(*this, Pos, DepClassTy::OPTIONAL); |
7369 | // "assumed" has at most the same bits as the MemBehaviorAA assumed |
7370 | // and at least "known". |
7371 | intersectAssumedBits(MemBehaviorAA.getAssumed()); |
7372 | return; |
7373 | } |
7374 | }; |
7375 | |
7376 | // Generally, look at the "may-properties" and adjust the assumed state if we |
7377 | // did not trigger special handling before. |
7378 | if (UserI->mayReadFromMemory()) |
7379 | removeAssumedBits(NO_READS); |
7380 | if (UserI->mayWriteToMemory()) |
7381 | removeAssumedBits(NO_WRITES); |
7382 | } |
7383 | |
7384 | /// -------------------- Memory Locations Attributes --------------------------- |
7385 | /// Includes read-none, argmemonly, inaccessiblememonly, |
7386 | /// inaccessiblememorargmemonly |
7387 | /// ---------------------------------------------------------------------------- |
7388 | |
7389 | std::string AAMemoryLocation::getMemoryLocationsAsStr( |
7390 | AAMemoryLocation::MemoryLocationsKind MLK) { |
7391 | if (0 == (MLK & AAMemoryLocation::NO_LOCATIONS)) |
7392 | return "all memory"; |
7393 | if (MLK == AAMemoryLocation::NO_LOCATIONS) |
7394 | return "no memory"; |
7395 | std::string S = "memory:"; |
7396 | if (0 == (MLK & AAMemoryLocation::NO_LOCAL_MEM)) |
7397 | S += "stack,"; |
7398 | if (0 == (MLK & AAMemoryLocation::NO_CONST_MEM)) |
7399 | S += "constant,"; |
7400 | if (0 == (MLK & AAMemoryLocation::NO_GLOBAL_INTERNAL_MEM)) |
7401 | S += "internal global,"; |
7402 | if (0 == (MLK & AAMemoryLocation::NO_GLOBAL_EXTERNAL_MEM)) |
7403 | S += "external global,"; |
7404 | if (0 == (MLK & AAMemoryLocation::NO_ARGUMENT_MEM)) |
7405 | S += "argument,"; |
7406 | if (0 == (MLK & AAMemoryLocation::NO_INACCESSIBLE_MEM)) |
7407 | S += "inaccessible,"; |
7408 | if (0 == (MLK & AAMemoryLocation::NO_MALLOCED_MEM)) |
7409 | S += "malloced,"; |
7410 | if (0 == (MLK & AAMemoryLocation::NO_UNKOWN_MEM)) |
7411 | S += "unknown,"; |
7412 | S.pop_back(); |
7413 | return S; |
7414 | } |
7415 | |
7416 | namespace { |
7417 | struct AAMemoryLocationImpl : public AAMemoryLocation { |
7418 | |
7419 | AAMemoryLocationImpl(const IRPosition &IRP, Attributor &A) |
7420 | : AAMemoryLocation(IRP, A), Allocator(A.Allocator) { |
7421 | for (unsigned u = 0; u < llvm::CTLog2<VALID_STATE>(); ++u) |
7422 | AccessKind2Accesses[u] = nullptr; |
7423 | } |
7424 | |
7425 | ~AAMemoryLocationImpl() { |
7426 | // The AccessSets are allocated via a BumpPtrAllocator, we call |
7427 | // the destructor manually. |
7428 | for (unsigned u = 0; u < llvm::CTLog2<VALID_STATE>(); ++u) |
7429 | if (AccessKind2Accesses[u]) |
7430 | AccessKind2Accesses[u]->~AccessSet(); |
7431 | } |
7432 | |
7433 | /// See AbstractAttribute::initialize(...). |
7434 | void initialize(Attributor &A) override { |
7435 | intersectAssumedBits(BEST_STATE); |
7436 | getKnownStateFromValue(A, getIRPosition(), getState()); |
7437 | AAMemoryLocation::initialize(A); |
7438 | } |
7439 | |
7440 | /// Return the memory behavior information encoded in the IR for \p IRP. |
7441 | static void getKnownStateFromValue(Attributor &A, const IRPosition &IRP, |
7442 | BitIntegerState &State, |
7443 | bool IgnoreSubsumingPositions = false) { |
7444 | // For internal functions we ignore `argmemonly` and |
7445 | // `inaccessiblememorargmemonly` as we might break it via interprocedural |
7446 | // constant propagation. It is unclear if this is the best way but it is |
7447 | // unlikely this will cause real performance problems. If we are deriving |
7448 | // attributes for the anchor function we even remove the attribute in |
7449 | // addition to ignoring it. |
7450 | bool UseArgMemOnly = true; |
7451 | Function *AnchorFn = IRP.getAnchorScope(); |
7452 | if (AnchorFn && A.isRunOn(*AnchorFn)) |
7453 | UseArgMemOnly = !AnchorFn->hasLocalLinkage(); |
7454 | |
7455 | SmallVector<Attribute, 2> Attrs; |
7456 | IRP.getAttrs(AttrKinds, Attrs, IgnoreSubsumingPositions); |
7457 | for (const Attribute &Attr : Attrs) { |
7458 | switch (Attr.getKindAsEnum()) { |
7459 | case Attribute::ReadNone: |
7460 | State.addKnownBits(NO_LOCAL_MEM | NO_CONST_MEM); |
7461 | break; |
7462 | case Attribute::InaccessibleMemOnly: |
7463 | State.addKnownBits(inverseLocation(NO_INACCESSIBLE_MEM, true, true)); |
7464 | break; |
7465 | case Attribute::ArgMemOnly: |
7466 | if (UseArgMemOnly) |
7467 | State.addKnownBits(inverseLocation(NO_ARGUMENT_MEM, true, true)); |
7468 | else |
7469 | IRP.removeAttrs({Attribute::ArgMemOnly}); |
7470 | break; |
7471 | case Attribute::InaccessibleMemOrArgMemOnly: |
7472 | if (UseArgMemOnly) |
7473 | State.addKnownBits(inverseLocation( |
7474 | NO_INACCESSIBLE_MEM | NO_ARGUMENT_MEM, true, true)); |
7475 | else |
7476 | IRP.removeAttrs({Attribute::InaccessibleMemOrArgMemOnly}); |
7477 | break; |
7478 | default: |
7479 | llvm_unreachable("Unexpected attribute!")__builtin_unreachable(); |
7480 | } |
7481 | } |
7482 | } |
7483 | |
7484 | /// See AbstractAttribute::getDeducedAttributes(...). |
7485 | void getDeducedAttributes(LLVMContext &Ctx, |
7486 | SmallVectorImpl<Attribute> &Attrs) const override { |
7487 | assert(Attrs.size() == 0)((void)0); |
7488 | if (isAssumedReadNone()) { |
7489 | Attrs.push_back(Attribute::get(Ctx, Attribute::ReadNone)); |
7490 | } else if (getIRPosition().getPositionKind() == IRPosition::IRP_FUNCTION) { |
7491 | if (isAssumedInaccessibleMemOnly()) |
7492 | Attrs.push_back(Attribute::get(Ctx, Attribute::InaccessibleMemOnly)); |
7493 | else if (isAssumedArgMemOnly()) |
7494 | Attrs.push_back(Attribute::get(Ctx, Attribute::ArgMemOnly)); |
7495 | else if (isAssumedInaccessibleOrArgMemOnly()) |
7496 | Attrs.push_back( |
7497 | Attribute::get(Ctx, Attribute::InaccessibleMemOrArgMemOnly)); |
7498 | } |
7499 | assert(Attrs.size() <= 1)((void)0); |
7500 | } |
7501 | |
7502 | /// See AbstractAttribute::manifest(...). |
7503 | ChangeStatus manifest(Attributor &A) override { |
7504 | const IRPosition &IRP = getIRPosition(); |
7505 | |
7506 | // Check if we would improve the existing attributes first. |
7507 | SmallVector<Attribute, 4> DeducedAttrs; |
7508 | getDeducedAttributes(IRP.getAnchorValue().getContext(), DeducedAttrs); |
7509 | if (llvm::all_of(DeducedAttrs, [&](const Attribute &Attr) { |
7510 | return IRP.hasAttr(Attr.getKindAsEnum(), |
7511 | /* IgnoreSubsumingPositions */ true); |
7512 | })) |
7513 | return ChangeStatus::UNCHANGED; |
7514 | |
7515 | // Clear existing attributes. |
7516 | IRP.removeAttrs(AttrKinds); |
7517 | if (isAssumedReadNone()) |
7518 | IRP.removeAttrs(AAMemoryBehaviorImpl::AttrKinds); |
7519 | |
7520 | // Use the generic manifest method. |
7521 | return IRAttribute::manifest(A); |
7522 | } |
7523 | |
7524 | /// See AAMemoryLocation::checkForAllAccessesToMemoryKind(...). |
7525 | bool checkForAllAccessesToMemoryKind( |
7526 | function_ref<bool(const Instruction *, const Value *, AccessKind, |
7527 | MemoryLocationsKind)> |
7528 | Pred, |
7529 | MemoryLocationsKind RequestedMLK) const override { |
7530 | if (!isValidState()) |
7531 | return false; |
7532 | |
7533 | MemoryLocationsKind AssumedMLK = getAssumedNotAccessedLocation(); |
7534 | if (AssumedMLK == NO_LOCATIONS) |
7535 | return true; |
7536 | |
7537 | unsigned Idx = 0; |
7538 | for (MemoryLocationsKind CurMLK = 1; CurMLK < NO_LOCATIONS; |
7539 | CurMLK *= 2, ++Idx) { |
7540 | if (CurMLK & RequestedMLK) |
7541 | continue; |
7542 | |
7543 | if (const AccessSet *Accesses = AccessKind2Accesses[Idx]) |
7544 | for (const AccessInfo &AI : *Accesses) |
7545 | if (!Pred(AI.I, AI.Ptr, AI.Kind, CurMLK)) |
7546 | return false; |
7547 | } |
7548 | |
7549 | return true; |
7550 | } |
7551 | |
7552 | ChangeStatus indicatePessimisticFixpoint() override { |
7553 | // If we give up and indicate a pessimistic fixpoint this instruction will |
7554 | // become an access for all potential access kinds: |
7555 | // TODO: Add pointers for argmemonly and globals to improve the results of |
7556 | // checkForAllAccessesToMemoryKind. |
7557 | bool Changed = false; |
7558 | MemoryLocationsKind KnownMLK = getKnown(); |
7559 | Instruction *I = dyn_cast<Instruction>(&getAssociatedValue()); |
7560 | for (MemoryLocationsKind CurMLK = 1; CurMLK < NO_LOCATIONS; CurMLK *= 2) |
7561 | if (!(CurMLK & KnownMLK)) |
7562 | updateStateAndAccessesMap(getState(), CurMLK, I, nullptr, Changed, |
7563 | getAccessKindFromInst(I)); |
7564 | return AAMemoryLocation::indicatePessimisticFixpoint(); |
7565 | } |
7566 | |
7567 | protected: |
7568 | /// Helper struct to tie together an instruction that has a read or write |
7569 | /// effect with the pointer it accesses (if any). |
7570 | struct AccessInfo { |
7571 | |
7572 | /// The instruction that caused the access. |
7573 | const Instruction *I; |
7574 | |
7575 | /// The base pointer that is accessed, or null if unknown. |
7576 | const Value *Ptr; |
7577 | |
7578 | /// The kind of access (read/write/read+write). |
7579 | AccessKind Kind; |
7580 | |
7581 | bool operator==(const AccessInfo &RHS) const { |
7582 | return I == RHS.I && Ptr == RHS.Ptr && Kind == RHS.Kind; |
7583 | } |
7584 | bool operator()(const AccessInfo &LHS, const AccessInfo &RHS) const { |
7585 | if (LHS.I != RHS.I) |
7586 | return LHS.I < RHS.I; |
7587 | if (LHS.Ptr != RHS.Ptr) |
7588 | return LHS.Ptr < RHS.Ptr; |
7589 | if (LHS.Kind != RHS.Kind) |
7590 | return LHS.Kind < RHS.Kind; |
7591 | return false; |
7592 | } |
7593 | }; |
7594 | |
7595 | /// Mapping from *single* memory location kinds, e.g., LOCAL_MEM with the |
7596 | /// value of NO_LOCAL_MEM, to the accesses encountered for this memory kind. |
7597 | using AccessSet = SmallSet<AccessInfo, 2, AccessInfo>; |
7598 | AccessSet *AccessKind2Accesses[llvm::CTLog2<VALID_STATE>()]; |
7599 | |
7600 | /// Categorize the pointer arguments of CB that might access memory in |
7601 | /// AccessedLoc and update the state and access map accordingly. |
7602 | void |
7603 | categorizeArgumentPointerLocations(Attributor &A, CallBase &CB, |
7604 | AAMemoryLocation::StateType &AccessedLocs, |
7605 | bool &Changed); |
7606 | |
7607 | /// Return the kind(s) of location that may be accessed by \p V. |
7608 | AAMemoryLocation::MemoryLocationsKind |
7609 | categorizeAccessedLocations(Attributor &A, Instruction &I, bool &Changed); |
7610 | |
7611 | /// Return the access kind as determined by \p I. |
7612 | AccessKind getAccessKindFromInst(const Instruction *I) { |
7613 | AccessKind AK = READ_WRITE; |
7614 | if (I) { |
7615 | AK = I->mayReadFromMemory() ? READ : NONE; |
7616 | AK = AccessKind(AK | (I->mayWriteToMemory() ? WRITE : NONE)); |
7617 | } |
7618 | return AK; |
7619 | } |
7620 | |
7621 | /// Update the state \p State and the AccessKind2Accesses given that \p I is |
7622 | /// an access of kind \p AK to a \p MLK memory location with the access |
7623 | /// pointer \p Ptr. |
7624 | void updateStateAndAccessesMap(AAMemoryLocation::StateType &State, |
7625 | MemoryLocationsKind MLK, const Instruction *I, |
7626 | const Value *Ptr, bool &Changed, |
7627 | AccessKind AK = READ_WRITE) { |
7628 | |
7629 | assert(isPowerOf2_32(MLK) && "Expected a single location set!")((void)0); |
7630 | auto *&Accesses = AccessKind2Accesses[llvm::Log2_32(MLK)]; |
7631 | if (!Accesses) |
7632 | Accesses = new (Allocator) AccessSet(); |
7633 | Changed |= Accesses->insert(AccessInfo{I, Ptr, AK}).second; |
7634 | State.removeAssumedBits(MLK); |
7635 | } |
7636 | |
7637 | /// Determine the underlying locations kinds for \p Ptr, e.g., globals or |
7638 | /// arguments, and update the state and access map accordingly. |
7639 | void categorizePtrValue(Attributor &A, const Instruction &I, const Value &Ptr, |
7640 | AAMemoryLocation::StateType &State, bool &Changed); |
7641 | |
7642 | /// Used to allocate access sets. |
7643 | BumpPtrAllocator &Allocator; |
7644 | |
7645 | /// The set of IR attributes AAMemoryLocation deals with. |
7646 | static const Attribute::AttrKind AttrKinds[4]; |
7647 | }; |
7648 | |
7649 | const Attribute::AttrKind AAMemoryLocationImpl::AttrKinds[] = { |
7650 | Attribute::ReadNone, Attribute::InaccessibleMemOnly, Attribute::ArgMemOnly, |
7651 | Attribute::InaccessibleMemOrArgMemOnly}; |
7652 | |
7653 | void AAMemoryLocationImpl::categorizePtrValue( |
7654 | Attributor &A, const Instruction &I, const Value &Ptr, |
7655 | AAMemoryLocation::StateType &State, bool &Changed) { |
7656 | LLVM_DEBUG(dbgs() << "[AAMemoryLocation] Categorize pointer locations for "do { } while (false) |
7657 | << Ptr << " ["do { } while (false) |
7658 | << getMemoryLocationsAsStr(State.getAssumed()) << "]\n")do { } while (false); |
7659 | |
7660 | SmallVector<Value *, 8> Objects; |
7661 | if (!AA::getAssumedUnderlyingObjects(A, Ptr, Objects, *this, &I)) { |
7662 | LLVM_DEBUG(do { } while (false) |
7663 | dbgs() << "[AAMemoryLocation] Pointer locations not categorized\n")do { } while (false); |
7664 | updateStateAndAccessesMap(State, NO_UNKOWN_MEM, &I, nullptr, Changed, |
7665 | getAccessKindFromInst(&I)); |
7666 | return; |
7667 | } |
7668 | |
7669 | for (Value *Obj : Objects) { |
7670 | // TODO: recognize the TBAA used for constant accesses. |
7671 | MemoryLocationsKind MLK = NO_LOCATIONS; |
7672 | assert(!isa<GEPOperator>(Obj) && "GEPs should have been stripped.")((void)0); |
7673 | if (isa<UndefValue>(Obj)) |
7674 | continue; |
7675 | if (auto *Arg = dyn_cast<Argument>(Obj)) { |
7676 | if (Arg->hasByValAttr()) |
7677 | MLK = NO_LOCAL_MEM; |
7678 | else |
7679 | MLK = NO_ARGUMENT_MEM; |
7680 | } else if (auto *GV = dyn_cast<GlobalValue>(Obj)) { |
7681 | // Reading constant memory is not treated as a read "effect" by the |
7682 | // function attr pass so we won't neither. Constants defined by TBAA are |
7683 | // similar. (We know we do not write it because it is constant.) |
7684 | if (auto *GVar = dyn_cast<GlobalVariable>(GV)) |
7685 | if (GVar->isConstant()) |
7686 | continue; |
7687 | |
7688 | if (GV->hasLocalLinkage()) |
7689 | MLK = NO_GLOBAL_INTERNAL_MEM; |
7690 | else |
7691 | MLK = NO_GLOBAL_EXTERNAL_MEM; |
7692 | } else if (isa<ConstantPointerNull>(Obj) && |
7693 | !NullPointerIsDefined(getAssociatedFunction(), |
7694 | Ptr.getType()->getPointerAddressSpace())) { |
7695 | continue; |
7696 | } else if (isa<AllocaInst>(Obj)) { |
7697 | MLK = NO_LOCAL_MEM; |
7698 | } else if (const auto *CB = dyn_cast<CallBase>(Obj)) { |
7699 | const auto &NoAliasAA = A.getAAFor<AANoAlias>( |
7700 | *this, IRPosition::callsite_returned(*CB), DepClassTy::OPTIONAL); |
7701 | if (NoAliasAA.isAssumedNoAlias()) |
7702 | MLK = NO_MALLOCED_MEM; |
7703 | else |
7704 | MLK = NO_UNKOWN_MEM; |
7705 | } else { |
7706 | MLK = NO_UNKOWN_MEM; |
7707 | } |
7708 | |
7709 | assert(MLK != NO_LOCATIONS && "No location specified!")((void)0); |
7710 | LLVM_DEBUG(dbgs() << "[AAMemoryLocation] Ptr value can be categorized: "do { } while (false) |
7711 | << *Obj << " -> " << getMemoryLocationsAsStr(MLK)do { } while (false) |
7712 | << "\n")do { } while (false); |
7713 | updateStateAndAccessesMap(getState(), MLK, &I, Obj, Changed, |
7714 | getAccessKindFromInst(&I)); |
7715 | } |
7716 | |
7717 | LLVM_DEBUG(do { } while (false) |
7718 | dbgs() << "[AAMemoryLocation] Accessed locations with pointer locations: "do { } while (false) |
7719 | << getMemoryLocationsAsStr(State.getAssumed()) << "\n")do { } while (false); |
7720 | } |
7721 | |
7722 | void AAMemoryLocationImpl::categorizeArgumentPointerLocations( |
7723 | Attributor &A, CallBase &CB, AAMemoryLocation::StateType &AccessedLocs, |
7724 | bool &Changed) { |
7725 | for (unsigned ArgNo = 0, E = CB.getNumArgOperands(); ArgNo < E; ++ArgNo) { |
7726 | |
7727 | // Skip non-pointer arguments. |
7728 | const Value *ArgOp = CB.getArgOperand(ArgNo); |
7729 | if (!ArgOp->getType()->isPtrOrPtrVectorTy()) |
7730 | continue; |
7731 | |
7732 | // Skip readnone arguments. |
7733 | const IRPosition &ArgOpIRP = IRPosition::callsite_argument(CB, ArgNo); |
7734 | const auto &ArgOpMemLocationAA = |
7735 | A.getAAFor<AAMemoryBehavior>(*this, ArgOpIRP, DepClassTy::OPTIONAL); |
7736 | |
7737 | if (ArgOpMemLocationAA.isAssumedReadNone()) |
7738 | continue; |
7739 | |
7740 | // Categorize potentially accessed pointer arguments as if there was an |
7741 | // access instruction with them as pointer. |
7742 | categorizePtrValue(A, CB, *ArgOp, AccessedLocs, Changed); |
7743 | } |
7744 | } |
7745 | |
7746 | AAMemoryLocation::MemoryLocationsKind |
7747 | AAMemoryLocationImpl::categorizeAccessedLocations(Attributor &A, Instruction &I, |
7748 | bool &Changed) { |
7749 | LLVM_DEBUG(dbgs() << "[AAMemoryLocation] Categorize accessed locations for "do { } while (false) |
7750 | << I << "\n")do { } while (false); |
7751 | |
7752 | AAMemoryLocation::StateType AccessedLocs; |
7753 | AccessedLocs.intersectAssumedBits(NO_LOCATIONS); |
7754 | |
7755 | if (auto *CB = dyn_cast<CallBase>(&I)) { |
7756 | |
7757 | // First check if we assume any memory is access is visible. |
7758 | const auto &CBMemLocationAA = A.getAAFor<AAMemoryLocation>( |
7759 | *this, IRPosition::callsite_function(*CB), DepClassTy::OPTIONAL); |
7760 | LLVM_DEBUG(dbgs() << "[AAMemoryLocation] Categorize call site: " << Ido { } while (false) |
7761 | << " [" << CBMemLocationAA << "]\n")do { } while (false); |
7762 | |
7763 | if (CBMemLocationAA.isAssumedReadNone()) |
7764 | return NO_LOCATIONS; |
7765 | |
7766 | if (CBMemLocationAA.isAssumedInaccessibleMemOnly()) { |
7767 | updateStateAndAccessesMap(AccessedLocs, NO_INACCESSIBLE_MEM, &I, nullptr, |
7768 | Changed, getAccessKindFromInst(&I)); |
7769 | return AccessedLocs.getAssumed(); |
7770 | } |
7771 | |
7772 | uint32_t CBAssumedNotAccessedLocs = |
7773 | CBMemLocationAA.getAssumedNotAccessedLocation(); |
7774 | |
7775 | // Set the argmemonly and global bit as we handle them separately below. |
7776 | uint32_t CBAssumedNotAccessedLocsNoArgMem = |
7777 | CBAssumedNotAccessedLocs | NO_ARGUMENT_MEM | NO_GLOBAL_MEM; |
7778 | |
7779 | for (MemoryLocationsKind CurMLK = 1; CurMLK < NO_LOCATIONS; CurMLK *= 2) { |
7780 | if (CBAssumedNotAccessedLocsNoArgMem & CurMLK) |
7781 | continue; |
7782 | updateStateAndAccessesMap(AccessedLocs, CurMLK, &I, nullptr, Changed, |
7783 | getAccessKindFromInst(&I)); |
7784 | } |
7785 | |
7786 | // Now handle global memory if it might be accessed. This is slightly tricky |
7787 | // as NO_GLOBAL_MEM has multiple bits set. |
7788 | bool HasGlobalAccesses = ((~CBAssumedNotAccessedLocs) & NO_GLOBAL_MEM); |
7789 | if (HasGlobalAccesses) { |
7790 | auto AccessPred = [&](const Instruction *, const Value *Ptr, |
7791 | AccessKind Kind, MemoryLocationsKind MLK) { |
7792 | updateStateAndAccessesMap(AccessedLocs, MLK, &I, Ptr, Changed, |
7793 | getAccessKindFromInst(&I)); |
7794 | return true; |
7795 | }; |
7796 | if (!CBMemLocationAA.checkForAllAccessesToMemoryKind( |
7797 | AccessPred, inverseLocation(NO_GLOBAL_MEM, false, false))) |
7798 | return AccessedLocs.getWorstState(); |
7799 | } |
7800 | |
7801 | LLVM_DEBUG(do { } while (false) |
7802 | dbgs() << "[AAMemoryLocation] Accessed state before argument handling: "do { } while (false) |
7803 | << getMemoryLocationsAsStr(AccessedLocs.getAssumed()) << "\n")do { } while (false); |
7804 | |
7805 | // Now handle argument memory if it might be accessed. |
7806 | bool HasArgAccesses = ((~CBAssumedNotAccessedLocs) & NO_ARGUMENT_MEM); |
7807 | if (HasArgAccesses) |
7808 | categorizeArgumentPointerLocations(A, *CB, AccessedLocs, Changed); |
7809 | |
7810 | LLVM_DEBUG(do { } while (false) |
7811 | dbgs() << "[AAMemoryLocation] Accessed state after argument handling: "do { } while (false) |
7812 | << getMemoryLocationsAsStr(AccessedLocs.getAssumed()) << "\n")do { } while (false); |
7813 | |
7814 | return AccessedLocs.getAssumed(); |
7815 | } |
7816 | |
7817 | if (const Value *Ptr = getPointerOperand(&I, /* AllowVolatile */ true)) { |
7818 | LLVM_DEBUG(do { } while (false) |
7819 | dbgs() << "[AAMemoryLocation] Categorize memory access with pointer: "do { } while (false) |
7820 | << I << " [" << *Ptr << "]\n")do { } while (false); |
7821 | categorizePtrValue(A, I, *Ptr, AccessedLocs, Changed); |
7822 | return AccessedLocs.getAssumed(); |
7823 | } |
7824 | |
7825 | LLVM_DEBUG(dbgs() << "[AAMemoryLocation] Failed to categorize instruction: "do { } while (false) |
7826 | << I << "\n")do { } while (false); |
7827 | updateStateAndAccessesMap(AccessedLocs, NO_UNKOWN_MEM, &I, nullptr, Changed, |
7828 | getAccessKindFromInst(&I)); |
7829 | return AccessedLocs.getAssumed(); |
7830 | } |
7831 | |
7832 | /// An AA to represent the memory behavior function attributes. |
7833 | struct AAMemoryLocationFunction final : public AAMemoryLocationImpl { |
7834 | AAMemoryLocationFunction(const IRPosition &IRP, Attributor &A) |
7835 | : AAMemoryLocationImpl(IRP, A) {} |
7836 | |
7837 | /// See AbstractAttribute::updateImpl(Attributor &A). |
7838 | virtual ChangeStatus updateImpl(Attributor &A) override { |
7839 | |
7840 | const auto &MemBehaviorAA = |
7841 | A.getAAFor<AAMemoryBehavior>(*this, getIRPosition(), DepClassTy::NONE); |
7842 | if (MemBehaviorAA.isAssumedReadNone()) { |
7843 | if (MemBehaviorAA.isKnownReadNone()) |
7844 | return indicateOptimisticFixpoint(); |
7845 | assert(isAssumedReadNone() &&((void)0) |
7846 | "AAMemoryLocation was not read-none but AAMemoryBehavior was!")((void)0); |
7847 | A.recordDependence(MemBehaviorAA, *this, DepClassTy::OPTIONAL); |
7848 | return ChangeStatus::UNCHANGED; |
7849 | } |
7850 | |
7851 | // The current assumed state used to determine a change. |
7852 | auto AssumedState = getAssumed(); |
7853 | bool Changed = false; |
7854 | |
7855 | auto CheckRWInst = [&](Instruction &I) { |
7856 | MemoryLocationsKind MLK = categorizeAccessedLocations(A, I, Changed); |
7857 | LLVM_DEBUG(dbgs() << "[AAMemoryLocation] Accessed locations for " << Ido { } while (false) |
7858 | << ": " << getMemoryLocationsAsStr(MLK) << "\n")do { } while (false); |
7859 | removeAssumedBits(inverseLocation(MLK, false, false)); |
7860 | // Stop once only the valid bit set in the *not assumed location*, thus |
7861 | // once we don't actually exclude any memory locations in the state. |
7862 | return getAssumedNotAccessedLocation() != VALID_STATE; |
7863 | }; |
7864 | |
7865 | bool UsedAssumedInformation = false; |
7866 | if (!A.checkForAllReadWriteInstructions(CheckRWInst, *this, |
7867 | UsedAssumedInformation)) |
7868 | return indicatePessimisticFixpoint(); |
7869 | |
7870 | Changed |= AssumedState != getAssumed(); |
7871 | return Changed ? ChangeStatus::CHANGED : ChangeStatus::UNCHANGED; |
7872 | } |
7873 | |
7874 | /// See AbstractAttribute::trackStatistics() |
7875 | void trackStatistics() const override { |
7876 | if (isAssumedReadNone()) |
7877 | STATS_DECLTRACK_FN_ATTR(readnone){ static llvm::Statistic NumIRFunction_readnone = {"attributor" , "NumIRFunction_readnone", ("Number of " "functions" " marked '" "readnone" "'")};; ++(NumIRFunction_readnone); } |
7878 | else if (isAssumedArgMemOnly()) |
7879 | STATS_DECLTRACK_FN_ATTR(argmemonly){ static llvm::Statistic NumIRFunction_argmemonly = {"attributor" , "NumIRFunction_argmemonly", ("Number of " "functions" " marked '" "argmemonly" "'")};; ++(NumIRFunction_argmemonly); } |
7880 | else if (isAssumedInaccessibleMemOnly()) |
7881 | STATS_DECLTRACK_FN_ATTR(inaccessiblememonly){ static llvm::Statistic NumIRFunction_inaccessiblememonly = { "attributor", "NumIRFunction_inaccessiblememonly", ("Number of " "functions" " marked '" "inaccessiblememonly" "'")};; ++(NumIRFunction_inaccessiblememonly ); } |
7882 | else if (isAssumedInaccessibleOrArgMemOnly()) |
7883 | STATS_DECLTRACK_FN_ATTR(inaccessiblememorargmemonly){ static llvm::Statistic NumIRFunction_inaccessiblememorargmemonly = {"attributor", "NumIRFunction_inaccessiblememorargmemonly" , ("Number of " "functions" " marked '" "inaccessiblememorargmemonly" "'")};; ++(NumIRFunction_inaccessiblememorargmemonly); } |
7884 | } |
7885 | }; |
7886 | |
7887 | /// AAMemoryLocation attribute for call sites. |
7888 | struct AAMemoryLocationCallSite final : AAMemoryLocationImpl { |
7889 | AAMemoryLocationCallSite(const IRPosition &IRP, Attributor &A) |
7890 | : AAMemoryLocationImpl(IRP, A) {} |
7891 | |
7892 | /// See AbstractAttribute::initialize(...). |
7893 | void initialize(Attributor &A) override { |
7894 | AAMemoryLocationImpl::initialize(A); |
7895 | Function *F = getAssociatedFunction(); |
7896 | if (!F || F->isDeclaration()) |
7897 | indicatePessimisticFixpoint(); |
7898 | } |
7899 | |
7900 | /// See AbstractAttribute::updateImpl(...). |
7901 | ChangeStatus updateImpl(Attributor &A) override { |
7902 | // TODO: Once we have call site specific value information we can provide |
7903 | // call site specific liveness liveness information and then it makes |
7904 | // sense to specialize attributes for call sites arguments instead of |
7905 | // redirecting requests to the callee argument. |
7906 | Function *F = getAssociatedFunction(); |
7907 | const IRPosition &FnPos = IRPosition::function(*F); |
7908 | auto &FnAA = |
7909 | A.getAAFor<AAMemoryLocation>(*this, FnPos, DepClassTy::REQUIRED); |
7910 | bool Changed = false; |
7911 | auto AccessPred = [&](const Instruction *I, const Value *Ptr, |
7912 | AccessKind Kind, MemoryLocationsKind MLK) { |
7913 | updateStateAndAccessesMap(getState(), MLK, I, Ptr, Changed, |
7914 | getAccessKindFromInst(I)); |
7915 | return true; |
7916 | }; |
7917 | if (!FnAA.checkForAllAccessesToMemoryKind(AccessPred, ALL_LOCATIONS)) |
7918 | return indicatePessimisticFixpoint(); |
7919 | return Changed ? ChangeStatus::CHANGED : ChangeStatus::UNCHANGED; |
7920 | } |
7921 | |
7922 | /// See AbstractAttribute::trackStatistics() |
7923 | void trackStatistics() const override { |
7924 | if (isAssumedReadNone()) |
7925 | STATS_DECLTRACK_CS_ATTR(readnone){ static llvm::Statistic NumIRCS_readnone = {"attributor", "NumIRCS_readnone" , ("Number of " "call site" " marked '" "readnone" "'")};; ++ (NumIRCS_readnone); } |
7926 | } |
7927 | }; |
7928 | |
7929 | /// ------------------ Value Constant Range Attribute ------------------------- |
7930 | |
7931 | struct AAValueConstantRangeImpl : AAValueConstantRange { |
7932 | using StateType = IntegerRangeState; |
7933 | AAValueConstantRangeImpl(const IRPosition &IRP, Attributor &A) |
7934 | : AAValueConstantRange(IRP, A) {} |
7935 | |
7936 | /// See AbstractAttribute::initialize(..). |
7937 | void initialize(Attributor &A) override { |
7938 | if (A.hasSimplificationCallback(getIRPosition())) { |
7939 | indicatePessimisticFixpoint(); |
7940 | return; |
7941 | } |
7942 | |
7943 | // Intersect a range given by SCEV. |
7944 | intersectKnown(getConstantRangeFromSCEV(A, getCtxI())); |
7945 | |
7946 | // Intersect a range given by LVI. |
7947 | intersectKnown(getConstantRangeFromLVI(A, getCtxI())); |
7948 | } |
7949 | |
7950 | /// See AbstractAttribute::getAsStr(). |
7951 | const std::string getAsStr() const override { |
7952 | std::string Str; |
7953 | llvm::raw_string_ostream OS(Str); |
7954 | OS << "range(" << getBitWidth() << ")<"; |
7955 | getKnown().print(OS); |
7956 | OS << " / "; |
7957 | getAssumed().print(OS); |
7958 | OS << ">"; |
7959 | return OS.str(); |
7960 | } |
7961 | |
7962 | /// Helper function to get a SCEV expr for the associated value at program |
7963 | /// point \p I. |
7964 | const SCEV *getSCEV(Attributor &A, const Instruction *I = nullptr) const { |
7965 | if (!getAnchorScope()) |
7966 | return nullptr; |
7967 | |
7968 | ScalarEvolution *SE = |
7969 | A.getInfoCache().getAnalysisResultForFunction<ScalarEvolutionAnalysis>( |
7970 | *getAnchorScope()); |
7971 | |
7972 | LoopInfo *LI = A.getInfoCache().getAnalysisResultForFunction<LoopAnalysis>( |
7973 | *getAnchorScope()); |
7974 | |
7975 | if (!SE || !LI) |
7976 | return nullptr; |
7977 | |
7978 | const SCEV *S = SE->getSCEV(&getAssociatedValue()); |
7979 | if (!I) |
7980 | return S; |
7981 | |
7982 | return SE->getSCEVAtScope(S, LI->getLoopFor(I->getParent())); |
7983 | } |
7984 | |
7985 | /// Helper function to get a range from SCEV for the associated value at |
7986 | /// program point \p I. |
7987 | ConstantRange getConstantRangeFromSCEV(Attributor &A, |
7988 | const Instruction *I = nullptr) const { |
7989 | if (!getAnchorScope()) |
7990 | return getWorstState(getBitWidth()); |
7991 | |
7992 | ScalarEvolution *SE = |
7993 | A.getInfoCache().getAnalysisResultForFunction<ScalarEvolutionAnalysis>( |
7994 | *getAnchorScope()); |
7995 | |
7996 | const SCEV *S = getSCEV(A, I); |
7997 | if (!SE || !S) |
7998 | return getWorstState(getBitWidth()); |
7999 | |
8000 | return SE->getUnsignedRange(S); |
8001 | } |
8002 | |
8003 | /// Helper function to get a range from LVI for the associated value at |
8004 | /// program point \p I. |
8005 | ConstantRange |
8006 | getConstantRangeFromLVI(Attributor &A, |
8007 | const Instruction *CtxI = nullptr) const { |
8008 | if (!getAnchorScope()) |
8009 | return getWorstState(getBitWidth()); |
8010 | |
8011 | LazyValueInfo *LVI = |
8012 | A.getInfoCache().getAnalysisResultForFunction<LazyValueAnalysis>( |
8013 | *getAnchorScope()); |
8014 | |
8015 | if (!LVI || !CtxI) |
8016 | return getWorstState(getBitWidth()); |
8017 | return LVI->getConstantRange(&getAssociatedValue(), |
8018 | const_cast<Instruction *>(CtxI)); |
8019 | } |
8020 | |
8021 | /// Return true if \p CtxI is valid for querying outside analyses. |
8022 | /// This basically makes sure we do not ask intra-procedural analysis |
8023 | /// about a context in the wrong function or a context that violates |
8024 | /// dominance assumptions they might have. The \p AllowAACtxI flag indicates |
8025 | /// if the original context of this AA is OK or should be considered invalid. |
8026 | bool isValidCtxInstructionForOutsideAnalysis(Attributor &A, |
8027 | const Instruction *CtxI, |
8028 | bool AllowAACtxI) const { |
8029 | if (!CtxI || (!AllowAACtxI && CtxI == getCtxI())) |
8030 | return false; |
8031 | |
8032 | // Our context might be in a different function, neither intra-procedural |
8033 | // analysis (ScalarEvolution nor LazyValueInfo) can handle that. |
8034 | if (!AA::isValidInScope(getAssociatedValue(), CtxI->getFunction())) |
8035 | return false; |
8036 | |
8037 | // If the context is not dominated by the value there are paths to the |
8038 | // context that do not define the value. This cannot be handled by |
8039 | // LazyValueInfo so we need to bail. |
8040 | if (auto *I = dyn_cast<Instruction>(&getAssociatedValue())) { |
8041 | InformationCache &InfoCache = A.getInfoCache(); |
8042 | const DominatorTree *DT = |
8043 | InfoCache.getAnalysisResultForFunction<DominatorTreeAnalysis>( |
8044 | *I->getFunction()); |
8045 | return DT && DT->dominates(I, CtxI); |
8046 | } |
8047 | |
8048 | return true; |
8049 | } |
8050 | |
8051 | /// See AAValueConstantRange::getKnownConstantRange(..). |
8052 | ConstantRange |
8053 | getKnownConstantRange(Attributor &A, |
8054 | const Instruction *CtxI = nullptr) const override { |
8055 | if (!isValidCtxInstructionForOutsideAnalysis(A, CtxI, |
8056 | /* AllowAACtxI */ false)) |
8057 | return getKnown(); |
8058 | |
8059 | ConstantRange LVIR = getConstantRangeFromLVI(A, CtxI); |
8060 | ConstantRange SCEVR = getConstantRangeFromSCEV(A, CtxI); |
8061 | return getKnown().intersectWith(SCEVR).intersectWith(LVIR); |
8062 | } |
8063 | |
8064 | /// See AAValueConstantRange::getAssumedConstantRange(..). |
8065 | ConstantRange |
8066 | getAssumedConstantRange(Attributor &A, |
8067 | const Instruction *CtxI = nullptr) const override { |
8068 | // TODO: Make SCEV use Attributor assumption. |
8069 | // We may be able to bound a variable range via assumptions in |
8070 | // Attributor. ex.) If x is assumed to be in [1, 3] and y is known to |
8071 | // evolve to x^2 + x, then we can say that y is in [2, 12]. |
8072 | if (!isValidCtxInstructionForOutsideAnalysis(A, CtxI, |
8073 | /* AllowAACtxI */ false)) |
8074 | return getAssumed(); |
8075 | |
8076 | ConstantRange LVIR = getConstantRangeFromLVI(A, CtxI); |
8077 | ConstantRange SCEVR = getConstantRangeFromSCEV(A, CtxI); |
8078 | return getAssumed().intersectWith(SCEVR).intersectWith(LVIR); |
8079 | } |
8080 | |
8081 | /// Helper function to create MDNode for range metadata. |
8082 | static MDNode * |
8083 | getMDNodeForConstantRange(Type *Ty, LLVMContext &Ctx, |
8084 | const ConstantRange &AssumedConstantRange) { |
8085 | Metadata *LowAndHigh[] = {ConstantAsMetadata::get(ConstantInt::get( |
8086 | Ty, AssumedConstantRange.getLower())), |
8087 | ConstantAsMetadata::get(ConstantInt::get( |
8088 | Ty, AssumedConstantRange.getUpper()))}; |
8089 | return MDNode::get(Ctx, LowAndHigh); |
8090 | } |
8091 | |
8092 | /// Return true if \p Assumed is included in \p KnownRanges. |
8093 | static bool isBetterRange(const ConstantRange &Assumed, MDNode *KnownRanges) { |
8094 | |
8095 | if (Assumed.isFullSet()) |
8096 | return false; |
8097 | |
8098 | if (!KnownRanges) |
8099 | return true; |
8100 | |
8101 | // If multiple ranges are annotated in IR, we give up to annotate assumed |
8102 | // range for now. |
8103 | |
8104 | // TODO: If there exists a known range which containts assumed range, we |
8105 | // can say assumed range is better. |
8106 | if (KnownRanges->getNumOperands() > 2) |
8107 | return false; |
8108 | |
8109 | ConstantInt *Lower = |
8110 | mdconst::extract<ConstantInt>(KnownRanges->getOperand(0)); |
8111 | ConstantInt *Upper = |
8112 | mdconst::extract<ConstantInt>(KnownRanges->getOperand(1)); |
8113 | |
8114 | ConstantRange Known(Lower->getValue(), Upper->getValue()); |
8115 | return Known.contains(Assumed) && Known != Assumed; |
8116 | } |
8117 | |
8118 | /// Helper function to set range metadata. |
8119 | static bool |
8120 | setRangeMetadataIfisBetterRange(Instruction *I, |
8121 | const ConstantRange &AssumedConstantRange) { |
8122 | auto *OldRangeMD = I->getMetadata(LLVMContext::MD_range); |
8123 | if (isBetterRange(AssumedConstantRange, OldRangeMD)) { |
8124 | if (!AssumedConstantRange.isEmptySet()) { |
8125 | I->setMetadata(LLVMContext::MD_range, |
8126 | getMDNodeForConstantRange(I->getType(), I->getContext(), |
8127 | AssumedConstantRange)); |
8128 | return true; |
8129 | } |
8130 | } |
8131 | return false; |
8132 | } |
8133 | |
8134 | /// See AbstractAttribute::manifest() |
8135 | ChangeStatus manifest(Attributor &A) override { |
8136 | ChangeStatus Changed = ChangeStatus::UNCHANGED; |
8137 | ConstantRange AssumedConstantRange = getAssumedConstantRange(A); |
8138 | assert(!AssumedConstantRange.isFullSet() && "Invalid state")((void)0); |
8139 | |
8140 | auto &V = getAssociatedValue(); |
8141 | if (!AssumedConstantRange.isEmptySet() && |
8142 | !AssumedConstantRange.isSingleElement()) { |
8143 | if (Instruction *I = dyn_cast<Instruction>(&V)) { |
8144 | assert(I == getCtxI() && "Should not annotate an instruction which is "((void)0) |
8145 | "not the context instruction")((void)0); |
8146 | if (isa<CallInst>(I) || isa<LoadInst>(I)) |
8147 | if (setRangeMetadataIfisBetterRange(I, AssumedConstantRange)) |
8148 | Changed = ChangeStatus::CHANGED; |
8149 | } |
8150 | } |
8151 | |
8152 | return Changed; |
8153 | } |
8154 | }; |
8155 | |
8156 | struct AAValueConstantRangeArgument final |
8157 | : AAArgumentFromCallSiteArguments< |
8158 | AAValueConstantRange, AAValueConstantRangeImpl, IntegerRangeState, |
8159 | true /* BridgeCallBaseContext */> { |
8160 | using Base = AAArgumentFromCallSiteArguments< |
8161 | AAValueConstantRange, AAValueConstantRangeImpl, IntegerRangeState, |
8162 | true /* BridgeCallBaseContext */>; |
8163 | AAValueConstantRangeArgument(const IRPosition &IRP, Attributor &A) |
8164 | : Base(IRP, A) {} |
8165 | |
8166 | /// See AbstractAttribute::initialize(..). |
8167 | void initialize(Attributor &A) override { |
8168 | if (!getAnchorScope() || getAnchorScope()->isDeclaration()) { |
8169 | indicatePessimisticFixpoint(); |
8170 | } else { |
8171 | Base::initialize(A); |
8172 | } |
8173 | } |
8174 | |
8175 | /// See AbstractAttribute::trackStatistics() |
8176 | void trackStatistics() const override { |
8177 | STATS_DECLTRACK_ARG_ATTR(value_range){ static llvm::Statistic NumIRArguments_value_range = {"attributor" , "NumIRArguments_value_range", ("Number of " "arguments" " marked '" "value_range" "'")};; ++(NumIRArguments_value_range); } |
8178 | } |
8179 | }; |
8180 | |
8181 | struct AAValueConstantRangeReturned |
8182 | : AAReturnedFromReturnedValues<AAValueConstantRange, |
8183 | AAValueConstantRangeImpl, |
8184 | AAValueConstantRangeImpl::StateType, |
8185 | /* PropogateCallBaseContext */ true> { |
8186 | using Base = |
8187 | AAReturnedFromReturnedValues<AAValueConstantRange, |
8188 | AAValueConstantRangeImpl, |
8189 | AAValueConstantRangeImpl::StateType, |
8190 | /* PropogateCallBaseContext */ true>; |
8191 | AAValueConstantRangeReturned(const IRPosition &IRP, Attributor &A) |
8192 | : Base(IRP, A) {} |
8193 | |
8194 | /// See AbstractAttribute::initialize(...). |
8195 | void initialize(Attributor &A) override {} |
8196 | |
8197 | /// See AbstractAttribute::trackStatistics() |
8198 | void trackStatistics() const override { |
8199 | STATS_DECLTRACK_FNRET_ATTR(value_range){ static llvm::Statistic NumIRFunctionReturn_value_range = {"attributor" , "NumIRFunctionReturn_value_range", ("Number of " "function returns" " marked '" "value_range" "'")};; ++(NumIRFunctionReturn_value_range ); } |
8200 | } |
8201 | }; |
8202 | |
8203 | struct AAValueConstantRangeFloating : AAValueConstantRangeImpl { |
8204 | AAValueConstantRangeFloating(const IRPosition &IRP, Attributor &A) |
8205 | : AAValueConstantRangeImpl(IRP, A) {} |
8206 | |
8207 | /// See AbstractAttribute::initialize(...). |
8208 | void initialize(Attributor &A) override { |
8209 | AAValueConstantRangeImpl::initialize(A); |
8210 | if (isAtFixpoint()) |
8211 | return; |
8212 | |
8213 | Value &V = getAssociatedValue(); |
8214 | |
8215 | if (auto *C = dyn_cast<ConstantInt>(&V)) { |
8216 | unionAssumed(ConstantRange(C->getValue())); |
8217 | indicateOptimisticFixpoint(); |
8218 | return; |
8219 | } |
8220 | |
8221 | if (isa<UndefValue>(&V)) { |
8222 | // Collapse the undef state to 0. |
8223 | unionAssumed(ConstantRange(APInt(getBitWidth(), 0))); |
8224 | indicateOptimisticFixpoint(); |
8225 | return; |
8226 | } |
8227 | |
8228 | if (isa<CallBase>(&V)) |
8229 | return; |
8230 | |
8231 | if (isa<BinaryOperator>(&V) || isa<CmpInst>(&V) || isa<CastInst>(&V)) |
8232 | return; |
8233 | |
8234 | // If it is a load instruction with range metadata, use it. |
8235 | if (LoadInst *LI = dyn_cast<LoadInst>(&V)) |
8236 | if (auto *RangeMD = LI->getMetadata(LLVMContext::MD_range)) { |
8237 | intersectKnown(getConstantRangeFromMetadata(*RangeMD)); |
8238 | return; |
8239 | } |
8240 | |
8241 | // We can work with PHI and select instruction as we traverse their operands |
8242 | // during update. |
8243 | if (isa<SelectInst>(V) || isa<PHINode>(V)) |
8244 | return; |
8245 | |
8246 | // Otherwise we give up. |
8247 | indicatePessimisticFixpoint(); |
8248 | |
8249 | LLVM_DEBUG(dbgs() << "[AAValueConstantRange] We give up: "do { } while (false) |
8250 | << getAssociatedValue() << "\n")do { } while (false); |
8251 | } |
8252 | |
8253 | bool calculateBinaryOperator( |
8254 | Attributor &A, BinaryOperator *BinOp, IntegerRangeState &T, |
8255 | const Instruction *CtxI, |
8256 | SmallVectorImpl<const AAValueConstantRange *> &QuerriedAAs) { |
8257 | Value *LHS = BinOp->getOperand(0); |
8258 | Value *RHS = BinOp->getOperand(1); |
8259 | |
8260 | // Simplify the operands first. |
8261 | bool UsedAssumedInformation = false; |
8262 | const auto &SimplifiedLHS = |
8263 | A.getAssumedSimplified(IRPosition::value(*LHS, getCallBaseContext()), |
8264 | *this, UsedAssumedInformation); |
8265 | if (!SimplifiedLHS.hasValue()) |
8266 | return true; |
8267 | if (!SimplifiedLHS.getValue()) |
8268 | return false; |
8269 | LHS = *SimplifiedLHS; |
8270 | |
8271 | const auto &SimplifiedRHS = |
8272 | A.getAssumedSimplified(IRPosition::value(*RHS, getCallBaseContext()), |
8273 | *this, UsedAssumedInformation); |
8274 | if (!SimplifiedRHS.hasValue()) |
8275 | return true; |
8276 | if (!SimplifiedRHS.getValue()) |
8277 | return false; |
8278 | RHS = *SimplifiedRHS; |
8279 | |
8280 | // TODO: Allow non integers as well. |
8281 | if (!LHS->getType()->isIntegerTy() || !RHS->getType()->isIntegerTy()) |
8282 | return false; |
8283 | |
8284 | auto &LHSAA = A.getAAFor<AAValueConstantRange>( |
8285 | *this, IRPosition::value(*LHS, getCallBaseContext()), |
8286 | DepClassTy::REQUIRED); |
8287 | QuerriedAAs.push_back(&LHSAA); |
8288 | auto LHSAARange = LHSAA.getAssumedConstantRange(A, CtxI); |
8289 | |
8290 | auto &RHSAA = A.getAAFor<AAValueConstantRange>( |
8291 | *this, IRPosition::value(*RHS, getCallBaseContext()), |
8292 | DepClassTy::REQUIRED); |
8293 | QuerriedAAs.push_back(&RHSAA); |
8294 | auto RHSAARange = RHSAA.getAssumedConstantRange(A, CtxI); |
8295 | |
8296 | auto AssumedRange = LHSAARange.binaryOp(BinOp->getOpcode(), RHSAARange); |
8297 | |
8298 | T.unionAssumed(AssumedRange); |
8299 | |
8300 | // TODO: Track a known state too. |
8301 | |
8302 | return T.isValidState(); |
8303 | } |
8304 | |
8305 | bool calculateCastInst( |
8306 | Attributor &A, CastInst *CastI, IntegerRangeState &T, |
8307 | const Instruction *CtxI, |
8308 | SmallVectorImpl<const AAValueConstantRange *> &QuerriedAAs) { |
8309 | assert(CastI->getNumOperands() == 1 && "Expected cast to be unary!")((void)0); |
8310 | // TODO: Allow non integers as well. |
8311 | Value *OpV = CastI->getOperand(0); |
8312 | |
8313 | // Simplify the operand first. |
8314 | bool UsedAssumedInformation = false; |
8315 | const auto &SimplifiedOpV = |
8316 | A.getAssumedSimplified(IRPosition::value(*OpV, getCallBaseContext()), |
8317 | *this, UsedAssumedInformation); |
8318 | if (!SimplifiedOpV.hasValue()) |
8319 | return true; |
8320 | if (!SimplifiedOpV.getValue()) |
8321 | return false; |
8322 | OpV = *SimplifiedOpV; |
8323 | |
8324 | if (!OpV->getType()->isIntegerTy()) |
8325 | return false; |
8326 | |
8327 | auto &OpAA = A.getAAFor<AAValueConstantRange>( |
8328 | *this, IRPosition::value(*OpV, getCallBaseContext()), |
8329 | DepClassTy::REQUIRED); |
8330 | QuerriedAAs.push_back(&OpAA); |
8331 | T.unionAssumed( |
8332 | OpAA.getAssumed().castOp(CastI->getOpcode(), getState().getBitWidth())); |
8333 | return T.isValidState(); |
8334 | } |
8335 | |
8336 | bool |
8337 | calculateCmpInst(Attributor &A, CmpInst *CmpI, IntegerRangeState &T, |
8338 | const Instruction *CtxI, |
8339 | SmallVectorImpl<const AAValueConstantRange *> &QuerriedAAs) { |
8340 | Value *LHS = CmpI->getOperand(0); |
8341 | Value *RHS = CmpI->getOperand(1); |
8342 | |
8343 | // Simplify the operands first. |
8344 | bool UsedAssumedInformation = false; |
8345 | const auto &SimplifiedLHS = |
8346 | A.getAssumedSimplified(IRPosition::value(*LHS, getCallBaseContext()), |
8347 | *this, UsedAssumedInformation); |
8348 | if (!SimplifiedLHS.hasValue()) |
8349 | return true; |
8350 | if (!SimplifiedLHS.getValue()) |
8351 | return false; |
8352 | LHS = *SimplifiedLHS; |
8353 | |
8354 | const auto &SimplifiedRHS = |
8355 | A.getAssumedSimplified(IRPosition::value(*RHS, getCallBaseContext()), |
8356 | *this, UsedAssumedInformation); |
8357 | if (!SimplifiedRHS.hasValue()) |
8358 | return true; |
8359 | if (!SimplifiedRHS.getValue()) |
8360 | return false; |
8361 | RHS = *SimplifiedRHS; |
8362 | |
8363 | // TODO: Allow non integers as well. |
8364 | if (!LHS->getType()->isIntegerTy() || !RHS->getType()->isIntegerTy()) |
8365 | return false; |
8366 | |
8367 | auto &LHSAA = A.getAAFor<AAValueConstantRange>( |
8368 | *this, IRPosition::value(*LHS, getCallBaseContext()), |
8369 | DepClassTy::REQUIRED); |
8370 | QuerriedAAs.push_back(&LHSAA); |
8371 | auto &RHSAA = A.getAAFor<AAValueConstantRange>( |
8372 | *this, IRPosition::value(*RHS, getCallBaseContext()), |
8373 | DepClassTy::REQUIRED); |
8374 | QuerriedAAs.push_back(&RHSAA); |
8375 | auto LHSAARange = LHSAA.getAssumedConstantRange(A, CtxI); |
8376 | auto RHSAARange = RHSAA.getAssumedConstantRange(A, CtxI); |
8377 | |
8378 | // If one of them is empty set, we can't decide. |
8379 | if (LHSAARange.isEmptySet() || RHSAARange.isEmptySet()) |
8380 | return true; |
8381 | |
8382 | bool MustTrue = false, MustFalse = false; |
8383 | |
8384 | auto AllowedRegion = |
8385 | ConstantRange::makeAllowedICmpRegion(CmpI->getPredicate(), RHSAARange); |
8386 | |
8387 | if (AllowedRegion.intersectWith(LHSAARange).isEmptySet()) |
8388 | MustFalse = true; |
8389 | |
8390 | if (LHSAARange.icmp(CmpI->getPredicate(), RHSAARange)) |
8391 | MustTrue = true; |
8392 | |
8393 | assert((!MustTrue || !MustFalse) &&((void)0) |
8394 | "Either MustTrue or MustFalse should be false!")((void)0); |
8395 | |
8396 | if (MustTrue) |
8397 | T.unionAssumed(ConstantRange(APInt(/* numBits */ 1, /* val */ 1))); |
8398 | else if (MustFalse) |
8399 | T.unionAssumed(ConstantRange(APInt(/* numBits */ 1, /* val */ 0))); |
8400 | else |
8401 | T.unionAssumed(ConstantRange(/* BitWidth */ 1, /* isFullSet */ true)); |
8402 | |
8403 | LLVM_DEBUG(dbgs() << "[AAValueConstantRange] " << *CmpI << " " << LHSAAdo { } while (false) |
8404 | << " " << RHSAA << "\n")do { } while (false); |
8405 | |
8406 | // TODO: Track a known state too. |
8407 | return T.isValidState(); |
8408 | } |
8409 | |
8410 | /// See AbstractAttribute::updateImpl(...). |
8411 | ChangeStatus updateImpl(Attributor &A) override { |
8412 | auto VisitValueCB = [&](Value &V, const Instruction *CtxI, |
8413 | IntegerRangeState &T, bool Stripped) -> bool { |
8414 | Instruction *I = dyn_cast<Instruction>(&V); |
8415 | if (!I || isa<CallBase>(I)) { |
8416 | |
8417 | // Simplify the operand first. |
8418 | bool UsedAssumedInformation = false; |
8419 | const auto &SimplifiedOpV = |
8420 | A.getAssumedSimplified(IRPosition::value(V, getCallBaseContext()), |
8421 | *this, UsedAssumedInformation); |
8422 | if (!SimplifiedOpV.hasValue()) |
8423 | return true; |
8424 | if (!SimplifiedOpV.getValue()) |
8425 | return false; |
8426 | Value *VPtr = *SimplifiedOpV; |
8427 | |
8428 | // If the value is not instruction, we query AA to Attributor. |
8429 | const auto &AA = A.getAAFor<AAValueConstantRange>( |
8430 | *this, IRPosition::value(*VPtr, getCallBaseContext()), |
8431 | DepClassTy::REQUIRED); |
8432 | |
8433 | // Clamp operator is not used to utilize a program point CtxI. |
8434 | T.unionAssumed(AA.getAssumedConstantRange(A, CtxI)); |
8435 | |
8436 | return T.isValidState(); |
8437 | } |
8438 | |
8439 | SmallVector<const AAValueConstantRange *, 4> QuerriedAAs; |
8440 | if (auto *BinOp = dyn_cast<BinaryOperator>(I)) { |
8441 | if (!calculateBinaryOperator(A, BinOp, T, CtxI, QuerriedAAs)) |
8442 | return false; |
8443 | } else if (auto *CmpI = dyn_cast<CmpInst>(I)) { |
8444 | if (!calculateCmpInst(A, CmpI, T, CtxI, QuerriedAAs)) |
8445 | return false; |
8446 | } else if (auto *CastI = dyn_cast<CastInst>(I)) { |
8447 | if (!calculateCastInst(A, CastI, T, CtxI, QuerriedAAs)) |
8448 | return false; |
8449 | } else { |
8450 | // Give up with other instructions. |
8451 | // TODO: Add other instructions |
8452 | |
8453 | T.indicatePessimisticFixpoint(); |
8454 | return false; |
8455 | } |
8456 | |
8457 | // Catch circular reasoning in a pessimistic way for now. |
8458 | // TODO: Check how the range evolves and if we stripped anything, see also |
8459 | // AADereferenceable or AAAlign for similar situations. |
8460 | for (const AAValueConstantRange *QueriedAA : QuerriedAAs) { |
8461 | if (QueriedAA != this) |
8462 | continue; |
8463 | // If we are in a stady state we do not need to worry. |
8464 | if (T.getAssumed() == getState().getAssumed()) |
8465 | continue; |
8466 | T.indicatePessimisticFixpoint(); |
8467 | } |
8468 | |
8469 | return T.isValidState(); |
8470 | }; |
8471 | |
8472 | IntegerRangeState T(getBitWidth()); |
8473 | |
8474 | if (!genericValueTraversal<IntegerRangeState>(A, getIRPosition(), *this, T, |
8475 | VisitValueCB, getCtxI(), |
8476 | /* UseValueSimplify */ false)) |
8477 | return indicatePessimisticFixpoint(); |
8478 | |
8479 | return clampStateAndIndicateChange(getState(), T); |
8480 | } |
8481 | |
8482 | /// See AbstractAttribute::trackStatistics() |
8483 | void trackStatistics() const override { |
8484 | STATS_DECLTRACK_FLOATING_ATTR(value_range){ static llvm::Statistic NumIRFloating_value_range = {"attributor" , "NumIRFloating_value_range", ("Number of floating values known to be '" "value_range" "'")};; ++(NumIRFloating_value_range); } |
8485 | } |
8486 | }; |
8487 | |
8488 | struct AAValueConstantRangeFunction : AAValueConstantRangeImpl { |
8489 | AAValueConstantRangeFunction(const IRPosition &IRP, Attributor &A) |
8490 | : AAValueConstantRangeImpl(IRP, A) {} |
8491 | |
8492 | /// See AbstractAttribute::initialize(...). |
8493 | ChangeStatus updateImpl(Attributor &A) override { |
8494 | llvm_unreachable("AAValueConstantRange(Function|CallSite)::updateImpl will "__builtin_unreachable() |
8495 | "not be called")__builtin_unreachable(); |
8496 | } |
8497 | |
8498 | /// See AbstractAttribute::trackStatistics() |
8499 | void trackStatistics() const override { STATS_DECLTRACK_FN_ATTR(value_range){ static llvm::Statistic NumIRFunction_value_range = {"attributor" , "NumIRFunction_value_range", ("Number of " "functions" " marked '" "value_range" "'")};; ++(NumIRFunction_value_range); } } |
8500 | }; |
8501 | |
8502 | struct AAValueConstantRangeCallSite : AAValueConstantRangeFunction { |
8503 | AAValueConstantRangeCallSite(const IRPosition &IRP, Attributor &A) |
8504 | : AAValueConstantRangeFunction(IRP, A) {} |
8505 | |
8506 | /// See AbstractAttribute::trackStatistics() |
8507 | void trackStatistics() const override { STATS_DECLTRACK_CS_ATTR(value_range){ static llvm::Statistic NumIRCS_value_range = {"attributor", "NumIRCS_value_range", ("Number of " "call site" " marked '" "value_range" "'")};; ++(NumIRCS_value_range); } } |
8508 | }; |
8509 | |
8510 | struct AAValueConstantRangeCallSiteReturned |
8511 | : AACallSiteReturnedFromReturned<AAValueConstantRange, |
8512 | AAValueConstantRangeImpl, |
8513 | AAValueConstantRangeImpl::StateType, |
8514 | /* IntroduceCallBaseContext */ true> { |
8515 | AAValueConstantRangeCallSiteReturned(const IRPosition &IRP, Attributor &A) |
8516 | : AACallSiteReturnedFromReturned<AAValueConstantRange, |
8517 | AAValueConstantRangeImpl, |
8518 | AAValueConstantRangeImpl::StateType, |
8519 | /* IntroduceCallBaseContext */ true>(IRP, |
8520 | A) { |
8521 | } |
8522 | |
8523 | /// See AbstractAttribute::initialize(...). |
8524 | void initialize(Attributor &A) override { |
8525 | // If it is a load instruction with range metadata, use the metadata. |
8526 | if (CallInst *CI = dyn_cast<CallInst>(&getAssociatedValue())) |
8527 | if (auto *RangeMD = CI->getMetadata(LLVMContext::MD_range)) |
8528 | intersectKnown(getConstantRangeFromMetadata(*RangeMD)); |
8529 | |
8530 | AAValueConstantRangeImpl::initialize(A); |
8531 | } |
8532 | |
8533 | /// See AbstractAttribute::trackStatistics() |
8534 | void trackStatistics() const override { |
8535 | STATS_DECLTRACK_CSRET_ATTR(value_range){ static llvm::Statistic NumIRCSReturn_value_range = {"attributor" , "NumIRCSReturn_value_range", ("Number of " "call site returns" " marked '" "value_range" "'")};; ++(NumIRCSReturn_value_range ); } |
8536 | } |
8537 | }; |
8538 | struct AAValueConstantRangeCallSiteArgument : AAValueConstantRangeFloating { |
8539 | AAValueConstantRangeCallSiteArgument(const IRPosition &IRP, Attributor &A) |
8540 | : AAValueConstantRangeFloating(IRP, A) {} |
8541 | |
8542 | /// See AbstractAttribute::manifest() |
8543 | ChangeStatus manifest(Attributor &A) override { |
8544 | return ChangeStatus::UNCHANGED; |
8545 | } |
8546 | |
8547 | /// See AbstractAttribute::trackStatistics() |
8548 | void trackStatistics() const override { |
8549 | STATS_DECLTRACK_CSARG_ATTR(value_range){ static llvm::Statistic NumIRCSArguments_value_range = {"attributor" , "NumIRCSArguments_value_range", ("Number of " "call site arguments" " marked '" "value_range" "'")};; ++(NumIRCSArguments_value_range ); } |
8550 | } |
8551 | }; |
8552 | |
8553 | /// ------------------ Potential Values Attribute ------------------------- |
8554 | |
8555 | struct AAPotentialValuesImpl : AAPotentialValues { |
8556 | using StateType = PotentialConstantIntValuesState; |
8557 | |
8558 | AAPotentialValuesImpl(const IRPosition &IRP, Attributor &A) |
8559 | : AAPotentialValues(IRP, A) {} |
8560 | |
8561 | /// See AbstractAttribute::initialize(..). |
8562 | void initialize(Attributor &A) override { |
8563 | if (A.hasSimplificationCallback(getIRPosition())) |
8564 | indicatePessimisticFixpoint(); |
8565 | else |
8566 | AAPotentialValues::initialize(A); |
8567 | } |
8568 | |
8569 | /// See AbstractAttribute::getAsStr(). |
8570 | const std::string getAsStr() const override { |
8571 | std::string Str; |
8572 | llvm::raw_string_ostream OS(Str); |
8573 | OS << getState(); |
8574 | return OS.str(); |
8575 | } |
8576 | |
8577 | /// See AbstractAttribute::updateImpl(...). |
8578 | ChangeStatus updateImpl(Attributor &A) override { |
8579 | return indicatePessimisticFixpoint(); |
8580 | } |
8581 | }; |
8582 | |
8583 | struct AAPotentialValuesArgument final |
8584 | : AAArgumentFromCallSiteArguments<AAPotentialValues, AAPotentialValuesImpl, |
8585 | PotentialConstantIntValuesState> { |
8586 | using Base = |
8587 | AAArgumentFromCallSiteArguments<AAPotentialValues, AAPotentialValuesImpl, |
8588 | PotentialConstantIntValuesState>; |
8589 | AAPotentialValuesArgument(const IRPosition &IRP, Attributor &A) |
8590 | : Base(IRP, A) {} |
8591 | |
8592 | /// See AbstractAttribute::initialize(..). |
8593 | void initialize(Attributor &A) override { |
8594 | if (!getAnchorScope() || getAnchorScope()->isDeclaration()) { |
8595 | indicatePessimisticFixpoint(); |
8596 | } else { |
8597 | Base::initialize(A); |
8598 | } |
8599 | } |
8600 | |
8601 | /// See AbstractAttribute::trackStatistics() |
8602 | void trackStatistics() const override { |
8603 | STATS_DECLTRACK_ARG_ATTR(potential_values){ static llvm::Statistic NumIRArguments_potential_values = {"attributor" , "NumIRArguments_potential_values", ("Number of " "arguments" " marked '" "potential_values" "'")};; ++(NumIRArguments_potential_values ); } |
8604 | } |
8605 | }; |
8606 | |
8607 | struct AAPotentialValuesReturned |
8608 | : AAReturnedFromReturnedValues<AAPotentialValues, AAPotentialValuesImpl> { |
8609 | using Base = |
8610 | AAReturnedFromReturnedValues<AAPotentialValues, AAPotentialValuesImpl>; |
8611 | AAPotentialValuesReturned(const IRPosition &IRP, Attributor &A) |
8612 | : Base(IRP, A) {} |
8613 | |
8614 | /// See AbstractAttribute::trackStatistics() |
8615 | void trackStatistics() const override { |
8616 | STATS_DECLTRACK_FNRET_ATTR(potential_values){ static llvm::Statistic NumIRFunctionReturn_potential_values = {"attributor", "NumIRFunctionReturn_potential_values", ("Number of " "function returns" " marked '" "potential_values" "'")};; ++ (NumIRFunctionReturn_potential_values); } |
8617 | } |
8618 | }; |
8619 | |
8620 | struct AAPotentialValuesFloating : AAPotentialValuesImpl { |
8621 | AAPotentialValuesFloating(const IRPosition &IRP, Attributor &A) |
8622 | : AAPotentialValuesImpl(IRP, A) {} |
8623 | |
8624 | /// See AbstractAttribute::initialize(..). |
8625 | void initialize(Attributor &A) override { |
8626 | AAPotentialValuesImpl::initialize(A); |
8627 | if (isAtFixpoint()) |
8628 | return; |
8629 | |
8630 | Value &V = getAssociatedValue(); |
8631 | |
8632 | if (auto *C = dyn_cast<ConstantInt>(&V)) { |
8633 | unionAssumed(C->getValue()); |
8634 | indicateOptimisticFixpoint(); |
8635 | return; |
8636 | } |
8637 | |
8638 | if (isa<UndefValue>(&V)) { |
8639 | unionAssumedWithUndef(); |
8640 | indicateOptimisticFixpoint(); |
8641 | return; |
8642 | } |
8643 | |
8644 | if (isa<BinaryOperator>(&V) || isa<ICmpInst>(&V) || isa<CastInst>(&V)) |
8645 | return; |
8646 | |
8647 | if (isa<SelectInst>(V) || isa<PHINode>(V) || isa<LoadInst>(V)) |
8648 | return; |
8649 | |
8650 | indicatePessimisticFixpoint(); |
8651 | |
8652 | LLVM_DEBUG(dbgs() << "[AAPotentialValues] We give up: "do { } while (false) |
8653 | << getAssociatedValue() << "\n")do { } while (false); |
8654 | } |
8655 | |
8656 | static bool calculateICmpInst(const ICmpInst *ICI, const APInt &LHS, |
8657 | const APInt &RHS) { |
8658 | ICmpInst::Predicate Pred = ICI->getPredicate(); |
8659 | switch (Pred) { |
8660 | case ICmpInst::ICMP_UGT: |
8661 | return LHS.ugt(RHS); |
8662 | case ICmpInst::ICMP_SGT: |
8663 | return LHS.sgt(RHS); |
8664 | case ICmpInst::ICMP_EQ: |
8665 | return LHS.eq(RHS); |
8666 | case ICmpInst::ICMP_UGE: |
8667 | return LHS.uge(RHS); |
8668 | case ICmpInst::ICMP_SGE: |
8669 | return LHS.sge(RHS); |
8670 | case ICmpInst::ICMP_ULT: |
8671 | return LHS.ult(RHS); |
8672 | case ICmpInst::ICMP_SLT: |
8673 | return LHS.slt(RHS); |
8674 | case ICmpInst::ICMP_NE: |
8675 | return LHS.ne(RHS); |
8676 | case ICmpInst::ICMP_ULE: |
8677 | return LHS.ule(RHS); |
8678 | case ICmpInst::ICMP_SLE: |
8679 | return LHS.sle(RHS); |
8680 | default: |
8681 | llvm_unreachable("Invalid ICmp predicate!")__builtin_unreachable(); |
8682 | } |
8683 | } |
8684 | |
8685 | static APInt calculateCastInst(const CastInst *CI, const APInt &Src, |
8686 | uint32_t ResultBitWidth) { |
8687 | Instruction::CastOps CastOp = CI->getOpcode(); |
8688 | switch (CastOp) { |
8689 | default: |
8690 | llvm_unreachable("unsupported or not integer cast")__builtin_unreachable(); |
8691 | case Instruction::Trunc: |
8692 | return Src.trunc(ResultBitWidth); |
8693 | case Instruction::SExt: |
8694 | return Src.sext(ResultBitWidth); |
8695 | case Instruction::ZExt: |
8696 | return Src.zext(ResultBitWidth); |
8697 | case Instruction::BitCast: |
8698 | return Src; |
8699 | } |
8700 | } |
8701 | |
8702 | static APInt calculateBinaryOperator(const BinaryOperator *BinOp, |
8703 | const APInt &LHS, const APInt &RHS, |
8704 | bool &SkipOperation, bool &Unsupported) { |
8705 | Instruction::BinaryOps BinOpcode = BinOp->getOpcode(); |
8706 | // Unsupported is set to true when the binary operator is not supported. |
8707 | // SkipOperation is set to true when UB occur with the given operand pair |
8708 | // (LHS, RHS). |
8709 | // TODO: we should look at nsw and nuw keywords to handle operations |
8710 | // that create poison or undef value. |
8711 | switch (BinOpcode) { |
8712 | default: |
8713 | Unsupported = true; |
8714 | return LHS; |
8715 | case Instruction::Add: |
8716 | return LHS + RHS; |
8717 | case Instruction::Sub: |
8718 | return LHS - RHS; |
8719 | case Instruction::Mul: |
8720 | return LHS * RHS; |
8721 | case Instruction::UDiv: |
8722 | if (RHS.isNullValue()) { |
8723 | SkipOperation = true; |
8724 | return LHS; |
8725 | } |
8726 | return LHS.udiv(RHS); |
8727 | case Instruction::SDiv: |
8728 | if (RHS.isNullValue()) { |
8729 | SkipOperation = true; |
8730 | return LHS; |
8731 | } |
8732 | return LHS.sdiv(RHS); |
8733 | case Instruction::URem: |
8734 | if (RHS.isNullValue()) { |
8735 | SkipOperation = true; |
8736 | return LHS; |
8737 | } |
8738 | return LHS.urem(RHS); |
8739 | case Instruction::SRem: |
8740 | if (RHS.isNullValue()) { |
8741 | SkipOperation = true; |
8742 | return LHS; |
8743 | } |
8744 | return LHS.srem(RHS); |
8745 | case Instruction::Shl: |
8746 | return LHS.shl(RHS); |
8747 | case Instruction::LShr: |
8748 | return LHS.lshr(RHS); |
8749 | case Instruction::AShr: |
8750 | return LHS.ashr(RHS); |
8751 | case Instruction::And: |
8752 | return LHS & RHS; |
8753 | case Instruction::Or: |
8754 | return LHS | RHS; |
8755 | case Instruction::Xor: |
8756 | return LHS ^ RHS; |
8757 | } |
8758 | } |
8759 | |
8760 | bool calculateBinaryOperatorAndTakeUnion(const BinaryOperator *BinOp, |
8761 | const APInt &LHS, const APInt &RHS) { |
8762 | bool SkipOperation = false; |
8763 | bool Unsupported = false; |
8764 | APInt Result = |
8765 | calculateBinaryOperator(BinOp, LHS, RHS, SkipOperation, Unsupported); |
8766 | if (Unsupported) |
8767 | return false; |
8768 | // If SkipOperation is true, we can ignore this operand pair (L, R). |
8769 | if (!SkipOperation) |
8770 | unionAssumed(Result); |
8771 | return isValidState(); |
8772 | } |
8773 | |
8774 | ChangeStatus updateWithICmpInst(Attributor &A, ICmpInst *ICI) { |
8775 | auto AssumedBefore = getAssumed(); |
8776 | Value *LHS = ICI->getOperand(0); |
8777 | Value *RHS = ICI->getOperand(1); |
8778 | |
8779 | // Simplify the operands first. |
8780 | bool UsedAssumedInformation = false; |
8781 | const auto &SimplifiedLHS = |
8782 | A.getAssumedSimplified(IRPosition::value(*LHS, getCallBaseContext()), |
8783 | *this, UsedAssumedInformation); |
8784 | if (!SimplifiedLHS.hasValue()) |
8785 | return ChangeStatus::UNCHANGED; |
8786 | if (!SimplifiedLHS.getValue()) |
8787 | return indicatePessimisticFixpoint(); |
8788 | LHS = *SimplifiedLHS; |
8789 | |
8790 | const auto &SimplifiedRHS = |
8791 | A.getAssumedSimplified(IRPosition::value(*RHS, getCallBaseContext()), |
8792 | *this, UsedAssumedInformation); |
8793 | if (!SimplifiedRHS.hasValue()) |
8794 | return ChangeStatus::UNCHANGED; |
8795 | if (!SimplifiedRHS.getValue()) |
8796 | return indicatePessimisticFixpoint(); |
8797 | RHS = *SimplifiedRHS; |
8798 | |
8799 | if (!LHS->getType()->isIntegerTy() || !RHS->getType()->isIntegerTy()) |
8800 | return indicatePessimisticFixpoint(); |
8801 | |
8802 | auto &LHSAA = A.getAAFor<AAPotentialValues>(*this, IRPosition::value(*LHS), |
8803 | DepClassTy::REQUIRED); |
8804 | if (!LHSAA.isValidState()) |
8805 | return indicatePessimisticFixpoint(); |
8806 | |
8807 | auto &RHSAA = A.getAAFor<AAPotentialValues>(*this, IRPosition::value(*RHS), |
8808 | DepClassTy::REQUIRED); |
8809 | if (!RHSAA.isValidState()) |
8810 | return indicatePessimisticFixpoint(); |
8811 | |
8812 | const DenseSet<APInt> &LHSAAPVS = LHSAA.getAssumedSet(); |
8813 | const DenseSet<APInt> &RHSAAPVS = RHSAA.getAssumedSet(); |
8814 | |
8815 | // TODO: make use of undef flag to limit potential values aggressively. |
8816 | bool MaybeTrue = false, MaybeFalse = false; |
8817 | const APInt Zero(RHS->getType()->getIntegerBitWidth(), 0); |
8818 | if (LHSAA.undefIsContained() && RHSAA.undefIsContained()) { |
8819 | // The result of any comparison between undefs can be soundly replaced |
8820 | // with undef. |
8821 | unionAssumedWithUndef(); |
8822 | } else if (LHSAA.undefIsContained()) { |
8823 | for (const APInt &R : RHSAAPVS) { |
8824 | bool CmpResult = calculateICmpInst(ICI, Zero, R); |
8825 | MaybeTrue |= CmpResult; |
8826 | MaybeFalse |= !CmpResult; |
8827 | if (MaybeTrue & MaybeFalse) |
8828 | return indicatePessimisticFixpoint(); |
8829 | } |
8830 | } else if (RHSAA.undefIsContained()) { |
8831 | for (const APInt &L : LHSAAPVS) { |
8832 | bool CmpResult = calculateICmpInst(ICI, L, Zero); |
8833 | MaybeTrue |= CmpResult; |
8834 | MaybeFalse |= !CmpResult; |
8835 | if (MaybeTrue & MaybeFalse) |
8836 | return indicatePessimisticFixpoint(); |
8837 | } |
8838 | } else { |
8839 | for (const APInt &L : LHSAAPVS) { |
8840 | for (const APInt &R : RHSAAPVS) { |
8841 | bool CmpResult = calculateICmpInst(ICI, L, R); |
8842 | MaybeTrue |= CmpResult; |
8843 | MaybeFalse |= !CmpResult; |
8844 | if (MaybeTrue & MaybeFalse) |
8845 | return indicatePessimisticFixpoint(); |
8846 | } |
8847 | } |
8848 | } |
8849 | if (MaybeTrue) |
8850 | unionAssumed(APInt(/* numBits */ 1, /* val */ 1)); |
8851 | if (MaybeFalse) |
8852 | unionAssumed(APInt(/* numBits */ 1, /* val */ 0)); |
8853 | return AssumedBefore == getAssumed() ? ChangeStatus::UNCHANGED |
8854 | : ChangeStatus::CHANGED; |
8855 | } |
8856 | |
8857 | ChangeStatus updateWithSelectInst(Attributor &A, SelectInst *SI) { |
8858 | auto AssumedBefore = getAssumed(); |
8859 | Value *LHS = SI->getTrueValue(); |
8860 | Value *RHS = SI->getFalseValue(); |
8861 | |
8862 | // Simplify the operands first. |
8863 | bool UsedAssumedInformation = false; |
8864 | const auto &SimplifiedLHS = |
8865 | A.getAssumedSimplified(IRPosition::value(*LHS, getCallBaseContext()), |
8866 | *this, UsedAssumedInformation); |
8867 | if (!SimplifiedLHS.hasValue()) |
8868 | return ChangeStatus::UNCHANGED; |
8869 | if (!SimplifiedLHS.getValue()) |
8870 | return indicatePessimisticFixpoint(); |
8871 | LHS = *SimplifiedLHS; |
8872 | |
8873 | const auto &SimplifiedRHS = |
8874 | A.getAssumedSimplified(IRPosition::value(*RHS, getCallBaseContext()), |
8875 | *this, UsedAssumedInformation); |
8876 | if (!SimplifiedRHS.hasValue()) |
8877 | return ChangeStatus::UNCHANGED; |
8878 | if (!SimplifiedRHS.getValue()) |
8879 | return indicatePessimisticFixpoint(); |
8880 | RHS = *SimplifiedRHS; |
8881 | |
8882 | if (!LHS->getType()->isIntegerTy() || !RHS->getType()->isIntegerTy()) |
8883 | return indicatePessimisticFixpoint(); |
8884 | |
8885 | Optional<Constant *> C = A.getAssumedConstant(*SI->getCondition(), *this, |
8886 | UsedAssumedInformation); |
8887 | |
8888 | // Check if we only need one operand. |
8889 | bool OnlyLeft = false, OnlyRight = false; |
8890 | if (C.hasValue() && *C && (*C)->isOneValue()) |
8891 | OnlyLeft = true; |
8892 | else if (C.hasValue() && *C && (*C)->isZeroValue()) |
8893 | OnlyRight = true; |
8894 | |
8895 | const AAPotentialValues *LHSAA = nullptr, *RHSAA = nullptr; |
8896 | if (!OnlyRight) { |
8897 | LHSAA = &A.getAAFor<AAPotentialValues>(*this, IRPosition::value(*LHS), |
8898 | DepClassTy::REQUIRED); |
8899 | if (!LHSAA->isValidState()) |
8900 | return indicatePessimisticFixpoint(); |
8901 | } |
8902 | if (!OnlyLeft) { |
8903 | RHSAA = &A.getAAFor<AAPotentialValues>(*this, IRPosition::value(*RHS), |
8904 | DepClassTy::REQUIRED); |
8905 | if (!RHSAA->isValidState()) |
8906 | return indicatePessimisticFixpoint(); |
8907 | } |
8908 | |
8909 | if (!LHSAA || !RHSAA) { |
8910 | // select (true/false), lhs, rhs |
8911 | auto *OpAA = LHSAA ? LHSAA : RHSAA; |
8912 | |
8913 | if (OpAA->undefIsContained()) |
8914 | unionAssumedWithUndef(); |
8915 | else |
8916 | unionAssumed(*OpAA); |
8917 | |
8918 | } else if (LHSAA->undefIsContained() && RHSAA->undefIsContained()) { |
8919 | // select i1 *, undef , undef => undef |
8920 | unionAssumedWithUndef(); |
8921 | } else { |
8922 | unionAssumed(*LHSAA); |
8923 | unionAssumed(*RHSAA); |
8924 | } |
8925 | return AssumedBefore == getAssumed() ? ChangeStatus::UNCHANGED |
8926 | : ChangeStatus::CHANGED; |
8927 | } |
8928 | |
8929 | ChangeStatus updateWithCastInst(Attributor &A, CastInst *CI) { |
8930 | auto AssumedBefore = getAssumed(); |
8931 | if (!CI->isIntegerCast()) |
8932 | return indicatePessimisticFixpoint(); |
8933 | assert(CI->getNumOperands() == 1 && "Expected cast to be unary!")((void)0); |
8934 | uint32_t ResultBitWidth = CI->getDestTy()->getIntegerBitWidth(); |
8935 | Value *Src = CI->getOperand(0); |
8936 | |
8937 | // Simplify the operand first. |
8938 | bool UsedAssumedInformation = false; |
8939 | const auto &SimplifiedSrc = |
8940 | A.getAssumedSimplified(IRPosition::value(*Src, getCallBaseContext()), |
8941 | *this, UsedAssumedInformation); |
8942 | if (!SimplifiedSrc.hasValue()) |
8943 | return ChangeStatus::UNCHANGED; |
8944 | if (!SimplifiedSrc.getValue()) |
8945 | return indicatePessimisticFixpoint(); |
8946 | Src = *SimplifiedSrc; |
8947 | |
8948 | auto &SrcAA = A.getAAFor<AAPotentialValues>(*this, IRPosition::value(*Src), |
8949 | DepClassTy::REQUIRED); |
8950 | if (!SrcAA.isValidState()) |
8951 | return indicatePessimisticFixpoint(); |
8952 | const DenseSet<APInt> &SrcAAPVS = SrcAA.getAssumedSet(); |
8953 | if (SrcAA.undefIsContained()) |
8954 | unionAssumedWithUndef(); |
8955 | else { |
8956 | for (const APInt &S : SrcAAPVS) { |
8957 | APInt T = calculateCastInst(CI, S, ResultBitWidth); |
8958 | unionAssumed(T); |
8959 | } |
8960 | } |
8961 | return AssumedBefore == getAssumed() ? ChangeStatus::UNCHANGED |
8962 | : ChangeStatus::CHANGED; |
8963 | } |
8964 | |
8965 | ChangeStatus updateWithBinaryOperator(Attributor &A, BinaryOperator *BinOp) { |
8966 | auto AssumedBefore = getAssumed(); |
8967 | Value *LHS = BinOp->getOperand(0); |
8968 | Value *RHS = BinOp->getOperand(1); |
8969 | |
8970 | // Simplify the operands first. |
8971 | bool UsedAssumedInformation = false; |
8972 | const auto &SimplifiedLHS = |
8973 | A.getAssumedSimplified(IRPosition::value(*LHS, getCallBaseContext()), |
8974 | *this, UsedAssumedInformation); |
8975 | if (!SimplifiedLHS.hasValue()) |
8976 | return ChangeStatus::UNCHANGED; |
8977 | if (!SimplifiedLHS.getValue()) |
8978 | return indicatePessimisticFixpoint(); |
8979 | LHS = *SimplifiedLHS; |
8980 | |
8981 | const auto &SimplifiedRHS = |
8982 | A.getAssumedSimplified(IRPosition::value(*RHS, getCallBaseContext()), |
8983 | *this, UsedAssumedInformation); |
8984 | if (!SimplifiedRHS.hasValue()) |
8985 | return ChangeStatus::UNCHANGED; |
8986 | if (!SimplifiedRHS.getValue()) |
8987 | return indicatePessimisticFixpoint(); |
8988 | RHS = *SimplifiedRHS; |
8989 | |
8990 | if (!LHS->getType()->isIntegerTy() || !RHS->getType()->isIntegerTy()) |
8991 | return indicatePessimisticFixpoint(); |
8992 | |
8993 | auto &LHSAA = A.getAAFor<AAPotentialValues>(*this, IRPosition::value(*LHS), |
8994 | DepClassTy::REQUIRED); |
8995 | if (!LHSAA.isValidState()) |
8996 | return indicatePessimisticFixpoint(); |
8997 | |
8998 | auto &RHSAA = A.getAAFor<AAPotentialValues>(*this, IRPosition::value(*RHS), |
8999 | DepClassTy::REQUIRED); |
9000 | if (!RHSAA.isValidState()) |
9001 | return indicatePessimisticFixpoint(); |
9002 | |
9003 | const DenseSet<APInt> &LHSAAPVS = LHSAA.getAssumedSet(); |
9004 | const DenseSet<APInt> &RHSAAPVS = RHSAA.getAssumedSet(); |
9005 | const APInt Zero = APInt(LHS->getType()->getIntegerBitWidth(), 0); |
9006 | |
9007 | // TODO: make use of undef flag to limit potential values aggressively. |
9008 | if (LHSAA.undefIsContained() && RHSAA.undefIsContained()) { |
9009 | if (!calculateBinaryOperatorAndTakeUnion(BinOp, Zero, Zero)) |
9010 | return indicatePessimisticFixpoint(); |
9011 | } else if (LHSAA.undefIsContained()) { |
9012 | for (const APInt &R : RHSAAPVS) { |
9013 | if (!calculateBinaryOperatorAndTakeUnion(BinOp, Zero, R)) |
9014 | return indicatePessimisticFixpoint(); |
9015 | } |
9016 | } else if (RHSAA.undefIsContained()) { |
9017 | for (const APInt &L : LHSAAPVS) { |
9018 | if (!calculateBinaryOperatorAndTakeUnion(BinOp, L, Zero)) |
9019 | return indicatePessimisticFixpoint(); |
9020 | } |
9021 | } else { |
9022 | for (const APInt &L : LHSAAPVS) { |
9023 | for (const APInt &R : RHSAAPVS) { |
9024 | if (!calculateBinaryOperatorAndTakeUnion(BinOp, L, R)) |
9025 | return indicatePessimisticFixpoint(); |
9026 | } |
9027 | } |
9028 | } |
9029 | return AssumedBefore == getAssumed() ? ChangeStatus::UNCHANGED |
9030 | : ChangeStatus::CHANGED; |
9031 | } |
9032 | |
9033 | ChangeStatus updateWithPHINode(Attributor &A, PHINode *PHI) { |
9034 | auto AssumedBefore = getAssumed(); |
9035 | for (unsigned u = 0, e = PHI->getNumIncomingValues(); u < e; u++) { |
9036 | Value *IncomingValue = PHI->getIncomingValue(u); |
9037 | |
9038 | // Simplify the operand first. |
9039 | bool UsedAssumedInformation = false; |
9040 | const auto &SimplifiedIncomingValue = A.getAssumedSimplified( |
9041 | IRPosition::value(*IncomingValue, getCallBaseContext()), *this, |
9042 | UsedAssumedInformation); |
9043 | if (!SimplifiedIncomingValue.hasValue()) |
9044 | continue; |
9045 | if (!SimplifiedIncomingValue.getValue()) |
9046 | return indicatePessimisticFixpoint(); |
9047 | IncomingValue = *SimplifiedIncomingValue; |
9048 | |
9049 | auto &PotentialValuesAA = A.getAAFor<AAPotentialValues>( |
9050 | *this, IRPosition::value(*IncomingValue), DepClassTy::REQUIRED); |
9051 | if (!PotentialValuesAA.isValidState()) |
9052 | return indicatePessimisticFixpoint(); |
9053 | if (PotentialValuesAA.undefIsContained()) |
9054 | unionAssumedWithUndef(); |
9055 | else |
9056 | unionAssumed(PotentialValuesAA.getAssumed()); |
9057 | } |
9058 | return AssumedBefore == getAssumed() ? ChangeStatus::UNCHANGED |
9059 | : ChangeStatus::CHANGED; |
9060 | } |
9061 | |
9062 | ChangeStatus updateWithLoad(Attributor &A, LoadInst &L) { |
9063 | if (!L.getType()->isIntegerTy()) |
9064 | return indicatePessimisticFixpoint(); |
9065 | |
9066 | auto Union = [&](Value &V) { |
9067 | if (isa<UndefValue>(V)) { |
9068 | unionAssumedWithUndef(); |
9069 | return true; |
9070 | } |
9071 | if (ConstantInt *CI = dyn_cast<ConstantInt>(&V)) { |
9072 | unionAssumed(CI->getValue()); |
9073 | return true; |
9074 | } |
9075 | return false; |
9076 | }; |
9077 | auto AssumedBefore = getAssumed(); |
9078 | |
9079 | if (!AAValueSimplifyImpl::handleLoad(A, *this, L, Union)) |
9080 | return indicatePessimisticFixpoint(); |
9081 | |
9082 | return AssumedBefore == getAssumed() ? ChangeStatus::UNCHANGED |
9083 | : ChangeStatus::CHANGED; |
9084 | } |
9085 | |
9086 | /// See AbstractAttribute::updateImpl(...). |
9087 | ChangeStatus updateImpl(Attributor &A) override { |
9088 | Value &V = getAssociatedValue(); |
9089 | Instruction *I = dyn_cast<Instruction>(&V); |
9090 | |
9091 | if (auto *ICI = dyn_cast<ICmpInst>(I)) |
9092 | return updateWithICmpInst(A, ICI); |
9093 | |
9094 | if (auto *SI = dyn_cast<SelectInst>(I)) |
9095 | return updateWithSelectInst(A, SI); |
9096 | |
9097 | if (auto *CI = dyn_cast<CastInst>(I)) |
9098 | return updateWithCastInst(A, CI); |
9099 | |
9100 | if (auto *BinOp = dyn_cast<BinaryOperator>(I)) |
9101 | return updateWithBinaryOperator(A, BinOp); |
9102 | |
9103 | if (auto *PHI = dyn_cast<PHINode>(I)) |
9104 | return updateWithPHINode(A, PHI); |
9105 | |
9106 | if (auto *L = dyn_cast<LoadInst>(I)) |
9107 | return updateWithLoad(A, *L); |
9108 | |
9109 | return indicatePessimisticFixpoint(); |
9110 | } |
9111 | |
9112 | /// See AbstractAttribute::trackStatistics() |
9113 | void trackStatistics() const override { |
9114 | STATS_DECLTRACK_FLOATING_ATTR(potential_values){ static llvm::Statistic NumIRFloating_potential_values = {"attributor" , "NumIRFloating_potential_values", ("Number of floating values known to be '" "potential_values" "'")};; ++(NumIRFloating_potential_values ); } |
9115 | } |
9116 | }; |
9117 | |
9118 | struct AAPotentialValuesFunction : AAPotentialValuesImpl { |
9119 | AAPotentialValuesFunction(const IRPosition &IRP, Attributor &A) |
9120 | : AAPotentialValuesImpl(IRP, A) {} |
9121 | |
9122 | /// See AbstractAttribute::initialize(...). |
9123 | ChangeStatus updateImpl(Attributor &A) override { |
9124 | llvm_unreachable("AAPotentialValues(Function|CallSite)::updateImpl will "__builtin_unreachable() |
9125 | "not be called")__builtin_unreachable(); |
9126 | } |
9127 | |
9128 | /// See AbstractAttribute::trackStatistics() |
9129 | void trackStatistics() const override { |
9130 | STATS_DECLTRACK_FN_ATTR(potential_values){ static llvm::Statistic NumIRFunction_potential_values = {"attributor" , "NumIRFunction_potential_values", ("Number of " "functions" " marked '" "potential_values" "'")};; ++(NumIRFunction_potential_values ); } |
9131 | } |
9132 | }; |
9133 | |
9134 | struct AAPotentialValuesCallSite : AAPotentialValuesFunction { |
9135 | AAPotentialValuesCallSite(const IRPosition &IRP, Attributor &A) |
9136 | : AAPotentialValuesFunction(IRP, A) {} |
9137 | |
9138 | /// See AbstractAttribute::trackStatistics() |
9139 | void trackStatistics() const override { |
9140 | STATS_DECLTRACK_CS_ATTR(potential_values){ static llvm::Statistic NumIRCS_potential_values = {"attributor" , "NumIRCS_potential_values", ("Number of " "call site" " marked '" "potential_values" "'")};; ++(NumIRCS_potential_values); } |
9141 | } |
9142 | }; |
9143 | |
9144 | struct AAPotentialValuesCallSiteReturned |
9145 | : AACallSiteReturnedFromReturned<AAPotentialValues, AAPotentialValuesImpl> { |
9146 | AAPotentialValuesCallSiteReturned(const IRPosition &IRP, Attributor &A) |
9147 | : AACallSiteReturnedFromReturned<AAPotentialValues, |
9148 | AAPotentialValuesImpl>(IRP, A) {} |
9149 | |
9150 | /// See AbstractAttribute::trackStatistics() |
9151 | void trackStatistics() const override { |
9152 | STATS_DECLTRACK_CSRET_ATTR(potential_values){ static llvm::Statistic NumIRCSReturn_potential_values = {"attributor" , "NumIRCSReturn_potential_values", ("Number of " "call site returns" " marked '" "potential_values" "'")};; ++(NumIRCSReturn_potential_values ); } |
9153 | } |
9154 | }; |
9155 | |
9156 | struct AAPotentialValuesCallSiteArgument : AAPotentialValuesFloating { |
9157 | AAPotentialValuesCallSiteArgument(const IRPosition &IRP, Attributor &A) |
9158 | : AAPotentialValuesFloating(IRP, A) {} |
9159 | |
9160 | /// See AbstractAttribute::initialize(..). |
9161 | void initialize(Attributor &A) override { |
9162 | AAPotentialValuesImpl::initialize(A); |
9163 | if (isAtFixpoint()) |
9164 | return; |
9165 | |
9166 | Value &V = getAssociatedValue(); |
9167 | |
9168 | if (auto *C = dyn_cast<ConstantInt>(&V)) { |
9169 | unionAssumed(C->getValue()); |
9170 | indicateOptimisticFixpoint(); |
9171 | return; |
9172 | } |
9173 | |
9174 | if (isa<UndefValue>(&V)) { |
9175 | unionAssumedWithUndef(); |
9176 | indicateOptimisticFixpoint(); |
9177 | return; |
9178 | } |
9179 | } |
9180 | |
9181 | /// See AbstractAttribute::updateImpl(...). |
9182 | ChangeStatus updateImpl(Attributor &A) override { |
9183 | Value &V = getAssociatedValue(); |
9184 | auto AssumedBefore = getAssumed(); |
9185 | auto &AA = A.getAAFor<AAPotentialValues>(*this, IRPosition::value(V), |
9186 | DepClassTy::REQUIRED); |
9187 | const auto &S = AA.getAssumed(); |
9188 | unionAssumed(S); |
9189 | return AssumedBefore == getAssumed() ? ChangeStatus::UNCHANGED |
9190 | : ChangeStatus::CHANGED; |
9191 | } |
9192 | |
9193 | /// See AbstractAttribute::trackStatistics() |
9194 | void trackStatistics() const override { |
9195 | STATS_DECLTRACK_CSARG_ATTR(potential_values){ static llvm::Statistic NumIRCSArguments_potential_values = { "attributor", "NumIRCSArguments_potential_values", ("Number of " "call site arguments" " marked '" "potential_values" "'")};; ++(NumIRCSArguments_potential_values); } |
9196 | } |
9197 | }; |
9198 | |
9199 | /// ------------------------ NoUndef Attribute --------------------------------- |
9200 | struct AANoUndefImpl : AANoUndef { |
9201 | AANoUndefImpl(const IRPosition &IRP, Attributor &A) : AANoUndef(IRP, A) {} |
9202 | |
9203 | /// See AbstractAttribute::initialize(...). |
9204 | void initialize(Attributor &A) override { |
9205 | if (getIRPosition().hasAttr({Attribute::NoUndef})) { |
9206 | indicateOptimisticFixpoint(); |
9207 | return; |
9208 | } |
9209 | Value &V = getAssociatedValue(); |
9210 | if (isa<UndefValue>(V)) |
9211 | indicatePessimisticFixpoint(); |
9212 | else if (isa<FreezeInst>(V)) |
9213 | indicateOptimisticFixpoint(); |
9214 | else if (getPositionKind() != IRPosition::IRP_RETURNED && |
9215 | isGuaranteedNotToBeUndefOrPoison(&V)) |
9216 | indicateOptimisticFixpoint(); |
9217 | else |
9218 | AANoUndef::initialize(A); |
9219 | } |
9220 | |
9221 | /// See followUsesInMBEC |
9222 | bool followUseInMBEC(Attributor &A, const Use *U, const Instruction *I, |
9223 | AANoUndef::StateType &State) { |
9224 | const Value *UseV = U->get(); |
9225 | const DominatorTree *DT = nullptr; |
9226 | AssumptionCache *AC = nullptr; |
9227 | InformationCache &InfoCache = A.getInfoCache(); |
9228 | if (Function *F = getAnchorScope()) { |
9229 | DT = InfoCache.getAnalysisResultForFunction<DominatorTreeAnalysis>(*F); |
9230 | AC = InfoCache.getAnalysisResultForFunction<AssumptionAnalysis>(*F); |
9231 | } |
9232 | State.setKnown(isGuaranteedNotToBeUndefOrPoison(UseV, AC, I, DT)); |
9233 | bool TrackUse = false; |
9234 | // Track use for instructions which must produce undef or poison bits when |
9235 | // at least one operand contains such bits. |
9236 | if (isa<CastInst>(*I) || isa<GetElementPtrInst>(*I)) |
9237 | TrackUse = true; |
9238 | return TrackUse; |
9239 | } |
9240 | |
9241 | /// See AbstractAttribute::getAsStr(). |
9242 | const std::string getAsStr() const override { |
9243 | return getAssumed() ? "noundef" : "may-undef-or-poison"; |
9244 | } |
9245 | |
9246 | ChangeStatus manifest(Attributor &A) override { |
9247 | // We don't manifest noundef attribute for dead positions because the |
9248 | // associated values with dead positions would be replaced with undef |
9249 | // values. |
9250 | bool UsedAssumedInformation = false; |
9251 | if (A.isAssumedDead(getIRPosition(), nullptr, nullptr, |
9252 | UsedAssumedInformation)) |
9253 | return ChangeStatus::UNCHANGED; |
9254 | // A position whose simplified value does not have any value is |
9255 | // considered to be dead. We don't manifest noundef in such positions for |
9256 | // the same reason above. |
9257 | if (!A.getAssumedSimplified(getIRPosition(), *this, UsedAssumedInformation) |
9258 | .hasValue()) |
9259 | return ChangeStatus::UNCHANGED; |
9260 | return AANoUndef::manifest(A); |
9261 | } |
9262 | }; |
9263 | |
9264 | struct AANoUndefFloating : public AANoUndefImpl { |
9265 | AANoUndefFloating(const IRPosition &IRP, Attributor &A) |
9266 | : AANoUndefImpl(IRP, A) {} |
9267 | |
9268 | /// See AbstractAttribute::initialize(...). |
9269 | void initialize(Attributor &A) override { |
9270 | AANoUndefImpl::initialize(A); |
9271 | if (!getState().isAtFixpoint()) |
9272 | if (Instruction *CtxI = getCtxI()) |
9273 | followUsesInMBEC(*this, A, getState(), *CtxI); |
9274 | } |
9275 | |
9276 | /// See AbstractAttribute::updateImpl(...). |
9277 | ChangeStatus updateImpl(Attributor &A) override { |
9278 | auto VisitValueCB = [&](Value &V, const Instruction *CtxI, |
9279 | AANoUndef::StateType &T, bool Stripped) -> bool { |
9280 | const auto &AA = A.getAAFor<AANoUndef>(*this, IRPosition::value(V), |
9281 | DepClassTy::REQUIRED); |
9282 | if (!Stripped && this == &AA) { |
9283 | T.indicatePessimisticFixpoint(); |
9284 | } else { |
9285 | const AANoUndef::StateType &S = |
9286 | static_cast<const AANoUndef::StateType &>(AA.getState()); |
9287 | T ^= S; |
9288 | } |
9289 | return T.isValidState(); |
9290 | }; |
9291 | |
9292 | StateType T; |
9293 | if (!genericValueTraversal<StateType>(A, getIRPosition(), *this, T, |
9294 | VisitValueCB, getCtxI())) |
9295 | return indicatePessimisticFixpoint(); |
9296 | |
9297 | return clampStateAndIndicateChange(getState(), T); |
9298 | } |
9299 | |
9300 | /// See AbstractAttribute::trackStatistics() |
9301 | void trackStatistics() const override { STATS_DECLTRACK_FNRET_ATTR(noundef){ static llvm::Statistic NumIRFunctionReturn_noundef = {"attributor" , "NumIRFunctionReturn_noundef", ("Number of " "function returns" " marked '" "noundef" "'")};; ++(NumIRFunctionReturn_noundef ); } } |
9302 | }; |
9303 | |
9304 | struct AANoUndefReturned final |
9305 | : AAReturnedFromReturnedValues<AANoUndef, AANoUndefImpl> { |
9306 | AANoUndefReturned(const IRPosition &IRP, Attributor &A) |
9307 | : AAReturnedFromReturnedValues<AANoUndef, AANoUndefImpl>(IRP, A) {} |
9308 | |
9309 | /// See AbstractAttribute::trackStatistics() |
9310 | void trackStatistics() const override { STATS_DECLTRACK_FNRET_ATTR(noundef){ static llvm::Statistic NumIRFunctionReturn_noundef = {"attributor" , "NumIRFunctionReturn_noundef", ("Number of " "function returns" " marked '" "noundef" "'")};; ++(NumIRFunctionReturn_noundef ); } } |
9311 | }; |
9312 | |
9313 | struct AANoUndefArgument final |
9314 | : AAArgumentFromCallSiteArguments<AANoUndef, AANoUndefImpl> { |
9315 | AANoUndefArgument(const IRPosition &IRP, Attributor &A) |
9316 | : AAArgumentFromCallSiteArguments<AANoUndef, AANoUndefImpl>(IRP, A) {} |
9317 | |
9318 | /// See AbstractAttribute::trackStatistics() |
9319 | void trackStatistics() const override { STATS_DECLTRACK_ARG_ATTR(noundef){ static llvm::Statistic NumIRArguments_noundef = {"attributor" , "NumIRArguments_noundef", ("Number of " "arguments" " marked '" "noundef" "'")};; ++(NumIRArguments_noundef); } } |
9320 | }; |
9321 | |
9322 | struct AANoUndefCallSiteArgument final : AANoUndefFloating { |
9323 | AANoUndefCallSiteArgument(const IRPosition &IRP, Attributor &A) |
9324 | : AANoUndefFloating(IRP, A) {} |
9325 | |
9326 | /// See AbstractAttribute::trackStatistics() |
9327 | void trackStatistics() const override { STATS_DECLTRACK_CSARG_ATTR(noundef){ static llvm::Statistic NumIRCSArguments_noundef = {"attributor" , "NumIRCSArguments_noundef", ("Number of " "call site arguments" " marked '" "noundef" "'")};; ++(NumIRCSArguments_noundef); } } |
9328 | }; |
9329 | |
9330 | struct AANoUndefCallSiteReturned final |
9331 | : AACallSiteReturnedFromReturned<AANoUndef, AANoUndefImpl> { |
9332 | AANoUndefCallSiteReturned(const IRPosition &IRP, Attributor &A) |
9333 | : AACallSiteReturnedFromReturned<AANoUndef, AANoUndefImpl>(IRP, A) {} |
9334 | |
9335 | /// See AbstractAttribute::trackStatistics() |
9336 | void trackStatistics() const override { STATS_DECLTRACK_CSRET_ATTR(noundef){ static llvm::Statistic NumIRCSReturn_noundef = {"attributor" , "NumIRCSReturn_noundef", ("Number of " "call site returns" " marked '" "noundef" "'")};; ++(NumIRCSReturn_noundef); } } |
9337 | }; |
9338 | |
9339 | struct AACallEdgesFunction : public AACallEdges { |
9340 | AACallEdgesFunction(const IRPosition &IRP, Attributor &A) |
9341 | : AACallEdges(IRP, A) {} |
9342 | |
9343 | /// See AbstractAttribute::updateImpl(...). |
9344 | ChangeStatus updateImpl(Attributor &A) override { |
9345 | ChangeStatus Change = ChangeStatus::UNCHANGED; |
9346 | bool OldHasUnknownCallee = HasUnknownCallee; |
9347 | bool OldHasUnknownCalleeNonAsm = HasUnknownCalleeNonAsm; |
9348 | |
9349 | auto AddCalledFunction = [&](Function *Fn) { |
9350 | if (CalledFunctions.insert(Fn)) { |
9351 | Change = ChangeStatus::CHANGED; |
9352 | LLVM_DEBUG(dbgs() << "[AACallEdges] New call edge: " << Fn->getName()do { } while (false) |
9353 | << "\n")do { } while (false); |
9354 | } |
9355 | }; |
9356 | |
9357 | auto VisitValue = [&](Value &V, const Instruction *CtxI, bool &HasUnknown, |
9358 | bool Stripped) -> bool { |
9359 | if (Function *Fn = dyn_cast<Function>(&V)) { |
9360 | AddCalledFunction(Fn); |
9361 | } else { |
9362 | LLVM_DEBUG(dbgs() << "[AACallEdges] Unrecognized value: " << V << "\n")do { } while (false); |
9363 | HasUnknown = true; |
9364 | HasUnknownCalleeNonAsm = true; |
9365 | } |
9366 | |
9367 | // Explore all values. |
9368 | return true; |
9369 | }; |
9370 | |
9371 | // Process any value that we might call. |
9372 | auto ProcessCalledOperand = [&](Value *V, Instruction *Ctx) { |
9373 | if (!genericValueTraversal<bool>(A, IRPosition::value(*V), *this, |
9374 | HasUnknownCallee, VisitValue, nullptr, |
9375 | false)) { |
9376 | // If we haven't gone through all values, assume that there are unknown |
9377 | // callees. |
9378 | HasUnknownCallee = true; |
9379 | HasUnknownCalleeNonAsm = true; |
9380 | } |
9381 | }; |
9382 | |
9383 | auto ProcessCallInst = [&](Instruction &Inst) { |
9384 | CallBase &CB = static_cast<CallBase &>(Inst); |
9385 | if (CB.isInlineAsm()) { |
9386 | HasUnknownCallee = true; |
9387 | return true; |
9388 | } |
9389 | |
9390 | // Process callee metadata if available. |
9391 | if (auto *MD = Inst.getMetadata(LLVMContext::MD_callees)) { |
9392 | for (auto &Op : MD->operands()) { |
9393 | Function *Callee = mdconst::extract_or_null<Function>(Op); |
9394 | if (Callee) |
9395 | AddCalledFunction(Callee); |
9396 | } |
9397 | // Callees metadata grantees that the called function is one of its |
9398 | // operands, So we are done. |
9399 | return true; |
9400 | } |
9401 | |
9402 | // The most simple case. |
9403 | ProcessCalledOperand(CB.getCalledOperand(), &Inst); |
9404 | |
9405 | // Process callback functions. |
9406 | SmallVector<const Use *, 4u> CallbackUses; |
9407 | AbstractCallSite::getCallbackUses(CB, CallbackUses); |
9408 | for (const Use *U : CallbackUses) |
9409 | ProcessCalledOperand(U->get(), &Inst); |
9410 | |
9411 | return true; |
9412 | }; |
9413 | |
9414 | // Visit all callable instructions. |
9415 | bool UsedAssumedInformation = false; |
9416 | if (!A.checkForAllCallLikeInstructions(ProcessCallInst, *this, |
9417 | UsedAssumedInformation)) { |
9418 | // If we haven't looked at all call like instructions, assume that there |
9419 | // are unknown callees. |
9420 | HasUnknownCallee = true; |
9421 | HasUnknownCalleeNonAsm = true; |
9422 | } |
9423 | |
9424 | // Track changes. |
9425 | if (OldHasUnknownCallee != HasUnknownCallee || |
9426 | OldHasUnknownCalleeNonAsm != HasUnknownCalleeNonAsm) |
9427 | Change = ChangeStatus::CHANGED; |
9428 | |
9429 | return Change; |
9430 | } |
9431 | |
9432 | virtual const SetVector<Function *> &getOptimisticEdges() const override { |
9433 | return CalledFunctions; |
9434 | }; |
9435 | |
9436 | virtual bool hasUnknownCallee() const override { return HasUnknownCallee; } |
9437 | |
9438 | virtual bool hasNonAsmUnknownCallee() const override { |
9439 | return HasUnknownCalleeNonAsm; |
9440 | } |
9441 | |
9442 | const std::string getAsStr() const override { |
9443 | return "CallEdges[" + std::to_string(HasUnknownCallee) + "," + |
9444 | std::to_string(CalledFunctions.size()) + "]"; |
9445 | } |
9446 | |
9447 | void trackStatistics() const override {} |
9448 | |
9449 | /// Optimistic set of functions that might be called by this function. |
9450 | SetVector<Function *> CalledFunctions; |
9451 | |
9452 | /// Is there any call with a unknown callee. |
9453 | bool HasUnknownCallee = false; |
9454 | |
9455 | /// Is there any call with a unknown callee, excluding any inline asm. |
9456 | bool HasUnknownCalleeNonAsm = false; |
9457 | }; |
9458 | |
9459 | struct AAFunctionReachabilityFunction : public AAFunctionReachability { |
9460 | AAFunctionReachabilityFunction(const IRPosition &IRP, Attributor &A) |
9461 | : AAFunctionReachability(IRP, A) {} |
9462 | |
9463 | bool canReach(Attributor &A, Function *Fn) const override { |
9464 | // Assume that we can reach any function if we can reach a call with |
9465 | // unknown callee. |
9466 | if (CanReachUnknownCallee) |
9467 | return true; |
9468 | |
9469 | if (ReachableQueries.count(Fn)) |
9470 | return true; |
9471 | |
9472 | if (UnreachableQueries.count(Fn)) |
9473 | return false; |
9474 | |
9475 | const AACallEdges &AAEdges = |
9476 | A.getAAFor<AACallEdges>(*this, getIRPosition(), DepClassTy::REQUIRED); |
9477 | |
9478 | const SetVector<Function *> &Edges = AAEdges.getOptimisticEdges(); |
9479 | bool Result = checkIfReachable(A, Edges, Fn); |
9480 | |
9481 | // Attributor returns attributes as const, so this function has to be |
9482 | // const for users of this attribute to use it without having to do |
9483 | // a const_cast. |
9484 | // This is a hack for us to be able to cache queries. |
9485 | auto *NonConstThis = const_cast<AAFunctionReachabilityFunction *>(this); |
9486 | |
9487 | if (Result) |
9488 | NonConstThis->ReachableQueries.insert(Fn); |
9489 | else |
9490 | NonConstThis->UnreachableQueries.insert(Fn); |
9491 | |
9492 | return Result; |
9493 | } |
9494 | |
9495 | /// See AbstractAttribute::updateImpl(...). |
9496 | ChangeStatus updateImpl(Attributor &A) override { |
9497 | if (CanReachUnknownCallee) |
9498 | return ChangeStatus::UNCHANGED; |
9499 | |
9500 | const AACallEdges &AAEdges = |
9501 | A.getAAFor<AACallEdges>(*this, getIRPosition(), DepClassTy::REQUIRED); |
9502 | const SetVector<Function *> &Edges = AAEdges.getOptimisticEdges(); |
9503 | ChangeStatus Change = ChangeStatus::UNCHANGED; |
9504 | |
9505 | if (AAEdges.hasUnknownCallee()) { |
9506 | bool OldCanReachUnknown = CanReachUnknownCallee; |
9507 | CanReachUnknownCallee = true; |
9508 | return OldCanReachUnknown ? ChangeStatus::UNCHANGED |
9509 | : ChangeStatus::CHANGED; |
9510 | } |
9511 | |
9512 | // Check if any of the unreachable functions become reachable. |
9513 | for (auto Current = UnreachableQueries.begin(); |
9514 | Current != UnreachableQueries.end();) { |
9515 | if (!checkIfReachable(A, Edges, *Current)) { |
9516 | Current++; |
9517 | continue; |
9518 | } |
9519 | ReachableQueries.insert(*Current); |
9520 | UnreachableQueries.erase(*Current++); |
9521 | Change = ChangeStatus::CHANGED; |
9522 | } |
9523 | |
9524 | return Change; |
9525 | } |
9526 | |
9527 | const std::string getAsStr() const override { |
9528 | size_t QueryCount = ReachableQueries.size() + UnreachableQueries.size(); |
9529 | |
9530 | return "FunctionReachability [" + std::to_string(ReachableQueries.size()) + |
9531 | "," + std::to_string(QueryCount) + "]"; |
9532 | } |
9533 | |
9534 | void trackStatistics() const override {} |
9535 | |
9536 | private: |
9537 | bool canReachUnknownCallee() const override { return CanReachUnknownCallee; } |
9538 | |
9539 | bool checkIfReachable(Attributor &A, const SetVector<Function *> &Edges, |
9540 | Function *Fn) const { |
9541 | if (Edges.count(Fn)) |
9542 | return true; |
9543 | |
9544 | for (Function *Edge : Edges) { |
9545 | // We don't need a dependency if the result is reachable. |
9546 | const AAFunctionReachability &EdgeReachability = |
9547 | A.getAAFor<AAFunctionReachability>(*this, IRPosition::function(*Edge), |
9548 | DepClassTy::NONE); |
9549 | |
9550 | if (EdgeReachability.canReach(A, Fn)) |
9551 | return true; |
9552 | } |
9553 | for (Function *Fn : Edges) |
9554 | A.getAAFor<AAFunctionReachability>(*this, IRPosition::function(*Fn), |
9555 | DepClassTy::REQUIRED); |
9556 | |
9557 | return false; |
9558 | } |
9559 | |
9560 | /// Set of functions that we know for sure is reachable. |
9561 | SmallPtrSet<Function *, 8> ReachableQueries; |
9562 | |
9563 | /// Set of functions that are unreachable, but might become reachable. |
9564 | SmallPtrSet<Function *, 8> UnreachableQueries; |
9565 | |
9566 | /// If we can reach a function with a call to a unknown function we assume |
9567 | /// that we can reach any function. |
9568 | bool CanReachUnknownCallee = false; |
9569 | }; |
9570 | |
9571 | } // namespace |
9572 | |
9573 | AACallGraphNode *AACallEdgeIterator::operator*() const { |
9574 | return static_cast<AACallGraphNode *>(const_cast<AACallEdges *>( |
9575 | &A.getOrCreateAAFor<AACallEdges>(IRPosition::function(**I)))); |
9576 | } |
9577 | |
9578 | void AttributorCallGraph::print() { llvm::WriteGraph(outs(), this); } |
9579 | |
9580 | const char AAReturnedValues::ID = 0; |
9581 | const char AANoUnwind::ID = 0; |
9582 | const char AANoSync::ID = 0; |
9583 | const char AANoFree::ID = 0; |
9584 | const char AANonNull::ID = 0; |
9585 | const char AANoRecurse::ID = 0; |
9586 | const char AAWillReturn::ID = 0; |
9587 | const char AAUndefinedBehavior::ID = 0; |
9588 | const char AANoAlias::ID = 0; |
9589 | const char AAReachability::ID = 0; |
9590 | const char AANoReturn::ID = 0; |
9591 | const char AAIsDead::ID = 0; |
9592 | const char AADereferenceable::ID = 0; |
9593 | const char AAAlign::ID = 0; |
9594 | const char AANoCapture::ID = 0; |
9595 | const char AAValueSimplify::ID = 0; |
9596 | const char AAHeapToStack::ID = 0; |
9597 | const char AAPrivatizablePtr::ID = 0; |
9598 | const char AAMemoryBehavior::ID = 0; |
9599 | const char AAMemoryLocation::ID = 0; |
9600 | const char AAValueConstantRange::ID = 0; |
9601 | const char AAPotentialValues::ID = 0; |
9602 | const char AANoUndef::ID = 0; |
9603 | const char AACallEdges::ID = 0; |
9604 | const char AAFunctionReachability::ID = 0; |
9605 | const char AAPointerInfo::ID = 0; |
9606 | |
9607 | // Macro magic to create the static generator function for attributes that |
9608 | // follow the naming scheme. |
9609 | |
9610 | #define SWITCH_PK_INV(CLASS, PK, POS_NAME) \ |
9611 | case IRPosition::PK: \ |
9612 | llvm_unreachable("Cannot create " #CLASS " for a " POS_NAME " position!")__builtin_unreachable(); |
9613 | |
9614 | #define SWITCH_PK_CREATE(CLASS, IRP, PK, SUFFIX) \ |
9615 | case IRPosition::PK: \ |
9616 | AA = new (A.Allocator) CLASS##SUFFIX(IRP, A); \ |
9617 | ++NumAAs; \ |
9618 | break; |
9619 | |
9620 | #define CREATE_FUNCTION_ABSTRACT_ATTRIBUTE_FOR_POSITION(CLASS) \ |
9621 | CLASS &CLASS::createForPosition(const IRPosition &IRP, Attributor &A) { \ |
9622 | CLASS *AA = nullptr; \ |
9623 | switch (IRP.getPositionKind()) { \ |
9624 | SWITCH_PK_INV(CLASS, IRP_INVALID, "invalid") \ |
9625 | SWITCH_PK_INV(CLASS, IRP_FLOAT, "floating") \ |
9626 | SWITCH_PK_INV(CLASS, IRP_ARGUMENT, "argument") \ |
9627 | SWITCH_PK_INV(CLASS, IRP_RETURNED, "returned") \ |
9628 | SWITCH_PK_INV(CLASS, IRP_CALL_SITE_RETURNED, "call site returned") \ |
9629 | SWITCH_PK_INV(CLASS, IRP_CALL_SITE_ARGUMENT, "call site argument") \ |
9630 | SWITCH_PK_CREATE(CLASS, IRP, IRP_FUNCTION, Function) \ |
9631 | SWITCH_PK_CREATE(CLASS, IRP, IRP_CALL_SITE, CallSite) \ |
9632 | } \ |
9633 | return *AA; \ |
9634 | } |
9635 | |
9636 | #define CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION(CLASS) \ |
9637 | CLASS &CLASS::createForPosition(const IRPosition &IRP, Attributor &A) { \ |
9638 | CLASS *AA = nullptr; \ |
9639 | switch (IRP.getPositionKind()) { \ |
9640 | SWITCH_PK_INV(CLASS, IRP_INVALID, "invalid") \ |
9641 | SWITCH_PK_INV(CLASS, IRP_FUNCTION, "function") \ |
9642 | SWITCH_PK_INV(CLASS, IRP_CALL_SITE, "call site") \ |
9643 | SWITCH_PK_CREATE(CLASS, IRP, IRP_FLOAT, Floating) \ |
9644 | SWITCH_PK_CREATE(CLASS, IRP, IRP_ARGUMENT, Argument) \ |
9645 | SWITCH_PK_CREATE(CLASS, IRP, IRP_RETURNED, Returned) \ |
9646 | SWITCH_PK_CREATE(CLASS, IRP, IRP_CALL_SITE_RETURNED, CallSiteReturned) \ |
9647 | SWITCH_PK_CREATE(CLASS, IRP, IRP_CALL_SITE_ARGUMENT, CallSiteArgument) \ |
9648 | } \ |
9649 | return *AA; \ |
9650 | } |
9651 | |
9652 | #define CREATE_ALL_ABSTRACT_ATTRIBUTE_FOR_POSITION(CLASS) \ |
9653 | CLASS &CLASS::createForPosition(const IRPosition &IRP, Attributor &A) { \ |
9654 | CLASS *AA = nullptr; \ |
9655 | switch (IRP.getPositionKind()) { \ |
9656 | SWITCH_PK_INV(CLASS, IRP_INVALID, "invalid") \ |
9657 | SWITCH_PK_CREATE(CLASS, IRP, IRP_FUNCTION, Function) \ |
9658 | SWITCH_PK_CREATE(CLASS, IRP, IRP_CALL_SITE, CallSite) \ |
9659 | SWITCH_PK_CREATE(CLASS, IRP, IRP_FLOAT, Floating) \ |
9660 | SWITCH_PK_CREATE(CLASS, IRP, IRP_ARGUMENT, Argument) \ |
9661 | SWITCH_PK_CREATE(CLASS, IRP, IRP_RETURNED, Returned) \ |
9662 | SWITCH_PK_CREATE(CLASS, IRP, IRP_CALL_SITE_RETURNED, CallSiteReturned) \ |
9663 | SWITCH_PK_CREATE(CLASS, IRP, IRP_CALL_SITE_ARGUMENT, CallSiteArgument) \ |
9664 | } \ |
9665 | return *AA; \ |
9666 | } |
9667 | |
9668 | #define CREATE_FUNCTION_ONLY_ABSTRACT_ATTRIBUTE_FOR_POSITION(CLASS) \ |
9669 | CLASS &CLASS::createForPosition(const IRPosition &IRP, Attributor &A) { \ |
9670 | CLASS *AA = nullptr; \ |
9671 | switch (IRP.getPositionKind()) { \ |
9672 | SWITCH_PK_INV(CLASS, IRP_INVALID, "invalid") \ |
9673 | SWITCH_PK_INV(CLASS, IRP_ARGUMENT, "argument") \ |
9674 | SWITCH_PK_INV(CLASS, IRP_FLOAT, "floating") \ |
9675 | SWITCH_PK_INV(CLASS, IRP_RETURNED, "returned") \ |
9676 | SWITCH_PK_INV(CLASS, IRP_CALL_SITE_RETURNED, "call site returned") \ |
9677 | SWITCH_PK_INV(CLASS, IRP_CALL_SITE_ARGUMENT, "call site argument") \ |
9678 | SWITCH_PK_INV(CLASS, IRP_CALL_SITE, "call site") \ |
9679 | SWITCH_PK_CREATE(CLASS, IRP, IRP_FUNCTION, Function) \ |
9680 | } \ |
9681 | return *AA; \ |
9682 | } |
9683 | |
9684 | #define CREATE_NON_RET_ABSTRACT_ATTRIBUTE_FOR_POSITION(CLASS) \ |
9685 | CLASS &CLASS::createForPosition(const IRPosition &IRP, Attributor &A) { \ |
9686 | CLASS *AA = nullptr; \ |
9687 | switch (IRP.getPositionKind()) { \ |
9688 | SWITCH_PK_INV(CLASS, IRP_INVALID, "invalid") \ |
9689 | SWITCH_PK_INV(CLASS, IRP_RETURNED, "returned") \ |
9690 | SWITCH_PK_CREATE(CLASS, IRP, IRP_FUNCTION, Function) \ |
9691 | SWITCH_PK_CREATE(CLASS, IRP, IRP_CALL_SITE, CallSite) \ |
9692 | SWITCH_PK_CREATE(CLASS, IRP, IRP_FLOAT, Floating) \ |
9693 | SWITCH_PK_CREATE(CLASS, IRP, IRP_ARGUMENT, Argument) \ |
9694 | SWITCH_PK_CREATE(CLASS, IRP, IRP_CALL_SITE_RETURNED, CallSiteReturned) \ |
9695 | SWITCH_PK_CREATE(CLASS, IRP, IRP_CALL_SITE_ARGUMENT, CallSiteArgument) \ |
9696 | } \ |
9697 | return *AA; \ |
9698 | } |
9699 | |
9700 | CREATE_FUNCTION_ABSTRACT_ATTRIBUTE_FOR_POSITION(AANoUnwind) |
9701 | CREATE_FUNCTION_ABSTRACT_ATTRIBUTE_FOR_POSITION(AANoSync) |
9702 | CREATE_FUNCTION_ABSTRACT_ATTRIBUTE_FOR_POSITION(AANoRecurse) |
9703 | CREATE_FUNCTION_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAWillReturn) |
9704 | CREATE_FUNCTION_ABSTRACT_ATTRIBUTE_FOR_POSITION(AANoReturn) |
9705 | CREATE_FUNCTION_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAReturnedValues) |
9706 | CREATE_FUNCTION_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAMemoryLocation) |
9707 | |
9708 | CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION(AANonNull) |
9709 | CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION(AANoAlias) |
9710 | CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAPrivatizablePtr) |
9711 | CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION(AADereferenceable) |
9712 | CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAAlign) |
9713 | CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION(AANoCapture) |
9714 | CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAValueConstantRange) |
9715 | CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAPotentialValues) |
9716 | CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION(AANoUndef) |
9717 | CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAPointerInfo) |
9718 | |
9719 | CREATE_ALL_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAValueSimplify) |
9720 | CREATE_ALL_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAIsDead) |
9721 | CREATE_ALL_ABSTRACT_ATTRIBUTE_FOR_POSITION(AANoFree) |
9722 | |
9723 | CREATE_FUNCTION_ONLY_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAHeapToStack) |
9724 | CREATE_FUNCTION_ONLY_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAReachability) |
9725 | CREATE_FUNCTION_ONLY_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAUndefinedBehavior) |
9726 | CREATE_FUNCTION_ONLY_ABSTRACT_ATTRIBUTE_FOR_POSITION(AACallEdges) |
9727 | CREATE_FUNCTION_ONLY_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAFunctionReachability) |
9728 | |
9729 | CREATE_NON_RET_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAMemoryBehavior) |
9730 | |
9731 | #undef CREATE_FUNCTION_ONLY_ABSTRACT_ATTRIBUTE_FOR_POSITION |
9732 | #undef CREATE_FUNCTION_ABSTRACT_ATTRIBUTE_FOR_POSITION |
9733 | #undef CREATE_NON_RET_ABSTRACT_ATTRIBUTE_FOR_POSITION |
9734 | #undef CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION |
9735 | #undef CREATE_ALL_ABSTRACT_ATTRIBUTE_FOR_POSITION |
9736 | #undef SWITCH_PK_CREATE |
9737 | #undef SWITCH_PK_INV |