File: | src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Analysis/ValueTracking.h |
Warning: | line 282, column 49 Called C++ object pointer is null |
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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
| ||||||||
4266 | if (GEP->hasAllConstantIndices()) | ||||||||
4267 | TrackUse = true; | ||||||||
4268 | return 0; | ||||||||
4269 | } | ||||||||
4270 | |||||||||
4271 | MaybeAlign MA; | ||||||||
4272 | if (const auto *CB
| ||||||||
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
| ||||||||
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); | ||||||||