File: | src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/ADT/APInt.h |
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1 | //===- LazyValueInfo.cpp - Value constraint analysis ------------*- C++ -*-===// | ||||||
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 | // This file defines the interface for lazy computation of value constraint | ||||||
10 | // information. | ||||||
11 | // | ||||||
12 | //===----------------------------------------------------------------------===// | ||||||
13 | |||||||
14 | #include "llvm/Analysis/LazyValueInfo.h" | ||||||
15 | #include "llvm/ADT/DenseSet.h" | ||||||
16 | #include "llvm/ADT/Optional.h" | ||||||
17 | #include "llvm/ADT/STLExtras.h" | ||||||
18 | #include "llvm/Analysis/AssumptionCache.h" | ||||||
19 | #include "llvm/Analysis/ConstantFolding.h" | ||||||
20 | #include "llvm/Analysis/InstructionSimplify.h" | ||||||
21 | #include "llvm/Analysis/TargetLibraryInfo.h" | ||||||
22 | #include "llvm/Analysis/ValueLattice.h" | ||||||
23 | #include "llvm/Analysis/ValueTracking.h" | ||||||
24 | #include "llvm/IR/AssemblyAnnotationWriter.h" | ||||||
25 | #include "llvm/IR/CFG.h" | ||||||
26 | #include "llvm/IR/ConstantRange.h" | ||||||
27 | #include "llvm/IR/Constants.h" | ||||||
28 | #include "llvm/IR/DataLayout.h" | ||||||
29 | #include "llvm/IR/Dominators.h" | ||||||
30 | #include "llvm/IR/Instructions.h" | ||||||
31 | #include "llvm/IR/IntrinsicInst.h" | ||||||
32 | #include "llvm/IR/Intrinsics.h" | ||||||
33 | #include "llvm/IR/LLVMContext.h" | ||||||
34 | #include "llvm/IR/PatternMatch.h" | ||||||
35 | #include "llvm/IR/ValueHandle.h" | ||||||
36 | #include "llvm/InitializePasses.h" | ||||||
37 | #include "llvm/Support/Debug.h" | ||||||
38 | #include "llvm/Support/FormattedStream.h" | ||||||
39 | #include "llvm/Support/KnownBits.h" | ||||||
40 | #include "llvm/Support/raw_ostream.h" | ||||||
41 | #include <map> | ||||||
42 | using namespace llvm; | ||||||
43 | using namespace PatternMatch; | ||||||
44 | |||||||
45 | #define DEBUG_TYPE"lazy-value-info" "lazy-value-info" | ||||||
46 | |||||||
47 | // This is the number of worklist items we will process to try to discover an | ||||||
48 | // answer for a given value. | ||||||
49 | static const unsigned MaxProcessedPerValue = 500; | ||||||
50 | |||||||
51 | char LazyValueInfoWrapperPass::ID = 0; | ||||||
52 | LazyValueInfoWrapperPass::LazyValueInfoWrapperPass() : FunctionPass(ID) { | ||||||
53 | initializeLazyValueInfoWrapperPassPass(*PassRegistry::getPassRegistry()); | ||||||
54 | } | ||||||
55 | INITIALIZE_PASS_BEGIN(LazyValueInfoWrapperPass, "lazy-value-info",static void *initializeLazyValueInfoWrapperPassPassOnce(PassRegistry &Registry) { | ||||||
56 | "Lazy Value Information Analysis", false, true)static void *initializeLazyValueInfoWrapperPassPassOnce(PassRegistry &Registry) { | ||||||
57 | INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)initializeAssumptionCacheTrackerPass(Registry); | ||||||
58 | INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)initializeTargetLibraryInfoWrapperPassPass(Registry); | ||||||
59 | INITIALIZE_PASS_END(LazyValueInfoWrapperPass, "lazy-value-info",PassInfo *PI = new PassInfo( "Lazy Value Information Analysis" , "lazy-value-info", &LazyValueInfoWrapperPass::ID, PassInfo ::NormalCtor_t(callDefaultCtor<LazyValueInfoWrapperPass> ), false, true); Registry.registerPass(*PI, true); return PI; } static llvm::once_flag InitializeLazyValueInfoWrapperPassPassFlag ; void llvm::initializeLazyValueInfoWrapperPassPass(PassRegistry &Registry) { llvm::call_once(InitializeLazyValueInfoWrapperPassPassFlag , initializeLazyValueInfoWrapperPassPassOnce, std::ref(Registry )); } | ||||||
60 | "Lazy Value Information Analysis", false, true)PassInfo *PI = new PassInfo( "Lazy Value Information Analysis" , "lazy-value-info", &LazyValueInfoWrapperPass::ID, PassInfo ::NormalCtor_t(callDefaultCtor<LazyValueInfoWrapperPass> ), false, true); Registry.registerPass(*PI, true); return PI; } static llvm::once_flag InitializeLazyValueInfoWrapperPassPassFlag ; void llvm::initializeLazyValueInfoWrapperPassPass(PassRegistry &Registry) { llvm::call_once(InitializeLazyValueInfoWrapperPassPassFlag , initializeLazyValueInfoWrapperPassPassOnce, std::ref(Registry )); } | ||||||
61 | |||||||
62 | namespace llvm { | ||||||
63 | FunctionPass *createLazyValueInfoPass() { return new LazyValueInfoWrapperPass(); } | ||||||
64 | } | ||||||
65 | |||||||
66 | AnalysisKey LazyValueAnalysis::Key; | ||||||
67 | |||||||
68 | /// Returns true if this lattice value represents at most one possible value. | ||||||
69 | /// This is as precise as any lattice value can get while still representing | ||||||
70 | /// reachable code. | ||||||
71 | static bool hasSingleValue(const ValueLatticeElement &Val) { | ||||||
72 | if (Val.isConstantRange() && | ||||||
73 | Val.getConstantRange().isSingleElement()) | ||||||
74 | // Integer constants are single element ranges | ||||||
75 | return true; | ||||||
76 | if (Val.isConstant()) | ||||||
77 | // Non integer constants | ||||||
78 | return true; | ||||||
79 | return false; | ||||||
80 | } | ||||||
81 | |||||||
82 | /// Combine two sets of facts about the same value into a single set of | ||||||
83 | /// facts. Note that this method is not suitable for merging facts along | ||||||
84 | /// different paths in a CFG; that's what the mergeIn function is for. This | ||||||
85 | /// is for merging facts gathered about the same value at the same location | ||||||
86 | /// through two independent means. | ||||||
87 | /// Notes: | ||||||
88 | /// * This method does not promise to return the most precise possible lattice | ||||||
89 | /// value implied by A and B. It is allowed to return any lattice element | ||||||
90 | /// which is at least as strong as *either* A or B (unless our facts | ||||||
91 | /// conflict, see below). | ||||||
92 | /// * Due to unreachable code, the intersection of two lattice values could be | ||||||
93 | /// contradictory. If this happens, we return some valid lattice value so as | ||||||
94 | /// not confuse the rest of LVI. Ideally, we'd always return Undefined, but | ||||||
95 | /// we do not make this guarantee. TODO: This would be a useful enhancement. | ||||||
96 | static ValueLatticeElement intersect(const ValueLatticeElement &A, | ||||||
97 | const ValueLatticeElement &B) { | ||||||
98 | // Undefined is the strongest state. It means the value is known to be along | ||||||
99 | // an unreachable path. | ||||||
100 | if (A.isUnknown()) | ||||||
101 | return A; | ||||||
102 | if (B.isUnknown()) | ||||||
103 | return B; | ||||||
104 | |||||||
105 | // If we gave up for one, but got a useable fact from the other, use it. | ||||||
106 | if (A.isOverdefined()) | ||||||
107 | return B; | ||||||
108 | if (B.isOverdefined()) | ||||||
109 | return A; | ||||||
110 | |||||||
111 | // Can't get any more precise than constants. | ||||||
112 | if (hasSingleValue(A)) | ||||||
113 | return A; | ||||||
114 | if (hasSingleValue(B)) | ||||||
115 | return B; | ||||||
116 | |||||||
117 | // Could be either constant range or not constant here. | ||||||
118 | if (!A.isConstantRange() || !B.isConstantRange()) { | ||||||
119 | // TODO: Arbitrary choice, could be improved | ||||||
120 | return A; | ||||||
121 | } | ||||||
122 | |||||||
123 | // Intersect two constant ranges | ||||||
124 | ConstantRange Range = | ||||||
125 | A.getConstantRange().intersectWith(B.getConstantRange()); | ||||||
126 | // Note: An empty range is implicitly converted to unknown or undef depending | ||||||
127 | // on MayIncludeUndef internally. | ||||||
128 | return ValueLatticeElement::getRange( | ||||||
129 | std::move(Range), /*MayIncludeUndef=*/A.isConstantRangeIncludingUndef() | | ||||||
130 | B.isConstantRangeIncludingUndef()); | ||||||
131 | } | ||||||
132 | |||||||
133 | //===----------------------------------------------------------------------===// | ||||||
134 | // LazyValueInfoCache Decl | ||||||
135 | //===----------------------------------------------------------------------===// | ||||||
136 | |||||||
137 | namespace { | ||||||
138 | /// A callback value handle updates the cache when values are erased. | ||||||
139 | class LazyValueInfoCache; | ||||||
140 | struct LVIValueHandle final : public CallbackVH { | ||||||
141 | LazyValueInfoCache *Parent; | ||||||
142 | |||||||
143 | LVIValueHandle(Value *V, LazyValueInfoCache *P = nullptr) | ||||||
144 | : CallbackVH(V), Parent(P) { } | ||||||
145 | |||||||
146 | void deleted() override; | ||||||
147 | void allUsesReplacedWith(Value *V) override { | ||||||
148 | deleted(); | ||||||
149 | } | ||||||
150 | }; | ||||||
151 | } // end anonymous namespace | ||||||
152 | |||||||
153 | namespace { | ||||||
154 | using NonNullPointerSet = SmallDenseSet<AssertingVH<Value>, 2>; | ||||||
155 | |||||||
156 | /// This is the cache kept by LazyValueInfo which | ||||||
157 | /// maintains information about queries across the clients' queries. | ||||||
158 | class LazyValueInfoCache { | ||||||
159 | /// This is all of the cached information for one basic block. It contains | ||||||
160 | /// the per-value lattice elements, as well as a separate set for | ||||||
161 | /// overdefined values to reduce memory usage. Additionally pointers | ||||||
162 | /// dereferenced in the block are cached for nullability queries. | ||||||
163 | struct BlockCacheEntry { | ||||||
164 | SmallDenseMap<AssertingVH<Value>, ValueLatticeElement, 4> LatticeElements; | ||||||
165 | SmallDenseSet<AssertingVH<Value>, 4> OverDefined; | ||||||
166 | // None indicates that the nonnull pointers for this basic block | ||||||
167 | // block have not been computed yet. | ||||||
168 | Optional<NonNullPointerSet> NonNullPointers; | ||||||
169 | }; | ||||||
170 | |||||||
171 | /// Cached information per basic block. | ||||||
172 | DenseMap<PoisoningVH<BasicBlock>, std::unique_ptr<BlockCacheEntry>> | ||||||
173 | BlockCache; | ||||||
174 | /// Set of value handles used to erase values from the cache on deletion. | ||||||
175 | DenseSet<LVIValueHandle, DenseMapInfo<Value *>> ValueHandles; | ||||||
176 | |||||||
177 | const BlockCacheEntry *getBlockEntry(BasicBlock *BB) const { | ||||||
178 | auto It = BlockCache.find_as(BB); | ||||||
179 | if (It == BlockCache.end()) | ||||||
180 | return nullptr; | ||||||
181 | return It->second.get(); | ||||||
182 | } | ||||||
183 | |||||||
184 | BlockCacheEntry *getOrCreateBlockEntry(BasicBlock *BB) { | ||||||
185 | auto It = BlockCache.find_as(BB); | ||||||
186 | if (It == BlockCache.end()) | ||||||
187 | It = BlockCache.insert({ BB, std::make_unique<BlockCacheEntry>() }) | ||||||
188 | .first; | ||||||
189 | |||||||
190 | return It->second.get(); | ||||||
191 | } | ||||||
192 | |||||||
193 | void addValueHandle(Value *Val) { | ||||||
194 | auto HandleIt = ValueHandles.find_as(Val); | ||||||
195 | if (HandleIt == ValueHandles.end()) | ||||||
196 | ValueHandles.insert({ Val, this }); | ||||||
197 | } | ||||||
198 | |||||||
199 | public: | ||||||
200 | void insertResult(Value *Val, BasicBlock *BB, | ||||||
201 | const ValueLatticeElement &Result) { | ||||||
202 | BlockCacheEntry *Entry = getOrCreateBlockEntry(BB); | ||||||
203 | |||||||
204 | // Insert over-defined values into their own cache to reduce memory | ||||||
205 | // overhead. | ||||||
206 | if (Result.isOverdefined()) | ||||||
207 | Entry->OverDefined.insert(Val); | ||||||
208 | else | ||||||
209 | Entry->LatticeElements.insert({ Val, Result }); | ||||||
210 | |||||||
211 | addValueHandle(Val); | ||||||
212 | } | ||||||
213 | |||||||
214 | Optional<ValueLatticeElement> getCachedValueInfo(Value *V, | ||||||
215 | BasicBlock *BB) const { | ||||||
216 | const BlockCacheEntry *Entry = getBlockEntry(BB); | ||||||
217 | if (!Entry) | ||||||
218 | return None; | ||||||
219 | |||||||
220 | if (Entry->OverDefined.count(V)) | ||||||
221 | return ValueLatticeElement::getOverdefined(); | ||||||
222 | |||||||
223 | auto LatticeIt = Entry->LatticeElements.find_as(V); | ||||||
224 | if (LatticeIt == Entry->LatticeElements.end()) | ||||||
225 | return None; | ||||||
226 | |||||||
227 | return LatticeIt->second; | ||||||
228 | } | ||||||
229 | |||||||
230 | bool isNonNullAtEndOfBlock( | ||||||
231 | Value *V, BasicBlock *BB, | ||||||
232 | function_ref<NonNullPointerSet(BasicBlock *)> InitFn) { | ||||||
233 | BlockCacheEntry *Entry = getOrCreateBlockEntry(BB); | ||||||
234 | if (!Entry->NonNullPointers) { | ||||||
235 | Entry->NonNullPointers = InitFn(BB); | ||||||
236 | for (Value *V : *Entry->NonNullPointers) | ||||||
237 | addValueHandle(V); | ||||||
238 | } | ||||||
239 | |||||||
240 | return Entry->NonNullPointers->count(V); | ||||||
241 | } | ||||||
242 | |||||||
243 | /// clear - Empty the cache. | ||||||
244 | void clear() { | ||||||
245 | BlockCache.clear(); | ||||||
246 | ValueHandles.clear(); | ||||||
247 | } | ||||||
248 | |||||||
249 | /// Inform the cache that a given value has been deleted. | ||||||
250 | void eraseValue(Value *V); | ||||||
251 | |||||||
252 | /// This is part of the update interface to inform the cache | ||||||
253 | /// that a block has been deleted. | ||||||
254 | void eraseBlock(BasicBlock *BB); | ||||||
255 | |||||||
256 | /// Updates the cache to remove any influence an overdefined value in | ||||||
257 | /// OldSucc might have (unless also overdefined in NewSucc). This just | ||||||
258 | /// flushes elements from the cache and does not add any. | ||||||
259 | void threadEdgeImpl(BasicBlock *OldSucc,BasicBlock *NewSucc); | ||||||
260 | }; | ||||||
261 | } | ||||||
262 | |||||||
263 | void LazyValueInfoCache::eraseValue(Value *V) { | ||||||
264 | for (auto &Pair : BlockCache) { | ||||||
265 | Pair.second->LatticeElements.erase(V); | ||||||
266 | Pair.second->OverDefined.erase(V); | ||||||
267 | if (Pair.second->NonNullPointers) | ||||||
268 | Pair.second->NonNullPointers->erase(V); | ||||||
269 | } | ||||||
270 | |||||||
271 | auto HandleIt = ValueHandles.find_as(V); | ||||||
272 | if (HandleIt != ValueHandles.end()) | ||||||
273 | ValueHandles.erase(HandleIt); | ||||||
274 | } | ||||||
275 | |||||||
276 | void LVIValueHandle::deleted() { | ||||||
277 | // This erasure deallocates *this, so it MUST happen after we're done | ||||||
278 | // using any and all members of *this. | ||||||
279 | Parent->eraseValue(*this); | ||||||
280 | } | ||||||
281 | |||||||
282 | void LazyValueInfoCache::eraseBlock(BasicBlock *BB) { | ||||||
283 | BlockCache.erase(BB); | ||||||
284 | } | ||||||
285 | |||||||
286 | void LazyValueInfoCache::threadEdgeImpl(BasicBlock *OldSucc, | ||||||
287 | BasicBlock *NewSucc) { | ||||||
288 | // When an edge in the graph has been threaded, values that we could not | ||||||
289 | // determine a value for before (i.e. were marked overdefined) may be | ||||||
290 | // possible to solve now. We do NOT try to proactively update these values. | ||||||
291 | // Instead, we clear their entries from the cache, and allow lazy updating to | ||||||
292 | // recompute them when needed. | ||||||
293 | |||||||
294 | // The updating process is fairly simple: we need to drop cached info | ||||||
295 | // for all values that were marked overdefined in OldSucc, and for those same | ||||||
296 | // values in any successor of OldSucc (except NewSucc) in which they were | ||||||
297 | // also marked overdefined. | ||||||
298 | std::vector<BasicBlock*> worklist; | ||||||
299 | worklist.push_back(OldSucc); | ||||||
300 | |||||||
301 | const BlockCacheEntry *Entry = getBlockEntry(OldSucc); | ||||||
302 | if (!Entry || Entry->OverDefined.empty()) | ||||||
303 | return; // Nothing to process here. | ||||||
304 | SmallVector<Value *, 4> ValsToClear(Entry->OverDefined.begin(), | ||||||
305 | Entry->OverDefined.end()); | ||||||
306 | |||||||
307 | // Use a worklist to perform a depth-first search of OldSucc's successors. | ||||||
308 | // NOTE: We do not need a visited list since any blocks we have already | ||||||
309 | // visited will have had their overdefined markers cleared already, and we | ||||||
310 | // thus won't loop to their successors. | ||||||
311 | while (!worklist.empty()) { | ||||||
312 | BasicBlock *ToUpdate = worklist.back(); | ||||||
313 | worklist.pop_back(); | ||||||
314 | |||||||
315 | // Skip blocks only accessible through NewSucc. | ||||||
316 | if (ToUpdate == NewSucc) continue; | ||||||
317 | |||||||
318 | // If a value was marked overdefined in OldSucc, and is here too... | ||||||
319 | auto OI = BlockCache.find_as(ToUpdate); | ||||||
320 | if (OI == BlockCache.end() || OI->second->OverDefined.empty()) | ||||||
321 | continue; | ||||||
322 | auto &ValueSet = OI->second->OverDefined; | ||||||
323 | |||||||
324 | bool changed = false; | ||||||
325 | for (Value *V : ValsToClear) { | ||||||
326 | if (!ValueSet.erase(V)) | ||||||
327 | continue; | ||||||
328 | |||||||
329 | // If we removed anything, then we potentially need to update | ||||||
330 | // blocks successors too. | ||||||
331 | changed = true; | ||||||
332 | } | ||||||
333 | |||||||
334 | if (!changed) continue; | ||||||
335 | |||||||
336 | llvm::append_range(worklist, successors(ToUpdate)); | ||||||
337 | } | ||||||
338 | } | ||||||
339 | |||||||
340 | |||||||
341 | namespace { | ||||||
342 | /// An assembly annotator class to print LazyValueCache information in | ||||||
343 | /// comments. | ||||||
344 | class LazyValueInfoImpl; | ||||||
345 | class LazyValueInfoAnnotatedWriter : public AssemblyAnnotationWriter { | ||||||
346 | LazyValueInfoImpl *LVIImpl; | ||||||
347 | // While analyzing which blocks we can solve values for, we need the dominator | ||||||
348 | // information. | ||||||
349 | DominatorTree &DT; | ||||||
350 | |||||||
351 | public: | ||||||
352 | LazyValueInfoAnnotatedWriter(LazyValueInfoImpl *L, DominatorTree &DTree) | ||||||
353 | : LVIImpl(L), DT(DTree) {} | ||||||
354 | |||||||
355 | void emitBasicBlockStartAnnot(const BasicBlock *BB, | ||||||
356 | formatted_raw_ostream &OS) override; | ||||||
357 | |||||||
358 | void emitInstructionAnnot(const Instruction *I, | ||||||
359 | formatted_raw_ostream &OS) override; | ||||||
360 | }; | ||||||
361 | } | ||||||
362 | namespace { | ||||||
363 | // The actual implementation of the lazy analysis and update. Note that the | ||||||
364 | // inheritance from LazyValueInfoCache is intended to be temporary while | ||||||
365 | // splitting the code and then transitioning to a has-a relationship. | ||||||
366 | class LazyValueInfoImpl { | ||||||
367 | |||||||
368 | /// Cached results from previous queries | ||||||
369 | LazyValueInfoCache TheCache; | ||||||
370 | |||||||
371 | /// This stack holds the state of the value solver during a query. | ||||||
372 | /// It basically emulates the callstack of the naive | ||||||
373 | /// recursive value lookup process. | ||||||
374 | SmallVector<std::pair<BasicBlock*, Value*>, 8> BlockValueStack; | ||||||
375 | |||||||
376 | /// Keeps track of which block-value pairs are in BlockValueStack. | ||||||
377 | DenseSet<std::pair<BasicBlock*, Value*> > BlockValueSet; | ||||||
378 | |||||||
379 | /// Push BV onto BlockValueStack unless it's already in there. | ||||||
380 | /// Returns true on success. | ||||||
381 | bool pushBlockValue(const std::pair<BasicBlock *, Value *> &BV) { | ||||||
382 | if (!BlockValueSet.insert(BV).second) | ||||||
383 | return false; // It's already in the stack. | ||||||
384 | |||||||
385 | LLVM_DEBUG(dbgs() << "PUSH: " << *BV.second << " in "do { } while (false) | ||||||
386 | << BV.first->getName() << "\n")do { } while (false); | ||||||
387 | BlockValueStack.push_back(BV); | ||||||
388 | return true; | ||||||
389 | } | ||||||
390 | |||||||
391 | AssumptionCache *AC; ///< A pointer to the cache of @llvm.assume calls. | ||||||
392 | const DataLayout &DL; ///< A mandatory DataLayout | ||||||
393 | |||||||
394 | /// Declaration of the llvm.experimental.guard() intrinsic, | ||||||
395 | /// if it exists in the module. | ||||||
396 | Function *GuardDecl; | ||||||
397 | |||||||
398 | Optional<ValueLatticeElement> getBlockValue(Value *Val, BasicBlock *BB); | ||||||
399 | Optional<ValueLatticeElement> getEdgeValue(Value *V, BasicBlock *F, | ||||||
400 | BasicBlock *T, Instruction *CxtI = nullptr); | ||||||
401 | |||||||
402 | // These methods process one work item and may add more. A false value | ||||||
403 | // returned means that the work item was not completely processed and must | ||||||
404 | // be revisited after going through the new items. | ||||||
405 | bool solveBlockValue(Value *Val, BasicBlock *BB); | ||||||
406 | Optional<ValueLatticeElement> solveBlockValueImpl(Value *Val, BasicBlock *BB); | ||||||
407 | Optional<ValueLatticeElement> solveBlockValueNonLocal(Value *Val, | ||||||
408 | BasicBlock *BB); | ||||||
409 | Optional<ValueLatticeElement> solveBlockValuePHINode(PHINode *PN, | ||||||
410 | BasicBlock *BB); | ||||||
411 | Optional<ValueLatticeElement> solveBlockValueSelect(SelectInst *S, | ||||||
412 | BasicBlock *BB); | ||||||
413 | Optional<ConstantRange> getRangeFor(Value *V, Instruction *CxtI, | ||||||
414 | BasicBlock *BB); | ||||||
415 | Optional<ValueLatticeElement> solveBlockValueBinaryOpImpl( | ||||||
416 | Instruction *I, BasicBlock *BB, | ||||||
417 | std::function<ConstantRange(const ConstantRange &, | ||||||
418 | const ConstantRange &)> OpFn); | ||||||
419 | Optional<ValueLatticeElement> solveBlockValueBinaryOp(BinaryOperator *BBI, | ||||||
420 | BasicBlock *BB); | ||||||
421 | Optional<ValueLatticeElement> solveBlockValueCast(CastInst *CI, | ||||||
422 | BasicBlock *BB); | ||||||
423 | Optional<ValueLatticeElement> solveBlockValueOverflowIntrinsic( | ||||||
424 | WithOverflowInst *WO, BasicBlock *BB); | ||||||
425 | Optional<ValueLatticeElement> solveBlockValueIntrinsic(IntrinsicInst *II, | ||||||
426 | BasicBlock *BB); | ||||||
427 | Optional<ValueLatticeElement> solveBlockValueExtractValue( | ||||||
428 | ExtractValueInst *EVI, BasicBlock *BB); | ||||||
429 | bool isNonNullAtEndOfBlock(Value *Val, BasicBlock *BB); | ||||||
430 | void intersectAssumeOrGuardBlockValueConstantRange(Value *Val, | ||||||
431 | ValueLatticeElement &BBLV, | ||||||
432 | Instruction *BBI); | ||||||
433 | |||||||
434 | void solve(); | ||||||
435 | |||||||
436 | public: | ||||||
437 | /// This is the query interface to determine the lattice value for the | ||||||
438 | /// specified Value* at the context instruction (if specified) or at the | ||||||
439 | /// start of the block. | ||||||
440 | ValueLatticeElement getValueInBlock(Value *V, BasicBlock *BB, | ||||||
441 | Instruction *CxtI = nullptr); | ||||||
442 | |||||||
443 | /// This is the query interface to determine the lattice value for the | ||||||
444 | /// specified Value* at the specified instruction using only information | ||||||
445 | /// from assumes/guards and range metadata. Unlike getValueInBlock(), no | ||||||
446 | /// recursive query is performed. | ||||||
447 | ValueLatticeElement getValueAt(Value *V, Instruction *CxtI); | ||||||
448 | |||||||
449 | /// This is the query interface to determine the lattice | ||||||
450 | /// value for the specified Value* that is true on the specified edge. | ||||||
451 | ValueLatticeElement getValueOnEdge(Value *V, BasicBlock *FromBB, | ||||||
452 | BasicBlock *ToBB, | ||||||
453 | Instruction *CxtI = nullptr); | ||||||
454 | |||||||
455 | /// Complete flush all previously computed values | ||||||
456 | void clear() { | ||||||
457 | TheCache.clear(); | ||||||
458 | } | ||||||
459 | |||||||
460 | /// Printing the LazyValueInfo Analysis. | ||||||
461 | void printLVI(Function &F, DominatorTree &DTree, raw_ostream &OS) { | ||||||
462 | LazyValueInfoAnnotatedWriter Writer(this, DTree); | ||||||
463 | F.print(OS, &Writer); | ||||||
464 | } | ||||||
465 | |||||||
466 | /// This is part of the update interface to inform the cache | ||||||
467 | /// that a block has been deleted. | ||||||
468 | void eraseBlock(BasicBlock *BB) { | ||||||
469 | TheCache.eraseBlock(BB); | ||||||
470 | } | ||||||
471 | |||||||
472 | /// This is the update interface to inform the cache that an edge from | ||||||
473 | /// PredBB to OldSucc has been threaded to be from PredBB to NewSucc. | ||||||
474 | void threadEdge(BasicBlock *PredBB,BasicBlock *OldSucc,BasicBlock *NewSucc); | ||||||
475 | |||||||
476 | LazyValueInfoImpl(AssumptionCache *AC, const DataLayout &DL, | ||||||
477 | Function *GuardDecl) | ||||||
478 | : AC(AC), DL(DL), GuardDecl(GuardDecl) {} | ||||||
479 | }; | ||||||
480 | } // end anonymous namespace | ||||||
481 | |||||||
482 | |||||||
483 | void LazyValueInfoImpl::solve() { | ||||||
484 | SmallVector<std::pair<BasicBlock *, Value *>, 8> StartingStack( | ||||||
485 | BlockValueStack.begin(), BlockValueStack.end()); | ||||||
486 | |||||||
487 | unsigned processedCount = 0; | ||||||
488 | while (!BlockValueStack.empty()) { | ||||||
489 | processedCount++; | ||||||
490 | // Abort if we have to process too many values to get a result for this one. | ||||||
491 | // Because of the design of the overdefined cache currently being per-block | ||||||
492 | // to avoid naming-related issues (IE it wants to try to give different | ||||||
493 | // results for the same name in different blocks), overdefined results don't | ||||||
494 | // get cached globally, which in turn means we will often try to rediscover | ||||||
495 | // the same overdefined result again and again. Once something like | ||||||
496 | // PredicateInfo is used in LVI or CVP, we should be able to make the | ||||||
497 | // overdefined cache global, and remove this throttle. | ||||||
498 | if (processedCount > MaxProcessedPerValue) { | ||||||
499 | LLVM_DEBUG(do { } while (false) | ||||||
500 | dbgs() << "Giving up on stack because we are getting too deep\n")do { } while (false); | ||||||
501 | // Fill in the original values | ||||||
502 | while (!StartingStack.empty()) { | ||||||
503 | std::pair<BasicBlock *, Value *> &e = StartingStack.back(); | ||||||
504 | TheCache.insertResult(e.second, e.first, | ||||||
505 | ValueLatticeElement::getOverdefined()); | ||||||
506 | StartingStack.pop_back(); | ||||||
507 | } | ||||||
508 | BlockValueSet.clear(); | ||||||
509 | BlockValueStack.clear(); | ||||||
510 | return; | ||||||
511 | } | ||||||
512 | std::pair<BasicBlock *, Value *> e = BlockValueStack.back(); | ||||||
513 | assert(BlockValueSet.count(e) && "Stack value should be in BlockValueSet!")((void)0); | ||||||
514 | |||||||
515 | if (solveBlockValue(e.second, e.first)) { | ||||||
516 | // The work item was completely processed. | ||||||
517 | assert(BlockValueStack.back() == e && "Nothing should have been pushed!")((void)0); | ||||||
518 | #ifndef NDEBUG1 | ||||||
519 | Optional<ValueLatticeElement> BBLV = | ||||||
520 | TheCache.getCachedValueInfo(e.second, e.first); | ||||||
521 | assert(BBLV && "Result should be in cache!")((void)0); | ||||||
522 | LLVM_DEBUG(do { } while (false) | ||||||
523 | dbgs() << "POP " << *e.second << " in " << e.first->getName() << " = "do { } while (false) | ||||||
524 | << *BBLV << "\n")do { } while (false); | ||||||
525 | #endif | ||||||
526 | |||||||
527 | BlockValueStack.pop_back(); | ||||||
528 | BlockValueSet.erase(e); | ||||||
529 | } else { | ||||||
530 | // More work needs to be done before revisiting. | ||||||
531 | assert(BlockValueStack.back() != e && "Stack should have been pushed!")((void)0); | ||||||
532 | } | ||||||
533 | } | ||||||
534 | } | ||||||
535 | |||||||
536 | Optional<ValueLatticeElement> LazyValueInfoImpl::getBlockValue(Value *Val, | ||||||
537 | BasicBlock *BB) { | ||||||
538 | // If already a constant, there is nothing to compute. | ||||||
539 | if (Constant *VC = dyn_cast<Constant>(Val)) | ||||||
540 | return ValueLatticeElement::get(VC); | ||||||
541 | |||||||
542 | if (Optional<ValueLatticeElement> OptLatticeVal = | ||||||
543 | TheCache.getCachedValueInfo(Val, BB)) | ||||||
544 | return OptLatticeVal; | ||||||
545 | |||||||
546 | // We have hit a cycle, assume overdefined. | ||||||
547 | if (!pushBlockValue({ BB, Val })) | ||||||
548 | return ValueLatticeElement::getOverdefined(); | ||||||
549 | |||||||
550 | // Yet to be resolved. | ||||||
551 | return None; | ||||||
552 | } | ||||||
553 | |||||||
554 | static ValueLatticeElement getFromRangeMetadata(Instruction *BBI) { | ||||||
555 | switch (BBI->getOpcode()) { | ||||||
556 | default: break; | ||||||
557 | case Instruction::Load: | ||||||
558 | case Instruction::Call: | ||||||
559 | case Instruction::Invoke: | ||||||
560 | if (MDNode *Ranges = BBI->getMetadata(LLVMContext::MD_range)) | ||||||
561 | if (isa<IntegerType>(BBI->getType())) { | ||||||
562 | return ValueLatticeElement::getRange( | ||||||
563 | getConstantRangeFromMetadata(*Ranges)); | ||||||
564 | } | ||||||
565 | break; | ||||||
566 | }; | ||||||
567 | // Nothing known - will be intersected with other facts | ||||||
568 | return ValueLatticeElement::getOverdefined(); | ||||||
569 | } | ||||||
570 | |||||||
571 | bool LazyValueInfoImpl::solveBlockValue(Value *Val, BasicBlock *BB) { | ||||||
572 | assert(!isa<Constant>(Val) && "Value should not be constant")((void)0); | ||||||
573 | assert(!TheCache.getCachedValueInfo(Val, BB) &&((void)0) | ||||||
574 | "Value should not be in cache")((void)0); | ||||||
575 | |||||||
576 | // Hold off inserting this value into the Cache in case we have to return | ||||||
577 | // false and come back later. | ||||||
578 | Optional<ValueLatticeElement> Res = solveBlockValueImpl(Val, BB); | ||||||
579 | if (!Res) | ||||||
580 | // Work pushed, will revisit | ||||||
581 | return false; | ||||||
582 | |||||||
583 | TheCache.insertResult(Val, BB, *Res); | ||||||
584 | return true; | ||||||
585 | } | ||||||
586 | |||||||
587 | Optional<ValueLatticeElement> LazyValueInfoImpl::solveBlockValueImpl( | ||||||
588 | Value *Val, BasicBlock *BB) { | ||||||
589 | Instruction *BBI = dyn_cast<Instruction>(Val); | ||||||
590 | if (!BBI || BBI->getParent() != BB) | ||||||
591 | return solveBlockValueNonLocal(Val, BB); | ||||||
592 | |||||||
593 | if (PHINode *PN = dyn_cast<PHINode>(BBI)) | ||||||
594 | return solveBlockValuePHINode(PN, BB); | ||||||
595 | |||||||
596 | if (auto *SI = dyn_cast<SelectInst>(BBI)) | ||||||
597 | return solveBlockValueSelect(SI, BB); | ||||||
598 | |||||||
599 | // If this value is a nonnull pointer, record it's range and bailout. Note | ||||||
600 | // that for all other pointer typed values, we terminate the search at the | ||||||
601 | // definition. We could easily extend this to look through geps, bitcasts, | ||||||
602 | // and the like to prove non-nullness, but it's not clear that's worth it | ||||||
603 | // compile time wise. The context-insensitive value walk done inside | ||||||
604 | // isKnownNonZero gets most of the profitable cases at much less expense. | ||||||
605 | // This does mean that we have a sensitivity to where the defining | ||||||
606 | // instruction is placed, even if it could legally be hoisted much higher. | ||||||
607 | // That is unfortunate. | ||||||
608 | PointerType *PT = dyn_cast<PointerType>(BBI->getType()); | ||||||
609 | if (PT && isKnownNonZero(BBI, DL)) | ||||||
610 | return ValueLatticeElement::getNot(ConstantPointerNull::get(PT)); | ||||||
611 | |||||||
612 | if (BBI->getType()->isIntegerTy()) { | ||||||
613 | if (auto *CI = dyn_cast<CastInst>(BBI)) | ||||||
614 | return solveBlockValueCast(CI, BB); | ||||||
615 | |||||||
616 | if (BinaryOperator *BO = dyn_cast<BinaryOperator>(BBI)) | ||||||
617 | return solveBlockValueBinaryOp(BO, BB); | ||||||
618 | |||||||
619 | if (auto *EVI = dyn_cast<ExtractValueInst>(BBI)) | ||||||
620 | return solveBlockValueExtractValue(EVI, BB); | ||||||
621 | |||||||
622 | if (auto *II = dyn_cast<IntrinsicInst>(BBI)) | ||||||
623 | return solveBlockValueIntrinsic(II, BB); | ||||||
624 | } | ||||||
625 | |||||||
626 | LLVM_DEBUG(dbgs() << " compute BB '" << BB->getName()do { } while (false) | ||||||
627 | << "' - unknown inst def found.\n")do { } while (false); | ||||||
628 | return getFromRangeMetadata(BBI); | ||||||
629 | } | ||||||
630 | |||||||
631 | static void AddNonNullPointer(Value *Ptr, NonNullPointerSet &PtrSet) { | ||||||
632 | // TODO: Use NullPointerIsDefined instead. | ||||||
633 | if (Ptr->getType()->getPointerAddressSpace() == 0) | ||||||
634 | PtrSet.insert(getUnderlyingObject(Ptr)); | ||||||
635 | } | ||||||
636 | |||||||
637 | static void AddNonNullPointersByInstruction( | ||||||
638 | Instruction *I, NonNullPointerSet &PtrSet) { | ||||||
639 | if (LoadInst *L = dyn_cast<LoadInst>(I)) { | ||||||
640 | AddNonNullPointer(L->getPointerOperand(), PtrSet); | ||||||
641 | } else if (StoreInst *S = dyn_cast<StoreInst>(I)) { | ||||||
642 | AddNonNullPointer(S->getPointerOperand(), PtrSet); | ||||||
643 | } else if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(I)) { | ||||||
644 | if (MI->isVolatile()) return; | ||||||
645 | |||||||
646 | // FIXME: check whether it has a valuerange that excludes zero? | ||||||
647 | ConstantInt *Len = dyn_cast<ConstantInt>(MI->getLength()); | ||||||
648 | if (!Len || Len->isZero()) return; | ||||||
649 | |||||||
650 | AddNonNullPointer(MI->getRawDest(), PtrSet); | ||||||
651 | if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(MI)) | ||||||
652 | AddNonNullPointer(MTI->getRawSource(), PtrSet); | ||||||
653 | } | ||||||
654 | } | ||||||
655 | |||||||
656 | bool LazyValueInfoImpl::isNonNullAtEndOfBlock(Value *Val, BasicBlock *BB) { | ||||||
657 | if (NullPointerIsDefined(BB->getParent(), | ||||||
658 | Val->getType()->getPointerAddressSpace())) | ||||||
659 | return false; | ||||||
660 | |||||||
661 | Val = Val->stripInBoundsOffsets(); | ||||||
662 | return TheCache.isNonNullAtEndOfBlock(Val, BB, [](BasicBlock *BB) { | ||||||
663 | NonNullPointerSet NonNullPointers; | ||||||
664 | for (Instruction &I : *BB) | ||||||
665 | AddNonNullPointersByInstruction(&I, NonNullPointers); | ||||||
666 | return NonNullPointers; | ||||||
667 | }); | ||||||
668 | } | ||||||
669 | |||||||
670 | Optional<ValueLatticeElement> LazyValueInfoImpl::solveBlockValueNonLocal( | ||||||
671 | Value *Val, BasicBlock *BB) { | ||||||
672 | ValueLatticeElement Result; // Start Undefined. | ||||||
673 | |||||||
674 | // If this is the entry block, we must be asking about an argument. The | ||||||
675 | // value is overdefined. | ||||||
676 | if (BB->isEntryBlock()) { | ||||||
677 | assert(isa<Argument>(Val) && "Unknown live-in to the entry block")((void)0); | ||||||
678 | return ValueLatticeElement::getOverdefined(); | ||||||
679 | } | ||||||
680 | |||||||
681 | // Loop over all of our predecessors, merging what we know from them into | ||||||
682 | // result. If we encounter an unexplored predecessor, we eagerly explore it | ||||||
683 | // in a depth first manner. In practice, this has the effect of discovering | ||||||
684 | // paths we can't analyze eagerly without spending compile times analyzing | ||||||
685 | // other paths. This heuristic benefits from the fact that predecessors are | ||||||
686 | // frequently arranged such that dominating ones come first and we quickly | ||||||
687 | // find a path to function entry. TODO: We should consider explicitly | ||||||
688 | // canonicalizing to make this true rather than relying on this happy | ||||||
689 | // accident. | ||||||
690 | for (BasicBlock *Pred : predecessors(BB)) { | ||||||
691 | Optional<ValueLatticeElement> EdgeResult = getEdgeValue(Val, Pred, BB); | ||||||
692 | if (!EdgeResult) | ||||||
693 | // Explore that input, then return here | ||||||
694 | return None; | ||||||
695 | |||||||
696 | Result.mergeIn(*EdgeResult); | ||||||
697 | |||||||
698 | // If we hit overdefined, exit early. The BlockVals entry is already set | ||||||
699 | // to overdefined. | ||||||
700 | if (Result.isOverdefined()) { | ||||||
701 | LLVM_DEBUG(dbgs() << " compute BB '" << BB->getName()do { } while (false) | ||||||
702 | << "' - overdefined because of pred (non local).\n")do { } while (false); | ||||||
703 | return Result; | ||||||
704 | } | ||||||
705 | } | ||||||
706 | |||||||
707 | // Return the merged value, which is more precise than 'overdefined'. | ||||||
708 | assert(!Result.isOverdefined())((void)0); | ||||||
709 | return Result; | ||||||
710 | } | ||||||
711 | |||||||
712 | Optional<ValueLatticeElement> LazyValueInfoImpl::solveBlockValuePHINode( | ||||||
713 | PHINode *PN, BasicBlock *BB) { | ||||||
714 | ValueLatticeElement Result; // Start Undefined. | ||||||
715 | |||||||
716 | // Loop over all of our predecessors, merging what we know from them into | ||||||
717 | // result. See the comment about the chosen traversal order in | ||||||
718 | // solveBlockValueNonLocal; the same reasoning applies here. | ||||||
719 | for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) { | ||||||
720 | BasicBlock *PhiBB = PN->getIncomingBlock(i); | ||||||
721 | Value *PhiVal = PN->getIncomingValue(i); | ||||||
722 | // Note that we can provide PN as the context value to getEdgeValue, even | ||||||
723 | // though the results will be cached, because PN is the value being used as | ||||||
724 | // the cache key in the caller. | ||||||
725 | Optional<ValueLatticeElement> EdgeResult = | ||||||
726 | getEdgeValue(PhiVal, PhiBB, BB, PN); | ||||||
727 | if (!EdgeResult) | ||||||
728 | // Explore that input, then return here | ||||||
729 | return None; | ||||||
730 | |||||||
731 | Result.mergeIn(*EdgeResult); | ||||||
732 | |||||||
733 | // If we hit overdefined, exit early. The BlockVals entry is already set | ||||||
734 | // to overdefined. | ||||||
735 | if (Result.isOverdefined()) { | ||||||
736 | LLVM_DEBUG(dbgs() << " compute BB '" << BB->getName()do { } while (false) | ||||||
737 | << "' - overdefined because of pred (local).\n")do { } while (false); | ||||||
738 | |||||||
739 | return Result; | ||||||
740 | } | ||||||
741 | } | ||||||
742 | |||||||
743 | // Return the merged value, which is more precise than 'overdefined'. | ||||||
744 | assert(!Result.isOverdefined() && "Possible PHI in entry block?")((void)0); | ||||||
745 | return Result; | ||||||
746 | } | ||||||
747 | |||||||
748 | static ValueLatticeElement getValueFromCondition(Value *Val, Value *Cond, | ||||||
749 | bool isTrueDest = true); | ||||||
750 | |||||||
751 | // If we can determine a constraint on the value given conditions assumed by | ||||||
752 | // the program, intersect those constraints with BBLV | ||||||
753 | void LazyValueInfoImpl::intersectAssumeOrGuardBlockValueConstantRange( | ||||||
754 | Value *Val, ValueLatticeElement &BBLV, Instruction *BBI) { | ||||||
755 | BBI = BBI ? BBI : dyn_cast<Instruction>(Val); | ||||||
756 | if (!BBI) | ||||||
757 | return; | ||||||
758 | |||||||
759 | BasicBlock *BB = BBI->getParent(); | ||||||
760 | for (auto &AssumeVH : AC->assumptionsFor(Val)) { | ||||||
761 | if (!AssumeVH) | ||||||
762 | continue; | ||||||
763 | |||||||
764 | // Only check assumes in the block of the context instruction. Other | ||||||
765 | // assumes will have already been taken into account when the value was | ||||||
766 | // propagated from predecessor blocks. | ||||||
767 | auto *I = cast<CallInst>(AssumeVH); | ||||||
768 | if (I->getParent() != BB || !isValidAssumeForContext(I, BBI)) | ||||||
769 | continue; | ||||||
770 | |||||||
771 | BBLV = intersect(BBLV, getValueFromCondition(Val, I->getArgOperand(0))); | ||||||
772 | } | ||||||
773 | |||||||
774 | // If guards are not used in the module, don't spend time looking for them | ||||||
775 | if (GuardDecl && !GuardDecl->use_empty() && | ||||||
776 | BBI->getIterator() != BB->begin()) { | ||||||
777 | for (Instruction &I : make_range(std::next(BBI->getIterator().getReverse()), | ||||||
778 | BB->rend())) { | ||||||
779 | Value *Cond = nullptr; | ||||||
780 | if (match(&I, m_Intrinsic<Intrinsic::experimental_guard>(m_Value(Cond)))) | ||||||
781 | BBLV = intersect(BBLV, getValueFromCondition(Val, Cond)); | ||||||
782 | } | ||||||
783 | } | ||||||
784 | |||||||
785 | if (BBLV.isOverdefined()) { | ||||||
786 | // Check whether we're checking at the terminator, and the pointer has | ||||||
787 | // been dereferenced in this block. | ||||||
788 | PointerType *PTy = dyn_cast<PointerType>(Val->getType()); | ||||||
789 | if (PTy && BB->getTerminator() == BBI && | ||||||
790 | isNonNullAtEndOfBlock(Val, BB)) | ||||||
791 | BBLV = ValueLatticeElement::getNot(ConstantPointerNull::get(PTy)); | ||||||
792 | } | ||||||
793 | } | ||||||
794 | |||||||
795 | Optional<ValueLatticeElement> LazyValueInfoImpl::solveBlockValueSelect( | ||||||
796 | SelectInst *SI, BasicBlock *BB) { | ||||||
797 | // Recurse on our inputs if needed | ||||||
798 | Optional<ValueLatticeElement> OptTrueVal = | ||||||
799 | getBlockValue(SI->getTrueValue(), BB); | ||||||
800 | if (!OptTrueVal) | ||||||
801 | return None; | ||||||
802 | ValueLatticeElement &TrueVal = *OptTrueVal; | ||||||
803 | |||||||
804 | Optional<ValueLatticeElement> OptFalseVal = | ||||||
805 | getBlockValue(SI->getFalseValue(), BB); | ||||||
806 | if (!OptFalseVal) | ||||||
807 | return None; | ||||||
808 | ValueLatticeElement &FalseVal = *OptFalseVal; | ||||||
809 | |||||||
810 | if (TrueVal.isConstantRange() && FalseVal.isConstantRange()) { | ||||||
811 | const ConstantRange &TrueCR = TrueVal.getConstantRange(); | ||||||
812 | const ConstantRange &FalseCR = FalseVal.getConstantRange(); | ||||||
813 | Value *LHS = nullptr; | ||||||
814 | Value *RHS = nullptr; | ||||||
815 | SelectPatternResult SPR = matchSelectPattern(SI, LHS, RHS); | ||||||
816 | // Is this a min specifically of our two inputs? (Avoid the risk of | ||||||
817 | // ValueTracking getting smarter looking back past our immediate inputs.) | ||||||
818 | if (SelectPatternResult::isMinOrMax(SPR.Flavor) && | ||||||
819 | LHS == SI->getTrueValue() && RHS == SI->getFalseValue()) { | ||||||
820 | ConstantRange ResultCR = [&]() { | ||||||
821 | switch (SPR.Flavor) { | ||||||
822 | default: | ||||||
823 | llvm_unreachable("unexpected minmax type!")__builtin_unreachable(); | ||||||
824 | case SPF_SMIN: /// Signed minimum | ||||||
825 | return TrueCR.smin(FalseCR); | ||||||
826 | case SPF_UMIN: /// Unsigned minimum | ||||||
827 | return TrueCR.umin(FalseCR); | ||||||
828 | case SPF_SMAX: /// Signed maximum | ||||||
829 | return TrueCR.smax(FalseCR); | ||||||
830 | case SPF_UMAX: /// Unsigned maximum | ||||||
831 | return TrueCR.umax(FalseCR); | ||||||
832 | }; | ||||||
833 | }(); | ||||||
834 | return ValueLatticeElement::getRange( | ||||||
835 | ResultCR, TrueVal.isConstantRangeIncludingUndef() | | ||||||
836 | FalseVal.isConstantRangeIncludingUndef()); | ||||||
837 | } | ||||||
838 | |||||||
839 | if (SPR.Flavor == SPF_ABS) { | ||||||
840 | if (LHS == SI->getTrueValue()) | ||||||
841 | return ValueLatticeElement::getRange( | ||||||
842 | TrueCR.abs(), TrueVal.isConstantRangeIncludingUndef()); | ||||||
843 | if (LHS == SI->getFalseValue()) | ||||||
844 | return ValueLatticeElement::getRange( | ||||||
845 | FalseCR.abs(), FalseVal.isConstantRangeIncludingUndef()); | ||||||
846 | } | ||||||
847 | |||||||
848 | if (SPR.Flavor == SPF_NABS) { | ||||||
849 | ConstantRange Zero(APInt::getNullValue(TrueCR.getBitWidth())); | ||||||
850 | if (LHS == SI->getTrueValue()) | ||||||
851 | return ValueLatticeElement::getRange( | ||||||
852 | Zero.sub(TrueCR.abs()), FalseVal.isConstantRangeIncludingUndef()); | ||||||
853 | if (LHS == SI->getFalseValue()) | ||||||
854 | return ValueLatticeElement::getRange( | ||||||
855 | Zero.sub(FalseCR.abs()), FalseVal.isConstantRangeIncludingUndef()); | ||||||
856 | } | ||||||
857 | } | ||||||
858 | |||||||
859 | // Can we constrain the facts about the true and false values by using the | ||||||
860 | // condition itself? This shows up with idioms like e.g. select(a > 5, a, 5). | ||||||
861 | // TODO: We could potentially refine an overdefined true value above. | ||||||
862 | Value *Cond = SI->getCondition(); | ||||||
863 | TrueVal = intersect(TrueVal, | ||||||
864 | getValueFromCondition(SI->getTrueValue(), Cond, true)); | ||||||
865 | FalseVal = intersect(FalseVal, | ||||||
866 | getValueFromCondition(SI->getFalseValue(), Cond, false)); | ||||||
867 | |||||||
868 | ValueLatticeElement Result = TrueVal; | ||||||
869 | Result.mergeIn(FalseVal); | ||||||
870 | return Result; | ||||||
871 | } | ||||||
872 | |||||||
873 | Optional<ConstantRange> LazyValueInfoImpl::getRangeFor(Value *V, | ||||||
874 | Instruction *CxtI, | ||||||
875 | BasicBlock *BB) { | ||||||
876 | Optional<ValueLatticeElement> OptVal = getBlockValue(V, BB); | ||||||
877 | if (!OptVal) | ||||||
878 | return None; | ||||||
879 | |||||||
880 | ValueLatticeElement &Val = *OptVal; | ||||||
881 | intersectAssumeOrGuardBlockValueConstantRange(V, Val, CxtI); | ||||||
882 | if (Val.isConstantRange()) | ||||||
883 | return Val.getConstantRange(); | ||||||
884 | |||||||
885 | const unsigned OperandBitWidth = DL.getTypeSizeInBits(V->getType()); | ||||||
886 | return ConstantRange::getFull(OperandBitWidth); | ||||||
887 | } | ||||||
888 | |||||||
889 | Optional<ValueLatticeElement> LazyValueInfoImpl::solveBlockValueCast( | ||||||
890 | CastInst *CI, BasicBlock *BB) { | ||||||
891 | // Without knowing how wide the input is, we can't analyze it in any useful | ||||||
892 | // way. | ||||||
893 | if (!CI->getOperand(0)->getType()->isSized()) | ||||||
894 | return ValueLatticeElement::getOverdefined(); | ||||||
895 | |||||||
896 | // Filter out casts we don't know how to reason about before attempting to | ||||||
897 | // recurse on our operand. This can cut a long search short if we know we're | ||||||
898 | // not going to be able to get any useful information anways. | ||||||
899 | switch (CI->getOpcode()) { | ||||||
900 | case Instruction::Trunc: | ||||||
901 | case Instruction::SExt: | ||||||
902 | case Instruction::ZExt: | ||||||
903 | case Instruction::BitCast: | ||||||
904 | break; | ||||||
905 | default: | ||||||
906 | // Unhandled instructions are overdefined. | ||||||
907 | LLVM_DEBUG(dbgs() << " compute BB '" << BB->getName()do { } while (false) | ||||||
908 | << "' - overdefined (unknown cast).\n")do { } while (false); | ||||||
909 | return ValueLatticeElement::getOverdefined(); | ||||||
910 | } | ||||||
911 | |||||||
912 | // Figure out the range of the LHS. If that fails, we still apply the | ||||||
913 | // transfer rule on the full set since we may be able to locally infer | ||||||
914 | // interesting facts. | ||||||
915 | Optional<ConstantRange> LHSRes = getRangeFor(CI->getOperand(0), CI, BB); | ||||||
916 | if (!LHSRes.hasValue()) | ||||||
917 | // More work to do before applying this transfer rule. | ||||||
918 | return None; | ||||||
919 | const ConstantRange &LHSRange = LHSRes.getValue(); | ||||||
920 | |||||||
921 | const unsigned ResultBitWidth = CI->getType()->getIntegerBitWidth(); | ||||||
922 | |||||||
923 | // NOTE: We're currently limited by the set of operations that ConstantRange | ||||||
924 | // can evaluate symbolically. Enhancing that set will allows us to analyze | ||||||
925 | // more definitions. | ||||||
926 | return ValueLatticeElement::getRange(LHSRange.castOp(CI->getOpcode(), | ||||||
927 | ResultBitWidth)); | ||||||
928 | } | ||||||
929 | |||||||
930 | Optional<ValueLatticeElement> LazyValueInfoImpl::solveBlockValueBinaryOpImpl( | ||||||
931 | Instruction *I, BasicBlock *BB, | ||||||
932 | std::function<ConstantRange(const ConstantRange &, | ||||||
933 | const ConstantRange &)> OpFn) { | ||||||
934 | // Figure out the ranges of the operands. If that fails, use a | ||||||
935 | // conservative range, but apply the transfer rule anyways. This | ||||||
936 | // lets us pick up facts from expressions like "and i32 (call i32 | ||||||
937 | // @foo()), 32" | ||||||
938 | Optional<ConstantRange> LHSRes = getRangeFor(I->getOperand(0), I, BB); | ||||||
939 | Optional<ConstantRange> RHSRes = getRangeFor(I->getOperand(1), I, BB); | ||||||
940 | if (!LHSRes.hasValue() || !RHSRes.hasValue()) | ||||||
941 | // More work to do before applying this transfer rule. | ||||||
942 | return None; | ||||||
943 | |||||||
944 | const ConstantRange &LHSRange = LHSRes.getValue(); | ||||||
945 | const ConstantRange &RHSRange = RHSRes.getValue(); | ||||||
946 | return ValueLatticeElement::getRange(OpFn(LHSRange, RHSRange)); | ||||||
947 | } | ||||||
948 | |||||||
949 | Optional<ValueLatticeElement> LazyValueInfoImpl::solveBlockValueBinaryOp( | ||||||
950 | BinaryOperator *BO, BasicBlock *BB) { | ||||||
951 | assert(BO->getOperand(0)->getType()->isSized() &&((void)0) | ||||||
952 | "all operands to binary operators are sized")((void)0); | ||||||
953 | if (BO->getOpcode() == Instruction::Xor) { | ||||||
954 | // Xor is the only operation not supported by ConstantRange::binaryOp(). | ||||||
955 | LLVM_DEBUG(dbgs() << " compute BB '" << BB->getName()do { } while (false) | ||||||
956 | << "' - overdefined (unknown binary operator).\n")do { } while (false); | ||||||
957 | return ValueLatticeElement::getOverdefined(); | ||||||
958 | } | ||||||
959 | |||||||
960 | if (auto *OBO = dyn_cast<OverflowingBinaryOperator>(BO)) { | ||||||
961 | unsigned NoWrapKind = 0; | ||||||
962 | if (OBO->hasNoUnsignedWrap()) | ||||||
963 | NoWrapKind |= OverflowingBinaryOperator::NoUnsignedWrap; | ||||||
964 | if (OBO->hasNoSignedWrap()) | ||||||
965 | NoWrapKind |= OverflowingBinaryOperator::NoSignedWrap; | ||||||
966 | |||||||
967 | return solveBlockValueBinaryOpImpl( | ||||||
968 | BO, BB, | ||||||
969 | [BO, NoWrapKind](const ConstantRange &CR1, const ConstantRange &CR2) { | ||||||
970 | return CR1.overflowingBinaryOp(BO->getOpcode(), CR2, NoWrapKind); | ||||||
971 | }); | ||||||
972 | } | ||||||
973 | |||||||
974 | return solveBlockValueBinaryOpImpl( | ||||||
975 | BO, BB, [BO](const ConstantRange &CR1, const ConstantRange &CR2) { | ||||||
976 | return CR1.binaryOp(BO->getOpcode(), CR2); | ||||||
977 | }); | ||||||
978 | } | ||||||
979 | |||||||
980 | Optional<ValueLatticeElement> | ||||||
981 | LazyValueInfoImpl::solveBlockValueOverflowIntrinsic(WithOverflowInst *WO, | ||||||
982 | BasicBlock *BB) { | ||||||
983 | return solveBlockValueBinaryOpImpl( | ||||||
984 | WO, BB, [WO](const ConstantRange &CR1, const ConstantRange &CR2) { | ||||||
985 | return CR1.binaryOp(WO->getBinaryOp(), CR2); | ||||||
986 | }); | ||||||
987 | } | ||||||
988 | |||||||
989 | Optional<ValueLatticeElement> LazyValueInfoImpl::solveBlockValueIntrinsic( | ||||||
990 | IntrinsicInst *II, BasicBlock *BB) { | ||||||
991 | if (!ConstantRange::isIntrinsicSupported(II->getIntrinsicID())) { | ||||||
992 | LLVM_DEBUG(dbgs() << " compute BB '" << BB->getName()do { } while (false) | ||||||
993 | << "' - unknown intrinsic.\n")do { } while (false); | ||||||
994 | return getFromRangeMetadata(II); | ||||||
995 | } | ||||||
996 | |||||||
997 | SmallVector<ConstantRange, 2> OpRanges; | ||||||
998 | for (Value *Op : II->args()) { | ||||||
999 | Optional<ConstantRange> Range = getRangeFor(Op, II, BB); | ||||||
1000 | if (!Range) | ||||||
1001 | return None; | ||||||
1002 | OpRanges.push_back(*Range); | ||||||
1003 | } | ||||||
1004 | |||||||
1005 | return ValueLatticeElement::getRange( | ||||||
1006 | ConstantRange::intrinsic(II->getIntrinsicID(), OpRanges)); | ||||||
1007 | } | ||||||
1008 | |||||||
1009 | Optional<ValueLatticeElement> LazyValueInfoImpl::solveBlockValueExtractValue( | ||||||
1010 | ExtractValueInst *EVI, BasicBlock *BB) { | ||||||
1011 | if (auto *WO = dyn_cast<WithOverflowInst>(EVI->getAggregateOperand())) | ||||||
1012 | if (EVI->getNumIndices() == 1 && *EVI->idx_begin() == 0) | ||||||
1013 | return solveBlockValueOverflowIntrinsic(WO, BB); | ||||||
1014 | |||||||
1015 | // Handle extractvalue of insertvalue to allow further simplification | ||||||
1016 | // based on replaced with.overflow intrinsics. | ||||||
1017 | if (Value *V = SimplifyExtractValueInst( | ||||||
1018 | EVI->getAggregateOperand(), EVI->getIndices(), | ||||||
1019 | EVI->getModule()->getDataLayout())) | ||||||
1020 | return getBlockValue(V, BB); | ||||||
1021 | |||||||
1022 | LLVM_DEBUG(dbgs() << " compute BB '" << BB->getName()do { } while (false) | ||||||
1023 | << "' - overdefined (unknown extractvalue).\n")do { } while (false); | ||||||
1024 | return ValueLatticeElement::getOverdefined(); | ||||||
1025 | } | ||||||
1026 | |||||||
1027 | static bool matchICmpOperand(APInt &Offset, Value *LHS, Value *Val, | ||||||
1028 | ICmpInst::Predicate Pred) { | ||||||
1029 | if (LHS == Val) | ||||||
1030 | return true; | ||||||
1031 | |||||||
1032 | // Handle range checking idiom produced by InstCombine. We will subtract the | ||||||
1033 | // offset from the allowed range for RHS in this case. | ||||||
1034 | const APInt *C; | ||||||
1035 | if (match(LHS, m_Add(m_Specific(Val), m_APInt(C)))) { | ||||||
1036 | Offset = *C; | ||||||
1037 | return true; | ||||||
1038 | } | ||||||
1039 | |||||||
1040 | // Handle the symmetric case. This appears in saturation patterns like | ||||||
1041 | // (x == 16) ? 16 : (x + 1). | ||||||
1042 | if (match(Val, m_Add(m_Specific(LHS), m_APInt(C)))) { | ||||||
1043 | Offset = -*C; | ||||||
1044 | return true; | ||||||
1045 | } | ||||||
1046 | |||||||
1047 | // If (x | y) < C, then (x < C) && (y < C). | ||||||
1048 | if (match(LHS, m_c_Or(m_Specific(Val), m_Value())) && | ||||||
1049 | (Pred == ICmpInst::ICMP_ULT || Pred == ICmpInst::ICMP_ULE)) | ||||||
1050 | return true; | ||||||
1051 | |||||||
1052 | // If (x & y) > C, then (x > C) && (y > C). | ||||||
1053 | if (match(LHS, m_c_And(m_Specific(Val), m_Value())) && | ||||||
1054 | (Pred == ICmpInst::ICMP_UGT || Pred == ICmpInst::ICMP_UGE)) | ||||||
1055 | return true; | ||||||
1056 | |||||||
1057 | return false; | ||||||
1058 | } | ||||||
1059 | |||||||
1060 | /// Get value range for a "(Val + Offset) Pred RHS" condition. | ||||||
1061 | static ValueLatticeElement getValueFromSimpleICmpCondition( | ||||||
1062 | CmpInst::Predicate Pred, Value *RHS, const APInt &Offset) { | ||||||
1063 | ConstantRange RHSRange(RHS->getType()->getIntegerBitWidth(), | ||||||
1064 | /*isFullSet=*/true); | ||||||
1065 | if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) | ||||||
1066 | RHSRange = ConstantRange(CI->getValue()); | ||||||
1067 | else if (Instruction *I = dyn_cast<Instruction>(RHS)) | ||||||
1068 | if (auto *Ranges = I->getMetadata(LLVMContext::MD_range)) | ||||||
1069 | RHSRange = getConstantRangeFromMetadata(*Ranges); | ||||||
1070 | |||||||
1071 | ConstantRange TrueValues = | ||||||
1072 | ConstantRange::makeAllowedICmpRegion(Pred, RHSRange); | ||||||
1073 | return ValueLatticeElement::getRange(TrueValues.subtract(Offset)); | ||||||
1074 | } | ||||||
1075 | |||||||
1076 | static ValueLatticeElement getValueFromICmpCondition(Value *Val, ICmpInst *ICI, | ||||||
1077 | bool isTrueDest) { | ||||||
1078 | Value *LHS = ICI->getOperand(0); | ||||||
1079 | Value *RHS = ICI->getOperand(1); | ||||||
1080 | |||||||
1081 | // Get the predicate that must hold along the considered edge. | ||||||
1082 | CmpInst::Predicate EdgePred = | ||||||
1083 | isTrueDest ? ICI->getPredicate() : ICI->getInversePredicate(); | ||||||
1084 | |||||||
1085 | if (isa<Constant>(RHS)) { | ||||||
1086 | if (ICI->isEquality() && LHS == Val) { | ||||||
1087 | if (EdgePred == ICmpInst::ICMP_EQ) | ||||||
1088 | return ValueLatticeElement::get(cast<Constant>(RHS)); | ||||||
1089 | else if (!isa<UndefValue>(RHS)) | ||||||
1090 | return ValueLatticeElement::getNot(cast<Constant>(RHS)); | ||||||
1091 | } | ||||||
1092 | } | ||||||
1093 | |||||||
1094 | Type *Ty = Val->getType(); | ||||||
1095 | if (!Ty->isIntegerTy()) | ||||||
1096 | return ValueLatticeElement::getOverdefined(); | ||||||
1097 | |||||||
1098 | APInt Offset(Ty->getScalarSizeInBits(), 0); | ||||||
1099 | if (matchICmpOperand(Offset, LHS, Val, EdgePred)) | ||||||
1100 | return getValueFromSimpleICmpCondition(EdgePred, RHS, Offset); | ||||||
1101 | |||||||
1102 | CmpInst::Predicate SwappedPred = CmpInst::getSwappedPredicate(EdgePred); | ||||||
1103 | if (matchICmpOperand(Offset, RHS, Val, SwappedPred)) | ||||||
1104 | return getValueFromSimpleICmpCondition(SwappedPred, LHS, Offset); | ||||||
1105 | |||||||
1106 | const APInt *Mask, *C; | ||||||
1107 | if (match(LHS, m_And(m_Specific(Val), m_APInt(Mask))) && | ||||||
1108 | match(RHS, m_APInt(C))) { | ||||||
1109 | // If (Val & Mask) == C then all the masked bits are known and we can | ||||||
1110 | // compute a value range based on that. | ||||||
1111 | if (EdgePred == ICmpInst::ICMP_EQ) { | ||||||
1112 | KnownBits Known; | ||||||
1113 | Known.Zero = ~*C & *Mask; | ||||||
1114 | Known.One = *C & *Mask; | ||||||
1115 | return ValueLatticeElement::getRange( | ||||||
1116 | ConstantRange::fromKnownBits(Known, /*IsSigned*/ false)); | ||||||
1117 | } | ||||||
1118 | // If (Val & Mask) != 0 then the value must be larger than the lowest set | ||||||
1119 | // bit of Mask. | ||||||
1120 | if (EdgePred == ICmpInst::ICMP_NE && !Mask->isNullValue() && | ||||||
1121 | C->isNullValue()) { | ||||||
1122 | unsigned BitWidth = Ty->getIntegerBitWidth(); | ||||||
1123 | return ValueLatticeElement::getRange(ConstantRange::getNonEmpty( | ||||||
1124 | APInt::getOneBitSet(BitWidth, Mask->countTrailingZeros()), | ||||||
1125 | APInt::getNullValue(BitWidth))); | ||||||
1126 | } | ||||||
1127 | } | ||||||
1128 | |||||||
1129 | return ValueLatticeElement::getOverdefined(); | ||||||
1130 | } | ||||||
1131 | |||||||
1132 | // Handle conditions of the form | ||||||
1133 | // extractvalue(op.with.overflow(%x, C), 1). | ||||||
1134 | static ValueLatticeElement getValueFromOverflowCondition( | ||||||
1135 | Value *Val, WithOverflowInst *WO, bool IsTrueDest) { | ||||||
1136 | // TODO: This only works with a constant RHS for now. We could also compute | ||||||
1137 | // the range of the RHS, but this doesn't fit into the current structure of | ||||||
1138 | // the edge value calculation. | ||||||
1139 | const APInt *C; | ||||||
1140 | if (WO->getLHS() != Val || !match(WO->getRHS(), m_APInt(C))) | ||||||
1141 | return ValueLatticeElement::getOverdefined(); | ||||||
1142 | |||||||
1143 | // Calculate the possible values of %x for which no overflow occurs. | ||||||
1144 | ConstantRange NWR = ConstantRange::makeExactNoWrapRegion( | ||||||
1145 | WO->getBinaryOp(), *C, WO->getNoWrapKind()); | ||||||
1146 | |||||||
1147 | // If overflow is false, %x is constrained to NWR. If overflow is true, %x is | ||||||
1148 | // constrained to it's inverse (all values that might cause overflow). | ||||||
1149 | if (IsTrueDest) | ||||||
1150 | NWR = NWR.inverse(); | ||||||
1151 | return ValueLatticeElement::getRange(NWR); | ||||||
1152 | } | ||||||
1153 | |||||||
1154 | static Optional<ValueLatticeElement> | ||||||
1155 | getValueFromConditionImpl(Value *Val, Value *Cond, bool isTrueDest, | ||||||
1156 | bool isRevisit, | ||||||
1157 | SmallDenseMap<Value *, ValueLatticeElement> &Visited, | ||||||
1158 | SmallVectorImpl<Value *> &Worklist) { | ||||||
1159 | if (!isRevisit) { | ||||||
| |||||||
1160 | if (ICmpInst *ICI
| ||||||
1161 | return getValueFromICmpCondition(Val, ICI, isTrueDest); | ||||||
1162 | |||||||
1163 | if (auto *EVI = dyn_cast<ExtractValueInst>(Cond)) | ||||||
1164 | if (auto *WO = dyn_cast<WithOverflowInst>(EVI->getAggregateOperand())) | ||||||
1165 | if (EVI->getNumIndices() == 1 && *EVI->idx_begin() == 1) | ||||||
1166 | return getValueFromOverflowCondition(Val, WO, isTrueDest); | ||||||
1167 | } | ||||||
1168 | |||||||
1169 | Value *L, *R; | ||||||
1170 | bool IsAnd; | ||||||
1171 | if (match(Cond, m_LogicalAnd(m_Value(L), m_Value(R)))) | ||||||
1172 | IsAnd = true; | ||||||
1173 | else if (match(Cond, m_LogicalOr(m_Value(L), m_Value(R)))) | ||||||
1174 | IsAnd = false; | ||||||
1175 | else | ||||||
1176 | return ValueLatticeElement::getOverdefined(); | ||||||
1177 | |||||||
1178 | auto LV = Visited.find(L); | ||||||
1179 | auto RV = Visited.find(R); | ||||||
1180 | |||||||
1181 | // if (L && R) -> intersect L and R | ||||||
1182 | // if (!(L || R)) -> intersect L and R | ||||||
1183 | // if (L || R) -> union L and R | ||||||
1184 | // if (!(L && R)) -> union L and R | ||||||
1185 | if ((isTrueDest ^ IsAnd) && (LV != Visited.end())) { | ||||||
1186 | ValueLatticeElement V = LV->second; | ||||||
1187 | if (V.isOverdefined()) | ||||||
1188 | return V; | ||||||
1189 | if (RV != Visited.end()) { | ||||||
1190 | V.mergeIn(RV->second); | ||||||
1191 | return V; | ||||||
1192 | } | ||||||
1193 | } | ||||||
1194 | |||||||
1195 | if (LV == Visited.end() || RV == Visited.end()) { | ||||||
1196 | assert(!isRevisit)((void)0); | ||||||
1197 | if (LV == Visited.end()) | ||||||
1198 | Worklist.push_back(L); | ||||||
1199 | if (RV == Visited.end()) | ||||||
1200 | Worklist.push_back(R); | ||||||
1201 | return None; | ||||||
1202 | } | ||||||
1203 | |||||||
1204 | return intersect(LV->second, RV->second); | ||||||
1205 | } | ||||||
1206 | |||||||
1207 | ValueLatticeElement getValueFromCondition(Value *Val, Value *Cond, | ||||||
1208 | bool isTrueDest) { | ||||||
1209 | assert(Cond && "precondition")((void)0); | ||||||
1210 | SmallDenseMap<Value*, ValueLatticeElement> Visited; | ||||||
1211 | SmallVector<Value *> Worklist; | ||||||
1212 | |||||||
1213 | Worklist.push_back(Cond); | ||||||
1214 | do { | ||||||
1215 | Value *CurrentCond = Worklist.back(); | ||||||
1216 | // Insert an Overdefined placeholder into the set to prevent | ||||||
1217 | // infinite recursion if there exists IRs that use not | ||||||
1218 | // dominated by its def as in this example: | ||||||
1219 | // "%tmp3 = or i1 undef, %tmp4" | ||||||
1220 | // "%tmp4 = or i1 undef, %tmp3" | ||||||
1221 | auto Iter = | ||||||
1222 | Visited.try_emplace(CurrentCond, ValueLatticeElement::getOverdefined()); | ||||||
1223 | bool isRevisit = !Iter.second; | ||||||
1224 | Optional<ValueLatticeElement> Result = getValueFromConditionImpl( | ||||||
1225 | Val, CurrentCond, isTrueDest, isRevisit, Visited, Worklist); | ||||||
1226 | if (Result) { | ||||||
1227 | Visited[CurrentCond] = *Result; | ||||||
1228 | Worklist.pop_back(); | ||||||
1229 | } | ||||||
1230 | } while (!Worklist.empty()); | ||||||
1231 | |||||||
1232 | auto Result = Visited.find(Cond); | ||||||
1233 | assert(Result != Visited.end())((void)0); | ||||||
1234 | return Result->second; | ||||||
1235 | } | ||||||
1236 | |||||||
1237 | // Return true if Usr has Op as an operand, otherwise false. | ||||||
1238 | static bool usesOperand(User *Usr, Value *Op) { | ||||||
1239 | return is_contained(Usr->operands(), Op); | ||||||
1240 | } | ||||||
1241 | |||||||
1242 | // Return true if the instruction type of Val is supported by | ||||||
1243 | // constantFoldUser(). Currently CastInst, BinaryOperator and FreezeInst only. | ||||||
1244 | // Call this before calling constantFoldUser() to find out if it's even worth | ||||||
1245 | // attempting to call it. | ||||||
1246 | static bool isOperationFoldable(User *Usr) { | ||||||
1247 | return isa<CastInst>(Usr) || isa<BinaryOperator>(Usr) || isa<FreezeInst>(Usr); | ||||||
1248 | } | ||||||
1249 | |||||||
1250 | // Check if Usr can be simplified to an integer constant when the value of one | ||||||
1251 | // of its operands Op is an integer constant OpConstVal. If so, return it as an | ||||||
1252 | // lattice value range with a single element or otherwise return an overdefined | ||||||
1253 | // lattice value. | ||||||
1254 | static ValueLatticeElement constantFoldUser(User *Usr, Value *Op, | ||||||
1255 | const APInt &OpConstVal, | ||||||
1256 | const DataLayout &DL) { | ||||||
1257 | assert(isOperationFoldable(Usr) && "Precondition")((void)0); | ||||||
1258 | Constant* OpConst = Constant::getIntegerValue(Op->getType(), OpConstVal); | ||||||
1259 | // Check if Usr can be simplified to a constant. | ||||||
1260 | if (auto *CI = dyn_cast<CastInst>(Usr)) { | ||||||
1261 | assert(CI->getOperand(0) == Op && "Operand 0 isn't Op")((void)0); | ||||||
1262 | if (auto *C = dyn_cast_or_null<ConstantInt>( | ||||||
1263 | SimplifyCastInst(CI->getOpcode(), OpConst, | ||||||
1264 | CI->getDestTy(), DL))) { | ||||||
1265 | return ValueLatticeElement::getRange(ConstantRange(C->getValue())); | ||||||
1266 | } | ||||||
1267 | } else if (auto *BO = dyn_cast<BinaryOperator>(Usr)) { | ||||||
1268 | bool Op0Match = BO->getOperand(0) == Op; | ||||||
1269 | bool Op1Match = BO->getOperand(1) == Op; | ||||||
1270 | assert((Op0Match || Op1Match) &&((void)0) | ||||||
1271 | "Operand 0 nor Operand 1 isn't a match")((void)0); | ||||||
1272 | Value *LHS = Op0Match ? OpConst : BO->getOperand(0); | ||||||
1273 | Value *RHS = Op1Match ? OpConst : BO->getOperand(1); | ||||||
1274 | if (auto *C = dyn_cast_or_null<ConstantInt>( | ||||||
1275 | SimplifyBinOp(BO->getOpcode(), LHS, RHS, DL))) { | ||||||
1276 | return ValueLatticeElement::getRange(ConstantRange(C->getValue())); | ||||||
1277 | } | ||||||
1278 | } else if (isa<FreezeInst>(Usr)) { | ||||||
1279 | assert(cast<FreezeInst>(Usr)->getOperand(0) == Op && "Operand 0 isn't Op")((void)0); | ||||||
1280 | return ValueLatticeElement::getRange(ConstantRange(OpConstVal)); | ||||||
1281 | } | ||||||
1282 | return ValueLatticeElement::getOverdefined(); | ||||||
1283 | } | ||||||
1284 | |||||||
1285 | /// Compute the value of Val on the edge BBFrom -> BBTo. Returns false if | ||||||
1286 | /// Val is not constrained on the edge. Result is unspecified if return value | ||||||
1287 | /// is false. | ||||||
1288 | static Optional<ValueLatticeElement> getEdgeValueLocal(Value *Val, | ||||||
1289 | BasicBlock *BBFrom, | ||||||
1290 | BasicBlock *BBTo) { | ||||||
1291 | // TODO: Handle more complex conditionals. If (v == 0 || v2 < 1) is false, we | ||||||
1292 | // know that v != 0. | ||||||
1293 | if (BranchInst *BI = dyn_cast<BranchInst>(BBFrom->getTerminator())) { | ||||||
1294 | // If this is a conditional branch and only one successor goes to BBTo, then | ||||||
1295 | // we may be able to infer something from the condition. | ||||||
1296 | if (BI->isConditional() && | ||||||
1297 | BI->getSuccessor(0) != BI->getSuccessor(1)) { | ||||||
1298 | bool isTrueDest = BI->getSuccessor(0) == BBTo; | ||||||
1299 | assert(BI->getSuccessor(!isTrueDest) == BBTo &&((void)0) | ||||||
1300 | "BBTo isn't a successor of BBFrom")((void)0); | ||||||
1301 | Value *Condition = BI->getCondition(); | ||||||
1302 | |||||||
1303 | // If V is the condition of the branch itself, then we know exactly what | ||||||
1304 | // it is. | ||||||
1305 | if (Condition == Val) | ||||||
1306 | return ValueLatticeElement::get(ConstantInt::get( | ||||||
1307 | Type::getInt1Ty(Val->getContext()), isTrueDest)); | ||||||
1308 | |||||||
1309 | // If the condition of the branch is an equality comparison, we may be | ||||||
1310 | // able to infer the value. | ||||||
1311 | ValueLatticeElement Result = getValueFromCondition(Val, Condition, | ||||||
1312 | isTrueDest); | ||||||
1313 | if (!Result.isOverdefined()) | ||||||
1314 | return Result; | ||||||
1315 | |||||||
1316 | if (User *Usr = dyn_cast<User>(Val)) { | ||||||
1317 | assert(Result.isOverdefined() && "Result isn't overdefined")((void)0); | ||||||
1318 | // Check with isOperationFoldable() first to avoid linearly iterating | ||||||
1319 | // over the operands unnecessarily which can be expensive for | ||||||
1320 | // instructions with many operands. | ||||||
1321 | if (isa<IntegerType>(Usr->getType()) && isOperationFoldable(Usr)) { | ||||||
1322 | const DataLayout &DL = BBTo->getModule()->getDataLayout(); | ||||||
1323 | if (usesOperand(Usr, Condition)) { | ||||||
1324 | // If Val has Condition as an operand and Val can be folded into a | ||||||
1325 | // constant with either Condition == true or Condition == false, | ||||||
1326 | // propagate the constant. | ||||||
1327 | // eg. | ||||||
1328 | // ; %Val is true on the edge to %then. | ||||||
1329 | // %Val = and i1 %Condition, true. | ||||||
1330 | // br %Condition, label %then, label %else | ||||||
1331 | APInt ConditionVal(1, isTrueDest ? 1 : 0); | ||||||
1332 | Result = constantFoldUser(Usr, Condition, ConditionVal, DL); | ||||||
1333 | } else { | ||||||
1334 | // If one of Val's operand has an inferred value, we may be able to | ||||||
1335 | // infer the value of Val. | ||||||
1336 | // eg. | ||||||
1337 | // ; %Val is 94 on the edge to %then. | ||||||
1338 | // %Val = add i8 %Op, 1 | ||||||
1339 | // %Condition = icmp eq i8 %Op, 93 | ||||||
1340 | // br i1 %Condition, label %then, label %else | ||||||
1341 | for (unsigned i = 0; i < Usr->getNumOperands(); ++i) { | ||||||
1342 | Value *Op = Usr->getOperand(i); | ||||||
1343 | ValueLatticeElement OpLatticeVal = | ||||||
1344 | getValueFromCondition(Op, Condition, isTrueDest); | ||||||
1345 | if (Optional<APInt> OpConst = OpLatticeVal.asConstantInteger()) { | ||||||
1346 | Result = constantFoldUser(Usr, Op, OpConst.getValue(), DL); | ||||||
1347 | break; | ||||||
1348 | } | ||||||
1349 | } | ||||||
1350 | } | ||||||
1351 | } | ||||||
1352 | } | ||||||
1353 | if (!Result.isOverdefined()) | ||||||
1354 | return Result; | ||||||
1355 | } | ||||||
1356 | } | ||||||
1357 | |||||||
1358 | // If the edge was formed by a switch on the value, then we may know exactly | ||||||
1359 | // what it is. | ||||||
1360 | if (SwitchInst *SI = dyn_cast<SwitchInst>(BBFrom->getTerminator())) { | ||||||
1361 | Value *Condition = SI->getCondition(); | ||||||
1362 | if (!isa<IntegerType>(Val->getType())) | ||||||
1363 | return None; | ||||||
1364 | bool ValUsesConditionAndMayBeFoldable = false; | ||||||
1365 | if (Condition != Val) { | ||||||
1366 | // Check if Val has Condition as an operand. | ||||||
1367 | if (User *Usr = dyn_cast<User>(Val)) | ||||||
1368 | ValUsesConditionAndMayBeFoldable = isOperationFoldable(Usr) && | ||||||
1369 | usesOperand(Usr, Condition); | ||||||
1370 | if (!ValUsesConditionAndMayBeFoldable) | ||||||
1371 | return None; | ||||||
1372 | } | ||||||
1373 | assert((Condition == Val || ValUsesConditionAndMayBeFoldable) &&((void)0) | ||||||
1374 | "Condition != Val nor Val doesn't use Condition")((void)0); | ||||||
1375 | |||||||
1376 | bool DefaultCase = SI->getDefaultDest() == BBTo; | ||||||
1377 | unsigned BitWidth = Val->getType()->getIntegerBitWidth(); | ||||||
1378 | ConstantRange EdgesVals(BitWidth, DefaultCase/*isFullSet*/); | ||||||
1379 | |||||||
1380 | for (auto Case : SI->cases()) { | ||||||
1381 | APInt CaseValue = Case.getCaseValue()->getValue(); | ||||||
1382 | ConstantRange EdgeVal(CaseValue); | ||||||
1383 | if (ValUsesConditionAndMayBeFoldable) { | ||||||
1384 | User *Usr = cast<User>(Val); | ||||||
1385 | const DataLayout &DL = BBTo->getModule()->getDataLayout(); | ||||||
1386 | ValueLatticeElement EdgeLatticeVal = | ||||||
1387 | constantFoldUser(Usr, Condition, CaseValue, DL); | ||||||
1388 | if (EdgeLatticeVal.isOverdefined()) | ||||||
1389 | return None; | ||||||
1390 | EdgeVal = EdgeLatticeVal.getConstantRange(); | ||||||
1391 | } | ||||||
1392 | if (DefaultCase) { | ||||||
1393 | // It is possible that the default destination is the destination of | ||||||
1394 | // some cases. We cannot perform difference for those cases. | ||||||
1395 | // We know Condition != CaseValue in BBTo. In some cases we can use | ||||||
1396 | // this to infer Val == f(Condition) is != f(CaseValue). For now, we | ||||||
1397 | // only do this when f is identity (i.e. Val == Condition), but we | ||||||
1398 | // should be able to do this for any injective f. | ||||||
1399 | if (Case.getCaseSuccessor() != BBTo && Condition == Val) | ||||||
1400 | EdgesVals = EdgesVals.difference(EdgeVal); | ||||||
1401 | } else if (Case.getCaseSuccessor() == BBTo) | ||||||
1402 | EdgesVals = EdgesVals.unionWith(EdgeVal); | ||||||
1403 | } | ||||||
1404 | return ValueLatticeElement::getRange(std::move(EdgesVals)); | ||||||
1405 | } | ||||||
1406 | return None; | ||||||
1407 | } | ||||||
1408 | |||||||
1409 | /// Compute the value of Val on the edge BBFrom -> BBTo or the value at | ||||||
1410 | /// the basic block if the edge does not constrain Val. | ||||||
1411 | Optional<ValueLatticeElement> LazyValueInfoImpl::getEdgeValue( | ||||||
1412 | Value *Val, BasicBlock *BBFrom, BasicBlock *BBTo, Instruction *CxtI) { | ||||||
1413 | // If already a constant, there is nothing to compute. | ||||||
1414 | if (Constant *VC = dyn_cast<Constant>(Val)) | ||||||
1415 | return ValueLatticeElement::get(VC); | ||||||
1416 | |||||||
1417 | ValueLatticeElement LocalResult = getEdgeValueLocal(Val, BBFrom, BBTo) | ||||||
1418 | .getValueOr(ValueLatticeElement::getOverdefined()); | ||||||
1419 | if (hasSingleValue(LocalResult)) | ||||||
1420 | // Can't get any more precise here | ||||||
1421 | return LocalResult; | ||||||
1422 | |||||||
1423 | Optional<ValueLatticeElement> OptInBlock = getBlockValue(Val, BBFrom); | ||||||
1424 | if (!OptInBlock) | ||||||
1425 | return None; | ||||||
1426 | ValueLatticeElement &InBlock = *OptInBlock; | ||||||
1427 | |||||||
1428 | // Try to intersect ranges of the BB and the constraint on the edge. | ||||||
1429 | intersectAssumeOrGuardBlockValueConstantRange(Val, InBlock, | ||||||
1430 | BBFrom->getTerminator()); | ||||||
1431 | // We can use the context instruction (generically the ultimate instruction | ||||||
1432 | // the calling pass is trying to simplify) here, even though the result of | ||||||
1433 | // this function is generally cached when called from the solve* functions | ||||||
1434 | // (and that cached result might be used with queries using a different | ||||||
1435 | // context instruction), because when this function is called from the solve* | ||||||
1436 | // functions, the context instruction is not provided. When called from | ||||||
1437 | // LazyValueInfoImpl::getValueOnEdge, the context instruction is provided, | ||||||
1438 | // but then the result is not cached. | ||||||
1439 | intersectAssumeOrGuardBlockValueConstantRange(Val, InBlock, CxtI); | ||||||
1440 | |||||||
1441 | return intersect(LocalResult, InBlock); | ||||||
1442 | } | ||||||
1443 | |||||||
1444 | ValueLatticeElement LazyValueInfoImpl::getValueInBlock(Value *V, BasicBlock *BB, | ||||||
1445 | Instruction *CxtI) { | ||||||
1446 | LLVM_DEBUG(dbgs() << "LVI Getting block end value " << *V << " at '"do { } while (false) | ||||||
1447 | << BB->getName() << "'\n")do { } while (false); | ||||||
1448 | |||||||
1449 | assert(BlockValueStack.empty() && BlockValueSet.empty())((void)0); | ||||||
1450 | Optional<ValueLatticeElement> OptResult = getBlockValue(V, BB); | ||||||
1451 | if (!OptResult) { | ||||||
1452 | solve(); | ||||||
1453 | OptResult = getBlockValue(V, BB); | ||||||
1454 | assert(OptResult && "Value not available after solving")((void)0); | ||||||
1455 | } | ||||||
1456 | ValueLatticeElement Result = *OptResult; | ||||||
1457 | intersectAssumeOrGuardBlockValueConstantRange(V, Result, CxtI); | ||||||
1458 | |||||||
1459 | LLVM_DEBUG(dbgs() << " Result = " << Result << "\n")do { } while (false); | ||||||
1460 | return Result; | ||||||
1461 | } | ||||||
1462 | |||||||
1463 | ValueLatticeElement LazyValueInfoImpl::getValueAt(Value *V, Instruction *CxtI) { | ||||||
1464 | LLVM_DEBUG(dbgs() << "LVI Getting value " << *V << " at '" << CxtI->getName()do { } while (false) | ||||||
1465 | << "'\n")do { } while (false); | ||||||
1466 | |||||||
1467 | if (auto *C = dyn_cast<Constant>(V)) | ||||||
1468 | return ValueLatticeElement::get(C); | ||||||
1469 | |||||||
1470 | ValueLatticeElement Result = ValueLatticeElement::getOverdefined(); | ||||||
1471 | if (auto *I = dyn_cast<Instruction>(V)) | ||||||
1472 | Result = getFromRangeMetadata(I); | ||||||
1473 | intersectAssumeOrGuardBlockValueConstantRange(V, Result, CxtI); | ||||||
1474 | |||||||
1475 | LLVM_DEBUG(dbgs() << " Result = " << Result << "\n")do { } while (false); | ||||||
1476 | return Result; | ||||||
1477 | } | ||||||
1478 | |||||||
1479 | ValueLatticeElement LazyValueInfoImpl:: | ||||||
1480 | getValueOnEdge(Value *V, BasicBlock *FromBB, BasicBlock *ToBB, | ||||||
1481 | Instruction *CxtI) { | ||||||
1482 | LLVM_DEBUG(dbgs() << "LVI Getting edge value " << *V << " from '"do { } while (false) | ||||||
1483 | << FromBB->getName() << "' to '" << ToBB->getName()do { } while (false) | ||||||
1484 | << "'\n")do { } while (false); | ||||||
1485 | |||||||
1486 | Optional<ValueLatticeElement> Result = getEdgeValue(V, FromBB, ToBB, CxtI); | ||||||
1487 | if (!Result) { | ||||||
1488 | solve(); | ||||||
1489 | Result = getEdgeValue(V, FromBB, ToBB, CxtI); | ||||||
1490 | assert(Result && "More work to do after problem solved?")((void)0); | ||||||
1491 | } | ||||||
1492 | |||||||
1493 | LLVM_DEBUG(dbgs() << " Result = " << *Result << "\n")do { } while (false); | ||||||
1494 | return *Result; | ||||||
1495 | } | ||||||
1496 | |||||||
1497 | void LazyValueInfoImpl::threadEdge(BasicBlock *PredBB, BasicBlock *OldSucc, | ||||||
1498 | BasicBlock *NewSucc) { | ||||||
1499 | TheCache.threadEdgeImpl(OldSucc, NewSucc); | ||||||
1500 | } | ||||||
1501 | |||||||
1502 | //===----------------------------------------------------------------------===// | ||||||
1503 | // LazyValueInfo Impl | ||||||
1504 | //===----------------------------------------------------------------------===// | ||||||
1505 | |||||||
1506 | /// This lazily constructs the LazyValueInfoImpl. | ||||||
1507 | static LazyValueInfoImpl &getImpl(void *&PImpl, AssumptionCache *AC, | ||||||
1508 | const Module *M) { | ||||||
1509 | if (!PImpl) { | ||||||
1510 | assert(M && "getCache() called with a null Module")((void)0); | ||||||
1511 | const DataLayout &DL = M->getDataLayout(); | ||||||
1512 | Function *GuardDecl = M->getFunction( | ||||||
1513 | Intrinsic::getName(Intrinsic::experimental_guard)); | ||||||
1514 | PImpl = new LazyValueInfoImpl(AC, DL, GuardDecl); | ||||||
1515 | } | ||||||
1516 | return *static_cast<LazyValueInfoImpl*>(PImpl); | ||||||
1517 | } | ||||||
1518 | |||||||
1519 | bool LazyValueInfoWrapperPass::runOnFunction(Function &F) { | ||||||
1520 | Info.AC = &getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F); | ||||||
1521 | Info.TLI = &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI(F); | ||||||
1522 | |||||||
1523 | if (Info.PImpl) | ||||||
1524 | getImpl(Info.PImpl, Info.AC, F.getParent()).clear(); | ||||||
1525 | |||||||
1526 | // Fully lazy. | ||||||
1527 | return false; | ||||||
1528 | } | ||||||
1529 | |||||||
1530 | void LazyValueInfoWrapperPass::getAnalysisUsage(AnalysisUsage &AU) const { | ||||||
1531 | AU.setPreservesAll(); | ||||||
1532 | AU.addRequired<AssumptionCacheTracker>(); | ||||||
1533 | AU.addRequired<TargetLibraryInfoWrapperPass>(); | ||||||
1534 | } | ||||||
1535 | |||||||
1536 | LazyValueInfo &LazyValueInfoWrapperPass::getLVI() { return Info; } | ||||||
1537 | |||||||
1538 | LazyValueInfo::~LazyValueInfo() { releaseMemory(); } | ||||||
1539 | |||||||
1540 | void LazyValueInfo::releaseMemory() { | ||||||
1541 | // If the cache was allocated, free it. | ||||||
1542 | if (PImpl) { | ||||||
1543 | delete &getImpl(PImpl, AC, nullptr); | ||||||
1544 | PImpl = nullptr; | ||||||
1545 | } | ||||||
1546 | } | ||||||
1547 | |||||||
1548 | bool LazyValueInfo::invalidate(Function &F, const PreservedAnalyses &PA, | ||||||
1549 | FunctionAnalysisManager::Invalidator &Inv) { | ||||||
1550 | // We need to invalidate if we have either failed to preserve this analyses | ||||||
1551 | // result directly or if any of its dependencies have been invalidated. | ||||||
1552 | auto PAC = PA.getChecker<LazyValueAnalysis>(); | ||||||
1553 | if (!(PAC.preserved() || PAC.preservedSet<AllAnalysesOn<Function>>())) | ||||||
1554 | return true; | ||||||
1555 | |||||||
1556 | return false; | ||||||
1557 | } | ||||||
1558 | |||||||
1559 | void LazyValueInfoWrapperPass::releaseMemory() { Info.releaseMemory(); } | ||||||
1560 | |||||||
1561 | LazyValueInfo LazyValueAnalysis::run(Function &F, | ||||||
1562 | FunctionAnalysisManager &FAM) { | ||||||
1563 | auto &AC = FAM.getResult<AssumptionAnalysis>(F); | ||||||
1564 | auto &TLI = FAM.getResult<TargetLibraryAnalysis>(F); | ||||||
1565 | |||||||
1566 | return LazyValueInfo(&AC, &F.getParent()->getDataLayout(), &TLI); | ||||||
1567 | } | ||||||
1568 | |||||||
1569 | /// Returns true if we can statically tell that this value will never be a | ||||||
1570 | /// "useful" constant. In practice, this means we've got something like an | ||||||
1571 | /// alloca or a malloc call for which a comparison against a constant can | ||||||
1572 | /// only be guarding dead code. Note that we are potentially giving up some | ||||||
1573 | /// precision in dead code (a constant result) in favour of avoiding a | ||||||
1574 | /// expensive search for a easily answered common query. | ||||||
1575 | static bool isKnownNonConstant(Value *V) { | ||||||
1576 | V = V->stripPointerCasts(); | ||||||
1577 | // The return val of alloc cannot be a Constant. | ||||||
1578 | if (isa<AllocaInst>(V)) | ||||||
1579 | return true; | ||||||
1580 | return false; | ||||||
1581 | } | ||||||
1582 | |||||||
1583 | Constant *LazyValueInfo::getConstant(Value *V, Instruction *CxtI) { | ||||||
1584 | // Bail out early if V is known not to be a Constant. | ||||||
1585 | if (isKnownNonConstant(V)) | ||||||
1586 | return nullptr; | ||||||
1587 | |||||||
1588 | BasicBlock *BB = CxtI->getParent(); | ||||||
1589 | ValueLatticeElement Result = | ||||||
1590 | getImpl(PImpl, AC, BB->getModule()).getValueInBlock(V, BB, CxtI); | ||||||
1591 | |||||||
1592 | if (Result.isConstant()) | ||||||
1593 | return Result.getConstant(); | ||||||
1594 | if (Result.isConstantRange()) { | ||||||
1595 | const ConstantRange &CR = Result.getConstantRange(); | ||||||
1596 | if (const APInt *SingleVal = CR.getSingleElement()) | ||||||
1597 | return ConstantInt::get(V->getContext(), *SingleVal); | ||||||
1598 | } | ||||||
1599 | return nullptr; | ||||||
1600 | } | ||||||
1601 | |||||||
1602 | ConstantRange LazyValueInfo::getConstantRange(Value *V, Instruction *CxtI, | ||||||
1603 | bool UndefAllowed) { | ||||||
1604 | assert(V->getType()->isIntegerTy())((void)0); | ||||||
1605 | unsigned Width = V->getType()->getIntegerBitWidth(); | ||||||
1606 | BasicBlock *BB = CxtI->getParent(); | ||||||
1607 | ValueLatticeElement Result = | ||||||
1608 | getImpl(PImpl, AC, BB->getModule()).getValueInBlock(V, BB, CxtI); | ||||||
1609 | if (Result.isUnknown()) | ||||||
1610 | return ConstantRange::getEmpty(Width); | ||||||
1611 | if (Result.isConstantRange(UndefAllowed)) | ||||||
1612 | return Result.getConstantRange(UndefAllowed); | ||||||
1613 | // We represent ConstantInt constants as constant ranges but other kinds | ||||||
1614 | // of integer constants, i.e. ConstantExpr will be tagged as constants | ||||||
1615 | assert(!(Result.isConstant() && isa<ConstantInt>(Result.getConstant())) &&((void)0) | ||||||
1616 | "ConstantInt value must be represented as constantrange")((void)0); | ||||||
1617 | return ConstantRange::getFull(Width); | ||||||
1618 | } | ||||||
1619 | |||||||
1620 | /// Determine whether the specified value is known to be a | ||||||
1621 | /// constant on the specified edge. Return null if not. | ||||||
1622 | Constant *LazyValueInfo::getConstantOnEdge(Value *V, BasicBlock *FromBB, | ||||||
1623 | BasicBlock *ToBB, | ||||||
1624 | Instruction *CxtI) { | ||||||
1625 | Module *M = FromBB->getModule(); | ||||||
1626 | ValueLatticeElement Result = | ||||||
1627 | getImpl(PImpl, AC, M).getValueOnEdge(V, FromBB, ToBB, CxtI); | ||||||
1628 | |||||||
1629 | if (Result.isConstant()) | ||||||
1630 | return Result.getConstant(); | ||||||
1631 | if (Result.isConstantRange()) { | ||||||
1632 | const ConstantRange &CR = Result.getConstantRange(); | ||||||
1633 | if (const APInt *SingleVal = CR.getSingleElement()) | ||||||
1634 | return ConstantInt::get(V->getContext(), *SingleVal); | ||||||
1635 | } | ||||||
1636 | return nullptr; | ||||||
1637 | } | ||||||
1638 | |||||||
1639 | ConstantRange LazyValueInfo::getConstantRangeOnEdge(Value *V, | ||||||
1640 | BasicBlock *FromBB, | ||||||
1641 | BasicBlock *ToBB, | ||||||
1642 | Instruction *CxtI) { | ||||||
1643 | unsigned Width = V->getType()->getIntegerBitWidth(); | ||||||
1644 | Module *M = FromBB->getModule(); | ||||||
1645 | ValueLatticeElement Result = | ||||||
1646 | getImpl(PImpl, AC, M).getValueOnEdge(V, FromBB, ToBB, CxtI); | ||||||
1647 | |||||||
1648 | if (Result.isUnknown()) | ||||||
1649 | return ConstantRange::getEmpty(Width); | ||||||
1650 | if (Result.isConstantRange()) | ||||||
1651 | return Result.getConstantRange(); | ||||||
1652 | // We represent ConstantInt constants as constant ranges but other kinds | ||||||
1653 | // of integer constants, i.e. ConstantExpr will be tagged as constants | ||||||
1654 | assert(!(Result.isConstant() && isa<ConstantInt>(Result.getConstant())) &&((void)0) | ||||||
1655 | "ConstantInt value must be represented as constantrange")((void)0); | ||||||
1656 | return ConstantRange::getFull(Width); | ||||||
1657 | } | ||||||
1658 | |||||||
1659 | static LazyValueInfo::Tristate | ||||||
1660 | getPredicateResult(unsigned Pred, Constant *C, const ValueLatticeElement &Val, | ||||||
1661 | const DataLayout &DL, TargetLibraryInfo *TLI) { | ||||||
1662 | // If we know the value is a constant, evaluate the conditional. | ||||||
1663 | Constant *Res = nullptr; | ||||||
1664 | if (Val.isConstant()) { | ||||||
1665 | Res = ConstantFoldCompareInstOperands(Pred, Val.getConstant(), C, DL, TLI); | ||||||
1666 | if (ConstantInt *ResCI = dyn_cast<ConstantInt>(Res)) | ||||||
1667 | return ResCI->isZero() ? LazyValueInfo::False : LazyValueInfo::True; | ||||||
1668 | return LazyValueInfo::Unknown; | ||||||
1669 | } | ||||||
1670 | |||||||
1671 | if (Val.isConstantRange()) { | ||||||
1672 | ConstantInt *CI = dyn_cast<ConstantInt>(C); | ||||||
1673 | if (!CI) return LazyValueInfo::Unknown; | ||||||
1674 | |||||||
1675 | const ConstantRange &CR = Val.getConstantRange(); | ||||||
1676 | if (Pred == ICmpInst::ICMP_EQ) { | ||||||
1677 | if (!CR.contains(CI->getValue())) | ||||||
1678 | return LazyValueInfo::False; | ||||||
1679 | |||||||
1680 | if (CR.isSingleElement()) | ||||||
1681 | return LazyValueInfo::True; | ||||||
1682 | } else if (Pred == ICmpInst::ICMP_NE) { | ||||||
1683 | if (!CR.contains(CI->getValue())) | ||||||
1684 | return LazyValueInfo::True; | ||||||
1685 | |||||||
1686 | if (CR.isSingleElement()) | ||||||
1687 | return LazyValueInfo::False; | ||||||
1688 | } else { | ||||||
1689 | // Handle more complex predicates. | ||||||
1690 | ConstantRange TrueValues = ConstantRange::makeExactICmpRegion( | ||||||
1691 | (ICmpInst::Predicate)Pred, CI->getValue()); | ||||||
1692 | if (TrueValues.contains(CR)) | ||||||
1693 | return LazyValueInfo::True; | ||||||
1694 | if (TrueValues.inverse().contains(CR)) | ||||||
1695 | return LazyValueInfo::False; | ||||||
1696 | } | ||||||
1697 | return LazyValueInfo::Unknown; | ||||||
1698 | } | ||||||
1699 | |||||||
1700 | if (Val.isNotConstant()) { | ||||||
1701 | // If this is an equality comparison, we can try to fold it knowing that | ||||||
1702 | // "V != C1". | ||||||
1703 | if (Pred == ICmpInst::ICMP_EQ) { | ||||||
1704 | // !C1 == C -> false iff C1 == C. | ||||||
1705 | Res = ConstantFoldCompareInstOperands(ICmpInst::ICMP_NE, | ||||||
1706 | Val.getNotConstant(), C, DL, | ||||||
1707 | TLI); | ||||||
1708 | if (Res->isNullValue()) | ||||||
1709 | return LazyValueInfo::False; | ||||||
1710 | } else if (Pred == ICmpInst::ICMP_NE) { | ||||||
1711 | // !C1 != C -> true iff C1 == C. | ||||||
1712 | Res = ConstantFoldCompareInstOperands(ICmpInst::ICMP_NE, | ||||||
1713 | Val.getNotConstant(), C, DL, | ||||||
1714 | TLI); | ||||||
1715 | if (Res->isNullValue()) | ||||||
1716 | return LazyValueInfo::True; | ||||||
1717 | } | ||||||
1718 | return LazyValueInfo::Unknown; | ||||||
1719 | } | ||||||
1720 | |||||||
1721 | return LazyValueInfo::Unknown; | ||||||
1722 | } | ||||||
1723 | |||||||
1724 | /// Determine whether the specified value comparison with a constant is known to | ||||||
1725 | /// be true or false on the specified CFG edge. Pred is a CmpInst predicate. | ||||||
1726 | LazyValueInfo::Tristate | ||||||
1727 | LazyValueInfo::getPredicateOnEdge(unsigned Pred, Value *V, Constant *C, | ||||||
1728 | BasicBlock *FromBB, BasicBlock *ToBB, | ||||||
1729 | Instruction *CxtI) { | ||||||
1730 | Module *M = FromBB->getModule(); | ||||||
1731 | ValueLatticeElement Result = | ||||||
1732 | getImpl(PImpl, AC, M).getValueOnEdge(V, FromBB, ToBB, CxtI); | ||||||
1733 | |||||||
1734 | return getPredicateResult(Pred, C, Result, M->getDataLayout(), TLI); | ||||||
1735 | } | ||||||
1736 | |||||||
1737 | LazyValueInfo::Tristate | ||||||
1738 | LazyValueInfo::getPredicateAt(unsigned Pred, Value *V, Constant *C, | ||||||
1739 | Instruction *CxtI, bool UseBlockValue) { | ||||||
1740 | // Is or is not NonNull are common predicates being queried. If | ||||||
1741 | // isKnownNonZero can tell us the result of the predicate, we can | ||||||
1742 | // return it quickly. But this is only a fastpath, and falling | ||||||
1743 | // through would still be correct. | ||||||
1744 | Module *M = CxtI->getModule(); | ||||||
1745 | const DataLayout &DL = M->getDataLayout(); | ||||||
1746 | if (V->getType()->isPointerTy() && C->isNullValue() && | ||||||
1747 | isKnownNonZero(V->stripPointerCastsSameRepresentation(), DL)) { | ||||||
1748 | if (Pred == ICmpInst::ICMP_EQ) | ||||||
1749 | return LazyValueInfo::False; | ||||||
1750 | else if (Pred == ICmpInst::ICMP_NE) | ||||||
1751 | return LazyValueInfo::True; | ||||||
1752 | } | ||||||
1753 | |||||||
1754 | ValueLatticeElement Result = UseBlockValue | ||||||
1755 | ? getImpl(PImpl, AC, M).getValueInBlock(V, CxtI->getParent(), CxtI) | ||||||
1756 | : getImpl(PImpl, AC, M).getValueAt(V, CxtI); | ||||||
1757 | Tristate Ret = getPredicateResult(Pred, C, Result, DL, TLI); | ||||||
1758 | if (Ret != Unknown) | ||||||
1759 | return Ret; | ||||||
1760 | |||||||
1761 | // Note: The following bit of code is somewhat distinct from the rest of LVI; | ||||||
1762 | // LVI as a whole tries to compute a lattice value which is conservatively | ||||||
1763 | // correct at a given location. In this case, we have a predicate which we | ||||||
1764 | // weren't able to prove about the merged result, and we're pushing that | ||||||
1765 | // predicate back along each incoming edge to see if we can prove it | ||||||
1766 | // separately for each input. As a motivating example, consider: | ||||||
1767 | // bb1: | ||||||
1768 | // %v1 = ... ; constantrange<1, 5> | ||||||
1769 | // br label %merge | ||||||
1770 | // bb2: | ||||||
1771 | // %v2 = ... ; constantrange<10, 20> | ||||||
1772 | // br label %merge | ||||||
1773 | // merge: | ||||||
1774 | // %phi = phi [%v1, %v2] ; constantrange<1,20> | ||||||
1775 | // %pred = icmp eq i32 %phi, 8 | ||||||
1776 | // We can't tell from the lattice value for '%phi' that '%pred' is false | ||||||
1777 | // along each path, but by checking the predicate over each input separately, | ||||||
1778 | // we can. | ||||||
1779 | // We limit the search to one step backwards from the current BB and value. | ||||||
1780 | // We could consider extending this to search further backwards through the | ||||||
1781 | // CFG and/or value graph, but there are non-obvious compile time vs quality | ||||||
1782 | // tradeoffs. | ||||||
1783 | if (CxtI) { | ||||||
1784 | BasicBlock *BB = CxtI->getParent(); | ||||||
1785 | |||||||
1786 | // Function entry or an unreachable block. Bail to avoid confusing | ||||||
1787 | // analysis below. | ||||||
1788 | pred_iterator PI = pred_begin(BB), PE = pred_end(BB); | ||||||
1789 | if (PI == PE) | ||||||
1790 | return Unknown; | ||||||
1791 | |||||||
1792 | // If V is a PHI node in the same block as the context, we need to ask | ||||||
1793 | // questions about the predicate as applied to the incoming value along | ||||||
1794 | // each edge. This is useful for eliminating cases where the predicate is | ||||||
1795 | // known along all incoming edges. | ||||||
1796 | if (auto *PHI = dyn_cast<PHINode>(V)) | ||||||
1797 | if (PHI->getParent() == BB) { | ||||||
1798 | Tristate Baseline = Unknown; | ||||||
1799 | for (unsigned i = 0, e = PHI->getNumIncomingValues(); i < e; i++) { | ||||||
1800 | Value *Incoming = PHI->getIncomingValue(i); | ||||||
1801 | BasicBlock *PredBB = PHI->getIncomingBlock(i); | ||||||
1802 | // Note that PredBB may be BB itself. | ||||||
1803 | Tristate Result = getPredicateOnEdge(Pred, Incoming, C, PredBB, BB, | ||||||
1804 | CxtI); | ||||||
1805 | |||||||
1806 | // Keep going as long as we've seen a consistent known result for | ||||||
1807 | // all inputs. | ||||||
1808 | Baseline = (i == 0) ? Result /* First iteration */ | ||||||
1809 | : (Baseline == Result ? Baseline : Unknown); /* All others */ | ||||||
1810 | if (Baseline == Unknown) | ||||||
1811 | break; | ||||||
1812 | } | ||||||
1813 | if (Baseline != Unknown) | ||||||
1814 | return Baseline; | ||||||
1815 | } | ||||||
1816 | |||||||
1817 | // For a comparison where the V is outside this block, it's possible | ||||||
1818 | // that we've branched on it before. Look to see if the value is known | ||||||
1819 | // on all incoming edges. | ||||||
1820 | if (!isa<Instruction>(V) || | ||||||
1821 | cast<Instruction>(V)->getParent() != BB) { | ||||||
1822 | // For predecessor edge, determine if the comparison is true or false | ||||||
1823 | // on that edge. If they're all true or all false, we can conclude | ||||||
1824 | // the value of the comparison in this block. | ||||||
1825 | Tristate Baseline = getPredicateOnEdge(Pred, V, C, *PI, BB, CxtI); | ||||||
1826 | if (Baseline != Unknown) { | ||||||
1827 | // Check that all remaining incoming values match the first one. | ||||||
1828 | while (++PI != PE) { | ||||||
1829 | Tristate Ret = getPredicateOnEdge(Pred, V, C, *PI, BB, CxtI); | ||||||
1830 | if (Ret != Baseline) break; | ||||||
1831 | } | ||||||
1832 | // If we terminated early, then one of the values didn't match. | ||||||
1833 | if (PI == PE) { | ||||||
1834 | return Baseline; | ||||||
1835 | } | ||||||
1836 | } | ||||||
1837 | } | ||||||
1838 | } | ||||||
1839 | return Unknown; | ||||||
1840 | } | ||||||
1841 | |||||||
1842 | LazyValueInfo::Tristate LazyValueInfo::getPredicateAt(unsigned P, Value *LHS, | ||||||
1843 | Value *RHS, | ||||||
1844 | Instruction *CxtI, | ||||||
1845 | bool UseBlockValue) { | ||||||
1846 | CmpInst::Predicate Pred = (CmpInst::Predicate)P; | ||||||
1847 | |||||||
1848 | if (auto *C = dyn_cast<Constant>(RHS)) | ||||||
1849 | return getPredicateAt(P, LHS, C, CxtI, UseBlockValue); | ||||||
1850 | if (auto *C = dyn_cast<Constant>(LHS)) | ||||||
1851 | return getPredicateAt(CmpInst::getSwappedPredicate(Pred), RHS, C, CxtI, | ||||||
1852 | UseBlockValue); | ||||||
1853 | |||||||
1854 | // Got two non-Constant values. While we could handle them somewhat, | ||||||
1855 | // by getting their constant ranges, and applying ConstantRange::icmp(), | ||||||
1856 | // so far it did not appear to be profitable. | ||||||
1857 | return LazyValueInfo::Unknown; | ||||||
1858 | } | ||||||
1859 | |||||||
1860 | void LazyValueInfo::threadEdge(BasicBlock *PredBB, BasicBlock *OldSucc, | ||||||
1861 | BasicBlock *NewSucc) { | ||||||
1862 | if (PImpl) { | ||||||
1863 | getImpl(PImpl, AC, PredBB->getModule()) | ||||||
1864 | .threadEdge(PredBB, OldSucc, NewSucc); | ||||||
1865 | } | ||||||
1866 | } | ||||||
1867 | |||||||
1868 | void LazyValueInfo::eraseBlock(BasicBlock *BB) { | ||||||
1869 | if (PImpl) { | ||||||
1870 | getImpl(PImpl, AC, BB->getModule()).eraseBlock(BB); | ||||||
1871 | } | ||||||
1872 | } | ||||||
1873 | |||||||
1874 | |||||||
1875 | void LazyValueInfo::printLVI(Function &F, DominatorTree &DTree, raw_ostream &OS) { | ||||||
1876 | if (PImpl) { | ||||||
1877 | getImpl(PImpl, AC, F.getParent()).printLVI(F, DTree, OS); | ||||||
1878 | } | ||||||
1879 | } | ||||||
1880 | |||||||
1881 | // Print the LVI for the function arguments at the start of each basic block. | ||||||
1882 | void LazyValueInfoAnnotatedWriter::emitBasicBlockStartAnnot( | ||||||
1883 | const BasicBlock *BB, formatted_raw_ostream &OS) { | ||||||
1884 | // Find if there are latticevalues defined for arguments of the function. | ||||||
1885 | auto *F = BB->getParent(); | ||||||
1886 | for (auto &Arg : F->args()) { | ||||||
1887 | ValueLatticeElement Result = LVIImpl->getValueInBlock( | ||||||
1888 | const_cast<Argument *>(&Arg), const_cast<BasicBlock *>(BB)); | ||||||
1889 | if (Result.isUnknown()) | ||||||
1890 | continue; | ||||||
1891 | OS << "; LatticeVal for: '" << Arg << "' is: " << Result << "\n"; | ||||||
1892 | } | ||||||
1893 | } | ||||||
1894 | |||||||
1895 | // This function prints the LVI analysis for the instruction I at the beginning | ||||||
1896 | // of various basic blocks. It relies on calculated values that are stored in | ||||||
1897 | // the LazyValueInfoCache, and in the absence of cached values, recalculate the | ||||||
1898 | // LazyValueInfo for `I`, and print that info. | ||||||
1899 | void LazyValueInfoAnnotatedWriter::emitInstructionAnnot( | ||||||
1900 | const Instruction *I, formatted_raw_ostream &OS) { | ||||||
1901 | |||||||
1902 | auto *ParentBB = I->getParent(); | ||||||
1903 | SmallPtrSet<const BasicBlock*, 16> BlocksContainingLVI; | ||||||
1904 | // We can generate (solve) LVI values only for blocks that are dominated by | ||||||
1905 | // the I's parent. However, to avoid generating LVI for all dominating blocks, | ||||||
1906 | // that contain redundant/uninteresting information, we print LVI for | ||||||
1907 | // blocks that may use this LVI information (such as immediate successor | ||||||
1908 | // blocks, and blocks that contain uses of `I`). | ||||||
1909 | auto printResult = [&](const BasicBlock *BB) { | ||||||
1910 | if (!BlocksContainingLVI.insert(BB).second) | ||||||
1911 | return; | ||||||
1912 | ValueLatticeElement Result = LVIImpl->getValueInBlock( | ||||||
1913 | const_cast<Instruction *>(I), const_cast<BasicBlock *>(BB)); | ||||||
1914 | OS << "; LatticeVal for: '" << *I << "' in BB: '"; | ||||||
1915 | BB->printAsOperand(OS, false); | ||||||
1916 | OS << "' is: " << Result << "\n"; | ||||||
1917 | }; | ||||||
1918 | |||||||
1919 | printResult(ParentBB); | ||||||
1920 | // Print the LVI analysis results for the immediate successor blocks, that | ||||||
1921 | // are dominated by `ParentBB`. | ||||||
1922 | for (auto *BBSucc : successors(ParentBB)) | ||||||
1923 | if (DT.dominates(ParentBB, BBSucc)) | ||||||
1924 | printResult(BBSucc); | ||||||
1925 | |||||||
1926 | // Print LVI in blocks where `I` is used. | ||||||
1927 | for (auto *U : I->users()) | ||||||
1928 | if (auto *UseI = dyn_cast<Instruction>(U)) | ||||||
1929 | if (!isa<PHINode>(UseI) || DT.dominates(ParentBB, UseI->getParent())) | ||||||
1930 | printResult(UseI->getParent()); | ||||||
1931 | |||||||
1932 | } | ||||||
1933 | |||||||
1934 | namespace { | ||||||
1935 | // Printer class for LazyValueInfo results. | ||||||
1936 | class LazyValueInfoPrinter : public FunctionPass { | ||||||
1937 | public: | ||||||
1938 | static char ID; // Pass identification, replacement for typeid | ||||||
1939 | LazyValueInfoPrinter() : FunctionPass(ID) { | ||||||
1940 | initializeLazyValueInfoPrinterPass(*PassRegistry::getPassRegistry()); | ||||||
1941 | } | ||||||
1942 | |||||||
1943 | void getAnalysisUsage(AnalysisUsage &AU) const override { | ||||||
1944 | AU.setPreservesAll(); | ||||||
1945 | AU.addRequired<LazyValueInfoWrapperPass>(); | ||||||
1946 | AU.addRequired<DominatorTreeWrapperPass>(); | ||||||
1947 | } | ||||||
1948 | |||||||
1949 | // Get the mandatory dominator tree analysis and pass this in to the | ||||||
1950 | // LVIPrinter. We cannot rely on the LVI's DT, since it's optional. | ||||||
1951 | bool runOnFunction(Function &F) override { | ||||||
1952 | dbgs() << "LVI for function '" << F.getName() << "':\n"; | ||||||
1953 | auto &LVI = getAnalysis<LazyValueInfoWrapperPass>().getLVI(); | ||||||
1954 | auto &DTree = getAnalysis<DominatorTreeWrapperPass>().getDomTree(); | ||||||
1955 | LVI.printLVI(F, DTree, dbgs()); | ||||||
1956 | return false; | ||||||
1957 | } | ||||||
1958 | }; | ||||||
1959 | } | ||||||
1960 | |||||||
1961 | char LazyValueInfoPrinter::ID = 0; | ||||||
1962 | INITIALIZE_PASS_BEGIN(LazyValueInfoPrinter, "print-lazy-value-info",static void *initializeLazyValueInfoPrinterPassOnce(PassRegistry &Registry) { | ||||||
1963 | "Lazy Value Info Printer Pass", false, false)static void *initializeLazyValueInfoPrinterPassOnce(PassRegistry &Registry) { | ||||||
1964 | INITIALIZE_PASS_DEPENDENCY(LazyValueInfoWrapperPass)initializeLazyValueInfoWrapperPassPass(Registry); | ||||||
1965 | INITIALIZE_PASS_END(LazyValueInfoPrinter, "print-lazy-value-info",PassInfo *PI = new PassInfo( "Lazy Value Info Printer Pass", "print-lazy-value-info" , &LazyValueInfoPrinter::ID, PassInfo::NormalCtor_t(callDefaultCtor <LazyValueInfoPrinter>), false, false); Registry.registerPass (*PI, true); return PI; } static llvm::once_flag InitializeLazyValueInfoPrinterPassFlag ; void llvm::initializeLazyValueInfoPrinterPass(PassRegistry & Registry) { llvm::call_once(InitializeLazyValueInfoPrinterPassFlag , initializeLazyValueInfoPrinterPassOnce, std::ref(Registry)) ; } | ||||||
1966 | "Lazy Value Info Printer Pass", false, false)PassInfo *PI = new PassInfo( "Lazy Value Info Printer Pass", "print-lazy-value-info" , &LazyValueInfoPrinter::ID, PassInfo::NormalCtor_t(callDefaultCtor <LazyValueInfoPrinter>), false, false); Registry.registerPass (*PI, true); return PI; } static llvm::once_flag InitializeLazyValueInfoPrinterPassFlag ; void llvm::initializeLazyValueInfoPrinterPass(PassRegistry & Registry) { llvm::call_once(InitializeLazyValueInfoPrinterPassFlag , initializeLazyValueInfoPrinterPassOnce, std::ref(Registry)) ; } |
1 | //===- ValueLattice.h - Value constraint analysis ---------------*- C++ -*-===// |
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 | #ifndef LLVM_ANALYSIS_VALUELATTICE_H |
10 | #define LLVM_ANALYSIS_VALUELATTICE_H |
11 | |
12 | #include "llvm/IR/ConstantRange.h" |
13 | #include "llvm/IR/Constants.h" |
14 | #include "llvm/IR/Instructions.h" |
15 | // |
16 | //===----------------------------------------------------------------------===// |
17 | // ValueLatticeElement |
18 | //===----------------------------------------------------------------------===// |
19 | |
20 | namespace llvm { |
21 | |
22 | /// This class represents lattice values for constants. |
23 | /// |
24 | /// FIXME: This is basically just for bringup, this can be made a lot more rich |
25 | /// in the future. |
26 | /// |
27 | class ValueLatticeElement { |
28 | enum ValueLatticeElementTy { |
29 | /// This Value has no known value yet. As a result, this implies the |
30 | /// producing instruction is dead. Caution: We use this as the starting |
31 | /// state in our local meet rules. In this usage, it's taken to mean |
32 | /// "nothing known yet". |
33 | /// Transition to any other state allowed. |
34 | unknown, |
35 | |
36 | /// This Value is an UndefValue constant or produces undef. Undefined values |
37 | /// can be merged with constants (or single element constant ranges), |
38 | /// assuming all uses of the result will be replaced. |
39 | /// Transition allowed to the following states: |
40 | /// constant |
41 | /// constantrange_including_undef |
42 | /// overdefined |
43 | undef, |
44 | |
45 | /// This Value has a specific constant value. The constant cannot be undef. |
46 | /// (For constant integers, constantrange is used instead. Integer typed |
47 | /// constantexprs can appear as constant.) Note that the constant state |
48 | /// can be reached by merging undef & constant states. |
49 | /// Transition allowed to the following states: |
50 | /// overdefined |
51 | constant, |
52 | |
53 | /// This Value is known to not have the specified value. (For constant |
54 | /// integers, constantrange is used instead. As above, integer typed |
55 | /// constantexprs can appear here.) |
56 | /// Transition allowed to the following states: |
57 | /// overdefined |
58 | notconstant, |
59 | |
60 | /// The Value falls within this range. (Used only for integer typed values.) |
61 | /// Transition allowed to the following states: |
62 | /// constantrange (new range must be a superset of the existing range) |
63 | /// constantrange_including_undef |
64 | /// overdefined |
65 | constantrange, |
66 | |
67 | /// This Value falls within this range, but also may be undef. |
68 | /// Merging it with other constant ranges results in |
69 | /// constantrange_including_undef. |
70 | /// Transition allowed to the following states: |
71 | /// overdefined |
72 | constantrange_including_undef, |
73 | |
74 | /// We can not precisely model the dynamic values this value might take. |
75 | /// No transitions are allowed after reaching overdefined. |
76 | overdefined, |
77 | }; |
78 | |
79 | ValueLatticeElementTy Tag : 8; |
80 | /// Number of times a constant range has been extended with widening enabled. |
81 | unsigned NumRangeExtensions : 8; |
82 | |
83 | /// The union either stores a pointer to a constant or a constant range, |
84 | /// associated to the lattice element. We have to ensure that Range is |
85 | /// initialized or destroyed when changing state to or from constantrange. |
86 | union { |
87 | Constant *ConstVal; |
88 | ConstantRange Range; |
89 | }; |
90 | |
91 | /// Destroy contents of lattice value, without destructing the object. |
92 | void destroy() { |
93 | switch (Tag) { |
94 | case overdefined: |
95 | case unknown: |
96 | case undef: |
97 | case constant: |
98 | case notconstant: |
99 | break; |
100 | case constantrange_including_undef: |
101 | case constantrange: |
102 | Range.~ConstantRange(); |
103 | break; |
104 | }; |
105 | } |
106 | |
107 | public: |
108 | /// Struct to control some aspects related to merging constant ranges. |
109 | struct MergeOptions { |
110 | /// The merge value may include undef. |
111 | bool MayIncludeUndef; |
112 | |
113 | /// Handle repeatedly extending a range by going to overdefined after a |
114 | /// number of steps. |
115 | bool CheckWiden; |
116 | |
117 | /// The number of allowed widening steps (including setting the range |
118 | /// initially). |
119 | unsigned MaxWidenSteps; |
120 | |
121 | MergeOptions() : MergeOptions(false, false) {} |
122 | |
123 | MergeOptions(bool MayIncludeUndef, bool CheckWiden, |
124 | unsigned MaxWidenSteps = 1) |
125 | : MayIncludeUndef(MayIncludeUndef), CheckWiden(CheckWiden), |
126 | MaxWidenSteps(MaxWidenSteps) {} |
127 | |
128 | MergeOptions &setMayIncludeUndef(bool V = true) { |
129 | MayIncludeUndef = V; |
130 | return *this; |
131 | } |
132 | |
133 | MergeOptions &setCheckWiden(bool V = true) { |
134 | CheckWiden = V; |
135 | return *this; |
136 | } |
137 | |
138 | MergeOptions &setMaxWidenSteps(unsigned Steps = 1) { |
139 | CheckWiden = true; |
140 | MaxWidenSteps = Steps; |
141 | return *this; |
142 | } |
143 | }; |
144 | |
145 | // ConstVal and Range are initialized on-demand. |
146 | ValueLatticeElement() : Tag(unknown), NumRangeExtensions(0) {} |
147 | |
148 | ~ValueLatticeElement() { destroy(); } |
149 | |
150 | ValueLatticeElement(const ValueLatticeElement &Other) |
151 | : Tag(Other.Tag), NumRangeExtensions(0) { |
152 | switch (Other.Tag) { |
153 | case constantrange: |
154 | case constantrange_including_undef: |
155 | new (&Range) ConstantRange(Other.Range); |
156 | NumRangeExtensions = Other.NumRangeExtensions; |
157 | break; |
158 | case constant: |
159 | case notconstant: |
160 | ConstVal = Other.ConstVal; |
161 | break; |
162 | case overdefined: |
163 | case unknown: |
164 | case undef: |
165 | break; |
166 | } |
167 | } |
168 | |
169 | ValueLatticeElement(ValueLatticeElement &&Other) |
170 | : Tag(Other.Tag), NumRangeExtensions(0) { |
171 | switch (Other.Tag) { |
172 | case constantrange: |
173 | case constantrange_including_undef: |
174 | new (&Range) ConstantRange(std::move(Other.Range)); |
175 | NumRangeExtensions = Other.NumRangeExtensions; |
176 | break; |
177 | case constant: |
178 | case notconstant: |
179 | ConstVal = Other.ConstVal; |
180 | break; |
181 | case overdefined: |
182 | case unknown: |
183 | case undef: |
184 | break; |
185 | } |
186 | Other.Tag = unknown; |
187 | } |
188 | |
189 | ValueLatticeElement &operator=(const ValueLatticeElement &Other) { |
190 | destroy(); |
191 | new (this) ValueLatticeElement(Other); |
192 | return *this; |
193 | } |
194 | |
195 | ValueLatticeElement &operator=(ValueLatticeElement &&Other) { |
196 | destroy(); |
197 | new (this) ValueLatticeElement(std::move(Other)); |
198 | return *this; |
199 | } |
200 | |
201 | static ValueLatticeElement get(Constant *C) { |
202 | ValueLatticeElement Res; |
203 | if (isa<UndefValue>(C)) |
204 | Res.markUndef(); |
205 | else |
206 | Res.markConstant(C); |
207 | return Res; |
208 | } |
209 | static ValueLatticeElement getNot(Constant *C) { |
210 | ValueLatticeElement Res; |
211 | assert(!isa<UndefValue>(C) && "!= undef is not supported")((void)0); |
212 | Res.markNotConstant(C); |
213 | return Res; |
214 | } |
215 | static ValueLatticeElement getRange(ConstantRange CR, |
216 | bool MayIncludeUndef = false) { |
217 | if (CR.isFullSet()) |
218 | return getOverdefined(); |
219 | |
220 | if (CR.isEmptySet()) { |
221 | ValueLatticeElement Res; |
222 | if (MayIncludeUndef) |
223 | Res.markUndef(); |
224 | return Res; |
225 | } |
226 | |
227 | ValueLatticeElement Res; |
228 | Res.markConstantRange(std::move(CR), |
229 | MergeOptions().setMayIncludeUndef(MayIncludeUndef)); |
230 | return Res; |
231 | } |
232 | static ValueLatticeElement getOverdefined() { |
233 | ValueLatticeElement Res; |
234 | Res.markOverdefined(); |
235 | return Res; |
236 | } |
237 | |
238 | bool isUndef() const { return Tag == undef; } |
239 | bool isUnknown() const { return Tag == unknown; } |
240 | bool isUnknownOrUndef() const { return Tag == unknown || Tag == undef; } |
241 | bool isConstant() const { return Tag == constant; } |
242 | bool isNotConstant() const { return Tag == notconstant; } |
243 | bool isConstantRangeIncludingUndef() const { |
244 | return Tag == constantrange_including_undef; |
245 | } |
246 | /// Returns true if this value is a constant range. Use \p UndefAllowed to |
247 | /// exclude non-singleton constant ranges that may also be undef. Note that |
248 | /// this function also returns true if the range may include undef, but only |
249 | /// contains a single element. In that case, it can be replaced by a constant. |
250 | bool isConstantRange(bool UndefAllowed = true) const { |
251 | return Tag == constantrange || (Tag == constantrange_including_undef && |
252 | (UndefAllowed || Range.isSingleElement())); |
253 | } |
254 | bool isOverdefined() const { return Tag == overdefined; } |
255 | |
256 | Constant *getConstant() const { |
257 | assert(isConstant() && "Cannot get the constant of a non-constant!")((void)0); |
258 | return ConstVal; |
259 | } |
260 | |
261 | Constant *getNotConstant() const { |
262 | assert(isNotConstant() && "Cannot get the constant of a non-notconstant!")((void)0); |
263 | return ConstVal; |
264 | } |
265 | |
266 | /// Returns the constant range for this value. Use \p UndefAllowed to exclude |
267 | /// non-singleton constant ranges that may also be undef. Note that this |
268 | /// function also returns a range if the range may include undef, but only |
269 | /// contains a single element. In that case, it can be replaced by a constant. |
270 | const ConstantRange &getConstantRange(bool UndefAllowed = true) const { |
271 | assert(isConstantRange(UndefAllowed) &&((void)0) |
272 | "Cannot get the constant-range of a non-constant-range!")((void)0); |
273 | return Range; |
274 | } |
275 | |
276 | Optional<APInt> asConstantInteger() const { |
277 | if (isConstant() && isa<ConstantInt>(getConstant())) { |
278 | return cast<ConstantInt>(getConstant())->getValue(); |
279 | } else if (isConstantRange() && getConstantRange().isSingleElement()) { |
280 | return *getConstantRange().getSingleElement(); |
281 | } |
282 | return None; |
283 | } |
284 | |
285 | bool markOverdefined() { |
286 | if (isOverdefined()) |
287 | return false; |
288 | destroy(); |
289 | Tag = overdefined; |
290 | return true; |
291 | } |
292 | |
293 | bool markUndef() { |
294 | if (isUndef()) |
295 | return false; |
296 | |
297 | assert(isUnknown())((void)0); |
298 | Tag = undef; |
299 | return true; |
300 | } |
301 | |
302 | bool markConstant(Constant *V, bool MayIncludeUndef = false) { |
303 | if (isa<UndefValue>(V)) |
304 | return markUndef(); |
305 | |
306 | if (isConstant()) { |
307 | assert(getConstant() == V && "Marking constant with different value")((void)0); |
308 | return false; |
309 | } |
310 | |
311 | if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) |
312 | return markConstantRange( |
313 | ConstantRange(CI->getValue()), |
314 | MergeOptions().setMayIncludeUndef(MayIncludeUndef)); |
315 | |
316 | assert(isUnknown() || isUndef())((void)0); |
317 | Tag = constant; |
318 | ConstVal = V; |
319 | return true; |
320 | } |
321 | |
322 | bool markNotConstant(Constant *V) { |
323 | assert(V && "Marking constant with NULL")((void)0); |
324 | if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) |
325 | return markConstantRange( |
326 | ConstantRange(CI->getValue() + 1, CI->getValue())); |
327 | |
328 | if (isa<UndefValue>(V)) |
329 | return false; |
330 | |
331 | if (isNotConstant()) { |
332 | assert(getNotConstant() == V && "Marking !constant with different value")((void)0); |
333 | return false; |
334 | } |
335 | |
336 | assert(isUnknown())((void)0); |
337 | Tag = notconstant; |
338 | ConstVal = V; |
339 | return true; |
340 | } |
341 | |
342 | /// Mark the object as constant range with \p NewR. If the object is already a |
343 | /// constant range, nothing changes if the existing range is equal to \p |
344 | /// NewR and the tag. Otherwise \p NewR must be a superset of the existing |
345 | /// range or the object must be undef. The tag is set to |
346 | /// constant_range_including_undef if either the existing value or the new |
347 | /// range may include undef. |
348 | bool markConstantRange(ConstantRange NewR, |
349 | MergeOptions Opts = MergeOptions()) { |
350 | assert(!NewR.isEmptySet() && "should only be called for non-empty sets")((void)0); |
351 | |
352 | if (NewR.isFullSet()) |
353 | return markOverdefined(); |
354 | |
355 | ValueLatticeElementTy OldTag = Tag; |
356 | ValueLatticeElementTy NewTag = |
357 | (isUndef() || isConstantRangeIncludingUndef() || Opts.MayIncludeUndef) |
358 | ? constantrange_including_undef |
359 | : constantrange; |
360 | if (isConstantRange()) { |
361 | Tag = NewTag; |
362 | if (getConstantRange() == NewR) |
363 | return Tag != OldTag; |
364 | |
365 | // Simple form of widening. If a range is extended multiple times, go to |
366 | // overdefined. |
367 | if (Opts.CheckWiden && ++NumRangeExtensions > Opts.MaxWidenSteps) |
368 | return markOverdefined(); |
369 | |
370 | assert(NewR.contains(getConstantRange()) &&((void)0) |
371 | "Existing range must be a subset of NewR")((void)0); |
372 | Range = std::move(NewR); |
373 | return true; |
374 | } |
375 | |
376 | assert(isUnknown() || isUndef())((void)0); |
377 | |
378 | NumRangeExtensions = 0; |
379 | Tag = NewTag; |
380 | new (&Range) ConstantRange(std::move(NewR)); |
381 | return true; |
382 | } |
383 | |
384 | /// Updates this object to approximate both this object and RHS. Returns |
385 | /// true if this object has been changed. |
386 | bool mergeIn(const ValueLatticeElement &RHS, |
387 | MergeOptions Opts = MergeOptions()) { |
388 | if (RHS.isUnknown() || isOverdefined()) |
389 | return false; |
390 | if (RHS.isOverdefined()) { |
391 | markOverdefined(); |
392 | return true; |
393 | } |
394 | |
395 | if (isUndef()) { |
396 | assert(!RHS.isUnknown())((void)0); |
397 | if (RHS.isUndef()) |
398 | return false; |
399 | if (RHS.isConstant()) |
400 | return markConstant(RHS.getConstant(), true); |
401 | if (RHS.isConstantRange()) |
402 | return markConstantRange(RHS.getConstantRange(true), |
403 | Opts.setMayIncludeUndef()); |
404 | return markOverdefined(); |
405 | } |
406 | |
407 | if (isUnknown()) { |
408 | assert(!RHS.isUnknown() && "Unknow RHS should be handled earlier")((void)0); |
409 | *this = RHS; |
410 | return true; |
411 | } |
412 | |
413 | if (isConstant()) { |
414 | if (RHS.isConstant() && getConstant() == RHS.getConstant()) |
415 | return false; |
416 | if (RHS.isUndef()) |
417 | return false; |
418 | markOverdefined(); |
419 | return true; |
420 | } |
421 | |
422 | if (isNotConstant()) { |
423 | if (RHS.isNotConstant() && getNotConstant() == RHS.getNotConstant()) |
424 | return false; |
425 | markOverdefined(); |
426 | return true; |
427 | } |
428 | |
429 | auto OldTag = Tag; |
430 | assert(isConstantRange() && "New ValueLattice type?")((void)0); |
431 | if (RHS.isUndef()) { |
432 | Tag = constantrange_including_undef; |
433 | return OldTag != Tag; |
434 | } |
435 | |
436 | if (!RHS.isConstantRange()) { |
437 | // We can get here if we've encountered a constantexpr of integer type |
438 | // and merge it with a constantrange. |
439 | markOverdefined(); |
440 | return true; |
441 | } |
442 | |
443 | ConstantRange NewR = getConstantRange().unionWith(RHS.getConstantRange()); |
444 | return markConstantRange( |
445 | std::move(NewR), |
446 | Opts.setMayIncludeUndef(RHS.isConstantRangeIncludingUndef())); |
447 | } |
448 | |
449 | // Compares this symbolic value with Other using Pred and returns either |
450 | /// true, false or undef constants, or nullptr if the comparison cannot be |
451 | /// evaluated. |
452 | Constant *getCompare(CmpInst::Predicate Pred, Type *Ty, |
453 | const ValueLatticeElement &Other) const { |
454 | if (isUnknownOrUndef() || Other.isUnknownOrUndef()) |
455 | return UndefValue::get(Ty); |
456 | |
457 | if (isConstant() && Other.isConstant()) |
458 | return ConstantExpr::getCompare(Pred, getConstant(), Other.getConstant()); |
459 | |
460 | if (ICmpInst::isEquality(Pred)) { |
461 | // not(C) != C => true, not(C) == C => false. |
462 | if ((isNotConstant() && Other.isConstant() && |
463 | getNotConstant() == Other.getConstant()) || |
464 | (isConstant() && Other.isNotConstant() && |
465 | getConstant() == Other.getNotConstant())) |
466 | return Pred == ICmpInst::ICMP_NE |
467 | ? ConstantInt::getTrue(Ty) : ConstantInt::getFalse(Ty); |
468 | } |
469 | |
470 | // Integer constants are represented as ConstantRanges with single |
471 | // elements. |
472 | if (!isConstantRange() || !Other.isConstantRange()) |
473 | return nullptr; |
474 | |
475 | const auto &CR = getConstantRange(); |
476 | const auto &OtherCR = Other.getConstantRange(); |
477 | if (CR.icmp(Pred, OtherCR)) |
478 | return ConstantInt::getTrue(Ty); |
479 | if (CR.icmp(CmpInst::getInversePredicate(Pred), OtherCR)) |
480 | return ConstantInt::getFalse(Ty); |
481 | |
482 | return nullptr; |
483 | } |
484 | |
485 | unsigned getNumRangeExtensions() const { return NumRangeExtensions; } |
486 | void setNumRangeExtensions(unsigned N) { NumRangeExtensions = N; } |
487 | }; |
488 | |
489 | static_assert(sizeof(ValueLatticeElement) <= 40, |
490 | "size of ValueLatticeElement changed unexpectedly"); |
491 | |
492 | raw_ostream &operator<<(raw_ostream &OS, const ValueLatticeElement &Val); |
493 | } // end namespace llvm |
494 | #endif |
1 | //===-- llvm/ADT/APInt.h - For Arbitrary Precision Integer -----*- C++ -*--===// | |||
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 | /// \file | |||
10 | /// This file implements a class to represent arbitrary precision | |||
11 | /// integral constant values and operations on them. | |||
12 | /// | |||
13 | //===----------------------------------------------------------------------===// | |||
14 | ||||
15 | #ifndef LLVM_ADT_APINT_H | |||
16 | #define LLVM_ADT_APINT_H | |||
17 | ||||
18 | #include "llvm/Support/Compiler.h" | |||
19 | #include "llvm/Support/MathExtras.h" | |||
20 | #include <cassert> | |||
21 | #include <climits> | |||
22 | #include <cstring> | |||
23 | #include <utility> | |||
24 | ||||
25 | namespace llvm { | |||
26 | class FoldingSetNodeID; | |||
27 | class StringRef; | |||
28 | class hash_code; | |||
29 | class raw_ostream; | |||
30 | ||||
31 | template <typename T> class SmallVectorImpl; | |||
32 | template <typename T> class ArrayRef; | |||
33 | template <typename T> class Optional; | |||
34 | template <typename T> struct DenseMapInfo; | |||
35 | ||||
36 | class APInt; | |||
37 | ||||
38 | inline APInt operator-(APInt); | |||
39 | ||||
40 | //===----------------------------------------------------------------------===// | |||
41 | // APInt Class | |||
42 | //===----------------------------------------------------------------------===// | |||
43 | ||||
44 | /// Class for arbitrary precision integers. | |||
45 | /// | |||
46 | /// APInt is a functional replacement for common case unsigned integer type like | |||
47 | /// "unsigned", "unsigned long" or "uint64_t", but also allows non-byte-width | |||
48 | /// integer sizes and large integer value types such as 3-bits, 15-bits, or more | |||
49 | /// than 64-bits of precision. APInt provides a variety of arithmetic operators | |||
50 | /// and methods to manipulate integer values of any bit-width. It supports both | |||
51 | /// the typical integer arithmetic and comparison operations as well as bitwise | |||
52 | /// manipulation. | |||
53 | /// | |||
54 | /// The class has several invariants worth noting: | |||
55 | /// * All bit, byte, and word positions are zero-based. | |||
56 | /// * Once the bit width is set, it doesn't change except by the Truncate, | |||
57 | /// SignExtend, or ZeroExtend operations. | |||
58 | /// * All binary operators must be on APInt instances of the same bit width. | |||
59 | /// Attempting to use these operators on instances with different bit | |||
60 | /// widths will yield an assertion. | |||
61 | /// * The value is stored canonically as an unsigned value. For operations | |||
62 | /// where it makes a difference, there are both signed and unsigned variants | |||
63 | /// of the operation. For example, sdiv and udiv. However, because the bit | |||
64 | /// widths must be the same, operations such as Mul and Add produce the same | |||
65 | /// results regardless of whether the values are interpreted as signed or | |||
66 | /// not. | |||
67 | /// * In general, the class tries to follow the style of computation that LLVM | |||
68 | /// uses in its IR. This simplifies its use for LLVM. | |||
69 | /// | |||
70 | class LLVM_NODISCARD[[clang::warn_unused_result]] APInt { | |||
71 | public: | |||
72 | typedef uint64_t WordType; | |||
73 | ||||
74 | /// This enum is used to hold the constants we needed for APInt. | |||
75 | enum : unsigned { | |||
76 | /// Byte size of a word. | |||
77 | APINT_WORD_SIZE = sizeof(WordType), | |||
78 | /// Bits in a word. | |||
79 | APINT_BITS_PER_WORD = APINT_WORD_SIZE * CHAR_BIT8 | |||
80 | }; | |||
81 | ||||
82 | enum class Rounding { | |||
83 | DOWN, | |||
84 | TOWARD_ZERO, | |||
85 | UP, | |||
86 | }; | |||
87 | ||||
88 | static constexpr WordType WORDTYPE_MAX = ~WordType(0); | |||
89 | ||||
90 | private: | |||
91 | /// This union is used to store the integer value. When the | |||
92 | /// integer bit-width <= 64, it uses VAL, otherwise it uses pVal. | |||
93 | union { | |||
94 | uint64_t VAL; ///< Used to store the <= 64 bits integer value. | |||
95 | uint64_t *pVal; ///< Used to store the >64 bits integer value. | |||
96 | } U; | |||
97 | ||||
98 | unsigned BitWidth; ///< The number of bits in this APInt. | |||
99 | ||||
100 | friend struct DenseMapInfo<APInt>; | |||
101 | ||||
102 | friend class APSInt; | |||
103 | ||||
104 | /// Fast internal constructor | |||
105 | /// | |||
106 | /// This constructor is used only internally for speed of construction of | |||
107 | /// temporaries. It is unsafe for general use so it is not public. | |||
108 | APInt(uint64_t *val, unsigned bits) : BitWidth(bits) { | |||
109 | U.pVal = val; | |||
110 | } | |||
111 | ||||
112 | /// Determine which word a bit is in. | |||
113 | /// | |||
114 | /// \returns the word position for the specified bit position. | |||
115 | static unsigned whichWord(unsigned bitPosition) { | |||
116 | return bitPosition / APINT_BITS_PER_WORD; | |||
117 | } | |||
118 | ||||
119 | /// Determine which bit in a word a bit is in. | |||
120 | /// | |||
121 | /// \returns the bit position in a word for the specified bit position | |||
122 | /// in the APInt. | |||
123 | static unsigned whichBit(unsigned bitPosition) { | |||
124 | return bitPosition % APINT_BITS_PER_WORD; | |||
125 | } | |||
126 | ||||
127 | /// Get a single bit mask. | |||
128 | /// | |||
129 | /// \returns a uint64_t with only bit at "whichBit(bitPosition)" set | |||
130 | /// This method generates and returns a uint64_t (word) mask for a single | |||
131 | /// bit at a specific bit position. This is used to mask the bit in the | |||
132 | /// corresponding word. | |||
133 | static uint64_t maskBit(unsigned bitPosition) { | |||
134 | return 1ULL << whichBit(bitPosition); | |||
135 | } | |||
136 | ||||
137 | /// Clear unused high order bits | |||
138 | /// | |||
139 | /// This method is used internally to clear the top "N" bits in the high order | |||
140 | /// word that are not used by the APInt. This is needed after the most | |||
141 | /// significant word is assigned a value to ensure that those bits are | |||
142 | /// zero'd out. | |||
143 | APInt &clearUnusedBits() { | |||
144 | // Compute how many bits are used in the final word | |||
145 | unsigned WordBits = ((BitWidth-1) % APINT_BITS_PER_WORD) + 1; | |||
146 | ||||
147 | // Mask out the high bits. | |||
148 | uint64_t mask = WORDTYPE_MAX >> (APINT_BITS_PER_WORD - WordBits); | |||
149 | if (isSingleWord()) | |||
150 | U.VAL &= mask; | |||
151 | else | |||
152 | U.pVal[getNumWords() - 1] &= mask; | |||
153 | return *this; | |||
154 | } | |||
155 | ||||
156 | /// Get the word corresponding to a bit position | |||
157 | /// \returns the corresponding word for the specified bit position. | |||
158 | uint64_t getWord(unsigned bitPosition) const { | |||
159 | return isSingleWord() ? U.VAL : U.pVal[whichWord(bitPosition)]; | |||
160 | } | |||
161 | ||||
162 | /// Utility method to change the bit width of this APInt to new bit width, | |||
163 | /// allocating and/or deallocating as necessary. There is no guarantee on the | |||
164 | /// value of any bits upon return. Caller should populate the bits after. | |||
165 | void reallocate(unsigned NewBitWidth); | |||
166 | ||||
167 | /// Convert a char array into an APInt | |||
168 | /// | |||
169 | /// \param radix 2, 8, 10, 16, or 36 | |||
170 | /// Converts a string into a number. The string must be non-empty | |||
171 | /// and well-formed as a number of the given base. The bit-width | |||
172 | /// must be sufficient to hold the result. | |||
173 | /// | |||
174 | /// This is used by the constructors that take string arguments. | |||
175 | /// | |||
176 | /// StringRef::getAsInteger is superficially similar but (1) does | |||
177 | /// not assume that the string is well-formed and (2) grows the | |||
178 | /// result to hold the input. | |||
179 | void fromString(unsigned numBits, StringRef str, uint8_t radix); | |||
180 | ||||
181 | /// An internal division function for dividing APInts. | |||
182 | /// | |||
183 | /// This is used by the toString method to divide by the radix. It simply | |||
184 | /// provides a more convenient form of divide for internal use since KnuthDiv | |||
185 | /// has specific constraints on its inputs. If those constraints are not met | |||
186 | /// then it provides a simpler form of divide. | |||
187 | static void divide(const WordType *LHS, unsigned lhsWords, | |||
188 | const WordType *RHS, unsigned rhsWords, WordType *Quotient, | |||
189 | WordType *Remainder); | |||
190 | ||||
191 | /// out-of-line slow case for inline constructor | |||
192 | void initSlowCase(uint64_t val, bool isSigned); | |||
193 | ||||
194 | /// shared code between two array constructors | |||
195 | void initFromArray(ArrayRef<uint64_t> array); | |||
196 | ||||
197 | /// out-of-line slow case for inline copy constructor | |||
198 | void initSlowCase(const APInt &that); | |||
199 | ||||
200 | /// out-of-line slow case for shl | |||
201 | void shlSlowCase(unsigned ShiftAmt); | |||
202 | ||||
203 | /// out-of-line slow case for lshr. | |||
204 | void lshrSlowCase(unsigned ShiftAmt); | |||
205 | ||||
206 | /// out-of-line slow case for ashr. | |||
207 | void ashrSlowCase(unsigned ShiftAmt); | |||
208 | ||||
209 | /// out-of-line slow case for operator= | |||
210 | void AssignSlowCase(const APInt &RHS); | |||
211 | ||||
212 | /// out-of-line slow case for operator== | |||
213 | bool EqualSlowCase(const APInt &RHS) const LLVM_READONLY__attribute__((__pure__)); | |||
214 | ||||
215 | /// out-of-line slow case for countLeadingZeros | |||
216 | unsigned countLeadingZerosSlowCase() const LLVM_READONLY__attribute__((__pure__)); | |||
217 | ||||
218 | /// out-of-line slow case for countLeadingOnes. | |||
219 | unsigned countLeadingOnesSlowCase() const LLVM_READONLY__attribute__((__pure__)); | |||
220 | ||||
221 | /// out-of-line slow case for countTrailingZeros. | |||
222 | unsigned countTrailingZerosSlowCase() const LLVM_READONLY__attribute__((__pure__)); | |||
223 | ||||
224 | /// out-of-line slow case for countTrailingOnes | |||
225 | unsigned countTrailingOnesSlowCase() const LLVM_READONLY__attribute__((__pure__)); | |||
226 | ||||
227 | /// out-of-line slow case for countPopulation | |||
228 | unsigned countPopulationSlowCase() const LLVM_READONLY__attribute__((__pure__)); | |||
229 | ||||
230 | /// out-of-line slow case for intersects. | |||
231 | bool intersectsSlowCase(const APInt &RHS) const LLVM_READONLY__attribute__((__pure__)); | |||
232 | ||||
233 | /// out-of-line slow case for isSubsetOf. | |||
234 | bool isSubsetOfSlowCase(const APInt &RHS) const LLVM_READONLY__attribute__((__pure__)); | |||
235 | ||||
236 | /// out-of-line slow case for setBits. | |||
237 | void setBitsSlowCase(unsigned loBit, unsigned hiBit); | |||
238 | ||||
239 | /// out-of-line slow case for flipAllBits. | |||
240 | void flipAllBitsSlowCase(); | |||
241 | ||||
242 | /// out-of-line slow case for operator&=. | |||
243 | void AndAssignSlowCase(const APInt& RHS); | |||
244 | ||||
245 | /// out-of-line slow case for operator|=. | |||
246 | void OrAssignSlowCase(const APInt& RHS); | |||
247 | ||||
248 | /// out-of-line slow case for operator^=. | |||
249 | void XorAssignSlowCase(const APInt& RHS); | |||
250 | ||||
251 | /// Unsigned comparison. Returns -1, 0, or 1 if this APInt is less than, equal | |||
252 | /// to, or greater than RHS. | |||
253 | int compare(const APInt &RHS) const LLVM_READONLY__attribute__((__pure__)); | |||
254 | ||||
255 | /// Signed comparison. Returns -1, 0, or 1 if this APInt is less than, equal | |||
256 | /// to, or greater than RHS. | |||
257 | int compareSigned(const APInt &RHS) const LLVM_READONLY__attribute__((__pure__)); | |||
258 | ||||
259 | public: | |||
260 | /// \name Constructors | |||
261 | /// @{ | |||
262 | ||||
263 | /// Create a new APInt of numBits width, initialized as val. | |||
264 | /// | |||
265 | /// If isSigned is true then val is treated as if it were a signed value | |||
266 | /// (i.e. as an int64_t) and the appropriate sign extension to the bit width | |||
267 | /// will be done. Otherwise, no sign extension occurs (high order bits beyond | |||
268 | /// the range of val are zero filled). | |||
269 | /// | |||
270 | /// \param numBits the bit width of the constructed APInt | |||
271 | /// \param val the initial value of the APInt | |||
272 | /// \param isSigned how to treat signedness of val | |||
273 | APInt(unsigned numBits, uint64_t val, bool isSigned = false) | |||
274 | : BitWidth(numBits) { | |||
275 | assert(BitWidth && "bitwidth too small")((void)0); | |||
276 | if (isSingleWord()) { | |||
277 | U.VAL = val; | |||
278 | clearUnusedBits(); | |||
279 | } else { | |||
280 | initSlowCase(val, isSigned); | |||
281 | } | |||
282 | } | |||
283 | ||||
284 | /// Construct an APInt of numBits width, initialized as bigVal[]. | |||
285 | /// | |||
286 | /// Note that bigVal.size() can be smaller or larger than the corresponding | |||
287 | /// bit width but any extraneous bits will be dropped. | |||
288 | /// | |||
289 | /// \param numBits the bit width of the constructed APInt | |||
290 | /// \param bigVal a sequence of words to form the initial value of the APInt | |||
291 | APInt(unsigned numBits, ArrayRef<uint64_t> bigVal); | |||
292 | ||||
293 | /// Equivalent to APInt(numBits, ArrayRef<uint64_t>(bigVal, numWords)), but | |||
294 | /// deprecated because this constructor is prone to ambiguity with the | |||
295 | /// APInt(unsigned, uint64_t, bool) constructor. | |||
296 | /// | |||
297 | /// If this overload is ever deleted, care should be taken to prevent calls | |||
298 | /// from being incorrectly captured by the APInt(unsigned, uint64_t, bool) | |||
299 | /// constructor. | |||
300 | APInt(unsigned numBits, unsigned numWords, const uint64_t bigVal[]); | |||
301 | ||||
302 | /// Construct an APInt from a string representation. | |||
303 | /// | |||
304 | /// This constructor interprets the string \p str in the given radix. The | |||
305 | /// interpretation stops when the first character that is not suitable for the | |||
306 | /// radix is encountered, or the end of the string. Acceptable radix values | |||
307 | /// are 2, 8, 10, 16, and 36. It is an error for the value implied by the | |||
308 | /// string to require more bits than numBits. | |||
309 | /// | |||
310 | /// \param numBits the bit width of the constructed APInt | |||
311 | /// \param str the string to be interpreted | |||
312 | /// \param radix the radix to use for the conversion | |||
313 | APInt(unsigned numBits, StringRef str, uint8_t radix); | |||
314 | ||||
315 | /// Simply makes *this a copy of that. | |||
316 | /// Copy Constructor. | |||
317 | APInt(const APInt &that) : BitWidth(that.BitWidth) { | |||
318 | if (isSingleWord()) | |||
319 | U.VAL = that.U.VAL; | |||
320 | else | |||
321 | initSlowCase(that); | |||
322 | } | |||
323 | ||||
324 | /// Move Constructor. | |||
325 | APInt(APInt &&that) : BitWidth(that.BitWidth) { | |||
| ||||
326 | memcpy(&U, &that.U, sizeof(U)); | |||
327 | that.BitWidth = 0; | |||
328 | } | |||
329 | ||||
330 | /// Destructor. | |||
331 | ~APInt() { | |||
332 | if (needsCleanup()) | |||
333 | delete[] U.pVal; | |||
334 | } | |||
335 | ||||
336 | /// Default constructor that creates an uninteresting APInt | |||
337 | /// representing a 1-bit zero value. | |||
338 | /// | |||
339 | /// This is useful for object deserialization (pair this with the static | |||
340 | /// method Read). | |||
341 | explicit APInt() : BitWidth(1) { U.VAL = 0; } | |||
342 | ||||
343 | /// Returns whether this instance allocated memory. | |||
344 | bool needsCleanup() const { return !isSingleWord(); } | |||
345 | ||||
346 | /// Used to insert APInt objects, or objects that contain APInt objects, into | |||
347 | /// FoldingSets. | |||
348 | void Profile(FoldingSetNodeID &id) const; | |||
349 | ||||
350 | /// @} | |||
351 | /// \name Value Tests | |||
352 | /// @{ | |||
353 | ||||
354 | /// Determine if this APInt just has one word to store value. | |||
355 | /// | |||
356 | /// \returns true if the number of bits <= 64, false otherwise. | |||
357 | bool isSingleWord() const { return BitWidth <= APINT_BITS_PER_WORD; } | |||
358 | ||||
359 | /// Determine sign of this APInt. | |||
360 | /// | |||
361 | /// This tests the high bit of this APInt to determine if it is set. | |||
362 | /// | |||
363 | /// \returns true if this APInt is negative, false otherwise | |||
364 | bool isNegative() const { return (*this)[BitWidth - 1]; } | |||
365 | ||||
366 | /// Determine if this APInt Value is non-negative (>= 0) | |||
367 | /// | |||
368 | /// This tests the high bit of the APInt to determine if it is unset. | |||
369 | bool isNonNegative() const { return !isNegative(); } | |||
370 | ||||
371 | /// Determine if sign bit of this APInt is set. | |||
372 | /// | |||
373 | /// This tests the high bit of this APInt to determine if it is set. | |||
374 | /// | |||
375 | /// \returns true if this APInt has its sign bit set, false otherwise. | |||
376 | bool isSignBitSet() const { return (*this)[BitWidth-1]; } | |||
377 | ||||
378 | /// Determine if sign bit of this APInt is clear. | |||
379 | /// | |||
380 | /// This tests the high bit of this APInt to determine if it is clear. | |||
381 | /// | |||
382 | /// \returns true if this APInt has its sign bit clear, false otherwise. | |||
383 | bool isSignBitClear() const { return !isSignBitSet(); } | |||
384 | ||||
385 | /// Determine if this APInt Value is positive. | |||
386 | /// | |||
387 | /// This tests if the value of this APInt is positive (> 0). Note | |||
388 | /// that 0 is not a positive value. | |||
389 | /// | |||
390 | /// \returns true if this APInt is positive. | |||
391 | bool isStrictlyPositive() const { return isNonNegative() && !isNullValue(); } | |||
392 | ||||
393 | /// Determine if this APInt Value is non-positive (<= 0). | |||
394 | /// | |||
395 | /// \returns true if this APInt is non-positive. | |||
396 | bool isNonPositive() const { return !isStrictlyPositive(); } | |||
397 | ||||
398 | /// Determine if all bits are set | |||
399 | /// | |||
400 | /// This checks to see if the value has all bits of the APInt are set or not. | |||
401 | bool isAllOnesValue() const { | |||
402 | if (isSingleWord()) | |||
403 | return U.VAL == WORDTYPE_MAX >> (APINT_BITS_PER_WORD - BitWidth); | |||
404 | return countTrailingOnesSlowCase() == BitWidth; | |||
405 | } | |||
406 | ||||
407 | /// Determine if all bits are clear | |||
408 | /// | |||
409 | /// This checks to see if the value has all bits of the APInt are clear or | |||
410 | /// not. | |||
411 | bool isNullValue() const { return !*this; } | |||
412 | ||||
413 | /// Determine if this is a value of 1. | |||
414 | /// | |||
415 | /// This checks to see if the value of this APInt is one. | |||
416 | bool isOneValue() const { | |||
417 | if (isSingleWord()) | |||
418 | return U.VAL == 1; | |||
419 | return countLeadingZerosSlowCase() == BitWidth - 1; | |||
420 | } | |||
421 | ||||
422 | /// Determine if this is the largest unsigned value. | |||
423 | /// | |||
424 | /// This checks to see if the value of this APInt is the maximum unsigned | |||
425 | /// value for the APInt's bit width. | |||
426 | bool isMaxValue() const { return isAllOnesValue(); } | |||
427 | ||||
428 | /// Determine if this is the largest signed value. | |||
429 | /// | |||
430 | /// This checks to see if the value of this APInt is the maximum signed | |||
431 | /// value for the APInt's bit width. | |||
432 | bool isMaxSignedValue() const { | |||
433 | if (isSingleWord()) | |||
434 | return U.VAL == ((WordType(1) << (BitWidth - 1)) - 1); | |||
435 | return !isNegative() && countTrailingOnesSlowCase() == BitWidth - 1; | |||
436 | } | |||
437 | ||||
438 | /// Determine if this is the smallest unsigned value. | |||
439 | /// | |||
440 | /// This checks to see if the value of this APInt is the minimum unsigned | |||
441 | /// value for the APInt's bit width. | |||
442 | bool isMinValue() const { return isNullValue(); } | |||
443 | ||||
444 | /// Determine if this is the smallest signed value. | |||
445 | /// | |||
446 | /// This checks to see if the value of this APInt is the minimum signed | |||
447 | /// value for the APInt's bit width. | |||
448 | bool isMinSignedValue() const { | |||
449 | if (isSingleWord()) | |||
450 | return U.VAL == (WordType(1) << (BitWidth - 1)); | |||
451 | return isNegative() && countTrailingZerosSlowCase() == BitWidth - 1; | |||
452 | } | |||
453 | ||||
454 | /// Check if this APInt has an N-bits unsigned integer value. | |||
455 | bool isIntN(unsigned N) const { | |||
456 | assert(N && "N == 0 ???")((void)0); | |||
457 | return getActiveBits() <= N; | |||
458 | } | |||
459 | ||||
460 | /// Check if this APInt has an N-bits signed integer value. | |||
461 | bool isSignedIntN(unsigned N) const { | |||
462 | assert(N && "N == 0 ???")((void)0); | |||
463 | return getMinSignedBits() <= N; | |||
464 | } | |||
465 | ||||
466 | /// Check if this APInt's value is a power of two greater than zero. | |||
467 | /// | |||
468 | /// \returns true if the argument APInt value is a power of two > 0. | |||
469 | bool isPowerOf2() const { | |||
470 | if (isSingleWord()) | |||
471 | return isPowerOf2_64(U.VAL); | |||
472 | return countPopulationSlowCase() == 1; | |||
473 | } | |||
474 | ||||
475 | /// Check if the APInt's value is returned by getSignMask. | |||
476 | /// | |||
477 | /// \returns true if this is the value returned by getSignMask. | |||
478 | bool isSignMask() const { return isMinSignedValue(); } | |||
479 | ||||
480 | /// Convert APInt to a boolean value. | |||
481 | /// | |||
482 | /// This converts the APInt to a boolean value as a test against zero. | |||
483 | bool getBoolValue() const { return !!*this; } | |||
484 | ||||
485 | /// If this value is smaller than the specified limit, return it, otherwise | |||
486 | /// return the limit value. This causes the value to saturate to the limit. | |||
487 | uint64_t getLimitedValue(uint64_t Limit = UINT64_MAX0xffffffffffffffffULL) const { | |||
488 | return ugt(Limit) ? Limit : getZExtValue(); | |||
489 | } | |||
490 | ||||
491 | /// Check if the APInt consists of a repeated bit pattern. | |||
492 | /// | |||
493 | /// e.g. 0x01010101 satisfies isSplat(8). | |||
494 | /// \param SplatSizeInBits The size of the pattern in bits. Must divide bit | |||
495 | /// width without remainder. | |||
496 | bool isSplat(unsigned SplatSizeInBits) const; | |||
497 | ||||
498 | /// \returns true if this APInt value is a sequence of \param numBits ones | |||
499 | /// starting at the least significant bit with the remainder zero. | |||
500 | bool isMask(unsigned numBits) const { | |||
501 | assert(numBits != 0 && "numBits must be non-zero")((void)0); | |||
502 | assert(numBits <= BitWidth && "numBits out of range")((void)0); | |||
503 | if (isSingleWord()) | |||
504 | return U.VAL == (WORDTYPE_MAX >> (APINT_BITS_PER_WORD - numBits)); | |||
505 | unsigned Ones = countTrailingOnesSlowCase(); | |||
506 | return (numBits == Ones) && | |||
507 | ((Ones + countLeadingZerosSlowCase()) == BitWidth); | |||
508 | } | |||
509 | ||||
510 | /// \returns true if this APInt is a non-empty sequence of ones starting at | |||
511 | /// the least significant bit with the remainder zero. | |||
512 | /// Ex. isMask(0x0000FFFFU) == true. | |||
513 | bool isMask() const { | |||
514 | if (isSingleWord()) | |||
515 | return isMask_64(U.VAL); | |||
516 | unsigned Ones = countTrailingOnesSlowCase(); | |||
517 | return (Ones > 0) && ((Ones + countLeadingZerosSlowCase()) == BitWidth); | |||
518 | } | |||
519 | ||||
520 | /// Return true if this APInt value contains a sequence of ones with | |||
521 | /// the remainder zero. | |||
522 | bool isShiftedMask() const { | |||
523 | if (isSingleWord()) | |||
524 | return isShiftedMask_64(U.VAL); | |||
525 | unsigned Ones = countPopulationSlowCase(); | |||
526 | unsigned LeadZ = countLeadingZerosSlowCase(); | |||
527 | return (Ones + LeadZ + countTrailingZeros()) == BitWidth; | |||
528 | } | |||
529 | ||||
530 | /// @} | |||
531 | /// \name Value Generators | |||
532 | /// @{ | |||
533 | ||||
534 | /// Gets maximum unsigned value of APInt for specific bit width. | |||
535 | static APInt getMaxValue(unsigned numBits) { | |||
536 | return getAllOnesValue(numBits); | |||
537 | } | |||
538 | ||||
539 | /// Gets maximum signed value of APInt for a specific bit width. | |||
540 | static APInt getSignedMaxValue(unsigned numBits) { | |||
541 | APInt API = getAllOnesValue(numBits); | |||
542 | API.clearBit(numBits - 1); | |||
543 | return API; | |||
544 | } | |||
545 | ||||
546 | /// Gets minimum unsigned value of APInt for a specific bit width. | |||
547 | static APInt getMinValue(unsigned numBits) { return APInt(numBits, 0); } | |||
548 | ||||
549 | /// Gets minimum signed value of APInt for a specific bit width. | |||
550 | static APInt getSignedMinValue(unsigned numBits) { | |||
551 | APInt API(numBits, 0); | |||
552 | API.setBit(numBits - 1); | |||
553 | return API; | |||
554 | } | |||
555 | ||||
556 | /// Get the SignMask for a specific bit width. | |||
557 | /// | |||
558 | /// This is just a wrapper function of getSignedMinValue(), and it helps code | |||
559 | /// readability when we want to get a SignMask. | |||
560 | static APInt getSignMask(unsigned BitWidth) { | |||
561 | return getSignedMinValue(BitWidth); | |||
562 | } | |||
563 | ||||
564 | /// Get the all-ones value. | |||
565 | /// | |||
566 | /// \returns the all-ones value for an APInt of the specified bit-width. | |||
567 | static APInt getAllOnesValue(unsigned numBits) { | |||
568 | return APInt(numBits, WORDTYPE_MAX, true); | |||
569 | } | |||
570 | ||||
571 | /// Get the '0' value. | |||
572 | /// | |||
573 | /// \returns the '0' value for an APInt of the specified bit-width. | |||
574 | static APInt getNullValue(unsigned numBits) { return APInt(numBits, 0); } | |||
575 | ||||
576 | /// Compute an APInt containing numBits highbits from this APInt. | |||
577 | /// | |||
578 | /// Get an APInt with the same BitWidth as this APInt, just zero mask | |||
579 | /// the low bits and right shift to the least significant bit. | |||
580 | /// | |||
581 | /// \returns the high "numBits" bits of this APInt. | |||
582 | APInt getHiBits(unsigned numBits) const; | |||
583 | ||||
584 | /// Compute an APInt containing numBits lowbits from this APInt. | |||
585 | /// | |||
586 | /// Get an APInt with the same BitWidth as this APInt, just zero mask | |||
587 | /// the high bits. | |||
588 | /// | |||
589 | /// \returns the low "numBits" bits of this APInt. | |||
590 | APInt getLoBits(unsigned numBits) const; | |||
591 | ||||
592 | /// Return an APInt with exactly one bit set in the result. | |||
593 | static APInt getOneBitSet(unsigned numBits, unsigned BitNo) { | |||
594 | APInt Res(numBits, 0); | |||
595 | Res.setBit(BitNo); | |||
596 | return Res; | |||
597 | } | |||
598 | ||||
599 | /// Get a value with a block of bits set. | |||
600 | /// | |||
601 | /// Constructs an APInt value that has a contiguous range of bits set. The | |||
602 | /// bits from loBit (inclusive) to hiBit (exclusive) will be set. All other | |||
603 | /// bits will be zero. For example, with parameters(32, 0, 16) you would get | |||
604 | /// 0x0000FFFF. Please call getBitsSetWithWrap if \p loBit may be greater than | |||
605 | /// \p hiBit. | |||
606 | /// | |||
607 | /// \param numBits the intended bit width of the result | |||
608 | /// \param loBit the index of the lowest bit set. | |||
609 | /// \param hiBit the index of the highest bit set. | |||
610 | /// | |||
611 | /// \returns An APInt value with the requested bits set. | |||
612 | static APInt getBitsSet(unsigned numBits, unsigned loBit, unsigned hiBit) { | |||
613 | assert(loBit <= hiBit && "loBit greater than hiBit")((void)0); | |||
614 | APInt Res(numBits, 0); | |||
615 | Res.setBits(loBit, hiBit); | |||
616 | return Res; | |||
617 | } | |||
618 | ||||
619 | /// Wrap version of getBitsSet. | |||
620 | /// If \p hiBit is bigger than \p loBit, this is same with getBitsSet. | |||
621 | /// If \p hiBit is not bigger than \p loBit, the set bits "wrap". For example, | |||
622 | /// with parameters (32, 28, 4), you would get 0xF000000F. | |||
623 | /// If \p hiBit is equal to \p loBit, you would get a result with all bits | |||
624 | /// set. | |||
625 | static APInt getBitsSetWithWrap(unsigned numBits, unsigned loBit, | |||
626 | unsigned hiBit) { | |||
627 | APInt Res(numBits, 0); | |||
628 | Res.setBitsWithWrap(loBit, hiBit); | |||
629 | return Res; | |||
630 | } | |||
631 | ||||
632 | /// Get a value with upper bits starting at loBit set. | |||
633 | /// | |||
634 | /// Constructs an APInt value that has a contiguous range of bits set. The | |||
635 | /// bits from loBit (inclusive) to numBits (exclusive) will be set. All other | |||
636 | /// bits will be zero. For example, with parameters(32, 12) you would get | |||
637 | /// 0xFFFFF000. | |||
638 | /// | |||
639 | /// \param numBits the intended bit width of the result | |||
640 | /// \param loBit the index of the lowest bit to set. | |||
641 | /// | |||
642 | /// \returns An APInt value with the requested bits set. | |||
643 | static APInt getBitsSetFrom(unsigned numBits, unsigned loBit) { | |||
644 | APInt Res(numBits, 0); | |||
645 | Res.setBitsFrom(loBit); | |||
646 | return Res; | |||
647 | } | |||
648 | ||||
649 | /// Get a value with high bits set | |||
650 | /// | |||
651 | /// Constructs an APInt value that has the top hiBitsSet bits set. | |||
652 | /// | |||
653 | /// \param numBits the bitwidth of the result | |||
654 | /// \param hiBitsSet the number of high-order bits set in the result. | |||
655 | static APInt getHighBitsSet(unsigned numBits, unsigned hiBitsSet) { | |||
656 | APInt Res(numBits, 0); | |||
657 | Res.setHighBits(hiBitsSet); | |||
658 | return Res; | |||
659 | } | |||
660 | ||||
661 | /// Get a value with low bits set | |||
662 | /// | |||
663 | /// Constructs an APInt value that has the bottom loBitsSet bits set. | |||
664 | /// | |||
665 | /// \param numBits the bitwidth of the result | |||
666 | /// \param loBitsSet the number of low-order bits set in the result. | |||
667 | static APInt getLowBitsSet(unsigned numBits, unsigned loBitsSet) { | |||
668 | APInt Res(numBits, 0); | |||
669 | Res.setLowBits(loBitsSet); | |||
670 | return Res; | |||
671 | } | |||
672 | ||||
673 | /// Return a value containing V broadcasted over NewLen bits. | |||
674 | static APInt getSplat(unsigned NewLen, const APInt &V); | |||
675 | ||||
676 | /// Determine if two APInts have the same value, after zero-extending | |||
677 | /// one of them (if needed!) to ensure that the bit-widths match. | |||
678 | static bool isSameValue(const APInt &I1, const APInt &I2) { | |||
679 | if (I1.getBitWidth() == I2.getBitWidth()) | |||
680 | return I1 == I2; | |||
681 | ||||
682 | if (I1.getBitWidth() > I2.getBitWidth()) | |||
683 | return I1 == I2.zext(I1.getBitWidth()); | |||
684 | ||||
685 | return I1.zext(I2.getBitWidth()) == I2; | |||
686 | } | |||
687 | ||||
688 | /// Overload to compute a hash_code for an APInt value. | |||
689 | friend hash_code hash_value(const APInt &Arg); | |||
690 | ||||
691 | /// This function returns a pointer to the internal storage of the APInt. | |||
692 | /// This is useful for writing out the APInt in binary form without any | |||
693 | /// conversions. | |||
694 | const uint64_t *getRawData() const { | |||
695 | if (isSingleWord()) | |||
696 | return &U.VAL; | |||
697 | return &U.pVal[0]; | |||
698 | } | |||
699 | ||||
700 | /// @} | |||
701 | /// \name Unary Operators | |||
702 | /// @{ | |||
703 | ||||
704 | /// Postfix increment operator. | |||
705 | /// | |||
706 | /// Increments *this by 1. | |||
707 | /// | |||
708 | /// \returns a new APInt value representing the original value of *this. | |||
709 | const APInt operator++(int) { | |||
710 | APInt API(*this); | |||
711 | ++(*this); | |||
712 | return API; | |||
713 | } | |||
714 | ||||
715 | /// Prefix increment operator. | |||
716 | /// | |||
717 | /// \returns *this incremented by one | |||
718 | APInt &operator++(); | |||
719 | ||||
720 | /// Postfix decrement operator. | |||
721 | /// | |||
722 | /// Decrements *this by 1. | |||
723 | /// | |||
724 | /// \returns a new APInt value representing the original value of *this. | |||
725 | const APInt operator--(int) { | |||
726 | APInt API(*this); | |||
727 | --(*this); | |||
728 | return API; | |||
729 | } | |||
730 | ||||
731 | /// Prefix decrement operator. | |||
732 | /// | |||
733 | /// \returns *this decremented by one. | |||
734 | APInt &operator--(); | |||
735 | ||||
736 | /// Logical negation operator. | |||
737 | /// | |||
738 | /// Performs logical negation operation on this APInt. | |||
739 | /// | |||
740 | /// \returns true if *this is zero, false otherwise. | |||
741 | bool operator!() const { | |||
742 | if (isSingleWord()) | |||
743 | return U.VAL == 0; | |||
744 | return countLeadingZerosSlowCase() == BitWidth; | |||
745 | } | |||
746 | ||||
747 | /// @} | |||
748 | /// \name Assignment Operators | |||
749 | /// @{ | |||
750 | ||||
751 | /// Copy assignment operator. | |||
752 | /// | |||
753 | /// \returns *this after assignment of RHS. | |||
754 | APInt &operator=(const APInt &RHS) { | |||
755 | // If the bitwidths are the same, we can avoid mucking with memory | |||
756 | if (isSingleWord() && RHS.isSingleWord()) { | |||
757 | U.VAL = RHS.U.VAL; | |||
758 | BitWidth = RHS.BitWidth; | |||
759 | return clearUnusedBits(); | |||
760 | } | |||
761 | ||||
762 | AssignSlowCase(RHS); | |||
763 | return *this; | |||
764 | } | |||
765 | ||||
766 | /// Move assignment operator. | |||
767 | APInt &operator=(APInt &&that) { | |||
768 | #ifdef EXPENSIVE_CHECKS | |||
769 | // Some std::shuffle implementations still do self-assignment. | |||
770 | if (this == &that) | |||
771 | return *this; | |||
772 | #endif | |||
773 | assert(this != &that && "Self-move not supported")((void)0); | |||
774 | if (!isSingleWord()) | |||
775 | delete[] U.pVal; | |||
776 | ||||
777 | // Use memcpy so that type based alias analysis sees both VAL and pVal | |||
778 | // as modified. | |||
779 | memcpy(&U, &that.U, sizeof(U)); | |||
780 | ||||
781 | BitWidth = that.BitWidth; | |||
782 | that.BitWidth = 0; | |||
783 | ||||
784 | return *this; | |||
785 | } | |||
786 | ||||
787 | /// Assignment operator. | |||
788 | /// | |||
789 | /// The RHS value is assigned to *this. If the significant bits in RHS exceed | |||
790 | /// the bit width, the excess bits are truncated. If the bit width is larger | |||
791 | /// than 64, the value is zero filled in the unspecified high order bits. | |||
792 | /// | |||
793 | /// \returns *this after assignment of RHS value. | |||
794 | APInt &operator=(uint64_t RHS) { | |||
795 | if (isSingleWord()) { | |||
796 | U.VAL = RHS; | |||
797 | return clearUnusedBits(); | |||
798 | } | |||
799 | U.pVal[0] = RHS; | |||
800 | memset(U.pVal + 1, 0, (getNumWords() - 1) * APINT_WORD_SIZE); | |||
801 | return *this; | |||
802 | } | |||
803 | ||||
804 | /// Bitwise AND assignment operator. | |||
805 | /// | |||
806 | /// Performs a bitwise AND operation on this APInt and RHS. The result is | |||
807 | /// assigned to *this. | |||
808 | /// | |||
809 | /// \returns *this after ANDing with RHS. | |||
810 | APInt &operator&=(const APInt &RHS) { | |||
811 | assert(BitWidth == RHS.BitWidth && "Bit widths must be the same")((void)0); | |||
812 | if (isSingleWord()) | |||
813 | U.VAL &= RHS.U.VAL; | |||
814 | else | |||
815 | AndAssignSlowCase(RHS); | |||
816 | return *this; | |||
817 | } | |||
818 | ||||
819 | /// Bitwise AND assignment operator. | |||
820 | /// | |||
821 | /// Performs a bitwise AND operation on this APInt and RHS. RHS is | |||
822 | /// logically zero-extended or truncated to match the bit-width of | |||
823 | /// the LHS. | |||
824 | APInt &operator&=(uint64_t RHS) { | |||
825 | if (isSingleWord()) { | |||
826 | U.VAL &= RHS; | |||
827 | return *this; | |||
828 | } | |||
829 | U.pVal[0] &= RHS; | |||
830 | memset(U.pVal+1, 0, (getNumWords() - 1) * APINT_WORD_SIZE); | |||
831 | return *this; | |||
832 | } | |||
833 | ||||
834 | /// Bitwise OR assignment operator. | |||
835 | /// | |||
836 | /// Performs a bitwise OR operation on this APInt and RHS. The result is | |||
837 | /// assigned *this; | |||
838 | /// | |||
839 | /// \returns *this after ORing with RHS. | |||
840 | APInt &operator|=(const APInt &RHS) { | |||
841 | assert(BitWidth == RHS.BitWidth && "Bit widths must be the same")((void)0); | |||
842 | if (isSingleWord()) | |||
843 | U.VAL |= RHS.U.VAL; | |||
844 | else | |||
845 | OrAssignSlowCase(RHS); | |||
846 | return *this; | |||
847 | } | |||
848 | ||||
849 | /// Bitwise OR assignment operator. | |||
850 | /// | |||
851 | /// Performs a bitwise OR operation on this APInt and RHS. RHS is | |||
852 | /// logically zero-extended or truncated to match the bit-width of | |||
853 | /// the LHS. | |||
854 | APInt &operator|=(uint64_t RHS) { | |||
855 | if (isSingleWord()) { | |||
856 | U.VAL |= RHS; | |||
857 | return clearUnusedBits(); | |||
858 | } | |||
859 | U.pVal[0] |= RHS; | |||
860 | return *this; | |||
861 | } | |||
862 | ||||
863 | /// Bitwise XOR assignment operator. | |||
864 | /// | |||
865 | /// Performs a bitwise XOR operation on this APInt and RHS. The result is | |||
866 | /// assigned to *this. | |||
867 | /// | |||
868 | /// \returns *this after XORing with RHS. | |||
869 | APInt &operator^=(const APInt &RHS) { | |||
870 | assert(BitWidth == RHS.BitWidth && "Bit widths must be the same")((void)0); | |||
871 | if (isSingleWord()) | |||
872 | U.VAL ^= RHS.U.VAL; | |||
873 | else | |||
874 | XorAssignSlowCase(RHS); | |||
875 | return *this; | |||
876 | } | |||
877 | ||||
878 | /// Bitwise XOR assignment operator. | |||
879 | /// | |||
880 | /// Performs a bitwise XOR operation on this APInt and RHS. RHS is | |||
881 | /// logically zero-extended or truncated to match the bit-width of | |||
882 | /// the LHS. | |||
883 | APInt &operator^=(uint64_t RHS) { | |||
884 | if (isSingleWord()) { | |||
885 | U.VAL ^= RHS; | |||
886 | return clearUnusedBits(); | |||
887 | } | |||
888 | U.pVal[0] ^= RHS; | |||
889 | return *this; | |||
890 | } | |||
891 | ||||
892 | /// Multiplication assignment operator. | |||
893 | /// | |||
894 | /// Multiplies this APInt by RHS and assigns the result to *this. | |||
895 | /// | |||
896 | /// \returns *this | |||
897 | APInt &operator*=(const APInt &RHS); | |||
898 | APInt &operator*=(uint64_t RHS); | |||
899 | ||||
900 | /// Addition assignment operator. | |||
901 | /// | |||
902 | /// Adds RHS to *this and assigns the result to *this. | |||
903 | /// | |||
904 | /// \returns *this | |||
905 | APInt &operator+=(const APInt &RHS); | |||
906 | APInt &operator+=(uint64_t RHS); | |||
907 | ||||
908 | /// Subtraction assignment operator. | |||
909 | /// | |||
910 | /// Subtracts RHS from *this and assigns the result to *this. | |||
911 | /// | |||
912 | /// \returns *this | |||
913 | APInt &operator-=(const APInt &RHS); | |||
914 | APInt &operator-=(uint64_t RHS); | |||
915 | ||||
916 | /// Left-shift assignment function. | |||
917 | /// | |||
918 | /// Shifts *this left by shiftAmt and assigns the result to *this. | |||
919 | /// | |||
920 | /// \returns *this after shifting left by ShiftAmt | |||
921 | APInt &operator<<=(unsigned ShiftAmt) { | |||
922 | assert(ShiftAmt <= BitWidth && "Invalid shift amount")((void)0); | |||
923 | if (isSingleWord()) { | |||
924 | if (ShiftAmt == BitWidth) | |||
925 | U.VAL = 0; | |||
926 | else | |||
927 | U.VAL <<= ShiftAmt; | |||
928 | return clearUnusedBits(); | |||
929 | } | |||
930 | shlSlowCase(ShiftAmt); | |||
931 | return *this; | |||
932 | } | |||
933 | ||||
934 | /// Left-shift assignment function. | |||
935 | /// | |||
936 | /// Shifts *this left by shiftAmt and assigns the result to *this. | |||
937 | /// | |||
938 | /// \returns *this after shifting left by ShiftAmt | |||
939 | APInt &operator<<=(const APInt &ShiftAmt); | |||
940 | ||||
941 | /// @} | |||
942 | /// \name Binary Operators | |||
943 | /// @{ | |||
944 | ||||
945 | /// Multiplication operator. | |||
946 | /// | |||
947 | /// Multiplies this APInt by RHS and returns the result. | |||
948 | APInt operator*(const APInt &RHS) const; | |||
949 | ||||
950 | /// Left logical shift operator. | |||
951 | /// | |||
952 | /// Shifts this APInt left by \p Bits and returns the result. | |||
953 | APInt operator<<(unsigned Bits) const { return shl(Bits); } | |||
954 | ||||
955 | /// Left logical shift operator. | |||
956 | /// | |||
957 | /// Shifts this APInt left by \p Bits and returns the result. | |||
958 | APInt operator<<(const APInt &Bits) const { return shl(Bits); } | |||
959 | ||||
960 | /// Arithmetic right-shift function. | |||
961 | /// | |||
962 | /// Arithmetic right-shift this APInt by shiftAmt. | |||
963 | APInt ashr(unsigned ShiftAmt) const { | |||
964 | APInt R(*this); | |||
965 | R.ashrInPlace(ShiftAmt); | |||
966 | return R; | |||
967 | } | |||
968 | ||||
969 | /// Arithmetic right-shift this APInt by ShiftAmt in place. | |||
970 | void ashrInPlace(unsigned ShiftAmt) { | |||
971 | assert(ShiftAmt <= BitWidth && "Invalid shift amount")((void)0); | |||
972 | if (isSingleWord()) { | |||
973 | int64_t SExtVAL = SignExtend64(U.VAL, BitWidth); | |||
974 | if (ShiftAmt == BitWidth) | |||
975 | U.VAL = SExtVAL >> (APINT_BITS_PER_WORD - 1); // Fill with sign bit. | |||
976 | else | |||
977 | U.VAL = SExtVAL >> ShiftAmt; | |||
978 | clearUnusedBits(); | |||
979 | return; | |||
980 | } | |||
981 | ashrSlowCase(ShiftAmt); | |||
982 | } | |||
983 | ||||
984 | /// Logical right-shift function. | |||
985 | /// | |||
986 | /// Logical right-shift this APInt by shiftAmt. | |||
987 | APInt lshr(unsigned shiftAmt) const { | |||
988 | APInt R(*this); | |||
989 | R.lshrInPlace(shiftAmt); | |||
990 | return R; | |||
991 | } | |||
992 | ||||
993 | /// Logical right-shift this APInt by ShiftAmt in place. | |||
994 | void lshrInPlace(unsigned ShiftAmt) { | |||
995 | assert(ShiftAmt <= BitWidth && "Invalid shift amount")((void)0); | |||
996 | if (isSingleWord()) { | |||
997 | if (ShiftAmt == BitWidth) | |||
998 | U.VAL = 0; | |||
999 | else | |||
1000 | U.VAL >>= ShiftAmt; | |||
1001 | return; | |||
1002 | } | |||
1003 | lshrSlowCase(ShiftAmt); | |||
1004 | } | |||
1005 | ||||
1006 | /// Left-shift function. | |||
1007 | /// | |||
1008 | /// Left-shift this APInt by shiftAmt. | |||
1009 | APInt shl(unsigned shiftAmt) const { | |||
1010 | APInt R(*this); | |||
1011 | R <<= shiftAmt; | |||
1012 | return R; | |||
1013 | } | |||
1014 | ||||
1015 | /// Rotate left by rotateAmt. | |||
1016 | APInt rotl(unsigned rotateAmt) const; | |||
1017 | ||||
1018 | /// Rotate right by rotateAmt. | |||
1019 | APInt rotr(unsigned rotateAmt) const; | |||
1020 | ||||
1021 | /// Arithmetic right-shift function. | |||
1022 | /// | |||
1023 | /// Arithmetic right-shift this APInt by shiftAmt. | |||
1024 | APInt ashr(const APInt &ShiftAmt) const { | |||
1025 | APInt R(*this); | |||
1026 | R.ashrInPlace(ShiftAmt); | |||
1027 | return R; | |||
1028 | } | |||
1029 | ||||
1030 | /// Arithmetic right-shift this APInt by shiftAmt in place. | |||
1031 | void ashrInPlace(const APInt &shiftAmt); | |||
1032 | ||||
1033 | /// Logical right-shift function. | |||
1034 | /// | |||
1035 | /// Logical right-shift this APInt by shiftAmt. | |||
1036 | APInt lshr(const APInt &ShiftAmt) const { | |||
1037 | APInt R(*this); | |||
1038 | R.lshrInPlace(ShiftAmt); | |||
1039 | return R; | |||
1040 | } | |||
1041 | ||||
1042 | /// Logical right-shift this APInt by ShiftAmt in place. | |||
1043 | void lshrInPlace(const APInt &ShiftAmt); | |||
1044 | ||||
1045 | /// Left-shift function. | |||
1046 | /// | |||
1047 | /// Left-shift this APInt by shiftAmt. | |||
1048 | APInt shl(const APInt &ShiftAmt) const { | |||
1049 | APInt R(*this); | |||
1050 | R <<= ShiftAmt; | |||
1051 | return R; | |||
1052 | } | |||
1053 | ||||
1054 | /// Rotate left by rotateAmt. | |||
1055 | APInt rotl(const APInt &rotateAmt) const; | |||
1056 | ||||
1057 | /// Rotate right by rotateAmt. | |||
1058 | APInt rotr(const APInt &rotateAmt) const; | |||
1059 | ||||
1060 | /// Unsigned division operation. | |||
1061 | /// | |||
1062 | /// Perform an unsigned divide operation on this APInt by RHS. Both this and | |||
1063 | /// RHS are treated as unsigned quantities for purposes of this division. | |||
1064 | /// | |||
1065 | /// \returns a new APInt value containing the division result, rounded towards | |||
1066 | /// zero. | |||
1067 | APInt udiv(const APInt &RHS) const; | |||
1068 | APInt udiv(uint64_t RHS) const; | |||
1069 | ||||
1070 | /// Signed division function for APInt. | |||
1071 | /// | |||
1072 | /// Signed divide this APInt by APInt RHS. | |||
1073 | /// | |||
1074 | /// The result is rounded towards zero. | |||
1075 | APInt sdiv(const APInt &RHS) const; | |||
1076 | APInt sdiv(int64_t RHS) const; | |||
1077 | ||||
1078 | /// Unsigned remainder operation. | |||
1079 | /// | |||
1080 | /// Perform an unsigned remainder operation on this APInt with RHS being the | |||
1081 | /// divisor. Both this and RHS are treated as unsigned quantities for purposes | |||
1082 | /// of this operation. Note that this is a true remainder operation and not a | |||
1083 | /// modulo operation because the sign follows the sign of the dividend which | |||
1084 | /// is *this. | |||
1085 | /// | |||
1086 | /// \returns a new APInt value containing the remainder result | |||
1087 | APInt urem(const APInt &RHS) const; | |||
1088 | uint64_t urem(uint64_t RHS) const; | |||
1089 | ||||
1090 | /// Function for signed remainder operation. | |||
1091 | /// | |||
1092 | /// Signed remainder operation on APInt. | |||
1093 | APInt srem(const APInt &RHS) const; | |||
1094 | int64_t srem(int64_t RHS) const; | |||
1095 | ||||
1096 | /// Dual division/remainder interface. | |||
1097 | /// | |||
1098 | /// Sometimes it is convenient to divide two APInt values and obtain both the | |||
1099 | /// quotient and remainder. This function does both operations in the same | |||
1100 | /// computation making it a little more efficient. The pair of input arguments | |||
1101 | /// may overlap with the pair of output arguments. It is safe to call | |||
1102 | /// udivrem(X, Y, X, Y), for example. | |||
1103 | static void udivrem(const APInt &LHS, const APInt &RHS, APInt &Quotient, | |||
1104 | APInt &Remainder); | |||
1105 | static void udivrem(const APInt &LHS, uint64_t RHS, APInt &Quotient, | |||
1106 | uint64_t &Remainder); | |||
1107 | ||||
1108 | static void sdivrem(const APInt &LHS, const APInt &RHS, APInt &Quotient, | |||
1109 | APInt &Remainder); | |||
1110 | static void sdivrem(const APInt &LHS, int64_t RHS, APInt &Quotient, | |||
1111 | int64_t &Remainder); | |||
1112 | ||||
1113 | // Operations that return overflow indicators. | |||
1114 | APInt sadd_ov(const APInt &RHS, bool &Overflow) const; | |||
1115 | APInt uadd_ov(const APInt &RHS, bool &Overflow) const; | |||
1116 | APInt ssub_ov(const APInt &RHS, bool &Overflow) const; | |||
1117 | APInt usub_ov(const APInt &RHS, bool &Overflow) const; | |||
1118 | APInt sdiv_ov(const APInt &RHS, bool &Overflow) const; | |||
1119 | APInt smul_ov(const APInt &RHS, bool &Overflow) const; | |||
1120 | APInt umul_ov(const APInt &RHS, bool &Overflow) const; | |||
1121 | APInt sshl_ov(const APInt &Amt, bool &Overflow) const; | |||
1122 | APInt ushl_ov(const APInt &Amt, bool &Overflow) const; | |||
1123 | ||||
1124 | // Operations that saturate | |||
1125 | APInt sadd_sat(const APInt &RHS) const; | |||
1126 | APInt uadd_sat(const APInt &RHS) const; | |||
1127 | APInt ssub_sat(const APInt &RHS) const; | |||
1128 | APInt usub_sat(const APInt &RHS) const; | |||
1129 | APInt smul_sat(const APInt &RHS) const; | |||
1130 | APInt umul_sat(const APInt &RHS) const; | |||
1131 | APInt sshl_sat(const APInt &RHS) const; | |||
1132 | APInt ushl_sat(const APInt &RHS) const; | |||
1133 | ||||
1134 | /// Array-indexing support. | |||
1135 | /// | |||
1136 | /// \returns the bit value at bitPosition | |||
1137 | bool operator[](unsigned bitPosition) const { | |||
1138 | assert(bitPosition < getBitWidth() && "Bit position out of bounds!")((void)0); | |||
1139 | return (maskBit(bitPosition) & getWord(bitPosition)) != 0; | |||
1140 | } | |||
1141 | ||||
1142 | /// @} | |||
1143 | /// \name Comparison Operators | |||
1144 | /// @{ | |||
1145 | ||||
1146 | /// Equality operator. | |||
1147 | /// | |||
1148 | /// Compares this APInt with RHS for the validity of the equality | |||
1149 | /// relationship. | |||
1150 | bool operator==(const APInt &RHS) const { | |||
1151 | assert(BitWidth == RHS.BitWidth && "Comparison requires equal bit widths")((void)0); | |||
1152 | if (isSingleWord()) | |||
1153 | return U.VAL == RHS.U.VAL; | |||
1154 | return EqualSlowCase(RHS); | |||
1155 | } | |||
1156 | ||||
1157 | /// Equality operator. | |||
1158 | /// | |||
1159 | /// Compares this APInt with a uint64_t for the validity of the equality | |||
1160 | /// relationship. | |||
1161 | /// | |||
1162 | /// \returns true if *this == Val | |||
1163 | bool operator==(uint64_t Val) const { | |||
1164 | return (isSingleWord() || getActiveBits() <= 64) && getZExtValue() == Val; | |||
1165 | } | |||
1166 | ||||
1167 | /// Equality comparison. | |||
1168 | /// | |||
1169 | /// Compares this APInt with RHS for the validity of the equality | |||
1170 | /// relationship. | |||
1171 | /// | |||
1172 | /// \returns true if *this == Val | |||
1173 | bool eq(const APInt &RHS) const { return (*this) == RHS; } | |||
1174 | ||||
1175 | /// Inequality operator. | |||
1176 | /// | |||
1177 | /// Compares this APInt with RHS for the validity of the inequality | |||
1178 | /// relationship. | |||
1179 | /// | |||
1180 | /// \returns true if *this != Val | |||
1181 | bool operator!=(const APInt &RHS) const { return !((*this) == RHS); } | |||
1182 | ||||
1183 | /// Inequality operator. | |||
1184 | /// | |||
1185 | /// Compares this APInt with a uint64_t for the validity of the inequality | |||
1186 | /// relationship. | |||
1187 | /// | |||
1188 | /// \returns true if *this != Val | |||
1189 | bool operator!=(uint64_t Val) const { return !((*this) == Val); } | |||
1190 | ||||
1191 | /// Inequality comparison | |||
1192 | /// | |||
1193 | /// Compares this APInt with RHS for the validity of the inequality | |||
1194 | /// relationship. | |||
1195 | /// | |||
1196 | /// \returns true if *this != Val | |||
1197 | bool ne(const APInt &RHS) const { return !((*this) == RHS); } | |||
1198 | ||||
1199 | /// Unsigned less than comparison | |||
1200 | /// | |||
1201 | /// Regards both *this and RHS as unsigned quantities and compares them for | |||
1202 | /// the validity of the less-than relationship. | |||
1203 | /// | |||
1204 | /// \returns true if *this < RHS when both are considered unsigned. | |||
1205 | bool ult(const APInt &RHS) const { return compare(RHS) < 0; } | |||
1206 | ||||
1207 | /// Unsigned less than comparison | |||
1208 | /// | |||
1209 | /// Regards both *this as an unsigned quantity and compares it with RHS for | |||
1210 | /// the validity of the less-than relationship. | |||
1211 | /// | |||
1212 | /// \returns true if *this < RHS when considered unsigned. | |||
1213 | bool ult(uint64_t RHS) const { | |||
1214 | // Only need to check active bits if not a single word. | |||
1215 | return (isSingleWord() || getActiveBits() <= 64) && getZExtValue() < RHS; | |||
1216 | } | |||
1217 | ||||
1218 | /// Signed less than comparison | |||
1219 | /// | |||
1220 | /// Regards both *this and RHS as signed quantities and compares them for | |||
1221 | /// validity of the less-than relationship. | |||
1222 | /// | |||
1223 | /// \returns true if *this < RHS when both are considered signed. | |||
1224 | bool slt(const APInt &RHS) const { return compareSigned(RHS) < 0; } | |||
1225 | ||||
1226 | /// Signed less than comparison | |||
1227 | /// | |||
1228 | /// Regards both *this as a signed quantity and compares it with RHS for | |||
1229 | /// the validity of the less-than relationship. | |||
1230 | /// | |||
1231 | /// \returns true if *this < RHS when considered signed. | |||
1232 | bool slt(int64_t RHS) const { | |||
1233 | return (!isSingleWord() && getMinSignedBits() > 64) ? isNegative() | |||
1234 | : getSExtValue() < RHS; | |||
1235 | } | |||
1236 | ||||
1237 | /// Unsigned less or equal comparison | |||
1238 | /// | |||
1239 | /// Regards both *this and RHS as unsigned quantities and compares them for | |||
1240 | /// validity of the less-or-equal relationship. | |||
1241 | /// | |||
1242 | /// \returns true if *this <= RHS when both are considered unsigned. | |||
1243 | bool ule(const APInt &RHS) const { return compare(RHS) <= 0; } | |||
1244 | ||||
1245 | /// Unsigned less or equal comparison | |||
1246 | /// | |||
1247 | /// Regards both *this as an unsigned quantity and compares it with RHS for | |||
1248 | /// the validity of the less-or-equal relationship. | |||
1249 | /// | |||
1250 | /// \returns true if *this <= RHS when considered unsigned. | |||
1251 | bool ule(uint64_t RHS) const { return !ugt(RHS); } | |||
1252 | ||||
1253 | /// Signed less or equal comparison | |||
1254 | /// | |||
1255 | /// Regards both *this and RHS as signed quantities and compares them for | |||
1256 | /// validity of the less-or-equal relationship. | |||
1257 | /// | |||
1258 | /// \returns true if *this <= RHS when both are considered signed. | |||
1259 | bool sle(const APInt &RHS) const { return compareSigned(RHS) <= 0; } | |||
1260 | ||||
1261 | /// Signed less or equal comparison | |||
1262 | /// | |||
1263 | /// Regards both *this as a signed quantity and compares it with RHS for the | |||
1264 | /// validity of the less-or-equal relationship. | |||
1265 | /// | |||
1266 | /// \returns true if *this <= RHS when considered signed. | |||
1267 | bool sle(uint64_t RHS) const { return !sgt(RHS); } | |||
1268 | ||||
1269 | /// Unsigned greater than comparison | |||
1270 | /// | |||
1271 | /// Regards both *this and RHS as unsigned quantities and compares them for | |||
1272 | /// the validity of the greater-than relationship. | |||
1273 | /// | |||
1274 | /// \returns true if *this > RHS when both are considered unsigned. | |||
1275 | bool ugt(const APInt &RHS) const { return !ule(RHS); } | |||
1276 | ||||
1277 | /// Unsigned greater than comparison | |||
1278 | /// | |||
1279 | /// Regards both *this as an unsigned quantity and compares it with RHS for | |||
1280 | /// the validity of the greater-than relationship. | |||
1281 | /// | |||
1282 | /// \returns true if *this > RHS when considered unsigned. | |||
1283 | bool ugt(uint64_t RHS) const { | |||
1284 | // Only need to check active bits if not a single word. | |||
1285 | return (!isSingleWord() && getActiveBits() > 64) || getZExtValue() > RHS; | |||
1286 | } | |||
1287 | ||||
1288 | /// Signed greater than comparison | |||
1289 | /// | |||
1290 | /// Regards both *this and RHS as signed quantities and compares them for the | |||
1291 | /// validity of the greater-than relationship. | |||
1292 | /// | |||
1293 | /// \returns true if *this > RHS when both are considered signed. | |||
1294 | bool sgt(const APInt &RHS) const { return !sle(RHS); } | |||
1295 | ||||
1296 | /// Signed greater than comparison | |||
1297 | /// | |||
1298 | /// Regards both *this as a signed quantity and compares it with RHS for | |||
1299 | /// the validity of the greater-than relationship. | |||
1300 | /// | |||
1301 | /// \returns true if *this > RHS when considered signed. | |||
1302 | bool sgt(int64_t RHS) const { | |||
1303 | return (!isSingleWord() && getMinSignedBits() > 64) ? !isNegative() | |||
1304 | : getSExtValue() > RHS; | |||
1305 | } | |||
1306 | ||||
1307 | /// Unsigned greater or equal comparison | |||
1308 | /// | |||
1309 | /// Regards both *this and RHS as unsigned quantities and compares them for | |||
1310 | /// validity of the greater-or-equal relationship. | |||
1311 | /// | |||
1312 | /// \returns true if *this >= RHS when both are considered unsigned. | |||
1313 | bool uge(const APInt &RHS) const { return !ult(RHS); } | |||
1314 | ||||
1315 | /// Unsigned greater or equal comparison | |||
1316 | /// | |||
1317 | /// Regards both *this as an unsigned quantity and compares it with RHS for | |||
1318 | /// the validity of the greater-or-equal relationship. | |||
1319 | /// | |||
1320 | /// \returns true if *this >= RHS when considered unsigned. | |||
1321 | bool uge(uint64_t RHS) const { return !ult(RHS); } | |||
1322 | ||||
1323 | /// Signed greater or equal comparison | |||
1324 | /// | |||
1325 | /// Regards both *this and RHS as signed quantities and compares them for | |||
1326 | /// validity of the greater-or-equal relationship. | |||
1327 | /// | |||
1328 | /// \returns true if *this >= RHS when both are considered signed. | |||
1329 | bool sge(const APInt &RHS) const { return !slt(RHS); } | |||
1330 | ||||
1331 | /// Signed greater or equal comparison | |||
1332 | /// | |||
1333 | /// Regards both *this as a signed quantity and compares it with RHS for | |||
1334 | /// the validity of the greater-or-equal relationship. | |||
1335 | /// | |||
1336 | /// \returns true if *this >= RHS when considered signed. | |||
1337 | bool sge(int64_t RHS) const { return !slt(RHS); } | |||
1338 | ||||
1339 | /// This operation tests if there are any pairs of corresponding bits | |||
1340 | /// between this APInt and RHS that are both set. | |||
1341 | bool intersects(const APInt &RHS) const { | |||
1342 | assert(BitWidth == RHS.BitWidth && "Bit widths must be the same")((void)0); | |||
1343 | if (isSingleWord()) | |||
1344 | return (U.VAL & RHS.U.VAL) != 0; | |||
1345 | return intersectsSlowCase(RHS); | |||
1346 | } | |||
1347 | ||||
1348 | /// This operation checks that all bits set in this APInt are also set in RHS. | |||
1349 | bool isSubsetOf(const APInt &RHS) const { | |||
1350 | assert(BitWidth == RHS.BitWidth && "Bit widths must be the same")((void)0); | |||
1351 | if (isSingleWord()) | |||
1352 | return (U.VAL & ~RHS.U.VAL) == 0; | |||
1353 | return isSubsetOfSlowCase(RHS); | |||
1354 | } | |||
1355 | ||||
1356 | /// @} | |||
1357 | /// \name Resizing Operators | |||
1358 | /// @{ | |||
1359 | ||||
1360 | /// Truncate to new width. | |||
1361 | /// | |||
1362 | /// Truncate the APInt to a specified width. It is an error to specify a width | |||
1363 | /// that is greater than or equal to the current width. | |||
1364 | APInt trunc(unsigned width) const; | |||
1365 | ||||
1366 | /// Truncate to new width with unsigned saturation. | |||
1367 | /// | |||
1368 | /// If the APInt, treated as unsigned integer, can be losslessly truncated to | |||
1369 | /// the new bitwidth, then return truncated APInt. Else, return max value. | |||
1370 | APInt truncUSat(unsigned width) const; | |||
1371 | ||||
1372 | /// Truncate to new width with signed saturation. | |||
1373 | /// | |||
1374 | /// If this APInt, treated as signed integer, can be losslessly truncated to | |||
1375 | /// the new bitwidth, then return truncated APInt. Else, return either | |||
1376 | /// signed min value if the APInt was negative, or signed max value. | |||
1377 | APInt truncSSat(unsigned width) const; | |||
1378 | ||||
1379 | /// Sign extend to a new width. | |||
1380 | /// | |||
1381 | /// This operation sign extends the APInt to a new width. If the high order | |||
1382 | /// bit is set, the fill on the left will be done with 1 bits, otherwise zero. | |||
1383 | /// It is an error to specify a width that is less than or equal to the | |||
1384 | /// current width. | |||
1385 | APInt sext(unsigned width) const; | |||
1386 | ||||
1387 | /// Zero extend to a new width. | |||
1388 | /// | |||
1389 | /// This operation zero extends the APInt to a new width. The high order bits | |||
1390 | /// are filled with 0 bits. It is an error to specify a width that is less | |||
1391 | /// than or equal to the current width. | |||
1392 | APInt zext(unsigned width) const; | |||
1393 | ||||
1394 | /// Sign extend or truncate to width | |||
1395 | /// | |||
1396 | /// Make this APInt have the bit width given by \p width. The value is sign | |||
1397 | /// extended, truncated, or left alone to make it that width. | |||
1398 | APInt sextOrTrunc(unsigned width) const; | |||
1399 | ||||
1400 | /// Zero extend or truncate to width | |||
1401 | /// | |||
1402 | /// Make this APInt have the bit width given by \p width. The value is zero | |||
1403 | /// extended, truncated, or left alone to make it that width. | |||
1404 | APInt zextOrTrunc(unsigned width) const; | |||
1405 | ||||
1406 | /// Truncate to width | |||
1407 | /// | |||
1408 | /// Make this APInt have the bit width given by \p width. The value is | |||
1409 | /// truncated or left alone to make it that width. | |||
1410 | APInt truncOrSelf(unsigned width) const; | |||
1411 | ||||
1412 | /// Sign extend or truncate to width | |||
1413 | /// | |||
1414 | /// Make this APInt have the bit width given by \p width. The value is sign | |||
1415 | /// extended, or left alone to make it that width. | |||
1416 | APInt sextOrSelf(unsigned width) const; | |||
1417 | ||||
1418 | /// Zero extend or truncate to width | |||
1419 | /// | |||
1420 | /// Make this APInt have the bit width given by \p width. The value is zero | |||
1421 | /// extended, or left alone to make it that width. | |||
1422 | APInt zextOrSelf(unsigned width) const; | |||
1423 | ||||
1424 | /// @} | |||
1425 | /// \name Bit Manipulation Operators | |||
1426 | /// @{ | |||
1427 | ||||
1428 | /// Set every bit to 1. | |||
1429 | void setAllBits() { | |||
1430 | if (isSingleWord()) | |||
1431 | U.VAL = WORDTYPE_MAX; | |||
1432 | else | |||
1433 | // Set all the bits in all the words. | |||
1434 | memset(U.pVal, -1, getNumWords() * APINT_WORD_SIZE); | |||
1435 | // Clear the unused ones | |||
1436 | clearUnusedBits(); | |||
1437 | } | |||
1438 | ||||
1439 | /// Set a given bit to 1. | |||
1440 | /// | |||
1441 | /// Set the given bit to 1 whose position is given as "bitPosition". | |||
1442 | void setBit(unsigned BitPosition) { | |||
1443 | assert(BitPosition < BitWidth && "BitPosition out of range")((void)0); | |||
1444 | WordType Mask = maskBit(BitPosition); | |||
1445 | if (isSingleWord()) | |||
1446 | U.VAL |= Mask; | |||
1447 | else | |||
1448 | U.pVal[whichWord(BitPosition)] |= Mask; | |||
1449 | } | |||
1450 | ||||
1451 | /// Set the sign bit to 1. | |||
1452 | void setSignBit() { | |||
1453 | setBit(BitWidth - 1); | |||
1454 | } | |||
1455 | ||||
1456 | /// Set a given bit to a given value. | |||
1457 | void setBitVal(unsigned BitPosition, bool BitValue) { | |||
1458 | if (BitValue) | |||
1459 | setBit(BitPosition); | |||
1460 | else | |||
1461 | clearBit(BitPosition); | |||
1462 | } | |||
1463 | ||||
1464 | /// Set the bits from loBit (inclusive) to hiBit (exclusive) to 1. | |||
1465 | /// This function handles "wrap" case when \p loBit >= \p hiBit, and calls | |||
1466 | /// setBits when \p loBit < \p hiBit. | |||
1467 | /// For \p loBit == \p hiBit wrap case, set every bit to 1. | |||
1468 | void setBitsWithWrap(unsigned loBit, unsigned hiBit) { | |||
1469 | assert(hiBit <= BitWidth && "hiBit out of range")((void)0); | |||
1470 | assert(loBit <= BitWidth && "loBit out of range")((void)0); | |||
1471 | if (loBit < hiBit) { | |||
1472 | setBits(loBit, hiBit); | |||
1473 | return; | |||
1474 | } | |||
1475 | setLowBits(hiBit); | |||
1476 | setHighBits(BitWidth - loBit); | |||
1477 | } | |||
1478 | ||||
1479 | /// Set the bits from loBit (inclusive) to hiBit (exclusive) to 1. | |||
1480 | /// This function handles case when \p loBit <= \p hiBit. | |||
1481 | void setBits(unsigned loBit, unsigned hiBit) { | |||
1482 | assert(hiBit <= BitWidth && "hiBit out of range")((void)0); | |||
1483 | assert(loBit <= BitWidth && "loBit out of range")((void)0); | |||
1484 | assert(loBit <= hiBit && "loBit greater than hiBit")((void)0); | |||
1485 | if (loBit == hiBit) | |||
1486 | return; | |||
1487 | if (loBit < APINT_BITS_PER_WORD && hiBit <= APINT_BITS_PER_WORD) { | |||
1488 | uint64_t mask = WORDTYPE_MAX >> (APINT_BITS_PER_WORD - (hiBit - loBit)); | |||
1489 | mask <<= loBit; | |||
1490 | if (isSingleWord()) | |||
1491 | U.VAL |= mask; | |||
1492 | else | |||
1493 | U.pVal[0] |= mask; | |||
1494 | } else { | |||
1495 | setBitsSlowCase(loBit, hiBit); | |||
1496 | } | |||
1497 | } | |||
1498 | ||||
1499 | /// Set the top bits starting from loBit. | |||
1500 | void setBitsFrom(unsigned loBit) { | |||
1501 | return setBits(loBit, BitWidth); | |||
1502 | } | |||
1503 | ||||
1504 | /// Set the bottom loBits bits. | |||
1505 | void setLowBits(unsigned loBits) { | |||
1506 | return setBits(0, loBits); | |||
1507 | } | |||
1508 | ||||
1509 | /// Set the top hiBits bits. | |||
1510 | void setHighBits(unsigned hiBits) { | |||
1511 | return setBits(BitWidth - hiBits, BitWidth); | |||
1512 | } | |||
1513 | ||||
1514 | /// Set every bit to 0. | |||
1515 | void clearAllBits() { | |||
1516 | if (isSingleWord()) | |||
1517 | U.VAL = 0; | |||
1518 | else | |||
1519 | memset(U.pVal, 0, getNumWords() * APINT_WORD_SIZE); | |||
1520 | } | |||
1521 | ||||
1522 | /// Set a given bit to 0. | |||
1523 | /// | |||
1524 | /// Set the given bit to 0 whose position is given as "bitPosition". | |||
1525 | void clearBit(unsigned BitPosition) { | |||
1526 | assert(BitPosition < BitWidth && "BitPosition out of range")((void)0); | |||
1527 | WordType Mask = ~maskBit(BitPosition); | |||
1528 | if (isSingleWord()) | |||
1529 | U.VAL &= Mask; | |||
1530 | else | |||
1531 | U.pVal[whichWord(BitPosition)] &= Mask; | |||
1532 | } | |||
1533 | ||||
1534 | /// Set bottom loBits bits to 0. | |||
1535 | void clearLowBits(unsigned loBits) { | |||
1536 | assert(loBits <= BitWidth && "More bits than bitwidth")((void)0); | |||
1537 | APInt Keep = getHighBitsSet(BitWidth, BitWidth - loBits); | |||
1538 | *this &= Keep; | |||
1539 | } | |||
1540 | ||||
1541 | /// Set the sign bit to 0. | |||
1542 | void clearSignBit() { | |||
1543 | clearBit(BitWidth - 1); | |||
1544 | } | |||
1545 | ||||
1546 | /// Toggle every bit to its opposite value. | |||
1547 | void flipAllBits() { | |||
1548 | if (isSingleWord()) { | |||
1549 | U.VAL ^= WORDTYPE_MAX; | |||
1550 | clearUnusedBits(); | |||
1551 | } else { | |||
1552 | flipAllBitsSlowCase(); | |||
1553 | } | |||
1554 | } | |||
1555 | ||||
1556 | /// Toggles a given bit to its opposite value. | |||
1557 | /// | |||
1558 | /// Toggle a given bit to its opposite value whose position is given | |||
1559 | /// as "bitPosition". | |||
1560 | void flipBit(unsigned bitPosition); | |||
1561 | ||||
1562 | /// Negate this APInt in place. | |||
1563 | void negate() { | |||
1564 | flipAllBits(); | |||
1565 | ++(*this); | |||
1566 | } | |||
1567 | ||||
1568 | /// Insert the bits from a smaller APInt starting at bitPosition. | |||
1569 | void insertBits(const APInt &SubBits, unsigned bitPosition); | |||
1570 | void insertBits(uint64_t SubBits, unsigned bitPosition, unsigned numBits); | |||
1571 | ||||
1572 | /// Return an APInt with the extracted bits [bitPosition,bitPosition+numBits). | |||
1573 | APInt extractBits(unsigned numBits, unsigned bitPosition) const; | |||
1574 | uint64_t extractBitsAsZExtValue(unsigned numBits, unsigned bitPosition) const; | |||
1575 | ||||
1576 | /// @} | |||
1577 | /// \name Value Characterization Functions | |||
1578 | /// @{ | |||
1579 | ||||
1580 | /// Return the number of bits in the APInt. | |||
1581 | unsigned getBitWidth() const { return BitWidth; } | |||
1582 | ||||
1583 | /// Get the number of words. | |||
1584 | /// | |||
1585 | /// Here one word's bitwidth equals to that of uint64_t. | |||
1586 | /// | |||
1587 | /// \returns the number of words to hold the integer value of this APInt. | |||
1588 | unsigned getNumWords() const { return getNumWords(BitWidth); } | |||
1589 | ||||
1590 | /// Get the number of words. | |||
1591 | /// | |||
1592 | /// *NOTE* Here one word's bitwidth equals to that of uint64_t. | |||
1593 | /// | |||
1594 | /// \returns the number of words to hold the integer value with a given bit | |||
1595 | /// width. | |||
1596 | static unsigned getNumWords(unsigned BitWidth) { | |||
1597 | return ((uint64_t)BitWidth + APINT_BITS_PER_WORD - 1) / APINT_BITS_PER_WORD; | |||
1598 | } | |||
1599 | ||||
1600 | /// Compute the number of active bits in the value | |||
1601 | /// | |||
1602 | /// This function returns the number of active bits which is defined as the | |||
1603 | /// bit width minus the number of leading zeros. This is used in several | |||
1604 | /// computations to see how "wide" the value is. | |||
1605 | unsigned getActiveBits() const { return BitWidth - countLeadingZeros(); } | |||
1606 | ||||
1607 | /// Compute the number of active words in the value of this APInt. | |||
1608 | /// | |||
1609 | /// This is used in conjunction with getActiveData to extract the raw value of | |||
1610 | /// the APInt. | |||
1611 | unsigned getActiveWords() const { | |||
1612 | unsigned numActiveBits = getActiveBits(); | |||
1613 | return numActiveBits ? whichWord(numActiveBits - 1) + 1 : 1; | |||
1614 | } | |||
1615 | ||||
1616 | /// Get the minimum bit size for this signed APInt | |||
1617 | /// | |||
1618 | /// Computes the minimum bit width for this APInt while considering it to be a | |||
1619 | /// signed (and probably negative) value. If the value is not negative, this | |||
1620 | /// function returns the same value as getActiveBits()+1. Otherwise, it | |||
1621 | /// returns the smallest bit width that will retain the negative value. For | |||
1622 | /// example, -1 can be written as 0b1 or 0xFFFFFFFFFF. 0b1 is shorter and so | |||
1623 | /// for -1, this function will always return 1. | |||
1624 | unsigned getMinSignedBits() const { return BitWidth - getNumSignBits() + 1; } | |||
1625 | ||||
1626 | /// Get zero extended value | |||
1627 | /// | |||
1628 | /// This method attempts to return the value of this APInt as a zero extended | |||
1629 | /// uint64_t. The bitwidth must be <= 64 or the value must fit within a | |||
1630 | /// uint64_t. Otherwise an assertion will result. | |||
1631 | uint64_t getZExtValue() const { | |||
1632 | if (isSingleWord()) | |||
1633 | return U.VAL; | |||
1634 | assert(getActiveBits() <= 64 && "Too many bits for uint64_t")((void)0); | |||
1635 | return U.pVal[0]; | |||
1636 | } | |||
1637 | ||||
1638 | /// Get sign extended value | |||
1639 | /// | |||
1640 | /// This method attempts to return the value of this APInt as a sign extended | |||
1641 | /// int64_t. The bit width must be <= 64 or the value must fit within an | |||
1642 | /// int64_t. Otherwise an assertion will result. | |||
1643 | int64_t getSExtValue() const { | |||
1644 | if (isSingleWord()) | |||
1645 | return SignExtend64(U.VAL, BitWidth); | |||
1646 | assert(getMinSignedBits() <= 64 && "Too many bits for int64_t")((void)0); | |||
1647 | return int64_t(U.pVal[0]); | |||
1648 | } | |||
1649 | ||||
1650 | /// Get bits required for string value. | |||
1651 | /// | |||
1652 | /// This method determines how many bits are required to hold the APInt | |||
1653 | /// equivalent of the string given by \p str. | |||
1654 | static unsigned getBitsNeeded(StringRef str, uint8_t radix); | |||
1655 | ||||
1656 | /// The APInt version of the countLeadingZeros functions in | |||
1657 | /// MathExtras.h. | |||
1658 | /// | |||
1659 | /// It counts the number of zeros from the most significant bit to the first | |||
1660 | /// one bit. | |||
1661 | /// | |||
1662 | /// \returns BitWidth if the value is zero, otherwise returns the number of | |||
1663 | /// zeros from the most significant bit to the first one bits. | |||
1664 | unsigned countLeadingZeros() const { | |||
1665 | if (isSingleWord()) { | |||
1666 | unsigned unusedBits = APINT_BITS_PER_WORD - BitWidth; | |||
1667 | return llvm::countLeadingZeros(U.VAL) - unusedBits; | |||
1668 | } | |||
1669 | return countLeadingZerosSlowCase(); | |||
1670 | } | |||
1671 | ||||
1672 | /// Count the number of leading one bits. | |||
1673 | /// | |||
1674 | /// This function is an APInt version of the countLeadingOnes | |||
1675 | /// functions in MathExtras.h. It counts the number of ones from the most | |||
1676 | /// significant bit to the first zero bit. | |||
1677 | /// | |||
1678 | /// \returns 0 if the high order bit is not set, otherwise returns the number | |||
1679 | /// of 1 bits from the most significant to the least | |||
1680 | unsigned countLeadingOnes() const { | |||
1681 | if (isSingleWord()) | |||
1682 | return llvm::countLeadingOnes(U.VAL << (APINT_BITS_PER_WORD - BitWidth)); | |||
1683 | return countLeadingOnesSlowCase(); | |||
1684 | } | |||
1685 | ||||
1686 | /// Computes the number of leading bits of this APInt that are equal to its | |||
1687 | /// sign bit. | |||
1688 | unsigned getNumSignBits() const { | |||
1689 | return isNegative() ? countLeadingOnes() : countLeadingZeros(); | |||
1690 | } | |||
1691 | ||||
1692 | /// Count the number of trailing zero bits. | |||
1693 | /// | |||
1694 | /// This function is an APInt version of the countTrailingZeros | |||
1695 | /// functions in MathExtras.h. It counts the number of zeros from the least | |||
1696 | /// significant bit to the first set bit. | |||
1697 | /// | |||
1698 | /// \returns BitWidth if the value is zero, otherwise returns the number of | |||
1699 | /// zeros from the least significant bit to the first one bit. | |||
1700 | unsigned countTrailingZeros() const { | |||
1701 | if (isSingleWord()) { | |||
1702 | unsigned TrailingZeros = llvm::countTrailingZeros(U.VAL); | |||
1703 | return (TrailingZeros > BitWidth ? BitWidth : TrailingZeros); | |||
1704 | } | |||
1705 | return countTrailingZerosSlowCase(); | |||
1706 | } | |||
1707 | ||||
1708 | /// Count the number of trailing one bits. | |||
1709 | /// | |||
1710 | /// This function is an APInt version of the countTrailingOnes | |||
1711 | /// functions in MathExtras.h. It counts the number of ones from the least | |||
1712 | /// significant bit to the first zero bit. | |||
1713 | /// | |||
1714 | /// \returns BitWidth if the value is all ones, otherwise returns the number | |||
1715 | /// of ones from the least significant bit to the first zero bit. | |||
1716 | unsigned countTrailingOnes() const { | |||
1717 | if (isSingleWord()) | |||
1718 | return llvm::countTrailingOnes(U.VAL); | |||
1719 | return countTrailingOnesSlowCase(); | |||
1720 | } | |||
1721 | ||||
1722 | /// Count the number of bits set. | |||
1723 | /// | |||
1724 | /// This function is an APInt version of the countPopulation functions | |||
1725 | /// in MathExtras.h. It counts the number of 1 bits in the APInt value. | |||
1726 | /// | |||
1727 | /// \returns 0 if the value is zero, otherwise returns the number of set bits. | |||
1728 | unsigned countPopulation() const { | |||
1729 | if (isSingleWord()) | |||
1730 | return llvm::countPopulation(U.VAL); | |||
1731 | return countPopulationSlowCase(); | |||
1732 | } | |||
1733 | ||||
1734 | /// @} | |||
1735 | /// \name Conversion Functions | |||
1736 | /// @{ | |||
1737 | void print(raw_ostream &OS, bool isSigned) const; | |||
1738 | ||||
1739 | /// Converts an APInt to a string and append it to Str. Str is commonly a | |||
1740 | /// SmallString. | |||
1741 | void toString(SmallVectorImpl<char> &Str, unsigned Radix, bool Signed, | |||
1742 | bool formatAsCLiteral = false) const; | |||
1743 | ||||
1744 | /// Considers the APInt to be unsigned and converts it into a string in the | |||
1745 | /// radix given. The radix can be 2, 8, 10 16, or 36. | |||
1746 | void toStringUnsigned(SmallVectorImpl<char> &Str, unsigned Radix = 10) const { | |||
1747 | toString(Str, Radix, false, false); | |||
1748 | } | |||
1749 | ||||
1750 | /// Considers the APInt to be signed and converts it into a string in the | |||
1751 | /// radix given. The radix can be 2, 8, 10, 16, or 36. | |||
1752 | void toStringSigned(SmallVectorImpl<char> &Str, unsigned Radix = 10) const { | |||
1753 | toString(Str, Radix, true, false); | |||
1754 | } | |||
1755 | ||||
1756 | /// \returns a byte-swapped representation of this APInt Value. | |||
1757 | APInt byteSwap() const; | |||
1758 | ||||
1759 | /// \returns the value with the bit representation reversed of this APInt | |||
1760 | /// Value. | |||
1761 | APInt reverseBits() const; | |||
1762 | ||||
1763 | /// Converts this APInt to a double value. | |||
1764 | double roundToDouble(bool isSigned) const; | |||
1765 | ||||
1766 | /// Converts this unsigned APInt to a double value. | |||
1767 | double roundToDouble() const { return roundToDouble(false); } | |||
1768 | ||||
1769 | /// Converts this signed APInt to a double value. | |||
1770 | double signedRoundToDouble() const { return roundToDouble(true); } | |||
1771 | ||||
1772 | /// Converts APInt bits to a double | |||
1773 | /// | |||
1774 | /// The conversion does not do a translation from integer to double, it just | |||
1775 | /// re-interprets the bits as a double. Note that it is valid to do this on | |||
1776 | /// any bit width. Exactly 64 bits will be translated. | |||
1777 | double bitsToDouble() const { | |||
1778 | return BitsToDouble(getWord(0)); | |||
1779 | } | |||
1780 | ||||
1781 | /// Converts APInt bits to a float | |||
1782 | /// | |||
1783 | /// The conversion does not do a translation from integer to float, it just | |||
1784 | /// re-interprets the bits as a float. Note that it is valid to do this on | |||
1785 | /// any bit width. Exactly 32 bits will be translated. | |||
1786 | float bitsToFloat() const { | |||
1787 | return BitsToFloat(static_cast<uint32_t>(getWord(0))); | |||
1788 | } | |||
1789 | ||||
1790 | /// Converts a double to APInt bits. | |||
1791 | /// | |||
1792 | /// The conversion does not do a translation from double to integer, it just | |||
1793 | /// re-interprets the bits of the double. | |||
1794 | static APInt doubleToBits(double V) { | |||
1795 | return APInt(sizeof(double) * CHAR_BIT8, DoubleToBits(V)); | |||
1796 | } | |||
1797 | ||||
1798 | /// Converts a float to APInt bits. | |||
1799 | /// | |||
1800 | /// The conversion does not do a translation from float to integer, it just | |||
1801 | /// re-interprets the bits of the float. | |||
1802 | static APInt floatToBits(float V) { | |||
1803 | return APInt(sizeof(float) * CHAR_BIT8, FloatToBits(V)); | |||
1804 | } | |||
1805 | ||||
1806 | /// @} | |||
1807 | /// \name Mathematics Operations | |||
1808 | /// @{ | |||
1809 | ||||
1810 | /// \returns the floor log base 2 of this APInt. | |||
1811 | unsigned logBase2() const { return getActiveBits() - 1; } | |||
1812 | ||||
1813 | /// \returns the ceil log base 2 of this APInt. | |||
1814 | unsigned ceilLogBase2() const { | |||
1815 | APInt temp(*this); | |||
1816 | --temp; | |||
1817 | return temp.getActiveBits(); | |||
1818 | } | |||
1819 | ||||
1820 | /// \returns the nearest log base 2 of this APInt. Ties round up. | |||
1821 | /// | |||
1822 | /// NOTE: When we have a BitWidth of 1, we define: | |||
1823 | /// | |||
1824 | /// log2(0) = UINT32_MAX | |||
1825 | /// log2(1) = 0 | |||
1826 | /// | |||
1827 | /// to get around any mathematical concerns resulting from | |||
1828 | /// referencing 2 in a space where 2 does no exist. | |||
1829 | unsigned nearestLogBase2() const { | |||
1830 | // Special case when we have a bitwidth of 1. If VAL is 1, then we | |||
1831 | // get 0. If VAL is 0, we get WORDTYPE_MAX which gets truncated to | |||
1832 | // UINT32_MAX. | |||
1833 | if (BitWidth == 1) | |||
1834 | return U.VAL - 1; | |||
1835 | ||||
1836 | // Handle the zero case. | |||
1837 | if (isNullValue()) | |||
1838 | return UINT32_MAX0xffffffffU; | |||
1839 | ||||
1840 | // The non-zero case is handled by computing: | |||
1841 | // | |||
1842 | // nearestLogBase2(x) = logBase2(x) + x[logBase2(x)-1]. | |||
1843 | // | |||
1844 | // where x[i] is referring to the value of the ith bit of x. | |||
1845 | unsigned lg = logBase2(); | |||
1846 | return lg + unsigned((*this)[lg - 1]); | |||
1847 | } | |||
1848 | ||||
1849 | /// \returns the log base 2 of this APInt if its an exact power of two, -1 | |||
1850 | /// otherwise | |||
1851 | int32_t exactLogBase2() const { | |||
1852 | if (!isPowerOf2()) | |||
1853 | return -1; | |||
1854 | return logBase2(); | |||
1855 | } | |||
1856 | ||||
1857 | /// Compute the square root | |||
1858 | APInt sqrt() const; | |||
1859 | ||||
1860 | /// Get the absolute value; | |||
1861 | /// | |||
1862 | /// If *this is < 0 then return -(*this), otherwise *this; | |||
1863 | APInt abs() const { | |||
1864 | if (isNegative()) | |||
1865 | return -(*this); | |||
1866 | return *this; | |||
1867 | } | |||
1868 | ||||
1869 | /// \returns the multiplicative inverse for a given modulo. | |||
1870 | APInt multiplicativeInverse(const APInt &modulo) const; | |||
1871 | ||||
1872 | /// @} | |||
1873 | /// \name Support for division by constant | |||
1874 | /// @{ | |||
1875 | ||||
1876 | /// Calculate the magic number for signed division by a constant. | |||
1877 | struct ms; | |||
1878 | ms magic() const; | |||
1879 | ||||
1880 | /// Calculate the magic number for unsigned division by a constant. | |||
1881 | struct mu; | |||
1882 | mu magicu(unsigned LeadingZeros = 0) const; | |||
1883 | ||||
1884 | /// @} | |||
1885 | /// \name Building-block Operations for APInt and APFloat | |||
1886 | /// @{ | |||
1887 | ||||
1888 | // These building block operations operate on a representation of arbitrary | |||
1889 | // precision, two's-complement, bignum integer values. They should be | |||
1890 | // sufficient to implement APInt and APFloat bignum requirements. Inputs are | |||
1891 | // generally a pointer to the base of an array of integer parts, representing | |||
1892 | // an unsigned bignum, and a count of how many parts there are. | |||
1893 | ||||
1894 | /// Sets the least significant part of a bignum to the input value, and zeroes | |||
1895 | /// out higher parts. | |||
1896 | static void tcSet(WordType *, WordType, unsigned); | |||
1897 | ||||
1898 | /// Assign one bignum to another. | |||
1899 | static void tcAssign(WordType *, const WordType *, unsigned); | |||
1900 | ||||
1901 | /// Returns true if a bignum is zero, false otherwise. | |||
1902 | static bool tcIsZero(const WordType *, unsigned); | |||
1903 | ||||
1904 | /// Extract the given bit of a bignum; returns 0 or 1. Zero-based. | |||
1905 | static int tcExtractBit(const WordType *, unsigned bit); | |||
1906 | ||||
1907 | /// Copy the bit vector of width srcBITS from SRC, starting at bit srcLSB, to | |||
1908 | /// DST, of dstCOUNT parts, such that the bit srcLSB becomes the least | |||
1909 | /// significant bit of DST. All high bits above srcBITS in DST are | |||
1910 | /// zero-filled. | |||
1911 | static void tcExtract(WordType *, unsigned dstCount, | |||
1912 | const WordType *, unsigned srcBits, | |||
1913 | unsigned srcLSB); | |||
1914 | ||||
1915 | /// Set the given bit of a bignum. Zero-based. | |||
1916 | static void tcSetBit(WordType *, unsigned bit); | |||
1917 | ||||
1918 | /// Clear the given bit of a bignum. Zero-based. | |||
1919 | static void tcClearBit(WordType *, unsigned bit); | |||
1920 | ||||
1921 | /// Returns the bit number of the least or most significant set bit of a | |||
1922 | /// number. If the input number has no bits set -1U is returned. | |||
1923 | static unsigned tcLSB(const WordType *, unsigned n); | |||
1924 | static unsigned tcMSB(const WordType *parts, unsigned n); | |||
1925 | ||||
1926 | /// Negate a bignum in-place. | |||
1927 | static void tcNegate(WordType *, unsigned); | |||
1928 | ||||
1929 | /// DST += RHS + CARRY where CARRY is zero or one. Returns the carry flag. | |||
1930 | static WordType tcAdd(WordType *, const WordType *, | |||
1931 | WordType carry, unsigned); | |||
1932 | /// DST += RHS. Returns the carry flag. | |||
1933 | static WordType tcAddPart(WordType *, WordType, unsigned); | |||
1934 | ||||
1935 | /// DST -= RHS + CARRY where CARRY is zero or one. Returns the carry flag. | |||
1936 | static WordType tcSubtract(WordType *, const WordType *, | |||
1937 | WordType carry, unsigned); | |||
1938 | /// DST -= RHS. Returns the carry flag. | |||
1939 | static WordType tcSubtractPart(WordType *, WordType, unsigned); | |||
1940 | ||||
1941 | /// DST += SRC * MULTIPLIER + PART if add is true | |||
1942 | /// DST = SRC * MULTIPLIER + PART if add is false | |||
1943 | /// | |||
1944 | /// Requires 0 <= DSTPARTS <= SRCPARTS + 1. If DST overlaps SRC they must | |||
1945 | /// start at the same point, i.e. DST == SRC. | |||
1946 | /// | |||
1947 | /// If DSTPARTS == SRC_PARTS + 1 no overflow occurs and zero is returned. | |||
1948 | /// Otherwise DST is filled with the least significant DSTPARTS parts of the | |||
1949 | /// result, and if all of the omitted higher parts were zero return zero, | |||
1950 | /// otherwise overflow occurred and return one. | |||
1951 | static int tcMultiplyPart(WordType *dst, const WordType *src, | |||
1952 | WordType multiplier, WordType carry, | |||
1953 | unsigned srcParts, unsigned dstParts, | |||
1954 | bool add); | |||
1955 | ||||
1956 | /// DST = LHS * RHS, where DST has the same width as the operands and is | |||
1957 | /// filled with the least significant parts of the result. Returns one if | |||
1958 | /// overflow occurred, otherwise zero. DST must be disjoint from both | |||
1959 | /// operands. | |||
1960 | static int tcMultiply(WordType *, const WordType *, const WordType *, | |||
1961 | unsigned); | |||
1962 | ||||
1963 | /// DST = LHS * RHS, where DST has width the sum of the widths of the | |||
1964 | /// operands. No overflow occurs. DST must be disjoint from both operands. | |||
1965 | static void tcFullMultiply(WordType *, const WordType *, | |||
1966 | const WordType *, unsigned, unsigned); | |||
1967 | ||||
1968 | /// If RHS is zero LHS and REMAINDER are left unchanged, return one. | |||
1969 | /// Otherwise set LHS to LHS / RHS with the fractional part discarded, set | |||
1970 | /// REMAINDER to the remainder, return zero. i.e. | |||
1971 | /// | |||
1972 | /// OLD_LHS = RHS * LHS + REMAINDER | |||
1973 | /// | |||
1974 | /// SCRATCH is a bignum of the same size as the operands and result for use by | |||
1975 | /// the routine; its contents need not be initialized and are destroyed. LHS, | |||
1976 | /// REMAINDER and SCRATCH must be distinct. | |||
1977 | static int tcDivide(WordType *lhs, const WordType *rhs, | |||
1978 | WordType *remainder, WordType *scratch, | |||
1979 | unsigned parts); | |||
1980 | ||||
1981 | /// Shift a bignum left Count bits. Shifted in bits are zero. There are no | |||
1982 | /// restrictions on Count. | |||
1983 | static void tcShiftLeft(WordType *, unsigned Words, unsigned Count); | |||
1984 | ||||
1985 | /// Shift a bignum right Count bits. Shifted in bits are zero. There are no | |||
1986 | /// restrictions on Count. | |||
1987 | static void tcShiftRight(WordType *, unsigned Words, unsigned Count); | |||
1988 | ||||
1989 | /// The obvious AND, OR and XOR and complement operations. | |||
1990 | static void tcAnd(WordType *, const WordType *, unsigned); | |||
1991 | static void tcOr(WordType *, const WordType *, unsigned); | |||
1992 | static void tcXor(WordType *, const WordType *, unsigned); | |||
1993 | static void tcComplement(WordType *, unsigned); | |||
1994 | ||||
1995 | /// Comparison (unsigned) of two bignums. | |||
1996 | static int tcCompare(const WordType *, const WordType *, unsigned); | |||
1997 | ||||
1998 | /// Increment a bignum in-place. Return the carry flag. | |||
1999 | static WordType tcIncrement(WordType *dst, unsigned parts) { | |||
2000 | return tcAddPart(dst, 1, parts); | |||
2001 | } | |||
2002 | ||||
2003 | /// Decrement a bignum in-place. Return the borrow flag. | |||
2004 | static WordType tcDecrement(WordType *dst, unsigned parts) { | |||
2005 | return tcSubtractPart(dst, 1, parts); | |||
2006 | } | |||
2007 | ||||
2008 | /// Set the least significant BITS and clear the rest. | |||
2009 | static void tcSetLeastSignificantBits(WordType *, unsigned, unsigned bits); | |||
2010 | ||||
2011 | /// debug method | |||
2012 | void dump() const; | |||
2013 | ||||
2014 | /// @} | |||
2015 | }; | |||
2016 | ||||
2017 | /// Magic data for optimising signed division by a constant. | |||
2018 | struct APInt::ms { | |||
2019 | APInt m; ///< magic number | |||
2020 | unsigned s; ///< shift amount | |||
2021 | }; | |||
2022 | ||||
2023 | /// Magic data for optimising unsigned division by a constant. | |||
2024 | struct APInt::mu { | |||
2025 | APInt m; ///< magic number | |||
2026 | bool a; ///< add indicator | |||
2027 | unsigned s; ///< shift amount | |||
2028 | }; | |||
2029 | ||||
2030 | inline bool operator==(uint64_t V1, const APInt &V2) { return V2 == V1; } | |||
2031 | ||||
2032 | inline bool operator!=(uint64_t V1, const APInt &V2) { return V2 != V1; } | |||
2033 | ||||
2034 | /// Unary bitwise complement operator. | |||
2035 | /// | |||
2036 | /// \returns an APInt that is the bitwise complement of \p v. | |||
2037 | inline APInt operator~(APInt v) { | |||
2038 | v.flipAllBits(); | |||
2039 | return v; | |||
2040 | } | |||
2041 | ||||
2042 | inline APInt operator&(APInt a, const APInt &b) { | |||
2043 | a &= b; | |||
2044 | return a; | |||
2045 | } | |||
2046 | ||||
2047 | inline APInt operator&(const APInt &a, APInt &&b) { | |||
2048 | b &= a; | |||
2049 | return std::move(b); | |||
2050 | } | |||
2051 | ||||
2052 | inline APInt operator&(APInt a, uint64_t RHS) { | |||
2053 | a &= RHS; | |||
2054 | return a; | |||
2055 | } | |||
2056 | ||||
2057 | inline APInt operator&(uint64_t LHS, APInt b) { | |||
2058 | b &= LHS; | |||
2059 | return b; | |||
2060 | } | |||
2061 | ||||
2062 | inline APInt operator|(APInt a, const APInt &b) { | |||
2063 | a |= b; | |||
2064 | return a; | |||
2065 | } | |||
2066 | ||||
2067 | inline APInt operator|(const APInt &a, APInt &&b) { | |||
2068 | b |= a; | |||
2069 | return std::move(b); | |||
2070 | } | |||
2071 | ||||
2072 | inline APInt operator|(APInt a, uint64_t RHS) { | |||
2073 | a |= RHS; | |||
2074 | return a; | |||
2075 | } | |||
2076 | ||||
2077 | inline APInt operator|(uint64_t LHS, APInt b) { | |||
2078 | b |= LHS; | |||
2079 | return b; | |||
2080 | } | |||
2081 | ||||
2082 | inline APInt operator^(APInt a, const APInt &b) { | |||
2083 | a ^= b; | |||
2084 | return a; | |||
2085 | } | |||
2086 | ||||
2087 | inline APInt operator^(const APInt &a, APInt &&b) { | |||
2088 | b ^= a; | |||
2089 | return std::move(b); | |||
2090 | } | |||
2091 | ||||
2092 | inline APInt operator^(APInt a, uint64_t RHS) { | |||
2093 | a ^= RHS; | |||
2094 | return a; | |||
2095 | } | |||
2096 | ||||
2097 | inline APInt operator^(uint64_t LHS, APInt b) { | |||
2098 | b ^= LHS; | |||
2099 | return b; | |||
2100 | } | |||
2101 | ||||
2102 | inline raw_ostream &operator<<(raw_ostream &OS, const APInt &I) { | |||
2103 | I.print(OS, true); | |||
2104 | return OS; | |||
2105 | } | |||
2106 | ||||
2107 | inline APInt operator-(APInt v) { | |||
2108 | v.negate(); | |||
2109 | return v; | |||
2110 | } | |||
2111 | ||||
2112 | inline APInt operator+(APInt a, const APInt &b) { | |||
2113 | a += b; | |||
2114 | return a; | |||
2115 | } | |||
2116 | ||||
2117 | inline APInt operator+(const APInt &a, APInt &&b) { | |||
2118 | b += a; | |||
2119 | return std::move(b); | |||
2120 | } | |||
2121 | ||||
2122 | inline APInt operator+(APInt a, uint64_t RHS) { | |||
2123 | a += RHS; | |||
2124 | return a; | |||
2125 | } | |||
2126 | ||||
2127 | inline APInt operator+(uint64_t LHS, APInt b) { | |||
2128 | b += LHS; | |||
2129 | return b; | |||
2130 | } | |||
2131 | ||||
2132 | inline APInt operator-(APInt a, const APInt &b) { | |||
2133 | a -= b; | |||
2134 | return a; | |||
2135 | } | |||
2136 | ||||
2137 | inline APInt operator-(const APInt &a, APInt &&b) { | |||
2138 | b.negate(); | |||
2139 | b += a; | |||
2140 | return std::move(b); | |||
2141 | } | |||
2142 | ||||
2143 | inline APInt operator-(APInt a, uint64_t RHS) { | |||
2144 | a -= RHS; | |||
2145 | return a; | |||
2146 | } | |||
2147 | ||||
2148 | inline APInt operator-(uint64_t LHS, APInt b) { | |||
2149 | b.negate(); | |||
2150 | b += LHS; | |||
2151 | return b; | |||
2152 | } | |||
2153 | ||||
2154 | inline APInt operator*(APInt a, uint64_t RHS) { | |||
2155 | a *= RHS; | |||
2156 | return a; | |||
2157 | } | |||
2158 | ||||
2159 | inline APInt operator*(uint64_t LHS, APInt b) { | |||
2160 | b *= LHS; | |||
2161 | return b; | |||
2162 | } | |||
2163 | ||||
2164 | ||||
2165 | namespace APIntOps { | |||
2166 | ||||
2167 | /// Determine the smaller of two APInts considered to be signed. | |||
2168 | inline const APInt &smin(const APInt &A, const APInt &B) { | |||
2169 | return A.slt(B) ? A : B; | |||
2170 | } | |||
2171 | ||||
2172 | /// Determine the larger of two APInts considered to be signed. | |||
2173 | inline const APInt &smax(const APInt &A, const APInt &B) { | |||
2174 | return A.sgt(B) ? A : B; | |||
2175 | } | |||
2176 | ||||
2177 | /// Determine the smaller of two APInts considered to be unsigned. | |||
2178 | inline const APInt &umin(const APInt &A, const APInt &B) { | |||
2179 | return A.ult(B) ? A : B; | |||
2180 | } | |||
2181 | ||||
2182 | /// Determine the larger of two APInts considered to be unsigned. | |||
2183 | inline const APInt &umax(const APInt &A, const APInt &B) { | |||
2184 | return A.ugt(B) ? A : B; | |||
2185 | } | |||
2186 | ||||
2187 | /// Compute GCD of two unsigned APInt values. | |||
2188 | /// | |||
2189 | /// This function returns the greatest common divisor of the two APInt values | |||
2190 | /// using Stein's algorithm. | |||
2191 | /// | |||
2192 | /// \returns the greatest common divisor of A and B. | |||
2193 | APInt GreatestCommonDivisor(APInt A, APInt B); | |||
2194 | ||||
2195 | /// Converts the given APInt to a double value. | |||
2196 | /// | |||
2197 | /// Treats the APInt as an unsigned value for conversion purposes. | |||
2198 | inline double RoundAPIntToDouble(const APInt &APIVal) { | |||
2199 | return APIVal.roundToDouble(); | |||
2200 | } | |||
2201 | ||||
2202 | /// Converts the given APInt to a double value. | |||
2203 | /// | |||
2204 | /// Treats the APInt as a signed value for conversion purposes. | |||
2205 | inline double RoundSignedAPIntToDouble(const APInt &APIVal) { | |||
2206 | return APIVal.signedRoundToDouble(); | |||
2207 | } | |||
2208 | ||||
2209 | /// Converts the given APInt to a float value. | |||
2210 | inline float RoundAPIntToFloat(const APInt &APIVal) { | |||
2211 | return float(RoundAPIntToDouble(APIVal)); | |||
2212 | } | |||
2213 | ||||
2214 | /// Converts the given APInt to a float value. | |||
2215 | /// | |||
2216 | /// Treats the APInt as a signed value for conversion purposes. | |||
2217 | inline float RoundSignedAPIntToFloat(const APInt &APIVal) { | |||
2218 | return float(APIVal.signedRoundToDouble()); | |||
2219 | } | |||
2220 | ||||
2221 | /// Converts the given double value into a APInt. | |||
2222 | /// | |||
2223 | /// This function convert a double value to an APInt value. | |||
2224 | APInt RoundDoubleToAPInt(double Double, unsigned width); | |||
2225 | ||||
2226 | /// Converts a float value into a APInt. | |||
2227 | /// | |||
2228 | /// Converts a float value into an APInt value. | |||
2229 | inline APInt RoundFloatToAPInt(float Float, unsigned width) { | |||
2230 | return RoundDoubleToAPInt(double(Float), width); | |||
2231 | } | |||
2232 | ||||
2233 | /// Return A unsign-divided by B, rounded by the given rounding mode. | |||
2234 | APInt RoundingUDiv(const APInt &A, const APInt &B, APInt::Rounding RM); | |||
2235 | ||||
2236 | /// Return A sign-divided by B, rounded by the given rounding mode. | |||
2237 | APInt RoundingSDiv(const APInt &A, const APInt &B, APInt::Rounding RM); | |||
2238 | ||||
2239 | /// Let q(n) = An^2 + Bn + C, and BW = bit width of the value range | |||
2240 | /// (e.g. 32 for i32). | |||
2241 | /// This function finds the smallest number n, such that | |||
2242 | /// (a) n >= 0 and q(n) = 0, or | |||
2243 | /// (b) n >= 1 and q(n-1) and q(n), when evaluated in the set of all | |||
2244 | /// integers, belong to two different intervals [Rk, Rk+R), | |||
2245 | /// where R = 2^BW, and k is an integer. | |||
2246 | /// The idea here is to find when q(n) "overflows" 2^BW, while at the | |||
2247 | /// same time "allowing" subtraction. In unsigned modulo arithmetic a | |||
2248 | /// subtraction (treated as addition of negated numbers) would always | |||
2249 | /// count as an overflow, but here we want to allow values to decrease | |||
2250 | /// and increase as long as they are within the same interval. | |||
2251 | /// Specifically, adding of two negative numbers should not cause an | |||
2252 | /// overflow (as long as the magnitude does not exceed the bit width). | |||
2253 | /// On the other hand, given a positive number, adding a negative | |||
2254 | /// number to it can give a negative result, which would cause the | |||
2255 | /// value to go from [-2^BW, 0) to [0, 2^BW). In that sense, zero is | |||
2256 | /// treated as a special case of an overflow. | |||
2257 | /// | |||
2258 | /// This function returns None if after finding k that minimizes the | |||
2259 | /// positive solution to q(n) = kR, both solutions are contained between | |||
2260 | /// two consecutive integers. | |||
2261 | /// | |||
2262 | /// There are cases where q(n) > T, and q(n+1) < T (assuming evaluation | |||
2263 | /// in arithmetic modulo 2^BW, and treating the values as signed) by the | |||
2264 | /// virtue of *signed* overflow. This function will *not* find such an n, | |||
2265 | /// however it may find a value of n satisfying the inequalities due to | |||
2266 | /// an *unsigned* overflow (if the values are treated as unsigned). | |||
2267 | /// To find a solution for a signed overflow, treat it as a problem of | |||
2268 | /// finding an unsigned overflow with a range with of BW-1. | |||
2269 | /// | |||
2270 | /// The returned value may have a different bit width from the input | |||
2271 | /// coefficients. | |||
2272 | Optional<APInt> SolveQuadraticEquationWrap(APInt A, APInt B, APInt C, | |||
2273 | unsigned RangeWidth); | |||
2274 | ||||
2275 | /// Compare two values, and if they are different, return the position of the | |||
2276 | /// most significant bit that is different in the values. | |||
2277 | Optional<unsigned> GetMostSignificantDifferentBit(const APInt &A, | |||
2278 | const APInt &B); | |||
2279 | ||||
2280 | } // End of APIntOps namespace | |||
2281 | ||||
2282 | // See friend declaration above. This additional declaration is required in | |||
2283 | // order to compile LLVM with IBM xlC compiler. | |||
2284 | hash_code hash_value(const APInt &Arg); | |||
2285 | ||||
2286 | /// StoreIntToMemory - Fills the StoreBytes bytes of memory starting from Dst | |||
2287 | /// with the integer held in IntVal. | |||
2288 | void StoreIntToMemory(const APInt &IntVal, uint8_t *Dst, unsigned StoreBytes); | |||
2289 | ||||
2290 | /// LoadIntFromMemory - Loads the integer stored in the LoadBytes bytes starting | |||
2291 | /// from Src into IntVal, which is assumed to be wide enough and to hold zero. | |||
2292 | void LoadIntFromMemory(APInt &IntVal, const uint8_t *Src, unsigned LoadBytes); | |||
2293 | ||||
2294 | /// Provide DenseMapInfo for APInt. | |||
2295 | template <> struct DenseMapInfo<APInt> { | |||
2296 | static inline APInt getEmptyKey() { | |||
2297 | APInt V(nullptr, 0); | |||
2298 | V.U.VAL = 0; | |||
2299 | return V; | |||
2300 | } | |||
2301 | ||||
2302 | static inline APInt getTombstoneKey() { | |||
2303 | APInt V(nullptr, 0); | |||
2304 | V.U.VAL = 1; | |||
2305 | return V; | |||
2306 | } | |||
2307 | ||||
2308 | static unsigned getHashValue(const APInt &Key); | |||
2309 | ||||
2310 | static bool isEqual(const APInt &LHS, const APInt &RHS) { | |||
2311 | return LHS.getBitWidth() == RHS.getBitWidth() && LHS == RHS; | |||
2312 | } | |||
2313 | }; | |||
2314 | ||||
2315 | } // namespace llvm | |||
2316 | ||||
2317 | #endif |