File: | src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Transforms/Scalar/JumpThreading.cpp |
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1 | //===- JumpThreading.cpp - Thread control through conditional blocks ------===// | |||
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 implements the Jump Threading pass. | |||
10 | // | |||
11 | //===----------------------------------------------------------------------===// | |||
12 | ||||
13 | #include "llvm/Transforms/Scalar/JumpThreading.h" | |||
14 | #include "llvm/ADT/DenseMap.h" | |||
15 | #include "llvm/ADT/DenseSet.h" | |||
16 | #include "llvm/ADT/MapVector.h" | |||
17 | #include "llvm/ADT/Optional.h" | |||
18 | #include "llvm/ADT/STLExtras.h" | |||
19 | #include "llvm/ADT/SmallPtrSet.h" | |||
20 | #include "llvm/ADT/SmallVector.h" | |||
21 | #include "llvm/ADT/Statistic.h" | |||
22 | #include "llvm/Analysis/AliasAnalysis.h" | |||
23 | #include "llvm/Analysis/BlockFrequencyInfo.h" | |||
24 | #include "llvm/Analysis/BranchProbabilityInfo.h" | |||
25 | #include "llvm/Analysis/CFG.h" | |||
26 | #include "llvm/Analysis/ConstantFolding.h" | |||
27 | #include "llvm/Analysis/DomTreeUpdater.h" | |||
28 | #include "llvm/Analysis/GlobalsModRef.h" | |||
29 | #include "llvm/Analysis/GuardUtils.h" | |||
30 | #include "llvm/Analysis/InstructionSimplify.h" | |||
31 | #include "llvm/Analysis/LazyValueInfo.h" | |||
32 | #include "llvm/Analysis/Loads.h" | |||
33 | #include "llvm/Analysis/LoopInfo.h" | |||
34 | #include "llvm/Analysis/MemoryLocation.h" | |||
35 | #include "llvm/Analysis/TargetLibraryInfo.h" | |||
36 | #include "llvm/Analysis/TargetTransformInfo.h" | |||
37 | #include "llvm/Analysis/ValueTracking.h" | |||
38 | #include "llvm/IR/BasicBlock.h" | |||
39 | #include "llvm/IR/CFG.h" | |||
40 | #include "llvm/IR/Constant.h" | |||
41 | #include "llvm/IR/ConstantRange.h" | |||
42 | #include "llvm/IR/Constants.h" | |||
43 | #include "llvm/IR/DataLayout.h" | |||
44 | #include "llvm/IR/Dominators.h" | |||
45 | #include "llvm/IR/Function.h" | |||
46 | #include "llvm/IR/InstrTypes.h" | |||
47 | #include "llvm/IR/Instruction.h" | |||
48 | #include "llvm/IR/Instructions.h" | |||
49 | #include "llvm/IR/IntrinsicInst.h" | |||
50 | #include "llvm/IR/Intrinsics.h" | |||
51 | #include "llvm/IR/LLVMContext.h" | |||
52 | #include "llvm/IR/MDBuilder.h" | |||
53 | #include "llvm/IR/Metadata.h" | |||
54 | #include "llvm/IR/Module.h" | |||
55 | #include "llvm/IR/PassManager.h" | |||
56 | #include "llvm/IR/PatternMatch.h" | |||
57 | #include "llvm/IR/Type.h" | |||
58 | #include "llvm/IR/Use.h" | |||
59 | #include "llvm/IR/User.h" | |||
60 | #include "llvm/IR/Value.h" | |||
61 | #include "llvm/InitializePasses.h" | |||
62 | #include "llvm/Pass.h" | |||
63 | #include "llvm/Support/BlockFrequency.h" | |||
64 | #include "llvm/Support/BranchProbability.h" | |||
65 | #include "llvm/Support/Casting.h" | |||
66 | #include "llvm/Support/CommandLine.h" | |||
67 | #include "llvm/Support/Debug.h" | |||
68 | #include "llvm/Support/raw_ostream.h" | |||
69 | #include "llvm/Transforms/Scalar.h" | |||
70 | #include "llvm/Transforms/Utils/BasicBlockUtils.h" | |||
71 | #include "llvm/Transforms/Utils/Cloning.h" | |||
72 | #include "llvm/Transforms/Utils/Local.h" | |||
73 | #include "llvm/Transforms/Utils/SSAUpdater.h" | |||
74 | #include "llvm/Transforms/Utils/ValueMapper.h" | |||
75 | #include <algorithm> | |||
76 | #include <cassert> | |||
77 | #include <cstddef> | |||
78 | #include <cstdint> | |||
79 | #include <iterator> | |||
80 | #include <memory> | |||
81 | #include <utility> | |||
82 | ||||
83 | using namespace llvm; | |||
84 | using namespace jumpthreading; | |||
85 | ||||
86 | #define DEBUG_TYPE"jump-threading" "jump-threading" | |||
87 | ||||
88 | STATISTIC(NumThreads, "Number of jumps threaded")static llvm::Statistic NumThreads = {"jump-threading", "NumThreads" , "Number of jumps threaded"}; | |||
89 | STATISTIC(NumFolds, "Number of terminators folded")static llvm::Statistic NumFolds = {"jump-threading", "NumFolds" , "Number of terminators folded"}; | |||
90 | STATISTIC(NumDupes, "Number of branch blocks duplicated to eliminate phi")static llvm::Statistic NumDupes = {"jump-threading", "NumDupes" , "Number of branch blocks duplicated to eliminate phi"}; | |||
91 | ||||
92 | static cl::opt<unsigned> | |||
93 | BBDuplicateThreshold("jump-threading-threshold", | |||
94 | cl::desc("Max block size to duplicate for jump threading"), | |||
95 | cl::init(6), cl::Hidden); | |||
96 | ||||
97 | static cl::opt<unsigned> | |||
98 | ImplicationSearchThreshold( | |||
99 | "jump-threading-implication-search-threshold", | |||
100 | cl::desc("The number of predecessors to search for a stronger " | |||
101 | "condition to use to thread over a weaker condition"), | |||
102 | cl::init(3), cl::Hidden); | |||
103 | ||||
104 | static cl::opt<bool> PrintLVIAfterJumpThreading( | |||
105 | "print-lvi-after-jump-threading", | |||
106 | cl::desc("Print the LazyValueInfo cache after JumpThreading"), cl::init(false), | |||
107 | cl::Hidden); | |||
108 | ||||
109 | static cl::opt<bool> JumpThreadingFreezeSelectCond( | |||
110 | "jump-threading-freeze-select-cond", | |||
111 | cl::desc("Freeze the condition when unfolding select"), cl::init(false), | |||
112 | cl::Hidden); | |||
113 | ||||
114 | static cl::opt<bool> ThreadAcrossLoopHeaders( | |||
115 | "jump-threading-across-loop-headers", | |||
116 | cl::desc("Allow JumpThreading to thread across loop headers, for testing"), | |||
117 | cl::init(false), cl::Hidden); | |||
118 | ||||
119 | ||||
120 | namespace { | |||
121 | ||||
122 | /// This pass performs 'jump threading', which looks at blocks that have | |||
123 | /// multiple predecessors and multiple successors. If one or more of the | |||
124 | /// predecessors of the block can be proven to always jump to one of the | |||
125 | /// successors, we forward the edge from the predecessor to the successor by | |||
126 | /// duplicating the contents of this block. | |||
127 | /// | |||
128 | /// An example of when this can occur is code like this: | |||
129 | /// | |||
130 | /// if () { ... | |||
131 | /// X = 4; | |||
132 | /// } | |||
133 | /// if (X < 3) { | |||
134 | /// | |||
135 | /// In this case, the unconditional branch at the end of the first if can be | |||
136 | /// revectored to the false side of the second if. | |||
137 | class JumpThreading : public FunctionPass { | |||
138 | JumpThreadingPass Impl; | |||
139 | ||||
140 | public: | |||
141 | static char ID; // Pass identification | |||
142 | ||||
143 | JumpThreading(bool InsertFreezeWhenUnfoldingSelect = false, int T = -1) | |||
144 | : FunctionPass(ID), Impl(InsertFreezeWhenUnfoldingSelect, T) { | |||
145 | initializeJumpThreadingPass(*PassRegistry::getPassRegistry()); | |||
146 | } | |||
147 | ||||
148 | bool runOnFunction(Function &F) override; | |||
149 | ||||
150 | void getAnalysisUsage(AnalysisUsage &AU) const override { | |||
151 | AU.addRequired<DominatorTreeWrapperPass>(); | |||
152 | AU.addPreserved<DominatorTreeWrapperPass>(); | |||
153 | AU.addRequired<AAResultsWrapperPass>(); | |||
154 | AU.addRequired<LazyValueInfoWrapperPass>(); | |||
155 | AU.addPreserved<LazyValueInfoWrapperPass>(); | |||
156 | AU.addPreserved<GlobalsAAWrapperPass>(); | |||
157 | AU.addRequired<TargetLibraryInfoWrapperPass>(); | |||
158 | AU.addRequired<TargetTransformInfoWrapperPass>(); | |||
159 | } | |||
160 | ||||
161 | void releaseMemory() override { Impl.releaseMemory(); } | |||
162 | }; | |||
163 | ||||
164 | } // end anonymous namespace | |||
165 | ||||
166 | char JumpThreading::ID = 0; | |||
167 | ||||
168 | INITIALIZE_PASS_BEGIN(JumpThreading, "jump-threading",static void *initializeJumpThreadingPassOnce(PassRegistry & Registry) { | |||
169 | "Jump Threading", false, false)static void *initializeJumpThreadingPassOnce(PassRegistry & Registry) { | |||
170 | INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)initializeDominatorTreeWrapperPassPass(Registry); | |||
171 | INITIALIZE_PASS_DEPENDENCY(LazyValueInfoWrapperPass)initializeLazyValueInfoWrapperPassPass(Registry); | |||
172 | INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)initializeTargetLibraryInfoWrapperPassPass(Registry); | |||
173 | INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)initializeAAResultsWrapperPassPass(Registry); | |||
174 | INITIALIZE_PASS_END(JumpThreading, "jump-threading",PassInfo *PI = new PassInfo( "Jump Threading", "jump-threading" , &JumpThreading::ID, PassInfo::NormalCtor_t(callDefaultCtor <JumpThreading>), false, false); Registry.registerPass( *PI, true); return PI; } static llvm::once_flag InitializeJumpThreadingPassFlag ; void llvm::initializeJumpThreadingPass(PassRegistry &Registry ) { llvm::call_once(InitializeJumpThreadingPassFlag, initializeJumpThreadingPassOnce , std::ref(Registry)); } | |||
175 | "Jump Threading", false, false)PassInfo *PI = new PassInfo( "Jump Threading", "jump-threading" , &JumpThreading::ID, PassInfo::NormalCtor_t(callDefaultCtor <JumpThreading>), false, false); Registry.registerPass( *PI, true); return PI; } static llvm::once_flag InitializeJumpThreadingPassFlag ; void llvm::initializeJumpThreadingPass(PassRegistry &Registry ) { llvm::call_once(InitializeJumpThreadingPassFlag, initializeJumpThreadingPassOnce , std::ref(Registry)); } | |||
176 | ||||
177 | // Public interface to the Jump Threading pass | |||
178 | FunctionPass *llvm::createJumpThreadingPass(bool InsertFr, int Threshold) { | |||
179 | return new JumpThreading(InsertFr, Threshold); | |||
180 | } | |||
181 | ||||
182 | JumpThreadingPass::JumpThreadingPass(bool InsertFr, int T) { | |||
183 | InsertFreezeWhenUnfoldingSelect = JumpThreadingFreezeSelectCond | InsertFr; | |||
184 | DefaultBBDupThreshold = (T == -1) ? BBDuplicateThreshold : unsigned(T); | |||
185 | } | |||
186 | ||||
187 | // Update branch probability information according to conditional | |||
188 | // branch probability. This is usually made possible for cloned branches | |||
189 | // in inline instances by the context specific profile in the caller. | |||
190 | // For instance, | |||
191 | // | |||
192 | // [Block PredBB] | |||
193 | // [Branch PredBr] | |||
194 | // if (t) { | |||
195 | // Block A; | |||
196 | // } else { | |||
197 | // Block B; | |||
198 | // } | |||
199 | // | |||
200 | // [Block BB] | |||
201 | // cond = PN([true, %A], [..., %B]); // PHI node | |||
202 | // [Branch CondBr] | |||
203 | // if (cond) { | |||
204 | // ... // P(cond == true) = 1% | |||
205 | // } | |||
206 | // | |||
207 | // Here we know that when block A is taken, cond must be true, which means | |||
208 | // P(cond == true | A) = 1 | |||
209 | // | |||
210 | // Given that P(cond == true) = P(cond == true | A) * P(A) + | |||
211 | // P(cond == true | B) * P(B) | |||
212 | // we get: | |||
213 | // P(cond == true ) = P(A) + P(cond == true | B) * P(B) | |||
214 | // | |||
215 | // which gives us: | |||
216 | // P(A) is less than P(cond == true), i.e. | |||
217 | // P(t == true) <= P(cond == true) | |||
218 | // | |||
219 | // In other words, if we know P(cond == true) is unlikely, we know | |||
220 | // that P(t == true) is also unlikely. | |||
221 | // | |||
222 | static void updatePredecessorProfileMetadata(PHINode *PN, BasicBlock *BB) { | |||
223 | BranchInst *CondBr = dyn_cast<BranchInst>(BB->getTerminator()); | |||
224 | if (!CondBr) | |||
225 | return; | |||
226 | ||||
227 | uint64_t TrueWeight, FalseWeight; | |||
228 | if (!CondBr->extractProfMetadata(TrueWeight, FalseWeight)) | |||
229 | return; | |||
230 | ||||
231 | if (TrueWeight + FalseWeight == 0) | |||
232 | // Zero branch_weights do not give a hint for getting branch probabilities. | |||
233 | // Technically it would result in division by zero denominator, which is | |||
234 | // TrueWeight + FalseWeight. | |||
235 | return; | |||
236 | ||||
237 | // Returns the outgoing edge of the dominating predecessor block | |||
238 | // that leads to the PhiNode's incoming block: | |||
239 | auto GetPredOutEdge = | |||
240 | [](BasicBlock *IncomingBB, | |||
241 | BasicBlock *PhiBB) -> std::pair<BasicBlock *, BasicBlock *> { | |||
242 | auto *PredBB = IncomingBB; | |||
243 | auto *SuccBB = PhiBB; | |||
244 | SmallPtrSet<BasicBlock *, 16> Visited; | |||
245 | while (true) { | |||
246 | BranchInst *PredBr = dyn_cast<BranchInst>(PredBB->getTerminator()); | |||
247 | if (PredBr && PredBr->isConditional()) | |||
248 | return {PredBB, SuccBB}; | |||
249 | Visited.insert(PredBB); | |||
250 | auto *SinglePredBB = PredBB->getSinglePredecessor(); | |||
251 | if (!SinglePredBB) | |||
252 | return {nullptr, nullptr}; | |||
253 | ||||
254 | // Stop searching when SinglePredBB has been visited. It means we see | |||
255 | // an unreachable loop. | |||
256 | if (Visited.count(SinglePredBB)) | |||
257 | return {nullptr, nullptr}; | |||
258 | ||||
259 | SuccBB = PredBB; | |||
260 | PredBB = SinglePredBB; | |||
261 | } | |||
262 | }; | |||
263 | ||||
264 | for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) { | |||
265 | Value *PhiOpnd = PN->getIncomingValue(i); | |||
266 | ConstantInt *CI = dyn_cast<ConstantInt>(PhiOpnd); | |||
267 | ||||
268 | if (!CI || !CI->getType()->isIntegerTy(1)) | |||
269 | continue; | |||
270 | ||||
271 | BranchProbability BP = | |||
272 | (CI->isOne() ? BranchProbability::getBranchProbability( | |||
273 | TrueWeight, TrueWeight + FalseWeight) | |||
274 | : BranchProbability::getBranchProbability( | |||
275 | FalseWeight, TrueWeight + FalseWeight)); | |||
276 | ||||
277 | auto PredOutEdge = GetPredOutEdge(PN->getIncomingBlock(i), BB); | |||
278 | if (!PredOutEdge.first) | |||
279 | return; | |||
280 | ||||
281 | BasicBlock *PredBB = PredOutEdge.first; | |||
282 | BranchInst *PredBr = dyn_cast<BranchInst>(PredBB->getTerminator()); | |||
283 | if (!PredBr) | |||
284 | return; | |||
285 | ||||
286 | uint64_t PredTrueWeight, PredFalseWeight; | |||
287 | // FIXME: We currently only set the profile data when it is missing. | |||
288 | // With PGO, this can be used to refine even existing profile data with | |||
289 | // context information. This needs to be done after more performance | |||
290 | // testing. | |||
291 | if (PredBr->extractProfMetadata(PredTrueWeight, PredFalseWeight)) | |||
292 | continue; | |||
293 | ||||
294 | // We can not infer anything useful when BP >= 50%, because BP is the | |||
295 | // upper bound probability value. | |||
296 | if (BP >= BranchProbability(50, 100)) | |||
297 | continue; | |||
298 | ||||
299 | SmallVector<uint32_t, 2> Weights; | |||
300 | if (PredBr->getSuccessor(0) == PredOutEdge.second) { | |||
301 | Weights.push_back(BP.getNumerator()); | |||
302 | Weights.push_back(BP.getCompl().getNumerator()); | |||
303 | } else { | |||
304 | Weights.push_back(BP.getCompl().getNumerator()); | |||
305 | Weights.push_back(BP.getNumerator()); | |||
306 | } | |||
307 | PredBr->setMetadata(LLVMContext::MD_prof, | |||
308 | MDBuilder(PredBr->getParent()->getContext()) | |||
309 | .createBranchWeights(Weights)); | |||
310 | } | |||
311 | } | |||
312 | ||||
313 | /// runOnFunction - Toplevel algorithm. | |||
314 | bool JumpThreading::runOnFunction(Function &F) { | |||
315 | if (skipFunction(F)) | |||
316 | return false; | |||
317 | auto TTI = &getAnalysis<TargetTransformInfoWrapperPass>().getTTI(F); | |||
318 | // Jump Threading has no sense for the targets with divergent CF | |||
319 | if (TTI->hasBranchDivergence()) | |||
320 | return false; | |||
321 | auto TLI = &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI(F); | |||
322 | auto DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree(); | |||
323 | auto LVI = &getAnalysis<LazyValueInfoWrapperPass>().getLVI(); | |||
324 | auto AA = &getAnalysis<AAResultsWrapperPass>().getAAResults(); | |||
325 | DomTreeUpdater DTU(*DT, DomTreeUpdater::UpdateStrategy::Lazy); | |||
326 | std::unique_ptr<BlockFrequencyInfo> BFI; | |||
327 | std::unique_ptr<BranchProbabilityInfo> BPI; | |||
328 | if (F.hasProfileData()) { | |||
329 | LoopInfo LI{DominatorTree(F)}; | |||
330 | BPI.reset(new BranchProbabilityInfo(F, LI, TLI)); | |||
331 | BFI.reset(new BlockFrequencyInfo(F, *BPI, LI)); | |||
332 | } | |||
333 | ||||
334 | bool Changed = Impl.runImpl(F, TLI, LVI, AA, &DTU, F.hasProfileData(), | |||
335 | std::move(BFI), std::move(BPI)); | |||
336 | if (PrintLVIAfterJumpThreading) { | |||
337 | dbgs() << "LVI for function '" << F.getName() << "':\n"; | |||
338 | LVI->printLVI(F, DTU.getDomTree(), dbgs()); | |||
339 | } | |||
340 | return Changed; | |||
341 | } | |||
342 | ||||
343 | PreservedAnalyses JumpThreadingPass::run(Function &F, | |||
344 | FunctionAnalysisManager &AM) { | |||
345 | auto &TTI = AM.getResult<TargetIRAnalysis>(F); | |||
346 | // Jump Threading has no sense for the targets with divergent CF | |||
347 | if (TTI.hasBranchDivergence()) | |||
348 | return PreservedAnalyses::all(); | |||
349 | auto &TLI = AM.getResult<TargetLibraryAnalysis>(F); | |||
350 | auto &DT = AM.getResult<DominatorTreeAnalysis>(F); | |||
351 | auto &LVI = AM.getResult<LazyValueAnalysis>(F); | |||
352 | auto &AA = AM.getResult<AAManager>(F); | |||
353 | DomTreeUpdater DTU(DT, DomTreeUpdater::UpdateStrategy::Lazy); | |||
354 | ||||
355 | std::unique_ptr<BlockFrequencyInfo> BFI; | |||
356 | std::unique_ptr<BranchProbabilityInfo> BPI; | |||
357 | if (F.hasProfileData()) { | |||
358 | LoopInfo LI{DominatorTree(F)}; | |||
359 | BPI.reset(new BranchProbabilityInfo(F, LI, &TLI)); | |||
360 | BFI.reset(new BlockFrequencyInfo(F, *BPI, LI)); | |||
361 | } | |||
362 | ||||
363 | bool Changed = runImpl(F, &TLI, &LVI, &AA, &DTU, F.hasProfileData(), | |||
364 | std::move(BFI), std::move(BPI)); | |||
365 | ||||
366 | if (PrintLVIAfterJumpThreading) { | |||
367 | dbgs() << "LVI for function '" << F.getName() << "':\n"; | |||
368 | LVI.printLVI(F, DTU.getDomTree(), dbgs()); | |||
369 | } | |||
370 | ||||
371 | if (!Changed) | |||
372 | return PreservedAnalyses::all(); | |||
373 | PreservedAnalyses PA; | |||
374 | PA.preserve<DominatorTreeAnalysis>(); | |||
375 | PA.preserve<LazyValueAnalysis>(); | |||
376 | return PA; | |||
377 | } | |||
378 | ||||
379 | bool JumpThreadingPass::runImpl(Function &F, TargetLibraryInfo *TLI_, | |||
380 | LazyValueInfo *LVI_, AliasAnalysis *AA_, | |||
381 | DomTreeUpdater *DTU_, bool HasProfileData_, | |||
382 | std::unique_ptr<BlockFrequencyInfo> BFI_, | |||
383 | std::unique_ptr<BranchProbabilityInfo> BPI_) { | |||
384 | LLVM_DEBUG(dbgs() << "Jump threading on function '" << F.getName() << "'\n")do { } while (false); | |||
385 | TLI = TLI_; | |||
386 | LVI = LVI_; | |||
387 | AA = AA_; | |||
388 | DTU = DTU_; | |||
389 | BFI.reset(); | |||
390 | BPI.reset(); | |||
391 | // When profile data is available, we need to update edge weights after | |||
392 | // successful jump threading, which requires both BPI and BFI being available. | |||
393 | HasProfileData = HasProfileData_; | |||
394 | auto *GuardDecl = F.getParent()->getFunction( | |||
395 | Intrinsic::getName(Intrinsic::experimental_guard)); | |||
396 | HasGuards = GuardDecl && !GuardDecl->use_empty(); | |||
397 | if (HasProfileData) { | |||
398 | BPI = std::move(BPI_); | |||
399 | BFI = std::move(BFI_); | |||
400 | } | |||
401 | ||||
402 | // Reduce the number of instructions duplicated when optimizing strictly for | |||
403 | // size. | |||
404 | if (BBDuplicateThreshold.getNumOccurrences()) | |||
405 | BBDupThreshold = BBDuplicateThreshold; | |||
406 | else if (F.hasFnAttribute(Attribute::MinSize)) | |||
407 | BBDupThreshold = 3; | |||
408 | else | |||
409 | BBDupThreshold = DefaultBBDupThreshold; | |||
410 | ||||
411 | // JumpThreading must not processes blocks unreachable from entry. It's a | |||
412 | // waste of compute time and can potentially lead to hangs. | |||
413 | SmallPtrSet<BasicBlock *, 16> Unreachable; | |||
414 | assert(DTU && "DTU isn't passed into JumpThreading before using it.")((void)0); | |||
415 | assert(DTU->hasDomTree() && "JumpThreading relies on DomTree to proceed.")((void)0); | |||
416 | DominatorTree &DT = DTU->getDomTree(); | |||
417 | for (auto &BB : F) | |||
418 | if (!DT.isReachableFromEntry(&BB)) | |||
419 | Unreachable.insert(&BB); | |||
420 | ||||
421 | if (!ThreadAcrossLoopHeaders) | |||
422 | findLoopHeaders(F); | |||
423 | ||||
424 | bool EverChanged = false; | |||
425 | bool Changed; | |||
426 | do { | |||
427 | Changed = false; | |||
428 | for (auto &BB : F) { | |||
429 | if (Unreachable.count(&BB)) | |||
430 | continue; | |||
431 | while (processBlock(&BB)) // Thread all of the branches we can over BB. | |||
432 | Changed = true; | |||
433 | ||||
434 | // Jump threading may have introduced redundant debug values into BB | |||
435 | // which should be removed. | |||
436 | if (Changed) | |||
437 | RemoveRedundantDbgInstrs(&BB); | |||
438 | ||||
439 | // Stop processing BB if it's the entry or is now deleted. The following | |||
440 | // routines attempt to eliminate BB and locating a suitable replacement | |||
441 | // for the entry is non-trivial. | |||
442 | if (&BB == &F.getEntryBlock() || DTU->isBBPendingDeletion(&BB)) | |||
443 | continue; | |||
444 | ||||
445 | if (pred_empty(&BB)) { | |||
446 | // When processBlock makes BB unreachable it doesn't bother to fix up | |||
447 | // the instructions in it. We must remove BB to prevent invalid IR. | |||
448 | LLVM_DEBUG(dbgs() << " JT: Deleting dead block '" << BB.getName()do { } while (false) | |||
449 | << "' with terminator: " << *BB.getTerminator()do { } while (false) | |||
450 | << '\n')do { } while (false); | |||
451 | LoopHeaders.erase(&BB); | |||
452 | LVI->eraseBlock(&BB); | |||
453 | DeleteDeadBlock(&BB, DTU); | |||
454 | Changed = true; | |||
455 | continue; | |||
456 | } | |||
457 | ||||
458 | // processBlock doesn't thread BBs with unconditional TIs. However, if BB | |||
459 | // is "almost empty", we attempt to merge BB with its sole successor. | |||
460 | auto *BI = dyn_cast<BranchInst>(BB.getTerminator()); | |||
461 | if (BI && BI->isUnconditional()) { | |||
462 | BasicBlock *Succ = BI->getSuccessor(0); | |||
463 | if ( | |||
464 | // The terminator must be the only non-phi instruction in BB. | |||
465 | BB.getFirstNonPHIOrDbg(true)->isTerminator() && | |||
466 | // Don't alter Loop headers and latches to ensure another pass can | |||
467 | // detect and transform nested loops later. | |||
468 | !LoopHeaders.count(&BB) && !LoopHeaders.count(Succ) && | |||
469 | TryToSimplifyUncondBranchFromEmptyBlock(&BB, DTU)) { | |||
470 | RemoveRedundantDbgInstrs(Succ); | |||
471 | // BB is valid for cleanup here because we passed in DTU. F remains | |||
472 | // BB's parent until a DTU->getDomTree() event. | |||
473 | LVI->eraseBlock(&BB); | |||
474 | Changed = true; | |||
475 | } | |||
476 | } | |||
477 | } | |||
478 | EverChanged |= Changed; | |||
479 | } while (Changed); | |||
480 | ||||
481 | LoopHeaders.clear(); | |||
482 | return EverChanged; | |||
483 | } | |||
484 | ||||
485 | // Replace uses of Cond with ToVal when safe to do so. If all uses are | |||
486 | // replaced, we can remove Cond. We cannot blindly replace all uses of Cond | |||
487 | // because we may incorrectly replace uses when guards/assumes are uses of | |||
488 | // of `Cond` and we used the guards/assume to reason about the `Cond` value | |||
489 | // at the end of block. RAUW unconditionally replaces all uses | |||
490 | // including the guards/assumes themselves and the uses before the | |||
491 | // guard/assume. | |||
492 | static void replaceFoldableUses(Instruction *Cond, Value *ToVal) { | |||
493 | assert(Cond->getType() == ToVal->getType())((void)0); | |||
494 | auto *BB = Cond->getParent(); | |||
495 | // We can unconditionally replace all uses in non-local blocks (i.e. uses | |||
496 | // strictly dominated by BB), since LVI information is true from the | |||
497 | // terminator of BB. | |||
498 | replaceNonLocalUsesWith(Cond, ToVal); | |||
499 | for (Instruction &I : reverse(*BB)) { | |||
500 | // Reached the Cond whose uses we are trying to replace, so there are no | |||
501 | // more uses. | |||
502 | if (&I == Cond) | |||
503 | break; | |||
504 | // We only replace uses in instructions that are guaranteed to reach the end | |||
505 | // of BB, where we know Cond is ToVal. | |||
506 | if (!isGuaranteedToTransferExecutionToSuccessor(&I)) | |||
507 | break; | |||
508 | I.replaceUsesOfWith(Cond, ToVal); | |||
509 | } | |||
510 | if (Cond->use_empty() && !Cond->mayHaveSideEffects()) | |||
511 | Cond->eraseFromParent(); | |||
512 | } | |||
513 | ||||
514 | /// Return the cost of duplicating a piece of this block from first non-phi | |||
515 | /// and before StopAt instruction to thread across it. Stop scanning the block | |||
516 | /// when exceeding the threshold. If duplication is impossible, returns ~0U. | |||
517 | static unsigned getJumpThreadDuplicationCost(BasicBlock *BB, | |||
518 | Instruction *StopAt, | |||
519 | unsigned Threshold) { | |||
520 | assert(StopAt->getParent() == BB && "Not an instruction from proper BB?")((void)0); | |||
521 | /// Ignore PHI nodes, these will be flattened when duplication happens. | |||
522 | BasicBlock::const_iterator I(BB->getFirstNonPHI()); | |||
523 | ||||
524 | // FIXME: THREADING will delete values that are just used to compute the | |||
525 | // branch, so they shouldn't count against the duplication cost. | |||
526 | ||||
527 | unsigned Bonus = 0; | |||
528 | if (BB->getTerminator() == StopAt) { | |||
529 | // Threading through a switch statement is particularly profitable. If this | |||
530 | // block ends in a switch, decrease its cost to make it more likely to | |||
531 | // happen. | |||
532 | if (isa<SwitchInst>(StopAt)) | |||
533 | Bonus = 6; | |||
534 | ||||
535 | // The same holds for indirect branches, but slightly more so. | |||
536 | if (isa<IndirectBrInst>(StopAt)) | |||
537 | Bonus = 8; | |||
538 | } | |||
539 | ||||
540 | // Bump the threshold up so the early exit from the loop doesn't skip the | |||
541 | // terminator-based Size adjustment at the end. | |||
542 | Threshold += Bonus; | |||
543 | ||||
544 | // Sum up the cost of each instruction until we get to the terminator. Don't | |||
545 | // include the terminator because the copy won't include it. | |||
546 | unsigned Size = 0; | |||
547 | for (; &*I != StopAt; ++I) { | |||
548 | ||||
549 | // Stop scanning the block if we've reached the threshold. | |||
550 | if (Size > Threshold) | |||
551 | return Size; | |||
552 | ||||
553 | // Debugger intrinsics don't incur code size. | |||
554 | if (isa<DbgInfoIntrinsic>(I)) continue; | |||
555 | ||||
556 | // Pseudo-probes don't incur code size. | |||
557 | if (isa<PseudoProbeInst>(I)) | |||
558 | continue; | |||
559 | ||||
560 | // If this is a pointer->pointer bitcast, it is free. | |||
561 | if (isa<BitCastInst>(I) && I->getType()->isPointerTy()) | |||
562 | continue; | |||
563 | ||||
564 | // Freeze instruction is free, too. | |||
565 | if (isa<FreezeInst>(I)) | |||
566 | continue; | |||
567 | ||||
568 | // Bail out if this instruction gives back a token type, it is not possible | |||
569 | // to duplicate it if it is used outside this BB. | |||
570 | if (I->getType()->isTokenTy() && I->isUsedOutsideOfBlock(BB)) | |||
571 | return ~0U; | |||
572 | ||||
573 | // All other instructions count for at least one unit. | |||
574 | ++Size; | |||
575 | ||||
576 | // Calls are more expensive. If they are non-intrinsic calls, we model them | |||
577 | // as having cost of 4. If they are a non-vector intrinsic, we model them | |||
578 | // as having cost of 2 total, and if they are a vector intrinsic, we model | |||
579 | // them as having cost 1. | |||
580 | if (const CallInst *CI = dyn_cast<CallInst>(I)) { | |||
581 | if (CI->cannotDuplicate() || CI->isConvergent()) | |||
582 | // Blocks with NoDuplicate are modelled as having infinite cost, so they | |||
583 | // are never duplicated. | |||
584 | return ~0U; | |||
585 | else if (!isa<IntrinsicInst>(CI)) | |||
586 | Size += 3; | |||
587 | else if (!CI->getType()->isVectorTy()) | |||
588 | Size += 1; | |||
589 | } | |||
590 | } | |||
591 | ||||
592 | return Size > Bonus ? Size - Bonus : 0; | |||
593 | } | |||
594 | ||||
595 | /// findLoopHeaders - We do not want jump threading to turn proper loop | |||
596 | /// structures into irreducible loops. Doing this breaks up the loop nesting | |||
597 | /// hierarchy and pessimizes later transformations. To prevent this from | |||
598 | /// happening, we first have to find the loop headers. Here we approximate this | |||
599 | /// by finding targets of backedges in the CFG. | |||
600 | /// | |||
601 | /// Note that there definitely are cases when we want to allow threading of | |||
602 | /// edges across a loop header. For example, threading a jump from outside the | |||
603 | /// loop (the preheader) to an exit block of the loop is definitely profitable. | |||
604 | /// It is also almost always profitable to thread backedges from within the loop | |||
605 | /// to exit blocks, and is often profitable to thread backedges to other blocks | |||
606 | /// within the loop (forming a nested loop). This simple analysis is not rich | |||
607 | /// enough to track all of these properties and keep it up-to-date as the CFG | |||
608 | /// mutates, so we don't allow any of these transformations. | |||
609 | void JumpThreadingPass::findLoopHeaders(Function &F) { | |||
610 | SmallVector<std::pair<const BasicBlock*,const BasicBlock*>, 32> Edges; | |||
611 | FindFunctionBackedges(F, Edges); | |||
612 | ||||
613 | for (const auto &Edge : Edges) | |||
614 | LoopHeaders.insert(Edge.second); | |||
615 | } | |||
616 | ||||
617 | /// getKnownConstant - Helper method to determine if we can thread over a | |||
618 | /// terminator with the given value as its condition, and if so what value to | |||
619 | /// use for that. What kind of value this is depends on whether we want an | |||
620 | /// integer or a block address, but an undef is always accepted. | |||
621 | /// Returns null if Val is null or not an appropriate constant. | |||
622 | static Constant *getKnownConstant(Value *Val, ConstantPreference Preference) { | |||
623 | if (!Val) | |||
624 | return nullptr; | |||
625 | ||||
626 | // Undef is "known" enough. | |||
627 | if (UndefValue *U = dyn_cast<UndefValue>(Val)) | |||
628 | return U; | |||
629 | ||||
630 | if (Preference == WantBlockAddress) | |||
631 | return dyn_cast<BlockAddress>(Val->stripPointerCasts()); | |||
632 | ||||
633 | return dyn_cast<ConstantInt>(Val); | |||
634 | } | |||
635 | ||||
636 | /// computeValueKnownInPredecessors - Given a basic block BB and a value V, see | |||
637 | /// if we can infer that the value is a known ConstantInt/BlockAddress or undef | |||
638 | /// in any of our predecessors. If so, return the known list of value and pred | |||
639 | /// BB in the result vector. | |||
640 | /// | |||
641 | /// This returns true if there were any known values. | |||
642 | bool JumpThreadingPass::computeValueKnownInPredecessorsImpl( | |||
643 | Value *V, BasicBlock *BB, PredValueInfo &Result, | |||
644 | ConstantPreference Preference, DenseSet<Value *> &RecursionSet, | |||
645 | Instruction *CxtI) { | |||
646 | // This method walks up use-def chains recursively. Because of this, we could | |||
647 | // get into an infinite loop going around loops in the use-def chain. To | |||
648 | // prevent this, keep track of what (value, block) pairs we've already visited | |||
649 | // and terminate the search if we loop back to them | |||
650 | if (!RecursionSet.insert(V).second) | |||
651 | return false; | |||
652 | ||||
653 | // If V is a constant, then it is known in all predecessors. | |||
654 | if (Constant *KC = getKnownConstant(V, Preference)) { | |||
655 | for (BasicBlock *Pred : predecessors(BB)) | |||
656 | Result.emplace_back(KC, Pred); | |||
657 | ||||
658 | return !Result.empty(); | |||
659 | } | |||
660 | ||||
661 | // If V is a non-instruction value, or an instruction in a different block, | |||
662 | // then it can't be derived from a PHI. | |||
663 | Instruction *I = dyn_cast<Instruction>(V); | |||
664 | if (!I || I->getParent() != BB) { | |||
665 | ||||
666 | // Okay, if this is a live-in value, see if it has a known value at the end | |||
667 | // of any of our predecessors. | |||
668 | // | |||
669 | // FIXME: This should be an edge property, not a block end property. | |||
670 | /// TODO: Per PR2563, we could infer value range information about a | |||
671 | /// predecessor based on its terminator. | |||
672 | // | |||
673 | // FIXME: change this to use the more-rich 'getPredicateOnEdge' method if | |||
674 | // "I" is a non-local compare-with-a-constant instruction. This would be | |||
675 | // able to handle value inequalities better, for example if the compare is | |||
676 | // "X < 4" and "X < 3" is known true but "X < 4" itself is not available. | |||
677 | // Perhaps getConstantOnEdge should be smart enough to do this? | |||
678 | for (BasicBlock *P : predecessors(BB)) { | |||
679 | // If the value is known by LazyValueInfo to be a constant in a | |||
680 | // predecessor, use that information to try to thread this block. | |||
681 | Constant *PredCst = LVI->getConstantOnEdge(V, P, BB, CxtI); | |||
682 | if (Constant *KC = getKnownConstant(PredCst, Preference)) | |||
683 | Result.emplace_back(KC, P); | |||
684 | } | |||
685 | ||||
686 | return !Result.empty(); | |||
687 | } | |||
688 | ||||
689 | /// If I is a PHI node, then we know the incoming values for any constants. | |||
690 | if (PHINode *PN = dyn_cast<PHINode>(I)) { | |||
691 | for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) { | |||
692 | Value *InVal = PN->getIncomingValue(i); | |||
693 | if (Constant *KC = getKnownConstant(InVal, Preference)) { | |||
694 | Result.emplace_back(KC, PN->getIncomingBlock(i)); | |||
695 | } else { | |||
696 | Constant *CI = LVI->getConstantOnEdge(InVal, | |||
697 | PN->getIncomingBlock(i), | |||
698 | BB, CxtI); | |||
699 | if (Constant *KC = getKnownConstant(CI, Preference)) | |||
700 | Result.emplace_back(KC, PN->getIncomingBlock(i)); | |||
701 | } | |||
702 | } | |||
703 | ||||
704 | return !Result.empty(); | |||
705 | } | |||
706 | ||||
707 | // Handle Cast instructions. | |||
708 | if (CastInst *CI = dyn_cast<CastInst>(I)) { | |||
709 | Value *Source = CI->getOperand(0); | |||
710 | computeValueKnownInPredecessorsImpl(Source, BB, Result, Preference, | |||
711 | RecursionSet, CxtI); | |||
712 | if (Result.empty()) | |||
713 | return false; | |||
714 | ||||
715 | // Convert the known values. | |||
716 | for (auto &R : Result) | |||
717 | R.first = ConstantExpr::getCast(CI->getOpcode(), R.first, CI->getType()); | |||
718 | ||||
719 | return true; | |||
720 | } | |||
721 | ||||
722 | if (FreezeInst *FI = dyn_cast<FreezeInst>(I)) { | |||
723 | Value *Source = FI->getOperand(0); | |||
724 | computeValueKnownInPredecessorsImpl(Source, BB, Result, Preference, | |||
725 | RecursionSet, CxtI); | |||
726 | ||||
727 | erase_if(Result, [](auto &Pair) { | |||
728 | return !isGuaranteedNotToBeUndefOrPoison(Pair.first); | |||
729 | }); | |||
730 | ||||
731 | return !Result.empty(); | |||
732 | } | |||
733 | ||||
734 | // Handle some boolean conditions. | |||
735 | if (I->getType()->getPrimitiveSizeInBits() == 1) { | |||
736 | using namespace PatternMatch; | |||
737 | ||||
738 | assert(Preference == WantInteger && "One-bit non-integer type?")((void)0); | |||
739 | // X | true -> true | |||
740 | // X & false -> false | |||
741 | Value *Op0, *Op1; | |||
742 | if (match(I, m_LogicalOr(m_Value(Op0), m_Value(Op1))) || | |||
743 | match(I, m_LogicalAnd(m_Value(Op0), m_Value(Op1)))) { | |||
744 | PredValueInfoTy LHSVals, RHSVals; | |||
745 | ||||
746 | computeValueKnownInPredecessorsImpl(Op0, BB, LHSVals, WantInteger, | |||
747 | RecursionSet, CxtI); | |||
748 | computeValueKnownInPredecessorsImpl(Op1, BB, RHSVals, WantInteger, | |||
749 | RecursionSet, CxtI); | |||
750 | ||||
751 | if (LHSVals.empty() && RHSVals.empty()) | |||
752 | return false; | |||
753 | ||||
754 | ConstantInt *InterestingVal; | |||
755 | if (match(I, m_LogicalOr())) | |||
756 | InterestingVal = ConstantInt::getTrue(I->getContext()); | |||
757 | else | |||
758 | InterestingVal = ConstantInt::getFalse(I->getContext()); | |||
759 | ||||
760 | SmallPtrSet<BasicBlock*, 4> LHSKnownBBs; | |||
761 | ||||
762 | // Scan for the sentinel. If we find an undef, force it to the | |||
763 | // interesting value: x|undef -> true and x&undef -> false. | |||
764 | for (const auto &LHSVal : LHSVals) | |||
765 | if (LHSVal.first == InterestingVal || isa<UndefValue>(LHSVal.first)) { | |||
766 | Result.emplace_back(InterestingVal, LHSVal.second); | |||
767 | LHSKnownBBs.insert(LHSVal.second); | |||
768 | } | |||
769 | for (const auto &RHSVal : RHSVals) | |||
770 | if (RHSVal.first == InterestingVal || isa<UndefValue>(RHSVal.first)) { | |||
771 | // If we already inferred a value for this block on the LHS, don't | |||
772 | // re-add it. | |||
773 | if (!LHSKnownBBs.count(RHSVal.second)) | |||
774 | Result.emplace_back(InterestingVal, RHSVal.second); | |||
775 | } | |||
776 | ||||
777 | return !Result.empty(); | |||
778 | } | |||
779 | ||||
780 | // Handle the NOT form of XOR. | |||
781 | if (I->getOpcode() == Instruction::Xor && | |||
782 | isa<ConstantInt>(I->getOperand(1)) && | |||
783 | cast<ConstantInt>(I->getOperand(1))->isOne()) { | |||
784 | computeValueKnownInPredecessorsImpl(I->getOperand(0), BB, Result, | |||
785 | WantInteger, RecursionSet, CxtI); | |||
786 | if (Result.empty()) | |||
787 | return false; | |||
788 | ||||
789 | // Invert the known values. | |||
790 | for (auto &R : Result) | |||
791 | R.first = ConstantExpr::getNot(R.first); | |||
792 | ||||
793 | return true; | |||
794 | } | |||
795 | ||||
796 | // Try to simplify some other binary operator values. | |||
797 | } else if (BinaryOperator *BO = dyn_cast<BinaryOperator>(I)) { | |||
798 | assert(Preference != WantBlockAddress((void)0) | |||
799 | && "A binary operator creating a block address?")((void)0); | |||
800 | if (ConstantInt *CI = dyn_cast<ConstantInt>(BO->getOperand(1))) { | |||
801 | PredValueInfoTy LHSVals; | |||
802 | computeValueKnownInPredecessorsImpl(BO->getOperand(0), BB, LHSVals, | |||
803 | WantInteger, RecursionSet, CxtI); | |||
804 | ||||
805 | // Try to use constant folding to simplify the binary operator. | |||
806 | for (const auto &LHSVal : LHSVals) { | |||
807 | Constant *V = LHSVal.first; | |||
808 | Constant *Folded = ConstantExpr::get(BO->getOpcode(), V, CI); | |||
809 | ||||
810 | if (Constant *KC = getKnownConstant(Folded, WantInteger)) | |||
811 | Result.emplace_back(KC, LHSVal.second); | |||
812 | } | |||
813 | } | |||
814 | ||||
815 | return !Result.empty(); | |||
816 | } | |||
817 | ||||
818 | // Handle compare with phi operand, where the PHI is defined in this block. | |||
819 | if (CmpInst *Cmp = dyn_cast<CmpInst>(I)) { | |||
820 | assert(Preference == WantInteger && "Compares only produce integers")((void)0); | |||
821 | Type *CmpType = Cmp->getType(); | |||
822 | Value *CmpLHS = Cmp->getOperand(0); | |||
823 | Value *CmpRHS = Cmp->getOperand(1); | |||
824 | CmpInst::Predicate Pred = Cmp->getPredicate(); | |||
825 | ||||
826 | PHINode *PN = dyn_cast<PHINode>(CmpLHS); | |||
827 | if (!PN) | |||
828 | PN = dyn_cast<PHINode>(CmpRHS); | |||
829 | if (PN && PN->getParent() == BB) { | |||
830 | const DataLayout &DL = PN->getModule()->getDataLayout(); | |||
831 | // We can do this simplification if any comparisons fold to true or false. | |||
832 | // See if any do. | |||
833 | for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) { | |||
834 | BasicBlock *PredBB = PN->getIncomingBlock(i); | |||
835 | Value *LHS, *RHS; | |||
836 | if (PN == CmpLHS) { | |||
837 | LHS = PN->getIncomingValue(i); | |||
838 | RHS = CmpRHS->DoPHITranslation(BB, PredBB); | |||
839 | } else { | |||
840 | LHS = CmpLHS->DoPHITranslation(BB, PredBB); | |||
841 | RHS = PN->getIncomingValue(i); | |||
842 | } | |||
843 | Value *Res = SimplifyCmpInst(Pred, LHS, RHS, {DL}); | |||
844 | if (!Res) { | |||
845 | if (!isa<Constant>(RHS)) | |||
846 | continue; | |||
847 | ||||
848 | // getPredicateOnEdge call will make no sense if LHS is defined in BB. | |||
849 | auto LHSInst = dyn_cast<Instruction>(LHS); | |||
850 | if (LHSInst && LHSInst->getParent() == BB) | |||
851 | continue; | |||
852 | ||||
853 | LazyValueInfo::Tristate | |||
854 | ResT = LVI->getPredicateOnEdge(Pred, LHS, | |||
855 | cast<Constant>(RHS), PredBB, BB, | |||
856 | CxtI ? CxtI : Cmp); | |||
857 | if (ResT == LazyValueInfo::Unknown) | |||
858 | continue; | |||
859 | Res = ConstantInt::get(Type::getInt1Ty(LHS->getContext()), ResT); | |||
860 | } | |||
861 | ||||
862 | if (Constant *KC = getKnownConstant(Res, WantInteger)) | |||
863 | Result.emplace_back(KC, PredBB); | |||
864 | } | |||
865 | ||||
866 | return !Result.empty(); | |||
867 | } | |||
868 | ||||
869 | // If comparing a live-in value against a constant, see if we know the | |||
870 | // live-in value on any predecessors. | |||
871 | if (isa<Constant>(CmpRHS) && !CmpType->isVectorTy()) { | |||
872 | Constant *CmpConst = cast<Constant>(CmpRHS); | |||
873 | ||||
874 | if (!isa<Instruction>(CmpLHS) || | |||
875 | cast<Instruction>(CmpLHS)->getParent() != BB) { | |||
876 | for (BasicBlock *P : predecessors(BB)) { | |||
877 | // If the value is known by LazyValueInfo to be a constant in a | |||
878 | // predecessor, use that information to try to thread this block. | |||
879 | LazyValueInfo::Tristate Res = | |||
880 | LVI->getPredicateOnEdge(Pred, CmpLHS, | |||
881 | CmpConst, P, BB, CxtI ? CxtI : Cmp); | |||
882 | if (Res == LazyValueInfo::Unknown) | |||
883 | continue; | |||
884 | ||||
885 | Constant *ResC = ConstantInt::get(CmpType, Res); | |||
886 | Result.emplace_back(ResC, P); | |||
887 | } | |||
888 | ||||
889 | return !Result.empty(); | |||
890 | } | |||
891 | ||||
892 | // InstCombine can fold some forms of constant range checks into | |||
893 | // (icmp (add (x, C1)), C2). See if we have we have such a thing with | |||
894 | // x as a live-in. | |||
895 | { | |||
896 | using namespace PatternMatch; | |||
897 | ||||
898 | Value *AddLHS; | |||
899 | ConstantInt *AddConst; | |||
900 | if (isa<ConstantInt>(CmpConst) && | |||
901 | match(CmpLHS, m_Add(m_Value(AddLHS), m_ConstantInt(AddConst)))) { | |||
902 | if (!isa<Instruction>(AddLHS) || | |||
903 | cast<Instruction>(AddLHS)->getParent() != BB) { | |||
904 | for (BasicBlock *P : predecessors(BB)) { | |||
905 | // If the value is known by LazyValueInfo to be a ConstantRange in | |||
906 | // a predecessor, use that information to try to thread this | |||
907 | // block. | |||
908 | ConstantRange CR = LVI->getConstantRangeOnEdge( | |||
909 | AddLHS, P, BB, CxtI ? CxtI : cast<Instruction>(CmpLHS)); | |||
910 | // Propagate the range through the addition. | |||
911 | CR = CR.add(AddConst->getValue()); | |||
912 | ||||
913 | // Get the range where the compare returns true. | |||
914 | ConstantRange CmpRange = ConstantRange::makeExactICmpRegion( | |||
915 | Pred, cast<ConstantInt>(CmpConst)->getValue()); | |||
916 | ||||
917 | Constant *ResC; | |||
918 | if (CmpRange.contains(CR)) | |||
919 | ResC = ConstantInt::getTrue(CmpType); | |||
920 | else if (CmpRange.inverse().contains(CR)) | |||
921 | ResC = ConstantInt::getFalse(CmpType); | |||
922 | else | |||
923 | continue; | |||
924 | ||||
925 | Result.emplace_back(ResC, P); | |||
926 | } | |||
927 | ||||
928 | return !Result.empty(); | |||
929 | } | |||
930 | } | |||
931 | } | |||
932 | ||||
933 | // Try to find a constant value for the LHS of a comparison, | |||
934 | // and evaluate it statically if we can. | |||
935 | PredValueInfoTy LHSVals; | |||
936 | computeValueKnownInPredecessorsImpl(I->getOperand(0), BB, LHSVals, | |||
937 | WantInteger, RecursionSet, CxtI); | |||
938 | ||||
939 | for (const auto &LHSVal : LHSVals) { | |||
940 | Constant *V = LHSVal.first; | |||
941 | Constant *Folded = ConstantExpr::getCompare(Pred, V, CmpConst); | |||
942 | if (Constant *KC = getKnownConstant(Folded, WantInteger)) | |||
943 | Result.emplace_back(KC, LHSVal.second); | |||
944 | } | |||
945 | ||||
946 | return !Result.empty(); | |||
947 | } | |||
948 | } | |||
949 | ||||
950 | if (SelectInst *SI = dyn_cast<SelectInst>(I)) { | |||
951 | // Handle select instructions where at least one operand is a known constant | |||
952 | // and we can figure out the condition value for any predecessor block. | |||
953 | Constant *TrueVal = getKnownConstant(SI->getTrueValue(), Preference); | |||
954 | Constant *FalseVal = getKnownConstant(SI->getFalseValue(), Preference); | |||
955 | PredValueInfoTy Conds; | |||
956 | if ((TrueVal || FalseVal) && | |||
957 | computeValueKnownInPredecessorsImpl(SI->getCondition(), BB, Conds, | |||
958 | WantInteger, RecursionSet, CxtI)) { | |||
959 | for (auto &C : Conds) { | |||
960 | Constant *Cond = C.first; | |||
961 | ||||
962 | // Figure out what value to use for the condition. | |||
963 | bool KnownCond; | |||
964 | if (ConstantInt *CI = dyn_cast<ConstantInt>(Cond)) { | |||
965 | // A known boolean. | |||
966 | KnownCond = CI->isOne(); | |||
967 | } else { | |||
968 | assert(isa<UndefValue>(Cond) && "Unexpected condition value")((void)0); | |||
969 | // Either operand will do, so be sure to pick the one that's a known | |||
970 | // constant. | |||
971 | // FIXME: Do this more cleverly if both values are known constants? | |||
972 | KnownCond = (TrueVal != nullptr); | |||
973 | } | |||
974 | ||||
975 | // See if the select has a known constant value for this predecessor. | |||
976 | if (Constant *Val = KnownCond ? TrueVal : FalseVal) | |||
977 | Result.emplace_back(Val, C.second); | |||
978 | } | |||
979 | ||||
980 | return !Result.empty(); | |||
981 | } | |||
982 | } | |||
983 | ||||
984 | // If all else fails, see if LVI can figure out a constant value for us. | |||
985 | assert(CxtI->getParent() == BB && "CxtI should be in BB")((void)0); | |||
986 | Constant *CI = LVI->getConstant(V, CxtI); | |||
987 | if (Constant *KC = getKnownConstant(CI, Preference)) { | |||
988 | for (BasicBlock *Pred : predecessors(BB)) | |||
989 | Result.emplace_back(KC, Pred); | |||
990 | } | |||
991 | ||||
992 | return !Result.empty(); | |||
993 | } | |||
994 | ||||
995 | /// GetBestDestForBranchOnUndef - If we determine that the specified block ends | |||
996 | /// in an undefined jump, decide which block is best to revector to. | |||
997 | /// | |||
998 | /// Since we can pick an arbitrary destination, we pick the successor with the | |||
999 | /// fewest predecessors. This should reduce the in-degree of the others. | |||
1000 | static unsigned getBestDestForJumpOnUndef(BasicBlock *BB) { | |||
1001 | Instruction *BBTerm = BB->getTerminator(); | |||
1002 | unsigned MinSucc = 0; | |||
1003 | BasicBlock *TestBB = BBTerm->getSuccessor(MinSucc); | |||
1004 | // Compute the successor with the minimum number of predecessors. | |||
1005 | unsigned MinNumPreds = pred_size(TestBB); | |||
1006 | for (unsigned i = 1, e = BBTerm->getNumSuccessors(); i != e; ++i) { | |||
1007 | TestBB = BBTerm->getSuccessor(i); | |||
1008 | unsigned NumPreds = pred_size(TestBB); | |||
1009 | if (NumPreds < MinNumPreds) { | |||
1010 | MinSucc = i; | |||
1011 | MinNumPreds = NumPreds; | |||
1012 | } | |||
1013 | } | |||
1014 | ||||
1015 | return MinSucc; | |||
1016 | } | |||
1017 | ||||
1018 | static bool hasAddressTakenAndUsed(BasicBlock *BB) { | |||
1019 | if (!BB->hasAddressTaken()) return false; | |||
1020 | ||||
1021 | // If the block has its address taken, it may be a tree of dead constants | |||
1022 | // hanging off of it. These shouldn't keep the block alive. | |||
1023 | BlockAddress *BA = BlockAddress::get(BB); | |||
1024 | BA->removeDeadConstantUsers(); | |||
1025 | return !BA->use_empty(); | |||
1026 | } | |||
1027 | ||||
1028 | /// processBlock - If there are any predecessors whose control can be threaded | |||
1029 | /// through to a successor, transform them now. | |||
1030 | bool JumpThreadingPass::processBlock(BasicBlock *BB) { | |||
1031 | // If the block is trivially dead, just return and let the caller nuke it. | |||
1032 | // This simplifies other transformations. | |||
1033 | if (DTU->isBBPendingDeletion(BB) || | |||
1034 | (pred_empty(BB) && BB != &BB->getParent()->getEntryBlock())) | |||
1035 | return false; | |||
1036 | ||||
1037 | // If this block has a single predecessor, and if that pred has a single | |||
1038 | // successor, merge the blocks. This encourages recursive jump threading | |||
1039 | // because now the condition in this block can be threaded through | |||
1040 | // predecessors of our predecessor block. | |||
1041 | if (maybeMergeBasicBlockIntoOnlyPred(BB)) | |||
1042 | return true; | |||
1043 | ||||
1044 | if (tryToUnfoldSelectInCurrBB(BB)) | |||
1045 | return true; | |||
1046 | ||||
1047 | // Look if we can propagate guards to predecessors. | |||
1048 | if (HasGuards && processGuards(BB)) | |||
1049 | return true; | |||
1050 | ||||
1051 | // What kind of constant we're looking for. | |||
1052 | ConstantPreference Preference = WantInteger; | |||
1053 | ||||
1054 | // Look to see if the terminator is a conditional branch, switch or indirect | |||
1055 | // branch, if not we can't thread it. | |||
1056 | Value *Condition; | |||
1057 | Instruction *Terminator = BB->getTerminator(); | |||
1058 | if (BranchInst *BI = dyn_cast<BranchInst>(Terminator)) { | |||
1059 | // Can't thread an unconditional jump. | |||
1060 | if (BI->isUnconditional()) return false; | |||
1061 | Condition = BI->getCondition(); | |||
1062 | } else if (SwitchInst *SI = dyn_cast<SwitchInst>(Terminator)) { | |||
1063 | Condition = SI->getCondition(); | |||
1064 | } else if (IndirectBrInst *IB = dyn_cast<IndirectBrInst>(Terminator)) { | |||
1065 | // Can't thread indirect branch with no successors. | |||
1066 | if (IB->getNumSuccessors() == 0) return false; | |||
1067 | Condition = IB->getAddress()->stripPointerCasts(); | |||
1068 | Preference = WantBlockAddress; | |||
1069 | } else { | |||
1070 | return false; // Must be an invoke or callbr. | |||
1071 | } | |||
1072 | ||||
1073 | // Keep track if we constant folded the condition in this invocation. | |||
1074 | bool ConstantFolded = false; | |||
1075 | ||||
1076 | // Run constant folding to see if we can reduce the condition to a simple | |||
1077 | // constant. | |||
1078 | if (Instruction *I = dyn_cast<Instruction>(Condition)) { | |||
1079 | Value *SimpleVal = | |||
1080 | ConstantFoldInstruction(I, BB->getModule()->getDataLayout(), TLI); | |||
1081 | if (SimpleVal) { | |||
1082 | I->replaceAllUsesWith(SimpleVal); | |||
1083 | if (isInstructionTriviallyDead(I, TLI)) | |||
1084 | I->eraseFromParent(); | |||
1085 | Condition = SimpleVal; | |||
1086 | ConstantFolded = true; | |||
1087 | } | |||
1088 | } | |||
1089 | ||||
1090 | // If the terminator is branching on an undef or freeze undef, we can pick any | |||
1091 | // of the successors to branch to. Let getBestDestForJumpOnUndef decide. | |||
1092 | auto *FI = dyn_cast<FreezeInst>(Condition); | |||
1093 | if (isa<UndefValue>(Condition) || | |||
1094 | (FI && isa<UndefValue>(FI->getOperand(0)) && FI->hasOneUse())) { | |||
1095 | unsigned BestSucc = getBestDestForJumpOnUndef(BB); | |||
1096 | std::vector<DominatorTree::UpdateType> Updates; | |||
1097 | ||||
1098 | // Fold the branch/switch. | |||
1099 | Instruction *BBTerm = BB->getTerminator(); | |||
1100 | Updates.reserve(BBTerm->getNumSuccessors()); | |||
1101 | for (unsigned i = 0, e = BBTerm->getNumSuccessors(); i != e; ++i) { | |||
1102 | if (i == BestSucc) continue; | |||
1103 | BasicBlock *Succ = BBTerm->getSuccessor(i); | |||
1104 | Succ->removePredecessor(BB, true); | |||
1105 | Updates.push_back({DominatorTree::Delete, BB, Succ}); | |||
1106 | } | |||
1107 | ||||
1108 | LLVM_DEBUG(dbgs() << " In block '" << BB->getName()do { } while (false) | |||
1109 | << "' folding undef terminator: " << *BBTerm << '\n')do { } while (false); | |||
1110 | BranchInst::Create(BBTerm->getSuccessor(BestSucc), BBTerm); | |||
1111 | ++NumFolds; | |||
1112 | BBTerm->eraseFromParent(); | |||
1113 | DTU->applyUpdatesPermissive(Updates); | |||
1114 | if (FI) | |||
1115 | FI->eraseFromParent(); | |||
1116 | return true; | |||
1117 | } | |||
1118 | ||||
1119 | // If the terminator of this block is branching on a constant, simplify the | |||
1120 | // terminator to an unconditional branch. This can occur due to threading in | |||
1121 | // other blocks. | |||
1122 | if (getKnownConstant(Condition, Preference)) { | |||
1123 | LLVM_DEBUG(dbgs() << " In block '" << BB->getName()do { } while (false) | |||
1124 | << "' folding terminator: " << *BB->getTerminator()do { } while (false) | |||
1125 | << '\n')do { } while (false); | |||
1126 | ++NumFolds; | |||
1127 | ConstantFoldTerminator(BB, true, nullptr, DTU); | |||
1128 | if (HasProfileData) | |||
1129 | BPI->eraseBlock(BB); | |||
1130 | return true; | |||
1131 | } | |||
1132 | ||||
1133 | Instruction *CondInst = dyn_cast<Instruction>(Condition); | |||
1134 | ||||
1135 | // All the rest of our checks depend on the condition being an instruction. | |||
1136 | if (!CondInst) { | |||
1137 | // FIXME: Unify this with code below. | |||
1138 | if (processThreadableEdges(Condition, BB, Preference, Terminator)) | |||
1139 | return true; | |||
1140 | return ConstantFolded; | |||
1141 | } | |||
1142 | ||||
1143 | if (CmpInst *CondCmp = dyn_cast<CmpInst>(CondInst)) { | |||
1144 | // If we're branching on a conditional, LVI might be able to determine | |||
1145 | // it's value at the branch instruction. We only handle comparisons | |||
1146 | // against a constant at this time. | |||
1147 | // TODO: This should be extended to handle switches as well. | |||
1148 | BranchInst *CondBr = dyn_cast<BranchInst>(BB->getTerminator()); | |||
1149 | Constant *CondConst = dyn_cast<Constant>(CondCmp->getOperand(1)); | |||
1150 | if (CondBr && CondConst) { | |||
1151 | // We should have returned as soon as we turn a conditional branch to | |||
1152 | // unconditional. Because its no longer interesting as far as jump | |||
1153 | // threading is concerned. | |||
1154 | assert(CondBr->isConditional() && "Threading on unconditional terminator")((void)0); | |||
1155 | ||||
1156 | LazyValueInfo::Tristate Ret = | |||
1157 | LVI->getPredicateAt(CondCmp->getPredicate(), CondCmp->getOperand(0), | |||
1158 | CondConst, CondBr, /*UseBlockValue=*/false); | |||
1159 | if (Ret != LazyValueInfo::Unknown) { | |||
1160 | unsigned ToRemove = Ret == LazyValueInfo::True ? 1 : 0; | |||
1161 | unsigned ToKeep = Ret == LazyValueInfo::True ? 0 : 1; | |||
1162 | BasicBlock *ToRemoveSucc = CondBr->getSuccessor(ToRemove); | |||
1163 | ToRemoveSucc->removePredecessor(BB, true); | |||
1164 | BranchInst *UncondBr = | |||
1165 | BranchInst::Create(CondBr->getSuccessor(ToKeep), CondBr); | |||
1166 | UncondBr->setDebugLoc(CondBr->getDebugLoc()); | |||
1167 | ++NumFolds; | |||
1168 | CondBr->eraseFromParent(); | |||
1169 | if (CondCmp->use_empty()) | |||
1170 | CondCmp->eraseFromParent(); | |||
1171 | // We can safely replace *some* uses of the CondInst if it has | |||
1172 | // exactly one value as returned by LVI. RAUW is incorrect in the | |||
1173 | // presence of guards and assumes, that have the `Cond` as the use. This | |||
1174 | // is because we use the guards/assume to reason about the `Cond` value | |||
1175 | // at the end of block, but RAUW unconditionally replaces all uses | |||
1176 | // including the guards/assumes themselves and the uses before the | |||
1177 | // guard/assume. | |||
1178 | else if (CondCmp->getParent() == BB) { | |||
1179 | auto *CI = Ret == LazyValueInfo::True ? | |||
1180 | ConstantInt::getTrue(CondCmp->getType()) : | |||
1181 | ConstantInt::getFalse(CondCmp->getType()); | |||
1182 | replaceFoldableUses(CondCmp, CI); | |||
1183 | } | |||
1184 | DTU->applyUpdatesPermissive( | |||
1185 | {{DominatorTree::Delete, BB, ToRemoveSucc}}); | |||
1186 | if (HasProfileData) | |||
1187 | BPI->eraseBlock(BB); | |||
1188 | return true; | |||
1189 | } | |||
1190 | ||||
1191 | // We did not manage to simplify this branch, try to see whether | |||
1192 | // CondCmp depends on a known phi-select pattern. | |||
1193 | if (tryToUnfoldSelect(CondCmp, BB)) | |||
1194 | return true; | |||
1195 | } | |||
1196 | } | |||
1197 | ||||
1198 | if (SwitchInst *SI = dyn_cast<SwitchInst>(BB->getTerminator())) | |||
1199 | if (tryToUnfoldSelect(SI, BB)) | |||
1200 | return true; | |||
1201 | ||||
1202 | // Check for some cases that are worth simplifying. Right now we want to look | |||
1203 | // for loads that are used by a switch or by the condition for the branch. If | |||
1204 | // we see one, check to see if it's partially redundant. If so, insert a PHI | |||
1205 | // which can then be used to thread the values. | |||
1206 | Value *SimplifyValue = CondInst; | |||
1207 | ||||
1208 | if (auto *FI = dyn_cast<FreezeInst>(SimplifyValue)) | |||
1209 | // Look into freeze's operand | |||
1210 | SimplifyValue = FI->getOperand(0); | |||
1211 | ||||
1212 | if (CmpInst *CondCmp = dyn_cast<CmpInst>(SimplifyValue)) | |||
1213 | if (isa<Constant>(CondCmp->getOperand(1))) | |||
1214 | SimplifyValue = CondCmp->getOperand(0); | |||
1215 | ||||
1216 | // TODO: There are other places where load PRE would be profitable, such as | |||
1217 | // more complex comparisons. | |||
1218 | if (LoadInst *LoadI = dyn_cast<LoadInst>(SimplifyValue)) | |||
1219 | if (simplifyPartiallyRedundantLoad(LoadI)) | |||
1220 | return true; | |||
1221 | ||||
1222 | // Before threading, try to propagate profile data backwards: | |||
1223 | if (PHINode *PN = dyn_cast<PHINode>(CondInst)) | |||
1224 | if (PN->getParent() == BB && isa<BranchInst>(BB->getTerminator())) | |||
1225 | updatePredecessorProfileMetadata(PN, BB); | |||
1226 | ||||
1227 | // Handle a variety of cases where we are branching on something derived from | |||
1228 | // a PHI node in the current block. If we can prove that any predecessors | |||
1229 | // compute a predictable value based on a PHI node, thread those predecessors. | |||
1230 | if (processThreadableEdges(CondInst, BB, Preference, Terminator)) | |||
1231 | return true; | |||
1232 | ||||
1233 | // If this is an otherwise-unfoldable branch on a phi node or freeze(phi) in | |||
1234 | // the current block, see if we can simplify. | |||
1235 | PHINode *PN = dyn_cast<PHINode>( | |||
1236 | isa<FreezeInst>(CondInst) ? cast<FreezeInst>(CondInst)->getOperand(0) | |||
1237 | : CondInst); | |||
1238 | ||||
1239 | if (PN && PN->getParent() == BB && isa<BranchInst>(BB->getTerminator())) | |||
1240 | return processBranchOnPHI(PN); | |||
1241 | ||||
1242 | // If this is an otherwise-unfoldable branch on a XOR, see if we can simplify. | |||
1243 | if (CondInst->getOpcode() == Instruction::Xor && | |||
1244 | CondInst->getParent() == BB && isa<BranchInst>(BB->getTerminator())) | |||
1245 | return processBranchOnXOR(cast<BinaryOperator>(CondInst)); | |||
1246 | ||||
1247 | // Search for a stronger dominating condition that can be used to simplify a | |||
1248 | // conditional branch leaving BB. | |||
1249 | if (processImpliedCondition(BB)) | |||
1250 | return true; | |||
1251 | ||||
1252 | return false; | |||
1253 | } | |||
1254 | ||||
1255 | bool JumpThreadingPass::processImpliedCondition(BasicBlock *BB) { | |||
1256 | auto *BI = dyn_cast<BranchInst>(BB->getTerminator()); | |||
1257 | if (!BI || !BI->isConditional()) | |||
1258 | return false; | |||
1259 | ||||
1260 | Value *Cond = BI->getCondition(); | |||
1261 | BasicBlock *CurrentBB = BB; | |||
1262 | BasicBlock *CurrentPred = BB->getSinglePredecessor(); | |||
1263 | unsigned Iter = 0; | |||
1264 | ||||
1265 | auto &DL = BB->getModule()->getDataLayout(); | |||
1266 | ||||
1267 | while (CurrentPred && Iter++ < ImplicationSearchThreshold) { | |||
1268 | auto *PBI = dyn_cast<BranchInst>(CurrentPred->getTerminator()); | |||
1269 | if (!PBI || !PBI->isConditional()) | |||
1270 | return false; | |||
1271 | if (PBI->getSuccessor(0) != CurrentBB && PBI->getSuccessor(1) != CurrentBB) | |||
1272 | return false; | |||
1273 | ||||
1274 | bool CondIsTrue = PBI->getSuccessor(0) == CurrentBB; | |||
1275 | Optional<bool> Implication = | |||
1276 | isImpliedCondition(PBI->getCondition(), Cond, DL, CondIsTrue); | |||
1277 | if (Implication) { | |||
1278 | BasicBlock *KeepSucc = BI->getSuccessor(*Implication ? 0 : 1); | |||
1279 | BasicBlock *RemoveSucc = BI->getSuccessor(*Implication ? 1 : 0); | |||
1280 | RemoveSucc->removePredecessor(BB); | |||
1281 | BranchInst *UncondBI = BranchInst::Create(KeepSucc, BI); | |||
1282 | UncondBI->setDebugLoc(BI->getDebugLoc()); | |||
1283 | ++NumFolds; | |||
1284 | BI->eraseFromParent(); | |||
1285 | DTU->applyUpdatesPermissive({{DominatorTree::Delete, BB, RemoveSucc}}); | |||
1286 | if (HasProfileData) | |||
1287 | BPI->eraseBlock(BB); | |||
1288 | return true; | |||
1289 | } | |||
1290 | CurrentBB = CurrentPred; | |||
1291 | CurrentPred = CurrentBB->getSinglePredecessor(); | |||
1292 | } | |||
1293 | ||||
1294 | return false; | |||
1295 | } | |||
1296 | ||||
1297 | /// Return true if Op is an instruction defined in the given block. | |||
1298 | static bool isOpDefinedInBlock(Value *Op, BasicBlock *BB) { | |||
1299 | if (Instruction *OpInst = dyn_cast<Instruction>(Op)) | |||
1300 | if (OpInst->getParent() == BB) | |||
1301 | return true; | |||
1302 | return false; | |||
1303 | } | |||
1304 | ||||
1305 | /// simplifyPartiallyRedundantLoad - If LoadI is an obviously partially | |||
1306 | /// redundant load instruction, eliminate it by replacing it with a PHI node. | |||
1307 | /// This is an important optimization that encourages jump threading, and needs | |||
1308 | /// to be run interlaced with other jump threading tasks. | |||
1309 | bool JumpThreadingPass::simplifyPartiallyRedundantLoad(LoadInst *LoadI) { | |||
1310 | // Don't hack volatile and ordered loads. | |||
1311 | if (!LoadI->isUnordered()) return false; | |||
| ||||
1312 | ||||
1313 | // If the load is defined in a block with exactly one predecessor, it can't be | |||
1314 | // partially redundant. | |||
1315 | BasicBlock *LoadBB = LoadI->getParent(); | |||
1316 | if (LoadBB->getSinglePredecessor()) | |||
1317 | return false; | |||
1318 | ||||
1319 | // If the load is defined in an EH pad, it can't be partially redundant, | |||
1320 | // because the edges between the invoke and the EH pad cannot have other | |||
1321 | // instructions between them. | |||
1322 | if (LoadBB->isEHPad()) | |||
1323 | return false; | |||
1324 | ||||
1325 | Value *LoadedPtr = LoadI->getOperand(0); | |||
1326 | ||||
1327 | // If the loaded operand is defined in the LoadBB and its not a phi, | |||
1328 | // it can't be available in predecessors. | |||
1329 | if (isOpDefinedInBlock(LoadedPtr, LoadBB) && !isa<PHINode>(LoadedPtr)) | |||
1330 | return false; | |||
1331 | ||||
1332 | // Scan a few instructions up from the load, to see if it is obviously live at | |||
1333 | // the entry to its block. | |||
1334 | BasicBlock::iterator BBIt(LoadI); | |||
1335 | bool IsLoadCSE; | |||
1336 | if (Value *AvailableVal = FindAvailableLoadedValue( | |||
1337 | LoadI, LoadBB, BBIt, DefMaxInstsToScan, AA, &IsLoadCSE)) { | |||
1338 | // If the value of the load is locally available within the block, just use | |||
1339 | // it. This frequently occurs for reg2mem'd allocas. | |||
1340 | ||||
1341 | if (IsLoadCSE) { | |||
1342 | LoadInst *NLoadI = cast<LoadInst>(AvailableVal); | |||
1343 | combineMetadataForCSE(NLoadI, LoadI, false); | |||
1344 | }; | |||
1345 | ||||
1346 | // If the returned value is the load itself, replace with an undef. This can | |||
1347 | // only happen in dead loops. | |||
1348 | if (AvailableVal == LoadI) | |||
1349 | AvailableVal = UndefValue::get(LoadI->getType()); | |||
1350 | if (AvailableVal->getType() != LoadI->getType()) | |||
1351 | AvailableVal = CastInst::CreateBitOrPointerCast( | |||
1352 | AvailableVal, LoadI->getType(), "", LoadI); | |||
1353 | LoadI->replaceAllUsesWith(AvailableVal); | |||
1354 | LoadI->eraseFromParent(); | |||
1355 | return true; | |||
1356 | } | |||
1357 | ||||
1358 | // Otherwise, if we scanned the whole block and got to the top of the block, | |||
1359 | // we know the block is locally transparent to the load. If not, something | |||
1360 | // might clobber its value. | |||
1361 | if (BBIt != LoadBB->begin()) | |||
1362 | return false; | |||
1363 | ||||
1364 | // If all of the loads and stores that feed the value have the same AA tags, | |||
1365 | // then we can propagate them onto any newly inserted loads. | |||
1366 | AAMDNodes AATags; | |||
1367 | LoadI->getAAMetadata(AATags); | |||
1368 | ||||
1369 | SmallPtrSet<BasicBlock*, 8> PredsScanned; | |||
1370 | ||||
1371 | using AvailablePredsTy = SmallVector<std::pair<BasicBlock *, Value *>, 8>; | |||
1372 | ||||
1373 | AvailablePredsTy AvailablePreds; | |||
1374 | BasicBlock *OneUnavailablePred = nullptr; | |||
1375 | SmallVector<LoadInst*, 8> CSELoads; | |||
1376 | ||||
1377 | // If we got here, the loaded value is transparent through to the start of the | |||
1378 | // block. Check to see if it is available in any of the predecessor blocks. | |||
1379 | for (BasicBlock *PredBB : predecessors(LoadBB)) { | |||
1380 | // If we already scanned this predecessor, skip it. | |||
1381 | if (!PredsScanned.insert(PredBB).second) | |||
1382 | continue; | |||
1383 | ||||
1384 | BBIt = PredBB->end(); | |||
1385 | unsigned NumScanedInst = 0; | |||
1386 | Value *PredAvailable = nullptr; | |||
1387 | // NOTE: We don't CSE load that is volatile or anything stronger than | |||
1388 | // unordered, that should have been checked when we entered the function. | |||
1389 | assert(LoadI->isUnordered() &&((void)0) | |||
1390 | "Attempting to CSE volatile or atomic loads")((void)0); | |||
1391 | // If this is a load on a phi pointer, phi-translate it and search | |||
1392 | // for available load/store to the pointer in predecessors. | |||
1393 | Type *AccessTy = LoadI->getType(); | |||
1394 | const auto &DL = LoadI->getModule()->getDataLayout(); | |||
1395 | MemoryLocation Loc(LoadedPtr->DoPHITranslation(LoadBB, PredBB), | |||
1396 | LocationSize::precise(DL.getTypeStoreSize(AccessTy)), | |||
1397 | AATags); | |||
1398 | PredAvailable = findAvailablePtrLoadStore(Loc, AccessTy, LoadI->isAtomic(), | |||
1399 | PredBB, BBIt, DefMaxInstsToScan, | |||
1400 | AA, &IsLoadCSE, &NumScanedInst); | |||
1401 | ||||
1402 | // If PredBB has a single predecessor, continue scanning through the | |||
1403 | // single predecessor. | |||
1404 | BasicBlock *SinglePredBB = PredBB; | |||
1405 | while (!PredAvailable && SinglePredBB && BBIt == SinglePredBB->begin() && | |||
1406 | NumScanedInst < DefMaxInstsToScan) { | |||
1407 | SinglePredBB = SinglePredBB->getSinglePredecessor(); | |||
1408 | if (SinglePredBB) { | |||
1409 | BBIt = SinglePredBB->end(); | |||
1410 | PredAvailable = findAvailablePtrLoadStore( | |||
1411 | Loc, AccessTy, LoadI->isAtomic(), SinglePredBB, BBIt, | |||
1412 | (DefMaxInstsToScan - NumScanedInst), AA, &IsLoadCSE, | |||
1413 | &NumScanedInst); | |||
1414 | } | |||
1415 | } | |||
1416 | ||||
1417 | if (!PredAvailable) { | |||
1418 | OneUnavailablePred = PredBB; | |||
1419 | continue; | |||
1420 | } | |||
1421 | ||||
1422 | if (IsLoadCSE) | |||
1423 | CSELoads.push_back(cast<LoadInst>(PredAvailable)); | |||
1424 | ||||
1425 | // If so, this load is partially redundant. Remember this info so that we | |||
1426 | // can create a PHI node. | |||
1427 | AvailablePreds.emplace_back(PredBB, PredAvailable); | |||
1428 | } | |||
1429 | ||||
1430 | // If the loaded value isn't available in any predecessor, it isn't partially | |||
1431 | // redundant. | |||
1432 | if (AvailablePreds.empty()) return false; | |||
1433 | ||||
1434 | // Okay, the loaded value is available in at least one (and maybe all!) | |||
1435 | // predecessors. If the value is unavailable in more than one unique | |||
1436 | // predecessor, we want to insert a merge block for those common predecessors. | |||
1437 | // This ensures that we only have to insert one reload, thus not increasing | |||
1438 | // code size. | |||
1439 | BasicBlock *UnavailablePred = nullptr; | |||
1440 | ||||
1441 | // If the value is unavailable in one of predecessors, we will end up | |||
1442 | // inserting a new instruction into them. It is only valid if all the | |||
1443 | // instructions before LoadI are guaranteed to pass execution to its | |||
1444 | // successor, or if LoadI is safe to speculate. | |||
1445 | // TODO: If this logic becomes more complex, and we will perform PRE insertion | |||
1446 | // farther than to a predecessor, we need to reuse the code from GVN's PRE. | |||
1447 | // It requires domination tree analysis, so for this simple case it is an | |||
1448 | // overkill. | |||
1449 | if (PredsScanned.size() != AvailablePreds.size() && | |||
1450 | !isSafeToSpeculativelyExecute(LoadI)) | |||
1451 | for (auto I = LoadBB->begin(); &*I != LoadI; ++I) | |||
1452 | if (!isGuaranteedToTransferExecutionToSuccessor(&*I)) | |||
1453 | return false; | |||
1454 | ||||
1455 | // If there is exactly one predecessor where the value is unavailable, the | |||
1456 | // already computed 'OneUnavailablePred' block is it. If it ends in an | |||
1457 | // unconditional branch, we know that it isn't a critical edge. | |||
1458 | if (PredsScanned.size() == AvailablePreds.size()+1 && | |||
1459 | OneUnavailablePred->getTerminator()->getNumSuccessors() == 1) { | |||
| ||||
1460 | UnavailablePred = OneUnavailablePred; | |||
1461 | } else if (PredsScanned.size() != AvailablePreds.size()) { | |||
1462 | // Otherwise, we had multiple unavailable predecessors or we had a critical | |||
1463 | // edge from the one. | |||
1464 | SmallVector<BasicBlock*, 8> PredsToSplit; | |||
1465 | SmallPtrSet<BasicBlock*, 8> AvailablePredSet; | |||
1466 | ||||
1467 | for (const auto &AvailablePred : AvailablePreds) | |||
1468 | AvailablePredSet.insert(AvailablePred.first); | |||
1469 | ||||
1470 | // Add all the unavailable predecessors to the PredsToSplit list. | |||
1471 | for (BasicBlock *P : predecessors(LoadBB)) { | |||
1472 | // If the predecessor is an indirect goto, we can't split the edge. | |||
1473 | // Same for CallBr. | |||
1474 | if (isa<IndirectBrInst>(P->getTerminator()) || | |||
1475 | isa<CallBrInst>(P->getTerminator())) | |||
1476 | return false; | |||
1477 | ||||
1478 | if (!AvailablePredSet.count(P)) | |||
1479 | PredsToSplit.push_back(P); | |||
1480 | } | |||
1481 | ||||
1482 | // Split them out to their own block. | |||
1483 | UnavailablePred = splitBlockPreds(LoadBB, PredsToSplit, "thread-pre-split"); | |||
1484 | } | |||
1485 | ||||
1486 | // If the value isn't available in all predecessors, then there will be | |||
1487 | // exactly one where it isn't available. Insert a load on that edge and add | |||
1488 | // it to the AvailablePreds list. | |||
1489 | if (UnavailablePred) { | |||
1490 | assert(UnavailablePred->getTerminator()->getNumSuccessors() == 1 &&((void)0) | |||
1491 | "Can't handle critical edge here!")((void)0); | |||
1492 | LoadInst *NewVal = new LoadInst( | |||
1493 | LoadI->getType(), LoadedPtr->DoPHITranslation(LoadBB, UnavailablePred), | |||
1494 | LoadI->getName() + ".pr", false, LoadI->getAlign(), | |||
1495 | LoadI->getOrdering(), LoadI->getSyncScopeID(), | |||
1496 | UnavailablePred->getTerminator()); | |||
1497 | NewVal->setDebugLoc(LoadI->getDebugLoc()); | |||
1498 | if (AATags) | |||
1499 | NewVal->setAAMetadata(AATags); | |||
1500 | ||||
1501 | AvailablePreds.emplace_back(UnavailablePred, NewVal); | |||
1502 | } | |||
1503 | ||||
1504 | // Now we know that each predecessor of this block has a value in | |||
1505 | // AvailablePreds, sort them for efficient access as we're walking the preds. | |||
1506 | array_pod_sort(AvailablePreds.begin(), AvailablePreds.end()); | |||
1507 | ||||
1508 | // Create a PHI node at the start of the block for the PRE'd load value. | |||
1509 | pred_iterator PB = pred_begin(LoadBB), PE = pred_end(LoadBB); | |||
1510 | PHINode *PN = PHINode::Create(LoadI->getType(), std::distance(PB, PE), "", | |||
1511 | &LoadBB->front()); | |||
1512 | PN->takeName(LoadI); | |||
1513 | PN->setDebugLoc(LoadI->getDebugLoc()); | |||
1514 | ||||
1515 | // Insert new entries into the PHI for each predecessor. A single block may | |||
1516 | // have multiple entries here. | |||
1517 | for (pred_iterator PI = PB; PI != PE; ++PI) { | |||
1518 | BasicBlock *P = *PI; | |||
1519 | AvailablePredsTy::iterator I = | |||
1520 | llvm::lower_bound(AvailablePreds, std::make_pair(P, (Value *)nullptr)); | |||
1521 | ||||
1522 | assert(I != AvailablePreds.end() && I->first == P &&((void)0) | |||
1523 | "Didn't find entry for predecessor!")((void)0); | |||
1524 | ||||
1525 | // If we have an available predecessor but it requires casting, insert the | |||
1526 | // cast in the predecessor and use the cast. Note that we have to update the | |||
1527 | // AvailablePreds vector as we go so that all of the PHI entries for this | |||
1528 | // predecessor use the same bitcast. | |||
1529 | Value *&PredV = I->second; | |||
1530 | if (PredV->getType() != LoadI->getType()) | |||
1531 | PredV = CastInst::CreateBitOrPointerCast(PredV, LoadI->getType(), "", | |||
1532 | P->getTerminator()); | |||
1533 | ||||
1534 | PN->addIncoming(PredV, I->first); | |||
1535 | } | |||
1536 | ||||
1537 | for (LoadInst *PredLoadI : CSELoads) { | |||
1538 | combineMetadataForCSE(PredLoadI, LoadI, true); | |||
1539 | } | |||
1540 | ||||
1541 | LoadI->replaceAllUsesWith(PN); | |||
1542 | LoadI->eraseFromParent(); | |||
1543 | ||||
1544 | return true; | |||
1545 | } | |||
1546 | ||||
1547 | /// findMostPopularDest - The specified list contains multiple possible | |||
1548 | /// threadable destinations. Pick the one that occurs the most frequently in | |||
1549 | /// the list. | |||
1550 | static BasicBlock * | |||
1551 | findMostPopularDest(BasicBlock *BB, | |||
1552 | const SmallVectorImpl<std::pair<BasicBlock *, | |||
1553 | BasicBlock *>> &PredToDestList) { | |||
1554 | assert(!PredToDestList.empty())((void)0); | |||
1555 | ||||
1556 | // Determine popularity. If there are multiple possible destinations, we | |||
1557 | // explicitly choose to ignore 'undef' destinations. We prefer to thread | |||
1558 | // blocks with known and real destinations to threading undef. We'll handle | |||
1559 | // them later if interesting. | |||
1560 | MapVector<BasicBlock *, unsigned> DestPopularity; | |||
1561 | ||||
1562 | // Populate DestPopularity with the successors in the order they appear in the | |||
1563 | // successor list. This way, we ensure determinism by iterating it in the | |||
1564 | // same order in std::max_element below. We map nullptr to 0 so that we can | |||
1565 | // return nullptr when PredToDestList contains nullptr only. | |||
1566 | DestPopularity[nullptr] = 0; | |||
1567 | for (auto *SuccBB : successors(BB)) | |||
1568 | DestPopularity[SuccBB] = 0; | |||
1569 | ||||
1570 | for (const auto &PredToDest : PredToDestList) | |||
1571 | if (PredToDest.second) | |||
1572 | DestPopularity[PredToDest.second]++; | |||
1573 | ||||
1574 | // Find the most popular dest. | |||
1575 | using VT = decltype(DestPopularity)::value_type; | |||
1576 | auto MostPopular = std::max_element( | |||
1577 | DestPopularity.begin(), DestPopularity.end(), | |||
1578 | [](const VT &L, const VT &R) { return L.second < R.second; }); | |||
1579 | ||||
1580 | // Okay, we have finally picked the most popular destination. | |||
1581 | return MostPopular->first; | |||
1582 | } | |||
1583 | ||||
1584 | // Try to evaluate the value of V when the control flows from PredPredBB to | |||
1585 | // BB->getSinglePredecessor() and then on to BB. | |||
1586 | Constant *JumpThreadingPass::evaluateOnPredecessorEdge(BasicBlock *BB, | |||
1587 | BasicBlock *PredPredBB, | |||
1588 | Value *V) { | |||
1589 | BasicBlock *PredBB = BB->getSinglePredecessor(); | |||
1590 | assert(PredBB && "Expected a single predecessor")((void)0); | |||
1591 | ||||
1592 | if (Constant *Cst = dyn_cast<Constant>(V)) { | |||
1593 | return Cst; | |||
1594 | } | |||
1595 | ||||
1596 | // Consult LVI if V is not an instruction in BB or PredBB. | |||
1597 | Instruction *I = dyn_cast<Instruction>(V); | |||
1598 | if (!I || (I->getParent() != BB && I->getParent() != PredBB)) { | |||
1599 | return LVI->getConstantOnEdge(V, PredPredBB, PredBB, nullptr); | |||
1600 | } | |||
1601 | ||||
1602 | // Look into a PHI argument. | |||
1603 | if (PHINode *PHI = dyn_cast<PHINode>(V)) { | |||
1604 | if (PHI->getParent() == PredBB) | |||
1605 | return dyn_cast<Constant>(PHI->getIncomingValueForBlock(PredPredBB)); | |||
1606 | return nullptr; | |||
1607 | } | |||
1608 | ||||
1609 | // If we have a CmpInst, try to fold it for each incoming edge into PredBB. | |||
1610 | if (CmpInst *CondCmp = dyn_cast<CmpInst>(V)) { | |||
1611 | if (CondCmp->getParent() == BB) { | |||
1612 | Constant *Op0 = | |||
1613 | evaluateOnPredecessorEdge(BB, PredPredBB, CondCmp->getOperand(0)); | |||
1614 | Constant *Op1 = | |||
1615 | evaluateOnPredecessorEdge(BB, PredPredBB, CondCmp->getOperand(1)); | |||
1616 | if (Op0 && Op1) { | |||
1617 | return ConstantExpr::getCompare(CondCmp->getPredicate(), Op0, Op1); | |||
1618 | } | |||
1619 | } | |||
1620 | return nullptr; | |||
1621 | } | |||
1622 | ||||
1623 | return nullptr; | |||
1624 | } | |||
1625 | ||||
1626 | bool JumpThreadingPass::processThreadableEdges(Value *Cond, BasicBlock *BB, | |||
1627 | ConstantPreference Preference, | |||
1628 | Instruction *CxtI) { | |||
1629 | // If threading this would thread across a loop header, don't even try to | |||
1630 | // thread the edge. | |||
1631 | if (LoopHeaders.count(BB)) | |||
1632 | return false; | |||
1633 | ||||
1634 | PredValueInfoTy PredValues; | |||
1635 | if (!computeValueKnownInPredecessors(Cond, BB, PredValues, Preference, | |||
1636 | CxtI)) { | |||
1637 | // We don't have known values in predecessors. See if we can thread through | |||
1638 | // BB and its sole predecessor. | |||
1639 | return maybethreadThroughTwoBasicBlocks(BB, Cond); | |||
1640 | } | |||
1641 | ||||
1642 | assert(!PredValues.empty() &&((void)0) | |||
1643 | "computeValueKnownInPredecessors returned true with no values")((void)0); | |||
1644 | ||||
1645 | LLVM_DEBUG(dbgs() << "IN BB: " << *BB;do { } while (false) | |||
1646 | for (const auto &PredValue : PredValues) {do { } while (false) | |||
1647 | dbgs() << " BB '" << BB->getName()do { } while (false) | |||
1648 | << "': FOUND condition = " << *PredValue.firstdo { } while (false) | |||
1649 | << " for pred '" << PredValue.second->getName() << "'.\n";do { } while (false) | |||
1650 | })do { } while (false); | |||
1651 | ||||
1652 | // Decide what we want to thread through. Convert our list of known values to | |||
1653 | // a list of known destinations for each pred. This also discards duplicate | |||
1654 | // predecessors and keeps track of the undefined inputs (which are represented | |||
1655 | // as a null dest in the PredToDestList). | |||
1656 | SmallPtrSet<BasicBlock*, 16> SeenPreds; | |||
1657 | SmallVector<std::pair<BasicBlock*, BasicBlock*>, 16> PredToDestList; | |||
1658 | ||||
1659 | BasicBlock *OnlyDest = nullptr; | |||
1660 | BasicBlock *MultipleDestSentinel = (BasicBlock*)(intptr_t)~0ULL; | |||
1661 | Constant *OnlyVal = nullptr; | |||
1662 | Constant *MultipleVal = (Constant *)(intptr_t)~0ULL; | |||
1663 | ||||
1664 | for (const auto &PredValue : PredValues) { | |||
1665 | BasicBlock *Pred = PredValue.second; | |||
1666 | if (!SeenPreds.insert(Pred).second) | |||
1667 | continue; // Duplicate predecessor entry. | |||
1668 | ||||
1669 | Constant *Val = PredValue.first; | |||
1670 | ||||
1671 | BasicBlock *DestBB; | |||
1672 | if (isa<UndefValue>(Val)) | |||
1673 | DestBB = nullptr; | |||
1674 | else if (BranchInst *BI = dyn_cast<BranchInst>(BB->getTerminator())) { | |||
1675 | assert(isa<ConstantInt>(Val) && "Expecting a constant integer")((void)0); | |||
1676 | DestBB = BI->getSuccessor(cast<ConstantInt>(Val)->isZero()); | |||
1677 | } else if (SwitchInst *SI = dyn_cast<SwitchInst>(BB->getTerminator())) { | |||
1678 | assert(isa<ConstantInt>(Val) && "Expecting a constant integer")((void)0); | |||
1679 | DestBB = SI->findCaseValue(cast<ConstantInt>(Val))->getCaseSuccessor(); | |||
1680 | } else { | |||
1681 | assert(isa<IndirectBrInst>(BB->getTerminator())((void)0) | |||
1682 | && "Unexpected terminator")((void)0); | |||
1683 | assert(isa<BlockAddress>(Val) && "Expecting a constant blockaddress")((void)0); | |||
1684 | DestBB = cast<BlockAddress>(Val)->getBasicBlock(); | |||
1685 | } | |||
1686 | ||||
1687 | // If we have exactly one destination, remember it for efficiency below. | |||
1688 | if (PredToDestList.empty()) { | |||
1689 | OnlyDest = DestBB; | |||
1690 | OnlyVal = Val; | |||
1691 | } else { | |||
1692 | if (OnlyDest != DestBB) | |||
1693 | OnlyDest = MultipleDestSentinel; | |||
1694 | // It possible we have same destination, but different value, e.g. default | |||
1695 | // case in switchinst. | |||
1696 | if (Val != OnlyVal) | |||
1697 | OnlyVal = MultipleVal; | |||
1698 | } | |||
1699 | ||||
1700 | // If the predecessor ends with an indirect goto, we can't change its | |||
1701 | // destination. Same for CallBr. | |||
1702 | if (isa<IndirectBrInst>(Pred->getTerminator()) || | |||
1703 | isa<CallBrInst>(Pred->getTerminator())) | |||
1704 | continue; | |||
1705 | ||||
1706 | PredToDestList.emplace_back(Pred, DestBB); | |||
1707 | } | |||
1708 | ||||
1709 | // If all edges were unthreadable, we fail. | |||
1710 | if (PredToDestList.empty()) | |||
1711 | return false; | |||
1712 | ||||
1713 | // If all the predecessors go to a single known successor, we want to fold, | |||
1714 | // not thread. By doing so, we do not need to duplicate the current block and | |||
1715 | // also miss potential opportunities in case we dont/cant duplicate. | |||
1716 | if (OnlyDest && OnlyDest != MultipleDestSentinel) { | |||
1717 | if (BB->hasNPredecessors(PredToDestList.size())) { | |||
1718 | bool SeenFirstBranchToOnlyDest = false; | |||
1719 | std::vector <DominatorTree::UpdateType> Updates; | |||
1720 | Updates.reserve(BB->getTerminator()->getNumSuccessors() - 1); | |||
1721 | for (BasicBlock *SuccBB : successors(BB)) { | |||
1722 | if (SuccBB == OnlyDest && !SeenFirstBranchToOnlyDest) { | |||
1723 | SeenFirstBranchToOnlyDest = true; // Don't modify the first branch. | |||
1724 | } else { | |||
1725 | SuccBB->removePredecessor(BB, true); // This is unreachable successor. | |||
1726 | Updates.push_back({DominatorTree::Delete, BB, SuccBB}); | |||
1727 | } | |||
1728 | } | |||
1729 | ||||
1730 | // Finally update the terminator. | |||
1731 | Instruction *Term = BB->getTerminator(); | |||
1732 | BranchInst::Create(OnlyDest, Term); | |||
1733 | ++NumFolds; | |||
1734 | Term->eraseFromParent(); | |||
1735 | DTU->applyUpdatesPermissive(Updates); | |||
1736 | if (HasProfileData) | |||
1737 | BPI->eraseBlock(BB); | |||
1738 | ||||
1739 | // If the condition is now dead due to the removal of the old terminator, | |||
1740 | // erase it. | |||
1741 | if (auto *CondInst = dyn_cast<Instruction>(Cond)) { | |||
1742 | if (CondInst->use_empty() && !CondInst->mayHaveSideEffects()) | |||
1743 | CondInst->eraseFromParent(); | |||
1744 | // We can safely replace *some* uses of the CondInst if it has | |||
1745 | // exactly one value as returned by LVI. RAUW is incorrect in the | |||
1746 | // presence of guards and assumes, that have the `Cond` as the use. This | |||
1747 | // is because we use the guards/assume to reason about the `Cond` value | |||
1748 | // at the end of block, but RAUW unconditionally replaces all uses | |||
1749 | // including the guards/assumes themselves and the uses before the | |||
1750 | // guard/assume. | |||
1751 | else if (OnlyVal && OnlyVal != MultipleVal && | |||
1752 | CondInst->getParent() == BB) | |||
1753 | replaceFoldableUses(CondInst, OnlyVal); | |||
1754 | } | |||
1755 | return true; | |||
1756 | } | |||
1757 | } | |||
1758 | ||||
1759 | // Determine which is the most common successor. If we have many inputs and | |||
1760 | // this block is a switch, we want to start by threading the batch that goes | |||
1761 | // to the most popular destination first. If we only know about one | |||
1762 | // threadable destination (the common case) we can avoid this. | |||
1763 | BasicBlock *MostPopularDest = OnlyDest; | |||
1764 | ||||
1765 | if (MostPopularDest == MultipleDestSentinel) { | |||
1766 | // Remove any loop headers from the Dest list, threadEdge conservatively | |||
1767 | // won't process them, but we might have other destination that are eligible | |||
1768 | // and we still want to process. | |||
1769 | erase_if(PredToDestList, | |||
1770 | [&](const std::pair<BasicBlock *, BasicBlock *> &PredToDest) { | |||
1771 | return LoopHeaders.contains(PredToDest.second); | |||
1772 | }); | |||
1773 | ||||
1774 | if (PredToDestList.empty()) | |||
1775 | return false; | |||
1776 | ||||
1777 | MostPopularDest = findMostPopularDest(BB, PredToDestList); | |||
1778 | } | |||
1779 | ||||
1780 | // Now that we know what the most popular destination is, factor all | |||
1781 | // predecessors that will jump to it into a single predecessor. | |||
1782 | SmallVector<BasicBlock*, 16> PredsToFactor; | |||
1783 | for (const auto &PredToDest : PredToDestList) | |||
1784 | if (PredToDest.second == MostPopularDest) { | |||
1785 | BasicBlock *Pred = PredToDest.first; | |||
1786 | ||||
1787 | // This predecessor may be a switch or something else that has multiple | |||
1788 | // edges to the block. Factor each of these edges by listing them | |||
1789 | // according to # occurrences in PredsToFactor. | |||
1790 | for (BasicBlock *Succ : successors(Pred)) | |||
1791 | if (Succ == BB) | |||
1792 | PredsToFactor.push_back(Pred); | |||
1793 | } | |||
1794 | ||||
1795 | // If the threadable edges are branching on an undefined value, we get to pick | |||
1796 | // the destination that these predecessors should get to. | |||
1797 | if (!MostPopularDest) | |||
1798 | MostPopularDest = BB->getTerminator()-> | |||
1799 | getSuccessor(getBestDestForJumpOnUndef(BB)); | |||
1800 | ||||
1801 | // Ok, try to thread it! | |||
1802 | return tryThreadEdge(BB, PredsToFactor, MostPopularDest); | |||
1803 | } | |||
1804 | ||||
1805 | /// processBranchOnPHI - We have an otherwise unthreadable conditional branch on | |||
1806 | /// a PHI node (or freeze PHI) in the current block. See if there are any | |||
1807 | /// simplifications we can do based on inputs to the phi node. | |||
1808 | bool JumpThreadingPass::processBranchOnPHI(PHINode *PN) { | |||
1809 | BasicBlock *BB = PN->getParent(); | |||
1810 | ||||
1811 | // TODO: We could make use of this to do it once for blocks with common PHI | |||
1812 | // values. | |||
1813 | SmallVector<BasicBlock*, 1> PredBBs; | |||
1814 | PredBBs.resize(1); | |||
1815 | ||||
1816 | // If any of the predecessor blocks end in an unconditional branch, we can | |||
1817 | // *duplicate* the conditional branch into that block in order to further | |||
1818 | // encourage jump threading and to eliminate cases where we have branch on a | |||
1819 | // phi of an icmp (branch on icmp is much better). | |||
1820 | // This is still beneficial when a frozen phi is used as the branch condition | |||
1821 | // because it allows CodeGenPrepare to further canonicalize br(freeze(icmp)) | |||
1822 | // to br(icmp(freeze ...)). | |||
1823 | for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) { | |||
1824 | BasicBlock *PredBB = PN->getIncomingBlock(i); | |||
1825 | if (BranchInst *PredBr = dyn_cast<BranchInst>(PredBB->getTerminator())) | |||
1826 | if (PredBr->isUnconditional()) { | |||
1827 | PredBBs[0] = PredBB; | |||
1828 | // Try to duplicate BB into PredBB. | |||
1829 | if (duplicateCondBranchOnPHIIntoPred(BB, PredBBs)) | |||
1830 | return true; | |||
1831 | } | |||
1832 | } | |||
1833 | ||||
1834 | return false; | |||
1835 | } | |||
1836 | ||||
1837 | /// processBranchOnXOR - We have an otherwise unthreadable conditional branch on | |||
1838 | /// a xor instruction in the current block. See if there are any | |||
1839 | /// simplifications we can do based on inputs to the xor. | |||
1840 | bool JumpThreadingPass::processBranchOnXOR(BinaryOperator *BO) { | |||
1841 | BasicBlock *BB = BO->getParent(); | |||
1842 | ||||
1843 | // If either the LHS or RHS of the xor is a constant, don't do this | |||
1844 | // optimization. | |||
1845 | if (isa<ConstantInt>(BO->getOperand(0)) || | |||
1846 | isa<ConstantInt>(BO->getOperand(1))) | |||
1847 | return false; | |||
1848 | ||||
1849 | // If the first instruction in BB isn't a phi, we won't be able to infer | |||
1850 | // anything special about any particular predecessor. | |||
1851 | if (!isa<PHINode>(BB->front())) | |||
1852 | return false; | |||
1853 | ||||
1854 | // If this BB is a landing pad, we won't be able to split the edge into it. | |||
1855 | if (BB->isEHPad()) | |||
1856 | return false; | |||
1857 | ||||
1858 | // If we have a xor as the branch input to this block, and we know that the | |||
1859 | // LHS or RHS of the xor in any predecessor is true/false, then we can clone | |||
1860 | // the condition into the predecessor and fix that value to true, saving some | |||
1861 | // logical ops on that path and encouraging other paths to simplify. | |||
1862 | // | |||
1863 | // This copies something like this: | |||
1864 | // | |||
1865 | // BB: | |||
1866 | // %X = phi i1 [1], [%X'] | |||
1867 | // %Y = icmp eq i32 %A, %B | |||
1868 | // %Z = xor i1 %X, %Y | |||
1869 | // br i1 %Z, ... | |||
1870 | // | |||
1871 | // Into: | |||
1872 | // BB': | |||
1873 | // %Y = icmp ne i32 %A, %B | |||
1874 | // br i1 %Y, ... | |||
1875 | ||||
1876 | PredValueInfoTy XorOpValues; | |||
1877 | bool isLHS = true; | |||
1878 | if (!computeValueKnownInPredecessors(BO->getOperand(0), BB, XorOpValues, | |||
1879 | WantInteger, BO)) { | |||
1880 | assert(XorOpValues.empty())((void)0); | |||
1881 | if (!computeValueKnownInPredecessors(BO->getOperand(1), BB, XorOpValues, | |||
1882 | WantInteger, BO)) | |||
1883 | return false; | |||
1884 | isLHS = false; | |||
1885 | } | |||
1886 | ||||
1887 | assert(!XorOpValues.empty() &&((void)0) | |||
1888 | "computeValueKnownInPredecessors returned true with no values")((void)0); | |||
1889 | ||||
1890 | // Scan the information to see which is most popular: true or false. The | |||
1891 | // predecessors can be of the set true, false, or undef. | |||
1892 | unsigned NumTrue = 0, NumFalse = 0; | |||
1893 | for (const auto &XorOpValue : XorOpValues) { | |||
1894 | if (isa<UndefValue>(XorOpValue.first)) | |||
1895 | // Ignore undefs for the count. | |||
1896 | continue; | |||
1897 | if (cast<ConstantInt>(XorOpValue.first)->isZero()) | |||
1898 | ++NumFalse; | |||
1899 | else | |||
1900 | ++NumTrue; | |||
1901 | } | |||
1902 | ||||
1903 | // Determine which value to split on, true, false, or undef if neither. | |||
1904 | ConstantInt *SplitVal = nullptr; | |||
1905 | if (NumTrue > NumFalse) | |||
1906 | SplitVal = ConstantInt::getTrue(BB->getContext()); | |||
1907 | else if (NumTrue != 0 || NumFalse != 0) | |||
1908 | SplitVal = ConstantInt::getFalse(BB->getContext()); | |||
1909 | ||||
1910 | // Collect all of the blocks that this can be folded into so that we can | |||
1911 | // factor this once and clone it once. | |||
1912 | SmallVector<BasicBlock*, 8> BlocksToFoldInto; | |||
1913 | for (const auto &XorOpValue : XorOpValues) { | |||
1914 | if (XorOpValue.first != SplitVal && !isa<UndefValue>(XorOpValue.first)) | |||
1915 | continue; | |||
1916 | ||||
1917 | BlocksToFoldInto.push_back(XorOpValue.second); | |||
1918 | } | |||
1919 | ||||
1920 | // If we inferred a value for all of the predecessors, then duplication won't | |||
1921 | // help us. However, we can just replace the LHS or RHS with the constant. | |||
1922 | if (BlocksToFoldInto.size() == | |||
1923 | cast<PHINode>(BB->front()).getNumIncomingValues()) { | |||
1924 | if (!SplitVal) { | |||
1925 | // If all preds provide undef, just nuke the xor, because it is undef too. | |||
1926 | BO->replaceAllUsesWith(UndefValue::get(BO->getType())); | |||
1927 | BO->eraseFromParent(); | |||
1928 | } else if (SplitVal->isZero()) { | |||
1929 | // If all preds provide 0, replace the xor with the other input. | |||
1930 | BO->replaceAllUsesWith(BO->getOperand(isLHS)); | |||
1931 | BO->eraseFromParent(); | |||
1932 | } else { | |||
1933 | // If all preds provide 1, set the computed value to 1. | |||
1934 | BO->setOperand(!isLHS, SplitVal); | |||
1935 | } | |||
1936 | ||||
1937 | return true; | |||
1938 | } | |||
1939 | ||||
1940 | // If any of predecessors end with an indirect goto, we can't change its | |||
1941 | // destination. Same for CallBr. | |||
1942 | if (any_of(BlocksToFoldInto, [](BasicBlock *Pred) { | |||
1943 | return isa<IndirectBrInst>(Pred->getTerminator()) || | |||
1944 | isa<CallBrInst>(Pred->getTerminator()); | |||
1945 | })) | |||
1946 | return false; | |||
1947 | ||||
1948 | // Try to duplicate BB into PredBB. | |||
1949 | return duplicateCondBranchOnPHIIntoPred(BB, BlocksToFoldInto); | |||
1950 | } | |||
1951 | ||||
1952 | /// addPHINodeEntriesForMappedBlock - We're adding 'NewPred' as a new | |||
1953 | /// predecessor to the PHIBB block. If it has PHI nodes, add entries for | |||
1954 | /// NewPred using the entries from OldPred (suitably mapped). | |||
1955 | static void addPHINodeEntriesForMappedBlock(BasicBlock *PHIBB, | |||
1956 | BasicBlock *OldPred, | |||
1957 | BasicBlock *NewPred, | |||
1958 | DenseMap<Instruction*, Value*> &ValueMap) { | |||
1959 | for (PHINode &PN : PHIBB->phis()) { | |||
1960 | // Ok, we have a PHI node. Figure out what the incoming value was for the | |||
1961 | // DestBlock. | |||
1962 | Value *IV = PN.getIncomingValueForBlock(OldPred); | |||
1963 | ||||
1964 | // Remap the value if necessary. | |||
1965 | if (Instruction *Inst = dyn_cast<Instruction>(IV)) { | |||
1966 | DenseMap<Instruction*, Value*>::iterator I = ValueMap.find(Inst); | |||
1967 | if (I != ValueMap.end()) | |||
1968 | IV = I->second; | |||
1969 | } | |||
1970 | ||||
1971 | PN.addIncoming(IV, NewPred); | |||
1972 | } | |||
1973 | } | |||
1974 | ||||
1975 | /// Merge basic block BB into its sole predecessor if possible. | |||
1976 | bool JumpThreadingPass::maybeMergeBasicBlockIntoOnlyPred(BasicBlock *BB) { | |||
1977 | BasicBlock *SinglePred = BB->getSinglePredecessor(); | |||
1978 | if (!SinglePred) | |||
1979 | return false; | |||
1980 | ||||
1981 | const Instruction *TI = SinglePred->getTerminator(); | |||
1982 | if (TI->isExceptionalTerminator() || TI->getNumSuccessors() != 1 || | |||
1983 | SinglePred == BB || hasAddressTakenAndUsed(BB)) | |||
1984 | return false; | |||
1985 | ||||
1986 | // If SinglePred was a loop header, BB becomes one. | |||
1987 | if (LoopHeaders.erase(SinglePred)) | |||
1988 | LoopHeaders.insert(BB); | |||
1989 | ||||
1990 | LVI->eraseBlock(SinglePred); | |||
1991 | MergeBasicBlockIntoOnlyPred(BB, DTU); | |||
1992 | ||||
1993 | // Now that BB is merged into SinglePred (i.e. SinglePred code followed by | |||
1994 | // BB code within one basic block `BB`), we need to invalidate the LVI | |||
1995 | // information associated with BB, because the LVI information need not be | |||
1996 | // true for all of BB after the merge. For example, | |||
1997 | // Before the merge, LVI info and code is as follows: | |||
1998 | // SinglePred: <LVI info1 for %p val> | |||
1999 | // %y = use of %p | |||
2000 | // call @exit() // need not transfer execution to successor. | |||
2001 | // assume(%p) // from this point on %p is true | |||
2002 | // br label %BB | |||
2003 | // BB: <LVI info2 for %p val, i.e. %p is true> | |||
2004 | // %x = use of %p | |||
2005 | // br label exit | |||
2006 | // | |||
2007 | // Note that this LVI info for blocks BB and SinglPred is correct for %p | |||
2008 | // (info2 and info1 respectively). After the merge and the deletion of the | |||
2009 | // LVI info1 for SinglePred. We have the following code: | |||
2010 | // BB: <LVI info2 for %p val> | |||
2011 | // %y = use of %p | |||
2012 | // call @exit() | |||
2013 | // assume(%p) | |||
2014 | // %x = use of %p <-- LVI info2 is correct from here onwards. | |||
2015 | // br label exit | |||
2016 | // LVI info2 for BB is incorrect at the beginning of BB. | |||
2017 | ||||
2018 | // Invalidate LVI information for BB if the LVI is not provably true for | |||
2019 | // all of BB. | |||
2020 | if (!isGuaranteedToTransferExecutionToSuccessor(BB)) | |||
2021 | LVI->eraseBlock(BB); | |||
2022 | return true; | |||
2023 | } | |||
2024 | ||||
2025 | /// Update the SSA form. NewBB contains instructions that are copied from BB. | |||
2026 | /// ValueMapping maps old values in BB to new ones in NewBB. | |||
2027 | void JumpThreadingPass::updateSSA( | |||
2028 | BasicBlock *BB, BasicBlock *NewBB, | |||
2029 | DenseMap<Instruction *, Value *> &ValueMapping) { | |||
2030 | // If there were values defined in BB that are used outside the block, then we | |||
2031 | // now have to update all uses of the value to use either the original value, | |||
2032 | // the cloned value, or some PHI derived value. This can require arbitrary | |||
2033 | // PHI insertion, of which we are prepared to do, clean these up now. | |||
2034 | SSAUpdater SSAUpdate; | |||
2035 | SmallVector<Use *, 16> UsesToRename; | |||
2036 | ||||
2037 | for (Instruction &I : *BB) { | |||
2038 | // Scan all uses of this instruction to see if it is used outside of its | |||
2039 | // block, and if so, record them in UsesToRename. | |||
2040 | for (Use &U : I.uses()) { | |||
2041 | Instruction *User = cast<Instruction>(U.getUser()); | |||
2042 | if (PHINode *UserPN = dyn_cast<PHINode>(User)) { | |||
2043 | if (UserPN->getIncomingBlock(U) == BB) | |||
2044 | continue; | |||
2045 | } else if (User->getParent() == BB) | |||
2046 | continue; | |||
2047 | ||||
2048 | UsesToRename.push_back(&U); | |||
2049 | } | |||
2050 | ||||
2051 | // If there are no uses outside the block, we're done with this instruction. | |||
2052 | if (UsesToRename.empty()) | |||
2053 | continue; | |||
2054 | LLVM_DEBUG(dbgs() << "JT: Renaming non-local uses of: " << I << "\n")do { } while (false); | |||
2055 | ||||
2056 | // We found a use of I outside of BB. Rename all uses of I that are outside | |||
2057 | // its block to be uses of the appropriate PHI node etc. See ValuesInBlocks | |||
2058 | // with the two values we know. | |||
2059 | SSAUpdate.Initialize(I.getType(), I.getName()); | |||
2060 | SSAUpdate.AddAvailableValue(BB, &I); | |||
2061 | SSAUpdate.AddAvailableValue(NewBB, ValueMapping[&I]); | |||
2062 | ||||
2063 | while (!UsesToRename.empty()) | |||
2064 | SSAUpdate.RewriteUse(*UsesToRename.pop_back_val()); | |||
2065 | LLVM_DEBUG(dbgs() << "\n")do { } while (false); | |||
2066 | } | |||
2067 | } | |||
2068 | ||||
2069 | /// Clone instructions in range [BI, BE) to NewBB. For PHI nodes, we only clone | |||
2070 | /// arguments that come from PredBB. Return the map from the variables in the | |||
2071 | /// source basic block to the variables in the newly created basic block. | |||
2072 | DenseMap<Instruction *, Value *> | |||
2073 | JumpThreadingPass::cloneInstructions(BasicBlock::iterator BI, | |||
2074 | BasicBlock::iterator BE, BasicBlock *NewBB, | |||
2075 | BasicBlock *PredBB) { | |||
2076 | // We are going to have to map operands from the source basic block to the new | |||
2077 | // copy of the block 'NewBB'. If there are PHI nodes in the source basic | |||
2078 | // block, evaluate them to account for entry from PredBB. | |||
2079 | DenseMap<Instruction *, Value *> ValueMapping; | |||
2080 | ||||
2081 | // Clone the phi nodes of the source basic block into NewBB. The resulting | |||
2082 | // phi nodes are trivial since NewBB only has one predecessor, but SSAUpdater | |||
2083 | // might need to rewrite the operand of the cloned phi. | |||
2084 | for (; PHINode *PN = dyn_cast<PHINode>(BI); ++BI) { | |||
2085 | PHINode *NewPN = PHINode::Create(PN->getType(), 1, PN->getName(), NewBB); | |||
2086 | NewPN->addIncoming(PN->getIncomingValueForBlock(PredBB), PredBB); | |||
2087 | ValueMapping[PN] = NewPN; | |||
2088 | } | |||
2089 | ||||
2090 | // Clone noalias scope declarations in the threaded block. When threading a | |||
2091 | // loop exit, we would otherwise end up with two idential scope declarations | |||
2092 | // visible at the same time. | |||
2093 | SmallVector<MDNode *> NoAliasScopes; | |||
2094 | DenseMap<MDNode *, MDNode *> ClonedScopes; | |||
2095 | LLVMContext &Context = PredBB->getContext(); | |||
2096 | identifyNoAliasScopesToClone(BI, BE, NoAliasScopes); | |||
2097 | cloneNoAliasScopes(NoAliasScopes, ClonedScopes, "thread", Context); | |||
2098 | ||||
2099 | // Clone the non-phi instructions of the source basic block into NewBB, | |||
2100 | // keeping track of the mapping and using it to remap operands in the cloned | |||
2101 | // instructions. | |||
2102 | for (; BI != BE; ++BI) { | |||
2103 | Instruction *New = BI->clone(); | |||
2104 | New->setName(BI->getName()); | |||
2105 | NewBB->getInstList().push_back(New); | |||
2106 | ValueMapping[&*BI] = New; | |||
2107 | adaptNoAliasScopes(New, ClonedScopes, Context); | |||
2108 | ||||
2109 | // Remap operands to patch up intra-block references. | |||
2110 | for (unsigned i = 0, e = New->getNumOperands(); i != e; ++i) | |||
2111 | if (Instruction *Inst = dyn_cast<Instruction>(New->getOperand(i))) { | |||
2112 | DenseMap<Instruction *, Value *>::iterator I = ValueMapping.find(Inst); | |||
2113 | if (I != ValueMapping.end()) | |||
2114 | New->setOperand(i, I->second); | |||
2115 | } | |||
2116 | } | |||
2117 | ||||
2118 | return ValueMapping; | |||
2119 | } | |||
2120 | ||||
2121 | /// Attempt to thread through two successive basic blocks. | |||
2122 | bool JumpThreadingPass::maybethreadThroughTwoBasicBlocks(BasicBlock *BB, | |||
2123 | Value *Cond) { | |||
2124 | // Consider: | |||
2125 | // | |||
2126 | // PredBB: | |||
2127 | // %var = phi i32* [ null, %bb1 ], [ @a, %bb2 ] | |||
2128 | // %tobool = icmp eq i32 %cond, 0 | |||
2129 | // br i1 %tobool, label %BB, label ... | |||
2130 | // | |||
2131 | // BB: | |||
2132 | // %cmp = icmp eq i32* %var, null | |||
2133 | // br i1 %cmp, label ..., label ... | |||
2134 | // | |||
2135 | // We don't know the value of %var at BB even if we know which incoming edge | |||
2136 | // we take to BB. However, once we duplicate PredBB for each of its incoming | |||
2137 | // edges (say, PredBB1 and PredBB2), we know the value of %var in each copy of | |||
2138 | // PredBB. Then we can thread edges PredBB1->BB and PredBB2->BB through BB. | |||
2139 | ||||
2140 | // Require that BB end with a Branch for simplicity. | |||
2141 | BranchInst *CondBr = dyn_cast<BranchInst>(BB->getTerminator()); | |||
2142 | if (!CondBr) | |||
2143 | return false; | |||
2144 | ||||
2145 | // BB must have exactly one predecessor. | |||
2146 | BasicBlock *PredBB = BB->getSinglePredecessor(); | |||
2147 | if (!PredBB) | |||
2148 | return false; | |||
2149 | ||||
2150 | // Require that PredBB end with a conditional Branch. If PredBB ends with an | |||
2151 | // unconditional branch, we should be merging PredBB and BB instead. For | |||
2152 | // simplicity, we don't deal with a switch. | |||
2153 | BranchInst *PredBBBranch = dyn_cast<BranchInst>(PredBB->getTerminator()); | |||
2154 | if (!PredBBBranch || PredBBBranch->isUnconditional()) | |||
2155 | return false; | |||
2156 | ||||
2157 | // If PredBB has exactly one incoming edge, we don't gain anything by copying | |||
2158 | // PredBB. | |||
2159 | if (PredBB->getSinglePredecessor()) | |||
2160 | return false; | |||
2161 | ||||
2162 | // Don't thread through PredBB if it contains a successor edge to itself, in | |||
2163 | // which case we would infinite loop. Suppose we are threading an edge from | |||
2164 | // PredPredBB through PredBB and BB to SuccBB with PredBB containing a | |||
2165 | // successor edge to itself. If we allowed jump threading in this case, we | |||
2166 | // could duplicate PredBB and BB as, say, PredBB.thread and BB.thread. Since | |||
2167 | // PredBB.thread has a successor edge to PredBB, we would immediately come up | |||
2168 | // with another jump threading opportunity from PredBB.thread through PredBB | |||
2169 | // and BB to SuccBB. This jump threading would repeatedly occur. That is, we | |||
2170 | // would keep peeling one iteration from PredBB. | |||
2171 | if (llvm::is_contained(successors(PredBB), PredBB)) | |||
2172 | return false; | |||
2173 | ||||
2174 | // Don't thread across a loop header. | |||
2175 | if (LoopHeaders.count(PredBB)) | |||
2176 | return false; | |||
2177 | ||||
2178 | // Avoid complication with duplicating EH pads. | |||
2179 | if (PredBB->isEHPad()) | |||
2180 | return false; | |||
2181 | ||||
2182 | // Find a predecessor that we can thread. For simplicity, we only consider a | |||
2183 | // successor edge out of BB to which we thread exactly one incoming edge into | |||
2184 | // PredBB. | |||
2185 | unsigned ZeroCount = 0; | |||
2186 | unsigned OneCount = 0; | |||
2187 | BasicBlock *ZeroPred = nullptr; | |||
2188 | BasicBlock *OnePred = nullptr; | |||
2189 | for (BasicBlock *P : predecessors(PredBB)) { | |||
2190 | if (ConstantInt *CI = dyn_cast_or_null<ConstantInt>( | |||
2191 | evaluateOnPredecessorEdge(BB, P, Cond))) { | |||
2192 | if (CI->isZero()) { | |||
2193 | ZeroCount++; | |||
2194 | ZeroPred = P; | |||
2195 | } else if (CI->isOne()) { | |||
2196 | OneCount++; | |||
2197 | OnePred = P; | |||
2198 | } | |||
2199 | } | |||
2200 | } | |||
2201 | ||||
2202 | // Disregard complicated cases where we have to thread multiple edges. | |||
2203 | BasicBlock *PredPredBB; | |||
2204 | if (ZeroCount == 1) { | |||
2205 | PredPredBB = ZeroPred; | |||
2206 | } else if (OneCount == 1) { | |||
2207 | PredPredBB = OnePred; | |||
2208 | } else { | |||
2209 | return false; | |||
2210 | } | |||
2211 | ||||
2212 | BasicBlock *SuccBB = CondBr->getSuccessor(PredPredBB == ZeroPred); | |||
2213 | ||||
2214 | // If threading to the same block as we come from, we would infinite loop. | |||
2215 | if (SuccBB == BB) { | |||
2216 | LLVM_DEBUG(dbgs() << " Not threading across BB '" << BB->getName()do { } while (false) | |||
2217 | << "' - would thread to self!\n")do { } while (false); | |||
2218 | return false; | |||
2219 | } | |||
2220 | ||||
2221 | // If threading this would thread across a loop header, don't thread the edge. | |||
2222 | // See the comments above findLoopHeaders for justifications and caveats. | |||
2223 | if (LoopHeaders.count(BB) || LoopHeaders.count(SuccBB)) { | |||
2224 | LLVM_DEBUG({do { } while (false) | |||
2225 | bool BBIsHeader = LoopHeaders.count(BB);do { } while (false) | |||
2226 | bool SuccIsHeader = LoopHeaders.count(SuccBB);do { } while (false) | |||
2227 | dbgs() << " Not threading across "do { } while (false) | |||
2228 | << (BBIsHeader ? "loop header BB '" : "block BB '")do { } while (false) | |||
2229 | << BB->getName() << "' to dest "do { } while (false) | |||
2230 | << (SuccIsHeader ? "loop header BB '" : "block BB '")do { } while (false) | |||
2231 | << SuccBB->getName()do { } while (false) | |||
2232 | << "' - it might create an irreducible loop!\n";do { } while (false) | |||
2233 | })do { } while (false); | |||
2234 | return false; | |||
2235 | } | |||
2236 | ||||
2237 | // Compute the cost of duplicating BB and PredBB. | |||
2238 | unsigned BBCost = | |||
2239 | getJumpThreadDuplicationCost(BB, BB->getTerminator(), BBDupThreshold); | |||
2240 | unsigned PredBBCost = getJumpThreadDuplicationCost( | |||
2241 | PredBB, PredBB->getTerminator(), BBDupThreshold); | |||
2242 | ||||
2243 | // Give up if costs are too high. We need to check BBCost and PredBBCost | |||
2244 | // individually before checking their sum because getJumpThreadDuplicationCost | |||
2245 | // return (unsigned)~0 for those basic blocks that cannot be duplicated. | |||
2246 | if (BBCost > BBDupThreshold || PredBBCost > BBDupThreshold || | |||
2247 | BBCost + PredBBCost > BBDupThreshold) { | |||
2248 | LLVM_DEBUG(dbgs() << " Not threading BB '" << BB->getName()do { } while (false) | |||
2249 | << "' - Cost is too high: " << PredBBCostdo { } while (false) | |||
2250 | << " for PredBB, " << BBCost << "for BB\n")do { } while (false); | |||
2251 | return false; | |||
2252 | } | |||
2253 | ||||
2254 | // Now we are ready to duplicate PredBB. | |||
2255 | threadThroughTwoBasicBlocks(PredPredBB, PredBB, BB, SuccBB); | |||
2256 | return true; | |||
2257 | } | |||
2258 | ||||
2259 | void JumpThreadingPass::threadThroughTwoBasicBlocks(BasicBlock *PredPredBB, | |||
2260 | BasicBlock *PredBB, | |||
2261 | BasicBlock *BB, | |||
2262 | BasicBlock *SuccBB) { | |||
2263 | LLVM_DEBUG(dbgs() << " Threading through '" << PredBB->getName() << "' and '"do { } while (false) | |||
2264 | << BB->getName() << "'\n")do { } while (false); | |||
2265 | ||||
2266 | BranchInst *CondBr = cast<BranchInst>(BB->getTerminator()); | |||
2267 | BranchInst *PredBBBranch = cast<BranchInst>(PredBB->getTerminator()); | |||
2268 | ||||
2269 | BasicBlock *NewBB = | |||
2270 | BasicBlock::Create(PredBB->getContext(), PredBB->getName() + ".thread", | |||
2271 | PredBB->getParent(), PredBB); | |||
2272 | NewBB->moveAfter(PredBB); | |||
2273 | ||||
2274 | // Set the block frequency of NewBB. | |||
2275 | if (HasProfileData) { | |||
2276 | auto NewBBFreq = BFI->getBlockFreq(PredPredBB) * | |||
2277 | BPI->getEdgeProbability(PredPredBB, PredBB); | |||
2278 | BFI->setBlockFreq(NewBB, NewBBFreq.getFrequency()); | |||
2279 | } | |||
2280 | ||||
2281 | // We are going to have to map operands from the original BB block to the new | |||
2282 | // copy of the block 'NewBB'. If there are PHI nodes in PredBB, evaluate them | |||
2283 | // to account for entry from PredPredBB. | |||
2284 | DenseMap<Instruction *, Value *> ValueMapping = | |||
2285 | cloneInstructions(PredBB->begin(), PredBB->end(), NewBB, PredPredBB); | |||
2286 | ||||
2287 | // Copy the edge probabilities from PredBB to NewBB. | |||
2288 | if (HasProfileData) | |||
2289 | BPI->copyEdgeProbabilities(PredBB, NewBB); | |||
2290 | ||||
2291 | // Update the terminator of PredPredBB to jump to NewBB instead of PredBB. | |||
2292 | // This eliminates predecessors from PredPredBB, which requires us to simplify | |||
2293 | // any PHI nodes in PredBB. | |||
2294 | Instruction *PredPredTerm = PredPredBB->getTerminator(); | |||
2295 | for (unsigned i = 0, e = PredPredTerm->getNumSuccessors(); i != e; ++i) | |||
2296 | if (PredPredTerm->getSuccessor(i) == PredBB) { | |||
2297 | PredBB->removePredecessor(PredPredBB, true); | |||
2298 | PredPredTerm->setSuccessor(i, NewBB); | |||
2299 | } | |||
2300 | ||||
2301 | addPHINodeEntriesForMappedBlock(PredBBBranch->getSuccessor(0), PredBB, NewBB, | |||
2302 | ValueMapping); | |||
2303 | addPHINodeEntriesForMappedBlock(PredBBBranch->getSuccessor(1), PredBB, NewBB, | |||
2304 | ValueMapping); | |||
2305 | ||||
2306 | DTU->applyUpdatesPermissive( | |||
2307 | {{DominatorTree::Insert, NewBB, CondBr->getSuccessor(0)}, | |||
2308 | {DominatorTree::Insert, NewBB, CondBr->getSuccessor(1)}, | |||
2309 | {DominatorTree::Insert, PredPredBB, NewBB}, | |||
2310 | {DominatorTree::Delete, PredPredBB, PredBB}}); | |||
2311 | ||||
2312 | updateSSA(PredBB, NewBB, ValueMapping); | |||
2313 | ||||
2314 | // Clean up things like PHI nodes with single operands, dead instructions, | |||
2315 | // etc. | |||
2316 | SimplifyInstructionsInBlock(NewBB, TLI); | |||
2317 | SimplifyInstructionsInBlock(PredBB, TLI); | |||
2318 | ||||
2319 | SmallVector<BasicBlock *, 1> PredsToFactor; | |||
2320 | PredsToFactor.push_back(NewBB); | |||
2321 | threadEdge(BB, PredsToFactor, SuccBB); | |||
2322 | } | |||
2323 | ||||
2324 | /// tryThreadEdge - Thread an edge if it's safe and profitable to do so. | |||
2325 | bool JumpThreadingPass::tryThreadEdge( | |||
2326 | BasicBlock *BB, const SmallVectorImpl<BasicBlock *> &PredBBs, | |||
2327 | BasicBlock *SuccBB) { | |||
2328 | // If threading to the same block as we come from, we would infinite loop. | |||
2329 | if (SuccBB == BB) { | |||
2330 | LLVM_DEBUG(dbgs() << " Not threading across BB '" << BB->getName()do { } while (false) | |||
2331 | << "' - would thread to self!\n")do { } while (false); | |||
2332 | return false; | |||
2333 | } | |||
2334 | ||||
2335 | // If threading this would thread across a loop header, don't thread the edge. | |||
2336 | // See the comments above findLoopHeaders for justifications and caveats. | |||
2337 | if (LoopHeaders.count(BB) || LoopHeaders.count(SuccBB)) { | |||
2338 | LLVM_DEBUG({do { } while (false) | |||
2339 | bool BBIsHeader = LoopHeaders.count(BB);do { } while (false) | |||
2340 | bool SuccIsHeader = LoopHeaders.count(SuccBB);do { } while (false) | |||
2341 | dbgs() << " Not threading across "do { } while (false) | |||
2342 | << (BBIsHeader ? "loop header BB '" : "block BB '") << BB->getName()do { } while (false) | |||
2343 | << "' to dest " << (SuccIsHeader ? "loop header BB '" : "block BB '")do { } while (false) | |||
2344 | << SuccBB->getName() << "' - it might create an irreducible loop!\n";do { } while (false) | |||
2345 | })do { } while (false); | |||
2346 | return false; | |||
2347 | } | |||
2348 | ||||
2349 | unsigned JumpThreadCost = | |||
2350 | getJumpThreadDuplicationCost(BB, BB->getTerminator(), BBDupThreshold); | |||
2351 | if (JumpThreadCost > BBDupThreshold) { | |||
2352 | LLVM_DEBUG(dbgs() << " Not threading BB '" << BB->getName()do { } while (false) | |||
2353 | << "' - Cost is too high: " << JumpThreadCost << "\n")do { } while (false); | |||
2354 | return false; | |||
2355 | } | |||
2356 | ||||
2357 | threadEdge(BB, PredBBs, SuccBB); | |||
2358 | return true; | |||
2359 | } | |||
2360 | ||||
2361 | /// threadEdge - We have decided that it is safe and profitable to factor the | |||
2362 | /// blocks in PredBBs to one predecessor, then thread an edge from it to SuccBB | |||
2363 | /// across BB. Transform the IR to reflect this change. | |||
2364 | void JumpThreadingPass::threadEdge(BasicBlock *BB, | |||
2365 | const SmallVectorImpl<BasicBlock *> &PredBBs, | |||
2366 | BasicBlock *SuccBB) { | |||
2367 | assert(SuccBB != BB && "Don't create an infinite loop")((void)0); | |||
2368 | ||||
2369 | assert(!LoopHeaders.count(BB) && !LoopHeaders.count(SuccBB) &&((void)0) | |||
2370 | "Don't thread across loop headers")((void)0); | |||
2371 | ||||
2372 | // And finally, do it! Start by factoring the predecessors if needed. | |||
2373 | BasicBlock *PredBB; | |||
2374 | if (PredBBs.size() == 1) | |||
2375 | PredBB = PredBBs[0]; | |||
2376 | else { | |||
2377 | LLVM_DEBUG(dbgs() << " Factoring out " << PredBBs.size()do { } while (false) | |||
2378 | << " common predecessors.\n")do { } while (false); | |||
2379 | PredBB = splitBlockPreds(BB, PredBBs, ".thr_comm"); | |||
2380 | } | |||
2381 | ||||
2382 | // And finally, do it! | |||
2383 | LLVM_DEBUG(dbgs() << " Threading edge from '" << PredBB->getName()do { } while (false) | |||
2384 | << "' to '" << SuccBB->getName()do { } while (false) | |||
2385 | << ", across block:\n " << *BB << "\n")do { } while (false); | |||
2386 | ||||
2387 | LVI->threadEdge(PredBB, BB, SuccBB); | |||
2388 | ||||
2389 | BasicBlock *NewBB = BasicBlock::Create(BB->getContext(), | |||
2390 | BB->getName()+".thread", | |||
2391 | BB->getParent(), BB); | |||
2392 | NewBB->moveAfter(PredBB); | |||
2393 | ||||
2394 | // Set the block frequency of NewBB. | |||
2395 | if (HasProfileData) { | |||
2396 | auto NewBBFreq = | |||
2397 | BFI->getBlockFreq(PredBB) * BPI->getEdgeProbability(PredBB, BB); | |||
2398 | BFI->setBlockFreq(NewBB, NewBBFreq.getFrequency()); | |||
2399 | } | |||
2400 | ||||
2401 | // Copy all the instructions from BB to NewBB except the terminator. | |||
2402 | DenseMap<Instruction *, Value *> ValueMapping = | |||
2403 | cloneInstructions(BB->begin(), std::prev(BB->end()), NewBB, PredBB); | |||
2404 | ||||
2405 | // We didn't copy the terminator from BB over to NewBB, because there is now | |||
2406 | // an unconditional jump to SuccBB. Insert the unconditional jump. | |||
2407 | BranchInst *NewBI = BranchInst::Create(SuccBB, NewBB); | |||
2408 | NewBI->setDebugLoc(BB->getTerminator()->getDebugLoc()); | |||
2409 | ||||
2410 | // Check to see if SuccBB has PHI nodes. If so, we need to add entries to the | |||
2411 | // PHI nodes for NewBB now. | |||
2412 | addPHINodeEntriesForMappedBlock(SuccBB, BB, NewBB, ValueMapping); | |||
2413 | ||||
2414 | // Update the terminator of PredBB to jump to NewBB instead of BB. This | |||
2415 | // eliminates predecessors from BB, which requires us to simplify any PHI | |||
2416 | // nodes in BB. | |||
2417 | Instruction *PredTerm = PredBB->getTerminator(); | |||
2418 | for (unsigned i = 0, e = PredTerm->getNumSuccessors(); i != e; ++i) | |||
2419 | if (PredTerm->getSuccessor(i) == BB) { | |||
2420 | BB->removePredecessor(PredBB, true); | |||
2421 | PredTerm->setSuccessor(i, NewBB); | |||
2422 | } | |||
2423 | ||||
2424 | // Enqueue required DT updates. | |||
2425 | DTU->applyUpdatesPermissive({{DominatorTree::Insert, NewBB, SuccBB}, | |||
2426 | {DominatorTree::Insert, PredBB, NewBB}, | |||
2427 | {DominatorTree::Delete, PredBB, BB}}); | |||
2428 | ||||
2429 | updateSSA(BB, NewBB, ValueMapping); | |||
2430 | ||||
2431 | // At this point, the IR is fully up to date and consistent. Do a quick scan | |||
2432 | // over the new instructions and zap any that are constants or dead. This | |||
2433 | // frequently happens because of phi translation. | |||
2434 | SimplifyInstructionsInBlock(NewBB, TLI); | |||
2435 | ||||
2436 | // Update the edge weight from BB to SuccBB, which should be less than before. | |||
2437 | updateBlockFreqAndEdgeWeight(PredBB, BB, NewBB, SuccBB); | |||
2438 | ||||
2439 | // Threaded an edge! | |||
2440 | ++NumThreads; | |||
2441 | } | |||
2442 | ||||
2443 | /// Create a new basic block that will be the predecessor of BB and successor of | |||
2444 | /// all blocks in Preds. When profile data is available, update the frequency of | |||
2445 | /// this new block. | |||
2446 | BasicBlock *JumpThreadingPass::splitBlockPreds(BasicBlock *BB, | |||
2447 | ArrayRef<BasicBlock *> Preds, | |||
2448 | const char *Suffix) { | |||
2449 | SmallVector<BasicBlock *, 2> NewBBs; | |||
2450 | ||||
2451 | // Collect the frequencies of all predecessors of BB, which will be used to | |||
2452 | // update the edge weight of the result of splitting predecessors. | |||
2453 | DenseMap<BasicBlock *, BlockFrequency> FreqMap; | |||
2454 | if (HasProfileData) | |||
2455 | for (auto Pred : Preds) | |||
2456 | FreqMap.insert(std::make_pair( | |||
2457 | Pred, BFI->getBlockFreq(Pred) * BPI->getEdgeProbability(Pred, BB))); | |||
2458 | ||||
2459 | // In the case when BB is a LandingPad block we create 2 new predecessors | |||
2460 | // instead of just one. | |||
2461 | if (BB->isLandingPad()) { | |||
2462 | std::string NewName = std::string(Suffix) + ".split-lp"; | |||
2463 | SplitLandingPadPredecessors(BB, Preds, Suffix, NewName.c_str(), NewBBs); | |||
2464 | } else { | |||
2465 | NewBBs.push_back(SplitBlockPredecessors(BB, Preds, Suffix)); | |||
2466 | } | |||
2467 | ||||
2468 | std::vector<DominatorTree::UpdateType> Updates; | |||
2469 | Updates.reserve((2 * Preds.size()) + NewBBs.size()); | |||
2470 | for (auto NewBB : NewBBs) { | |||
2471 | BlockFrequency NewBBFreq(0); | |||
2472 | Updates.push_back({DominatorTree::Insert, NewBB, BB}); | |||
2473 | for (auto Pred : predecessors(NewBB)) { | |||
2474 | Updates.push_back({DominatorTree::Delete, Pred, BB}); | |||
2475 | Updates.push_back({DominatorTree::Insert, Pred, NewBB}); | |||
2476 | if (HasProfileData) // Update frequencies between Pred -> NewBB. | |||
2477 | NewBBFreq += FreqMap.lookup(Pred); | |||
2478 | } | |||
2479 | if (HasProfileData) // Apply the summed frequency to NewBB. | |||
2480 | BFI->setBlockFreq(NewBB, NewBBFreq.getFrequency()); | |||
2481 | } | |||
2482 | ||||
2483 | DTU->applyUpdatesPermissive(Updates); | |||
2484 | return NewBBs[0]; | |||
2485 | } | |||
2486 | ||||
2487 | bool JumpThreadingPass::doesBlockHaveProfileData(BasicBlock *BB) { | |||
2488 | const Instruction *TI = BB->getTerminator(); | |||
2489 | assert(TI->getNumSuccessors() > 1 && "not a split")((void)0); | |||
2490 | ||||
2491 | MDNode *WeightsNode = TI->getMetadata(LLVMContext::MD_prof); | |||
2492 | if (!WeightsNode) | |||
2493 | return false; | |||
2494 | ||||
2495 | MDString *MDName = cast<MDString>(WeightsNode->getOperand(0)); | |||
2496 | if (MDName->getString() != "branch_weights") | |||
2497 | return false; | |||
2498 | ||||
2499 | // Ensure there are weights for all of the successors. Note that the first | |||
2500 | // operand to the metadata node is a name, not a weight. | |||
2501 | return WeightsNode->getNumOperands() == TI->getNumSuccessors() + 1; | |||
2502 | } | |||
2503 | ||||
2504 | /// Update the block frequency of BB and branch weight and the metadata on the | |||
2505 | /// edge BB->SuccBB. This is done by scaling the weight of BB->SuccBB by 1 - | |||
2506 | /// Freq(PredBB->BB) / Freq(BB->SuccBB). | |||
2507 | void JumpThreadingPass::updateBlockFreqAndEdgeWeight(BasicBlock *PredBB, | |||
2508 | BasicBlock *BB, | |||
2509 | BasicBlock *NewBB, | |||
2510 | BasicBlock *SuccBB) { | |||
2511 | if (!HasProfileData) | |||
2512 | return; | |||
2513 | ||||
2514 | assert(BFI && BPI && "BFI & BPI should have been created here")((void)0); | |||
2515 | ||||
2516 | // As the edge from PredBB to BB is deleted, we have to update the block | |||
2517 | // frequency of BB. | |||
2518 | auto BBOrigFreq = BFI->getBlockFreq(BB); | |||
2519 | auto NewBBFreq = BFI->getBlockFreq(NewBB); | |||
2520 | auto BB2SuccBBFreq = BBOrigFreq * BPI->getEdgeProbability(BB, SuccBB); | |||
2521 | auto BBNewFreq = BBOrigFreq - NewBBFreq; | |||
2522 | BFI->setBlockFreq(BB, BBNewFreq.getFrequency()); | |||
2523 | ||||
2524 | // Collect updated outgoing edges' frequencies from BB and use them to update | |||
2525 | // edge probabilities. | |||
2526 | SmallVector<uint64_t, 4> BBSuccFreq; | |||
2527 | for (BasicBlock *Succ : successors(BB)) { | |||
2528 | auto SuccFreq = (Succ == SuccBB) | |||
2529 | ? BB2SuccBBFreq - NewBBFreq | |||
2530 | : BBOrigFreq * BPI->getEdgeProbability(BB, Succ); | |||
2531 | BBSuccFreq.push_back(SuccFreq.getFrequency()); | |||
2532 | } | |||
2533 | ||||
2534 | uint64_t MaxBBSuccFreq = | |||
2535 | *std::max_element(BBSuccFreq.begin(), BBSuccFreq.end()); | |||
2536 | ||||
2537 | SmallVector<BranchProbability, 4> BBSuccProbs; | |||
2538 | if (MaxBBSuccFreq == 0) | |||
2539 | BBSuccProbs.assign(BBSuccFreq.size(), | |||
2540 | {1, static_cast<unsigned>(BBSuccFreq.size())}); | |||
2541 | else { | |||
2542 | for (uint64_t Freq : BBSuccFreq) | |||
2543 | BBSuccProbs.push_back( | |||
2544 | BranchProbability::getBranchProbability(Freq, MaxBBSuccFreq)); | |||
2545 | // Normalize edge probabilities so that they sum up to one. | |||
2546 | BranchProbability::normalizeProbabilities(BBSuccProbs.begin(), | |||
2547 | BBSuccProbs.end()); | |||
2548 | } | |||
2549 | ||||
2550 | // Update edge probabilities in BPI. | |||
2551 | BPI->setEdgeProbability(BB, BBSuccProbs); | |||
2552 | ||||
2553 | // Update the profile metadata as well. | |||
2554 | // | |||
2555 | // Don't do this if the profile of the transformed blocks was statically | |||
2556 | // estimated. (This could occur despite the function having an entry | |||
2557 | // frequency in completely cold parts of the CFG.) | |||
2558 | // | |||
2559 | // In this case we don't want to suggest to subsequent passes that the | |||
2560 | // calculated weights are fully consistent. Consider this graph: | |||
2561 | // | |||
2562 | // check_1 | |||
2563 | // 50% / | | |||
2564 | // eq_1 | 50% | |||
2565 | // \ | | |||
2566 | // check_2 | |||
2567 | // 50% / | | |||
2568 | // eq_2 | 50% | |||
2569 | // \ | | |||
2570 | // check_3 | |||
2571 | // 50% / | | |||
2572 | // eq_3 | 50% | |||
2573 | // \ | | |||
2574 | // | |||
2575 | // Assuming the blocks check_* all compare the same value against 1, 2 and 3, | |||
2576 | // the overall probabilities are inconsistent; the total probability that the | |||
2577 | // value is either 1, 2 or 3 is 150%. | |||
2578 | // | |||
2579 | // As a consequence if we thread eq_1 -> check_2 to check_3, check_2->check_3 | |||
2580 | // becomes 0%. This is even worse if the edge whose probability becomes 0% is | |||
2581 | // the loop exit edge. Then based solely on static estimation we would assume | |||
2582 | // the loop was extremely hot. | |||
2583 | // | |||
2584 | // FIXME this locally as well so that BPI and BFI are consistent as well. We | |||
2585 | // shouldn't make edges extremely likely or unlikely based solely on static | |||
2586 | // estimation. | |||
2587 | if (BBSuccProbs.size() >= 2 && doesBlockHaveProfileData(BB)) { | |||
2588 | SmallVector<uint32_t, 4> Weights; | |||
2589 | for (auto Prob : BBSuccProbs) | |||
2590 | Weights.push_back(Prob.getNumerator()); | |||
2591 | ||||
2592 | auto TI = BB->getTerminator(); | |||
2593 | TI->setMetadata( | |||
2594 | LLVMContext::MD_prof, | |||
2595 | MDBuilder(TI->getParent()->getContext()).createBranchWeights(Weights)); | |||
2596 | } | |||
2597 | } | |||
2598 | ||||
2599 | /// duplicateCondBranchOnPHIIntoPred - PredBB contains an unconditional branch | |||
2600 | /// to BB which contains an i1 PHI node and a conditional branch on that PHI. | |||
2601 | /// If we can duplicate the contents of BB up into PredBB do so now, this | |||
2602 | /// improves the odds that the branch will be on an analyzable instruction like | |||
2603 | /// a compare. | |||
2604 | bool JumpThreadingPass::duplicateCondBranchOnPHIIntoPred( | |||
2605 | BasicBlock *BB, const SmallVectorImpl<BasicBlock *> &PredBBs) { | |||
2606 | assert(!PredBBs.empty() && "Can't handle an empty set")((void)0); | |||
2607 | ||||
2608 | // If BB is a loop header, then duplicating this block outside the loop would | |||
2609 | // cause us to transform this into an irreducible loop, don't do this. | |||
2610 | // See the comments above findLoopHeaders for justifications and caveats. | |||
2611 | if (LoopHeaders.count(BB)) { | |||
2612 | LLVM_DEBUG(dbgs() << " Not duplicating loop header '" << BB->getName()do { } while (false) | |||
2613 | << "' into predecessor block '" << PredBBs[0]->getName()do { } while (false) | |||
2614 | << "' - it might create an irreducible loop!\n")do { } while (false); | |||
2615 | return false; | |||
2616 | } | |||
2617 | ||||
2618 | unsigned DuplicationCost = | |||
2619 | getJumpThreadDuplicationCost(BB, BB->getTerminator(), BBDupThreshold); | |||
2620 | if (DuplicationCost > BBDupThreshold) { | |||
2621 | LLVM_DEBUG(dbgs() << " Not duplicating BB '" << BB->getName()do { } while (false) | |||
2622 | << "' - Cost is too high: " << DuplicationCost << "\n")do { } while (false); | |||
2623 | return false; | |||
2624 | } | |||
2625 | ||||
2626 | // And finally, do it! Start by factoring the predecessors if needed. | |||
2627 | std::vector<DominatorTree::UpdateType> Updates; | |||
2628 | BasicBlock *PredBB; | |||
2629 | if (PredBBs.size() == 1) | |||
2630 | PredBB = PredBBs[0]; | |||
2631 | else { | |||
2632 | LLVM_DEBUG(dbgs() << " Factoring out " << PredBBs.size()do { } while (false) | |||
2633 | << " common predecessors.\n")do { } while (false); | |||
2634 | PredBB = splitBlockPreds(BB, PredBBs, ".thr_comm"); | |||
2635 | } | |||
2636 | Updates.push_back({DominatorTree::Delete, PredBB, BB}); | |||
2637 | ||||
2638 | // Okay, we decided to do this! Clone all the instructions in BB onto the end | |||
2639 | // of PredBB. | |||
2640 | LLVM_DEBUG(dbgs() << " Duplicating block '" << BB->getName()do { } while (false) | |||
2641 | << "' into end of '" << PredBB->getName()do { } while (false) | |||
2642 | << "' to eliminate branch on phi. Cost: "do { } while (false) | |||
2643 | << DuplicationCost << " block is:" << *BB << "\n")do { } while (false); | |||
2644 | ||||
2645 | // Unless PredBB ends with an unconditional branch, split the edge so that we | |||
2646 | // can just clone the bits from BB into the end of the new PredBB. | |||
2647 | BranchInst *OldPredBranch = dyn_cast<BranchInst>(PredBB->getTerminator()); | |||
2648 | ||||
2649 | if (!OldPredBranch || !OldPredBranch->isUnconditional()) { | |||
2650 | BasicBlock *OldPredBB = PredBB; | |||
2651 | PredBB = SplitEdge(OldPredBB, BB); | |||
2652 | Updates.push_back({DominatorTree::Insert, OldPredBB, PredBB}); | |||
2653 | Updates.push_back({DominatorTree::Insert, PredBB, BB}); | |||
2654 | Updates.push_back({DominatorTree::Delete, OldPredBB, BB}); | |||
2655 | OldPredBranch = cast<BranchInst>(PredBB->getTerminator()); | |||
2656 | } | |||
2657 | ||||
2658 | // We are going to have to map operands from the original BB block into the | |||
2659 | // PredBB block. Evaluate PHI nodes in BB. | |||
2660 | DenseMap<Instruction*, Value*> ValueMapping; | |||
2661 | ||||
2662 | BasicBlock::iterator BI = BB->begin(); | |||
2663 | for (; PHINode *PN = dyn_cast<PHINode>(BI); ++BI) | |||
2664 | ValueMapping[PN] = PN->getIncomingValueForBlock(PredBB); | |||
2665 | // Clone the non-phi instructions of BB into PredBB, keeping track of the | |||
2666 | // mapping and using it to remap operands in the cloned instructions. | |||
2667 | for (; BI != BB->end(); ++BI) { | |||
2668 | Instruction *New = BI->clone(); | |||
2669 | ||||
2670 | // Remap operands to patch up intra-block references. | |||
2671 | for (unsigned i = 0, e = New->getNumOperands(); i != e; ++i) | |||
2672 | if (Instruction *Inst = dyn_cast<Instruction>(New->getOperand(i))) { | |||
2673 | DenseMap<Instruction*, Value*>::iterator I = ValueMapping.find(Inst); | |||
2674 | if (I != ValueMapping.end()) | |||
2675 | New->setOperand(i, I->second); | |||
2676 | } | |||
2677 | ||||
2678 | // If this instruction can be simplified after the operands are updated, | |||
2679 | // just use the simplified value instead. This frequently happens due to | |||
2680 | // phi translation. | |||
2681 | if (Value *IV = SimplifyInstruction( | |||
2682 | New, | |||
2683 | {BB->getModule()->getDataLayout(), TLI, nullptr, nullptr, New})) { | |||
2684 | ValueMapping[&*BI] = IV; | |||
2685 | if (!New->mayHaveSideEffects()) { | |||
2686 | New->deleteValue(); | |||
2687 | New = nullptr; | |||
2688 | } | |||
2689 | } else { | |||
2690 | ValueMapping[&*BI] = New; | |||
2691 | } | |||
2692 | if (New) { | |||
2693 | // Otherwise, insert the new instruction into the block. | |||
2694 | New->setName(BI->getName()); | |||
2695 | PredBB->getInstList().insert(OldPredBranch->getIterator(), New); | |||
2696 | // Update Dominance from simplified New instruction operands. | |||
2697 | for (unsigned i = 0, e = New->getNumOperands(); i != e; ++i) | |||
2698 | if (BasicBlock *SuccBB = dyn_cast<BasicBlock>(New->getOperand(i))) | |||
2699 | Updates.push_back({DominatorTree::Insert, PredBB, SuccBB}); | |||
2700 | } | |||
2701 | } | |||
2702 | ||||
2703 | // Check to see if the targets of the branch had PHI nodes. If so, we need to | |||
2704 | // add entries to the PHI nodes for branch from PredBB now. | |||
2705 | BranchInst *BBBranch = cast<BranchInst>(BB->getTerminator()); | |||
2706 | addPHINodeEntriesForMappedBlock(BBBranch->getSuccessor(0), BB, PredBB, | |||
2707 | ValueMapping); | |||
2708 | addPHINodeEntriesForMappedBlock(BBBranch->getSuccessor(1), BB, PredBB, | |||
2709 | ValueMapping); | |||
2710 | ||||
2711 | updateSSA(BB, PredBB, ValueMapping); | |||
2712 | ||||
2713 | // PredBB no longer jumps to BB, remove entries in the PHI node for the edge | |||
2714 | // that we nuked. | |||
2715 | BB->removePredecessor(PredBB, true); | |||
2716 | ||||
2717 | // Remove the unconditional branch at the end of the PredBB block. | |||
2718 | OldPredBranch->eraseFromParent(); | |||
2719 | if (HasProfileData) | |||
2720 | BPI->copyEdgeProbabilities(BB, PredBB); | |||
2721 | DTU->applyUpdatesPermissive(Updates); | |||
2722 | ||||
2723 | ++NumDupes; | |||
2724 | return true; | |||
2725 | } | |||
2726 | ||||
2727 | // Pred is a predecessor of BB with an unconditional branch to BB. SI is | |||
2728 | // a Select instruction in Pred. BB has other predecessors and SI is used in | |||
2729 | // a PHI node in BB. SI has no other use. | |||
2730 | // A new basic block, NewBB, is created and SI is converted to compare and | |||
2731 | // conditional branch. SI is erased from parent. | |||
2732 | void JumpThreadingPass::unfoldSelectInstr(BasicBlock *Pred, BasicBlock *BB, | |||
2733 | SelectInst *SI, PHINode *SIUse, | |||
2734 | unsigned Idx) { | |||
2735 | // Expand the select. | |||
2736 | // | |||
2737 | // Pred -- | |||
2738 | // | v | |||
2739 | // | NewBB | |||
2740 | // | | | |||
2741 | // |----- | |||
2742 | // v | |||
2743 | // BB | |||
2744 | BranchInst *PredTerm = cast<BranchInst>(Pred->getTerminator()); | |||
2745 | BasicBlock *NewBB = BasicBlock::Create(BB->getContext(), "select.unfold", | |||
2746 | BB->getParent(), BB); | |||
2747 | // Move the unconditional branch to NewBB. | |||
2748 | PredTerm->removeFromParent(); | |||
2749 | NewBB->getInstList().insert(NewBB->end(), PredTerm); | |||
2750 | // Create a conditional branch and update PHI nodes. | |||
2751 | auto *BI = BranchInst::Create(NewBB, BB, SI->getCondition(), Pred); | |||
2752 | BI->applyMergedLocation(PredTerm->getDebugLoc(), SI->getDebugLoc()); | |||
2753 | SIUse->setIncomingValue(Idx, SI->getFalseValue()); | |||
2754 | SIUse->addIncoming(SI->getTrueValue(), NewBB); | |||
2755 | ||||
2756 | // The select is now dead. | |||
2757 | SI->eraseFromParent(); | |||
2758 | DTU->applyUpdatesPermissive({{DominatorTree::Insert, NewBB, BB}, | |||
2759 | {DominatorTree::Insert, Pred, NewBB}}); | |||
2760 | ||||
2761 | // Update any other PHI nodes in BB. | |||
2762 | for (BasicBlock::iterator BI = BB->begin(); | |||
2763 | PHINode *Phi = dyn_cast<PHINode>(BI); ++BI) | |||
2764 | if (Phi != SIUse) | |||
2765 | Phi->addIncoming(Phi->getIncomingValueForBlock(Pred), NewBB); | |||
2766 | } | |||
2767 | ||||
2768 | bool JumpThreadingPass::tryToUnfoldSelect(SwitchInst *SI, BasicBlock *BB) { | |||
2769 | PHINode *CondPHI = dyn_cast<PHINode>(SI->getCondition()); | |||
2770 | ||||
2771 | if (!CondPHI || CondPHI->getParent() != BB) | |||
2772 | return false; | |||
2773 | ||||
2774 | for (unsigned I = 0, E = CondPHI->getNumIncomingValues(); I != E; ++I) { | |||
2775 | BasicBlock *Pred = CondPHI->getIncomingBlock(I); | |||
2776 | SelectInst *PredSI = dyn_cast<SelectInst>(CondPHI->getIncomingValue(I)); | |||
2777 | ||||
2778 | // The second and third condition can be potentially relaxed. Currently | |||
2779 | // the conditions help to simplify the code and allow us to reuse existing | |||
2780 | // code, developed for tryToUnfoldSelect(CmpInst *, BasicBlock *) | |||
2781 | if (!PredSI || PredSI->getParent() != Pred || !PredSI->hasOneUse()) | |||
2782 | continue; | |||
2783 | ||||
2784 | BranchInst *PredTerm = dyn_cast<BranchInst>(Pred->getTerminator()); | |||
2785 | if (!PredTerm || !PredTerm->isUnconditional()) | |||
2786 | continue; | |||
2787 | ||||
2788 | unfoldSelectInstr(Pred, BB, PredSI, CondPHI, I); | |||
2789 | return true; | |||
2790 | } | |||
2791 | return false; | |||
2792 | } | |||
2793 | ||||
2794 | /// tryToUnfoldSelect - Look for blocks of the form | |||
2795 | /// bb1: | |||
2796 | /// %a = select | |||
2797 | /// br bb2 | |||
2798 | /// | |||
2799 | /// bb2: | |||
2800 | /// %p = phi [%a, %bb1] ... | |||
2801 | /// %c = icmp %p | |||
2802 | /// br i1 %c | |||
2803 | /// | |||
2804 | /// And expand the select into a branch structure if one of its arms allows %c | |||
2805 | /// to be folded. This later enables threading from bb1 over bb2. | |||
2806 | bool JumpThreadingPass::tryToUnfoldSelect(CmpInst *CondCmp, BasicBlock *BB) { | |||
2807 | BranchInst *CondBr = dyn_cast<BranchInst>(BB->getTerminator()); | |||
2808 | PHINode *CondLHS = dyn_cast<PHINode>(CondCmp->getOperand(0)); | |||
2809 | Constant *CondRHS = cast<Constant>(CondCmp->getOperand(1)); | |||
2810 | ||||
2811 | if (!CondBr || !CondBr->isConditional() || !CondLHS || | |||
2812 | CondLHS->getParent() != BB) | |||
2813 | return false; | |||
2814 | ||||
2815 | for (unsigned I = 0, E = CondLHS->getNumIncomingValues(); I != E; ++I) { | |||
2816 | BasicBlock *Pred = CondLHS->getIncomingBlock(I); | |||
2817 | SelectInst *SI = dyn_cast<SelectInst>(CondLHS->getIncomingValue(I)); | |||
2818 | ||||
2819 | // Look if one of the incoming values is a select in the corresponding | |||
2820 | // predecessor. | |||
2821 | if (!SI || SI->getParent() != Pred || !SI->hasOneUse()) | |||
2822 | continue; | |||
2823 | ||||
2824 | BranchInst *PredTerm = dyn_cast<BranchInst>(Pred->getTerminator()); | |||
2825 | if (!PredTerm || !PredTerm->isUnconditional()) | |||
2826 | continue; | |||
2827 | ||||
2828 | // Now check if one of the select values would allow us to constant fold the | |||
2829 | // terminator in BB. We don't do the transform if both sides fold, those | |||
2830 | // cases will be threaded in any case. | |||
2831 | LazyValueInfo::Tristate LHSFolds = | |||
2832 | LVI->getPredicateOnEdge(CondCmp->getPredicate(), SI->getOperand(1), | |||
2833 | CondRHS, Pred, BB, CondCmp); | |||
2834 | LazyValueInfo::Tristate RHSFolds = | |||
2835 | LVI->getPredicateOnEdge(CondCmp->getPredicate(), SI->getOperand(2), | |||
2836 | CondRHS, Pred, BB, CondCmp); | |||
2837 | if ((LHSFolds != LazyValueInfo::Unknown || | |||
2838 | RHSFolds != LazyValueInfo::Unknown) && | |||
2839 | LHSFolds != RHSFolds) { | |||
2840 | unfoldSelectInstr(Pred, BB, SI, CondLHS, I); | |||
2841 | return true; | |||
2842 | } | |||
2843 | } | |||
2844 | return false; | |||
2845 | } | |||
2846 | ||||
2847 | /// tryToUnfoldSelectInCurrBB - Look for PHI/Select or PHI/CMP/Select in the | |||
2848 | /// same BB in the form | |||
2849 | /// bb: | |||
2850 | /// %p = phi [false, %bb1], [true, %bb2], [false, %bb3], [true, %bb4], ... | |||
2851 | /// %s = select %p, trueval, falseval | |||
2852 | /// | |||
2853 | /// or | |||
2854 | /// | |||
2855 | /// bb: | |||
2856 | /// %p = phi [0, %bb1], [1, %bb2], [0, %bb3], [1, %bb4], ... | |||
2857 | /// %c = cmp %p, 0 | |||
2858 | /// %s = select %c, trueval, falseval | |||
2859 | /// | |||
2860 | /// And expand the select into a branch structure. This later enables | |||
2861 | /// jump-threading over bb in this pass. | |||
2862 | /// | |||
2863 | /// Using the similar approach of SimplifyCFG::FoldCondBranchOnPHI(), unfold | |||
2864 | /// select if the associated PHI has at least one constant. If the unfolded | |||
2865 | /// select is not jump-threaded, it will be folded again in the later | |||
2866 | /// optimizations. | |||
2867 | bool JumpThreadingPass::tryToUnfoldSelectInCurrBB(BasicBlock *BB) { | |||
2868 | // This transform would reduce the quality of msan diagnostics. | |||
2869 | // Disable this transform under MemorySanitizer. | |||
2870 | if (BB->getParent()->hasFnAttribute(Attribute::SanitizeMemory)) | |||
2871 | return false; | |||
2872 | ||||
2873 | // If threading this would thread across a loop header, don't thread the edge. | |||
2874 | // See the comments above findLoopHeaders for justifications and caveats. | |||
2875 | if (LoopHeaders.count(BB)) | |||
2876 | return false; | |||
2877 | ||||
2878 | for (BasicBlock::iterator BI = BB->begin(); | |||
2879 | PHINode *PN = dyn_cast<PHINode>(BI); ++BI) { | |||
2880 | // Look for a Phi having at least one constant incoming value. | |||
2881 | if (llvm::all_of(PN->incoming_values(), | |||
2882 | [](Value *V) { return !isa<ConstantInt>(V); })) | |||
2883 | continue; | |||
2884 | ||||
2885 | auto isUnfoldCandidate = [BB](SelectInst *SI, Value *V) { | |||
2886 | using namespace PatternMatch; | |||
2887 | ||||
2888 | // Check if SI is in BB and use V as condition. | |||
2889 | if (SI->getParent() != BB) | |||
2890 | return false; | |||
2891 | Value *Cond = SI->getCondition(); | |||
2892 | bool IsAndOr = match(SI, m_CombineOr(m_LogicalAnd(), m_LogicalOr())); | |||
2893 | return Cond && Cond == V && Cond->getType()->isIntegerTy(1) && !IsAndOr; | |||
2894 | }; | |||
2895 | ||||
2896 | SelectInst *SI = nullptr; | |||
2897 | for (Use &U : PN->uses()) { | |||
2898 | if (ICmpInst *Cmp = dyn_cast<ICmpInst>(U.getUser())) { | |||
2899 | // Look for a ICmp in BB that compares PN with a constant and is the | |||
2900 | // condition of a Select. | |||
2901 | if (Cmp->getParent() == BB && Cmp->hasOneUse() && | |||
2902 | isa<ConstantInt>(Cmp->getOperand(1 - U.getOperandNo()))) | |||
2903 | if (SelectInst *SelectI = dyn_cast<SelectInst>(Cmp->user_back())) | |||
2904 | if (isUnfoldCandidate(SelectI, Cmp->use_begin()->get())) { | |||
2905 | SI = SelectI; | |||
2906 | break; | |||
2907 | } | |||
2908 | } else if (SelectInst *SelectI = dyn_cast<SelectInst>(U.getUser())) { | |||
2909 | // Look for a Select in BB that uses PN as condition. | |||
2910 | if (isUnfoldCandidate(SelectI, U.get())) { | |||
2911 | SI = SelectI; | |||
2912 | break; | |||
2913 | } | |||
2914 | } | |||
2915 | } | |||
2916 | ||||
2917 | if (!SI) | |||
2918 | continue; | |||
2919 | // Expand the select. | |||
2920 | Value *Cond = SI->getCondition(); | |||
2921 | if (InsertFreezeWhenUnfoldingSelect && | |||
2922 | !isGuaranteedNotToBeUndefOrPoison(Cond, nullptr, SI, | |||
2923 | &DTU->getDomTree())) | |||
2924 | Cond = new FreezeInst(Cond, "cond.fr", SI); | |||
2925 | Instruction *Term = SplitBlockAndInsertIfThen(Cond, SI, false); | |||
2926 | BasicBlock *SplitBB = SI->getParent(); | |||
2927 | BasicBlock *NewBB = Term->getParent(); | |||
2928 | PHINode *NewPN = PHINode::Create(SI->getType(), 2, "", SI); | |||
2929 | NewPN->addIncoming(SI->getTrueValue(), Term->getParent()); | |||
2930 | NewPN->addIncoming(SI->getFalseValue(), BB); | |||
2931 | SI->replaceAllUsesWith(NewPN); | |||
2932 | SI->eraseFromParent(); | |||
2933 | // NewBB and SplitBB are newly created blocks which require insertion. | |||
2934 | std::vector<DominatorTree::UpdateType> Updates; | |||
2935 | Updates.reserve((2 * SplitBB->getTerminator()->getNumSuccessors()) + 3); | |||
2936 | Updates.push_back({DominatorTree::Insert, BB, SplitBB}); | |||
2937 | Updates.push_back({DominatorTree::Insert, BB, NewBB}); | |||
2938 | Updates.push_back({DominatorTree::Insert, NewBB, SplitBB}); | |||
2939 | // BB's successors were moved to SplitBB, update DTU accordingly. | |||
2940 | for (auto *Succ : successors(SplitBB)) { | |||
2941 | Updates.push_back({DominatorTree::Delete, BB, Succ}); | |||
2942 | Updates.push_back({DominatorTree::Insert, SplitBB, Succ}); | |||
2943 | } | |||
2944 | DTU->applyUpdatesPermissive(Updates); | |||
2945 | return true; | |||
2946 | } | |||
2947 | return false; | |||
2948 | } | |||
2949 | ||||
2950 | /// Try to propagate a guard from the current BB into one of its predecessors | |||
2951 | /// in case if another branch of execution implies that the condition of this | |||
2952 | /// guard is always true. Currently we only process the simplest case that | |||
2953 | /// looks like: | |||
2954 | /// | |||
2955 | /// Start: | |||
2956 | /// %cond = ... | |||
2957 | /// br i1 %cond, label %T1, label %F1 | |||
2958 | /// T1: | |||
2959 | /// br label %Merge | |||
2960 | /// F1: | |||
2961 | /// br label %Merge | |||
2962 | /// Merge: | |||
2963 | /// %condGuard = ... | |||
2964 | /// call void(i1, ...) @llvm.experimental.guard( i1 %condGuard )[ "deopt"() ] | |||
2965 | /// | |||
2966 | /// And cond either implies condGuard or !condGuard. In this case all the | |||
2967 | /// instructions before the guard can be duplicated in both branches, and the | |||
2968 | /// guard is then threaded to one of them. | |||
2969 | bool JumpThreadingPass::processGuards(BasicBlock *BB) { | |||
2970 | using namespace PatternMatch; | |||
2971 | ||||
2972 | // We only want to deal with two predecessors. | |||
2973 | BasicBlock *Pred1, *Pred2; | |||
2974 | auto PI = pred_begin(BB), PE = pred_end(BB); | |||
2975 | if (PI == PE) | |||
2976 | return false; | |||
2977 | Pred1 = *PI++; | |||
2978 | if (PI == PE) | |||
2979 | return false; | |||
2980 | Pred2 = *PI++; | |||
2981 | if (PI != PE) | |||
2982 | return false; | |||
2983 | if (Pred1 == Pred2) | |||
2984 | return false; | |||
2985 | ||||
2986 | // Try to thread one of the guards of the block. | |||
2987 | // TODO: Look up deeper than to immediate predecessor? | |||
2988 | auto *Parent = Pred1->getSinglePredecessor(); | |||
2989 | if (!Parent || Parent != Pred2->getSinglePredecessor()) | |||
2990 | return false; | |||
2991 | ||||
2992 | if (auto *BI = dyn_cast<BranchInst>(Parent->getTerminator())) | |||
2993 | for (auto &I : *BB) | |||
2994 | if (isGuard(&I) && threadGuard(BB, cast<IntrinsicInst>(&I), BI)) | |||
2995 | return true; | |||
2996 | ||||
2997 | return false; | |||
2998 | } | |||
2999 | ||||
3000 | /// Try to propagate the guard from BB which is the lower block of a diamond | |||
3001 | /// to one of its branches, in case if diamond's condition implies guard's | |||
3002 | /// condition. | |||
3003 | bool JumpThreadingPass::threadGuard(BasicBlock *BB, IntrinsicInst *Guard, | |||
3004 | BranchInst *BI) { | |||
3005 | assert(BI->getNumSuccessors() == 2 && "Wrong number of successors?")((void)0); | |||
3006 | assert(BI->isConditional() && "Unconditional branch has 2 successors?")((void)0); | |||
3007 | Value *GuardCond = Guard->getArgOperand(0); | |||
3008 | Value *BranchCond = BI->getCondition(); | |||
3009 | BasicBlock *TrueDest = BI->getSuccessor(0); | |||
3010 | BasicBlock *FalseDest = BI->getSuccessor(1); | |||
3011 | ||||
3012 | auto &DL = BB->getModule()->getDataLayout(); | |||
3013 | bool TrueDestIsSafe = false; | |||
3014 | bool FalseDestIsSafe = false; | |||
3015 | ||||
3016 | // True dest is safe if BranchCond => GuardCond. | |||
3017 | auto Impl = isImpliedCondition(BranchCond, GuardCond, DL); | |||
3018 | if (Impl && *Impl) | |||
3019 | TrueDestIsSafe = true; | |||
3020 | else { | |||
3021 | // False dest is safe if !BranchCond => GuardCond. | |||
3022 | Impl = isImpliedCondition(BranchCond, GuardCond, DL, /* LHSIsTrue */ false); | |||
3023 | if (Impl && *Impl) | |||
3024 | FalseDestIsSafe = true; | |||
3025 | } | |||
3026 | ||||
3027 | if (!TrueDestIsSafe && !FalseDestIsSafe) | |||
3028 | return false; | |||
3029 | ||||
3030 | BasicBlock *PredUnguardedBlock = TrueDestIsSafe ? TrueDest : FalseDest; | |||
3031 | BasicBlock *PredGuardedBlock = FalseDestIsSafe ? TrueDest : FalseDest; | |||
3032 | ||||
3033 | ValueToValueMapTy UnguardedMapping, GuardedMapping; | |||
3034 | Instruction *AfterGuard = Guard->getNextNode(); | |||
3035 | unsigned Cost = getJumpThreadDuplicationCost(BB, AfterGuard, BBDupThreshold); | |||
3036 | if (Cost > BBDupThreshold) | |||
3037 | return false; | |||
3038 | // Duplicate all instructions before the guard and the guard itself to the | |||
3039 | // branch where implication is not proved. | |||
3040 | BasicBlock *GuardedBlock = DuplicateInstructionsInSplitBetween( | |||
3041 | BB, PredGuardedBlock, AfterGuard, GuardedMapping, *DTU); | |||
3042 | assert(GuardedBlock && "Could not create the guarded block?")((void)0); | |||
3043 | // Duplicate all instructions before the guard in the unguarded branch. | |||
3044 | // Since we have successfully duplicated the guarded block and this block | |||
3045 | // has fewer instructions, we expect it to succeed. | |||
3046 | BasicBlock *UnguardedBlock = DuplicateInstructionsInSplitBetween( | |||
3047 | BB, PredUnguardedBlock, Guard, UnguardedMapping, *DTU); | |||
3048 | assert(UnguardedBlock && "Could not create the unguarded block?")((void)0); | |||
3049 | LLVM_DEBUG(dbgs() << "Moved guard " << *Guard << " to block "do { } while (false) | |||
3050 | << GuardedBlock->getName() << "\n")do { } while (false); | |||
3051 | // Some instructions before the guard may still have uses. For them, we need | |||
3052 | // to create Phi nodes merging their copies in both guarded and unguarded | |||
3053 | // branches. Those instructions that have no uses can be just removed. | |||
3054 | SmallVector<Instruction *, 4> ToRemove; | |||
3055 | for (auto BI = BB->begin(); &*BI != AfterGuard; ++BI) | |||
3056 | if (!isa<PHINode>(&*BI)) | |||
3057 | ToRemove.push_back(&*BI); | |||
3058 | ||||
3059 | Instruction *InsertionPoint = &*BB->getFirstInsertionPt(); | |||
3060 | assert(InsertionPoint && "Empty block?")((void)0); | |||
3061 | // Substitute with Phis & remove. | |||
3062 | for (auto *Inst : reverse(ToRemove)) { | |||
3063 | if (!Inst->use_empty()) { | |||
3064 | PHINode *NewPN = PHINode::Create(Inst->getType(), 2); | |||
3065 | NewPN->addIncoming(UnguardedMapping[Inst], UnguardedBlock); | |||
3066 | NewPN->addIncoming(GuardedMapping[Inst], GuardedBlock); | |||
3067 | NewPN->insertBefore(InsertionPoint); | |||
3068 | Inst->replaceAllUsesWith(NewPN); | |||
3069 | } | |||
3070 | Inst->eraseFromParent(); | |||
3071 | } | |||
3072 | return true; | |||
3073 | } |
1 | //===- llvm/Instructions.h - Instruction subclass definitions ---*- 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 exposes the class definitions of all of the subclasses of the |
10 | // Instruction class. This is meant to be an easy way to get access to all |
11 | // instruction subclasses. |
12 | // |
13 | //===----------------------------------------------------------------------===// |
14 | |
15 | #ifndef LLVM_IR_INSTRUCTIONS_H |
16 | #define LLVM_IR_INSTRUCTIONS_H |
17 | |
18 | #include "llvm/ADT/ArrayRef.h" |
19 | #include "llvm/ADT/Bitfields.h" |
20 | #include "llvm/ADT/MapVector.h" |
21 | #include "llvm/ADT/None.h" |
22 | #include "llvm/ADT/STLExtras.h" |
23 | #include "llvm/ADT/SmallVector.h" |
24 | #include "llvm/ADT/StringRef.h" |
25 | #include "llvm/ADT/Twine.h" |
26 | #include "llvm/ADT/iterator.h" |
27 | #include "llvm/ADT/iterator_range.h" |
28 | #include "llvm/IR/Attributes.h" |
29 | #include "llvm/IR/BasicBlock.h" |
30 | #include "llvm/IR/CallingConv.h" |
31 | #include "llvm/IR/CFG.h" |
32 | #include "llvm/IR/Constant.h" |
33 | #include "llvm/IR/DerivedTypes.h" |
34 | #include "llvm/IR/Function.h" |
35 | #include "llvm/IR/InstrTypes.h" |
36 | #include "llvm/IR/Instruction.h" |
37 | #include "llvm/IR/OperandTraits.h" |
38 | #include "llvm/IR/Type.h" |
39 | #include "llvm/IR/Use.h" |
40 | #include "llvm/IR/User.h" |
41 | #include "llvm/IR/Value.h" |
42 | #include "llvm/Support/AtomicOrdering.h" |
43 | #include "llvm/Support/Casting.h" |
44 | #include "llvm/Support/ErrorHandling.h" |
45 | #include <cassert> |
46 | #include <cstddef> |
47 | #include <cstdint> |
48 | #include <iterator> |
49 | |
50 | namespace llvm { |
51 | |
52 | class APInt; |
53 | class ConstantInt; |
54 | class DataLayout; |
55 | class LLVMContext; |
56 | |
57 | //===----------------------------------------------------------------------===// |
58 | // AllocaInst Class |
59 | //===----------------------------------------------------------------------===// |
60 | |
61 | /// an instruction to allocate memory on the stack |
62 | class AllocaInst : public UnaryInstruction { |
63 | Type *AllocatedType; |
64 | |
65 | using AlignmentField = AlignmentBitfieldElementT<0>; |
66 | using UsedWithInAllocaField = BoolBitfieldElementT<AlignmentField::NextBit>; |
67 | using SwiftErrorField = BoolBitfieldElementT<UsedWithInAllocaField::NextBit>; |
68 | static_assert(Bitfield::areContiguous<AlignmentField, UsedWithInAllocaField, |
69 | SwiftErrorField>(), |
70 | "Bitfields must be contiguous"); |
71 | |
72 | protected: |
73 | // Note: Instruction needs to be a friend here to call cloneImpl. |
74 | friend class Instruction; |
75 | |
76 | AllocaInst *cloneImpl() const; |
77 | |
78 | public: |
79 | explicit AllocaInst(Type *Ty, unsigned AddrSpace, Value *ArraySize, |
80 | const Twine &Name, Instruction *InsertBefore); |
81 | AllocaInst(Type *Ty, unsigned AddrSpace, Value *ArraySize, |
82 | const Twine &Name, BasicBlock *InsertAtEnd); |
83 | |
84 | AllocaInst(Type *Ty, unsigned AddrSpace, const Twine &Name, |
85 | Instruction *InsertBefore); |
86 | AllocaInst(Type *Ty, unsigned AddrSpace, |
87 | const Twine &Name, BasicBlock *InsertAtEnd); |
88 | |
89 | AllocaInst(Type *Ty, unsigned AddrSpace, Value *ArraySize, Align Align, |
90 | const Twine &Name = "", Instruction *InsertBefore = nullptr); |
91 | AllocaInst(Type *Ty, unsigned AddrSpace, Value *ArraySize, Align Align, |
92 | const Twine &Name, BasicBlock *InsertAtEnd); |
93 | |
94 | /// Return true if there is an allocation size parameter to the allocation |
95 | /// instruction that is not 1. |
96 | bool isArrayAllocation() const; |
97 | |
98 | /// Get the number of elements allocated. For a simple allocation of a single |
99 | /// element, this will return a constant 1 value. |
100 | const Value *getArraySize() const { return getOperand(0); } |
101 | Value *getArraySize() { return getOperand(0); } |
102 | |
103 | /// Overload to return most specific pointer type. |
104 | PointerType *getType() const { |
105 | return cast<PointerType>(Instruction::getType()); |
106 | } |
107 | |
108 | /// Get allocation size in bits. Returns None if size can't be determined, |
109 | /// e.g. in case of a VLA. |
110 | Optional<TypeSize> getAllocationSizeInBits(const DataLayout &DL) const; |
111 | |
112 | /// Return the type that is being allocated by the instruction. |
113 | Type *getAllocatedType() const { return AllocatedType; } |
114 | /// for use only in special circumstances that need to generically |
115 | /// transform a whole instruction (eg: IR linking and vectorization). |
116 | void setAllocatedType(Type *Ty) { AllocatedType = Ty; } |
117 | |
118 | /// Return the alignment of the memory that is being allocated by the |
119 | /// instruction. |
120 | Align getAlign() const { |
121 | return Align(1ULL << getSubclassData<AlignmentField>()); |
122 | } |
123 | |
124 | void setAlignment(Align Align) { |
125 | setSubclassData<AlignmentField>(Log2(Align)); |
126 | } |
127 | |
128 | // FIXME: Remove this one transition to Align is over. |
129 | unsigned getAlignment() const { return getAlign().value(); } |
130 | |
131 | /// Return true if this alloca is in the entry block of the function and is a |
132 | /// constant size. If so, the code generator will fold it into the |
133 | /// prolog/epilog code, so it is basically free. |
134 | bool isStaticAlloca() const; |
135 | |
136 | /// Return true if this alloca is used as an inalloca argument to a call. Such |
137 | /// allocas are never considered static even if they are in the entry block. |
138 | bool isUsedWithInAlloca() const { |
139 | return getSubclassData<UsedWithInAllocaField>(); |
140 | } |
141 | |
142 | /// Specify whether this alloca is used to represent the arguments to a call. |
143 | void setUsedWithInAlloca(bool V) { |
144 | setSubclassData<UsedWithInAllocaField>(V); |
145 | } |
146 | |
147 | /// Return true if this alloca is used as a swifterror argument to a call. |
148 | bool isSwiftError() const { return getSubclassData<SwiftErrorField>(); } |
149 | /// Specify whether this alloca is used to represent a swifterror. |
150 | void setSwiftError(bool V) { setSubclassData<SwiftErrorField>(V); } |
151 | |
152 | // Methods for support type inquiry through isa, cast, and dyn_cast: |
153 | static bool classof(const Instruction *I) { |
154 | return (I->getOpcode() == Instruction::Alloca); |
155 | } |
156 | static bool classof(const Value *V) { |
157 | return isa<Instruction>(V) && classof(cast<Instruction>(V)); |
158 | } |
159 | |
160 | private: |
161 | // Shadow Instruction::setInstructionSubclassData with a private forwarding |
162 | // method so that subclasses cannot accidentally use it. |
163 | template <typename Bitfield> |
164 | void setSubclassData(typename Bitfield::Type Value) { |
165 | Instruction::setSubclassData<Bitfield>(Value); |
166 | } |
167 | }; |
168 | |
169 | //===----------------------------------------------------------------------===// |
170 | // LoadInst Class |
171 | //===----------------------------------------------------------------------===// |
172 | |
173 | /// An instruction for reading from memory. This uses the SubclassData field in |
174 | /// Value to store whether or not the load is volatile. |
175 | class LoadInst : public UnaryInstruction { |
176 | using VolatileField = BoolBitfieldElementT<0>; |
177 | using AlignmentField = AlignmentBitfieldElementT<VolatileField::NextBit>; |
178 | using OrderingField = AtomicOrderingBitfieldElementT<AlignmentField::NextBit>; |
179 | static_assert( |
180 | Bitfield::areContiguous<VolatileField, AlignmentField, OrderingField>(), |
181 | "Bitfields must be contiguous"); |
182 | |
183 | void AssertOK(); |
184 | |
185 | protected: |
186 | // Note: Instruction needs to be a friend here to call cloneImpl. |
187 | friend class Instruction; |
188 | |
189 | LoadInst *cloneImpl() const; |
190 | |
191 | public: |
192 | LoadInst(Type *Ty, Value *Ptr, const Twine &NameStr, |
193 | Instruction *InsertBefore); |
194 | LoadInst(Type *Ty, Value *Ptr, const Twine &NameStr, BasicBlock *InsertAtEnd); |
195 | LoadInst(Type *Ty, Value *Ptr, const Twine &NameStr, bool isVolatile, |
196 | Instruction *InsertBefore); |
197 | LoadInst(Type *Ty, Value *Ptr, const Twine &NameStr, bool isVolatile, |
198 | BasicBlock *InsertAtEnd); |
199 | LoadInst(Type *Ty, Value *Ptr, const Twine &NameStr, bool isVolatile, |
200 | Align Align, Instruction *InsertBefore = nullptr); |
201 | LoadInst(Type *Ty, Value *Ptr, const Twine &NameStr, bool isVolatile, |
202 | Align Align, BasicBlock *InsertAtEnd); |
203 | LoadInst(Type *Ty, Value *Ptr, const Twine &NameStr, bool isVolatile, |
204 | Align Align, AtomicOrdering Order, |
205 | SyncScope::ID SSID = SyncScope::System, |
206 | Instruction *InsertBefore = nullptr); |
207 | LoadInst(Type *Ty, Value *Ptr, const Twine &NameStr, bool isVolatile, |
208 | Align Align, AtomicOrdering Order, SyncScope::ID SSID, |
209 | BasicBlock *InsertAtEnd); |
210 | |
211 | /// Return true if this is a load from a volatile memory location. |
212 | bool isVolatile() const { return getSubclassData<VolatileField>(); } |
213 | |
214 | /// Specify whether this is a volatile load or not. |
215 | void setVolatile(bool V) { setSubclassData<VolatileField>(V); } |
216 | |
217 | /// Return the alignment of the access that is being performed. |
218 | /// FIXME: Remove this function once transition to Align is over. |
219 | /// Use getAlign() instead. |
220 | unsigned getAlignment() const { return getAlign().value(); } |
221 | |
222 | /// Return the alignment of the access that is being performed. |
223 | Align getAlign() const { |
224 | return Align(1ULL << (getSubclassData<AlignmentField>())); |
225 | } |
226 | |
227 | void setAlignment(Align Align) { |
228 | setSubclassData<AlignmentField>(Log2(Align)); |
229 | } |
230 | |
231 | /// Returns the ordering constraint of this load instruction. |
232 | AtomicOrdering getOrdering() const { |
233 | return getSubclassData<OrderingField>(); |
234 | } |
235 | /// Sets the ordering constraint of this load instruction. May not be Release |
236 | /// or AcquireRelease. |
237 | void setOrdering(AtomicOrdering Ordering) { |
238 | setSubclassData<OrderingField>(Ordering); |
239 | } |
240 | |
241 | /// Returns the synchronization scope ID of this load instruction. |
242 | SyncScope::ID getSyncScopeID() const { |
243 | return SSID; |
244 | } |
245 | |
246 | /// Sets the synchronization scope ID of this load instruction. |
247 | void setSyncScopeID(SyncScope::ID SSID) { |
248 | this->SSID = SSID; |
249 | } |
250 | |
251 | /// Sets the ordering constraint and the synchronization scope ID of this load |
252 | /// instruction. |
253 | void setAtomic(AtomicOrdering Ordering, |
254 | SyncScope::ID SSID = SyncScope::System) { |
255 | setOrdering(Ordering); |
256 | setSyncScopeID(SSID); |
257 | } |
258 | |
259 | bool isSimple() const { return !isAtomic() && !isVolatile(); } |
260 | |
261 | bool isUnordered() const { |
262 | return (getOrdering() == AtomicOrdering::NotAtomic || |
263 | getOrdering() == AtomicOrdering::Unordered) && |
264 | !isVolatile(); |
265 | } |
266 | |
267 | Value *getPointerOperand() { return getOperand(0); } |
268 | const Value *getPointerOperand() const { return getOperand(0); } |
269 | static unsigned getPointerOperandIndex() { return 0U; } |
270 | Type *getPointerOperandType() const { return getPointerOperand()->getType(); } |
271 | |
272 | /// Returns the address space of the pointer operand. |
273 | unsigned getPointerAddressSpace() const { |
274 | return getPointerOperandType()->getPointerAddressSpace(); |
275 | } |
276 | |
277 | // Methods for support type inquiry through isa, cast, and dyn_cast: |
278 | static bool classof(const Instruction *I) { |
279 | return I->getOpcode() == Instruction::Load; |
280 | } |
281 | static bool classof(const Value *V) { |
282 | return isa<Instruction>(V) && classof(cast<Instruction>(V)); |
283 | } |
284 | |
285 | private: |
286 | // Shadow Instruction::setInstructionSubclassData with a private forwarding |
287 | // method so that subclasses cannot accidentally use it. |
288 | template <typename Bitfield> |
289 | void setSubclassData(typename Bitfield::Type Value) { |
290 | Instruction::setSubclassData<Bitfield>(Value); |
291 | } |
292 | |
293 | /// The synchronization scope ID of this load instruction. Not quite enough |
294 | /// room in SubClassData for everything, so synchronization scope ID gets its |
295 | /// own field. |
296 | SyncScope::ID SSID; |
297 | }; |
298 | |
299 | //===----------------------------------------------------------------------===// |
300 | // StoreInst Class |
301 | //===----------------------------------------------------------------------===// |
302 | |
303 | /// An instruction for storing to memory. |
304 | class StoreInst : public Instruction { |
305 | using VolatileField = BoolBitfieldElementT<0>; |
306 | using AlignmentField = AlignmentBitfieldElementT<VolatileField::NextBit>; |
307 | using OrderingField = AtomicOrderingBitfieldElementT<AlignmentField::NextBit>; |
308 | static_assert( |
309 | Bitfield::areContiguous<VolatileField, AlignmentField, OrderingField>(), |
310 | "Bitfields must be contiguous"); |
311 | |
312 | void AssertOK(); |
313 | |
314 | protected: |
315 | // Note: Instruction needs to be a friend here to call cloneImpl. |
316 | friend class Instruction; |
317 | |
318 | StoreInst *cloneImpl() const; |
319 | |
320 | public: |
321 | StoreInst(Value *Val, Value *Ptr, Instruction *InsertBefore); |
322 | StoreInst(Value *Val, Value *Ptr, BasicBlock *InsertAtEnd); |
323 | StoreInst(Value *Val, Value *Ptr, bool isVolatile, Instruction *InsertBefore); |
324 | StoreInst(Value *Val, Value *Ptr, bool isVolatile, BasicBlock *InsertAtEnd); |
325 | StoreInst(Value *Val, Value *Ptr, bool isVolatile, Align Align, |
326 | Instruction *InsertBefore = nullptr); |
327 | StoreInst(Value *Val, Value *Ptr, bool isVolatile, Align Align, |
328 | BasicBlock *InsertAtEnd); |
329 | StoreInst(Value *Val, Value *Ptr, bool isVolatile, Align Align, |
330 | AtomicOrdering Order, SyncScope::ID SSID = SyncScope::System, |
331 | Instruction *InsertBefore = nullptr); |
332 | StoreInst(Value *Val, Value *Ptr, bool isVolatile, Align Align, |
333 | AtomicOrdering Order, SyncScope::ID SSID, BasicBlock *InsertAtEnd); |
334 | |
335 | // allocate space for exactly two operands |
336 | void *operator new(size_t S) { return User::operator new(S, 2); } |
337 | void operator delete(void *Ptr) { User::operator delete(Ptr); } |
338 | |
339 | /// Return true if this is a store to a volatile memory location. |
340 | bool isVolatile() const { return getSubclassData<VolatileField>(); } |
341 | |
342 | /// Specify whether this is a volatile store or not. |
343 | void setVolatile(bool V) { setSubclassData<VolatileField>(V); } |
344 | |
345 | /// Transparently provide more efficient getOperand methods. |
346 | DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value)public: inline Value *getOperand(unsigned) const; inline void setOperand(unsigned, Value*); inline op_iterator op_begin(); inline const_op_iterator op_begin() const; inline op_iterator op_end(); inline const_op_iterator op_end() const; protected : template <int> inline Use &Op(); template <int > inline const Use &Op() const; public: inline unsigned getNumOperands() const; |
347 | |
348 | /// Return the alignment of the access that is being performed |
349 | /// FIXME: Remove this function once transition to Align is over. |
350 | /// Use getAlign() instead. |
351 | unsigned getAlignment() const { return getAlign().value(); } |
352 | |
353 | Align getAlign() const { |
354 | return Align(1ULL << (getSubclassData<AlignmentField>())); |
355 | } |
356 | |
357 | void setAlignment(Align Align) { |
358 | setSubclassData<AlignmentField>(Log2(Align)); |
359 | } |
360 | |
361 | /// Returns the ordering constraint of this store instruction. |
362 | AtomicOrdering getOrdering() const { |
363 | return getSubclassData<OrderingField>(); |
364 | } |
365 | |
366 | /// Sets the ordering constraint of this store instruction. May not be |
367 | /// Acquire or AcquireRelease. |
368 | void setOrdering(AtomicOrdering Ordering) { |
369 | setSubclassData<OrderingField>(Ordering); |
370 | } |
371 | |
372 | /// Returns the synchronization scope ID of this store instruction. |
373 | SyncScope::ID getSyncScopeID() const { |
374 | return SSID; |
375 | } |
376 | |
377 | /// Sets the synchronization scope ID of this store instruction. |
378 | void setSyncScopeID(SyncScope::ID SSID) { |
379 | this->SSID = SSID; |
380 | } |
381 | |
382 | /// Sets the ordering constraint and the synchronization scope ID of this |
383 | /// store instruction. |
384 | void setAtomic(AtomicOrdering Ordering, |
385 | SyncScope::ID SSID = SyncScope::System) { |
386 | setOrdering(Ordering); |
387 | setSyncScopeID(SSID); |
388 | } |
389 | |
390 | bool isSimple() const { return !isAtomic() && !isVolatile(); } |
391 | |
392 | bool isUnordered() const { |
393 | return (getOrdering() == AtomicOrdering::NotAtomic || |
394 | getOrdering() == AtomicOrdering::Unordered) && |
395 | !isVolatile(); |
396 | } |
397 | |
398 | Value *getValueOperand() { return getOperand(0); } |
399 | const Value *getValueOperand() const { return getOperand(0); } |
400 | |
401 | Value *getPointerOperand() { return getOperand(1); } |
402 | const Value *getPointerOperand() const { return getOperand(1); } |
403 | static unsigned getPointerOperandIndex() { return 1U; } |
404 | Type *getPointerOperandType() const { return getPointerOperand()->getType(); } |
405 | |
406 | /// Returns the address space of the pointer operand. |
407 | unsigned getPointerAddressSpace() const { |
408 | return getPointerOperandType()->getPointerAddressSpace(); |
409 | } |
410 | |
411 | // Methods for support type inquiry through isa, cast, and dyn_cast: |
412 | static bool classof(const Instruction *I) { |
413 | return I->getOpcode() == Instruction::Store; |
414 | } |
415 | static bool classof(const Value *V) { |
416 | return isa<Instruction>(V) && classof(cast<Instruction>(V)); |
417 | } |
418 | |
419 | private: |
420 | // Shadow Instruction::setInstructionSubclassData with a private forwarding |
421 | // method so that subclasses cannot accidentally use it. |
422 | template <typename Bitfield> |
423 | void setSubclassData(typename Bitfield::Type Value) { |
424 | Instruction::setSubclassData<Bitfield>(Value); |
425 | } |
426 | |
427 | /// The synchronization scope ID of this store instruction. Not quite enough |
428 | /// room in SubClassData for everything, so synchronization scope ID gets its |
429 | /// own field. |
430 | SyncScope::ID SSID; |
431 | }; |
432 | |
433 | template <> |
434 | struct OperandTraits<StoreInst> : public FixedNumOperandTraits<StoreInst, 2> { |
435 | }; |
436 | |
437 | DEFINE_TRANSPARENT_OPERAND_ACCESSORS(StoreInst, Value)StoreInst::op_iterator StoreInst::op_begin() { return OperandTraits <StoreInst>::op_begin(this); } StoreInst::const_op_iterator StoreInst::op_begin() const { return OperandTraits<StoreInst >::op_begin(const_cast<StoreInst*>(this)); } StoreInst ::op_iterator StoreInst::op_end() { return OperandTraits<StoreInst >::op_end(this); } StoreInst::const_op_iterator StoreInst:: op_end() const { return OperandTraits<StoreInst>::op_end (const_cast<StoreInst*>(this)); } Value *StoreInst::getOperand (unsigned i_nocapture) const { ((void)0); return cast_or_null <Value>( OperandTraits<StoreInst>::op_begin(const_cast <StoreInst*>(this))[i_nocapture].get()); } void StoreInst ::setOperand(unsigned i_nocapture, Value *Val_nocapture) { (( void)0); OperandTraits<StoreInst>::op_begin(this)[i_nocapture ] = Val_nocapture; } unsigned StoreInst::getNumOperands() const { return OperandTraits<StoreInst>::operands(this); } template <int Idx_nocapture> Use &StoreInst::Op() { return this ->OpFrom<Idx_nocapture>(this); } template <int Idx_nocapture > const Use &StoreInst::Op() const { return this->OpFrom <Idx_nocapture>(this); } |
438 | |
439 | //===----------------------------------------------------------------------===// |
440 | // FenceInst Class |
441 | //===----------------------------------------------------------------------===// |
442 | |
443 | /// An instruction for ordering other memory operations. |
444 | class FenceInst : public Instruction { |
445 | using OrderingField = AtomicOrderingBitfieldElementT<0>; |
446 | |
447 | void Init(AtomicOrdering Ordering, SyncScope::ID SSID); |
448 | |
449 | protected: |
450 | // Note: Instruction needs to be a friend here to call cloneImpl. |
451 | friend class Instruction; |
452 | |
453 | FenceInst *cloneImpl() const; |
454 | |
455 | public: |
456 | // Ordering may only be Acquire, Release, AcquireRelease, or |
457 | // SequentiallyConsistent. |
458 | FenceInst(LLVMContext &C, AtomicOrdering Ordering, |
459 | SyncScope::ID SSID = SyncScope::System, |
460 | Instruction *InsertBefore = nullptr); |
461 | FenceInst(LLVMContext &C, AtomicOrdering Ordering, SyncScope::ID SSID, |
462 | BasicBlock *InsertAtEnd); |
463 | |
464 | // allocate space for exactly zero operands |
465 | void *operator new(size_t S) { return User::operator new(S, 0); } |
466 | void operator delete(void *Ptr) { User::operator delete(Ptr); } |
467 | |
468 | /// Returns the ordering constraint of this fence instruction. |
469 | AtomicOrdering getOrdering() const { |
470 | return getSubclassData<OrderingField>(); |
471 | } |
472 | |
473 | /// Sets the ordering constraint of this fence instruction. May only be |
474 | /// Acquire, Release, AcquireRelease, or SequentiallyConsistent. |
475 | void setOrdering(AtomicOrdering Ordering) { |
476 | setSubclassData<OrderingField>(Ordering); |
477 | } |
478 | |
479 | /// Returns the synchronization scope ID of this fence instruction. |
480 | SyncScope::ID getSyncScopeID() const { |
481 | return SSID; |
482 | } |
483 | |
484 | /// Sets the synchronization scope ID of this fence instruction. |
485 | void setSyncScopeID(SyncScope::ID SSID) { |
486 | this->SSID = SSID; |
487 | } |
488 | |
489 | // Methods for support type inquiry through isa, cast, and dyn_cast: |
490 | static bool classof(const Instruction *I) { |
491 | return I->getOpcode() == Instruction::Fence; |
492 | } |
493 | static bool classof(const Value *V) { |
494 | return isa<Instruction>(V) && classof(cast<Instruction>(V)); |
495 | } |
496 | |
497 | private: |
498 | // Shadow Instruction::setInstructionSubclassData with a private forwarding |
499 | // method so that subclasses cannot accidentally use it. |
500 | template <typename Bitfield> |
501 | void setSubclassData(typename Bitfield::Type Value) { |
502 | Instruction::setSubclassData<Bitfield>(Value); |
503 | } |
504 | |
505 | /// The synchronization scope ID of this fence instruction. Not quite enough |
506 | /// room in SubClassData for everything, so synchronization scope ID gets its |
507 | /// own field. |
508 | SyncScope::ID SSID; |
509 | }; |
510 | |
511 | //===----------------------------------------------------------------------===// |
512 | // AtomicCmpXchgInst Class |
513 | //===----------------------------------------------------------------------===// |
514 | |
515 | /// An instruction that atomically checks whether a |
516 | /// specified value is in a memory location, and, if it is, stores a new value |
517 | /// there. The value returned by this instruction is a pair containing the |
518 | /// original value as first element, and an i1 indicating success (true) or |
519 | /// failure (false) as second element. |
520 | /// |
521 | class AtomicCmpXchgInst : public Instruction { |
522 | void Init(Value *Ptr, Value *Cmp, Value *NewVal, Align Align, |
523 | AtomicOrdering SuccessOrdering, AtomicOrdering FailureOrdering, |
524 | SyncScope::ID SSID); |
525 | |
526 | template <unsigned Offset> |
527 | using AtomicOrderingBitfieldElement = |
528 | typename Bitfield::Element<AtomicOrdering, Offset, 3, |
529 | AtomicOrdering::LAST>; |
530 | |
531 | protected: |
532 | // Note: Instruction needs to be a friend here to call cloneImpl. |
533 | friend class Instruction; |
534 | |
535 | AtomicCmpXchgInst *cloneImpl() const; |
536 | |
537 | public: |
538 | AtomicCmpXchgInst(Value *Ptr, Value *Cmp, Value *NewVal, Align Alignment, |
539 | AtomicOrdering SuccessOrdering, |
540 | AtomicOrdering FailureOrdering, SyncScope::ID SSID, |
541 | Instruction *InsertBefore = nullptr); |
542 | AtomicCmpXchgInst(Value *Ptr, Value *Cmp, Value *NewVal, Align Alignment, |
543 | AtomicOrdering SuccessOrdering, |
544 | AtomicOrdering FailureOrdering, SyncScope::ID SSID, |
545 | BasicBlock *InsertAtEnd); |
546 | |
547 | // allocate space for exactly three operands |
548 | void *operator new(size_t S) { return User::operator new(S, 3); } |
549 | void operator delete(void *Ptr) { User::operator delete(Ptr); } |
550 | |
551 | using VolatileField = BoolBitfieldElementT<0>; |
552 | using WeakField = BoolBitfieldElementT<VolatileField::NextBit>; |
553 | using SuccessOrderingField = |
554 | AtomicOrderingBitfieldElementT<WeakField::NextBit>; |
555 | using FailureOrderingField = |
556 | AtomicOrderingBitfieldElementT<SuccessOrderingField::NextBit>; |
557 | using AlignmentField = |
558 | AlignmentBitfieldElementT<FailureOrderingField::NextBit>; |
559 | static_assert( |
560 | Bitfield::areContiguous<VolatileField, WeakField, SuccessOrderingField, |
561 | FailureOrderingField, AlignmentField>(), |
562 | "Bitfields must be contiguous"); |
563 | |
564 | /// Return the alignment of the memory that is being allocated by the |
565 | /// instruction. |
566 | Align getAlign() const { |
567 | return Align(1ULL << getSubclassData<AlignmentField>()); |
568 | } |
569 | |
570 | void setAlignment(Align Align) { |
571 | setSubclassData<AlignmentField>(Log2(Align)); |
572 | } |
573 | |
574 | /// Return true if this is a cmpxchg from a volatile memory |
575 | /// location. |
576 | /// |
577 | bool isVolatile() const { return getSubclassData<VolatileField>(); } |
578 | |
579 | /// Specify whether this is a volatile cmpxchg. |
580 | /// |
581 | void setVolatile(bool V) { setSubclassData<VolatileField>(V); } |
582 | |
583 | /// Return true if this cmpxchg may spuriously fail. |
584 | bool isWeak() const { return getSubclassData<WeakField>(); } |
585 | |
586 | void setWeak(bool IsWeak) { setSubclassData<WeakField>(IsWeak); } |
587 | |
588 | /// Transparently provide more efficient getOperand methods. |
589 | DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value)public: inline Value *getOperand(unsigned) const; inline void setOperand(unsigned, Value*); inline op_iterator op_begin(); inline const_op_iterator op_begin() const; inline op_iterator op_end(); inline const_op_iterator op_end() const; protected : template <int> inline Use &Op(); template <int > inline const Use &Op() const; public: inline unsigned getNumOperands() const; |
590 | |
591 | static bool isValidSuccessOrdering(AtomicOrdering Ordering) { |
592 | return Ordering != AtomicOrdering::NotAtomic && |
593 | Ordering != AtomicOrdering::Unordered; |
594 | } |
595 | |
596 | static bool isValidFailureOrdering(AtomicOrdering Ordering) { |
597 | return Ordering != AtomicOrdering::NotAtomic && |
598 | Ordering != AtomicOrdering::Unordered && |
599 | Ordering != AtomicOrdering::AcquireRelease && |
600 | Ordering != AtomicOrdering::Release; |
601 | } |
602 | |
603 | /// Returns the success ordering constraint of this cmpxchg instruction. |
604 | AtomicOrdering getSuccessOrdering() const { |
605 | return getSubclassData<SuccessOrderingField>(); |
606 | } |
607 | |
608 | /// Sets the success ordering constraint of this cmpxchg instruction. |
609 | void setSuccessOrdering(AtomicOrdering Ordering) { |
610 | assert(isValidSuccessOrdering(Ordering) &&((void)0) |
611 | "invalid CmpXchg success ordering")((void)0); |
612 | setSubclassData<SuccessOrderingField>(Ordering); |
613 | } |
614 | |
615 | /// Returns the failure ordering constraint of this cmpxchg instruction. |
616 | AtomicOrdering getFailureOrdering() const { |
617 | return getSubclassData<FailureOrderingField>(); |
618 | } |
619 | |
620 | /// Sets the failure ordering constraint of this cmpxchg instruction. |
621 | void setFailureOrdering(AtomicOrdering Ordering) { |
622 | assert(isValidFailureOrdering(Ordering) &&((void)0) |
623 | "invalid CmpXchg failure ordering")((void)0); |
624 | setSubclassData<FailureOrderingField>(Ordering); |
625 | } |
626 | |
627 | /// Returns a single ordering which is at least as strong as both the |
628 | /// success and failure orderings for this cmpxchg. |
629 | AtomicOrdering getMergedOrdering() const { |
630 | if (getFailureOrdering() == AtomicOrdering::SequentiallyConsistent) |
631 | return AtomicOrdering::SequentiallyConsistent; |
632 | if (getFailureOrdering() == AtomicOrdering::Acquire) { |
633 | if (getSuccessOrdering() == AtomicOrdering::Monotonic) |
634 | return AtomicOrdering::Acquire; |
635 | if (getSuccessOrdering() == AtomicOrdering::Release) |
636 | return AtomicOrdering::AcquireRelease; |
637 | } |
638 | return getSuccessOrdering(); |
639 | } |
640 | |
641 | /// Returns the synchronization scope ID of this cmpxchg instruction. |
642 | SyncScope::ID getSyncScopeID() const { |
643 | return SSID; |
644 | } |
645 | |
646 | /// Sets the synchronization scope ID of this cmpxchg instruction. |
647 | void setSyncScopeID(SyncScope::ID SSID) { |
648 | this->SSID = SSID; |
649 | } |
650 | |
651 | Value *getPointerOperand() { return getOperand(0); } |
652 | const Value *getPointerOperand() const { return getOperand(0); } |
653 | static unsigned getPointerOperandIndex() { return 0U; } |
654 | |
655 | Value *getCompareOperand() { return getOperand(1); } |
656 | const Value *getCompareOperand() const { return getOperand(1); } |
657 | |
658 | Value *getNewValOperand() { return getOperand(2); } |
659 | const Value *getNewValOperand() const { return getOperand(2); } |
660 | |
661 | /// Returns the address space of the pointer operand. |
662 | unsigned getPointerAddressSpace() const { |
663 | return getPointerOperand()->getType()->getPointerAddressSpace(); |
664 | } |
665 | |
666 | /// Returns the strongest permitted ordering on failure, given the |
667 | /// desired ordering on success. |
668 | /// |
669 | /// If the comparison in a cmpxchg operation fails, there is no atomic store |
670 | /// so release semantics cannot be provided. So this function drops explicit |
671 | /// Release requests from the AtomicOrdering. A SequentiallyConsistent |
672 | /// operation would remain SequentiallyConsistent. |
673 | static AtomicOrdering |
674 | getStrongestFailureOrdering(AtomicOrdering SuccessOrdering) { |
675 | switch (SuccessOrdering) { |
676 | default: |
677 | llvm_unreachable("invalid cmpxchg success ordering")__builtin_unreachable(); |
678 | case AtomicOrdering::Release: |
679 | case AtomicOrdering::Monotonic: |
680 | return AtomicOrdering::Monotonic; |
681 | case AtomicOrdering::AcquireRelease: |
682 | case AtomicOrdering::Acquire: |
683 | return AtomicOrdering::Acquire; |
684 | case AtomicOrdering::SequentiallyConsistent: |
685 | return AtomicOrdering::SequentiallyConsistent; |
686 | } |
687 | } |
688 | |
689 | // Methods for support type inquiry through isa, cast, and dyn_cast: |
690 | static bool classof(const Instruction *I) { |
691 | return I->getOpcode() == Instruction::AtomicCmpXchg; |
692 | } |
693 | static bool classof(const Value *V) { |
694 | return isa<Instruction>(V) && classof(cast<Instruction>(V)); |
695 | } |
696 | |
697 | private: |
698 | // Shadow Instruction::setInstructionSubclassData with a private forwarding |
699 | // method so that subclasses cannot accidentally use it. |
700 | template <typename Bitfield> |
701 | void setSubclassData(typename Bitfield::Type Value) { |
702 | Instruction::setSubclassData<Bitfield>(Value); |
703 | } |
704 | |
705 | /// The synchronization scope ID of this cmpxchg instruction. Not quite |
706 | /// enough room in SubClassData for everything, so synchronization scope ID |
707 | /// gets its own field. |
708 | SyncScope::ID SSID; |
709 | }; |
710 | |
711 | template <> |
712 | struct OperandTraits<AtomicCmpXchgInst> : |
713 | public FixedNumOperandTraits<AtomicCmpXchgInst, 3> { |
714 | }; |
715 | |
716 | DEFINE_TRANSPARENT_OPERAND_ACCESSORS(AtomicCmpXchgInst, Value)AtomicCmpXchgInst::op_iterator AtomicCmpXchgInst::op_begin() { return OperandTraits<AtomicCmpXchgInst>::op_begin(this ); } AtomicCmpXchgInst::const_op_iterator AtomicCmpXchgInst:: op_begin() const { return OperandTraits<AtomicCmpXchgInst> ::op_begin(const_cast<AtomicCmpXchgInst*>(this)); } AtomicCmpXchgInst ::op_iterator AtomicCmpXchgInst::op_end() { return OperandTraits <AtomicCmpXchgInst>::op_end(this); } AtomicCmpXchgInst:: const_op_iterator AtomicCmpXchgInst::op_end() const { return OperandTraits <AtomicCmpXchgInst>::op_end(const_cast<AtomicCmpXchgInst *>(this)); } Value *AtomicCmpXchgInst::getOperand(unsigned i_nocapture) const { ((void)0); return cast_or_null<Value >( OperandTraits<AtomicCmpXchgInst>::op_begin(const_cast <AtomicCmpXchgInst*>(this))[i_nocapture].get()); } void AtomicCmpXchgInst::setOperand(unsigned i_nocapture, Value *Val_nocapture ) { ((void)0); OperandTraits<AtomicCmpXchgInst>::op_begin (this)[i_nocapture] = Val_nocapture; } unsigned AtomicCmpXchgInst ::getNumOperands() const { return OperandTraits<AtomicCmpXchgInst >::operands(this); } template <int Idx_nocapture> Use &AtomicCmpXchgInst::Op() { return this->OpFrom<Idx_nocapture >(this); } template <int Idx_nocapture> const Use & AtomicCmpXchgInst::Op() const { return this->OpFrom<Idx_nocapture >(this); } |
717 | |
718 | //===----------------------------------------------------------------------===// |
719 | // AtomicRMWInst Class |
720 | //===----------------------------------------------------------------------===// |
721 | |
722 | /// an instruction that atomically reads a memory location, |
723 | /// combines it with another value, and then stores the result back. Returns |
724 | /// the old value. |
725 | /// |
726 | class AtomicRMWInst : public Instruction { |
727 | protected: |
728 | // Note: Instruction needs to be a friend here to call cloneImpl. |
729 | friend class Instruction; |
730 | |
731 | AtomicRMWInst *cloneImpl() const; |
732 | |
733 | public: |
734 | /// This enumeration lists the possible modifications atomicrmw can make. In |
735 | /// the descriptions, 'p' is the pointer to the instruction's memory location, |
736 | /// 'old' is the initial value of *p, and 'v' is the other value passed to the |
737 | /// instruction. These instructions always return 'old'. |
738 | enum BinOp : unsigned { |
739 | /// *p = v |
740 | Xchg, |
741 | /// *p = old + v |
742 | Add, |
743 | /// *p = old - v |
744 | Sub, |
745 | /// *p = old & v |
746 | And, |
747 | /// *p = ~(old & v) |
748 | Nand, |
749 | /// *p = old | v |
750 | Or, |
751 | /// *p = old ^ v |
752 | Xor, |
753 | /// *p = old >signed v ? old : v |
754 | Max, |
755 | /// *p = old <signed v ? old : v |
756 | Min, |
757 | /// *p = old >unsigned v ? old : v |
758 | UMax, |
759 | /// *p = old <unsigned v ? old : v |
760 | UMin, |
761 | |
762 | /// *p = old + v |
763 | FAdd, |
764 | |
765 | /// *p = old - v |
766 | FSub, |
767 | |
768 | FIRST_BINOP = Xchg, |
769 | LAST_BINOP = FSub, |
770 | BAD_BINOP |
771 | }; |
772 | |
773 | private: |
774 | template <unsigned Offset> |
775 | using AtomicOrderingBitfieldElement = |
776 | typename Bitfield::Element<AtomicOrdering, Offset, 3, |
777 | AtomicOrdering::LAST>; |
778 | |
779 | template <unsigned Offset> |
780 | using BinOpBitfieldElement = |
781 | typename Bitfield::Element<BinOp, Offset, 4, BinOp::LAST_BINOP>; |
782 | |
783 | public: |
784 | AtomicRMWInst(BinOp Operation, Value *Ptr, Value *Val, Align Alignment, |
785 | AtomicOrdering Ordering, SyncScope::ID SSID, |
786 | Instruction *InsertBefore = nullptr); |
787 | AtomicRMWInst(BinOp Operation, Value *Ptr, Value *Val, Align Alignment, |
788 | AtomicOrdering Ordering, SyncScope::ID SSID, |
789 | BasicBlock *InsertAtEnd); |
790 | |
791 | // allocate space for exactly two operands |
792 | void *operator new(size_t S) { return User::operator new(S, 2); } |
793 | void operator delete(void *Ptr) { User::operator delete(Ptr); } |
794 | |
795 | using VolatileField = BoolBitfieldElementT<0>; |
796 | using AtomicOrderingField = |
797 | AtomicOrderingBitfieldElementT<VolatileField::NextBit>; |
798 | using OperationField = BinOpBitfieldElement<AtomicOrderingField::NextBit>; |
799 | using AlignmentField = AlignmentBitfieldElementT<OperationField::NextBit>; |
800 | static_assert(Bitfield::areContiguous<VolatileField, AtomicOrderingField, |
801 | OperationField, AlignmentField>(), |
802 | "Bitfields must be contiguous"); |
803 | |
804 | BinOp getOperation() const { return getSubclassData<OperationField>(); } |
805 | |
806 | static StringRef getOperationName(BinOp Op); |
807 | |
808 | static bool isFPOperation(BinOp Op) { |
809 | switch (Op) { |
810 | case AtomicRMWInst::FAdd: |
811 | case AtomicRMWInst::FSub: |
812 | return true; |
813 | default: |
814 | return false; |
815 | } |
816 | } |
817 | |
818 | void setOperation(BinOp Operation) { |
819 | setSubclassData<OperationField>(Operation); |
820 | } |
821 | |
822 | /// Return the alignment of the memory that is being allocated by the |
823 | /// instruction. |
824 | Align getAlign() const { |
825 | return Align(1ULL << getSubclassData<AlignmentField>()); |
826 | } |
827 | |
828 | void setAlignment(Align Align) { |
829 | setSubclassData<AlignmentField>(Log2(Align)); |
830 | } |
831 | |
832 | /// Return true if this is a RMW on a volatile memory location. |
833 | /// |
834 | bool isVolatile() const { return getSubclassData<VolatileField>(); } |
835 | |
836 | /// Specify whether this is a volatile RMW or not. |
837 | /// |
838 | void setVolatile(bool V) { setSubclassData<VolatileField>(V); } |
839 | |
840 | /// Transparently provide more efficient getOperand methods. |
841 | DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value)public: inline Value *getOperand(unsigned) const; inline void setOperand(unsigned, Value*); inline op_iterator op_begin(); inline const_op_iterator op_begin() const; inline op_iterator op_end(); inline const_op_iterator op_end() const; protected : template <int> inline Use &Op(); template <int > inline const Use &Op() const; public: inline unsigned getNumOperands() const; |
842 | |
843 | /// Returns the ordering constraint of this rmw instruction. |
844 | AtomicOrdering getOrdering() const { |
845 | return getSubclassData<AtomicOrderingField>(); |
846 | } |
847 | |
848 | /// Sets the ordering constraint of this rmw instruction. |
849 | void setOrdering(AtomicOrdering Ordering) { |
850 | assert(Ordering != AtomicOrdering::NotAtomic &&((void)0) |
851 | "atomicrmw instructions can only be atomic.")((void)0); |
852 | setSubclassData<AtomicOrderingField>(Ordering); |
853 | } |
854 | |
855 | /// Returns the synchronization scope ID of this rmw instruction. |
856 | SyncScope::ID getSyncScopeID() const { |
857 | return SSID; |
858 | } |
859 | |
860 | /// Sets the synchronization scope ID of this rmw instruction. |
861 | void setSyncScopeID(SyncScope::ID SSID) { |
862 | this->SSID = SSID; |
863 | } |
864 | |
865 | Value *getPointerOperand() { return getOperand(0); } |
866 | const Value *getPointerOperand() const { return getOperand(0); } |
867 | static unsigned getPointerOperandIndex() { return 0U; } |
868 | |
869 | Value *getValOperand() { return getOperand(1); } |
870 | const Value *getValOperand() const { return getOperand(1); } |
871 | |
872 | /// Returns the address space of the pointer operand. |
873 | unsigned getPointerAddressSpace() const { |
874 | return getPointerOperand()->getType()->getPointerAddressSpace(); |
875 | } |
876 | |
877 | bool isFloatingPointOperation() const { |
878 | return isFPOperation(getOperation()); |
879 | } |
880 | |
881 | // Methods for support type inquiry through isa, cast, and dyn_cast: |
882 | static bool classof(const Instruction *I) { |
883 | return I->getOpcode() == Instruction::AtomicRMW; |
884 | } |
885 | static bool classof(const Value *V) { |
886 | return isa<Instruction>(V) && classof(cast<Instruction>(V)); |
887 | } |
888 | |
889 | private: |
890 | void Init(BinOp Operation, Value *Ptr, Value *Val, Align Align, |
891 | AtomicOrdering Ordering, SyncScope::ID SSID); |
892 | |
893 | // Shadow Instruction::setInstructionSubclassData with a private forwarding |
894 | // method so that subclasses cannot accidentally use it. |
895 | template <typename Bitfield> |
896 | void setSubclassData(typename Bitfield::Type Value) { |
897 | Instruction::setSubclassData<Bitfield>(Value); |
898 | } |
899 | |
900 | /// The synchronization scope ID of this rmw instruction. Not quite enough |
901 | /// room in SubClassData for everything, so synchronization scope ID gets its |
902 | /// own field. |
903 | SyncScope::ID SSID; |
904 | }; |
905 | |
906 | template <> |
907 | struct OperandTraits<AtomicRMWInst> |
908 | : public FixedNumOperandTraits<AtomicRMWInst,2> { |
909 | }; |
910 | |
911 | DEFINE_TRANSPARENT_OPERAND_ACCESSORS(AtomicRMWInst, Value)AtomicRMWInst::op_iterator AtomicRMWInst::op_begin() { return OperandTraits<AtomicRMWInst>::op_begin(this); } AtomicRMWInst ::const_op_iterator AtomicRMWInst::op_begin() const { return OperandTraits <AtomicRMWInst>::op_begin(const_cast<AtomicRMWInst*> (this)); } AtomicRMWInst::op_iterator AtomicRMWInst::op_end() { return OperandTraits<AtomicRMWInst>::op_end(this); } AtomicRMWInst::const_op_iterator AtomicRMWInst::op_end() const { return OperandTraits<AtomicRMWInst>::op_end(const_cast <AtomicRMWInst*>(this)); } Value *AtomicRMWInst::getOperand (unsigned i_nocapture) const { ((void)0); return cast_or_null <Value>( OperandTraits<AtomicRMWInst>::op_begin(const_cast <AtomicRMWInst*>(this))[i_nocapture].get()); } void AtomicRMWInst ::setOperand(unsigned i_nocapture, Value *Val_nocapture) { (( void)0); OperandTraits<AtomicRMWInst>::op_begin(this)[i_nocapture ] = Val_nocapture; } unsigned AtomicRMWInst::getNumOperands() const { return OperandTraits<AtomicRMWInst>::operands( this); } template <int Idx_nocapture> Use &AtomicRMWInst ::Op() { return this->OpFrom<Idx_nocapture>(this); } template <int Idx_nocapture> const Use &AtomicRMWInst ::Op() const { return this->OpFrom<Idx_nocapture>(this ); } |
912 | |
913 | //===----------------------------------------------------------------------===// |
914 | // GetElementPtrInst Class |
915 | //===----------------------------------------------------------------------===// |
916 | |
917 | // checkGEPType - Simple wrapper function to give a better assertion failure |
918 | // message on bad indexes for a gep instruction. |
919 | // |
920 | inline Type *checkGEPType(Type *Ty) { |
921 | assert(Ty && "Invalid GetElementPtrInst indices for type!")((void)0); |
922 | return Ty; |
923 | } |
924 | |
925 | /// an instruction for type-safe pointer arithmetic to |
926 | /// access elements of arrays and structs |
927 | /// |
928 | class GetElementPtrInst : public Instruction { |
929 | Type *SourceElementType; |
930 | Type *ResultElementType; |
931 | |
932 | GetElementPtrInst(const GetElementPtrInst &GEPI); |
933 | |
934 | /// Constructors - Create a getelementptr instruction with a base pointer an |
935 | /// list of indices. The first ctor can optionally insert before an existing |
936 | /// instruction, the second appends the new instruction to the specified |
937 | /// BasicBlock. |
938 | inline GetElementPtrInst(Type *PointeeType, Value *Ptr, |
939 | ArrayRef<Value *> IdxList, unsigned Values, |
940 | const Twine &NameStr, Instruction *InsertBefore); |
941 | inline GetElementPtrInst(Type *PointeeType, Value *Ptr, |
942 | ArrayRef<Value *> IdxList, unsigned Values, |
943 | const Twine &NameStr, BasicBlock *InsertAtEnd); |
944 | |
945 | void init(Value *Ptr, ArrayRef<Value *> IdxList, const Twine &NameStr); |
946 | |
947 | protected: |
948 | // Note: Instruction needs to be a friend here to call cloneImpl. |
949 | friend class Instruction; |
950 | |
951 | GetElementPtrInst *cloneImpl() const; |
952 | |
953 | public: |
954 | static GetElementPtrInst *Create(Type *PointeeType, Value *Ptr, |
955 | ArrayRef<Value *> IdxList, |
956 | const Twine &NameStr = "", |
957 | Instruction *InsertBefore = nullptr) { |
958 | unsigned Values = 1 + unsigned(IdxList.size()); |
959 | assert(PointeeType && "Must specify element type")((void)0); |
960 | assert(cast<PointerType>(Ptr->getType()->getScalarType())((void)0) |
961 | ->isOpaqueOrPointeeTypeMatches(PointeeType))((void)0); |
962 | return new (Values) GetElementPtrInst(PointeeType, Ptr, IdxList, Values, |
963 | NameStr, InsertBefore); |
964 | } |
965 | |
966 | static GetElementPtrInst *Create(Type *PointeeType, Value *Ptr, |
967 | ArrayRef<Value *> IdxList, |
968 | const Twine &NameStr, |
969 | BasicBlock *InsertAtEnd) { |
970 | unsigned Values = 1 + unsigned(IdxList.size()); |
971 | assert(PointeeType && "Must specify element type")((void)0); |
972 | assert(cast<PointerType>(Ptr->getType()->getScalarType())((void)0) |
973 | ->isOpaqueOrPointeeTypeMatches(PointeeType))((void)0); |
974 | return new (Values) GetElementPtrInst(PointeeType, Ptr, IdxList, Values, |
975 | NameStr, InsertAtEnd); |
976 | } |
977 | |
978 | LLVM_ATTRIBUTE_DEPRECATED(static GetElementPtrInst *CreateInBounds([[deprecated("Use the version with explicit element type instead" )]] static GetElementPtrInst *CreateInBounds( Value *Ptr, ArrayRef <Value *> IdxList, const Twine &NameStr = "", Instruction *InsertBefore = nullptr) |
979 | Value *Ptr, ArrayRef<Value *> IdxList, const Twine &NameStr = "",[[deprecated("Use the version with explicit element type instead" )]] static GetElementPtrInst *CreateInBounds( Value *Ptr, ArrayRef <Value *> IdxList, const Twine &NameStr = "", Instruction *InsertBefore = nullptr) |
980 | Instruction *InsertBefore = nullptr),[[deprecated("Use the version with explicit element type instead" )]] static GetElementPtrInst *CreateInBounds( Value *Ptr, ArrayRef <Value *> IdxList, const Twine &NameStr = "", Instruction *InsertBefore = nullptr) |
981 | "Use the version with explicit element type instead")[[deprecated("Use the version with explicit element type instead" )]] static GetElementPtrInst *CreateInBounds( Value *Ptr, ArrayRef <Value *> IdxList, const Twine &NameStr = "", Instruction *InsertBefore = nullptr) { |
982 | return CreateInBounds( |
983 | Ptr->getType()->getScalarType()->getPointerElementType(), Ptr, IdxList, |
984 | NameStr, InsertBefore); |
985 | } |
986 | |
987 | /// Create an "inbounds" getelementptr. See the documentation for the |
988 | /// "inbounds" flag in LangRef.html for details. |
989 | static GetElementPtrInst * |
990 | CreateInBounds(Type *PointeeType, Value *Ptr, ArrayRef<Value *> IdxList, |
991 | const Twine &NameStr = "", |
992 | Instruction *InsertBefore = nullptr) { |
993 | GetElementPtrInst *GEP = |
994 | Create(PointeeType, Ptr, IdxList, NameStr, InsertBefore); |
995 | GEP->setIsInBounds(true); |
996 | return GEP; |
997 | } |
998 | |
999 | LLVM_ATTRIBUTE_DEPRECATED(static GetElementPtrInst *CreateInBounds([[deprecated("Use the version with explicit element type instead" )]] static GetElementPtrInst *CreateInBounds( Value *Ptr, ArrayRef <Value *> IdxList, const Twine &NameStr, BasicBlock *InsertAtEnd) |
1000 | Value *Ptr, ArrayRef<Value *> IdxList, const Twine &NameStr,[[deprecated("Use the version with explicit element type instead" )]] static GetElementPtrInst *CreateInBounds( Value *Ptr, ArrayRef <Value *> IdxList, const Twine &NameStr, BasicBlock *InsertAtEnd) |
1001 | BasicBlock *InsertAtEnd),[[deprecated("Use the version with explicit element type instead" )]] static GetElementPtrInst *CreateInBounds( Value *Ptr, ArrayRef <Value *> IdxList, const Twine &NameStr, BasicBlock *InsertAtEnd) |
1002 | "Use the version with explicit element type instead")[[deprecated("Use the version with explicit element type instead" )]] static GetElementPtrInst *CreateInBounds( Value *Ptr, ArrayRef <Value *> IdxList, const Twine &NameStr, BasicBlock *InsertAtEnd) { |
1003 | return CreateInBounds( |
1004 | Ptr->getType()->getScalarType()->getPointerElementType(), Ptr, IdxList, |
1005 | NameStr, InsertAtEnd); |
1006 | } |
1007 | |
1008 | static GetElementPtrInst *CreateInBounds(Type *PointeeType, Value *Ptr, |
1009 | ArrayRef<Value *> IdxList, |
1010 | const Twine &NameStr, |
1011 | BasicBlock *InsertAtEnd) { |
1012 | GetElementPtrInst *GEP = |
1013 | Create(PointeeType, Ptr, IdxList, NameStr, InsertAtEnd); |
1014 | GEP->setIsInBounds(true); |
1015 | return GEP; |
1016 | } |
1017 | |
1018 | /// Transparently provide more efficient getOperand methods. |
1019 | DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value)public: inline Value *getOperand(unsigned) const; inline void setOperand(unsigned, Value*); inline op_iterator op_begin(); inline const_op_iterator op_begin() const; inline op_iterator op_end(); inline const_op_iterator op_end() const; protected : template <int> inline Use &Op(); template <int > inline const Use &Op() const; public: inline unsigned getNumOperands() const; |
1020 | |
1021 | Type *getSourceElementType() const { return SourceElementType; } |
1022 | |
1023 | void setSourceElementType(Type *Ty) { SourceElementType = Ty; } |
1024 | void setResultElementType(Type *Ty) { ResultElementType = Ty; } |
1025 | |
1026 | Type *getResultElementType() const { |
1027 | assert(cast<PointerType>(getType()->getScalarType())((void)0) |
1028 | ->isOpaqueOrPointeeTypeMatches(ResultElementType))((void)0); |
1029 | return ResultElementType; |
1030 | } |
1031 | |
1032 | /// Returns the address space of this instruction's pointer type. |
1033 | unsigned getAddressSpace() const { |
1034 | // Note that this is always the same as the pointer operand's address space |
1035 | // and that is cheaper to compute, so cheat here. |
1036 | return getPointerAddressSpace(); |
1037 | } |
1038 | |
1039 | /// Returns the result type of a getelementptr with the given source |
1040 | /// element type and indexes. |
1041 | /// |
1042 | /// Null is returned if the indices are invalid for the specified |
1043 | /// source element type. |
1044 | static Type *getIndexedType(Type *Ty, ArrayRef<Value *> IdxList); |
1045 | static Type *getIndexedType(Type *Ty, ArrayRef<Constant *> IdxList); |
1046 | static Type *getIndexedType(Type *Ty, ArrayRef<uint64_t> IdxList); |
1047 | |
1048 | /// Return the type of the element at the given index of an indexable |
1049 | /// type. This is equivalent to "getIndexedType(Agg, {Zero, Idx})". |
1050 | /// |
1051 | /// Returns null if the type can't be indexed, or the given index is not |
1052 | /// legal for the given type. |
1053 | static Type *getTypeAtIndex(Type *Ty, Value *Idx); |
1054 | static Type *getTypeAtIndex(Type *Ty, uint64_t Idx); |
1055 | |
1056 | inline op_iterator idx_begin() { return op_begin()+1; } |
1057 | inline const_op_iterator idx_begin() const { return op_begin()+1; } |
1058 | inline op_iterator idx_end() { return op_end(); } |
1059 | inline const_op_iterator idx_end() const { return op_end(); } |
1060 | |
1061 | inline iterator_range<op_iterator> indices() { |
1062 | return make_range(idx_begin(), idx_end()); |
1063 | } |
1064 | |
1065 | inline iterator_range<const_op_iterator> indices() const { |
1066 | return make_range(idx_begin(), idx_end()); |
1067 | } |
1068 | |
1069 | Value *getPointerOperand() { |
1070 | return getOperand(0); |
1071 | } |
1072 | const Value *getPointerOperand() const { |
1073 | return getOperand(0); |
1074 | } |
1075 | static unsigned getPointerOperandIndex() { |
1076 | return 0U; // get index for modifying correct operand. |
1077 | } |
1078 | |
1079 | /// Method to return the pointer operand as a |
1080 | /// PointerType. |
1081 | Type *getPointerOperandType() const { |
1082 | return getPointerOperand()->getType(); |
1083 | } |
1084 | |
1085 | /// Returns the address space of the pointer operand. |
1086 | unsigned getPointerAddressSpace() const { |
1087 | return getPointerOperandType()->getPointerAddressSpace(); |
1088 | } |
1089 | |
1090 | /// Returns the pointer type returned by the GEP |
1091 | /// instruction, which may be a vector of pointers. |
1092 | static Type *getGEPReturnType(Type *ElTy, Value *Ptr, |
1093 | ArrayRef<Value *> IdxList) { |
1094 | PointerType *OrigPtrTy = cast<PointerType>(Ptr->getType()->getScalarType()); |
1095 | unsigned AddrSpace = OrigPtrTy->getAddressSpace(); |
1096 | Type *ResultElemTy = checkGEPType(getIndexedType(ElTy, IdxList)); |
1097 | Type *PtrTy = OrigPtrTy->isOpaque() |
1098 | ? PointerType::get(OrigPtrTy->getContext(), AddrSpace) |
1099 | : PointerType::get(ResultElemTy, AddrSpace); |
1100 | // Vector GEP |
1101 | if (auto *PtrVTy = dyn_cast<VectorType>(Ptr->getType())) { |
1102 | ElementCount EltCount = PtrVTy->getElementCount(); |
1103 | return VectorType::get(PtrTy, EltCount); |
1104 | } |
1105 | for (Value *Index : IdxList) |
1106 | if (auto *IndexVTy = dyn_cast<VectorType>(Index->getType())) { |
1107 | ElementCount EltCount = IndexVTy->getElementCount(); |
1108 | return VectorType::get(PtrTy, EltCount); |
1109 | } |
1110 | // Scalar GEP |
1111 | return PtrTy; |
1112 | } |
1113 | |
1114 | unsigned getNumIndices() const { // Note: always non-negative |
1115 | return getNumOperands() - 1; |
1116 | } |
1117 | |
1118 | bool hasIndices() const { |
1119 | return getNumOperands() > 1; |
1120 | } |
1121 | |
1122 | /// Return true if all of the indices of this GEP are |
1123 | /// zeros. If so, the result pointer and the first operand have the same |
1124 | /// value, just potentially different types. |
1125 | bool hasAllZeroIndices() const; |
1126 | |
1127 | /// Return true if all of the indices of this GEP are |
1128 | /// constant integers. If so, the result pointer and the first operand have |
1129 | /// a constant offset between them. |
1130 | bool hasAllConstantIndices() const; |
1131 | |
1132 | /// Set or clear the inbounds flag on this GEP instruction. |
1133 | /// See LangRef.html for the meaning of inbounds on a getelementptr. |
1134 | void setIsInBounds(bool b = true); |
1135 | |
1136 | /// Determine whether the GEP has the inbounds flag. |
1137 | bool isInBounds() const; |
1138 | |
1139 | /// Accumulate the constant address offset of this GEP if possible. |
1140 | /// |
1141 | /// This routine accepts an APInt into which it will accumulate the constant |
1142 | /// offset of this GEP if the GEP is in fact constant. If the GEP is not |
1143 | /// all-constant, it returns false and the value of the offset APInt is |
1144 | /// undefined (it is *not* preserved!). The APInt passed into this routine |
1145 | /// must be at least as wide as the IntPtr type for the address space of |
1146 | /// the base GEP pointer. |
1147 | bool accumulateConstantOffset(const DataLayout &DL, APInt &Offset) const; |
1148 | bool collectOffset(const DataLayout &DL, unsigned BitWidth, |
1149 | MapVector<Value *, APInt> &VariableOffsets, |
1150 | APInt &ConstantOffset) const; |
1151 | // Methods for support type inquiry through isa, cast, and dyn_cast: |
1152 | static bool classof(const Instruction *I) { |
1153 | return (I->getOpcode() == Instruction::GetElementPtr); |
1154 | } |
1155 | static bool classof(const Value *V) { |
1156 | return isa<Instruction>(V) && classof(cast<Instruction>(V)); |
1157 | } |
1158 | }; |
1159 | |
1160 | template <> |
1161 | struct OperandTraits<GetElementPtrInst> : |
1162 | public VariadicOperandTraits<GetElementPtrInst, 1> { |
1163 | }; |
1164 | |
1165 | GetElementPtrInst::GetElementPtrInst(Type *PointeeType, Value *Ptr, |
1166 | ArrayRef<Value *> IdxList, unsigned Values, |
1167 | const Twine &NameStr, |
1168 | Instruction *InsertBefore) |
1169 | : Instruction(getGEPReturnType(PointeeType, Ptr, IdxList), GetElementPtr, |
1170 | OperandTraits<GetElementPtrInst>::op_end(this) - Values, |
1171 | Values, InsertBefore), |
1172 | SourceElementType(PointeeType), |
1173 | ResultElementType(getIndexedType(PointeeType, IdxList)) { |
1174 | assert(cast<PointerType>(getType()->getScalarType())((void)0) |
1175 | ->isOpaqueOrPointeeTypeMatches(ResultElementType))((void)0); |
1176 | init(Ptr, IdxList, NameStr); |
1177 | } |
1178 | |
1179 | GetElementPtrInst::GetElementPtrInst(Type *PointeeType, Value *Ptr, |
1180 | ArrayRef<Value *> IdxList, unsigned Values, |
1181 | const Twine &NameStr, |
1182 | BasicBlock *InsertAtEnd) |
1183 | : Instruction(getGEPReturnType(PointeeType, Ptr, IdxList), GetElementPtr, |
1184 | OperandTraits<GetElementPtrInst>::op_end(this) - Values, |
1185 | Values, InsertAtEnd), |
1186 | SourceElementType(PointeeType), |
1187 | ResultElementType(getIndexedType(PointeeType, IdxList)) { |
1188 | assert(cast<PointerType>(getType()->getScalarType())((void)0) |
1189 | ->isOpaqueOrPointeeTypeMatches(ResultElementType))((void)0); |
1190 | init(Ptr, IdxList, NameStr); |
1191 | } |
1192 | |
1193 | DEFINE_TRANSPARENT_OPERAND_ACCESSORS(GetElementPtrInst, Value)GetElementPtrInst::op_iterator GetElementPtrInst::op_begin() { return OperandTraits<GetElementPtrInst>::op_begin(this ); } GetElementPtrInst::const_op_iterator GetElementPtrInst:: op_begin() const { return OperandTraits<GetElementPtrInst> ::op_begin(const_cast<GetElementPtrInst*>(this)); } GetElementPtrInst ::op_iterator GetElementPtrInst::op_end() { return OperandTraits <GetElementPtrInst>::op_end(this); } GetElementPtrInst:: const_op_iterator GetElementPtrInst::op_end() const { return OperandTraits <GetElementPtrInst>::op_end(const_cast<GetElementPtrInst *>(this)); } Value *GetElementPtrInst::getOperand(unsigned i_nocapture) const { ((void)0); return cast_or_null<Value >( OperandTraits<GetElementPtrInst>::op_begin(const_cast <GetElementPtrInst*>(this))[i_nocapture].get()); } void GetElementPtrInst::setOperand(unsigned i_nocapture, Value *Val_nocapture ) { ((void)0); OperandTraits<GetElementPtrInst>::op_begin (this)[i_nocapture] = Val_nocapture; } unsigned GetElementPtrInst ::getNumOperands() const { return OperandTraits<GetElementPtrInst >::operands(this); } template <int Idx_nocapture> Use &GetElementPtrInst::Op() { return this->OpFrom<Idx_nocapture >(this); } template <int Idx_nocapture> const Use & GetElementPtrInst::Op() const { return this->OpFrom<Idx_nocapture >(this); } |
1194 | |
1195 | //===----------------------------------------------------------------------===// |
1196 | // ICmpInst Class |
1197 | //===----------------------------------------------------------------------===// |
1198 | |
1199 | /// This instruction compares its operands according to the predicate given |
1200 | /// to the constructor. It only operates on integers or pointers. The operands |
1201 | /// must be identical types. |
1202 | /// Represent an integer comparison operator. |
1203 | class ICmpInst: public CmpInst { |
1204 | void AssertOK() { |
1205 | assert(isIntPredicate() &&((void)0) |
1206 | "Invalid ICmp predicate value")((void)0); |
1207 | assert(getOperand(0)->getType() == getOperand(1)->getType() &&((void)0) |
1208 | "Both operands to ICmp instruction are not of the same type!")((void)0); |
1209 | // Check that the operands are the right type |
1210 | assert((getOperand(0)->getType()->isIntOrIntVectorTy() ||((void)0) |
1211 | getOperand(0)->getType()->isPtrOrPtrVectorTy()) &&((void)0) |
1212 | "Invalid operand types for ICmp instruction")((void)0); |
1213 | } |
1214 | |
1215 | protected: |
1216 | // Note: Instruction needs to be a friend here to call cloneImpl. |
1217 | friend class Instruction; |
1218 | |
1219 | /// Clone an identical ICmpInst |
1220 | ICmpInst *cloneImpl() const; |
1221 | |
1222 | public: |
1223 | /// Constructor with insert-before-instruction semantics. |
1224 | ICmpInst( |
1225 | Instruction *InsertBefore, ///< Where to insert |
1226 | Predicate pred, ///< The predicate to use for the comparison |
1227 | Value *LHS, ///< The left-hand-side of the expression |
1228 | Value *RHS, ///< The right-hand-side of the expression |
1229 | const Twine &NameStr = "" ///< Name of the instruction |
1230 | ) : CmpInst(makeCmpResultType(LHS->getType()), |
1231 | Instruction::ICmp, pred, LHS, RHS, NameStr, |
1232 | InsertBefore) { |
1233 | #ifndef NDEBUG1 |
1234 | AssertOK(); |
1235 | #endif |
1236 | } |
1237 | |
1238 | /// Constructor with insert-at-end semantics. |
1239 | ICmpInst( |
1240 | BasicBlock &InsertAtEnd, ///< Block to insert into. |
1241 | Predicate pred, ///< The predicate to use for the comparison |
1242 | Value *LHS, ///< The left-hand-side of the expression |
1243 | Value *RHS, ///< The right-hand-side of the expression |
1244 | const Twine &NameStr = "" ///< Name of the instruction |
1245 | ) : CmpInst(makeCmpResultType(LHS->getType()), |
1246 | Instruction::ICmp, pred, LHS, RHS, NameStr, |
1247 | &InsertAtEnd) { |
1248 | #ifndef NDEBUG1 |
1249 | AssertOK(); |
1250 | #endif |
1251 | } |
1252 | |
1253 | /// Constructor with no-insertion semantics |
1254 | ICmpInst( |
1255 | Predicate pred, ///< The predicate to use for the comparison |
1256 | Value *LHS, ///< The left-hand-side of the expression |
1257 | Value *RHS, ///< The right-hand-side of the expression |
1258 | const Twine &NameStr = "" ///< Name of the instruction |
1259 | ) : CmpInst(makeCmpResultType(LHS->getType()), |
1260 | Instruction::ICmp, pred, LHS, RHS, NameStr) { |
1261 | #ifndef NDEBUG1 |
1262 | AssertOK(); |
1263 | #endif |
1264 | } |
1265 | |
1266 | /// For example, EQ->EQ, SLE->SLE, UGT->SGT, etc. |
1267 | /// @returns the predicate that would be the result if the operand were |
1268 | /// regarded as signed. |
1269 | /// Return the signed version of the predicate |
1270 | Predicate getSignedPredicate() const { |
1271 | return getSignedPredicate(getPredicate()); |
1272 | } |
1273 | |
1274 | /// This is a static version that you can use without an instruction. |
1275 | /// Return the signed version of the predicate. |
1276 | static Predicate getSignedPredicate(Predicate pred); |
1277 | |
1278 | /// For example, EQ->EQ, SLE->ULE, UGT->UGT, etc. |
1279 | /// @returns the predicate that would be the result if the operand were |
1280 | /// regarded as unsigned. |
1281 | /// Return the unsigned version of the predicate |
1282 | Predicate getUnsignedPredicate() const { |
1283 | return getUnsignedPredicate(getPredicate()); |
1284 | } |
1285 | |
1286 | /// This is a static version that you can use without an instruction. |
1287 | /// Return the unsigned version of the predicate. |
1288 | static Predicate getUnsignedPredicate(Predicate pred); |
1289 | |
1290 | /// Return true if this predicate is either EQ or NE. This also |
1291 | /// tests for commutativity. |
1292 | static bool isEquality(Predicate P) { |
1293 | return P == ICMP_EQ || P == ICMP_NE; |
1294 | } |
1295 | |
1296 | /// Return true if this predicate is either EQ or NE. This also |
1297 | /// tests for commutativity. |
1298 | bool isEquality() const { |
1299 | return isEquality(getPredicate()); |
1300 | } |
1301 | |
1302 | /// @returns true if the predicate of this ICmpInst is commutative |
1303 | /// Determine if this relation is commutative. |
1304 | bool isCommutative() const { return isEquality(); } |
1305 | |
1306 | /// Return true if the predicate is relational (not EQ or NE). |
1307 | /// |
1308 | bool isRelational() const { |
1309 | return !isEquality(); |
1310 | } |
1311 | |
1312 | /// Return true if the predicate is relational (not EQ or NE). |
1313 | /// |
1314 | static bool isRelational(Predicate P) { |
1315 | return !isEquality(P); |
1316 | } |
1317 | |
1318 | /// Return true if the predicate is SGT or UGT. |
1319 | /// |
1320 | static bool isGT(Predicate P) { |
1321 | return P == ICMP_SGT || P == ICMP_UGT; |
1322 | } |
1323 | |
1324 | /// Return true if the predicate is SLT or ULT. |
1325 | /// |
1326 | static bool isLT(Predicate P) { |
1327 | return P == ICMP_SLT || P == ICMP_ULT; |
1328 | } |
1329 | |
1330 | /// Return true if the predicate is SGE or UGE. |
1331 | /// |
1332 | static bool isGE(Predicate P) { |
1333 | return P == ICMP_SGE || P == ICMP_UGE; |
1334 | } |
1335 | |
1336 | /// Return true if the predicate is SLE or ULE. |
1337 | /// |
1338 | static bool isLE(Predicate P) { |
1339 | return P == ICMP_SLE || P == ICMP_ULE; |
1340 | } |
1341 | |
1342 | /// Exchange the two operands to this instruction in such a way that it does |
1343 | /// not modify the semantics of the instruction. The predicate value may be |
1344 | /// changed to retain the same result if the predicate is order dependent |
1345 | /// (e.g. ult). |
1346 | /// Swap operands and adjust predicate. |
1347 | void swapOperands() { |
1348 | setPredicate(getSwappedPredicate()); |
1349 | Op<0>().swap(Op<1>()); |
1350 | } |
1351 | |
1352 | // Methods for support type inquiry through isa, cast, and dyn_cast: |
1353 | static bool classof(const Instruction *I) { |
1354 | return I->getOpcode() == Instruction::ICmp; |
1355 | } |
1356 | static bool classof(const Value *V) { |
1357 | return isa<Instruction>(V) && classof(cast<Instruction>(V)); |
1358 | } |
1359 | }; |
1360 | |
1361 | //===----------------------------------------------------------------------===// |
1362 | // FCmpInst Class |
1363 | //===----------------------------------------------------------------------===// |
1364 | |
1365 | /// This instruction compares its operands according to the predicate given |
1366 | /// to the constructor. It only operates on floating point values or packed |
1367 | /// vectors of floating point values. The operands must be identical types. |
1368 | /// Represents a floating point comparison operator. |
1369 | class FCmpInst: public CmpInst { |
1370 | void AssertOK() { |
1371 | assert(isFPPredicate() && "Invalid FCmp predicate value")((void)0); |
1372 | assert(getOperand(0)->getType() == getOperand(1)->getType() &&((void)0) |
1373 | "Both operands to FCmp instruction are not of the same type!")((void)0); |
1374 | // Check that the operands are the right type |
1375 | assert(getOperand(0)->getType()->isFPOrFPVectorTy() &&((void)0) |
1376 | "Invalid operand types for FCmp instruction")((void)0); |
1377 | } |
1378 | |
1379 | protected: |
1380 | // Note: Instruction needs to be a friend here to call cloneImpl. |
1381 | friend class Instruction; |
1382 | |
1383 | /// Clone an identical FCmpInst |
1384 | FCmpInst *cloneImpl() const; |
1385 | |
1386 | public: |
1387 | /// Constructor with insert-before-instruction semantics. |
1388 | FCmpInst( |
1389 | Instruction *InsertBefore, ///< Where to insert |
1390 | Predicate pred, ///< The predicate to use for the comparison |
1391 | Value *LHS, ///< The left-hand-side of the expression |
1392 | Value *RHS, ///< The right-hand-side of the expression |
1393 | const Twine &NameStr = "" ///< Name of the instruction |
1394 | ) : CmpInst(makeCmpResultType(LHS->getType()), |
1395 | Instruction::FCmp, pred, LHS, RHS, NameStr, |
1396 | InsertBefore) { |
1397 | AssertOK(); |
1398 | } |
1399 | |
1400 | /// Constructor with insert-at-end semantics. |
1401 | FCmpInst( |
1402 | BasicBlock &InsertAtEnd, ///< Block to insert into. |
1403 | Predicate pred, ///< The predicate to use for the comparison |
1404 | Value *LHS, ///< The left-hand-side of the expression |
1405 | Value *RHS, ///< The right-hand-side of the expression |
1406 | const Twine &NameStr = "" ///< Name of the instruction |
1407 | ) : CmpInst(makeCmpResultType(LHS->getType()), |
1408 | Instruction::FCmp, pred, LHS, RHS, NameStr, |
1409 | &InsertAtEnd) { |
1410 | AssertOK(); |
1411 | } |
1412 | |
1413 | /// Constructor with no-insertion semantics |
1414 | FCmpInst( |
1415 | Predicate Pred, ///< The predicate to use for the comparison |
1416 | Value *LHS, ///< The left-hand-side of the expression |
1417 | Value *RHS, ///< The right-hand-side of the expression |
1418 | const Twine &NameStr = "", ///< Name of the instruction |
1419 | Instruction *FlagsSource = nullptr |
1420 | ) : CmpInst(makeCmpResultType(LHS->getType()), Instruction::FCmp, Pred, LHS, |
1421 | RHS, NameStr, nullptr, FlagsSource) { |
1422 | AssertOK(); |
1423 | } |
1424 | |
1425 | /// @returns true if the predicate of this instruction is EQ or NE. |
1426 | /// Determine if this is an equality predicate. |
1427 | static bool isEquality(Predicate Pred) { |
1428 | return Pred == FCMP_OEQ || Pred == FCMP_ONE || Pred == FCMP_UEQ || |
1429 | Pred == FCMP_UNE; |
1430 | } |
1431 | |
1432 | /// @returns true if the predicate of this instruction is EQ or NE. |
1433 | /// Determine if this is an equality predicate. |
1434 | bool isEquality() const { return isEquality(getPredicate()); } |
1435 | |
1436 | /// @returns true if the predicate of this instruction is commutative. |
1437 | /// Determine if this is a commutative predicate. |
1438 | bool isCommutative() const { |
1439 | return isEquality() || |
1440 | getPredicate() == FCMP_FALSE || |
1441 | getPredicate() == FCMP_TRUE || |
1442 | getPredicate() == FCMP_ORD || |
1443 | getPredicate() == FCMP_UNO; |
1444 | } |
1445 | |
1446 | /// @returns true if the predicate is relational (not EQ or NE). |
1447 | /// Determine if this a relational predicate. |
1448 | bool isRelational() const { return !isEquality(); } |
1449 | |
1450 | /// Exchange the two operands to this instruction in such a way that it does |
1451 | /// not modify the semantics of the instruction. The predicate value may be |
1452 | /// changed to retain the same result if the predicate is order dependent |
1453 | /// (e.g. ult). |
1454 | /// Swap operands and adjust predicate. |
1455 | void swapOperands() { |
1456 | setPredicate(getSwappedPredicate()); |
1457 | Op<0>().swap(Op<1>()); |
1458 | } |
1459 | |
1460 | /// Methods for support type inquiry through isa, cast, and dyn_cast: |
1461 | static bool classof(const Instruction *I) { |
1462 | return I->getOpcode() == Instruction::FCmp; |
1463 | } |
1464 | static bool classof(const Value *V) { |
1465 | return isa<Instruction>(V) && classof(cast<Instruction>(V)); |
1466 | } |
1467 | }; |
1468 | |
1469 | //===----------------------------------------------------------------------===// |
1470 | /// This class represents a function call, abstracting a target |
1471 | /// machine's calling convention. This class uses low bit of the SubClassData |
1472 | /// field to indicate whether or not this is a tail call. The rest of the bits |
1473 | /// hold the calling convention of the call. |
1474 | /// |
1475 | class CallInst : public CallBase { |
1476 | CallInst(const CallInst &CI); |
1477 | |
1478 | /// Construct a CallInst given a range of arguments. |
1479 | /// Construct a CallInst from a range of arguments |
1480 | inline CallInst(FunctionType *Ty, Value *Func, ArrayRef<Value *> Args, |
1481 | ArrayRef<OperandBundleDef> Bundles, const Twine &NameStr, |
1482 | Instruction *InsertBefore); |
1483 | |
1484 | inline CallInst(FunctionType *Ty, Value *Func, ArrayRef<Value *> Args, |
1485 | const Twine &NameStr, Instruction *InsertBefore) |
1486 | : CallInst(Ty, Func, Args, None, NameStr, InsertBefore) {} |
1487 | |
1488 | /// Construct a CallInst given a range of arguments. |
1489 | /// Construct a CallInst from a range of arguments |
1490 | inline CallInst(FunctionType *Ty, Value *Func, ArrayRef<Value *> Args, |
1491 | ArrayRef<OperandBundleDef> Bundles, const Twine &NameStr, |
1492 | BasicBlock *InsertAtEnd); |
1493 | |
1494 | explicit CallInst(FunctionType *Ty, Value *F, const Twine &NameStr, |
1495 | Instruction *InsertBefore); |
1496 | |
1497 | CallInst(FunctionType *ty, Value *F, const Twine &NameStr, |
1498 | BasicBlock *InsertAtEnd); |
1499 | |
1500 | void init(FunctionType *FTy, Value *Func, ArrayRef<Value *> Args, |
1501 | ArrayRef<OperandBundleDef> Bundles, const Twine &NameStr); |
1502 | void init(FunctionType *FTy, Value *Func, const Twine &NameStr); |
1503 | |
1504 | /// Compute the number of operands to allocate. |
1505 | static int ComputeNumOperands(int NumArgs, int NumBundleInputs = 0) { |
1506 | // We need one operand for the called function, plus the input operand |
1507 | // counts provided. |
1508 | return 1 + NumArgs + NumBundleInputs; |
1509 | } |
1510 | |
1511 | protected: |
1512 | // Note: Instruction needs to be a friend here to call cloneImpl. |
1513 | friend class Instruction; |
1514 | |
1515 | CallInst *cloneImpl() const; |
1516 | |
1517 | public: |
1518 | static CallInst *Create(FunctionType *Ty, Value *F, const Twine &NameStr = "", |
1519 | Instruction *InsertBefore = nullptr) { |
1520 | return new (ComputeNumOperands(0)) CallInst(Ty, F, NameStr, InsertBefore); |
1521 | } |
1522 | |
1523 | static CallInst *Create(FunctionType *Ty, Value *Func, ArrayRef<Value *> Args, |
1524 | const Twine &NameStr, |
1525 | Instruction *InsertBefore = nullptr) { |
1526 | return new (ComputeNumOperands(Args.size())) |
1527 | CallInst(Ty, Func, Args, None, NameStr, InsertBefore); |
1528 | } |
1529 | |
1530 | static CallInst *Create(FunctionType *Ty, Value *Func, ArrayRef<Value *> Args, |
1531 | ArrayRef<OperandBundleDef> Bundles = None, |
1532 | const Twine &NameStr = "", |
1533 | Instruction *InsertBefore = nullptr) { |
1534 | const int NumOperands = |
1535 | ComputeNumOperands(Args.size(), CountBundleInputs(Bundles)); |
1536 | const unsigned DescriptorBytes = Bundles.size() * sizeof(BundleOpInfo); |
1537 | |
1538 | return new (NumOperands, DescriptorBytes) |
1539 | CallInst(Ty, Func, Args, Bundles, NameStr, InsertBefore); |
1540 | } |
1541 | |
1542 | static CallInst *Create(FunctionType *Ty, Value *F, const Twine &NameStr, |
1543 | BasicBlock *InsertAtEnd) { |
1544 | return new (ComputeNumOperands(0)) CallInst(Ty, F, NameStr, InsertAtEnd); |
1545 | } |
1546 | |
1547 | static CallInst *Create(FunctionType *Ty, Value *Func, ArrayRef<Value *> Args, |
1548 | const Twine &NameStr, BasicBlock *InsertAtEnd) { |
1549 | return new (ComputeNumOperands(Args.size())) |
1550 | CallInst(Ty, Func, Args, None, NameStr, InsertAtEnd); |
1551 | } |
1552 | |
1553 | static CallInst *Create(FunctionType *Ty, Value *Func, ArrayRef<Value *> Args, |
1554 | ArrayRef<OperandBundleDef> Bundles, |
1555 | const Twine &NameStr, BasicBlock *InsertAtEnd) { |
1556 | const int NumOperands = |
1557 | ComputeNumOperands(Args.size(), CountBundleInputs(Bundles)); |
1558 | const unsigned DescriptorBytes = Bundles.size() * sizeof(BundleOpInfo); |
1559 | |
1560 | return new (NumOperands, DescriptorBytes) |
1561 | CallInst(Ty, Func, Args, Bundles, NameStr, InsertAtEnd); |
1562 | } |
1563 | |
1564 | static CallInst *Create(FunctionCallee Func, const Twine &NameStr = "", |
1565 | Instruction *InsertBefore = nullptr) { |
1566 | return Create(Func.getFunctionType(), Func.getCallee(), NameStr, |
1567 | InsertBefore); |
1568 | } |
1569 | |
1570 | static CallInst *Create(FunctionCallee Func, ArrayRef<Value *> Args, |
1571 | ArrayRef<OperandBundleDef> Bundles = None, |
1572 | const Twine &NameStr = "", |
1573 | Instruction *InsertBefore = nullptr) { |
1574 | return Create(Func.getFunctionType(), Func.getCallee(), Args, Bundles, |
1575 | NameStr, InsertBefore); |
1576 | } |
1577 | |
1578 | static CallInst *Create(FunctionCallee Func, ArrayRef<Value *> Args, |
1579 | const Twine &NameStr, |
1580 | Instruction *InsertBefore = nullptr) { |
1581 | return Create(Func.getFunctionType(), Func.getCallee(), Args, NameStr, |
1582 | InsertBefore); |
1583 | } |
1584 | |
1585 | static CallInst *Create(FunctionCallee Func, const Twine &NameStr, |
1586 | BasicBlock *InsertAtEnd) { |
1587 | return Create(Func.getFunctionType(), Func.getCallee(), NameStr, |
1588 | InsertAtEnd); |
1589 | } |
1590 | |
1591 | static CallInst *Create(FunctionCallee Func, ArrayRef<Value *> Args, |
1592 | const Twine &NameStr, BasicBlock *InsertAtEnd) { |
1593 | return Create(Func.getFunctionType(), Func.getCallee(), Args, NameStr, |
1594 | InsertAtEnd); |
1595 | } |
1596 | |
1597 | static CallInst *Create(FunctionCallee Func, ArrayRef<Value *> Args, |
1598 | ArrayRef<OperandBundleDef> Bundles, |
1599 | const Twine &NameStr, BasicBlock *InsertAtEnd) { |
1600 | return Create(Func.getFunctionType(), Func.getCallee(), Args, Bundles, |
1601 | NameStr, InsertAtEnd); |
1602 | } |
1603 | |
1604 | /// Create a clone of \p CI with a different set of operand bundles and |
1605 | /// insert it before \p InsertPt. |
1606 | /// |
1607 | /// The returned call instruction is identical \p CI in every way except that |
1608 | /// the operand bundles for the new instruction are set to the operand bundles |
1609 | /// in \p Bundles. |
1610 | static CallInst *Create(CallInst *CI, ArrayRef<OperandBundleDef> Bundles, |
1611 | Instruction *InsertPt = nullptr); |
1612 | |
1613 | /// Generate the IR for a call to malloc: |
1614 | /// 1. Compute the malloc call's argument as the specified type's size, |
1615 | /// possibly multiplied by the array size if the array size is not |
1616 | /// constant 1. |
1617 | /// 2. Call malloc with that argument. |
1618 | /// 3. Bitcast the result of the malloc call to the specified type. |
1619 | static Instruction *CreateMalloc(Instruction *InsertBefore, Type *IntPtrTy, |
1620 | Type *AllocTy, Value *AllocSize, |
1621 | Value *ArraySize = nullptr, |
1622 | Function *MallocF = nullptr, |
1623 | const Twine &Name = ""); |
1624 | static Instruction *CreateMalloc(BasicBlock *InsertAtEnd, Type *IntPtrTy, |
1625 | Type *AllocTy, Value *AllocSize, |
1626 | Value *ArraySize = nullptr, |
1627 | Function *MallocF = nullptr, |
1628 | const Twine &Name = ""); |
1629 | static Instruction *CreateMalloc(Instruction *InsertBefore, Type *IntPtrTy, |
1630 | Type *AllocTy, Value *AllocSize, |
1631 | Value *ArraySize = nullptr, |
1632 | ArrayRef<OperandBundleDef> Bundles = None, |
1633 | Function *MallocF = nullptr, |
1634 | const Twine &Name = ""); |
1635 | static Instruction *CreateMalloc(BasicBlock *InsertAtEnd, Type *IntPtrTy, |
1636 | Type *AllocTy, Value *AllocSize, |
1637 | Value *ArraySize = nullptr, |
1638 | ArrayRef<OperandBundleDef> Bundles = None, |
1639 | Function *MallocF = nullptr, |
1640 | const Twine &Name = ""); |
1641 | /// Generate the IR for a call to the builtin free function. |
1642 | static Instruction *CreateFree(Value *Source, Instruction *InsertBefore); |
1643 | static Instruction *CreateFree(Value *Source, BasicBlock *InsertAtEnd); |
1644 | static Instruction *CreateFree(Value *Source, |
1645 | ArrayRef<OperandBundleDef> Bundles, |
1646 | Instruction *InsertBefore); |
1647 | static Instruction *CreateFree(Value *Source, |
1648 | ArrayRef<OperandBundleDef> Bundles, |
1649 | BasicBlock *InsertAtEnd); |
1650 | |
1651 | // Note that 'musttail' implies 'tail'. |
1652 | enum TailCallKind : unsigned { |
1653 | TCK_None = 0, |
1654 | TCK_Tail = 1, |
1655 | TCK_MustTail = 2, |
1656 | TCK_NoTail = 3, |
1657 | TCK_LAST = TCK_NoTail |
1658 | }; |
1659 | |
1660 | using TailCallKindField = Bitfield::Element<TailCallKind, 0, 2, TCK_LAST>; |
1661 | static_assert( |
1662 | Bitfield::areContiguous<TailCallKindField, CallBase::CallingConvField>(), |
1663 | "Bitfields must be contiguous"); |
1664 | |
1665 | TailCallKind getTailCallKind() const { |
1666 | return getSubclassData<TailCallKindField>(); |
1667 | } |
1668 | |
1669 | bool isTailCall() const { |
1670 | TailCallKind Kind = getTailCallKind(); |
1671 | return Kind == TCK_Tail || Kind == TCK_MustTail; |
1672 | } |
1673 | |
1674 | bool isMustTailCall() const { return getTailCallKind() == TCK_MustTail; } |
1675 | |
1676 | bool isNoTailCall() const { return getTailCallKind() == TCK_NoTail; } |
1677 | |
1678 | void setTailCallKind(TailCallKind TCK) { |
1679 | setSubclassData<TailCallKindField>(TCK); |
1680 | } |
1681 | |
1682 | void setTailCall(bool IsTc = true) { |
1683 | setTailCallKind(IsTc ? TCK_Tail : TCK_None); |
1684 | } |
1685 | |
1686 | /// Return true if the call can return twice |
1687 | bool canReturnTwice() const { return hasFnAttr(Attribute::ReturnsTwice); } |
1688 | void setCanReturnTwice() { |
1689 | addAttribute(AttributeList::FunctionIndex, Attribute::ReturnsTwice); |
1690 | } |
1691 | |
1692 | // Methods for support type inquiry through isa, cast, and dyn_cast: |
1693 | static bool classof(const Instruction *I) { |
1694 | return I->getOpcode() == Instruction::Call; |
1695 | } |
1696 | static bool classof(const Value *V) { |
1697 | return isa<Instruction>(V) && classof(cast<Instruction>(V)); |
1698 | } |
1699 | |
1700 | /// Updates profile metadata by scaling it by \p S / \p T. |
1701 | void updateProfWeight(uint64_t S, uint64_t T); |
1702 | |
1703 | private: |
1704 | // Shadow Instruction::setInstructionSubclassData with a private forwarding |
1705 | // method so that subclasses cannot accidentally use it. |
1706 | template <typename Bitfield> |
1707 | void setSubclassData(typename Bitfield::Type Value) { |
1708 | Instruction::setSubclassData<Bitfield>(Value); |
1709 | } |
1710 | }; |
1711 | |
1712 | CallInst::CallInst(FunctionType *Ty, Value *Func, ArrayRef<Value *> Args, |
1713 | ArrayRef<OperandBundleDef> Bundles, const Twine &NameStr, |
1714 | BasicBlock *InsertAtEnd) |
1715 | : CallBase(Ty->getReturnType(), Instruction::Call, |
1716 | OperandTraits<CallBase>::op_end(this) - |
1717 | (Args.size() + CountBundleInputs(Bundles) + 1), |
1718 | unsigned(Args.size() + CountBundleInputs(Bundles) + 1), |
1719 | InsertAtEnd) { |
1720 | init(Ty, Func, Args, Bundles, NameStr); |
1721 | } |
1722 | |
1723 | CallInst::CallInst(FunctionType *Ty, Value *Func, ArrayRef<Value *> Args, |
1724 | ArrayRef<OperandBundleDef> Bundles, const Twine &NameStr, |
1725 | Instruction *InsertBefore) |
1726 | : CallBase(Ty->getReturnType(), Instruction::Call, |
1727 | OperandTraits<CallBase>::op_end(this) - |
1728 | (Args.size() + CountBundleInputs(Bundles) + 1), |
1729 | unsigned(Args.size() + CountBundleInputs(Bundles) + 1), |
1730 | InsertBefore) { |
1731 | init(Ty, Func, Args, Bundles, NameStr); |
1732 | } |
1733 | |
1734 | //===----------------------------------------------------------------------===// |
1735 | // SelectInst Class |
1736 | //===----------------------------------------------------------------------===// |
1737 | |
1738 | /// This class represents the LLVM 'select' instruction. |
1739 | /// |
1740 | class SelectInst : public Instruction { |
1741 | SelectInst(Value *C, Value *S1, Value *S2, const Twine &NameStr, |
1742 | Instruction *InsertBefore) |
1743 | : Instruction(S1->getType(), Instruction::Select, |
1744 | &Op<0>(), 3, InsertBefore) { |
1745 | init(C, S1, S2); |
1746 | setName(NameStr); |
1747 | } |
1748 | |
1749 | SelectInst(Value *C, Value *S1, Value *S2, const Twine &NameStr, |
1750 | BasicBlock *InsertAtEnd) |
1751 | : Instruction(S1->getType(), Instruction::Select, |
1752 | &Op<0>(), 3, InsertAtEnd) { |
1753 | init(C, S1, S2); |
1754 | setName(NameStr); |
1755 | } |
1756 | |
1757 | void init(Value *C, Value *S1, Value *S2) { |
1758 | assert(!areInvalidOperands(C, S1, S2) && "Invalid operands for select")((void)0); |
1759 | Op<0>() = C; |
1760 | Op<1>() = S1; |
1761 | Op<2>() = S2; |
1762 | } |
1763 | |
1764 | protected: |
1765 | // Note: Instruction needs to be a friend here to call cloneImpl. |
1766 | friend class Instruction; |
1767 | |
1768 | SelectInst *cloneImpl() const; |
1769 | |
1770 | public: |
1771 | static SelectInst *Create(Value *C, Value *S1, Value *S2, |
1772 | const Twine &NameStr = "", |
1773 | Instruction *InsertBefore = nullptr, |
1774 | Instruction *MDFrom = nullptr) { |
1775 | SelectInst *Sel = new(3) SelectInst(C, S1, S2, NameStr, InsertBefore); |
1776 | if (MDFrom) |
1777 | Sel->copyMetadata(*MDFrom); |
1778 | return Sel; |
1779 | } |
1780 | |
1781 | static SelectInst *Create(Value *C, Value *S1, Value *S2, |
1782 | const Twine &NameStr, |
1783 | BasicBlock *InsertAtEnd) { |
1784 | return new(3) SelectInst(C, S1, S2, NameStr, InsertAtEnd); |
1785 | } |
1786 | |
1787 | const Value *getCondition() const { return Op<0>(); } |
1788 | const Value *getTrueValue() const { return Op<1>(); } |
1789 | const Value *getFalseValue() const { return Op<2>(); } |
1790 | Value *getCondition() { return Op<0>(); } |
1791 | Value *getTrueValue() { return Op<1>(); } |
1792 | Value *getFalseValue() { return Op<2>(); } |
1793 | |
1794 | void setCondition(Value *V) { Op<0>() = V; } |
1795 | void setTrueValue(Value *V) { Op<1>() = V; } |
1796 | void setFalseValue(Value *V) { Op<2>() = V; } |
1797 | |
1798 | /// Swap the true and false values of the select instruction. |
1799 | /// This doesn't swap prof metadata. |
1800 | void swapValues() { Op<1>().swap(Op<2>()); } |
1801 | |
1802 | /// Return a string if the specified operands are invalid |
1803 | /// for a select operation, otherwise return null. |
1804 | static const char *areInvalidOperands(Value *Cond, Value *True, Value *False); |
1805 | |
1806 | /// Transparently provide more efficient getOperand methods. |
1807 | DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value)public: inline Value *getOperand(unsigned) const; inline void setOperand(unsigned, Value*); inline op_iterator op_begin(); inline const_op_iterator op_begin() const; inline op_iterator op_end(); inline const_op_iterator op_end() const; protected : template <int> inline Use &Op(); template <int > inline const Use &Op() const; public: inline unsigned getNumOperands() const; |
1808 | |
1809 | OtherOps getOpcode() const { |
1810 | return static_cast<OtherOps>(Instruction::getOpcode()); |
1811 | } |
1812 | |
1813 | // Methods for support type inquiry through isa, cast, and dyn_cast: |
1814 | static bool classof(const Instruction *I) { |
1815 | return I->getOpcode() == Instruction::Select; |
1816 | } |
1817 | static bool classof(const Value *V) { |
1818 | return isa<Instruction>(V) && classof(cast<Instruction>(V)); |
1819 | } |
1820 | }; |
1821 | |
1822 | template <> |
1823 | struct OperandTraits<SelectInst> : public FixedNumOperandTraits<SelectInst, 3> { |
1824 | }; |
1825 | |
1826 | DEFINE_TRANSPARENT_OPERAND_ACCESSORS(SelectInst, Value)SelectInst::op_iterator SelectInst::op_begin() { return OperandTraits <SelectInst>::op_begin(this); } SelectInst::const_op_iterator SelectInst::op_begin() const { return OperandTraits<SelectInst >::op_begin(const_cast<SelectInst*>(this)); } SelectInst ::op_iterator SelectInst::op_end() { return OperandTraits< SelectInst>::op_end(this); } SelectInst::const_op_iterator SelectInst::op_end() const { return OperandTraits<SelectInst >::op_end(const_cast<SelectInst*>(this)); } Value *SelectInst ::getOperand(unsigned i_nocapture) const { ((void)0); return cast_or_null <Value>( OperandTraits<SelectInst>::op_begin(const_cast <SelectInst*>(this))[i_nocapture].get()); } void SelectInst ::setOperand(unsigned i_nocapture, Value *Val_nocapture) { (( void)0); OperandTraits<SelectInst>::op_begin(this)[i_nocapture ] = Val_nocapture; } unsigned SelectInst::getNumOperands() const { return OperandTraits<SelectInst>::operands(this); } template <int Idx_nocapture> Use &SelectInst::Op() { return this->OpFrom<Idx_nocapture>(this); } template <int Idx_nocapture> const Use &SelectInst::Op() const { return this->OpFrom<Idx_nocapture>(this); } |
1827 | |
1828 | //===----------------------------------------------------------------------===// |
1829 | // VAArgInst Class |
1830 | //===----------------------------------------------------------------------===// |
1831 | |
1832 | /// This class represents the va_arg llvm instruction, which returns |
1833 | /// an argument of the specified type given a va_list and increments that list |
1834 | /// |
1835 | class VAArgInst : public UnaryInstruction { |
1836 | protected: |
1837 | // Note: Instruction needs to be a friend here to call cloneImpl. |
1838 | friend class Instruction; |
1839 | |
1840 | VAArgInst *cloneImpl() const; |
1841 | |
1842 | public: |
1843 | VAArgInst(Value *List, Type *Ty, const Twine &NameStr = "", |
1844 | Instruction *InsertBefore = nullptr) |
1845 | : UnaryInstruction(Ty, VAArg, List, InsertBefore) { |
1846 | setName(NameStr); |
1847 | } |
1848 | |
1849 | VAArgInst(Value *List, Type *Ty, const Twine &NameStr, |
1850 | BasicBlock *InsertAtEnd) |
1851 | : UnaryInstruction(Ty, VAArg, List, InsertAtEnd) { |
1852 | setName(NameStr); |
1853 | } |
1854 | |
1855 | Value *getPointerOperand() { return getOperand(0); } |
1856 | const Value *getPointerOperand() const { return getOperand(0); } |
1857 | static unsigned getPointerOperandIndex() { return 0U; } |
1858 | |
1859 | // Methods for support type inquiry through isa, cast, and dyn_cast: |
1860 | static bool classof(const Instruction *I) { |
1861 | return I->getOpcode() == VAArg; |
1862 | } |
1863 | static bool classof(const Value *V) { |
1864 | return isa<Instruction>(V) && classof(cast<Instruction>(V)); |
1865 | } |
1866 | }; |
1867 | |
1868 | //===----------------------------------------------------------------------===// |
1869 | // ExtractElementInst Class |
1870 | //===----------------------------------------------------------------------===// |
1871 | |
1872 | /// This instruction extracts a single (scalar) |
1873 | /// element from a VectorType value |
1874 | /// |
1875 | class ExtractElementInst : public Instruction { |
1876 | ExtractElementInst(Value *Vec, Value *Idx, const Twine &NameStr = "", |
1877 | Instruction *InsertBefore = nullptr); |
1878 | ExtractElementInst(Value *Vec, Value *Idx, const Twine &NameStr, |
1879 | BasicBlock *InsertAtEnd); |
1880 | |
1881 | protected: |
1882 | // Note: Instruction needs to be a friend here to call cloneImpl. |
1883 | friend class Instruction; |
1884 | |
1885 | ExtractElementInst *cloneImpl() const; |
1886 | |
1887 | public: |
1888 | static ExtractElementInst *Create(Value *Vec, Value *Idx, |
1889 | const Twine &NameStr = "", |
1890 | Instruction *InsertBefore = nullptr) { |
1891 | return new(2) ExtractElementInst(Vec, Idx, NameStr, InsertBefore); |
1892 | } |
1893 | |
1894 | static ExtractElementInst *Create(Value *Vec, Value *Idx, |
1895 | const Twine &NameStr, |
1896 | BasicBlock *InsertAtEnd) { |
1897 | return new(2) ExtractElementInst(Vec, Idx, NameStr, InsertAtEnd); |
1898 | } |
1899 | |
1900 | /// Return true if an extractelement instruction can be |
1901 | /// formed with the specified operands. |
1902 | static bool isValidOperands(const Value *Vec, const Value *Idx); |
1903 | |
1904 | Value *getVectorOperand() { return Op<0>(); } |
1905 | Value *getIndexOperand() { return Op<1>(); } |
1906 | const Value *getVectorOperand() const { return Op<0>(); } |
1907 | const Value *getIndexOperand() const { return Op<1>(); } |
1908 | |
1909 | VectorType *getVectorOperandType() const { |
1910 | return cast<VectorType>(getVectorOperand()->getType()); |
1911 | } |
1912 | |
1913 | /// Transparently provide more efficient getOperand methods. |
1914 | DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value)public: inline Value *getOperand(unsigned) const; inline void setOperand(unsigned, Value*); inline op_iterator op_begin(); inline const_op_iterator op_begin() const; inline op_iterator op_end(); inline const_op_iterator op_end() const; protected : template <int> inline Use &Op(); template <int > inline const Use &Op() const; public: inline unsigned getNumOperands() const; |
1915 | |
1916 | // Methods for support type inquiry through isa, cast, and dyn_cast: |
1917 | static bool classof(const Instruction *I) { |
1918 | return I->getOpcode() == Instruction::ExtractElement; |
1919 | } |
1920 | static bool classof(const Value *V) { |
1921 | return isa<Instruction>(V) && classof(cast<Instruction>(V)); |
1922 | } |
1923 | }; |
1924 | |
1925 | template <> |
1926 | struct OperandTraits<ExtractElementInst> : |
1927 | public FixedNumOperandTraits<ExtractElementInst, 2> { |
1928 | }; |
1929 | |
1930 | DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ExtractElementInst, Value)ExtractElementInst::op_iterator ExtractElementInst::op_begin( ) { return OperandTraits<ExtractElementInst>::op_begin( this); } ExtractElementInst::const_op_iterator ExtractElementInst ::op_begin() const { return OperandTraits<ExtractElementInst >::op_begin(const_cast<ExtractElementInst*>(this)); } ExtractElementInst::op_iterator ExtractElementInst::op_end() { return OperandTraits<ExtractElementInst>::op_end(this ); } ExtractElementInst::const_op_iterator ExtractElementInst ::op_end() const { return OperandTraits<ExtractElementInst >::op_end(const_cast<ExtractElementInst*>(this)); } Value *ExtractElementInst::getOperand(unsigned i_nocapture) const { ((void)0); return cast_or_null<Value>( OperandTraits< ExtractElementInst>::op_begin(const_cast<ExtractElementInst *>(this))[i_nocapture].get()); } void ExtractElementInst:: setOperand(unsigned i_nocapture, Value *Val_nocapture) { ((void )0); OperandTraits<ExtractElementInst>::op_begin(this)[ i_nocapture] = Val_nocapture; } unsigned ExtractElementInst:: getNumOperands() const { return OperandTraits<ExtractElementInst >::operands(this); } template <int Idx_nocapture> Use &ExtractElementInst::Op() { return this->OpFrom<Idx_nocapture >(this); } template <int Idx_nocapture> const Use & ExtractElementInst::Op() const { return this->OpFrom<Idx_nocapture >(this); } |
1931 | |
1932 | //===----------------------------------------------------------------------===// |
1933 | // InsertElementInst Class |
1934 | //===----------------------------------------------------------------------===// |
1935 | |
1936 | /// This instruction inserts a single (scalar) |
1937 | /// element into a VectorType value |
1938 | /// |
1939 | class InsertElementInst : public Instruction { |
1940 | InsertElementInst(Value *Vec, Value *NewElt, Value *Idx, |
1941 | const Twine &NameStr = "", |
1942 | Instruction *InsertBefore = nullptr); |
1943 | InsertElementInst(Value *Vec, Value *NewElt, Value *Idx, const Twine &NameStr, |
1944 | BasicBlock *InsertAtEnd); |
1945 | |
1946 | protected: |
1947 | // Note: Instruction needs to be a friend here to call cloneImpl. |
1948 | friend class Instruction; |
1949 | |
1950 | InsertElementInst *cloneImpl() const; |
1951 | |
1952 | public: |
1953 | static InsertElementInst *Create(Value *Vec, Value *NewElt, Value *Idx, |
1954 | const Twine &NameStr = "", |
1955 | Instruction *InsertBefore = nullptr) { |
1956 | return new(3) InsertElementInst(Vec, NewElt, Idx, NameStr, InsertBefore); |
1957 | } |
1958 | |
1959 | static InsertElementInst *Create(Value *Vec, Value *NewElt, Value *Idx, |
1960 | const Twine &NameStr, |
1961 | BasicBlock *InsertAtEnd) { |
1962 | return new(3) InsertElementInst(Vec, NewElt, Idx, NameStr, InsertAtEnd); |
1963 | } |
1964 | |
1965 | /// Return true if an insertelement instruction can be |
1966 | /// formed with the specified operands. |
1967 | static bool isValidOperands(const Value *Vec, const Value *NewElt, |
1968 | const Value *Idx); |
1969 | |
1970 | /// Overload to return most specific vector type. |
1971 | /// |
1972 | VectorType *getType() const { |
1973 | return cast<VectorType>(Instruction::getType()); |
1974 | } |
1975 | |
1976 | /// Transparently provide more efficient getOperand methods. |
1977 | DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value)public: inline Value *getOperand(unsigned) const; inline void setOperand(unsigned, Value*); inline op_iterator op_begin(); inline const_op_iterator op_begin() const; inline op_iterator op_end(); inline const_op_iterator op_end() const; protected : template <int> inline Use &Op(); template <int > inline const Use &Op() const; public: inline unsigned getNumOperands() const; |
1978 | |
1979 | // Methods for support type inquiry through isa, cast, and dyn_cast: |
1980 | static bool classof(const Instruction *I) { |
1981 | return I->getOpcode() == Instruction::InsertElement; |
1982 | } |
1983 | static bool classof(const Value *V) { |
1984 | return isa<Instruction>(V) && classof(cast<Instruction>(V)); |
1985 | } |
1986 | }; |
1987 | |
1988 | template <> |
1989 | struct OperandTraits<InsertElementInst> : |
1990 | public FixedNumOperandTraits<InsertElementInst, 3> { |
1991 | }; |
1992 | |
1993 | DEFINE_TRANSPARENT_OPERAND_ACCESSORS(InsertElementInst, Value)InsertElementInst::op_iterator InsertElementInst::op_begin() { return OperandTraits<InsertElementInst>::op_begin(this ); } InsertElementInst::const_op_iterator InsertElementInst:: op_begin() const { return OperandTraits<InsertElementInst> ::op_begin(const_cast<InsertElementInst*>(this)); } InsertElementInst ::op_iterator InsertElementInst::op_end() { return OperandTraits <InsertElementInst>::op_end(this); } InsertElementInst:: const_op_iterator InsertElementInst::op_end() const { return OperandTraits <InsertElementInst>::op_end(const_cast<InsertElementInst *>(this)); } Value *InsertElementInst::getOperand(unsigned i_nocapture) const { ((void)0); return cast_or_null<Value >( OperandTraits<InsertElementInst>::op_begin(const_cast <InsertElementInst*>(this))[i_nocapture].get()); } void InsertElementInst::setOperand(unsigned i_nocapture, Value *Val_nocapture ) { ((void)0); OperandTraits<InsertElementInst>::op_begin (this)[i_nocapture] = Val_nocapture; } unsigned InsertElementInst ::getNumOperands() const { return OperandTraits<InsertElementInst >::operands(this); } template <int Idx_nocapture> Use &InsertElementInst::Op() { return this->OpFrom<Idx_nocapture >(this); } template <int Idx_nocapture> const Use & InsertElementInst::Op() const { return this->OpFrom<Idx_nocapture >(this); } |
1994 | |
1995 | //===----------------------------------------------------------------------===// |
1996 | // ShuffleVectorInst Class |
1997 | //===----------------------------------------------------------------------===// |
1998 | |
1999 | constexpr int UndefMaskElem = -1; |
2000 | |
2001 | /// This instruction constructs a fixed permutation of two |
2002 | /// input vectors. |
2003 | /// |
2004 | /// For each element of the result vector, the shuffle mask selects an element |
2005 | /// from one of the input vectors to copy to the result. Non-negative elements |
2006 | /// in the mask represent an index into the concatenated pair of input vectors. |
2007 | /// UndefMaskElem (-1) specifies that the result element is undefined. |
2008 | /// |
2009 | /// For scalable vectors, all the elements of the mask must be 0 or -1. This |
2010 | /// requirement may be relaxed in the future. |
2011 | class ShuffleVectorInst : public Instruction { |
2012 | SmallVector<int, 4> ShuffleMask; |
2013 | Constant *ShuffleMaskForBitcode; |
2014 | |
2015 | protected: |
2016 | // Note: Instruction needs to be a friend here to call cloneImpl. |
2017 | friend class Instruction; |
2018 | |
2019 | ShuffleVectorInst *cloneImpl() const; |
2020 | |
2021 | public: |
2022 | ShuffleVectorInst(Value *V1, Value *V2, Value *Mask, |
2023 | const Twine &NameStr = "", |
2024 | Instruction *InsertBefor = nullptr); |
2025 | ShuffleVectorInst(Value *V1, Value *V2, Value *Mask, |
2026 | const Twine &NameStr, BasicBlock *InsertAtEnd); |
2027 | ShuffleVectorInst(Value *V1, Value *V2, ArrayRef<int> Mask, |
2028 | const Twine &NameStr = "", |
2029 | Instruction *InsertBefor = nullptr); |
2030 | ShuffleVectorInst(Value *V1, Value *V2, ArrayRef<int> Mask, |
2031 | const Twine &NameStr, BasicBlock *InsertAtEnd); |
2032 | |
2033 | void *operator new(size_t S) { return User::operator new(S, 2); } |
2034 | void operator delete(void *Ptr) { return User::operator delete(Ptr); } |
2035 | |
2036 | /// Swap the operands and adjust the mask to preserve the semantics |
2037 | /// of the instruction. |
2038 | void commute(); |
2039 | |
2040 | /// Return true if a shufflevector instruction can be |
2041 | /// formed with the specified operands. |
2042 | static bool isValidOperands(const Value *V1, const Value *V2, |
2043 | const Value *Mask); |
2044 | static bool isValidOperands(const Value *V1, const Value *V2, |
2045 | ArrayRef<int> Mask); |
2046 | |
2047 | /// Overload to return most specific vector type. |
2048 | /// |
2049 | VectorType *getType() const { |
2050 | return cast<VectorType>(Instruction::getType()); |
2051 | } |
2052 | |
2053 | /// Transparently provide more efficient getOperand methods. |
2054 | DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value)public: inline Value *getOperand(unsigned) const; inline void setOperand(unsigned, Value*); inline op_iterator op_begin(); inline const_op_iterator op_begin() const; inline op_iterator op_end(); inline const_op_iterator op_end() const; protected : template <int> inline Use &Op(); template <int > inline const Use &Op() const; public: inline unsigned getNumOperands() const; |
2055 | |
2056 | /// Return the shuffle mask value of this instruction for the given element |
2057 | /// index. Return UndefMaskElem if the element is undef. |
2058 | int getMaskValue(unsigned Elt) const { return ShuffleMask[Elt]; } |
2059 | |
2060 | /// Convert the input shuffle mask operand to a vector of integers. Undefined |
2061 | /// elements of the mask are returned as UndefMaskElem. |
2062 | static void getShuffleMask(const Constant *Mask, |
2063 | SmallVectorImpl<int> &Result); |
2064 | |
2065 | /// Return the mask for this instruction as a vector of integers. Undefined |
2066 | /// elements of the mask are returned as UndefMaskElem. |
2067 | void getShuffleMask(SmallVectorImpl<int> &Result) const { |
2068 | Result.assign(ShuffleMask.begin(), ShuffleMask.end()); |
2069 | } |
2070 | |
2071 | /// Return the mask for this instruction, for use in bitcode. |
2072 | /// |
2073 | /// TODO: This is temporary until we decide a new bitcode encoding for |
2074 | /// shufflevector. |
2075 | Constant *getShuffleMaskForBitcode() const { return ShuffleMaskForBitcode; } |
2076 | |
2077 | static Constant *convertShuffleMaskForBitcode(ArrayRef<int> Mask, |
2078 | Type *ResultTy); |
2079 | |
2080 | void setShuffleMask(ArrayRef<int> Mask); |
2081 | |
2082 | ArrayRef<int> getShuffleMask() const { return ShuffleMask; } |
2083 | |
2084 | /// Return true if this shuffle returns a vector with a different number of |
2085 | /// elements than its source vectors. |
2086 | /// Examples: shufflevector <4 x n> A, <4 x n> B, <1,2,3> |
2087 | /// shufflevector <4 x n> A, <4 x n> B, <1,2,3,4,5> |
2088 | bool changesLength() const { |
2089 | unsigned NumSourceElts = cast<VectorType>(Op<0>()->getType()) |
2090 | ->getElementCount() |
2091 | .getKnownMinValue(); |
2092 | unsigned NumMaskElts = ShuffleMask.size(); |
2093 | return NumSourceElts != NumMaskElts; |
2094 | } |
2095 | |
2096 | /// Return true if this shuffle returns a vector with a greater number of |
2097 | /// elements than its source vectors. |
2098 | /// Example: shufflevector <2 x n> A, <2 x n> B, <1,2,3> |
2099 | bool increasesLength() const { |
2100 | unsigned NumSourceElts = cast<VectorType>(Op<0>()->getType()) |
2101 | ->getElementCount() |
2102 | .getKnownMinValue(); |
2103 | unsigned NumMaskElts = ShuffleMask.size(); |
2104 | return NumSourceElts < NumMaskElts; |
2105 | } |
2106 | |
2107 | /// Return true if this shuffle mask chooses elements from exactly one source |
2108 | /// vector. |
2109 | /// Example: <7,5,undef,7> |
2110 | /// This assumes that vector operands are the same length as the mask. |
2111 | static bool isSingleSourceMask(ArrayRef<int> Mask); |
2112 | static bool isSingleSourceMask(const Constant *Mask) { |
2113 | assert(Mask->getType()->isVectorTy() && "Shuffle needs vector constant.")((void)0); |
2114 | SmallVector<int, 16> MaskAsInts; |
2115 | getShuffleMask(Mask, MaskAsInts); |
2116 | return isSingleSourceMask(MaskAsInts); |
2117 | } |
2118 | |
2119 | /// Return true if this shuffle chooses elements from exactly one source |
2120 | /// vector without changing the length of that vector. |
2121 | /// Example: shufflevector <4 x n> A, <4 x n> B, <3,0,undef,3> |
2122 | /// TODO: Optionally allow length-changing shuffles. |
2123 | bool isSingleSource() const { |
2124 | return !changesLength() && isSingleSourceMask(ShuffleMask); |
2125 | } |
2126 | |
2127 | /// Return true if this shuffle mask chooses elements from exactly one source |
2128 | /// vector without lane crossings. A shuffle using this mask is not |
2129 | /// necessarily a no-op because it may change the number of elements from its |
2130 | /// input vectors or it may provide demanded bits knowledge via undef lanes. |
2131 | /// Example: <undef,undef,2,3> |
2132 | static bool isIdentityMask(ArrayRef<int> Mask); |
2133 | static bool isIdentityMask(const Constant *Mask) { |
2134 | assert(Mask->getType()->isVectorTy() && "Shuffle needs vector constant.")((void)0); |
2135 | SmallVector<int, 16> MaskAsInts; |
2136 | getShuffleMask(Mask, MaskAsInts); |
2137 | return isIdentityMask(MaskAsInts); |
2138 | } |
2139 | |
2140 | /// Return true if this shuffle chooses elements from exactly one source |
2141 | /// vector without lane crossings and does not change the number of elements |
2142 | /// from its input vectors. |
2143 | /// Example: shufflevector <4 x n> A, <4 x n> B, <4,undef,6,undef> |
2144 | bool isIdentity() const { |
2145 | return !changesLength() && isIdentityMask(ShuffleMask); |
2146 | } |
2147 | |
2148 | /// Return true if this shuffle lengthens exactly one source vector with |
2149 | /// undefs in the high elements. |
2150 | bool isIdentityWithPadding() const; |
2151 | |
2152 | /// Return true if this shuffle extracts the first N elements of exactly one |
2153 | /// source vector. |
2154 | bool isIdentityWithExtract() const; |
2155 | |
2156 | /// Return true if this shuffle concatenates its 2 source vectors. This |
2157 | /// returns false if either input is undefined. In that case, the shuffle is |
2158 | /// is better classified as an identity with padding operation. |
2159 | bool isConcat() const; |
2160 | |
2161 | /// Return true if this shuffle mask chooses elements from its source vectors |
2162 | /// without lane crossings. A shuffle using this mask would be |
2163 | /// equivalent to a vector select with a constant condition operand. |
2164 | /// Example: <4,1,6,undef> |
2165 | /// This returns false if the mask does not choose from both input vectors. |
2166 | /// In that case, the shuffle is better classified as an identity shuffle. |
2167 | /// This assumes that vector operands are the same length as the mask |
2168 | /// (a length-changing shuffle can never be equivalent to a vector select). |
2169 | static bool isSelectMask(ArrayRef<int> Mask); |
2170 | static bool isSelectMask(const Constant *Mask) { |
2171 | assert(Mask->getType()->isVectorTy() && "Shuffle needs vector constant.")((void)0); |
2172 | SmallVector<int, 16> MaskAsInts; |
2173 | getShuffleMask(Mask, MaskAsInts); |
2174 | return isSelectMask(MaskAsInts); |
2175 | } |
2176 | |
2177 | /// Return true if this shuffle chooses elements from its source vectors |
2178 | /// without lane crossings and all operands have the same number of elements. |
2179 | /// In other words, this shuffle is equivalent to a vector select with a |
2180 | /// constant condition operand. |
2181 | /// Example: shufflevector <4 x n> A, <4 x n> B, <undef,1,6,3> |
2182 | /// This returns false if the mask does not choose from both input vectors. |
2183 | /// In that case, the shuffle is better classified as an identity shuffle. |
2184 | /// TODO: Optionally allow length-changing shuffles. |
2185 | bool isSelect() const { |
2186 | return !changesLength() && isSelectMask(ShuffleMask); |
2187 | } |
2188 | |
2189 | /// Return true if this shuffle mask swaps the order of elements from exactly |
2190 | /// one source vector. |
2191 | /// Example: <7,6,undef,4> |
2192 | /// This assumes that vector operands are the same length as the mask. |
2193 | static bool isReverseMask(ArrayRef<int> Mask); |
2194 | static bool isReverseMask(const Constant *Mask) { |
2195 | assert(Mask->getType()->isVectorTy() && "Shuffle needs vector constant.")((void)0); |
2196 | SmallVector<int, 16> MaskAsInts; |
2197 | getShuffleMask(Mask, MaskAsInts); |
2198 | return isReverseMask(MaskAsInts); |
2199 | } |
2200 | |
2201 | /// Return true if this shuffle swaps the order of elements from exactly |
2202 | /// one source vector. |
2203 | /// Example: shufflevector <4 x n> A, <4 x n> B, <3,undef,1,undef> |
2204 | /// TODO: Optionally allow length-changing shuffles. |
2205 | bool isReverse() const { |
2206 | return !changesLength() && isReverseMask(ShuffleMask); |
2207 | } |
2208 | |
2209 | /// Return true if this shuffle mask chooses all elements with the same value |
2210 | /// as the first element of exactly one source vector. |
2211 | /// Example: <4,undef,undef,4> |
2212 | /// This assumes that vector operands are the same length as the mask. |
2213 | static bool isZeroEltSplatMask(ArrayRef<int> Mask); |
2214 | static bool isZeroEltSplatMask(const Constant *Mask) { |
2215 | assert(Mask->getType()->isVectorTy() && "Shuffle needs vector constant.")((void)0); |
2216 | SmallVector<int, 16> MaskAsInts; |
2217 | getShuffleMask(Mask, MaskAsInts); |
2218 | return isZeroEltSplatMask(MaskAsInts); |
2219 | } |
2220 | |
2221 | /// Return true if all elements of this shuffle are the same value as the |
2222 | /// first element of exactly one source vector without changing the length |
2223 | /// of that vector. |
2224 | /// Example: shufflevector <4 x n> A, <4 x n> B, <undef,0,undef,0> |
2225 | /// TODO: Optionally allow length-changing shuffles. |
2226 | /// TODO: Optionally allow splats from other elements. |
2227 | bool isZeroEltSplat() const { |
2228 | return !changesLength() && isZeroEltSplatMask(ShuffleMask); |
2229 | } |
2230 | |
2231 | /// Return true if this shuffle mask is a transpose mask. |
2232 | /// Transpose vector masks transpose a 2xn matrix. They read corresponding |
2233 | /// even- or odd-numbered vector elements from two n-dimensional source |
2234 | /// vectors and write each result into consecutive elements of an |
2235 | /// n-dimensional destination vector. Two shuffles are necessary to complete |
2236 | /// the transpose, one for the even elements and another for the odd elements. |
2237 | /// This description closely follows how the TRN1 and TRN2 AArch64 |
2238 | /// instructions operate. |
2239 | /// |
2240 | /// For example, a simple 2x2 matrix can be transposed with: |
2241 | /// |
2242 | /// ; Original matrix |
2243 | /// m0 = < a, b > |
2244 | /// m1 = < c, d > |
2245 | /// |
2246 | /// ; Transposed matrix |
2247 | /// t0 = < a, c > = shufflevector m0, m1, < 0, 2 > |
2248 | /// t1 = < b, d > = shufflevector m0, m1, < 1, 3 > |
2249 | /// |
2250 | /// For matrices having greater than n columns, the resulting nx2 transposed |
2251 | /// matrix is stored in two result vectors such that one vector contains |
2252 | /// interleaved elements from all the even-numbered rows and the other vector |
2253 | /// contains interleaved elements from all the odd-numbered rows. For example, |
2254 | /// a 2x4 matrix can be transposed with: |
2255 | /// |
2256 | /// ; Original matrix |
2257 | /// m0 = < a, b, c, d > |
2258 | /// m1 = < e, f, g, h > |
2259 | /// |
2260 | /// ; Transposed matrix |
2261 | /// t0 = < a, e, c, g > = shufflevector m0, m1 < 0, 4, 2, 6 > |
2262 | /// t1 = < b, f, d, h > = shufflevector m0, m1 < 1, 5, 3, 7 > |
2263 | static bool isTransposeMask(ArrayRef<int> Mask); |
2264 | static bool isTransposeMask(const Constant *Mask) { |
2265 | assert(Mask->getType()->isVectorTy() && "Shuffle needs vector constant.")((void)0); |
2266 | SmallVector<int, 16> MaskAsInts; |
2267 | getShuffleMask(Mask, MaskAsInts); |
2268 | return isTransposeMask(MaskAsInts); |
2269 | } |
2270 | |
2271 | /// Return true if this shuffle transposes the elements of its inputs without |
2272 | /// changing the length of the vectors. This operation may also be known as a |
2273 | /// merge or interleave. See the description for isTransposeMask() for the |
2274 | /// exact specification. |
2275 | /// Example: shufflevector <4 x n> A, <4 x n> B, <0,4,2,6> |
2276 | bool isTranspose() const { |
2277 | return !changesLength() && isTransposeMask(ShuffleMask); |
2278 | } |
2279 | |
2280 | /// Return true if this shuffle mask is an extract subvector mask. |
2281 | /// A valid extract subvector mask returns a smaller vector from a single |
2282 | /// source operand. The base extraction index is returned as well. |
2283 | static bool isExtractSubvectorMask(ArrayRef<int> Mask, int NumSrcElts, |
2284 | int &Index); |
2285 | static bool isExtractSubvectorMask(const Constant *Mask, int NumSrcElts, |
2286 | int &Index) { |
2287 | assert(Mask->getType()->isVectorTy() && "Shuffle needs vector constant.")((void)0); |
2288 | // Not possible to express a shuffle mask for a scalable vector for this |
2289 | // case. |
2290 | if (isa<ScalableVectorType>(Mask->getType())) |
2291 | return false; |
2292 | SmallVector<int, 16> MaskAsInts; |
2293 | getShuffleMask(Mask, MaskAsInts); |
2294 | return isExtractSubvectorMask(MaskAsInts, NumSrcElts, Index); |
2295 | } |
2296 | |
2297 | /// Return true if this shuffle mask is an extract subvector mask. |
2298 | bool isExtractSubvectorMask(int &Index) const { |
2299 | // Not possible to express a shuffle mask for a scalable vector for this |
2300 | // case. |
2301 | if (isa<ScalableVectorType>(getType())) |
2302 | return false; |
2303 | |
2304 | int NumSrcElts = |
2305 | cast<FixedVectorType>(Op<0>()->getType())->getNumElements(); |
2306 | return isExtractSubvectorMask(ShuffleMask, NumSrcElts, Index); |
2307 | } |
2308 | |
2309 | /// Change values in a shuffle permute mask assuming the two vector operands |
2310 | /// of length InVecNumElts have swapped position. |
2311 | static void commuteShuffleMask(MutableArrayRef<int> Mask, |
2312 | unsigned InVecNumElts) { |
2313 | for (int &Idx : Mask) { |
2314 | if (Idx == -1) |
2315 | continue; |
2316 | Idx = Idx < (int)InVecNumElts ? Idx + InVecNumElts : Idx - InVecNumElts; |
2317 | assert(Idx >= 0 && Idx < (int)InVecNumElts * 2 &&((void)0) |
2318 | "shufflevector mask index out of range")((void)0); |
2319 | } |
2320 | } |
2321 | |
2322 | // Methods for support type inquiry through isa, cast, and dyn_cast: |
2323 | static bool classof(const Instruction *I) { |
2324 | return I->getOpcode() == Instruction::ShuffleVector; |
2325 | } |
2326 | static bool classof(const Value *V) { |
2327 | return isa<Instruction>(V) && classof(cast<Instruction>(V)); |
2328 | } |
2329 | }; |
2330 | |
2331 | template <> |
2332 | struct OperandTraits<ShuffleVectorInst> |
2333 | : public FixedNumOperandTraits<ShuffleVectorInst, 2> {}; |
2334 | |
2335 | DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ShuffleVectorInst, Value)ShuffleVectorInst::op_iterator ShuffleVectorInst::op_begin() { return OperandTraits<ShuffleVectorInst>::op_begin(this ); } ShuffleVectorInst::const_op_iterator ShuffleVectorInst:: op_begin() const { return OperandTraits<ShuffleVectorInst> ::op_begin(const_cast<ShuffleVectorInst*>(this)); } ShuffleVectorInst ::op_iterator ShuffleVectorInst::op_end() { return OperandTraits <ShuffleVectorInst>::op_end(this); } ShuffleVectorInst:: const_op_iterator ShuffleVectorInst::op_end() const { return OperandTraits <ShuffleVectorInst>::op_end(const_cast<ShuffleVectorInst *>(this)); } Value *ShuffleVectorInst::getOperand(unsigned i_nocapture) const { ((void)0); return cast_or_null<Value >( OperandTraits<ShuffleVectorInst>::op_begin(const_cast <ShuffleVectorInst*>(this))[i_nocapture].get()); } void ShuffleVectorInst::setOperand(unsigned i_nocapture, Value *Val_nocapture ) { ((void)0); OperandTraits<ShuffleVectorInst>::op_begin (this)[i_nocapture] = Val_nocapture; } unsigned ShuffleVectorInst ::getNumOperands() const { return OperandTraits<ShuffleVectorInst >::operands(this); } template <int Idx_nocapture> Use &ShuffleVectorInst::Op() { return this->OpFrom<Idx_nocapture >(this); } template <int Idx_nocapture> const Use & ShuffleVectorInst::Op() const { return this->OpFrom<Idx_nocapture >(this); } |
2336 | |
2337 | //===----------------------------------------------------------------------===// |
2338 | // ExtractValueInst Class |
2339 | //===----------------------------------------------------------------------===// |
2340 | |
2341 | /// This instruction extracts a struct member or array |
2342 | /// element value from an aggregate value. |
2343 | /// |
2344 | class ExtractValueInst : public UnaryInstruction { |
2345 | SmallVector<unsigned, 4> Indices; |
2346 | |
2347 | ExtractValueInst(const ExtractValueInst &EVI); |
2348 | |
2349 | /// Constructors - Create a extractvalue instruction with a base aggregate |
2350 | /// value and a list of indices. The first ctor can optionally insert before |
2351 | /// an existing instruction, the second appends the new instruction to the |
2352 | /// specified BasicBlock. |
2353 | inline ExtractValueInst(Value *Agg, |
2354 | ArrayRef<unsigned> Idxs, |
2355 | const Twine &NameStr, |
2356 | Instruction *InsertBefore); |
2357 | inline ExtractValueInst(Value *Agg, |
2358 | ArrayRef<unsigned> Idxs, |
2359 | const Twine &NameStr, BasicBlock *InsertAtEnd); |
2360 | |
2361 | void init(ArrayRef<unsigned> Idxs, const Twine &NameStr); |
2362 | |
2363 | protected: |
2364 | // Note: Instruction needs to be a friend here to call cloneImpl. |
2365 | friend class Instruction; |
2366 | |
2367 | ExtractValueInst *cloneImpl() const; |
2368 | |
2369 | public: |
2370 | static ExtractValueInst *Create(Value *Agg, |
2371 | ArrayRef<unsigned> Idxs, |
2372 | const Twine &NameStr = "", |
2373 | Instruction *InsertBefore = nullptr) { |
2374 | return new |
2375 | ExtractValueInst(Agg, Idxs, NameStr, InsertBefore); |
2376 | } |
2377 | |
2378 | static ExtractValueInst *Create(Value *Agg, |
2379 | ArrayRef<unsigned> Idxs, |
2380 | const Twine &NameStr, |
2381 | BasicBlock *InsertAtEnd) { |
2382 | return new ExtractValueInst(Agg, Idxs, NameStr, InsertAtEnd); |
2383 | } |
2384 | |
2385 | /// Returns the type of the element that would be extracted |
2386 | /// with an extractvalue instruction with the specified parameters. |
2387 | /// |
2388 | /// Null is returned if the indices are invalid for the specified type. |
2389 | static Type *getIndexedType(Type *Agg, ArrayRef<unsigned> Idxs); |
2390 | |
2391 | using idx_iterator = const unsigned*; |
2392 | |
2393 | inline idx_iterator idx_begin() const { return Indices.begin(); } |
2394 | inline idx_iterator idx_end() const { return Indices.end(); } |
2395 | inline iterator_range<idx_iterator> indices() const { |
2396 | return make_range(idx_begin(), idx_end()); |
2397 | } |
2398 | |
2399 | Value *getAggregateOperand() { |
2400 | return getOperand(0); |
2401 | } |
2402 | const Value *getAggregateOperand() const { |
2403 | return getOperand(0); |
2404 | } |
2405 | static unsigned getAggregateOperandIndex() { |
2406 | return 0U; // get index for modifying correct operand |
2407 | } |
2408 | |
2409 | ArrayRef<unsigned> getIndices() const { |
2410 | return Indices; |
2411 | } |
2412 | |
2413 | unsigned getNumIndices() const { |
2414 | return (unsigned)Indices.size(); |
2415 | } |
2416 | |
2417 | bool hasIndices() const { |
2418 | return true; |
2419 | } |
2420 | |
2421 | // Methods for support type inquiry through isa, cast, and dyn_cast: |
2422 | static bool classof(const Instruction *I) { |
2423 | return I->getOpcode() == Instruction::ExtractValue; |
2424 | } |
2425 | static bool classof(const Value *V) { |
2426 | return isa<Instruction>(V) && classof(cast<Instruction>(V)); |
2427 | } |
2428 | }; |
2429 | |
2430 | ExtractValueInst::ExtractValueInst(Value *Agg, |
2431 | ArrayRef<unsigned> Idxs, |
2432 | const Twine &NameStr, |
2433 | Instruction *InsertBefore) |
2434 | : UnaryInstruction(checkGEPType(getIndexedType(Agg->getType(), Idxs)), |
2435 | ExtractValue, Agg, InsertBefore) { |
2436 | init(Idxs, NameStr); |
2437 | } |
2438 | |
2439 | ExtractValueInst::ExtractValueInst(Value *Agg, |
2440 | ArrayRef<unsigned> Idxs, |
2441 | const Twine &NameStr, |
2442 | BasicBlock *InsertAtEnd) |
2443 | : UnaryInstruction(checkGEPType(getIndexedType(Agg->getType(), Idxs)), |
2444 | ExtractValue, Agg, InsertAtEnd) { |
2445 | init(Idxs, NameStr); |
2446 | } |
2447 | |
2448 | //===----------------------------------------------------------------------===// |
2449 | // InsertValueInst Class |
2450 | //===----------------------------------------------------------------------===// |
2451 | |
2452 | /// This instruction inserts a struct field of array element |
2453 | /// value into an aggregate value. |
2454 | /// |
2455 | class InsertValueInst : public Instruction { |
2456 | SmallVector<unsigned, 4> Indices; |
2457 | |
2458 | InsertValueInst(const InsertValueInst &IVI); |
2459 | |
2460 | /// Constructors - Create a insertvalue instruction with a base aggregate |
2461 | /// value, a value to insert, and a list of indices. The first ctor can |
2462 | /// optionally insert before an existing instruction, the second appends |
2463 | /// the new instruction to the specified BasicBlock. |
2464 | inline InsertValueInst(Value *Agg, Value *Val, |
2465 | ArrayRef<unsigned> Idxs, |
2466 | const Twine &NameStr, |
2467 | Instruction *InsertBefore); |
2468 | inline InsertValueInst(Value *Agg, Value *Val, |
2469 | ArrayRef<unsigned> Idxs, |
2470 | const Twine &NameStr, BasicBlock *InsertAtEnd); |
2471 | |
2472 | /// Constructors - These two constructors are convenience methods because one |
2473 | /// and two index insertvalue instructions are so common. |
2474 | InsertValueInst(Value *Agg, Value *Val, unsigned Idx, |
2475 | const Twine &NameStr = "", |
2476 | Instruction *InsertBefore = nullptr); |
2477 | InsertValueInst(Value *Agg, Value *Val, unsigned Idx, const Twine &NameStr, |
2478 | BasicBlock *InsertAtEnd); |
2479 | |
2480 | void init(Value *Agg, Value *Val, ArrayRef<unsigned> Idxs, |
2481 | const Twine &NameStr); |
2482 | |
2483 | protected: |
2484 | // Note: Instruction needs to be a friend here to call cloneImpl. |
2485 | friend class Instruction; |
2486 | |
2487 | InsertValueInst *cloneImpl() const; |
2488 | |
2489 | public: |
2490 | // allocate space for exactly two operands |
2491 | void *operator new(size_t S) { return User::operator new(S, 2); } |
2492 | void operator delete(void *Ptr) { User::operator delete(Ptr); } |
2493 | |
2494 | static InsertValueInst *Create(Value *Agg, Value *Val, |
2495 | ArrayRef<unsigned> Idxs, |
2496 | const Twine &NameStr = "", |
2497 | Instruction *InsertBefore = nullptr) { |
2498 | return new InsertValueInst(Agg, Val, Idxs, NameStr, InsertBefore); |
2499 | } |
2500 | |
2501 | static InsertValueInst *Create(Value *Agg, Value *Val, |
2502 | ArrayRef<unsigned> Idxs, |
2503 | const Twine &NameStr, |
2504 | BasicBlock *InsertAtEnd) { |
2505 | return new InsertValueInst(Agg, Val, Idxs, NameStr, InsertAtEnd); |
2506 | } |
2507 | |
2508 | /// Transparently provide more efficient getOperand methods. |
2509 | DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value)public: inline Value *getOperand(unsigned) const; inline void setOperand(unsigned, Value*); inline op_iterator op_begin(); inline const_op_iterator op_begin() const; inline op_iterator op_end(); inline const_op_iterator op_end() const; protected : template <int> inline Use &Op(); template <int > inline const Use &Op() const; public: inline unsigned getNumOperands() const; |
2510 | |
2511 | using idx_iterator = const unsigned*; |
2512 | |
2513 | inline idx_iterator idx_begin() const { return Indices.begin(); } |
2514 | inline idx_iterator idx_end() const { return Indices.end(); } |
2515 | inline iterator_range<idx_iterator> indices() const { |
2516 | return make_range(idx_begin(), idx_end()); |
2517 | } |
2518 | |
2519 | Value *getAggregateOperand() { |
2520 | return getOperand(0); |
2521 | } |
2522 | const Value *getAggregateOperand() const { |
2523 | return getOperand(0); |
2524 | } |
2525 | static unsigned getAggregateOperandIndex() { |
2526 | return 0U; // get index for modifying correct operand |
2527 | } |
2528 | |
2529 | Value *getInsertedValueOperand() { |
2530 | return getOperand(1); |
2531 | } |
2532 | const Value *getInsertedValueOperand() const { |
2533 | return getOperand(1); |
2534 | } |
2535 | static unsigned getInsertedValueOperandIndex() { |
2536 | return 1U; // get index for modifying correct operand |
2537 | } |
2538 | |
2539 | ArrayRef<unsigned> getIndices() const { |
2540 | return Indices; |
2541 | } |
2542 | |
2543 | unsigned getNumIndices() const { |
2544 | return (unsigned)Indices.size(); |
2545 | } |
2546 | |
2547 | bool hasIndices() const { |
2548 | return true; |
2549 | } |
2550 | |
2551 | // Methods for support type inquiry through isa, cast, and dyn_cast: |
2552 | static bool classof(const Instruction *I) { |
2553 | return I->getOpcode() == Instruction::InsertValue; |
2554 | } |
2555 | static bool classof(const Value *V) { |
2556 | return isa<Instruction>(V) && classof(cast<Instruction>(V)); |
2557 | } |
2558 | }; |
2559 | |
2560 | template <> |
2561 | struct OperandTraits<InsertValueInst> : |
2562 | public FixedNumOperandTraits<InsertValueInst, 2> { |
2563 | }; |
2564 | |
2565 | InsertValueInst::InsertValueInst(Value *Agg, |
2566 | Value *Val, |
2567 | ArrayRef<unsigned> Idxs, |
2568 | const Twine &NameStr, |
2569 | Instruction *InsertBefore) |
2570 | : Instruction(Agg->getType(), InsertValue, |
2571 | OperandTraits<InsertValueInst>::op_begin(this), |
2572 | 2, InsertBefore) { |
2573 | init(Agg, Val, Idxs, NameStr); |
2574 | } |
2575 | |
2576 | InsertValueInst::InsertValueInst(Value *Agg, |
2577 | Value *Val, |
2578 | ArrayRef<unsigned> Idxs, |
2579 | const Twine &NameStr, |
2580 | BasicBlock *InsertAtEnd) |
2581 | : Instruction(Agg->getType(), InsertValue, |
2582 | OperandTraits<InsertValueInst>::op_begin(this), |
2583 | 2, InsertAtEnd) { |
2584 | init(Agg, Val, Idxs, NameStr); |
2585 | } |
2586 | |
2587 | DEFINE_TRANSPARENT_OPERAND_ACCESSORS(InsertValueInst, Value)InsertValueInst::op_iterator InsertValueInst::op_begin() { return OperandTraits<InsertValueInst>::op_begin(this); } InsertValueInst ::const_op_iterator InsertValueInst::op_begin() const { return OperandTraits<InsertValueInst>::op_begin(const_cast< InsertValueInst*>(this)); } InsertValueInst::op_iterator InsertValueInst ::op_end() { return OperandTraits<InsertValueInst>::op_end (this); } InsertValueInst::const_op_iterator InsertValueInst:: op_end() const { return OperandTraits<InsertValueInst>:: op_end(const_cast<InsertValueInst*>(this)); } Value *InsertValueInst ::getOperand(unsigned i_nocapture) const { ((void)0); return cast_or_null <Value>( OperandTraits<InsertValueInst>::op_begin (const_cast<InsertValueInst*>(this))[i_nocapture].get() ); } void InsertValueInst::setOperand(unsigned i_nocapture, Value *Val_nocapture) { ((void)0); OperandTraits<InsertValueInst >::op_begin(this)[i_nocapture] = Val_nocapture; } unsigned InsertValueInst::getNumOperands() const { return OperandTraits <InsertValueInst>::operands(this); } template <int Idx_nocapture > Use &InsertValueInst::Op() { return this->OpFrom< Idx_nocapture>(this); } template <int Idx_nocapture> const Use &InsertValueInst::Op() const { return this-> OpFrom<Idx_nocapture>(this); } |
2588 | |
2589 | //===----------------------------------------------------------------------===// |
2590 | // PHINode Class |
2591 | //===----------------------------------------------------------------------===// |
2592 | |
2593 | // PHINode - The PHINode class is used to represent the magical mystical PHI |
2594 | // node, that can not exist in nature, but can be synthesized in a computer |
2595 | // scientist's overactive imagination. |
2596 | // |
2597 | class PHINode : public Instruction { |
2598 | /// The number of operands actually allocated. NumOperands is |
2599 | /// the number actually in use. |
2600 | unsigned ReservedSpace; |
2601 | |
2602 | PHINode(const PHINode &PN); |
2603 | |
2604 | explicit PHINode(Type *Ty, unsigned NumReservedValues, |
2605 | const Twine &NameStr = "", |
2606 | Instruction *InsertBefore = nullptr) |
2607 | : Instruction(Ty, Instruction::PHI, nullptr, 0, InsertBefore), |
2608 | ReservedSpace(NumReservedValues) { |
2609 | assert(!Ty->isTokenTy() && "PHI nodes cannot have token type!")((void)0); |
2610 | setName(NameStr); |
2611 | allocHungoffUses(ReservedSpace); |
2612 | } |
2613 | |
2614 | PHINode(Type *Ty, unsigned NumReservedValues, const Twine &NameStr, |
2615 | BasicBlock *InsertAtEnd) |
2616 | : Instruction(Ty, Instruction::PHI, nullptr, 0, InsertAtEnd), |
2617 | ReservedSpace(NumReservedValues) { |
2618 | assert(!Ty->isTokenTy() && "PHI nodes cannot have token type!")((void)0); |
2619 | setName(NameStr); |
2620 | allocHungoffUses(ReservedSpace); |
2621 | } |
2622 | |
2623 | protected: |
2624 | // Note: Instruction needs to be a friend here to call cloneImpl. |
2625 | friend class Instruction; |
2626 | |
2627 | PHINode *cloneImpl() const; |
2628 | |
2629 | // allocHungoffUses - this is more complicated than the generic |
2630 | // User::allocHungoffUses, because we have to allocate Uses for the incoming |
2631 | // values and pointers to the incoming blocks, all in one allocation. |
2632 | void allocHungoffUses(unsigned N) { |
2633 | User::allocHungoffUses(N, /* IsPhi */ true); |
2634 | } |
2635 | |
2636 | public: |
2637 | /// Constructors - NumReservedValues is a hint for the number of incoming |
2638 | /// edges that this phi node will have (use 0 if you really have no idea). |
2639 | static PHINode *Create(Type *Ty, unsigned NumReservedValues, |
2640 | const Twine &NameStr = "", |
2641 | Instruction *InsertBefore = nullptr) { |
2642 | return new PHINode(Ty, NumReservedValues, NameStr, InsertBefore); |
2643 | } |
2644 | |
2645 | static PHINode *Create(Type *Ty, unsigned NumReservedValues, |
2646 | const Twine &NameStr, BasicBlock *InsertAtEnd) { |
2647 | return new PHINode(Ty, NumReservedValues, NameStr, InsertAtEnd); |
2648 | } |
2649 | |
2650 | /// Provide fast operand accessors |
2651 | DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value)public: inline Value *getOperand(unsigned) const; inline void setOperand(unsigned, Value*); inline op_iterator op_begin(); inline const_op_iterator op_begin() const; inline op_iterator op_end(); inline const_op_iterator op_end() const; protected : template <int> inline Use &Op(); template <int > inline const Use &Op() const; public: inline unsigned getNumOperands() const; |
2652 | |
2653 | // Block iterator interface. This provides access to the list of incoming |
2654 | // basic blocks, which parallels the list of incoming values. |
2655 | |
2656 | using block_iterator = BasicBlock **; |
2657 | using const_block_iterator = BasicBlock * const *; |
2658 | |
2659 | block_iterator block_begin() { |
2660 | return reinterpret_cast<block_iterator>(op_begin() + ReservedSpace); |
2661 | } |
2662 | |
2663 | const_block_iterator block_begin() const { |
2664 | return reinterpret_cast<const_block_iterator>(op_begin() + ReservedSpace); |
2665 | } |
2666 | |
2667 | block_iterator block_end() { |
2668 | return block_begin() + getNumOperands(); |
2669 | } |
2670 | |
2671 | const_block_iterator block_end() const { |
2672 | return block_begin() + getNumOperands(); |
2673 | } |
2674 | |
2675 | iterator_range<block_iterator> blocks() { |
2676 | return make_range(block_begin(), block_end()); |
2677 | } |
2678 | |
2679 | iterator_range<const_block_iterator> blocks() const { |
2680 | return make_range(block_begin(), block_end()); |
2681 | } |
2682 | |
2683 | op_range incoming_values() { return operands(); } |
2684 | |
2685 | const_op_range incoming_values() const { return operands(); } |
2686 | |
2687 | /// Return the number of incoming edges |
2688 | /// |
2689 | unsigned getNumIncomingValues() const { return getNumOperands(); } |
2690 | |
2691 | /// Return incoming value number x |
2692 | /// |
2693 | Value *getIncomingValue(unsigned i) const { |
2694 | return getOperand(i); |
2695 | } |
2696 | void setIncomingValue(unsigned i, Value *V) { |
2697 | assert(V && "PHI node got a null value!")((void)0); |
2698 | assert(getType() == V->getType() &&((void)0) |
2699 | "All operands to PHI node must be the same type as the PHI node!")((void)0); |
2700 | setOperand(i, V); |
2701 | } |
2702 | |
2703 | static unsigned getOperandNumForIncomingValue(unsigned i) { |
2704 | return i; |
2705 | } |
2706 | |
2707 | static unsigned getIncomingValueNumForOperand(unsigned i) { |
2708 | return i; |
2709 | } |
2710 | |
2711 | /// Return incoming basic block number @p i. |
2712 | /// |
2713 | BasicBlock *getIncomingBlock(unsigned i) const { |
2714 | return block_begin()[i]; |
2715 | } |
2716 | |
2717 | /// Return incoming basic block corresponding |
2718 | /// to an operand of the PHI. |
2719 | /// |
2720 | BasicBlock *getIncomingBlock(const Use &U) const { |
2721 | assert(this == U.getUser() && "Iterator doesn't point to PHI's Uses?")((void)0); |
2722 | return getIncomingBlock(unsigned(&U - op_begin())); |
2723 | } |
2724 | |
2725 | /// Return incoming basic block corresponding |
2726 | /// to value use iterator. |
2727 | /// |
2728 | BasicBlock *getIncomingBlock(Value::const_user_iterator I) const { |
2729 | return getIncomingBlock(I.getUse()); |
2730 | } |
2731 | |
2732 | void setIncomingBlock(unsigned i, BasicBlock *BB) { |
2733 | assert(BB && "PHI node got a null basic block!")((void)0); |
2734 | block_begin()[i] = BB; |
2735 | } |
2736 | |
2737 | /// Replace every incoming basic block \p Old to basic block \p New. |
2738 | void replaceIncomingBlockWith(const BasicBlock *Old, BasicBlock *New) { |
2739 | assert(New && Old && "PHI node got a null basic block!")((void)0); |
2740 | for (unsigned Op = 0, NumOps = getNumOperands(); Op != NumOps; ++Op) |