diff options
| -rw-r--r-- | llvm/lib/Transforms/Scalar/LoopRotation.cpp | 161 |
1 files changed, 82 insertions, 79 deletions
diff --git a/llvm/lib/Transforms/Scalar/LoopRotation.cpp b/llvm/lib/Transforms/Scalar/LoopRotation.cpp index 6f8a35ecae2..5e6c2da08cc 100644 --- a/llvm/lib/Transforms/Scalar/LoopRotation.cpp +++ b/llvm/lib/Transforms/Scalar/LoopRotation.cpp @@ -45,65 +45,6 @@ DefaultRotationThreshold("rotation-max-header-size", cl::init(16), cl::Hidden, cl::desc("The default maximum header size for automatic loop rotation")); STATISTIC(NumRotated, "Number of loops rotated"); -namespace { - - class LoopRotate : public LoopPass { - public: - static char ID; // Pass ID, replacement for typeid - LoopRotate(int SpecifiedMaxHeaderSize = -1) : LoopPass(ID) { - initializeLoopRotatePass(*PassRegistry::getPassRegistry()); - if (SpecifiedMaxHeaderSize == -1) - MaxHeaderSize = DefaultRotationThreshold; - else - MaxHeaderSize = unsigned(SpecifiedMaxHeaderSize); - } - - // LCSSA form makes instruction renaming easier. - void getAnalysisUsage(AnalysisUsage &AU) const override { - AU.addPreserved<AAResultsWrapperPass>(); - AU.addRequired<AssumptionCacheTracker>(); - AU.addPreserved<DominatorTreeWrapperPass>(); - AU.addRequired<LoopInfoWrapperPass>(); - AU.addPreserved<LoopInfoWrapperPass>(); - AU.addRequiredID(LoopSimplifyID); - AU.addPreservedID(LoopSimplifyID); - AU.addRequiredID(LCSSAID); - AU.addPreservedID(LCSSAID); - AU.addPreserved<ScalarEvolutionWrapperPass>(); - AU.addPreserved<SCEVAAWrapperPass>(); - AU.addRequired<TargetTransformInfoWrapperPass>(); - AU.addPreserved<BasicAAWrapperPass>(); - AU.addPreserved<GlobalsAAWrapperPass>(); - } - - bool runOnLoop(Loop *L, LPPassManager &LPM) override; - bool simplifyLoopLatch(Loop *L); - bool rotateLoop(Loop *L, bool SimplifiedLatch); - - private: - unsigned MaxHeaderSize; - LoopInfo *LI; - const TargetTransformInfo *TTI; - AssumptionCache *AC; - DominatorTree *DT; - }; -} - -char LoopRotate::ID = 0; -INITIALIZE_PASS_BEGIN(LoopRotate, "loop-rotate", "Rotate Loops", false, false) -INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass) -INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker) -INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass) -INITIALIZE_PASS_DEPENDENCY(LoopSimplify) -INITIALIZE_PASS_DEPENDENCY(LCSSA) -INITIALIZE_PASS_DEPENDENCY(SCEVAAWrapperPass) -INITIALIZE_PASS_DEPENDENCY(BasicAAWrapperPass) -INITIALIZE_PASS_DEPENDENCY(GlobalsAAWrapperPass) -INITIALIZE_PASS_END(LoopRotate, "loop-rotate", "Rotate Loops", false, false) - -Pass *llvm::createLoopRotatePass(int MaxHeaderSize) { - return new LoopRotate(MaxHeaderSize); -} /// RewriteUsesOfClonedInstructions - We just cloned the instructions from the /// old header into the preheader. If there were uses of the values produced by @@ -180,7 +121,10 @@ static void RewriteUsesOfClonedInstructions(BasicBlock *OrigHeader, /// rotation. LoopRotate should be repeatable and converge to a canonical /// form. This property is satisfied because simplifying the loop latch can only /// happen once across multiple invocations of the LoopRotate pass. -bool LoopRotate::rotateLoop(Loop *L, bool SimplifiedLatch) { +static bool rotateLoop(Loop *L, unsigned MaxHeaderSize, LoopInfo *LI, + const TargetTransformInfo *TTI, AssumptionCache *AC, + DominatorTree *DT, ScalarEvolution *SE, + bool SimplifiedLatch) { // If the loop has only one block then there is not much to rotate. if (L->getBlocks().size() == 1) return false; @@ -235,8 +179,8 @@ bool LoopRotate::rotateLoop(Loop *L, bool SimplifiedLatch) { // Anything ScalarEvolution may know about this loop or the PHI nodes // in its header will soon be invalidated. - if (auto *SEWP = getAnalysisIfAvailable<ScalarEvolutionWrapperPass>()) - SEWP->getSE().forgetLoop(L); + if (SE) + SE->forgetLoop(L); DEBUG(dbgs() << "LoopRotation: rotating "; L->dump()); @@ -538,7 +482,7 @@ static bool shouldSpeculateInstrs(BasicBlock::iterator Begin, /// canonical form so downstream passes can handle it. /// /// I don't believe this invalidates SCEV. -bool LoopRotate::simplifyLoopLatch(Loop *L) { +static bool simplifyLoopLatch(Loop *L, LoopInfo *LI, DominatorTree *DT) { BasicBlock *Latch = L->getLoopLatch(); if (!Latch || Latch->hasAddressTaken()) return false; @@ -583,31 +527,23 @@ bool LoopRotate::simplifyLoopLatch(Loop *L) { return true; } -/// Rotate Loop L as many times as possible. Return true if -/// the loop is rotated at least once. -bool LoopRotate::runOnLoop(Loop *L, LPPassManager &LPM) { - if (skipOptnoneFunction(L)) - return false; - +/// Rotate \c L as many times as possible. Return true if the loop is rotated +/// at least once. +static bool iterativelyRotateLoop(Loop *L, unsigned MaxHeaderSize, LoopInfo *LI, + const TargetTransformInfo *TTI, + AssumptionCache *AC, DominatorTree *DT, + ScalarEvolution *SE) { // Save the loop metadata. MDNode *LoopMD = L->getLoopID(); - Function &F = *L->getHeader()->getParent(); - - LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo(); - TTI = &getAnalysis<TargetTransformInfoWrapperPass>().getTTI(F); - AC = &getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F); - auto *DTWP = getAnalysisIfAvailable<DominatorTreeWrapperPass>(); - DT = DTWP ? &DTWP->getDomTree() : nullptr; - // Simplify the loop latch before attempting to rotate the header // upward. Rotation may not be needed if the loop tail can be folded into the // loop exit. - bool SimplifiedLatch = simplifyLoopLatch(L); + bool SimplifiedLatch = simplifyLoopLatch(L, LI, DT); // One loop can be rotated multiple times. bool MadeChange = false; - while (rotateLoop(L, SimplifiedLatch)) { + while (rotateLoop(L, MaxHeaderSize, LI, TTI, AC, DT, SE, SimplifiedLatch)) { MadeChange = true; SimplifiedLatch = false; } @@ -619,3 +555,70 @@ bool LoopRotate::runOnLoop(Loop *L, LPPassManager &LPM) { return MadeChange; } + +namespace { + +class LoopRotate : public LoopPass { + unsigned MaxHeaderSize; + +public: + static char ID; // Pass ID, replacement for typeid + LoopRotate(int SpecifiedMaxHeaderSize = -1) : LoopPass(ID) { + initializeLoopRotatePass(*PassRegistry::getPassRegistry()); + if (SpecifiedMaxHeaderSize == -1) + MaxHeaderSize = DefaultRotationThreshold; + else + MaxHeaderSize = unsigned(SpecifiedMaxHeaderSize); + } + + // LCSSA form makes instruction renaming easier. + void getAnalysisUsage(AnalysisUsage &AU) const override { + AU.addPreserved<AAResultsWrapperPass>(); + AU.addRequired<AssumptionCacheTracker>(); + AU.addPreserved<DominatorTreeWrapperPass>(); + AU.addRequired<LoopInfoWrapperPass>(); + AU.addPreserved<LoopInfoWrapperPass>(); + AU.addRequiredID(LoopSimplifyID); + AU.addPreservedID(LoopSimplifyID); + AU.addRequiredID(LCSSAID); + AU.addPreservedID(LCSSAID); + AU.addPreserved<ScalarEvolutionWrapperPass>(); + AU.addPreserved<SCEVAAWrapperPass>(); + AU.addRequired<TargetTransformInfoWrapperPass>(); + AU.addPreserved<BasicAAWrapperPass>(); + AU.addPreserved<GlobalsAAWrapperPass>(); + } + + bool runOnLoop(Loop *L, LPPassManager &LPM) override { + if (skipOptnoneFunction(L)) + return false; + Function &F = *L->getHeader()->getParent(); + + auto *LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo(); + const auto *TTI = &getAnalysis<TargetTransformInfoWrapperPass>().getTTI(F); + auto *AC = &getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F); + auto *DTWP = getAnalysisIfAvailable<DominatorTreeWrapperPass>(); + auto *DT = DTWP ? &DTWP->getDomTree() : nullptr; + auto *SEWP = getAnalysisIfAvailable<ScalarEvolutionWrapperPass>(); + auto *SE = SEWP ? &SEWP->getSE() : nullptr; + + return iterativelyRotateLoop(L, MaxHeaderSize, LI, TTI, AC, DT, SE); + } +}; +} + +char LoopRotate::ID = 0; +INITIALIZE_PASS_BEGIN(LoopRotate, "loop-rotate", "Rotate Loops", false, false) +INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass) +INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker) +INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass) +INITIALIZE_PASS_DEPENDENCY(LoopSimplify) +INITIALIZE_PASS_DEPENDENCY(LCSSA) +INITIALIZE_PASS_DEPENDENCY(SCEVAAWrapperPass) +INITIALIZE_PASS_DEPENDENCY(BasicAAWrapperPass) +INITIALIZE_PASS_DEPENDENCY(GlobalsAAWrapperPass) +INITIALIZE_PASS_END(LoopRotate, "loop-rotate", "Rotate Loops", false, false) + +Pass *llvm::createLoopRotatePass(int MaxHeaderSize) { + return new LoopRotate(MaxHeaderSize); +} |
