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-rw-r--r--lib/Transforms/Scalar/LoopIdiomRecognize.cpp428
1 files changed, 301 insertions, 127 deletions
diff --git a/lib/Transforms/Scalar/LoopIdiomRecognize.cpp b/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
index 4521640e3947..1468676a3543 100644
--- a/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
+++ b/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
@@ -26,22 +26,21 @@
// i64 and larger types when i64 is legal and the value has few bits set. It
// would be good to enhance isel to emit a loop for ctpop in this case.
//
-// We should enhance the memset/memcpy recognition to handle multiple stores in
-// the loop. This would handle things like:
-// void foo(_Complex float *P)
-// for (i) { __real__(*P) = 0; __imag__(*P) = 0; }
-//
// This could recognize common matrix multiplies and dot product idioms and
// replace them with calls to BLAS (if linked in??).
//
//===----------------------------------------------------------------------===//
-#include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Scalar/LoopIdiomRecognize.h"
+#include "llvm/ADT/MapVector.h"
+#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/BasicAliasAnalysis.h"
#include "llvm/Analysis/GlobalsModRef.h"
+#include "llvm/Analysis/LoopAccessAnalysis.h"
#include "llvm/Analysis/LoopPass.h"
+#include "llvm/Analysis/LoopPassManager.h"
#include "llvm/Analysis/ScalarEvolutionAliasAnalysis.h"
#include "llvm/Analysis/ScalarEvolutionExpander.h"
#include "llvm/Analysis/ScalarEvolutionExpressions.h"
@@ -55,7 +54,10 @@
#include "llvm/IR/Module.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
+#include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Utils/BuildLibCalls.h"
#include "llvm/Transforms/Utils/Local.h"
+#include "llvm/Transforms/Utils/LoopUtils.h"
using namespace llvm;
#define DEBUG_TYPE "loop-idiom"
@@ -65,7 +67,7 @@ STATISTIC(NumMemCpy, "Number of memcpy's formed from loop load+stores");
namespace {
-class LoopIdiomRecognize : public LoopPass {
+class LoopIdiomRecognize {
Loop *CurLoop;
AliasAnalysis *AA;
DominatorTree *DT;
@@ -76,39 +78,21 @@ class LoopIdiomRecognize : public LoopPass {
const DataLayout *DL;
public:
- static char ID;
- explicit LoopIdiomRecognize() : LoopPass(ID) {
- initializeLoopIdiomRecognizePass(*PassRegistry::getPassRegistry());
- }
+ explicit LoopIdiomRecognize(AliasAnalysis *AA, DominatorTree *DT,
+ LoopInfo *LI, ScalarEvolution *SE,
+ TargetLibraryInfo *TLI,
+ const TargetTransformInfo *TTI,
+ const DataLayout *DL)
+ : CurLoop(nullptr), AA(AA), DT(DT), LI(LI), SE(SE), TLI(TLI), TTI(TTI),
+ DL(DL) {}
- bool runOnLoop(Loop *L, LPPassManager &LPM) override;
-
- /// This transformation requires natural loop information & requires that
- /// loop preheaders be inserted into the CFG.
- ///
- void getAnalysisUsage(AnalysisUsage &AU) const override {
- AU.addRequired<LoopInfoWrapperPass>();
- AU.addPreserved<LoopInfoWrapperPass>();
- AU.addRequiredID(LoopSimplifyID);
- AU.addPreservedID(LoopSimplifyID);
- AU.addRequiredID(LCSSAID);
- AU.addPreservedID(LCSSAID);
- AU.addRequired<AAResultsWrapperPass>();
- AU.addPreserved<AAResultsWrapperPass>();
- AU.addRequired<ScalarEvolutionWrapperPass>();
- AU.addPreserved<ScalarEvolutionWrapperPass>();
- AU.addPreserved<SCEVAAWrapperPass>();
- AU.addRequired<DominatorTreeWrapperPass>();
- AU.addPreserved<DominatorTreeWrapperPass>();
- AU.addRequired<TargetLibraryInfoWrapperPass>();
- AU.addRequired<TargetTransformInfoWrapperPass>();
- AU.addPreserved<BasicAAWrapperPass>();
- AU.addPreserved<GlobalsAAWrapperPass>();
- }
+ bool runOnLoop(Loop *L);
private:
typedef SmallVector<StoreInst *, 8> StoreList;
- StoreList StoreRefsForMemset;
+ typedef MapVector<Value *, StoreList> StoreListMap;
+ StoreListMap StoreRefsForMemset;
+ StoreListMap StoreRefsForMemsetPattern;
StoreList StoreRefsForMemcpy;
bool HasMemset;
bool HasMemsetPattern;
@@ -122,14 +106,18 @@ private:
SmallVectorImpl<BasicBlock *> &ExitBlocks);
void collectStores(BasicBlock *BB);
- bool isLegalStore(StoreInst *SI, bool &ForMemset, bool &ForMemcpy);
- bool processLoopStore(StoreInst *SI, const SCEV *BECount);
+ bool isLegalStore(StoreInst *SI, bool &ForMemset, bool &ForMemsetPattern,
+ bool &ForMemcpy);
+ bool processLoopStores(SmallVectorImpl<StoreInst *> &SL, const SCEV *BECount,
+ bool ForMemset);
bool processLoopMemSet(MemSetInst *MSI, const SCEV *BECount);
bool processLoopStridedStore(Value *DestPtr, unsigned StoreSize,
unsigned StoreAlignment, Value *StoredVal,
- Instruction *TheStore, const SCEVAddRecExpr *Ev,
- const SCEV *BECount, bool NegStride);
+ Instruction *TheStore,
+ SmallPtrSetImpl<Instruction *> &Stores,
+ const SCEVAddRecExpr *Ev, const SCEV *BECount,
+ bool NegStride);
bool processLoopStoreOfLoopLoad(StoreInst *SI, const SCEV *BECount);
/// @}
@@ -145,38 +133,82 @@ private:
/// @}
};
+class LoopIdiomRecognizeLegacyPass : public LoopPass {
+public:
+ static char ID;
+ explicit LoopIdiomRecognizeLegacyPass() : LoopPass(ID) {
+ initializeLoopIdiomRecognizeLegacyPassPass(
+ *PassRegistry::getPassRegistry());
+ }
+
+ bool runOnLoop(Loop *L, LPPassManager &LPM) override {
+ if (skipLoop(L))
+ return false;
+
+ AliasAnalysis *AA = &getAnalysis<AAResultsWrapperPass>().getAAResults();
+ DominatorTree *DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
+ LoopInfo *LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
+ ScalarEvolution *SE = &getAnalysis<ScalarEvolutionWrapperPass>().getSE();
+ TargetLibraryInfo *TLI =
+ &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
+ const TargetTransformInfo *TTI =
+ &getAnalysis<TargetTransformInfoWrapperPass>().getTTI(
+ *L->getHeader()->getParent());
+ const DataLayout *DL = &L->getHeader()->getModule()->getDataLayout();
+
+ LoopIdiomRecognize LIR(AA, DT, LI, SE, TLI, TTI, DL);
+ return LIR.runOnLoop(L);
+ }
+
+ /// This transformation requires natural loop information & requires that
+ /// loop preheaders be inserted into the CFG.
+ ///
+ void getAnalysisUsage(AnalysisUsage &AU) const override {
+ AU.addRequired<TargetLibraryInfoWrapperPass>();
+ AU.addRequired<TargetTransformInfoWrapperPass>();
+ getLoopAnalysisUsage(AU);
+ }
+};
} // End anonymous namespace.
-char LoopIdiomRecognize::ID = 0;
-INITIALIZE_PASS_BEGIN(LoopIdiomRecognize, "loop-idiom", "Recognize loop idioms",
- false, false)
-INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(LoopSimplify)
-INITIALIZE_PASS_DEPENDENCY(LCSSA)
-INITIALIZE_PASS_DEPENDENCY(ScalarEvolutionWrapperPass)
+PreservedAnalyses LoopIdiomRecognizePass::run(Loop &L,
+ AnalysisManager<Loop> &AM) {
+ const auto &FAM =
+ AM.getResult<FunctionAnalysisManagerLoopProxy>(L).getManager();
+ Function *F = L.getHeader()->getParent();
+
+ // Use getCachedResult because Loop pass cannot trigger a function analysis.
+ auto *AA = FAM.getCachedResult<AAManager>(*F);
+ auto *DT = FAM.getCachedResult<DominatorTreeAnalysis>(*F);
+ auto *LI = FAM.getCachedResult<LoopAnalysis>(*F);
+ auto *SE = FAM.getCachedResult<ScalarEvolutionAnalysis>(*F);
+ auto *TLI = FAM.getCachedResult<TargetLibraryAnalysis>(*F);
+ const auto *TTI = FAM.getCachedResult<TargetIRAnalysis>(*F);
+ const auto *DL = &L.getHeader()->getModule()->getDataLayout();
+ assert((AA && DT && LI && SE && TLI && TTI && DL) &&
+ "Analyses for Loop Idiom Recognition not available");
+
+ LoopIdiomRecognize LIR(AA, DT, LI, SE, TLI, TTI, DL);
+ if (!LIR.runOnLoop(&L))
+ return PreservedAnalyses::all();
+
+ return getLoopPassPreservedAnalyses();
+}
+
+char LoopIdiomRecognizeLegacyPass::ID = 0;
+INITIALIZE_PASS_BEGIN(LoopIdiomRecognizeLegacyPass, "loop-idiom",
+ "Recognize loop idioms", false, false)
+INITIALIZE_PASS_DEPENDENCY(LoopPass)
INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(BasicAAWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(GlobalsAAWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(SCEVAAWrapperPass)
INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
-INITIALIZE_PASS_END(LoopIdiomRecognize, "loop-idiom", "Recognize loop idioms",
- false, false)
+INITIALIZE_PASS_END(LoopIdiomRecognizeLegacyPass, "loop-idiom",
+ "Recognize loop idioms", false, false)
-Pass *llvm::createLoopIdiomPass() { return new LoopIdiomRecognize(); }
+Pass *llvm::createLoopIdiomPass() { return new LoopIdiomRecognizeLegacyPass(); }
-/// deleteDeadInstruction - Delete this instruction. Before we do, go through
-/// and zero out all the operands of this instruction. If any of them become
-/// dead, delete them and the computation tree that feeds them.
-///
-static void deleteDeadInstruction(Instruction *I,
- const TargetLibraryInfo *TLI) {
- SmallVector<Value *, 16> Operands(I->value_op_begin(), I->value_op_end());
+static void deleteDeadInstruction(Instruction *I) {
I->replaceAllUsesWith(UndefValue::get(I->getType()));
I->eraseFromParent();
- for (Value *Op : Operands)
- RecursivelyDeleteTriviallyDeadInstructions(Op, TLI);
}
//===----------------------------------------------------------------------===//
@@ -185,10 +217,7 @@ static void deleteDeadInstruction(Instruction *I,
//
//===----------------------------------------------------------------------===//
-bool LoopIdiomRecognize::runOnLoop(Loop *L, LPPassManager &LPM) {
- if (skipOptnoneFunction(L))
- return false;
-
+bool LoopIdiomRecognize::runOnLoop(Loop *L) {
CurLoop = L;
// If the loop could not be converted to canonical form, it must have an
// indirectbr in it, just give up.
@@ -200,15 +229,6 @@ bool LoopIdiomRecognize::runOnLoop(Loop *L, LPPassManager &LPM) {
if (Name == "memset" || Name == "memcpy")
return false;
- AA = &getAnalysis<AAResultsWrapperPass>().getAAResults();
- DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
- LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
- SE = &getAnalysis<ScalarEvolutionWrapperPass>().getSE();
- TLI = &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
- TTI = &getAnalysis<TargetTransformInfoWrapperPass>().getTTI(
- *CurLoop->getHeader()->getParent());
- DL = &CurLoop->getHeader()->getModule()->getDataLayout();
-
HasMemset = TLI->has(LibFunc::memset);
HasMemsetPattern = TLI->has(LibFunc::memset_pattern16);
HasMemcpy = TLI->has(LibFunc::memcpy);
@@ -240,6 +260,14 @@ bool LoopIdiomRecognize::runOnCountableLoop() {
<< CurLoop->getHeader()->getName() << "\n");
bool MadeChange = false;
+
+ // The following transforms hoist stores/memsets into the loop pre-header.
+ // Give up if the loop has instructions may throw.
+ LoopSafetyInfo SafetyInfo;
+ computeLoopSafetyInfo(&SafetyInfo, CurLoop);
+ if (SafetyInfo.MayThrow)
+ return MadeChange;
+
// Scan all the blocks in the loop that are not in subloops.
for (auto *BB : CurLoop->getBlocks()) {
// Ignore blocks in subloops.
@@ -258,9 +286,9 @@ static unsigned getStoreSizeInBytes(StoreInst *SI, const DataLayout *DL) {
return (unsigned)SizeInBits >> 3;
}
-static unsigned getStoreStride(const SCEVAddRecExpr *StoreEv) {
+static APInt getStoreStride(const SCEVAddRecExpr *StoreEv) {
const SCEVConstant *ConstStride = cast<SCEVConstant>(StoreEv->getOperand(1));
- return ConstStride->getAPInt().getZExtValue();
+ return ConstStride->getAPInt();
}
/// getMemSetPatternValue - If a strided store of the specified value is safe to
@@ -305,11 +333,15 @@ static Constant *getMemSetPatternValue(Value *V, const DataLayout *DL) {
}
bool LoopIdiomRecognize::isLegalStore(StoreInst *SI, bool &ForMemset,
- bool &ForMemcpy) {
+ bool &ForMemsetPattern, bool &ForMemcpy) {
// Don't touch volatile stores.
if (!SI->isSimple())
return false;
+ // Avoid merging nontemporal stores.
+ if (SI->getMetadata(LLVMContext::MD_nontemporal))
+ return false;
+
Value *StoredVal = SI->getValueOperand();
Value *StorePtr = SI->getPointerOperand();
@@ -353,7 +385,7 @@ bool LoopIdiomRecognize::isLegalStore(StoreInst *SI, bool &ForMemset,
StorePtr->getType()->getPointerAddressSpace() == 0 &&
(PatternValue = getMemSetPatternValue(StoredVal, DL))) {
// It looks like we can use PatternValue!
- ForMemset = true;
+ ForMemsetPattern = true;
return true;
}
@@ -361,7 +393,7 @@ bool LoopIdiomRecognize::isLegalStore(StoreInst *SI, bool &ForMemset,
if (HasMemcpy) {
// Check to see if the stride matches the size of the store. If so, then we
// know that every byte is touched in the loop.
- unsigned Stride = getStoreStride(StoreEv);
+ APInt Stride = getStoreStride(StoreEv);
unsigned StoreSize = getStoreSizeInBytes(SI, DL);
if (StoreSize != Stride && StoreSize != -Stride)
return false;
@@ -393,6 +425,7 @@ bool LoopIdiomRecognize::isLegalStore(StoreInst *SI, bool &ForMemset,
void LoopIdiomRecognize::collectStores(BasicBlock *BB) {
StoreRefsForMemset.clear();
+ StoreRefsForMemsetPattern.clear();
StoreRefsForMemcpy.clear();
for (Instruction &I : *BB) {
StoreInst *SI = dyn_cast<StoreInst>(&I);
@@ -400,15 +433,22 @@ void LoopIdiomRecognize::collectStores(BasicBlock *BB) {
continue;
bool ForMemset = false;
+ bool ForMemsetPattern = false;
bool ForMemcpy = false;
// Make sure this is a strided store with a constant stride.
- if (!isLegalStore(SI, ForMemset, ForMemcpy))
+ if (!isLegalStore(SI, ForMemset, ForMemsetPattern, ForMemcpy))
continue;
// Save the store locations.
- if (ForMemset)
- StoreRefsForMemset.push_back(SI);
- else if (ForMemcpy)
+ if (ForMemset) {
+ // Find the base pointer.
+ Value *Ptr = GetUnderlyingObject(SI->getPointerOperand(), *DL);
+ StoreRefsForMemset[Ptr].push_back(SI);
+ } else if (ForMemsetPattern) {
+ // Find the base pointer.
+ Value *Ptr = GetUnderlyingObject(SI->getPointerOperand(), *DL);
+ StoreRefsForMemsetPattern[Ptr].push_back(SI);
+ } else if (ForMemcpy)
StoreRefsForMemcpy.push_back(SI);
}
}
@@ -430,9 +470,14 @@ bool LoopIdiomRecognize::runOnLoopBlock(
// Look for store instructions, which may be optimized to memset/memcpy.
collectStores(BB);
- // Look for a single store which can be optimized into a memset.
- for (auto &SI : StoreRefsForMemset)
- MadeChange |= processLoopStore(SI, BECount);
+ // Look for a single store or sets of stores with a common base, which can be
+ // optimized into a memset (memset_pattern). The latter most commonly happens
+ // with structs and handunrolled loops.
+ for (auto &SL : StoreRefsForMemset)
+ MadeChange |= processLoopStores(SL.second, BECount, true);
+
+ for (auto &SL : StoreRefsForMemsetPattern)
+ MadeChange |= processLoopStores(SL.second, BECount, false);
// Optimize the store into a memcpy, if it feeds an similarly strided load.
for (auto &SI : StoreRefsForMemcpy)
@@ -458,26 +503,144 @@ bool LoopIdiomRecognize::runOnLoopBlock(
return MadeChange;
}
-/// processLoopStore - See if this store can be promoted to a memset.
-bool LoopIdiomRecognize::processLoopStore(StoreInst *SI, const SCEV *BECount) {
- assert(SI->isSimple() && "Expected only non-volatile stores.");
+/// processLoopStores - See if this store(s) can be promoted to a memset.
+bool LoopIdiomRecognize::processLoopStores(SmallVectorImpl<StoreInst *> &SL,
+ const SCEV *BECount,
+ bool ForMemset) {
+ // Try to find consecutive stores that can be transformed into memsets.
+ SetVector<StoreInst *> Heads, Tails;
+ SmallDenseMap<StoreInst *, StoreInst *> ConsecutiveChain;
+
+ // Do a quadratic search on all of the given stores and find
+ // all of the pairs of stores that follow each other.
+ SmallVector<unsigned, 16> IndexQueue;
+ for (unsigned i = 0, e = SL.size(); i < e; ++i) {
+ assert(SL[i]->isSimple() && "Expected only non-volatile stores.");
+
+ Value *FirstStoredVal = SL[i]->getValueOperand();
+ Value *FirstStorePtr = SL[i]->getPointerOperand();
+ const SCEVAddRecExpr *FirstStoreEv =
+ cast<SCEVAddRecExpr>(SE->getSCEV(FirstStorePtr));
+ APInt FirstStride = getStoreStride(FirstStoreEv);
+ unsigned FirstStoreSize = getStoreSizeInBytes(SL[i], DL);
+
+ // See if we can optimize just this store in isolation.
+ if (FirstStride == FirstStoreSize || -FirstStride == FirstStoreSize) {
+ Heads.insert(SL[i]);
+ continue;
+ }
- Value *StoredVal = SI->getValueOperand();
- Value *StorePtr = SI->getPointerOperand();
+ Value *FirstSplatValue = nullptr;
+ Constant *FirstPatternValue = nullptr;
- // Check to see if the stride matches the size of the store. If so, then we
- // know that every byte is touched in the loop.
- const SCEVAddRecExpr *StoreEv = cast<SCEVAddRecExpr>(SE->getSCEV(StorePtr));
- unsigned Stride = getStoreStride(StoreEv);
- unsigned StoreSize = getStoreSizeInBytes(SI, DL);
- if (StoreSize != Stride && StoreSize != -Stride)
- return false;
+ if (ForMemset)
+ FirstSplatValue = isBytewiseValue(FirstStoredVal);
+ else
+ FirstPatternValue = getMemSetPatternValue(FirstStoredVal, DL);
+
+ assert((FirstSplatValue || FirstPatternValue) &&
+ "Expected either splat value or pattern value.");
+
+ IndexQueue.clear();
+ // If a store has multiple consecutive store candidates, search Stores
+ // array according to the sequence: from i+1 to e, then from i-1 to 0.
+ // This is because usually pairing with immediate succeeding or preceding
+ // candidate create the best chance to find memset opportunity.
+ unsigned j = 0;
+ for (j = i + 1; j < e; ++j)
+ IndexQueue.push_back(j);
+ for (j = i; j > 0; --j)
+ IndexQueue.push_back(j - 1);
+
+ for (auto &k : IndexQueue) {
+ assert(SL[k]->isSimple() && "Expected only non-volatile stores.");
+ Value *SecondStorePtr = SL[k]->getPointerOperand();
+ const SCEVAddRecExpr *SecondStoreEv =
+ cast<SCEVAddRecExpr>(SE->getSCEV(SecondStorePtr));
+ APInt SecondStride = getStoreStride(SecondStoreEv);
+
+ if (FirstStride != SecondStride)
+ continue;
- bool NegStride = StoreSize == -Stride;
+ Value *SecondStoredVal = SL[k]->getValueOperand();
+ Value *SecondSplatValue = nullptr;
+ Constant *SecondPatternValue = nullptr;
+
+ if (ForMemset)
+ SecondSplatValue = isBytewiseValue(SecondStoredVal);
+ else
+ SecondPatternValue = getMemSetPatternValue(SecondStoredVal, DL);
+
+ assert((SecondSplatValue || SecondPatternValue) &&
+ "Expected either splat value or pattern value.");
+
+ if (isConsecutiveAccess(SL[i], SL[k], *DL, *SE, false)) {
+ if (ForMemset) {
+ if (FirstSplatValue != SecondSplatValue)
+ continue;
+ } else {
+ if (FirstPatternValue != SecondPatternValue)
+ continue;
+ }
+ Tails.insert(SL[k]);
+ Heads.insert(SL[i]);
+ ConsecutiveChain[SL[i]] = SL[k];
+ break;
+ }
+ }
+ }
+
+ // We may run into multiple chains that merge into a single chain. We mark the
+ // stores that we transformed so that we don't visit the same store twice.
+ SmallPtrSet<Value *, 16> TransformedStores;
+ bool Changed = false;
+
+ // For stores that start but don't end a link in the chain:
+ for (SetVector<StoreInst *>::iterator it = Heads.begin(), e = Heads.end();
+ it != e; ++it) {
+ if (Tails.count(*it))
+ continue;
+
+ // We found a store instr that starts a chain. Now follow the chain and try
+ // to transform it.
+ SmallPtrSet<Instruction *, 8> AdjacentStores;
+ StoreInst *I = *it;
+
+ StoreInst *HeadStore = I;
+ unsigned StoreSize = 0;
+
+ // Collect the chain into a list.
+ while (Tails.count(I) || Heads.count(I)) {
+ if (TransformedStores.count(I))
+ break;
+ AdjacentStores.insert(I);
+
+ StoreSize += getStoreSizeInBytes(I, DL);
+ // Move to the next value in the chain.
+ I = ConsecutiveChain[I];
+ }
- // See if we can optimize just this store in isolation.
- return processLoopStridedStore(StorePtr, StoreSize, SI->getAlignment(),
- StoredVal, SI, StoreEv, BECount, NegStride);
+ Value *StoredVal = HeadStore->getValueOperand();
+ Value *StorePtr = HeadStore->getPointerOperand();
+ const SCEVAddRecExpr *StoreEv = cast<SCEVAddRecExpr>(SE->getSCEV(StorePtr));
+ APInt Stride = getStoreStride(StoreEv);
+
+ // Check to see if the stride matches the size of the stores. If so, then
+ // we know that every byte is touched in the loop.
+ if (StoreSize != Stride && StoreSize != -Stride)
+ continue;
+
+ bool NegStride = StoreSize == -Stride;
+
+ if (processLoopStridedStore(StorePtr, StoreSize, HeadStore->getAlignment(),
+ StoredVal, HeadStore, AdjacentStores, StoreEv,
+ BECount, NegStride)) {
+ TransformedStores.insert(AdjacentStores.begin(), AdjacentStores.end());
+ Changed = true;
+ }
+ }
+
+ return Changed;
}
/// processLoopMemSet - See if this memset can be promoted to a large memset.
@@ -488,7 +651,7 @@ bool LoopIdiomRecognize::processLoopMemSet(MemSetInst *MSI,
return false;
// If we're not allowed to hack on memset, we fail.
- if (!TLI->has(LibFunc::memset))
+ if (!HasMemset)
return false;
Value *Pointer = MSI->getDest();
@@ -507,11 +670,12 @@ bool LoopIdiomRecognize::processLoopMemSet(MemSetInst *MSI,
// Check to see if the stride matches the size of the memset. If so, then we
// know that every byte is touched in the loop.
- const SCEVConstant *Stride = dyn_cast<SCEVConstant>(Ev->getOperand(1));
+ const SCEVConstant *ConstStride = dyn_cast<SCEVConstant>(Ev->getOperand(1));
+ if (!ConstStride)
+ return false;
- // TODO: Could also handle negative stride here someday, that will require the
- // validity check in mayLoopAccessLocation to be updated though.
- if (!Stride || MSI->getLength() != Stride->getValue())
+ APInt Stride = ConstStride->getAPInt();
+ if (SizeInBytes != Stride && SizeInBytes != -Stride)
return false;
// Verify that the memset value is loop invariant. If not, we can't promote
@@ -520,18 +684,22 @@ bool LoopIdiomRecognize::processLoopMemSet(MemSetInst *MSI,
if (!SplatValue || !CurLoop->isLoopInvariant(SplatValue))
return false;
+ SmallPtrSet<Instruction *, 1> MSIs;
+ MSIs.insert(MSI);
+ bool NegStride = SizeInBytes == -Stride;
return processLoopStridedStore(Pointer, (unsigned)SizeInBytes,
- MSI->getAlignment(), SplatValue, MSI, Ev,
- BECount, /*NegStride=*/false);
+ MSI->getAlignment(), SplatValue, MSI, MSIs, Ev,
+ BECount, NegStride);
}
/// mayLoopAccessLocation - Return true if the specified loop might access the
/// specified pointer location, which is a loop-strided access. The 'Access'
/// argument specifies what the verboten forms of access are (read or write).
-static bool mayLoopAccessLocation(Value *Ptr, ModRefInfo Access, Loop *L,
- const SCEV *BECount, unsigned StoreSize,
- AliasAnalysis &AA,
- Instruction *IgnoredStore) {
+static bool
+mayLoopAccessLocation(Value *Ptr, ModRefInfo Access, Loop *L,
+ const SCEV *BECount, unsigned StoreSize,
+ AliasAnalysis &AA,
+ SmallPtrSetImpl<Instruction *> &IgnoredStores) {
// Get the location that may be stored across the loop. Since the access is
// strided positively through memory, we say that the modified location starts
// at the pointer and has infinite size.
@@ -550,8 +718,9 @@ static bool mayLoopAccessLocation(Value *Ptr, ModRefInfo Access, Loop *L,
for (Loop::block_iterator BI = L->block_begin(), E = L->block_end(); BI != E;
++BI)
- for (BasicBlock::iterator I = (*BI)->begin(), E = (*BI)->end(); I != E; ++I)
- if (&*I != IgnoredStore && (AA.getModRefInfo(&*I, StoreLoc) & Access))
+ for (Instruction &I : **BI)
+ if (IgnoredStores.count(&I) == 0 &&
+ (AA.getModRefInfo(&I, StoreLoc) & Access))
return true;
return false;
@@ -574,7 +743,8 @@ static const SCEV *getStartForNegStride(const SCEV *Start, const SCEV *BECount,
/// transform this into a memset or memset_pattern in the loop preheader, do so.
bool LoopIdiomRecognize::processLoopStridedStore(
Value *DestPtr, unsigned StoreSize, unsigned StoreAlignment,
- Value *StoredVal, Instruction *TheStore, const SCEVAddRecExpr *Ev,
+ Value *StoredVal, Instruction *TheStore,
+ SmallPtrSetImpl<Instruction *> &Stores, const SCEVAddRecExpr *Ev,
const SCEV *BECount, bool NegStride) {
Value *SplatValue = isBytewiseValue(StoredVal);
Constant *PatternValue = nullptr;
@@ -609,7 +779,7 @@ bool LoopIdiomRecognize::processLoopStridedStore(
Value *BasePtr =
Expander.expandCodeFor(Start, DestInt8PtrTy, Preheader->getTerminator());
if (mayLoopAccessLocation(BasePtr, MRI_ModRef, CurLoop, BECount, StoreSize,
- *AA, TheStore)) {
+ *AA, Stores)) {
Expander.clear();
// If we generated new code for the base pointer, clean up.
RecursivelyDeleteTriviallyDeadInstructions(BasePtr, TLI);
@@ -644,13 +814,14 @@ bool LoopIdiomRecognize::processLoopStridedStore(
Value *MSP =
M->getOrInsertFunction("memset_pattern16", Builder.getVoidTy(),
Int8PtrTy, Int8PtrTy, IntPtr, (void *)nullptr);
+ inferLibFuncAttributes(*M->getFunction("memset_pattern16"), *TLI);
// Otherwise we should form a memset_pattern16. PatternValue is known to be
// an constant array of 16-bytes. Plop the value into a mergable global.
GlobalVariable *GV = new GlobalVariable(*M, PatternValue->getType(), true,
GlobalValue::PrivateLinkage,
PatternValue, ".memset_pattern");
- GV->setUnnamedAddr(true); // Ok to merge these.
+ GV->setUnnamedAddr(GlobalValue::UnnamedAddr::Global); // Ok to merge these.
GV->setAlignment(16);
Value *PatternPtr = ConstantExpr::getBitCast(GV, Int8PtrTy);
NewCall = Builder.CreateCall(MSP, {BasePtr, PatternPtr, NumBytes});
@@ -662,7 +833,8 @@ bool LoopIdiomRecognize::processLoopStridedStore(
// Okay, the memset has been formed. Zap the original store and anything that
// feeds into it.
- deleteDeadInstruction(TheStore, TLI);
+ for (auto *I : Stores)
+ deleteDeadInstruction(I);
++NumMemSet;
return true;
}
@@ -676,7 +848,7 @@ bool LoopIdiomRecognize::processLoopStoreOfLoopLoad(StoreInst *SI,
Value *StorePtr = SI->getPointerOperand();
const SCEVAddRecExpr *StoreEv = cast<SCEVAddRecExpr>(SE->getSCEV(StorePtr));
- unsigned Stride = getStoreStride(StoreEv);
+ APInt Stride = getStoreStride(StoreEv);
unsigned StoreSize = getStoreSizeInBytes(SI, DL);
bool NegStride = StoreSize == -Stride;
@@ -714,8 +886,10 @@ bool LoopIdiomRecognize::processLoopStoreOfLoopLoad(StoreInst *SI,
Value *StoreBasePtr = Expander.expandCodeFor(
StrStart, Builder.getInt8PtrTy(StrAS), Preheader->getTerminator());
+ SmallPtrSet<Instruction *, 1> Stores;
+ Stores.insert(SI);
if (mayLoopAccessLocation(StoreBasePtr, MRI_ModRef, CurLoop, BECount,
- StoreSize, *AA, SI)) {
+ StoreSize, *AA, Stores)) {
Expander.clear();
// If we generated new code for the base pointer, clean up.
RecursivelyDeleteTriviallyDeadInstructions(StoreBasePtr, TLI);
@@ -735,7 +909,7 @@ bool LoopIdiomRecognize::processLoopStoreOfLoopLoad(StoreInst *SI,
LdStart, Builder.getInt8PtrTy(LdAS), Preheader->getTerminator());
if (mayLoopAccessLocation(LoadBasePtr, MRI_Mod, CurLoop, BECount, StoreSize,
- *AA, SI)) {
+ *AA, Stores)) {
Expander.clear();
// If we generated new code for the base pointer, clean up.
RecursivelyDeleteTriviallyDeadInstructions(LoadBasePtr, TLI);
@@ -769,7 +943,7 @@ bool LoopIdiomRecognize::processLoopStoreOfLoopLoad(StoreInst *SI,
// Okay, the memcpy has been formed. Zap the original store and anything that
// feeds into it.
- deleteDeadInstruction(SI, TLI);
+ deleteDeadInstruction(SI);
++NumMemCpy;
return true;
}
@@ -993,7 +1167,7 @@ bool LoopIdiomRecognize::recognizePopcount() {
}
static CallInst *createPopcntIntrinsic(IRBuilder<> &IRBuilder, Value *Val,
- DebugLoc DL) {
+ const DebugLoc &DL) {
Value *Ops[] = {Val};
Type *Tys[] = {Val->getType()};
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-19 21:46:26 +0000