#include "llvm/Analysis/LoopPass.h"
#include "llvm/Analysis/ScalarEvolutionExpander.h"
#include "llvm/Analysis/ScalarEvolutionExpressions.h"
+#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
-#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/Transforms/Utils/Local.h"
using namespace llvm;
namespace {
- class LoopIdiomRecognize;
+class LoopIdiomRecognize;
- /// This class defines some utility functions for loop idiom recognization.
- class LIRUtil {
- public:
- /// Return true iff the block contains nothing but an uncondition branch
- /// (aka goto instruction).
- static bool isAlmostEmpty(BasicBlock *);
+/// This class defines some utility functions for loop idiom recognization.
+class LIRUtil {
+public:
+ /// Return true iff the block contains nothing but an uncondition branch
+ /// (aka goto instruction).
+ static bool isAlmostEmpty(BasicBlock *);
- static BranchInst *getBranch(BasicBlock *BB) {
- return dyn_cast<BranchInst>(BB->getTerminator());
- }
+ static BranchInst *getBranch(BasicBlock *BB) {
+ return dyn_cast<BranchInst>(BB->getTerminator());
+ }
- /// Derive the precondition block (i.e the block that guards the loop
- /// preheader) from the given preheader.
- static BasicBlock *getPrecondBb(BasicBlock *PreHead);
- };
-
- /// This class is to recoginize idioms of population-count conducted in
- /// a noncountable loop. Currently it only recognizes this pattern:
- /// \code
- /// while(x) {cnt++; ...; x &= x - 1; ...}
- /// \endcode
- class NclPopcountRecognize {
- LoopIdiomRecognize &LIR;
- Loop *CurLoop;
- BasicBlock *PreCondBB;
-
- typedef IRBuilder<> IRBuilderTy;
-
- public:
- explicit NclPopcountRecognize(LoopIdiomRecognize &TheLIR);
- bool recognize();
-
- private:
- /// Take a glimpse of the loop to see if we need to go ahead recoginizing
- /// the idiom.
- bool preliminaryScreen();
-
- /// Check if the given conditional branch is based on the comparison
- /// between a variable and zero, and if the variable is non-zero, the
- /// control yields to the loop entry. If the branch matches the behavior,
- /// the variable involved in the comparion is returned. This function will
- /// be called to see if the precondition and postcondition of the loop
- /// are in desirable form.
- Value *matchCondition(BranchInst *Br, BasicBlock *NonZeroTarget) const;
-
- /// Return true iff the idiom is detected in the loop. and 1) \p CntInst
- /// is set to the instruction counting the population bit. 2) \p CntPhi
- /// is set to the corresponding phi node. 3) \p Var is set to the value
- /// whose population bits are being counted.
- bool detectIdiom
- (Instruction *&CntInst, PHINode *&CntPhi, Value *&Var) const;
-
- /// Insert ctpop intrinsic function and some obviously dead instructions.
- void transform(Instruction *CntInst, PHINode *CntPhi, Value *Var);
-
- /// Create llvm.ctpop.* intrinsic function.
- CallInst *createPopcntIntrinsic(IRBuilderTy &IRB, Value *Val, DebugLoc DL);
- };
-
- class LoopIdiomRecognize : public LoopPass {
- Loop *CurLoop;
- const DataLayout *DL;
- DominatorTree *DT;
- ScalarEvolution *SE;
- TargetLibraryInfo *TLI;
- const TargetTransformInfo *TTI;
- public:
- static char ID;
- explicit LoopIdiomRecognize() : LoopPass(ID) {
- initializeLoopIdiomRecognizePass(*PassRegistry::getPassRegistry());
- DL = nullptr; DT = nullptr; SE = nullptr; TLI = nullptr; TTI = nullptr;
- }
+ /// Derive the precondition block (i.e the block that guards the loop
+ /// preheader) from the given preheader.
+ static BasicBlock *getPrecondBb(BasicBlock *PreHead);
+};
+
+/// This class is to recoginize idioms of population-count conducted in
+/// a noncountable loop. Currently it only recognizes this pattern:
+/// \code
+/// while(x) {cnt++; ...; x &= x - 1; ...}
+/// \endcode
+class NclPopcountRecognize {
+ LoopIdiomRecognize &LIR;
+ Loop *CurLoop;
+ BasicBlock *PreCondBB;
+
+ typedef IRBuilder<> IRBuilderTy;
+
+public:
+ explicit NclPopcountRecognize(LoopIdiomRecognize &TheLIR);
+ bool recognize();
+
+private:
+ /// Take a glimpse of the loop to see if we need to go ahead recoginizing
+ /// the idiom.
+ bool preliminaryScreen();
+
+ /// Check if the given conditional branch is based on the comparison
+ /// between a variable and zero, and if the variable is non-zero, the
+ /// control yields to the loop entry. If the branch matches the behavior,
+ /// the variable involved in the comparion is returned. This function will
+ /// be called to see if the precondition and postcondition of the loop
+ /// are in desirable form.
+ Value *matchCondition(BranchInst *Br, BasicBlock *NonZeroTarget) const;
+
+ /// Return true iff the idiom is detected in the loop. and 1) \p CntInst
+ /// is set to the instruction counting the population bit. 2) \p CntPhi
+ /// is set to the corresponding phi node. 3) \p Var is set to the value
+ /// whose population bits are being counted.
+ bool detectIdiom(Instruction *&CntInst, PHINode *&CntPhi, Value *&Var) const;
+
+ /// Insert ctpop intrinsic function and some obviously dead instructions.
+ void transform(Instruction *CntInst, PHINode *CntPhi, Value *Var);
+
+ /// Create llvm.ctpop.* intrinsic function.
+ CallInst *createPopcntIntrinsic(IRBuilderTy &IRB, Value *Val, DebugLoc DL);
+};
+
+class LoopIdiomRecognize : public LoopPass {
+ Loop *CurLoop;
+ DominatorTree *DT;
+ ScalarEvolution *SE;
+ TargetLibraryInfo *TLI;
+ const TargetTransformInfo *TTI;
+
+public:
+ static char ID;
+ explicit LoopIdiomRecognize() : LoopPass(ID) {
+ initializeLoopIdiomRecognizePass(*PassRegistry::getPassRegistry());
+ DT = nullptr;
+ SE = nullptr;
+ TLI = nullptr;
+ TTI = nullptr;
+ }
- bool runOnLoop(Loop *L, LPPassManager &LPM) override;
- bool runOnLoopBlock(BasicBlock *BB, const SCEV *BECount,
- SmallVectorImpl<BasicBlock*> &ExitBlocks);
-
- bool processLoopStore(StoreInst *SI, const SCEV *BECount);
- bool processLoopMemSet(MemSetInst *MSI, const SCEV *BECount);
-
- bool processLoopStridedStore(Value *DestPtr, unsigned StoreSize,
- unsigned StoreAlignment,
- Value *SplatValue, Instruction *TheStore,
- const SCEVAddRecExpr *Ev,
- const SCEV *BECount);
- bool processLoopStoreOfLoopLoad(StoreInst *SI, unsigned StoreSize,
- const SCEVAddRecExpr *StoreEv,
- const SCEVAddRecExpr *LoadEv,
- const SCEV *BECount);
-
- /// This transformation requires natural loop information & requires that
- /// loop preheaders be inserted into the CFG.
- ///
- void getAnalysisUsage(AnalysisUsage &AU) const override {
- AU.addRequired<LoopInfo>();
- AU.addPreserved<LoopInfo>();
- AU.addRequiredID(LoopSimplifyID);
- AU.addPreservedID(LoopSimplifyID);
- AU.addRequiredID(LCSSAID);
- AU.addPreservedID(LCSSAID);
- AU.addRequired<AliasAnalysis>();
- AU.addPreserved<AliasAnalysis>();
- AU.addRequired<ScalarEvolution>();
- AU.addPreserved<ScalarEvolution>();
- AU.addPreserved<DominatorTreeWrapperPass>();
- AU.addRequired<DominatorTreeWrapperPass>();
- AU.addRequired<TargetLibraryInfoWrapperPass>();
- AU.addRequired<TargetTransformInfo>();
- }
+ bool runOnLoop(Loop *L, LPPassManager &LPM) override;
+ bool runOnLoopBlock(BasicBlock *BB, const SCEV *BECount,
+ SmallVectorImpl<BasicBlock *> &ExitBlocks);
+
+ bool processLoopStore(StoreInst *SI, const SCEV *BECount);
+ bool processLoopMemSet(MemSetInst *MSI, const SCEV *BECount);
+
+ bool processLoopStridedStore(Value *DestPtr, unsigned StoreSize,
+ unsigned StoreAlignment, Value *SplatValue,
+ Instruction *TheStore, const SCEVAddRecExpr *Ev,
+ const SCEV *BECount);
+ bool processLoopStoreOfLoopLoad(StoreInst *SI, unsigned StoreSize,
+ const SCEVAddRecExpr *StoreEv,
+ const SCEVAddRecExpr *LoadEv,
+ const SCEV *BECount);
+
+ /// 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<AliasAnalysis>();
+ AU.addPreserved<AliasAnalysis>();
+ AU.addRequired<ScalarEvolution>();
+ AU.addPreserved<ScalarEvolution>();
+ AU.addPreserved<DominatorTreeWrapperPass>();
+ AU.addRequired<DominatorTreeWrapperPass>();
+ AU.addRequired<TargetLibraryInfoWrapperPass>();
+ AU.addRequired<TargetTransformInfoWrapperPass>();
+ }
- const DataLayout *getDataLayout() {
- if (DL)
- return DL;
- DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>();
- DL = DLP ? &DLP->getDataLayout() : nullptr;
- return DL;
- }
+ DominatorTree *getDominatorTree() {
+ return DT ? DT
+ : (DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree());
+ }
- DominatorTree *getDominatorTree() {
- return DT ? DT
- : (DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree());
- }
+ ScalarEvolution *getScalarEvolution() {
+ return SE ? SE : (SE = &getAnalysis<ScalarEvolution>());
+ }
- ScalarEvolution *getScalarEvolution() {
- return SE ? SE : (SE = &getAnalysis<ScalarEvolution>());
- }
+ TargetLibraryInfo *getTargetLibraryInfo() {
+ if (!TLI)
+ TLI = &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
- TargetLibraryInfo *getTargetLibraryInfo() {
- if (!TLI)
- TLI = &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
+ return TLI;
+ }
- return TLI;
- }
+ const TargetTransformInfo *getTargetTransformInfo() {
+ return TTI ? TTI
+ : (TTI = &getAnalysis<TargetTransformInfoWrapperPass>().getTTI(
+ *CurLoop->getHeader()->getParent()));
+ }
- const TargetTransformInfo *getTargetTransformInfo() {
- return TTI ? TTI : (TTI = &getAnalysis<TargetTransformInfo>());
- }
+ Loop *getLoop() const { return CurLoop; }
- Loop *getLoop() const { return CurLoop; }
+private:
+ bool runOnNoncountableLoop();
+ bool runOnCountableLoop();
+};
- private:
- bool runOnNoncountableLoop();
- bool runOnCountableLoop();
- };
-}
+} // End anonymous namespace.
char LoopIdiomRecognize::ID = 0;
INITIALIZE_PASS_BEGIN(LoopIdiomRecognize, "loop-idiom", "Recognize loop idioms",
false, false)
-INITIALIZE_PASS_DEPENDENCY(LoopInfo)
+INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
INITIALIZE_PASS_DEPENDENCY(LoopSimplify)
INITIALIZE_PASS_DEPENDENCY(LCSSA)
INITIALIZE_PASS_DEPENDENCY(ScalarEvolution)
INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
-INITIALIZE_AG_DEPENDENCY(TargetTransformInfo)
+INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
INITIALIZE_PASS_END(LoopIdiomRecognize, "loop-idiom", "Recognize loop idioms",
false, false)
/// 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, ScalarEvolution &SE,
+static void deleteDeadInstruction(Instruction *I,
const TargetLibraryInfo *TLI) {
- SmallVector<Instruction*, 32> NowDeadInsts;
-
- NowDeadInsts.push_back(I);
-
- // Before we touch this instruction, remove it from SE!
- do {
- Instruction *DeadInst = NowDeadInsts.pop_back_val();
-
- // This instruction is dead, zap it, in stages. Start by removing it from
- // SCEV.
- SE.forgetValue(DeadInst);
-
- for (unsigned op = 0, e = DeadInst->getNumOperands(); op != e; ++op) {
- Value *Op = DeadInst->getOperand(op);
- DeadInst->setOperand(op, nullptr);
-
- // If this operand just became dead, add it to the NowDeadInsts list.
- if (!Op->use_empty()) continue;
-
- if (Instruction *OpI = dyn_cast<Instruction>(Op))
- if (isInstructionTriviallyDead(OpI, TLI))
- NowDeadInsts.push_back(OpI);
- }
-
- DeadInst->eraseFromParent();
-
- } while (!NowDeadInsts.empty());
-}
-
-/// deleteIfDeadInstruction - If the specified value is a dead instruction,
-/// delete it and any recursively used instructions.
-static void deleteIfDeadInstruction(Value *V, ScalarEvolution &SE,
- const TargetLibraryInfo *TLI) {
- if (Instruction *I = dyn_cast<Instruction>(V))
- if (isInstructionTriviallyDead(I, TLI))
- deleteDeadInstruction(I, SE, TLI);
+ SmallVector<Value *, 16> Operands(I->value_op_begin(), I->value_op_end());
+ I->replaceAllUsesWith(UndefValue::get(I->getType()));
+ I->eraseFromParent();
+ for (Value *Op : Operands)
+ RecursivelyDeleteTriviallyDeadInstructions(Op, TLI);
}
//===----------------------------------------------------------------------===//
// the concern of breaking data dependence.
bool LIRUtil::isAlmostEmpty(BasicBlock *BB) {
if (BranchInst *Br = getBranch(BB)) {
- return Br->isUnconditional() && BB->size() == 1;
+ return Br->isUnconditional() && Br == BB->begin();
}
return false;
}
//
//===----------------------------------------------------------------------===//
-NclPopcountRecognize::NclPopcountRecognize(LoopIdiomRecognize &TheLIR):
- LIR(TheLIR), CurLoop(TheLIR.getLoop()), PreCondBB(nullptr) {
-}
+NclPopcountRecognize::NclPopcountRecognize(LoopIdiomRecognize &TheLIR)
+ : LIR(TheLIR), CurLoop(TheLIR.getLoop()), PreCondBB(nullptr) {}
bool NclPopcountRecognize::preliminaryScreen() {
const TargetTransformInfo *TTI = LIR.getTargetTransformInfo();
return nullptr;
}
-bool NclPopcountRecognize::detectIdiom(Instruction *&CntInst,
- PHINode *&CntPhi,
+bool NclPopcountRecognize::detectIdiom(Instruction *&CntInst, PHINode *&CntPhi,
Value *&Var) const {
// Following code tries to detect this idiom:
//
// step 1: Check if the loop-back branch is in desirable form.
{
- if (Value *T = matchCondition (LIRUtil::getBranch(LoopEntry), LoopEntry))
+ if (Value *T = matchCondition(LIRUtil::getBranch(LoopEntry), LoopEntry))
DefX2 = dyn_cast<Instruction>(T);
else
return false;
ConstantInt *Dec = dyn_cast<ConstantInt>(SubInst->getOperand(1));
if (!Dec ||
!((SubInst->getOpcode() == Instruction::Sub && Dec->isOne()) ||
- (SubInst->getOpcode() == Instruction::Add && Dec->isAllOnesValue()))) {
+ (SubInst->getOpcode() == Instruction::Add &&
+ Dec->isAllOnesValue()))) {
return false;
}
}
{
CountInst = nullptr;
for (BasicBlock::iterator Iter = LoopEntry->getFirstNonPHI(),
- IterE = LoopEntry->end(); Iter != IterE; Iter++) {
+ IterE = LoopEntry->end();
+ Iter != IterE; Iter++) {
Instruction *Inst = Iter;
if (Inst->getOpcode() != Instruction::Add)
continue;
bool LiveOutLoop = false;
for (User *U : Inst->users()) {
if ((cast<Instruction>(U))->getParent() != LoopEntry) {
- LiveOutLoop = true; break;
+ LiveOutLoop = true;
+ break;
}
}
// "if (x != 0) goto loop-head ; else goto somewhere-we-don't-care;"
{
BranchInst *PreCondBr = LIRUtil::getBranch(PreCondBB);
- Value *T = matchCondition (PreCondBr, CurLoop->getLoopPreheader());
+ Value *T = matchCondition(PreCondBr, CurLoop->getLoopPreheader());
if (T != PhiX->getOperand(0) && T != PhiX->getOperand(1))
return false;
return true;
}
-void NclPopcountRecognize::transform(Instruction *CntInst,
- PHINode *CntPhi, Value *Var) {
+void NclPopcountRecognize::transform(Instruction *CntInst, PHINode *CntPhi,
+ Value *Var) {
ScalarEvolution *SE = LIR.getScalarEvolution();
TargetLibraryInfo *TLI = LIR.getTargetLibraryInfo();
{
PopCnt = createPopcntIntrinsic(Builder, Var, DL);
NewCount = PopCntZext =
- Builder.CreateZExtOrTrunc(PopCnt, cast<IntegerType>(CntPhi->getType()));
+ Builder.CreateZExtOrTrunc(PopCnt, cast<IntegerType>(CntPhi->getType()));
if (NewCount != PopCnt)
(cast<Instruction>(NewCount))->setDebugLoc(DL);
if (PreCond->getOperand(0) != Var)
std::swap(Opnd0, Opnd1);
- ICmpInst *NewPreCond =
- cast<ICmpInst>(Builder.CreateICmp(PreCond->getPredicate(), Opnd0, Opnd1));
- PreCond->replaceAllUsesWith(NewPreCond);
+ ICmpInst *NewPreCond = cast<ICmpInst>(
+ Builder.CreateICmp(PreCond->getPredicate(), Opnd0, Opnd1));
+ PreCondBr->setCondition(NewPreCond);
- deleteDeadInstruction(PreCond, *SE, TLI);
+ RecursivelyDeleteTriviallyDeadInstructions(PreCond, TLI);
}
// Step 3: Note that the population count is exactly the trip count of the
Builder.SetInsertPoint(LbCond);
Value *Opnd1 = cast<Value>(TcPhi);
Value *Opnd2 = cast<Value>(ConstantInt::get(Ty, 1));
- Instruction *TcDec =
- cast<Instruction>(Builder.CreateSub(Opnd1, Opnd2, "tcdec", false, true));
+ Instruction *TcDec = cast<Instruction>(
+ Builder.CreateSub(Opnd1, Opnd2, "tcdec", false, true));
TcPhi->addIncoming(TripCnt, PreHead);
TcPhi->addIncoming(TcDec, Body);
- CmpInst::Predicate Pred = (LbBr->getSuccessor(0) == Body) ?
- CmpInst::ICMP_UGT : CmpInst::ICMP_SLE;
+ CmpInst::Predicate Pred =
+ (LbBr->getSuccessor(0) == Body) ? CmpInst::ICMP_UGT : CmpInst::ICMP_SLE;
LbCond->setPredicate(Pred);
LbCond->setOperand(0, TcDec);
LbCond->setOperand(1, cast<Value>(ConstantInt::get(Ty, 0)));
// Step 4: All the references to the original population counter outside
// the loop are replaced with the NewCount -- the value returned from
// __builtin_ctpop().
- {
- SmallVector<Value *, 4> CntUses;
- for (User *U : CntInst->users())
- if (cast<Instruction>(U)->getParent() != Body)
- CntUses.push_back(U);
- for (unsigned Idx = 0; Idx < CntUses.size(); Idx++) {
- (cast<Instruction>(CntUses[Idx]))->replaceUsesOfWith(CntInst, NewCount);
- }
- }
+ CntInst->replaceUsesOutsideBlock(NewCount, Body);
// step 5: Forget the "non-computable" trip-count SCEV associated with the
// loop. The loop would otherwise not be deleted even if it becomes empty.
CallInst *NclPopcountRecognize::createPopcntIntrinsic(IRBuilderTy &IRBuilder,
Value *Val, DebugLoc DL) {
- Value *Ops[] = { Val };
- Type *Tys[] = { Val->getType() };
+ Value *Ops[] = {Val};
+ Type *Tys[] = {Val->getType()};
Module *M = (*(CurLoop->block_begin()))->getParent()->getParent();
Value *Func = Intrinsic::getDeclaration(M, Intrinsic::ctpop, Tys);
bool LoopIdiomRecognize::runOnCountableLoop() {
const SCEV *BECount = SE->getBackedgeTakenCount(CurLoop);
- if (isa<SCEVCouldNotCompute>(BECount)) return false;
+ assert(!isa<SCEVCouldNotCompute>(BECount) &&
+ "runOnCountableLoop() called on a loop without a predictable"
+ "backedge-taken count");
// If this loop executes exactly one time, then it should be peeled, not
// optimized by this pass.
if (BECst->getValue()->getValue() == 0)
return false;
- // We require target data for now.
- if (!getDataLayout())
- return false;
-
// set DT
(void)getDominatorTree();
- LoopInfo &LI = getAnalysis<LoopInfo>();
+ LoopInfo &LI = getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
TLI = &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
// set TLI
(void)getTargetLibraryInfo();
- SmallVector<BasicBlock*, 8> ExitBlocks;
+ SmallVector<BasicBlock *, 8> ExitBlocks;
CurLoop->getUniqueExitBlocks(ExitBlocks);
DEBUG(dbgs() << "loop-idiom Scanning: F["
- << CurLoop->getHeader()->getParent()->getName()
- << "] Loop %" << CurLoop->getHeader()->getName() << "\n");
+ << CurLoop->getHeader()->getParent()->getName() << "] Loop %"
+ << CurLoop->getHeader()->getName() << "\n");
bool MadeChange = false;
// Scan all the blocks in the loop that are not in subloops.
- for (Loop::block_iterator BI = CurLoop->block_begin(),
- E = CurLoop->block_end(); BI != E; ++BI) {
+ for (auto *BB : CurLoop->getBlocks()) {
// Ignore blocks in subloops.
- if (LI.getLoopFor(*BI) != CurLoop)
+ if (LI.getLoopFor(BB) != CurLoop)
continue;
- MadeChange |= runOnLoopBlock(*BI, BECount, ExitBlocks);
+ MadeChange |= runOnLoopBlock(BB, BECount, ExitBlocks);
}
return MadeChange;
}
/// runOnLoopBlock - Process the specified block, which lives in a counted loop
/// with the specified backedge count. This block is known to be in the current
/// loop and not in any subloops.
-bool LoopIdiomRecognize::runOnLoopBlock(BasicBlock *BB, const SCEV *BECount,
- SmallVectorImpl<BasicBlock*> &ExitBlocks) {
+bool LoopIdiomRecognize::runOnLoopBlock(
+ BasicBlock *BB, const SCEV *BECount,
+ SmallVectorImpl<BasicBlock *> &ExitBlocks) {
// We can only promote stores in this block if they are unconditionally
// executed in the loop. For a block to be unconditionally executed, it has
// to dominate all the exit blocks of the loop. Verify this now.
return false;
bool MadeChange = false;
- for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ) {
+ for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E;) {
Instruction *Inst = I++;
// Look for store instructions, which may be optimized to memset/memcpy.
- if (StoreInst *SI = dyn_cast<StoreInst>(Inst)) {
+ if (StoreInst *SI = dyn_cast<StoreInst>(Inst)) {
WeakVH InstPtr(I);
- if (!processLoopStore(SI, BECount)) continue;
+ if (!processLoopStore(SI, BECount))
+ continue;
MadeChange = true;
// If processing the store invalidated our iterator, start over from the
}
// Look for memset instructions, which may be optimized to a larger memset.
- if (MemSetInst *MSI = dyn_cast<MemSetInst>(Inst)) {
+ if (MemSetInst *MSI = dyn_cast<MemSetInst>(Inst)) {
WeakVH InstPtr(I);
- if (!processLoopMemSet(MSI, BECount)) continue;
+ if (!processLoopMemSet(MSI, BECount))
+ continue;
MadeChange = true;
// If processing the memset invalidated our iterator, start over from the
return MadeChange;
}
-
/// processLoopStore - See if this store can be promoted to a memset or memcpy.
bool LoopIdiomRecognize::processLoopStore(StoreInst *SI, const SCEV *BECount) {
- if (!SI->isSimple()) return false;
+ if (!SI->isSimple())
+ return false;
Value *StoredVal = SI->getValueOperand();
Value *StorePtr = SI->getPointerOperand();
// Reject stores that are so large that they overflow an unsigned.
- uint64_t SizeInBits = DL->getTypeSizeInBits(StoredVal->getType());
+ auto &DL = CurLoop->getHeader()->getModule()->getDataLayout();
+ uint64_t SizeInBits = DL.getTypeSizeInBits(StoredVal->getType());
if ((SizeInBits & 7) || (SizeInBits >> 32) != 0)
return false;
// loop, which indicates a strided store. If we have something else, it's a
// random store we can't handle.
const SCEVAddRecExpr *StoreEv =
- dyn_cast<SCEVAddRecExpr>(SE->getSCEV(StorePtr));
+ dyn_cast<SCEVAddRecExpr>(SE->getSCEV(StorePtr));
if (!StoreEv || StoreEv->getLoop() != CurLoop || !StoreEv->isAffine())
return false;
// for (i) A[i] = B[i];
if (LoadInst *LI = dyn_cast<LoadInst>(StoredVal)) {
const SCEVAddRecExpr *LoadEv =
- dyn_cast<SCEVAddRecExpr>(SE->getSCEV(LI->getOperand(0)));
+ dyn_cast<SCEVAddRecExpr>(SE->getSCEV(LI->getOperand(0)));
if (LoadEv && LoadEv->getLoop() == CurLoop && LoadEv->isAffine() &&
StoreEv->getOperand(1) == LoadEv->getOperand(1) && LI->isSimple())
if (processLoopStoreOfLoopLoad(SI, StoreSize, StoreEv, LoadEv, BECount))
return true;
}
- //errs() << "UNHANDLED strided store: " << *StoreEv << " - " << *SI << "\n";
+ // errs() << "UNHANDLED strided store: " << *StoreEv << " - " << *SI << "\n";
return false;
}
/// processLoopMemSet - See if this memset can be promoted to a large memset.
-bool LoopIdiomRecognize::
-processLoopMemSet(MemSetInst *MSI, const SCEV *BECount) {
+bool LoopIdiomRecognize::processLoopMemSet(MemSetInst *MSI,
+ const SCEV *BECount) {
// We can only handle non-volatile memsets with a constant size.
- if (MSI->isVolatile() || !isa<ConstantInt>(MSI->getLength())) return false;
+ if (MSI->isVolatile() || !isa<ConstantInt>(MSI->getLength()))
+ return false;
// If we're not allowed to hack on memset, we fail.
if (!TLI->has(LibFunc::memset))
return false;
return processLoopStridedStore(Pointer, (unsigned)SizeInBytes,
- MSI->getAlignment(), MSI->getValue(),
- MSI, Ev, BECount);
+ MSI->getAlignment(), MSI->getValue(), MSI, Ev,
+ BECount);
}
-
/// 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,AliasAnalysis::ModRefResult Access,
- Loop *L, const SCEV *BECount,
- unsigned StoreSize, AliasAnalysis &AA,
+static bool mayLoopAccessLocation(Value *Ptr, ModRefInfo Access, Loop *L,
+ const SCEV *BECount, unsigned StoreSize,
+ AliasAnalysis &AA,
Instruction *IgnoredStore) {
// 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.
- uint64_t AccessSize = AliasAnalysis::UnknownSize;
+ uint64_t AccessSize = MemoryLocation::UnknownSize;
// If the loop iterates a fixed number of times, we can refine the access size
// to be exactly the size of the memset, which is (BECount+1)*StoreSize
if (const SCEVConstant *BECst = dyn_cast<SCEVConstant>(BECount))
- AccessSize = (BECst->getValue()->getZExtValue()+1)*StoreSize;
+ AccessSize = (BECst->getValue()->getZExtValue() + 1) * StoreSize;
// TODO: For this to be really effective, we have to dive into the pointer
// operand in the store. Store to &A[i] of 100 will always return may alias
// with store of &A[100], we need to StoreLoc to be "A" with size of 100,
// which will then no-alias a store to &A[100].
- AliasAnalysis::Location StoreLoc(Ptr, AccessSize);
+ MemoryLocation StoreLoc(Ptr, AccessSize);
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))
+ if (&*I != IgnoredStore && (AA.getModRefInfo(I, StoreLoc) & Access))
return true;
return false;
// array. We could theoretically do a store to an alloca or something, but
// that doesn't seem worthwhile.
Constant *C = dyn_cast<Constant>(V);
- if (!C) return nullptr;
+ if (!C)
+ return nullptr;
// Only handle simple values that are a power of two bytes in size.
uint64_t Size = DL.getTypeSizeInBits(V->getType());
- if (Size == 0 || (Size & 7) || (Size & (Size-1)))
+ if (Size == 0 || (Size & 7) || (Size & (Size - 1)))
return nullptr;
// Don't care enough about darwin/ppc to implement this.
// TODO: If CI is larger than 16-bytes, we can try slicing it in half to see
// if the top and bottom are the same (e.g. for vectors and large integers).
- if (Size > 16) return nullptr;
+ if (Size > 16)
+ return nullptr;
// If the constant is exactly 16 bytes, just use it.
- if (Size == 16) return C;
+ if (Size == 16)
+ return C;
// Otherwise, we'll use an array of the constants.
- unsigned ArraySize = 16/Size;
+ unsigned ArraySize = 16 / Size;
ArrayType *AT = ArrayType::get(V->getType(), ArraySize);
- return ConstantArray::get(AT, std::vector<Constant*>(ArraySize, C));
+ return ConstantArray::get(AT, std::vector<Constant *>(ArraySize, C));
}
-
/// processLoopStridedStore - We see a strided store of some value. If we can
/// 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,
- const SCEV *BECount) {
+bool LoopIdiomRecognize::processLoopStridedStore(
+ Value *DestPtr, unsigned StoreSize, unsigned StoreAlignment,
+ Value *StoredVal, Instruction *TheStore, const SCEVAddRecExpr *Ev,
+ const SCEV *BECount) {
// If the stored value is a byte-wise value (like i32 -1), then it may be
// turned into a memset of i8 -1, assuming that all the consecutive bytes
// but it can be turned into memset_pattern if the target supports it.
Value *SplatValue = isBytewiseValue(StoredVal);
Constant *PatternValue = nullptr;
-
+ auto &DL = CurLoop->getHeader()->getModule()->getDataLayout();
unsigned DestAS = DestPtr->getType()->getPointerAddressSpace();
// If we're allowed to form a memset, and the stored value would be acceptable
CurLoop->isLoopInvariant(SplatValue)) {
// Keep and use SplatValue.
PatternValue = nullptr;
- } else if (DestAS == 0 &&
- TLI->has(LibFunc::memset_pattern16) &&
- (PatternValue = getMemSetPatternValue(StoredVal, *DL))) {
+ } else if (DestAS == 0 && TLI->has(LibFunc::memset_pattern16) &&
+ (PatternValue = getMemSetPatternValue(StoredVal, DL))) {
// Don't create memset_pattern16s with address spaces.
// It looks like we can use PatternValue!
SplatValue = nullptr;
// header. This allows us to insert code for it in the preheader.
BasicBlock *Preheader = CurLoop->getLoopPreheader();
IRBuilder<> Builder(Preheader->getTerminator());
- SCEVExpander Expander(*SE, "loop-idiom");
+ SCEVExpander Expander(*SE, DL, "loop-idiom");
Type *DestInt8PtrTy = Builder.getInt8PtrTy(DestAS);
// would be unsafe to do if there is anything else in the loop that may read
// or write to the aliased location. Check for any overlap by generating the
// base pointer and checking the region.
- Value *BasePtr =
- Expander.expandCodeFor(Ev->getStart(), DestInt8PtrTy,
- Preheader->getTerminator());
+ Value *BasePtr = Expander.expandCodeFor(Ev->getStart(), DestInt8PtrTy,
+ Preheader->getTerminator());
- if (mayLoopAccessLocation(BasePtr, AliasAnalysis::ModRef,
- CurLoop, BECount,
- StoreSize, getAnalysis<AliasAnalysis>(), TheStore)) {
+ if (mayLoopAccessLocation(BasePtr, MRI_ModRef, CurLoop, BECount, StoreSize,
+ getAnalysis<AliasAnalysis>(), TheStore)) {
Expander.clear();
// If we generated new code for the base pointer, clean up.
- deleteIfDeadInstruction(BasePtr, *SE, TLI);
+ RecursivelyDeleteTriviallyDeadInstructions(BasePtr, TLI);
return false;
}
Type *IntPtr = Builder.getIntPtrTy(DL, DestAS);
BECount = SE->getTruncateOrZeroExtend(BECount, IntPtr);
- const SCEV *NumBytesS = SE->getAddExpr(BECount, SE->getConstant(IntPtr, 1),
- SCEV::FlagNUW);
+ const SCEV *NumBytesS =
+ SE->getAddExpr(BECount, SE->getConstant(IntPtr, 1), SCEV::FlagNUW);
if (StoreSize != 1) {
NumBytesS = SE->getMulExpr(NumBytesS, SE->getConstant(IntPtr, StoreSize),
SCEV::FlagNUW);
}
Value *NumBytes =
- Expander.expandCodeFor(NumBytesS, IntPtr, Preheader->getTerminator());
+ Expander.expandCodeFor(NumBytesS, IntPtr, Preheader->getTerminator());
CallInst *NewCall;
if (SplatValue) {
- NewCall = Builder.CreateMemSet(BasePtr,
- SplatValue,
- NumBytes,
- StoreAlignment);
+ NewCall =
+ Builder.CreateMemSet(BasePtr, SplatValue, NumBytes, StoreAlignment);
} else {
// Everything is emitted in default address space
Type *Int8PtrTy = DestInt8PtrTy;
Module *M = TheStore->getParent()->getParent()->getParent();
- Value *MSP = M->getOrInsertFunction("memset_pattern16",
- Builder.getVoidTy(),
- Int8PtrTy,
- Int8PtrTy,
- IntPtr,
- (void*)nullptr);
+ Value *MSP =
+ M->getOrInsertFunction("memset_pattern16", Builder.getVoidTy(),
+ Int8PtrTy, Int8PtrTy, IntPtr, (void *)nullptr);
// 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::InternalLinkage,
+ GlobalValue::PrivateLinkage,
PatternValue, ".memset_pattern");
GV->setUnnamedAddr(true); // Ok to merge these.
GV->setAlignment(16);
Value *PatternPtr = ConstantExpr::getBitCast(GV, Int8PtrTy);
- NewCall = Builder.CreateCall3(MSP, BasePtr, PatternPtr, NumBytes);
+ NewCall = Builder.CreateCall(MSP, {BasePtr, PatternPtr, NumBytes});
}
DEBUG(dbgs() << " Formed memset: " << *NewCall << "\n"
// Okay, the memset has been formed. Zap the original store and anything that
// feeds into it.
- deleteDeadInstruction(TheStore, *SE, TLI);
+ deleteDeadInstruction(TheStore, TLI);
++NumMemSet;
return true;
}
/// processLoopStoreOfLoopLoad - We see a strided store whose value is a
/// same-strided load.
-bool LoopIdiomRecognize::
-processLoopStoreOfLoopLoad(StoreInst *SI, unsigned StoreSize,
- const SCEVAddRecExpr *StoreEv,
- const SCEVAddRecExpr *LoadEv,
- const SCEV *BECount) {
+bool LoopIdiomRecognize::processLoopStoreOfLoopLoad(
+ StoreInst *SI, unsigned StoreSize, const SCEVAddRecExpr *StoreEv,
+ const SCEVAddRecExpr *LoadEv, const SCEV *BECount) {
// If we're not allowed to form memcpy, we fail.
if (!TLI->has(LibFunc::memcpy))
return false;
// header. This allows us to insert code for it in the preheader.
BasicBlock *Preheader = CurLoop->getLoopPreheader();
IRBuilder<> Builder(Preheader->getTerminator());
- SCEVExpander Expander(*SE, "loop-idiom");
+ const DataLayout &DL = Preheader->getModule()->getDataLayout();
+ SCEVExpander Expander(*SE, DL, "loop-idiom");
// Okay, we have a strided store "p[i]" of a loaded value. We can turn
// this into a memcpy in the loop preheader now if we want. However, this
// or write the memory region we're storing to. This includes the load that
// feeds the stores. Check for an alias by generating the base address and
// checking everything.
- Value *StoreBasePtr =
- Expander.expandCodeFor(StoreEv->getStart(),
- Builder.getInt8PtrTy(SI->getPointerAddressSpace()),
- Preheader->getTerminator());
+ Value *StoreBasePtr = Expander.expandCodeFor(
+ StoreEv->getStart(), Builder.getInt8PtrTy(SI->getPointerAddressSpace()),
+ Preheader->getTerminator());
- if (mayLoopAccessLocation(StoreBasePtr, AliasAnalysis::ModRef,
- CurLoop, BECount, StoreSize,
- getAnalysis<AliasAnalysis>(), SI)) {
+ if (mayLoopAccessLocation(StoreBasePtr, MRI_ModRef, CurLoop, BECount,
+ StoreSize, getAnalysis<AliasAnalysis>(), SI)) {
Expander.clear();
// If we generated new code for the base pointer, clean up.
- deleteIfDeadInstruction(StoreBasePtr, *SE, TLI);
+ RecursivelyDeleteTriviallyDeadInstructions(StoreBasePtr, TLI);
return false;
}
// For a memcpy, we have to make sure that the input array is not being
// mutated by the loop.
- Value *LoadBasePtr =
- Expander.expandCodeFor(LoadEv->getStart(),
- Builder.getInt8PtrTy(LI->getPointerAddressSpace()),
- Preheader->getTerminator());
+ Value *LoadBasePtr = Expander.expandCodeFor(
+ LoadEv->getStart(), Builder.getInt8PtrTy(LI->getPointerAddressSpace()),
+ Preheader->getTerminator());
- if (mayLoopAccessLocation(LoadBasePtr, AliasAnalysis::Mod, CurLoop, BECount,
- StoreSize, getAnalysis<AliasAnalysis>(), SI)) {
+ if (mayLoopAccessLocation(LoadBasePtr, MRI_Mod, CurLoop, BECount, StoreSize,
+ getAnalysis<AliasAnalysis>(), SI)) {
Expander.clear();
// If we generated new code for the base pointer, clean up.
- deleteIfDeadInstruction(LoadBasePtr, *SE, TLI);
- deleteIfDeadInstruction(StoreBasePtr, *SE, TLI);
+ RecursivelyDeleteTriviallyDeadInstructions(LoadBasePtr, TLI);
+ RecursivelyDeleteTriviallyDeadInstructions(StoreBasePtr, TLI);
return false;
}
// Okay, everything is safe, we can transform this!
-
// The # stored bytes is (BECount+1)*Size. Expand the trip count out to
// pointer size if it isn't already.
Type *IntPtrTy = Builder.getIntPtrTy(DL, SI->getPointerAddressSpace());
BECount = SE->getTruncateOrZeroExtend(BECount, IntPtrTy);
- const SCEV *NumBytesS = SE->getAddExpr(BECount, SE->getConstant(IntPtrTy, 1),
- SCEV::FlagNUW);
+ const SCEV *NumBytesS =
+ SE->getAddExpr(BECount, SE->getConstant(IntPtrTy, 1), SCEV::FlagNUW);
if (StoreSize != 1)
NumBytesS = SE->getMulExpr(NumBytesS, SE->getConstant(IntPtrTy, StoreSize),
SCEV::FlagNUW);
Value *NumBytes =
- Expander.expandCodeFor(NumBytesS, IntPtrTy, Preheader->getTerminator());
+ Expander.expandCodeFor(NumBytesS, IntPtrTy, Preheader->getTerminator());
CallInst *NewCall =
- Builder.CreateMemCpy(StoreBasePtr, LoadBasePtr, NumBytes,
- std::min(SI->getAlignment(), LI->getAlignment()));
+ Builder.CreateMemCpy(StoreBasePtr, LoadBasePtr, NumBytes,
+ std::min(SI->getAlignment(), LI->getAlignment()));
NewCall->setDebugLoc(SI->getDebugLoc());
DEBUG(dbgs() << " Formed memcpy: " << *NewCall << "\n"
<< " from load ptr=" << *LoadEv << " at: " << *LI << "\n"
<< " from store ptr=" << *StoreEv << " at: " << *SI << "\n");
-
// Okay, the memset has been formed. Zap the original store and anything that
// feeds into it.
- deleteDeadInstruction(SI, *SE, TLI);
+ deleteDeadInstruction(SI, TLI);
++NumMemCpy;
return true;
}