#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/InstructionSimplify.h"
+#include "llvm/Analysis/TargetLibraryInfo.h"
+#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/IR/CallSite.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/InlineAsm.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/MDBuilder.h"
#include "llvm/IR/PatternMatch.h"
+#include "llvm/IR/Statepoint.h"
#include "llvm/IR/ValueHandle.h"
#include "llvm/IR/ValueMap.h"
#include "llvm/Pass.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
-#include "llvm/Target/TargetLibraryInfo.h"
#include "llvm/Target/TargetLowering.h"
#include "llvm/Target/TargetSubtargetInfo.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/BuildLibCalls.h"
#include "llvm/Transforms/Utils/BypassSlowDivision.h"
#include "llvm/Transforms/Utils/Local.h"
+#include "llvm/Transforms/Utils/SimplifyLibCalls.h"
using namespace llvm;
using namespace llvm::PatternMatch;
STATISTIC(NumDbgValueMoved, "Number of debug value instructions moved");
STATISTIC(NumSelectsExpanded, "Number of selects turned into branches");
STATISTIC(NumAndCmpsMoved, "Number of and/cmp's pushed into branches");
+STATISTIC(NumStoreExtractExposed, "Number of store(extractelement) exposed");
static cl::opt<bool> DisableBranchOpts(
"disable-cgp-branch-opts", cl::Hidden, cl::init(false),
cl::desc("Disable branch optimizations in CodeGenPrepare"));
+static cl::opt<bool>
+ DisableGCOpts("disable-cgp-gc-opts", cl::Hidden, cl::init(false),
+ cl::desc("Disable GC optimizations in CodeGenPrepare"));
+
static cl::opt<bool> DisableSelectToBranch(
"disable-cgp-select2branch", cl::Hidden, cl::init(false),
cl::desc("Disable select to branch conversion."));
"enable-andcmp-sinking", cl::Hidden, cl::init(true),
cl::desc("Enable sinkinig and/cmp into branches."));
+static cl::opt<bool> DisableStoreExtract(
+ "disable-cgp-store-extract", cl::Hidden, cl::init(false),
+ cl::desc("Disable store(extract) optimizations in CodeGenPrepare"));
+
+static cl::opt<bool> StressStoreExtract(
+ "stress-cgp-store-extract", cl::Hidden, cl::init(false),
+ cl::desc("Stress test store(extract) optimizations in CodeGenPrepare"));
+
+static cl::opt<bool> DisableExtLdPromotion(
+ "disable-cgp-ext-ld-promotion", cl::Hidden, cl::init(false),
+ cl::desc("Disable ext(promotable(ld)) -> promoted(ext(ld)) optimization in "
+ "CodeGenPrepare"));
+
+static cl::opt<bool> StressExtLdPromotion(
+ "stress-cgp-ext-ld-promotion", cl::Hidden, cl::init(false),
+ cl::desc("Stress test ext(promotable(ld)) -> promoted(ext(ld)) "
+ "optimization in CodeGenPrepare"));
+
namespace {
typedef SmallPtrSet<Instruction *, 16> SetOfInstrs;
-typedef DenseMap<Instruction *, Type *> InstrToOrigTy;
+struct TypeIsSExt {
+ Type *Ty;
+ bool IsSExt;
+ TypeIsSExt(Type *Ty, bool IsSExt) : Ty(Ty), IsSExt(IsSExt) {}
+};
+typedef DenseMap<Instruction *, TypeIsSExt> InstrToOrigTy;
+class TypePromotionTransaction;
class CodeGenPrepare : public FunctionPass {
/// TLI - Keep a pointer of a TargetLowering to consult for determining
/// transformation profitability.
const TargetMachine *TM;
const TargetLowering *TLI;
+ const TargetTransformInfo *TTI;
const TargetLibraryInfo *TLInfo;
- DominatorTree *DT;
/// CurInstIterator - As we scan instructions optimizing them, this is the
/// next instruction to optimize. Xforms that can invalidate this should
/// promotion for the current function.
InstrToOrigTy PromotedInsts;
- /// ModifiedDT - If CFG is modified in anyway, dominator tree may need to
- /// be updated.
+ /// ModifiedDT - If CFG is modified in anyway.
bool ModifiedDT;
/// OptSize - True if optimizing for size.
public:
static char ID; // Pass identification, replacement for typeid
explicit CodeGenPrepare(const TargetMachine *TM = nullptr)
- : FunctionPass(ID), TM(TM), TLI(nullptr) {
+ : FunctionPass(ID), TM(TM), TLI(nullptr), TTI(nullptr) {
initializeCodeGenPreparePass(*PassRegistry::getPassRegistry());
}
bool runOnFunction(Function &F) override;
void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.addPreserved<DominatorTreeWrapperPass>();
- AU.addRequired<TargetLibraryInfo>();
+ AU.addRequired<TargetLibraryInfoWrapperPass>();
+ AU.addRequired<TargetTransformInfoWrapperPass>();
}
private:
bool EliminateMostlyEmptyBlocks(Function &F);
bool CanMergeBlocks(const BasicBlock *BB, const BasicBlock *DestBB) const;
void EliminateMostlyEmptyBlock(BasicBlock *BB);
- bool OptimizeBlock(BasicBlock &BB);
- bool OptimizeInst(Instruction *I);
+ bool OptimizeBlock(BasicBlock &BB, bool& ModifiedDT);
+ bool OptimizeInst(Instruction *I, bool& ModifiedDT);
bool OptimizeMemoryInst(Instruction *I, Value *Addr, Type *AccessTy);
bool OptimizeInlineAsmInst(CallInst *CS);
- bool OptimizeCallInst(CallInst *CI);
- bool MoveExtToFormExtLoad(Instruction *I);
+ bool OptimizeCallInst(CallInst *CI, bool& ModifiedDT);
+ bool MoveExtToFormExtLoad(Instruction *&I);
bool OptimizeExtUses(Instruction *I);
bool OptimizeSelectInst(SelectInst *SI);
bool OptimizeShuffleVectorInst(ShuffleVectorInst *SI);
+ bool OptimizeExtractElementInst(Instruction *Inst);
bool DupRetToEnableTailCallOpts(BasicBlock *BB);
bool PlaceDbgValues(Function &F);
bool sinkAndCmp(Function &F);
+ bool ExtLdPromotion(TypePromotionTransaction &TPT, LoadInst *&LI,
+ Instruction *&Inst,
+ const SmallVectorImpl<Instruction *> &Exts,
+ unsigned CreatedInstCost);
+ bool splitBranchCondition(Function &F);
+ bool simplifyOffsetableRelocate(Instruction &I);
};
}
PromotedInsts.clear();
ModifiedDT = false;
- if (TM) TLI = TM->getTargetLowering();
- TLInfo = &getAnalysis<TargetLibraryInfo>();
- DominatorTreeWrapperPass *DTWP =
- getAnalysisIfAvailable<DominatorTreeWrapperPass>();
- DT = DTWP ? &DTWP->getDomTree() : nullptr;
- OptSize = F.getAttributes().hasAttribute(AttributeSet::FunctionIndex,
- Attribute::OptimizeForSize);
+ if (TM)
+ TLI = TM->getSubtargetImpl(F)->getTargetLowering();
+ TLInfo = &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
+ TTI = &getAnalysis<TargetTransformInfoWrapperPass>().getTTI(F);
+ OptSize = F.hasFnAttribute(Attribute::OptimizeForSize);
/// This optimization identifies DIV instructions that can be
/// profitably bypassed and carried out with a shorter, faster divide.
// into a single target instruction, push the mask and compare into branch
// users. Do this before OptimizeBlock -> OptimizeInst ->
// OptimizeCmpExpression, which perturbs the pattern being searched for.
- if (!DisableBranchOpts)
+ if (!DisableBranchOpts) {
EverMadeChange |= sinkAndCmp(F);
+ EverMadeChange |= splitBranchCondition(F);
+ }
bool MadeChange = true;
while (MadeChange) {
MadeChange = false;
for (Function::iterator I = F.begin(); I != F.end(); ) {
BasicBlock *BB = I++;
- MadeChange |= OptimizeBlock(*BB);
+ bool ModifiedDTOnIteration = false;
+ MadeChange |= OptimizeBlock(*BB, ModifiedDTOnIteration);
+
+ // Restart BB iteration if the dominator tree of the Function was changed
+ if (ModifiedDTOnIteration)
+ break;
}
EverMadeChange |= MadeChange;
}
if (!DisableBranchOpts) {
MadeChange = false;
SmallPtrSet<BasicBlock*, 8> WorkList;
- for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
- SmallVector<BasicBlock*, 2> Successors(succ_begin(BB), succ_end(BB));
- MadeChange |= ConstantFoldTerminator(BB, true);
+ for (BasicBlock &BB : F) {
+ SmallVector<BasicBlock *, 2> Successors(succ_begin(&BB), succ_end(&BB));
+ MadeChange |= ConstantFoldTerminator(&BB, true);
if (!MadeChange) continue;
for (SmallVectorImpl<BasicBlock*>::iterator
if (EverMadeChange || MadeChange)
MadeChange |= EliminateFallThrough(F);
- if (MadeChange)
- ModifiedDT = true;
EverMadeChange |= MadeChange;
}
- if (ModifiedDT && DT)
- DT->recalculate(F);
+ if (!DisableGCOpts) {
+ SmallVector<Instruction *, 2> Statepoints;
+ for (BasicBlock &BB : F)
+ for (Instruction &I : BB)
+ if (isStatepoint(I))
+ Statepoints.push_back(&I);
+ for (auto &I : Statepoints)
+ EverMadeChange |= simplifyOffsetableRelocate(*I);
+ }
return EverMadeChange;
}
// Remember if SinglePred was the entry block of the function.
// If so, we will need to move BB back to the entry position.
bool isEntry = SinglePred == &SinglePred->getParent()->getEntryBlock();
- MergeBasicBlockIntoOnlyPred(BB, this);
+ MergeBasicBlockIntoOnlyPred(BB, nullptr);
if (isEntry && BB != &BB->getParent()->getEntryBlock())
BB->moveBefore(&BB->getParent()->getEntryBlock());
// Remember if SinglePred was the entry block of the function. If so, we
// will need to move BB back to the entry position.
bool isEntry = SinglePred == &SinglePred->getParent()->getEntryBlock();
- MergeBasicBlockIntoOnlyPred(DestBB, this);
+ MergeBasicBlockIntoOnlyPred(DestBB, nullptr);
if (isEntry && BB != &BB->getParent()->getEntryBlock())
BB->moveBefore(&BB->getParent()->getEntryBlock());
// The PHIs are now updated, change everything that refers to BB to use
// DestBB and remove BB.
BB->replaceAllUsesWith(DestBB);
- if (DT && !ModifiedDT) {
- BasicBlock *BBIDom = DT->getNode(BB)->getIDom()->getBlock();
- BasicBlock *DestBBIDom = DT->getNode(DestBB)->getIDom()->getBlock();
- BasicBlock *NewIDom = DT->findNearestCommonDominator(BBIDom, DestBBIDom);
- DT->changeImmediateDominator(DestBB, NewIDom);
- DT->eraseNode(BB);
- }
BB->eraseFromParent();
++NumBlocksElim;
DEBUG(dbgs() << "AFTER:\n" << *DestBB << "\n\n\n");
}
+// Computes a map of base pointer relocation instructions to corresponding
+// derived pointer relocation instructions given a vector of all relocate calls
+static void computeBaseDerivedRelocateMap(
+ const SmallVectorImpl<User *> &AllRelocateCalls,
+ DenseMap<IntrinsicInst *, SmallVector<IntrinsicInst *, 2>> &
+ RelocateInstMap) {
+ // Collect information in two maps: one primarily for locating the base object
+ // while filling the second map; the second map is the final structure holding
+ // a mapping between Base and corresponding Derived relocate calls
+ DenseMap<std::pair<unsigned, unsigned>, IntrinsicInst *> RelocateIdxMap;
+ for (auto &U : AllRelocateCalls) {
+ GCRelocateOperands ThisRelocate(U);
+ IntrinsicInst *I = cast<IntrinsicInst>(U);
+ auto K = std::make_pair(ThisRelocate.basePtrIndex(),
+ ThisRelocate.derivedPtrIndex());
+ RelocateIdxMap.insert(std::make_pair(K, I));
+ }
+ for (auto &Item : RelocateIdxMap) {
+ std::pair<unsigned, unsigned> Key = Item.first;
+ if (Key.first == Key.second)
+ // Base relocation: nothing to insert
+ continue;
+
+ IntrinsicInst *I = Item.second;
+ auto BaseKey = std::make_pair(Key.first, Key.first);
+
+ // We're iterating over RelocateIdxMap so we cannot modify it.
+ auto MaybeBase = RelocateIdxMap.find(BaseKey);
+ if (MaybeBase == RelocateIdxMap.end())
+ // TODO: We might want to insert a new base object relocate and gep off
+ // that, if there are enough derived object relocates.
+ continue;
+
+ RelocateInstMap[MaybeBase->second].push_back(I);
+ }
+}
+
+// Accepts a GEP and extracts the operands into a vector provided they're all
+// small integer constants
+static bool getGEPSmallConstantIntOffsetV(GetElementPtrInst *GEP,
+ SmallVectorImpl<Value *> &OffsetV) {
+ for (unsigned i = 1; i < GEP->getNumOperands(); i++) {
+ // Only accept small constant integer operands
+ auto Op = dyn_cast<ConstantInt>(GEP->getOperand(i));
+ if (!Op || Op->getZExtValue() > 20)
+ return false;
+ }
+
+ for (unsigned i = 1; i < GEP->getNumOperands(); i++)
+ OffsetV.push_back(GEP->getOperand(i));
+ return true;
+}
+
+// Takes a RelocatedBase (base pointer relocation instruction) and Targets to
+// replace, computes a replacement, and affects it.
+static bool
+simplifyRelocatesOffABase(IntrinsicInst *RelocatedBase,
+ const SmallVectorImpl<IntrinsicInst *> &Targets) {
+ bool MadeChange = false;
+ for (auto &ToReplace : Targets) {
+ GCRelocateOperands MasterRelocate(RelocatedBase);
+ GCRelocateOperands ThisRelocate(ToReplace);
+
+ assert(ThisRelocate.basePtrIndex() == MasterRelocate.basePtrIndex() &&
+ "Not relocating a derived object of the original base object");
+ if (ThisRelocate.basePtrIndex() == ThisRelocate.derivedPtrIndex()) {
+ // A duplicate relocate call. TODO: coalesce duplicates.
+ continue;
+ }
+
+ Value *Base = ThisRelocate.basePtr();
+ auto Derived = dyn_cast<GetElementPtrInst>(ThisRelocate.derivedPtr());
+ if (!Derived || Derived->getPointerOperand() != Base)
+ continue;
+
+ SmallVector<Value *, 2> OffsetV;
+ if (!getGEPSmallConstantIntOffsetV(Derived, OffsetV))
+ continue;
+
+ // Create a Builder and replace the target callsite with a gep
+ IRBuilder<> Builder(ToReplace);
+ Builder.SetCurrentDebugLocation(ToReplace->getDebugLoc());
+ Value *Replacement = Builder.CreateGEP(
+ Derived->getSourceElementType(), RelocatedBase, makeArrayRef(OffsetV));
+ Instruction *ReplacementInst = cast<Instruction>(Replacement);
+ ReplacementInst->removeFromParent();
+ ReplacementInst->insertAfter(RelocatedBase);
+ Replacement->takeName(ToReplace);
+ ToReplace->replaceAllUsesWith(Replacement);
+ ToReplace->eraseFromParent();
+
+ MadeChange = true;
+ }
+ return MadeChange;
+}
+
+// Turns this:
+//
+// %base = ...
+// %ptr = gep %base + 15
+// %tok = statepoint (%fun, i32 0, i32 0, i32 0, %base, %ptr)
+// %base' = relocate(%tok, i32 4, i32 4)
+// %ptr' = relocate(%tok, i32 4, i32 5)
+// %val = load %ptr'
+//
+// into this:
+//
+// %base = ...
+// %ptr = gep %base + 15
+// %tok = statepoint (%fun, i32 0, i32 0, i32 0, %base, %ptr)
+// %base' = gc.relocate(%tok, i32 4, i32 4)
+// %ptr' = gep %base' + 15
+// %val = load %ptr'
+bool CodeGenPrepare::simplifyOffsetableRelocate(Instruction &I) {
+ bool MadeChange = false;
+ SmallVector<User *, 2> AllRelocateCalls;
+
+ for (auto *U : I.users())
+ if (isGCRelocate(dyn_cast<Instruction>(U)))
+ // Collect all the relocate calls associated with a statepoint
+ AllRelocateCalls.push_back(U);
+
+ // We need atleast one base pointer relocation + one derived pointer
+ // relocation to mangle
+ if (AllRelocateCalls.size() < 2)
+ return false;
+
+ // RelocateInstMap is a mapping from the base relocate instruction to the
+ // corresponding derived relocate instructions
+ DenseMap<IntrinsicInst *, SmallVector<IntrinsicInst *, 2>> RelocateInstMap;
+ computeBaseDerivedRelocateMap(AllRelocateCalls, RelocateInstMap);
+ if (RelocateInstMap.empty())
+ return false;
+
+ for (auto &Item : RelocateInstMap)
+ // Item.first is the RelocatedBase to offset against
+ // Item.second is the vector of Targets to replace
+ MadeChange = simplifyRelocatesOffABase(Item.first, Item.second);
+ return MadeChange;
+}
+
/// SinkCast - Sink the specified cast instruction into its user blocks
static bool SinkCast(CastInst *CI) {
BasicBlock *DefBB = CI->getParent();
if (!ISDOpcode)
continue;
- // If the use is actually a legal node, there will not be an implicit
- // truncate.
- if (TLI.isOperationLegalOrCustom(ISDOpcode,
- EVT::getEVT(TruncUser->getType())))
+ // If the use is actually a legal node, there will not be an
+ // implicit truncate.
+ // FIXME: always querying the result type is just an
+ // approximation; some nodes' legality is determined by the
+ // operand or other means. There's no good way to find out though.
+ if (TLI.isOperationLegalOrCustom(
+ ISDOpcode, TLI.getValueType(TruncUser->getType(), true)))
continue;
// Don't bother for PHI nodes.
return MadeChange;
}
-namespace {
-class CodeGenPrepareFortifiedLibCalls : public SimplifyFortifiedLibCalls {
-protected:
- void replaceCall(Value *With) override {
- CI->replaceAllUsesWith(With);
- CI->eraseFromParent();
+// ScalarizeMaskedLoad() translates masked load intrinsic, like
+// <16 x i32 > @llvm.masked.load( <16 x i32>* %addr, i32 align,
+// <16 x i1> %mask, <16 x i32> %passthru)
+// to a chain of basic blocks, whith loading element one-by-one if
+// the appropriate mask bit is set
+//
+// %1 = bitcast i8* %addr to i32*
+// %2 = extractelement <16 x i1> %mask, i32 0
+// %3 = icmp eq i1 %2, true
+// br i1 %3, label %cond.load, label %else
+//
+//cond.load: ; preds = %0
+// %4 = getelementptr i32* %1, i32 0
+// %5 = load i32* %4
+// %6 = insertelement <16 x i32> undef, i32 %5, i32 0
+// br label %else
+//
+//else: ; preds = %0, %cond.load
+// %res.phi.else = phi <16 x i32> [ %6, %cond.load ], [ undef, %0 ]
+// %7 = extractelement <16 x i1> %mask, i32 1
+// %8 = icmp eq i1 %7, true
+// br i1 %8, label %cond.load1, label %else2
+//
+//cond.load1: ; preds = %else
+// %9 = getelementptr i32* %1, i32 1
+// %10 = load i32* %9
+// %11 = insertelement <16 x i32> %res.phi.else, i32 %10, i32 1
+// br label %else2
+//
+//else2: ; preds = %else, %cond.load1
+// %res.phi.else3 = phi <16 x i32> [ %11, %cond.load1 ], [ %res.phi.else, %else ]
+// %12 = extractelement <16 x i1> %mask, i32 2
+// %13 = icmp eq i1 %12, true
+// br i1 %13, label %cond.load4, label %else5
+//
+static void ScalarizeMaskedLoad(CallInst *CI) {
+ Value *Ptr = CI->getArgOperand(0);
+ Value *Src0 = CI->getArgOperand(3);
+ Value *Mask = CI->getArgOperand(2);
+ VectorType *VecType = dyn_cast<VectorType>(CI->getType());
+ Type *EltTy = VecType->getElementType();
+
+ assert(VecType && "Unexpected return type of masked load intrinsic");
+
+ IRBuilder<> Builder(CI->getContext());
+ Instruction *InsertPt = CI;
+ BasicBlock *IfBlock = CI->getParent();
+ BasicBlock *CondBlock = nullptr;
+ BasicBlock *PrevIfBlock = CI->getParent();
+ Builder.SetInsertPoint(InsertPt);
+
+ Builder.SetCurrentDebugLocation(CI->getDebugLoc());
+
+ // Bitcast %addr fron i8* to EltTy*
+ Type *NewPtrType =
+ EltTy->getPointerTo(cast<PointerType>(Ptr->getType())->getAddressSpace());
+ Value *FirstEltPtr = Builder.CreateBitCast(Ptr, NewPtrType);
+ Value *UndefVal = UndefValue::get(VecType);
+
+ // The result vector
+ Value *VResult = UndefVal;
+
+ PHINode *Phi = nullptr;
+ Value *PrevPhi = UndefVal;
+
+ unsigned VectorWidth = VecType->getNumElements();
+ for (unsigned Idx = 0; Idx < VectorWidth; ++Idx) {
+
+ // Fill the "else" block, created in the previous iteration
+ //
+ // %res.phi.else3 = phi <16 x i32> [ %11, %cond.load1 ], [ %res.phi.else, %else ]
+ // %mask_1 = extractelement <16 x i1> %mask, i32 Idx
+ // %to_load = icmp eq i1 %mask_1, true
+ // br i1 %to_load, label %cond.load, label %else
+ //
+ if (Idx > 0) {
+ Phi = Builder.CreatePHI(VecType, 2, "res.phi.else");
+ Phi->addIncoming(VResult, CondBlock);
+ Phi->addIncoming(PrevPhi, PrevIfBlock);
+ PrevPhi = Phi;
+ VResult = Phi;
+ }
+
+ Value *Predicate = Builder.CreateExtractElement(Mask, Builder.getInt32(Idx));
+ Value *Cmp = Builder.CreateICmp(ICmpInst::ICMP_EQ, Predicate,
+ ConstantInt::get(Predicate->getType(), 1));
+
+ // Create "cond" block
+ //
+ // %EltAddr = getelementptr i32* %1, i32 0
+ // %Elt = load i32* %EltAddr
+ // VResult = insertelement <16 x i32> VResult, i32 %Elt, i32 Idx
+ //
+ CondBlock = IfBlock->splitBasicBlock(InsertPt, "cond.load");
+ Builder.SetInsertPoint(InsertPt);
+
+ Value *Gep =
+ Builder.CreateInBoundsGEP(EltTy, FirstEltPtr, Builder.getInt32(Idx));
+ LoadInst* Load = Builder.CreateLoad(Gep, false);
+ VResult = Builder.CreateInsertElement(VResult, Load, Builder.getInt32(Idx));
+
+ // Create "else" block, fill it in the next iteration
+ BasicBlock *NewIfBlock = CondBlock->splitBasicBlock(InsertPt, "else");
+ Builder.SetInsertPoint(InsertPt);
+ Instruction *OldBr = IfBlock->getTerminator();
+ BranchInst::Create(CondBlock, NewIfBlock, Cmp, OldBr);
+ OldBr->eraseFromParent();
+ PrevIfBlock = IfBlock;
+ IfBlock = NewIfBlock;
}
- bool isFoldable(unsigned SizeCIOp, unsigned, bool) const override {
- if (ConstantInt *SizeCI =
- dyn_cast<ConstantInt>(CI->getArgOperand(SizeCIOp)))
- return SizeCI->isAllOnesValue();
- return false;
+
+ Phi = Builder.CreatePHI(VecType, 2, "res.phi.select");
+ Phi->addIncoming(VResult, CondBlock);
+ Phi->addIncoming(PrevPhi, PrevIfBlock);
+ Value *NewI = Builder.CreateSelect(Mask, Phi, Src0);
+ CI->replaceAllUsesWith(NewI);
+ CI->eraseFromParent();
+}
+
+// ScalarizeMaskedStore() translates masked store intrinsic, like
+// void @llvm.masked.store(<16 x i32> %src, <16 x i32>* %addr, i32 align,
+// <16 x i1> %mask)
+// to a chain of basic blocks, that stores element one-by-one if
+// the appropriate mask bit is set
+//
+// %1 = bitcast i8* %addr to i32*
+// %2 = extractelement <16 x i1> %mask, i32 0
+// %3 = icmp eq i1 %2, true
+// br i1 %3, label %cond.store, label %else
+//
+// cond.store: ; preds = %0
+// %4 = extractelement <16 x i32> %val, i32 0
+// %5 = getelementptr i32* %1, i32 0
+// store i32 %4, i32* %5
+// br label %else
+//
+// else: ; preds = %0, %cond.store
+// %6 = extractelement <16 x i1> %mask, i32 1
+// %7 = icmp eq i1 %6, true
+// br i1 %7, label %cond.store1, label %else2
+//
+// cond.store1: ; preds = %else
+// %8 = extractelement <16 x i32> %val, i32 1
+// %9 = getelementptr i32* %1, i32 1
+// store i32 %8, i32* %9
+// br label %else2
+// . . .
+static void ScalarizeMaskedStore(CallInst *CI) {
+ Value *Ptr = CI->getArgOperand(1);
+ Value *Src = CI->getArgOperand(0);
+ Value *Mask = CI->getArgOperand(3);
+
+ VectorType *VecType = dyn_cast<VectorType>(Src->getType());
+ Type *EltTy = VecType->getElementType();
+
+ assert(VecType && "Unexpected data type in masked store intrinsic");
+
+ IRBuilder<> Builder(CI->getContext());
+ Instruction *InsertPt = CI;
+ BasicBlock *IfBlock = CI->getParent();
+ Builder.SetInsertPoint(InsertPt);
+ Builder.SetCurrentDebugLocation(CI->getDebugLoc());
+
+ // Bitcast %addr fron i8* to EltTy*
+ Type *NewPtrType =
+ EltTy->getPointerTo(cast<PointerType>(Ptr->getType())->getAddressSpace());
+ Value *FirstEltPtr = Builder.CreateBitCast(Ptr, NewPtrType);
+
+ unsigned VectorWidth = VecType->getNumElements();
+ for (unsigned Idx = 0; Idx < VectorWidth; ++Idx) {
+
+ // Fill the "else" block, created in the previous iteration
+ //
+ // %mask_1 = extractelement <16 x i1> %mask, i32 Idx
+ // %to_store = icmp eq i1 %mask_1, true
+ // br i1 %to_load, label %cond.store, label %else
+ //
+ Value *Predicate = Builder.CreateExtractElement(Mask, Builder.getInt32(Idx));
+ Value *Cmp = Builder.CreateICmp(ICmpInst::ICMP_EQ, Predicate,
+ ConstantInt::get(Predicate->getType(), 1));
+
+ // Create "cond" block
+ //
+ // %OneElt = extractelement <16 x i32> %Src, i32 Idx
+ // %EltAddr = getelementptr i32* %1, i32 0
+ // %store i32 %OneElt, i32* %EltAddr
+ //
+ BasicBlock *CondBlock = IfBlock->splitBasicBlock(InsertPt, "cond.store");
+ Builder.SetInsertPoint(InsertPt);
+
+ Value *OneElt = Builder.CreateExtractElement(Src, Builder.getInt32(Idx));
+ Value *Gep =
+ Builder.CreateInBoundsGEP(EltTy, FirstEltPtr, Builder.getInt32(Idx));
+ Builder.CreateStore(OneElt, Gep);
+
+ // Create "else" block, fill it in the next iteration
+ BasicBlock *NewIfBlock = CondBlock->splitBasicBlock(InsertPt, "else");
+ Builder.SetInsertPoint(InsertPt);
+ Instruction *OldBr = IfBlock->getTerminator();
+ BranchInst::Create(CondBlock, NewIfBlock, Cmp, OldBr);
+ OldBr->eraseFromParent();
+ IfBlock = NewIfBlock;
}
-};
-} // end anonymous namespace
+ CI->eraseFromParent();
+}
-bool CodeGenPrepare::OptimizeCallInst(CallInst *CI) {
+bool CodeGenPrepare::OptimizeCallInst(CallInst *CI, bool& ModifiedDT) {
BasicBlock *BB = CI->getParent();
// Lower inline assembly if we can.
return true;
}
- // Lower all uses of llvm.objectsize.*
- IntrinsicInst *II = dyn_cast<IntrinsicInst>(CI);
- if (II && II->getIntrinsicID() == Intrinsic::objectsize) {
- bool Min = (cast<ConstantInt>(II->getArgOperand(1))->getZExtValue() == 1);
- Type *ReturnTy = CI->getType();
- Constant *RetVal = ConstantInt::get(ReturnTy, Min ? 0 : -1ULL);
-
- // Substituting this can cause recursive simplifications, which can
- // invalidate our iterator. Use a WeakVH to hold onto it in case this
- // happens.
- WeakVH IterHandle(CurInstIterator);
-
- replaceAndRecursivelySimplify(CI, RetVal,
- TLI ? TLI->getDataLayout() : nullptr,
- TLInfo, ModifiedDT ? nullptr : DT);
+ const DataLayout *TD = TLI ? TLI->getDataLayout() : nullptr;
- // If the iterator instruction was recursively deleted, start over at the
- // start of the block.
- if (IterHandle != CurInstIterator) {
- CurInstIterator = BB->begin();
- SunkAddrs.clear();
+ // Align the pointer arguments to this call if the target thinks it's a good
+ // idea
+ unsigned MinSize, PrefAlign;
+ if (TLI && TD && TLI->shouldAlignPointerArgs(CI, MinSize, PrefAlign)) {
+ for (auto &Arg : CI->arg_operands()) {
+ // We want to align both objects whose address is used directly and
+ // objects whose address is used in casts and GEPs, though it only makes
+ // sense for GEPs if the offset is a multiple of the desired alignment and
+ // if size - offset meets the size threshold.
+ if (!Arg->getType()->isPointerTy())
+ continue;
+ APInt Offset(TD->getPointerSizeInBits(
+ cast<PointerType>(Arg->getType())->getAddressSpace()), 0);
+ Value *Val = Arg->stripAndAccumulateInBoundsConstantOffsets(*TD, Offset);
+ uint64_t Offset2 = Offset.getLimitedValue();
+ AllocaInst *AI;
+ if ((Offset2 & (PrefAlign-1)) == 0 &&
+ (AI = dyn_cast<AllocaInst>(Val)) &&
+ AI->getAlignment() < PrefAlign &&
+ TD->getTypeAllocSize(AI->getAllocatedType()) >= MinSize + Offset2)
+ AI->setAlignment(PrefAlign);
+ // TODO: Also align GlobalVariables
+ }
+ // If this is a memcpy (or similar) then we may be able to improve the
+ // alignment
+ if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(CI)) {
+ unsigned Align = getKnownAlignment(MI->getDest(), *TD);
+ if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(MI))
+ Align = std::min(Align, getKnownAlignment(MTI->getSource(), *TD));
+ if (Align > MI->getAlignment())
+ MI->setAlignment(ConstantInt::get(MI->getAlignmentType(), Align));
}
- return true;
}
- if (II && TLI) {
- SmallVector<Value*, 2> PtrOps;
- Type *AccessTy;
- if (TLI->GetAddrModeArguments(II, PtrOps, AccessTy))
- while (!PtrOps.empty())
- if (OptimizeMemoryInst(II, PtrOps.pop_back_val(), AccessTy))
- return true;
+ IntrinsicInst *II = dyn_cast<IntrinsicInst>(CI);
+ if (II) {
+ switch (II->getIntrinsicID()) {
+ default: break;
+ case Intrinsic::objectsize: {
+ // Lower all uses of llvm.objectsize.*
+ bool Min = (cast<ConstantInt>(II->getArgOperand(1))->getZExtValue() == 1);
+ Type *ReturnTy = CI->getType();
+ Constant *RetVal = ConstantInt::get(ReturnTy, Min ? 0 : -1ULL);
+
+ // Substituting this can cause recursive simplifications, which can
+ // invalidate our iterator. Use a WeakVH to hold onto it in case this
+ // happens.
+ WeakVH IterHandle(CurInstIterator);
+
+ replaceAndRecursivelySimplify(CI, RetVal,
+ TLInfo, nullptr);
+
+ // If the iterator instruction was recursively deleted, start over at the
+ // start of the block.
+ if (IterHandle != CurInstIterator) {
+ CurInstIterator = BB->begin();
+ SunkAddrs.clear();
+ }
+ return true;
+ }
+ case Intrinsic::masked_load: {
+ // Scalarize unsupported vector masked load
+ if (!TTI->isLegalMaskedLoad(CI->getType(), 1)) {
+ ScalarizeMaskedLoad(CI);
+ ModifiedDT = true;
+ return true;
+ }
+ return false;
+ }
+ case Intrinsic::masked_store: {
+ if (!TTI->isLegalMaskedStore(CI->getArgOperand(0)->getType(), 1)) {
+ ScalarizeMaskedStore(CI);
+ ModifiedDT = true;
+ return true;
+ }
+ return false;
+ }
+ }
+
+ if (TLI) {
+ SmallVector<Value*, 2> PtrOps;
+ Type *AccessTy;
+ if (TLI->GetAddrModeArguments(II, PtrOps, AccessTy))
+ while (!PtrOps.empty())
+ if (OptimizeMemoryInst(II, PtrOps.pop_back_val(), AccessTy))
+ return true;
+ }
}
// From here on out we're working with named functions.
if (!CI->getCalledFunction()) return false;
- // We'll need DataLayout from here on out.
- const DataLayout *TD = TLI ? TLI->getDataLayout() : nullptr;
- if (!TD) return false;
-
// Lower all default uses of _chk calls. This is very similar
// to what InstCombineCalls does, but here we are only lowering calls
- // that have the default "don't know" as the objectsize. Anything else
- // should be left alone.
- CodeGenPrepareFortifiedLibCalls Simplifier;
- return Simplifier.fold(CI, TD, TLInfo);
+ // to fortified library functions (e.g. __memcpy_chk) that have the default
+ // "don't know" as the objectsize. Anything else should be left alone.
+ FortifiedLibCallSimplifier Simplifier(TLInfo, true);
+ if (Value *V = Simplifier.optimizeCall(CI)) {
+ CI->replaceAllUsesWith(V);
+ CI->eraseFromParent();
+ return true;
+ }
+ return false;
}
/// DupRetToEnableTailCallOpts - Look for opportunities to duplicate return
} else {
SmallPtrSet<BasicBlock*, 4> VisitedBBs;
for (pred_iterator PI = pred_begin(BB), PE = pred_end(BB); PI != PE; ++PI) {
- if (!VisitedBBs.insert(*PI))
+ if (!VisitedBBs.insert(*PI).second)
continue;
BasicBlock::InstListType &InstList = (*PI)->getInstList();
/// \brief Build a truncate instruction.
class TruncBuilder : public TypePromotionAction {
+ Value *Val;
public:
/// \brief Build a truncate instruction of \p Opnd producing a \p Ty
/// result.
/// trunc Opnd to Ty.
TruncBuilder(Instruction *Opnd, Type *Ty) : TypePromotionAction(Opnd) {
IRBuilder<> Builder(Opnd);
- Inst = cast<Instruction>(Builder.CreateTrunc(Opnd, Ty, "promoted"));
- DEBUG(dbgs() << "Do: TruncBuilder: " << *Inst << "\n");
+ Val = Builder.CreateTrunc(Opnd, Ty, "promoted");
+ DEBUG(dbgs() << "Do: TruncBuilder: " << *Val << "\n");
}
- /// \brief Get the built instruction.
- Instruction *getBuiltInstruction() { return Inst; }
+ /// \brief Get the built value.
+ Value *getBuiltValue() { return Val; }
/// \brief Remove the built instruction.
void undo() override {
- DEBUG(dbgs() << "Undo: TruncBuilder: " << *Inst << "\n");
- Inst->eraseFromParent();
+ DEBUG(dbgs() << "Undo: TruncBuilder: " << *Val << "\n");
+ if (Instruction *IVal = dyn_cast<Instruction>(Val))
+ IVal->eraseFromParent();
}
};
/// \brief Build a sign extension instruction.
class SExtBuilder : public TypePromotionAction {
+ Value *Val;
public:
/// \brief Build a sign extension instruction of \p Opnd producing a \p Ty
/// result.
/// sext Opnd to Ty.
SExtBuilder(Instruction *InsertPt, Value *Opnd, Type *Ty)
- : TypePromotionAction(Inst) {
+ : TypePromotionAction(InsertPt) {
IRBuilder<> Builder(InsertPt);
- Inst = cast<Instruction>(Builder.CreateSExt(Opnd, Ty, "promoted"));
- DEBUG(dbgs() << "Do: SExtBuilder: " << *Inst << "\n");
+ Val = Builder.CreateSExt(Opnd, Ty, "promoted");
+ DEBUG(dbgs() << "Do: SExtBuilder: " << *Val << "\n");
}
- /// \brief Get the built instruction.
- Instruction *getBuiltInstruction() { return Inst; }
+ /// \brief Get the built value.
+ Value *getBuiltValue() { return Val; }
/// \brief Remove the built instruction.
void undo() override {
- DEBUG(dbgs() << "Undo: SExtBuilder: " << *Inst << "\n");
- Inst->eraseFromParent();
+ DEBUG(dbgs() << "Undo: SExtBuilder: " << *Val << "\n");
+ if (Instruction *IVal = dyn_cast<Instruction>(Val))
+ IVal->eraseFromParent();
+ }
+ };
+
+ /// \brief Build a zero extension instruction.
+ class ZExtBuilder : public TypePromotionAction {
+ Value *Val;
+ public:
+ /// \brief Build a zero extension instruction of \p Opnd producing a \p Ty
+ /// result.
+ /// zext Opnd to Ty.
+ ZExtBuilder(Instruction *InsertPt, Value *Opnd, Type *Ty)
+ : TypePromotionAction(InsertPt) {
+ IRBuilder<> Builder(InsertPt);
+ Val = Builder.CreateZExt(Opnd, Ty, "promoted");
+ DEBUG(dbgs() << "Do: ZExtBuilder: " << *Val << "\n");
+ }
+
+ /// \brief Get the built value.
+ Value *getBuiltValue() { return Val; }
+
+ /// \brief Remove the built instruction.
+ void undo() override {
+ DEBUG(dbgs() << "Undo: ZExtBuilder: " << *Val << "\n");
+ if (Instruction *IVal = dyn_cast<Instruction>(Val))
+ IVal->eraseFromParent();
}
};
/// Same as Value::mutateType.
void mutateType(Instruction *Inst, Type *NewTy);
/// Same as IRBuilder::createTrunc.
- Instruction *createTrunc(Instruction *Opnd, Type *Ty);
+ Value *createTrunc(Instruction *Opnd, Type *Ty);
/// Same as IRBuilder::createSExt.
- Instruction *createSExt(Instruction *Inst, Value *Opnd, Type *Ty);
+ Value *createSExt(Instruction *Inst, Value *Opnd, Type *Ty);
+ /// Same as IRBuilder::createZExt.
+ Value *createZExt(Instruction *Inst, Value *Opnd, Type *Ty);
/// Same as Instruction::moveBefore.
void moveBefore(Instruction *Inst, Instruction *Before);
/// @}
Actions.push_back(make_unique<TypePromotionTransaction::TypeMutator>(Inst, NewTy));
}
-Instruction *TypePromotionTransaction::createTrunc(Instruction *Opnd,
- Type *Ty) {
+Value *TypePromotionTransaction::createTrunc(Instruction *Opnd,
+ Type *Ty) {
std::unique_ptr<TruncBuilder> Ptr(new TruncBuilder(Opnd, Ty));
- Instruction *I = Ptr->getBuiltInstruction();
+ Value *Val = Ptr->getBuiltValue();
Actions.push_back(std::move(Ptr));
- return I;
+ return Val;
}
-Instruction *TypePromotionTransaction::createSExt(Instruction *Inst,
- Value *Opnd, Type *Ty) {
+Value *TypePromotionTransaction::createSExt(Instruction *Inst,
+ Value *Opnd, Type *Ty) {
std::unique_ptr<SExtBuilder> Ptr(new SExtBuilder(Inst, Opnd, Ty));
- Instruction *I = Ptr->getBuiltInstruction();
+ Value *Val = Ptr->getBuiltValue();
+ Actions.push_back(std::move(Ptr));
+ return Val;
+}
+
+Value *TypePromotionTransaction::createZExt(Instruction *Inst,
+ Value *Opnd, Type *Ty) {
+ std::unique_ptr<ZExtBuilder> Ptr(new ZExtBuilder(Inst, Opnd, Ty));
+ Value *Val = Ptr->getBuiltValue();
Actions.push_back(std::move(Ptr));
- return I;
+ return Val;
}
void TypePromotionTransaction::moveBefore(Instruction *Inst,
/// This encapsulates the logic for matching the target-legal addressing modes.
class AddressingModeMatcher {
SmallVectorImpl<Instruction*> &AddrModeInsts;
+ const TargetMachine &TM;
const TargetLowering &TLI;
/// AccessTy/MemoryInst - This is the type for the access (e.g. double) and
/// always returns true.
bool IgnoreProfitability;
- AddressingModeMatcher(SmallVectorImpl<Instruction*> &AMI,
- const TargetLowering &T, Type *AT,
- Instruction *MI, ExtAddrMode &AM,
- const SetOfInstrs &InsertedTruncs,
+ AddressingModeMatcher(SmallVectorImpl<Instruction *> &AMI,
+ const TargetMachine &TM, Type *AT, Instruction *MI,
+ ExtAddrMode &AM, const SetOfInstrs &InsertedTruncs,
InstrToOrigTy &PromotedInsts,
TypePromotionTransaction &TPT)
- : AddrModeInsts(AMI), TLI(T), AccessTy(AT), MemoryInst(MI), AddrMode(AM),
+ : AddrModeInsts(AMI), TM(TM),
+ TLI(*TM.getSubtargetImpl(*MI->getParent()->getParent())
+ ->getTargetLowering()),
+ AccessTy(AT), MemoryInst(MI), AddrMode(AM),
InsertedTruncs(InsertedTruncs), PromotedInsts(PromotedInsts), TPT(TPT) {
IgnoreProfitability = false;
}
static ExtAddrMode Match(Value *V, Type *AccessTy,
Instruction *MemoryInst,
SmallVectorImpl<Instruction*> &AddrModeInsts,
- const TargetLowering &TLI,
+ const TargetMachine &TM,
const SetOfInstrs &InsertedTruncs,
InstrToOrigTy &PromotedInsts,
TypePromotionTransaction &TPT) {
ExtAddrMode Result;
- bool Success = AddressingModeMatcher(AddrModeInsts, TLI, AccessTy,
+ bool Success = AddressingModeMatcher(AddrModeInsts, TM, AccessTy,
MemoryInst, Result, InsertedTruncs,
PromotedInsts, TPT).MatchAddr(V, 0);
(void)Success; assert(Success && "Couldn't select *anything*?");
ExtAddrMode &AMBefore,
ExtAddrMode &AMAfter);
bool ValueAlreadyLiveAtInst(Value *Val, Value *KnownLive1, Value *KnownLive2);
- bool IsPromotionProfitable(unsigned MatchedSize, unsigned SizeWithPromotion,
+ bool IsPromotionProfitable(unsigned NewCost, unsigned OldCost,
Value *PromotedOperand) const;
};
}
}
+/// \brief Check whether or not \p Val is a legal instruction for \p TLI.
+/// \note \p Val is assumed to be the product of some type promotion.
+/// Therefore if \p Val has an undefined state in \p TLI, this is assumed
+/// to be legal, as the non-promoted value would have had the same state.
+static bool isPromotedInstructionLegal(const TargetLowering &TLI, Value *Val) {
+ Instruction *PromotedInst = dyn_cast<Instruction>(Val);
+ if (!PromotedInst)
+ return false;
+ int ISDOpcode = TLI.InstructionOpcodeToISD(PromotedInst->getOpcode());
+ // If the ISDOpcode is undefined, it was undefined before the promotion.
+ if (!ISDOpcode)
+ return true;
+ // Otherwise, check if the promoted instruction is legal or not.
+ return TLI.isOperationLegalOrCustom(
+ ISDOpcode, TLI.getValueType(PromotedInst->getType()));
+}
+
/// \brief Hepler class to perform type promotion.
class TypePromotionHelper {
- /// \brief Utility function to check whether or not a sign extension of
- /// \p Inst with \p ConsideredSExtType can be moved through \p Inst by either
- /// using the operands of \p Inst or promoting \p Inst.
+ /// \brief Utility function to check whether or not a sign or zero extension
+ /// of \p Inst with \p ConsideredExtType can be moved through \p Inst by
+ /// either using the operands of \p Inst or promoting \p Inst.
+ /// The type of the extension is defined by \p IsSExt.
/// In other words, check if:
- /// sext (Ty Inst opnd1 opnd2 ... opndN) to ConsideredSExtType.
+ /// ext (Ty Inst opnd1 opnd2 ... opndN) to ConsideredExtType.
/// #1 Promotion applies:
- /// ConsideredSExtType Inst (sext opnd1 to ConsideredSExtType, ...).
+ /// ConsideredExtType Inst (ext opnd1 to ConsideredExtType, ...).
/// #2 Operand reuses:
- /// sext opnd1 to ConsideredSExtType.
+ /// ext opnd1 to ConsideredExtType.
/// \p PromotedInsts maps the instructions to their type before promotion.
- static bool canGetThrough(const Instruction *Inst, Type *ConsideredSExtType,
- const InstrToOrigTy &PromotedInsts);
+ static bool canGetThrough(const Instruction *Inst, Type *ConsideredExtType,
+ const InstrToOrigTy &PromotedInsts, bool IsSExt);
/// \brief Utility function to determine if \p OpIdx should be promoted when
/// promoting \p Inst.
- static bool shouldSExtOperand(const Instruction *Inst, int OpIdx) {
+ static bool shouldExtOperand(const Instruction *Inst, int OpIdx) {
if (isa<SelectInst>(Inst) && OpIdx == 0)
return false;
return true;
}
- /// \brief Utility function to promote the operand of \p SExt when this
- /// operand is a promotable trunc or sext.
+ /// \brief Utility function to promote the operand of \p Ext when this
+ /// operand is a promotable trunc or sext or zext.
/// \p PromotedInsts maps the instructions to their type before promotion.
- /// \p CreatedInsts[out] contains how many non-free instructions have been
- /// created to promote the operand of SExt.
+ /// \p CreatedInstsCost[out] contains the cost of all instructions
+ /// created to promote the operand of Ext.
+ /// Newly added extensions are inserted in \p Exts.
+ /// Newly added truncates are inserted in \p Truncs.
/// Should never be called directly.
- /// \return The promoted value which is used instead of SExt.
- static Value *promoteOperandForTruncAndSExt(Instruction *SExt,
- TypePromotionTransaction &TPT,
- InstrToOrigTy &PromotedInsts,
- unsigned &CreatedInsts);
-
- /// \brief Utility function to promote the operand of \p SExt when this
+ /// \return The promoted value which is used instead of Ext.
+ static Value *promoteOperandForTruncAndAnyExt(
+ Instruction *Ext, TypePromotionTransaction &TPT,
+ InstrToOrigTy &PromotedInsts, unsigned &CreatedInstsCost,
+ SmallVectorImpl<Instruction *> *Exts,
+ SmallVectorImpl<Instruction *> *Truncs, const TargetLowering &TLI);
+
+ /// \brief Utility function to promote the operand of \p Ext when this
/// operand is promotable and is not a supported trunc or sext.
/// \p PromotedInsts maps the instructions to their type before promotion.
- /// \p CreatedInsts[out] contains how many non-free instructions have been
- /// created to promote the operand of SExt.
+ /// \p CreatedInstsCost[out] contains the cost of all the instructions
+ /// created to promote the operand of Ext.
+ /// Newly added extensions are inserted in \p Exts.
+ /// Newly added truncates are inserted in \p Truncs.
/// Should never be called directly.
- /// \return The promoted value which is used instead of SExt.
- static Value *promoteOperandForOther(Instruction *SExt,
+ /// \return The promoted value which is used instead of Ext.
+ static Value *promoteOperandForOther(Instruction *Ext,
TypePromotionTransaction &TPT,
InstrToOrigTy &PromotedInsts,
- unsigned &CreatedInsts);
+ unsigned &CreatedInstsCost,
+ SmallVectorImpl<Instruction *> *Exts,
+ SmallVectorImpl<Instruction *> *Truncs,
+ const TargetLowering &TLI, bool IsSExt);
+
+ /// \see promoteOperandForOther.
+ static Value *signExtendOperandForOther(
+ Instruction *Ext, TypePromotionTransaction &TPT,
+ InstrToOrigTy &PromotedInsts, unsigned &CreatedInstsCost,
+ SmallVectorImpl<Instruction *> *Exts,
+ SmallVectorImpl<Instruction *> *Truncs, const TargetLowering &TLI) {
+ return promoteOperandForOther(Ext, TPT, PromotedInsts, CreatedInstsCost,
+ Exts, Truncs, TLI, true);
+ }
+
+ /// \see promoteOperandForOther.
+ static Value *zeroExtendOperandForOther(
+ Instruction *Ext, TypePromotionTransaction &TPT,
+ InstrToOrigTy &PromotedInsts, unsigned &CreatedInstsCost,
+ SmallVectorImpl<Instruction *> *Exts,
+ SmallVectorImpl<Instruction *> *Truncs, const TargetLowering &TLI) {
+ return promoteOperandForOther(Ext, TPT, PromotedInsts, CreatedInstsCost,
+ Exts, Truncs, TLI, false);
+ }
public:
- /// Type for the utility function that promotes the operand of SExt.
- typedef Value *(*Action)(Instruction *SExt, TypePromotionTransaction &TPT,
+ /// Type for the utility function that promotes the operand of Ext.
+ typedef Value *(*Action)(Instruction *Ext, TypePromotionTransaction &TPT,
InstrToOrigTy &PromotedInsts,
- unsigned &CreatedInsts);
- /// \brief Given a sign extend instruction \p SExt, return the approriate
- /// action to promote the operand of \p SExt instead of using SExt.
+ unsigned &CreatedInstsCost,
+ SmallVectorImpl<Instruction *> *Exts,
+ SmallVectorImpl<Instruction *> *Truncs,
+ const TargetLowering &TLI);
+ /// \brief Given a sign/zero extend instruction \p Ext, return the approriate
+ /// action to promote the operand of \p Ext instead of using Ext.
/// \return NULL if no promotable action is possible with the current
/// sign extension.
/// \p InsertedTruncs keeps track of all the truncate instructions inserted by
/// because we do not want to promote these instructions as CodeGenPrepare
/// will reinsert them later. Thus creating an infinite loop: create/remove.
/// \p PromotedInsts maps the instructions to their type before promotion.
- static Action getAction(Instruction *SExt, const SetOfInstrs &InsertedTruncs,
+ static Action getAction(Instruction *Ext, const SetOfInstrs &InsertedTruncs,
const TargetLowering &TLI,
const InstrToOrigTy &PromotedInsts);
};
bool TypePromotionHelper::canGetThrough(const Instruction *Inst,
- Type *ConsideredSExtType,
- const InstrToOrigTy &PromotedInsts) {
- // We can always get through sext.
- if (isa<SExtInst>(Inst))
+ Type *ConsideredExtType,
+ const InstrToOrigTy &PromotedInsts,
+ bool IsSExt) {
+ // The promotion helper does not know how to deal with vector types yet.
+ // To be able to fix that, we would need to fix the places where we
+ // statically extend, e.g., constants and such.
+ if (Inst->getType()->isVectorTy())
+ return false;
+
+ // We can always get through zext.
+ if (isa<ZExtInst>(Inst))
+ return true;
+
+ // sext(sext) is ok too.
+ if (IsSExt && isa<SExtInst>(Inst))
return true;
// We can get through binary operator, if it is legal. In other words, the
// binary operator must have a nuw or nsw flag.
const BinaryOperator *BinOp = dyn_cast<BinaryOperator>(Inst);
if (BinOp && isa<OverflowingBinaryOperator>(BinOp) &&
- (BinOp->hasNoUnsignedWrap() || BinOp->hasNoSignedWrap()))
+ ((!IsSExt && BinOp->hasNoUnsignedWrap()) ||
+ (IsSExt && BinOp->hasNoSignedWrap())))
return true;
// Check if we can do the following simplification.
- // sext(trunc(sext)) --> sext
+ // ext(trunc(opnd)) --> ext(opnd)
if (!isa<TruncInst>(Inst))
return false;
Value *OpndVal = Inst->getOperand(0);
- // Check if we can use this operand in the sext.
- // If the type is larger than the result type of the sign extension,
+ // Check if we can use this operand in the extension.
+ // If the type is larger than the result type of the extension,
// we cannot.
- if (OpndVal->getType()->getIntegerBitWidth() >
- ConsideredSExtType->getIntegerBitWidth())
+ if (!OpndVal->getType()->isIntegerTy() ||
+ OpndVal->getType()->getIntegerBitWidth() >
+ ConsideredExtType->getIntegerBitWidth())
return false;
// If the operand of the truncate is not an instruction, we will not have
return false;
// Check if the source of the type is narrow enough.
- // I.e., check that trunc just drops sign extended bits.
- // #1 get the type of the operand.
+ // I.e., check that trunc just drops extended bits of the same kind of
+ // the extension.
+ // #1 get the type of the operand and check the kind of the extended bits.
const Type *OpndType;
InstrToOrigTy::const_iterator It = PromotedInsts.find(Opnd);
- if (It != PromotedInsts.end())
- OpndType = It->second;
- else if (isa<SExtInst>(Opnd))
- OpndType = cast<Instruction>(Opnd)->getOperand(0)->getType();
+ if (It != PromotedInsts.end() && It->second.IsSExt == IsSExt)
+ OpndType = It->second.Ty;
+ else if ((IsSExt && isa<SExtInst>(Opnd)) || (!IsSExt && isa<ZExtInst>(Opnd)))
+ OpndType = Opnd->getOperand(0)->getType();
else
return false;
- // #2 check that the truncate just drop sign extended bits.
+ // #2 check that the truncate just drop extended bits.
if (Inst->getType()->getIntegerBitWidth() >= OpndType->getIntegerBitWidth())
return true;
}
TypePromotionHelper::Action TypePromotionHelper::getAction(
- Instruction *SExt, const SetOfInstrs &InsertedTruncs,
+ Instruction *Ext, const SetOfInstrs &InsertedTruncs,
const TargetLowering &TLI, const InstrToOrigTy &PromotedInsts) {
- Instruction *SExtOpnd = dyn_cast<Instruction>(SExt->getOperand(0));
- Type *SExtTy = SExt->getType();
- // If the operand of the sign extension is not an instruction, we cannot
+ assert((isa<SExtInst>(Ext) || isa<ZExtInst>(Ext)) &&
+ "Unexpected instruction type");
+ Instruction *ExtOpnd = dyn_cast<Instruction>(Ext->getOperand(0));
+ Type *ExtTy = Ext->getType();
+ bool IsSExt = isa<SExtInst>(Ext);
+ // If the operand of the extension is not an instruction, we cannot
// get through.
// If it, check we can get through.
- if (!SExtOpnd || !canGetThrough(SExtOpnd, SExtTy, PromotedInsts))
+ if (!ExtOpnd || !canGetThrough(ExtOpnd, ExtTy, PromotedInsts, IsSExt))
return nullptr;
// Do not promote if the operand has been added by codegenprepare.
// Otherwise, it means we are undoing an optimization that is likely to be
// redone, thus causing potential infinite loop.
- if (isa<TruncInst>(SExtOpnd) && InsertedTruncs.count(SExtOpnd))
+ if (isa<TruncInst>(ExtOpnd) && InsertedTruncs.count(ExtOpnd))
return nullptr;
// SExt or Trunc instructions.
// Return the related handler.
- if (isa<SExtInst>(SExtOpnd) || isa<TruncInst>(SExtOpnd))
- return promoteOperandForTruncAndSExt;
+ if (isa<SExtInst>(ExtOpnd) || isa<TruncInst>(ExtOpnd) ||
+ isa<ZExtInst>(ExtOpnd))
+ return promoteOperandForTruncAndAnyExt;
// Regular instruction.
// Abort early if we will have to insert non-free instructions.
- if (!SExtOpnd->hasOneUse() &&
- !TLI.isTruncateFree(SExtTy, SExtOpnd->getType()))
+ if (!ExtOpnd->hasOneUse() && !TLI.isTruncateFree(ExtTy, ExtOpnd->getType()))
return nullptr;
- return promoteOperandForOther;
+ return IsSExt ? signExtendOperandForOther : zeroExtendOperandForOther;
}
-Value *TypePromotionHelper::promoteOperandForTruncAndSExt(
+Value *TypePromotionHelper::promoteOperandForTruncAndAnyExt(
llvm::Instruction *SExt, TypePromotionTransaction &TPT,
- InstrToOrigTy &PromotedInsts, unsigned &CreatedInsts) {
+ InstrToOrigTy &PromotedInsts, unsigned &CreatedInstsCost,
+ SmallVectorImpl<Instruction *> *Exts,
+ SmallVectorImpl<Instruction *> *Truncs, const TargetLowering &TLI) {
// By construction, the operand of SExt is an instruction. Otherwise we cannot
// get through it and this method should not be called.
Instruction *SExtOpnd = cast<Instruction>(SExt->getOperand(0));
- // Replace sext(trunc(opnd)) or sext(sext(opnd))
- // => sext(opnd).
- TPT.setOperand(SExt, 0, SExtOpnd->getOperand(0));
- CreatedInsts = 0;
+ Value *ExtVal = SExt;
+ bool HasMergedNonFreeExt = false;
+ if (isa<ZExtInst>(SExtOpnd)) {
+ // Replace s|zext(zext(opnd))
+ // => zext(opnd).
+ HasMergedNonFreeExt = !TLI.isExtFree(SExtOpnd);
+ Value *ZExt =
+ TPT.createZExt(SExt, SExtOpnd->getOperand(0), SExt->getType());
+ TPT.replaceAllUsesWith(SExt, ZExt);
+ TPT.eraseInstruction(SExt);
+ ExtVal = ZExt;
+ } else {
+ // Replace z|sext(trunc(opnd)) or sext(sext(opnd))
+ // => z|sext(opnd).
+ TPT.setOperand(SExt, 0, SExtOpnd->getOperand(0));
+ }
+ CreatedInstsCost = 0;
// Remove dead code.
if (SExtOpnd->use_empty())
TPT.eraseInstruction(SExtOpnd);
- // Check if the sext is still needed.
- if (SExt->getType() != SExt->getOperand(0)->getType())
- return SExt;
+ // Check if the extension is still needed.
+ Instruction *ExtInst = dyn_cast<Instruction>(ExtVal);
+ if (!ExtInst || ExtInst->getType() != ExtInst->getOperand(0)->getType()) {
+ if (ExtInst) {
+ if (Exts)
+ Exts->push_back(ExtInst);
+ CreatedInstsCost = !TLI.isExtFree(ExtInst) && !HasMergedNonFreeExt;
+ }
+ return ExtVal;
+ }
- // At this point we have: sext ty opnd to ty.
- // Reassign the uses of SExt to the opnd and remove SExt.
- Value *NextVal = SExt->getOperand(0);
- TPT.eraseInstruction(SExt, NextVal);
+ // At this point we have: ext ty opnd to ty.
+ // Reassign the uses of ExtInst to the opnd and remove ExtInst.
+ Value *NextVal = ExtInst->getOperand(0);
+ TPT.eraseInstruction(ExtInst, NextVal);
return NextVal;
}
-Value *
-TypePromotionHelper::promoteOperandForOther(Instruction *SExt,
- TypePromotionTransaction &TPT,
- InstrToOrigTy &PromotedInsts,
- unsigned &CreatedInsts) {
- // By construction, the operand of SExt is an instruction. Otherwise we cannot
+Value *TypePromotionHelper::promoteOperandForOther(
+ Instruction *Ext, TypePromotionTransaction &TPT,
+ InstrToOrigTy &PromotedInsts, unsigned &CreatedInstsCost,
+ SmallVectorImpl<Instruction *> *Exts,
+ SmallVectorImpl<Instruction *> *Truncs, const TargetLowering &TLI,
+ bool IsSExt) {
+ // By construction, the operand of Ext is an instruction. Otherwise we cannot
// get through it and this method should not be called.
- Instruction *SExtOpnd = cast<Instruction>(SExt->getOperand(0));
- CreatedInsts = 0;
- if (!SExtOpnd->hasOneUse()) {
- // SExtOpnd will be promoted.
- // All its uses, but SExt, will need to use a truncated value of the
+ Instruction *ExtOpnd = cast<Instruction>(Ext->getOperand(0));
+ CreatedInstsCost = 0;
+ if (!ExtOpnd->hasOneUse()) {
+ // ExtOpnd will be promoted.
+ // All its uses, but Ext, will need to use a truncated value of the
// promoted version.
// Create the truncate now.
- Instruction *Trunc = TPT.createTrunc(SExt, SExtOpnd->getType());
- Trunc->removeFromParent();
- // Insert it just after the definition.
- Trunc->insertAfter(SExtOpnd);
+ Value *Trunc = TPT.createTrunc(Ext, ExtOpnd->getType());
+ if (Instruction *ITrunc = dyn_cast<Instruction>(Trunc)) {
+ ITrunc->removeFromParent();
+ // Insert it just after the definition.
+ ITrunc->insertAfter(ExtOpnd);
+ if (Truncs)
+ Truncs->push_back(ITrunc);
+ }
- TPT.replaceAllUsesWith(SExtOpnd, Trunc);
- // Restore the operand of SExt (which has been replace by the previous call
+ TPT.replaceAllUsesWith(ExtOpnd, Trunc);
+ // Restore the operand of Ext (which has been replace by the previous call
// to replaceAllUsesWith) to avoid creating a cycle trunc <-> sext.
- TPT.setOperand(SExt, 0, SExtOpnd);
+ TPT.setOperand(Ext, 0, ExtOpnd);
}
// Get through the Instruction:
// 1. Update its type.
- // 2. Replace the uses of SExt by Inst.
- // 3. Sign extend each operand that needs to be sign extended.
+ // 2. Replace the uses of Ext by Inst.
+ // 3. Extend each operand that needs to be extended.
// Remember the original type of the instruction before promotion.
// This is useful to know that the high bits are sign extended bits.
- PromotedInsts.insert(
- std::pair<Instruction *, Type *>(SExtOpnd, SExtOpnd->getType()));
+ PromotedInsts.insert(std::pair<Instruction *, TypeIsSExt>(
+ ExtOpnd, TypeIsSExt(ExtOpnd->getType(), IsSExt)));
// Step #1.
- TPT.mutateType(SExtOpnd, SExt->getType());
+ TPT.mutateType(ExtOpnd, Ext->getType());
// Step #2.
- TPT.replaceAllUsesWith(SExt, SExtOpnd);
+ TPT.replaceAllUsesWith(Ext, ExtOpnd);
// Step #3.
- Instruction *SExtForOpnd = SExt;
+ Instruction *ExtForOpnd = Ext;
- DEBUG(dbgs() << "Propagate SExt to operands\n");
- for (int OpIdx = 0, EndOpIdx = SExtOpnd->getNumOperands(); OpIdx != EndOpIdx;
+ DEBUG(dbgs() << "Propagate Ext to operands\n");
+ for (int OpIdx = 0, EndOpIdx = ExtOpnd->getNumOperands(); OpIdx != EndOpIdx;
++OpIdx) {
- DEBUG(dbgs() << "Operand:\n" << *(SExtOpnd->getOperand(OpIdx)) << '\n');
- if (SExtOpnd->getOperand(OpIdx)->getType() == SExt->getType() ||
- !shouldSExtOperand(SExtOpnd, OpIdx)) {
+ DEBUG(dbgs() << "Operand:\n" << *(ExtOpnd->getOperand(OpIdx)) << '\n');
+ if (ExtOpnd->getOperand(OpIdx)->getType() == Ext->getType() ||
+ !shouldExtOperand(ExtOpnd, OpIdx)) {
DEBUG(dbgs() << "No need to propagate\n");
continue;
}
- // Check if we can statically sign extend the operand.
- Value *Opnd = SExtOpnd->getOperand(OpIdx);
+ // Check if we can statically extend the operand.
+ Value *Opnd = ExtOpnd->getOperand(OpIdx);
if (const ConstantInt *Cst = dyn_cast<ConstantInt>(Opnd)) {
- DEBUG(dbgs() << "Statically sign extend\n");
- TPT.setOperand(
- SExtOpnd, OpIdx,
- ConstantInt::getSigned(SExt->getType(), Cst->getSExtValue()));
+ DEBUG(dbgs() << "Statically extend\n");
+ unsigned BitWidth = Ext->getType()->getIntegerBitWidth();
+ APInt CstVal = IsSExt ? Cst->getValue().sext(BitWidth)
+ : Cst->getValue().zext(BitWidth);
+ TPT.setOperand(ExtOpnd, OpIdx, ConstantInt::get(Ext->getType(), CstVal));
continue;
}
// UndefValue are typed, so we have to statically sign extend them.
if (isa<UndefValue>(Opnd)) {
- DEBUG(dbgs() << "Statically sign extend\n");
- TPT.setOperand(SExtOpnd, OpIdx, UndefValue::get(SExt->getType()));
+ DEBUG(dbgs() << "Statically extend\n");
+ TPT.setOperand(ExtOpnd, OpIdx, UndefValue::get(Ext->getType()));
continue;
}
// Otherwise we have to explicity sign extend the operand.
- // Check if SExt was reused to sign extend an operand.
- if (!SExtForOpnd) {
+ // Check if Ext was reused to extend an operand.
+ if (!ExtForOpnd) {
// If yes, create a new one.
- DEBUG(dbgs() << "More operands to sext\n");
- SExtForOpnd = TPT.createSExt(SExt, Opnd, SExt->getType());
- ++CreatedInsts;
+ DEBUG(dbgs() << "More operands to ext\n");
+ Value *ValForExtOpnd = IsSExt ? TPT.createSExt(Ext, Opnd, Ext->getType())
+ : TPT.createZExt(Ext, Opnd, Ext->getType());
+ if (!isa<Instruction>(ValForExtOpnd)) {
+ TPT.setOperand(ExtOpnd, OpIdx, ValForExtOpnd);
+ continue;
+ }
+ ExtForOpnd = cast<Instruction>(ValForExtOpnd);
}
-
- TPT.setOperand(SExtForOpnd, 0, Opnd);
+ if (Exts)
+ Exts->push_back(ExtForOpnd);
+ TPT.setOperand(ExtForOpnd, 0, Opnd);
// Move the sign extension before the insertion point.
- TPT.moveBefore(SExtForOpnd, SExtOpnd);
- TPT.setOperand(SExtOpnd, OpIdx, SExtForOpnd);
+ TPT.moveBefore(ExtForOpnd, ExtOpnd);
+ TPT.setOperand(ExtOpnd, OpIdx, ExtForOpnd);
+ CreatedInstsCost += !TLI.isExtFree(ExtForOpnd);
// If more sext are required, new instructions will have to be created.
- SExtForOpnd = nullptr;
+ ExtForOpnd = nullptr;
}
- if (SExtForOpnd == SExt) {
- DEBUG(dbgs() << "Sign extension is useless now\n");
- TPT.eraseInstruction(SExt);
+ if (ExtForOpnd == Ext) {
+ DEBUG(dbgs() << "Extension is useless now\n");
+ TPT.eraseInstruction(Ext);
}
- return SExtOpnd;
+ return ExtOpnd;
}
/// IsPromotionProfitable - Check whether or not promoting an instruction
/// to a wider type was profitable.
-/// \p MatchedSize gives the number of instructions that have been matched
-/// in the addressing mode after the promotion was applied.
-/// \p SizeWithPromotion gives the number of created instructions for
-/// the promotion plus the number of instructions that have been
-/// matched in the addressing mode before the promotion.
+/// \p NewCost gives the cost of extension instructions created by the
+/// promotion.
+/// \p OldCost gives the cost of extension instructions before the promotion
+/// plus the number of instructions that have been
+/// matched in the addressing mode the promotion.
/// \p PromotedOperand is the value that has been promoted.
/// \return True if the promotion is profitable, false otherwise.
-bool
-AddressingModeMatcher::IsPromotionProfitable(unsigned MatchedSize,
- unsigned SizeWithPromotion,
- Value *PromotedOperand) const {
- // We folded less instructions than what we created to promote the operand.
+bool AddressingModeMatcher::IsPromotionProfitable(
+ unsigned NewCost, unsigned OldCost, Value *PromotedOperand) const {
+ DEBUG(dbgs() << "OldCost: " << OldCost << "\tNewCost: " << NewCost << '\n');
+ // The cost of the new extensions is greater than the cost of the
+ // old extension plus what we folded.
// This is not profitable.
- if (MatchedSize < SizeWithPromotion)
+ if (NewCost > OldCost)
return false;
- if (MatchedSize > SizeWithPromotion)
+ if (NewCost < OldCost)
return true;
// The promotion is neutral but it may help folding the sign extension in
// loads for instance.
// Check that we did not create an illegal instruction.
- Instruction *PromotedInst = dyn_cast<Instruction>(PromotedOperand);
- if (!PromotedInst)
- return false;
- int ISDOpcode = TLI.InstructionOpcodeToISD(PromotedInst->getOpcode());
- // If the ISDOpcode is undefined, it was undefined before the promotion.
- if (!ISDOpcode)
- return true;
- // Otherwise, check if the promoted instruction is legal or not.
- return TLI.isOperationLegalOrCustom(ISDOpcode,
- EVT::getEVT(PromotedInst->getType()));
+ return isPromotedInstructionLegal(TLI, PromotedOperand);
}
/// MatchOperationAddr - Given an instruction or constant expr, see if we can
case Instruction::Shl: {
// Can only handle X*C and X << C.
ConstantInt *RHS = dyn_cast<ConstantInt>(AddrInst->getOperand(1));
- if (!RHS) return false;
+ if (!RHS)
+ return false;
int64_t Scale = RHS->getSExtValue();
if (Opcode == Instruction::Shl)
Scale = 1LL << Scale;
return true;
}
- case Instruction::SExt: {
- // Make sure this isn't a ConstantExpr (PR20314).
- Instruction *SExt = dyn_cast<Instruction>(AddrInst);
- if (!SExt) return false;
+ case Instruction::SExt:
+ case Instruction::ZExt: {
+ Instruction *Ext = dyn_cast<Instruction>(AddrInst);
+ if (!Ext)
+ return false;
- // Try to move this sext out of the way of the addressing mode.
+ // Try to move this ext out of the way of the addressing mode.
// Ask for a method for doing so.
- TypePromotionHelper::Action TPH = TypePromotionHelper::getAction(
- SExt, InsertedTruncs, TLI, PromotedInsts);
+ TypePromotionHelper::Action TPH =
+ TypePromotionHelper::getAction(Ext, InsertedTruncs, TLI, PromotedInsts);
if (!TPH)
return false;
TypePromotionTransaction::ConstRestorationPt LastKnownGood =
TPT.getRestorationPoint();
- unsigned CreatedInsts = 0;
- Value *PromotedOperand = TPH(SExt, TPT, PromotedInsts, CreatedInsts);
+ unsigned CreatedInstsCost = 0;
+ unsigned ExtCost = !TLI.isExtFree(Ext);
+ Value *PromotedOperand =
+ TPH(Ext, TPT, PromotedInsts, CreatedInstsCost, nullptr, nullptr, TLI);
// SExt has been moved away.
// Thus either it will be rematched later in the recursive calls or it is
// gone. Anyway, we must not fold it into the addressing mode at this point.
// E.g.,
// op = add opnd, 1
- // idx = sext op
+ // idx = ext op
// addr = gep base, idx
// is now:
- // promotedOpnd = sext opnd <- no match here
+ // promotedOpnd = ext opnd <- no match here
// op = promoted_add promotedOpnd, 1 <- match (later in recursive calls)
// addr = gep base, op <- match
if (MovedAway)
unsigned OldSize = AddrModeInsts.size();
if (!MatchAddr(PromotedOperand, Depth) ||
- !IsPromotionProfitable(AddrModeInsts.size(), OldSize + CreatedInsts,
+ // The total of the new cost is equals to the cost of the created
+ // instructions.
+ // The total of the old cost is equals to the cost of the extension plus
+ // what we have saved in the addressing mode.
+ !IsPromotionProfitable(CreatedInstsCost,
+ ExtCost + (AddrModeInsts.size() - OldSize),
PromotedOperand)) {
AddrMode = BackupAddrMode;
AddrModeInsts.resize(OldSize);
/// inline asm call are due to memory operands. If so, return true, otherwise
/// return false.
static bool IsOperandAMemoryOperand(CallInst *CI, InlineAsm *IA, Value *OpVal,
- const TargetLowering &TLI) {
- TargetLowering::AsmOperandInfoVector TargetConstraints = TLI.ParseConstraints(ImmutableCallSite(CI));
+ const TargetMachine &TM) {
+ const Function *F = CI->getParent()->getParent();
+ const TargetLowering *TLI = TM.getSubtargetImpl(*F)->getTargetLowering();
+ const TargetRegisterInfo *TRI = TM.getSubtargetImpl(*F)->getRegisterInfo();
+ TargetLowering::AsmOperandInfoVector TargetConstraints =
+ TLI->ParseConstraints(TRI, ImmutableCallSite(CI));
for (unsigned i = 0, e = TargetConstraints.size(); i != e; ++i) {
TargetLowering::AsmOperandInfo &OpInfo = TargetConstraints[i];
// Compute the constraint code and ConstraintType to use.
- TLI.ComputeConstraintToUse(OpInfo, SDValue());
+ TLI->ComputeConstraintToUse(OpInfo, SDValue());
// If this asm operand is our Value*, and if it isn't an indirect memory
// operand, we can't fold it!
/// FindAllMemoryUses - Recursively walk all the uses of I until we find a
/// memory use. If we find an obviously non-foldable instruction, return true.
/// Add the ultimately found memory instructions to MemoryUses.
-static bool FindAllMemoryUses(Instruction *I,
- SmallVectorImpl<std::pair<Instruction*,unsigned> > &MemoryUses,
- SmallPtrSet<Instruction*, 16> &ConsideredInsts,
- const TargetLowering &TLI) {
+static bool FindAllMemoryUses(
+ Instruction *I,
+ SmallVectorImpl<std::pair<Instruction *, unsigned>> &MemoryUses,
+ SmallPtrSetImpl<Instruction *> &ConsideredInsts, const TargetMachine &TM) {
// If we already considered this instruction, we're done.
- if (!ConsideredInsts.insert(I))
+ if (!ConsideredInsts.insert(I).second)
return false;
// If this is an obviously unfoldable instruction, bail out.
if (!IA) return true;
// If this is a memory operand, we're cool, otherwise bail out.
- if (!IsOperandAMemoryOperand(CI, IA, I, TLI))
+ if (!IsOperandAMemoryOperand(CI, IA, I, TM))
return true;
continue;
}
- if (FindAllMemoryUses(UserI, MemoryUses, ConsideredInsts, TLI))
+ if (FindAllMemoryUses(UserI, MemoryUses, ConsideredInsts, TM))
return true;
}
// uses.
SmallVector<std::pair<Instruction*,unsigned>, 16> MemoryUses;
SmallPtrSet<Instruction*, 16> ConsideredInsts;
- if (FindAllMemoryUses(I, MemoryUses, ConsideredInsts, TLI))
+ if (FindAllMemoryUses(I, MemoryUses, ConsideredInsts, TM))
return false; // Has a non-memory, non-foldable use!
// Now that we know that all uses of this instruction are part of a chain of
ExtAddrMode Result;
TypePromotionTransaction::ConstRestorationPt LastKnownGood =
TPT.getRestorationPoint();
- AddressingModeMatcher Matcher(MatchedAddrModeInsts, TLI, AddressAccessTy,
+ AddressingModeMatcher Matcher(MatchedAddrModeInsts, TM, AddressAccessTy,
MemoryInst, Result, InsertedTruncs,
PromotedInsts, TPT);
Matcher.IgnoreProfitability = true;
worklist.pop_back();
// Break use-def graph loops.
- if (!Visited.insert(V)) {
+ if (!Visited.insert(V).second) {
Consensus = nullptr;
break;
}
// For non-PHIs, determine the addressing mode being computed.
SmallVector<Instruction*, 16> NewAddrModeInsts;
ExtAddrMode NewAddrMode = AddressingModeMatcher::Match(
- V, AccessTy, MemoryInst, NewAddrModeInsts, *TLI, InsertedTruncsSet,
+ V, AccessTy, MemoryInst, NewAddrModeInsts, *TM, InsertedTruncsSet,
PromotedInsts, TPT);
// This check is broken into two cases with very similar code to avoid using
<< *MemoryInst << "\n");
if (SunkAddr->getType() != Addr->getType())
SunkAddr = Builder.CreateBitCast(SunkAddr, Addr->getType());
- } else if (AddrSinkUsingGEPs || (!AddrSinkUsingGEPs.getNumOccurrences() &&
- TM && TM->getSubtarget<TargetSubtargetInfo>().useAA())) {
+ } else if (AddrSinkUsingGEPs ||
+ (!AddrSinkUsingGEPs.getNumOccurrences() && TM &&
+ TM->getSubtargetImpl(*MemoryInst->getParent()->getParent())
+ ->useAA())) {
// By default, we use the GEP-based method when AA is used later. This
// prevents new inttoptr/ptrtoint pairs from degrading AA capabilities.
DEBUG(dbgs() << "CGP: SINKING nonlocal addrmode: " << AddrMode << " for "
return false;
} else {
Type *I8PtrTy =
- Builder.getInt8PtrTy(Addr->getType()->getPointerAddressSpace());
+ Builder.getInt8PtrTy(Addr->getType()->getPointerAddressSpace());
+ Type *I8Ty = Builder.getInt8Ty();
// Start with the base register. Do this first so that subsequent address
// matching finds it last, which will prevent it from trying to match it
if (AddrMode.BaseOffs) {
Value *V = ConstantInt::get(IntPtrTy, AddrMode.BaseOffs);
if (ResultIndex) {
- // We need to add this separately from the scale above to help with
- // SDAG consecutive load/store merging.
+ // We need to add this separately from the scale above to help with
+ // SDAG consecutive load/store merging.
if (ResultPtr->getType() != I8PtrTy)
ResultPtr = Builder.CreateBitCast(ResultPtr, I8PtrTy);
- ResultPtr = Builder.CreateGEP(ResultPtr, ResultIndex, "sunkaddr");
+ ResultPtr = Builder.CreateGEP(I8Ty, ResultPtr, ResultIndex, "sunkaddr");
}
ResultIndex = V;
} else {
if (ResultPtr->getType() != I8PtrTy)
ResultPtr = Builder.CreateBitCast(ResultPtr, I8PtrTy);
- SunkAddr = Builder.CreateGEP(ResultPtr, ResultIndex, "sunkaddr");
+ SunkAddr = Builder.CreateGEP(I8Ty, ResultPtr, ResultIndex, "sunkaddr");
}
if (SunkAddr->getType() != Addr->getType())
bool CodeGenPrepare::OptimizeInlineAsmInst(CallInst *CS) {
bool MadeChange = false;
+ const TargetRegisterInfo *TRI =
+ TM->getSubtargetImpl(*CS->getParent()->getParent())->getRegisterInfo();
TargetLowering::AsmOperandInfoVector
- TargetConstraints = TLI->ParseConstraints(CS);
+ TargetConstraints = TLI->ParseConstraints(TRI, CS);
unsigned ArgNo = 0;
for (unsigned i = 0, e = TargetConstraints.size(); i != e; ++i) {
TargetLowering::AsmOperandInfo &OpInfo = TargetConstraints[i];
return MadeChange;
}
+/// \brief Check if all the uses of \p Inst are equivalent (or free) zero or
+/// sign extensions.
+static bool hasSameExtUse(Instruction *Inst, const TargetLowering &TLI) {
+ assert(!Inst->use_empty() && "Input must have at least one use");
+ const Instruction *FirstUser = cast<Instruction>(*Inst->user_begin());
+ bool IsSExt = isa<SExtInst>(FirstUser);
+ Type *ExtTy = FirstUser->getType();
+ for (const User *U : Inst->users()) {
+ const Instruction *UI = cast<Instruction>(U);
+ if ((IsSExt && !isa<SExtInst>(UI)) || (!IsSExt && !isa<ZExtInst>(UI)))
+ return false;
+ Type *CurTy = UI->getType();
+ // Same input and output types: Same instruction after CSE.
+ if (CurTy == ExtTy)
+ continue;
+
+ // If IsSExt is true, we are in this situation:
+ // a = Inst
+ // b = sext ty1 a to ty2
+ // c = sext ty1 a to ty3
+ // Assuming ty2 is shorter than ty3, this could be turned into:
+ // a = Inst
+ // b = sext ty1 a to ty2
+ // c = sext ty2 b to ty3
+ // However, the last sext is not free.
+ if (IsSExt)
+ return false;
+
+ // This is a ZExt, maybe this is free to extend from one type to another.
+ // In that case, we would not account for a different use.
+ Type *NarrowTy;
+ Type *LargeTy;
+ if (ExtTy->getScalarType()->getIntegerBitWidth() >
+ CurTy->getScalarType()->getIntegerBitWidth()) {
+ NarrowTy = CurTy;
+ LargeTy = ExtTy;
+ } else {
+ NarrowTy = ExtTy;
+ LargeTy = CurTy;
+ }
+
+ if (!TLI.isZExtFree(NarrowTy, LargeTy))
+ return false;
+ }
+ // All uses are the same or can be derived from one another for free.
+ return true;
+}
+
+/// \brief Try to form ExtLd by promoting \p Exts until they reach a
+/// load instruction.
+/// If an ext(load) can be formed, it is returned via \p LI for the load
+/// and \p Inst for the extension.
+/// Otherwise LI == nullptr and Inst == nullptr.
+/// When some promotion happened, \p TPT contains the proper state to
+/// revert them.
+///
+/// \return true when promoting was necessary to expose the ext(load)
+/// opportunity, false otherwise.
+///
+/// Example:
+/// \code
+/// %ld = load i32* %addr
+/// %add = add nuw i32 %ld, 4
+/// %zext = zext i32 %add to i64
+/// \endcode
+/// =>
+/// \code
+/// %ld = load i32* %addr
+/// %zext = zext i32 %ld to i64
+/// %add = add nuw i64 %zext, 4
+/// \encode
+/// Thanks to the promotion, we can match zext(load i32*) to i64.
+bool CodeGenPrepare::ExtLdPromotion(TypePromotionTransaction &TPT,
+ LoadInst *&LI, Instruction *&Inst,
+ const SmallVectorImpl<Instruction *> &Exts,
+ unsigned CreatedInstsCost = 0) {
+ // Iterate over all the extensions to see if one form an ext(load).
+ for (auto I : Exts) {
+ // Check if we directly have ext(load).
+ if ((LI = dyn_cast<LoadInst>(I->getOperand(0)))) {
+ Inst = I;
+ // No promotion happened here.
+ return false;
+ }
+ // Check whether or not we want to do any promotion.
+ if (!TLI || !TLI->enableExtLdPromotion() || DisableExtLdPromotion)
+ continue;
+ // Get the action to perform the promotion.
+ TypePromotionHelper::Action TPH = TypePromotionHelper::getAction(
+ I, InsertedTruncsSet, *TLI, PromotedInsts);
+ // Check if we can promote.
+ if (!TPH)
+ continue;
+ // Save the current state.
+ TypePromotionTransaction::ConstRestorationPt LastKnownGood =
+ TPT.getRestorationPoint();
+ SmallVector<Instruction *, 4> NewExts;
+ unsigned NewCreatedInstsCost = 0;
+ unsigned ExtCost = !TLI->isExtFree(I);
+ // Promote.
+ Value *PromotedVal = TPH(I, TPT, PromotedInsts, NewCreatedInstsCost,
+ &NewExts, nullptr, *TLI);
+ assert(PromotedVal &&
+ "TypePromotionHelper should have filtered out those cases");
+
+ // We would be able to merge only one extension in a load.
+ // Therefore, if we have more than 1 new extension we heuristically
+ // cut this search path, because it means we degrade the code quality.
+ // With exactly 2, the transformation is neutral, because we will merge
+ // one extension but leave one. However, we optimistically keep going,
+ // because the new extension may be removed too.
+ long long TotalCreatedInstsCost = CreatedInstsCost + NewCreatedInstsCost;
+ TotalCreatedInstsCost -= ExtCost;
+ if (!StressExtLdPromotion &&
+ (TotalCreatedInstsCost > 1 ||
+ !isPromotedInstructionLegal(*TLI, PromotedVal))) {
+ // The promotion is not profitable, rollback to the previous state.
+ TPT.rollback(LastKnownGood);
+ continue;
+ }
+ // The promotion is profitable.
+ // Check if it exposes an ext(load).
+ (void)ExtLdPromotion(TPT, LI, Inst, NewExts, TotalCreatedInstsCost);
+ if (LI && (StressExtLdPromotion || NewCreatedInstsCost <= ExtCost ||
+ // If we have created a new extension, i.e., now we have two
+ // extensions. We must make sure one of them is merged with
+ // the load, otherwise we may degrade the code quality.
+ (LI->hasOneUse() || hasSameExtUse(LI, *TLI))))
+ // Promotion happened.
+ return true;
+ // If this does not help to expose an ext(load) then, rollback.
+ TPT.rollback(LastKnownGood);
+ }
+ // None of the extension can form an ext(load).
+ LI = nullptr;
+ Inst = nullptr;
+ return false;
+}
+
/// MoveExtToFormExtLoad - Move a zext or sext fed by a load into the same
/// basic block as the load, unless conditions are unfavorable. This allows
/// SelectionDAG to fold the extend into the load.
+/// \p I[in/out] the extension may be modified during the process if some
+/// promotions apply.
///
-bool CodeGenPrepare::MoveExtToFormExtLoad(Instruction *I) {
+bool CodeGenPrepare::MoveExtToFormExtLoad(Instruction *&I) {
+ // Try to promote a chain of computation if it allows to form
+ // an extended load.
+ TypePromotionTransaction TPT;
+ TypePromotionTransaction::ConstRestorationPt LastKnownGood =
+ TPT.getRestorationPoint();
+ SmallVector<Instruction *, 1> Exts;
+ Exts.push_back(I);
// Look for a load being extended.
- LoadInst *LI = dyn_cast<LoadInst>(I->getOperand(0));
- if (!LI) return false;
+ LoadInst *LI = nullptr;
+ Instruction *OldExt = I;
+ bool HasPromoted = ExtLdPromotion(TPT, LI, I, Exts);
+ if (!LI || !I) {
+ assert(!HasPromoted && !LI && "If we did not match any load instruction "
+ "the code must remain the same");
+ I = OldExt;
+ return false;
+ }
// If they're already in the same block, there's nothing to do.
- if (LI->getParent() == I->getParent())
+ // Make the cheap checks first if we did not promote.
+ // If we promoted, we need to check if it is indeed profitable.
+ if (!HasPromoted && LI->getParent() == I->getParent())
return false;
+ EVT VT = TLI->getValueType(I->getType());
+ EVT LoadVT = TLI->getValueType(LI->getType());
+
// If the load has other users and the truncate is not free, this probably
// isn't worthwhile.
- if (!LI->hasOneUse() &&
- TLI && (TLI->isTypeLegal(TLI->getValueType(LI->getType())) ||
- !TLI->isTypeLegal(TLI->getValueType(I->getType()))) &&
- !TLI->isTruncateFree(I->getType(), LI->getType()))
+ if (!LI->hasOneUse() && TLI &&
+ (TLI->isTypeLegal(LoadVT) || !TLI->isTypeLegal(VT)) &&
+ !TLI->isTruncateFree(I->getType(), LI->getType())) {
+ I = OldExt;
+ TPT.rollback(LastKnownGood);
return false;
+ }
// Check whether the target supports casts folded into loads.
unsigned LType;
assert(isa<SExtInst>(I) && "Unexpected ext type!");
LType = ISD::SEXTLOAD;
}
- if (TLI && !TLI->isLoadExtLegal(LType, TLI->getValueType(LI->getType())))
+ if (TLI && !TLI->isLoadExtLegal(LType, VT, LoadVT)) {
+ I = OldExt;
+ TPT.rollback(LastKnownGood);
return false;
+ }
// Move the extend into the same block as the load, so that SelectionDAG
// can fold it.
+ TPT.commit();
I->removeFromParent();
I->insertAfter(LI);
++NumExtsMoved;
return MadeChange;
}
-bool CodeGenPrepare::OptimizeInst(Instruction *I) {
+namespace {
+/// \brief Helper class to promote a scalar operation to a vector one.
+/// This class is used to move downward extractelement transition.
+/// E.g.,
+/// a = vector_op <2 x i32>
+/// b = extractelement <2 x i32> a, i32 0
+/// c = scalar_op b
+/// store c
+///
+/// =>
+/// a = vector_op <2 x i32>
+/// c = vector_op a (equivalent to scalar_op on the related lane)
+/// * d = extractelement <2 x i32> c, i32 0
+/// * store d
+/// Assuming both extractelement and store can be combine, we get rid of the
+/// transition.
+class VectorPromoteHelper {
+ /// Used to perform some checks on the legality of vector operations.
+ const TargetLowering &TLI;
+
+ /// Used to estimated the cost of the promoted chain.
+ const TargetTransformInfo &TTI;
+
+ /// The transition being moved downwards.
+ Instruction *Transition;
+ /// The sequence of instructions to be promoted.
+ SmallVector<Instruction *, 4> InstsToBePromoted;
+ /// Cost of combining a store and an extract.
+ unsigned StoreExtractCombineCost;
+ /// Instruction that will be combined with the transition.
+ Instruction *CombineInst;
+
+ /// \brief The instruction that represents the current end of the transition.
+ /// Since we are faking the promotion until we reach the end of the chain
+ /// of computation, we need a way to get the current end of the transition.
+ Instruction *getEndOfTransition() const {
+ if (InstsToBePromoted.empty())
+ return Transition;
+ return InstsToBePromoted.back();
+ }
+
+ /// \brief Return the index of the original value in the transition.
+ /// E.g., for "extractelement <2 x i32> c, i32 1" the original value,
+ /// c, is at index 0.
+ unsigned getTransitionOriginalValueIdx() const {
+ assert(isa<ExtractElementInst>(Transition) &&
+ "Other kind of transitions are not supported yet");
+ return 0;
+ }
+
+ /// \brief Return the index of the index in the transition.
+ /// E.g., for "extractelement <2 x i32> c, i32 0" the index
+ /// is at index 1.
+ unsigned getTransitionIdx() const {
+ assert(isa<ExtractElementInst>(Transition) &&
+ "Other kind of transitions are not supported yet");
+ return 1;
+ }
+
+ /// \brief Get the type of the transition.
+ /// This is the type of the original value.
+ /// E.g., for "extractelement <2 x i32> c, i32 1" the type of the
+ /// transition is <2 x i32>.
+ Type *getTransitionType() const {
+ return Transition->getOperand(getTransitionOriginalValueIdx())->getType();
+ }
+
+ /// \brief Promote \p ToBePromoted by moving \p Def downward through.
+ /// I.e., we have the following sequence:
+ /// Def = Transition <ty1> a to <ty2>
+ /// b = ToBePromoted <ty2> Def, ...
+ /// =>
+ /// b = ToBePromoted <ty1> a, ...
+ /// Def = Transition <ty1> ToBePromoted to <ty2>
+ void promoteImpl(Instruction *ToBePromoted);
+
+ /// \brief Check whether or not it is profitable to promote all the
+ /// instructions enqueued to be promoted.
+ bool isProfitableToPromote() {
+ Value *ValIdx = Transition->getOperand(getTransitionOriginalValueIdx());
+ unsigned Index = isa<ConstantInt>(ValIdx)
+ ? cast<ConstantInt>(ValIdx)->getZExtValue()
+ : -1;
+ Type *PromotedType = getTransitionType();
+
+ StoreInst *ST = cast<StoreInst>(CombineInst);
+ unsigned AS = ST->getPointerAddressSpace();
+ unsigned Align = ST->getAlignment();
+ // Check if this store is supported.
+ if (!TLI.allowsMisalignedMemoryAccesses(
+ TLI.getValueType(ST->getValueOperand()->getType()), AS, Align)) {
+ // If this is not supported, there is no way we can combine
+ // the extract with the store.
+ return false;
+ }
+
+ // The scalar chain of computation has to pay for the transition
+ // scalar to vector.
+ // The vector chain has to account for the combining cost.
+ uint64_t ScalarCost =
+ TTI.getVectorInstrCost(Transition->getOpcode(), PromotedType, Index);
+ uint64_t VectorCost = StoreExtractCombineCost;
+ for (const auto &Inst : InstsToBePromoted) {
+ // Compute the cost.
+ // By construction, all instructions being promoted are arithmetic ones.
+ // Moreover, one argument is a constant that can be viewed as a splat
+ // constant.
+ Value *Arg0 = Inst->getOperand(0);
+ bool IsArg0Constant = isa<UndefValue>(Arg0) || isa<ConstantInt>(Arg0) ||
+ isa<ConstantFP>(Arg0);
+ TargetTransformInfo::OperandValueKind Arg0OVK =
+ IsArg0Constant ? TargetTransformInfo::OK_UniformConstantValue
+ : TargetTransformInfo::OK_AnyValue;
+ TargetTransformInfo::OperandValueKind Arg1OVK =
+ !IsArg0Constant ? TargetTransformInfo::OK_UniformConstantValue
+ : TargetTransformInfo::OK_AnyValue;
+ ScalarCost += TTI.getArithmeticInstrCost(
+ Inst->getOpcode(), Inst->getType(), Arg0OVK, Arg1OVK);
+ VectorCost += TTI.getArithmeticInstrCost(Inst->getOpcode(), PromotedType,
+ Arg0OVK, Arg1OVK);
+ }
+ DEBUG(dbgs() << "Estimated cost of computation to be promoted:\nScalar: "
+ << ScalarCost << "\nVector: " << VectorCost << '\n');
+ return ScalarCost > VectorCost;
+ }
+
+ /// \brief Generate a constant vector with \p Val with the same
+ /// number of elements as the transition.
+ /// \p UseSplat defines whether or not \p Val should be replicated
+ /// accross the whole vector.
+ /// In other words, if UseSplat == true, we generate <Val, Val, ..., Val>,
+ /// otherwise we generate a vector with as many undef as possible:
+ /// <undef, ..., undef, Val, undef, ..., undef> where \p Val is only
+ /// used at the index of the extract.
+ Value *getConstantVector(Constant *Val, bool UseSplat) const {
+ unsigned ExtractIdx = UINT_MAX;
+ if (!UseSplat) {
+ // If we cannot determine where the constant must be, we have to
+ // use a splat constant.
+ Value *ValExtractIdx = Transition->getOperand(getTransitionIdx());
+ if (ConstantInt *CstVal = dyn_cast<ConstantInt>(ValExtractIdx))
+ ExtractIdx = CstVal->getSExtValue();
+ else
+ UseSplat = true;
+ }
+
+ unsigned End = getTransitionType()->getVectorNumElements();
+ if (UseSplat)
+ return ConstantVector::getSplat(End, Val);
+
+ SmallVector<Constant *, 4> ConstVec;
+ UndefValue *UndefVal = UndefValue::get(Val->getType());
+ for (unsigned Idx = 0; Idx != End; ++Idx) {
+ if (Idx == ExtractIdx)
+ ConstVec.push_back(Val);
+ else
+ ConstVec.push_back(UndefVal);
+ }
+ return ConstantVector::get(ConstVec);
+ }
+
+ /// \brief Check if promoting to a vector type an operand at \p OperandIdx
+ /// in \p Use can trigger undefined behavior.
+ static bool canCauseUndefinedBehavior(const Instruction *Use,
+ unsigned OperandIdx) {
+ // This is not safe to introduce undef when the operand is on
+ // the right hand side of a division-like instruction.
+ if (OperandIdx != 1)
+ return false;
+ switch (Use->getOpcode()) {
+ default:
+ return false;
+ case Instruction::SDiv:
+ case Instruction::UDiv:
+ case Instruction::SRem:
+ case Instruction::URem:
+ return true;
+ case Instruction::FDiv:
+ case Instruction::FRem:
+ return !Use->hasNoNaNs();
+ }
+ llvm_unreachable(nullptr);
+ }
+
+public:
+ VectorPromoteHelper(const TargetLowering &TLI, const TargetTransformInfo &TTI,
+ Instruction *Transition, unsigned CombineCost)
+ : TLI(TLI), TTI(TTI), Transition(Transition),
+ StoreExtractCombineCost(CombineCost), CombineInst(nullptr) {
+ assert(Transition && "Do not know how to promote null");
+ }
+
+ /// \brief Check if we can promote \p ToBePromoted to \p Type.
+ bool canPromote(const Instruction *ToBePromoted) const {
+ // We could support CastInst too.
+ return isa<BinaryOperator>(ToBePromoted);
+ }
+
+ /// \brief Check if it is profitable to promote \p ToBePromoted
+ /// by moving downward the transition through.
+ bool shouldPromote(const Instruction *ToBePromoted) const {
+ // Promote only if all the operands can be statically expanded.
+ // Indeed, we do not want to introduce any new kind of transitions.
+ for (const Use &U : ToBePromoted->operands()) {
+ const Value *Val = U.get();
+ if (Val == getEndOfTransition()) {
+ // If the use is a division and the transition is on the rhs,
+ // we cannot promote the operation, otherwise we may create a
+ // division by zero.
+ if (canCauseUndefinedBehavior(ToBePromoted, U.getOperandNo()))
+ return false;
+ continue;
+ }
+ if (!isa<ConstantInt>(Val) && !isa<UndefValue>(Val) &&
+ !isa<ConstantFP>(Val))
+ return false;
+ }
+ // Check that the resulting operation is legal.
+ int ISDOpcode = TLI.InstructionOpcodeToISD(ToBePromoted->getOpcode());
+ if (!ISDOpcode)
+ return false;
+ return StressStoreExtract ||
+ TLI.isOperationLegalOrCustom(
+ ISDOpcode, TLI.getValueType(getTransitionType(), true));
+ }
+
+ /// \brief Check whether or not \p Use can be combined
+ /// with the transition.
+ /// I.e., is it possible to do Use(Transition) => AnotherUse?
+ bool canCombine(const Instruction *Use) { return isa<StoreInst>(Use); }
+
+ /// \brief Record \p ToBePromoted as part of the chain to be promoted.
+ void enqueueForPromotion(Instruction *ToBePromoted) {
+ InstsToBePromoted.push_back(ToBePromoted);
+ }
+
+ /// \brief Set the instruction that will be combined with the transition.
+ void recordCombineInstruction(Instruction *ToBeCombined) {
+ assert(canCombine(ToBeCombined) && "Unsupported instruction to combine");
+ CombineInst = ToBeCombined;
+ }
+
+ /// \brief Promote all the instructions enqueued for promotion if it is
+ /// is profitable.
+ /// \return True if the promotion happened, false otherwise.
+ bool promote() {
+ // Check if there is something to promote.
+ // Right now, if we do not have anything to combine with,
+ // we assume the promotion is not profitable.
+ if (InstsToBePromoted.empty() || !CombineInst)
+ return false;
+
+ // Check cost.
+ if (!StressStoreExtract && !isProfitableToPromote())
+ return false;
+
+ // Promote.
+ for (auto &ToBePromoted : InstsToBePromoted)
+ promoteImpl(ToBePromoted);
+ InstsToBePromoted.clear();
+ return true;
+ }
+};
+} // End of anonymous namespace.
+
+void VectorPromoteHelper::promoteImpl(Instruction *ToBePromoted) {
+ // At this point, we know that all the operands of ToBePromoted but Def
+ // can be statically promoted.
+ // For Def, we need to use its parameter in ToBePromoted:
+ // b = ToBePromoted ty1 a
+ // Def = Transition ty1 b to ty2
+ // Move the transition down.
+ // 1. Replace all uses of the promoted operation by the transition.
+ // = ... b => = ... Def.
+ assert(ToBePromoted->getType() == Transition->getType() &&
+ "The type of the result of the transition does not match "
+ "the final type");
+ ToBePromoted->replaceAllUsesWith(Transition);
+ // 2. Update the type of the uses.
+ // b = ToBePromoted ty2 Def => b = ToBePromoted ty1 Def.
+ Type *TransitionTy = getTransitionType();
+ ToBePromoted->mutateType(TransitionTy);
+ // 3. Update all the operands of the promoted operation with promoted
+ // operands.
+ // b = ToBePromoted ty1 Def => b = ToBePromoted ty1 a.
+ for (Use &U : ToBePromoted->operands()) {
+ Value *Val = U.get();
+ Value *NewVal = nullptr;
+ if (Val == Transition)
+ NewVal = Transition->getOperand(getTransitionOriginalValueIdx());
+ else if (isa<UndefValue>(Val) || isa<ConstantInt>(Val) ||
+ isa<ConstantFP>(Val)) {
+ // Use a splat constant if it is not safe to use undef.
+ NewVal = getConstantVector(
+ cast<Constant>(Val),
+ isa<UndefValue>(Val) ||
+ canCauseUndefinedBehavior(ToBePromoted, U.getOperandNo()));
+ } else
+ llvm_unreachable("Did you modified shouldPromote and forgot to update "
+ "this?");
+ ToBePromoted->setOperand(U.getOperandNo(), NewVal);
+ }
+ Transition->removeFromParent();
+ Transition->insertAfter(ToBePromoted);
+ Transition->setOperand(getTransitionOriginalValueIdx(), ToBePromoted);
+}
+
+/// Some targets can do store(extractelement) with one instruction.
+/// Try to push the extractelement towards the stores when the target
+/// has this feature and this is profitable.
+bool CodeGenPrepare::OptimizeExtractElementInst(Instruction *Inst) {
+ unsigned CombineCost = UINT_MAX;
+ if (DisableStoreExtract || !TLI ||
+ (!StressStoreExtract &&
+ !TLI->canCombineStoreAndExtract(Inst->getOperand(0)->getType(),
+ Inst->getOperand(1), CombineCost)))
+ return false;
+
+ // At this point we know that Inst is a vector to scalar transition.
+ // Try to move it down the def-use chain, until:
+ // - We can combine the transition with its single use
+ // => we got rid of the transition.
+ // - We escape the current basic block
+ // => we would need to check that we are moving it at a cheaper place and
+ // we do not do that for now.
+ BasicBlock *Parent = Inst->getParent();
+ DEBUG(dbgs() << "Found an interesting transition: " << *Inst << '\n');
+ VectorPromoteHelper VPH(*TLI, *TTI, Inst, CombineCost);
+ // If the transition has more than one use, assume this is not going to be
+ // beneficial.
+ while (Inst->hasOneUse()) {
+ Instruction *ToBePromoted = cast<Instruction>(*Inst->user_begin());
+ DEBUG(dbgs() << "Use: " << *ToBePromoted << '\n');
+
+ if (ToBePromoted->getParent() != Parent) {
+ DEBUG(dbgs() << "Instruction to promote is in a different block ("
+ << ToBePromoted->getParent()->getName()
+ << ") than the transition (" << Parent->getName() << ").\n");
+ return false;
+ }
+
+ if (VPH.canCombine(ToBePromoted)) {
+ DEBUG(dbgs() << "Assume " << *Inst << '\n'
+ << "will be combined with: " << *ToBePromoted << '\n');
+ VPH.recordCombineInstruction(ToBePromoted);
+ bool Changed = VPH.promote();
+ NumStoreExtractExposed += Changed;
+ return Changed;
+ }
+
+ DEBUG(dbgs() << "Try promoting.\n");
+ if (!VPH.canPromote(ToBePromoted) || !VPH.shouldPromote(ToBePromoted))
+ return false;
+
+ DEBUG(dbgs() << "Promoting is possible... Enqueue for promotion!\n");
+
+ VPH.enqueueForPromotion(ToBePromoted);
+ Inst = ToBePromoted;
+ }
+ return false;
+}
+
+bool CodeGenPrepare::OptimizeInst(Instruction *I, bool& ModifiedDT) {
if (PHINode *P = dyn_cast<PHINode>(I)) {
// It is possible for very late stage optimizations (such as SimplifyCFG)
// to introduce PHI nodes too late to be cleaned up. If we detect such a
// trivial PHI, go ahead and zap it here.
- if (Value *V = SimplifyInstruction(P, TLI ? TLI->getDataLayout() : nullptr,
- TLInfo, DT)) {
+ const DataLayout &DL = I->getModule()->getDataLayout();
+ if (Value *V = SimplifyInstruction(P, DL, TLInfo, nullptr)) {
P->replaceAllUsesWith(V);
P->eraseFromParent();
++NumPHIsElim;
GEPI->replaceAllUsesWith(NC);
GEPI->eraseFromParent();
++NumGEPsElim;
- OptimizeInst(NC);
+ OptimizeInst(NC, ModifiedDT);
return true;
}
return false;
}
if (CallInst *CI = dyn_cast<CallInst>(I))
- return OptimizeCallInst(CI);
+ return OptimizeCallInst(CI, ModifiedDT);
if (SelectInst *SI = dyn_cast<SelectInst>(I))
return OptimizeSelectInst(SI);
if (ShuffleVectorInst *SVI = dyn_cast<ShuffleVectorInst>(I))
return OptimizeShuffleVectorInst(SVI);
+ if (isa<ExtractElementInst>(I))
+ return OptimizeExtractElementInst(I);
+
return false;
}
// In this pass we look for GEP and cast instructions that are used
// across basic blocks and rewrite them to improve basic-block-at-a-time
// selection.
-bool CodeGenPrepare::OptimizeBlock(BasicBlock &BB) {
+bool CodeGenPrepare::OptimizeBlock(BasicBlock &BB, bool& ModifiedDT) {
SunkAddrs.clear();
bool MadeChange = false;
CurInstIterator = BB.begin();
- while (CurInstIterator != BB.end())
- MadeChange |= OptimizeInst(CurInstIterator++);
-
+ while (CurInstIterator != BB.end()) {
+ MadeChange |= OptimizeInst(CurInstIterator++, ModifiedDT);
+ if (ModifiedDT)
+ return true;
+ }
MadeChange |= DupRetToEnableTailCallOpts(&BB);
return MadeChange;
// find a node corresponding to the value.
bool CodeGenPrepare::PlaceDbgValues(Function &F) {
bool MadeChange = false;
- for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I) {
+ for (BasicBlock &BB : F) {
Instruction *PrevNonDbgInst = nullptr;
- for (BasicBlock::iterator BI = I->begin(), BE = I->end(); BI != BE;) {
- Instruction *Insn = BI; ++BI;
+ for (BasicBlock::iterator BI = BB.begin(), BE = BB.end(); BI != BE;) {
+ Instruction *Insn = BI++;
DbgValueInst *DVI = dyn_cast<DbgValueInst>(Insn);
// Leave dbg.values that refer to an alloca alone. These
// instrinsics describe the address of a variable (= the alloca)
}
return MadeChange;
}
+
+/// \brief Retrieve the probabilities of a conditional branch. Returns true on
+/// success, or returns false if no or invalid metadata was found.
+static bool extractBranchMetadata(BranchInst *BI,
+ uint64_t &ProbTrue, uint64_t &ProbFalse) {
+ assert(BI->isConditional() &&
+ "Looking for probabilities on unconditional branch?");
+ auto *ProfileData = BI->getMetadata(LLVMContext::MD_prof);
+ if (!ProfileData || ProfileData->getNumOperands() != 3)
+ return false;
+
+ const auto *CITrue =
+ mdconst::dyn_extract<ConstantInt>(ProfileData->getOperand(1));
+ const auto *CIFalse =
+ mdconst::dyn_extract<ConstantInt>(ProfileData->getOperand(2));
+ if (!CITrue || !CIFalse)
+ return false;
+
+ ProbTrue = CITrue->getValue().getZExtValue();
+ ProbFalse = CIFalse->getValue().getZExtValue();
+
+ return true;
+}
+
+/// \brief Scale down both weights to fit into uint32_t.
+static void scaleWeights(uint64_t &NewTrue, uint64_t &NewFalse) {
+ uint64_t NewMax = (NewTrue > NewFalse) ? NewTrue : NewFalse;
+ uint32_t Scale = (NewMax / UINT32_MAX) + 1;
+ NewTrue = NewTrue / Scale;
+ NewFalse = NewFalse / Scale;
+}
+
+/// \brief Some targets prefer to split a conditional branch like:
+/// \code
+/// %0 = icmp ne i32 %a, 0
+/// %1 = icmp ne i32 %b, 0
+/// %or.cond = or i1 %0, %1
+/// br i1 %or.cond, label %TrueBB, label %FalseBB
+/// \endcode
+/// into multiple branch instructions like:
+/// \code
+/// bb1:
+/// %0 = icmp ne i32 %a, 0
+/// br i1 %0, label %TrueBB, label %bb2
+/// bb2:
+/// %1 = icmp ne i32 %b, 0
+/// br i1 %1, label %TrueBB, label %FalseBB
+/// \endcode
+/// This usually allows instruction selection to do even further optimizations
+/// and combine the compare with the branch instruction. Currently this is
+/// applied for targets which have "cheap" jump instructions.
+///
+/// FIXME: Remove the (equivalent?) implementation in SelectionDAG.
+///
+bool CodeGenPrepare::splitBranchCondition(Function &F) {
+ if (!TM || !TM->Options.EnableFastISel || !TLI || TLI->isJumpExpensive())
+ return false;
+
+ bool MadeChange = false;
+ for (auto &BB : F) {
+ // Does this BB end with the following?
+ // %cond1 = icmp|fcmp|binary instruction ...
+ // %cond2 = icmp|fcmp|binary instruction ...
+ // %cond.or = or|and i1 %cond1, cond2
+ // br i1 %cond.or label %dest1, label %dest2"
+ BinaryOperator *LogicOp;
+ BasicBlock *TBB, *FBB;
+ if (!match(BB.getTerminator(), m_Br(m_OneUse(m_BinOp(LogicOp)), TBB, FBB)))
+ continue;
+
+ unsigned Opc;
+ Value *Cond1, *Cond2;
+ if (match(LogicOp, m_And(m_OneUse(m_Value(Cond1)),
+ m_OneUse(m_Value(Cond2)))))
+ Opc = Instruction::And;
+ else if (match(LogicOp, m_Or(m_OneUse(m_Value(Cond1)),
+ m_OneUse(m_Value(Cond2)))))
+ Opc = Instruction::Or;
+ else
+ continue;
+
+ if (!match(Cond1, m_CombineOr(m_Cmp(), m_BinOp())) ||
+ !match(Cond2, m_CombineOr(m_Cmp(), m_BinOp())) )
+ continue;
+
+ DEBUG(dbgs() << "Before branch condition splitting\n"; BB.dump());
+
+ // Create a new BB.
+ auto *InsertBefore = std::next(Function::iterator(BB))
+ .getNodePtrUnchecked();
+ auto TmpBB = BasicBlock::Create(BB.getContext(),
+ BB.getName() + ".cond.split",
+ BB.getParent(), InsertBefore);
+
+ // Update original basic block by using the first condition directly by the
+ // branch instruction and removing the no longer needed and/or instruction.
+ auto *Br1 = cast<BranchInst>(BB.getTerminator());
+ Br1->setCondition(Cond1);
+ LogicOp->eraseFromParent();
+
+ // Depending on the conditon we have to either replace the true or the false
+ // successor of the original branch instruction.
+ if (Opc == Instruction::And)
+ Br1->setSuccessor(0, TmpBB);
+ else
+ Br1->setSuccessor(1, TmpBB);
+
+ // Fill in the new basic block.
+ auto *Br2 = IRBuilder<>(TmpBB).CreateCondBr(Cond2, TBB, FBB);
+ if (auto *I = dyn_cast<Instruction>(Cond2)) {
+ I->removeFromParent();
+ I->insertBefore(Br2);
+ }
+
+ // Update PHI nodes in both successors. The original BB needs to be
+ // replaced in one succesor's PHI nodes, because the branch comes now from
+ // the newly generated BB (NewBB). In the other successor we need to add one
+ // incoming edge to the PHI nodes, because both branch instructions target
+ // now the same successor. Depending on the original branch condition
+ // (and/or) we have to swap the successors (TrueDest, FalseDest), so that
+ // we perfrom the correct update for the PHI nodes.
+ // This doesn't change the successor order of the just created branch
+ // instruction (or any other instruction).
+ if (Opc == Instruction::Or)
+ std::swap(TBB, FBB);
+
+ // Replace the old BB with the new BB.
+ for (auto &I : *TBB) {
+ PHINode *PN = dyn_cast<PHINode>(&I);
+ if (!PN)
+ break;
+ int i;
+ while ((i = PN->getBasicBlockIndex(&BB)) >= 0)
+ PN->setIncomingBlock(i, TmpBB);
+ }
+
+ // Add another incoming edge form the new BB.
+ for (auto &I : *FBB) {
+ PHINode *PN = dyn_cast<PHINode>(&I);
+ if (!PN)
+ break;
+ auto *Val = PN->getIncomingValueForBlock(&BB);
+ PN->addIncoming(Val, TmpBB);
+ }
+
+ // Update the branch weights (from SelectionDAGBuilder::
+ // FindMergedConditions).
+ if (Opc == Instruction::Or) {
+ // Codegen X | Y as:
+ // BB1:
+ // jmp_if_X TBB
+ // jmp TmpBB
+ // TmpBB:
+ // jmp_if_Y TBB
+ // jmp FBB
+ //
+
+ // We have flexibility in setting Prob for BB1 and Prob for NewBB.
+ // The requirement is that
+ // TrueProb for BB1 + (FalseProb for BB1 * TrueProb for TmpBB)
+ // = TrueProb for orignal BB.
+ // Assuming the orignal weights are A and B, one choice is to set BB1's
+ // weights to A and A+2B, and set TmpBB's weights to A and 2B. This choice
+ // assumes that
+ // TrueProb for BB1 == FalseProb for BB1 * TrueProb for TmpBB.
+ // Another choice is to assume TrueProb for BB1 equals to TrueProb for
+ // TmpBB, but the math is more complicated.
+ uint64_t TrueWeight, FalseWeight;
+ if (extractBranchMetadata(Br1, TrueWeight, FalseWeight)) {
+ uint64_t NewTrueWeight = TrueWeight;
+ uint64_t NewFalseWeight = TrueWeight + 2 * FalseWeight;
+ scaleWeights(NewTrueWeight, NewFalseWeight);
+ Br1->setMetadata(LLVMContext::MD_prof, MDBuilder(Br1->getContext())
+ .createBranchWeights(TrueWeight, FalseWeight));
+
+ NewTrueWeight = TrueWeight;
+ NewFalseWeight = 2 * FalseWeight;
+ scaleWeights(NewTrueWeight, NewFalseWeight);
+ Br2->setMetadata(LLVMContext::MD_prof, MDBuilder(Br2->getContext())
+ .createBranchWeights(TrueWeight, FalseWeight));
+ }
+ } else {
+ // Codegen X & Y as:
+ // BB1:
+ // jmp_if_X TmpBB
+ // jmp FBB
+ // TmpBB:
+ // jmp_if_Y TBB
+ // jmp FBB
+ //
+ // This requires creation of TmpBB after CurBB.
+
+ // We have flexibility in setting Prob for BB1 and Prob for TmpBB.
+ // The requirement is that
+ // FalseProb for BB1 + (TrueProb for BB1 * FalseProb for TmpBB)
+ // = FalseProb for orignal BB.
+ // Assuming the orignal weights are A and B, one choice is to set BB1's
+ // weights to 2A+B and B, and set TmpBB's weights to 2A and B. This choice
+ // assumes that
+ // FalseProb for BB1 == TrueProb for BB1 * FalseProb for TmpBB.
+ uint64_t TrueWeight, FalseWeight;
+ if (extractBranchMetadata(Br1, TrueWeight, FalseWeight)) {
+ uint64_t NewTrueWeight = 2 * TrueWeight + FalseWeight;
+ uint64_t NewFalseWeight = FalseWeight;
+ scaleWeights(NewTrueWeight, NewFalseWeight);
+ Br1->setMetadata(LLVMContext::MD_prof, MDBuilder(Br1->getContext())
+ .createBranchWeights(TrueWeight, FalseWeight));
+
+ NewTrueWeight = 2 * TrueWeight;
+ NewFalseWeight = FalseWeight;
+ scaleWeights(NewTrueWeight, NewFalseWeight);
+ Br2->setMetadata(LLVMContext::MD_prof, MDBuilder(Br2->getContext())
+ .createBranchWeights(TrueWeight, FalseWeight));
+ }
+ }
+
+ // Note: No point in getting fancy here, since the DT info is never
+ // available to CodeGenPrepare.
+ ModifiedDT = true;
+
+ MadeChange = true;
+
+ DEBUG(dbgs() << "After branch condition splitting\n"; BB.dump();
+ TmpBB->dump());
+ }
+ return MadeChange;
+}
projects / oota-llvm.git / blobdiff