diff options
Diffstat (limited to 'lib/Transforms/InstCombine')
| -rw-r--r-- | lib/Transforms/InstCombine/CMakeLists.txt | 8 | ||||
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombine.h | 5 | ||||
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineAndOrXor.cpp | 47 | ||||
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineCalls.cpp | 121 | ||||
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineCasts.cpp | 34 | ||||
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineCompares.cpp | 461 | ||||
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp | 71 | ||||
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineMulDivRem.cpp | 11 | ||||
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombinePHI.cpp | 10 | ||||
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineSelect.cpp | 14 | ||||
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineShifts.cpp | 47 | ||||
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp | 12 | ||||
| -rw-r--r-- | lib/Transforms/InstCombine/InstructionCombining.cpp | 593 |
13 files changed, 982 insertions, 452 deletions
diff --git a/lib/Transforms/InstCombine/CMakeLists.txt b/lib/Transforms/InstCombine/CMakeLists.txt index d070ccc..a46d5ad 100644 --- a/lib/Transforms/InstCombine/CMakeLists.txt +++ b/lib/Transforms/InstCombine/CMakeLists.txt @@ -13,3 +13,11 @@ add_llvm_library(LLVMInstCombine InstCombineSimplifyDemanded.cpp InstCombineVectorOps.cpp ) + +add_llvm_library_dependencies(LLVMInstCombine + LLVMAnalysis + LLVMCore + LLVMSupport + LLVMTarget + LLVMTransformUtils + ) diff --git a/lib/Transforms/InstCombine/InstCombine.h b/lib/Transforms/InstCombine/InstCombine.h index c6bdb08..3808278 100644 --- a/lib/Transforms/InstCombine/InstCombine.h +++ b/lib/Transforms/InstCombine/InstCombine.h @@ -11,6 +11,7 @@ #define INSTCOMBINE_INSTCOMBINE_H #include "InstCombineWorklist.h" +#include "llvm/IntrinsicInst.h" #include "llvm/Operator.h" #include "llvm/Pass.h" #include "llvm/Analysis/ValueTracking.h" @@ -192,6 +193,7 @@ public: Instruction *visitExtractElementInst(ExtractElementInst &EI); Instruction *visitShuffleVectorInst(ShuffleVectorInst &SVI); Instruction *visitExtractValueInst(ExtractValueInst &EV); + Instruction *visitLandingPadInst(LandingPadInst &LI); // visitInstruction - Specify what to return for unhandled instructions... Instruction *visitInstruction(Instruction &I) { return 0; } @@ -214,7 +216,8 @@ private: Instruction *visitCallSite(CallSite CS); Instruction *tryOptimizeCall(CallInst *CI, const TargetData *TD); bool transformConstExprCastCall(CallSite CS); - Instruction *transformCallThroughTrampoline(CallSite CS); + Instruction *transformCallThroughTrampoline(CallSite CS, + IntrinsicInst *Tramp); Instruction *transformZExtICmp(ICmpInst *ICI, Instruction &CI, bool DoXform = true); Instruction *transformSExtICmp(ICmpInst *ICI, Instruction &CI); diff --git a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp index 32920fa..5e0bfe8 100644 --- a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp +++ b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp @@ -1174,30 +1174,31 @@ Instruction *InstCombiner::visitAnd(BinaryOperator &I) { ((A == C && B == D) || (A == D && B == C))) return BinaryOperator::CreateXor(A, B); - if (Op0->hasOneUse() && - match(Op0, m_Xor(m_Value(A), m_Value(B)))) { - if (A == Op1) { // (A^B)&A -> A&(A^B) - I.swapOperands(); // Simplify below - std::swap(Op0, Op1); - } else if (B == Op1) { // (A^B)&B -> B&(B^A) - cast<BinaryOperator>(Op0)->swapOperands(); - I.swapOperands(); // Simplify below - std::swap(Op0, Op1); + // A&(A^B) => A & ~B + { + Value *tmpOp0 = Op0; + Value *tmpOp1 = Op1; + if (Op0->hasOneUse() && + match(Op0, m_Xor(m_Value(A), m_Value(B)))) { + if (A == Op1 || B == Op1 ) { + tmpOp1 = Op0; + tmpOp0 = Op1; + // Simplify below + } } - } - if (Op1->hasOneUse() && - match(Op1, m_Xor(m_Value(A), m_Value(B)))) { - if (B == Op0) { // B&(A^B) -> B&(B^A) - cast<BinaryOperator>(Op1)->swapOperands(); - std::swap(A, B); + if (tmpOp1->hasOneUse() && + match(tmpOp1, m_Xor(m_Value(A), m_Value(B)))) { + if (B == tmpOp0) { + std::swap(A, B); + } + // Notice that the patten (A&(~B)) is actually (A&(-1^B)), so if + // A is originally -1 (or a vector of -1 and undefs), then we enter + // an endless loop. By checking that A is non-constant we ensure that + // we will never get to the loop. + if (A == tmpOp0 && !isa<Constant>(A)) // A&(A^B) -> A & ~B + return BinaryOperator::CreateAnd(A, Builder->CreateNot(B)); } - // Notice that the patten (A&(~B)) is actually (A&(-1^B)), so if - // A is originally -1 (or a vector of -1 and undefs), then we enter - // an endless loop. By checking that A is non-constant we ensure that - // we will never get to the loop. - if (A == Op0 && !isa<Constant>(A)) // A&(A^B) -> A & ~B - return BinaryOperator::CreateAnd(A, Builder->CreateNot(B, "tmp")); } // (A&((~A)|B)) -> A&B @@ -2227,14 +2228,14 @@ Instruction *InstCombiner::visitXor(BinaryOperator &I) { if (A == Op1) // (B|A)^B == (A|B)^B std::swap(A, B); if (B == Op1) // (A|B)^B == A & ~B - return BinaryOperator::CreateAnd(A, Builder->CreateNot(Op1, "tmp")); + return BinaryOperator::CreateAnd(A, Builder->CreateNot(Op1)); } else if (match(Op0I, m_And(m_Value(A), m_Value(B))) && Op0I->hasOneUse()){ if (A == Op1) // (A&B)^A -> (B&A)^A std::swap(A, B); if (B == Op1 && // (B&A)^A == ~B & A !isa<ConstantInt>(Op1)) { // Canonical form is (B&C)^C - return BinaryOperator::CreateAnd(Builder->CreateNot(A, "tmp"), Op1); + return BinaryOperator::CreateAnd(Builder->CreateNot(A), Op1); } } } diff --git a/lib/Transforms/InstCombine/InstCombineCalls.cpp b/lib/Transforms/InstCombine/InstCombineCalls.cpp index c33dec1..c7b3ff8 100644 --- a/lib/Transforms/InstCombine/InstCombineCalls.cpp +++ b/lib/Transforms/InstCombine/InstCombineCalls.cpp @@ -12,7 +12,6 @@ //===----------------------------------------------------------------------===// #include "InstCombine.h" -#include "llvm/IntrinsicInst.h" #include "llvm/Support/CallSite.h" #include "llvm/Target/TargetData.h" #include "llvm/Analysis/MemoryBuiltins.h" @@ -655,15 +654,13 @@ Instruction *InstCombiner::visitCallInst(CallInst &CI) { if (ExtractedElts[Idx] == 0) { ExtractedElts[Idx] = - Builder->CreateExtractElement(Idx < 16 ? Op0 : Op1, - ConstantInt::get(Type::getInt32Ty(II->getContext()), - Idx&15, false), "tmp"); + Builder->CreateExtractElement(Idx < 16 ? Op0 : Op1, + Builder->getInt32(Idx&15)); } // Insert this value into the result vector. Result = Builder->CreateInsertElement(Result, ExtractedElts[Idx], - ConstantInt::get(Type::getInt32Ty(II->getContext()), - i, false), "tmp"); + Builder->getInt32(i)); } return CastInst::Create(Instruction::BitCast, Result, CI.getType()); } @@ -732,9 +729,11 @@ Instruction *InstCombiner::visitCallInst(CallInst &CI) { } } - // If the stack restore is in a return/unwind block and if there are no - // allocas or calls between the restore and the return, nuke the restore. - if (!CannotRemove && (isa<ReturnInst>(TI) || isa<UnwindInst>(TI))) + // If the stack restore is in a return, resume, or unwind block and if there + // are no allocas or calls between the restore and the return, nuke the + // restore. + if (!CannotRemove && (isa<ReturnInst>(TI) || isa<ResumeInst>(TI) || + isa<UnwindInst>(TI))) return EraseInstFromFunction(CI); break; } @@ -819,6 +818,83 @@ Instruction *InstCombiner::tryOptimizeCall(CallInst *CI, const TargetData *TD) { return Simplifier.NewInstruction; } +static IntrinsicInst *FindInitTrampolineFromAlloca(Value *TrampMem) { + // Strip off at most one level of pointer casts, looking for an alloca. This + // is good enough in practice and simpler than handling any number of casts. + Value *Underlying = TrampMem->stripPointerCasts(); + if (Underlying != TrampMem && + (!Underlying->hasOneUse() || *Underlying->use_begin() != TrampMem)) + return 0; + if (!isa<AllocaInst>(Underlying)) + return 0; + + IntrinsicInst *InitTrampoline = 0; + for (Value::use_iterator I = TrampMem->use_begin(), E = TrampMem->use_end(); + I != E; I++) { + IntrinsicInst *II = dyn_cast<IntrinsicInst>(*I); + if (!II) + return 0; + if (II->getIntrinsicID() == Intrinsic::init_trampoline) { + if (InitTrampoline) + // More than one init_trampoline writes to this value. Give up. + return 0; + InitTrampoline = II; + continue; + } + if (II->getIntrinsicID() == Intrinsic::adjust_trampoline) + // Allow any number of calls to adjust.trampoline. + continue; + return 0; + } + + // No call to init.trampoline found. + if (!InitTrampoline) + return 0; + + // Check that the alloca is being used in the expected way. + if (InitTrampoline->getOperand(0) != TrampMem) + return 0; + + return InitTrampoline; +} + +static IntrinsicInst *FindInitTrampolineFromBB(IntrinsicInst *AdjustTramp, + Value *TrampMem) { + // Visit all the previous instructions in the basic block, and try to find a + // init.trampoline which has a direct path to the adjust.trampoline. + for (BasicBlock::iterator I = AdjustTramp, + E = AdjustTramp->getParent()->begin(); I != E; ) { + Instruction *Inst = --I; + if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I)) + if (II->getIntrinsicID() == Intrinsic::init_trampoline && + II->getOperand(0) == TrampMem) + return II; + if (Inst->mayWriteToMemory()) + return 0; + } + return 0; +} + +// Given a call to llvm.adjust.trampoline, find and return the corresponding +// call to llvm.init.trampoline if the call to the trampoline can be optimized +// to a direct call to a function. Otherwise return NULL. +// +static IntrinsicInst *FindInitTrampoline(Value *Callee) { + Callee = Callee->stripPointerCasts(); + IntrinsicInst *AdjustTramp = dyn_cast<IntrinsicInst>(Callee); + if (!AdjustTramp || + AdjustTramp->getIntrinsicID() != Intrinsic::adjust_trampoline) + return 0; + + Value *TrampMem = AdjustTramp->getOperand(0); + + if (IntrinsicInst *IT = FindInitTrampolineFromAlloca(TrampMem)) + return IT; + if (IntrinsicInst *IT = FindInitTrampolineFromBB(AdjustTramp, TrampMem)) + return IT; + return 0; +} + // visitCallSite - Improvements for call and invoke instructions. // Instruction *InstCombiner::visitCallSite(CallSite CS) { @@ -878,10 +954,8 @@ Instruction *InstCombiner::visitCallSite(CallSite CS) { return EraseInstFromFunction(*CS.getInstruction()); } - if (BitCastInst *BC = dyn_cast<BitCastInst>(Callee)) - if (IntrinsicInst *In = dyn_cast<IntrinsicInst>(BC->getOperand(0))) - if (In->getIntrinsicID() == Intrinsic::init_trampoline) - return transformCallThroughTrampoline(CS); + if (IntrinsicInst *II = FindInitTrampoline(Callee)) + return transformCallThroughTrampoline(CS, II); PointerType *PTy = cast<PointerType>(Callee->getType()); FunctionType *FTy = cast<FunctionType>(PTy->getElementType()); @@ -1067,7 +1141,7 @@ bool InstCombiner::transformConstExprCastCall(CallSite CS) { } else { Instruction::CastOps opcode = CastInst::getCastOpcode(*AI, false, ParamTy, false); - Args.push_back(Builder->CreateCast(opcode, *AI, ParamTy, "tmp")); + Args.push_back(Builder->CreateCast(opcode, *AI, ParamTy)); } // Add any parameter attributes. @@ -1093,7 +1167,7 @@ bool InstCombiner::transformConstExprCastCall(CallSite CS) { // Must promote to pass through va_arg area! Instruction::CastOps opcode = CastInst::getCastOpcode(*AI, false, PTy, false); - Args.push_back(Builder->CreateCast(opcode, *AI, PTy, "tmp")); + Args.push_back(Builder->CreateCast(opcode, *AI, PTy)); } else { Args.push_back(*AI); } @@ -1137,13 +1211,13 @@ bool InstCombiner::transformConstExprCastCall(CallSite CS) { if (!NV->getType()->isVoidTy()) { Instruction::CastOps opcode = CastInst::getCastOpcode(NC, false, OldRetTy, false); - NV = NC = CastInst::Create(opcode, NC, OldRetTy, "tmp"); + NV = NC = CastInst::Create(opcode, NC, OldRetTy); NC->setDebugLoc(Caller->getDebugLoc()); // If this is an invoke instruction, we should insert it after the first // non-phi, instruction in the normal successor block. if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) { - BasicBlock::iterator I = II->getNormalDest()->getFirstNonPHI(); + BasicBlock::iterator I = II->getNormalDest()->getFirstInsertionPt(); InsertNewInstBefore(NC, *I); } else { // Otherwise, it's a call, just insert cast right after the call. @@ -1162,10 +1236,13 @@ bool InstCombiner::transformConstExprCastCall(CallSite CS) { return true; } -// transformCallThroughTrampoline - Turn a call to a function created by the -// init_trampoline intrinsic into a direct call to the underlying function. +// transformCallThroughTrampoline - Turn a call to a function created by +// init_trampoline / adjust_trampoline intrinsic pair into a direct call to the +// underlying function. // -Instruction *InstCombiner::transformCallThroughTrampoline(CallSite CS) { +Instruction * +InstCombiner::transformCallThroughTrampoline(CallSite CS, + IntrinsicInst *Tramp) { Value *Callee = CS.getCalledValue(); PointerType *PTy = cast<PointerType>(Callee->getType()); FunctionType *FTy = cast<FunctionType>(PTy->getElementType()); @@ -1176,8 +1253,8 @@ Instruction *InstCombiner::transformCallThroughTrampoline(CallSite CS) { if (Attrs.hasAttrSomewhere(Attribute::Nest)) return 0; - IntrinsicInst *Tramp = - cast<IntrinsicInst>(cast<BitCastInst>(Callee)->getOperand(0)); + assert(Tramp && + "transformCallThroughTrampoline called with incorrect CallSite."); Function *NestF =cast<Function>(Tramp->getArgOperand(1)->stripPointerCasts()); PointerType *NestFPTy = cast<PointerType>(NestF->getType()); diff --git a/lib/Transforms/InstCombine/InstCombineCasts.cpp b/lib/Transforms/InstCombine/InstCombineCasts.cpp index f99e457..f10e48a 100644 --- a/lib/Transforms/InstCombine/InstCombineCasts.cpp +++ b/lib/Transforms/InstCombine/InstCombineCasts.cpp @@ -12,6 +12,7 @@ //===----------------------------------------------------------------------===// #include "InstCombine.h" +#include "llvm/Analysis/ConstantFolding.h" #include "llvm/Target/TargetData.h" #include "llvm/Support/PatternMatch.h" using namespace llvm; @@ -121,13 +122,13 @@ Instruction *InstCombiner::PromoteCastOfAllocation(BitCastInst &CI, } else { Amt = ConstantInt::get(AI.getArraySize()->getType(), Scale); // Insert before the alloca, not before the cast. - Amt = AllocaBuilder.CreateMul(Amt, NumElements, "tmp"); + Amt = AllocaBuilder.CreateMul(Amt, NumElements); } if (uint64_t Offset = (AllocElTySize*ArrayOffset)/CastElTySize) { Value *Off = ConstantInt::get(AI.getArraySize()->getType(), Offset, true); - Amt = AllocaBuilder.CreateAdd(Amt, Off, "tmp"); + Amt = AllocaBuilder.CreateAdd(Amt, Off); } AllocaInst *New = AllocaBuilder.CreateAlloca(CastElTy, Amt); @@ -456,7 +457,7 @@ Instruction *InstCombiner::visitTrunc(TruncInst &CI) { // Canonicalize trunc x to i1 -> (icmp ne (and x, 1), 0), likewise for vector. if (DestTy->getScalarSizeInBits() == 1) { Constant *One = ConstantInt::get(Src->getType(), 1); - Src = Builder->CreateAnd(Src, One, "tmp"); + Src = Builder->CreateAnd(Src, One); Value *Zero = Constant::getNullValue(Src->getType()); return new ICmpInst(ICmpInst::ICMP_NE, Src, Zero); } @@ -518,7 +519,7 @@ Instruction *InstCombiner::transformZExtICmp(ICmpInst *ICI, Instruction &CI, In->getType()->getScalarSizeInBits()-1); In = Builder->CreateLShr(In, Sh, In->getName()+".lobit"); if (In->getType() != CI.getType()) - In = Builder->CreateIntCast(In, CI.getType(), false/*ZExt*/, "tmp"); + In = Builder->CreateIntCast(In, CI.getType(), false/*ZExt*/); if (ICI->getPredicate() == ICmpInst::ICMP_SGT) { Constant *One = ConstantInt::get(In->getType(), 1); @@ -572,7 +573,7 @@ Instruction *InstCombiner::transformZExtICmp(ICmpInst *ICI, Instruction &CI, if ((Op1CV != 0) == isNE) { // Toggle the low bit. Constant *One = ConstantInt::get(In->getType(), 1); - In = Builder->CreateXor(In, One, "tmp"); + In = Builder->CreateXor(In, One); } if (CI.getType() == In->getType()) @@ -820,7 +821,7 @@ Instruction *InstCombiner::visitZExt(ZExtInst &CI) { AndValue)); } if (SrcSize > DstSize) { - Value *Trunc = Builder->CreateTrunc(A, CI.getType(), "tmp"); + Value *Trunc = Builder->CreateTrunc(A, CI.getType()); APInt AndValue(APInt::getLowBitsSet(DstSize, MidSize)); return BinaryOperator::CreateAnd(Trunc, ConstantInt::get(Trunc->getType(), @@ -867,7 +868,7 @@ Instruction *InstCombiner::visitZExt(ZExtInst &CI) { Value *TI0 = TI->getOperand(0); if (TI0->getType() == CI.getType()) { Constant *ZC = ConstantExpr::getZExt(C, CI.getType()); - Value *NewAnd = Builder->CreateAnd(TI0, ZC, "tmp"); + Value *NewAnd = Builder->CreateAnd(TI0, ZC); return BinaryOperator::CreateXor(NewAnd, ZC); } } @@ -900,7 +901,7 @@ Instruction *InstCombiner::transformSExtICmp(ICmpInst *ICI, Instruction &CI) { Op0->getType()->getScalarSizeInBits()-1); Value *In = Builder->CreateAShr(Op0, Sh, Op0->getName()+".lobit"); if (In->getType() != CI.getType()) - In = Builder->CreateIntCast(In, CI.getType(), true/*SExt*/, "tmp"); + In = Builder->CreateIntCast(In, CI.getType(), true/*SExt*/); if (Pred == ICmpInst::ICMP_SGT) In = Builder->CreateNot(In, In->getName()+".not"); @@ -1306,13 +1307,13 @@ Instruction *InstCombiner::visitIntToPtr(IntToPtrInst &CI) { if (CI.getOperand(0)->getType()->getScalarSizeInBits() > TD->getPointerSizeInBits()) { Value *P = Builder->CreateTrunc(CI.getOperand(0), - TD->getIntPtrType(CI.getContext()), "tmp"); + TD->getIntPtrType(CI.getContext())); return new IntToPtrInst(P, CI.getType()); } if (CI.getOperand(0)->getType()->getScalarSizeInBits() < TD->getPointerSizeInBits()) { Value *P = Builder->CreateZExt(CI.getOperand(0), - TD->getIntPtrType(CI.getContext()), "tmp"); + TD->getIntPtrType(CI.getContext())); return new IntToPtrInst(P, CI.getType()); } } @@ -1359,9 +1360,8 @@ Instruction *InstCombiner::commonPointerCastTransforms(CastInst &CI) { // and bitcast the result. This eliminates one bitcast, potentially // two. Value *NGEP = cast<GEPOperator>(GEP)->isInBounds() ? - Builder->CreateInBoundsGEP(OrigBase, - NewIndices.begin(), NewIndices.end()) : - Builder->CreateGEP(OrigBase, NewIndices.begin(), NewIndices.end()); + Builder->CreateInBoundsGEP(OrigBase, NewIndices) : + Builder->CreateGEP(OrigBase, NewIndices); NGEP->takeName(GEP); if (isa<BitCastInst>(CI)) @@ -1382,14 +1382,12 @@ Instruction *InstCombiner::visitPtrToInt(PtrToIntInst &CI) { if (TD) { if (CI.getType()->getScalarSizeInBits() < TD->getPointerSizeInBits()) { Value *P = Builder->CreatePtrToInt(CI.getOperand(0), - TD->getIntPtrType(CI.getContext()), - "tmp"); + TD->getIntPtrType(CI.getContext())); return new TruncInst(P, CI.getType()); } if (CI.getType()->getScalarSizeInBits() > TD->getPointerSizeInBits()) { Value *P = Builder->CreatePtrToInt(CI.getOperand(0), - TD->getIntPtrType(CI.getContext()), - "tmp"); + TD->getIntPtrType(CI.getContext())); return new ZExtInst(P, CI.getType()); } } @@ -1693,7 +1691,7 @@ Instruction *InstCombiner::visitBitCast(BitCastInst &CI) { // If we found a path from the src to dest, create the getelementptr now. if (SrcElTy == DstElTy) { SmallVector<Value*, 8> Idxs(NumZeros+1, ZeroUInt); - return GetElementPtrInst::CreateInBounds(Src, Idxs.begin(), Idxs.end()); + return GetElementPtrInst::CreateInBounds(Src, Idxs); } } diff --git a/lib/Transforms/InstCombine/InstCombineCompares.cpp b/lib/Transforms/InstCombine/InstCombineCompares.cpp index b8ce4b7..bb1cbfa 100644 --- a/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -13,6 +13,7 @@ #include "InstCombine.h" #include "llvm/IntrinsicInst.h" +#include "llvm/Analysis/ConstantFolding.h" #include "llvm/Analysis/InstructionSimplify.h" #include "llvm/Analysis/MemoryBuiltins.h" #include "llvm/Target/TargetData.h" @@ -78,7 +79,7 @@ static bool HasSubOverflow(ConstantInt *Result, bool IsSigned) { if (!IsSigned) return Result->getValue().ugt(In1->getValue()); - + if (In2->isNegative()) return Result->getValue().slt(In1->getValue()); @@ -128,7 +129,7 @@ static bool isSignBitCheck(ICmpInst::Predicate pred, ConstantInt *RHS, // True if LHS u> RHS and RHS == high-bit-mask - 1 TrueIfSigned = true; return RHS->isMaxValue(true); - case ICmpInst::ICMP_UGE: + case ICmpInst::ICMP_UGE: // True if LHS u>= RHS and RHS == high-bit-mask (2^7, 2^15, 2^31, etc) TrueIfSigned = true; return RHS->getValue().isSignBit(); @@ -143,7 +144,7 @@ static bool isHighOnes(const ConstantInt *CI) { return (~CI->getValue() + 1).isPowerOf2(); } -/// ComputeSignedMinMaxValuesFromKnownBits - Given a signed integer type and a +/// ComputeSignedMinMaxValuesFromKnownBits - Given a signed integer type and a /// set of known zero and one bits, compute the maximum and minimum values that /// could have the specified known zero and known one bits, returning them in /// min/max. @@ -160,7 +161,7 @@ static void ComputeSignedMinMaxValuesFromKnownBits(const APInt& KnownZero, // bit if it is unknown. Min = KnownOne; Max = KnownOne|UnknownBits; - + if (UnknownBits.isNegative()) { // Sign bit is unknown Min.setBit(Min.getBitWidth()-1); Max.clearBit(Max.getBitWidth()-1); @@ -179,7 +180,7 @@ static void ComputeUnsignedMinMaxValuesFromKnownBits(const APInt &KnownZero, KnownZero.getBitWidth() == Max.getBitWidth() && "Ty, KnownZero, KnownOne and Min, Max must have equal bitwidth."); APInt UnknownBits = ~(KnownZero|KnownOne); - + // The minimum value is when the unknown bits are all zeros. Min = KnownOne; // The maximum value is when the unknown bits are all ones. @@ -201,10 +202,10 @@ FoldCmpLoadFromIndexedGlobal(GetElementPtrInst *GEP, GlobalVariable *GV, CmpInst &ICI, ConstantInt *AndCst) { // We need TD information to know the pointer size unless this is inbounds. if (!GEP->isInBounds() && TD == 0) return 0; - + ConstantArray *Init = dyn_cast<ConstantArray>(GV->getInitializer()); if (Init == 0 || Init->getNumOperands() > 1024) return 0; - + // There are many forms of this optimization we can handle, for now, just do // the simple index into a single-dimensional array. // @@ -219,15 +220,15 @@ FoldCmpLoadFromIndexedGlobal(GetElementPtrInst *GEP, GlobalVariable *GV, // type they index. Collect the indices. This is typically for arrays of // structs. SmallVector<unsigned, 4> LaterIndices; - + Type *EltTy = cast<ArrayType>(Init->getType())->getElementType(); for (unsigned i = 3, e = GEP->getNumOperands(); i != e; ++i) { ConstantInt *Idx = dyn_cast<ConstantInt>(GEP->getOperand(i)); if (Idx == 0) return 0; // Variable index. - + uint64_t IdxVal = Idx->getZExtValue(); if ((unsigned)IdxVal != IdxVal) return 0; // Too large array index. - + if (StructType *STy = dyn_cast<StructType>(EltTy)) EltTy = STy->getElementType(IdxVal); else if (ArrayType *ATy = dyn_cast<ArrayType>(EltTy)) { @@ -236,14 +237,14 @@ FoldCmpLoadFromIndexedGlobal(GetElementPtrInst *GEP, GlobalVariable *GV, } else { return 0; // Unknown type. } - + LaterIndices.push_back(IdxVal); } - + enum { Overdefined = -3, Undefined = -2 }; // Variables for our state machines. - + // FirstTrueElement/SecondTrueElement - Used to emit a comparison of the form // "i == 47 | i == 87", where 47 is the first index the condition is true for, // and 87 is the second (and last) index. FirstTrueElement is -2 when @@ -254,7 +255,7 @@ FoldCmpLoadFromIndexedGlobal(GetElementPtrInst *GEP, GlobalVariable *GV, // FirstFalseElement/SecondFalseElement - Used to emit a comparison of the // form "i != 47 & i != 87". Same state transitions as for true elements. int FirstFalseElement = Undefined, SecondFalseElement = Undefined; - + /// TrueRangeEnd/FalseRangeEnd - In conjunction with First*Element, these /// define a state machine that triggers for ranges of values that the index /// is true or false for. This triggers on things like "abbbbc"[i] == 'b'. @@ -262,25 +263,25 @@ FoldCmpLoadFromIndexedGlobal(GetElementPtrInst *GEP, GlobalVariable *GV, /// index in the range (inclusive). We use -2 for undefined here because we /// use relative comparisons and don't want 0-1 to match -1. int TrueRangeEnd = Undefined, FalseRangeEnd = Undefined; - + // MagicBitvector - This is a magic bitvector where we set a bit if the // comparison is true for element 'i'. If there are 64 elements or less in // the array, this will fully represent all the comparison results. uint64_t MagicBitvector = 0; - - + + // Scan the array and see if one of our patterns matches. Constant *CompareRHS = cast<Constant>(ICI.getOperand(1)); for (unsigned i = 0, e = Init->getNumOperands(); i != e; ++i) { Constant *Elt = Init->getOperand(i); - + // If this is indexing an array of structures, get the structure element. if (!LaterIndices.empty()) Elt = ConstantExpr::getExtractValue(Elt, LaterIndices); - + // If the element is masked, handle it. if (AndCst) Elt = ConstantExpr::getAnd(Elt, AndCst); - + // Find out if the comparison would be true or false for the i'th element. Constant *C = ConstantFoldCompareInstOperands(ICI.getPredicate(), Elt, CompareRHS, TD); @@ -294,15 +295,15 @@ FoldCmpLoadFromIndexedGlobal(GetElementPtrInst *GEP, GlobalVariable *GV, FalseRangeEnd = i; continue; } - + // If we can't compute the result for any of the elements, we have to give // up evaluating the entire conditional. if (!isa<ConstantInt>(C)) return 0; - + // Otherwise, we know if the comparison is true or false for this element, // update our state machines. bool IsTrueForElt = !cast<ConstantInt>(C)->isZero(); - + // State machine for single/double/range index comparison. if (IsTrueForElt) { // Update the TrueElement state machine. @@ -314,7 +315,7 @@ FoldCmpLoadFromIndexedGlobal(GetElementPtrInst *GEP, GlobalVariable *GV, SecondTrueElement = i; else SecondTrueElement = Overdefined; - + // Update range state machine. if (TrueRangeEnd == (int)i-1) TrueRangeEnd = i; @@ -331,7 +332,7 @@ FoldCmpLoadFromIndexedGlobal(GetElementPtrInst *GEP, GlobalVariable *GV, SecondFalseElement = i; else SecondFalseElement = Overdefined; - + // Update range state machine. if (FalseRangeEnd == (int)i-1) FalseRangeEnd = i; @@ -339,12 +340,12 @@ FoldCmpLoadFromIndexedGlobal(GetElementPtrInst *GEP, GlobalVariable *GV, FalseRangeEnd = Overdefined; } } - - + + // If this element is in range, update our magic bitvector. if (i < 64 && IsTrueForElt) MagicBitvector |= 1ULL << i; - + // If all of our states become overdefined, bail out early. Since the // predicate is expensive, only check it every 8 elements. This is only // really useful for really huge arrays. @@ -364,20 +365,20 @@ FoldCmpLoadFromIndexedGlobal(GetElementPtrInst *GEP, GlobalVariable *GV, if (!GEP->isInBounds() && Idx->getType()->getPrimitiveSizeInBits() > TD->getPointerSizeInBits()) Idx = Builder->CreateTrunc(Idx, TD->getIntPtrType(Idx->getContext())); - + // If the comparison is only true for one or two elements, emit direct // comparisons. if (SecondTrueElement != Overdefined) { // None true -> false. if (FirstTrueElement == Undefined) return ReplaceInstUsesWith(ICI, ConstantInt::getFalse(GEP->getContext())); - + Value *FirstTrueIdx = ConstantInt::get(Idx->getType(), FirstTrueElement); - + // True for one element -> 'i == 47'. if (SecondTrueElement == Undefined) return new ICmpInst(ICmpInst::ICMP_EQ, Idx, FirstTrueIdx); - + // True for two elements -> 'i == 47 | i == 72'. Value *C1 = Builder->CreateICmpEQ(Idx, FirstTrueIdx); Value *SecondTrueIdx = ConstantInt::get(Idx->getType(), SecondTrueElement); @@ -391,36 +392,36 @@ FoldCmpLoadFromIndexedGlobal(GetElementPtrInst *GEP, GlobalVariable *GV, // None false -> true. if (FirstFalseElement == Undefined) return ReplaceInstUsesWith(ICI, ConstantInt::getTrue(GEP->getContext())); - + Value *FirstFalseIdx = ConstantInt::get(Idx->getType(), FirstFalseElement); // False for one element -> 'i != 47'. if (SecondFalseElement == Undefined) return new ICmpInst(ICmpInst::ICMP_NE, Idx, FirstFalseIdx); - + // False for two elements -> 'i != 47 & i != 72'. Value *C1 = Builder->CreateICmpNE(Idx, FirstFalseIdx); Value *SecondFalseIdx = ConstantInt::get(Idx->getType(),SecondFalseElement); Value *C2 = Builder->CreateICmpNE(Idx, SecondFalseIdx); return BinaryOperator::CreateAnd(C1, C2); } - + // If the comparison can be replaced with a range comparison for the elements // where it is true, emit the range check. if (TrueRangeEnd != Overdefined) { assert(TrueRangeEnd != FirstTrueElement && "Should emit single compare"); - + // Generate (i-FirstTrue) <u (TrueRangeEnd-FirstTrue+1). if (FirstTrueElement) { Value *Offs = ConstantInt::get(Idx->getType(), -FirstTrueElement); Idx = Builder->CreateAdd(Idx, Offs); } - + Value *End = ConstantInt::get(Idx->getType(), TrueRangeEnd-FirstTrueElement+1); return new ICmpInst(ICmpInst::ICMP_ULT, Idx, End); } - + // False range check. if (FalseRangeEnd != Overdefined) { assert(FalseRangeEnd != FirstFalseElement && "Should emit single compare"); @@ -429,13 +430,13 @@ FoldCmpLoadFromIndexedGlobal(GetElementPtrInst *GEP, GlobalVariable *GV, Value *Offs = ConstantInt::get(Idx->getType(), -FirstFalseElement); Idx = Builder->CreateAdd(Idx, Offs); } - + Value *End = ConstantInt::get(Idx->getType(), FalseRangeEnd-FirstFalseElement); return new ICmpInst(ICmpInst::ICMP_UGT, Idx, End); } - - + + // If a 32-bit or 64-bit magic bitvector captures the entire comparison state // of this load, replace it with computation that does: // ((magic_cst >> i) & 1) != 0 @@ -451,7 +452,7 @@ FoldCmpLoadFromIndexedGlobal(GetElementPtrInst *GEP, GlobalVariable *GV, V = Builder->CreateAnd(ConstantInt::get(Ty, 1), V); return new ICmpInst(ICmpInst::ICMP_NE, V, ConstantInt::get(Ty, 0)); } - + return 0; } @@ -465,11 +466,11 @@ FoldCmpLoadFromIndexedGlobal(GetElementPtrInst *GEP, GlobalVariable *GV, /// to generate the first by knowing that pointer arithmetic doesn't overflow. /// /// If we can't emit an optimized form for this expression, this returns null. -/// +/// static Value *EvaluateGEPOffsetExpression(User *GEP, InstCombiner &IC) { TargetData &TD = *IC.getTargetData(); gep_type_iterator GTI = gep_type_begin(GEP); - + // Check to see if this gep only has a single variable index. If so, and if // any constant indices are a multiple of its scale, then we can compute this // in terms of the scale of the variable index. For example, if the GEP @@ -481,7 +482,7 @@ static Value *EvaluateGEPOffsetExpression(User *GEP, InstCombiner &IC) { if (ConstantInt *CI = dyn_cast<ConstantInt>(GEP->getOperand(i))) { // Compute the aggregate offset of constant indices. if (CI->isZero()) continue; - + // Handle a struct index, which adds its field offset to the pointer. if (StructType *STy = dyn_cast<StructType>(*GTI)) { Offset += TD.getStructLayout(STy)->getElementOffset(CI->getZExtValue()); @@ -494,24 +495,24 @@ static Value *EvaluateGEPOffsetExpression(User *GEP, InstCombiner &IC) { break; } } - + // If there are no variable indices, we must have a constant offset, just // evaluate it the general way. if (i == e) return 0; - + Value *VariableIdx = GEP->getOperand(i); // Determine the scale factor of the variable element. For example, this is // 4 if the variable index is into an array of i32. uint64_t VariableScale = TD.getTypeAllocSize(GTI.getIndexedType()); - + // Verify that there are no other variable indices. If so, emit the hard way. for (++i, ++GTI; i != e; ++i, ++GTI) { ConstantInt *CI = dyn_cast<ConstantInt>(GEP->getOperand(i)); if (!CI) return 0; - + // Compute the aggregate offset of constant indices. if (CI->isZero()) continue; - + // Handle a struct index, which adds its field offset to the pointer. if (StructType *STy = dyn_cast<StructType>(*GTI)) { Offset += TD.getStructLayout(STy)->getElementOffset(CI->getZExtValue()); @@ -520,7 +521,7 @@ static Value *EvaluateGEPOffsetExpression(User *GEP, InstCombiner &IC) { Offset += Size*CI->getSExtValue(); } } - + // Okay, we know we have a single variable index, which must be a // pointer/array/vector index. If there is no offset, life is simple, return // the index. @@ -535,14 +536,14 @@ static Value *EvaluateGEPOffsetExpression(User *GEP, InstCombiner &IC) { } return VariableIdx; } - + // Otherwise, there is an index. The computation we will do will be modulo // the pointer size, so get it. uint64_t PtrSizeMask = ~0ULL >> (64-IntPtrWidth); - + Offset &= PtrSizeMask; VariableScale &= PtrSizeMask; - + // To do this transformation, any constant index must be a multiple of the // variable scale factor. For example, we can evaluate "12 + 4*i" as "3 + i", // but we can't evaluate "10 + 3*i" in terms of i. Check that the offset is a @@ -550,7 +551,7 @@ static Value *EvaluateGEPOffsetExpression(User *GEP, InstCombiner &IC) { int64_t NewOffs = Offset / (int64_t)VariableScale; if (Offset != NewOffs*(int64_t)VariableScale) return 0; - + // Okay, we can do this evaluation. Start by converting the index to intptr. Type *IntPtrTy = TD.getIntPtrType(VariableIdx->getContext()); if (VariableIdx->getType() != IntPtrTy) @@ -576,7 +577,7 @@ Instruction *InstCombiner::FoldGEPICmp(GEPOperator *GEPLHS, Value *RHS, // know pointers can't overflow since the gep is inbounds. See if we can // output an optimized form. Value *Offset = EvaluateGEPOffsetExpression(GEPLHS, *this); - + // If not, synthesize the offset the hard way. if (Offset == 0) Offset = EmitGEPOffset(GEPLHS); @@ -686,7 +687,7 @@ Instruction *InstCombiner::FoldICmpAddOpCst(ICmpInst &ICI, bool isTrue = ICmpInst::isTrueWhenEqual(Pred); return ReplaceInstUsesWith(ICI, ConstantInt::get(ICI.getType(), isTrue)); } - + // (X+4) == X -> false. if (Pred == ICmpInst::ICMP_EQ) return ReplaceInstUsesWith(ICI, ConstantInt::getFalse(X->getContext())); @@ -698,22 +699,22 @@ Instruction *InstCombiner::FoldICmpAddOpCst(ICmpInst &ICI, // From this point on, we know that (X+C <= X) --> (X+C < X) because C != 0, // so the values can never be equal. Similarly for all other "or equals" // operators. - + // (X+1) <u X --> X >u (MAXUINT-1) --> X == 255 // (X+2) <u X --> X >u (MAXUINT-2) --> X > 253 // (X+MAXUINT) <u X --> X >u (MAXUINT-MAXUINT) --> X != 0 if (Pred == ICmpInst::ICMP_ULT || Pred == ICmpInst::ICMP_ULE) { - Value *R = + Value *R = ConstantExpr::getSub(ConstantInt::getAllOnesValue(CI->getType()), CI); return new ICmpInst(ICmpInst::ICMP_UGT, X, R); } - + // (X+1) >u X --> X <u (0-1) --> X != 255 // (X+2) >u X --> X <u (0-2) --> X <u 254 // (X+MAXUINT) >u X --> X <u (0-MAXUINT) --> X <u 1 --> X == 0 if (Pred == ICmpInst::ICMP_UGT || Pred == ICmpInst::ICMP_UGE) return new ICmpInst(ICmpInst::ICMP_ULT, X, ConstantExpr::getNeg(CI)); - + unsigned BitWidth = CI->getType()->getPrimitiveSizeInBits(); ConstantInt *SMax = ConstantInt::get(X->getContext(), APInt::getSignedMaxValue(BitWidth)); @@ -726,14 +727,14 @@ Instruction *InstCombiner::FoldICmpAddOpCst(ICmpInst &ICI, // (X+ -1) <s X --> X >s (MAXSINT- -1) --> X != 127 if (Pred == ICmpInst::ICMP_SLT || Pred == ICmpInst::ICMP_SLE) return new ICmpInst(ICmpInst::ICMP_SGT, X, ConstantExpr::getSub(SMax, CI)); - + // (X+ 1) >s X --> X <s (MAXSINT-(1-1)) --> X != 127 // (X+ 2) >s X --> X <s (MAXSINT-(2-1)) --> X <s 126 // (X+MAXSINT) >s X --> X <s (MAXSINT-(MAXSINT-1)) --> X <s 1 // (X+MINSINT) >s X --> X <s (MAXSINT-(MINSINT-1)) --> X <s -2 // (X+ -2) >s X --> X <s (MAXSINT-(-2-1)) --> X <s -126 // (X+ -1) >s X --> X <s (MAXSINT-(-1-1)) --> X == -128 - + assert(Pred == ICmpInst::ICMP_SGT || Pred == ICmpInst::ICMP_SGE); Constant *C = ConstantInt::get(X->getContext(), CI->getValue()-1); return new ICmpInst(ICmpInst::ICMP_SLT, X, ConstantExpr::getSub(SMax, C)); @@ -745,14 +746,14 @@ Instruction *InstCombiner::FoldICmpDivCst(ICmpInst &ICI, BinaryOperator *DivI, ConstantInt *DivRHS) { ConstantInt *CmpRHS = cast<ConstantInt>(ICI.getOperand(1)); const APInt &CmpRHSV = CmpRHS->getValue(); - - // FIXME: If the operand types don't match the type of the divide + + // FIXME: If the operand types don't match the type of the divide // then don't attempt this transform. The code below doesn't have the // logic to deal with a signed divide and an unsigned compare (and - // vice versa). This is because (x /s C1) <s C2 produces different + // vice versa). This is because (x /s C1) <s C2 produces different // results than (x /s C1) <u C2 or (x /u C1) <s C2 or even - // (x /u C1) <u C2. Simply casting the operands and result won't - // work. :( The if statement below tests that condition and bails + // (x /u C1) <u C2. Simply casting the operands and result won't + // work. :( The if statement below tests that condition and bails // if it finds it. bool DivIsSigned = DivI->getOpcode() == Instruction::SDiv; if (!ICI.isEquality() && DivIsSigned != ICI.isSigned()) @@ -768,14 +769,14 @@ Instruction *InstCombiner::FoldICmpDivCst(ICmpInst &ICI, BinaryOperator *DivI, } // Compute Prod = CI * DivRHS. We are essentially solving an equation - // of form X/C1=C2. We solve for X by multiplying C1 (DivRHS) and - // C2 (CI). By solving for X we can turn this into a range check - // instead of computing a divide. + // of form X/C1=C2. We solve for X by multiplying C1 (DivRHS) and + // C2 (CI). By solving for X we can turn this into a range check + // instead of computing a divide. Constant *Prod = ConstantExpr::getMul(CmpRHS, DivRHS); // Determine if the product overflows by seeing if the product is // not equal to the divide. Make sure we do the same kind of divide - // as in the LHS instruction that we're folding. + // as in the LHS instruction that we're folding. bool ProdOV = (DivIsSigned ? ConstantExpr::getSDiv(Prod, DivRHS) : ConstantExpr::getUDiv(Prod, DivRHS)) != CmpRHS; @@ -785,9 +786,9 @@ Instruction *InstCombiner::FoldICmpDivCst(ICmpInst &ICI, BinaryOperator *DivI, /// If the division is known to be exact, then there is no remainder from the /// divide, so the covered range size is unit, otherwise it is the divisor. ConstantInt *RangeSize = DivI->isExact() ? getOne(Prod) : DivRHS; - + // Figure out the interval that is being checked. For example, a comparison - // like "X /u 5 == 0" is really checking that X is in the interval [0, 5). + // like "X /u 5 == 0" is really checking that X is in the interval [0, 5). // Compute this interval based on the constants involved and the signedness of // the compare/divide. This computes a half-open interval, keeping track of // whether either value in the interval overflows. After analysis each @@ -805,7 +806,7 @@ Instruction *InstCombiner::FoldICmpDivCst(ICmpInst &ICI, BinaryOperator *DivI, // to the same result value. HiOverflow = AddWithOverflow(HiBound, LoBound, RangeSize, false); } - + } else if (DivRHS->getValue().isStrictlyPositive()) { // Divisor is > 0. if (CmpRHSV == 0) { // (X / pos) op 0 // Can't overflow. e.g. X/2 op 0 --> [-1, 2) @@ -848,7 +849,7 @@ Instruction *InstCombiner::FoldICmpDivCst(ICmpInst &ICI, BinaryOperator *DivI, if (!HiOverflow) HiOverflow = SubWithOverflow(HiBound, Prod, RangeSize, true); } - + // Dividing by a negative swaps the condition. LT <-> GT Pred = ICmpInst::getSwappedPredicate(Pred); } @@ -901,7 +902,7 @@ Instruction *InstCombiner::FoldICmpDivCst(ICmpInst &ICI, BinaryOperator *DivI, Instruction *InstCombiner::FoldICmpShrCst(ICmpInst &ICI, BinaryOperator *Shr, ConstantInt *ShAmt) { const APInt &CmpRHSV = cast<ConstantInt>(ICI.getOperand(1))->getValue(); - + // Check that the shift amount is in range. If not, don't perform // undefined shifts. When the shift is visited it will be // simplified. @@ -909,48 +910,48 @@ Instruction *InstCombiner::FoldICmpShrCst(ICmpInst &ICI, BinaryOperator *Shr, uint32_t ShAmtVal = (uint32_t)ShAmt->getLimitedValue(TypeBits); if (ShAmtVal >= TypeBits || ShAmtVal == 0) return 0; - + if (!ICI.isEquality()) { // If we have an unsigned comparison and an ashr, we can't simplify this. // Similarly for signed comparisons with lshr. if (ICI.isSigned() != (Shr->getOpcode() == Instruction::AShr)) return 0; - + // Otherwise, all lshr and most exact ashr's are equivalent to a udiv/sdiv // by a power of 2. Since we already have logic to simplify these, // transform to div and then simplify the resultant comparison. if (Shr->getOpcode() == Instruction::AShr && (!Shr->isExact() || ShAmtVal == TypeBits - 1)) return 0; - + // Revisit the shift (to delete it). Worklist.Add(Shr); - + Constant *DivCst = ConstantInt::get(Shr->getType(), APInt::getOneBitSet(TypeBits, ShAmtVal)); - + Value *Tmp = Shr->getOpcode() == Instruction::AShr ? Builder->CreateSDiv(Shr->getOperand(0), DivCst, "", Shr->isExact()) : Builder->CreateUDiv(Shr->getOperand(0), DivCst, "", Shr->isExact()); - + ICI.setOperand(0, Tmp); - + // If the builder folded the binop, just return it. BinaryOperator *TheDiv = dyn_cast<BinaryOperator>(Tmp); if (TheDiv == 0) return &ICI; - + // Otherwise, fold this div/compare. assert(TheDiv->getOpcode() == Instruction::SDiv || TheDiv->getOpcode() == Instruction::UDiv); - + Instruction *Res = FoldICmpDivCst(ICI, TheDiv, cast<ConstantInt>(DivCst)); assert(Res && "This div/cst should have folded!"); return Res; } - - + + // If we are comparing against bits always shifted out, the // comparison cannot succeed. APInt Comp = CmpRHSV << ShAmtVal; @@ -959,25 +960,25 @@ Instruction *InstCombiner::FoldICmpShrCst(ICmpInst &ICI, BinaryOperator *Shr, Comp = Comp.lshr(ShAmtVal); else Comp = Comp.ashr(ShAmtVal); - + if (Comp != CmpRHSV) { // Comparing against a bit that we know is zero. bool IsICMP_NE = ICI.getPredicate() == ICmpInst::ICMP_NE; Constant *Cst = ConstantInt::get(Type::getInt1Ty(ICI.getContext()), IsICMP_NE); return ReplaceInstUsesWith(ICI, Cst); } - + // Otherwise, check to see if the bits shifted out are known to be zero. // If so, we can compare against the unshifted value: // (X & 4) >> 1 == 2 --> (X & 4) == 4. if (Shr->hasOneUse() && Shr->isExact()) return new ICmpInst(ICI.getPredicate(), Shr->getOperand(0), ShiftedCmpRHS); - + if (Shr->hasOneUse()) { // Otherwise strength reduce the shift into an and. APInt Val(APInt::getHighBitsSet(TypeBits, TypeBits - ShAmtVal)); Constant *Mask = ConstantInt::get(ICI.getContext(), Val); - + Value *And = Builder->CreateAnd(Shr->getOperand(0), Mask, Shr->getName()+".mask"); return new ICmpInst(ICI.getPredicate(), And, ShiftedCmpRHS); @@ -992,7 +993,7 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, Instruction *LHSI, ConstantInt *RHS) { const APInt &RHSV = RHS->getValue(); - + switch (LHSI->getOpcode()) { case Instruction::Trunc: if (ICI.isEquality() && LHSI->hasOneUse()) { @@ -1003,7 +1004,7 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, APInt Mask(APInt::getHighBitsSet(SrcBits, SrcBits-DstBits)); APInt KnownZero(SrcBits, 0), KnownOne(SrcBits, 0); ComputeMaskedBits(LHSI->getOperand(0), Mask, KnownZero, KnownOne); - + // If all the high bits are known, we can do this xform. if ((KnownZero|KnownOne).countLeadingOnes() >= SrcBits-DstBits) { // Pull in the high bits from known-ones set. @@ -1014,7 +1015,7 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, } } break; - + case Instruction::Xor: // (icmp pred (xor X, XorCST), CI) if (ConstantInt *XorCST = dyn_cast<ConstantInt>(LHSI->getOperand(1))) { // If this is a comparison that tests the signbit (X < 0) or (x > -1), @@ -1022,7 +1023,7 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, if ((ICI.getPredicate() == ICmpInst::ICMP_SLT && RHSV == 0) || (ICI.getPredicate() == ICmpInst::ICMP_SGT && RHSV.isAllOnesValue())) { Value *CompareVal = LHSI->getOperand(0); - + // If the sign bit of the XorCST is not set, there is no change to // the operation, just stop using the Xor. if (!XorCST->isNegative()) { @@ -1030,13 +1031,13 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, Worklist.Add(LHSI); return &ICI; } - + // Was the old condition true if the operand is positive? bool isTrueIfPositive = ICI.getPredicate() == ICmpInst::ICMP_SGT; - + // If so, the new one isn't. isTrueIfPositive ^= true; - + if (isTrueIfPositive) return new ICmpInst(ICmpInst::ICMP_SGT, CompareVal, SubOne(RHS)); @@ -1075,13 +1076,13 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, if (LHSI->hasOneUse() && isa<ConstantInt>(LHSI->getOperand(1)) && LHSI->getOperand(0)->hasOneUse()) { ConstantInt *AndCST = cast<ConstantInt>(LHSI->getOperand(1)); - + // If the LHS is an AND of a truncating cast, we can widen the // and/compare to be the input width without changing the value // produced, eliminating a cast. if (TruncInst *Cast = dyn_cast<TruncInst>(LHSI->getOperand(0))) { // We can do this transformation if either the AND constant does not - // have its sign bit set or if it is an equality comparison. + // have its sign bit set or if it is an equality comparison. // Extending a relational comparison when we're checking the sign // bit would not work. if (ICI.isEquality() || @@ -1118,12 +1119,12 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, BinaryOperator *Shift = dyn_cast<BinaryOperator>(LHSI->getOperand(0)); if (Shift && !Shift->isShift()) Shift = 0; - + ConstantInt *ShAmt; ShAmt = Shift ? dyn_cast<ConstantInt>(Shift->getOperand(1)) : 0; Type *Ty = Shift ? Shift->getType() : 0; // Type of the shift. Type *AndTy = AndCST->getType(); // Type of the and. - + // We can fold this as long as we can't shift unknown bits // into the mask. This can only happen with signed shift // rights, as they sign-extend. @@ -1134,20 +1135,20 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, // of the bits shifted in could be tested after the mask. uint32_t TyBits = Ty->getPrimitiveSizeInBits(); int ShAmtVal = TyBits - ShAmt->getLimitedValue(TyBits); - + uint32_t BitWidth = AndTy->getPrimitiveSizeInBits(); - if ((APInt::getHighBitsSet(BitWidth, BitWidth-ShAmtVal) & + if ((APInt::getHighBitsSet(BitWidth, BitWidth-ShAmtVal) & AndCST->getValue()) == 0) CanFold = true; } - + if (CanFold) { Constant *NewCst; if (Shift->getOpcode() == Instruction::Shl) NewCst = ConstantExpr::getLShr(RHS, ShAmt); else NewCst = ConstantExpr::getShl(RHS, ShAmt); - + // Check to see if we are shifting out any of the bits being // compared. if (ConstantExpr::get(Shift->getOpcode(), @@ -1175,7 +1176,7 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, } } } - + // Turn ((X >> Y) & C) == 0 into (X & (C << Y)) == 0. The later is // preferable because it allows the C<<Y expression to be hoisted out // of a loop if Y is invariant and X is not. @@ -1185,21 +1186,21 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, // Compute C << Y. Value *NS; if (Shift->getOpcode() == Instruction::LShr) { - NS = Builder->CreateShl(AndCST, Shift->getOperand(1), "tmp"); + NS = Builder->CreateShl(AndCST, Shift->getOperand(1)); } else { // Insert a logical shift. - NS = Builder->CreateLShr(AndCST, Shift->getOperand(1), "tmp"); + NS = Builder->CreateLShr(AndCST, Shift->getOperand(1)); } - + // Compute X & (C << Y). - Value *NewAnd = + Value *NewAnd = Builder->CreateAnd(Shift->getOperand(0), NS, LHSI->getName()); - + ICI.setOperand(0, NewAnd); return &ICI; } } - + // Try to optimize things like "A[i]&42 == 0" to index computations. if (LoadInst *LI = dyn_cast<LoadInst>(LHSI->getOperand(0))) { if (GetElementPtrInst *GEP = @@ -1234,19 +1235,19 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, } break; } - + case Instruction::Shl: { // (icmp pred (shl X, ShAmt), CI) ConstantInt *ShAmt = dyn_cast<ConstantInt>(LHSI->getOperand(1)); if (!ShAmt) break; - + uint32_t TypeBits = RHSV.getBitWidth(); - + // Check that the shift amount is in range. If not, don't perform // undefined shifts. When the shift is visited it will be // simplified. if (ShAmt->uge(TypeBits)) break; - + if (ICI.isEquality()) { // If we are comparing against bits always shifted out, the // comparison cannot succeed. @@ -1259,34 +1260,34 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, ConstantInt::get(Type::getInt1Ty(ICI.getContext()), IsICMP_NE); return ReplaceInstUsesWith(ICI, Cst); } - + // If the shift is NUW, then it is just shifting out zeros, no need for an // AND. if (cast<BinaryOperator>(LHSI)->hasNoUnsignedWrap()) return new ICmpInst(ICI.getPredicate(), LHSI->getOperand(0), ConstantExpr::getLShr(RHS, ShAmt)); - + if (LHSI->hasOneUse()) { // Otherwise strength reduce the shift into an and. uint32_t ShAmtVal = (uint32_t)ShAmt->getLimitedValue(TypeBits); Constant *Mask = - ConstantInt::get(ICI.getContext(), APInt::getLowBitsSet(TypeBits, + ConstantInt::get(ICI.getContext(), APInt::getLowBitsSet(TypeBits, TypeBits-ShAmtVal)); - + Value *And = Builder->CreateAnd(LHSI->getOperand(0),Mask, LHSI->getName()+".mask"); return new ICmpInst(ICI.getPredicate(), And, ConstantExpr::getLShr(RHS, ShAmt)); } } - + // Otherwise, if this is a comparison of the sign bit, simplify to and/test. bool TrueIfSigned = false; if (LHSI->hasOneUse() && isSignBitCheck(ICI.getPredicate(), RHS, TrueIfSigned)) { // (X << 31) <s 0 --> (X&1) != 0 Constant *Mask = ConstantInt::get(LHSI->getOperand(0)->getType(), - APInt::getOneBitSet(TypeBits, + APInt::getOneBitSet(TypeBits, TypeBits-ShAmt->getZExtValue()-1)); Value *And = Builder->CreateAnd(LHSI->getOperand(0), Mask, LHSI->getName()+".mask"); @@ -1295,7 +1296,7 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, } break; } - + case Instruction::LShr: // (icmp pred (shr X, ShAmt), CI) case Instruction::AShr: { // Handle equality comparisons of shift-by-constant. @@ -1312,13 +1313,13 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, } break; } - + case Instruction::SDiv: case Instruction::UDiv: // Fold: icmp pred ([us]div X, C1), C2 -> range test - // Fold this div into the comparison, producing a range check. - // Determine, based on the divide type, what the range is being - // checked. If there is an overflow on the low or high side, remember + // Fold this div into the comparison, producing a range check. + // Determine, based on the divide type, what the range is being + // checked. If there is an overflow on the low or high side, remember // it, otherwise compute the range [low, hi) bounding the new value. // See: InsertRangeTest above for the kinds of replacements possible. if (ConstantInt *DivRHS = dyn_cast<ConstantInt>(LHSI->getOperand(1))) @@ -1357,12 +1358,12 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, } break; } - + // Simplify icmp_eq and icmp_ne instructions with integer constant RHS. if (ICI.isEquality()) { bool isICMP_NE = ICI.getPredicate() == ICmpInst::ICMP_NE; - - // If the first operand is (add|sub|and|or|xor|rem) with a constant, and + + // If the first operand is (add|sub|and|or|xor|rem) with a constant, and // the second operand is a constant, simplify a bit. if (BinaryOperator *BO = dyn_cast<BinaryOperator>(LHSI)) { switch (BO->getOpcode()) { @@ -1389,7 +1390,7 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, // Replace ((add A, B) != 0) with (A != -B) if A or B is // efficiently invertible, or if the add has just this one use. Value *BOp0 = BO->getOperand(0), *BOp1 = BO->getOperand(1); - + if (Value *NegVal = dyn_castNegVal(BOp1)) return new ICmpInst(ICI.getPredicate(), BOp0, NegVal); if (Value *NegVal = dyn_castNegVal(BOp0)) @@ -1432,11 +1433,11 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, Constant *NotCI = ConstantExpr::getNot(RHS); if (!ConstantExpr::getAnd(BOC, NotCI)->isNullValue()) return ReplaceInstUsesWith(ICI, - ConstantInt::get(Type::getInt1Ty(ICI.getContext()), + ConstantInt::get(Type::getInt1Ty(ICI.getContext()), isICMP_NE)); } break; - + case Instruction::And: if (ConstantInt *BOC = dyn_cast<ConstantInt>(BO->getOperand(1))) { // If bits are being compared against that are and'd out, then the @@ -1445,7 +1446,7 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, return ReplaceInstUsesWith(ICI, ConstantInt::get(Type::getInt1Ty(ICI.getContext()), isICMP_NE)); - + // If we have ((X & C) == C), turn it into ((X & C) != 0). if (RHS == BOC && RHSV.isPowerOf2()) return new ICmpInst(isICMP_NE ? ICmpInst::ICMP_EQ : @@ -1460,16 +1461,16 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, if (BOC->getValue().isSignBit()) { Value *X = BO->getOperand(0); Constant *Zero = Constant::getNullValue(X->getType()); - ICmpInst::Predicate pred = isICMP_NE ? + ICmpInst::Predicate pred = isICMP_NE ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_SGE; return new ICmpInst(pred, X, Zero); } - + // ((X & ~7) == 0) --> X < 8 if (RHSV == 0 && isHighOnes(BOC)) { Value *X = BO->getOperand(0); Constant *NegX = ConstantExpr::getNeg(BOC); - ICmpInst::Predicate pred = isICMP_NE ? + ICmpInst::Predicate pred = isICMP_NE ? ICmpInst::ICMP_UGE : ICmpInst::ICMP_ULT; return new ICmpInst(pred, X, NegX); } @@ -1521,7 +1522,7 @@ Instruction *InstCombiner::visitICmpInstWithCastAndCast(ICmpInst &ICI) { Type *DestTy = LHSCI->getType(); Value *RHSCIOp; - // Turn icmp (ptrtoint x), (ptrtoint/c) into a compare of the input if the + // Turn icmp (ptrtoint x), (ptrtoint/c) into a compare of the input if the // integer type is the same size as the pointer type. if (TD && LHSCI->getOpcode() == Instruction::PtrToInt && TD->getPointerSizeInBits() == @@ -1539,7 +1540,7 @@ Instruction *InstCombiner::visitICmpInstWithCastAndCast(ICmpInst &ICI) { if (RHSOp) return new ICmpInst(ICI.getPredicate(), LHSCIOp, RHSOp); } - + // The code below only handles extension cast instructions, so far. // Enforce this. if (LHSCI->getOpcode() != Instruction::ZExt && @@ -1552,9 +1553,9 @@ Instruction *InstCombiner::visitICmpInstWithCastAndCast(ICmpInst &ICI) { if (CastInst *CI = dyn_cast<CastInst>(ICI.getOperand(1))) { // Not an extension from the same type? RHSCIOp = CI->getOperand(0); - if (RHSCIOp->getType() != LHSCIOp->getType()) + if (RHSCIOp->getType() != LHSCIOp->getType()) return 0; - + // If the signedness of the two casts doesn't agree (i.e. one is a sext // and the other is a zext), then we can't handle this. if (CI->getOpcode() != LHSCI->getOpcode()) @@ -1599,7 +1600,7 @@ Instruction *InstCombiner::visitICmpInstWithCastAndCast(ICmpInst &ICI) { return new ICmpInst(ICI.getUnsignedPredicate(), LHSCIOp, Res1); } - // The re-extended constant changed so the constant cannot be represented + // The re-extended constant changed so the constant cannot be represented // in the shorter type. Consequently, we cannot emit a simple comparison. // All the cases that fold to true or false will have already been handled // by SimplifyICmpInst, so only deal with the tricky case. @@ -1637,26 +1638,26 @@ static Instruction *ProcessUGT_ADDCST_ADD(ICmpInst &I, Value *A, Value *B, // llvm.sadd.with.overflow. To do this, we have to replace the original add // with a narrower add, and discard the add-with-constant that is part of the // range check (if we can't eliminate it, this isn't profitable). - + // In order to eliminate the add-with-constant, the compare can be its only // use. Instruction *AddWithCst = cast<Instruction>(I.getOperand(0)); if (!AddWithCst->hasOneUse()) return 0; - + // If CI2 is 2^7, 2^15, 2^31, then it might be an sadd.with.overflow. if (!CI2->getValue().isPowerOf2()) return 0; unsigned NewWidth = CI2->getValue().countTrailingZeros(); if (NewWidth != 7 && NewWidth != 15 && NewWidth != 31) return 0; - + // The width of the new add formed is 1 more than the bias. ++NewWidth; - + // Check to see that CI1 is an all-ones value with NewWidth bits. if (CI1->getBitWidth() == NewWidth || CI1->getValue() != APInt::getLowBitsSet(CI1->getBitWidth(), NewWidth)) return 0; - - // In order to replace the original add with a narrower + + // In order to replace the original add with a narrower // llvm.sadd.with.overflow, the only uses allowed are the add-with-constant // and truncates that discard the high bits of the add. Verify that this is // the case. @@ -1664,7 +1665,7 @@ static Instruction *ProcessUGT_ADDCST_ADD(ICmpInst &I, Value *A, Value *B, for (Value::use_iterator UI = OrigAdd->use_begin(), E = OrigAdd->use_end(); UI != E; ++UI) { if (*UI == AddWithCst) continue; - + // Only accept truncates for now. We would really like a nice recursive // predicate like SimplifyDemandedBits, but which goes downwards the use-def // chain to see which bits of a value are actually demanded. If the @@ -1674,32 +1675,32 @@ static Instruction *ProcessUGT_ADDCST_ADD(ICmpInst &I, Value *A, Value *B, if (TI == 0 || TI->getType()->getPrimitiveSizeInBits() > NewWidth) return 0; } - + // If the pattern matches, truncate the inputs to the narrower type and // use the sadd_with_overflow intrinsic to efficiently compute both the // result and the overflow bit. Module *M = I.getParent()->getParent()->getParent(); - + Type *NewType = IntegerType::get(OrigAdd->getContext(), NewWidth); Value *F = Intrinsic::getDeclaration(M, Intrinsic::sadd_with_overflow, NewType); InstCombiner::BuilderTy *Builder = IC.Builder; - + // Put the new code above the original add, in case there are any uses of the // add between the add and the compare. Builder->SetInsertPoint(OrigAdd); - + Value *TruncA = Builder->CreateTrunc(A, NewType, A->getName()+".trunc"); Value *TruncB = Builder->CreateTrunc(B, NewType, B->getName()+".trunc"); CallInst *Call = Builder->CreateCall2(F, TruncA, TruncB, "sadd"); Value *Add = Builder->CreateExtractValue(Call, 0, "sadd.result"); Value *ZExt = Builder->CreateZExt(Add, OrigAdd->getType()); - + // The inner add was the result of the narrow add, zero extended to the // wider type. Replace it with the result computed by the intrinsic. IC.ReplaceInstUsesWith(*OrigAdd, ZExt); - + // The original icmp gets replaced with the overflow value. return ExtractValueInst::Create(Call, 1, "sadd.overflow"); } @@ -1709,13 +1710,13 @@ static Instruction *ProcessUAddIdiom(Instruction &I, Value *OrigAddV, // Don't bother doing this transformation for pointers, don't do it for // vectors. if (!isa<IntegerType>(OrigAddV->getType())) return 0; - + // If the add is a constant expr, then we don't bother transforming it. Instruction *OrigAdd = dyn_cast<Instruction>(OrigAddV); if (OrigAdd == 0) return 0; - + Value *LHS = OrigAdd->getOperand(0), *RHS = OrigAdd->getOperand(1); - + // Put the new code above the original add, in case there are any uses of the // add between the add and the compare. InstCombiner::BuilderTy *Builder = IC.Builder; @@ -1740,13 +1741,13 @@ static APInt DemandedBitsLHSMask(ICmpInst &I, unsigned BitWidth, bool isSignCheck) { if (isSignCheck) return APInt::getSignBit(BitWidth); - + ConstantInt *CI = dyn_cast<ConstantInt>(I.getOperand(1)); if (!CI) return APInt::getAllOnesValue(BitWidth); const APInt &RHS = CI->getValue(); - + switch (I.getPredicate()) { - // For a UGT comparison, we don't care about any bits that + // For a UGT comparison, we don't care about any bits that // correspond to the trailing ones of the comparand. The value of these // bits doesn't impact the outcome of the comparison, because any value // greater than the RHS must differ in a bit higher than these due to carry. @@ -1755,7 +1756,7 @@ static APInt DemandedBitsLHSMask(ICmpInst &I, APInt lowBitsSet = APInt::getLowBitsSet(BitWidth, trailingOnes); return ~lowBitsSet; } - + // Similarly, for a ULT comparison, we don't care about the trailing zeros. // Any value less than the RHS must differ in a higher bit because of carries. case ICmpInst::ICMP_ULT: { @@ -1763,17 +1764,17 @@ static APInt DemandedBitsLHSMask(ICmpInst &I, APInt lowBitsSet = APInt::getLowBitsSet(BitWidth, trailingZeros); return ~lowBitsSet; } - + default: return APInt::getAllOnesValue(BitWidth); } - + } Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { bool Changed = false; Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1); - + /// Orders the operands of the compare so that they are listed from most /// complex to least complex. This puts constants before unary operators, /// before binary operators. @@ -1782,10 +1783,10 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { std::swap(Op0, Op1); Changed = true; } - + if (Value *V = SimplifyICmpInst(I.getPredicate(), Op0, Op1, TD)) return ReplaceInstUsesWith(I, V); - + Type *Ty = Op0->getType(); // icmp's with boolean values can always be turned into bitwise operations @@ -1835,13 +1836,13 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { BitWidth = Ty->getScalarSizeInBits(); else if (TD) // Pointers require TD info to get their size. BitWidth = TD->getTypeSizeInBits(Ty->getScalarType()); - + bool isSignBit = false; // See if we are doing a comparison with a constant. if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1)) { Value *A = 0, *B = 0; - + // Match the following pattern, which is a common idiom when writing // overflow-safe integer arithmetic function. The source performs an // addition in wider type, and explicitly checks for overflow using @@ -1849,9 +1850,9 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { // sadd_with_overflow intrinsic. // // TODO: This could probably be generalized to handle other overflow-safe - // operations if we worked out the formulas to compute the appropriate + // operations if we worked out the formulas to compute the appropriate // magic constants. - // + // // sum = a + b // if (sum+128 >u 255) ... -> llvm.sadd.with.overflow.i8 { @@ -1861,14 +1862,14 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { if (Instruction *Res = ProcessUGT_ADDCST_ADD(I, A, B, CI2, CI, *this)) return Res; } - + // (icmp ne/eq (sub A B) 0) -> (icmp ne/eq A, B) if (I.isEquality() && CI->isZero() && match(Op0, m_Sub(m_Value(A), m_Value(B)))) { // (icmp cond A B) if cond is equality return new ICmpInst(I.getPredicate(), A, B); } - + // If we have an icmp le or icmp ge instruction, turn it into the // appropriate icmp lt or icmp gt instruction. This allows us to rely on // them being folded in the code below. The SimplifyICmpInst code has @@ -1892,7 +1893,7 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { return new ICmpInst(ICmpInst::ICMP_SGT, Op0, ConstantInt::get(CI->getContext(), CI->getValue()-1)); } - + // If this comparison is a normal comparison, it demands all // bits, if it is a sign bit comparison, it only demands the sign bit. bool UnusedBit; @@ -1948,7 +1949,7 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { case ICmpInst::ICMP_EQ: { if (Op0Max.ult(Op1Min) || Op0Min.ugt(Op1Max)) return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getType())); - + // If all bits are known zero except for one, then we know at most one // bit is set. If the comparison is against zero, then this is a check // to see if *that* bit is set. @@ -1960,7 +1961,7 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { if (!match(Op0, m_And(m_Value(LHS), m_ConstantInt(LHSC))) || LHSC->getValue() != Op0KnownZeroInverted) LHS = Op0; - + // If the LHS is 1 << x, and we know the result is a power of 2 like 8, // then turn "((1 << x)&8) == 0" into "x != 3". Value *X = 0; @@ -1969,7 +1970,7 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { return new ICmpInst(ICmpInst::ICMP_NE, X, ConstantInt::get(X->getType(), CmpVal)); } - + // If the LHS is 8 >>u x, and we know the result is a power of 2 like 1, // then turn "((8 >>u x)&1) == 0" into "x != 3". const APInt *CI; @@ -1979,13 +1980,13 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { ConstantInt::get(X->getType(), CI->countTrailingZeros())); } - + break; } case ICmpInst::ICMP_NE: { if (Op0Max.ult(Op1Min) || Op0Min.ugt(Op1Max)) return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getType())); - + // If all bits are known zero except for one, then we know at most one // bit is set. If the comparison is against zero, then this is a check // to see if *that* bit is set. @@ -1997,7 +1998,7 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { if (!match(Op0, m_And(m_Value(LHS), m_ConstantInt(LHSC))) || LHSC->getValue() != Op0KnownZeroInverted) LHS = Op0; - + // If the LHS is 1 << x, and we know the result is a power of 2 like 8, // then turn "((1 << x)&8) != 0" into "x == 3". Value *X = 0; @@ -2006,7 +2007,7 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { return new ICmpInst(ICmpInst::ICMP_EQ, X, ConstantInt::get(X->getType(), CmpVal)); } - + // If the LHS is 8 >>u x, and we know the result is a power of 2 like 1, // then turn "((8 >>u x)&1) != 0" into "x == 3". const APInt *CI; @@ -2016,7 +2017,7 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { ConstantInt::get(X->getType(), CI->countTrailingZeros())); } - + break; } case ICmpInst::ICMP_ULT: @@ -2137,9 +2138,9 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { // See if we are doing a comparison between a constant and an instruction that // can be folded into the comparison. if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1)) { - // Since the RHS is a ConstantInt (CI), if the left hand side is an - // instruction, see if that instruction also has constants so that the - // instruction can be folded into the icmp + // Since the RHS is a ConstantInt (CI), if the left hand side is an + // instruction, see if that instruction also has constants so that the + // instruction can be folded into the icmp if (Instruction *LHSI = dyn_cast<Instruction>(Op0)) if (Instruction *Res = visitICmpInstWithInstAndIntCst(I, LHSI, CI)) return Res; @@ -2194,7 +2195,7 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { case Instruction::IntToPtr: // icmp pred inttoptr(X), null -> icmp pred X, 0 if (RHSC->isNullValue() && TD && - TD->getIntPtrType(RHSC->getContext()) == + TD->getIntPtrType(RHSC->getContext()) == LHSI->getOperand(0)->getType()) return new ICmpInst(I.getPredicate(), LHSI->getOperand(0), Constant::getNullValue(LHSI->getOperand(0)->getType())); @@ -2227,8 +2228,8 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { // values. If the ptr->ptr cast can be stripped off both arguments, we do so // now. if (BitCastInst *CI = dyn_cast<BitCastInst>(Op0)) { - if (Op0->getType()->isPointerTy() && - (isa<Constant>(Op1) || isa<BitCastInst>(Op1))) { + if (Op0->getType()->isPointerTy() && + (isa<Constant>(Op1) || isa<BitCastInst>(Op1))) { // We keep moving the cast from the left operand over to the right // operand, where it can often be eliminated completely. Op0 = CI->getOperand(0); @@ -2250,7 +2251,7 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { return new ICmpInst(I.getPredicate(), Op0, Op1); } } - + if (isa<CastInst>(Op0)) { // Handle the special case of: icmp (cast bool to X), <cst> // This comes up when you have code like @@ -2384,7 +2385,7 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { return new ICmpInst(Pred, BO0->getOperand(0), BO1->getOperand(0)); } - + if (CI->isMaxValue(true)) { ICmpInst::Predicate Pred = I.isSigned() ? I.getUnsignedPredicate() @@ -2404,7 +2405,7 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { // Mask = -1 >> count-trailing-zeros(Cst). if (!CI->isZero() && !CI->isOne()) { const APInt &AP = CI->getValue(); - ConstantInt *Mask = ConstantInt::get(I.getContext(), + ConstantInt *Mask = ConstantInt::get(I.getContext(), APInt::getLowBitsSet(AP.getBitWidth(), AP.getBitWidth() - AP.countTrailingZeros())); @@ -2438,7 +2439,7 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { } } } - + { Value *A, *B; // ~x < ~y --> y < x // ~x < cst --> ~cst < x @@ -2452,11 +2453,11 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { // (a+b) <u a --> llvm.uadd.with.overflow. // (a+b) <u b --> llvm.uadd.with.overflow. if (I.getPredicate() == ICmpInst::ICMP_ULT && - match(Op0, m_Add(m_Value(A), m_Value(B))) && + match(Op0, m_Add(m_Value(A), m_Value(B))) && (Op1 == A || Op1 == B)) if (Instruction *R = ProcessUAddIdiom(I, Op0, *this)) return R; - + // a >u (a+b) --> llvm.uadd.with.overflow. // b >u (a+b) --> llvm.uadd.with.overflow. if (I.getPredicate() == ICmpInst::ICMP_UGT && @@ -2465,7 +2466,7 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { if (Instruction *R = ProcessUAddIdiom(I, Op1, *this)) return R; } - + if (I.isEquality()) { Value *A, *B, *C, *D; @@ -2483,10 +2484,10 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { match(D, m_ConstantInt(C2)) && Op1->hasOneUse()) { Constant *NC = ConstantInt::get(I.getContext(), C1->getValue() ^ C2->getValue()); - Value *Xor = Builder->CreateXor(C, NC, "tmp"); + Value *Xor = Builder->CreateXor(C, NC); return new ICmpInst(I.getPredicate(), A, Xor); } - + // A^B == A^D -> B == D if (A == C) return new ICmpInst(I.getPredicate(), B, D); if (A == D) return new ICmpInst(I.getPredicate(), B, C); @@ -2494,7 +2495,7 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { if (B == D) return new ICmpInst(I.getPredicate(), A, C); } } - + if (match(Op1, m_Xor(m_Value(A), m_Value(B))) && (A == Op0 || B == Op0)) { // A == (A^B) -> B == 0 @@ -2504,10 +2505,10 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { } // (X&Z) == (Y&Z) -> (X^Y) & Z == 0 - if (match(Op0, m_OneUse(m_And(m_Value(A), m_Value(B)))) && + if (match(Op0, m_OneUse(m_And(m_Value(A), m_Value(B)))) && match(Op1, m_OneUse(m_And(m_Value(C), m_Value(D))))) { Value *X = 0, *Y = 0, *Z = 0; - + if (A == C) { X = B; Y = D; Z = A; } else if (A == D) { @@ -2517,16 +2518,16 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { } else if (B == D) { X = A; Y = C; Z = B; } - + if (X) { // Build (X^Y) & Z - Op1 = Builder->CreateXor(X, Y, "tmp"); - Op1 = Builder->CreateAnd(Op1, Z, "tmp"); + Op1 = Builder->CreateXor(X, Y); + Op1 = Builder->CreateAnd(Op1, Z); I.setOperand(0, Op1); I.setOperand(1, Constant::getNullValue(Op1->getType())); return &I; } } - + // Transform "icmp eq (trunc (lshr(X, cst1)), cst" to // "icmp (and X, mask), cst" uint64_t ShAmt = 0; @@ -2539,21 +2540,21 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { // when it exposes other optimizations. !A->hasOneUse()) { unsigned ASize =cast<IntegerType>(A->getType())->getPrimitiveSizeInBits(); - + if (ShAmt < ASize) { APInt MaskV = APInt::getLowBitsSet(ASize, Op0->getType()->getPrimitiveSizeInBits()); MaskV <<= ShAmt; - + APInt CmpV = Cst1->getValue().zext(ASize); CmpV <<= ShAmt; - + Value *Mask = Builder->CreateAnd(A, Builder->getInt(MaskV)); return new ICmpInst(I.getPredicate(), Mask, Builder->getInt(CmpV)); } } } - + { Value *X; ConstantInt *Cst; // icmp X+Cst, X @@ -2579,31 +2580,31 @@ Instruction *InstCombiner::FoldFCmp_IntToFP_Cst(FCmpInst &I, Constant *RHSC) { if (!isa<ConstantFP>(RHSC)) return 0; const APFloat &RHS = cast<ConstantFP>(RHSC)->getValueAPF(); - + // Get the width of the mantissa. We don't want to hack on conversions that // might lose information from the integer, e.g. "i64 -> float" int MantissaWidth = LHSI->getType()->getFPMantissaWidth(); if (MantissaWidth == -1) return 0; // Unknown. - + // Check to see that the input is converted from an integer type that is small // enough that preserves all bits. TODO: check here for "known" sign bits. // This would allow us to handle (fptosi (x >>s 62) to float) if x is i64 f.e. unsigned InputSize = LHSI->getOperand(0)->getType()->getScalarSizeInBits(); - + // If this is a uitofp instruction, we need an extra bit to hold the sign. bool LHSUnsigned = isa<UIToFPInst>(LHSI); if (LHSUnsigned) ++InputSize; - + // If the conversion would lose info, don't hack on this. if ((int)InputSize > MantissaWidth) return 0; - + // Otherwise, we can potentially simplify the comparison. We know that it // will always come through as an integer value and we know the constant is // not a NAN (it would have been previously simplified). assert(!RHS.isNaN() && "NaN comparison not already folded!"); - + ICmpInst::Predicate Pred; switch (I.getPredicate()) { default: llvm_unreachable("Unexpected predicate!"); @@ -2636,15 +2637,15 @@ Instruction *InstCombiner::FoldFCmp_IntToFP_Cst(FCmpInst &I, case FCmpInst::FCMP_UNO: return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getContext())); } - + IntegerType *IntTy = cast<IntegerType>(LHSI->getOperand(0)->getType()); - + // Now we know that the APFloat is a normal number, zero or inf. - + // See if the FP constant is too large for the integer. For example, // comparing an i8 to 300.0. unsigned IntWidth = IntTy->getScalarSizeInBits(); - + if (!LHSUnsigned) { // If the RHS value is > SignedMax, fold the comparison. This handles +INF // and large values. @@ -2670,7 +2671,7 @@ Instruction *InstCombiner::FoldFCmp_IntToFP_Cst(FCmpInst &I, return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getContext())); } } - + if (!LHSUnsigned) { // See if the RHS value is < SignedMin. APFloat SMin(RHS.getSemantics(), APFloat::fcZero, false); @@ -2766,7 +2767,7 @@ Instruction *InstCombiner::FoldFCmp_IntToFP_Cst(FCmpInst &I, Instruction *InstCombiner::visitFCmpInst(FCmpInst &I) { bool Changed = false; - + /// Orders the operands of the compare so that they are listed from most /// complex to least complex. This puts constants before unary operators, /// before binary operators. @@ -2776,7 +2777,7 @@ Instruction *InstCombiner::visitFCmpInst(FCmpInst &I) { } Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1); - + if (Value *V = SimplifyFCmpInst(I.getPredicate(), Op0, Op1, TD)) return ReplaceInstUsesWith(I, V); @@ -2792,7 +2793,7 @@ Instruction *InstCombiner::visitFCmpInst(FCmpInst &I) { I.setPredicate(FCmpInst::FCMP_UNO); I.setOperand(1, Constant::getNullValue(Op0->getType())); return &I; - + case FCmpInst::FCMP_ORD: // True if ordered (no nans) case FCmpInst::FCMP_OEQ: // True if ordered and equal case FCmpInst::FCMP_OGE: // True if ordered and greater than or equal @@ -2803,7 +2804,7 @@ Instruction *InstCombiner::visitFCmpInst(FCmpInst &I) { return &I; } } - + // Handle fcmp with constant RHS if (Constant *RHSC = dyn_cast<Constant>(Op1)) { if (Instruction *LHSI = dyn_cast<Instruction>(Op0)) @@ -2836,10 +2837,14 @@ Instruction *InstCombiner::visitFCmpInst(FCmpInst &I) { APFloat F = RHSF->getValueAPF(); F.convert(*Sem, APFloat::rmNearestTiesToEven, &Lossy); - // Avoid lossy conversions and denormals. + // Avoid lossy conversions and denormals. Zero is a special case + // that's OK to convert. + APFloat Fabs = F; + Fabs.clearSign(); if (!Lossy && - F.compare(APFloat::getSmallestNormalized(*Sem)) != - APFloat::cmpLessThan) + ((Fabs.compare(APFloat::getSmallestNormalized(*Sem)) != + APFloat::cmpLessThan) || Fabs.isZero())) + return new FCmpInst(I.getPredicate(), LHSExt->getOperand(0), ConstantFP::get(RHSC->getContext(), F)); break; diff --git a/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp b/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp index bdd2edb..7446a51 100644 --- a/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp +++ b/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp @@ -58,8 +58,7 @@ Instruction *InstCombiner::visitAllocaInst(AllocaInst &AI) { Idx[0] = NullIdx; Idx[1] = NullIdx; Instruction *GEP = - GetElementPtrInst::CreateInBounds(New, Idx, Idx + 2, - New->getName()+".sub"); + GetElementPtrInst::CreateInBounds(New, Idx, New->getName()+".sub"); InsertNewInstBefore(GEP, *It); // Now make everything use the getelementptr instead of the original @@ -113,7 +112,7 @@ static Instruction *InstCombineLoadCast(InstCombiner &IC, LoadInst &LI, Value *Idxs[2]; Idxs[0] = Constant::getNullValue(Type::getInt32Ty(LI.getContext())); Idxs[1] = Idxs[0]; - CastOp = ConstantExpr::getGetElementPtr(CSrc, Idxs, 2); + CastOp = ConstantExpr::getGetElementPtr(CSrc, Idxs); SrcTy = cast<PointerType>(CastOp->getType()); SrcPTy = SrcTy->getElementType(); } @@ -133,6 +132,7 @@ static Instruction *InstCombineLoadCast(InstCombiner &IC, LoadInst &LI, LoadInst *NewLoad = IC.Builder->CreateLoad(CastOp, LI.isVolatile(), CI->getName()); NewLoad->setAlignment(LI.getAlignment()); + NewLoad->setAtomic(LI.getOrdering(), LI.getSynchScope()); // Now cast the result of the load. return new BitCastInst(NewLoad, LI.getType()); } @@ -163,8 +163,9 @@ Instruction *InstCombiner::visitLoadInst(LoadInst &LI) { if (Instruction *Res = InstCombineLoadCast(*this, LI, TD)) return Res; - // None of the following transforms are legal for volatile loads. - if (LI.isVolatile()) return 0; + // None of the following transforms are legal for volatile/atomic loads. + // FIXME: Some of it is okay for atomic loads; needs refactoring. + if (!LI.isSimple()) return 0; // Do really simple store-to-load forwarding and load CSE, to catch cases // where there are several consecutive memory accesses to the same location, @@ -327,8 +328,7 @@ static Instruction *InstCombineStoreToCast(InstCombiner &IC, StoreInst &SI) { // SIOp0 is a pointer to aggregate and this is a store to the first field, // emit a GEP to index into its first field. if (!NewGEPIndices.empty()) - CastOp = IC.Builder->CreateInBoundsGEP(CastOp, NewGEPIndices.begin(), - NewGEPIndices.end()); + CastOp = IC.Builder->CreateInBoundsGEP(CastOp, NewGEPIndices); NewCast = IC.Builder->CreateCast(opcode, SIOp0, CastDstTy, SIOp0->getName()+".c"); @@ -370,21 +370,6 @@ Instruction *InstCombiner::visitStoreInst(StoreInst &SI) { Value *Val = SI.getOperand(0); Value *Ptr = SI.getOperand(1); - // If the RHS is an alloca with a single use, zapify the store, making the - // alloca dead. - if (!SI.isVolatile()) { - if (Ptr->hasOneUse()) { - if (isa<AllocaInst>(Ptr)) - return EraseInstFromFunction(SI); - if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Ptr)) { - if (isa<AllocaInst>(GEP->getOperand(0))) { - if (GEP->getOperand(0)->hasOneUse()) - return EraseInstFromFunction(SI); - } - } - } - } - // Attempt to improve the alignment. if (TD) { unsigned KnownAlign = @@ -400,6 +385,23 @@ Instruction *InstCombiner::visitStoreInst(StoreInst &SI) { SI.setAlignment(EffectiveStoreAlign); } + // Don't hack volatile/atomic stores. + // FIXME: Some bits are legal for atomic stores; needs refactoring. + if (!SI.isSimple()) return 0; + + // If the RHS is an alloca with a single use, zapify the store, making the + // alloca dead. + if (Ptr->hasOneUse()) { + if (isa<AllocaInst>(Ptr)) + return EraseInstFromFunction(SI); + if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Ptr)) { + if (isa<AllocaInst>(GEP->getOperand(0))) { + if (GEP->getOperand(0)->hasOneUse()) + return EraseInstFromFunction(SI); + } + } + } + // Do really simple DSE, to catch cases where there are several consecutive // stores to the same location, separated by a few arithmetic operations. This // situation often occurs with bitfield accesses. @@ -417,8 +419,8 @@ Instruction *InstCombiner::visitStoreInst(StoreInst &SI) { if (StoreInst *PrevSI = dyn_cast<StoreInst>(BBI)) { // Prev store isn't volatile, and stores to the same location? - if (!PrevSI->isVolatile() &&equivalentAddressValues(PrevSI->getOperand(1), - SI.getOperand(1))) { + if (PrevSI->isSimple() && equivalentAddressValues(PrevSI->getOperand(1), + SI.getOperand(1))) { ++NumDeadStore; ++BBI; EraseInstFromFunction(*PrevSI); @@ -432,7 +434,7 @@ Instruction *InstCombiner::visitStoreInst(StoreInst &SI) { // then *this* store is dead (X = load P; store X -> P). if (LoadInst *LI = dyn_cast<LoadInst>(BBI)) { if (LI == Val && equivalentAddressValues(LI->getOperand(0), Ptr) && - !SI.isVolatile()) + LI->isSimple()) return EraseInstFromFunction(SI); // Otherwise, this is a load from some other location. Stores before it @@ -444,9 +446,6 @@ Instruction *InstCombiner::visitStoreInst(StoreInst &SI) { if (BBI->mayWriteToMemory() || BBI->mayReadFromMemory()) break; } - - - if (SI.isVolatile()) return 0; // Don't hack volatile stores. // store X, null -> turns into 'unreachable' in SimplifyCFG if (isa<ConstantPointerNull>(Ptr) && SI.getPointerAddressSpace() == 0) { @@ -549,11 +548,11 @@ bool InstCombiner::SimplifyStoreAtEndOfBlock(StoreInst &SI) { return false; --BBI; } - // If this isn't a store, isn't a store to the same location, or if the - // alignments differ, bail out. + // If this isn't a store, isn't a store to the same location, or is not the + // right kind of store, bail out. OtherStore = dyn_cast<StoreInst>(BBI); if (!OtherStore || OtherStore->getOperand(1) != SI.getOperand(1) || - OtherStore->getAlignment() != SI.getAlignment()) + !SI.isSameOperationAs(OtherStore)) return false; } else { // Otherwise, the other block ended with a conditional branch. If one of the @@ -569,7 +568,7 @@ bool InstCombiner::SimplifyStoreAtEndOfBlock(StoreInst &SI) { // Check to see if we find the matching store. if ((OtherStore = dyn_cast<StoreInst>(BBI))) { if (OtherStore->getOperand(1) != SI.getOperand(1) || - OtherStore->getAlignment() != SI.getAlignment()) + !SI.isSameOperationAs(OtherStore)) return false; break; } @@ -601,10 +600,12 @@ bool InstCombiner::SimplifyStoreAtEndOfBlock(StoreInst &SI) { // Advance to a place where it is safe to insert the new store and // insert it. - BBI = DestBB->getFirstNonPHI(); + BBI = DestBB->getFirstInsertionPt(); StoreInst *NewSI = new StoreInst(MergedVal, SI.getOperand(1), - OtherStore->isVolatile(), - SI.getAlignment()); + SI.isVolatile(), + SI.getAlignment(), + SI.getOrdering(), + SI.getSynchScope()); InsertNewInstBefore(NewSI, *BBI); NewSI->setDebugLoc(OtherStore->getDebugLoc()); diff --git a/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp index 53341cc..7f48125 100644 --- a/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp +++ b/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp @@ -38,7 +38,7 @@ static Value *simplifyValueKnownNonZero(Value *V, InstCombiner &IC) { m_Value(B))) && // The "1" can be any value known to be a power of 2. isPowerOfTwo(PowerOf2, IC.getTargetData())) { - A = IC.Builder->CreateSub(A, B, "tmp"); + A = IC.Builder->CreateSub(A, B); return IC.Builder->CreateShl(PowerOf2, A); } @@ -131,7 +131,7 @@ Instruction *InstCombiner::visitMul(BinaryOperator &I) { { Value *X; ConstantInt *C1; if (Op0->hasOneUse() && match(Op0, m_Add(m_Value(X), m_ConstantInt(C1)))) { - Value *Add = Builder->CreateMul(X, CI, "tmp"); + Value *Add = Builder->CreateMul(X, CI); return BinaryOperator::CreateAdd(Add, Builder->CreateMul(C1, CI)); } } @@ -244,7 +244,7 @@ Instruction *InstCombiner::visitMul(BinaryOperator &I) { if (BoolCast) { Value *V = Builder->CreateSub(Constant::getNullValue(I.getType()), - BoolCast, "tmp"); + BoolCast); return BinaryOperator::CreateAnd(V, OtherOp); } } @@ -466,8 +466,7 @@ Instruction *InstCombiner::visitUDiv(BinaryOperator &I) { { const APInt *CI; Value *N; if (match(Op1, m_Shl(m_Power2(CI), m_Value(N)))) { if (*CI != 1) - N = Builder->CreateAdd(N, ConstantInt::get(I.getType(), CI->logBase2()), - "tmp"); + N = Builder->CreateAdd(N, ConstantInt::get(I.getType(),CI->logBase2())); if (I.isExact()) return BinaryOperator::CreateExactLShr(Op0, N); return BinaryOperator::CreateLShr(Op0, N); @@ -630,7 +629,7 @@ Instruction *InstCombiner::visitURem(BinaryOperator &I) { // Turn A % (C << N), where C is 2^k, into A & ((C << N)-1) if (match(Op1, m_Shl(m_Power2(), m_Value()))) { Constant *N1 = Constant::getAllOnesValue(I.getType()); - Value *Add = Builder->CreateAdd(Op1, N1, "tmp"); + Value *Add = Builder->CreateAdd(Op1, N1); return BinaryOperator::CreateAnd(Op0, Add); } diff --git a/lib/Transforms/InstCombine/InstCombinePHI.cpp b/lib/Transforms/InstCombine/InstCombinePHI.cpp index bf1049d..664546c 100644 --- a/lib/Transforms/InstCombine/InstCombinePHI.cpp +++ b/lib/Transforms/InstCombine/InstCombinePHI.cpp @@ -229,8 +229,7 @@ Instruction *InstCombiner::FoldPHIArgGEPIntoPHI(PHINode &PN) { Value *Base = FixedOperands[0]; GetElementPtrInst *NewGEP = - GetElementPtrInst::Create(Base, FixedOperands.begin()+1, - FixedOperands.end()); + GetElementPtrInst::Create(Base, makeArrayRef(FixedOperands).slice(1)); if (AllInBounds) NewGEP->setIsInBounds(); NewGEP->setDebugLoc(FirstInst->getDebugLoc()); return NewGEP; @@ -287,7 +286,12 @@ static bool isSafeAndProfitableToSinkLoad(LoadInst *L) { Instruction *InstCombiner::FoldPHIArgLoadIntoPHI(PHINode &PN) { LoadInst *FirstLI = cast<LoadInst>(PN.getIncomingValue(0)); - + + // FIXME: This is overconservative; this transform is allowed in some cases + // for atomic operations. + if (FirstLI->isAtomic()) + return 0; + // When processing loads, we need to propagate two bits of information to the // sunk load: whether it is volatile, and what its alignment is. We currently // don't sink loads when some have their alignment specified and some don't. diff --git a/lib/Transforms/InstCombine/InstCombineSelect.cpp b/lib/Transforms/InstCombine/InstCombineSelect.cpp index bd7f40d..91e60a4 100644 --- a/lib/Transforms/InstCombine/InstCombineSelect.cpp +++ b/lib/Transforms/InstCombine/InstCombineSelect.cpp @@ -13,6 +13,7 @@ #include "InstCombine.h" #include "llvm/Support/PatternMatch.h" +#include "llvm/Analysis/ConstantFolding.h" #include "llvm/Analysis/InstructionSimplify.h" using namespace llvm; using namespace PatternMatch; @@ -323,9 +324,14 @@ static Value *SimplifyWithOpReplaced(Value *V, Value *Op, Value *RepOp, } // All operands were constants, fold it. - if (ConstOps.size() == I->getNumOperands()) + if (ConstOps.size() == I->getNumOperands()) { + if (LoadInst *LI = dyn_cast<LoadInst>(I)) + if (!LI->isVolatile()) + return ConstantFoldLoadFromConstPtr(ConstOps[0], TD); + return ConstantFoldInstOperands(I->getOpcode(), I->getType(), ConstOps, TD); + } } return 0; @@ -476,10 +482,16 @@ Instruction *InstCombiner::visitSelectInstWithICmp(SelectInst &SI, if (SimplifyWithOpReplaced(FalseVal, CmpLHS, CmpRHS, TD) == TrueVal || SimplifyWithOpReplaced(FalseVal, CmpRHS, CmpLHS, TD) == TrueVal) return ReplaceInstUsesWith(SI, FalseVal); + if (SimplifyWithOpReplaced(TrueVal, CmpLHS, CmpRHS, TD) == FalseVal || + SimplifyWithOpReplaced(TrueVal, CmpRHS, CmpLHS, TD) == FalseVal) + return ReplaceInstUsesWith(SI, FalseVal); } else if (Pred == ICmpInst::ICMP_NE) { if (SimplifyWithOpReplaced(TrueVal, CmpLHS, CmpRHS, TD) == FalseVal || SimplifyWithOpReplaced(TrueVal, CmpRHS, CmpLHS, TD) == FalseVal) return ReplaceInstUsesWith(SI, TrueVal); + if (SimplifyWithOpReplaced(FalseVal, CmpLHS, CmpRHS, TD) == TrueVal || + SimplifyWithOpReplaced(FalseVal, CmpRHS, CmpLHS, TD) == TrueVal) + return ReplaceInstUsesWith(SI, TrueVal); } // NOTE: if we wanted to, this is where to detect integer MIN/MAX diff --git a/lib/Transforms/InstCombine/InstCombineShifts.cpp b/lib/Transforms/InstCombine/InstCombineShifts.cpp index 65d1a66..6d85add 100644 --- a/lib/Transforms/InstCombine/InstCombineShifts.cpp +++ b/lib/Transforms/InstCombine/InstCombineShifts.cpp @@ -13,6 +13,7 @@ #include "InstCombine.h" #include "llvm/IntrinsicInst.h" +#include "llvm/Analysis/ConstantFolding.h" #include "llvm/Analysis/InstructionSimplify.h" #include "llvm/Support/PatternMatch.h" using namespace llvm; @@ -207,11 +208,12 @@ static Value *GetShiftedValue(Value *V, unsigned NumBits, bool isLeftShift, return I; case Instruction::Shl: { - unsigned TypeWidth = I->getType()->getScalarSizeInBits(); + BinaryOperator *BO = cast<BinaryOperator>(I); + unsigned TypeWidth = BO->getType()->getScalarSizeInBits(); // We only accept shifts-by-a-constant in CanEvaluateShifted. - ConstantInt *CI = cast<ConstantInt>(I->getOperand(1)); - + ConstantInt *CI = cast<ConstantInt>(BO->getOperand(1)); + // We can always fold shl(c1)+shl(c2) -> shl(c1+c2). if (isLeftShift) { // If this is oversized composite shift, then unsigned shifts get 0. @@ -219,7 +221,9 @@ static Value *GetShiftedValue(Value *V, unsigned NumBits, bool isLeftShift, if (NewShAmt >= TypeWidth) return Constant::getNullValue(I->getType()); - I->setOperand(1, ConstantInt::get(I->getType(), NewShAmt)); + BO->setOperand(1, ConstantInt::get(BO->getType(), NewShAmt)); + BO->setHasNoUnsignedWrap(false); + BO->setHasNoSignedWrap(false); return I; } @@ -227,11 +231,11 @@ static Value *GetShiftedValue(Value *V, unsigned NumBits, bool isLeftShift, // zeros. if (CI->getValue() == NumBits) { APInt Mask(APInt::getLowBitsSet(TypeWidth, TypeWidth - NumBits)); - V = IC.Builder->CreateAnd(I->getOperand(0), - ConstantInt::get(I->getContext(), Mask)); + V = IC.Builder->CreateAnd(BO->getOperand(0), + ConstantInt::get(BO->getContext(), Mask)); if (Instruction *VI = dyn_cast<Instruction>(V)) { - VI->moveBefore(I); - VI->takeName(I); + VI->moveBefore(BO); + VI->takeName(BO); } return V; } @@ -239,23 +243,27 @@ static Value *GetShiftedValue(Value *V, unsigned NumBits, bool isLeftShift, // We turn shl(c1)+shr(c2) -> shl(c3)+and(c4), but only when we know that // the and won't be needed. assert(CI->getZExtValue() > NumBits); - I->setOperand(1, ConstantInt::get(I->getType(), - CI->getZExtValue() - NumBits)); - return I; + BO->setOperand(1, ConstantInt::get(BO->getType(), + CI->getZExtValue() - NumBits)); + BO->setHasNoUnsignedWrap(false); + BO->setHasNoSignedWrap(false); + return BO; } case Instruction::LShr: { - unsigned TypeWidth = I->getType()->getScalarSizeInBits(); + BinaryOperator *BO = cast<BinaryOperator>(I); + unsigned TypeWidth = BO->getType()->getScalarSizeInBits(); // We only accept shifts-by-a-constant in CanEvaluateShifted. - ConstantInt *CI = cast<ConstantInt>(I->getOperand(1)); + ConstantInt *CI = cast<ConstantInt>(BO->getOperand(1)); // We can always fold lshr(c1)+lshr(c2) -> lshr(c1+c2). if (!isLeftShift) { // If this is oversized composite shift, then unsigned shifts get 0. unsigned NewShAmt = NumBits+CI->getZExtValue(); if (NewShAmt >= TypeWidth) - return Constant::getNullValue(I->getType()); + return Constant::getNullValue(BO->getType()); - I->setOperand(1, ConstantInt::get(I->getType(), NewShAmt)); + BO->setOperand(1, ConstantInt::get(BO->getType(), NewShAmt)); + BO->setIsExact(false); return I; } @@ -264,7 +272,7 @@ static Value *GetShiftedValue(Value *V, unsigned NumBits, bool isLeftShift, if (CI->getValue() == NumBits) { APInt Mask(APInt::getHighBitsSet(TypeWidth, TypeWidth - NumBits)); V = IC.Builder->CreateAnd(I->getOperand(0), - ConstantInt::get(I->getContext(), Mask)); + ConstantInt::get(BO->getContext(), Mask)); if (Instruction *VI = dyn_cast<Instruction>(V)) { VI->moveBefore(I); VI->takeName(I); @@ -275,9 +283,10 @@ static Value *GetShiftedValue(Value *V, unsigned NumBits, bool isLeftShift, // We turn lshr(c1)+shl(c2) -> lshr(c3)+and(c4), but only when we know that // the and won't be needed. assert(CI->getZExtValue() > NumBits); - I->setOperand(1, ConstantInt::get(I->getType(), - CI->getZExtValue() - NumBits)); - return I; + BO->setOperand(1, ConstantInt::get(BO->getType(), + CI->getZExtValue() - NumBits)); + BO->setIsExact(false); + return BO; } case Instruction::Select: diff --git a/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp b/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp index 66f39be..5cd9a4b 100644 --- a/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp +++ b/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp @@ -325,8 +325,7 @@ Value *InstCombiner::SimplifyDemandedUseBits(Value *V, APInt DemandedMask, if ((RHSKnownOne & LHSKnownOne) == RHSKnownOne) { Constant *AndC = Constant::getIntegerValue(VTy, ~RHSKnownOne & DemandedMask); - Instruction *And = - BinaryOperator::CreateAnd(I->getOperand(0), AndC, "tmp"); + Instruction *And = BinaryOperator::CreateAnd(I->getOperand(0), AndC); return InsertNewInstWith(And, *I); } } @@ -351,14 +350,12 @@ Value *InstCombiner::SimplifyDemandedUseBits(Value *V, APInt DemandedMask, Constant *AndC = ConstantInt::get(I->getType(), NewMask & AndRHS->getValue()); - Instruction *NewAnd = - BinaryOperator::CreateAnd(I->getOperand(0), AndC, "tmp"); + Instruction *NewAnd = BinaryOperator::CreateAnd(I->getOperand(0), AndC); InsertNewInstWith(NewAnd, *I); Constant *XorC = ConstantInt::get(I->getType(), NewMask & XorRHS->getValue()); - Instruction *NewXor = - BinaryOperator::CreateXor(NewAnd, XorC, "tmp"); + Instruction *NewXor = BinaryOperator::CreateXor(NewAnd, XorC); return InsertNewInstWith(NewXor, *I); } @@ -962,6 +959,9 @@ Value *InstCombiner::SimplifyDemandedVectorElts(Value *V, APInt DemandedElts, unsigned MaskVal = Shuffle->getMaskValue(i); if (MaskVal == -1u) { UndefElts.setBit(i); + } else if (!DemandedElts[i]) { + NewUndefElts = true; + UndefElts.setBit(i); } else if (MaskVal < LHSVWidth) { if (UndefElts4[MaskVal]) { NewUndefElts = true; diff --git a/lib/Transforms/InstCombine/InstructionCombining.cpp b/lib/Transforms/InstCombine/InstructionCombining.cpp index 021ca13..288fe68 100644 --- a/lib/Transforms/InstCombine/InstructionCombining.cpp +++ b/lib/Transforms/InstCombine/InstructionCombining.cpp @@ -46,8 +46,10 @@ #include "llvm/Support/Debug.h" #include "llvm/Support/GetElementPtrTypeIterator.h" #include "llvm/Support/PatternMatch.h" +#include "llvm/Support/ValueHandle.h" #include "llvm/ADT/SmallPtrSet.h" #include "llvm/ADT/Statistic.h" +#include "llvm/ADT/StringSwitch.h" #include "llvm-c/Initialization.h" #include <algorithm> #include <climits> @@ -107,6 +109,43 @@ bool InstCombiner::ShouldChangeType(Type *From, Type *To) const { return true; } +// Return true, if No Signed Wrap should be maintained for I. +// The No Signed Wrap flag can be kept if the operation "B (I.getOpcode) C", +// where both B and C should be ConstantInts, results in a constant that does +// not overflow. This function only handles the Add and Sub opcodes. For +// all other opcodes, the function conservatively returns false. +static bool MaintainNoSignedWrap(BinaryOperator &I, Value *B, Value *C) { + OverflowingBinaryOperator *OBO = dyn_cast<OverflowingBinaryOperator>(&I); + if (!OBO || !OBO->hasNoSignedWrap()) { + return false; + } + + // We reason about Add and Sub Only. + Instruction::BinaryOps Opcode = I.getOpcode(); + if (Opcode != Instruction::Add && + Opcode != Instruction::Sub) { + return false; + } + + ConstantInt *CB = dyn_cast<ConstantInt>(B); + ConstantInt *CC = dyn_cast<ConstantInt>(C); + + if (!CB || !CC) { + return false; + } + + const APInt &BVal = CB->getValue(); + const APInt &CVal = CC->getValue(); + bool Overflow = false; + + if (Opcode == Instruction::Add) { + BVal.sadd_ov(CVal, Overflow); + } else { + BVal.ssub_ov(CVal, Overflow); + } + + return !Overflow; +} /// SimplifyAssociativeOrCommutative - This performs a few simplifications for /// operators which are associative or commutative: @@ -158,7 +197,16 @@ bool InstCombiner::SimplifyAssociativeOrCommutative(BinaryOperator &I) { I.setOperand(1, V); // Conservatively clear the optional flags, since they may not be // preserved by the reassociation. - I.clearSubclassOptionalData(); + if (MaintainNoSignedWrap(I, B, C) && + (!Op0 || (isa<BinaryOperator>(Op0) && Op0->hasNoSignedWrap()))) { + // Note: this is only valid because SimplifyBinOp doesn't look at + // the operands to Op0. + I.clearSubclassOptionalData(); + I.setHasNoSignedWrap(true); + } else { + I.clearSubclassOptionalData(); + } + Changed = true; ++NumReassoc; continue; @@ -240,7 +288,7 @@ bool InstCombiner::SimplifyAssociativeOrCommutative(BinaryOperator &I) { Constant *C2 = cast<Constant>(Op1->getOperand(1)); Constant *Folded = ConstantExpr::get(Opcode, C1, C2); - Instruction *New = BinaryOperator::Create(Opcode, A, B); + BinaryOperator *New = BinaryOperator::Create(Opcode, A, B); InsertNewInstWith(New, I); New->takeName(Op1); I.setOperand(0, New); @@ -248,6 +296,7 @@ bool InstCombiner::SimplifyAssociativeOrCommutative(BinaryOperator &I) { // Conservatively clear the optional flags, since they may not be // preserved by the reassociation. I.clearSubclassOptionalData(); + Changed = true; continue; } @@ -737,7 +786,15 @@ Type *InstCombiner::FindElementAtOffset(Type *Ty, int64_t Offset, return Ty; } - +static bool shouldMergeGEPs(GEPOperator &GEP, GEPOperator &Src) { + // If this GEP has only 0 indices, it is the same pointer as + // Src. If Src is not a trivial GEP too, don't combine + // the indices. + if (GEP.hasAllZeroIndices() && !Src.hasAllZeroIndices() && + !Src.hasOneUse()) + return false; + return true; +} Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { SmallVector<Value*, 8> Ops(GEP.op_begin(), GEP.op_end()); @@ -785,21 +842,15 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { // getelementptr instructions into a single instruction. // if (GEPOperator *Src = dyn_cast<GEPOperator>(PtrOp)) { - - // If this GEP has only 0 indices, it is the same pointer as - // Src. If Src is not a trivial GEP too, don't combine - // the indices. - if (GEP.hasAllZeroIndices() && !Src->hasAllZeroIndices() && - !Src->hasOneUse()) + if (!shouldMergeGEPs(*cast<GEPOperator>(&GEP), *Src)) return 0; // Note that if our source is a gep chain itself that we wait for that // chain to be resolved before we perform this transformation. This // avoids us creating a TON of code in some cases. - // - if (GetElementPtrInst *SrcGEP = - dyn_cast<GetElementPtrInst>(Src->getOperand(0))) - if (SrcGEP->getNumOperands() == 2) + if (GEPOperator *SrcGEP = + dyn_cast<GEPOperator>(Src->getOperand(0))) + if (SrcGEP->getNumOperands() == 2 && shouldMergeGEPs(*Src, *SrcGEP)) return 0; // Wait until our source is folded to completion. SmallVector<Value*, 8> Indices; @@ -851,10 +902,9 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { if (!Indices.empty()) return (GEP.isInBounds() && Src->isInBounds()) ? - GetElementPtrInst::CreateInBounds(Src->getOperand(0), Indices.begin(), - Indices.end(), GEP.getName()) : - GetElementPtrInst::Create(Src->getOperand(0), Indices.begin(), - Indices.end(), GEP.getName()); + GetElementPtrInst::CreateInBounds(Src->getOperand(0), Indices, + GEP.getName()) : + GetElementPtrInst::Create(Src->getOperand(0), Indices, GEP.getName()); } // Handle gep(bitcast x) and gep(gep x, 0, 0, 0). @@ -883,8 +933,7 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { // -> GEP i8* X, ... SmallVector<Value*, 8> Idx(GEP.idx_begin()+1, GEP.idx_end()); GetElementPtrInst *Res = - GetElementPtrInst::Create(StrippedPtr, Idx.begin(), - Idx.end(), GEP.getName()); + GetElementPtrInst::Create(StrippedPtr, Idx, GEP.getName()); Res->setIsInBounds(GEP.isInBounds()); return Res; } @@ -916,8 +965,8 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { Idx[0] = Constant::getNullValue(Type::getInt32Ty(GEP.getContext())); Idx[1] = GEP.getOperand(1); Value *NewGEP = GEP.isInBounds() ? - Builder->CreateInBoundsGEP(StrippedPtr, Idx, Idx + 2, GEP.getName()) : - Builder->CreateGEP(StrippedPtr, Idx, Idx + 2, GEP.getName()); + Builder->CreateInBoundsGEP(StrippedPtr, Idx, GEP.getName()) : + Builder->CreateGEP(StrippedPtr, Idx, GEP.getName()); // V and GEP are both pointer types --> BitCast return new BitCastInst(NewGEP, GEP.getType()); } @@ -975,8 +1024,8 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { Idx[0] = Constant::getNullValue(Type::getInt32Ty(GEP.getContext())); Idx[1] = NewIdx; Value *NewGEP = GEP.isInBounds() ? - Builder->CreateInBoundsGEP(StrippedPtr, Idx, Idx + 2,GEP.getName()): - Builder->CreateGEP(StrippedPtr, Idx, Idx + 2, GEP.getName()); + Builder->CreateInBoundsGEP(StrippedPtr, Idx, GEP.getName()): + Builder->CreateGEP(StrippedPtr, Idx, GEP.getName()); // The NewGEP must be pointer typed, so must the old one -> BitCast return new BitCastInst(NewGEP, GEP.getType()); } @@ -1027,10 +1076,8 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { cast<PointerType>(BCI->getOperand(0)->getType())->getElementType(); if (FindElementAtOffset(InTy, Offset, NewIndices)) { Value *NGEP = GEP.isInBounds() ? - Builder->CreateInBoundsGEP(BCI->getOperand(0), NewIndices.begin(), - NewIndices.end()) : - Builder->CreateGEP(BCI->getOperand(0), NewIndices.begin(), - NewIndices.end()); + Builder->CreateInBoundsGEP(BCI->getOperand(0), NewIndices) : + Builder->CreateGEP(BCI->getOperand(0), NewIndices); if (NGEP->getType() == GEP.getType()) return ReplaceInstUsesWith(GEP, NGEP); @@ -1045,15 +1092,43 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { -static bool IsOnlyNullComparedAndFreed(const Value &V) { - for (Value::const_use_iterator UI = V.use_begin(), UE = V.use_end(); +static bool IsOnlyNullComparedAndFreed(Value *V, SmallVectorImpl<WeakVH> &Users, + int Depth = 0) { + if (Depth == 8) + return false; + + for (Value::use_iterator UI = V->use_begin(), UE = V->use_end(); UI != UE; ++UI) { - const User *U = *UI; - if (isFreeCall(U)) + User *U = *UI; + if (isFreeCall(U)) { + Users.push_back(U); continue; - if (const ICmpInst *ICI = dyn_cast<ICmpInst>(U)) - if (ICI->isEquality() && isa<ConstantPointerNull>(ICI->getOperand(1))) + } + if (ICmpInst *ICI = dyn_cast<ICmpInst>(U)) { + if (ICI->isEquality() && isa<ConstantPointerNull>(ICI->getOperand(1))) { + Users.push_back(ICI); + continue; + } + } + if (BitCastInst *BCI = dyn_cast<BitCastInst>(U)) { + if (IsOnlyNullComparedAndFreed(BCI, Users, Depth+1)) { + Users.push_back(BCI); + continue; + } + } + if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(U)) { + if (IsOnlyNullComparedAndFreed(GEPI, Users, Depth+1)) { + Users.push_back(GEPI); + continue; + } + } + if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(U)) { + if (II->getIntrinsicID() == Intrinsic::lifetime_start || + II->getIntrinsicID() == Intrinsic::lifetime_end) { + Users.push_back(II); continue; + } + } return false; } return true; @@ -1063,25 +1138,20 @@ Instruction *InstCombiner::visitMalloc(Instruction &MI) { // If we have a malloc call which is only used in any amount of comparisons // to null and free calls, delete the calls and replace the comparisons with // true or false as appropriate. - if (IsOnlyNullComparedAndFreed(MI)) { - for (Value::use_iterator UI = MI.use_begin(), UE = MI.use_end(); - UI != UE;) { - // We can assume that every remaining use is a free call or an icmp eq/ne - // to null, so the cast is safe. - Instruction *I = cast<Instruction>(*UI); - - // Early increment here, as we're about to get rid of the user. - ++UI; - - if (isFreeCall(I)) { - EraseInstFromFunction(*cast<CallInst>(I)); - continue; + SmallVector<WeakVH, 64> Users; + if (IsOnlyNullComparedAndFreed(&MI, Users)) { + for (unsigned i = 0, e = Users.size(); i != e; ++i) { + Instruction *I = cast_or_null<Instruction>(&*Users[i]); + if (!I) continue; + + if (ICmpInst *C = dyn_cast<ICmpInst>(I)) { + ReplaceInstUsesWith(*C, + ConstantInt::get(Type::getInt1Ty(C->getContext()), + C->isFalseWhenEqual())); + } else if (isa<BitCastInst>(I) || isa<GetElementPtrInst>(I)) { + ReplaceInstUsesWith(*I, UndefValue::get(I->getType())); } - // Again, the cast is safe. - ICmpInst *C = cast<ICmpInst>(I); - ReplaceInstUsesWith(*C, ConstantInt::get(Type::getInt1Ty(C->getContext()), - C->isFalseWhenEqual())); - EraseInstFromFunction(*C); + EraseInstFromFunction(*I); } return EraseInstFromFunction(MI); } @@ -1120,8 +1190,7 @@ Instruction *InstCombiner::visitBranchInst(BranchInst &BI) { !isa<Constant>(X)) { // Swap Destinations and condition... BI.setCondition(X); - BI.setSuccessor(0, FalseDest); - BI.setSuccessor(1, TrueDest); + BI.swapSuccessors(); return &BI; } @@ -1136,8 +1205,7 @@ Instruction *InstCombiner::visitBranchInst(BranchInst &BI) { Cond->setPredicate(FCmpInst::getInversePredicate(FPred)); // Swap Destinations and condition. - BI.setSuccessor(0, FalseDest); - BI.setSuccessor(1, TrueDest); + BI.swapSuccessors(); Worklist.Add(Cond); return &BI; } @@ -1153,8 +1221,7 @@ Instruction *InstCombiner::visitBranchInst(BranchInst &BI) { ICmpInst *Cond = cast<ICmpInst>(BI.getCondition()); Cond->setPredicate(ICmpInst::getInversePredicate(IPred)); // Swap Destinations and condition. - BI.setSuccessor(0, FalseDest); - BI.setSuccessor(1, TrueDest); + BI.swapSuccessors(); Worklist.Add(Cond); return &BI; } @@ -1168,11 +1235,17 @@ Instruction *InstCombiner::visitSwitchInst(SwitchInst &SI) { if (I->getOpcode() == Instruction::Add) if (ConstantInt *AddRHS = dyn_cast<ConstantInt>(I->getOperand(1))) { // change 'switch (X+4) case 1:' into 'switch (X) case -3' - for (unsigned i = 2, e = SI.getNumOperands(); i != e; i += 2) - SI.setOperand(i, - ConstantExpr::getSub(cast<Constant>(SI.getOperand(i)), - AddRHS)); - SI.setOperand(0, I->getOperand(0)); + unsigned NumCases = SI.getNumCases(); + // Skip the first item since that's the default case. + for (unsigned i = 1; i < NumCases; ++i) { + ConstantInt* CaseVal = SI.getCaseValue(i); + Constant* NewCaseVal = ConstantExpr::getSub(cast<Constant>(CaseVal), + AddRHS); + assert(isa<ConstantInt>(NewCaseVal) && + "Result of expression should be constant"); + SI.setSuccessorValue(i, cast<ConstantInt>(NewCaseVal)); + } + SI.setCondition(I->getOperand(0)); Worklist.Add(I); return &SI; } @@ -1310,7 +1383,7 @@ Instruction *InstCombiner::visitExtractValueInst(ExtractValueInst &EV) { // load from a GEP. This reduces the size of the load. // FIXME: If a load is used only by extractvalue instructions then this // could be done regardless of having multiple uses. - if (!L->isVolatile() && L->hasOneUse()) { + if (L->isSimple() && L->hasOneUse()) { // extractvalue has integer indices, getelementptr has Value*s. Convert. SmallVector<Value*, 4> Indices; // Prefix an i32 0 since we need the first element. @@ -1322,8 +1395,7 @@ Instruction *InstCombiner::visitExtractValueInst(ExtractValueInst &EV) { // We need to insert these at the location of the old load, not at that of // the extractvalue. Builder->SetInsertPoint(L->getParent(), L); - Value *GEP = Builder->CreateInBoundsGEP(L->getPointerOperand(), - Indices.begin(), Indices.end()); + Value *GEP = Builder->CreateInBoundsGEP(L->getPointerOperand(), Indices); // Returning the load directly will cause the main loop to insert it in // the wrong spot, so use ReplaceInstUsesWith(). return ReplaceInstUsesWith(EV, Builder->CreateLoad(GEP)); @@ -1339,6 +1411,345 @@ Instruction *InstCombiner::visitExtractValueInst(ExtractValueInst &EV) { return 0; } +enum Personality_Type { + Unknown_Personality, + GNU_Ada_Personality, + GNU_CXX_Personality, + GNU_ObjC_Personality +}; + +/// RecognizePersonality - See if the given exception handling personality +/// function is one that we understand. If so, return a description of it; +/// otherwise return Unknown_Personality. +static Personality_Type RecognizePersonality(Value *Pers) { + Function *F = dyn_cast<Function>(Pers->stripPointerCasts()); + if (!F) + return Unknown_Personality; + return StringSwitch<Personality_Type>(F->getName()) + .Case("__gnat_eh_personality", GNU_Ada_Personality) + .Case("__gxx_personality_v0", GNU_CXX_Personality) + .Case("__objc_personality_v0", GNU_ObjC_Personality) + .Default(Unknown_Personality); +} + +/// isCatchAll - Return 'true' if the given typeinfo will match anything. +static bool isCatchAll(Personality_Type Personality, Constant *TypeInfo) { + switch (Personality) { + case Unknown_Personality: + return false; + case GNU_Ada_Personality: + // While __gnat_all_others_value will match any Ada exception, it doesn't + // match foreign exceptions (or didn't, before gcc-4.7). + return false; + case GNU_CXX_Personality: + case GNU_ObjC_Personality: + return TypeInfo->isNullValue(); + } + llvm_unreachable("Unknown personality!"); +} + +static bool shorter_filter(const Value *LHS, const Value *RHS) { + return + cast<ArrayType>(LHS->getType())->getNumElements() + < + cast<ArrayType>(RHS->getType())->getNumElements(); +} + +Instruction *InstCombiner::visitLandingPadInst(LandingPadInst &LI) { + // The logic here should be correct for any real-world personality function. + // However if that turns out not to be true, the offending logic can always + // be conditioned on the personality function, like the catch-all logic is. + Personality_Type Personality = RecognizePersonality(LI.getPersonalityFn()); + + // Simplify the list of clauses, eg by removing repeated catch clauses + // (these are often created by inlining). + bool MakeNewInstruction = false; // If true, recreate using the following: + SmallVector<Value *, 16> NewClauses; // - Clauses for the new instruction; + bool CleanupFlag = LI.isCleanup(); // - The new instruction is a cleanup. + + SmallPtrSet<Value *, 16> AlreadyCaught; // Typeinfos known caught already. + for (unsigned i = 0, e = LI.getNumClauses(); i != e; ++i) { + bool isLastClause = i + 1 == e; + if (LI.isCatch(i)) { + // A catch clause. + Value *CatchClause = LI.getClause(i); + Constant *TypeInfo = cast<Constant>(CatchClause->stripPointerCasts()); + + // If we already saw this clause, there is no point in having a second + // copy of it. + if (AlreadyCaught.insert(TypeInfo)) { + // This catch clause was not already seen. + NewClauses.push_back(CatchClause); + } else { + // Repeated catch clause - drop the redundant copy. + MakeNewInstruction = true; + } + + // If this is a catch-all then there is no point in keeping any following + // clauses or marking the landingpad as having a cleanup. + if (isCatchAll(Personality, TypeInfo)) { + if (!isLastClause) + MakeNewInstruction = true; + CleanupFlag = false; + break; + } + } else { + // A filter clause. If any of the filter elements were already caught + // then they can be dropped from the filter. It is tempting to try to + // exploit the filter further by saying that any typeinfo that does not + // occur in the filter can't be caught later (and thus can be dropped). + // However this would be wrong, since typeinfos can match without being + // equal (for example if one represents a C++ class, and the other some + // class derived from it). + assert(LI.isFilter(i) && "Unsupported landingpad clause!"); + Value *FilterClause = LI.getClause(i); + ArrayType *FilterType = cast<ArrayType>(FilterClause->getType()); + unsigned NumTypeInfos = FilterType->getNumElements(); + + // An empty filter catches everything, so there is no point in keeping any + // following clauses or marking the landingpad as having a cleanup. By + // dealing with this case here the following code is made a bit simpler. + if (!NumTypeInfos) { + NewClauses.push_back(FilterClause); + if (!isLastClause) + MakeNewInstruction = true; + CleanupFlag = false; + break; + } + + bool MakeNewFilter = false; // If true, make a new filter. + SmallVector<Constant *, 16> NewFilterElts; // New elements. + if (isa<ConstantAggregateZero>(FilterClause)) { + // Not an empty filter - it contains at least one null typeinfo. + assert(NumTypeInfos > 0 && "Should have handled empty filter already!"); + Constant *TypeInfo = + Constant::getNullValue(FilterType->getElementType()); + // If this typeinfo is a catch-all then the filter can never match. + if (isCatchAll(Personality, TypeInfo)) { + // Throw the filter away. + MakeNewInstruction = true; + continue; + } + + // There is no point in having multiple copies of this typeinfo, so + // discard all but the first copy if there is more than one. + NewFilterElts.push_back(TypeInfo); + if (NumTypeInfos > 1) + MakeNewFilter = true; + } else { + ConstantArray *Filter = cast<ConstantArray>(FilterClause); + SmallPtrSet<Value *, 16> SeenInFilter; // For uniquing the elements. + NewFilterElts.reserve(NumTypeInfos); + + // Remove any filter elements that were already caught or that already + // occurred in the filter. While there, see if any of the elements are + // catch-alls. If so, the filter can be discarded. + bool SawCatchAll = false; + for (unsigned j = 0; j != NumTypeInfos; ++j) { + Value *Elt = Filter->getOperand(j); + Constant *TypeInfo = cast<Constant>(Elt->stripPointerCasts()); + if (isCatchAll(Personality, TypeInfo)) { + // This element is a catch-all. Bail out, noting this fact. + SawCatchAll = true; + break; + } + if (AlreadyCaught.count(TypeInfo)) + // Already caught by an earlier clause, so having it in the filter + // is pointless. + continue; + // There is no point in having multiple copies of the same typeinfo in + // a filter, so only add it if we didn't already. + if (SeenInFilter.insert(TypeInfo)) + NewFilterElts.push_back(cast<Constant>(Elt)); + } + // A filter containing a catch-all cannot match anything by definition. + if (SawCatchAll) { + // Throw the filter away. + MakeNewInstruction = true; + continue; + } + + // If we dropped something from the filter, make a new one. + if (NewFilterElts.size() < NumTypeInfos) + MakeNewFilter = true; + } + if (MakeNewFilter) { + FilterType = ArrayType::get(FilterType->getElementType(), + NewFilterElts.size()); + FilterClause = ConstantArray::get(FilterType, NewFilterElts); + MakeNewInstruction = true; + } + + NewClauses.push_back(FilterClause); + + // If the new filter is empty then it will catch everything so there is + // no point in keeping any following clauses or marking the landingpad + // as having a cleanup. The case of the original filter being empty was + // already handled above. + if (MakeNewFilter && !NewFilterElts.size()) { + assert(MakeNewInstruction && "New filter but not a new instruction!"); + CleanupFlag = false; + break; + } + } + } + + // If several filters occur in a row then reorder them so that the shortest + // filters come first (those with the smallest number of elements). This is + // advantageous because shorter filters are more likely to match, speeding up + // unwinding, but mostly because it increases the effectiveness of the other + // filter optimizations below. + for (unsigned i = 0, e = NewClauses.size(); i + 1 < e; ) { + unsigned j; + // Find the maximal 'j' s.t. the range [i, j) consists entirely of filters. + for (j = i; j != e; ++j) + if (!isa<ArrayType>(NewClauses[j]->getType())) + break; + + // Check whether the filters are already sorted by length. We need to know + // if sorting them is actually going to do anything so that we only make a + // new landingpad instruction if it does. + for (unsigned k = i; k + 1 < j; ++k) + if (shorter_filter(NewClauses[k+1], NewClauses[k])) { + // Not sorted, so sort the filters now. Doing an unstable sort would be + // correct too but reordering filters pointlessly might confuse users. + std::stable_sort(NewClauses.begin() + i, NewClauses.begin() + j, + shorter_filter); + MakeNewInstruction = true; + break; + } + + // Look for the next batch of filters. + i = j + 1; + } + + // If typeinfos matched if and only if equal, then the elements of a filter L + // that occurs later than a filter F could be replaced by the intersection of + // the elements of F and L. In reality two typeinfos can match without being + // equal (for example if one represents a C++ class, and the other some class + // derived from it) so it would be wrong to perform this transform in general. + // However the transform is correct and useful if F is a subset of L. In that + // case L can be replaced by F, and thus removed altogether since repeating a + // filter is pointless. So here we look at all pairs of filters F and L where + // L follows F in the list of clauses, and remove L if every element of F is + // an element of L. This can occur when inlining C++ functions with exception + // specifications. + for (unsigned i = 0; i + 1 < NewClauses.size(); ++i) { + // Examine each filter in turn. + Value *Filter = NewClauses[i]; + ArrayType *FTy = dyn_cast<ArrayType>(Filter->getType()); + if (!FTy) + // Not a filter - skip it. + continue; + unsigned FElts = FTy->getNumElements(); + // Examine each filter following this one. Doing this backwards means that + // we don't have to worry about filters disappearing under us when removed. + for (unsigned j = NewClauses.size() - 1; j != i; --j) { + Value *LFilter = NewClauses[j]; + ArrayType *LTy = dyn_cast<ArrayType>(LFilter->getType()); + if (!LTy) + // Not a filter - skip it. + continue; + // If Filter is a subset of LFilter, i.e. every element of Filter is also + // an element of LFilter, then discard LFilter. + SmallVector<Value *, 16>::iterator J = NewClauses.begin() + j; + // If Filter is empty then it is a subset of LFilter. + if (!FElts) { + // Discard LFilter. + NewClauses.erase(J); + MakeNewInstruction = true; + // Move on to the next filter. + continue; + } + unsigned LElts = LTy->getNumElements(); + // If Filter is longer than LFilter then it cannot be a subset of it. + if (FElts > LElts) + // Move on to the next filter. + continue; + // At this point we know that LFilter has at least one element. + if (isa<ConstantAggregateZero>(LFilter)) { // LFilter only contains zeros. + // Filter is a subset of LFilter iff Filter contains only zeros (as we + // already know that Filter is not longer than LFilter). + if (isa<ConstantAggregateZero>(Filter)) { + assert(FElts <= LElts && "Should have handled this case earlier!"); + // Discard LFilter. + NewClauses.erase(J); + MakeNewInstruction = true; + } + // Move on to the next filter. + continue; + } + ConstantArray *LArray = cast<ConstantArray>(LFilter); + if (isa<ConstantAggregateZero>(Filter)) { // Filter only contains zeros. + // Since Filter is non-empty and contains only zeros, it is a subset of + // LFilter iff LFilter contains a zero. + assert(FElts > 0 && "Should have eliminated the empty filter earlier!"); + for (unsigned l = 0; l != LElts; ++l) + if (LArray->getOperand(l)->isNullValue()) { + // LFilter contains a zero - discard it. + NewClauses.erase(J); + MakeNewInstruction = true; + break; + } + // Move on to the next filter. + continue; + } + // At this point we know that both filters are ConstantArrays. Loop over + // operands to see whether every element of Filter is also an element of + // LFilter. Since filters tend to be short this is probably faster than + // using a method that scales nicely. + ConstantArray *FArray = cast<ConstantArray>(Filter); + bool AllFound = true; + for (unsigned f = 0; f != FElts; ++f) { + Value *FTypeInfo = FArray->getOperand(f)->stripPointerCasts(); + AllFound = false; + for (unsigned l = 0; l != LElts; ++l) { + Value *LTypeInfo = LArray->getOperand(l)->stripPointerCasts(); + if (LTypeInfo == FTypeInfo) { + AllFound = true; + break; + } + } + if (!AllFound) + break; + } + if (AllFound) { + // Discard LFilter. + NewClauses.erase(J); + MakeNewInstruction = true; + } + // Move on to the next filter. + } + } + + // If we changed any of the clauses, replace the old landingpad instruction + // with a new one. + if (MakeNewInstruction) { + LandingPadInst *NLI = LandingPadInst::Create(LI.getType(), + LI.getPersonalityFn(), + NewClauses.size()); + for (unsigned i = 0, e = NewClauses.size(); i != e; ++i) + NLI->addClause(NewClauses[i]); + // A landing pad with no clauses must have the cleanup flag set. It is + // theoretically possible, though highly unlikely, that we eliminated all + // clauses. If so, force the cleanup flag to true. + if (NewClauses.empty()) + CleanupFlag = true; + NLI->setCleanup(CleanupFlag); + return NLI; + } + + // Even if none of the clauses changed, we may nonetheless have understood + // that the cleanup flag is pointless. Clear it if so. + if (LI.isCleanup() != CleanupFlag) { + assert(!CleanupFlag && "Adding a cleanup, not removing one?!"); + LI.setCleanup(CleanupFlag); + return &LI; + } + + return 0; +} + @@ -1350,7 +1761,8 @@ static bool TryToSinkInstruction(Instruction *I, BasicBlock *DestBlock) { assert(I->hasOneUse() && "Invariants didn't hold!"); // Cannot move control-flow-involving, volatile loads, vaarg, etc. - if (isa<PHINode>(I) || I->mayHaveSideEffects() || isa<TerminatorInst>(I)) + if (isa<PHINode>(I) || isa<LandingPadInst>(I) || I->mayHaveSideEffects() || + isa<TerminatorInst>(I)) return false; // Do not sink alloca instructions out of the entry block. @@ -1367,8 +1779,7 @@ static bool TryToSinkInstruction(Instruction *I, BasicBlock *DestBlock) { return false; } - BasicBlock::iterator InsertPos = DestBlock->getFirstNonPHI(); - + BasicBlock::iterator InsertPos = DestBlock->getFirstInsertionPt(); I->moveBefore(InsertPos); ++NumSunkInst; return true; @@ -1503,27 +1914,29 @@ bool InstCombiner::DoOneIteration(Function &F, unsigned Iteration) { // Do a quick scan over the function. If we find any blocks that are // unreachable, remove any instructions inside of them. This prevents // the instcombine code from having to deal with some bad special cases. - for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) - if (!Visited.count(BB)) { - Instruction *Term = BB->getTerminator(); - while (Term != BB->begin()) { // Remove instrs bottom-up - BasicBlock::iterator I = Term; --I; - - DEBUG(errs() << "IC: DCE: " << *I << '\n'); - // A debug intrinsic shouldn't force another iteration if we weren't - // going to do one without it. - if (!isa<DbgInfoIntrinsic>(I)) { - ++NumDeadInst; - MadeIRChange = true; - } - - // If I is not void type then replaceAllUsesWith undef. - // This allows ValueHandlers and custom metadata to adjust itself. - if (!I->getType()->isVoidTy()) - I->replaceAllUsesWith(UndefValue::get(I->getType())); - I->eraseFromParent(); + for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) { + if (Visited.count(BB)) continue; + + // Delete the instructions backwards, as it has a reduced likelihood of + // having to update as many def-use and use-def chains. + Instruction *EndInst = BB->getTerminator(); // Last not to be deleted. + while (EndInst != BB->begin()) { + // Delete the next to last instruction. + BasicBlock::iterator I = EndInst; + Instruction *Inst = --I; + if (!Inst->use_empty()) + Inst->replaceAllUsesWith(UndefValue::get(Inst->getType())); + if (isa<LandingPadInst>(Inst)) { + EndInst = Inst; + continue; } + if (!isa<DbgInfoIntrinsic>(Inst)) { + ++NumDeadInst; + MadeIRChange = true; + } + Inst->eraseFromParent(); } + } } while (!Worklist.isEmpty()) { @@ -1604,13 +2017,13 @@ bool InstCombiner::DoOneIteration(Function &F, unsigned Iteration) { // Everything uses the new instruction now. I->replaceAllUsesWith(Result); + // Move the name to the new instruction first. + Result->takeName(I); + // Push the new instruction and any users onto the worklist. Worklist.Add(Result); Worklist.AddUsersToWorkList(*Result); - // Move the name to the new instruction first. - Result->takeName(I); - // Insert the new instruction into the basic block... BasicBlock *InstParent = I->getParent(); BasicBlock::iterator InsertPos = I; |