diff options
Diffstat (limited to 'contrib/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp')
| -rw-r--r-- | contrib/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp | 364 |
1 files changed, 217 insertions, 147 deletions
diff --git a/contrib/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp b/contrib/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp index 72377dc..b9c3d0f 100644 --- a/contrib/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp +++ b/contrib/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp @@ -14,11 +14,13 @@ #include "InstCombine.h" #include "llvm/Analysis/ConstantFolding.h" #include "llvm/IR/DataLayout.h" -#include "llvm/Support/PatternMatch.h" +#include "llvm/IR/PatternMatch.h" #include "llvm/Target/TargetLibraryInfo.h" using namespace llvm; using namespace PatternMatch; +#define DEBUG_TYPE "instcombine" + /// DecomposeSimpleLinearExpr - Analyze 'Val', seeing if it is a simple linear /// expression. If so, decompose it, returning some value X, such that Val is /// X*Scale+Offset. @@ -79,7 +81,7 @@ static Value *DecomposeSimpleLinearExpr(Value *Val, unsigned &Scale, Instruction *InstCombiner::PromoteCastOfAllocation(BitCastInst &CI, AllocaInst &AI) { // This requires DataLayout to get the alloca alignment and size information. - if (!TD) return 0; + if (!DL) return nullptr; PointerType *PTy = cast<PointerType>(CI.getType()); @@ -89,26 +91,26 @@ Instruction *InstCombiner::PromoteCastOfAllocation(BitCastInst &CI, // Get the type really allocated and the type casted to. Type *AllocElTy = AI.getAllocatedType(); Type *CastElTy = PTy->getElementType(); - if (!AllocElTy->isSized() || !CastElTy->isSized()) return 0; + if (!AllocElTy->isSized() || !CastElTy->isSized()) return nullptr; - unsigned AllocElTyAlign = TD->getABITypeAlignment(AllocElTy); - unsigned CastElTyAlign = TD->getABITypeAlignment(CastElTy); - if (CastElTyAlign < AllocElTyAlign) return 0; + unsigned AllocElTyAlign = DL->getABITypeAlignment(AllocElTy); + unsigned CastElTyAlign = DL->getABITypeAlignment(CastElTy); + if (CastElTyAlign < AllocElTyAlign) return nullptr; // If the allocation has multiple uses, only promote it if we are strictly // increasing the alignment of the resultant allocation. If we keep it the // same, we open the door to infinite loops of various kinds. - if (!AI.hasOneUse() && CastElTyAlign == AllocElTyAlign) return 0; + if (!AI.hasOneUse() && CastElTyAlign == AllocElTyAlign) return nullptr; - uint64_t AllocElTySize = TD->getTypeAllocSize(AllocElTy); - uint64_t CastElTySize = TD->getTypeAllocSize(CastElTy); - if (CastElTySize == 0 || AllocElTySize == 0) return 0; + uint64_t AllocElTySize = DL->getTypeAllocSize(AllocElTy); + uint64_t CastElTySize = DL->getTypeAllocSize(CastElTy); + if (CastElTySize == 0 || AllocElTySize == 0) return nullptr; // If the allocation has multiple uses, only promote it if we're not // shrinking the amount of memory being allocated. - uint64_t AllocElTyStoreSize = TD->getTypeStoreSize(AllocElTy); - uint64_t CastElTyStoreSize = TD->getTypeStoreSize(CastElTy); - if (!AI.hasOneUse() && CastElTyStoreSize < AllocElTyStoreSize) return 0; + uint64_t AllocElTyStoreSize = DL->getTypeStoreSize(AllocElTy); + uint64_t CastElTyStoreSize = DL->getTypeStoreSize(CastElTy); + if (!AI.hasOneUse() && CastElTyStoreSize < AllocElTyStoreSize) return nullptr; // See if we can satisfy the modulus by pulling a scale out of the array // size argument. @@ -120,10 +122,10 @@ Instruction *InstCombiner::PromoteCastOfAllocation(BitCastInst &CI, // If we can now satisfy the modulus, by using a non-1 scale, we really can // do the xform. if ((AllocElTySize*ArraySizeScale) % CastElTySize != 0 || - (AllocElTySize*ArrayOffset ) % CastElTySize != 0) return 0; + (AllocElTySize*ArrayOffset ) % CastElTySize != 0) return nullptr; unsigned Scale = (AllocElTySize*ArraySizeScale)/CastElTySize; - Value *Amt = 0; + Value *Amt = nullptr; if (Scale == 1) { Amt = NumElements; } else { @@ -141,6 +143,7 @@ Instruction *InstCombiner::PromoteCastOfAllocation(BitCastInst &CI, AllocaInst *New = AllocaBuilder.CreateAlloca(CastElTy, Amt); New->setAlignment(AI.getAlignment()); New->takeName(&AI); + New->setUsedWithInAlloca(AI.isUsedWithInAlloca()); // If the allocation has multiple real uses, insert a cast and change all // things that used it to use the new cast. This will also hack on CI, but it @@ -161,15 +164,15 @@ Value *InstCombiner::EvaluateInDifferentType(Value *V, Type *Ty, bool isSigned) { if (Constant *C = dyn_cast<Constant>(V)) { C = ConstantExpr::getIntegerCast(C, Ty, isSigned /*Sext or ZExt*/); - // If we got a constantexpr back, try to simplify it with TD info. + // If we got a constantexpr back, try to simplify it with DL info. if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) - C = ConstantFoldConstantExpression(CE, TD, TLI); + C = ConstantFoldConstantExpression(CE, DL, TLI); return C; } // Otherwise, it must be an instruction. Instruction *I = cast<Instruction>(V); - Instruction *Res = 0; + Instruction *Res = nullptr; unsigned Opc = I->getOpcode(); switch (Opc) { case Instruction::Add: @@ -235,7 +238,7 @@ isEliminableCastPair( const CastInst *CI, ///< The first cast instruction unsigned opcode, ///< The opcode of the second cast instruction Type *DstTy, ///< The target type for the second cast instruction - DataLayout *TD ///< The target data for pointer size + const DataLayout *DL ///< The target data for pointer size ) { Type *SrcTy = CI->getOperand(0)->getType(); // A from above @@ -244,12 +247,12 @@ isEliminableCastPair( // Get the opcodes of the two Cast instructions Instruction::CastOps firstOp = Instruction::CastOps(CI->getOpcode()); Instruction::CastOps secondOp = Instruction::CastOps(opcode); - Type *SrcIntPtrTy = TD && SrcTy->isPtrOrPtrVectorTy() ? - TD->getIntPtrType(SrcTy) : 0; - Type *MidIntPtrTy = TD && MidTy->isPtrOrPtrVectorTy() ? - TD->getIntPtrType(MidTy) : 0; - Type *DstIntPtrTy = TD && DstTy->isPtrOrPtrVectorTy() ? - TD->getIntPtrType(DstTy) : 0; + Type *SrcIntPtrTy = DL && SrcTy->isPtrOrPtrVectorTy() ? + DL->getIntPtrType(SrcTy) : nullptr; + Type *MidIntPtrTy = DL && MidTy->isPtrOrPtrVectorTy() ? + DL->getIntPtrType(MidTy) : nullptr; + Type *DstIntPtrTy = DL && DstTy->isPtrOrPtrVectorTy() ? + DL->getIntPtrType(DstTy) : nullptr; unsigned Res = CastInst::isEliminableCastPair(firstOp, secondOp, SrcTy, MidTy, DstTy, SrcIntPtrTy, MidIntPtrTy, DstIntPtrTy); @@ -275,7 +278,7 @@ bool InstCombiner::ShouldOptimizeCast(Instruction::CastOps opc, const Value *V, // If this is another cast that can be eliminated, we prefer to have it // eliminated. if (const CastInst *CI = dyn_cast<CastInst>(V)) - if (isEliminableCastPair(CI, opc, Ty, TD)) + if (isEliminableCastPair(CI, opc, Ty, DL)) return false; // If this is a vector sext from a compare, then we don't want to break the @@ -295,7 +298,7 @@ Instruction *InstCombiner::commonCastTransforms(CastInst &CI) { // eliminate it now. if (CastInst *CSrc = dyn_cast<CastInst>(Src)) { // A->B->C cast if (Instruction::CastOps opc = - isEliminableCastPair(CSrc, CI.getOpcode(), CI.getType(), TD)) { + isEliminableCastPair(CSrc, CI.getOpcode(), CI.getType(), DL)) { // The first cast (CSrc) is eliminable so we need to fix up or replace // the second cast (CI). CSrc will then have a good chance of being dead. return CastInst::Create(opc, CSrc->getOperand(0), CI.getType()); @@ -318,7 +321,7 @@ Instruction *InstCombiner::commonCastTransforms(CastInst &CI) { return NV; } - return 0; + return nullptr; } /// CanEvaluateTruncated - Return true if we can evaluate the specified @@ -470,7 +473,7 @@ Instruction *InstCombiner::visitTrunc(TruncInst &CI) { } // Transform trunc(lshr (zext A), Cst) to eliminate one type conversion. - Value *A = 0; ConstantInt *Cst = 0; + Value *A = nullptr; ConstantInt *Cst = nullptr; if (Src->hasOneUse() && match(Src, m_LShr(m_ZExt(m_Value(A)), m_ConstantInt(Cst)))) { // We have three types to worry about here, the type of A, the source of @@ -502,7 +505,7 @@ Instruction *InstCombiner::visitTrunc(TruncInst &CI) { ConstantExpr::getTrunc(Cst, CI.getType())); } - return 0; + return nullptr; } /// transformZExtICmp - Transform (zext icmp) to bitwise / integer operations @@ -550,7 +553,7 @@ Instruction *InstCombiner::transformZExtICmp(ICmpInst *ICI, Instruction &CI, // If Op1C some other power of two, convert: uint32_t BitWidth = Op1C->getType()->getBitWidth(); APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0); - ComputeMaskedBits(ICI->getOperand(0), KnownZero, KnownOne); + computeKnownBits(ICI->getOperand(0), KnownZero, KnownOne); APInt KnownZeroMask(~KnownZero); if (KnownZeroMask.isPowerOf2()) { // Exactly 1 possible 1? @@ -598,8 +601,8 @@ Instruction *InstCombiner::transformZExtICmp(ICmpInst *ICI, Instruction &CI, APInt KnownZeroLHS(BitWidth, 0), KnownOneLHS(BitWidth, 0); APInt KnownZeroRHS(BitWidth, 0), KnownOneRHS(BitWidth, 0); - ComputeMaskedBits(LHS, KnownZeroLHS, KnownOneLHS); - ComputeMaskedBits(RHS, KnownZeroRHS, KnownOneRHS); + computeKnownBits(LHS, KnownZeroLHS, KnownOneLHS); + computeKnownBits(RHS, KnownZeroRHS, KnownOneRHS); if (KnownZeroLHS == KnownZeroRHS && KnownOneLHS == KnownOneRHS) { APInt KnownBits = KnownZeroLHS | KnownOneLHS; @@ -627,7 +630,7 @@ Instruction *InstCombiner::transformZExtICmp(ICmpInst *ICI, Instruction &CI, } } - return 0; + return nullptr; } /// CanEvaluateZExtd - Determine if the specified value can be computed in the @@ -757,8 +760,8 @@ static bool CanEvaluateZExtd(Value *V, Type *Ty, unsigned &BitsToClear) { Instruction *InstCombiner::visitZExt(ZExtInst &CI) { // If this zero extend is only used by a truncate, let the truncate be // eliminated before we try to optimize this zext. - if (CI.hasOneUse() && isa<TruncInst>(CI.use_back())) - return 0; + if (CI.hasOneUse() && isa<TruncInst>(CI.user_back())) + return nullptr; // If one of the common conversion will work, do it. if (Instruction *Result = commonCastTransforms(CI)) @@ -858,42 +861,32 @@ Instruction *InstCombiner::visitZExt(ZExtInst &CI) { } } - // zext(trunc(t) & C) -> (t & zext(C)). - if (SrcI && SrcI->getOpcode() == Instruction::And && SrcI->hasOneUse()) - if (ConstantInt *C = dyn_cast<ConstantInt>(SrcI->getOperand(1))) - if (TruncInst *TI = dyn_cast<TruncInst>(SrcI->getOperand(0))) { - Value *TI0 = TI->getOperand(0); - if (TI0->getType() == CI.getType()) - return - BinaryOperator::CreateAnd(TI0, - ConstantExpr::getZExt(C, CI.getType())); - } - - // zext((trunc(t) & C) ^ C) -> ((t & zext(C)) ^ zext(C)). - if (SrcI && SrcI->getOpcode() == Instruction::Xor && SrcI->hasOneUse()) - if (ConstantInt *C = dyn_cast<ConstantInt>(SrcI->getOperand(1))) - if (BinaryOperator *And = dyn_cast<BinaryOperator>(SrcI->getOperand(0))) - if (And->getOpcode() == Instruction::And && And->hasOneUse() && - And->getOperand(1) == C) - if (TruncInst *TI = dyn_cast<TruncInst>(And->getOperand(0))) { - Value *TI0 = TI->getOperand(0); - if (TI0->getType() == CI.getType()) { - Constant *ZC = ConstantExpr::getZExt(C, CI.getType()); - Value *NewAnd = Builder->CreateAnd(TI0, ZC); - return BinaryOperator::CreateXor(NewAnd, ZC); - } - } + // zext(trunc(X) & C) -> (X & zext(C)). + Constant *C; + Value *X; + if (SrcI && + match(SrcI, m_OneUse(m_And(m_Trunc(m_Value(X)), m_Constant(C)))) && + X->getType() == CI.getType()) + return BinaryOperator::CreateAnd(X, ConstantExpr::getZExt(C, CI.getType())); + + // zext((trunc(X) & C) ^ C) -> ((X & zext(C)) ^ zext(C)). + Value *And; + if (SrcI && match(SrcI, m_OneUse(m_Xor(m_Value(And), m_Constant(C)))) && + match(And, m_OneUse(m_And(m_Trunc(m_Value(X)), m_Specific(C)))) && + X->getType() == CI.getType()) { + Constant *ZC = ConstantExpr::getZExt(C, CI.getType()); + return BinaryOperator::CreateXor(Builder->CreateAnd(X, ZC), ZC); + } // zext (xor i1 X, true) to i32 --> xor (zext i1 X to i32), 1 - Value *X; - if (SrcI && SrcI->hasOneUse() && SrcI->getType()->isIntegerTy(1) && - match(SrcI, m_Not(m_Value(X))) && - (!X->hasOneUse() || !isa<CmpInst>(X))) { + if (SrcI && SrcI->hasOneUse() && + SrcI->getType()->getScalarType()->isIntegerTy(1) && + match(SrcI, m_Not(m_Value(X))) && (!X->hasOneUse() || !isa<CmpInst>(X))) { Value *New = Builder->CreateZExt(X, CI.getType()); return BinaryOperator::CreateXor(New, ConstantInt::get(CI.getType(), 1)); } - return 0; + return nullptr; } /// transformSExtICmp - Transform (sext icmp) to bitwise / integer operations @@ -902,10 +895,10 @@ Instruction *InstCombiner::transformSExtICmp(ICmpInst *ICI, Instruction &CI) { Value *Op0 = ICI->getOperand(0), *Op1 = ICI->getOperand(1); ICmpInst::Predicate Pred = ICI->getPredicate(); - if (ConstantInt *Op1C = dyn_cast<ConstantInt>(Op1)) { + if (Constant *Op1C = dyn_cast<Constant>(Op1)) { // (x <s 0) ? -1 : 0 -> ashr x, 31 -> all ones if negative // (x >s -1) ? -1 : 0 -> not (ashr x, 31) -> all ones if positive - if ((Pred == ICmpInst::ICMP_SLT && Op1C->isZero()) || + if ((Pred == ICmpInst::ICMP_SLT && Op1C->isNullValue()) || (Pred == ICmpInst::ICMP_SGT && Op1C->isAllOnesValue())) { Value *Sh = ConstantInt::get(Op0->getType(), @@ -918,7 +911,9 @@ Instruction *InstCombiner::transformSExtICmp(ICmpInst *ICI, Instruction &CI) { In = Builder->CreateNot(In, In->getName()+".not"); return ReplaceInstUsesWith(CI, In); } + } + if (ConstantInt *Op1C = dyn_cast<ConstantInt>(Op1)) { // If we know that only one bit of the LHS of the icmp can be set and we // have an equality comparison with zero or a power of 2, we can transform // the icmp and sext into bitwise/integer operations. @@ -926,7 +921,7 @@ Instruction *InstCombiner::transformSExtICmp(ICmpInst *ICI, Instruction &CI) { ICI->isEquality() && (Op1C->isZero() || Op1C->getValue().isPowerOf2())){ unsigned BitWidth = Op1C->getType()->getBitWidth(); APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0); - ComputeMaskedBits(Op0, KnownZero, KnownOne); + computeKnownBits(Op0, KnownZero, KnownOne); APInt KnownZeroMask(~KnownZero); if (KnownZeroMask.isPowerOf2()) { @@ -975,20 +970,7 @@ Instruction *InstCombiner::transformSExtICmp(ICmpInst *ICI, Instruction &CI) { } } - // vector (x <s 0) ? -1 : 0 -> ashr x, 31 -> all ones if signed. - if (VectorType *VTy = dyn_cast<VectorType>(CI.getType())) { - if (Pred == ICmpInst::ICMP_SLT && match(Op1, m_Zero()) && - Op0->getType() == CI.getType()) { - Type *EltTy = VTy->getElementType(); - - // splat the shift constant to a constant vector. - Constant *VSh = ConstantInt::get(VTy, EltTy->getScalarSizeInBits()-1); - Value *In = Builder->CreateAShr(Op0, VSh, Op0->getName()+".lobit"); - return ReplaceInstUsesWith(CI, In); - } - } - - return 0; + return nullptr; } /// CanEvaluateSExtd - Return true if we can take the specified value @@ -1059,8 +1041,8 @@ static bool CanEvaluateSExtd(Value *V, Type *Ty) { Instruction *InstCombiner::visitSExt(SExtInst &CI) { // If this sign extend is only used by a truncate, let the truncate be // eliminated before we try to optimize this sext. - if (CI.hasOneUse() && isa<TruncInst>(CI.use_back())) - return 0; + if (CI.hasOneUse() && isa<TruncInst>(CI.user_back())) + return nullptr; if (Instruction *I = commonCastTransforms(CI)) return I; @@ -1128,9 +1110,9 @@ Instruction *InstCombiner::visitSExt(SExtInst &CI) { // into: // %a = shl i32 %i, 30 // %d = ashr i32 %a, 30 - Value *A = 0; + Value *A = nullptr; // TODO: Eventually this could be subsumed by EvaluateInDifferentType. - ConstantInt *BA = 0, *CA = 0; + ConstantInt *BA = nullptr, *CA = nullptr; if (match(Src, m_AShr(m_Shl(m_Trunc(m_Value(A)), m_ConstantInt(BA)), m_ConstantInt(CA))) && BA == CA && A->getType() == CI.getType()) { @@ -1142,7 +1124,7 @@ Instruction *InstCombiner::visitSExt(SExtInst &CI) { return BinaryOperator::CreateAShr(A, ShAmtV); } - return 0; + return nullptr; } @@ -1154,7 +1136,7 @@ static Constant *FitsInFPType(ConstantFP *CFP, const fltSemantics &Sem) { (void)F.convert(Sem, APFloat::rmNearestTiesToEven, &losesInfo); if (!losesInfo) return ConstantFP::get(CFP->getContext(), F); - return 0; + return nullptr; } /// LookThroughFPExtensions - If this is an fp extension instruction, look @@ -1189,43 +1171,112 @@ static Value *LookThroughFPExtensions(Value *V) { Instruction *InstCombiner::visitFPTrunc(FPTruncInst &CI) { if (Instruction *I = commonCastTransforms(CI)) return I; - - // If we have fptrunc(fadd (fpextend x), (fpextend y)), where x and y are - // smaller than the destination type, we can eliminate the truncate by doing - // the add as the smaller type. This applies to fadd/fsub/fmul/fdiv as well - // as many builtins (sqrt, etc). + // If we have fptrunc(OpI (fpextend x), (fpextend y)), we would like to + // simpilify this expression to avoid one or more of the trunc/extend + // operations if we can do so without changing the numerical results. + // + // The exact manner in which the widths of the operands interact to limit + // what we can and cannot do safely varies from operation to operation, and + // is explained below in the various case statements. BinaryOperator *OpI = dyn_cast<BinaryOperator>(CI.getOperand(0)); if (OpI && OpI->hasOneUse()) { + Value *LHSOrig = LookThroughFPExtensions(OpI->getOperand(0)); + Value *RHSOrig = LookThroughFPExtensions(OpI->getOperand(1)); + unsigned OpWidth = OpI->getType()->getFPMantissaWidth(); + unsigned LHSWidth = LHSOrig->getType()->getFPMantissaWidth(); + unsigned RHSWidth = RHSOrig->getType()->getFPMantissaWidth(); + unsigned SrcWidth = std::max(LHSWidth, RHSWidth); + unsigned DstWidth = CI.getType()->getFPMantissaWidth(); switch (OpI->getOpcode()) { - default: break; - case Instruction::FAdd: - case Instruction::FSub: - case Instruction::FMul: - case Instruction::FDiv: - case Instruction::FRem: - Type *SrcTy = OpI->getType(); - Value *LHSTrunc = LookThroughFPExtensions(OpI->getOperand(0)); - Value *RHSTrunc = LookThroughFPExtensions(OpI->getOperand(1)); - if (LHSTrunc->getType() != SrcTy && - RHSTrunc->getType() != SrcTy) { - unsigned DstSize = CI.getType()->getScalarSizeInBits(); - // If the source types were both smaller than the destination type of - // the cast, do this xform. - if (LHSTrunc->getType()->getScalarSizeInBits() <= DstSize && - RHSTrunc->getType()->getScalarSizeInBits() <= DstSize) { - LHSTrunc = Builder->CreateFPExt(LHSTrunc, CI.getType()); - RHSTrunc = Builder->CreateFPExt(RHSTrunc, CI.getType()); - return BinaryOperator::Create(OpI->getOpcode(), LHSTrunc, RHSTrunc); + default: break; + case Instruction::FAdd: + case Instruction::FSub: + // For addition and subtraction, the infinitely precise result can + // essentially be arbitrarily wide; proving that double rounding + // will not occur because the result of OpI is exact (as we will for + // FMul, for example) is hopeless. However, we *can* nonetheless + // frequently know that double rounding cannot occur (or that it is + // innocuous) by taking advantage of the specific structure of + // infinitely-precise results that admit double rounding. + // + // Specifically, if OpWidth >= 2*DstWdith+1 and DstWidth is sufficient + // to represent both sources, we can guarantee that the double + // rounding is innocuous (See p50 of Figueroa's 2000 PhD thesis, + // "A Rigorous Framework for Fully Supporting the IEEE Standard ..." + // for proof of this fact). + // + // Note: Figueroa does not consider the case where DstFormat != + // SrcFormat. It's possible (likely even!) that this analysis + // could be tightened for those cases, but they are rare (the main + // case of interest here is (float)((double)float + float)). + if (OpWidth >= 2*DstWidth+1 && DstWidth >= SrcWidth) { + if (LHSOrig->getType() != CI.getType()) + LHSOrig = Builder->CreateFPExt(LHSOrig, CI.getType()); + if (RHSOrig->getType() != CI.getType()) + RHSOrig = Builder->CreateFPExt(RHSOrig, CI.getType()); + Instruction *RI = + BinaryOperator::Create(OpI->getOpcode(), LHSOrig, RHSOrig); + RI->copyFastMathFlags(OpI); + return RI; } - } - break; + break; + case Instruction::FMul: + // For multiplication, the infinitely precise result has at most + // LHSWidth + RHSWidth significant bits; if OpWidth is sufficient + // that such a value can be exactly represented, then no double + // rounding can possibly occur; we can safely perform the operation + // in the destination format if it can represent both sources. + if (OpWidth >= LHSWidth + RHSWidth && DstWidth >= SrcWidth) { + if (LHSOrig->getType() != CI.getType()) + LHSOrig = Builder->CreateFPExt(LHSOrig, CI.getType()); + if (RHSOrig->getType() != CI.getType()) + RHSOrig = Builder->CreateFPExt(RHSOrig, CI.getType()); + Instruction *RI = + BinaryOperator::CreateFMul(LHSOrig, RHSOrig); + RI->copyFastMathFlags(OpI); + return RI; + } + break; + case Instruction::FDiv: + // For division, we use again use the bound from Figueroa's + // dissertation. I am entirely certain that this bound can be + // tightened in the unbalanced operand case by an analysis based on + // the diophantine rational approximation bound, but the well-known + // condition used here is a good conservative first pass. + // TODO: Tighten bound via rigorous analysis of the unbalanced case. + if (OpWidth >= 2*DstWidth && DstWidth >= SrcWidth) { + if (LHSOrig->getType() != CI.getType()) + LHSOrig = Builder->CreateFPExt(LHSOrig, CI.getType()); + if (RHSOrig->getType() != CI.getType()) + RHSOrig = Builder->CreateFPExt(RHSOrig, CI.getType()); + Instruction *RI = + BinaryOperator::CreateFDiv(LHSOrig, RHSOrig); + RI->copyFastMathFlags(OpI); + return RI; + } + break; + case Instruction::FRem: + // Remainder is straightforward. Remainder is always exact, so the + // type of OpI doesn't enter into things at all. We simply evaluate + // in whichever source type is larger, then convert to the + // destination type. + if (LHSWidth < SrcWidth) + LHSOrig = Builder->CreateFPExt(LHSOrig, RHSOrig->getType()); + else if (RHSWidth <= SrcWidth) + RHSOrig = Builder->CreateFPExt(RHSOrig, LHSOrig->getType()); + Value *ExactResult = Builder->CreateFRem(LHSOrig, RHSOrig); + if (Instruction *RI = dyn_cast<Instruction>(ExactResult)) + RI->copyFastMathFlags(OpI); + return CastInst::CreateFPCast(ExactResult, CI.getType()); } // (fptrunc (fneg x)) -> (fneg (fptrunc x)) if (BinaryOperator::isFNeg(OpI)) { Value *InnerTrunc = Builder->CreateFPTrunc(OpI->getOperand(1), CI.getType()); - return BinaryOperator::CreateFNeg(InnerTrunc); + Instruction *RI = BinaryOperator::CreateFNeg(InnerTrunc); + RI->copyFastMathFlags(OpI); + return RI; } } @@ -1297,7 +1348,7 @@ Instruction *InstCombiner::visitFPTrunc(FPTruncInst &CI) { } } - return 0; + return nullptr; } Instruction *InstCombiner::visitFPExt(CastInst &CI) { @@ -1306,7 +1357,7 @@ Instruction *InstCombiner::visitFPExt(CastInst &CI) { Instruction *InstCombiner::visitFPToUI(FPToUIInst &FI) { Instruction *OpI = dyn_cast<Instruction>(FI.getOperand(0)); - if (OpI == 0) + if (!OpI) return commonCastTransforms(FI); // fptoui(uitofp(X)) --> X @@ -1326,7 +1377,7 @@ Instruction *InstCombiner::visitFPToUI(FPToUIInst &FI) { Instruction *InstCombiner::visitFPToSI(FPToSIInst &FI) { Instruction *OpI = dyn_cast<Instruction>(FI.getOperand(0)); - if (OpI == 0) + if (!OpI) return commonCastTransforms(FI); // fptosi(sitofp(X)) --> X @@ -1357,11 +1408,11 @@ Instruction *InstCombiner::visitIntToPtr(IntToPtrInst &CI) { // trunc or zext to the intptr_t type, then inttoptr of it. This allows the // cast to be exposed to other transforms. - if (TD) { + if (DL) { unsigned AS = CI.getAddressSpace(); if (CI.getOperand(0)->getType()->getScalarSizeInBits() != - TD->getPointerSizeInBits(AS)) { - Type *Ty = TD->getIntPtrType(CI.getContext(), AS); + DL->getPointerSizeInBits(AS)) { + Type *Ty = DL->getIntPtrType(CI.getContext(), AS); if (CI.getType()->isVectorTy()) // Handle vectors of pointers. Ty = VectorType::get(Ty, CI.getType()->getVectorNumElements()); @@ -1373,7 +1424,7 @@ Instruction *InstCombiner::visitIntToPtr(IntToPtrInst &CI) { if (Instruction *I = commonCastTransforms(CI)) return I; - return 0; + return nullptr; } /// @brief Implement the transforms for cast of pointer (bitcast/ptrtoint) @@ -1383,7 +1434,12 @@ Instruction *InstCombiner::commonPointerCastTransforms(CastInst &CI) { if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Src)) { // If casting the result of a getelementptr instruction with no offset, turn // this into a cast of the original pointer! - if (GEP->hasAllZeroIndices()) { + if (GEP->hasAllZeroIndices() && + // If CI is an addrspacecast and GEP changes the poiner type, merging + // GEP into CI would undo canonicalizing addrspacecast with different + // pointer types, causing infinite loops. + (!isa<AddrSpaceCastInst>(CI) || + GEP->getType() == GEP->getPointerOperand()->getType())) { // Changing the cast operand is usually not a good idea but it is safe // here because the pointer operand is being replaced with another // pointer operand so the opcode doesn't need to change. @@ -1392,7 +1448,7 @@ Instruction *InstCombiner::commonPointerCastTransforms(CastInst &CI) { return &CI; } - if (!TD) + if (!DL) return commonCastTransforms(CI); // If the GEP has a single use, and the base pointer is a bitcast, and the @@ -1400,12 +1456,12 @@ Instruction *InstCombiner::commonPointerCastTransforms(CastInst &CI) { // instructions into fewer. This typically happens with unions and other // non-type-safe code. unsigned AS = GEP->getPointerAddressSpace(); - unsigned OffsetBits = TD->getPointerSizeInBits(AS); + unsigned OffsetBits = DL->getPointerSizeInBits(AS); APInt Offset(OffsetBits, 0); BitCastInst *BCI = dyn_cast<BitCastInst>(GEP->getOperand(0)); if (GEP->hasOneUse() && BCI && - GEP->accumulateConstantOffset(*TD, Offset)) { + GEP->accumulateConstantOffset(*DL, Offset)) { // Get the base pointer input of the bitcast, and the type it points to. Value *OrigBase = BCI->getOperand(0); SmallVector<Value*, 8> NewIndices; @@ -1436,16 +1492,16 @@ Instruction *InstCombiner::visitPtrToInt(PtrToIntInst &CI) { // do a ptrtoint to intptr_t then do a trunc or zext. This allows the cast // to be exposed to other transforms. - if (!TD) + if (!DL) return commonPointerCastTransforms(CI); Type *Ty = CI.getType(); unsigned AS = CI.getPointerAddressSpace(); - if (Ty->getScalarSizeInBits() == TD->getPointerSizeInBits(AS)) + if (Ty->getScalarSizeInBits() == DL->getPointerSizeInBits(AS)) return commonPointerCastTransforms(CI); - Type *PtrTy = TD->getIntPtrType(CI.getContext(), AS); + Type *PtrTy = DL->getIntPtrType(CI.getContext(), AS); if (Ty->isVectorTy()) // Handle vectors of pointers. PtrTy = VectorType::get(PtrTy, Ty->getVectorNumElements()); @@ -1472,7 +1528,7 @@ static Instruction *OptimizeVectorResize(Value *InVal, VectorType *DestTy, // there yet. if (SrcTy->getElementType()->getPrimitiveSizeInBits() != DestTy->getElementType()->getPrimitiveSizeInBits()) - return 0; + return nullptr; SrcTy = VectorType::get(DestTy->getElementType(), SrcTy->getNumElements()); InVal = IC.Builder->CreateBitCast(InVal, SrcTy); @@ -1550,7 +1606,7 @@ static bool CollectInsertionElements(Value *V, unsigned Shift, ElementIndex = Elements.size() - ElementIndex - 1; // Fail if multiple elements are inserted into this slot. - if (Elements[ElementIndex] != 0) + if (Elements[ElementIndex]) return false; Elements[ElementIndex] = V; @@ -1590,7 +1646,7 @@ static bool CollectInsertionElements(Value *V, unsigned Shift, if (!V->hasOneUse()) return false; Instruction *I = dyn_cast<Instruction>(V); - if (I == 0) return false; + if (!I) return false; switch (I->getOpcode()) { default: return false; // Unhandled case. case Instruction::BitCast: @@ -1611,7 +1667,7 @@ static bool CollectInsertionElements(Value *V, unsigned Shift, case Instruction::Shl: { // Must be shifting by a constant that is a multiple of the element size. ConstantInt *CI = dyn_cast<ConstantInt>(I->getOperand(1)); - if (CI == 0) return false; + if (!CI) return false; Shift += CI->getZExtValue(); if (!isMultipleOfTypeSize(Shift, VecEltTy)) return false; return CollectInsertionElements(I->getOperand(0), Shift, @@ -1639,7 +1695,7 @@ static bool CollectInsertionElements(Value *V, unsigned Shift, static Value *OptimizeIntegerToVectorInsertions(BitCastInst &CI, InstCombiner &IC) { // We need to know the target byte order to perform this optimization. - if (!IC.getDataLayout()) return 0; + if (!IC.getDataLayout()) return nullptr; VectorType *DestVecTy = cast<VectorType>(CI.getType()); Value *IntInput = CI.getOperand(0); @@ -1647,14 +1703,14 @@ static Value *OptimizeIntegerToVectorInsertions(BitCastInst &CI, SmallVector<Value*, 8> Elements(DestVecTy->getNumElements()); if (!CollectInsertionElements(IntInput, 0, Elements, DestVecTy->getElementType(), IC)) - return 0; + return nullptr; // If we succeeded, we know that all of the element are specified by Elements // or are zero if Elements has a null entry. Recast this as a set of // insertions. Value *Result = Constant::getNullValue(CI.getType()); for (unsigned i = 0, e = Elements.size(); i != e; ++i) { - if (Elements[i] == 0) continue; // Unset element. + if (!Elements[i]) continue; // Unset element. Result = IC.Builder->CreateInsertElement(Result, Elements[i], IC.Builder->getInt32(i)); @@ -1668,14 +1724,14 @@ static Value *OptimizeIntegerToVectorInsertions(BitCastInst &CI, /// bitcast. The various long double bitcasts can't get in here. static Instruction *OptimizeIntToFloatBitCast(BitCastInst &CI,InstCombiner &IC){ // We need to know the target byte order to perform this optimization. - if (!IC.getDataLayout()) return 0; + if (!IC.getDataLayout()) return nullptr; Value *Src = CI.getOperand(0); Type *DestTy = CI.getType(); // If this is a bitcast from int to float, check to see if the int is an // extraction from a vector. - Value *VecInput = 0; + Value *VecInput = nullptr; // bitcast(trunc(bitcast(somevector))) if (match(Src, m_Trunc(m_BitCast(m_Value(VecInput)))) && isa<VectorType>(VecInput->getType())) { @@ -1699,7 +1755,7 @@ static Instruction *OptimizeIntToFloatBitCast(BitCastInst &CI,InstCombiner &IC){ } // bitcast(trunc(lshr(bitcast(somevector), cst)) - ConstantInt *ShAmt = 0; + ConstantInt *ShAmt = nullptr; if (match(Src, m_Trunc(m_LShr(m_BitCast(m_Value(VecInput)), m_ConstantInt(ShAmt)))) && isa<VectorType>(VecInput->getType())) { @@ -1721,7 +1777,7 @@ static Instruction *OptimizeIntToFloatBitCast(BitCastInst &CI,InstCombiner &IC){ return ExtractElementInst::Create(VecInput, IC.Builder->getInt32(Elt)); } } - return 0; + return nullptr; } Instruction *InstCombiner::visitBitCast(BitCastInst &CI) { @@ -1741,11 +1797,6 @@ Instruction *InstCombiner::visitBitCast(BitCastInst &CI) { Type *DstElTy = DstPTy->getElementType(); Type *SrcElTy = SrcPTy->getElementType(); - // If the address spaces don't match, don't eliminate the bitcast, which is - // required for changing types. - if (SrcPTy->getAddressSpace() != DstPTy->getAddressSpace()) - return 0; - // If we are casting a alloca to a pointer to a type of the same // size, rewrite the allocation instruction to allocate the "right" type. // There is no need to modify malloc calls because it is their bitcast that @@ -1858,5 +1909,24 @@ Instruction *InstCombiner::visitBitCast(BitCastInst &CI) { } Instruction *InstCombiner::visitAddrSpaceCast(AddrSpaceCastInst &CI) { - return commonCastTransforms(CI); + // If the destination pointer element type is not the same as the source's + // first do a bitcast to the destination type, and then the addrspacecast. + // This allows the cast to be exposed to other transforms. + Value *Src = CI.getOperand(0); + PointerType *SrcTy = cast<PointerType>(Src->getType()->getScalarType()); + PointerType *DestTy = cast<PointerType>(CI.getType()->getScalarType()); + + Type *DestElemTy = DestTy->getElementType(); + if (SrcTy->getElementType() != DestElemTy) { + Type *MidTy = PointerType::get(DestElemTy, SrcTy->getAddressSpace()); + if (VectorType *VT = dyn_cast<VectorType>(CI.getType())) { + // Handle vectors of pointers. + MidTy = VectorType::get(MidTy, VT->getNumElements()); + } + + Value *NewBitCast = Builder->CreateBitCast(Src, MidTy); + return new AddrSpaceCastInst(NewBitCast, CI.getType()); + } + + return commonPointerCastTransforms(CI); } |
