X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FAnalysis%2FConstantFolding.cpp;h=bc0dffc473626481a1adc664b2be86285ce62ced;hb=85f6cbd1a5dc0071b3b4a7387e66479bbdfb3d13;hp=b5fafd685cd7b7f6aaa63263c291ba081df1af20;hpb=b065b06c12dba6001b8140df2744d0c856ef6ea1;p=oota-llvm.git diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp index b5fafd685cd..bc0dffc4736 100644 --- a/lib/Analysis/ConstantFolding.cpp +++ b/lib/Analysis/ConstantFolding.cpp @@ -9,29 +9,31 @@ // // This file defines routines for folding instructions into constants. // -// Also, to supplement the basic VMCore ConstantExpr simplifications, +// Also, to supplement the basic IR ConstantExpr simplifications, // this file defines some additional folding routines that can make use of -// TargetData information. These functions cannot go in VMCore due to library +// DataLayout information. These functions cannot go in IR due to library // dependency issues. // //===----------------------------------------------------------------------===// #include "llvm/Analysis/ConstantFolding.h" -#include "llvm/Constants.h" -#include "llvm/DerivedTypes.h" -#include "llvm/Function.h" -#include "llvm/GlobalVariable.h" -#include "llvm/Instructions.h" -#include "llvm/Intrinsics.h" -#include "llvm/Operator.h" -#include "llvm/Analysis/ValueTracking.h" -#include "llvm/Target/TargetData.h" +#include "llvm/ADT/SmallPtrSet.h" #include "llvm/ADT/SmallVector.h" #include "llvm/ADT/StringMap.h" +#include "llvm/Analysis/ValueTracking.h" +#include "llvm/IR/Constants.h" +#include "llvm/IR/DataLayout.h" +#include "llvm/IR/DerivedTypes.h" +#include "llvm/IR/Function.h" +#include "llvm/IR/GlobalVariable.h" +#include "llvm/IR/Instructions.h" +#include "llvm/IR/Intrinsics.h" +#include "llvm/IR/Operator.h" #include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/FEnv.h" #include "llvm/Support/GetElementPtrTypeIterator.h" #include "llvm/Support/MathExtras.h" -#include "llvm/Support/FEnv.h" +#include "llvm/Target/TargetLibraryInfo.h" #include #include using namespace llvm; @@ -40,80 +42,122 @@ using namespace llvm; // Constant Folding internal helper functions //===----------------------------------------------------------------------===// -/// FoldBitCast - Constant fold bitcast, symbolically evaluating it with -/// TargetData. This always returns a non-null constant, but it may be a +/// FoldBitCast - Constant fold bitcast, symbolically evaluating it with +/// DataLayout. This always returns a non-null constant, but it may be a /// ConstantExpr if unfoldable. -static Constant *FoldBitCast(Constant *C, const Type *DestTy, - const TargetData &TD) { - - // This only handles casts to vectors currently. - const VectorType *DestVTy = dyn_cast(DestTy); +static Constant *FoldBitCast(Constant *C, Type *DestTy, + const DataLayout &TD) { + // Catch the obvious splat cases. + if (C->isNullValue() && !DestTy->isX86_MMXTy()) + return Constant::getNullValue(DestTy); + if (C->isAllOnesValue() && !DestTy->isX86_MMXTy()) + return Constant::getAllOnesValue(DestTy); + + // Handle a vector->integer cast. + if (IntegerType *IT = dyn_cast(DestTy)) { + VectorType *VTy = dyn_cast(C->getType()); + if (VTy == 0) + return ConstantExpr::getBitCast(C, DestTy); + + unsigned NumSrcElts = VTy->getNumElements(); + Type *SrcEltTy = VTy->getElementType(); + + // If the vector is a vector of floating point, convert it to vector of int + // to simplify things. + if (SrcEltTy->isFloatingPointTy()) { + unsigned FPWidth = SrcEltTy->getPrimitiveSizeInBits(); + Type *SrcIVTy = + VectorType::get(IntegerType::get(C->getContext(), FPWidth), NumSrcElts); + // Ask IR to do the conversion now that #elts line up. + C = ConstantExpr::getBitCast(C, SrcIVTy); + } + + ConstantDataVector *CDV = dyn_cast(C); + if (CDV == 0) + return ConstantExpr::getBitCast(C, DestTy); + + // Now that we know that the input value is a vector of integers, just shift + // and insert them into our result. + unsigned BitShift = TD.getTypeAllocSizeInBits(SrcEltTy); + APInt Result(IT->getBitWidth(), 0); + for (unsigned i = 0; i != NumSrcElts; ++i) { + Result <<= BitShift; + if (TD.isLittleEndian()) + Result |= CDV->getElementAsInteger(NumSrcElts-i-1); + else + Result |= CDV->getElementAsInteger(i); + } + + return ConstantInt::get(IT, Result); + } + + // The code below only handles casts to vectors currently. + VectorType *DestVTy = dyn_cast(DestTy); if (DestVTy == 0) return ConstantExpr::getBitCast(C, DestTy); - + // If this is a scalar -> vector cast, convert the input into a <1 x scalar> // vector so the code below can handle it uniformly. if (isa(C) || isa(C)) { Constant *Ops = C; // don't take the address of C! return FoldBitCast(ConstantVector::get(Ops), DestTy, TD); } - + // If this is a bitcast from constant vector -> vector, fold it. - ConstantVector *CV = dyn_cast(C); - if (CV == 0) + if (!isa(C) && !isa(C)) return ConstantExpr::getBitCast(C, DestTy); - - // If the element types match, VMCore can fold it. + + // If the element types match, IR can fold it. unsigned NumDstElt = DestVTy->getNumElements(); - unsigned NumSrcElt = CV->getNumOperands(); + unsigned NumSrcElt = C->getType()->getVectorNumElements(); if (NumDstElt == NumSrcElt) return ConstantExpr::getBitCast(C, DestTy); - - const Type *SrcEltTy = CV->getType()->getElementType(); - const Type *DstEltTy = DestVTy->getElementType(); - - // Otherwise, we're changing the number of elements in a vector, which + + Type *SrcEltTy = C->getType()->getVectorElementType(); + Type *DstEltTy = DestVTy->getElementType(); + + // Otherwise, we're changing the number of elements in a vector, which // requires endianness information to do the right thing. For example, // bitcast (<2 x i64> to <4 x i32>) // folds to (little endian): // <4 x i32> // and to (big endian): // <4 x i32> - + // First thing is first. We only want to think about integer here, so if // we have something in FP form, recast it as integer. if (DstEltTy->isFloatingPointTy()) { // Fold to an vector of integers with same size as our FP type. unsigned FPWidth = DstEltTy->getPrimitiveSizeInBits(); - const Type *DestIVTy = + Type *DestIVTy = VectorType::get(IntegerType::get(C->getContext(), FPWidth), NumDstElt); // Recursively handle this integer conversion, if possible. C = FoldBitCast(C, DestIVTy, TD); - if (!C) return ConstantExpr::getBitCast(C, DestTy); - - // Finally, VMCore can handle this now that #elts line up. + + // Finally, IR can handle this now that #elts line up. return ConstantExpr::getBitCast(C, DestTy); } - + // Okay, we know the destination is integer, if the input is FP, convert // it to integer first. if (SrcEltTy->isFloatingPointTy()) { unsigned FPWidth = SrcEltTy->getPrimitiveSizeInBits(); - const Type *SrcIVTy = + Type *SrcIVTy = VectorType::get(IntegerType::get(C->getContext(), FPWidth), NumSrcElt); - // Ask VMCore to do the conversion now that #elts line up. + // Ask IR to do the conversion now that #elts line up. C = ConstantExpr::getBitCast(C, SrcIVTy); - CV = dyn_cast(C); - if (!CV) // If VMCore wasn't able to fold it, bail out. + // If IR wasn't able to fold it, bail out. + if (!isa(C) && // FIXME: Remove ConstantVector. + !isa(C)) return C; } - + // Now we know that the input and output vectors are both integer vectors // of the same size, and that their #elements is not the same. Do the // conversion here, which depends on whether the input or output has // more elements. bool isLittleEndian = TD.isLittleEndian(); - + SmallVector Result; if (NumDstElt < NumSrcElt) { // Handle: bitcast (<4 x i32> to <2 x i64>) @@ -126,48 +170,49 @@ static Constant *FoldBitCast(Constant *C, const Type *DestTy, Constant *Elt = Zero; unsigned ShiftAmt = isLittleEndian ? 0 : SrcBitSize*(Ratio-1); for (unsigned j = 0; j != Ratio; ++j) { - Constant *Src = dyn_cast(CV->getOperand(SrcElt++)); + Constant *Src =dyn_cast(C->getAggregateElement(SrcElt++)); if (!Src) // Reject constantexpr elements. return ConstantExpr::getBitCast(C, DestTy); - + // Zero extend the element to the right size. Src = ConstantExpr::getZExt(Src, Elt->getType()); - + // Shift it to the right place, depending on endianness. - Src = ConstantExpr::getShl(Src, + Src = ConstantExpr::getShl(Src, ConstantInt::get(Src->getType(), ShiftAmt)); ShiftAmt += isLittleEndian ? SrcBitSize : -SrcBitSize; - + // Mix it in. Elt = ConstantExpr::getOr(Elt, Src); } Result.push_back(Elt); } - } else { - // Handle: bitcast (<2 x i64> to <4 x i32>) - unsigned Ratio = NumDstElt/NumSrcElt; - unsigned DstBitSize = DstEltTy->getPrimitiveSizeInBits(); - - // Loop over each source value, expanding into multiple results. - for (unsigned i = 0; i != NumSrcElt; ++i) { - Constant *Src = dyn_cast(CV->getOperand(i)); - if (!Src) // Reject constantexpr elements. - return ConstantExpr::getBitCast(C, DestTy); - - unsigned ShiftAmt = isLittleEndian ? 0 : DstBitSize*(Ratio-1); - for (unsigned j = 0; j != Ratio; ++j) { - // Shift the piece of the value into the right place, depending on - // endianness. - Constant *Elt = ConstantExpr::getLShr(Src, - ConstantInt::get(Src->getType(), ShiftAmt)); - ShiftAmt += isLittleEndian ? DstBitSize : -DstBitSize; - - // Truncate and remember this piece. - Result.push_back(ConstantExpr::getTrunc(Elt, DstEltTy)); - } + return ConstantVector::get(Result); + } + + // Handle: bitcast (<2 x i64> to <4 x i32>) + unsigned Ratio = NumDstElt/NumSrcElt; + unsigned DstBitSize = DstEltTy->getPrimitiveSizeInBits(); + + // Loop over each source value, expanding into multiple results. + for (unsigned i = 0; i != NumSrcElt; ++i) { + Constant *Src = dyn_cast(C->getAggregateElement(i)); + if (!Src) // Reject constantexpr elements. + return ConstantExpr::getBitCast(C, DestTy); + + unsigned ShiftAmt = isLittleEndian ? 0 : DstBitSize*(Ratio-1); + for (unsigned j = 0; j != Ratio; ++j) { + // Shift the piece of the value into the right place, depending on + // endianness. + Constant *Elt = ConstantExpr::getLShr(Src, + ConstantInt::get(Src->getType(), ShiftAmt)); + ShiftAmt += isLittleEndian ? DstBitSize : -DstBitSize; + + // Truncate and remember this piece. + Result.push_back(ConstantExpr::getTrunc(Elt, DstEltTy)); } } - + return ConstantVector::get(Result); } @@ -176,53 +221,32 @@ static Constant *FoldBitCast(Constant *C, const Type *DestTy, /// from a global, return the global and the constant. Because of /// constantexprs, this function is recursive. static bool IsConstantOffsetFromGlobal(Constant *C, GlobalValue *&GV, - int64_t &Offset, const TargetData &TD) { + APInt &Offset, const DataLayout &TD) { // Trivial case, constant is the global. if ((GV = dyn_cast(C))) { - Offset = 0; + Offset.clearAllBits(); return true; } - + // Otherwise, if this isn't a constant expr, bail out. ConstantExpr *CE = dyn_cast(C); if (!CE) return false; - + // Look through ptr->int and ptr->ptr casts. if (CE->getOpcode() == Instruction::PtrToInt || CE->getOpcode() == Instruction::BitCast) return IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, TD); - - // i32* getelementptr ([5 x i32]* @a, i32 0, i32 5) - if (CE->getOpcode() == Instruction::GetElementPtr) { - // Cannot compute this if the element type of the pointer is missing size - // info. - if (!cast(CE->getOperand(0)->getType()) - ->getElementType()->isSized()) - return false; - + + // i32* getelementptr ([5 x i32]* @a, i32 0, i32 5) + if (GEPOperator *GEP = dyn_cast(CE)) { // If the base isn't a global+constant, we aren't either. if (!IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, TD)) return false; - + // Otherwise, add any offset that our operands provide. - gep_type_iterator GTI = gep_type_begin(CE); - for (User::const_op_iterator i = CE->op_begin() + 1, e = CE->op_end(); - i != e; ++i, ++GTI) { - ConstantInt *CI = dyn_cast(*i); - if (!CI) return false; // Index isn't a simple constant? - if (CI->isZero()) continue; // Not adding anything. - - if (const StructType *ST = dyn_cast(*GTI)) { - // N = N + Offset - Offset += TD.getStructLayout(ST)->getElementOffset(CI->getZExtValue()); - } else { - const SequentialType *SQT = cast(*GTI); - Offset += TD.getTypeAllocSize(SQT->getElementType())*CI->getSExtValue(); - } - } - return true; + return GEP->accumulateConstantOffset(TD, Offset); } - + return false; } @@ -232,30 +256,33 @@ static bool IsConstantOffsetFromGlobal(Constant *C, GlobalValue *&GV, /// the CurPtr buffer. TD is the target data. static bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset, unsigned char *CurPtr, unsigned BytesLeft, - const TargetData &TD) { + const DataLayout &TD) { assert(ByteOffset <= TD.getTypeAllocSize(C->getType()) && "Out of range access"); - + // If this element is zero or undefined, we can just return since *CurPtr is // zero initialized. if (isa(C) || isa(C)) return true; - + if (ConstantInt *CI = dyn_cast(C)) { if (CI->getBitWidth() > 64 || (CI->getBitWidth() & 7) != 0) return false; - + uint64_t Val = CI->getZExtValue(); unsigned IntBytes = unsigned(CI->getBitWidth()/8); - + for (unsigned i = 0; i != BytesLeft && ByteOffset != IntBytes; ++i) { - CurPtr[i] = (unsigned char)(Val >> (ByteOffset * 8)); + int n = ByteOffset; + if (!TD.isLittleEndian()) + n = IntBytes - n - 1; + CurPtr[i] = (unsigned char)(Val >> (n * 8)); ++ByteOffset; } return true; } - + if (ConstantFP *CFP = dyn_cast(C)) { if (CFP->getType()->isDoubleTy()) { C = FoldBitCast(C, Type::getInt64Ty(C->getContext()), TD); @@ -265,6 +292,10 @@ static bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset, C = FoldBitCast(C, Type::getInt32Ty(C->getContext()), TD); return ReadDataFromGlobal(C, ByteOffset, CurPtr, BytesLeft, TD); } + if (CFP->getType()->isHalfTy()){ + C = FoldBitCast(C, Type::getInt16Ty(C->getContext()), TD); + return ReadDataFromGlobal(C, ByteOffset, CurPtr, BytesLeft, TD); + } return false; } @@ -273,7 +304,7 @@ static bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset, unsigned Index = SL->getElementContainingOffset(ByteOffset); uint64_t CurEltOffset = SL->getElementOffset(Index); ByteOffset -= CurEltOffset; - + while (1) { // If the element access is to the element itself and not to tail padding, // read the bytes from the element. @@ -283,9 +314,9 @@ static bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset, !ReadDataFromGlobal(CS->getOperand(Index), ByteOffset, CurPtr, BytesLeft, TD)) return false; - + ++Index; - + // Check to see if we read from the last struct element, if so we're done. if (Index == CS->getType()->getNumElements()) return true; @@ -305,47 +336,40 @@ static bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset, // not reached. } - if (ConstantArray *CA = dyn_cast(C)) { - uint64_t EltSize = TD.getTypeAllocSize(CA->getType()->getElementType()); + if (isa(C) || isa(C) || + isa(C)) { + Type *EltTy = cast(C->getType())->getElementType(); + uint64_t EltSize = TD.getTypeAllocSize(EltTy); uint64_t Index = ByteOffset / EltSize; uint64_t Offset = ByteOffset - Index * EltSize; - for (; Index != CA->getType()->getNumElements(); ++Index) { - if (!ReadDataFromGlobal(CA->getOperand(Index), Offset, CurPtr, - BytesLeft, TD)) - return false; - if (EltSize >= BytesLeft) - return true; - - Offset = 0; - BytesLeft -= EltSize; - CurPtr += EltSize; - } - return true; - } - - if (ConstantVector *CV = dyn_cast(C)) { - uint64_t EltSize = TD.getTypeAllocSize(CV->getType()->getElementType()); - uint64_t Index = ByteOffset / EltSize; - uint64_t Offset = ByteOffset - Index * EltSize; - for (; Index != CV->getType()->getNumElements(); ++Index) { - if (!ReadDataFromGlobal(CV->getOperand(Index), Offset, CurPtr, + uint64_t NumElts; + if (ArrayType *AT = dyn_cast(C->getType())) + NumElts = AT->getNumElements(); + else + NumElts = cast(C->getType())->getNumElements(); + + for (; Index != NumElts; ++Index) { + if (!ReadDataFromGlobal(C->getAggregateElement(Index), Offset, CurPtr, BytesLeft, TD)) return false; - if (EltSize >= BytesLeft) + + uint64_t BytesWritten = EltSize - Offset; + assert(BytesWritten <= EltSize && "Not indexing into this element?"); + if (BytesWritten >= BytesLeft) return true; - + Offset = 0; - BytesLeft -= EltSize; - CurPtr += EltSize; + BytesLeft -= BytesWritten; + CurPtr += BytesWritten; } return true; } - + if (ConstantExpr *CE = dyn_cast(C)) { if (CE->getOpcode() == Instruction::IntToPtr && - CE->getOperand(0)->getType() == TD.getIntPtrType(CE->getContext())) - return ReadDataFromGlobal(CE->getOperand(0), ByteOffset, CurPtr, - BytesLeft, TD); + CE->getOperand(0)->getType() == TD.getIntPtrType(CE->getContext())) + return ReadDataFromGlobal(CE->getOperand(0), ByteOffset, CurPtr, + BytesLeft, TD); } // Otherwise, unknown initializer type. @@ -353,18 +377,20 @@ static bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset, } static Constant *FoldReinterpretLoadFromConstPtr(Constant *C, - const TargetData &TD) { - const Type *LoadTy = cast(C->getType())->getElementType(); - const IntegerType *IntType = dyn_cast(LoadTy); - + const DataLayout &TD) { + Type *LoadTy = cast(C->getType())->getElementType(); + IntegerType *IntType = dyn_cast(LoadTy); + // If this isn't an integer load we can't fold it directly. if (!IntType) { // If this is a float/double load, we can try folding it as an int32/64 load // and then bitcast the result. This can be useful for union cases. Note // that address spaces don't matter here since we're not going to result in // an actual new load. - const Type *MapTy; - if (LoadTy->isFloatTy()) + Type *MapTy; + if (LoadTy->isHalfTy()) + MapTy = Type::getInt16PtrTy(C->getContext()); + else if (LoadTy->isFloatTy()) MapTy = Type::getInt32PtrTy(C->getContext()); else if (LoadTy->isDoubleTy()) MapTy = Type::getInt64PtrTy(C->getContext()); @@ -380,15 +406,15 @@ static Constant *FoldReinterpretLoadFromConstPtr(Constant *C, return FoldBitCast(Res, LoadTy, TD); return 0; } - + unsigned BytesLoaded = (IntType->getBitWidth() + 7) / 8; if (BytesLoaded > 32 || BytesLoaded == 0) return 0; - + GlobalValue *GVal; - int64_t Offset; + APInt Offset(TD.getPointerSizeInBits(), 0); if (!IsConstantOffsetFromGlobal(C, GVal, Offset, TD)) return 0; - + GlobalVariable *GV = dyn_cast(GVal); if (!GV || !GV->isConstant() || !GV->hasDefinitiveInitializer() || !GV->getInitializer()->getType()->isSized()) @@ -396,21 +422,31 @@ static Constant *FoldReinterpretLoadFromConstPtr(Constant *C, // If we're loading off the beginning of the global, some bytes may be valid, // but we don't try to handle this. - if (Offset < 0) return 0; - + if (Offset.isNegative()) return 0; + // If we're not accessing anything in this constant, the result is undefined. - if (uint64_t(Offset) >= TD.getTypeAllocSize(GV->getInitializer()->getType())) + if (Offset.getZExtValue() >= + TD.getTypeAllocSize(GV->getInitializer()->getType())) return UndefValue::get(IntType); - + unsigned char RawBytes[32] = {0}; - if (!ReadDataFromGlobal(GV->getInitializer(), Offset, RawBytes, + if (!ReadDataFromGlobal(GV->getInitializer(), Offset.getZExtValue(), RawBytes, BytesLoaded, TD)) return 0; - APInt ResultVal = APInt(IntType->getBitWidth(), RawBytes[BytesLoaded-1]); - for (unsigned i = 1; i != BytesLoaded; ++i) { - ResultVal <<= 8; - ResultVal |= RawBytes[BytesLoaded-1-i]; + APInt ResultVal = APInt(IntType->getBitWidth(), 0); + if (TD.isLittleEndian()) { + ResultVal = RawBytes[BytesLoaded - 1]; + for (unsigned i = 1; i != BytesLoaded; ++i) { + ResultVal <<= 8; + ResultVal |= RawBytes[BytesLoaded-1-i]; + } + } else { + ResultVal = RawBytes[0]; + for (unsigned i = 1; i != BytesLoaded; ++i) { + ResultVal <<= 8; + ResultVal |= RawBytes[i]; + } } return ConstantInt::get(IntType->getContext(), ResultVal); @@ -420,7 +456,7 @@ static Constant *FoldReinterpretLoadFromConstPtr(Constant *C, /// produce if it is constant and determinable. If this is not determinable, /// return null. Constant *llvm::ConstantFoldLoadFromConstPtr(Constant *C, - const TargetData *TD) { + const DataLayout *TD) { // First, try the easy cases: if (GlobalVariable *GV = dyn_cast(C)) if (GV->isConstant() && GV->hasDefinitiveInitializer()) @@ -429,21 +465,21 @@ Constant *llvm::ConstantFoldLoadFromConstPtr(Constant *C, // If the loaded value isn't a constant expr, we can't handle it. ConstantExpr *CE = dyn_cast(C); if (!CE) return 0; - + if (CE->getOpcode() == Instruction::GetElementPtr) { if (GlobalVariable *GV = dyn_cast(CE->getOperand(0))) if (GV->isConstant() && GV->hasDefinitiveInitializer()) - if (Constant *V = + if (Constant *V = ConstantFoldLoadThroughGEPConstantExpr(GV->getInitializer(), CE)) return V; } - + // Instead of loading constant c string, use corresponding integer value // directly if string length is small enough. - std::string Str; - if (TD && GetConstantStringInfo(CE, Str) && !Str.empty()) { - unsigned StrLen = Str.length(); - const Type *Ty = cast(CE->getType())->getElementType(); + StringRef Str; + if (TD && getConstantStringInfo(CE, Str) && !Str.empty()) { + unsigned StrLen = Str.size(); + Type *Ty = cast(CE->getType())->getElementType(); unsigned NumBits = Ty->getPrimitiveSizeInBits(); // Replace load with immediate integer if the result is an integer or fp // value. @@ -465,38 +501,36 @@ Constant *llvm::ConstantFoldLoadFromConstPtr(Constant *C, SingleChar = 0; StrVal = (StrVal << 8) | SingleChar; } - + Constant *Res = ConstantInt::get(CE->getContext(), StrVal); if (Ty->isFloatingPointTy()) Res = ConstantExpr::getBitCast(Res, Ty); return Res; } } - + // If this load comes from anywhere in a constant global, and if the global // is all undef or zero, we know what it loads. if (GlobalVariable *GV = dyn_cast(GetUnderlyingObject(CE, TD))) { if (GV->isConstant() && GV->hasDefinitiveInitializer()) { - const Type *ResTy = cast(C->getType())->getElementType(); + Type *ResTy = cast(C->getType())->getElementType(); if (GV->getInitializer()->isNullValue()) return Constant::getNullValue(ResTy); if (isa(GV->getInitializer())) return UndefValue::get(ResTy); } } - - // Try hard to fold loads from bitcasted strange and non-type-safe things. We - // currently don't do any of this for big endian systems. It can be - // generalized in the future if someone is interested. - if (TD && TD->isLittleEndian()) + + // Try hard to fold loads from bitcasted strange and non-type-safe things. + if (TD) return FoldReinterpretLoadFromConstPtr(CE, *TD); return 0; } -static Constant *ConstantFoldLoadInst(const LoadInst *LI, const TargetData *TD){ +static Constant *ConstantFoldLoadInst(const LoadInst *LI, const DataLayout *TD){ if (LI->isVolatile()) return 0; - + if (Constant *C = dyn_cast(LI->getOperand(0))) return ConstantFoldLoadFromConstPtr(C, TD); @@ -505,50 +539,76 @@ static Constant *ConstantFoldLoadInst(const LoadInst *LI, const TargetData *TD){ /// SymbolicallyEvaluateBinop - One of Op0/Op1 is a constant expression. /// Attempt to symbolically evaluate the result of a binary operator merging -/// these together. If target data info is available, it is provided as TD, -/// otherwise TD is null. +/// these together. If target data info is available, it is provided as DL, +/// otherwise DL is null. static Constant *SymbolicallyEvaluateBinop(unsigned Opc, Constant *Op0, - Constant *Op1, const TargetData *TD){ + Constant *Op1, const DataLayout *DL){ // SROA - + // Fold (and 0xffffffff00000000, (shl x, 32)) -> shl. // Fold (lshr (or X, Y), 32) -> (lshr [X/Y], 32) if one doesn't contribute // bits. - - + + + if (Opc == Instruction::And && DL) { + unsigned BitWidth = DL->getTypeSizeInBits(Op0->getType()->getScalarType()); + APInt KnownZero0(BitWidth, 0), KnownOne0(BitWidth, 0); + APInt KnownZero1(BitWidth, 0), KnownOne1(BitWidth, 0); + ComputeMaskedBits(Op0, KnownZero0, KnownOne0, DL); + ComputeMaskedBits(Op1, KnownZero1, KnownOne1, DL); + if ((KnownOne1 | KnownZero0).isAllOnesValue()) { + // All the bits of Op0 that the 'and' could be masking are already zero. + return Op0; + } + if ((KnownOne0 | KnownZero1).isAllOnesValue()) { + // All the bits of Op1 that the 'and' could be masking are already zero. + return Op1; + } + + APInt KnownZero = KnownZero0 | KnownZero1; + APInt KnownOne = KnownOne0 & KnownOne1; + if ((KnownZero | KnownOne).isAllOnesValue()) { + return ConstantInt::get(Op0->getType(), KnownOne); + } + } + // If the constant expr is something like &A[123] - &A[4].f, fold this into a // constant. This happens frequently when iterating over a global array. - if (Opc == Instruction::Sub && TD) { + if (Opc == Instruction::Sub && DL) { GlobalValue *GV1, *GV2; - int64_t Offs1, Offs2; - - if (IsConstantOffsetFromGlobal(Op0, GV1, Offs1, *TD)) - if (IsConstantOffsetFromGlobal(Op1, GV2, Offs2, *TD) && + unsigned PtrSize = DL->getPointerSizeInBits(); + unsigned OpSize = DL->getTypeSizeInBits(Op0->getType()); + APInt Offs1(PtrSize, 0), Offs2(PtrSize, 0); + + if (IsConstantOffsetFromGlobal(Op0, GV1, Offs1, *DL)) + if (IsConstantOffsetFromGlobal(Op1, GV2, Offs2, *DL) && GV1 == GV2) { // (&GV+C1) - (&GV+C2) -> C1-C2, pointer arithmetic cannot overflow. - return ConstantInt::get(Op0->getType(), Offs1-Offs2); + // PtrToInt may change the bitwidth so we have convert to the right size + // first. + return ConstantInt::get(Op0->getType(), Offs1.zextOrTrunc(OpSize) - + Offs2.zextOrTrunc(OpSize)); } } - + return 0; } /// CastGEPIndices - If array indices are not pointer-sized integers, /// explicitly cast them so that they aren't implicitly casted by the /// getelementptr. -static Constant *CastGEPIndices(Constant *const *Ops, unsigned NumOps, - const Type *ResultTy, - const TargetData *TD) { +static Constant *CastGEPIndices(ArrayRef Ops, + Type *ResultTy, const DataLayout *TD, + const TargetLibraryInfo *TLI) { if (!TD) return 0; - const Type *IntPtrTy = TD->getIntPtrType(ResultTy->getContext()); + Type *IntPtrTy = TD->getIntPtrType(ResultTy->getContext()); bool Any = false; SmallVector NewIdxs; - for (unsigned i = 1; i != NumOps; ++i) { + for (unsigned i = 1, e = Ops.size(); i != e; ++i) { if ((i == 1 || !isa(GetElementPtrInst::getIndexedType(Ops[0]->getType(), - reinterpret_cast(Ops+1), - i-1))) && + Ops.slice(1, i-1)))) && Ops[i]->getType() != IntPtrTy) { Any = true; NewIdxs.push_back(ConstantExpr::getCast(CastInst::getCastOpcode(Ops[i], @@ -562,32 +622,49 @@ static Constant *CastGEPIndices(Constant *const *Ops, unsigned NumOps, if (!Any) return 0; Constant *C = - ConstantExpr::getGetElementPtr(Ops[0], &NewIdxs[0], NewIdxs.size()); + ConstantExpr::getGetElementPtr(Ops[0], NewIdxs); if (ConstantExpr *CE = dyn_cast(C)) - if (Constant *Folded = ConstantFoldConstantExpression(CE, TD)) + if (Constant *Folded = ConstantFoldConstantExpression(CE, TD, TLI)) C = Folded; return C; } +/// Strip the pointer casts, but preserve the address space information. +static Constant* StripPtrCastKeepAS(Constant* Ptr) { + assert(Ptr->getType()->isPointerTy() && "Not a pointer type"); + PointerType *OldPtrTy = cast(Ptr->getType()); + Ptr = cast(Ptr->stripPointerCasts()); + PointerType *NewPtrTy = cast(Ptr->getType()); + + // Preserve the address space number of the pointer. + if (NewPtrTy->getAddressSpace() != OldPtrTy->getAddressSpace()) { + NewPtrTy = NewPtrTy->getElementType()->getPointerTo( + OldPtrTy->getAddressSpace()); + Ptr = ConstantExpr::getBitCast(Ptr, NewPtrTy); + } + return Ptr; +} + /// SymbolicallyEvaluateGEP - If we can symbolically evaluate the specified GEP /// constant expression, do so. -static Constant *SymbolicallyEvaluateGEP(Constant *const *Ops, unsigned NumOps, - const Type *ResultTy, - const TargetData *TD) { +static Constant *SymbolicallyEvaluateGEP(ArrayRef Ops, + Type *ResultTy, const DataLayout *TD, + const TargetLibraryInfo *TLI) { Constant *Ptr = Ops[0]; - if (!TD || !cast(Ptr->getType())->getElementType()->isSized()) + if (!TD || !cast(Ptr->getType())->getElementType()->isSized() || + !Ptr->getType()->isPointerTy()) return 0; - - const Type *IntPtrTy = TD->getIntPtrType(Ptr->getContext()); + + Type *IntPtrTy = TD->getIntPtrType(Ptr->getContext()); // If this is a constant expr gep that is effectively computing an // "offsetof", fold it into 'cast int Size to T*' instead of 'gep 0, 0, 12' - for (unsigned i = 1; i != NumOps; ++i) + for (unsigned i = 1, e = Ops.size(); i != e; ++i) if (!isa(Ops[i])) { - + // If this is "gep i8* Ptr, (sub 0, V)", fold this as: // "inttoptr (sub (ptrtoint Ptr), V)" - if (NumOps == 2 && + if (Ops.size() == 2 && cast(ResultTy)->getElementType()->isIntegerTy(8)) { ConstantExpr *CE = dyn_cast(Ops[1]); assert((CE == 0 || CE->getType() == IntPtrTy) && @@ -598,18 +675,20 @@ static Constant *SymbolicallyEvaluateGEP(Constant *const *Ops, unsigned NumOps, Res = ConstantExpr::getSub(Res, CE->getOperand(1)); Res = ConstantExpr::getIntToPtr(Res, ResultTy); if (ConstantExpr *ResCE = dyn_cast(Res)) - Res = ConstantFoldConstantExpression(ResCE, TD); + Res = ConstantFoldConstantExpression(ResCE, TD, TLI); return Res; } } return 0; } - + unsigned BitWidth = TD->getTypeSizeInBits(IntPtrTy); - APInt Offset = APInt(BitWidth, - TD->getIndexedOffset(Ptr->getType(), - (Value**)Ops+1, NumOps-1)); - Ptr = cast(Ptr->stripPointerCasts()); + APInt Offset = + APInt(BitWidth, TD->getIndexedOffset(Ptr->getType(), + makeArrayRef((Value *const*) + Ops.data() + 1, + Ops.size() - 1))); + Ptr = StripPtrCastKeepAS(Ptr); // If this is a GEP of a GEP, fold it all into a single GEP. while (GEPOperator *GEP = dyn_cast(Ptr)) { @@ -627,10 +706,8 @@ static Constant *SymbolicallyEvaluateGEP(Constant *const *Ops, unsigned NumOps, Ptr = cast(GEP->getOperand(0)); Offset += APInt(BitWidth, - TD->getIndexedOffset(Ptr->getType(), - (Value**)NestedOps.data(), - NestedOps.size())); - Ptr = cast(Ptr->stripPointerCasts()); + TD->getIndexedOffset(Ptr->getType(), NestedOps)); + Ptr = StripPtrCastKeepAS(Ptr); } // If the base value for this address is a literal integer value, fold the @@ -649,23 +726,24 @@ static Constant *SymbolicallyEvaluateGEP(Constant *const *Ops, unsigned NumOps, // we eliminate over-indexing of the notional static type array bounds. // This makes it easy to determine if the getelementptr is "inbounds". // Also, this helps GlobalOpt do SROA on GlobalVariables. - const Type *Ty = Ptr->getType(); + Type *Ty = Ptr->getType(); + assert(Ty->isPointerTy() && "Forming regular GEP of non-pointer type"); SmallVector NewIdxs; do { - if (const SequentialType *ATy = dyn_cast(Ty)) { + if (SequentialType *ATy = dyn_cast(Ty)) { if (ATy->isPointerTy()) { // The only pointer indexing we'll do is on the first index of the GEP. if (!NewIdxs.empty()) break; - + // Only handle pointers to sized types, not pointers to functions. if (!ATy->getElementType()->isSized()) return 0; } - + // Determine which element of the array the offset points into. APInt ElemSize(BitWidth, TD->getTypeAllocSize(ATy->getElementType())); - const IntegerType *IntPtrTy = TD->getIntPtrType(Ty->getContext()); + IntegerType *IntPtrTy = TD->getIntPtrType(Ty->getContext()); if (ElemSize == 0) // The element size is 0. This may be [0 x Ty]*, so just use a zero // index for this level and proceed to the next level to see if it can @@ -679,11 +757,18 @@ static Constant *SymbolicallyEvaluateGEP(Constant *const *Ops, unsigned NumOps, NewIdxs.push_back(ConstantInt::get(IntPtrTy, NewIdx)); } Ty = ATy->getElementType(); - } else if (const StructType *STy = dyn_cast(Ty)) { - // Determine which field of the struct the offset points into. The - // getZExtValue is at least as safe as the StructLayout API because we - // know the offset is within the struct at this point. + } else if (StructType *STy = dyn_cast(Ty)) { + // If we end up with an offset that isn't valid for this struct type, we + // can't re-form this GEP in a regular form, so bail out. The pointer + // operand likely went through casts that are necessary to make the GEP + // sensible. const StructLayout &SL = *TD->getStructLayout(STy); + if (Offset.uge(SL.getSizeInBytes())) + break; + + // Determine which field of the struct the offset points into. The + // getZExtValue is fine as we've already ensured that the offset is + // within the range representable by the StructLayout API. unsigned ElIdx = SL.getElementContainingOffset(Offset.getZExtValue()); NewIdxs.push_back(ConstantInt::get(Type::getInt32Ty(Ty->getContext()), ElIdx)); @@ -703,7 +788,7 @@ static Constant *SymbolicallyEvaluateGEP(Constant *const *Ops, unsigned NumOps, // Create a GEP. Constant *C = - ConstantExpr::getGetElementPtr(Ptr, &NewIdxs[0], NewIdxs.size()); + ConstantExpr::getGetElementPtr(Ptr, NewIdxs); assert(cast(C->getType())->getElementType() == Ty && "Computed GetElementPtr has unexpected type!"); @@ -726,7 +811,9 @@ static Constant *SymbolicallyEvaluateGEP(Constant *const *Ops, unsigned NumOps, /// Note that this fails if not all of the operands are constant. Otherwise, /// this function can only fail when attempting to fold instructions like loads /// and stores, which have no constant expression form. -Constant *llvm::ConstantFoldInstruction(Instruction *I, const TargetData *TD) { +Constant *llvm::ConstantFoldInstruction(Instruction *I, + const DataLayout *TD, + const TargetLibraryInfo *TLI) { // Handle PHI nodes quickly here... if (PHINode *PN = dyn_cast(I)) { Constant *CommonValue = 0; @@ -739,14 +826,21 @@ Constant *llvm::ConstantFoldInstruction(Instruction *I, const TargetData *TD) { // all operands are constants. if (isa(Incoming)) continue; - // If the incoming value is not a constant, or is a different constant to - // the one we saw previously, then give up. + // If the incoming value is not a constant, then give up. Constant *C = dyn_cast(Incoming); - if (!C || (CommonValue && C != CommonValue)) + if (!C) + return 0; + // Fold the PHI's operands. + if (ConstantExpr *NewC = dyn_cast(C)) + C = ConstantFoldConstantExpression(NewC, TD, TLI); + // If the incoming value is a different constant to + // the one we saw previously, then give up. + if (CommonValue && C != CommonValue) return 0; CommonValue = C; } + // If we reach here, all incoming values are the same constant or undef. return CommonValue ? CommonValue : UndefValue::get(PN->getType()); } @@ -754,16 +848,22 @@ Constant *llvm::ConstantFoldInstruction(Instruction *I, const TargetData *TD) { // Scan the operand list, checking to see if they are all constants, if so, // hand off to ConstantFoldInstOperands. SmallVector Ops; - for (User::op_iterator i = I->op_begin(), e = I->op_end(); i != e; ++i) - if (Constant *Op = dyn_cast(*i)) - Ops.push_back(Op); - else + for (User::op_iterator i = I->op_begin(), e = I->op_end(); i != e; ++i) { + Constant *Op = dyn_cast(*i); + if (!Op) return 0; // All operands not constant! + // Fold the Instruction's operands. + if (ConstantExpr *NewCE = dyn_cast(Op)) + Op = ConstantFoldConstantExpression(NewCE, TD, TLI); + + Ops.push_back(Op); + } + if (const CmpInst *CI = dyn_cast(I)) return ConstantFoldCompareInstOperands(CI->getPredicate(), Ops[0], Ops[1], - TD); - + TD, TLI); + if (const LoadInst *LI = dyn_cast(I)) return ConstantFoldLoadInst(LI, TD); @@ -771,37 +871,47 @@ Constant *llvm::ConstantFoldInstruction(Instruction *I, const TargetData *TD) { return ConstantExpr::getInsertValue( cast(IVI->getAggregateOperand()), cast(IVI->getInsertedValueOperand()), - IVI->idx_begin(), IVI->getNumIndices()); + IVI->getIndices()); if (ExtractValueInst *EVI = dyn_cast(I)) return ConstantExpr::getExtractValue( cast(EVI->getAggregateOperand()), - EVI->idx_begin(), EVI->getNumIndices()); + EVI->getIndices()); - return ConstantFoldInstOperands(I->getOpcode(), I->getType(), - Ops.data(), Ops.size(), TD); + return ConstantFoldInstOperands(I->getOpcode(), I->getType(), Ops, TD, TLI); } -/// ConstantFoldConstantExpression - Attempt to fold the constant expression -/// using the specified TargetData. If successful, the constant result is -/// result is returned, if not, null is returned. -Constant *llvm::ConstantFoldConstantExpression(const ConstantExpr *CE, - const TargetData *TD) { - SmallVector Ops; - for (User::const_op_iterator i = CE->op_begin(), e = CE->op_end(); - i != e; ++i) { +static Constant * +ConstantFoldConstantExpressionImpl(const ConstantExpr *CE, const DataLayout *TD, + const TargetLibraryInfo *TLI, + SmallPtrSet &FoldedOps) { + SmallVector Ops; + for (User::const_op_iterator i = CE->op_begin(), e = CE->op_end(); i != e; + ++i) { Constant *NewC = cast(*i); - // Recursively fold the ConstantExpr's operands. - if (ConstantExpr *NewCE = dyn_cast(NewC)) - NewC = ConstantFoldConstantExpression(NewCE, TD); + // Recursively fold the ConstantExpr's operands. If we have already folded + // a ConstantExpr, we don't have to process it again. + if (ConstantExpr *NewCE = dyn_cast(NewC)) { + if (FoldedOps.insert(NewCE)) + NewC = ConstantFoldConstantExpressionImpl(NewCE, TD, TLI, FoldedOps); + } Ops.push_back(NewC); } if (CE->isCompare()) return ConstantFoldCompareInstOperands(CE->getPredicate(), Ops[0], Ops[1], - TD); - return ConstantFoldInstOperands(CE->getOpcode(), CE->getType(), - Ops.data(), Ops.size(), TD); + TD, TLI); + return ConstantFoldInstOperands(CE->getOpcode(), CE->getType(), Ops, TD, TLI); +} + +/// ConstantFoldConstantExpression - Attempt to fold the constant expression +/// using the specified DataLayout. If successful, the constant result is +/// result is returned, if not, null is returned. +Constant *llvm::ConstantFoldConstantExpression(const ConstantExpr *CE, + const DataLayout *TD, + const TargetLibraryInfo *TLI) { + SmallPtrSet FoldedOps; + return ConstantFoldConstantExpressionImpl(CE, TD, TLI, FoldedOps); } /// ConstantFoldInstOperands - Attempt to constant fold an instruction with the @@ -814,26 +924,27 @@ Constant *llvm::ConstantFoldConstantExpression(const ConstantExpr *CE, /// information, due to only being passed an opcode and operands. Constant /// folding using this function strips this information. /// -Constant *llvm::ConstantFoldInstOperands(unsigned Opcode, const Type *DestTy, - Constant* const* Ops, unsigned NumOps, - const TargetData *TD) { +Constant *llvm::ConstantFoldInstOperands(unsigned Opcode, Type *DestTy, + ArrayRef Ops, + const DataLayout *TD, + const TargetLibraryInfo *TLI) { // Handle easy binops first. if (Instruction::isBinaryOp(Opcode)) { if (isa(Ops[0]) || isa(Ops[1])) if (Constant *C = SymbolicallyEvaluateBinop(Opcode, Ops[0], Ops[1], TD)) return C; - + return ConstantExpr::get(Opcode, Ops[0], Ops[1]); } - + switch (Opcode) { default: return 0; case Instruction::ICmp: - case Instruction::FCmp: assert(0 && "Invalid for compares"); + case Instruction::FCmp: llvm_unreachable("Invalid for compares"); case Instruction::Call: - if (Function *F = dyn_cast(Ops[NumOps - 1])) + if (Function *F = dyn_cast(Ops.back())) if (canConstantFoldCallTo(F)) - return ConstantFoldCall(F, Ops, NumOps - 1); + return ConstantFoldCall(F, Ops.slice(0, Ops.size() - 1), TLI); return 0; case Instruction::PtrToInt: // If the input is a inttoptr, eliminate the pair. This requires knowing @@ -843,7 +954,7 @@ Constant *llvm::ConstantFoldInstOperands(unsigned Opcode, const Type *DestTy, Constant *Input = CE->getOperand(0); unsigned InWidth = Input->getType()->getScalarSizeInBits(); if (TD->getPointerSizeInBits() < InWidth) { - Constant *Mask = + Constant *Mask = ConstantInt::get(CE->getContext(), APInt::getLowBitsSet(InWidth, TD->getPointerSizeInBits())); Input = ConstantExpr::getAnd(Input, Mask); @@ -887,12 +998,12 @@ Constant *llvm::ConstantFoldInstOperands(unsigned Opcode, const Type *DestTy, case Instruction::ShuffleVector: return ConstantExpr::getShuffleVector(Ops[0], Ops[1], Ops[2]); case Instruction::GetElementPtr: - if (Constant *C = CastGEPIndices(Ops, NumOps, DestTy, TD)) + if (Constant *C = CastGEPIndices(Ops, DestTy, TD, TLI)) return C; - if (Constant *C = SymbolicallyEvaluateGEP(Ops, NumOps, DestTy, TD)) + if (Constant *C = SymbolicallyEvaluateGEP(Ops, DestTy, TD, TLI)) return C; - - return ConstantExpr::getGetElementPtr(Ops[0], Ops+1, NumOps-1); + + return ConstantExpr::getGetElementPtr(Ops[0], Ops.slice(1)); } } @@ -901,8 +1012,9 @@ Constant *llvm::ConstantFoldInstOperands(unsigned Opcode, const Type *DestTy, /// returns a constant expression of the specified operands. /// Constant *llvm::ConstantFoldCompareInstOperands(unsigned Predicate, - Constant *Ops0, Constant *Ops1, - const TargetData *TD) { + Constant *Ops0, Constant *Ops1, + const DataLayout *TD, + const TargetLibraryInfo *TLI) { // fold: icmp (inttoptr x), null -> icmp x, 0 // fold: icmp (ptrtoint x), 0 -> icmp x, null // fold: icmp (inttoptr x), (inttoptr y) -> icmp trunc/zext x, trunc/zext y @@ -912,29 +1024,29 @@ Constant *llvm::ConstantFoldCompareInstOperands(unsigned Predicate, // around to know if bit truncation is happening. if (ConstantExpr *CE0 = dyn_cast(Ops0)) { if (TD && Ops1->isNullValue()) { - const Type *IntPtrTy = TD->getIntPtrType(CE0->getContext()); + Type *IntPtrTy = TD->getIntPtrType(CE0->getContext()); if (CE0->getOpcode() == Instruction::IntToPtr) { // Convert the integer value to the right size to ensure we get the // proper extension or truncation. Constant *C = ConstantExpr::getIntegerCast(CE0->getOperand(0), IntPtrTy, false); Constant *Null = Constant::getNullValue(C->getType()); - return ConstantFoldCompareInstOperands(Predicate, C, Null, TD); + return ConstantFoldCompareInstOperands(Predicate, C, Null, TD, TLI); } - + // Only do this transformation if the int is intptrty in size, otherwise // there is a truncation or extension that we aren't modeling. - if (CE0->getOpcode() == Instruction::PtrToInt && + if (CE0->getOpcode() == Instruction::PtrToInt && CE0->getType() == IntPtrTy) { Constant *C = CE0->getOperand(0); Constant *Null = Constant::getNullValue(C->getType()); - return ConstantFoldCompareInstOperands(Predicate, C, Null, TD); + return ConstantFoldCompareInstOperands(Predicate, C, Null, TD, TLI); } } - + if (ConstantExpr *CE1 = dyn_cast(Ops1)) { if (TD && CE0->getOpcode() == CE1->getOpcode()) { - const Type *IntPtrTy = TD->getIntPtrType(CE0->getContext()); + Type *IntPtrTy = TD->getIntPtrType(CE0->getContext()); if (CE0->getOpcode() == Instruction::IntToPtr) { // Convert the integer value to the right size to ensure we get the @@ -943,7 +1055,7 @@ Constant *llvm::ConstantFoldCompareInstOperands(unsigned Predicate, IntPtrTy, false); Constant *C1 = ConstantExpr::getIntegerCast(CE1->getOperand(0), IntPtrTy, false); - return ConstantFoldCompareInstOperands(Predicate, C0, C1, TD); + return ConstantFoldCompareInstOperands(Predicate, C0, C1, TD, TLI); } // Only do this transformation if the int is intptrty in size, otherwise @@ -952,25 +1064,27 @@ Constant *llvm::ConstantFoldCompareInstOperands(unsigned Predicate, CE0->getType() == IntPtrTy && CE0->getOperand(0)->getType() == CE1->getOperand(0)->getType())) return ConstantFoldCompareInstOperands(Predicate, CE0->getOperand(0), - CE1->getOperand(0), TD); + CE1->getOperand(0), TD, TLI); } } - + // icmp eq (or x, y), 0 -> (icmp eq x, 0) & (icmp eq y, 0) // icmp ne (or x, y), 0 -> (icmp ne x, 0) | (icmp ne y, 0) if ((Predicate == ICmpInst::ICMP_EQ || Predicate == ICmpInst::ICMP_NE) && CE0->getOpcode() == Instruction::Or && Ops1->isNullValue()) { - Constant *LHS = - ConstantFoldCompareInstOperands(Predicate, CE0->getOperand(0), Ops1,TD); - Constant *RHS = - ConstantFoldCompareInstOperands(Predicate, CE0->getOperand(1), Ops1,TD); - unsigned OpC = + Constant *LHS = + ConstantFoldCompareInstOperands(Predicate, CE0->getOperand(0), Ops1, + TD, TLI); + Constant *RHS = + ConstantFoldCompareInstOperands(Predicate, CE0->getOperand(1), Ops1, + TD, TLI); + unsigned OpC = Predicate == ICmpInst::ICMP_EQ ? Instruction::And : Instruction::Or; Constant *Ops[] = { LHS, RHS }; - return ConstantFoldInstOperands(OpC, LHS->getType(), Ops, 2, TD); + return ConstantFoldInstOperands(OpC, LHS->getType(), Ops, TD, TLI); } } - + return ConstantExpr::getCompare(Predicate, Ops0, Ops1); } @@ -978,58 +1092,32 @@ Constant *llvm::ConstantFoldCompareInstOperands(unsigned Predicate, /// ConstantFoldLoadThroughGEPConstantExpr - Given a constant and a /// getelementptr constantexpr, return the constant value being addressed by the /// constant expression, or null if something is funny and we can't decide. -Constant *llvm::ConstantFoldLoadThroughGEPConstantExpr(Constant *C, +Constant *llvm::ConstantFoldLoadThroughGEPConstantExpr(Constant *C, ConstantExpr *CE) { - if (CE->getOperand(1) != Constant::getNullValue(CE->getOperand(1)->getType())) + if (!CE->getOperand(1)->isNullValue()) return 0; // Do not allow stepping over the value! - + // Loop over all of the operands, tracking down which value we are - // addressing... - gep_type_iterator I = gep_type_begin(CE), E = gep_type_end(CE); - for (++I; I != E; ++I) - if (const StructType *STy = dyn_cast(*I)) { - ConstantInt *CU = cast(I.getOperand()); - assert(CU->getZExtValue() < STy->getNumElements() && - "Struct index out of range!"); - unsigned El = (unsigned)CU->getZExtValue(); - if (ConstantStruct *CS = dyn_cast(C)) { - C = CS->getOperand(El); - } else if (isa(C)) { - C = Constant::getNullValue(STy->getElementType(El)); - } else if (isa(C)) { - C = UndefValue::get(STy->getElementType(El)); - } else { - return 0; - } - } else if (ConstantInt *CI = dyn_cast(I.getOperand())) { - if (const ArrayType *ATy = dyn_cast(*I)) { - if (CI->getZExtValue() >= ATy->getNumElements()) - return 0; - if (ConstantArray *CA = dyn_cast(C)) - C = CA->getOperand(CI->getZExtValue()); - else if (isa(C)) - C = Constant::getNullValue(ATy->getElementType()); - else if (isa(C)) - C = UndefValue::get(ATy->getElementType()); - else - return 0; - } else if (const VectorType *VTy = dyn_cast(*I)) { - if (CI->getZExtValue() >= VTy->getNumElements()) - return 0; - if (ConstantVector *CP = dyn_cast(C)) - C = CP->getOperand(CI->getZExtValue()); - else if (isa(C)) - C = Constant::getNullValue(VTy->getElementType()); - else if (isa(C)) - C = UndefValue::get(VTy->getElementType()); - else - return 0; - } else { - return 0; - } - } else { - return 0; - } + // addressing. + for (unsigned i = 2, e = CE->getNumOperands(); i != e; ++i) { + C = C->getAggregateElement(CE->getOperand(i)); + if (C == 0) return 0; + } + return C; +} + +/// ConstantFoldLoadThroughGEPIndices - Given a constant and getelementptr +/// indices (with an *implied* zero pointer index that is not in the list), +/// return the constant value being addressed by a virtual load, or null if +/// something is funny and we can't decide. +Constant *llvm::ConstantFoldLoadThroughGEPIndices(Constant *C, + ArrayRef Indices) { + // Loop over all of the operands, tracking down which value we are + // addressing. + for (unsigned i = 0, e = Indices.size(); i != e; ++i) { + C = C->getAggregateElement(Indices[i]); + if (C == 0) return 0; + } return C; } @@ -1043,7 +1131,15 @@ Constant *llvm::ConstantFoldLoadThroughGEPConstantExpr(Constant *C, bool llvm::canConstantFoldCallTo(const Function *F) { switch (F->getIntrinsicID()) { + case Intrinsic::fabs: + case Intrinsic::log: + case Intrinsic::log2: + case Intrinsic::log10: + case Intrinsic::exp: + case Intrinsic::exp2: + case Intrinsic::floor: case Intrinsic::sqrt: + case Intrinsic::pow: case Intrinsic::powi: case Intrinsic::bswap: case Intrinsic::ctpop: @@ -1073,15 +1169,14 @@ llvm::canConstantFoldCallTo(const Function *F) { if (!F->hasName()) return false; StringRef Name = F->getName(); - + // In these cases, the check of the length is required. We don't want to // return true for a name like "cos\0blah" which strcmp would return equal to // "cos", but has length 8. switch (Name[0]) { default: return false; case 'a': - return Name == "acos" || Name == "asin" || - Name == "atan" || Name == "atan2"; + return Name == "acos" || Name == "asin" || Name == "atan" || Name =="atan2"; case 'c': return Name == "cos" || Name == "ceil" || Name == "cosf" || Name == "cosh"; case 'e': @@ -1100,38 +1195,48 @@ llvm::canConstantFoldCallTo(const Function *F) { } } -static Constant *ConstantFoldFP(double (*NativeFP)(double), double V, - const Type *Ty) { +static Constant *ConstantFoldFP(double (*NativeFP)(double), double V, + Type *Ty) { sys::llvm_fenv_clearexcept(); V = NativeFP(V); if (sys::llvm_fenv_testexcept()) { sys::llvm_fenv_clearexcept(); return 0; } - + + if (Ty->isHalfTy()) { + APFloat APF(V); + bool unused; + APF.convert(APFloat::IEEEhalf, APFloat::rmNearestTiesToEven, &unused); + return ConstantFP::get(Ty->getContext(), APF); + } if (Ty->isFloatTy()) return ConstantFP::get(Ty->getContext(), APFloat((float)V)); if (Ty->isDoubleTy()) return ConstantFP::get(Ty->getContext(), APFloat(V)); - llvm_unreachable("Can only constant fold float/double"); - return 0; // dummy return to suppress warning + llvm_unreachable("Can only constant fold half/float/double"); } static Constant *ConstantFoldBinaryFP(double (*NativeFP)(double, double), - double V, double W, const Type *Ty) { + double V, double W, Type *Ty) { sys::llvm_fenv_clearexcept(); V = NativeFP(V, W); if (sys::llvm_fenv_testexcept()) { sys::llvm_fenv_clearexcept(); return 0; } - + + if (Ty->isHalfTy()) { + APFloat APF(V); + bool unused; + APF.convert(APFloat::IEEEhalf, APFloat::rmNearestTiesToEven, &unused); + return ConstantFP::get(Ty->getContext(), APF); + } if (Ty->isFloatTy()) return ConstantFP::get(Ty->getContext(), APFloat((float)V)); if (Ty->isDoubleTy()) return ConstantFP::get(Ty->getContext(), APFloat(V)); - llvm_unreachable("Can only constant fold float/double"); - return 0; // dummy return to suppress warning + llvm_unreachable("Can only constant fold half/float/double"); } /// ConstantFoldConvertToInt - Attempt to an SSE floating point to integer @@ -1142,11 +1247,8 @@ static Constant *ConstantFoldBinaryFP(double (*NativeFP)(double, double), /// available for the result. Returns null if the conversion cannot be /// performed, otherwise returns the Constant value resulting from the /// conversion. -static Constant *ConstantFoldConvertToInt(ConstantFP *Op, bool roundTowardZero, - const Type *Ty) { - assert(Op && "Called with NULL operand"); - APFloat Val(Op->getValueAPF()); - +static Constant *ConstantFoldConvertToInt(const APFloat &Val, + bool roundTowardZero, Type *Ty) { // All of these conversion intrinsics form an integer of at most 64bits. unsigned ResultWidth = cast(Ty)->getBitWidth(); assert(ResultWidth <= 64 && @@ -1167,13 +1269,13 @@ static Constant *ConstantFoldConvertToInt(ConstantFP *Op, bool roundTowardZero, /// ConstantFoldCall - Attempt to constant fold a call to the specified function /// with the specified arguments, returning null if unsuccessful. Constant * -llvm::ConstantFoldCall(Function *F, - Constant *const *Operands, unsigned NumOperands) { +llvm::ConstantFoldCall(Function *F, ArrayRef Operands, + const TargetLibraryInfo *TLI) { if (!F->hasName()) return 0; StringRef Name = F->getName(); - const Type *Ty = F->getReturnType(); - if (NumOperands == 1) { + Type *Ty = F->getReturnType(); + if (Operands.size() == 1) { if (ConstantFP *Op = dyn_cast(Operands[0])) { if (F->getIntrinsicID() == Intrinsic::convert_to_fp16) { APFloat Val(Op->getValueAPF()); @@ -1183,8 +1285,10 @@ llvm::ConstantFoldCall(Function *F, return ConstantInt::get(F->getContext(), Val.bitcastToAPInt()); } + if (!TLI) + return 0; - if (!Ty->isFloatTy() && !Ty->isDoubleTy()) + if (!Ty->isHalfTy() && !Ty->isFloatTy() && !Ty->isDoubleTy()) return 0; /// We only fold functions with finite arguments. Folding NaN and inf is @@ -1197,50 +1301,88 @@ llvm::ConstantFoldCall(Function *F, /// the host native double versions. Float versions are not called /// directly but for all these it is true (float)(f((double)arg)) == /// f(arg). Long double not supported yet. - double V = Ty->isFloatTy() ? (double)Op->getValueAPF().convertToFloat() : - Op->getValueAPF().convertToDouble(); + double V; + if (Ty->isFloatTy()) + V = Op->getValueAPF().convertToFloat(); + else if (Ty->isDoubleTy()) + V = Op->getValueAPF().convertToDouble(); + else { + bool unused; + APFloat APF = Op->getValueAPF(); + APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, &unused); + V = APF.convertToDouble(); + } + + switch (F->getIntrinsicID()) { + default: break; + case Intrinsic::fabs: + return ConstantFoldFP(fabs, V, Ty); +#if HAVE_LOG2 + case Intrinsic::log2: + return ConstantFoldFP(log2, V, Ty); +#endif +#if HAVE_LOG + case Intrinsic::log: + return ConstantFoldFP(log, V, Ty); +#endif +#if HAVE_LOG10 + case Intrinsic::log10: + return ConstantFoldFP(log10, V, Ty); +#endif +#if HAVE_EXP + case Intrinsic::exp: + return ConstantFoldFP(exp, V, Ty); +#endif +#if HAVE_EXP2 + case Intrinsic::exp2: + return ConstantFoldFP(exp2, V, Ty); +#endif + case Intrinsic::floor: + return ConstantFoldFP(floor, V, Ty); + } + switch (Name[0]) { case 'a': - if (Name == "acos") + if (Name == "acos" && TLI->has(LibFunc::acos)) return ConstantFoldFP(acos, V, Ty); - else if (Name == "asin") + else if (Name == "asin" && TLI->has(LibFunc::asin)) return ConstantFoldFP(asin, V, Ty); - else if (Name == "atan") + else if (Name == "atan" && TLI->has(LibFunc::atan)) return ConstantFoldFP(atan, V, Ty); break; case 'c': - if (Name == "ceil") + if (Name == "ceil" && TLI->has(LibFunc::ceil)) return ConstantFoldFP(ceil, V, Ty); - else if (Name == "cos") + else if (Name == "cos" && TLI->has(LibFunc::cos)) return ConstantFoldFP(cos, V, Ty); - else if (Name == "cosh") + else if (Name == "cosh" && TLI->has(LibFunc::cosh)) return ConstantFoldFP(cosh, V, Ty); - else if (Name == "cosf") + else if (Name == "cosf" && TLI->has(LibFunc::cosf)) return ConstantFoldFP(cos, V, Ty); break; case 'e': - if (Name == "exp") + if (Name == "exp" && TLI->has(LibFunc::exp)) return ConstantFoldFP(exp, V, Ty); - - if (Name == "exp2") { + + if (Name == "exp2" && TLI->has(LibFunc::exp2)) { // Constant fold exp2(x) as pow(2,x) in case the host doesn't have a // C99 library. return ConstantFoldBinaryFP(pow, 2.0, V, Ty); } break; case 'f': - if (Name == "fabs") + if (Name == "fabs" && TLI->has(LibFunc::fabs)) return ConstantFoldFP(fabs, V, Ty); - else if (Name == "floor") + else if (Name == "floor" && TLI->has(LibFunc::floor)) return ConstantFoldFP(floor, V, Ty); break; case 'l': - if (Name == "log" && V > 0) + if (Name == "log" && V > 0 && TLI->has(LibFunc::log)) return ConstantFoldFP(log, V, Ty); - else if (Name == "log10" && V > 0) + else if (Name == "log10" && V > 0 && TLI->has(LibFunc::log10)) return ConstantFoldFP(log10, V, Ty); else if (F->getIntrinsicID() == Intrinsic::sqrt && - (Ty->isFloatTy() || Ty->isDoubleTy())) { + (Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy())) { if (V >= -0.0) return ConstantFoldFP(sqrt, V, Ty); else // Undefined @@ -1248,21 +1390,21 @@ llvm::ConstantFoldCall(Function *F, } break; case 's': - if (Name == "sin") + if (Name == "sin" && TLI->has(LibFunc::sin)) return ConstantFoldFP(sin, V, Ty); - else if (Name == "sinh") + else if (Name == "sinh" && TLI->has(LibFunc::sinh)) return ConstantFoldFP(sinh, V, Ty); - else if (Name == "sqrt" && V >= 0) + else if (Name == "sqrt" && V >= 0 && TLI->has(LibFunc::sqrt)) return ConstantFoldFP(sqrt, V, Ty); - else if (Name == "sqrtf" && V >= 0) + else if (Name == "sqrtf" && V >= 0 && TLI->has(LibFunc::sqrtf)) return ConstantFoldFP(sqrt, V, Ty); - else if (Name == "sinf") + else if (Name == "sinf" && TLI->has(LibFunc::sinf)) return ConstantFoldFP(sin, V, Ty); break; case 't': - if (Name == "tan") + if (Name == "tan" && TLI->has(LibFunc::tan)) return ConstantFoldFP(tan, V, Ty); - else if (Name == "tanh") + else if (Name == "tanh" && TLI->has(LibFunc::tanh)) return ConstantFoldFP(tanh, V, Ty); break; default: @@ -1277,12 +1419,8 @@ llvm::ConstantFoldCall(Function *F, return ConstantInt::get(F->getContext(), Op->getValue().byteSwap()); case Intrinsic::ctpop: return ConstantInt::get(Ty, Op->getValue().countPopulation()); - case Intrinsic::cttz: - return ConstantInt::get(Ty, Op->getValue().countTrailingZeros()); - case Intrinsic::ctlz: - return ConstantInt::get(Ty, Op->getValue().countLeadingZeros()); case Intrinsic::convert_from_fp16: { - APFloat Val(Op->getValue()); + APFloat Val(APFloat::IEEEhalf, Op->getValue()); bool lost = false; APFloat::opStatus status = @@ -1300,21 +1438,28 @@ llvm::ConstantFoldCall(Function *F, } } - if (ConstantVector *Op = dyn_cast(Operands[0])) { + // Support ConstantVector in case we have an Undef in the top. + if (isa(Operands[0]) || + isa(Operands[0])) { + Constant *Op = cast(Operands[0]); switch (F->getIntrinsicID()) { default: break; case Intrinsic::x86_sse_cvtss2si: case Intrinsic::x86_sse_cvtss2si64: case Intrinsic::x86_sse2_cvtsd2si: case Intrinsic::x86_sse2_cvtsd2si64: - if (ConstantFP *FPOp = dyn_cast(Op->getOperand(0))) - return ConstantFoldConvertToInt(FPOp, /*roundTowardZero=*/false, Ty); + if (ConstantFP *FPOp = + dyn_cast_or_null(Op->getAggregateElement(0U))) + return ConstantFoldConvertToInt(FPOp->getValueAPF(), + /*roundTowardZero=*/false, Ty); case Intrinsic::x86_sse_cvttss2si: case Intrinsic::x86_sse_cvttss2si64: case Intrinsic::x86_sse2_cvttsd2si: case Intrinsic::x86_sse2_cvttsd2si64: - if (ConstantFP *FPOp = dyn_cast(Op->getOperand(0))) - return ConstantFoldConvertToInt(FPOp, /*roundTowardZero=*/true, Ty); + if (ConstantFP *FPOp = + dyn_cast_or_null(Op->getAggregateElement(0U))) + return ConstantFoldConvertToInt(FPOp->getValueAPF(), + /*roundTowardZero=*/true, Ty); } } @@ -1327,28 +1472,54 @@ llvm::ConstantFoldCall(Function *F, return 0; } - if (NumOperands == 2) { + if (Operands.size() == 2) { if (ConstantFP *Op1 = dyn_cast(Operands[0])) { - if (!Ty->isFloatTy() && !Ty->isDoubleTy()) + if (!Ty->isHalfTy() && !Ty->isFloatTy() && !Ty->isDoubleTy()) return 0; - double Op1V = Ty->isFloatTy() ? - (double)Op1->getValueAPF().convertToFloat() : - Op1->getValueAPF().convertToDouble(); + double Op1V; + if (Ty->isFloatTy()) + Op1V = Op1->getValueAPF().convertToFloat(); + else if (Ty->isDoubleTy()) + Op1V = Op1->getValueAPF().convertToDouble(); + else { + bool unused; + APFloat APF = Op1->getValueAPF(); + APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, &unused); + Op1V = APF.convertToDouble(); + } + if (ConstantFP *Op2 = dyn_cast(Operands[1])) { if (Op2->getType() != Op1->getType()) return 0; - - double Op2V = Ty->isFloatTy() ? - (double)Op2->getValueAPF().convertToFloat(): - Op2->getValueAPF().convertToDouble(); - if (Name == "pow") + double Op2V; + if (Ty->isFloatTy()) + Op2V = Op2->getValueAPF().convertToFloat(); + else if (Ty->isDoubleTy()) + Op2V = Op2->getValueAPF().convertToDouble(); + else { + bool unused; + APFloat APF = Op2->getValueAPF(); + APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, &unused); + Op2V = APF.convertToDouble(); + } + + if (F->getIntrinsicID() == Intrinsic::pow) { + return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty); + } + if (!TLI) + return 0; + if (Name == "pow" && TLI->has(LibFunc::pow)) return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty); - if (Name == "fmod") + if (Name == "fmod" && TLI->has(LibFunc::fmod)) return ConstantFoldBinaryFP(fmod, Op1V, Op2V, Ty); - if (Name == "atan2") + if (Name == "atan2" && TLI->has(LibFunc::atan2)) return ConstantFoldBinaryFP(atan2, Op1V, Op2V, Ty); } else if (ConstantInt *Op2C = dyn_cast(Operands[1])) { + if (F->getIntrinsicID() == Intrinsic::powi && Ty->isHalfTy()) + return ConstantFP::get(F->getContext(), + APFloat((float)std::pow((float)Op1V, + (int)Op2C->getZExtValue()))); if (F->getIntrinsicID() == Intrinsic::powi && Ty->isFloatTy()) return ConstantFP::get(F->getContext(), APFloat((float)std::pow((float)Op1V, @@ -1360,8 +1531,7 @@ llvm::ConstantFoldCall(Function *F, } return 0; } - - + if (ConstantInt *Op1 = dyn_cast(Operands[0])) { if (ConstantInt *Op2 = dyn_cast(Operands[1])) { switch (F->getIntrinsicID()) { @@ -1375,7 +1545,7 @@ llvm::ConstantFoldCall(Function *F, APInt Res; bool Overflow; switch (F->getIntrinsicID()) { - default: assert(0 && "Invalid case"); + default: llvm_unreachable("Invalid case"); case Intrinsic::sadd_with_overflow: Res = Op1->getValue().sadd_ov(Op2->getValue(), Overflow); break; @@ -1401,9 +1571,17 @@ llvm::ConstantFoldCall(Function *F, }; return ConstantStruct::get(cast(F->getReturnType()), Ops); } + case Intrinsic::cttz: + if (Op2->isOne() && Op1->isZero()) // cttz(0, 1) is undef. + return UndefValue::get(Ty); + return ConstantInt::get(Ty, Op1->getValue().countTrailingZeros()); + case Intrinsic::ctlz: + if (Op2->isOne() && Op1->isZero()) // ctlz(0, 1) is undef. + return UndefValue::get(Ty); + return ConstantInt::get(Ty, Op1->getValue().countLeadingZeros()); } } - + return 0; } return 0;