X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FAnalysis%2FConstantFolding.cpp;h=5582bfbe8eec0b141962e38e205c402146402222;hb=0df66b878ff02ddb051bdc7c08af0511f1a3c3c3;hp=4b4fa5cd4ea9c94dfc1eacca0d7f32d43e9ce0ef;hpb=e5742464895b7f1fcc6a5b968b72f6ec66a1fd44;p=oota-llvm.git diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp index 4b4fa5cd4ea..5582bfbe8ee 100644 --- a/lib/Analysis/ConstantFolding.cpp +++ b/lib/Analysis/ConstantFolding.cpp @@ -17,50 +17,56 @@ //===----------------------------------------------------------------------===// #include "llvm/Analysis/ConstantFolding.h" +#include "llvm/ADT/SmallPtrSet.h" #include "llvm/ADT/SmallVector.h" #include "llvm/ADT/StringMap.h" +#include "llvm/Analysis/TargetLibraryInfo.h" #include "llvm/Analysis/ValueTracking.h" +#include "llvm/Config/config.h" #include "llvm/IR/Constants.h" #include "llvm/IR/DataLayout.h" #include "llvm/IR/DerivedTypes.h" #include "llvm/IR/Function.h" +#include "llvm/IR/GetElementPtrTypeIterator.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/Target/TargetLibraryInfo.h" #include #include + +#ifdef HAVE_FENV_H +#include +#endif + using namespace llvm; //===----------------------------------------------------------------------===// // Constant Folding internal helper functions //===----------------------------------------------------------------------===// -/// FoldBitCast - Constant fold bitcast, symbolically evaluating it with -/// DataLayout. This always returns a non-null constant, but it may be a +/// 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, 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()) + if (C->isAllOnesValue() && !DestTy->isX86_MMXTy() && + !DestTy->isPtrOrPtrVectorTy()) // Don't get ones for ptr types! return Constant::getAllOnesValue(DestTy); // Handle a vector->integer cast. if (IntegerType *IT = dyn_cast(DestTy)) { - ConstantDataVector *CDV = dyn_cast(C); - if (CDV == 0) + VectorType *VTy = dyn_cast(C->getType()); + if (!VTy) return ConstantExpr::getBitCast(C, DestTy); - unsigned NumSrcElts = CDV->getType()->getNumElements(); - - Type *SrcEltTy = CDV->getType()->getElementType(); + 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. @@ -70,9 +76,12 @@ static Constant *FoldBitCast(Constant *C, Type *DestTy, VectorType::get(IntegerType::get(C->getContext(), FPWidth), NumSrcElts); // Ask IR to do the conversion now that #elts line up. C = ConstantExpr::getBitCast(C, SrcIVTy); - CDV = cast(C); } + ConstantDataVector *CDV = dyn_cast(C); + if (!CDV) + 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); @@ -90,7 +99,7 @@ static Constant *FoldBitCast(Constant *C, Type *DestTy, // The code below only handles casts to vectors currently. VectorType *DestVTy = dyn_cast(DestTy); - if (DestVTy == 0) + if (!DestVTy) return ConstantExpr::getBitCast(C, DestTy); // If this is a scalar -> vector cast, convert the input into a <1 x scalar> @@ -189,7 +198,7 @@ static Constant *FoldBitCast(Constant *C, Type *DestTy, // Handle: bitcast (<2 x i64> to <4 x i32>) unsigned Ratio = NumDstElt/NumSrcElt; - unsigned DstBitSize = DstEltTy->getPrimitiveSizeInBits(); + unsigned DstBitSize = TD.getTypeSizeInBits(DstEltTy); // Loop over each source value, expanding into multiple results. for (unsigned i = 0; i != NumSrcElt; ++i) { @@ -205,6 +214,15 @@ static Constant *FoldBitCast(Constant *C, Type *DestTy, ConstantInt::get(Src->getType(), ShiftAmt)); ShiftAmt += isLittleEndian ? DstBitSize : -DstBitSize; + // Truncate the element to an integer with the same pointer size and + // convert the element back to a pointer using a inttoptr. + if (DstEltTy->isPointerTy()) { + IntegerType *DstIntTy = Type::getIntNTy(C->getContext(), DstBitSize); + Constant *CE = ConstantExpr::getTrunc(Elt, DstIntTy); + Result.push_back(ConstantExpr::getIntToPtr(CE, DstEltTy)); + continue; + } + // Truncate and remember this piece. Result.push_back(ConstantExpr::getTrunc(Elt, DstEltTy)); } @@ -214,14 +232,14 @@ static Constant *FoldBitCast(Constant *C, Type *DestTy, } -/// IsConstantOffsetFromGlobal - If this constant is actually a constant offset -/// from a global, return the global and the constant. Because of -/// constantexprs, this function is recursive. +/// If this constant is a constant offset from a global, return the global and +/// the constant. Because of constantexprs, this function is recursive. static bool IsConstantOffsetFromGlobal(Constant *C, GlobalValue *&GV, APInt &Offset, const DataLayout &TD) { // Trivial case, constant is the global. if ((GV = dyn_cast(C))) { - Offset.clearAllBits(); + unsigned BitWidth = TD.getPointerTypeSizeInBits(GV->getType()); + Offset = APInt(BitWidth, 0); return true; } @@ -231,51 +249,34 @@ static bool IsConstantOffsetFromGlobal(Constant *C, GlobalValue *&GV, // Look through ptr->int and ptr->ptr casts. if (CE->getOpcode() == Instruction::PtrToInt || - CE->getOpcode() == Instruction::BitCast) + CE->getOpcode() == Instruction::BitCast || + CE->getOpcode() == Instruction::AddrSpaceCast) 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; + GEPOperator *GEP = dyn_cast(CE); + if (!GEP) + return false; - // If the base isn't a global+constant, we aren't either. - if (!IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, TD)) - return false; + unsigned BitWidth = TD.getPointerTypeSizeInBits(GEP->getType()); + APInt TmpOffset(BitWidth, 0); - // 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 (StructType *ST = dyn_cast(*GTI)) { - // N = N + Offset - Offset += - APInt(Offset.getBitWidth(), - TD.getStructLayout(ST)->getElementOffset(CI->getZExtValue())); - } else { - SequentialType *SQT = cast(*GTI); - Offset += APInt(Offset.getBitWidth(), - TD.getTypeAllocSize(SQT->getElementType()) * - CI->getSExtValue()); - } - } - return true; - } + // If the base isn't a global+constant, we aren't either. + if (!IsConstantOffsetFromGlobal(CE->getOperand(0), GV, TmpOffset, TD)) + return false; - return false; + // Otherwise, add any offset that our operands provide. + if (!GEP->accumulateConstantOffset(TD, TmpOffset)) + return false; + + Offset = TmpOffset; + return true; } -/// ReadDataFromGlobal - Recursive helper to read bits out of global. C is the -/// constant being copied out of. ByteOffset is an offset into C. CurPtr is the -/// pointer to copy results into and BytesLeft is the number of bytes left in -/// the CurPtr buffer. TD is the target data. +/// Recursive helper to read bits out of global. C is the constant being copied +/// out of. ByteOffset is an offset into C. CurPtr is the pointer to copy +/// results into and BytesLeft is the number of bytes left in +/// the CurPtr buffer. TD is the target data. static bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset, unsigned char *CurPtr, unsigned BytesLeft, const DataLayout &TD) { @@ -314,6 +315,10 @@ 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; } @@ -342,12 +347,12 @@ static bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset, // If we read all of the bytes we needed from this element we're done. uint64_t NextEltOffset = SL->getElementOffset(Index); - if (BytesLeft <= NextEltOffset-CurEltOffset-ByteOffset) + if (BytesLeft <= NextEltOffset - CurEltOffset - ByteOffset) return true; // Move to the next element of the struct. - CurPtr += NextEltOffset-CurEltOffset-ByteOffset; - BytesLeft -= NextEltOffset-CurEltOffset-ByteOffset; + CurPtr += NextEltOffset - CurEltOffset - ByteOffset; + BytesLeft -= NextEltOffset - CurEltOffset - ByteOffset; ByteOffset = 0; CurEltOffset = NextEltOffset; } @@ -356,7 +361,7 @@ static bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset, if (isa(C) || isa(C) || isa(C)) { - Type *EltTy = cast(C->getType())->getElementType(); + Type *EltTy = C->getType()->getSequentialElementType(); uint64_t EltSize = TD.getTypeAllocSize(EltTy); uint64_t Index = ByteOffset / EltSize; uint64_t Offset = ByteOffset - Index * EltSize; @@ -364,7 +369,7 @@ static bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset, if (ArrayType *AT = dyn_cast(C->getType())) NumElts = AT->getNumElements(); else - NumElts = cast(C->getType())->getNumElements(); + NumElts = C->getType()->getVectorNumElements(); for (; Index != NumElts; ++Index) { if (!ReadDataFromGlobal(C->getAggregateElement(Index), Offset, CurPtr, @@ -385,9 +390,10 @@ static bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset, if (ConstantExpr *CE = dyn_cast(C)) { if (CE->getOpcode() == Instruction::IntToPtr && - CE->getOperand(0)->getType() == TD.getIntPtrType(CE->getContext())) + CE->getOperand(0)->getType() == TD.getIntPtrType(CE->getType())) { return ReadDataFromGlobal(CE->getOperand(0), ByteOffset, CurPtr, BytesLeft, TD); + } } // Otherwise, unknown initializer type. @@ -396,49 +402,56 @@ static bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset, static Constant *FoldReinterpretLoadFromConstPtr(Constant *C, const DataLayout &TD) { - Type *LoadTy = cast(C->getType())->getElementType(); + PointerType *PTy = cast(C->getType()); + Type *LoadTy = PTy->getElementType(); IntegerType *IntType = dyn_cast(LoadTy); // If this isn't an integer load we can't fold it directly. if (!IntType) { + unsigned AS = PTy->getAddressSpace(); + // 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. Type *MapTy; - if (LoadTy->isFloatTy()) - MapTy = Type::getInt32PtrTy(C->getContext()); + if (LoadTy->isHalfTy()) + MapTy = Type::getInt16PtrTy(C->getContext(), AS); + else if (LoadTy->isFloatTy()) + MapTy = Type::getInt32PtrTy(C->getContext(), AS); else if (LoadTy->isDoubleTy()) - MapTy = Type::getInt64PtrTy(C->getContext()); + MapTy = Type::getInt64PtrTy(C->getContext(), AS); else if (LoadTy->isVectorTy()) { - MapTy = IntegerType::get(C->getContext(), - TD.getTypeAllocSizeInBits(LoadTy)); - MapTy = PointerType::getUnqual(MapTy); + MapTy = PointerType::getIntNPtrTy(C->getContext(), + TD.getTypeAllocSizeInBits(LoadTy), + AS); } else - return 0; + return nullptr; C = FoldBitCast(C, MapTy, TD); if (Constant *Res = FoldReinterpretLoadFromConstPtr(C, TD)) return FoldBitCast(Res, LoadTy, TD); - return 0; + return nullptr; } unsigned BytesLoaded = (IntType->getBitWidth() + 7) / 8; - if (BytesLoaded > 32 || BytesLoaded == 0) return 0; + if (BytesLoaded > 32 || BytesLoaded == 0) + return nullptr; GlobalValue *GVal; - APInt Offset(TD.getPointerSizeInBits(), 0); + APInt Offset; if (!IsConstantOffsetFromGlobal(C, GVal, Offset, TD)) - return 0; + return nullptr; GlobalVariable *GV = dyn_cast(GVal); if (!GV || !GV->isConstant() || !GV->hasDefinitiveInitializer() || !GV->getInitializer()->getType()->isSized()) - return 0; + return nullptr; // 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.isNegative()) return 0; + if (Offset.isNegative()) + return nullptr; // If we're not accessing anything in this constant, the result is undefined. if (Offset.getZExtValue() >= @@ -448,14 +461,14 @@ static Constant *FoldReinterpretLoadFromConstPtr(Constant *C, unsigned char RawBytes[32] = {0}; if (!ReadDataFromGlobal(GV->getInitializer(), Offset.getZExtValue(), RawBytes, BytesLoaded, TD)) - return 0; + return nullptr; 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]; + ResultVal |= RawBytes[BytesLoaded - 1 - i]; } } else { ResultVal = RawBytes[0]; @@ -468,9 +481,54 @@ static Constant *FoldReinterpretLoadFromConstPtr(Constant *C, return ConstantInt::get(IntType->getContext(), ResultVal); } -/// ConstantFoldLoadFromConstPtr - Return the value that a load from C would -/// produce if it is constant and determinable. If this is not determinable, -/// return null. +static Constant *ConstantFoldLoadThroughBitcast(ConstantExpr *CE, + const DataLayout *DL) { + if (!DL) + return nullptr; + auto *DestPtrTy = dyn_cast(CE->getType()); + if (!DestPtrTy) + return nullptr; + Type *DestTy = DestPtrTy->getElementType(); + + Constant *C = ConstantFoldLoadFromConstPtr(CE->getOperand(0), DL); + if (!C) + return nullptr; + + do { + Type *SrcTy = C->getType(); + + // If the type sizes are the same and a cast is legal, just directly + // cast the constant. + if (DL->getTypeSizeInBits(DestTy) == DL->getTypeSizeInBits(SrcTy)) { + Instruction::CastOps Cast = Instruction::BitCast; + // If we are going from a pointer to int or vice versa, we spell the cast + // differently. + if (SrcTy->isIntegerTy() && DestTy->isPointerTy()) + Cast = Instruction::IntToPtr; + else if (SrcTy->isPointerTy() && DestTy->isIntegerTy()) + Cast = Instruction::PtrToInt; + + if (CastInst::castIsValid(Cast, C, DestTy)) + return ConstantExpr::getCast(Cast, C, DestTy); + } + + // If this isn't an aggregate type, there is nothing we can do to drill down + // and find a bitcastable constant. + if (!SrcTy->isAggregateType()) + return nullptr; + + // We're simulating a load through a pointer that was bitcast to point to + // a different type, so we can try to walk down through the initial + // elements of an aggregate to see if some part of th e aggregate is + // castable to implement the "load" semantic model. + C = C->getAggregateElement(0u); + } while (C); + + return nullptr; +} + +/// Return the value that a load from C would produce if it is constant and +/// determinable. If this is not determinable, return null. Constant *llvm::ConstantFoldLoadFromConstPtr(Constant *C, const DataLayout *TD) { // First, try the easy cases: @@ -480,16 +538,23 @@ 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) + return nullptr; if (CE->getOpcode() == Instruction::GetElementPtr) { - if (GlobalVariable *GV = dyn_cast(CE->getOperand(0))) - if (GV->isConstant() && GV->hasDefinitiveInitializer()) + if (GlobalVariable *GV = dyn_cast(CE->getOperand(0))) { + if (GV->isConstant() && GV->hasDefinitiveInitializer()) { if (Constant *V = ConstantFoldLoadThroughGEPConstantExpr(GV->getInitializer(), CE)) return V; + } + } } + if (CE->getOpcode() == Instruction::BitCast) + if (Constant *LoadedC = ConstantFoldLoadThroughBitcast(CE, TD)) + return LoadedC; + // Instead of loading constant c string, use corresponding integer value // directly if string length is small enough. StringRef Str; @@ -541,24 +606,24 @@ Constant *llvm::ConstantFoldLoadFromConstPtr(Constant *C, // Try hard to fold loads from bitcasted strange and non-type-safe things. if (TD) return FoldReinterpretLoadFromConstPtr(CE, *TD); - return 0; + return nullptr; } static Constant *ConstantFoldLoadInst(const LoadInst *LI, const DataLayout *TD){ - if (LI->isVolatile()) return 0; + if (LI->isVolatile()) return nullptr; if (Constant *C = dyn_cast(LI->getOperand(0))) return ConstantFoldLoadFromConstPtr(C, TD); - return 0; + return nullptr; } -/// SymbolicallyEvaluateBinop - One of Op0/Op1 is a constant expression. +/// 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 DataLayout *TD){ + Constant *Op1, const DataLayout *DL){ // SROA // Fold (and 0xffffffff00000000, (shl x, 32)) -> shl. @@ -566,39 +631,67 @@ static Constant *SymbolicallyEvaluateBinop(unsigned Opc, Constant *Op0, // 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); + computeKnownBits(Op0, KnownZero0, KnownOne0, DL); + computeKnownBits(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; - APInt Offs1(TD->getPointerSizeInBits(), 0), - Offs2(TD->getPointerSizeInBits(), 0); + APInt Offs1, Offs2; - if (IsConstantOffsetFromGlobal(Op0, GV1, Offs1, *TD)) - if (IsConstantOffsetFromGlobal(Op1, GV2, Offs2, *TD) && + if (IsConstantOffsetFromGlobal(Op0, GV1, Offs1, *DL)) + if (IsConstantOffsetFromGlobal(Op1, GV2, Offs2, *DL) && GV1 == GV2) { + unsigned OpSize = DL->getTypeSizeInBits(Op0->getType()); + // (&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; + return nullptr; } -/// CastGEPIndices - If array indices are not pointer-sized integers, -/// explicitly cast them so that they aren't implicitly casted by the -/// getelementptr. +/// If array indices are not pointer-sized integers, explicitly cast them so +/// that they aren't implicitly casted by the getelementptr. static Constant *CastGEPIndices(ArrayRef Ops, Type *ResultTy, const DataLayout *TD, const TargetLibraryInfo *TLI) { - if (!TD) return 0; - Type *IntPtrTy = TD->getIntPtrType(ResultTy->getContext()); + if (!TD) + return nullptr; + + Type *IntPtrTy = TD->getIntPtrType(ResultTy); bool Any = false; SmallVector NewIdxs; for (unsigned i = 1, e = Ops.size(); i != e; ++i) { if ((i == 1 || - !isa(GetElementPtrInst::getIndexedType(Ops[0]->getType(), - Ops.slice(1, i-1)))) && + !isa(GetElementPtrInst::getIndexedType( + Ops[0]->getType(), + Ops.slice(1, i - 1)))) && Ops[i]->getType() != IntPtrTy) { Any = true; NewIdxs.push_back(ConstantExpr::getCast(CastInst::getCastOpcode(Ops[i], @@ -609,13 +702,16 @@ static Constant *CastGEPIndices(ArrayRef Ops, } else NewIdxs.push_back(Ops[i]); } - if (!Any) return 0; - Constant *C = - ConstantExpr::getGetElementPtr(Ops[0], NewIdxs); - if (ConstantExpr *CE = dyn_cast(C)) + if (!Any) + return nullptr; + + Constant *C = ConstantExpr::getGetElementPtr(Ops[0], NewIdxs); + if (ConstantExpr *CE = dyn_cast(C)) { if (Constant *Folded = ConstantFoldConstantExpression(CE, TD, TLI)) C = Folded; + } + return C; } @@ -623,29 +719,29 @@ static Constant *CastGEPIndices(ArrayRef Ops, static Constant* StripPtrCastKeepAS(Constant* Ptr) { assert(Ptr->getType()->isPointerTy() && "Not a pointer type"); PointerType *OldPtrTy = cast(Ptr->getType()); - Ptr = cast(Ptr->stripPointerCasts()); + Ptr = 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); + Ptr = ConstantExpr::getPointerCast(Ptr, NewPtrTy); } return Ptr; } -/// SymbolicallyEvaluateGEP - If we can symbolically evaluate the specified GEP -/// constant expression, do so. +/// If we can symbolically evaluate the GEP constant expression, do so. 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 || !Ptr->getType()->getPointerElementType()->isSized() || !Ptr->getType()->isPointerTy()) - return 0; + return nullptr; - Type *IntPtrTy = TD->getIntPtrType(Ptr->getContext()); + Type *IntPtrTy = TD->getIntPtrType(Ptr->getType()); + Type *ResultElementTy = ResultTy->getPointerElementType(); // 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' @@ -654,10 +750,9 @@ static Constant *SymbolicallyEvaluateGEP(ArrayRef Ops, // If this is "gep i8* Ptr, (sub 0, V)", fold this as: // "inttoptr (sub (ptrtoint Ptr), V)" - if (Ops.size() == 2 && - cast(ResultTy)->getElementType()->isIntegerTy(8)) { + if (Ops.size() == 2 && ResultElementTy->isIntegerTy(8)) { ConstantExpr *CE = dyn_cast(Ops[1]); - assert((CE == 0 || CE->getType() == IntPtrTy) && + assert((!CE || CE->getType() == IntPtrTy) && "CastGEPIndices didn't canonicalize index types!"); if (CE && CE->getOpcode() == Instruction::Sub && CE->getOperand(0)->isNullValue()) { @@ -669,7 +764,7 @@ static Constant *SymbolicallyEvaluateGEP(ArrayRef Ops, return Res; } } - return 0; + return nullptr; } unsigned BitWidth = TD->getTypeSizeInBits(IntPtrTy); @@ -682,7 +777,7 @@ static Constant *SymbolicallyEvaluateGEP(ArrayRef Ops, // If this is a GEP of a GEP, fold it all into a single GEP. while (GEPOperator *GEP = dyn_cast(Ptr)) { - SmallVector NestedOps(GEP->op_begin()+1, GEP->op_end()); + SmallVector NestedOps(GEP->op_begin() + 1, GEP->op_end()); // Do not try the incorporate the sub-GEP if some index is not a number. bool AllConstantInt = true; @@ -703,12 +798,15 @@ static Constant *SymbolicallyEvaluateGEP(ArrayRef Ops, // If the base value for this address is a literal integer value, fold the // getelementptr to the resulting integer value casted to the pointer type. APInt BasePtr(BitWidth, 0); - if (ConstantExpr *CE = dyn_cast(Ptr)) - if (CE->getOpcode() == Instruction::IntToPtr) + if (ConstantExpr *CE = dyn_cast(Ptr)) { + if (CE->getOpcode() == Instruction::IntToPtr) { if (ConstantInt *Base = dyn_cast(CE->getOperand(0))) BasePtr = Base->getValue().zextOrTrunc(BitWidth); + } + } + if (Ptr->isNullValue() || BasePtr != 0) { - Constant *C = ConstantInt::get(Ptr->getContext(), Offset+BasePtr); + Constant *C = ConstantInt::get(Ptr->getContext(), Offset + BasePtr); return ConstantExpr::getIntToPtr(C, ResultTy); } @@ -718,7 +816,8 @@ static Constant *SymbolicallyEvaluateGEP(ArrayRef Ops, // Also, this helps GlobalOpt do SROA on GlobalVariables. Type *Ty = Ptr->getType(); assert(Ty->isPointerTy() && "Forming regular GEP of non-pointer type"); - SmallVector NewIdxs; + SmallVector NewIdxs; + do { if (SequentialType *ATy = dyn_cast(Ty)) { if (ATy->isPointerTy()) { @@ -728,12 +827,11 @@ static Constant *SymbolicallyEvaluateGEP(ArrayRef Ops, // Only handle pointers to sized types, not pointers to functions. if (!ATy->getElementType()->isSized()) - return 0; + return nullptr; } // Determine which element of the array the offset points into. APInt ElemSize(BitWidth, TD->getTypeAllocSize(ATy->getElementType())); - 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 @@ -768,23 +866,22 @@ static Constant *SymbolicallyEvaluateGEP(ArrayRef Ops, // We've reached some non-indexable type. break; } - } while (Ty != cast(ResultTy)->getElementType()); + } while (Ty != ResultElementTy); // If we haven't used up the entire offset by descending the static // type, then the offset is pointing into the middle of an indivisible // member, so we can't simplify it. if (Offset != 0) - return 0; + return nullptr; // Create a GEP. - Constant *C = - ConstantExpr::getGetElementPtr(Ptr, NewIdxs); - assert(cast(C->getType())->getElementType() == Ty && + Constant *C = ConstantExpr::getGetElementPtr(Ptr, NewIdxs); + assert(C->getType()->getPointerElementType() == Ty && "Computed GetElementPtr has unexpected type!"); // If we ended up indexing a member with a type that doesn't match // the type of what the original indices indexed, add a cast. - if (Ty != cast(ResultTy)->getElementType()) + if (Ty != ResultElementTy) C = FoldBitCast(C, ResultTy, *TD); return C; @@ -796,7 +893,7 @@ static Constant *SymbolicallyEvaluateGEP(ArrayRef Ops, // Constant Folding public APIs //===----------------------------------------------------------------------===// -/// ConstantFoldInstruction - Try to constant fold the specified instruction. +/// Try to constant fold the specified instruction. /// If successful, the constant result is returned, if not, null is returned. /// 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 @@ -806,7 +903,7 @@ Constant *llvm::ConstantFoldInstruction(Instruction *I, const TargetLibraryInfo *TLI) { // Handle PHI nodes quickly here... if (PHINode *PN = dyn_cast(I)) { - Constant *CommonValue = 0; + Constant *CommonValue = nullptr; for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) { Value *Incoming = PN->getIncomingValue(i); @@ -819,14 +916,14 @@ Constant *llvm::ConstantFoldInstruction(Instruction *I, // If the incoming value is not a constant, then give up. Constant *C = dyn_cast(Incoming); if (!C) - return 0; + return nullptr; // 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; + return nullptr; CommonValue = C; } @@ -841,7 +938,7 @@ Constant *llvm::ConstantFoldInstruction(Instruction *I, 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! + return nullptr; // All operands not constant! // Fold the Instruction's operands. if (ConstantExpr *NewCE = dyn_cast(Op)) @@ -857,33 +954,36 @@ Constant *llvm::ConstantFoldInstruction(Instruction *I, if (const LoadInst *LI = dyn_cast(I)) return ConstantFoldLoadInst(LI, TD); - if (InsertValueInst *IVI = dyn_cast(I)) + if (InsertValueInst *IVI = dyn_cast(I)) { return ConstantExpr::getInsertValue( cast(IVI->getAggregateOperand()), cast(IVI->getInsertedValueOperand()), IVI->getIndices()); + } - if (ExtractValueInst *EVI = dyn_cast(I)) + if (ExtractValueInst *EVI = dyn_cast(I)) { return ConstantExpr::getExtractValue( cast(EVI->getAggregateOperand()), EVI->getIndices()); + } return ConstantFoldInstOperands(I->getOpcode(), I->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) { - 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, + SmallPtrSetImpl &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, TLI); + // 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).second) + NewC = ConstantFoldConstantExpressionImpl(NewCE, TD, TLI, FoldedOps); + } Ops.push_back(NewC); } @@ -893,7 +993,17 @@ Constant *llvm::ConstantFoldConstantExpression(const ConstantExpr *CE, return ConstantFoldInstOperands(CE->getOpcode(), CE->getType(), Ops, TD, TLI); } -/// ConstantFoldInstOperands - Attempt to constant fold an instruction with the +/// 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); +} + +/// Attempt to constant fold an instruction with the /// specified opcode and operands. If successful, the constant result is /// returned, if not, null is returned. Note that this function can fail when /// attempting to fold instructions like loads and stores, which have no @@ -909,22 +1019,23 @@ Constant *llvm::ConstantFoldInstOperands(unsigned Opcode, Type *DestTy, const TargetLibraryInfo *TLI) { // Handle easy binops first. if (Instruction::isBinaryOp(Opcode)) { - if (isa(Ops[0]) || isa(Ops[1])) + 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; + default: return nullptr; case Instruction::ICmp: case Instruction::FCmp: llvm_unreachable("Invalid for compares"); case Instruction::Call: if (Function *F = dyn_cast(Ops.back())) if (canConstantFoldCallTo(F)) return ConstantFoldCall(F, Ops.slice(0, Ops.size() - 1), TLI); - return 0; + return nullptr; case Instruction::PtrToInt: // If the input is a inttoptr, eliminate the pair. This requires knowing // the width of a pointer, so it can't be done in ConstantExpr::getCast. @@ -932,10 +1043,11 @@ Constant *llvm::ConstantFoldInstOperands(unsigned Opcode, Type *DestTy, if (TD && CE->getOpcode() == Instruction::IntToPtr) { Constant *Input = CE->getOperand(0); unsigned InWidth = Input->getType()->getScalarSizeInBits(); - if (TD->getPointerSizeInBits() < InWidth) { + unsigned PtrWidth = TD->getPointerTypeSizeInBits(CE->getType()); + if (PtrWidth < InWidth) { Constant *Mask = - ConstantInt::get(CE->getContext(), APInt::getLowBitsSet(InWidth, - TD->getPointerSizeInBits())); + ConstantInt::get(CE->getContext(), + APInt::getLowBitsSet(InWidth, PtrWidth)); Input = ConstantExpr::getAnd(Input, Mask); } // Do a zext or trunc to get to the dest size. @@ -945,13 +1057,22 @@ Constant *llvm::ConstantFoldInstOperands(unsigned Opcode, Type *DestTy, return ConstantExpr::getCast(Opcode, Ops[0], DestTy); case Instruction::IntToPtr: // If the input is a ptrtoint, turn the pair into a ptr to ptr bitcast if - // the int size is >= the ptr size. This requires knowing the width of a - // pointer, so it can't be done in ConstantExpr::getCast. - if (ConstantExpr *CE = dyn_cast(Ops[0])) - if (TD && - TD->getPointerSizeInBits() <= CE->getType()->getScalarSizeInBits() && - CE->getOpcode() == Instruction::PtrToInt) - return FoldBitCast(CE->getOperand(0), DestTy, *TD); + // the int size is >= the ptr size and the address spaces are the same. + // This requires knowing the width of a pointer, so it can't be done in + // ConstantExpr::getCast. + if (ConstantExpr *CE = dyn_cast(Ops[0])) { + if (TD && CE->getOpcode() == Instruction::PtrToInt) { + Constant *SrcPtr = CE->getOperand(0); + unsigned SrcPtrSize = TD->getPointerTypeSizeInBits(SrcPtr->getType()); + unsigned MidIntSize = CE->getType()->getScalarSizeInBits(); + + if (MidIntSize >= SrcPtrSize) { + unsigned SrcAS = SrcPtr->getType()->getPointerAddressSpace(); + if (SrcAS == DestTy->getPointerAddressSpace()) + return FoldBitCast(CE->getOperand(0), DestTy, *TD); + } + } + } return ConstantExpr::getCast(Opcode, Ops[0], DestTy); case Instruction::Trunc: @@ -963,6 +1084,7 @@ Constant *llvm::ConstantFoldInstOperands(unsigned Opcode, Type *DestTy, case Instruction::SIToFP: case Instruction::FPToUI: case Instruction::FPToSI: + case Instruction::AddrSpaceCast: return ConstantExpr::getCast(Opcode, Ops[0], DestTy); case Instruction::BitCast: if (TD) @@ -986,10 +1108,9 @@ Constant *llvm::ConstantFoldInstOperands(unsigned Opcode, Type *DestTy, } } -/// ConstantFoldCompareInstOperands - Attempt to constant fold a compare +/// Attempt to constant fold a compare /// instruction (icmp/fcmp) with the specified operands. If it fails, it /// returns a constant expression of the specified operands. -/// Constant *llvm::ConstantFoldCompareInstOperands(unsigned Predicate, Constant *Ops0, Constant *Ops1, const DataLayout *TD, @@ -1003,8 +1124,8 @@ Constant *llvm::ConstantFoldCompareInstOperands(unsigned Predicate, // around to know if bit truncation is happening. if (ConstantExpr *CE0 = dyn_cast(Ops0)) { if (TD && Ops1->isNullValue()) { - Type *IntPtrTy = TD->getIntPtrType(CE0->getContext()); if (CE0->getOpcode() == Instruction::IntToPtr) { + Type *IntPtrTy = TD->getIntPtrType(CE0->getType()); // Convert the integer value to the right size to ensure we get the // proper extension or truncation. Constant *C = ConstantExpr::getIntegerCast(CE0->getOperand(0), @@ -1015,19 +1136,21 @@ Constant *llvm::ConstantFoldCompareInstOperands(unsigned Predicate, // 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 && - CE0->getType() == IntPtrTy) { - Constant *C = CE0->getOperand(0); - Constant *Null = Constant::getNullValue(C->getType()); - return ConstantFoldCompareInstOperands(Predicate, C, Null, TD, TLI); + if (CE0->getOpcode() == Instruction::PtrToInt) { + Type *IntPtrTy = TD->getIntPtrType(CE0->getOperand(0)->getType()); + if (CE0->getType() == IntPtrTy) { + Constant *C = CE0->getOperand(0); + Constant *Null = Constant::getNullValue(C->getType()); + return ConstantFoldCompareInstOperands(Predicate, C, Null, TD, TLI); + } } } if (ConstantExpr *CE1 = dyn_cast(Ops1)) { if (TD && CE0->getOpcode() == CE1->getOpcode()) { - Type *IntPtrTy = TD->getIntPtrType(CE0->getContext()); - if (CE0->getOpcode() == Instruction::IntToPtr) { + Type *IntPtrTy = TD->getIntPtrType(CE0->getType()); + // Convert the integer value to the right size to ensure we get the // proper extension or truncation. Constant *C0 = ConstantExpr::getIntegerCast(CE0->getOperand(0), @@ -1039,11 +1162,17 @@ Constant *llvm::ConstantFoldCompareInstOperands(unsigned Predicate, // 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 && - CE0->getType() == IntPtrTy && - CE0->getOperand(0)->getType() == CE1->getOperand(0)->getType())) - return ConstantFoldCompareInstOperands(Predicate, CE0->getOperand(0), - CE1->getOperand(0), TD, TLI); + if (CE0->getOpcode() == Instruction::PtrToInt) { + Type *IntPtrTy = TD->getIntPtrType(CE0->getOperand(0)->getType()); + if (CE0->getType() == IntPtrTy && + CE0->getOperand(0)->getType() == CE1->getOperand(0)->getType()) { + return ConstantFoldCompareInstOperands(Predicate, + CE0->getOperand(0), + CE1->getOperand(0), + TD, + TLI); + } + } } } @@ -1068,34 +1197,35 @@ 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. +/// 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, ConstantExpr *CE) { if (!CE->getOperand(1)->isNullValue()) - return 0; // Do not allow stepping over the value! + return nullptr; // Do not allow stepping over the value! // Loop over all of the operands, tracking down which value we are // addressing. for (unsigned i = 2, e = CE->getNumOperands(); i != e; ++i) { C = C->getAggregateElement(CE->getOperand(i)); - if (C == 0) return 0; + if (!C) + return nullptr; } 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. +/// 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; + if (!C) + return nullptr; } return C; } @@ -1105,11 +1235,19 @@ Constant *llvm::ConstantFoldLoadThroughGEPIndices(Constant *C, // Constant Folding for Calls // -/// canConstantFoldCallTo - Return true if its even possible to fold a call to -/// the specified function. -bool -llvm::canConstantFoldCallTo(const Function *F) { +/// Return true if it's even possible to fold a call to the specified function. +bool llvm::canConstantFoldCallTo(const Function *F) { switch (F->getIntrinsicID()) { + case Intrinsic::fabs: + case Intrinsic::minnum: + case Intrinsic::maxnum: + case Intrinsic::log: + case Intrinsic::log2: + case Intrinsic::log10: + case Intrinsic::exp: + case Intrinsic::exp2: + case Intrinsic::floor: + case Intrinsic::ceil: case Intrinsic::sqrt: case Intrinsic::pow: case Intrinsic::powi: @@ -1117,6 +1255,10 @@ llvm::canConstantFoldCallTo(const Function *F) { case Intrinsic::ctpop: case Intrinsic::ctlz: case Intrinsic::cttz: + case Intrinsic::fma: + case Intrinsic::fmuladd: + case Intrinsic::copysign: + case Intrinsic::round: case Intrinsic::sadd_with_overflow: case Intrinsic::uadd_with_overflow: case Intrinsic::ssub_with_overflow: @@ -1139,7 +1281,8 @@ llvm::canConstantFoldCallTo(const Function *F) { case 0: break; } - if (!F->hasName()) return false; + if (!F->hasName()) + return false; StringRef Name = F->getName(); // In these cases, the check of the length is required. We don't want to @@ -1148,8 +1291,7 @@ llvm::canConstantFoldCallTo(const Function *F) { 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': @@ -1168,50 +1310,78 @@ llvm::canConstantFoldCallTo(const Function *F) { } } -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; +static Constant *GetConstantFoldFPValue(double V, Type *Ty) { + 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"); + llvm_unreachable("Can only constant fold half/float/double"); + +} + +namespace { +/// Clear the floating-point exception state. +static inline void llvm_fenv_clearexcept() { +#if defined(HAVE_FENV_H) && HAVE_DECL_FE_ALL_EXCEPT + feclearexcept(FE_ALL_EXCEPT); +#endif + errno = 0; +} + +/// Test if a floating-point exception was raised. +static inline bool llvm_fenv_testexcept() { + int errno_val = errno; + if (errno_val == ERANGE || errno_val == EDOM) + return true; +#if defined(HAVE_FENV_H) && HAVE_DECL_FE_ALL_EXCEPT && HAVE_DECL_FE_INEXACT + if (fetestexcept(FE_ALL_EXCEPT & ~FE_INEXACT)) + return true; +#endif + return false; +} +} // End namespace + +static Constant *ConstantFoldFP(double (*NativeFP)(double), double V, + Type *Ty) { + llvm_fenv_clearexcept(); + V = NativeFP(V); + if (llvm_fenv_testexcept()) { + llvm_fenv_clearexcept(); + return nullptr; + } + + return GetConstantFoldFPValue(V, Ty); } static Constant *ConstantFoldBinaryFP(double (*NativeFP)(double, double), double V, double W, Type *Ty) { - sys::llvm_fenv_clearexcept(); + llvm_fenv_clearexcept(); V = NativeFP(V, W); - if (sys::llvm_fenv_testexcept()) { - sys::llvm_fenv_clearexcept(); - return 0; + if (llvm_fenv_testexcept()) { + llvm_fenv_clearexcept(); + return nullptr; } - 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 GetConstantFoldFPValue(V, Ty); } -/// ConstantFoldConvertToInt - Attempt to an SSE floating point to integer -/// conversion of a constant floating point. If roundTowardZero is false, the -/// default IEEE rounding is used (toward nearest, ties to even). This matches -/// the behavior of the non-truncating SSE instructions in the default rounding -/// mode. The desired integer type Ty is used to select how many bits are -/// available for the result. Returns null if the conversion cannot be -/// performed, otherwise returns the Constant value resulting from the -/// conversion. +/// Attempt to fold an SSE floating point to integer conversion of a constant +/// floating point. If roundTowardZero is false, the default IEEE rounding is +/// used (toward nearest, ties to even). This matches the behavior of the +/// non-truncating SSE instructions in the default rounding mode. The desired +/// integer type Ty is used to select how many bits are available for the +/// result. Returns null if the conversion cannot be performed, otherwise +/// returns the Constant value resulting from the conversion. 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(); + unsigned ResultWidth = Ty->getIntegerBitWidth(); assert(ResultWidth <= 64 && "Can only constant fold conversions to 64 and 32 bit ints"); @@ -1223,47 +1393,83 @@ static Constant *ConstantFoldConvertToInt(const APFloat &Val, /*isSigned=*/true, mode, &isExact); if (status != APFloat::opOK && status != APFloat::opInexact) - return 0; + return nullptr; return ConstantInt::get(Ty, UIntVal, /*isSigned=*/true); } -/// ConstantFoldCall - Attempt to constant fold a call to the specified function -/// with the specified arguments, returning null if unsuccessful. -Constant * -llvm::ConstantFoldCall(Function *F, ArrayRef Operands, - const TargetLibraryInfo *TLI) { - if (!F->hasName()) return 0; - StringRef Name = F->getName(); +static double getValueAsDouble(ConstantFP *Op) { + Type *Ty = Op->getType(); - Type *Ty = F->getReturnType(); + if (Ty->isFloatTy()) + return Op->getValueAPF().convertToFloat(); + + if (Ty->isDoubleTy()) + return Op->getValueAPF().convertToDouble(); + + bool unused; + APFloat APF = Op->getValueAPF(); + APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, &unused); + return APF.convertToDouble(); +} + +static Constant *ConstantFoldScalarCall(StringRef Name, unsigned IntrinsicID, + Type *Ty, ArrayRef Operands, + const TargetLibraryInfo *TLI) { if (Operands.size() == 1) { if (ConstantFP *Op = dyn_cast(Operands[0])) { - if (F->getIntrinsicID() == Intrinsic::convert_to_fp16) { + if (IntrinsicID == Intrinsic::convert_to_fp16) { APFloat Val(Op->getValueAPF()); bool lost = false; Val.convert(APFloat::IEEEhalf, APFloat::rmNearestTiesToEven, &lost); - return ConstantInt::get(F->getContext(), Val.bitcastToAPInt()); + return ConstantInt::get(Ty->getContext(), Val.bitcastToAPInt()); } - if (!TLI) - return 0; - if (!Ty->isFloatTy() && !Ty->isDoubleTy()) - return 0; + if (!Ty->isHalfTy() && !Ty->isFloatTy() && !Ty->isDoubleTy()) + return nullptr; + + if (IntrinsicID == Intrinsic::round) { + APFloat V = Op->getValueAPF(); + V.roundToIntegral(APFloat::rmNearestTiesToAway); + return ConstantFP::get(Ty->getContext(), V); + } /// We only fold functions with finite arguments. Folding NaN and inf is /// likely to be aborted with an exception anyway, and some host libms /// have known errors raising exceptions. if (Op->getValueAPF().isNaN() || Op->getValueAPF().isInfinity()) - return 0; + return nullptr; /// Currently APFloat versions of these functions do not exist, so we use /// 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 = getValueAsDouble(Op); + + switch (IntrinsicID) { + default: break; + case Intrinsic::fabs: + return ConstantFoldFP(fabs, V, Ty); + case Intrinsic::log2: + return ConstantFoldFP(log2, V, Ty); + case Intrinsic::log: + return ConstantFoldFP(log, V, Ty); + case Intrinsic::log10: + return ConstantFoldFP(log10, V, Ty); + case Intrinsic::exp: + return ConstantFoldFP(exp, V, Ty); + case Intrinsic::exp2: + return ConstantFoldFP(exp2, V, Ty); + case Intrinsic::floor: + return ConstantFoldFP(floor, V, Ty); + case Intrinsic::ceil: + return ConstantFoldFP(ceil, V, Ty); + } + + if (!TLI) + return nullptr; + switch (Name[0]) { case 'a': if (Name == "acos" && TLI->has(LibFunc::acos)) @@ -1304,12 +1510,18 @@ llvm::ConstantFoldCall(Function *F, ArrayRef Operands, return ConstantFoldFP(log, V, Ty); 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())) { + else if (IntrinsicID == Intrinsic::sqrt && + (Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy())) { if (V >= -0.0) return ConstantFoldFP(sqrt, V, Ty); - else // Undefined - return Constant::getNullValue(Ty); + else { + // Unlike the sqrt definitions in C/C++, POSIX, and IEEE-754 - which + // all guarantee or favor returning NaN - the square root of a + // negative number is not defined for the LLVM sqrt intrinsic. + // This is because the intrinsic should only be emitted in place of + // libm's sqrt function when using "no-nans-fp-math". + return UndefValue::get(Ty); + } } break; case 's': @@ -1333,13 +1545,13 @@ llvm::ConstantFoldCall(Function *F, ArrayRef Operands, default: break; } - return 0; + return nullptr; } if (ConstantInt *Op = dyn_cast(Operands[0])) { - switch (F->getIntrinsicID()) { + switch (IntrinsicID) { case Intrinsic::bswap: - return ConstantInt::get(F->getContext(), Op->getValue().byteSwap()); + return ConstantInt::get(Ty->getContext(), Op->getValue().byteSwap()); case Intrinsic::ctpop: return ConstantInt::get(Ty, Op->getValue().countPopulation()); case Intrinsic::convert_from_fp16: { @@ -1354,10 +1566,10 @@ llvm::ConstantFoldCall(Function *F, ArrayRef Operands, assert(status == APFloat::opOK && !lost && "Precision lost during fp16 constfolding"); - return ConstantFP::get(F->getContext(), Val); + return ConstantFP::get(Ty->getContext(), Val); } default: - return 0; + return nullptr; } } @@ -1365,7 +1577,7 @@ llvm::ConstantFoldCall(Function *F, ArrayRef Operands, if (isa(Operands[0]) || isa(Operands[0])) { Constant *Op = cast(Operands[0]); - switch (F->getIntrinsicID()) { + switch (IntrinsicID) { default: break; case Intrinsic::x86_sse_cvtss2si: case Intrinsic::x86_sse_cvtss2si64: @@ -1387,34 +1599,49 @@ llvm::ConstantFoldCall(Function *F, ArrayRef Operands, } if (isa(Operands[0])) { - if (F->getIntrinsicID() == Intrinsic::bswap) + if (IntrinsicID == Intrinsic::bswap) return Operands[0]; - return 0; + return nullptr; } - return 0; + return nullptr; } if (Operands.size() == 2) { if (ConstantFP *Op1 = dyn_cast(Operands[0])) { - if (!Ty->isFloatTy() && !Ty->isDoubleTy()) - return 0; - double Op1V = Ty->isFloatTy() ? - (double)Op1->getValueAPF().convertToFloat() : - Op1->getValueAPF().convertToDouble(); + if (!Ty->isHalfTy() && !Ty->isFloatTy() && !Ty->isDoubleTy()) + return nullptr; + double Op1V = getValueAsDouble(Op1); + 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(); + return nullptr; - if (F->getIntrinsicID() == Intrinsic::pow) { + double Op2V = getValueAsDouble(Op2); + if (IntrinsicID == Intrinsic::pow) { return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty); } + if (IntrinsicID == Intrinsic::copysign) { + APFloat V1 = Op1->getValueAPF(); + APFloat V2 = Op2->getValueAPF(); + V1.copySign(V2); + return ConstantFP::get(Ty->getContext(), V1); + } + + if (IntrinsicID == Intrinsic::minnum) { + const APFloat &C1 = Op1->getValueAPF(); + const APFloat &C2 = Op2->getValueAPF(); + return ConstantFP::get(Ty->getContext(), minnum(C1, C2)); + } + + if (IntrinsicID == Intrinsic::maxnum) { + const APFloat &C1 = Op1->getValueAPF(); + const APFloat &C2 = Op2->getValueAPF(); + return ConstantFP::get(Ty->getContext(), maxnum(C1, C2)); + } + if (!TLI) - return 0; + return nullptr; if (Name == "pow" && TLI->has(LibFunc::pow)) return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty); if (Name == "fmod" && TLI->has(LibFunc::fmod)) @@ -1422,21 +1649,25 @@ llvm::ConstantFoldCall(Function *F, ArrayRef Operands, 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->isFloatTy()) - return ConstantFP::get(F->getContext(), + if (IntrinsicID == Intrinsic::powi && Ty->isHalfTy()) + return ConstantFP::get(Ty->getContext(), APFloat((float)std::pow((float)Op1V, (int)Op2C->getZExtValue()))); - if (F->getIntrinsicID() == Intrinsic::powi && Ty->isDoubleTy()) - return ConstantFP::get(F->getContext(), + if (IntrinsicID == Intrinsic::powi && Ty->isFloatTy()) + return ConstantFP::get(Ty->getContext(), + APFloat((float)std::pow((float)Op1V, + (int)Op2C->getZExtValue()))); + if (IntrinsicID == Intrinsic::powi && Ty->isDoubleTy()) + return ConstantFP::get(Ty->getContext(), APFloat((double)std::pow((double)Op1V, (int)Op2C->getZExtValue()))); } - return 0; + return nullptr; } if (ConstantInt *Op1 = dyn_cast(Operands[0])) { if (ConstantInt *Op2 = dyn_cast(Operands[1])) { - switch (F->getIntrinsicID()) { + switch (IntrinsicID) { default: break; case Intrinsic::sadd_with_overflow: case Intrinsic::uadd_with_overflow: @@ -1446,7 +1677,7 @@ llvm::ConstantFoldCall(Function *F, ArrayRef Operands, case Intrinsic::umul_with_overflow: { APInt Res; bool Overflow; - switch (F->getIntrinsicID()) { + switch (IntrinsicID) { default: llvm_unreachable("Invalid case"); case Intrinsic::sadd_with_overflow: Res = Op1->getValue().sadd_ov(Op2->getValue(), Overflow); @@ -1468,10 +1699,10 @@ llvm::ConstantFoldCall(Function *F, ArrayRef Operands, break; } Constant *Ops[] = { - ConstantInt::get(F->getContext(), Res), - ConstantInt::get(Type::getInt1Ty(F->getContext()), Overflow) + ConstantInt::get(Ty->getContext(), Res), + ConstantInt::get(Type::getInt1Ty(Ty->getContext()), Overflow) }; - return ConstantStruct::get(cast(F->getReturnType()), Ops); + return ConstantStruct::get(cast(Ty), Ops); } case Intrinsic::cttz: if (Op2->isOne() && Op1->isZero()) // cttz(0, 1) is undef. @@ -1484,9 +1715,79 @@ llvm::ConstantFoldCall(Function *F, ArrayRef Operands, } } - return 0; + return nullptr; + } + return nullptr; + } + + if (Operands.size() != 3) + return nullptr; + + if (const ConstantFP *Op1 = dyn_cast(Operands[0])) { + if (const ConstantFP *Op2 = dyn_cast(Operands[1])) { + if (const ConstantFP *Op3 = dyn_cast(Operands[2])) { + switch (IntrinsicID) { + default: break; + case Intrinsic::fma: + case Intrinsic::fmuladd: { + APFloat V = Op1->getValueAPF(); + APFloat::opStatus s = V.fusedMultiplyAdd(Op2->getValueAPF(), + Op3->getValueAPF(), + APFloat::rmNearestTiesToEven); + if (s != APFloat::opInvalidOp) + return ConstantFP::get(Ty->getContext(), V); + + return nullptr; + } + } + } + } + } + + return nullptr; +} + +static Constant *ConstantFoldVectorCall(StringRef Name, unsigned IntrinsicID, + VectorType *VTy, + ArrayRef Operands, + const TargetLibraryInfo *TLI) { + SmallVector Result(VTy->getNumElements()); + SmallVector Lane(Operands.size()); + Type *Ty = VTy->getElementType(); + + for (unsigned I = 0, E = VTy->getNumElements(); I != E; ++I) { + // Gather a column of constants. + for (unsigned J = 0, JE = Operands.size(); J != JE; ++J) { + Constant *Agg = Operands[J]->getAggregateElement(I); + if (!Agg) + return nullptr; + + Lane[J] = Agg; } - return 0; + + // Use the regular scalar folding to simplify this column. + Constant *Folded = ConstantFoldScalarCall(Name, IntrinsicID, Ty, Lane, TLI); + if (!Folded) + return nullptr; + Result[I] = Folded; } - return 0; + + return ConstantVector::get(Result); +} + +/// Attempt to constant fold a call to the specified function +/// with the specified arguments, returning null if unsuccessful. +Constant * +llvm::ConstantFoldCall(Function *F, ArrayRef Operands, + const TargetLibraryInfo *TLI) { + if (!F->hasName()) + return nullptr; + StringRef Name = F->getName(); + + Type *Ty = F->getReturnType(); + + if (VectorType *VTy = dyn_cast(Ty)) + return ConstantFoldVectorCall(Name, F->getIntrinsicID(), VTy, Operands, TLI); + + return ConstantFoldScalarCall(Name, F->getIntrinsicID(), Ty, Operands, TLI); }