X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FAnalysis%2FConstantFolding.cpp;h=55a10d716b95503c59e0a8c5791198d4f88394e2;hb=0e3fae27a1634f51943d06588e32a550dae6a4b9;hp=589bd321157a60b6c03458cc96f1ae99f78cea72;hpb=7b550ccfc5a3346c17e0390a59e2d6d19bc52705;p=oota-llvm.git diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp index 589bd321157..55a10d716b9 100644 --- a/lib/Analysis/ConstantFolding.cpp +++ b/lib/Analysis/ConstantFolding.cpp @@ -30,6 +30,7 @@ #include "llvm/Support/ErrorHandling.h" #include "llvm/Support/GetElementPtrTypeIterator.h" #include "llvm/Support/MathExtras.h" +#include "llvm/Support/FEnv.h" #include #include using namespace llvm; @@ -80,7 +81,7 @@ static Constant *FoldBitCast(Constant *C, const Type *DestTy, // 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->isFloatingPoint()) { + if (DstEltTy->isFloatingPointTy()) { // Fold to an vector of integers with same size as our FP type. unsigned FPWidth = DstEltTy->getPrimitiveSizeInBits(); const Type *DestIVTy = @@ -95,7 +96,7 @@ static Constant *FoldBitCast(Constant *C, const Type *DestTy, // Okay, we know the destination is integer, if the input is FP, convert // it to integer first. - if (SrcEltTy->isFloatingPoint()) { + if (SrcEltTy->isFloatingPointTy()) { unsigned FPWidth = SrcEltTy->getPrimitiveSizeInBits(); const Type *SrcIVTy = VectorType::get(IntegerType::get(C->getContext(), FPWidth), NumSrcElt); @@ -208,7 +209,7 @@ static bool IsConstantOffsetFromGlobal(Constant *C, GlobalValue *&GV, i != e; ++i, ++GTI) { ConstantInt *CI = dyn_cast(*i); if (!CI) return false; // Index isn't a simple constant? - if (CI->getZExtValue() == 0) continue; // Not adding anything. + if (CI->isZero()) continue; // Not adding anything. if (const StructType *ST = dyn_cast(*GTI)) { // N = N + Offset @@ -359,7 +360,7 @@ static Constant *FoldReinterpretLoadFromConstPtr(Constant *C, MapTy = Type::getInt32PtrTy(C->getContext()); else if (LoadTy->isDoubleTy()) MapTy = Type::getInt64PtrTy(C->getContext()); - else if (isa(LoadTy)) { + else if (LoadTy->isVectorTy()) { MapTy = IntegerType::get(C->getContext(), TD.getTypeAllocSizeInBits(LoadTy)); MapTy = PointerType::getUnqual(MapTy); @@ -398,10 +399,10 @@ static Constant *FoldReinterpretLoadFromConstPtr(Constant *C, BytesLoaded, TD)) return 0; - APInt ResultVal(IntType->getBitWidth(), 0); - for (unsigned i = 0; i != BytesLoaded; ++i) { + APInt ResultVal = APInt(IntType->getBitWidth(), RawBytes[BytesLoaded-1]); + for (unsigned i = 1; i != BytesLoaded; ++i) { ResultVal <<= 8; - ResultVal |= APInt(IntType->getBitWidth(), RawBytes[BytesLoaded-1-i]); + ResultVal |= RawBytes[BytesLoaded-1-i]; } return ConstantInt::get(IntType->getContext(), ResultVal); @@ -432,12 +433,14 @@ Constant *llvm::ConstantFoldLoadFromConstPtr(Constant *C, // Instead of loading constant c string, use corresponding integer value // directly if string length is small enough. std::string Str; - if (TD && GetConstantStringInfo(CE->getOperand(0), Str) && !Str.empty()) { + if (TD && GetConstantStringInfo(CE, Str) && !Str.empty()) { unsigned StrLen = Str.length(); const Type *Ty = cast(CE->getType())->getElementType(); unsigned NumBits = Ty->getPrimitiveSizeInBits(); - // Replace LI with immediate integer store. - if ((NumBits >> 3) == StrLen + 1) { + // Replace load with immediate integer if the result is an integer or fp + // value. + if ((NumBits >> 3) == StrLen + 1 && (NumBits & 7) == 0 && + (isa(Ty) || Ty->isFloatingPointTy())) { APInt StrVal(NumBits, 0); APInt SingleChar(NumBits, 0); if (TD->isLittleEndian()) { @@ -454,13 +457,17 @@ Constant *llvm::ConstantFoldLoadFromConstPtr(Constant *C, SingleChar = 0; StrVal = (StrVal << 8) | SingleChar; } - return ConstantInt::get(CE->getContext(), StrVal); + + 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(CE->getUnderlyingObject())){ + if (GlobalVariable *GV = dyn_cast(GetUnderlyingObject(CE))){ if (GV->isConstant() && GV->hasDefinitiveInitializer()) { const Type *ResTy = cast(C->getType())->getElementType(); if (GV->getInitializer()->isNullValue()) @@ -517,6 +524,42 @@ static Constant *SymbolicallyEvaluateBinop(unsigned Opc, Constant *Op0, 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) { + if (!TD) return 0; + const Type *IntPtrTy = TD->getIntPtrType(ResultTy->getContext()); + + bool Any = false; + SmallVector NewIdxs; + for (unsigned i = 1; i != NumOps; ++i) { + if ((i == 1 || + !isa(GetElementPtrInst::getIndexedType(Ops[0]->getType(), + reinterpret_cast(Ops+1), + i-1))) && + Ops[i]->getType() != IntPtrTy) { + Any = true; + NewIdxs.push_back(ConstantExpr::getCast(CastInst::getCastOpcode(Ops[i], + true, + IntPtrTy, + true), + Ops[i], IntPtrTy)); + } else + NewIdxs.push_back(Ops[i]); + } + if (!Any) return 0; + + Constant *C = + ConstantExpr::getGetElementPtr(Ops[0], &NewIdxs[0], NewIdxs.size()); + if (ConstantExpr *CE = dyn_cast(C)) + if (Constant *Folded = ConstantFoldConstantExpression(CE, TD)) + C = Folded; + return C; +} + /// SymbolicallyEvaluateGEP - If we can symbolically evaluate the specified GEP /// constant expression, do so. static Constant *SymbolicallyEvaluateGEP(Constant *const *Ops, unsigned NumOps, @@ -525,37 +568,70 @@ static Constant *SymbolicallyEvaluateGEP(Constant *const *Ops, unsigned NumOps, Constant *Ptr = Ops[0]; if (!TD || !cast(Ptr->getType())->getElementType()->isSized()) return 0; - - unsigned BitWidth = - TD->getTypeSizeInBits(TD->getIntPtrType(Ptr->getContext())); - APInt BasePtr(BitWidth, 0); - bool BaseIsInt = true; - if (!Ptr->isNullValue()) { - // If this is a inttoptr from a constant int, we can fold this as the base, - // otherwise we can't. - if (ConstantExpr *CE = dyn_cast(Ptr)) - if (CE->getOpcode() == Instruction::IntToPtr) - if (ConstantInt *Base = dyn_cast(CE->getOperand(0))) { - BasePtr = Base->getValue(); - BasePtr.zextOrTrunc(BitWidth); - } - - if (BasePtr == 0) - BaseIsInt = false; - } + + const 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) - if (!isa(Ops[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 && + cast(ResultTy)->getElementType()->isIntegerTy(8)) { + ConstantExpr *CE = dyn_cast(Ops[1]); + assert((CE == 0 || CE->getType() == IntPtrTy) && + "CastGEPIndices didn't canonicalize index types!"); + if (CE && CE->getOpcode() == Instruction::Sub && + CE->getOperand(0)->isNullValue()) { + Constant *Res = ConstantExpr::getPtrToInt(Ptr, CE->getType()); + Res = ConstantExpr::getSub(Res, CE->getOperand(1)); + Res = ConstantExpr::getIntToPtr(Res, ResultTy); + if (ConstantExpr *ResCE = dyn_cast(Res)) + Res = ConstantFoldConstantExpression(ResCE, TD); + 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()); + + // 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()); + + // Do not try the incorporate the sub-GEP if some index is not a number. + bool AllConstantInt = true; + for (unsigned i = 0, e = NestedOps.size(); i != e; ++i) + if (!isa(NestedOps[i])) { + AllConstantInt = false; + break; + } + if (!AllConstantInt) + break; + + Ptr = cast(GEP->getOperand(0)); + Offset += APInt(BitWidth, + TD->getIndexedOffset(Ptr->getType(), + (Value**)NestedOps.data(), + NestedOps.size())); + Ptr = cast(Ptr->stripPointerCasts()); + } + // 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. - if (BaseIsInt) { + APInt BasePtr(BitWidth, 0); + 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); return ConstantExpr::getIntToPtr(C, ResultTy); } @@ -568,17 +644,31 @@ static Constant *SymbolicallyEvaluateGEP(Constant *const *Ops, unsigned NumOps, SmallVector NewIdxs; do { if (const SequentialType *ATy = dyn_cast(Ty)) { - // The only pointer indexing we'll do is on the first index of the GEP. - if (isa(ATy) && !NewIdxs.empty()) - break; + 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()); if (ElemSize == 0) - return 0; - APInt NewIdx = Offset.udiv(ElemSize); - Offset -= NewIdx * ElemSize; - NewIdxs.push_back(ConstantInt::get(TD->getIntPtrType(Ty->getContext()), - NewIdx)); + // 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 + // accommodate the offset. + NewIdxs.push_back(ConstantInt::get(IntPtrTy, 0)); + else { + // The element size is non-zero divide the offset by the element + // size (rounding down), to compute the index at this level. + APInt NewIdx = Offset.udiv(ElemSize); + Offset -= NewIdx * ElemSize; + 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 @@ -622,27 +712,34 @@ static Constant *SymbolicallyEvaluateGEP(Constant *const *Ops, unsigned NumOps, // Constant Folding public APIs //===----------------------------------------------------------------------===// - -/// ConstantFoldInstruction - Attempt to constant fold the specified -/// instruction. If successful, the constant result is returned, if not, null -/// is returned. Note that this function can only fail when attempting to fold -/// instructions like loads and stores, which have no constant expression form. -/// +/// ConstantFoldInstruction - 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 +/// and stores, which have no constant expression form. Constant *llvm::ConstantFoldInstruction(Instruction *I, const TargetData *TD) { + // Handle PHI nodes quickly here... if (PHINode *PN = dyn_cast(I)) { - if (PN->getNumIncomingValues() == 0) - return UndefValue::get(PN->getType()); - - Constant *Result = dyn_cast(PN->getIncomingValue(0)); - if (Result == 0) return 0; + Constant *CommonValue = 0; - // Handle PHI nodes specially here... - for (unsigned i = 1, e = PN->getNumIncomingValues(); i != e; ++i) - if (PN->getIncomingValue(i) != Result && PN->getIncomingValue(i) != PN) - return 0; // Not all the same incoming constants... + for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) { + Value *Incoming = PN->getIncomingValue(i); + // If the incoming value is undef then skip it. Note that while we could + // skip the value if it is equal to the phi node itself we choose not to + // because that would break the rule that constant folding only applies if + // 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. + Constant *C = dyn_cast(Incoming); + if (!C || (CommonValue && C != CommonValue)) + return 0; + CommonValue = C; + } - // If we reach here, all incoming values are the same constant. - return Result; + // If we reach here, all incoming values are the same constant or undef. + return CommonValue ? CommonValue : UndefValue::get(PN->getType()); } // Scan the operand list, checking to see if they are all constants, if so, @@ -655,12 +752,23 @@ Constant *llvm::ConstantFoldInstruction(Instruction *I, const TargetData *TD) { return 0; // All operands not constant! if (const CmpInst *CI = dyn_cast(I)) - return ConstantFoldCompareInstOperands(CI->getPredicate(), - Ops.data(), Ops.size(), TD); + return ConstantFoldCompareInstOperands(CI->getPredicate(), Ops[0], Ops[1], + TD); if (const LoadInst *LI = dyn_cast(I)) return ConstantFoldLoadInst(LI, TD); - + + if (InsertValueInst *IVI = dyn_cast(I)) + return ConstantExpr::getInsertValue( + cast(IVI->getAggregateOperand()), + cast(IVI->getInsertedValueOperand()), + IVI->idx_begin(), IVI->getNumIndices()); + + if (ExtractValueInst *EVI = dyn_cast(I)) + return ConstantExpr::getExtractValue( + cast(EVI->getAggregateOperand()), + EVI->idx_begin(), EVI->getNumIndices()); + return ConstantFoldInstOperands(I->getOpcode(), I->getType(), Ops.data(), Ops.size(), TD); } @@ -668,15 +776,21 @@ Constant *llvm::ConstantFoldInstruction(Instruction *I, const TargetData *TD) { /// 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(ConstantExpr *CE, +Constant *llvm::ConstantFoldConstantExpression(const ConstantExpr *CE, const TargetData *TD) { SmallVector Ops; - for (User::op_iterator i = CE->op_begin(), e = CE->op_end(); i != e; ++i) - Ops.push_back(cast(*i)); + 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); + Ops.push_back(NewC); + } if (CE->isCompare()) - return ConstantFoldCompareInstOperands(CE->getPredicate(), - Ops.data(), Ops.size(), TD); + return ConstantFoldCompareInstOperands(CE->getPredicate(), Ops[0], Ops[1], + TD); return ConstantFoldInstOperands(CE->getOpcode(), CE->getType(), Ops.data(), Ops.size(), TD); } @@ -687,6 +801,10 @@ Constant *llvm::ConstantFoldConstantExpression(ConstantExpr *CE, /// attempting to fold instructions like loads and stores, which have no /// constant expression form. /// +/// TODO: This function neither utilizes nor preserves nsw/nuw/inbounds/etc +/// 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) { @@ -701,14 +819,13 @@ Constant *llvm::ConstantFoldInstOperands(unsigned Opcode, const Type *DestTy, switch (Opcode) { default: return 0; + case Instruction::ICmp: + case Instruction::FCmp: assert(0 && "Invalid for compares"); case Instruction::Call: - if (Function *F = dyn_cast(Ops[0])) + if (Function *F = dyn_cast(Ops[NumOps - 1])) if (canConstantFoldCallTo(F)) - return ConstantFoldCall(F, Ops+1, NumOps-1); + return ConstantFoldCall(F, Ops, NumOps - 1); return 0; - case Instruction::ICmp: - case Instruction::FCmp: - llvm_unreachable("This function is invalid for compares: no predicate specified"); 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. @@ -731,45 +848,12 @@ Constant *llvm::ConstantFoldInstOperands(unsigned Opcode, const Type *DestTy, // 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 (ConstantExpr *CE = dyn_cast(Ops[0])) if (TD && - TD->getPointerSizeInBits() <= - CE->getType()->getScalarSizeInBits()) { - if (CE->getOpcode() == Instruction::PtrToInt) - return FoldBitCast(CE->getOperand(0), DestTy, *TD); - - // If there's a constant offset added to the integer value before - // it is casted back to a pointer, see if the expression can be - // converted into a GEP. - if (CE->getOpcode() == Instruction::Add) - if (ConstantInt *L = dyn_cast(CE->getOperand(0))) - if (ConstantExpr *R = dyn_cast(CE->getOperand(1))) - if (R->getOpcode() == Instruction::PtrToInt) - if (GlobalVariable *GV = - dyn_cast(R->getOperand(0))) { - const PointerType *GVTy = cast(GV->getType()); - if (const ArrayType *AT = - dyn_cast(GVTy->getElementType())) { - const Type *ElTy = AT->getElementType(); - uint64_t AllocSize = TD->getTypeAllocSize(ElTy); - APInt PSA(L->getValue().getBitWidth(), AllocSize); - if (ElTy == cast(DestTy)->getElementType() && - L->getValue().urem(PSA) == 0) { - APInt ElemIdx = L->getValue().udiv(PSA); - if (ElemIdx.ult(APInt(ElemIdx.getBitWidth(), - AT->getNumElements()))) { - Constant *Index[] = { - Constant::getNullValue(CE->getType()), - ConstantInt::get(ElTy->getContext(), ElemIdx) - }; - return - ConstantExpr::getGetElementPtr(GV, &Index[0], 2); - } - } - } - } - } - } + TD->getPointerSizeInBits() <= CE->getType()->getScalarSizeInBits() && + CE->getOpcode() == Instruction::PtrToInt) + return FoldBitCast(CE->getOperand(0), DestTy, *TD); + return ConstantExpr::getCast(Opcode, Ops[0], DestTy); case Instruction::Trunc: case Instruction::ZExt: @@ -794,6 +878,8 @@ 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)) + return C; if (Constant *C = SymbolicallyEvaluateGEP(Ops, NumOps, DestTy, TD)) return C; @@ -806,8 +892,7 @@ Constant *llvm::ConstantFoldInstOperands(unsigned Opcode, const Type *DestTy, /// returns a constant expression of the specified operands. /// Constant *llvm::ConstantFoldCompareInstOperands(unsigned Predicate, - Constant *const *Ops, - unsigned NumOps, + Constant *Ops0, Constant *Ops1, const TargetData *TD) { // fold: icmp (inttoptr x), null -> icmp x, 0 // fold: icmp (ptrtoint x), 0 -> icmp x, null @@ -816,16 +901,16 @@ Constant *llvm::ConstantFoldCompareInstOperands(unsigned Predicate, // // ConstantExpr::getCompare cannot do this, because it doesn't have TD // around to know if bit truncation is happening. - if (ConstantExpr *CE0 = dyn_cast(Ops[0])) { - if (TD && Ops[1]->isNullValue()) { + if (ConstantExpr *CE0 = dyn_cast(Ops0)) { + if (TD && Ops1->isNullValue()) { const 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 *NewOps[] = { C, Constant::getNullValue(C->getType()) }; - return ConstantFoldCompareInstOperands(Predicate, NewOps, 2, TD); + Constant *Null = Constant::getNullValue(C->getType()); + return ConstantFoldCompareInstOperands(Predicate, C, Null, TD); } // Only do this transformation if the int is intptrty in size, otherwise @@ -833,13 +918,12 @@ Constant *llvm::ConstantFoldCompareInstOperands(unsigned Predicate, if (CE0->getOpcode() == Instruction::PtrToInt && CE0->getType() == IntPtrTy) { Constant *C = CE0->getOperand(0); - Constant *NewOps[] = { C, Constant::getNullValue(C->getType()) }; - // FIXME! - return ConstantFoldCompareInstOperands(Predicate, NewOps, 2, TD); + Constant *Null = Constant::getNullValue(C->getType()); + return ConstantFoldCompareInstOperands(Predicate, C, Null, TD); } } - if (ConstantExpr *CE1 = dyn_cast(Ops[1])) { + if (ConstantExpr *CE1 = dyn_cast(Ops1)) { if (TD && CE0->getOpcode() == CE1->getOpcode()) { const Type *IntPtrTy = TD->getIntPtrType(CE0->getContext()); @@ -850,24 +934,35 @@ Constant *llvm::ConstantFoldCompareInstOperands(unsigned Predicate, IntPtrTy, false); Constant *C1 = ConstantExpr::getIntegerCast(CE1->getOperand(0), IntPtrTy, false); - Constant *NewOps[] = { C0, C1 }; - return ConstantFoldCompareInstOperands(Predicate, NewOps, 2, TD); + return ConstantFoldCompareInstOperands(Predicate, C0, C1, TD); } // 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())) { - Constant *NewOps[] = { - CE0->getOperand(0), CE1->getOperand(0) - }; - return ConstantFoldCompareInstOperands(Predicate, NewOps, 2, TD); - } + CE0->getOperand(0)->getType() == CE1->getOperand(0)->getType())) + return ConstantFoldCompareInstOperands(Predicate, CE0->getOperand(0), + CE1->getOperand(0), TD); } } + + // 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 = + Predicate == ICmpInst::ICMP_EQ ? Instruction::And : Instruction::Or; + Constant *Ops[] = { LHS, RHS }; + return ConstantFoldInstOperands(OpC, LHS->getType(), Ops, 2, TD); + } } - return ConstantExpr::getCompare(Predicate, Ops[0], Ops[1]); + + return ConstantExpr::getCompare(Predicate, Ops0, Ops1); } @@ -949,6 +1044,17 @@ llvm::canConstantFoldCallTo(const Function *F) { case Intrinsic::usub_with_overflow: case Intrinsic::sadd_with_overflow: case Intrinsic::ssub_with_overflow: + case Intrinsic::smul_with_overflow: + case Intrinsic::convert_from_fp16: + case Intrinsic::convert_to_fp16: + case Intrinsic::x86_sse_cvtss2si: + case Intrinsic::x86_sse_cvtss2si64: + case Intrinsic::x86_sse_cvttss2si: + case Intrinsic::x86_sse_cvttss2si64: + case Intrinsic::x86_sse2_cvtsd2si: + case Intrinsic::x86_sse2_cvtsd2si64: + case Intrinsic::x86_sse2_cvttsd2si: + case Intrinsic::x86_sse2_cvttsd2si64: return true; default: return false; @@ -986,10 +1092,10 @@ llvm::canConstantFoldCallTo(const Function *F) { static Constant *ConstantFoldFP(double (*NativeFP)(double), double V, const Type *Ty) { - errno = 0; + sys::llvm_fenv_clearexcept(); V = NativeFP(V); - if (errno != 0) { - errno = 0; + if (sys::llvm_fenv_testexcept()) { + sys::llvm_fenv_clearexcept(); return 0; } @@ -1003,10 +1109,10 @@ static Constant *ConstantFoldFP(double (*NativeFP)(double), double V, static Constant *ConstantFoldBinaryFP(double (*NativeFP)(double, double), double V, double W, const Type *Ty) { - errno = 0; + sys::llvm_fenv_clearexcept(); V = NativeFP(V, W); - if (errno != 0) { - errno = 0; + if (sys::llvm_fenv_testexcept()) { + sys::llvm_fenv_clearexcept(); return 0; } @@ -1018,6 +1124,36 @@ static Constant *ConstantFoldBinaryFP(double (*NativeFP)(double, double), return 0; // dummy return to suppress warning } +/// 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. +static Constant *ConstantFoldConvertToInt(ConstantFP *Op, bool roundTowardZero, + const Type *Ty) { + assert(Op && "Called with NULL operand"); + APFloat Val(Op->getValueAPF()); + + // All of these conversion intrinsics form an integer of at most 64bits. + unsigned ResultWidth = cast(Ty)->getBitWidth(); + assert(ResultWidth <= 64 && + "Can only constant fold conversions to 64 and 32 bit ints"); + + uint64_t UIntVal; + bool isExact = false; + APFloat::roundingMode mode = roundTowardZero? APFloat::rmTowardZero + : APFloat::rmNearestTiesToEven; + APFloat::opStatus status = Val.convertToInteger(&UIntVal, ResultWidth, + /*isSigned=*/true, mode, + &isExact); + if (status != APFloat::opOK && status != APFloat::opInexact) + return 0; + 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 * @@ -1029,8 +1165,24 @@ llvm::ConstantFoldCall(Function *F, const Type *Ty = F->getReturnType(); if (NumOperands == 1) { if (ConstantFP *Op = dyn_cast(Operands[0])) { + if (F->getIntrinsicID() == 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()); + } + if (!Ty->isFloatTy() && !Ty->isDoubleTy()) return 0; + + /// 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; + /// 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)) == @@ -1071,8 +1223,8 @@ llvm::ConstantFoldCall(Function *F, return ConstantFoldFP(log, V, Ty); else if (Name == "log10" && V > 0) return ConstantFoldFP(log10, V, Ty); - else if (Name == "llvm.sqrt.f32" || - Name == "llvm.sqrt.f64") { + else if (F->getIntrinsicID() == Intrinsic::sqrt && + (Ty->isFloatTy() || Ty->isDoubleTy())) { if (V >= -0.0) return ConstantFoldFP(sqrt, V, Ty); else // Undefined @@ -1102,23 +1254,63 @@ llvm::ConstantFoldCall(Function *F, } return 0; } - - + if (ConstantInt *Op = dyn_cast(Operands[0])) { - if (Name.startswith("llvm.bswap")) + switch (F->getIntrinsicID()) { + case Intrinsic::bswap: return ConstantInt::get(F->getContext(), Op->getValue().byteSwap()); - else if (Name.startswith("llvm.ctpop")) + case Intrinsic::ctpop: return ConstantInt::get(Ty, Op->getValue().countPopulation()); - else if (Name.startswith("llvm.cttz")) + case Intrinsic::cttz: return ConstantInt::get(Ty, Op->getValue().countTrailingZeros()); - else if (Name.startswith("llvm.ctlz")) + case Intrinsic::ctlz: return ConstantInt::get(Ty, Op->getValue().countLeadingZeros()); + case Intrinsic::convert_from_fp16: { + APFloat Val(Op->getValue()); + + bool lost = false; + APFloat::opStatus status = + Val.convert(APFloat::IEEEsingle, APFloat::rmNearestTiesToEven, &lost); + + // Conversion is always precise. + (void)status; + assert(status == APFloat::opOK && !lost && + "Precision lost during fp16 constfolding"); + + return ConstantFP::get(F->getContext(), Val); + } + default: + return 0; + } + } + + if (ConstantVector *Op = dyn_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); + 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 (isa(Operands[0])) { + if (F->getIntrinsicID() == Intrinsic::bswap) + return Operands[0]; return 0; } - + return 0; } - + if (NumOperands == 2) { if (ConstantFP *Op1 = dyn_cast(Operands[0])) { if (!Ty->isFloatTy() && !Ty->isDoubleTy()) @@ -1141,11 +1333,11 @@ llvm::ConstantFoldCall(Function *F, if (Name == "atan2") return ConstantFoldBinaryFP(atan2, Op1V, Op2V, Ty); } else if (ConstantInt *Op2C = dyn_cast(Operands[1])) { - if (Name == "llvm.powi.f32") + if (F->getIntrinsicID() == Intrinsic::powi && Ty->isFloatTy()) return ConstantFP::get(F->getContext(), APFloat((float)std::pow((float)Op1V, (int)Op2C->getZExtValue()))); - if (Name == "llvm.powi.f64") + if (F->getIntrinsicID() == Intrinsic::powi && Ty->isDoubleTy()) return ConstantFP::get(F->getContext(), APFloat((double)std::pow((double)Op1V, (int)Op2C->getZExtValue()))); @@ -1158,42 +1350,37 @@ llvm::ConstantFoldCall(Function *F, if (ConstantInt *Op2 = dyn_cast(Operands[1])) { switch (F->getIntrinsicID()) { default: break; - case Intrinsic::uadd_with_overflow: { - Constant *Res = ConstantExpr::getAdd(Op1, Op2); // result. - Constant *Ops[] = { - Res, ConstantExpr::getICmp(CmpInst::ICMP_ULT, Res, Op1) // overflow. - }; - return ConstantStruct::get(F->getContext(), Ops, 2, false); - } - case Intrinsic::usub_with_overflow: { - Constant *Res = ConstantExpr::getSub(Op1, Op2); // result. + case Intrinsic::sadd_with_overflow: + case Intrinsic::uadd_with_overflow: + case Intrinsic::ssub_with_overflow: + case Intrinsic::usub_with_overflow: + case Intrinsic::smul_with_overflow: { + APInt Res; + bool Overflow; + switch (F->getIntrinsicID()) { + default: assert(0 && "Invalid case"); + case Intrinsic::sadd_with_overflow: + Res = Op1->getValue().sadd_ov(Op2->getValue(), Overflow); + break; + case Intrinsic::uadd_with_overflow: + Res = Op1->getValue().uadd_ov(Op2->getValue(), Overflow); + break; + case Intrinsic::ssub_with_overflow: + Res = Op1->getValue().ssub_ov(Op2->getValue(), Overflow); + break; + case Intrinsic::usub_with_overflow: + Res = Op1->getValue().usub_ov(Op2->getValue(), Overflow); + break; + case Intrinsic::smul_with_overflow: + Res = Op1->getValue().smul_ov(Op2->getValue(), Overflow); + break; + } Constant *Ops[] = { - Res, ConstantExpr::getICmp(CmpInst::ICMP_UGT, Res, Op1) // overflow. + ConstantInt::get(F->getContext(), Res), + ConstantInt::get(Type::getInt1Ty(F->getContext()), Overflow) }; return ConstantStruct::get(F->getContext(), Ops, 2, false); } - case Intrinsic::sadd_with_overflow: { - Constant *Res = ConstantExpr::getAdd(Op1, Op2); // result. - Constant *Overflow = ConstantExpr::getSelect( - ConstantExpr::getICmp(CmpInst::ICMP_SGT, - ConstantInt::get(Op1->getType(), 0), Op1), - ConstantExpr::getICmp(CmpInst::ICMP_SGT, Res, Op2), - ConstantExpr::getICmp(CmpInst::ICMP_SLT, Res, Op2)); // overflow. - - Constant *Ops[] = { Res, Overflow }; - return ConstantStruct::get(F->getContext(), Ops, 2, false); - } - case Intrinsic::ssub_with_overflow: { - Constant *Res = ConstantExpr::getSub(Op1, Op2); // result. - Constant *Overflow = ConstantExpr::getSelect( - ConstantExpr::getICmp(CmpInst::ICMP_SGT, - ConstantInt::get(Op2->getType(), 0), Op2), - ConstantExpr::getICmp(CmpInst::ICMP_SLT, Res, Op1), - ConstantExpr::getICmp(CmpInst::ICMP_SGT, Res, Op1)); // overflow. - - Constant *Ops[] = { Res, Overflow }; - return ConstantStruct::get(F->getContext(), Ops, 2, false); - } } } @@ -1203,4 +1390,3 @@ llvm::ConstantFoldCall(Function *F, } return 0; } -