diff options
Diffstat (limited to 'contrib/llvm/lib/IR/ConstantFold.cpp')
| -rw-r--r-- | contrib/llvm/lib/IR/ConstantFold.cpp | 96 |
1 files changed, 52 insertions, 44 deletions
diff --git a/contrib/llvm/lib/IR/ConstantFold.cpp b/contrib/llvm/lib/IR/ConstantFold.cpp index 098ff90..311b0a7 100644 --- a/contrib/llvm/lib/IR/ConstantFold.cpp +++ b/contrib/llvm/lib/IR/ConstantFold.cpp @@ -18,6 +18,7 @@ //===----------------------------------------------------------------------===// #include "ConstantFold.h" +#include "llvm/ADT/APSInt.h" #include "llvm/ADT/SmallVector.h" #include "llvm/IR/Constants.h" #include "llvm/IR/DerivedTypes.h" @@ -222,7 +223,7 @@ static Constant *ExtractConstantBytes(Constant *C, unsigned ByteStart, if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) { APInt V = CI->getValue(); if (ByteStart) - V = V.lshr(ByteStart*8); + V.lshrInPlace(ByteStart*8); V = V.trunc(ByteSize*8); return ConstantInt::get(CI->getContext(), V); } @@ -241,7 +242,7 @@ static Constant *ExtractConstantBytes(Constant *C, unsigned ByteStart, // X | -1 -> -1. if (ConstantInt *RHSC = dyn_cast<ConstantInt>(RHS)) - if (RHSC->isAllOnesValue()) + if (RHSC->isMinusOne()) return RHSC; Constant *LHS = ExtractConstantBytes(CE->getOperand(0), ByteStart,ByteSize); @@ -347,8 +348,7 @@ static Constant *ExtractConstantBytes(Constant *C, unsigned ByteStart, /// factors factored out. If Folded is false, return null if no factoring was /// possible, to avoid endlessly bouncing an unfoldable expression back into the /// top-level folder. -static Constant *getFoldedSizeOf(Type *Ty, Type *DestTy, - bool Folded) { +static Constant *getFoldedSizeOf(Type *Ty, Type *DestTy, bool Folded) { if (ArrayType *ATy = dyn_cast<ArrayType>(Ty)) { Constant *N = ConstantInt::get(DestTy, ATy->getNumElements()); Constant *E = getFoldedSizeOf(ATy->getElementType(), DestTy, true); @@ -403,8 +403,7 @@ static Constant *getFoldedSizeOf(Type *Ty, Type *DestTy, /// factors factored out. If Folded is false, return null if no factoring was /// possible, to avoid endlessly bouncing an unfoldable expression back into the /// top-level folder. -static Constant *getFoldedAlignOf(Type *Ty, Type *DestTy, - bool Folded) { +static Constant *getFoldedAlignOf(Type *Ty, Type *DestTy, bool Folded) { // The alignment of an array is equal to the alignment of the // array element. Note that this is not always true for vectors. if (ArrayType *ATy = dyn_cast<ArrayType>(Ty)) { @@ -468,8 +467,7 @@ static Constant *getFoldedAlignOf(Type *Ty, Type *DestTy, /// any known factors factored out. If Folded is false, return null if no /// factoring was possible, to avoid endlessly bouncing an unfoldable expression /// back into the top-level folder. -static Constant *getFoldedOffsetOf(Type *Ty, Constant *FieldNo, - Type *DestTy, +static Constant *getFoldedOffsetOf(Type *Ty, Constant *FieldNo, Type *DestTy, bool Folded) { if (ArrayType *ATy = dyn_cast<ArrayType>(Ty)) { Constant *N = ConstantExpr::getCast(CastInst::getCastOpcode(FieldNo, false, @@ -606,17 +604,15 @@ Constant *llvm::ConstantFoldCastInstruction(unsigned opc, Constant *V, if (ConstantFP *FPC = dyn_cast<ConstantFP>(V)) { const APFloat &V = FPC->getValueAPF(); bool ignored; - uint64_t x[2]; uint32_t DestBitWidth = cast<IntegerType>(DestTy)->getBitWidth(); + APSInt IntVal(DestBitWidth, opc == Instruction::FPToUI); if (APFloat::opInvalidOp == - V.convertToInteger(x, DestBitWidth, opc==Instruction::FPToSI, - APFloat::rmTowardZero, &ignored)) { + V.convertToInteger(IntVal, APFloat::rmTowardZero, &ignored)) { // Undefined behavior invoked - the destination type can't represent // the input constant. return UndefValue::get(DestTy); } - APInt Val(DestBitWidth, x); - return ConstantInt::get(FPC->getContext(), Val); + return ConstantInt::get(FPC->getContext(), IntVal); } return nullptr; // Can't fold. case Instruction::IntToPtr: //always treated as unsigned @@ -1019,33 +1015,33 @@ Constant *llvm::ConstantFoldBinaryInstruction(unsigned Opcode, if (ConstantInt *CI2 = dyn_cast<ConstantInt>(C2)) { switch (Opcode) { case Instruction::Add: - if (CI2->equalsInt(0)) return C1; // X + 0 == X + if (CI2->isZero()) return C1; // X + 0 == X break; case Instruction::Sub: - if (CI2->equalsInt(0)) return C1; // X - 0 == X + if (CI2->isZero()) return C1; // X - 0 == X break; case Instruction::Mul: - if (CI2->equalsInt(0)) return C2; // X * 0 == 0 - if (CI2->equalsInt(1)) + if (CI2->isZero()) return C2; // X * 0 == 0 + if (CI2->isOne()) return C1; // X * 1 == X break; case Instruction::UDiv: case Instruction::SDiv: - if (CI2->equalsInt(1)) + if (CI2->isOne()) return C1; // X / 1 == X - if (CI2->equalsInt(0)) + if (CI2->isZero()) return UndefValue::get(CI2->getType()); // X / 0 == undef break; case Instruction::URem: case Instruction::SRem: - if (CI2->equalsInt(1)) + if (CI2->isOne()) return Constant::getNullValue(CI2->getType()); // X % 1 == 0 - if (CI2->equalsInt(0)) + if (CI2->isZero()) return UndefValue::get(CI2->getType()); // X % 0 == undef break; case Instruction::And: if (CI2->isZero()) return C2; // X & 0 == 0 - if (CI2->isAllOnesValue()) + if (CI2->isMinusOne()) return C1; // X & -1 == X if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(C1)) { @@ -1082,12 +1078,12 @@ Constant *llvm::ConstantFoldBinaryInstruction(unsigned Opcode, } break; case Instruction::Or: - if (CI2->equalsInt(0)) return C1; // X | 0 == X - if (CI2->isAllOnesValue()) + if (CI2->isZero()) return C1; // X | 0 == X + if (CI2->isMinusOne()) return C2; // X | -1 == -1 break; case Instruction::Xor: - if (CI2->equalsInt(0)) return C1; // X ^ 0 == X + if (CI2->isZero()) return C1; // X ^ 0 == X if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(C1)) { switch (CE1->getOpcode()) { @@ -1095,7 +1091,7 @@ Constant *llvm::ConstantFoldBinaryInstruction(unsigned Opcode, case Instruction::ICmp: case Instruction::FCmp: // cmp pred ^ true -> cmp !pred - assert(CI2->equalsInt(1)); + assert(CI2->isOne()); CmpInst::Predicate pred = (CmpInst::Predicate)CE1->getPredicate(); pred = CmpInst::getInversePredicate(pred); return ConstantExpr::getCompare(pred, CE1->getOperand(0), @@ -1130,18 +1126,18 @@ Constant *llvm::ConstantFoldBinaryInstruction(unsigned Opcode, case Instruction::Mul: return ConstantInt::get(CI1->getContext(), C1V * C2V); case Instruction::UDiv: - assert(!CI2->isNullValue() && "Div by zero handled above"); + assert(!CI2->isZero() && "Div by zero handled above"); return ConstantInt::get(CI1->getContext(), C1V.udiv(C2V)); case Instruction::SDiv: - assert(!CI2->isNullValue() && "Div by zero handled above"); + assert(!CI2->isZero() && "Div by zero handled above"); if (C2V.isAllOnesValue() && C1V.isMinSignedValue()) return UndefValue::get(CI1->getType()); // MIN_INT / -1 -> undef return ConstantInt::get(CI1->getContext(), C1V.sdiv(C2V)); case Instruction::URem: - assert(!CI2->isNullValue() && "Div by zero handled above"); + assert(!CI2->isZero() && "Div by zero handled above"); return ConstantInt::get(CI1->getContext(), C1V.urem(C2V)); case Instruction::SRem: - assert(!CI2->isNullValue() && "Div by zero handled above"); + assert(!CI2->isZero() && "Div by zero handled above"); if (C2V.isAllOnesValue() && C1V.isMinSignedValue()) return UndefValue::get(CI1->getType()); // MIN_INT % -1 -> undef return ConstantInt::get(CI1->getContext(), C1V.srem(C2V)); @@ -1174,7 +1170,7 @@ Constant *llvm::ConstantFoldBinaryInstruction(unsigned Opcode, case Instruction::LShr: case Instruction::AShr: case Instruction::Shl: - if (CI1->equalsInt(0)) return C1; + if (CI1->isZero()) return C1; break; default: break; @@ -1209,10 +1205,15 @@ Constant *llvm::ConstantFoldBinaryInstruction(unsigned Opcode, SmallVector<Constant*, 16> Result; Type *Ty = IntegerType::get(VTy->getContext(), 32); for (unsigned i = 0, e = VTy->getNumElements(); i != e; ++i) { - Constant *LHS = - ConstantExpr::getExtractElement(C1, ConstantInt::get(Ty, i)); - Constant *RHS = - ConstantExpr::getExtractElement(C2, ConstantInt::get(Ty, i)); + Constant *ExtractIdx = ConstantInt::get(Ty, i); + Constant *LHS = ConstantExpr::getExtractElement(C1, ExtractIdx); + Constant *RHS = ConstantExpr::getExtractElement(C2, ExtractIdx); + + // If any element of a divisor vector is zero, the whole op is undef. + if ((Opcode == Instruction::SDiv || Opcode == Instruction::UDiv || + Opcode == Instruction::SRem || Opcode == Instruction::URem) && + RHS->isNullValue()) + return UndefValue::get(VTy); Result.push_back(ConstantExpr::get(Opcode, LHS, RHS)); } @@ -2037,9 +2038,6 @@ Constant *llvm::ConstantFoldGetElementPtr(Type *PointeeTy, Constant *C, Optional<unsigned> InRangeIndex, ArrayRef<Value *> Idxs) { if (Idxs.empty()) return C; - Constant *Idx0 = cast<Constant>(Idxs[0]); - if ((Idxs.size() == 1 && Idx0->isNullValue())) - return C; if (isa<UndefValue>(C)) { Type *GEPTy = GetElementPtrInst::getGEPReturnType( @@ -2047,10 +2045,15 @@ Constant *llvm::ConstantFoldGetElementPtr(Type *PointeeTy, Constant *C, return UndefValue::get(GEPTy); } + Constant *Idx0 = cast<Constant>(Idxs[0]); + if (Idxs.size() == 1 && (Idx0->isNullValue() || isa<UndefValue>(Idx0))) + return C; + if (C->isNullValue()) { bool isNull = true; for (unsigned i = 0, e = Idxs.size(); i != e; ++i) - if (!cast<Constant>(Idxs[i])->isNullValue()) { + if (!isa<UndefValue>(Idxs[i]) && + !cast<Constant>(Idxs[i])->isNullValue()) { isNull = false; break; } @@ -2094,15 +2097,19 @@ Constant *llvm::ConstantFoldGetElementPtr(Type *PointeeTy, Constant *C, // Subsequent evaluation would get confused and produce erroneous results. // // The following prohibits such a GEP from being formed by checking to see - // if the index is in-range with respect to an array or vector. + // if the index is in-range with respect to an array. + // TODO: This code may be extended to handle vectors as well. bool PerformFold = false; if (Idx0->isNullValue()) PerformFold = true; else if (LastI.isSequential()) if (ConstantInt *CI = dyn_cast<ConstantInt>(Idx0)) - PerformFold = - !LastI.isBoundedSequential() || - isIndexInRangeOfArrayType(LastI.getSequentialNumElements(), CI); + PerformFold = (!LastI.isBoundedSequential() || + isIndexInRangeOfArrayType( + LastI.getSequentialNumElements(), CI)) && + !CE->getOperand(CE->getNumOperands() - 1) + ->getType() + ->isVectorTy(); if (PerformFold) { SmallVector<Value*, 16> NewIndices; @@ -2231,7 +2238,8 @@ Constant *llvm::ConstantFoldGetElementPtr(Type *PointeeTy, Constant *C, ConstantInt *Factor = ConstantInt::get(CI->getType(), NumElements); NewIdxs[i] = ConstantExpr::getSRem(CI, Factor); - Constant *PrevIdx = cast<Constant>(Idxs[i - 1]); + Constant *PrevIdx = NewIdxs[i-1] ? NewIdxs[i-1] : + cast<Constant>(Idxs[i - 1]); Constant *Div = ConstantExpr::getSDiv(CI, Factor); unsigned CommonExtendedWidth = |
