diff options
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/Analysis/InstructionSimplify.cpp | 42 |
1 files changed, 32 insertions, 10 deletions
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp index 13e4fca781f..149a1967164 100644 --- a/llvm/lib/Analysis/InstructionSimplify.cpp +++ b/llvm/lib/Analysis/InstructionSimplify.cpp @@ -4163,6 +4163,28 @@ Value *llvm::SimplifyShuffleVectorInst(Value *Op0, Value *Op1, Constant *Mask, return ::SimplifyShuffleVectorInst(Op0, Op1, Mask, RetTy, Q, RecursionLimit); } +static Constant *propagateNaN(Constant *In) { + // If the input is a vector with undef elements, just return a default NaN. + if (!In->isNaN()) + return ConstantFP::getNaN(In->getType()); + + // Propagate the existing NaN constant when possible. + // TODO: Should we quiet a signaling NaN? + return In; +} + +static Constant *simplifyFPBinop(Value *Op0, Value *Op1) { + if (isa<UndefValue>(Op0) || isa<UndefValue>(Op1)) + return ConstantFP::getNaN(Op0->getType()); + + if (match(Op0, m_NaN())) + return propagateNaN(cast<Constant>(Op0)); + if (match(Op1, m_NaN())) + return propagateNaN(cast<Constant>(Op1)); + + return nullptr; +} + /// Given operands for an FAdd, see if we can fold the result. If not, this /// returns null. static Value *SimplifyFAddInst(Value *Op0, Value *Op1, FastMathFlags FMF, @@ -4170,8 +4192,8 @@ static Value *SimplifyFAddInst(Value *Op0, Value *Op1, FastMathFlags FMF, if (Constant *C = foldOrCommuteConstant(Instruction::FAdd, Op0, Op1, Q)) return C; - if (isa<UndefValue>(Op0) || isa<UndefValue>(Op1)) - return ConstantFP::getNaN(Op0->getType()); + if (Constant *C = simplifyFPBinop(Op0, Op1)) + return C; // fadd X, -0 ==> X if (match(Op1, m_NegZero())) @@ -4203,8 +4225,8 @@ static Value *SimplifyFSubInst(Value *Op0, Value *Op1, FastMathFlags FMF, if (Constant *C = foldOrCommuteConstant(Instruction::FSub, Op0, Op1, Q)) return C; - if (isa<UndefValue>(Op0) || isa<UndefValue>(Op1)) - return ConstantFP::getNaN(Op0->getType()); + if (Constant *C = simplifyFPBinop(Op0, Op1)) + return C; // fsub X, 0 ==> X if (match(Op1, m_Zero())) @@ -4238,8 +4260,8 @@ static Value *SimplifyFMulInst(Value *Op0, Value *Op1, FastMathFlags FMF, if (Constant *C = foldOrCommuteConstant(Instruction::FMul, Op0, Op1, Q)) return C; - if (isa<UndefValue>(Op0) || isa<UndefValue>(Op1)) - return ConstantFP::getNaN(Op0->getType()); + if (Constant *C = simplifyFPBinop(Op0, Op1)) + return C; // fmul X, 1.0 ==> X if (match(Op1, m_FPOne())) @@ -4282,8 +4304,8 @@ static Value *SimplifyFDivInst(Value *Op0, Value *Op1, FastMathFlags FMF, if (Constant *C = foldOrCommuteConstant(Instruction::FDiv, Op0, Op1, Q)) return C; - if (isa<UndefValue>(Op0) || isa<UndefValue>(Op1)) - return ConstantFP::getNaN(Op0->getType()); + if (Constant *C = simplifyFPBinop(Op0, Op1)) + return C; // X / 1.0 -> X if (match(Op1, m_FPOne())) @@ -4329,8 +4351,8 @@ static Value *SimplifyFRemInst(Value *Op0, Value *Op1, FastMathFlags FMF, if (Constant *C = foldOrCommuteConstant(Instruction::FRem, Op0, Op1, Q)) return C; - if (isa<UndefValue>(Op0) || isa<UndefValue>(Op1)) - return ConstantFP::getNaN(Op0->getType()); + if (Constant *C = simplifyFPBinop(Op0, Op1)) + return C; // Unlike fdiv, the result of frem always matches the sign of the dividend. // The constant match may include undef elements in a vector, so return a full |
