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| author | Matt Arsenault <Matthew.Arsenault@amd.com> | 2023-04-08 09:21:31 -0400 |
|---|---|---|
| committer | Matt Arsenault <arsenm2@gmail.com> | 2023-04-12 06:48:58 -0400 |
| commit | 6aca400986d5c394624759eaed1e93f13d0cbcbb (patch) | |
| tree | 1d19fbec6a29dfd840c8ad1eaf96ecddc0afd221 /llvm/lib/Analysis/ValueTracking.cpp | |
| parent | eb8e43a2a154b97cdf66764a2410be9ffc2387ab (diff) | |
| download | llvm-6aca400986d5c394624759eaed1e93f13d0cbcbb.zip llvm-6aca400986d5c394624759eaed1e93f13d0cbcbb.tar.gz llvm-6aca400986d5c394624759eaed1e93f13d0cbcbb.tar.bz2 | |
ValueTracking: Handle no-nan check for computeKnownFPClass for fadd/fsub
Copy the logic from isKnownNeverNaN for fadd/fsub.
Diffstat (limited to 'llvm/lib/Analysis/ValueTracking.cpp')
| -rw-r--r-- | llvm/lib/Analysis/ValueTracking.cpp | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp index 879015b..af82276 100644 --- a/llvm/lib/Analysis/ValueTracking.cpp +++ b/llvm/lib/Analysis/ValueTracking.cpp @@ -4439,6 +4439,25 @@ void computeKnownFPClass(const Value *V, const APInt &DemandedElts, break; } + case Instruction::FAdd: + case Instruction::FSub: { + KnownFPClass KnownLHS, KnownRHS; + computeKnownFPClass(Op->getOperand(1), DemandedElts, fcNan | fcInf, + KnownRHS, Depth + 1, Q, TLI); + if (KnownRHS.isKnownNeverNaN()) { + // RHS is canonically cheaper to compute. Skip inspecting the LHS if + // there's no point. + computeKnownFPClass(Op->getOperand(0), DemandedElts, fcNan | fcInf, + KnownLHS, Depth + 1, Q, TLI); + // Adding positive and negative infinity produces NaN. + // TODO: Check sign of infinities. + if (KnownLHS.isKnownNeverNaN() && + (KnownLHS.isKnownNeverInfinity() || KnownRHS.isKnownNeverInfinity())) + Known.knownNot(fcNan); + } + + break; + } case Instruction::SIToFP: case Instruction::UIToFP: { // Cannot produce nan |