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| author | Hubert Tong <hubert.reinterpretcast@gmail.com> | 2024-11-02 20:06:39 -0400 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2024-11-02 20:06:39 -0400 |
| commit | 5091a359d9807db8f7d62375696f93fc34226969 (patch) | |
| tree | 9179d8902f57398e561f04801a8677567609f808 /llvm/lib/Analysis/ConstantFolding.cpp | |
| parent | 6f10b65297707c1e964d570421ab4559dc2928d4 (diff) | |
| download | llvm-5091a359d9807db8f7d62375696f93fc34226969.zip llvm-5091a359d9807db8f7d62375696f93fc34226969.tar.gz llvm-5091a359d9807db8f7d62375696f93fc34226969.tar.bz2 | |
[ConstantFold] Special case log1p +/-0.0 (#114635)
C's Annex F specifies that log1p +/-0.0 returns the input value;
however, this behavior is optional and host C libraries may behave
differently. This change applies the Annex F behavior to constant
folding by LLVM.
Diffstat (limited to 'llvm/lib/Analysis/ConstantFolding.cpp')
| -rw-r--r-- | llvm/lib/Analysis/ConstantFolding.cpp | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/llvm/lib/Analysis/ConstantFolding.cpp b/llvm/lib/Analysis/ConstantFolding.cpp index c5a2c2f..88db315 100644 --- a/llvm/lib/Analysis/ConstantFolding.cpp +++ b/llvm/lib/Analysis/ConstantFolding.cpp @@ -2407,6 +2407,9 @@ static Constant *ConstantFoldScalarCall1(StringRef Name, break; case LibFunc_log1p: case LibFunc_log1pf: + // Implement optional behavior from C's Annex F for +/-0.0. + if (U.isZero()) + return ConstantFP::get(Ty->getContext(), U); if (APF > APFloat::getOne(APF.getSemantics(), true) && TLI->has(Func)) return ConstantFoldFP(log1p, APF, Ty); break; |