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| author | Juneyoung Lee <aqjune@gmail.com> | 2021-06-24 02:03:07 +0900 |
|---|---|---|
| committer | Juneyoung Lee <aqjune@gmail.com> | 2021-06-24 02:03:09 +0900 |
| commit | 2fd3037ac615643fe8058292d2b89bb19a49cb2f (patch) | |
| tree | b2fd7b6646dd4f53a2889f21ede614dab8cd4a25 /llvm/lib/IR/ConstantFold.cpp | |
| parent | 00d3f7cc3c264adc360d0282ba8a27de2a004b94 (diff) | |
| download | llvm-2fd3037ac615643fe8058292d2b89bb19a49cb2f.zip llvm-2fd3037ac615643fe8058292d2b89bb19a49cb2f.tar.gz llvm-2fd3037ac615643fe8058292d2b89bb19a49cb2f.tar.bz2 | |
[ConstantFold] Allow propagation of poison for and/or i1
They were disallowed due to its bad interaction with select i1 -> and/or i1.
The transformation is now disabled by D101191, so let's revive this.
Diffstat (limited to 'llvm/lib/IR/ConstantFold.cpp')
| -rw-r--r-- | llvm/lib/IR/ConstantFold.cpp | 9 |
1 files changed, 1 insertions, 8 deletions
diff --git a/llvm/lib/IR/ConstantFold.cpp b/llvm/lib/IR/ConstantFold.cpp index 652ccd3..e292578 100644 --- a/llvm/lib/IR/ConstantFold.cpp +++ b/llvm/lib/IR/ConstantFold.cpp @@ -1124,14 +1124,7 @@ Constant *llvm::ConstantFoldBinaryInstruction(unsigned Opcode, Constant *C1, } // Binary operations propagate poison. - // FIXME: Currently, or/and i1 poison aren't folded into poison because - // it causes miscompilation when combined with another optimization in - // InstCombine (select i1 -> and/or). The select fold is wrong, but - // fixing it requires an effort, so temporarily disable this until it is - // fixed. - bool PoisonFold = !C1->getType()->isIntegerTy(1) || - (Opcode != Instruction::Or && Opcode != Instruction::And); - if (PoisonFold && (isa<PoisonValue>(C1) || isa<PoisonValue>(C2))) + if (isa<PoisonValue>(C1) || isa<PoisonValue>(C2)) return PoisonValue::get(C1->getType()); // Handle scalar UndefValue and scalable vector UndefValue. Fixed-length |