diff options
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp index 94999ba3df2..784ff9eb56c 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -2872,6 +2872,8 @@ Instruction *InstCombiner::foldICmpInstWithConstantNotInt(ICmpInst &I) { /// Folds: /// x & (-1 >> y) SrcPred x to x DstPred (-1 >> y) /// The Mask can be a constant, too. +/// For some predicates, the operands are commutative. +/// For others, x can only be on a specific side. static Value *foldICmpWithLowBitMaskedVal(ICmpInst &I, InstCombiner::BuilderTy &Builder) { ICmpInst::Predicate SrcPred; @@ -2936,9 +2938,8 @@ static Value *foldICmpWithLowBitMaskedVal(ICmpInst &I, return nullptr; // Ignore the other case. DstPred = ICmpInst::Predicate::ICMP_SLE; break; - // TODO: more folds are possible, https://bugs.llvm.org/show_bug.cgi?id=38123 default: - return nullptr; + llvm_unreachable("All possible folds are handled."); } return Builder.CreateICmp(DstPred, X, M); |
