diff options
Diffstat (limited to 'llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp index 2926e268190..e0a1083b927 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -2338,12 +2338,15 @@ Instruction *InstCombiner::foldICmpAddConstant(ICmpInst &Cmp, CmpInst::Predicate Pred = Cmp.getPredicate(); // If the add does not wrap, we can always adjust the compare by subtracting - // the constants. Equality comparisons are handled elsewhere. SGE/SLE are - // canonicalized to SGT/SLT. - if (Add->hasNoSignedWrap() && - (Pred == ICmpInst::ICMP_SGT || Pred == ICmpInst::ICMP_SLT)) { + // the constants. Equality comparisons are handled elsewhere. SGE/SLE/UGE/ULE + // are canonicalized to SGT/SLT/UGT/ULT. + if ((Add->hasNoSignedWrap() && + (Pred == ICmpInst::ICMP_SGT || Pred == ICmpInst::ICMP_SLT)) || + (Add->hasNoUnsignedWrap() && + (Pred == ICmpInst::ICMP_UGT || Pred == ICmpInst::ICMP_ULT))) { bool Overflow; - APInt NewC = C.ssub_ov(*C2, Overflow); + APInt NewC = + Cmp.isSigned() ? C.ssub_ov(*C2, Overflow) : C.usub_ov(*C2, Overflow); // If there is overflow, the result must be true or false. // TODO: Can we assert there is no overflow because InstSimplify always // handles those cases? |
