diff options
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp | 6 | ||||
| -rw-r--r-- | llvm/test/Transforms/InstCombine/or.ll | 7 |
2 files changed, 8 insertions, 5 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp index efe1c068300..a661156f4ca 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp @@ -878,7 +878,7 @@ Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) { return RHS; case ICmpInst::ICMP_NE: // Special case to get the ordering right when the values wrap around - // zero. + // zero. Ie, we assumed the constants were unsigned when swapping earlier. if (LHSC->getValue() == 0 && RHSC->getValue().isAllOnesValue()) std::swap(LHSC, RHSC); if (LHSC == SubOne(RHSC)) { @@ -1785,6 +1785,10 @@ Value *InstCombiner::FoldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS, } } + // Special case to get the ordering right when the values wrap around + // zero. Ie, we assumed the constants were unsigned when swapping earlier. + if (LHSC->getValue() == 0 && RHSC->getValue().isAllOnesValue()) + std::swap(LHSC, RHSC); if (LHSC == SubOne(RHSC)) { // (X == 13 | X == 14) -> X-13 <=u 1 // An 'add' is the canonical IR form, so favor that over a 'sub'. diff --git a/llvm/test/Transforms/InstCombine/or.ll b/llvm/test/Transforms/InstCombine/or.ll index bf575418ce9..ad46023d8a5 100644 --- a/llvm/test/Transforms/InstCombine/or.ll +++ b/llvm/test/Transforms/InstCombine/or.ll @@ -271,10 +271,9 @@ define i1 @cmp_eq_with_diff_one(i8 %x) { define i1 @cmp_eq_with_diff_one_signed(i32 %x) { ; CHECK-LABEL: @cmp_eq_with_diff_one_signed( -; CHECK-NEXT: [[CMP1:%.*]] = icmp eq i32 %x, -1 -; CHECK-NEXT: [[CMP2:%.*]] = icmp eq i32 %x, 0 -; CHECK-NEXT: [[OR:%.*]] = or i1 [[CMP1]], [[CMP2]] -; CHECK-NEXT: ret i1 [[OR]] +; CHECK-NEXT: [[TMP1:%.*]] = add i32 %x, 1 +; CHECK-NEXT: [[TMP2:%.*]] = icmp ult i32 [[TMP1]], 2 +; CHECK-NEXT: ret i1 [[TMP2]] ; %cmp1 = icmp eq i32 %x, -1 %cmp2 = icmp eq i32 %x, 0 |
