diff options
Diffstat (limited to 'llvm')
| -rw-r--r-- | llvm/test/Transforms/CorrelatedValuePropagation/phi-common-val.ll | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/llvm/test/Transforms/CorrelatedValuePropagation/phi-common-val.ll b/llvm/test/Transforms/CorrelatedValuePropagation/phi-common-val.ll index b761fff0031..814dcba1586 100644 --- a/llvm/test/Transforms/CorrelatedValuePropagation/phi-common-val.ll +++ b/llvm/test/Transforms/CorrelatedValuePropagation/phi-common-val.ll @@ -123,3 +123,30 @@ return: ret i8* %r } +; FIXME: +; The sub has 'nsw', so it is not safe to propagate that value along +; the bb2 edge because that would propagate poison to the return. + +define i32 @PR43802(i32 %arg) { +; CHECK-LABEL: @PR43802( +; CHECK-NEXT: entry: +; CHECK-NEXT: [[SUB:%.*]] = sub nsw i32 0, [[ARG:%.*]] +; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[ARG]], -2147483648 +; CHECK-NEXT: br i1 [[CMP]], label [[BB2:%.*]], label [[BB3:%.*]] +; CHECK: bb2: +; CHECK-NEXT: br label [[BB3]] +; CHECK: bb3: +; CHECK-NEXT: ret i32 [[SUB]] +; +entry: + %sub = sub nsw i32 0, %arg + %cmp = icmp eq i32 %arg, -2147483648 + br i1 %cmp, label %bb2, label %bb3 + +bb2: + br label %bb3 + +bb3: + %r = phi i32 [ -2147483648, %bb2 ], [ %sub, %entry ] + ret i32 %r +} |
