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| author | Andrea Di Biagio <Andrea_DiBiagio@sn.scee.net> | 2014-10-09 12:41:49 +0000 |
|---|---|---|
| committer | Andrea Di Biagio <Andrea_DiBiagio@sn.scee.net> | 2014-10-09 12:41:49 +0000 |
| commit | 458a669f49e30a30b0fbfcc34fc4e556befbb73b (patch) | |
| tree | 3910473c2104a4a7138d9c50220f32f2bca5a13a /llvm/test | |
| parent | 9b280eab6699e4d1e3e203254ec93b424f10f40d (diff) | |
| download | bcm5719-llvm-458a669f49e30a30b0fbfcc34fc4e556befbb73b.tar.gz bcm5719-llvm-458a669f49e30a30b0fbfcc34fc4e556befbb73b.zip | |
[InstCombine] Fix wrong folding of constant comparisons involving ashr and negative values.
This patch fixes a bug in method InstCombiner::FoldCmpCstShrCst where we
wrongly computed the distance between the highest bits set of two negative
values.
This fixes PR21222.
Differential Revision: http://reviews.llvm.org/D5700
llvm-svn: 219406
Diffstat (limited to 'llvm/test')
| -rw-r--r-- | llvm/test/Transforms/InstCombine/icmp-shr.ll | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/llvm/test/Transforms/InstCombine/icmp-shr.ll b/llvm/test/Transforms/InstCombine/icmp-shr.ll index 8e7c906a545..7562f24a35d 100644 --- a/llvm/test/Transforms/InstCombine/icmp-shr.ll +++ b/llvm/test/Transforms/InstCombine/icmp-shr.ll @@ -688,3 +688,11 @@ define i1 @PR20945(i32 %B) { %cmp = icmp ne i32 %shr, -5 ret i1 %cmp } + +; CHECK-LABEL: @PR21222 +; CHECK: icmp eq i32 %B, 6 +define i1 @PR21222(i32 %B) { + %shr = ashr i32 -93, %B + %cmp = icmp eq i32 %shr, -2 + ret i1 %cmp +} |
