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| author | Reid Kleckner <reid@kleckner.net> | 2014-03-27 17:49:27 +0000 |
|---|---|---|
| committer | Reid Kleckner <reid@kleckner.net> | 2014-03-27 17:49:27 +0000 |
| commit | 63b11ef6d40b719d555c1398ca05b1f477ecfe39 (patch) | |
| tree | c9d1f41f4b3e4bf7db62725d68efb3313a82bb52 /test | |
| parent | 0c6d96cf160f2a6c63f59b5ab7e7a6bbe903ede3 (diff) | |
| download | llvm-63b11ef6d40b719d555c1398ca05b1f477ecfe39.tar.gz llvm-63b11ef6d40b719d555c1398ca05b1f477ecfe39.tar.bz2 llvm-63b11ef6d40b719d555c1398ca05b1f477ecfe39.tar.xz | |
InstCombine: Don't combine constants on unsigned icmps
Fixes a miscompile introduced in r204912. It would miscompile code like
(unsigned)(a + -49) <= 5U. The transform would turn this into
(unsigned)a < 55U, which would return true for values in [0, 49], when
it should not.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204948 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test')
| -rw-r--r-- | test/Transforms/InstCombine/icmp.ll | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/test/Transforms/InstCombine/icmp.ll b/test/Transforms/InstCombine/icmp.ll index 2e3ff24f6b..63fefc0877 100644 --- a/test/Transforms/InstCombine/icmp.ll +++ b/test/Transforms/InstCombine/icmp.ll @@ -1409,3 +1409,13 @@ entry: %conv = zext i1 %cmp to i32 ret i32 %conv } + +; CHECK-LABEL: icmp_add_const_ult +; CHECK: %cmp = icmp ult i32 %add, 6 +define i32 @icmp_add_const_ult(i32 %a) #0 { +entry: + %add = add nsw i32 %a, -49 + %cmp = icmp ult i32 %add, 6 + %conv = zext i1 %cmp to i32 + ret i32 %conv +} |