diff options
Diffstat (limited to 'test/Transforms/InstCombine/2004-02-23-ShiftShiftOverflow.ll')
-rw-r--r-- | test/Transforms/InstCombine/2004-02-23-ShiftShiftOverflow.ll | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/test/Transforms/InstCombine/2004-02-23-ShiftShiftOverflow.ll b/test/Transforms/InstCombine/2004-02-23-ShiftShiftOverflow.ll new file mode 100644 index 000000000000..3a4b66157dfe --- /dev/null +++ b/test/Transforms/InstCombine/2004-02-23-ShiftShiftOverflow.ll @@ -0,0 +1,15 @@ +; RUN: llvm-as < %s | opt -instcombine | llvm-dis | not grep 34 + +define i32 @test(i32 %X) { + ; Do not fold into shr X, 34, as this uses undefined behavior! + %Y = ashr i32 %X, 17 ; <i32> [#uses=1] + %Z = ashr i32 %Y, 17 ; <i32> [#uses=1] + ret i32 %Z +} + +define i32 @test2(i32 %X) { + ; Do not fold into shl X, 34, as this uses undefined behavior! + %Y = shl i32 %X, 17 ; <i32> [#uses=1] + %Z = shl i32 %Y, 17 ; <i32> [#uses=1] + ret i32 %Z +} |