llvm/test/Transforms/InstCombine/2004-02-23-ShiftShiftOverflow.ll
2008-03-01 09:15:35 +00:00

16 lines
537 B
LLVM

; 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
}