YouCompleteMe/cpp/llvm/test/Transforms/InstCombine/2004-02-23-ShiftShiftOverflow.ll
2012-07-05 17:51:06 -07:00

16 lines
519 B
LLVM

; RUN: opt < %s -instcombine -S | 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
}