llvm-project/llvm/test/Analysis/BasicAA/2003-02-26-AccessSizeTest.ll

21 lines
660 B
LLVM

; This testcase makes sure that size is taken to account when alias analysis
; is performed. It is not legal to delete the second load instruction because
; the value computed by the first load instruction is changed by the store.
; RUN: opt < %s -basicaa -gvn -instcombine -S | FileCheck %s
define i32 @test() {
; CHECK: %Y.DONOTREMOVE = load i32, i32* %A
; CHECK: %Z = sub i32 0, %Y.DONOTREMOVE
%A = alloca i32
store i32 0, i32* %A
%X = load i32, i32* %A
%B = bitcast i32* %A to i8*
%C = getelementptr i8, i8* %B, i64 1
store i8 1, i8* %C ; Aliases %A
%Y.DONOTREMOVE = load i32, i32* %A
%Z = sub i32 %X, %Y.DONOTREMOVE
ret i32 %Z
}