xref: /llvm-project/llvm/test/Analysis/GlobalsModRef/purecse.ll (revision 47f0b6630c78ab52c2197ec5e1c2d13a6acffed1)
1; Test that pure functions are cse'd away
2; RUN: opt < %s -aa-pipeline=globals-aa,basic-aa -passes='require<globals-aa>,gvn,instcombine' -S | FileCheck %s
3
4define i32 @pure(i32 %X) {
5        %Y = add i32 %X, 1              ; <i32> [#uses=1]
6        ret i32 %Y
7}
8
9define i32 @test1(i32 %X) {
10; CHECK:      %A = call i32 @pure(i32 %X)
11; CHECK-NEXT: ret i32 0
12        %A = call i32 @pure( i32 %X )           ; <i32> [#uses=1]
13        %B = call i32 @pure( i32 %X )           ; <i32> [#uses=1]
14        %C = sub i32 %A, %B             ; <i32> [#uses=1]
15        ret i32 %C
16}
17
18define i32 @test2(i32 %X, ptr %P) {
19; CHECK:      %A = call i32 @pure(i32 %X)
20; CHECK-NEXT: store i32 %X, ptr %P
21; CHECK-NEXT: ret i32 0
22        %A = call i32 @pure( i32 %X )           ; <i32> [#uses=1]
23        store i32 %X, ptr %P ;; Does not invalidate 'pure' call.
24        %B = call i32 @pure( i32 %X )           ; <i32> [#uses=1]
25        %C = sub i32 %A, %B             ; <i32> [#uses=1]
26        ret i32 %C
27}
28