xref: /llvm-project/llvm/test/Analysis/BasicAA/store-promote.ll (revision 3caf301a8be1ebeed466f998bf2b21497f6df760)
1; Test that LICM uses basicaa to do alias analysis, which is capable of
2; disambiguating some obvious cases.  If LICM is able to disambiguate the
3; two pointers, then the load should be hoisted, and the store sunk.
4
5; RUN: opt < %s -aa-pipeline=basic-aa -passes='loop-mssa(licm)' -S | FileCheck %s
6target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"
7
8@A = global i32 7               ; <ptr> [#uses=3]
9@B = global i32 8               ; <ptr> [#uses=2]
10@C = global [2 x i32] [ i32 4, i32 8 ]          ; <ptr> [#uses=2]
11
12define i32 @test1(i1 %c) {
13        %Atmp = load i32, ptr @A            ; <i32> [#uses=2]
14        br label %Loop
15
16Loop:           ; preds = %Loop, %0
17        %ToRemove = load i32, ptr @A                ; <i32> [#uses=1]
18        store i32 %Atmp, ptr @B
19        br i1 %c, label %Out, label %Loop
20
21Out:            ; preds = %Loop
22        %X = sub i32 %ToRemove, %Atmp           ; <i32> [#uses=1]
23        ret i32 %X
24
25; The Loop block should be empty after the load/store are promoted.
26; CHECK:     @test1
27; CHECK:        load i32, ptr @A
28; CHECK:         load i32, ptr @A
29; CHECK:         store i32 %Atmp, ptr @B
30; CHECK:      Loop:
31; CHECK-NEXT:   br i1 %c, label %Out, label %Loop
32; CHECK:      Out:
33}
34
35define i32 @test2(i1 %c) {
36        br label %Loop
37
38Loop:           ; preds = %Loop, %0
39        %AVal = load i32, ptr @A            ; <i32> [#uses=2]
40        %C0 = getelementptr [2 x i32], ptr @C, i64 0, i64 0         ; <ptr> [#uses=1]
41        store i32 %AVal, ptr %C0
42        %BVal = load i32, ptr @B            ; <i32> [#uses=2]
43        %C1 = getelementptr [2 x i32], ptr @C, i64 0, i64 1         ; <ptr> [#uses=1]
44        store i32 %BVal, ptr %C1
45        br i1 %c, label %Out, label %Loop
46
47Out:            ; preds = %Loop
48        %X = sub i32 %AVal, %BVal               ; <i32> [#uses=1]
49        ret i32 %X
50; The Loop block should be empty after the load/store are promoted.
51; CHECK:     @test2
52; CHECK:      Loop:
53; CHECK-NEXT:   br i1 %c, label %Out, label %Loop
54}
55
56