xref: /llvm-project/llvm/test/CodeGen/AArch64/global-alignment.ll (revision 5ddce70ef0e5a641d7fea95e31fc5e2439cb98cb)
1; RUN: llc -mtriple=aarch64-linux-gnu -verify-machineinstrs -o - %s | FileCheck %s
2
3@var32 = dso_local global [3 x i32] zeroinitializer
4@var64 = dso_local global [3 x i64] zeroinitializer
5@var32_align64 = dso_local global [3 x i32] zeroinitializer, align 8
6@alias = dso_local alias [3 x i32], ptr @var32_align64
7
8define dso_local i64 @test_align32() {
9; CHECK-LABEL: test_align32:
10
11  ; Since @var32 is only guaranteed to be aligned to 32-bits, it's invalid to
12  ; emit an "LDR x0, [x0, #:lo12:var32] instruction to implement this load.
13  %val = load i64, ptr @var32
14; CHECK: adrp [[HIBITS:x[0-9]+]], var32
15; CHECK: add x[[ADDR:[0-9]+]], [[HIBITS]], {{#?}}:lo12:var32
16; CHECK: ldr x0, [x[[ADDR]]]
17
18  ret i64 %val
19}
20
21define dso_local i64 @test_align64() {
22; CHECK-LABEL: test_align64:
23
24  ; However, var64 *is* properly aligned and emitting an adrp/add/ldr would be
25  ; inefficient.
26  %val = load i64, ptr @var64
27; CHECK: adrp x[[HIBITS:[0-9]+]], var64
28; CHECK-NOT: add x[[HIBITS]]
29; CHECK: ldr x0, [x[[HIBITS]], {{#?}}:lo12:var64]
30
31  ret i64 %val
32}
33
34define dso_local i64 @test_var32_align64() {
35; CHECK-LABEL: test_var32_align64:
36
37  ; Since @var32 is only guaranteed to be aligned to 32-bits, it's invalid to
38  ; emit an "LDR x0, [x0, #:lo12:var32] instruction to implement this load.
39  %val = load i64, ptr @var32_align64
40; CHECK: adrp x[[HIBITS:[0-9]+]], var32_align64
41; CHECK-NOT: add x[[HIBITS]]
42; CHECK: ldr x0, [x[[HIBITS]], {{#?}}:lo12:var32_align64]
43
44  ret i64 %val
45}
46
47define dso_local i64 @test_var32_alias() {
48; CHECK-LABEL: test_var32_alias:
49
50  ; We don't know anything about the alignment of aliases.
51  %val = load i64, ptr @alias
52; CHECK: adrp x[[HIBITS:[0-9]+]], alias
53; CHECK: add x[[ADDR:[0-9]+]], x[[HIBITS]], {{#?}}:lo12:alias
54; CHECK: ldr x0, [x[[ADDR]]]
55
56  ret i64 %val
57}
58
59@yet_another_var = external dso_local global {i32, i32}
60
61define dso_local i64 @test_yet_another_var() {
62; CHECK-LABEL: test_yet_another_var:
63
64  ; @yet_another_var has a preferred alignment of 8, but that's not enough if
65  ; we're going to be linking against other things. Its ABI alignment is only 4
66  ; so we can't fold the load.
67  %val = load i64, ptr @yet_another_var
68; CHECK: adrp [[HIBITS:x[0-9]+]], yet_another_var
69; CHECK: add x[[ADDR:[0-9]+]], [[HIBITS]], {{#?}}:lo12:yet_another_var
70; CHECK: ldr x0, [x[[ADDR]]]
71  ret i64 %val
72}
73
74define dso_local ptr @test_functions() {
75; CHECK-LABEL: test_functions:
76  ret ptr @test_yet_another_var
77; CHECK: adrp [[HIBITS:x[0-9]+]], test_yet_another_var
78; CHECK: add x0, [[HIBITS]], {{#?}}:lo12:test_yet_another_var
79}
80