1; RUN: opt < %s -S -globalopt | FileCheck %s
2
3; This global is externally_initialized, so if we split it into scalars we
4; should keep that flag set on all of the new globals. This will prevent the
5; store to @a[0] from being constant propagated to the load in @foo, but will not
6; prevent @a[1] from being removed since it is dead.
7; CHECK: @a.0 = internal unnamed_addr externally_initialized global i32 undef
8; CHECK-NOT: @a.1
9@a = internal externally_initialized global [2 x i32] undef, align 4
10; This is the same, but a struct rather than an array.
11; CHECK: @b.0 = internal unnamed_addr externally_initialized global i32 undef
12; CHECK-NOT: @b.1
13@b = internal externally_initialized global {i32, i32} undef, align 4
14
15define i32 @foo() {
16; CHECK-LABEL: define i32 @foo
17entry:
18; This load uses the split global, but cannot be constant-propagated away.
19; CHECK: %0 = load i32, i32* @a.0
20  %0 = load i32, i32* getelementptr inbounds ([2 x i32], [2 x i32]* @a, i32 0, i32 0), align 4
21  ret i32 %0
22}
23
24define i32 @bar() {
25; CHECK-LABEL: define i32 @bar
26entry:
27; This load uses the split global, but cannot be constant-propagated away.
28; CHECK: %0 = load i32, i32* @b.0
29  %0 = load i32, i32* getelementptr inbounds ({i32, i32}, {i32, i32}* @b, i32 0, i32 0), align 4
30  ret i32 %0
31}
32
33define void @init() {
34; CHECK-LABEL: define void @init
35entry:
36; This store uses the split global, but cannot be constant-propagated away.
37; CHECK: store i32 1, i32* @a.0
38  store i32 1, i32* getelementptr inbounds ([2 x i32], [2 x i32]* @a, i32 0, i32 0), align 4
39; This store can be removed, because the second element of @a is never read.
40; CHECK-NOT: store i32 2, i32* @a.1
41  store i32 2, i32* getelementptr inbounds ([2 x i32], [2 x i32]* @a, i32 0, i32 1), align 4
42
43; This store uses the split global, but cannot be constant-propagated away.
44; CHECK: store i32 3, i32* @b.0
45  store i32 3, i32* getelementptr inbounds ({i32, i32}, {i32, i32}* @b, i32 0, i32 0), align 4
46; This store can be removed, because the second element of @b is never read.
47; CHECK-NOT: store i32 4, i32* @b.1
48  store i32 4, i32* getelementptr inbounds ({i32, i32}, {i32, i32}* @b, i32 0, i32 1), align 4
49  ret void
50}
51