1 // compile-flags: -C no-prepopulate-passes -Z partially_uninit_const_threshold=1024
3 // Like uninit-consts.rs, but tests that we correctly generate partially-uninit consts
4 // when the (disabled by default) partially_uninit_const_threshold flag is used.
8 use std
::mem
::MaybeUninit
;
10 pub struct PartiallyUninit
{
12 y
: MaybeUninit
<[u8; 10]>
15 // This should be partially undef.
16 // CHECK: [[PARTIALLY_UNINIT:@[0-9]+]] = private unnamed_addr constant <{ [4 x i8], [12 x i8] }> <{ [4 x i8] c"\EF\BE\AD\DE", [12 x i8] undef }>, align 4
18 // This shouldn't contain undef, since it's larger than the 1024 byte limit.
19 // CHECK: [[UNINIT_PADDING_HUGE:@[0-9]+]] = private unnamed_addr constant <{ [32768 x i8] }> <{ [32768 x i8] c"{{.+}}" }>, align 4
21 // CHECK-LABEL: @partially_uninit
23 pub const fn partially_uninit() -> PartiallyUninit
{
24 const X
: PartiallyUninit
= PartiallyUninit { x: 0xdeadbeef, y: MaybeUninit::uninit() }
;
25 // CHECK: call void @llvm.memcpy.p0i8.p0i8.i{{(32|64)}}(i8* align 4 %1, i8* align 4 getelementptr inbounds (<{ [4 x i8], [12 x i8] }>, <{ [4 x i8], [12 x i8] }>* [[PARTIALLY_UNINIT]], i32 0, i32 0, i32 0), i{{(32|64)}} 16, i1 false)
29 // CHECK-LABEL: @uninit_padding_huge
31 pub const fn uninit_padding_huge() -> [(u32, u8); 4096] {
32 const X
: [(u32, u8); 4096] = [(123, 45); 4096];
33 // CHECK: call void @llvm.memcpy.p0i8.p0i8.i{{(32|64)}}(i8* align 4 %1, i8* align 4 getelementptr inbounds (<{ [32768 x i8] }>, <{ [32768 x i8] }>* [[UNINIT_PADDING_HUGE]], i32 0, i32 0, i32 0), i{{(32|64)}} 32768, i1 false)