blob: 732da0a179494c65123a7486253ade25e2fb5cae (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
|
// compile-flags: -O
#![crate_type = "lib"]
use std::mem::MaybeUninit;
// Boxing a `MaybeUninit` value should not copy junk from the stack
#[no_mangle]
pub fn box_uninitialized() -> Box<MaybeUninit<usize>> {
// CHECK-LABEL: @box_uninitialized
// CHECK-NOT: store
// CHECK-NOT: alloca
// CHECK-NOT: memcpy
// CHECK-NOT: memset
Box::new(MaybeUninit::uninit())
}
// https://github.com/rust-lang/rust/issues/58201
#[no_mangle]
pub fn box_uninitialized2() -> Box<MaybeUninit<[usize; 1024 * 1024]>> {
// CHECK-LABEL: @box_uninitialized2
// CHECK-NOT: store
// CHECK-NOT: alloca
// CHECK-NOT: memcpy
// CHECK-NOT: memset
Box::new(MaybeUninit::uninit())
}
#[repr(align(1024))]
pub struct LotsaPadding(usize);
// Boxing a value with padding should not copy junk from the stack
#[no_mangle]
pub fn box_lotsa_padding() -> Box<LotsaPadding> {
// CHECK-LABEL: @box_lotsa_padding
// CHECK-NOT: alloca
// CHECK-NOT: getelementptr
// CHECK-NOT: memcpy
// CHECK-NOT: memset
Box::new(LotsaPadding(42))
}
// Hide the `allocalign` attribute in the declaration of __rust_alloc
// from the CHECK-NOT above, and also verify the attributes got set reasonably.
// CHECK: declare {{(dso_local )?}}noalias noundef ptr @__rust_alloc(i{{[0-9]+}} noundef, i{{[0-9]+}} allocalign noundef) unnamed_addr [[RUST_ALLOC_ATTRS:#[0-9]+]]
// CHECK-DAG: attributes [[RUST_ALLOC_ATTRS]] = { {{.*}} allockind("alloc,uninitialized,aligned") allocsize(0) {{(uwtable )?}}"alloc-family"="__rust_alloc" {{.*}} }
|
