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
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
|
// `SetDiscriminant` does not actually write anything if the chosen variant is the untagged variant
// of a niche encoding. Verify that we do not thread over this case.
//@ unit-test: JumpThreading
#![feature(custom_mir)]
#![feature(core_intrinsics)]
use std::intrinsics::mir::*;
enum E<T> {
A,
B(T),
}
// EMIT_MIR set_no_discriminant.f.JumpThreading.diff
#[custom_mir(dialect = "runtime")]
pub fn f() -> usize {
// CHECK-LABEL: fn f(
// CHECK-NOT: goto
// CHECK: switchInt(
// CHECK-NOT: goto
mir!(
let a: isize;
let e: E<char>;
{
e = E::A;
SetDiscriminant(e, 1);
a = Discriminant(e);
match a {
0 => bb0,
_ => bb1,
}
}
bb0 = {
RET = 0;
Return()
}
bb1 = {
RET = 1;
Return()
}
)
}
// EMIT_MIR set_no_discriminant.generic.JumpThreading.diff
#[custom_mir(dialect = "runtime")]
pub fn generic<T>() -> usize {
// CHECK-LABEL: fn generic(
// CHECK-NOT: goto
// CHECK: switchInt(
// CHECK-NOT: goto
mir!(
let a: isize;
let e: E<T>;
{
e = E::A;
SetDiscriminant(e, 1);
a = Discriminant(e);
match a {
0 => bb0,
_ => bb1,
}
}
bb0 = {
RET = 0;
Return()
}
bb1 = {
RET = 1;
Return()
}
)
}
fn main() {
assert_eq!(f(), 0);
assert_eq!(generic::<char>(), 0);
}
|
