1 // ignore-debug: the debug assertions get in the way
2 // compile-flags: -O -Z merge-functions=disabled
3 // min-llvm-version: 16
4 #![crate_type = "lib"]
5
6 // Ensure that trivial casts of vec elements are O(1)
7
8 pub struct Wrapper<T>(T);
9
10 // previously repr(C) caused the optimization to fail
11 #[repr(C)]
12 pub struct Foo {
13 a: u64,
14 b: u64,
15 c: u64,
16 d: u64,
17 }
18
19 // implementing Copy exercises the TrustedRandomAccess specialization inside the in-place
20 // specialization
21 #[derive(Copy, Clone)]
22 pub struct Bar {
23 a: u64,
24 b: u64,
25 c: u64,
26 d: u64,
27 }
28
29 // this exercises the try-fold codepath
30 pub struct Baz {
31 a: u64,
32 b: u64,
33 c: u64,
34 d: u64,
35 }
36
37 // CHECK-LABEL: @vec_iterator_cast_primitive
38 #[no_mangle]
vec_iterator_cast_primitive(vec: Vec<i8>) -> Vec<u8>39 pub fn vec_iterator_cast_primitive(vec: Vec<i8>) -> Vec<u8> {
40 // CHECK-NOT: loop
41 // CHECK-NOT: call
42 vec.into_iter().map(|e| e as u8).collect()
43 }
44
45 // CHECK-LABEL: @vec_iterator_cast_wrapper
46 #[no_mangle]
vec_iterator_cast_wrapper(vec: Vec<u8>) -> Vec<Wrapper<u8>>47 pub fn vec_iterator_cast_wrapper(vec: Vec<u8>) -> Vec<Wrapper<u8>> {
48 // CHECK-NOT: loop
49 // CHECK-NOT: call
50 vec.into_iter().map(|e| Wrapper(e)).collect()
51 }
52
53 // CHECK-LABEL: @vec_iterator_cast_unwrap
54 #[no_mangle]
vec_iterator_cast_unwrap(vec: Vec<Wrapper<u8>>) -> Vec<u8>55 pub fn vec_iterator_cast_unwrap(vec: Vec<Wrapper<u8>>) -> Vec<u8> {
56 // CHECK-NOT: loop
57 // CHECK-NOT: call
58 vec.into_iter().map(|e| e.0).collect()
59 }
60
61 // CHECK-LABEL: @vec_iterator_cast_aggregate
62 #[no_mangle]
vec_iterator_cast_aggregate(vec: Vec<[u64; 4]>) -> Vec<Foo>63 pub fn vec_iterator_cast_aggregate(vec: Vec<[u64; 4]>) -> Vec<Foo> {
64 // CHECK-NOT: loop
65 // CHECK-NOT: call
66 vec.into_iter().map(|e| unsafe { std::mem::transmute(e) }).collect()
67 }
68
69 // CHECK-LABEL: @vec_iterator_cast_deaggregate_tra
70 #[no_mangle]
vec_iterator_cast_deaggregate_tra(vec: Vec<Bar>) -> Vec<[u64; 4]>71 pub fn vec_iterator_cast_deaggregate_tra(vec: Vec<Bar>) -> Vec<[u64; 4]> {
72 // CHECK-NOT: loop
73 // CHECK-NOT: call
74
75 // Safety: For the purpose of this test we assume that Bar layout matches [u64; 4].
76 // This currently is not guaranteed for repr(Rust) types, but it happens to work here and
77 // the UCG may add additional guarantees for homogenous types in the future that would make this
78 // correct.
79 vec.into_iter().map(|e| unsafe { std::mem::transmute(e) }).collect()
80 }
81
82 // CHECK-LABEL: @vec_iterator_cast_deaggregate_fold
83 #[no_mangle]
vec_iterator_cast_deaggregate_fold(vec: Vec<Baz>) -> Vec<[u64; 4]>84 pub fn vec_iterator_cast_deaggregate_fold(vec: Vec<Baz>) -> Vec<[u64; 4]> {
85 // CHECK-NOT: loop
86 // CHECK-NOT: call
87
88 // Safety: For the purpose of this test we assume that Bar layout matches [u64; 4].
89 // This currently is not guaranteed for repr(Rust) types, but it happens to work here and
90 // the UCG may add additional guarantees for homogenous types in the future that would make this
91 // correct.
92 vec.into_iter().map(|e| unsafe { std::mem::transmute(e) }).collect()
93 }
94