1//! Utility macros.
2
3#[allow(unused)]
4macro_rules! static_assert {
5 ($e:expr) => {
6 const {
7 assert!($e);
8 }
9 };
10 ($e:expr, $msg:expr) => {
11 const {
12 assert!($e, $msg);
13 }
14 };
15}
16
17#[allow(unused_macros)]
18macro_rules! static_assert_uimm_bits {
19 ($imm:ident, $bits:expr) => {
20 // `0 <= $imm` produces a warning if the immediate has an unsigned type
21 #[allow(unused_comparisons)]
22 {
23 static_assert!(
24 0 <= $imm && $imm < (1 << $bits),
25 concat!(
26 stringify!($imm),
27 " doesn't fit in ",
28 stringify!($bits),
29 " bits",
30 )
31 )
32 }
33 };
34}
35
36#[allow(unused_macros)]
37macro_rules! static_assert_simm_bits {
38 ($imm:ident, $bits:expr) => {
39 static_assert!(
40 (-1 << ($bits - 1)) - 1 <= $imm && $imm < (1 << ($bits - 1)),
41 concat!(
42 stringify!($imm),
43 " doesn't fit in ",
44 stringify!($bits),
45 " bits",
46 )
47 )
48 };
49}
50
51#[allow(unused)]
52macro_rules! types {
53 (
54 #![$stability_first:meta]
55 $(
56 #![$stability_more:meta]
57 )*
58
59 $(
60 $(#[$doc:meta])*
61 $(stability: [$stability_already: meta])*
62 pub struct $name:ident($len:literal x $v:vis $elem_type:ty);
63 )*
64 ) => (types! {
65 $(
66 #![$stability_more]
67 )*
68
69 $(
70 $(#[$doc])*
71 $(stability: [$stability_already])*
72 stability: [$stability_first]
73 pub struct $name($len x $v $elem_type);
74 )*
75 });
76
77 (
78 $(
79 $(#[$doc:meta])*
80 $(stability: [$stability: meta])+
81 pub struct $name:ident($len:literal x $v:vis $elem_type:ty);
82 )*
83 ) => ($(
84 $(#[$doc])*
85 $(#[$stability])+
86 #[derive(Copy, Clone)]
87 #[allow(non_camel_case_types)]
88 #[repr(simd)]
89 #[allow(clippy::missing_inline_in_public_items)]
90 pub struct $name($v [$elem_type; $len]);
91
92 impl $name {
93 /// Using `my_simd([x; N])` seemingly fails tests,
94 /// so use this internal helper for it instead.
95 #[inline(always)]
96 $v fn splat(value: $elem_type) -> $name {
97 #[derive(Copy, Clone)]
98 #[repr(simd)]
99 struct JustOne([$elem_type; 1]);
100 let one = JustOne([value]);
101 // SAFETY: 0 is always in-bounds because we're shuffling
102 // a simd type with exactly one element.
103 unsafe { simd_shuffle!(one, one, [0; $len]) }
104 }
105
106 /// Returns an array reference containing the entire SIMD vector.
107 $v const fn as_array(&self) -> &[$elem_type; $len] {
108 // SAFETY: this type is just an overaligned `[T; N]` with
109 // potential padding at the end, so pointer casting to a
110 // `&[T; N]` is safe.
111 //
112 // NOTE: This deliberately doesn't just use `&self.0` because it may soon be banned
113 // see https://github.com/rust-lang/compiler-team/issues/838
114 unsafe { &*(self as *const Self as *const [$elem_type; $len]) }
115
116 }
117
118 /// Returns a mutable array reference containing the entire SIMD vector.
119 #[inline]
120 $v fn as_mut_array(&mut self) -> &mut [$elem_type; $len] {
121 // SAFETY: this type is just an overaligned `[T; N]` with
122 // potential padding at the end, so pointer casting to a
123 // `&mut [T; N]` is safe.
124 //
125 // NOTE: This deliberately doesn't just use `&mut self.0` because it may soon be banned
126 // see https://github.com/rust-lang/compiler-team/issues/838
127 unsafe { &mut *(self as *mut Self as *mut [$elem_type; $len]) }
128 }
129 }
130
131 $(#[$stability])+
132 impl crate::fmt::Debug for $name {
133 #[inline]
134 fn fmt(&self, f: &mut crate::fmt::Formatter<'_>) -> crate::fmt::Result {
135 crate::core_arch::simd::debug_simd_finish(f, stringify!($name), self.0)
136 }
137 }
138 )*);
139}
140
141#[allow(unused)]
142#[repr(simd)]
143pub(crate) struct SimdShuffleIdx<const LEN: usize>(pub(crate) [u32; LEN]);
144
145#[allow(unused)]
146macro_rules! simd_shuffle {
147 ($x:expr, $y:expr, $idx:expr $(,)?) => {{
148 $crate::intrinsics::simd::simd_shuffle(
149 $x,
150 $y,
151 const { $crate::core_arch::macros::SimdShuffleIdx($idx) },
152 )
153 }};
154}
155
156#[allow(unused)]
157macro_rules! simd_insert {
158 ($x:expr, $idx:expr, $val:expr $(,)?) => {{ $crate::intrinsics::simd::simd_insert($x, const { $idx }, $val) }};
159}
160
161#[allow(unused)]
162macro_rules! simd_extract {
163 ($x:expr, $idx:expr $(,)?) => {{ $crate::intrinsics::simd::simd_extract($x, const { $idx }) }};
164 ($x:expr, $idx:expr, $ty:ty $(,)?) => {{ $crate::intrinsics::simd::simd_extract::<_, $ty>($x, const { $idx }) }};
165}
166