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
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156

use super::sealed::Sealed;
use crate::simd::{intrinsics, LaneCount, Simd, SimdCast, SimdElement, SupportedLaneCount};

/// Operations on SIMD vectors of unsigned integers.
pub trait SimdUint: Copy + Sealed {
    /// Scalar type contained by this SIMD vector type.
    type Scalar;

    /// A SIMD vector with a different element type.
    type Cast<T: SimdElement>;

    /// Performs elementwise conversion of this vector's elements to another SIMD-valid type.
    ///
    /// This follows the semantics of Rust's `as` conversion for casting integers (wrapping to
    /// other integer types, and saturating to float types).
    #[must_use]
    fn cast<T: SimdCast>(self) -> Self::Cast<T>;

    /// Lanewise saturating add.
    ///
    /// # Examples
    /// ```
    /// # #![feature(portable_simd)]
    /// # #[cfg(feature = "as_crate")] use core_simd::simd;
    /// # #[cfg(not(feature = "as_crate"))] use core::simd;
    /// # use simd::{Simd, SimdUint};
    /// use core::u32::MAX;
    /// let x = Simd::from_array([2, 1, 0, MAX]);
    /// let max = Simd::splat(MAX);
    /// let unsat = x + max;
    /// let sat = x.saturating_add(max);
    /// assert_eq!(unsat, Simd::from_array([1, 0, MAX, MAX - 1]));
    /// assert_eq!(sat, max);
    /// ```
    fn saturating_add(self, second: Self) -> Self;

    /// Lanewise saturating subtract.
    ///
    /// # Examples
    /// ```
    /// # #![feature(portable_simd)]
    /// # #[cfg(feature = "as_crate")] use core_simd::simd;
    /// # #[cfg(not(feature = "as_crate"))] use core::simd;
    /// # use simd::{Simd, SimdUint};
    /// use core::u32::MAX;
    /// let x = Simd::from_array([2, 1, 0, MAX]);
    /// let max = Simd::splat(MAX);
    /// let unsat = x - max;
    /// let sat = x.saturating_sub(max);
    /// assert_eq!(unsat, Simd::from_array([3, 2, 1, 0]));
    /// assert_eq!(sat, Simd::splat(0));
    fn saturating_sub(self, second: Self) -> Self;

    /// Returns the sum of the lanes of the vector, with wrapping addition.
    fn reduce_sum(self) -> Self::Scalar;

    /// Returns the product of the lanes of the vector, with wrapping multiplication.
    fn reduce_product(self) -> Self::Scalar;

    /// Returns the maximum lane in the vector.
    fn reduce_max(self) -> Self::Scalar;

    /// Returns the minimum lane in the vector.
    fn reduce_min(self) -> Self::Scalar;

    /// Returns the cumulative bitwise "and" across the lanes of the vector.
    fn reduce_and(self) -> Self::Scalar;

    /// Returns the cumulative bitwise "or" across the lanes of the vector.
    fn reduce_or(self) -> Self::Scalar;

    /// Returns the cumulative bitwise "xor" across the lanes of the vector.
    fn reduce_xor(self) -> Self::Scalar;
}

macro_rules! impl_trait {
    { $($ty:ty),* } => {
        $(
        impl<const LANES: usize> Sealed for Simd<$ty, LANES>
        where
            LaneCount<LANES>: SupportedLaneCount,
        {
        }

        impl<const LANES: usize> SimdUint for Simd<$ty, LANES>
        where
            LaneCount<LANES>: SupportedLaneCount,
        {
            type Scalar = $ty;
            type Cast<T: SimdElement> = Simd<T, LANES>;

            #[inline]
            fn cast<T: SimdCast>(self) -> Self::Cast<T> {
                // Safety: supported types are guaranteed by SimdCast
                unsafe { intrinsics::simd_as(self) }
            }

            #[inline]
            fn saturating_add(self, second: Self) -> Self {
                // Safety: `self` is a vector
                unsafe { intrinsics::simd_saturating_add(self, second) }
            }

            #[inline]
            fn saturating_sub(self, second: Self) -> Self {
                // Safety: `self` is a vector
                unsafe { intrinsics::simd_saturating_sub(self, second) }
            }

            #[inline]
            fn reduce_sum(self) -> Self::Scalar {
                // Safety: `self` is an integer vector
                unsafe { intrinsics::simd_reduce_add_ordered(self, 0) }
            }

            #[inline]
            fn reduce_product(self) -> Self::Scalar {
                // Safety: `self` is an integer vector
                unsafe { intrinsics::simd_reduce_mul_ordered(self, 1) }
            }

            #[inline]
            fn reduce_max(self) -> Self::Scalar {
                // Safety: `self` is an integer vector
                unsafe { intrinsics::simd_reduce_max(self) }
            }

            #[inline]
            fn reduce_min(self) -> Self::Scalar {
                // Safety: `self` is an integer vector
                unsafe { intrinsics::simd_reduce_min(self) }
            }

            #[inline]
            fn reduce_and(self) -> Self::Scalar {
                // Safety: `self` is an integer vector
                unsafe { intrinsics::simd_reduce_and(self) }
            }

            #[inline]
            fn reduce_or(self) -> Self::Scalar {
                // Safety: `self` is an integer vector
                unsafe { intrinsics::simd_reduce_or(self) }
            }

            #[inline]
            fn reduce_xor(self) -> Self::Scalar {
                // Safety: `self` is an integer vector
                unsafe { intrinsics::simd_reduce_xor(self) }
            }
        }
        )*
    }
}

impl_trait! { u8, u16, u32, u64, usize }