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

/// A trait for describing vector operations used by vectorized searchers.
///
/// The trait is highly constrained to low level vector operations needed. In
/// general, it was invented mostly to be generic over x86's __m128i and
/// __m256i types. It's likely that once std::simd becomes a thing, we can
/// migrate to that since the operations required are quite simple.
///
/// TODO: Consider moving this trait up a level and using it to implement
/// memchr as well. The trait might need to grow one or two methods, but
/// otherwise should be close to sufficient already.
///
/// # Safety
///
/// All methods are not safe since they are intended to be implemented using
/// vendor intrinsics, which are also not safe. Callers must ensure that the
/// appropriate target features are enabled in the calling function, and that
/// the current CPU supports them. All implementations should avoid marking the
/// routines with #[target_feature] and instead mark them as #[inline(always)]
/// to ensure they get appropriately inlined. (inline(always) cannot be used
/// with target_feature.)
pub(crate) trait Vector: Copy + core::fmt::Debug {
    /// _mm_set1_epi8 or _mm256_set1_epi8
    unsafe fn splat(byte: u8) -> Self;
    /// _mm_loadu_si128 or _mm256_loadu_si256
    unsafe fn load_unaligned(data: *const u8) -> Self;
    /// _mm_movemask_epi8 or _mm256_movemask_epi8
    unsafe fn movemask(self) -> u32;
    /// _mm_cmpeq_epi8 or _mm256_cmpeq_epi8
    unsafe fn cmpeq(self, vector2: Self) -> Self;
    /// _mm_and_si128 or _mm256_and_si256
    unsafe fn and(self, vector2: Self) -> Self;
}

#[cfg(target_arch = "x86_64")]
mod x86sse {
    use super::Vector;
    use core::arch::x86_64::*;

    impl Vector for __m128i {
        #[inline(always)]
        unsafe fn splat(byte: u8) -> __m128i {
            _mm_set1_epi8(byte as i8)
        }

        #[inline(always)]
        unsafe fn load_unaligned(data: *const u8) -> __m128i {
            _mm_loadu_si128(data as *const __m128i)
        }

        #[inline(always)]
        unsafe fn movemask(self) -> u32 {
            _mm_movemask_epi8(self) as u32
        }

        #[inline(always)]
        unsafe fn cmpeq(self, vector2: Self) -> __m128i {
            _mm_cmpeq_epi8(self, vector2)
        }

        #[inline(always)]
        unsafe fn and(self, vector2: Self) -> __m128i {
            _mm_and_si128(self, vector2)
        }
    }
}

#[cfg(all(feature = "std", target_arch = "x86_64"))]
mod x86avx {
    use super::Vector;
    use core::arch::x86_64::*;

    impl Vector for __m256i {
        #[inline(always)]
        unsafe fn splat(byte: u8) -> __m256i {
            _mm256_set1_epi8(byte as i8)
        }

        #[inline(always)]
        unsafe fn load_unaligned(data: *const u8) -> __m256i {
            _mm256_loadu_si256(data as *const __m256i)
        }

        #[inline(always)]
        unsafe fn movemask(self) -> u32 {
            _mm256_movemask_epi8(self) as u32
        }

        #[inline(always)]
        unsafe fn cmpeq(self, vector2: Self) -> __m256i {
            _mm256_cmpeq_epi8(self, vector2)
        }

        #[inline(always)]
        unsafe fn and(self, vector2: Self) -> __m256i {
            _mm256_and_si256(self, vector2)
        }
    }
}

#[cfg(target_arch = "wasm32")]
mod wasm_simd128 {
    use super::Vector;
    use core::arch::wasm32::*;

    impl Vector for v128 {
        #[inline(always)]
        unsafe fn splat(byte: u8) -> v128 {
            u8x16_splat(byte)
        }

        #[inline(always)]
        unsafe fn load_unaligned(data: *const u8) -> v128 {
            v128_load(data.cast())
        }

        #[inline(always)]
        unsafe fn movemask(self) -> u32 {
            u8x16_bitmask(self).into()
        }

        #[inline(always)]
        unsafe fn cmpeq(self, vector2: Self) -> v128 {
            u8x16_eq(self, vector2)
        }

        #[inline(always)]
        unsafe fn and(self, vector2: Self) -> v128 {
            v128_and(self, vector2)
        }
    }
}