sha2/sha256/
x86.rs

1//! SHA-256 `x86`/`x86_64` backend
2
3#![allow(clippy::many_single_char_names)]
4
5#[cfg(target_arch = "x86")]
6use core::arch::x86::*;
7#[cfg(target_arch = "x86_64")]
8use core::arch::x86_64::*;
9
10unsafe fn schedule(v0: __m128i, v1: __m128i, v2: __m128i, v3: __m128i) -> __m128i {
11    let t1 = _mm_sha256msg1_epu32(v0, v1);
12    let t2 = _mm_alignr_epi8(v3, v2, 4);
13    let t3 = _mm_add_epi32(t1, t2);
14    _mm_sha256msg2_epu32(t3, v3)
15}
16
17macro_rules! rounds4 {
18    ($abef:ident, $cdgh:ident, $rest:expr, $i:expr) => {{
19        let k = crate::consts::K32X4[$i];
20        let kv = _mm_set_epi32(k[0] as i32, k[1] as i32, k[2] as i32, k[3] as i32);
21        let t1 = _mm_add_epi32($rest, kv);
22        $cdgh = _mm_sha256rnds2_epu32($cdgh, $abef, t1);
23        let t2 = _mm_shuffle_epi32(t1, 0x0E);
24        $abef = _mm_sha256rnds2_epu32($abef, $cdgh, t2);
25    }};
26}
27
28macro_rules! schedule_rounds4 {
29    (
30        $abef:ident, $cdgh:ident,
31        $w0:expr, $w1:expr, $w2:expr, $w3:expr, $w4:expr,
32        $i: expr
33    ) => {{
34        $w4 = schedule($w0, $w1, $w2, $w3);
35        rounds4!($abef, $cdgh, $w4, $i);
36    }};
37}
38
39// we use unaligned loads with `__m128i` pointers
40#[allow(clippy::cast_ptr_alignment)]
41#[target_feature(enable = "sha,sse2,ssse3,sse4.1")]
42unsafe fn digest_blocks(state: &mut [u32; 8], blocks: &[[u8; 64]]) {
43    #[allow(non_snake_case)]
44    let MASK: __m128i = _mm_set_epi64x(
45        0x0C0D_0E0F_0809_0A0Bu64 as i64,
46        0x0405_0607_0001_0203u64 as i64,
47    );
48
49    let state_ptr = state.as_ptr() as *const __m128i;
50    let dcba = _mm_loadu_si128(state_ptr.add(0));
51    let efgh = _mm_loadu_si128(state_ptr.add(1));
52
53    let cdab = _mm_shuffle_epi32(dcba, 0xB1);
54    let efgh = _mm_shuffle_epi32(efgh, 0x1B);
55    let mut abef = _mm_alignr_epi8(cdab, efgh, 8);
56    let mut cdgh = _mm_blend_epi16(efgh, cdab, 0xF0);
57
58    for block in blocks {
59        let abef_save = abef;
60        let cdgh_save = cdgh;
61
62        let data_ptr = block.as_ptr() as *const __m128i;
63        let mut w0 = _mm_shuffle_epi8(_mm_loadu_si128(data_ptr.add(0)), MASK);
64        let mut w1 = _mm_shuffle_epi8(_mm_loadu_si128(data_ptr.add(1)), MASK);
65        let mut w2 = _mm_shuffle_epi8(_mm_loadu_si128(data_ptr.add(2)), MASK);
66        let mut w3 = _mm_shuffle_epi8(_mm_loadu_si128(data_ptr.add(3)), MASK);
67        let mut w4;
68
69        rounds4!(abef, cdgh, w0, 0);
70        rounds4!(abef, cdgh, w1, 1);
71        rounds4!(abef, cdgh, w2, 2);
72        rounds4!(abef, cdgh, w3, 3);
73        schedule_rounds4!(abef, cdgh, w0, w1, w2, w3, w4, 4);
74        schedule_rounds4!(abef, cdgh, w1, w2, w3, w4, w0, 5);
75        schedule_rounds4!(abef, cdgh, w2, w3, w4, w0, w1, 6);
76        schedule_rounds4!(abef, cdgh, w3, w4, w0, w1, w2, 7);
77        schedule_rounds4!(abef, cdgh, w4, w0, w1, w2, w3, 8);
78        schedule_rounds4!(abef, cdgh, w0, w1, w2, w3, w4, 9);
79        schedule_rounds4!(abef, cdgh, w1, w2, w3, w4, w0, 10);
80        schedule_rounds4!(abef, cdgh, w2, w3, w4, w0, w1, 11);
81        schedule_rounds4!(abef, cdgh, w3, w4, w0, w1, w2, 12);
82        schedule_rounds4!(abef, cdgh, w4, w0, w1, w2, w3, 13);
83        schedule_rounds4!(abef, cdgh, w0, w1, w2, w3, w4, 14);
84        schedule_rounds4!(abef, cdgh, w1, w2, w3, w4, w0, 15);
85
86        abef = _mm_add_epi32(abef, abef_save);
87        cdgh = _mm_add_epi32(cdgh, cdgh_save);
88    }
89
90    let feba = _mm_shuffle_epi32(abef, 0x1B);
91    let dchg = _mm_shuffle_epi32(cdgh, 0xB1);
92    let dcba = _mm_blend_epi16(feba, dchg, 0xF0);
93    let hgef = _mm_alignr_epi8(dchg, feba, 8);
94
95    let state_ptr_mut = state.as_mut_ptr() as *mut __m128i;
96    _mm_storeu_si128(state_ptr_mut.add(0), dcba);
97    _mm_storeu_si128(state_ptr_mut.add(1), hgef);
98}
99
100cpufeatures::new!(shani_cpuid, "sha", "sse2", "ssse3", "sse4.1");
101
102pub fn compress(state: &mut [u32; 8], blocks: &[[u8; 64]]) {
103    // TODO: Replace with https://github.com/rust-lang/rfcs/pull/2725
104    // after stabilization
105    if shani_cpuid::get() {
106        unsafe {
107            digest_blocks(state, blocks);
108        }
109    } else {
110        super::soft::compress(state, blocks);
111    }
112}
sha2/sha256/x86.rs

sha2/sha256/
x86.rs
