Botan 2.19.5 Crypto and TLS for C&

ghash_vperm.cpp
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1/*
2* (C) 2017 Jack Lloyd
3*
4* Botan is released under the Simplified BSD License (see license.txt)
5*/
6
7#include <botan/ghash.h>
8#include <immintrin.h>
9
10 namespace Botan {
11
12// TODO: extend this to support NEON and AltiVec
13
14 BOTAN_FUNC_ISA("ssse3")
15void GHASH::ghash_multiply_vperm(uint8_t x[16],
16 const uint64_t HM[256],
17 const uint8_t input_bytes[], size_t blocks)
18 {
19 const __m128i BSWAP_MASK = _mm_set_epi8(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15);
20
21 const __m128i* HM_mm = reinterpret_cast<const __m128i*>(HM);
22
23 __m128i X = _mm_loadu_si128(reinterpret_cast<__m128i*>(x));
24 X = _mm_shuffle_epi8(X, BSWAP_MASK);
25
26 const __m128i ones = _mm_set1_epi8(-1);
27
28 for(size_t b = 0; b != blocks; ++b)
29 {
30 __m128i M = _mm_loadu_si128(reinterpret_cast<const __m128i*>(input_bytes) + b);
31 M = _mm_shuffle_epi8(M, BSWAP_MASK);
32
33 X = _mm_xor_si128(X, M);
34
35 __m128i Z = _mm_setzero_si128();
36
37 for(size_t i = 0; i != 64; i += 2)
38 {
39 const __m128i HM0 = _mm_loadu_si128(HM_mm + 2*i);
40 const __m128i HM1 = _mm_loadu_si128(HM_mm + 2*i + 1);
41 const __m128i HM2 = _mm_loadu_si128(HM_mm + 2*i + 2);
42 const __m128i HM3 = _mm_loadu_si128(HM_mm + 2*i + 3);
43
44 const __m128i XMASK1 = _mm_add_epi64(_mm_srli_epi64(X, 63), ones);
45 X = _mm_slli_epi64(X, 1);
46 const __m128i XMASK2 = _mm_add_epi64(_mm_srli_epi64(X, 63), ones);
47 X = _mm_slli_epi64(X, 1);
48
49 Z = _mm_xor_si128(Z, _mm_andnot_si128(_mm_unpackhi_epi64(XMASK1, XMASK1), HM0));
50 Z = _mm_xor_si128(Z, _mm_andnot_si128(_mm_unpacklo_epi64(XMASK1, XMASK1), HM1));
51 Z = _mm_xor_si128(Z, _mm_andnot_si128(_mm_unpackhi_epi64(XMASK2, XMASK2), HM2));
52 Z = _mm_xor_si128(Z, _mm_andnot_si128(_mm_unpacklo_epi64(XMASK2, XMASK2), HM3));
53 }
54
55 X = _mm_shuffle_epi32(Z, _MM_SHUFFLE(1, 0, 3, 2));
56 }
57
58 X = _mm_shuffle_epi8(X, BSWAP_MASK);
59 _mm_storeu_si128(reinterpret_cast<__m128i*>(x), X);
60 }
61
62}
BOTAN_FUNC_ISA
#define BOTAN_FUNC_ISA(isa)
Definition: compiler.h:77
Z
fe Z
Definition: ge.cpp:29
X
fe X
Definition: ge.cpp:27
Botan
Definition: alg_id.cpp:13