2 * Copyright 2017 The OpenSSL Project Authors. All Rights Reserved.
3 * Copyright 2014-2016 Cryptography Research, Inc.
5 * Licensed under the OpenSSL license (the "License"). You may not use
6 * this file except in compliance with the License. You can obtain a copy
7 * in the file LICENSE in the source distribution or at
8 * https://www.openssl.org/source/license.html
10 * Originally written by Mike Hamburg
13 #define GF_HEADROOM 60
14 #define FIELD_LITERAL(a,b,c,d,e,f,g,h) {{a,b,c,d,e,f,g,h}}
15 #define LIMB_PLACE_VALUE(i) 56
17 void gf_add_RAW (gf out, const gf a, const gf b) {
18 for (unsigned int i=0; i<sizeof(*out)/sizeof(uint64xn_t); i++) {
19 ((uint64xn_t*)out)[i] = ((const uint64xn_t*)a)[i] + ((const uint64xn_t*)b)[i];
23 for (i=0; i<sizeof(*out)/sizeof(out->limb[0]); i++) {
24 out->limb[i] = a->limb[i] + b->limb[i];
29 void gf_sub_RAW (gf out, const gf a, const gf b) {
30 for (unsigned int i=0; i<sizeof(*out)/sizeof(uint64xn_t); i++) {
31 ((uint64xn_t*)out)[i] = ((const uint64xn_t*)a)[i] - ((const uint64xn_t*)b)[i];
35 for (i=0; i<sizeof(*out)/sizeof(out->limb[0]); i++) {
36 out->limb[i] = a->limb[i] - b->limb[i];
41 void gf_bias (gf a, int amt) {
42 uint64_t co1 = ((1ull<<56)-1)*amt, co2 = co1-amt;
45 uint64x4_t lo = {co1,co1,co1,co1}, hi = {co2,co1,co1,co1};
46 uint64x4_t *aa = (uint64x4_t*) a;
50 uint64x2_t lo = {co1,co1}, hi = {co2,co1};
51 uint64x2_t *aa = (uint64x2_t*) a;
57 for (unsigned int i=0; i<sizeof(*a)/sizeof(uint64_t); i++) {
58 a->limb[i] += (i==4) ? co2 : co1;
63 void gf_weak_reduce (gf a) {
64 /* PERF: use pshufb/palignr if anyone cares about speed of this */
65 uint64_t mask = (1ull<<56) - 1;
66 uint64_t tmp = a->limb[7] >> 56;
68 for (unsigned int i=7; i>0; i--) {
69 a->limb[i] = (a->limb[i] & mask) + (a->limb[i-1]>>56);
71 a->limb[0] = (a->limb[0] & mask) + tmp;