xref: /freebsd/contrib/bearssl/src/int/i32_mulacc.c (revision 2aaf9152a852aba9eb2036b95f4948ee77988826)
1*0957b409SSimon J. Gerraty /*
2*0957b409SSimon J. Gerraty  * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
3*0957b409SSimon J. Gerraty  *
4*0957b409SSimon J. Gerraty  * Permission is hereby granted, free of charge, to any person obtaining
5*0957b409SSimon J. Gerraty  * a copy of this software and associated documentation files (the
6*0957b409SSimon J. Gerraty  * "Software"), to deal in the Software without restriction, including
7*0957b409SSimon J. Gerraty  * without limitation the rights to use, copy, modify, merge, publish,
8*0957b409SSimon J. Gerraty  * distribute, sublicense, and/or sell copies of the Software, and to
9*0957b409SSimon J. Gerraty  * permit persons to whom the Software is furnished to do so, subject to
10*0957b409SSimon J. Gerraty  * the following conditions:
11*0957b409SSimon J. Gerraty  *
12*0957b409SSimon J. Gerraty  * The above copyright notice and this permission notice shall be
13*0957b409SSimon J. Gerraty  * included in all copies or substantial portions of the Software.
14*0957b409SSimon J. Gerraty  *
15*0957b409SSimon J. Gerraty  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16*0957b409SSimon J. Gerraty  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17*0957b409SSimon J. Gerraty  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18*0957b409SSimon J. Gerraty  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19*0957b409SSimon J. Gerraty  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20*0957b409SSimon J. Gerraty  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21*0957b409SSimon J. Gerraty  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22*0957b409SSimon J. Gerraty  * SOFTWARE.
23*0957b409SSimon J. Gerraty  */
24*0957b409SSimon J. Gerraty 
25*0957b409SSimon J. Gerraty #include "inner.h"
26*0957b409SSimon J. Gerraty 
27*0957b409SSimon J. Gerraty /* see inner.h */
28*0957b409SSimon J. Gerraty void
br_i32_mulacc(uint32_t * d,const uint32_t * a,const uint32_t * b)29*0957b409SSimon J. Gerraty br_i32_mulacc(uint32_t *d, const uint32_t *a, const uint32_t *b)
30*0957b409SSimon J. Gerraty {
31*0957b409SSimon J. Gerraty 	size_t alen, blen, u;
32*0957b409SSimon J. Gerraty 
33*0957b409SSimon J. Gerraty 	alen = (a[0] + 31) >> 5;
34*0957b409SSimon J. Gerraty 	blen = (b[0] + 31) >> 5;
35*0957b409SSimon J. Gerraty 	d[0] = a[0] + b[0];
36*0957b409SSimon J. Gerraty 	for (u = 0; u < blen; u ++) {
37*0957b409SSimon J. Gerraty 		uint32_t f;
38*0957b409SSimon J. Gerraty 		size_t v;
39*0957b409SSimon J. Gerraty #if BR_64
40*0957b409SSimon J. Gerraty 		uint64_t cc;
41*0957b409SSimon J. Gerraty #else
42*0957b409SSimon J. Gerraty 		uint32_t cc;
43*0957b409SSimon J. Gerraty #endif
44*0957b409SSimon J. Gerraty 
45*0957b409SSimon J. Gerraty 		f = b[1 + u];
46*0957b409SSimon J. Gerraty 		cc = 0;
47*0957b409SSimon J. Gerraty 		for (v = 0; v < alen; v ++) {
48*0957b409SSimon J. Gerraty 			uint64_t z;
49*0957b409SSimon J. Gerraty 
50*0957b409SSimon J. Gerraty 			z = (uint64_t)d[1 + u + v] + MUL(f, a[1 + v]) + cc;
51*0957b409SSimon J. Gerraty 			cc = z >> 32;
52*0957b409SSimon J. Gerraty 			d[1 + u + v] = (uint32_t)z;
53*0957b409SSimon J. Gerraty 		}
54*0957b409SSimon J. Gerraty 		d[1 + u + alen] = (uint32_t)cc;
55*0957b409SSimon J. Gerraty 	}
56*0957b409SSimon J. Gerraty }
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