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comparison libtommath/bn_mp_cnt_lsb.c @ 1692:1051e4eea25a

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Update LibTomMath to 1.2.0 (#84) * update C files * update other files * update headers * update makefiles * remove mp_set/get_double() * use ltm 1.2.0 API * update ltm_desc * use bundled tommath if system-tommath is too old * XMALLOC etc. were changed to MP_MALLOC etc.
author Steffen Jaeckel <s@jaeckel.eu>
date Tue, 26 May 2020 17:36:47 +0200
parents f52919ffd3b1
children
comparison
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1691:2d3745d58843 1692:1051e4eea25a
1 #include "tommath_private.h" 1 #include "tommath_private.h"
2 #ifdef BN_MP_CNT_LSB_C 2 #ifdef BN_MP_CNT_LSB_C
3 /* LibTomMath, multiple-precision integer library -- Tom St Denis 3 /* LibTomMath, multiple-precision integer library -- Tom St Denis */
4 * 4 /* SPDX-License-Identifier: Unlicense */
5 * LibTomMath is a library that provides multiple-precision
6 * integer arithmetic as well as number theoretic functionality.
7 *
8 * The library was designed directly after the MPI library by
9 * Michael Fromberger but has been written from scratch with
10 * additional optimizations in place.
11 *
12 * SPDX-License-Identifier: Unlicense
13 */
14 5
15 static const int lnz[16] = { 6 static const int lnz[16] = {
16 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0 7 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0
17 }; 8 };
18 9
21 { 12 {
22 int x; 13 int x;
23 mp_digit q, qq; 14 mp_digit q, qq;
24 15
25 /* easy out */ 16 /* easy out */
26 if (mp_iszero(a) == MP_YES) { 17 if (MP_IS_ZERO(a)) {
27 return 0; 18 return 0;
28 } 19 }
29 20
30 /* scan lower digits until non-zero */ 21 /* scan lower digits until non-zero */
31 for (x = 0; (x < a->used) && (a->dp[x] == 0u); x++) {} 22 for (x = 0; (x < a->used) && (a->dp[x] == 0u); x++) {}
32 q = a->dp[x]; 23 q = a->dp[x];
33 x *= DIGIT_BIT; 24 x *= MP_DIGIT_BIT;
34 25
35 /* now scan this digit until a 1 is found */ 26 /* now scan this digit until a 1 is found */
36 if ((q & 1u) == 0u) { 27 if ((q & 1u) == 0u) {
37 do { 28 do {
38 qq = q & 15u; 29 qq = q & 15u;
42 } 33 }
43 return x; 34 return x;
44 } 35 }
45 36
46 #endif 37 #endif
47
48 /* ref: HEAD -> master, tag: v1.1.0 */
49 /* git commit: 08549ad6bc8b0cede0b357a9c341c5c6473a9c55 */
50 /* commit time: 2019-01-28 20:32:32 +0100 */