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hcrypto: import libtommath v1.2.0

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This commit is contained in:
Luke Howard
2020-04-12 18:37:13 +10:00
parent 7181c109d0
commit c403b66082
287 changed files with 28273 additions and 38374 deletions
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36
lib/hcrypto/libtommath/bn_mp_cnt_lsb.c
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@@ -1,53 +1,37 @@
#include <tommath.h>
#include "tommath_private.h"
#ifdef BN_MP_CNT_LSB_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis
*
* LibTomMath is a library that provides multiple-precision
* integer arithmetic as well as number theoretic functionality.
*
* The library was designed directly after the MPI library by
* Michael Fromberger but has been written from scratch with
* additional optimizations in place.
*
* The library is free for all purposes without any express
* guarantee it works.
*
* Tom St Denis, tomstdenis@gmail.com, http://libtom.org
*/
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */
static const int lnz[16] = {
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0
};
/* Counts the number of lsbs which are zero before the first zero bit */
int mp_cnt_lsb(mp_int *a)
int mp_cnt_lsb(const mp_int *a)
{
int x;
mp_digit q, qq;
/* easy out */
if (mp_iszero(a) == 1) {
if (MP_IS_ZERO(a)) {
return 0;
}
/* scan lower digits until non-zero */
for (x = 0; x < a->used && a->dp[x] == 0; x++);
for (x = 0; (x < a->used) && (a->dp[x] == 0u); x++) {}
q = a->dp[x];
x *= DIGIT_BIT;
x *= MP_DIGIT_BIT;
/* now scan this digit until a 1 is found */
if ((q & 1) == 0) {
if ((q & 1u) == 0u) {
do {
qq = q & 15;
qq = q & 15u;
x += lnz[qq];
q >>= 4;
} while (qq == 0);
} while (qq == 0u);
}
return x;
}
#endif
/* $Source: /cvs/libtom/libtommath/bn_mp_cnt_lsb.c,v $ */
/* $Revision: 1.4 $ */
/* $Date: 2006/12/28 01:25:13 $ */