### view libtommath/bn_mp_xor.c @ 1692:1051e4eea25a

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 Tue, 26 May 2020 17:36:47 +0200 f52919ffd3b1
line wrap: on
line source
```#include "tommath_private.h"
#ifdef BN_MP_XOR_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis */

/* two complement xor */
mp_err mp_xor(const mp_int *a, const mp_int *b, mp_int *c)
{
int used = MP_MAX(a->used, b->used) + 1, i;
mp_err err;
mp_digit ac = 1, bc = 1, cc = 1;
mp_sign csign = (a->sign != b->sign) ? MP_NEG : MP_ZPOS;

if (c->alloc < used) {
if ((err = mp_grow(c, used)) != MP_OKAY) {
return err;
}
}

for (i = 0; i < used; i++) {
mp_digit x, y;

/* convert to two complement if negative */
if (a->sign == MP_NEG) {
ac >>= MP_DIGIT_BIT;
} else {
x = (i >= a->used) ? 0uL : a->dp[i];
}

/* convert to two complement if negative */
if (b->sign == MP_NEG) {
bc >>= MP_DIGIT_BIT;
} else {
y = (i >= b->used) ? 0uL : b->dp[i];
}

c->dp[i] = x ^ y;

/* convert to to sign-magnitude if negative */
if (csign == MP_NEG) {