libtommath/mp_neg.c
2019-10-27 18:36:55 +01:00

25 lines
478 B
C

#include "tommath_private.h"
#ifdef MP_NEG_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */
/* b = -a */
mp_err mp_neg(const mp_int *a, mp_int *b)
{
mp_err err;
if (a != b) {
if ((err = mp_copy(a, b)) != MP_OKAY) {
return err;
}
}
if (!mp_iszero(b)) {
b->sign = (a->sign == MP_ZPOS) ? MP_NEG : MP_ZPOS;
} else {
b->sign = MP_ZPOS;
}
return MP_OKAY;
}
#endif