libtommath/bn_mp_neg.c

41 lines
981 B
C

#include <tommath_private.h>
#ifdef BN_MP_NEG_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, tstdenis82@gmail.com, http://libtom.org
*/
/* b = -a */
int mp_neg(const mp_int *a, mp_int *b)
{
int res;
if (a != b) {
if ((res = mp_copy(a, b)) != MP_OKAY) {
return res;
}
}
if (mp_iszero(b) != MP_YES) {
b->sign = (a->sign == MP_ZPOS) ? MP_NEG : MP_ZPOS;
} else {
b->sign = MP_ZPOS;
}
return MP_OKAY;
}
#endif
/* ref: $Format:%D$ */
/* git commit: $Format:%H$ */
/* commit time: $Format:%ai$ */