tommath/bn_mp_sqr.c
2018-05-02 21:43:17 +02:00

58 lines
1.4 KiB
C

#include "tommath_private.h"
#ifdef BN_MP_SQR_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.
*/
/* computes b = a*a */
int mp_sqr(const mp_int *a, mp_int *b)
{
int res;
#ifdef BN_MP_TOOM_SQR_C
/* use Toom-Cook? */
if (a->used >= TOOM_SQR_CUTOFF) {
res = mp_toom_sqr(a, b);
/* Karatsuba? */
} else
#endif
#ifdef BN_MP_KARATSUBA_SQR_C
if (a->used >= KARATSUBA_SQR_CUTOFF) {
res = mp_karatsuba_sqr(a, b);
} else
#endif
{
#ifdef BN_FAST_S_MP_SQR_C
/* can we use the fast comba multiplier? */
if ((((a->used * 2) + 1) < (int)MP_WARRAY) &&
(a->used <
(int)(1u << (((sizeof(mp_word) * (size_t)CHAR_BIT) - (2u * (size_t)DIGIT_BIT)) - 1u)))) {
res = fast_s_mp_sqr(a, b);
} else
#endif
{
#ifdef BN_S_MP_SQR_C
res = s_mp_sqr(a, b);
#else
res = MP_VAL;
#endif
}
}
b->sign = MP_ZPOS;
return res;
}
#endif
/* ref: $Format:%D$ */
/* git commit: $Format:%H$ */
/* commit time: $Format:%ai$ */