tommath/bn_mp_sqr.c
2010-07-15 17:25:22 +02:00

40 lines
1.0 KiB
C

/* LibTomMath, multiple-precision integer library -- Tom St Denis
*
* LibTomMath is library that provides for multiple-precision
* integer arithmetic as well as number theoretic functionality.
*
* The library is 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@iahu.ca, http://math.libtomcrypt.org
*/
#include <tommath.h>
/* computes b = a*a */
int
mp_sqr (mp_int * a, mp_int * b)
{
int res;
if (a->used >= TOOM_SQR_CUTOFF) {
res = mp_toom_sqr(a, b);
} else if (a->used >= KARATSUBA_SQR_CUTOFF) {
res = mp_karatsuba_sqr (a, b);
} else {
/* can we use the fast multiplier? */
if ((a->used * 2 + 1) < MP_WARRAY &&
a->used <
(1 << (sizeof(mp_word) * CHAR_BIT - 2*DIGIT_BIT - 1))) {
res = fast_s_mp_sqr (a, b);
} else {
res = s_mp_sqr (a, b);
}
}
b->sign = MP_ZPOS;
return res;
}