tommath/bn_mp_sqr.c

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/* 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.
*
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* Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org
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*/
#include <tommath.h>
/* computes b = a*a */
int
mp_sqr (mp_int * a, mp_int * b)
{
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int res;
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if (a->used > KARATSUBA_SQR_CUTOFF) {
res = mp_karatsuba_sqr (a, b);
} else {
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/* can we use the fast multiplier? */
if (((a->used * 2 + 1) < 512)
&& a->used < (1 << ((CHAR_BIT * sizeof (mp_word)) - (2 * DIGIT_BIT) - 1))) {
res = fast_s_mp_sqr (a, b);
} else {
res = s_mp_sqr (a, b);
}
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}
b->sign = MP_ZPOS;
return res;
}