libtommath/bn_mp_get_double.c
2019-02-02 07:39:23 +01:00

32 lines
827 B
C

#include "tommath_private.h"
#ifdef BN_MP_GET_DOUBLE_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.
*
* SPDX-License-Identifier: Unlicense
*/
double mp_get_double(const mp_int *a)
{
int i;
double d = 0.0, fac = 1.0;
for (i = 0; i < DIGIT_BIT; ++i) {
fac *= 2.0;
}
for (i = a->used; i --> 0;) {
d = (d * fac) + (double)DIGIT(a, i);
}
return (mp_isneg(a) != MP_NO) ? -d : d;
}
#endif
/* ref: $Format:%D$ */
/* git commit: $Format:%H$ */
/* commit time: $Format:%ai$ */