42 lines
1.1 KiB
C
42 lines
1.1 KiB
C
|
#include <tommath.h>
|
||
|
|
#ifdef BN_MP_GET_LONG_LONG_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, tomstdenis@gmail.com, http://libtom.org
|
||
|
|
*/
|
||
|
|
|
||
|
|
/* get the lower unsigned long long of an mp_int, platform dependent */
|
||
|
|
unsigned long long mp_get_long_long (mp_int * a)
|
||
|
|
{
|
||
|
|
int i;
|
||
|
|
unsigned long long res;
|
||
|
|
|
||
|
|
if (a->used == 0) {
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* get number of digits of the lsb we have to read */
|
||
|
|
i = MIN(a->used,(int)((sizeof(unsigned long long)*CHAR_BIT+DIGIT_BIT-1)/DIGIT_BIT))-1;
|
||
|
|
|
||
|
|
/* get most significant digit of result */
|
||
|
|
res = DIGIT(a,i);
|
||
|
|
|
||
|
|
#if DIGIT_BIT < 64
|
||
|
|
while (--i >= 0) {
|
||
|
|
res = (res << DIGIT_BIT) | DIGIT(a,i);
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
return res;
|
||
|
|
}
|
||
|
|
#endif
|