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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.
*
* Tom St Denis, tomstdenis@iahu.ca, http://libtommath.iahu.ca
*/
#include <tommath.h>
/* shift left a certain amount of digits */
int
mp_lshd (mp_int * a, int b)
{
int x, res;
/* if its less than zero return */
if (b <= 0) {
return MP_OKAY;
}
/* grow to fit the new digits */
if ((res = mp_grow (a, a->used + b)) != MP_OKAY) {
return res;
}
/* increment the used by the shift amount than copy upwards */
a->used += b;
for (x = a->used - 1; x >= b; x--) {
a->dp[x] = a->dp[x - b];
}
/* zero the lower digits */
for (x = 0; x < b; x++) {
a->dp[x] = 0;
}
mp_clamp (a);
return MP_OKAY;
}