1 /* TomsFastMath, a fast ISO C bignum library.
3 * This project is meant to fill in where LibTomMath
4 * falls short. That is speed ;-)
6 * This project is public domain and free for all purposes.
8 * Tom St Denis, tomstdenis@gmail.com
10 #include <tfm_private.h>
13 void fp_mod_2d(fp_int *a, int b, fp_int *c)
17 /* zero if count less than or equal to zero */
23 /* get copy of input */
26 /* if 2**d is larger than we just return */
27 if (b >= (DIGIT_BIT * a->used)) {
31 /* zero digits above the last digit of the modulus */
32 for (x = (b / DIGIT_BIT) + ((b % DIGIT_BIT) == 0 ? 0 : 1); x < c->used; x++) {
35 /* clear the digit that is not completely outside/inside the modulus */
36 c->dp[b / DIGIT_BIT] &= ~((fp_digit)0) >> (DIGIT_BIT - b);