ARM Shanghai IoT Team (Internal) / newMiniTLS-GPL

change some parameters in the library to meet the needs of the website httpbin.org

Fork of MiniTLS-GPL by Donatien Garnier

math/numtheory/fp_gcd.c@5:95f70ebfe61f, 2015-02-06 (annotated)

Committer:
shiyilei
Date:
Fri Feb 06 06:17:33 2015 +0000
Revision:
5:95f70ebfe61f
Parent:
0:35aa5be3b78d 
change some parameters in the library to meet the needs of httpbin.org

Who changed what in which revision?

UserRevisionLine numberNew contents of line
MiniTLS 0:35aa5be3b78d 1 /* TomsFastMath, a fast ISO C bignum library.
MiniTLS 0:35aa5be3b78d 2 *
MiniTLS 0:35aa5be3b78d 3 * This project is meant to fill in where LibTomMath
MiniTLS 0:35aa5be3b78d 4 * falls short. That is speed ;-)
MiniTLS 0:35aa5be3b78d 5 *
MiniTLS 0:35aa5be3b78d 6 * This project is public domain and free for all purposes.
MiniTLS 0:35aa5be3b78d 7 *
MiniTLS 0:35aa5be3b78d 8 * Tom St Denis, tomstdenis@gmail.com
MiniTLS 0:35aa5be3b78d 9 */
MiniTLS 0:35aa5be3b78d 10 #include <tfm.h>
MiniTLS 0:35aa5be3b78d 11
MiniTLS 0:35aa5be3b78d 12 /* c = (a, b) */
MiniTLS 0:35aa5be3b78d 13 void fp_gcd(fp_int *a, fp_int *b, fp_int *c)
MiniTLS 0:35aa5be3b78d 14 {
MiniTLS 0:35aa5be3b78d 15 fp_int u, v, r;
MiniTLS 0:35aa5be3b78d 16
MiniTLS 0:35aa5be3b78d 17 /* either zero than gcd is the largest */
MiniTLS 0:35aa5be3b78d 18 if (fp_iszero (a) == 1 && fp_iszero (b) == 0) {
MiniTLS 0:35aa5be3b78d 19 fp_abs (b, c);
MiniTLS 0:35aa5be3b78d 20 return;
MiniTLS 0:35aa5be3b78d 21 }
MiniTLS 0:35aa5be3b78d 22 if (fp_iszero (a) == 0 && fp_iszero (b) == 1) {
MiniTLS 0:35aa5be3b78d 23 fp_abs (a, c);
MiniTLS 0:35aa5be3b78d 24 return;
MiniTLS 0:35aa5be3b78d 25 }
MiniTLS 0:35aa5be3b78d 26
MiniTLS 0:35aa5be3b78d 27 /* optimized. At this point if a == 0 then
MiniTLS 0:35aa5be3b78d 28 * b must equal zero too
MiniTLS 0:35aa5be3b78d 29 */
MiniTLS 0:35aa5be3b78d 30 if (fp_iszero (a) == 1) {
MiniTLS 0:35aa5be3b78d 31 fp_zero(c);
MiniTLS 0:35aa5be3b78d 32 return;
MiniTLS 0:35aa5be3b78d 33 }
MiniTLS 0:35aa5be3b78d 34
MiniTLS 0:35aa5be3b78d 35 /* sort inputs */
MiniTLS 0:35aa5be3b78d 36 if (fp_cmp_mag(a, b) != FP_LT) {
MiniTLS 0:35aa5be3b78d 37 fp_init_copy(&u, a);
MiniTLS 0:35aa5be3b78d 38 fp_init_copy(&v, b);
MiniTLS 0:35aa5be3b78d 39 } else {
MiniTLS 0:35aa5be3b78d 40 fp_init_copy(&u, b);
MiniTLS 0:35aa5be3b78d 41 fp_init_copy(&v, a);
MiniTLS 0:35aa5be3b78d 42 }
MiniTLS 0:35aa5be3b78d 43
MiniTLS 0:35aa5be3b78d 44 fp_zero(&r);
MiniTLS 0:35aa5be3b78d 45 while (fp_iszero(&v) == FP_NO) {
MiniTLS 0:35aa5be3b78d 46 fp_mod(&u, &v, &r);
MiniTLS 0:35aa5be3b78d 47 fp_copy(&v, &u);
MiniTLS 0:35aa5be3b78d 48 fp_copy(&r, &v);
MiniTLS 0:35aa5be3b78d 49 }
MiniTLS 0:35aa5be3b78d 50 fp_copy(&u, c);
MiniTLS 0:35aa5be3b78d 51 }
MiniTLS 0:35aa5be3b78d 52
MiniTLS 0:35aa5be3b78d 53 /* $Source: /cvs/libtom/tomsfastmath/src/numtheory/fp_gcd.c,v $ */
MiniTLS 0:35aa5be3b78d 54 /* $Revision: 1.1 $ */
MiniTLS 0:35aa5be3b78d 55 /* $Date: 2007/01/24 21:25:19 $ */