25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
|
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
|
-
+
-
+
-
+
-
-
-
-
-
-
+
+
+
+
+
+
-
-
-
+
+
+
-
-
-
+
+
+
-
-
-
+
+
+
+
-
+
-
-
-
+
+
+
|
if ((err = mp_init_multi(&u1, &u2, &u3, &v1, &v2, &v3, &t1, &t2, &t3, &q, &tmp, NULL)) != MP_OKAY) {
return err;
}
/* initialize, (u1,u2,u3) = (1,0,a) */
mp_set(&u1, 1);
if ((err = mp_copy(a, &u3)) != MP_OKAY) { goto _ERR; }
if ((err = mp_copy(a, &u3)) != MP_OKAY) { goto LBL_ERR; }
/* initialize, (v1,v2,v3) = (0,1,b) */
mp_set(&v2, 1);
if ((err = mp_copy(b, &v3)) != MP_OKAY) { goto _ERR; }
if ((err = mp_copy(b, &v3)) != MP_OKAY) { goto LBL_ERR; }
/* loop while v3 != 0 */
while (mp_iszero(&v3) == MP_NO) {
/* q = u3/v3 */
if ((err = mp_div(&u3, &v3, &q, NULL)) != MP_OKAY) { goto _ERR; }
if ((err = mp_div(&u3, &v3, &q, NULL)) != MP_OKAY) { goto LBL_ERR; }
/* (t1,t2,t3) = (u1,u2,u3) - (v1,v2,v3)q */
if ((err = mp_mul(&v1, &q, &tmp)) != MP_OKAY) { goto _ERR; }
if ((err = mp_sub(&u1, &tmp, &t1)) != MP_OKAY) { goto _ERR; }
if ((err = mp_mul(&v2, &q, &tmp)) != MP_OKAY) { goto _ERR; }
if ((err = mp_sub(&u2, &tmp, &t2)) != MP_OKAY) { goto _ERR; }
if ((err = mp_mul(&v3, &q, &tmp)) != MP_OKAY) { goto _ERR; }
if ((err = mp_sub(&u3, &tmp, &t3)) != MP_OKAY) { goto _ERR; }
if ((err = mp_mul(&v1, &q, &tmp)) != MP_OKAY) { goto LBL_ERR; }
if ((err = mp_sub(&u1, &tmp, &t1)) != MP_OKAY) { goto LBL_ERR; }
if ((err = mp_mul(&v2, &q, &tmp)) != MP_OKAY) { goto LBL_ERR; }
if ((err = mp_sub(&u2, &tmp, &t2)) != MP_OKAY) { goto LBL_ERR; }
if ((err = mp_mul(&v3, &q, &tmp)) != MP_OKAY) { goto LBL_ERR; }
if ((err = mp_sub(&u3, &tmp, &t3)) != MP_OKAY) { goto LBL_ERR; }
/* (u1,u2,u3) = (v1,v2,v3) */
if ((err = mp_copy(&v1, &u1)) != MP_OKAY) { goto _ERR; }
if ((err = mp_copy(&v2, &u2)) != MP_OKAY) { goto _ERR; }
if ((err = mp_copy(&v3, &u3)) != MP_OKAY) { goto _ERR; }
if ((err = mp_copy(&v1, &u1)) != MP_OKAY) { goto LBL_ERR; }
if ((err = mp_copy(&v2, &u2)) != MP_OKAY) { goto LBL_ERR; }
if ((err = mp_copy(&v3, &u3)) != MP_OKAY) { goto LBL_ERR; }
/* (v1,v2,v3) = (t1,t2,t3) */
if ((err = mp_copy(&t1, &v1)) != MP_OKAY) { goto _ERR; }
if ((err = mp_copy(&t2, &v2)) != MP_OKAY) { goto _ERR; }
if ((err = mp_copy(&t3, &v3)) != MP_OKAY) { goto _ERR; }
if ((err = mp_copy(&t1, &v1)) != MP_OKAY) { goto LBL_ERR; }
if ((err = mp_copy(&t2, &v2)) != MP_OKAY) { goto LBL_ERR; }
if ((err = mp_copy(&t3, &v3)) != MP_OKAY) { goto LBL_ERR; }
}
/* make sure U3 >= 0 */
if (u3.sign == MP_NEG) {
if ((err = mp_neg(&u1, &u1)) != MP_OKAY) { goto _ERR; }
if ((err = mp_neg(&u2, &u2)) != MP_OKAY) { goto _ERR; }
if ((err = mp_neg(&u3, &u3)) != MP_OKAY) { goto _ERR; }
if ((err = mp_neg(&u1, &u1)) != MP_OKAY) { goto LBL_ERR; }
if ((err = mp_neg(&u2, &u2)) != MP_OKAY) { goto LBL_ERR; }
if ((err = mp_neg(&u3, &u3)) != MP_OKAY) { goto LBL_ERR; }
}
/* copy result out */
if (U1 != NULL) { mp_exch(U1, &u1); }
if (U2 != NULL) { mp_exch(U2, &u2); }
if (U3 != NULL) { mp_exch(U3, &u3); }
err = MP_OKAY;
LBL_ERR:
_ERR: mp_clear_multi(&u1, &u2, &u3, &v1, &v2, &v3, &t1, &t2, &t3, &q, &tmp, NULL);
/* $Source$ */
/* $Revision$ */
/* $Date$ */
/* ref: HEAD -> release/1.0.1, tag: v1.0.1-rc2 */
/* git commit: e8c27ba7df0efb90708029115c94d681dfa7812f */
/* commit time: 2017-08-29 10:48:46 +0200 */
|