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**/*.S: Arrange assembler preambles consistently.
[catacomb] / math / prim.c
CommitLineData
fcdaa180 1/* -*-c-*-
fcdaa180 2 *
3 * Finding primitive elements
4 *
5 * (c) 1999 Straylight/Edgeware
6 */
7
45c0fd36 8/*----- Licensing notice --------------------------------------------------*
fcdaa180 9 *
10 * This file is part of Catacomb.
11 *
12 * Catacomb is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU Library General Public License as
14 * published by the Free Software Foundation; either version 2 of the
15 * License, or (at your option) any later version.
45c0fd36 16 *
fcdaa180 17 * Catacomb is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU Library General Public License for more details.
45c0fd36 21 *
fcdaa180 22 * You should have received a copy of the GNU Library General Public
23 * License along with Catacomb; if not, write to the Free
24 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
25 * MA 02111-1307, USA.
26 */
27
fcdaa180 28/*----- Header files ------------------------------------------------------*/
29
30#include "mp.h"
31#include "mpint.h"
32#include "mpmont.h"
33#include "mprand.h"
34#include "pgen.h"
35#include "prim.h"
36
37/*----- Main code ---------------------------------------------------------*/
38
39/* --- @prim_test@ --- */
40
41int prim_test(int rq, pgen_event *ev, void *p)
42{
43 prim_ctx *c = p;
44 int rc = rq;
45
46 switch (rq) {
47 case PGEN_BEGIN:
48 return (PGEN_TRY);
49 case PGEN_TRY: {
6f80d39f 50 mp *x;
fcdaa180 51 rc = PGEN_FAIL;
52
6f80d39f 53 if (!c->exp)
45c0fd36 54 x = mp_copy(ev->m);
6f80d39f 55 else {
56 x = mpmont_exp(&c->mm, MP_NEW, ev->m, c->exp);
22bab86c 57 if (MP_EQ(x, MP_ONE))
6f80d39f 58 goto done;
59 }
60 if (c->n == 0)
45c0fd36 61 goto ok;
6f80d39f 62 else {
63 size_t n = c->n;
64 mp **f = c->f;
65 mp *y = MP_NEW;
fcdaa180 66 while (n) {
6f80d39f 67 y = mpmont_exp(&c->mm, y, x, *f);
22bab86c 68 if (MP_EQ(y, MP_ONE)) {
6f80d39f 69 mp_drop(y);
fcdaa180 70 goto done;
6f80d39f 71 }
fcdaa180 72 n--; f++;
73 }
6f80d39f 74 mp_drop(y);
fcdaa180 75 }
6f80d39f 76 ok:
fcdaa180 77 rc = PGEN_DONE;
6f80d39f 78 mp_drop(ev->m);
79 ev->m = x;
80 break;
fcdaa180 81 done:
82 mp_drop(x);
83 } break;
84 }
85
86 return (rc);
87}
88
89/* --- Trivial stepping functions -----------------------------------------*/
90
91/* --- @prim_step@ --- */
92
93int prim_step(int rq, pgen_event *ev, void *p)
94{
95 unsigned *i = p;
96 switch (rq) {
97 case PGEN_BEGIN:
98 case PGEN_TRY:
99 if (*i >= NPRIME)
100 return PGEN_FAIL;
101 ev->m = mp_fromint(ev->m, primetab[(*i)++]);
102 return (PGEN_TRY);
103 }
104 return (0);
105}
106
107/*----- That's all, folks -------------------------------------------------*/