fcdaa180 |
1 | /* -*-c-*- |
2 | * |
3 | * $Id: prim.c,v 1.1 1999/12/22 15:58:59 mdw Exp $ |
4 | * |
5 | * Finding primitive elements |
6 | * |
7 | * (c) 1999 Straylight/Edgeware |
8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
11 | * |
12 | * This file is part of Catacomb. |
13 | * |
14 | * Catacomb is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU Library General Public License as |
16 | * published by the Free Software Foundation; either version 2 of the |
17 | * License, or (at your option) any later version. |
18 | * |
19 | * Catacomb is distributed in the hope that it will be useful, |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
22 | * GNU Library General Public License for more details. |
23 | * |
24 | * You should have received a copy of the GNU Library General Public |
25 | * License along with Catacomb; if not, write to the Free |
26 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
27 | * MA 02111-1307, USA. |
28 | */ |
29 | |
30 | /*----- Revision history --------------------------------------------------* |
31 | * |
32 | * $Log: prim.c,v $ |
33 | * Revision 1.1 1999/12/22 15:58:59 mdw |
34 | * Search for primitive elements using prime-search equipment. |
35 | * |
36 | */ |
37 | |
38 | /*----- Header files ------------------------------------------------------*/ |
39 | |
40 | #include "mp.h" |
41 | #include "mpint.h" |
42 | #include "mpmont.h" |
43 | #include "mprand.h" |
44 | #include "pgen.h" |
45 | #include "prim.h" |
46 | |
47 | /*----- Main code ---------------------------------------------------------*/ |
48 | |
49 | /* --- @prim_test@ --- */ |
50 | |
51 | int prim_test(int rq, pgen_event *ev, void *p) |
52 | { |
53 | prim_ctx *c = p; |
54 | int rc = rq; |
55 | |
56 | switch (rq) { |
57 | case PGEN_BEGIN: |
58 | return (PGEN_TRY); |
59 | case PGEN_TRY: { |
60 | mp *x = MP_NEW; |
61 | mp *f = c->f; |
62 | rc = PGEN_FAIL; |
63 | |
64 | x = mpmont_exp(&c->mm, x, ev->m, f); |
65 | if (MP_CMP(x, ==, MP_ONE)) |
66 | goto done; |
67 | if (c->n == 0) { |
68 | mp_drop(ev->m); |
69 | ev->m = MP_COPY(x); |
70 | } else { |
71 | size_t n = c->n - 1; |
72 | f++; |
73 | while (n) { |
74 | x = mpmont_exp(&c->mm, x, ev->m, f); |
75 | if (MP_CMP(x, ==, MP_ONE)) |
76 | goto done; |
77 | n--; f++; |
78 | } |
79 | } |
80 | rc = PGEN_DONE; |
81 | done: |
82 | mp_drop(x); |
83 | } break; |
84 | } |
85 | |
86 | return (rc); |
87 | } |
88 | |
89 | /* --- Trivial stepping functions -----------------------------------------*/ |
90 | |
91 | /* --- @prim_step@ --- */ |
92 | |
93 | int 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 -------------------------------------------------*/ |