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f46efa79 | 1 | /* -*-c-*- |
2 | * | |
f4535c64 | 3 | * $Id$ |
f46efa79 | 4 | * |
5 | * Efficient reduction modulo nice primes | |
6 | * | |
7 | * (c) 2004 Straylight/Edgeware | |
8 | */ | |
9 | ||
45c0fd36 | 10 | /*----- Licensing notice --------------------------------------------------* |
f46efa79 | 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. | |
45c0fd36 | 18 | * |
f46efa79 | 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. | |
45c0fd36 | 23 | * |
f46efa79 | 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 | ||
f46efa79 | 30 | #ifndef CATACOMB_MPREDUCE_H |
31 | #define CATACOMB_MPREDUCE_H | |
32 | ||
33 | #ifdef __cplusplus | |
34 | extern "C" { | |
35 | #endif | |
36 | ||
37 | /*----- Header files ------------------------------------------------------*/ | |
38 | ||
39 | /*----- Data structures ---------------------------------------------------*/ | |
40 | ||
41 | typedef struct mpreduce_instr { | |
42 | unsigned op; /* Instruction opcode */ | |
43 | size_t argx, argy; /* Immediate arguments */ | |
44 | } mpreduce_instr; | |
45 | ||
46 | enum { | |
47 | MPRI_ADD, /* Add @p@ offset by @x@ words */ | |
48 | MPRI_ADDLSL, /* Add @p << y@ offset by @x@ */ | |
49 | MPRI_SUB, /* Sub @p@ offset by @x@ words */ | |
50 | MPRI_SUBLSL, /* Sub @p << y@ offset by @x@ */ | |
51 | MPRI_MAX | |
52 | }; | |
53 | ||
54 | typedef struct mpreduce { | |
55 | size_t lim; /* Word containing top bit */ | |
56 | unsigned s; /* Shift for top word */ | |
57 | mp *p; /* Copy of the modulus */ | |
58 | size_t in; /* Number of instruction words */ | |
59 | mpreduce_instr *iv; /* Vector of instructions */ | |
60 | } mpreduce; | |
61 | ||
62 | /*----- Functions provided ------------------------------------------------*/ | |
63 | ||
64 | /* --- @mpreduce_create@ --- * | |
65 | * | |
66 | * Arguments: @gfreduce *r@ = structure to fill in | |
67 | * @mp *x@ = an integer | |
68 | * | |
f4535c64 | 69 | * Returns: Zero for success, nonzero on error. |
f46efa79 | 70 | * |
71 | * Use: Initializes a context structure for reduction. | |
72 | */ | |
73 | ||
f4535c64 | 74 | extern int mpreduce_create(mpreduce */*r*/, mp */*p*/); |
f46efa79 | 75 | |
76 | /* --- @mpreduce_destroy@ --- * | |
77 | * | |
78 | * Arguments: @mpreduce *r@ = structure to free | |
79 | * | |
80 | * Returns: --- | |
81 | * | |
82 | * Use: Reclaims the resources from a reduction context. | |
83 | */ | |
84 | ||
85 | extern void mpreduce_destroy(mpreduce */*r*/); | |
86 | ||
87 | /* --- @mpreduce_dump@ --- * | |
88 | * | |
89 | * Arguments: @mpreduce *r@ = structure to dump | |
90 | * @FILE *fp@ = file to dump on | |
91 | * | |
92 | * Returns: --- | |
93 | * | |
94 | * Use: Dumps a reduction context. | |
95 | */ | |
96 | ||
97 | extern void mpreduce_dump(mpreduce */*r*/, FILE */*fp*/); | |
98 | ||
99 | /* --- @mpreduce_do@ --- * | |
100 | * | |
101 | * Arguments: @mpreduce *r@ = reduction context | |
102 | * @mp *d@ = destination | |
103 | * @mp *x@ = source | |
104 | * | |
105 | * Returns: Destination, @x@ reduced modulo the reduction poly. | |
106 | */ | |
107 | ||
108 | extern mp *mpreduce_do(mpreduce */*r*/, mp */*d*/, mp */*x*/); | |
109 | ||
110 | /* --- @mpreduce_exp@ --- * | |
111 | * | |
112 | * Arguments: @mpreduce *mr@ = pointer to reduction context | |
45c0fd36 MW |
113 | * @mp *d@ = fake destination |
114 | * @mp *a@ = base | |
115 | * @mp *e@ = exponent | |
f46efa79 | 116 | * |
45c0fd36 | 117 | * Returns: Result, %$a^e \bmod m$%. |
f46efa79 | 118 | */ |
119 | ||
120 | extern mp *mpreduce_exp(mpreduce */*mr*/, mp */*d*/, mp */*a*/, mp */*e*/); | |
121 | ||
122 | /*----- That's all, folks -------------------------------------------------*/ | |
123 | ||
124 | #ifdef __cplusplus | |
125 | } | |
126 | #endif | |
127 | ||
128 | #endif |