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f46efa79 | 1 | /* -*-c-*- |
2 | * | |
f46efa79 | 3 | * Efficient reduction modulo nice primes |
4 | * | |
5 | * (c) 2004 Straylight/Edgeware | |
6 | */ | |
7 | ||
45c0fd36 | 8 | /*----- Licensing notice --------------------------------------------------* |
f46efa79 | 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 | * |
f46efa79 | 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 | * |
f46efa79 | 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 | ||
f46efa79 | 28 | #ifndef CATACOMB_MPREDUCE_H |
29 | #define CATACOMB_MPREDUCE_H | |
30 | ||
31 | #ifdef __cplusplus | |
32 | extern "C" { | |
33 | #endif | |
34 | ||
35 | /*----- Header files ------------------------------------------------------*/ | |
36 | ||
37 | /*----- Data structures ---------------------------------------------------*/ | |
38 | ||
39 | typedef struct mpreduce_instr { | |
40 | unsigned op; /* Instruction opcode */ | |
41 | size_t argx, argy; /* Immediate arguments */ | |
42 | } mpreduce_instr; | |
43 | ||
44 | enum { | |
45 | MPRI_ADD, /* Add @p@ offset by @x@ words */ | |
46 | MPRI_ADDLSL, /* Add @p << y@ offset by @x@ */ | |
47 | MPRI_SUB, /* Sub @p@ offset by @x@ words */ | |
48 | MPRI_SUBLSL, /* Sub @p << y@ offset by @x@ */ | |
49 | MPRI_MAX | |
50 | }; | |
51 | ||
52 | typedef struct mpreduce { | |
53 | size_t lim; /* Word containing top bit */ | |
54 | unsigned s; /* Shift for top word */ | |
55 | mp *p; /* Copy of the modulus */ | |
56 | size_t in; /* Number of instruction words */ | |
57 | mpreduce_instr *iv; /* Vector of instructions */ | |
58 | } mpreduce; | |
59 | ||
60 | /*----- Functions provided ------------------------------------------------*/ | |
61 | ||
62 | /* --- @mpreduce_create@ --- * | |
63 | * | |
64 | * Arguments: @gfreduce *r@ = structure to fill in | |
65 | * @mp *x@ = an integer | |
66 | * | |
f4535c64 | 67 | * Returns: Zero for success, nonzero on error. |
f46efa79 | 68 | * |
69 | * Use: Initializes a context structure for reduction. | |
70 | */ | |
71 | ||
f4535c64 | 72 | extern int mpreduce_create(mpreduce */*r*/, mp */*p*/); |
f46efa79 | 73 | |
74 | /* --- @mpreduce_destroy@ --- * | |
75 | * | |
76 | * Arguments: @mpreduce *r@ = structure to free | |
77 | * | |
78 | * Returns: --- | |
79 | * | |
80 | * Use: Reclaims the resources from a reduction context. | |
81 | */ | |
82 | ||
83 | extern void mpreduce_destroy(mpreduce */*r*/); | |
84 | ||
85 | /* --- @mpreduce_dump@ --- * | |
86 | * | |
87 | * Arguments: @mpreduce *r@ = structure to dump | |
88 | * @FILE *fp@ = file to dump on | |
89 | * | |
90 | * Returns: --- | |
91 | * | |
92 | * Use: Dumps a reduction context. | |
93 | */ | |
94 | ||
95 | extern void mpreduce_dump(mpreduce */*r*/, FILE */*fp*/); | |
96 | ||
97 | /* --- @mpreduce_do@ --- * | |
98 | * | |
99 | * Arguments: @mpreduce *r@ = reduction context | |
100 | * @mp *d@ = destination | |
101 | * @mp *x@ = source | |
102 | * | |
103 | * Returns: Destination, @x@ reduced modulo the reduction poly. | |
104 | */ | |
105 | ||
106 | extern mp *mpreduce_do(mpreduce */*r*/, mp */*d*/, mp */*x*/); | |
107 | ||
108 | /* --- @mpreduce_exp@ --- * | |
109 | * | |
110 | * Arguments: @mpreduce *mr@ = pointer to reduction context | |
45c0fd36 MW |
111 | * @mp *d@ = fake destination |
112 | * @mp *a@ = base | |
113 | * @mp *e@ = exponent | |
f46efa79 | 114 | * |
45c0fd36 | 115 | * Returns: Result, %$a^e \bmod m$%. |
f46efa79 | 116 | */ |
117 | ||
118 | extern mp *mpreduce_exp(mpreduce */*mr*/, mp */*d*/, mp */*a*/, mp */*e*/); | |
119 | ||
120 | /*----- That's all, folks -------------------------------------------------*/ | |
121 | ||
122 | #ifdef __cplusplus | |
123 | } | |
124 | #endif | |
125 | ||
126 | #endif |