fe81b478 |
1 | /* bmpbit.c |
2 | * Greg Cook, 9/Apr/2015 |
3 | */ |
4 | |
5 | /* CRC RevEng, an arbitrary-precision CRC calculator and algorithm finder |
6 | * Copyright (C) 2010, 2011, 2012, 2013, 2014, 2015 Gregory Cook |
7 | * |
8 | * This file is part of CRC RevEng. |
9 | * |
10 | * CRC RevEng is free software: you can redistribute it and/or modify |
11 | * it under the terms of the GNU General Public License as published by |
12 | * the Free Software Foundation, either version 3 of the License, or |
13 | * (at your option) any later version. |
14 | * |
15 | * CRC RevEng is distributed in the hope that it will be useful, |
16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
18 | * GNU General Public License for more details. |
19 | * |
20 | * You should have received a copy of the GNU General Public License |
21 | * along with CRC RevEng. If not, see <http://www.gnu.org/licenses/>. |
22 | */ |
23 | |
24 | #ifdef BMPTST |
25 | # include <stdio.h> |
26 | # include <stdlib.h> |
27 | #else |
28 | # define FILE void |
29 | #endif |
30 | #include "reveng.h" |
31 | |
32 | #if (defined BMPTST) || (BMP_BIT < 32) |
33 | /* Size in bits of a bmp_t. Not necessarily a power of two. */ |
34 | int bmpbit; |
35 | |
36 | /* The highest power of two that is strictly less than BMP_BIT. |
37 | * Initialises the index of a binary search for set bits in a bmp_t. |
38 | * (Computed correctly for BMP_BIT >= 2) |
39 | */ |
40 | int bmpsub; |
41 | |
42 | void |
43 | setbmp(void) { |
44 | /* Initialise BMP_BIT and BMP_SUB for the local architecture. */ |
45 | bmp_t bmpmax = ~(bmp_t) 0; |
46 | |
47 | bmpbit = 0; bmpsub = 1; |
48 | |
49 | while(bmpmax) { |
50 | bmpmax <<= 1; |
51 | ++bmpbit; |
52 | } |
53 | |
54 | while((bmpsub | (bmpsub - 1)) < bmpbit - 1) |
55 | bmpsub <<= 1; |
56 | } |
57 | #endif |
58 | |
59 | #ifdef BMPTST |
60 | int |
61 | main(int argc, char *argv[]) { |
62 | /* check the compile-time bitmap width is correct, otherwise |
63 | * searches run forever. */ |
64 | # if BMP_BIT > 0 |
65 | setbmp(); |
66 | if(BMP_BIT != bmpbit || BMP_SUB != bmpsub) { |
67 | fprintf(stderr,"reveng: configuration fault. Update " |
68 | "config.h with these definitions and " |
69 | "recompile:\n" |
70 | "\t#define BMP_BIT %d\n" |
71 | "\t#define BMP_SUB %d\n", |
72 | bmpbit, bmpsub); |
73 | exit(EXIT_FAILURE); |
74 | } |
75 | # endif /* BMP_BIT > 0 */ |
76 | /* check the bitmap constant macro */ |
77 | if(~(bmp_t) 0 != ~BMP_C(0)) { |
78 | fprintf(stderr, "reveng: configuration fault. Edit " |
79 | "the definition of BMP_C() in config.h to " |
80 | "match BMP_T and recompile.\n"); |
81 | exit(EXIT_FAILURE); |
82 | } |
83 | exit(EXIT_SUCCESS); |
84 | } |
85 | |
86 | #endif /* BMPTST */ |