1 #include <stdio.h>
2 #include "crc32c_defs.h"
3 #include <inttypes.h>
4
5 #define ENTRIES_PER_LINE 4
6
7 #if CRC_LE_BITS > 8
8 # define LE_TABLE_ROWS (CRC_LE_BITS/8)
9 # define LE_TABLE_SIZE 256
10 #else
11 # define LE_TABLE_ROWS 1
12 # define LE_TABLE_SIZE (1 << CRC_LE_BITS)
13 #endif
14
15 #if CRC_BE_BITS > 8
16 # define BE_TABLE_ROWS (CRC_BE_BITS/8)
17 # define BE_TABLE_SIZE 256
18 #else
19 # define BE_TABLE_ROWS 1
20 # define BE_TABLE_SIZE (1 << CRC_BE_BITS)
21 #endif
22
23 static uint32_t crc32table_be[BE_TABLE_ROWS][256];
24 static uint32_t crc32ctable_le[LE_TABLE_ROWS][256];
25
26 /**
27 * crc32init_le() - allocate and initialize LE table data
28 *
29 * crc is the crc of the byte i; other entries are filled in based on the
30 * fact that crctable[i^j] = crctable[i] ^ crctable[j].
31 *
32 */
crc32cinit_le(void)33 static void crc32cinit_le(void)
34 {
35 unsigned i, j;
36 uint32_t crc = 1;
37
38 crc32ctable_le[0][0] = 0;
39
40 for (i = LE_TABLE_SIZE >> 1; i; i >>= 1) {
41 crc = (crc >> 1) ^ ((crc & 1) ? CRC32C_POLY_LE : 0);
42 for (j = 0; j < LE_TABLE_SIZE; j += 2 * i)
43 crc32ctable_le[0][i + j] = crc ^ crc32ctable_le[0][j];
44 }
45 for (i = 0; i < LE_TABLE_SIZE; i++) {
46 crc = crc32ctable_le[0][i];
47 for (j = 1; j < LE_TABLE_ROWS; j++) {
48 crc = crc32ctable_le[0][crc & 0xff] ^ (crc >> 8);
49 crc32ctable_le[j][i] = crc;
50 }
51 }
52 }
53
54 /**
55 * crc32init_be() - allocate and initialize BE table data
56 */
crc32init_be(void)57 static void crc32init_be(void)
58 {
59 unsigned i, j;
60 uint32_t crc = 0x80000000;
61
62 crc32table_be[0][0] = 0;
63
64 for (i = 1; i < BE_TABLE_SIZE; i <<= 1) {
65 crc = (crc << 1) ^ ((crc & 0x80000000) ? CRCPOLY_BE : 0);
66 for (j = 0; j < i; j++)
67 crc32table_be[0][i + j] = crc ^ crc32table_be[0][j];
68 }
69 for (i = 0; i < BE_TABLE_SIZE; i++) {
70 crc = crc32table_be[0][i];
71 for (j = 1; j < BE_TABLE_ROWS; j++) {
72 crc = crc32table_be[0][(crc >> 24) & 0xff] ^ (crc << 8);
73 crc32table_be[j][i] = crc;
74 }
75 }
76 }
77
output_table(uint32_t (* table)[256],int rows,int len,char * trans)78 static void output_table(uint32_t (*table)[256], int rows, int len, char *trans)
79 {
80 int i, j;
81
82 for (j = 0 ; j < rows; j++) {
83 printf("{");
84 for (i = 0; i < len - 1; i++) {
85 if (i % ENTRIES_PER_LINE == 0)
86 printf("\n");
87 printf("%s(0x%8.8xL), ", trans, table[j][i]);
88 }
89 printf("%s(0x%8.8xL)},\n", trans, table[j][len - 1]);
90 }
91 }
92
main(int argc,char ** argv)93 int main(int argc, char **argv)
94 {
95 printf("/* this file is generated - do not edit */\n\n");
96
97 if (CRC_BE_BITS > 1) {
98 crc32init_be();
99 printf("static const uint32_t "
100 "crc32table_be[%d][%d] = {",
101 BE_TABLE_ROWS, BE_TABLE_SIZE);
102 output_table(crc32table_be, LE_TABLE_ROWS,
103 BE_TABLE_SIZE, "tobe");
104 printf("};\n");
105 }
106 if (CRC_LE_BITS > 1) {
107 crc32cinit_le();
108 printf("static const uint32_t "
109 "crc32ctable_le[%d][%d] = {",
110 LE_TABLE_ROWS, LE_TABLE_SIZE);
111 output_table(crc32ctable_le, LE_TABLE_ROWS,
112 LE_TABLE_SIZE, "tole");
113 printf("};\n");
114 }
115
116 return 0;
117 }
118