| #include <stdio.h> |
| #include "crc32c_defs.h" |
| #include <inttypes.h> |
| |
| #define ENTRIES_PER_LINE 4 |
| |
| #if CRC_LE_BITS <= 8 |
| #define LE_TABLE_SIZE (1 << CRC_LE_BITS) |
| #else |
| #define LE_TABLE_SIZE 256 |
| #endif |
| |
| #if CRC_BE_BITS <= 8 |
| #define BE_TABLE_SIZE (1 << CRC_BE_BITS) |
| #else |
| #define BE_TABLE_SIZE 256 |
| #endif |
| |
| static uint32_t crc32ctable_le[8][256]; |
| static uint32_t crc32ctable_be[8][256]; |
| |
| /** |
| * crc32cinit_le() - allocate and initialize LE table data |
| * |
| * crc is the crc of the byte i; other entries are filled in based on the |
| * fact that crctable[i^j] = crctable[i] ^ crctable[j]. |
| * |
| */ |
| static void crc32cinit_le(void) |
| { |
| unsigned i, j; |
| uint32_t crc = 1; |
| |
| crc32ctable_le[0][0] = 0; |
| |
| for (i = LE_TABLE_SIZE >> 1; i; i >>= 1) { |
| crc = (crc >> 1) ^ ((crc & 1) ? CRCPOLY_LE : 0); |
| for (j = 0; j < LE_TABLE_SIZE; j += 2 * i) |
| crc32ctable_le[0][i + j] = crc ^ crc32ctable_le[0][j]; |
| } |
| for (i = 0; i < LE_TABLE_SIZE; i++) { |
| crc = crc32ctable_le[0][i]; |
| for (j = 1; j < 8; j++) { |
| crc = crc32ctable_le[0][crc & 0xff] ^ (crc >> 8); |
| crc32ctable_le[j][i] = crc; |
| } |
| } |
| } |
| |
| /** |
| * crc32cinit_be() - allocate and initialize BE table data |
| */ |
| static void crc32cinit_be(void) |
| { |
| unsigned i, j; |
| uint32_t crc = 0x80000000; |
| |
| crc32ctable_be[0][0] = 0; |
| |
| for (i = 1; i < BE_TABLE_SIZE; i <<= 1) { |
| crc = (crc << 1) ^ ((crc & 0x80000000) ? CRCPOLY_BE : 0); |
| for (j = 0; j < i; j++) |
| crc32ctable_be[0][i + j] = crc ^ crc32ctable_be[0][j]; |
| } |
| for (i = 0; i < BE_TABLE_SIZE; i++) { |
| crc = crc32ctable_be[0][i]; |
| for (j = 1; j < 8; j++) { |
| crc = crc32ctable_be[0][(crc >> 24) & 0xff] ^ |
| (crc << 8); |
| crc32ctable_be[j][i] = crc; |
| } |
| } |
| } |
| |
| static void output_table(uint32_t table[8][256], int len, char trans) |
| { |
| int i, j; |
| |
| for (j = 0 ; j < 8; j++) { |
| printf("static const uint32_t t%d_%ce[] = {", j, trans); |
| for (i = 0; i < len - 1; i++) { |
| if ((i % ENTRIES_PER_LINE) == 0) |
| printf("\n"); |
| printf("to%ce(0x%8.8xL),", trans, table[j][i]); |
| if ((i % ENTRIES_PER_LINE) != (ENTRIES_PER_LINE - 1)) |
| printf(" "); |
| } |
| printf("to%ce(0x%8.8xL)};\n\n", trans, table[j][len - 1]); |
| |
| if (trans == 'l') { |
| if ((j+1)*8 >= CRC_LE_BITS) |
| break; |
| } else { |
| if ((j+1)*8 >= CRC_BE_BITS) |
| break; |
| } |
| } |
| } |
| |
| int main(int argc, char **argv) |
| { |
| printf("/*\n"); |
| printf(" * crc32ctable.h - CRC32c tables\n"); |
| printf(" * this file is generated - do not edit\n"); |
| printf(" * # gen_crc32ctable > crc32c_table.h\n"); |
| printf(" * with\n"); |
| printf(" * CRC_LE_BITS = %d\n", CRC_LE_BITS); |
| printf(" * CRC_BE_BITS = %d\n", CRC_BE_BITS); |
| printf(" */\n"); |
| printf("#include <stdint.h>\n"); |
| |
| if (CRC_LE_BITS > 1) { |
| crc32cinit_le(); |
| output_table(crc32ctable_le, LE_TABLE_SIZE, 'l'); |
| } |
| |
| if (CRC_BE_BITS > 1) { |
| crc32cinit_be(); |
| output_table(crc32ctable_be, BE_TABLE_SIZE, 'b'); |
| } |
| |
| return 0; |
| } |