crc32_tablegen.c revision 207753
1207753Smm/////////////////////////////////////////////////////////////////////////////// 2207753Smm// 3207753Smm/// \file crc32_tablegen.c 4207753Smm/// \brief Generate crc32_table_le.h and crc32_table_be.h 5207753Smm/// 6207753Smm/// Compiling: gcc -std=c99 -o crc32_tablegen crc32_tablegen.c 7207753Smm/// Add -DWORDS_BIGENDIAN to generate big endian table. 8207753Smm/// Add -DLZ_HASH_TABLE to generate lz_encoder_hash_table.h (little endian). 9207753Smm// 10207753Smm// Author: Lasse Collin 11207753Smm// 12207753Smm// This file has been put into the public domain. 13207753Smm// You can do whatever you want with this file. 14207753Smm// 15207753Smm/////////////////////////////////////////////////////////////////////////////// 16207753Smm 17207753Smm#include <stdio.h> 18207753Smm#include "../../common/tuklib_integer.h" 19207753Smm 20207753Smm 21207753Smmstatic uint32_t crc32_table[8][256]; 22207753Smm 23207753Smm 24207753Smmstatic void 25207753Smminit_crc32_table(void) 26207753Smm{ 27207753Smm static const uint32_t poly32 = UINT32_C(0xEDB88320); 28207753Smm 29207753Smm for (size_t s = 0; s < 8; ++s) { 30207753Smm for (size_t b = 0; b < 256; ++b) { 31207753Smm uint32_t r = s == 0 ? b : crc32_table[s - 1][b]; 32207753Smm 33207753Smm for (size_t i = 0; i < 8; ++i) { 34207753Smm if (r & 1) 35207753Smm r = (r >> 1) ^ poly32; 36207753Smm else 37207753Smm r >>= 1; 38207753Smm } 39207753Smm 40207753Smm crc32_table[s][b] = r; 41207753Smm } 42207753Smm } 43207753Smm 44207753Smm#ifdef WORDS_BIGENDIAN 45207753Smm for (size_t s = 0; s < 8; ++s) 46207753Smm for (size_t b = 0; b < 256; ++b) 47207753Smm crc32_table[s][b] = bswap32(crc32_table[s][b]); 48207753Smm#endif 49207753Smm 50207753Smm return; 51207753Smm} 52207753Smm 53207753Smm 54207753Smmstatic void 55207753Smmprint_crc32_table(void) 56207753Smm{ 57207753Smm printf("/* This file has been automatically generated by " 58207753Smm "crc32_tablegen.c. */\n\n" 59207753Smm "const uint32_t lzma_crc32_table[8][256] = {\n\t{"); 60207753Smm 61207753Smm for (size_t s = 0; s < 8; ++s) { 62207753Smm for (size_t b = 0; b < 256; ++b) { 63207753Smm if ((b % 4) == 0) 64207753Smm printf("\n\t\t"); 65207753Smm 66207753Smm printf("0x%08" PRIX32, crc32_table[s][b]); 67207753Smm 68207753Smm if (b != 255) 69207753Smm printf(",%s", (b+1) % 4 == 0 ? "" : " "); 70207753Smm } 71207753Smm 72207753Smm if (s == 7) 73207753Smm printf("\n\t}\n};\n"); 74207753Smm else 75207753Smm printf("\n\t}, {"); 76207753Smm } 77207753Smm 78207753Smm return; 79207753Smm} 80207753Smm 81207753Smm 82207753Smmstatic void 83207753Smmprint_lz_table(void) 84207753Smm{ 85207753Smm printf("/* This file has been automatically generated by " 86207753Smm "crc32_tablegen.c. */\n\n" 87207753Smm "const uint32_t lzma_lz_hash_table[256] = {"); 88207753Smm 89207753Smm for (size_t b = 0; b < 256; ++b) { 90207753Smm if ((b % 4) == 0) 91207753Smm printf("\n\t"); 92207753Smm 93207753Smm printf("0x%08" PRIX32, crc32_table[0][b]); 94207753Smm 95207753Smm if (b != 255) 96207753Smm printf(",%s", (b+1) % 4 == 0 ? "" : " "); 97207753Smm } 98207753Smm 99207753Smm printf("\n};\n"); 100207753Smm 101207753Smm return; 102207753Smm} 103207753Smm 104207753Smm 105207753Smmint 106207753Smmmain(void) 107207753Smm{ 108207753Smm init_crc32_table(); 109207753Smm 110207753Smm#ifdef LZ_HASH_TABLE 111207753Smm print_lz_table(); 112207753Smm#else 113207753Smm print_crc32_table(); 114207753Smm#endif 115207753Smm 116207753Smm return 0; 117207753Smm} 118