1 /////////////////////////////////////////////////////////////////////////////// 2 // 3 /// \file crc64_tablegen.c 4 /// \brief Generate crc64_table_le.h and crc64_table_be.h 5 /// 6 /// Compiling: gcc -std=c99 -o crc64_tablegen crc64_tablegen.c 7 /// Add -DWORDS_BIGENDIAN to generate big endian table. 8 // 9 // Author: Lasse Collin 10 // 11 // This file has been put into the public domain. 12 // You can do whatever you want with this file. 13 // 14 /////////////////////////////////////////////////////////////////////////////// 15 16 #include <stdio.h> 17 #include "../../common/tuklib_integer.h" 18 19 20 static uint64_t crc64_table[4][256]; 21 22 23 extern void 24 init_crc64_table(void) 25 { 26 static const uint64_t poly64 = UINT64_C(0xC96C5795D7870F42); 27 28 for (size_t s = 0; s < 4; ++s) { 29 for (size_t b = 0; b < 256; ++b) { 30 uint64_t r = s == 0 ? b : crc64_table[s - 1][b]; 31 32 for (size_t i = 0; i < 8; ++i) { 33 if (r & 1) 34 r = (r >> 1) ^ poly64; 35 else 36 r >>= 1; 37 } 38 39 crc64_table[s][b] = r; 40 } 41 } 42 43 #ifdef WORDS_BIGENDIAN 44 for (size_t s = 0; s < 4; ++s) 45 for (size_t b = 0; b < 256; ++b) 46 crc64_table[s][b] = bswap64(crc64_table[s][b]); 47 #endif 48 49 return; 50 } 51 52 53 static void 54 print_crc64_table(void) 55 { 56 printf("/* This file has been automatically generated by " 57 "crc64_tablegen.c. */\n\n" 58 "const uint64_t lzma_crc64_table[4][256] = {\n\t{"); 59 60 for (size_t s = 0; s < 4; ++s) { 61 for (size_t b = 0; b < 256; ++b) { 62 if ((b % 2) == 0) 63 printf("\n\t\t"); 64 65 printf("UINT64_C(0x%016" PRIX64 ")", 66 crc64_table[s][b]); 67 68 if (b != 255) 69 printf(",%s", (b+1) % 2 == 0 ? "" : " "); 70 } 71 72 if (s == 3) 73 printf("\n\t}\n};\n"); 74 else 75 printf("\n\t}, {"); 76 } 77 78 return; 79 } 80 81 82 int 83 main(void) 84 { 85 init_crc64_table(); 86 print_crc64_table(); 87 return 0; 88 } 89