1 // SPDX-License-Identifier: 0BSD 2 3 /////////////////////////////////////////////////////////////////////////////// 4 // 5 /// \file crc64_tablegen.c 6 /// \brief Generate crc64_table_le.h and crc64_table_be.h 7 /// 8 /// Compiling: gcc -std=c99 -o crc64_tablegen crc64_tablegen.c 9 /// Add -DWORDS_BIGENDIAN to generate big endian table. 10 // 11 // Author: Lasse Collin 12 // 13 /////////////////////////////////////////////////////////////////////////////// 14 15 #include <stdio.h> 16 #include "../../common/tuklib_integer.h" 17 18 19 static uint64_t crc64_table[4][256]; 20 21 22 extern void 23 init_crc64_table(void) 24 { 25 static const uint64_t poly64 = UINT64_C(0xC96C5795D7870F42); 26 27 for (size_t s = 0; s < 4; ++s) { 28 for (size_t b = 0; b < 256; ++b) { 29 uint64_t r = s == 0 ? b : crc64_table[s - 1][b]; 30 31 for (size_t i = 0; i < 8; ++i) { 32 if (r & 1) 33 r = (r >> 1) ^ poly64; 34 else 35 r >>= 1; 36 } 37 38 crc64_table[s][b] = r; 39 } 40 } 41 42 #ifdef WORDS_BIGENDIAN 43 for (size_t s = 0; s < 4; ++s) 44 for (size_t b = 0; b < 256; ++b) 45 crc64_table[s][b] = byteswap64(crc64_table[s][b]); 46 #endif 47 48 return; 49 } 50 51 52 static void 53 print_crc64_table(void) 54 { 55 // Split the SPDX string so that it won't accidentally match 56 // when tools search for the string. 57 printf("// SPDX" "-License-Identifier" ": 0BSD\n\n" 58 "// This file has been generated by crc64_tablegen.c.\n\n" 59 "const uint64_t lzma_crc64_table[4][256] = {\n\t{"); 60 61 for (size_t s = 0; s < 4; ++s) { 62 for (size_t b = 0; b < 256; ++b) { 63 if ((b % 2) == 0) 64 printf("\n\t\t"); 65 66 printf("UINT64_C(0x%016" PRIX64 ")", 67 crc64_table[s][b]); 68 69 if (b != 255) 70 printf(",%s", (b+1) % 2 == 0 ? "" : " "); 71 } 72 73 if (s == 3) 74 printf("\n\t}\n};\n"); 75 else 76 printf("\n\t}, {"); 77 } 78 79 return; 80 } 81 82 83 int 84 main(void) 85 { 86 init_crc64_table(); 87 print_crc64_table(); 88 return 0; 89 } 90