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| 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 } |
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