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| 1 /////////////////////////////////////////////////////////////////////////////// |
| 2 // |
| 3 /// \file crc32_tablegen.c |
| 4 /// \brief Generate crc32_table_le.h and crc32_table_be.h |
| 5 /// |
| 6 /// Compiling: gcc -std=c99 -o crc32_tablegen crc32_tablegen.c |
| 7 /// Add -DWORDS_BIGENDIAN to generate big endian table. |
| 8 /// Add -DLZ_HASH_TABLE to generate lz_encoder_hash_table.h (little endian). |
| 9 // |
| 10 // Author: Lasse Collin |
| 11 // |
| 12 // This file has been put into the public domain. |
| 13 // You can do whatever you want with this file. |
| 14 // |
| 15 /////////////////////////////////////////////////////////////////////////////// |
| 16 |
| 17 #include <stdio.h> |
| 18 #include "../../common/tuklib_integer.h" |
| 19 |
| 20 |
| 21 static uint32_t crc32_table[8][256]; |
| 22 |
| 23 |
| 24 static void |
| 25 init_crc32_table(void) |
| 26 { |
| 27 static const uint32_t poly32 = UINT32_C(0xEDB88320); |
| 28 |
| 29 for (size_t s = 0; s < 8; ++s) { |
| 30 for (size_t b = 0; b < 256; ++b) { |
| 31 uint32_t r = s == 0 ? b : crc32_table[s - 1][b]; |
| 32 |
| 33 for (size_t i = 0; i < 8; ++i) { |
| 34 if (r & 1) |
| 35 r = (r >> 1) ^ poly32; |
| 36 else |
| 37 r >>= 1; |
| 38 } |
| 39 |
| 40 crc32_table[s][b] = r; |
| 41 } |
| 42 } |
| 43 |
| 44 #ifdef WORDS_BIGENDIAN |
| 45 for (size_t s = 0; s < 8; ++s) |
| 46 for (size_t b = 0; b < 256; ++b) |
| 47 crc32_table[s][b] = bswap32(crc32_table[s][b]); |
| 48 #endif |
| 49 |
| 50 return; |
| 51 } |
| 52 |
| 53 |
| 54 static void |
| 55 print_crc32_table(void) |
| 56 { |
| 57 printf("/* This file has been automatically generated by " |
| 58 "crc32_tablegen.c. */\n\n" |
| 59 "const uint32_t lzma_crc32_table[8][256] = {\n\t{"); |
| 60 |
| 61 for (size_t s = 0; s < 8; ++s) { |
| 62 for (size_t b = 0; b < 256; ++b) { |
| 63 if ((b % 4) == 0) |
| 64 printf("\n\t\t"); |
| 65 |
| 66 printf("0x%08" PRIX32, crc32_table[s][b]); |
| 67 |
| 68 if (b != 255) |
| 69 printf(",%s", (b+1) % 4 == 0 ? "" : " "); |
| 70 } |
| 71 |
| 72 if (s == 7) |
| 73 printf("\n\t}\n};\n"); |
| 74 else |
| 75 printf("\n\t}, {"); |
| 76 } |
| 77 |
| 78 return; |
| 79 } |
| 80 |
| 81 |
| 82 static void |
| 83 print_lz_table(void) |
| 84 { |
| 85 printf("/* This file has been automatically generated by " |
| 86 "crc32_tablegen.c. */\n\n" |
| 87 "const uint32_t lzma_lz_hash_table[256] = {"); |
| 88 |
| 89 for (size_t b = 0; b < 256; ++b) { |
| 90 if ((b % 4) == 0) |
| 91 printf("\n\t"); |
| 92 |
| 93 printf("0x%08" PRIX32, crc32_table[0][b]); |
| 94 |
| 95 if (b != 255) |
| 96 printf(",%s", (b+1) % 4 == 0 ? "" : " "); |
| 97 } |
| 98 |
| 99 printf("\n};\n"); |
| 100 |
| 101 return; |
| 102 } |
| 103 |
| 104 |
| 105 int |
| 106 main(void) |
| 107 { |
| 108 init_crc32_table(); |
| 109 |
| 110 #ifdef LZ_HASH_TABLE |
| 111 print_lz_table(); |
| 112 #else |
| 113 print_crc32_table(); |
| 114 #endif |
| 115 |
| 116 return 0; |
| 117 } |
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