1 /* 7zCrcOpt.c -- CRC32 calculation 2 2015-03-01 : Igor Pavlov : Public domain */ 3 4 #include "Precomp.h" 5 6 #include "CpuArch.h" 7 8 #ifndef MY_CPU_BE 9 10 #define CRC_UPDATE_BYTE_2(crc, b) (table[((crc) ^ (b)) & 0xFF] ^ ((crc) >> 8)) 11 12 UInt32 MY_FAST_CALL CrcUpdateT4(UInt32 v, const void *data, size_t size, const UInt32 *table) 13 { 14 const Byte *p = (const Byte *)data; 15 for (; size > 0 && ((unsigned)(ptrdiff_t)p & 3) != 0; size--, p++) 16 v = CRC_UPDATE_BYTE_2(v, *p); 17 for (; size >= 4; size -= 4, p += 4) 18 { 19 v ^= *(const UInt32 *)p; 20 v = 21 table[0x300 + ((v ) & 0xFF)] 22 ^ table[0x200 + ((v >> 8) & 0xFF)] 23 ^ table[0x100 + ((v >> 16) & 0xFF)] 24 ^ table[0x000 + ((v >> 24))]; 25 } 26 for (; size > 0; size--, p++) 27 v = CRC_UPDATE_BYTE_2(v, *p); 28 return v; 29 } 30 31 UInt32 MY_FAST_CALL CrcUpdateT8(UInt32 v, const void *data, size_t size, const UInt32 *table) 32 { 33 const Byte *p = (const Byte *)data; 34 for (; size > 0 && ((unsigned)(ptrdiff_t)p & 7) != 0; size--, p++) 35 v = CRC_UPDATE_BYTE_2(v, *p); 36 for (; size >= 8; size -= 8, p += 8) 37 { 38 UInt32 d; 39 v ^= *(const UInt32 *)p; 40 v = 41 table[0x700 + ((v ) & 0xFF)] 42 ^ table[0x600 + ((v >> 8) & 0xFF)] 43 ^ table[0x500 + ((v >> 16) & 0xFF)] 44 ^ table[0x400 + ((v >> 24))]; 45 d = *((const UInt32 *)p + 1); 46 v ^= 47 table[0x300 + ((d ) & 0xFF)] 48 ^ table[0x200 + ((d >> 8) & 0xFF)] 49 ^ table[0x100 + ((d >> 16) & 0xFF)] 50 ^ table[0x000 + ((d >> 24))]; 51 } 52 for (; size > 0; size--, p++) 53 v = CRC_UPDATE_BYTE_2(v, *p); 54 return v; 55 } 56 57 #endif 58 59 60 #ifndef MY_CPU_LE 61 62 #define CRC_UINT32_SWAP(v) ((v >> 24) | ((v >> 8) & 0xFF00) | ((v << 8) & 0xFF0000) | (v << 24)) 63 64 #define CRC_UPDATE_BYTE_2_BE(crc, b) (table[(((crc) >> 24) ^ (b))] ^ ((crc) << 8)) 65 66 UInt32 MY_FAST_CALL CrcUpdateT1_BeT4(UInt32 v, const void *data, size_t size, const UInt32 *table) 67 { 68 const Byte *p = (const Byte *)data; 69 table += 0x100; 70 v = CRC_UINT32_SWAP(v); 71 for (; size > 0 && ((unsigned)(ptrdiff_t)p & 3) != 0; size--, p++) 72 v = CRC_UPDATE_BYTE_2_BE(v, *p); 73 for (; size >= 4; size -= 4, p += 4) 74 { 75 v ^= *(const UInt32 *)p; 76 v = 77 table[0x000 + ((v ) & 0xFF)] 78 ^ table[0x100 + ((v >> 8) & 0xFF)] 79 ^ table[0x200 + ((v >> 16) & 0xFF)] 80 ^ table[0x300 + ((v >> 24))]; 81 } 82 for (; size > 0; size--, p++) 83 v = CRC_UPDATE_BYTE_2_BE(v, *p); 84 return CRC_UINT32_SWAP(v); 85 } 86 87 UInt32 MY_FAST_CALL CrcUpdateT1_BeT8(UInt32 v, const void *data, size_t size, const UInt32 *table) 88 { 89 const Byte *p = (const Byte *)data; 90 table += 0x100; 91 v = CRC_UINT32_SWAP(v); 92 for (; size > 0 && ((unsigned)(ptrdiff_t)p & 7) != 0; size--, p++) 93 v = CRC_UPDATE_BYTE_2_BE(v, *p); 94 for (; size >= 8; size -= 8, p += 8) 95 { 96 UInt32 d; 97 v ^= *(const UInt32 *)p; 98 v = 99 table[0x400 + ((v ) & 0xFF)] 100 ^ table[0x500 + ((v >> 8) & 0xFF)] 101 ^ table[0x600 + ((v >> 16) & 0xFF)] 102 ^ table[0x700 + ((v >> 24))]; 103 d = *((const UInt32 *)p + 1); 104 v ^= 105 table[0x000 + ((d ) & 0xFF)] 106 ^ table[0x100 + ((d >> 8) & 0xFF)] 107 ^ table[0x200 + ((d >> 16) & 0xFF)] 108 ^ table[0x300 + ((d >> 24))]; 109 } 110 for (; size > 0; size--, p++) 111 v = CRC_UPDATE_BYTE_2_BE(v, *p); 112 return CRC_UINT32_SWAP(v); 113 } 114 115 #endif 116
