1 /* XzCrc64Opt.c -- CRC64 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 UInt64 MY_FAST_CALL XzCrc64UpdateT4(UInt64 v, const void *data, size_t size, const UInt64 *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 UInt32 d = (UInt32)v ^ *(const UInt32 *)p; 20 v = (v >> 32) 21 ^ table[0x300 + ((d ) & 0xFF)] 22 ^ table[0x200 + ((d >> 8) & 0xFF)] 23 ^ table[0x100 + ((d >> 16) & 0xFF)] 24 ^ table[0x000 + ((d >> 24))]; 25 } 26 for (; size > 0; size--, p++) 27 v = CRC_UPDATE_BYTE_2(v, *p); 28 return v; 29 } 30 31 #endif 32 33 34 #ifndef MY_CPU_LE 35 36 #define CRC_UINT64_SWAP(v) \ 37 ((v >> 56) \ 38 | ((v >> 40) & ((UInt64)0xFF << 8)) \ 39 | ((v >> 24) & ((UInt64)0xFF << 16)) \ 40 | ((v >> 8) & ((UInt64)0xFF << 24)) \ 41 | ((v << 8) & ((UInt64)0xFF << 32)) \ 42 | ((v << 24) & ((UInt64)0xFF << 40)) \ 43 | ((v << 40) & ((UInt64)0xFF << 48)) \ 44 | ((v << 56))) 45 46 #define CRC_UPDATE_BYTE_2_BE(crc, b) (table[(Byte)((crc) >> 56) ^ (b)] ^ ((crc) << 8)) 47 48 UInt64 MY_FAST_CALL XzCrc64UpdateT1_BeT4(UInt64 v, const void *data, size_t size, const UInt64 *table) 49 { 50 const Byte *p = (const Byte *)data; 51 table += 0x100; 52 v = CRC_UINT64_SWAP(v); 53 for (; size > 0 && ((unsigned)(ptrdiff_t)p & 3) != 0; size--, p++) 54 v = CRC_UPDATE_BYTE_2_BE(v, *p); 55 for (; size >= 4; size -= 4, p += 4) 56 { 57 UInt32 d = (UInt32)(v >> 32) ^ *(const UInt32 *)p; 58 v = (v << 32) 59 ^ table[0x000 + ((d ) & 0xFF)] 60 ^ table[0x100 + ((d >> 8) & 0xFF)] 61 ^ table[0x200 + ((d >> 16) & 0xFF)] 62 ^ table[0x300 + ((d >> 24))]; 63 } 64 for (; size > 0; size--, p++) 65 v = CRC_UPDATE_BYTE_2_BE(v, *p); 66 return CRC_UINT64_SWAP(v); 67 } 68 69 #endif 70
