| /* 7zCrcOpt.c -- CRC32 calculation : optimized version |
| 2009-11-23 : Igor Pavlov : Public domain */ |
| |
| #include "CpuArch.h" |
| |
| #ifdef MY_CPU_LE |
| |
| #define CRC_UPDATE_BYTE_2(crc, b) (table[((crc) ^ (b)) & 0xFF] ^ ((crc) >> 8)) |
| |
| UInt32 MY_FAST_CALL CrcUpdateT4(UInt32 v, const void *data, size_t size, const UInt32 *table) |
| { |
| const Byte *p = (const Byte *)data; |
| for (; size > 0 && ((unsigned)(ptrdiff_t)p & 3) != 0; size--, p++) |
| v = CRC_UPDATE_BYTE_2(v, *p); |
| for (; size >= 4; size -= 4, p += 4) |
| { |
| v ^= *(const UInt32 *)p; |
| v = |
| table[0x300 + (v & 0xFF)] ^ |
| table[0x200 + ((v >> 8) & 0xFF)] ^ |
| table[0x100 + ((v >> 16) & 0xFF)] ^ |
| table[0x000 + ((v >> 24))]; |
| } |
| for (; size > 0; size--, p++) |
| v = CRC_UPDATE_BYTE_2(v, *p); |
| return v; |
| } |
| |
| UInt32 MY_FAST_CALL CrcUpdateT8(UInt32 v, const void *data, size_t size, const UInt32 *table) |
| { |
| return CrcUpdateT4(v, data, size, table); |
| } |
| |
| #endif |