khanat-opennel-code/code/ryzom/client/src/seven_zip/XzCrc64Opt.cpp
2016-01-09 17:15:31 +01:00

69 lines
1.9 KiB
C++

/* XzCrc64Opt.c -- CRC64 calculation
2015-03-01 : Igor Pavlov : Public domain */
#include "Precomp.h"
#include "CpuArch.h"
#ifndef MY_CPU_BE
#define CRC_UPDATE_BYTE_2(crc, b) (table[((crc) ^ (b)) & 0xFF] ^ ((crc) >> 8))
UInt64 MY_FAST_CALL XzCrc64UpdateT4(UInt64 v, const void *data, size_t size, const UInt64 *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)
{
UInt32 d = (UInt32)v ^ *(const UInt32 *)p;
v = (v >> 32)
^ table[0x300 + ((d ) & 0xFF)]
^ table[0x200 + ((d >> 8) & 0xFF)]
^ table[0x100 + ((d >> 16) & 0xFF)]
^ table[0x000 + ((d >> 24))];
}
for (; size > 0; size--, p++)
v = CRC_UPDATE_BYTE_2(v, *p);
return v;
}
#endif
#ifndef MY_CPU_LE
#define CRC_UINT64_SWAP(v) \
((v >> 56) \
| ((v >> 40) & ((UInt64)0xFF << 8)) \
| ((v >> 24) & ((UInt64)0xFF << 16)) \
| ((v >> 8) & ((UInt64)0xFF << 24)) \
| ((v << 8) & ((UInt64)0xFF << 32)) \
| ((v << 24) & ((UInt64)0xFF << 40)) \
| ((v << 40) & ((UInt64)0xFF << 48)) \
| ((v << 56)))
#define CRC_UPDATE_BYTE_2_BE(crc, b) (table[(Byte)((crc) >> 56) ^ (b)] ^ ((crc) << 8))
UInt64 MY_FAST_CALL XzCrc64UpdateT1_BeT4(UInt64 v, const void *data, size_t size, const UInt64 *table)
{
const Byte *p = (const Byte *)data;
table += 0x100;
v = CRC_UINT64_SWAP(v);
for (; size > 0 && ((unsigned)(ptrdiff_t)p & 3) != 0; size--, p++)
v = CRC_UPDATE_BYTE_2_BE(v, *p);
for (; size >= 4; size -= 4, p += 4)
{
UInt32 d = (UInt32)(v >> 32) ^ *(const UInt32 *)p;
v = (v << 32)
^ table[0x000 + ((d ) & 0xFF)]
^ table[0x100 + ((d >> 8) & 0xFF)]
^ table[0x200 + ((d >> 16) & 0xFF)]
^ table[0x300 + ((d >> 24))];
}
for (; size > 0; size--, p++)
v = CRC_UPDATE_BYTE_2_BE(v, *p);
return CRC_UINT64_SWAP(v);
}
#endif