/* XzCrc64Opt.c -- CRC64 calculation | |
2017-06-30 : Igor Pavlov : Public domain */ | |
#include "Precomp.h" | |
#include "CpuArch.h" | |
#ifndef MY_CPU_BE | |
#define CRC64_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 = CRC64_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 = CRC64_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 CRC64_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 = CRC64_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 = CRC64_UPDATE_BYTE_2_BE(v, *p); | |
return CRC_UINT64_SWAP(v); | |
} | |
#endif |