/* 7zCrcOpt.c -- CRC32 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)) | |
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) | |
{ | |
const Byte *p = (const Byte *)data; | |
for (; size > 0 && ((unsigned)(ptrdiff_t)p & 7) != 0; size--, p++) | |
v = CRC_UPDATE_BYTE_2(v, *p); | |
for (; size >= 8; size -= 8, p += 8) | |
{ | |
UInt32 d; | |
v ^= *(const UInt32 *)p; | |
v = | |
table[0x700 + ((v ) & 0xFF)] | |
^ table[0x600 + ((v >> 8) & 0xFF)] | |
^ table[0x500 + ((v >> 16) & 0xFF)] | |
^ table[0x400 + ((v >> 24))]; | |
d = *((const UInt32 *)p + 1); | |
v ^= | |
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_UINT32_SWAP(v) ((v >> 24) | ((v >> 8) & 0xFF00) | ((v << 8) & 0xFF0000) | (v << 24)) | |
#define CRC_UPDATE_BYTE_2_BE(crc, b) (table[(((crc) >> 24) ^ (b))] ^ ((crc) << 8)) | |
UInt32 MY_FAST_CALL CrcUpdateT1_BeT4(UInt32 v, const void *data, size_t size, const UInt32 *table) | |
{ | |
const Byte *p = (const Byte *)data; | |
table += 0x100; | |
v = CRC_UINT32_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) | |
{ | |
v ^= *(const UInt32 *)p; | |
v = | |
table[0x000 + ((v ) & 0xFF)] | |
^ table[0x100 + ((v >> 8) & 0xFF)] | |
^ table[0x200 + ((v >> 16) & 0xFF)] | |
^ table[0x300 + ((v >> 24))]; | |
} | |
for (; size > 0; size--, p++) | |
v = CRC_UPDATE_BYTE_2_BE(v, *p); | |
return CRC_UINT32_SWAP(v); | |
} | |
UInt32 MY_FAST_CALL CrcUpdateT1_BeT8(UInt32 v, const void *data, size_t size, const UInt32 *table) | |
{ | |
const Byte *p = (const Byte *)data; | |
table += 0x100; | |
v = CRC_UINT32_SWAP(v); | |
for (; size > 0 && ((unsigned)(ptrdiff_t)p & 7) != 0; size--, p++) | |
v = CRC_UPDATE_BYTE_2_BE(v, *p); | |
for (; size >= 8; size -= 8, p += 8) | |
{ | |
UInt32 d; | |
v ^= *(const UInt32 *)p; | |
v = | |
table[0x400 + ((v ) & 0xFF)] | |
^ table[0x500 + ((v >> 8) & 0xFF)] | |
^ table[0x600 + ((v >> 16) & 0xFF)] | |
^ table[0x700 + ((v >> 24))]; | |
d = *((const UInt32 *)p + 1); | |
v ^= | |
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_UINT32_SWAP(v); | |
} | |
#endif |