raze/libraries/lzma/C/XzCrc64Opt.c
Christoph Oelckers aa54d3af10 backend update from GZDoom
LZMA update plus several ZScript improvements.
2023-10-07 18:44:31 +02:00

61 lines
1.8 KiB
C

/* XzCrc64Opt.c -- CRC64 calculation
2023-04-02 : 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 Z7_FASTCALL XzCrc64UpdateT4(UInt64 v, const void *data, size_t size, const UInt64 *table);
UInt64 Z7_FASTCALL 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)
{
const UInt32 d = (UInt32)v ^ *(const UInt32 *)(const void *)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 CRC64_UPDATE_BYTE_2_BE(crc, b) (table[(Byte)((crc) >> 56) ^ (b)] ^ ((crc) << 8))
UInt64 Z7_FASTCALL XzCrc64UpdateT1_BeT4(UInt64 v, const void *data, size_t size, const UInt64 *table);
UInt64 Z7_FASTCALL XzCrc64UpdateT1_BeT4(UInt64 v, const void *data, size_t size, const UInt64 *table)
{
const Byte *p = (const Byte *)data;
table += 0x100;
v = Z7_BSWAP64(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)
{
const UInt32 d = (UInt32)(v >> 32) ^ *(const UInt32 *)(const void *)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 Z7_BSWAP64(v);
}
#endif