mirror of
https://github.com/nillerusr/source-engine.git
synced 2024-12-22 22:27:05 +00:00
91 lines
2.0 KiB
C
91 lines
2.0 KiB
C
/* XzCrc64.c -- CRC64 calculation
|
|
2011-06-28 : Igor Pavlov : Public domain */
|
|
|
|
#include "Precomp.h"
|
|
|
|
#include "XzCrc64.h"
|
|
#include "CpuArch.h"
|
|
|
|
#define kCrc64Poly UINT64_CONST(0xC96C5795D7870F42)
|
|
|
|
#ifdef MY_CPU_LE
|
|
#define CRC_NUM_TABLES 4
|
|
#else
|
|
#define CRC_NUM_TABLES 5
|
|
#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))
|
|
UInt64 MY_FAST_CALL XzCrc64UpdateT1_BeT4(UInt64 v, const void *data, size_t size, const UInt64 *table);
|
|
#endif
|
|
|
|
#ifndef MY_CPU_BE
|
|
UInt64 MY_FAST_CALL XzCrc64UpdateT4(UInt64 v, const void *data, size_t size, const UInt64 *table);
|
|
#endif
|
|
|
|
typedef UInt64 (MY_FAST_CALL *CRC_FUNC)(UInt64 v, const void *data, size_t size, const UInt64 *table);
|
|
|
|
static CRC_FUNC g_Crc64Update;
|
|
UInt64 g_Crc64Table[256 * CRC_NUM_TABLES];
|
|
|
|
UInt64 MY_FAST_CALL Crc64Update(UInt64 v, const void *data, size_t size)
|
|
{
|
|
return g_Crc64Update(v, data, size, g_Crc64Table);
|
|
}
|
|
|
|
UInt64 MY_FAST_CALL Crc64Calc(const void *data, size_t size)
|
|
{
|
|
return g_Crc64Update(CRC64_INIT_VAL, data, size, g_Crc64Table) ^ CRC64_INIT_VAL;
|
|
}
|
|
|
|
void MY_FAST_CALL Crc64GenerateTable()
|
|
{
|
|
UInt32 i;
|
|
for (i = 0; i < 256; i++)
|
|
{
|
|
UInt64 r = i;
|
|
unsigned j;
|
|
for (j = 0; j < 8; j++)
|
|
r = (r >> 1) ^ (kCrc64Poly & ~((r & 1) - 1));
|
|
g_Crc64Table[i] = r;
|
|
}
|
|
for (; i < 256 * CRC_NUM_TABLES; i++)
|
|
{
|
|
UInt64 r = g_Crc64Table[i - 256];
|
|
g_Crc64Table[i] = g_Crc64Table[r & 0xFF] ^ (r >> 8);
|
|
}
|
|
|
|
#ifdef MY_CPU_LE
|
|
|
|
g_Crc64Update = XzCrc64UpdateT4;
|
|
|
|
|
|
|
|
|
|
|
|
|
|
#else
|
|
{
|
|
#ifndef MY_CPU_BE
|
|
UInt32 k = 1;
|
|
if (*(const Byte *)&k == 1)
|
|
g_Crc64Update = XzCrc64UpdateT4;
|
|
else
|
|
#endif
|
|
{
|
|
for (i = 256 * CRC_NUM_TABLES - 1; i >= 256; i--)
|
|
{
|
|
UInt64 x = g_Crc64Table[i - 256];
|
|
g_Crc64Table[i] = CRC_UINT64_SWAP(x);
|
|
}
|
|
g_Crc64Update = XzCrc64UpdateT1_BeT4;
|
|
}
|
|
}
|
|
#endif
|
|
}
|