XzCrc64.c revision baa3858d3f5d128a5c8466b700098109edcad5f2 
1/* XzCrc64.c -- CRC64 calculation
22010-04-16 : Igor Pavlov : Public domain */
3
4#include "XzCrc64.h"
5
6#define kCrc64Poly UINT64_CONST(0xC96C5795D7870F42)
7UInt64 g_Crc64Table[256];
8
9void MY_FAST_CALL Crc64GenerateTable(void)
10{
11  UInt32 i;
12  for (i = 0; i < 256; i++)
13  {
14    UInt64 r = i;
15    int j;
16    for (j = 0; j < 8; j++)
17      r = (r >> 1) ^ ((UInt64)kCrc64Poly & ~((r & 1) - 1));
18    g_Crc64Table[i] = r;
19  }
20}
21
22UInt64 MY_FAST_CALL Crc64Update(UInt64 v, const void *data, size_t size)
23{
24  const Byte *p = (const Byte *)data;
25  for (; size > 0 ; size--, p++)
26    v = CRC64_UPDATE_BYTE(v, *p);
27  return v;
28}
29
30UInt64 MY_FAST_CALL Crc64Calc(const void *data, size_t size)
31{
32  return CRC64_GET_DIGEST(Crc64Update(CRC64_INIT_VAL, data, size));
33}
34