1/* XzCrc64Opt.c -- CRC64 calculation
 22011-06-28 : Igor Pavlov : Public domain */
 3
 4#include "Precomp.h"
 5
 6#include "CpuArch.h"
 7
 8#define CRC_UPDATE_BYTE_2(crc, b) (table[((crc) ^ (b)) & 0xFF] ^ ((crc) >> 8))
 9
10#ifndef MY_CPU_BE
11
12UInt64 MY_FAST_CALL XzCrc64UpdateT4(UInt64 v, const void *data, size_t size, const UInt64 *table)
13{
14  const Byte *p = (const Byte *)data;
15  for (; size > 0 && ((unsigned)(ptrdiff_t)p & 3) != 0; size--, p++)
16    v = CRC_UPDATE_BYTE_2(v, *p);
17  for (; size >= 4; size -= 4, p += 4)
18  {
19    UInt32 d = (UInt32)v ^ *(const UInt32 *)p;
20    v = (v >> 32) ^
21      table[0x300 + ((d      ) & 0xFF)] ^
22      table[0x200 + ((d >>  8) & 0xFF)] ^
23      table[0x100 + ((d >> 16) & 0xFF)] ^
24      table[0x000 + ((d >> 24))];
25  }
26  for (; size > 0; size--, p++)
27    v = CRC_UPDATE_BYTE_2(v, *p);
28  return v;
29}
30
31#endif
32
33
34#ifndef MY_CPU_LE
35
36#define CRC_UINT64_SWAP(v) \
37  ((v >> 56) | \
38  ((v >> 40) & ((UInt64)0xFF <<  8)) | \
39  ((v >> 24) & ((UInt64)0xFF << 16)) | \
40  ((v >>  8) & ((UInt64)0xFF << 24)) | \
41  ((v <<  8) & ((UInt64)0xFF << 32)) | \
42  ((v << 24) & ((UInt64)0xFF << 40)) | \
43  ((v << 40) & ((UInt64)0xFF << 48)) | \
44   (v << 56))
45
46UInt64 MY_FAST_CALL XzCrc64UpdateT1_BeT4(UInt64 v, const void *data, size_t size, const UInt64 *table)
47{
48  const Byte *p = (const Byte *)data;
49  for (; size > 0 && ((unsigned)(ptrdiff_t)p & 3) != 0; size--, p++)
50    v = CRC_UPDATE_BYTE_2(v, *p);
51  v = CRC_UINT64_SWAP(v);
52  table += 0x100;
53  for (; size >= 4; size -= 4, p += 4)
54  {
55    UInt32 d = (UInt32)(v >> 32) ^ *(const UInt32 *)p;
56    v = (v << 32) ^
57      table[0x000 + ((d      ) & 0xFF)] ^
58      table[0x100 + ((d >>  8) & 0xFF)] ^
59      table[0x200 + ((d >> 16) & 0xFF)] ^
60      table[0x300 + ((d >> 24))];
61  }
62  table -= 0x100;
63  v = CRC_UINT64_SWAP(v);
64  for (; size > 0; size--, p++)
65    v = CRC_UPDATE_BYTE_2(v, *p);
66  return v;
67}
68
69#endif