1/* XzCrc64Opt.c -- CRC64 calculation
 22015-03-01 : Igor Pavlov : Public domain */
 3
 4#include "Precomp.h"
 5
 6#include "CpuArch.h"
 7
 8#ifndef MY_CPU_BE
 9
10#define CRC_UPDATE_BYTE_2(crc, b) (table[((crc) ^ (b)) & 0xFF] ^ ((crc) >> 8))
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
46#define CRC_UPDATE_BYTE_2_BE(crc, b) (table[(Byte)((crc) >> 56) ^ (b)] ^ ((crc) << 8))
47
48UInt64 MY_FAST_CALL XzCrc64UpdateT1_BeT4(UInt64 v, const void *data, size_t size, const UInt64 *table)
49{
50  const Byte *p = (const Byte *)data;
51  table += 0x100;
52  v = CRC_UINT64_SWAP(v);
53  for (; size > 0 && ((unsigned)(ptrdiff_t)p & 3) != 0; size--, p++)
54    v = CRC_UPDATE_BYTE_2_BE(v, *p);
55  for (; size >= 4; size -= 4, p += 4)
56  {
57    UInt32 d = (UInt32)(v >> 32) ^ *(const UInt32 *)p;
58    v = (v << 32)
59        ^ table[0x000 + ((d      ) & 0xFF)]
60        ^ table[0x100 + ((d >>  8) & 0xFF)]
61        ^ table[0x200 + ((d >> 16) & 0xFF)]
62        ^ table[0x300 + ((d >> 24))];
63  }
64  for (; size > 0; size--, p++)
65    v = CRC_UPDATE_BYTE_2_BE(v, *p);
66  return CRC_UINT64_SWAP(v);
67}
68
69#endif