1/* XzCrc64.c -- CRC64 calculation
 22011-06-28 : Igor Pavlov : Public domain */
 3
 4#include "Precomp.h"
 5
 6#include "XzCrc64.h"
 7#include "CpuArch.h"
 8
 9#define kCrc64Poly UINT64_CONST(0xC96C5795D7870F42)
10
11#ifdef MY_CPU_LE
12  #define CRC_NUM_TABLES 4
13#else
14  #define CRC_NUM_TABLES 5
15  #define CRC_UINT64_SWAP(v) \
16  ((v >> 56) | \
17  ((v >> 40) & ((UInt64)0xFF <<  8)) | \
18  ((v >> 24) & ((UInt64)0xFF << 16)) | \
19  ((v >>  8) & ((UInt64)0xFF << 24)) | \
20  ((v <<  8) & ((UInt64)0xFF << 32)) | \
21  ((v << 24) & ((UInt64)0xFF << 40)) | \
22  ((v << 40) & ((UInt64)0xFF << 48)) | \
23   (v << 56))
24  UInt64 MY_FAST_CALL XzCrc64UpdateT1_BeT4(UInt64 v, const void *data, size_t size, const UInt64 *table);
25#endif
26
27#ifndef MY_CPU_BE
28  UInt64 MY_FAST_CALL XzCrc64UpdateT4(UInt64 v, const void *data, size_t size, const UInt64 *table);
29#endif
30
31typedef UInt64 (MY_FAST_CALL *CRC_FUNC)(UInt64 v, const void *data, size_t size, const UInt64 *table);
32
33static CRC_FUNC g_Crc64Update;
34UInt64 g_Crc64Table[256 * CRC_NUM_TABLES];
35
36UInt64 MY_FAST_CALL Crc64Update(UInt64 v, const void *data, size_t size)
37{
38  return g_Crc64Update(v, data, size, g_Crc64Table);
39}
40
41UInt64 MY_FAST_CALL Crc64Calc(const void *data, size_t size)
42{
43  return g_Crc64Update(CRC64_INIT_VAL, data, size, g_Crc64Table) ^ CRC64_INIT_VAL;
44}
45
46void MY_FAST_CALL Crc64GenerateTable()
47{
48  UInt32 i;
49  for (i = 0; i < 256; i++)
50  {
51    UInt64 r = i;
52    unsigned j;
53    for (j = 0; j < 8; j++)
54      r = (r >> 1) ^ (kCrc64Poly & ~((r & 1) - 1));
55    g_Crc64Table[i] = r;
56  }
57  for (; i < 256 * CRC_NUM_TABLES; i++)
58  {
59    UInt64 r = g_Crc64Table[i - 256];
60    g_Crc64Table[i] = g_Crc64Table[r & 0xFF] ^ (r >> 8);
61  }
62  
63  #ifdef MY_CPU_LE
64
65  g_Crc64Update = XzCrc64UpdateT4;
66
67  
68
69
70
71
72  #else
73  {
74    #ifndef MY_CPU_BE
75    UInt32 k = 1;
76    if (*(const Byte *)&k == 1)
77      g_Crc64Update = XzCrc64UpdateT4;
78    else
79    #endif
80    {
81      for (i = 256 * CRC_NUM_TABLES - 1; i >= 256; i--)
82      {
83        UInt64 x = g_Crc64Table[i - 256];
84        g_Crc64Table[i] = CRC_UINT64_SWAP(x);
85      }
86      g_Crc64Update = XzCrc64UpdateT1_BeT4;
87    }
88  }
89  #endif
90}