1 /* XzCrc64.c -- CRC64 calculation
2 2011-06-28 : 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
31 typedef UInt64 (MY_FAST_CALL *CRC_FUNC)(UInt64 v, const void *data, size_t size, const UInt64 *table);
32
33 static CRC_FUNC g_Crc64Update;
34 UInt64 g_Crc64Table[256 * CRC_NUM_TABLES];
35
Crc64Update(UInt64 v,const void * data,size_t size)36 UInt64 MY_FAST_CALL Crc64Update(UInt64 v, const void *data, size_t size)
37 {
38 return g_Crc64Update(v, data, size, g_Crc64Table);
39 }
40
Crc64Calc(const void * data,size_t size)41 UInt64 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
Crc64GenerateTable()46 void 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 }
91