1 /* XzCrc64Opt.c -- CRC64 calculation
2 2011-06-28 : 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
XzCrc64UpdateT4(UInt64 v,const void * data,size_t size,const UInt64 * table)12 UInt64 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
XzCrc64UpdateT1_BeT4(UInt64 v,const void * data,size_t size,const UInt64 * table)46 UInt64 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
70