1 /* 7zCrcOpt.c -- CRC32 calculation
2 2017-04-03 : 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
CrcUpdateT4(UInt32 v,const void * data,size_t size,const UInt32 * table)12 UInt32 MY_FAST_CALL CrcUpdateT4(UInt32 v, const void *data, size_t size, const UInt32 *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 v ^= *(const UInt32 *)p;
20 v =
21 (table + 0x300)[((v ) & 0xFF)]
22 ^ (table + 0x200)[((v >> 8) & 0xFF)]
23 ^ (table + 0x100)[((v >> 16) & 0xFF)]
24 ^ (table + 0x000)[((v >> 24))];
25 }
26 for (; size > 0; size--, p++)
27 v = CRC_UPDATE_BYTE_2(v, *p);
28 return v;
29 }
30
CrcUpdateT8(UInt32 v,const void * data,size_t size,const UInt32 * table)31 UInt32 MY_FAST_CALL CrcUpdateT8(UInt32 v, const void *data, size_t size, const UInt32 *table)
32 {
33 const Byte *p = (const Byte *)data;
34 for (; size > 0 && ((unsigned)(ptrdiff_t)p & 7) != 0; size--, p++)
35 v = CRC_UPDATE_BYTE_2(v, *p);
36 for (; size >= 8; size -= 8, p += 8)
37 {
38 UInt32 d;
39 v ^= *(const UInt32 *)p;
40 v =
41 (table + 0x700)[((v ) & 0xFF)]
42 ^ (table + 0x600)[((v >> 8) & 0xFF)]
43 ^ (table + 0x500)[((v >> 16) & 0xFF)]
44 ^ (table + 0x400)[((v >> 24))];
45 d = *((const UInt32 *)p + 1);
46 v ^=
47 (table + 0x300)[((d ) & 0xFF)]
48 ^ (table + 0x200)[((d >> 8) & 0xFF)]
49 ^ (table + 0x100)[((d >> 16) & 0xFF)]
50 ^ (table + 0x000)[((d >> 24))];
51 }
52 for (; size > 0; size--, p++)
53 v = CRC_UPDATE_BYTE_2(v, *p);
54 return v;
55 }
56
57 #endif
58
59
60 #ifndef MY_CPU_LE
61
62 #define CRC_UINT32_SWAP(v) ((v >> 24) | ((v >> 8) & 0xFF00) | ((v << 8) & 0xFF0000) | (v << 24))
63
64 #define CRC_UPDATE_BYTE_2_BE(crc, b) (table[(((crc) >> 24) ^ (b))] ^ ((crc) << 8))
65
CrcUpdateT1_BeT4(UInt32 v,const void * data,size_t size,const UInt32 * table)66 UInt32 MY_FAST_CALL CrcUpdateT1_BeT4(UInt32 v, const void *data, size_t size, const UInt32 *table)
67 {
68 const Byte *p = (const Byte *)data;
69 table += 0x100;
70 v = CRC_UINT32_SWAP(v);
71 for (; size > 0 && ((unsigned)(ptrdiff_t)p & 3) != 0; size--, p++)
72 v = CRC_UPDATE_BYTE_2_BE(v, *p);
73 for (; size >= 4; size -= 4, p += 4)
74 {
75 v ^= *(const UInt32 *)p;
76 v =
77 (table + 0x000)[((v ) & 0xFF)]
78 ^ (table + 0x100)[((v >> 8) & 0xFF)]
79 ^ (table + 0x200)[((v >> 16) & 0xFF)]
80 ^ (table + 0x300)[((v >> 24))];
81 }
82 for (; size > 0; size--, p++)
83 v = CRC_UPDATE_BYTE_2_BE(v, *p);
84 return CRC_UINT32_SWAP(v);
85 }
86
CrcUpdateT1_BeT8(UInt32 v,const void * data,size_t size,const UInt32 * table)87 UInt32 MY_FAST_CALL CrcUpdateT1_BeT8(UInt32 v, const void *data, size_t size, const UInt32 *table)
88 {
89 const Byte *p = (const Byte *)data;
90 table += 0x100;
91 v = CRC_UINT32_SWAP(v);
92 for (; size > 0 && ((unsigned)(ptrdiff_t)p & 7) != 0; size--, p++)
93 v = CRC_UPDATE_BYTE_2_BE(v, *p);
94 for (; size >= 8; size -= 8, p += 8)
95 {
96 UInt32 d;
97 v ^= *(const UInt32 *)p;
98 v =
99 (table + 0x400)[((v ) & 0xFF)]
100 ^ (table + 0x500)[((v >> 8) & 0xFF)]
101 ^ (table + 0x600)[((v >> 16) & 0xFF)]
102 ^ (table + 0x700)[((v >> 24))];
103 d = *((const UInt32 *)p + 1);
104 v ^=
105 (table + 0x000)[((d ) & 0xFF)]
106 ^ (table + 0x100)[((d >> 8) & 0xFF)]
107 ^ (table + 0x200)[((d >> 16) & 0xFF)]
108 ^ (table + 0x300)[((d >> 24))];
109 }
110 for (; size > 0; size--, p++)
111 v = CRC_UPDATE_BYTE_2_BE(v, *p);
112 return CRC_UINT32_SWAP(v);
113 }
114
115 #endif
116