CRC32.c
上传用户:dzyhzl
上传日期:2019-04-29
资源大小:56270k
文件大小:14k
- //////////////////////////////////////////////////////////////////////////////////////
- //
- // FileName : CRC32.C
- // Creater : Freeway Chen
- // Date : 2000-6-15 18:25:43
- // Comment : Get source code from Zlib Project
- //
- //////////////////////////////////////////////////////////////////////////////////////
- /* crc32.c -- compute the CRC-32 of a data stream
- * Copyright (C) 1995-1998 Mark Adler
- * For conditions of distribution and use, see copyright notice in zlib.h
- */
- #ifdef _STANDALONE
- typedef unsigned long CRC_UINT32;
- typedef unsigned char CRC_BYTE;
- #else
- typedef unsigned __int32 CRC_UINT32;
- typedef unsigned __int8 CRC_BYTE;
- #endif
- #ifdef DYNAMIC_CRC_TABLE
- static int CRCTableEmptyFlag = 1;
- static CRC_UINT32 CRC_Table[256];
- static void MakeCRCTable(void);
- /*
- Generate a table for a byte-wise 32-bit CRC calculation on the polynomial:
- x^32+x^26+x^23+x^22+x^16+x^12+x^11+x^10+x^8+x^7+x^5+x^4+x^2+x+1.
- Polynomials over GF(2) are represented in binary, one bit per coefficient,
- with the lowest powers in the most significant bit. Then adding polynomials
- is just exclusive-or, and multiplying a polynomial by x is a right shift by
- one. If we call the above polynomial p, and represent a byte as the
- polynomial q, also with the lowest power in the most significant bit (so the
- byte 0xb1 is the polynomial x^7+x^3+x+1), then the CRC is (q*x^32) mod p,
- where a mod b means the remainder after dividing a by b.
- This calculation is done using the shift-register method of multiplying and
- taking the remainder. The register is initialized to zero, and for each
- incoming bit, x^32 is added mod p to the register if the bit is a one (where
- x^32 mod p is p+x^32 = x^26+...+1), and the register is multiplied mod p by
- x (which is shifting right by one and adding x^32 mod p if the bit shifted
- out is a one). We start with the highest power (least significant bit) of
- q and repeat for all eight bits of q.
- The table is simply the CRC of all possible eight bit values. This is all
- the information needed to generate CRC's on data a byte at a time for all
- combinations of CRC register values and incoming bytes.
- */
- static void MakeCRCTable()
- {
- CRC_UINT32 CRC;
- CRC_UINT32 n, k;
- CRC_UINT32 poly; /* polynomial exclusive-or pattern */
- /* terms of polynomial defining this crc (except x^32): */
- static const CRC_BYTE p[] = {0, 1, 2, 4, 5, 7, 8, 10, 11, 12, 16, 22, 23, 26};
- /* make exclusive-or pattern from polynomial (0xedb88320L) */
- poly = 0L;
- for (n = 0; n < sizeof(p) / sizeof(CRC_BYTE); n++)
- poly |= 1L << (31 - p[n]);
-
- for (n = 0; n < 256; n++)
- {
- CRC = n;
- for (k = 0; k < 8; k++)
- {
- if (CRC & 1)
- CRC = poly ^ (CRC >> 1);
- else
- CRC = CRC >> 1;
- }
- CRC_Table[n] = CRC;
- }
- CRCTableEmptyFlag = 0;
- }
- #else
- // ========================================================================
- // Table of CRC-32's of all single-byte values (made by make_crc_table)
- //
- static const CRC_UINT32 CRC_Table[256] = {
- 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
- 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
- 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
- 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
- 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
- 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
- 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
- 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
- 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
- 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
- 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
- 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
- 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
- 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
- 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
- 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
- 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
- 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
- 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
- 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
- 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
- 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
- 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
- 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
- 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
- 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
- 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
- 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
- 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
- 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
- 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
- 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
- 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
- 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
- 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
- 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
- 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
- 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
- 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
- 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
- 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
- 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
- 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
- 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
- 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
- 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
- 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
- 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
- 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
- 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
- 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
- 0x2d02ef8dL
- };
- #endif // DYNAMIC_CRC_TABLE
- // =========================================================================
- // This function can be used by asm versions of crc32()
- //
- const CRC_UINT32 * GetCRCTable()
- {
- #ifdef DYNAMIC_CRC_TABLE
- if (CRCTableEmptyFlag)
- MakeCRCTable();
- #endif
- return (const CRC_UINT32 *)CRC_Table;
- }
- // Use internal CRC32 function
- // =========================================================================
- #define DO1BYTE(pBuf) CRC = CRC_Table[(CRC ^ (*pBuf++)) & 0xff] ^ (CRC >> 8);
- //#define DO2(pBuf) DO1(pBuf); DO1(pBuf);
- //#define DO4(pBuf) DO2(pBuf); DO2(pBuf);
- //#define DO8(pBuf) DO4(pBuf); DO4(pBuf);
- // =========================================================================
- unsigned CRC32_C(unsigned CRC, const void *pvBuf, int nLen)
- //unsigned CRC32(unsigned CRC, const void *pvBuf, int nLen)
- {
- const CRC_BYTE *pBuf = (const CRC_BYTE *)pvBuf;
- if (pvBuf == (void *)0)
- return 0L;
- #ifdef DYNAMIC_CRC_TABLE
- if (CRCTableEmptyFlag)
- MakeCRCTable();
- #endif // DYNAMIC_CRC_TABLE
- CRC = CRC ^ 0xffffffffL; // equal CRC = ~CRC
- while (nLen >= 8)
- {
- // It's easy to debug
- DO1BYTE(pBuf); // 0
- DO1BYTE(pBuf); // 1
- DO1BYTE(pBuf); // 2
- DO1BYTE(pBuf); // 3
- DO1BYTE(pBuf); // 4
- DO1BYTE(pBuf); // 5
- DO1BYTE(pBuf); // 6
- DO1BYTE(pBuf); // 7
- nLen -= 8;
- }
- if (nLen)
- {
- do {
- DO1BYTE(pBuf);
- } while (--nLen);
- }
- return (CRC ^ 0xffffffffL); // equal return ~CRC
- }
- // ============================================================================
- //
- // ASM Part in Visual C++
- //
- // ============================================================================
- //#define DO1BYTE(pBuf) CRC = CRC_Table[(CRC ^ (*pBuf++)) & 0xff] ^ (CRC >> 8);
- #define DO1BYTEASM()
- __asm{ mov bl, [esi] }
- __asm{ inc esi }
- __asm{ xor ebx, eax }
- __asm{ shr eax, 8 }
- __asm{ and ebx, 0xff }
- __asm{ xor eax, CRC_Table[ebx * 4] }
- //unsigned CRC32_ASM(unsigned CRC, const void *pvBuf, int nLen)
- unsigned CRC32(unsigned CRC, const void *pvBuf, int nLen)
- {
- #ifndef WIN32
- return CRC32_C(CRC, pvBuf, nLen);
- #else
- unsigned RetCode = 0;
- if (!pvBuf)
- return RetCode;
- __asm mov esi, [pvBuf]
- __asm mov ecx, [nLen]
- __asm mov eax, [CRC]
- __asm shr ecx, 3
- __asm xor eax, 0xffffffff
- __asm test ecx, ecx
- __asm jz CRC_Last7Bytes
-
- __asm push ebp
- __asm mov ebp, ecx
- __asm xor edx, edx
- __asm xor ecx, ecx
- __asm align 4
- CRC_Loop1:
- // eax = CRC
- // edx first TableIndex
- // ecx second TableIndex
- // Process 4 bytes
- __asm mov ebx, [esi]
- __asm add esi, 4
-
- __asm mov dl, bl
- __asm mov cl, bh
- __asm xor dl, al
- __asm shr eax, 8
- __asm mov edi, CRC_Table[edx * 4]
- __asm shr ebx, 16
- __asm xor eax, edi
- __asm xor cl, al
- __asm shr eax, 8
- __asm mov edi, CRC_Table[ecx * 4]
- __asm mov dl, bl
- __asm xor eax, edi
- __asm xor dl, al
- __asm shr eax, 8
- __asm mov edi, CRC_Table[edx * 4]
- __asm mov cl, bh
- __asm xor eax, edi
- __asm mov ebx, [esi]
- __asm xor cl, al
- __asm shr eax, 8
- __asm mov edi, CRC_Table[ecx * 4]
- __asm add esi, 4
- __asm xor eax, edi
-
- __asm mov dl, bl
- __asm mov cl, bh
- __asm xor dl, al
- __asm shr eax, 8
- __asm mov edi, CRC_Table[edx * 4]
- __asm shr ebx, 16
- __asm xor eax, edi
- __asm xor cl, al
- __asm shr eax, 8
- __asm mov edi, CRC_Table[ecx * 4]
- __asm mov dl, bl
- __asm xor eax, edi
- __asm xor dl, al
- __asm shr eax, 8
- __asm mov edi, CRC_Table[edx * 4]
- __asm mov cl, bh
- __asm xor eax, edi
- __asm xor cl, al
- __asm shr eax, 8
- __asm xor eax, CRC_Table[ecx * 4]
- __asm dec ebp
- __asm jnz CRC_Loop1
- __asm pop ebp
- CRC_Last7Bytes:
- __asm mov ecx, [nLen]
- __asm xor edx, edx
- __asm and ecx, 0x7
- __asm jz CRC_Exit
- CRC_Loop2:
- __asm mov dl, [esi]
- __asm inc esi
- __asm xor dl, al
- __asm shr eax, 8
- __asm xor eax, CRC_Table[edx * 4]
- __asm dec ecx
- __asm jnz CRC_Loop2
- CRC_Exit:
- __asm xor eax, 0xffffffff
- __asm mov [RetCode], eax
- return RetCode;
- #endif
- }
- /*
- unsigned CRC32(unsigned CRC, const void *pvBuf, int nLen)
- {
- unsigned RetCode = 0;
- if (!pvBuf)
- return RetCode;
- __asm mov esi, [pvBuf]
- __asm mov ecx, [nLen]
- __asm mov eax, [CRC]
- __asm shr ecx, 3
- __asm xor eax, 0xffffffff
- __asm test ecx, ecx
- __asm jz CRC_Last7Bytes
- CRC_Loop1:
- __asm xor edx, edx
- // Process 4 bytes
- __asm mov ebx, [esi]
- __asm add esi, 4
-
- __asm mov dl, bl
- __asm shr ebx, 8
- __asm xor dl, al
- __asm shr eax, 8
- __asm mov edi, CRC_Table[edx * 4]
-
- __asm mov dl, bl
- __asm xor eax, edi
-
- __asm shr ebx, 8
- __asm xor dl, al
- __asm shr eax, 8
- __asm mov edi, CRC_Table[edx * 4]
- __asm mov dl, bl
- __asm xor eax, edi
-
- __asm shr ebx, 8
- __asm xor dl, al
- __asm shr eax, 8
- __asm mov edi, CRC_Table[edx * 4]
- __asm mov dl, bl
- __asm xor eax, edi
-
- __asm xor dl, al
- __asm shr eax, 8
- __asm xor eax, CRC_Table[edx * 4]
-
- // Process 4 bytes
- __asm mov ebx, [esi]
- __asm add esi, 4
-
- __asm mov dl, bl
- __asm shr ebx, 8
- __asm xor dl, al
- __asm shr eax, 8
- __asm mov edi, CRC_Table[edx * 4]
-
- __asm mov dl, bl
- __asm xor eax, edi
-
- __asm shr ebx, 8
- __asm xor dl, al
- __asm shr eax, 8
- __asm mov edi, CRC_Table[edx * 4]
- __asm mov dl, bl
- __asm xor eax, edi
-
- __asm shr ebx, 8
- __asm xor dl, al
- __asm shr eax, 8
- __asm mov edi, CRC_Table[edx * 4]
- __asm mov dl, bl
- __asm xor eax, edi
-
- __asm xor dl, al
- __asm shr eax, 8
- __asm xor eax, CRC_Table[edx * 4]
- __asm dec ecx
- __asm jnz CRC_Loop1
- CRC_Last7Bytes:
- __asm mov ecx, [nLen]
- __asm xor edx, edx
-
- __asm test ecx, 0x4
- __asm jz CRC_Last3Bytes
- // Process 4 bytes
- __asm mov ebx, [esi]
- __asm add esi, 4
-
- __asm mov dl, bl
- __asm shr ebx, 8
- __asm xor dl, al
- __asm shr eax, 8
- __asm mov edi, CRC_Table[edx * 4]
-
- __asm mov dl, bl
- __asm xor eax, edi
-
- __asm shr ebx, 8
- __asm xor dl, al
- __asm shr eax, 8
- __asm mov edi, CRC_Table[edx * 4]
- __asm mov dl, bl
- __asm xor eax, edi
-
- __asm shr ebx, 8
- __asm xor dl, al
- __asm shr eax, 8
- __asm mov edi, CRC_Table[edx * 4]
- __asm mov dl, bl
- __asm xor eax, edi
-
- __asm xor dl, al
- __asm shr eax, 8
- __asm xor eax, CRC_Table[edx * 4]
-
- CRC_Last3Bytes:
- __asm xor edx, edx
- __asm and ecx, 0x3
- __asm jz CRC_Exit
- CRC_Loop2:
- __asm mov dl, [esi]
- __asm inc esi
- __asm xor dl, al
- __asm shr eax, 8
- __asm xor eax, CRC_Table[edx * 4]
- __asm dec ecx
- __asm jnz CRC_Loop2
- CRC_Exit:
- __asm xor eax, 0xffffffff
- __asm mov [RetCode], eax
- return RetCode;
- }
- */