| repo sync | baa3858 | 2013-07-26 17:53:31 -0700 | [diff] [blame] | 1 | /* 7zCrcOpt.c -- CRC32 calculation : optimized version
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| 2 | 2009-11-23 : Igor Pavlov : Public domain */
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| 3 |
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| 4 | #include "CpuArch.h"
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| 5 |
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| 6 | #ifdef MY_CPU_LE
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| 7 |
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| 8 | #define CRC_UPDATE_BYTE_2(crc, b) (table[((crc) ^ (b)) & 0xFF] ^ ((crc) >> 8))
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| 9 |
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| 10 | UInt32 MY_FAST_CALL CrcUpdateT4(UInt32 v, const void *data, size_t size, const UInt32 *table)
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| 11 | {
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| 12 | const Byte *p = (const Byte *)data;
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| 13 | for (; size > 0 && ((unsigned)(ptrdiff_t)p & 3) != 0; size--, p++)
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| 14 | v = CRC_UPDATE_BYTE_2(v, *p);
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| 15 | for (; size >= 4; size -= 4, p += 4)
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| 16 | {
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| 17 | v ^= *(const UInt32 *)p;
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| 18 | v =
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| 19 | table[0x300 + (v & 0xFF)] ^
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| 20 | table[0x200 + ((v >> 8) & 0xFF)] ^
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| 21 | table[0x100 + ((v >> 16) & 0xFF)] ^
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| 22 | table[0x000 + ((v >> 24))];
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| 23 | }
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| 24 | for (; size > 0; size--, p++)
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| 25 | v = CRC_UPDATE_BYTE_2(v, *p);
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| 26 | return v;
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| 27 | }
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| 28 |
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| 29 | UInt32 MY_FAST_CALL CrcUpdateT8(UInt32 v, const void *data, size_t size, const UInt32 *table)
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| 30 | {
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| 31 | return CrcUpdateT4(v, data, size, table);
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| 32 | }
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| 33 |
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| 34 | #endif
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