1 /* XzCrc64Opt.c -- CRC64 calculation
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2 2015-03-01 : Igor Pavlov : Public domain */
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10 #define CRC_UPDATE_BYTE_2(crc, b) (table[((crc) ^ (b)) & 0xFF] ^ ((crc) >> 8))
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12 UInt64 MY_FAST_CALL XzCrc64UpdateT4(UInt64 v, const void *data, size_t size, const UInt64 *table)
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14 const Byte *p = (const Byte *)data;
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15 for (; size > 0 && ((unsigned)(ptrdiff_t)p & 3) != 0; size--, p++)
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16 v = CRC_UPDATE_BYTE_2(v, *p);
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17 for (; size >= 4; size -= 4, p += 4)
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19 UInt32 d = (UInt32)v ^ *(const UInt32 *)p;
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21 ^ table[0x300 + ((d ) & 0xFF)]
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22 ^ table[0x200 + ((d >> 8) & 0xFF)]
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23 ^ table[0x100 + ((d >> 16) & 0xFF)]
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24 ^ table[0x000 + ((d >> 24))];
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26 for (; size > 0; size--, p++)
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27 v = CRC_UPDATE_BYTE_2(v, *p);
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36 #define CRC_UINT64_SWAP(v) \
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38 | ((v >> 40) & ((UInt64)0xFF << 8)) \
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39 | ((v >> 24) & ((UInt64)0xFF << 16)) \
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40 | ((v >> 8) & ((UInt64)0xFF << 24)) \
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41 | ((v << 8) & ((UInt64)0xFF << 32)) \
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42 | ((v << 24) & ((UInt64)0xFF << 40)) \
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43 | ((v << 40) & ((UInt64)0xFF << 48)) \
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46 #define CRC_UPDATE_BYTE_2_BE(crc, b) (table[(Byte)((crc) >> 56) ^ (b)] ^ ((crc) << 8))
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48 UInt64 MY_FAST_CALL XzCrc64UpdateT1_BeT4(UInt64 v, const void *data, size_t size, const UInt64 *table)
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50 const Byte *p = (const Byte *)data;
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52 v = CRC_UINT64_SWAP(v);
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53 for (; size > 0 && ((unsigned)(ptrdiff_t)p & 3) != 0; size--, p++)
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54 v = CRC_UPDATE_BYTE_2_BE(v, *p);
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55 for (; size >= 4; size -= 4, p += 4)
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57 UInt32 d = (UInt32)(v >> 32) ^ *(const UInt32 *)p;
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59 ^ table[0x000 + ((d ) & 0xFF)]
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60 ^ table[0x100 + ((d >> 8) & 0xFF)]
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61 ^ table[0x200 + ((d >> 16) & 0xFF)]
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62 ^ table[0x300 + ((d >> 24))];
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64 for (; size > 0; size--, p++)
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65 v = CRC_UPDATE_BYTE_2_BE(v, *p);
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66 return CRC_UINT64_SWAP(v);
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