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https://github.com/alliedmodders/hl2sdk.git
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70 lines
1.9 KiB
C
70 lines
1.9 KiB
C
/* XzCrc64Opt.c -- CRC64 calculation
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2011-06-28 : Igor Pavlov : Public domain */
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#include "Precomp.h"
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#include "CpuArch.h"
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#define CRC_UPDATE_BYTE_2(crc, b) (table[((crc) ^ (b)) & 0xFF] ^ ((crc) >> 8))
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#ifndef MY_CPU_BE
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UInt64 MY_FAST_CALL XzCrc64UpdateT4(UInt64 v, const void *data, size_t size, const UInt64 *table)
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{
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const Byte *p = (const Byte *)data;
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for (; size > 0 && ((unsigned)(ptrdiff_t)p & 3) != 0; size--, p++)
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v = CRC_UPDATE_BYTE_2(v, *p);
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for (; size >= 4; size -= 4, p += 4)
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{
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UInt32 d = (UInt32)v ^ *(const UInt32 *)p;
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v = (v >> 32) ^
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table[0x300 + ((d ) & 0xFF)] ^
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table[0x200 + ((d >> 8) & 0xFF)] ^
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table[0x100 + ((d >> 16) & 0xFF)] ^
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table[0x000 + ((d >> 24))];
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}
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for (; size > 0; size--, p++)
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v = CRC_UPDATE_BYTE_2(v, *p);
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return v;
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}
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#endif
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#ifndef MY_CPU_LE
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#define CRC_UINT64_SWAP(v) \
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((v >> 56) | \
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((v >> 40) & ((UInt64)0xFF << 8)) | \
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((v >> 24) & ((UInt64)0xFF << 16)) | \
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((v >> 8) & ((UInt64)0xFF << 24)) | \
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((v << 8) & ((UInt64)0xFF << 32)) | \
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((v << 24) & ((UInt64)0xFF << 40)) | \
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((v << 40) & ((UInt64)0xFF << 48)) | \
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(v << 56))
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UInt64 MY_FAST_CALL XzCrc64UpdateT1_BeT4(UInt64 v, const void *data, size_t size, const UInt64 *table)
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{
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const Byte *p = (const Byte *)data;
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for (; size > 0 && ((unsigned)(ptrdiff_t)p & 3) != 0; size--, p++)
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v = CRC_UPDATE_BYTE_2(v, *p);
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v = CRC_UINT64_SWAP(v);
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table += 0x100;
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for (; size >= 4; size -= 4, p += 4)
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{
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UInt32 d = (UInt32)(v >> 32) ^ *(const UInt32 *)p;
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v = (v << 32) ^
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table[0x000 + ((d ) & 0xFF)] ^
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table[0x100 + ((d >> 8) & 0xFF)] ^
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table[0x200 + ((d >> 16) & 0xFF)] ^
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table[0x300 + ((d >> 24))];
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}
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table -= 0x100;
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v = CRC_UINT64_SWAP(v);
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for (; size > 0; size--, p++)
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v = CRC_UPDATE_BYTE_2(v, *p);
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return v;
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}
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#endif
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