nel/3rdparty/seven_zip/XzCrc64Opt.c

   1 /* XzCrc64Opt.c -- CRC64 calculation
   2 2017-06-30 : Igor Pavlov : Public domain */
   3
   4 #include "Precomp.h"
   5
   6 #include "CpuArch.h"
   7
   8 #ifndef MY_CPU_BE
   9
  10 #define CRC64_UPDATE_BYTE_2(crc, b) (table[((crc) ^ (b)) & 0xFF] ^ ((crc) >> 8))
  11
  12 UInt64 MY_FAST_CALL XzCrc64UpdateT4(UInt64 v, const void *data, size_t size, const UInt64 *table)
  13 {
  14   const Byte *p = (const Byte *)data;
  15   for (; size > 0 && ((unsigned)(ptrdiff_t)p & 3) != 0; size--, p++)
  16     v = CRC64_UPDATE_BYTE_2(v, *p);
  17   for (; size >= 4; size -= 4, p += 4)
  18   {
  19     UInt32 d = (UInt32)v ^ *(const UInt32 *)p;
  20     v = (v >> 32)
  21         ^ (table + 0x300)[((d      ) & 0xFF)]
  22         ^ (table + 0x200)[((d >>  8) & 0xFF)]
  23         ^ (table + 0x100)[((d >> 16) & 0xFF)]
  24         ^ (table + 0x000)[((d >> 24))];
  25   }
  26   for (; size > 0; size--, p++)
  27     v = CRC64_UPDATE_BYTE_2(v, *p);
  28   return v;
  29 }
  30
  31 #endif
  32
  33
  34 #ifndef MY_CPU_LE
  35
  36 #define CRC_UINT64_SWAP(v) \
  37       ((v >> 56) \
  38     | ((v >> 40) & ((UInt64)0xFF <<  8)) \
  39     | ((v >> 24) & ((UInt64)0xFF << 16)) \
  40     | ((v >>  8) & ((UInt64)0xFF << 24)) \
  41     | ((v <<  8) & ((UInt64)0xFF << 32)) \
  42     | ((v << 24) & ((UInt64)0xFF << 40)) \
  43     | ((v << 40) & ((UInt64)0xFF << 48)) \
  44     | ((v << 56)))
  45
  46 #define CRC64_UPDATE_BYTE_2_BE(crc, b) (table[(Byte)((crc) >> 56) ^ (b)] ^ ((crc) << 8))
  47
  48 UInt64 MY_FAST_CALL XzCrc64UpdateT1_BeT4(UInt64 v, const void *data, size_t size, const UInt64 *table)
  49 {
  50   const Byte *p = (const Byte *)data;
  51   table += 0x100;
  52   v = CRC_UINT64_SWAP(v);
  53   for (; size > 0 && ((unsigned)(ptrdiff_t)p & 3) != 0; size--, p++)
  54     v = CRC64_UPDATE_BYTE_2_BE(v, *p);
  55   for (; size >= 4; size -= 4, p += 4)
  56   {
  57     UInt32 d = (UInt32)(v >> 32) ^ *(const UInt32 *)p;
  58     v = (v << 32)
  59         ^ (table + 0x000)[((d      ) & 0xFF)]
  60         ^ (table + 0x100)[((d >>  8) & 0xFF)]
  61         ^ (table + 0x200)[((d >> 16) & 0xFF)]
  62         ^ (table + 0x300)[((d >> 24))];
  63   }
  64   for (; size > 0; size--, p++)
  65     v = CRC64_UPDATE_BYTE_2_BE(v, *p);
  66   return CRC_UINT64_SWAP(v);
  67 }
  68
  69 #endif