decr

int __cdecl decrypt(int src, int count, int dest, unsigned int key)
{
  unsigned int r1; // eax@1
  unsigned int r3; // edx@1
  unsigned int r2; // ecx@1
  int pos; // esi@2
  char byte; // bl@4
  char done; // zf@4

  r1 = key;
  r2 = key;
  r3 = key;
  if ( count > 0 )
  {
    pos = dest;
    while ( 1 )
    {
      r1 += (r1 >> 3) + 3;
      r2 += (r2 >> 5) + 5;
      key += -9 - (key << 9);
      byte = *(_BYTE *)(src - dest + pos++) ^ ((_BYTE)key + -7 - ((_BYTE)r3 << 7) + (_BYTE)r3 + r2 + (_BYTE)r1);
      done = count-- == 1;
      *(_BYTE *)(pos - 1) = byte;
      if ( done )
        break;
      r3 += -7 - (r3 << 7);
    }
  }
  return 0;
}