#ifdef COMPILER_GCC
inline dword _byteswap_ulong(dword x)
{
	asm("bswap %0" : "=r" (x) : "0" (x));
	return x;
}

inline uint64 _byteswap_uint64(uint64 x)
{
	asm("bswap %0" : "=r" (x) : "0" (x));
	return x;
}

inline word _byteswap_ushort(word x)
{
	__asm__("xchgb %b0,%h0" : "=q" (x) :  "0" (x));
	return x;
}
#endif

int MemCmp(const char *a, const char *b, size_t len)
{
	if(((size_t)a & 3) | ((size_t)b & 3))
		return memcmp(a, b, len);
	const dword *x = (dword *)a;
	const dword *y = (dword *)b;
	const dword *e = x + (len >> 2);
	while(x < e) {
		if(*x != *y)
			return int(_byteswap_ulong(*x) - _byteswap_ulong(*y));
		x++;
		y++;
	}
	if(len & 2)
		if(*(word *)x != *(word *)y)
			return int(_byteswap_ushort(*(word *)x) - _byteswap_ushort(*(word *)y));
	if(len & 1)
		return int(*((byte *)x + 2)) - int(*((byte *)y + 2));
	return 0;
}

   ...
   const static dword masks[4] = { 0x00000000, 0x000000FF, 0x0000FFFF, 0x00FFFFFF };  //Intel-like endian only!
   return int(_byteswap_ulong(*x & masks[len&3]) - _byteswap_ulong(*y & masks[len&3]));