#define MOV(dst, src)	dst = src;
#define SL(dst)		dst <<= 1;
#define SR(dst)		dst >>= 1;
#define SWAP(dst)	dst = (dst<<4 | dst>>4); //XXX: only for ACC!
#define AND(dst, src)	dst &= src;  //xxx: overloaded for acc/mem/imm
#define OR(dst, src)	dst |= src;
#define CLEAR(dst)	dst = 0;
#define ADD(dst, src)	dst += src; //xxx: overloaded for acc/mem/imm