Figure A$.2$ The code sequence for $C=A+B$ for four classes of instruction sets. Note

that the Add instruction has implicit operands for stack and accumulator architectures

and explicit operands for register architectures. It is assumed that A$,$ B$,$ and C all belong

in memory and that the values of A and $B$ cannot be destroyed. Figure A$.1$ shows the

Add operation for each class of architecture.