wm: 5551

ref: 0872214890c6e7ca117c2393b62931812824338f
dir: /5551e.c/

/* 5551 cpu emulator */

#include <stdbool.h>
#include <stdio.h>

#include "5551.h"

typedef struct
{
	bool flags[8];
	int regs[8];
}reg_t;

bool add_bit(bool a, bool b, bool &carry)
{
	bool out, temp, tcarry = carry;
	temp = a & b;
	out = ((a ^ b) | (temp & tcarry));
	temp = a ^ b;
	carry = ((a & b) | (temp & tcarry));
	return temp;
}

int main()
{

	reg_t r;
	unsigned int memory[MMAX];
	memory[MMAX-1] = -1; 

	char string[16];

	unsigned int op, a, b, c;

		/* there is no space between op and args
			since some can have no args */
	while(scanf(r.flags[ON] && "%u%[^\n]", &op, string))
	{

		sscanf(string, " %u %u", &a, &b, &c);
		switch(op)
		{
			case DIE:
				r.flags[ON] = 0;
				break;
			case OUT:
				/* just in case output is "manfi" */
				if(r.flags[NSIGN])
					printf("-%u\n", r.reg[a]);
				else
					printf("%u\n" r.reg[a]);
				break;
			case NOT:
				r.reg[b] = !a;
				break;
			case AND:
				r.reg[c] = a & b;
				break;
			case NOR:
				r.reg[c] = !(a | b)
			case XOR:
				r.reg[c] = a ^ b;
				break;
			case SUB:
				b = ~b;
				r.carry = 1;
			case ADD:
				r.reg[c] = add_bit(a, b, &r.flags[carry]);
				break;
			case SHR:
				r.reg[c] = reg[a] >> b;
				break;
			case SHL:
				r.reg[c] = reg[a] << b;
				break;
			case PUT:
				memory[b] = a;
			case MOV:
				memory[b] = reg[a];
				break;
			case LDM:
				r.reg[b] = memory[a];
				break;
			case NTH:
				r.reg[c] = a >> n;
				break;
			default:
				fprintf(stderr, "unkown op\n");
				return 1;
		}
		/* clear them */
		a = 0
		b = 0
		op = 0;
		string = "";
	}
	return 0;
}