isa/checker.cpp


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#include <cassert>

#include "isa/checker.h"
#include "isa/isa.h"

void funcchecker::execute() {
    if (!ctlregs[HALTED]) {
        inst = decode(ctlregs[FLAGS],
                      pc,
                      mem.fetch(pc),
                      interrupt);
        auto next_pc = inst.next_pc;

        if (inst.need_indirect_load) {
            auto addr = mem.fetch(inst.init_address.value());
            if (inst.need_autoinc_store) {
                addr = (addr + 1) & 07777;
                mem.store(*inst.init_address, addr);
            }
            auto df = (ctlregs[FLAGS] & FLAG_DF) >> FLAG_DF_SHIFT;
            inst.final_address = (df << 12) | addr;
        } else {
            assert(!inst.need_autoinc_store);
        }

        if (inst.need_exec_load)
            inst.data = mem.fetch(inst.final_address.value());

        if (inst.need_read_acc)
            inst.acc = acc;
        if (inst.need_read_link)
            inst.link = link;
        if (inst.need_read_mq)
            inst.mq = mq;
        if (inst.read_ctlreg.has_value())
            inst.ctlval = ctlregs[*inst.read_ctlreg];

        inst.execute();

        if (inst.need_write_acc)
            acc = inst.acc.value();
        if (inst.need_write_link)
            link = inst.link.value();
        if (inst.need_write_mq)
            mq = inst.mq.value();
        if (inst.write_ctlreg.has_value())
            ctlregs[*inst.write_ctlreg] = inst.ctlval.value();

        if (inst.need_exec_store)
            mem.store(inst.final_address.value(), inst.data.value());

        assert(inst.next_pc == next_pc || inst.possibly_redirects);
        pc = inst.next_pc;
    }

    interrupt = system.interact(icount++, ctlregs, true);
}