void n_ifelse::code_gen(status& stat, std::ostream& out)
{
stat.lock_register(out);
stat.set_assign_expr();
// check expression
left->code_gen(stat, out);
// branch over if statement, if the expression equals zero
std::string else_label = stat.label_gen();
out << "\tbeqz\t$t" << stat.get_register() << "," << else_label << "\n";
out << "\tnop\n";
stat.unlock_register(out);
stat.set_assign_expr();
// if statement
right->code_gen(stat, out);
if (else_node != NULL)
{
std::string end_label = stat.label_gen();
// branch over else statement, if if branch was executed
out << "\tb\t" << end_label << "\n";
out << "\tnop\n";
out << else_label << ":\n";
// else statement
else_node->code_gen(stat, out);
out << end_label << ":\n";
}
else
{
out << else_label << ":\n";
}
return;
}
void n_ternary::code_gen(status& stat, std::ostream& out)
{
bool unlock = false;
if (!stat.get_assign_expr())
{
stat.lock_register(out);
stat.set_assign_expr();
unlock = true;
}
cond->code_gen(stat, out); // the condition
std::string zero_label = stat.label_gen();
out << "\tbeqz\t$t" << stat.get_register() << "," << zero_label << "\n";
out << "\tnop\n";
left->code_gen(stat, out); // the first expression
std::string end_label = stat.label_gen();
out << "\tb\t" << end_label << "\n";
out << zero_label << ":\n";
right->code_gen(stat, out); // the second expression
out << end_label << ":\n";
if (unlock)
{
stat.unlock_register(out);
stat.set_assign_expr();
}
return;
}
void n_case::code_gen(status& stat, std::ostream& out)
{
if (left != NULL) // case:
{
stat.lock_register(out);
stat.set_assign_expr();
int op2 = stat.get_register();
left->code_gen(stat, out);
stat.unlock_register(out);
stat.set_assign_expr();
std::string next_case_label = stat.label_gen();
// if the expressions are not equal, branch over statement
out << "\tbne\t$t" << stat.get_register() << ",$t" << op2 << "," << next_case_label << "\n";
out << "\tnop\n";
// case body label
if (stat.get_case_label() != "empty")
out << stat.get_case_label() << ":\n";
stat.set_case_label();
if (right != NULL)
right->code_gen(stat, out); // case body
// fall through: need to jump to the next case body.
out << "\tb\t" << stat.get_case_label() << "\n";
out << "\tnop\n";
out << next_case_label << ":\n";
}
else // default:
{
if (right != NULL)
right->code_gen(stat, out);
}
return;
}
