void n_expression::code_gen(status& stat, std::ostream& out)
{
// left OP right : result_reg = t0 OP t1
bool unlock = false;
if (!stat.get_assign_expr())
{
stat.lock_register(out);
stat.set_assign_expr();
unlock = true;
}
if (opstr == "+")
{
if (left != NULL)
{
left->code_gen(stat, out);
stat.lock_register(out);
right->code_gen(stat, out);
int op2 = stat.get_register();
int op2f = stat.get_f_register();
stat.unlock_register(out);
if (stat.is_float())
out << "\tadd.s\t$f" << stat.get_f_register() << ",$f" << stat.get_f_register() << ",$f" << op2f << "\n";
else
out << "\tadd\t$t" << stat.get_register() << ",$t" << stat.get_register() << ",$t" << op2 << "\n";
}
else
{
right->code_gen(stat, out);
}
}
else if (opstr == "-")
{
if (left != NULL)
{
left->code_gen(stat, out);
stat.lock_register(out);
right->code_gen(stat, out);
int op2 = stat.get_register();
int op2f = stat.get_f_register();
stat.unlock_register(out);
if (stat.is_float())
out << "\tsub.s\t$f" << stat.get_f_register() << ",$f" << stat.get_f_register() << ",$f" << op2f << "\n";
else
out << "\tsub\t$t" << stat.get_register() << ",$t" << stat.get_register() << ",$t" << op2 << "\n";
}
else
{
stat.lock_register(out);
right->code_gen(stat, out);
int op2 = stat.get_register();
stat.unlock_register(out);
out << "\tneg\t$t" << stat.get_register() << ",$t" << op2 << "\n";
}
}
else if (opstr == "*")
{
if (left != NULL) // if operation is left MULT right
{
left->code_gen(stat, out);
stat.lock_register(out);
right->code_gen(stat, out);
int op2 = stat.get_register();
int op2f = stat.get_f_register();
stat.unlock_register(out);
if (stat.is_float())
out << "\tmul.s\t$f" << stat.get_f_register() << ",$f" << stat.get_f_register() << ",$f" << op2f << "\n";
else
out << "\tmul\t$t" << stat.get_register() << ",$t" << stat.get_register() << ",$t" << op2 << "\n";
}
else // if operation is dereferencing
{
if (stat.get_assign_var())
stat.lock_register(out);
int op2 = stat.get_register();
stat.set_dereference();
right->code_gen(stat, out);
stat.set_dereference();
if (stat.get_assign_var()) // if variable needs to be saved
stat.unlock_register(out);
out << "\t" << stat.pointer_opcode() << "\t$t" << stat.get_register() << ",($t" << op2 << ")\n";
}
}
else if (opstr == "/")
{
left->code_gen(stat, out);
stat.lock_register(out);
right->code_gen(stat, out);
int op2 = stat.get_register();
int op2f = stat.get_f_register();
stat.unlock_register(out);
if (stat.is_float())
out << "\tdiv.s\t$f" << stat.get_f_register() << ",$f" << stat.get_f_register() << ",$f" << op2f << "\n";
else
out << "\tdiv\t$t" << stat.get_register() << ",$t" << stat.get_register() << ",$t" << op2 << "\n";
}
else if (opstr == "%")
{
left->code_gen(stat, out);
stat.lock_register(out);
right->code_gen(stat, out);
int op2 = stat.get_register();
stat.unlock_register(out);
out << "\trem\t$t" << stat.get_register() << ",$t" << stat.get_register() << ",$t" << op2 << "\n";
}
else if (opstr == "&")
{
if (left != NULL) // if operation is left AND right
{
left->code_gen(stat, out);
stat.lock_register(out);
right->code_gen(stat, out);
int op2 = stat.get_register();
stat.unlock_register(out);
out << "\tand\t$t" << stat.get_register();
out << ",$t" << stat.get_register() << ",$t" << op2 << "\n";
}
else // if operation is referencing
{
stat.set_reference();
right->code_gen(stat, out);
stat.set_reference();
}
}
else if (opstr == "|")
{
left->code_gen(stat, out);
stat.lock_register(out);
right->code_gen(stat, out);
int op2 = stat.get_register();
stat.unlock_register(out);
out << "\tor\t$t" << stat.get_register();
out << ",$t" << stat.get_register() << ",$t" << op2 << "\n";
}
else if (opstr == "^")
{
left->code_gen(stat, out);
stat.lock_register(out);
right->code_gen(stat, out);
int op2 = stat.get_register();
stat.unlock_register(out);
out << "\txor\t$t" << stat.get_register();
out << ",$t" << stat.get_register() << ",$t" << op2 << "\n";
}
else if (opstr == "<<")
{
left->code_gen(stat, out);
stat.lock_register(out);
right->code_gen(stat, out);
int op2 = stat.get_register();
stat.unlock_register(out);
out << "\tsllv\t$t" << stat.get_register();
out << ",$t" << stat.get_register() << ",$t" << op2 << "\n";
}
else if (opstr == ">>")
{
left->code_gen(stat, out);
stat.lock_register(out);
right->code_gen(stat, out);
int op2 = stat.get_register();
stat.unlock_register(out);
out << "\tsrav\t$t" << stat.get_register();
out << ",$t" << stat.get_register() << ",$t" << op2 << "\n";
}
else if (opstr == "==")
{
left->code_gen(stat, out);
stat.lock_register(out);
right->code_gen(stat, out);
int op2 = stat.get_register();
stat.unlock_register(out);
out << "\tseq\t$t" << stat.get_register() << ",$t" << stat.get_register() << ",$t" << op2 << "\n";
}
else if (opstr == "!=")
{
left->code_gen(stat, out);
stat.lock_register(out);
right->code_gen(stat, out);
int op2 = stat.get_register();
stat.unlock_register(out);
out << "\tsne\t$t" << stat.get_register() << ",$t" << stat.get_register() << ",$t" << op2 << "\n";
}
else if (opstr == "<")
{
left->code_gen(stat, out);
stat.lock_register(out);
right->code_gen(stat, out);
int op2 = stat.get_register();
stat.unlock_register(out);
out << "\tslt\t$t" << stat.get_register() << ",$t" << stat.get_register() << ",$t" << op2 << "\n";
}
else if (opstr == ">")
{
left->code_gen(stat, out);
stat.lock_register(out);
right->code_gen(stat, out);
int op2 = stat.get_register();
stat.unlock_register(out);
out << "\tslt\t$t" << stat.get_register() << ",$t" << op2 << ",$t" << stat.get_register() << "\n";
}
else if (opstr == "<=")
{
left->code_gen(stat, out);
stat.lock_register(out);
right->code_gen(stat, out);
int op2 = stat.get_register();
stat.unlock_register(out);
out << "\tsge\t$t" << stat.get_register() << ",$t" << op2 << ",$t" << stat.get_register() << "\n";
}
else if (opstr == ">=")
{
left->code_gen(stat, out);
stat.lock_register(out);
right->code_gen(stat, out);
int op2 = stat.get_register();
stat.unlock_register(out);
out << "\tsge\t$t" << stat.get_register() << ",$t" << stat.get_register() << ",$t" << op2 << "\n";
}
else if (opstr == "++")
{
if (left != NULL) // postfix
{
left->code_gen(stat, out);
int op1 = stat.get_register();
stat.lock_register(out);
out << "\tadd\t$t" << stat.get_register() << ",$t" << op1 << ",1\n";
stat.set_assign_var();
left->code_gen(stat, out);
stat.set_assign_var();
stat.unlock_register(out);
}
else if (right != NULL) // prefix
{
right->code_gen(stat, out);
out << "\tadd\t$t" << stat.get_register() << ",$t" << stat.get_register() << ",1\n";
stat.set_assign_var();
right->code_gen(stat, out);
stat.set_assign_var();
}
}
else if (opstr == "--")
{
if (left != NULL) // postfix
{
left->code_gen(stat, out);
int op1 = stat.get_register();
stat.lock_register(out);
out << "\tsub\t$t" << stat.get_register() << ",$t" << op1 << ",1\n";
stat.set_assign_var();
left->code_gen(stat, out);
stat.set_assign_var();
stat.unlock_register(out);
}
else if (right != NULL) // prefix
{
right->code_gen(stat, out);
out << "\tsub\t$t" << stat.get_register() << ",$t" << stat.get_register() << ",1\n";
stat.set_assign_var();
right->code_gen(stat, out);
stat.set_assign_var();
}
}
else if (opstr == "[]")
{
if (stat.get_assign_var())
stat.lock_register(out);
// get offset of first element
stat.lock_register(out);
int op2 = stat.get_register();
stat.set_reference();
left->code_gen(stat, out);
stat.set_reference();
stat.unlock_register(out);
// evaluate operation
right->code_gen(stat, out);
// shift the operation to get number of bytes for array offset
out << "\tsll\t$t" << stat.get_register() << ",$t" << stat.get_register() << ",2\n";
// subtract array offset from first element offset
out << "\tsubu\t$t" << stat.get_register() << ",$t" << op2 << ",$t" << stat.get_register() << "\n";
// store or load the variable
op2 = stat.get_register();
if (stat.get_assign_var())
stat.unlock_register(out);
out << "\t" << stat.pointer_opcode() << "\t$t" << stat.get_register() << ",($t" << op2 << ")\n";
}
else if (opstr == "!")
{
left->code_gen(stat, out);
out << "\tseq\t$" << stat.get_register() << ",$zero,$t" << stat.get_register();
}
else if (opstr == "~")
{
left->code_gen(stat, out);
out << "\tnot\t$" << stat.get_register() << ",$t" << stat.get_register() << "\n";
}
else if (opstr == "=")
{
right->code_gen(stat, out);
stat.set_assign_var();
left->code_gen(stat, out);
stat.set_assign_var();
}
if (unlock)
{
stat.unlock_register(out);
stat.set_assign_expr();
}
return;
}
