static void
gen_expr(tree *expr)
{
struct variable *var;
switch(expr->tag) {
case node_arg:
var = get_global(ARG_NAME(expr));
codegen_load_file(expr, var);
break;
case node_call:
analyze_call(expr, true, codegen_size);
break;
case node_constant:
LOAD_CONSTANT(expr->value.constant, codegen_size);
break;
case node_symbol:
var = get_global(SYM_NAME(expr));
if (var->tag == sym_const) {
LOAD_CONSTANT(var->value, codegen_size);
} else {
codegen_load_file(expr, var);
}
break;
case node_unop:
gen_unop_expr(expr);
break;
case node_binop:
if (expr->value.binop.op == op_assign) {
analyze_error(expr, "assign operator = should be equal operator ==");
} else if ((expr->value.binop.op == op_lsh) ||
(expr->value.binop.op == op_rsh)) {
/* for shifts it is best to calculate the left side first */
gen_binop_expr(expr->value.binop.op,
expr->value.binop.p1,
expr->value.binop.p0);
} else {
/* for all others calculate the right side first */
gen_binop_expr(expr->value.binop.op,
expr->value.binop.p0,
expr->value.binop.p1);
}
break;
default:
assert(0);
}
}
static void
gen_binop_expr(enum node_op op, tree *p0, tree *p1)
{
char *reg1 = NULL;
char *reg2 = NULL;
struct variable *var;
gen_expr(p1);
if (p0->tag == node_call) {
reg1 = codegen_get_temp(codegen_size);
STORE_FILE(reg1, codegen_size, 0, false);
analyze_call(p0, true, codegen_size);
CODEGEN(op, codegen_size, false, 0, reg1);
} else if (p0->tag == node_constant) {
CODEGEN(op, codegen_size, true, p0->value.constant, NULL);
} else if (p0->tag == node_symbol) {
var = get_global(SYM_NAME(p0));
if (var->tag == sym_const) {
CODEGEN(op, codegen_size, true, var->value, NULL);
} else if (SYM_OFST(p0)) {
/* it is a complex expression, so save temp data */
reg1 = codegen_get_temp(codegen_size);
reg2 = codegen_get_temp(codegen_size);
STORE_FILE(reg1, codegen_size, 0, false);
codegen_load_file(p0, var);
STORE_FILE(reg2, codegen_size, 0, false);
LOAD_FILE(reg1, codegen_size, 0, false);
CODEGEN(op, codegen_size, false, 0, reg2);
} else {
CODEGEN(op, codegen_size, false, 0, var->name);
}
} else {
/* it is a complex expression so save temp data */
reg1 = codegen_get_temp(codegen_size);
STORE_FILE(reg1, codegen_size, 0, false);
gen_expr(p0);
CODEGEN(op, codegen_size, false, 0, reg1);
}
if (reg1)
free(reg1);
if (reg2)
free(reg2);
}
static void analyze_expr(short priority, short op_main)
{
short op, op_curr, op_not;
short prio;
short nparam;
inc_level();
op_curr = op_main;
op_not = RS_NONE;
nparam = (op_main == RS_NONE || op_main == RS_UNARY) ? 0 : 1;
if (PATTERN_is(*current, RS_NEW))
THROW("Cannot use NEW operator there");
READ_OPERAND:
//analyze_expr_check_first(op_curr);
analyze_single(op_curr);
nparam++;
if (nparam > MAX_PARAM_OP)
THROW("Expression too complex. Too many operands");
READ_OPERATOR:
if (!PATTERN_is_reserved(*current))
goto OPERATOR_END;
op = PATTERN_index(*current);
if (!RES_is_operator(op))
goto OPERATOR_END;
if (op == RS_AND || op == RS_OR)
if (PATTERN_is(current[1], RS_IF))
goto OPERATOR_END;
current++;
if (op == RS_NOT && PATTERN_is_reserved(*current))
{
op_not = PATTERN_index(*current);
if (RES_is_operator(op_not) && RES_can_have_not_before(op_not))
{
op = op_not + 1;
current++;
}
}
if (priority)
prio = priority;
else if (op_curr == RS_NONE)
prio = 0;
else
prio = RES_priority(op_curr);
if (op_curr == RS_NONE)
{
if (RES_is_binary(op) || RES_is_n_ary(op))
{
op_curr = op;
goto READ_OPERAND;
}
}
if (op_curr == op)
{
if (!(RES_is_binary(op) && nparam == 2))
goto READ_OPERAND;
}
if (RES_priority(op) > prio)
{
if (op == RS_LSQR)
analyze_array();
else if (op == RS_LBRA)
analyze_call();
else
analyze_expr(RES_priority(op), op);
goto READ_OPERATOR;
}
if (RES_priority(op) == prio)
{
add_operator(op_curr, nparam);
if (op == RS_LSQR)
{
analyze_array();
goto READ_OPERATOR;
}
else if (op == RS_LBRA)
{
analyze_call();
goto READ_OPERATOR;
}
else
{
if (RES_is_only(op_curr) || RES_is_only(op))
THROW("Ambiguous expression. Please use brackets");
nparam = 1;
op_curr = op;
goto READ_OPERAND;
}
}
if (RES_priority(op) < prio)
{
if ((op_main != RS_NONE) || (priority > 0))
{
add_operator(op_curr, nparam);
current--;
if (op_not != RS_NONE)
current--;
goto END;
}
add_operator(op_curr, nparam);
if (op == RS_LSQR)
{
analyze_array();
nparam = 1;
op_curr = op_main;
goto READ_OPERATOR;
}
else if (op == RS_LBRA)
{
analyze_call();
nparam = 1;
op_curr = op_main;
goto READ_OPERATOR;
}
else
{
nparam = 1;
op_curr = op;
goto READ_OPERAND;
}
}
dec_level();
return;
OPERATOR_END:
add_operator(op_curr, nparam);
END:
dec_level();
return;
}