Function simplify_expr

blakcomp/codeutil.c:506–527

/ * simplify_expr: Generate code to simplify the given expression * until it is an id or a constant. * If the expression is complicated, this involves * evaluating it into a temporary variable, and then changing the * expression to just evaluate to the temporary variable. * Returns highest # local variable used in code for expression. */

 *   Returns highest # local variable used in code for expression.
 */
int simplify_expr(expr_type expr, int maxlocal)
{
   int our_maxlocal = maxlocal;
   id_type id;

   if (is_base_level(expr))
      return our_maxlocal;
   
   id = make_temp_var(maxlocal + 1); /* Temporary to store expression */
   
   our_maxlocal = flatten_expr(expr, id, maxlocal);
   
   /* Count temp var, if rhs didn't use any new temps */
   if (our_maxlocal == maxlocal)
      our_maxlocal++;
   
   /* Modify expression to make it just a local variable */
   expr->value.idval = id;
   expr->type = E_IDENTIFIER;
      
   return our_maxlocal;
}