free_entry(struct hash_entry *entry)
{
ir_variable_refcount_entry *ivre = (ir_variable_refcount_entry *) entry->data;
+
+ /* Free assignment list */
+ exec_node *n;
+ while ((n = ivre->assign_list.pop_head()) != NULL) {
+ struct assignment_entry *assignment_entry =
+ exec_node_data(struct assignment_entry, n, link);
+ free(assignment_entry);
+ }
+
delete ivre;
}
ir_variable_refcount_entry::ir_variable_refcount_entry(ir_variable *var)
{
this->var = var;
- assign = NULL;
assigned_count = 0;
declaration = false;
referenced_count = 0;
entry = this->get_variable_entry(ir->lhs->variable_referenced());
if (entry) {
entry->assigned_count++;
- if (entry->assign == NULL)
- entry->assign = ir;
+
+ /* Build a list for dead code optimisation. Don't add assignment if it
+ * was declared out of scope (outside the instruction stream). Also don't
+ * bother adding any more to the list if there are more references than
+ * assignments as this means the variable is used and won't be optimised
+ * out.
+ */
+ assert(entry->referenced_count >= entry->assigned_count);
+ if (entry->referenced_count == entry->assigned_count) {
+ struct assignment_entry *assignment_entry =
+ (struct assignment_entry *)calloc(1, sizeof(*assignment_entry));
+ assignment_entry->assign = ir;
+ entry->assign_list.push_head(&assignment_entry->link);
+ }
}
return visit_continue;