#include "ir_visitor.h"
#include "ir_variable_refcount.h"
#include "glsl_types.h"
+#include "util/hash_table.h"
+ir_variable_refcount_visitor::ir_variable_refcount_visitor()
+{
+ this->mem_ctx = ralloc_context(NULL);
+ this->ht = _mesa_hash_table_create(NULL, _mesa_hash_pointer,
+ _mesa_key_pointer_equal);
+}
+
+static void
+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_visitor::~ir_variable_refcount_visitor()
+{
+ ralloc_free(this->mem_ctx);
+ _mesa_hash_table_destroy(this->ht, free_entry);
+}
// constructor
-variable_entry::variable_entry(ir_variable *var)
+ir_variable_refcount_entry::ir_variable_refcount_entry(ir_variable *var)
{
this->var = var;
- assign = NULL;
assigned_count = 0;
declaration = false;
referenced_count = 0;
}
-variable_entry *
+ir_variable_refcount_entry *
ir_variable_refcount_visitor::get_variable_entry(ir_variable *var)
{
assert(var);
- foreach_iter(exec_list_iterator, iter, this->variable_list) {
- variable_entry *entry = (variable_entry *)iter.get();
- if (entry->var == var)
- return entry;
- }
- variable_entry *entry = new(mem_ctx) variable_entry(var);
+ struct hash_entry *e = _mesa_hash_table_search(this->ht, var);
+ if (e)
+ return (ir_variable_refcount_entry *)e->data;
+
+ ir_variable_refcount_entry *entry = new ir_variable_refcount_entry(var);
assert(entry->referenced_count == 0);
- this->variable_list.push_tail(entry);
+ _mesa_hash_table_insert(this->ht, var, entry);
+
return entry;
}
ir_visitor_status
ir_variable_refcount_visitor::visit(ir_variable *ir)
{
- variable_entry *entry = this->get_variable_entry(ir);
+ ir_variable_refcount_entry *entry = this->get_variable_entry(ir);
if (entry)
entry->declaration = true;
ir_variable_refcount_visitor::visit(ir_dereference_variable *ir)
{
ir_variable *const var = ir->variable_referenced();
- variable_entry *entry = this->get_variable_entry(var);
+ ir_variable_refcount_entry *entry = this->get_variable_entry(var);
if (entry)
entry->referenced_count++;
ir_visitor_status
ir_variable_refcount_visitor::visit_leave(ir_assignment *ir)
{
- variable_entry *entry;
+ ir_variable_refcount_entry *entry;
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;