+/* Upon entering an ir_array_dereference, remove the current assignment from
+ * further consideration. Since the index of an array dereference must scalar,
+ * we are not able to vectorize it.
+ *
+ * FINISHME: If all of scalar indices are identical we could vectorize.
+ */
+ir_visitor_status
+ir_vectorize_visitor::visit_enter(ir_dereference_array *)
+{
+ this->current_assignment = NULL;
+ return visit_continue_with_parent;
+}
+
+/**
+ * Upon entering an ir_expression, remove the current assignment from further
+ * consideration if the expression operates horizontally on vectors.
+ */
+ir_visitor_status
+ir_vectorize_visitor::visit_enter(ir_expression *ir)
+{
+ if (ir->is_horizontal()) {
+ this->current_assignment = NULL;
+ return visit_continue_with_parent;
+ }
+ return visit_continue;
+}
+
+/* Since there is no statement to visit between the "then" and "else"
+ * instructions try to vectorize before, in between, and after them to avoid
+ * combining statements from different basic blocks.
+ */
+ir_visitor_status
+ir_vectorize_visitor::visit_enter(ir_if *ir)
+{
+ try_vectorize();
+
+ visit_list_elements(this, &ir->then_instructions);
+ try_vectorize();
+
+ visit_list_elements(this, &ir->else_instructions);
+ try_vectorize();
+
+ return visit_continue_with_parent;
+}
+
+/* Since there is no statement to visit between the instructions in the body of
+ * the loop and the instructions after it try to vectorize before and after the
+ * body to avoid combining statements from different basic blocks.
+ */
+ir_visitor_status
+ir_vectorize_visitor::visit_enter(ir_loop *ir)
+{
+ try_vectorize();
+
+ visit_list_elements(this, &ir->body_instructions);
+ try_vectorize();
+
+ return visit_continue_with_parent;
+}
+
+/**
+ * Upon entering an ir_texture, remove the current assignment from
+ * further consideration. Vectorizing multiple texture lookups into one
+ * is wrong.
+ */
+ir_visitor_status
+ir_vectorize_visitor::visit_enter(ir_texture *)
+{
+ this->current_assignment = NULL;
+ return visit_continue_with_parent;
+}
+