+static bool my_values_interfere2(ir_graph *const irg, ir_node const *a, ir_node const *b)
+{
+ if (value_dominates(b, a)) {
+ /* Adjust a and b so, that a dominates b if
+ * a dominates b or vice versa. */
+ ir_node const *const t = a;
+ a = b;
+ b = t;
+ } else if (!value_dominates(a, b)) {
+ /* If there is no dominance relation, they do not interfere. */
+ return 0;
+ }
+
+ ir_node *const bb = get_nodes_block(b);
+
+ /* If a is live end in b's block it is
+ * live at b's definition (a dominates b) */
+ be_lv_t *const lv = be_get_irg_liveness(irg);
+ if (be_is_live_end(lv, bb, a))
+ return true;
+
+ /* Look at all usages of a.
+ * If there's one usage of a in the block of b, then
+ * we check, if this use is dominated by b, if that's true
+ * a and b interfere. Note that b must strictly dominate the user,
+ * since if b is the last user of in the block, b and a do not
+ * interfere.
+ * Uses of a not in b's block can be disobeyed, because the
+ * check for a being live at the end of b's block is already
+ * performed. */
+ foreach_out_edge(a, edge) {
+ ir_node const *const user = get_edge_src_irn(edge);
+ if (is_Sync(user)) {
+ foreach_out_edge(user, edge2) {
+ ir_node const *const user2 = get_edge_src_irn(edge2);
+ assert(!is_Sync(user2));
+ if (get_nodes_block(user2) == bb && !is_Phi(user2) &&
+ _value_strictly_dominates_intrablock(b, user2))
+ return true;
+ }
+ } else {
+ if (get_nodes_block(user) == bb && !is_Phi(user) &&
+ _value_strictly_dominates_intrablock(b, user))
+ return true;
+ }
+ }
+
+ return false;
+}
+
+/**
+ * same as values_interfere but with special handling for Syncs
+ */
+static int my_values_interfere(ir_graph *irg, ir_node *a, ir_node *b)
+{
+ if (is_Sync(a)) {
+ int i, arity = get_irn_arity(a);
+ for (i = 0; i < arity; ++i) {
+ ir_node *in = get_irn_n(a, i);
+ if (my_values_interfere(irg, in, b))
+ return 1;
+ }
+ return 0;
+ } else if (is_Sync(b)) {
+ int i, arity = get_irn_arity(b);
+ for (i = 0; i < arity; ++i) {
+ ir_node *in = get_irn_n(b, i);
+ /* a is not a sync, so no need for my_values_interfere */
+ if (my_values_interfere2(irg, a, in))
+ return 1;
+ }
+ return 0;
+ }
+
+ return my_values_interfere2(irg, a, b);
+}
+