+static int push_through_perm(ir_node *perm, void *data)
+{
+ lower_env_t *env = data;
+ const arch_env_t *aenv = env->arch_env;
+
+ ir_graph *irg = get_irn_irg(perm);
+ ir_node *bl = get_nodes_block(perm);
+ ir_node *node;
+ int arity = get_irn_arity(perm);
+ int *map;
+ int *proj_map;
+ bitset_t *moved = bitset_alloca(arity);
+ int n_moved;
+ int new_size;
+ ir_node *frontier = bl;
+ FIRM_DBG_REGISTER(firm_dbg_module_t *mod, "firm.be.lower.permmove");
+
+ int i, n;
+ const ir_edge_t *edge;
+ ir_node *one_proj = NULL, *irn;
+ const arch_register_class_t *cls = NULL;
+
+ DBG((mod, LEVEL_1, "perm move %+F irg %+F\n", perm, irg));
+
+ /* get some Proj and find out the register class of that Proj. */
+ edge = get_irn_out_edge_first_kind(perm, EDGE_KIND_NORMAL);
+ one_proj = get_edge_src_irn(edge);
+ assert(is_Proj(one_proj));
+ cls = arch_get_irn_reg_class(aenv, one_proj, -1);
+
+ /* Find the point in the schedule after which the
+ * potentially movable nodes must be defined.
+ * A Perm will only be pushed up to first instruction
+ * which lets an operand of itself die.
+ * If we would allow to move the Perm above this instruction,
+ * the former dead operand would be live now at the point of
+ * the Perm, increasing the register pressure by one.
+ */
+ sched_foreach_reverse_from (sched_prev(perm), irn) {
+ for (i = get_irn_arity(irn) - 1; i >= 0; --i) {
+ ir_node *op = get_irn_n(irn, i);
+ if (arch_irn_consider_in_reg_alloc(aenv, cls, op) &&
+ !values_interfere(env->birg, op, one_proj)) {
+ frontier = irn;
+ goto found_front;
+ }
+ }
+ }
+found_front:
+
+ DBG((mod, LEVEL_2, "\tfrontier: %+F\n", frontier));
+
+ node = sched_prev(perm);
+ n_moved = 0;
+ while(!sched_is_begin(node)) {
+ const arch_register_req_t *req;
+ int input = -1;
+ ir_node *proj;
+
+ /* search if node is a INPUT of Perm */
+ foreach_out_edge(perm, edge) {
+ ir_node *out = get_edge_src_irn(edge);
+ int pn = get_Proj_proj(out);
+ ir_node *in = get_irn_n(perm, pn);
+ if (node == in) {
+ proj = out;
+ input = pn;
+ break;
+ }
+ }
+ /* it wasn't an input to the perm, we can't do anything more */
+ if(input < 0)
+ break;
+ if(!sched_comes_after(frontier, node))
+ break;
+ if(arch_irn_is(aenv, node, modify_flags))
+ break;
+ if(is_Proj(node)) {
+ req = arch_get_register_req(aenv, get_Proj_pred(node),
+ -1 - get_Proj_proj(node));
+ } else {
+ req = arch_get_register_req(aenv, node, -1);