+/** Removes Tuple nodes! **/
+/*--------------------------------------------------------------------*/
+
+
+/** Returns the amount of out edges for not yet visited successors. */
+static int _count_outs(ir_node *n) {
+ int start, i, res, irn_arity;
+
+ mark_irn_visited(n);
+ n->out = (ir_node **) 1; /* Space for array size. */
+
+ start = is_Block(n) ? 0 : -1;
+ irn_arity = get_irn_arity(n);
+ res = irn_arity - start + 1; /* --1 or --0; 1 for array size. */
+
+ for (i = start; i < irn_arity; ++i) {
+ /* Optimize Tuples. They annoy if walking the cfg. */
+ ir_node *pred = skip_Tuple(get_irn_n(n, i));
+ set_irn_n(n, i, pred);
+
+ /* count outs for successors */
+ if (irn_not_visited(pred))
+ res += _count_outs(pred);
+
+ /* Count my outs */
+ pred->out = (ir_node **)INT_TO_PTR(PTR_TO_INT(pred->out) + 1);
+ }
+ return res;
+}
+
+
+/** Returns the amount of out edges for not yet visited successors.
+ * This version handles some special nodes like irg_frame, irg_args etc.
+ */
+static int count_outs(ir_graph *irg) {
+ ir_node *n;
+ int res;
+
+ inc_irg_visited(irg);
+ res = _count_outs(get_irg_end(irg));
+
+ /* now handle special nodes */
+ n = get_irg_frame(irg);
+ if (irn_not_visited(n)) {
+ n->out = (ir_node **)1;
+ ++res;
+ }
+
+ n = get_irg_args(irg);
+ if (irn_not_visited(n)) {
+ n->out = (ir_node **)1;
+ ++res;
+ }
+
+ return res;
+}
+
+/**
+ * Enter memory for the outs to a node.
+ *
+ * @param n current node
+ * @param free current free address in the chunk allocated for the outs
+ *
+ * @return The next free address
+ */
+static ir_node **_set_out_edges(ir_node *n, ir_node **free) {
+ int n_outs, start, i, irn_arity;
+ ir_node *pred;
+
+ set_irn_visited(n, get_irg_visited(current_ir_graph));
+
+ /* Allocate my array */
+ n_outs = PTR_TO_INT(n->out);
+ n->out = free;
+#ifdef DEBUG_libfirm
+ n->out_valid = 1;
+#endif /* defined DEBUG_libfirm */
+ free += n_outs;
+ /* We count the successors again, the space will be sufficient.
+ We use this counter to remember the position for the next back
+ edge. */
+ n->out[0] = (ir_node *)0;
+
+ start = is_Block(n) ? 0 : -1;
+ irn_arity = get_irn_arity(n);
+
+ for (i = start; i < irn_arity; ++i) {
+ pred = get_irn_n(n, i);
+ /* Recursion */
+ if (get_irn_visited(pred) < get_irg_visited(current_ir_graph))
+ free = _set_out_edges(pred, free);
+ /* Remember our back edge */
+ pred->out[get_irn_n_outs(pred)+1] = n;
+ pred->out[0] = INT_TO_PTR(get_irn_n_outs(pred) + 1);
+ }
+ return free;
+}
+
+/**
+ * Enter memory for the outs to a node. Handles special nodes
+ *
+ * @param irg the graph
+ * @param free current free address in the chunk allocated for the outs
+ *
+ * @return The next free address
+ */
+static ir_node **set_out_edges(ir_graph *irg, ir_node **free) {
+ ir_node *n, *special[2];
+ int i, n_outs;
+
+ inc_irg_visited(irg);
+ free = _set_out_edges(get_irg_end(irg), free);
+
+ /* handle special nodes */
+ special[0] = get_irg_frame(irg);
+ special[1] = get_irg_args(irg);
+
+ for (i = 1; i >= 0; --i) {
+ n = special[i];
+
+ if (get_irn_visited(n) < get_irg_visited(current_ir_graph)) {
+ n_outs = PTR_TO_INT(n->out);
+ n->out = free;
+#ifdef DEBUG_libfirm
+ n->out_valid = 1;
+#endif /* defined DEBUG_libfirm */
+ free += n_outs;
+ }
+ }
+
+ return free;
+}
+
+
+/**
+ * We want that the out of ProjX from Start contains the next block at
+ * position 1, the Start block at position 2. This is necessary for
+ * the out block walker.
+ */
+static INLINE void fix_start_proj(ir_graph *irg) {
+ ir_node *proj = NULL;
+ ir_node *startbl = get_irg_start_block(irg);
+ int i;
+
+ if (get_Block_n_cfg_outs(startbl)) {
+ for (i = get_irn_n_outs(startbl) - 1; i >= 0; --i)
+ if (get_irn_mode(get_irn_out(startbl, i)) == mode_X) {
+ proj = get_irn_out(startbl, i);
+ break;
+ }
+
+ if (get_irn_out(proj, 0) == startbl) {
+ assert(get_irn_n_outs(proj) == 2);
+ set_irn_out(proj, 0, get_irn_out(proj, 1));
+ set_irn_out(proj, 1, startbl);
+ }
+ }
+}
+
+/* compute the outs for a given graph */
+void compute_irg_outs(ir_graph *irg) {
+ ir_graph *rem = current_ir_graph;
+ int n_out_edges = 0;
+ ir_node **end = NULL; /* Only for debugging */
+
+ current_ir_graph = irg;
+
+ /* Update graph state */
+ assert(get_irg_phase_state(current_ir_graph) != phase_building);
+
+ if (current_ir_graph->outs_state != outs_none)
+ free_irg_outs(current_ir_graph);
+
+ /* This first iteration counts the overall number of out edges and the
+ number of out edges for each node. */
+ n_out_edges = count_outs(irg);
+
+ /* allocate memory for all out edges. */
+ irg->outs = xcalloc(n_out_edges, sizeof(irg->outs[0]));
+#ifdef DEBUG_libfirm
+ irg->n_outs = n_out_edges;
+#endif /* defined DEBUG_libfirm */
+
+ /* The second iteration splits the irg->outs array into smaller arrays
+ for each node and writes the back edges into this array. */
+ end = set_out_edges(irg, irg->outs);
+
+ /* Check how much memory we have used */
+ assert (end == (irg->outs + n_out_edges));
+
+ /* We want that the out of ProjX from Start contains the next block at
+ position 1, the Start block at position 2. This is necessary for
+ the out block walker. */
+ fix_start_proj(irg);
+
+ current_ir_graph->outs_state = outs_consistent;
+ current_ir_graph = rem;