X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fana%2Firouts.c;h=48c9efa90268caaa51ce4102657cb78856cad1b9;hb=b2e280bcb4dcde092a0971ea045ee1269b114c4f;hp=490b437e8ce64d2d9fe581e04c098d505c4605f9;hpb=259dcba1e6f68045bcc5ba10faa9631dcff732ca;p=libfirm

diff --git a/ir/ana/irouts.c b/ir/ana/irouts.c
index 490b437e8..48c9efa90 100644
--- a/ir/ana/irouts.c
+++ b/ir/ana/irouts.c
@@ -1,96 +1,265 @@
-/* Copyright (C) 2002 by Universitaet Karlsruhe
-** All rights reserved.
-**
-** Authors:  Goetz Lindenmaier
-**
-** irouts.c --- Compute out edges for ir nodes (also called def-use
-** edges).
-**
-*/
-
-/* $Id$ */
-
-#define DDMSG2(X)    printf("%s(l.%i) %s%s: %ld\n", __FUNCTION__, __LINE__,          \
-                     id_to_str(get_irn_opident(X)), id_to_str(get_irn_modeident(X)), \
-                     get_irn_node_nr(X))
-#define DDMSG5(X)    printf("%s%s: %ld",          \
-                     id_to_str(get_irn_opident(X)), id_to_str(get_irn_modeident(X)), \
-                     get_irn_node_nr(X))
-
-
+/*
+ * Copyright (C) 1995-2007 University of Karlsruhe.  All right reserved.
+ *
+ * This file is part of libFirm.
+ *
+ * This file may be distributed and/or modified under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation and appearing in the file LICENSE.GPL included in the
+ * packaging of this file.
+ *
+ * Licensees holding valid libFirm Professional Edition licenses may use
+ * this file in accordance with the libFirm Commercial License.
+ * Agreement provided with the Software.
+ *
+ * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
+ * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE.
+ */
+
+/**
+ * @file
+ * @brief    Compute and access out edges (also called def-use edges).
+ * @author   Goetz Lindenmaier, Michael Beck
+ * @date     1.2002
+ * @version  $Id$
+ */
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
+
+#include "xmalloc.h"
 #include "irouts.h"
 #include "irnode_t.h"
-#include "irgraph_t.h"     /* To access irg->outs field (which is private to this module)
-			      without public access routine */
-
-/**********************************************************************/
+#include "irgraph_t.h"
+#include "irprog_t.h"
+#include "irgwalk.h"
+#include "irtools.h"
+
+#ifdef DEBUG_libfirm
+/* Note:  ir_node.out_valid and ir_graph.n_outs are only present when DEBUG_libfirm is defined */
+/* Accesses to out_valid and n_outs are fenced out to avoid breakage
+   when compiling with neither DEBUG_libfirm or NDEBUG defined */
+#endif /* defined DEBUG_libfirm */
+
+/*--------------------------------------------------------------------*/
 /** Accessing the out datastructures                                 **/
-/**********************************************************************/
+/*--------------------------------------------------------------------*/
+
+#ifdef DEBUG_libfirm
+/** Clear the outs of a node */
+static void reset_outs(ir_node *node, void *unused) {
+	(void) unused;
+	node->out       = NULL;
+	node->out_valid = 0;
+}
+#endif
 
 /* returns the number of successors of the node: */
-inline int              get_irn_n_outs    (ir_node *node) {
-  return (int)(node->out[0]);
+int get_irn_n_outs(ir_node *node) {
+	assert(node && node->kind == k_ir_node);
+#ifdef DEBUG_libfirm
+	/* assert(node->out_valid); */
+#endif /* defined DEBUG_libfirm */
+	return PTR_TO_INT(node->out[0]);
 }
 
 /* Access successor n */
-inline ir_node  *get_irn_out      (ir_node *node, int pos) {
-  assert(node);
-  assert(pos >= 0 && pos < get_irn_n_outs(node));
-  return node->out[pos+1];
+ir_node *get_irn_out(ir_node *node, int pos) {
+	assert(pos >= 0 && pos < get_irn_n_outs(node));
+#ifdef DEBUG_libfirm
+	/* assert(node->out_valid); */
+#endif /* defined DEBUG_libfirm */
+return node->out[pos+1];
+}
+
+void set_irn_out(ir_node *node, int pos, ir_node *out) {
+	assert(node && out);
+	assert(pos >= 0 && pos < get_irn_n_outs(node));
+#ifdef DEBUG_libfirm
+	node->out_valid = 1;          /* assume that this function is used correctly */
+#endif /* defined DEBUG_libfirm */
+	node->out[pos+1] = out;
+}
+
+/* Return the number of control flow successors, ignore keep-alives. */
+int get_Block_n_cfg_outs(ir_node *bl) {
+	int i, n_cfg_outs = 0;
+	assert(bl && is_Block(bl));
+#ifdef DEBUG_libfirm
+	assert(bl->out_valid);
+#endif /* defined DEBUG_libfirm */
+	for (i = 1; i <= PTR_TO_INT(bl->out[0]); ++i) {
+		ir_node *succ = bl->out[i];
+		if (get_irn_mode(succ) == mode_X && get_irn_op(succ) != op_End)
+			n_cfg_outs += PTR_TO_INT(succ->out[0]);
+	}
+	return n_cfg_outs;
+}
+
+/* Return the number of control flow successors, honor keep-alives. */
+int get_Block_n_cfg_outs_ka(ir_node *bl) {
+	int i, n_cfg_outs = 0;
+	assert(bl && is_Block(bl));
+#ifdef DEBUG_libfirm
+	assert(bl->out_valid);
+#endif /* defined DEBUG_libfirm */
+	for (i = 1; i <= PTR_TO_INT(bl->out[0]); ++i) {
+		ir_node *succ = bl->out[i];
+		if (get_irn_mode(succ) == mode_X) {
+
+			if (get_irn_op(succ) == op_End) {
+				/* ignore End if we are in the Endblock */
+				if (get_irn_n(succ, -1) == bl)
+					continue;
+				else /* count Keep-alive as one */
+					n_cfg_outs += 1;
+			} else
+				n_cfg_outs += PTR_TO_INT(succ->out[0]);
+		}
+	}
+	return n_cfg_outs;
 }
 
-inline void      set_irn_out      (ir_node *node, int pos, ir_node *out) {
-  assert(node && out);
-  assert(pos >= 0 && pos < get_irn_n_outs(node));
-  node->out[pos+1] = out;
+/* Access predecessor n, ignore keep-alives. */
+ir_node *get_Block_cfg_out(ir_node *bl, int pos) {
+	int i;
+	assert(bl && is_Block(bl));
+#ifdef DEBUG_libfirm
+	assert (bl->out_valid);
+#endif /* defined DEBUG_libfirm */
+	for (i = 1; i <= PTR_TO_INT(bl->out[0]); ++i) {
+		ir_node *succ = bl->out[i];
+		if (get_irn_mode(succ) == mode_X && get_irn_op(succ) != op_End) {
+			int n_outs = PTR_TO_INT(succ->out[0]);
+			if (pos < n_outs)
+				return succ->out[pos + 1];
+			else
+				pos -= n_outs;
+		}
+	}
+	return NULL;
 }
 
-void irg_out_walk_2(ir_node *node,  void (pre)(ir_node*, void*),
-		    void (post)(ir_node*, void*), void *env) {
-  int i;
-  ir_node *succ;
+/* Access predecessor n, honor keep-alives. */
+ir_node *get_Block_cfg_out_ka(ir_node *bl, int pos) {
+	int i, n_outs;
+	assert(bl && is_Block(bl));
+#ifdef DEBUG_libfirm
+	assert (bl->out_valid);
+#endif /* defined DEBUG_libfirm */
+	for (i = 1; i <= PTR_TO_INT(bl->out[0]); ++i) {
+		ir_node *succ = bl->out[i];
+		if (get_irn_mode(succ) == mode_X) {
+			if (get_irn_op(succ) == op_End) {
+				if (get_irn_n(succ, -1) == bl) {
+					/* ignore End if we are in the Endblock */
+					continue;
+				}
+				if (pos == 0) {
+					/* handle keep-alive here: return the Endblock instead of the End node */
+					return get_irn_n(succ, -1);
+				} else
+					--pos;
+			} else {
+				n_outs = PTR_TO_INT(succ->out[0]);
+				if (pos < n_outs)
+					return succ->out[pos + 1];
+				else
+					pos -= n_outs;
+			}
+		}
+	}
+	return NULL;
+}
 
-  //printf("++ in walker (%d outs) ", get_irn_n_outs(node)); DDMSG2(node);
+static void irg_out_walk_2(ir_node *node, irg_walk_func *pre,
+            irg_walk_func *post, void *env) {
+	int     i, n;
+	ir_node *succ;
 
-  assert(node);
-  assert(get_irn_visited(node) < get_irg_visited(current_ir_graph));
+	assert(node);
+	assert(get_irn_visited(node) < get_irg_visited(current_ir_graph));
 
-  set_irn_visited(node, get_irg_visited(current_ir_graph));
+	set_irn_visited(node, get_irg_visited(current_ir_graph));
 
-  if (pre) pre(node, env);
+	if (pre) pre(node, env);
 
-  for (i = 0; i < get_irn_n_outs(node); i++) {
-    succ = get_irn_out(node, i);
-    if (get_irn_visited(succ) < get_irg_visited(current_ir_graph))
-      irg_out_walk_2(succ, pre, post, env);
-  }
+	for (i = 0, n = get_irn_n_outs(node); i < n; ++i) {
+		succ = get_irn_out(node, i);
+		if (get_irn_visited(succ) < get_irg_visited(current_ir_graph))
+			irg_out_walk_2(succ, pre, post, env);
+	}
 
-  if (post) post(node, env);
+	if (post) post(node, env);
 
-  //printf("++ done walking "); DDMSG2(node);
-  return;
+	return;
 }
 
 void irg_out_walk(ir_node *node,
-		  void (pre)(ir_node*, void*), void (post)(ir_node*, void*),
-		  void *env) {
-  assert(node);
-  if (get_irg_outs_state(current_ir_graph) != no_outs) {
-    inc_irg_visited (current_ir_graph);
-    irg_out_walk_2(node, pre, post, env);
-  }
-  return;
+                  irg_walk_func *pre, irg_walk_func *post,
+                  void *env) {
+	assert(node);
+	if (get_irg_outs_state(current_ir_graph) != outs_none) {
+		inc_irg_visited (current_ir_graph);
+		irg_out_walk_2(node, pre, post, env);
+	}
+	return;
+}
+
+static void irg_out_block_walk2(ir_node *bl,
+                                irg_walk_func *pre, irg_walk_func *post,
+                                void *env) {
+	int i, n;
+
+	if (Block_not_block_visited(bl)) {
+		mark_Block_block_visited(bl);
+
+		if (pre)
+			pre(bl, env);
+
+		for (i = 0, n =  get_Block_n_cfg_outs(bl); i < n; ++i) {
+			/* find the corresponding predecessor block. */
+			ir_node *pred = get_Block_cfg_out(bl, i);
+			/* recursion */
+			irg_out_block_walk2(pred, pre, post, env);
+		}
+
+		if (post)
+			post(bl, env);
+	}
 }
 
 /* Walks only over Block nodes in the graph.  Has it's own visited
    flag, so that it can be interleaved with the other walker.         */
 void irg_out_block_walk(ir_node *node,
-			void (pre)(ir_node*, void*), void (post)(ir_node*, void*),
-			void *env) {
+                        irg_walk_func *pre, irg_walk_func *post,
+                        void *env) {
+
+	assert(is_Block(node) || (get_irn_mode(node) == mode_X));
+
+	inc_irg_block_visited(current_ir_graph);
+
+	if (get_irn_mode(node) == mode_X) {
+		int i, n;
+
+		for (i = 0, n = get_irn_n_outs(node); i < n; ++i) {
+			ir_node *succ = get_irn_out(node, i);
+			if (get_irn_visited(succ) < get_irg_visited(current_ir_graph))
+				irg_out_walk_2(succ, pre, post, env);
+		}
+	}
+	else {
+		irg_out_block_walk2(node, pre, post, env);
+	}
 }
 
-/**********************************************************************/
-/** Building and Removing the out datasturcture                      **/
+/*--------------------------------------------------------------------*/
+/** Building and Removing the out datastructure                      **/
 /**                                                                  **/
 /** The outs of a graph are allocated in a single, large array.      **/
 /** This allows to allocate and deallocate the memory for the outs   **/
@@ -105,90 +274,379 @@ void irg_out_block_walk(ir_node *node,
 /** Then the large array is allocated.  The second iteration chops   **/
 /** the large array into smaller parts, sets the out edges and       **/
 /** recounts the out edges.                                          **/
-/**********************************************************************/
+/** 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;
 
-/* Returns the amount of out edges for not yet visited successors. */
-int count_outs(ir_node *n) {
-  int start, i, res;
-  ir_node *succ;
+	inc_irg_visited(irg);
+	res = _count_outs(get_irg_end(irg));
 
-  set_irn_visited(n, get_irg_visited(current_ir_graph));
-  n->out = (ir_node **) 1;     /* Space for array size. */
+	/* now handle special nodes */
+	n = get_irg_frame(irg);
+	if (irn_not_visited(n)) {
+		n->out = (ir_node **)1;
+		++res;
+	}
 
-  if ((get_irn_op(n) == op_Block)) start = 0; else start = -1;
-  res = get_irn_arity(n) - start +1;  /* --1 or --0; 1 for array size. */
-  for (i = start; i < get_irn_arity(n); i++) {
-    succ = get_irn_n(n, i);
-    /* count outs for successors */
-    if (get_irn_visited(succ) < get_irg_visited(current_ir_graph))
-      res += count_outs(succ);
-    /* Count my outs */
-    succ->out = (ir_node **)( (int)succ->out +1);
-  }
-  return res;
+	n = get_irg_args(irg);
+	if (irn_not_visited(n)) {
+		n->out = (ir_node **)1;
+		++res;
+	}
+
+	return res;
 }
 
-ir_node **set_out_edges(ir_node *n, ir_node **free) {
-  int n_outs, start, i;
-  ir_node *succ;
+/**
+ * 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;
+}
 
-  set_irn_visited(n, get_irg_visited(current_ir_graph));
+/**
+ * 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;
+}
 
-  /* Allocate my array */
-  n_outs = (int) n->out;
-  n->out = free;
-  free = &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;
 
-  if (get_irn_op(n) == op_Block) start = 0; else start = -1;
-  for (i = start; i < get_irn_arity(n); i++) {
-    succ = get_irn_n(n, i);
-    /* Recursion */
-    if (get_irn_visited(succ) < get_irg_visited(current_ir_graph))
-      free = set_out_edges(succ, free);
-    /* Remember our back edge */
-    succ->out[get_irn_n_outs(succ)+1] = n;
-    succ->out[0] = (ir_node *) (get_irn_n_outs(succ) + 1);
-  }
-  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);
+		}
+	}
 }
 
-void compute_outs(ir_graph *irg) {
-  ir_graph *rem = current_ir_graph;
-  int n_out_edges = 0;
+/* 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);
 
-  current_ir_graph = irg;
+	/* 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);
 
-  /* Update graph state */
-  assert(get_irg_phase_state(current_ir_graph) != phase_building);
-  current_ir_graph->outs_state = outs_consistent;
+	/* 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 */
 
-  /* This first iteration counts the overall number of out edges and the
-     number of out edges for each node. */
-  inc_irg_visited(irg);
-  n_out_edges = count_outs(get_irg_end(irg));
+	/* 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);
 
-  /* allocate memory for all out edges. */
-  irg->outs = (ir_node **) malloc (n_out_edges * sizeof(ir_node *));
+	/* Check how much memory we have used */
+	assert (end == (irg->outs + n_out_edges));
 
-  /* The second iteration splits the irg->outs array into smaller arrays
-     for each node and writes the back edges into this array. */
-  inc_irg_visited(irg);
-  set_out_edges(get_irg_end(irg), irg->outs);
+	/* 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 = rem;
+	current_ir_graph->outs_state = outs_consistent;
+	current_ir_graph = rem;
 }
 
-void free_outs(ir_graph *irg) {
+void assure_irg_outs(ir_graph *irg) {
+	if (get_irg_outs_state(irg) != outs_consistent)
+		compute_irg_outs(irg);
+}
+
+void compute_irp_outs(void) {
+	int i;
+	for (i = get_irp_n_irgs() -1; i >= 0; --i)
+		compute_irg_outs(get_irp_irg(i));
+}
+
+void free_irp_outs(void) {
+	int i;
+	for (i = get_irp_n_irgs() -1; i >= 0; --i)
+		free_irg_outs(get_irp_irg(i));
+}
+
+
+/*------------------------------------------------------------*
+ *  This computes the outedges for in interprocedural graph.  *
+ *  There is one quirk:                                       *
+ *  The number of the outedges for each node is saved in      *
+ *  the first member of the ir_node** array. Maybe we should  *
+ *  change this to make it more portable...                   *
+ *------------------------------------------------------------*/
+
+
+#ifdef INTERPROCEDURAL_VIEW
+/**
+ * Inits the number of outedges for each node
+ * before counting.
+ */
+static void init_count(ir_node * node, void *env) {
+	(void) env;
+	node->out = (ir_node **) 1; /* 1 for the array size */
+}
+
+
+/**
+ * Adjusts the out edge count for its predecessors
+ * and adds the current arity to the overall count,
+ * which is saved in "env"
+ */
+static void node_arity_count(ir_node * node, void * env) {
+	int *anz = (int *) env, arity, n_outs, i, start;
+	ir_node *succ;
 
-  /* Update graph state */
-  assert(get_irg_phase_state(current_ir_graph) != phase_building);
-  current_ir_graph->outs_state = no_outs;
+	arity = get_irn_arity(node);
+	start = (is_Block(node)) ? 0 : -1;
 
-  if (irg->outs) free(irg->outs);
-  irg->outs = NULL;
+	n_outs = 1 + arity + (-start);  // ((is_Block(node)) ? 0 : 1);   // Why + 1??
+	*anz += n_outs;
+
+	for(i = start; i < arity; i++) {
+		succ = get_irn_n(node, i);
+		succ->out = (ir_node **)INT_TO_PTR(PTR_TO_INT(succ->out) + 1);
+	}
+}
+
+/*
+ * Inits all nodes for setting the outedges
+ * Returns the overall count of edges
+ */
+int count_ip_outs(void) {
+	int res = 0;
+
+	cg_walk(init_count, node_arity_count, &res);
+
+	return(res);
+}
+
+static int dummy_count = 0, global_count; /* Only for debugging */
+
+/**
+ * For each node: Sets the pointer to array
+ * in which the outedges are written later.
+ * The current array start is transported in env
+ */
+static void set_array_pointer(ir_node *node, void *env) {
+	int n_outs;
+	ir_node ***free = (ir_node ***) env;
+
+	/* Allocate my array */
+	n_outs = PTR_TO_INT(node->out);  /* We wrote the count here in count_ip_outs */
+	dummy_count += n_outs;
+	assert(dummy_count <= global_count && "More outedges than initially counted!");
+	node -> out = *free;
+	*free = &((*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. */
+	node -> out[0] = (ir_node *) 0;
+}
+
+
+/**
+ * Adds an outedge from the predecessor to the
+ * current node.
+ */
+static void set_out_pointer(ir_node * node, void *env) {
+	int i, arity = get_irn_arity(node);
+	ir_node *succ;
+	int start = (!is_Block(node)) ? -1 : 0;
+	(void) env;
+
+	for (i = start; i < arity; ++i) {
+		succ = get_irn_n(node, i);
+		succ->out[get_irn_n_outs(succ)+1] = node;
+		succ->out[0] = INT_TO_PTR(get_irn_n_outs(succ) + 1);
+	}
+}
+
+
+/*
+ * Sets the outedges for all nodes.
+ */
+void set_ip_outs(void) {
+	ir_node **outedge_array = get_irp_ip_outedges();
+	cg_walk(set_array_pointer, set_out_pointer, (void *) &outedge_array);
+}
+
+
+
+/*
+ * Counts the outedges, allocates memory to save the
+ * outedges and fills this outedge array in interprocedural
+ * view!
+ */
+void compute_ip_outs(void) {
+	int n_out_edges;
+	ir_node **out_edges;
+
+	assert(get_irp_ip_view_state() == ip_view_valid &&
+	 "Cannot construct outs for invalid ip view.");
+
+	if (irp->outs_state != outs_none) {
+		free_ip_outs();
+	}
+
+	global_count = n_out_edges = count_ip_outs();
+	out_edges = xcalloc(n_out_edges, sizeof(out_edges[0]));
+	set_irp_ip_outedges(out_edges);
+	set_ip_outs();
+}
+
+void free_ip_outs(void) {
+	ir_node **out_edges = get_irp_ip_outedges();
+	if (out_edges != NULL) {
+		free(out_edges);
+		set_irp_ip_outedges(NULL);
+	}
+	irp->outs_state = outs_none;
+}
+#endif
+
+
+void free_irg_outs(ir_graph *irg) {
+	/*   current_ir_graph->outs_state = outs_none; */
+	irg->outs_state = outs_none;
+
+	if (irg->outs) {
+#ifdef DEBUG_libfirm
+		memset(irg->outs, 0, irg->n_outs);
+#endif /* defined DEBUG_libfirm */
+		free(irg->outs);
+		irg->outs = NULL;
+#ifdef DEBUG_libfirm
+		irg->n_outs = 0;
+#endif /* defined DEBUG_libfirm */
+	}
+
+#ifdef DEBUG_libfirm
+	/* when debugging, *always* reset all nodes' outs!  irg->outs might
+	   have been lying to us */
+	irg_walk_graph (irg, reset_outs, NULL, NULL);
+#endif /* defined DEBUG_libfirm */
 }