update copyright message
[libfirm] / ir / ir / iredges.c
index 2619a14..55df700 100644 (file)
@@ -1,31 +1,92 @@
-/**
- * Always available outs.
- * @author Sebastian Hack
- * @date 14.1.2005
+/*
+ * Copyright (C) 1995-2008 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   Always available outs.
+ * @author  Sebastian Hack, Michael Beck, Andreas Schoesser
+ * @date    14.1.2005
+ * @version $Id$
+ * @summary
+ *   This are out-edges (also called def-use edges) that are dynamically
+ *   updated as the graph changes.
+ */
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 
-#ifdef HAVE_ALLOCA_H
-#include <alloca.h>
-#endif
-#ifdef HAVE_MALLOC_H
-#include <malloc.h>
-#endif
-
 #include "irnode_t.h"
+#include "iropt_t.h"
+#include "iredgekinds.h"
 #include "iredges_t.h"
+#include "irgwalk.h"
 #include "irdump_t.h"
 #include "irprintf.h"
 #include "irhooks.h"
 #include "debug.h"
 #include "set.h"
+#include "bitset.h"
+#include "xmalloc.h"
+
+/**
+ * A function that allows for setting an edge.
+ * This abstraction is necessary since different edge kind have
+ * different methods of setting edges.
+ */
+typedef void (set_edge_func_t)(ir_node *src, int pos, ir_node *tgt);
+
+typedef int (get_edge_src_arity_func_t)(const ir_node *src);
+
+typedef ir_node *(get_edge_src_n_func_t)(const ir_node *src, int pos);
+
+/**
+ * Additional data for an edge kind.
+ */
+typedef struct {
+       const char                *name;       /**< name of this edge kind */
+       set_edge_func_t           *set_edge;   /**< the set_edge function */
+       int                       first_idx;   /**< index of the first possible edge */
+       get_edge_src_arity_func_t *get_arity;  /**< the get_arity function */
+       get_edge_src_n_func_t     *get_n;      /**< the get_n function */
+} ir_edge_kind_info_t;
+
+/**
+ * Get the predecessor block.
+ */
+static ir_node *get_block_n(const ir_node *irn, int pos) {
+       if (is_Block(irn))
+               return get_Block_cfgpred_block(irn, pos);
+       /* might be a Bad */
+       return NULL;
+}
 
-static firm_dbg_module_t *dbg;
+static const ir_edge_kind_info_t edge_kind_info[EDGE_KIND_LAST] = {
+       { "normal"     , set_irn_n,   -1, get_irn_arity,  get_irn_n   },
+       { "block succs", NULL,         0, get_irn_arity,  get_block_n },
+       { "dependency",  set_irn_dep,  0, get_irn_deps,   get_irn_dep }
+};
 
-#if FIRM_EDGES_INPLACE
+#define foreach_tgt(irn, i, n, kind) for(i = edge_kind_info[kind].first_idx, n = edge_kind_info[kind].get_arity(irn); i < n; ++i)
+#define get_n(irn, pos, kind)        (edge_kind_info[kind].get_n(irn, pos))
+#define get_kind_str(kind)           (edge_kind_info[kind].name)
+
+DEBUG_ONLY(static firm_dbg_module_t *dbg;)
 
 /**
  * This flag is set to 1, if the edges get initialized for an irg.
@@ -33,10 +94,43 @@ static firm_dbg_module_t *dbg;
  */
 static int edges_used = 0;
 
+/**
+ * Summed size of all users private data
+ */
+
 static int edges_private_size = 0;
+#define EDGE_SIZE (sizeof(ir_edge_t) + edges_private_size)
 
-int edges_register_private_data(size_t n)
-{
+/**
+ * If set to 1, the list heads are checked every time an edge is changed.
+ */
+static int edges_dbg = 0;
+
+#ifdef DEBUG_libfirm
+/* a static variable holding the last number assigned to a new edge */
+static long last_edge_num = -1;
+#endif
+
+static INLINE long edge_get_id(const ir_edge_t *e) {
+#ifdef DEBUG_libfirm
+       return e->edge_nr;
+#else /* DEBUG_libfirm */
+       return (long)e;
+#endif /* DEBUG_libfirm */
+}
+
+/**
+ * Announce to reserve extra space for each edge to be allocated.
+ *
+ * @param n: Size of the space to reserve
+ *
+ * @return Offset at which the private data will begin
+ *
+ * Several users can reserve extra space for private usage.
+ * Each user has to remember his given offset and the size of his private data.
+ * To be called before FIRM is initialized.
+ */
+int edges_register_private_data(size_t n) {
        int res = edges_private_size;
 
        assert(!edges_used && "you cannot register private edge data, if edges have been initialized");
@@ -45,46 +139,60 @@ int edges_register_private_data(size_t n)
        return res;
 }
 
+/**
+ * Reset the user's private data at offset 'offset'
+ * The user has to remember his offset and the size of his data!
+ * Caution: Using wrong values here can destroy other users private data!
+ */
+void edges_reset_private_data(ir_graph *irg, int offset, size_t size) {
+       irg_edge_info_t *info = _get_irg_edge_info(irg, EDGE_KIND_NORMAL);
+       ir_edge_t       *edge;
+
+       foreach_set(info->edges, edge)  {
+               memset(edge + sizeof(*edge) + offset, 0, size);
+       }
+}
+
 #define TIMES37(x) (((x) << 5) + ((x) << 2) + (x))
 
 #define get_irn_out_list_head(irn) (&get_irn_out_info(irn)->outs)
 
-static int edge_cmp(const void *p1, const void *p2, size_t len)
-{
+/**
+ * Compare two edges.
+ */
+static int edge_cmp(const void *p1, const void *p2, size_t len) {
        const ir_edge_t *e1 = p1;
        const ir_edge_t *e2 = p2;
-       int res = e1->src == e2->src && e1->pos == e2->pos;
+       (void) len;
+
+       if(e1->src != e2->src)
+               return 1;
+       if(e1->pos != e1->pos)
+               return 1;
 
-       return !res;
+       return 0;
 }
 
 #define edge_hash(edge) (TIMES37((edge)->pos) + HASH_PTR((edge)->src))
 
 /**
  * Initialize the out information for a graph.
- * @note Dead node elim can call this on an already initialized graph.
+ * @note Dead node elimination can call this on an already initialized graph.
  */
-void edges_init_graph(ir_graph *irg)
-{
-       if(edges_activated(irg)) {
-               irg_edge_info_t *info = _get_irg_edge_info(irg);
+void edges_init_graph_kind(ir_graph *irg, ir_edge_kind_t kind) {
+       if (edges_activated_kind(irg, kind)) {
+               irg_edge_info_t *info = _get_irg_edge_info(irg, kind);
                int amount = 2048;
 
                edges_used = 1;
-
                if(info->edges) {
                        amount = set_count(info->edges);
                        del_set(info->edges);
                }
-
                info->edges = new_set(edge_cmp, amount);
        }
 }
 
-#define EDGE_SIZE(src) \
-    (edges_private_size + (is_Block(src) ? sizeof(ir_block_edge_t) : sizeof(ir_edge_t)))
-
-
 /**
  * Get the edge object of an outgoing edge at a node.
  * @param   irg The graph, the node is in.
@@ -93,347 +201,699 @@ void edges_init_graph(ir_graph *irg)
  * @return      The corresponding edge object or NULL,
  *              if no such edge exists.
  */
-const ir_edge_t *get_irn_edge(ir_graph *irg, const ir_node *src, int pos)
+const ir_edge_t *get_irn_edge_kind(ir_graph *irg, const ir_node *src, int pos, ir_edge_kind_t kind)
 {
-       if(edges_activated(irg)) {
-               irg_edge_info_t *info = _get_irg_edge_info(irg);
-               size_t size           = EDGE_SIZE(src);
-               ir_edge_t *templ      = alloca(size);
-
-               memset(templ, 0, size);
-               templ->src = (ir_node *) src;
-               templ->pos = pos;
-               return set_find(info->edges, templ, size, edge_hash(templ));
+       if (edges_activated_kind(irg, kind)) {
+               irg_edge_info_t *info = _get_irg_edge_info(irg, kind);
+               ir_edge_t       key;
+
+               key.src = (ir_node *)src;
+               key.pos = pos;
+               return set_find(info->edges, &key, EDGE_SIZE, edge_hash(&key));
        }
 
        return NULL;
 }
 
-void edges_notify_edge(ir_node *src, int pos, ir_node *tgt, ir_node *old_tgt, ir_graph *irg)
-{
-       const char *msg = "";
+/**
+ * Get the edge object of an outgoing edge at a node.
+ * Looks for an edge for all kinds.
+ */
+const ir_edge_t *get_irn_edge(ir_graph *irg, const ir_node *src, int pos) {
+       const ir_edge_t *edge;
+       if((edge = get_irn_edge_kind(irg, src, pos, EDGE_KIND_NORMAL)) == NULL)
+               edge = get_irn_edge_kind(irg, src, pos, EDGE_KIND_BLOCK);
+       return(edge);
+}
 
-       if(!edges_activated(irg))
-               return;
+/**
+ * Change the out count
+ *
+ * @param tgt  the edge target
+ * @param kind the kind of the edge
+ */
+static INLINE void edge_change_cnt(ir_node *tgt, ir_edge_kind_t kind, int ofs) {
+       irn_edge_info_t *info = _get_irn_edge_info(tgt, kind);
+       info->out_count += ofs;
 
 #if 0
-       assert(node_is_in_irgs_storage(irg, src) && "source not in irg");
+       assert(info->out_count >= 0);
+       if (info->out_count == 0 && kind == EDGE_KIND_NORMAL) {
+               /* tgt lost it's last user */
+               int i;
+
+               for (i = get_irn_arity(tgt) - 1; i >= -1; --i) {
+                       ir_node *prev = get_irn_n(tgt, i);
+
+                       edges_notify_edge(tgt, i, NULL, prev, current_ir_graph);
+               }
+               for (i = get_irn_deps(tgt) - 1; i >= 0; --i) {
+                       ir_node *prev = get_irn_dep(tgt, i);
+
+                       edges_notify_edge_kind(tgt, i, NULL, prev, EDGE_KIND_DEP, current_ir_graph);
+
+               }
+       }
 #endif
+}
+
+/**
+ * Verify the edge list of a node, ie. ensure it's a loop:
+ * head -> e_1 -> ... -> e_n -> head
+ */
+static INLINE void vrfy_list_head(ir_node *irn, ir_edge_kind_t kind) {
+       int                    err       = 0;
+       int                    num       = 0;
+       pset                   *lh_set   = pset_new_ptr(16);
+       const struct list_head *head     = _get_irn_outs_head(irn, kind);
+       const struct list_head *pos;
+
+       list_for_each(pos, head) {
+               if (pset_find_ptr(lh_set, pos)) {
+                       const ir_edge_t *edge = list_entry(pos, ir_edge_t, list);
+
+                       ir_fprintf(stderr, "EDGE Verifier: edge list broken (self loop not to head) for %+F:\n", irn);
+                       fprintf(stderr, "- at list entry %d\n", num);
+                       if (edge->invalid)
+                               fprintf(stderr, "- edge(%ld) is invalid\n", edge_get_id(edge));
+                       if (edge->src)
+                               ir_fprintf(stderr, "- edge(%ld) %+F(%d)\n", edge_get_id(edge), edge->src, edge->pos);
+                       err = 1;
+                       break;
+               }
+               num++;
+               pset_insert_ptr(lh_set, pos);
+       }
+
+       del_pset(lh_set);
+
+       assert(err == 0);
+}
+
+/* The edge from (src, pos) -> old_tgt is redirected to tgt */
+void edges_notify_edge_kind(ir_node *src, int pos, ir_node *tgt,
+                            ir_node *old_tgt, ir_edge_kind_t kind,
+                            ir_graph *irg)
+{
+       const char *msg = "";
+       irg_edge_info_t *info;
+       set *edges;
+       ir_edge_t *templ;
+       ir_edge_t *edge;
+
+       assert(edges_activated_kind(irg, kind));
 
        /*
         * Only do something, if the old and new target differ.
         */
-       if(tgt != old_tgt) {
-               int is_block_edge = is_Block(src);
-               set *edges = _get_irg_edge_info(irg)->edges;
-               ir_edge_t *edge;
-
-               /*
-                * This is scray, but:
-                * If two entries in a set do not have the same size, they are
-                * treated as unequal, ignoring the comparison function.
-                * So, edges from blocks have extra storage (they are
-                * ir_block_edge_t's).
-                *
-                * Also add the amount of registered private data to the
-                * size of the edge.
-                */
-               size_t size      = EDGE_SIZE(src);
-               ir_edge_t *templ = alloca(size);
-
-               /* Initialize the edge template to search in the set. */
-               memset(templ, 0, size);
+       if (tgt == old_tgt)
+               return;
+
+       info  = _get_irg_edge_info(irg, kind);
+       edges = info->edges;
+       templ = alloca(EDGE_SIZE);
+
+       /* Initialize the edge template to search in the set. */
+       memset(templ, 0, EDGE_SIZE);
+       templ->src     = src;
+       templ->pos     = pos;
+       templ->invalid = 0;
+       templ->present = 0;
+       templ->kind    = kind;
+       DEBUG_ONLY(templ->src_nr = get_irn_node_nr(src));
+
+       /*
+        * If the target is NULL, the edge shall be deleted.
+        */
+       if (tgt == NULL) {
+               /* search the edge in the set. */
+               edge = set_find(edges, templ, EDGE_SIZE, edge_hash(templ));
+
+               /* mark the edge invalid if it was found */
+               if (edge) {
+                       msg = "deleting";
+                       list_del(&edge->list);
+                       edge->invalid = 1;
+                       edge->pos = -2;
+                       edge->src = NULL;
 #ifdef DEBUG_libfirm
-               templ->src_nr = get_irn_node_nr(src);
-#endif
-               templ->src = src;
-               templ->pos = pos;
-               templ->invalid = 0;
-               templ->present = 0;
-
-               /*
-                * If the target is NULL, the edge shall be deleted.
-                */
-               if(tgt == NULL) {
-                       /* search the edge in the set. */
-                       edge = set_find(edges, templ, size, edge_hash(templ));
-
-                       /* mark the edge invalid if it was found */
-                       if(edge) {
-                               ir_block_edge_t *block_edge = (ir_block_edge_t *) edge;
-
-                               msg = "deleting";
-                               list_del(&edge->list);
-                               edge->invalid = 1;
-                               edge->pos = -2;
-                               edge->src = NULL;
-
-                               /*
-                                * If the edge is a cf edge, we delete it also
-                                * from the list of all block successor edges.
-                                */
-                               if(is_block_edge)
-                                       list_del(&block_edge->succ_list);
-                       }
-
-                       /* If the edge was not found issue a warning on the debug stream */
-                       else {
-                               msg = "edge to delete not found!\n";
-                       }
-               } /* if */
-
-               /*
-                * The target is not NULL and the old target differs
-                * from the new target, the edge shall be moved (if the
-                * old target was != NULL) or added (if the old target was
-                * NULL).
-                */
+                       edge->edge_nr = -1;
+#endif /* DEBUG_libfirm */
+                       edge_change_cnt(old_tgt, kind, -1);
+               }
+
+               /* If the edge was not found issue a warning on the debug stream */
                else {
-                       struct list_head *head = _get_irn_outs_head(tgt);
+                       msg = "edge to delete not found!\n";
+               }
+       } /* if */
+
+       /*
+        * The target is not NULL and the old target differs
+        * from the new target, the edge shall be moved (if the
+        * old target was != NULL) or added (if the old target was
+        * NULL).
+        */
+       else {
+               struct list_head *head = _get_irn_outs_head(tgt, kind);
 
-                       /*
-                        * The list head in the block of the edges target.
-                        * Therein all control flow edges directed at that block
-                        * are recorded.
-                        */
-                       struct list_head *succ_head =
-                               is_block_edge ? _get_block_succ_head(get_nodes_block(tgt)) : NULL;
+               assert(head->next && head->prev &&
+                               "target list head must have been initialized");
 
-                       ir_block_edge_t *block_edge;
+               /* If the old target is not null, the edge is moved. */
+               if (old_tgt) {
+                       edge = set_find(edges, templ, EDGE_SIZE, edge_hash(templ));
+                       assert(edge && "edge to redirect not found!");
+                       assert(! edge->invalid && "Invalid edge encountered");
 
-#if 0
-                       if(!node_is_in_irgs_storage(irg, tgt))
-                               return;
-#endif
-                       assert(head->next && head->prev &&
-                                       "target list head must have been initialized");
+                       msg = "redirecting";
 
-                       /*
-                        * insert the edge, if it is not yet in the set or return
-                        * the instance in the set.
-                        */
-                       edge = set_insert(edges, templ, size, edge_hash(templ));
-                       block_edge = (ir_block_edge_t *) edge;
+                       list_move(&edge->list, head);
+                       edge_change_cnt(old_tgt, kind, -1);
+               }
 
+               /* The old target was null, thus, the edge is newly created. */
+               else {
+                       edge = set_insert(edges, templ, EDGE_SIZE, edge_hash(templ));
+
+                       assert(! edge->invalid && "Freshly inserted edge is invalid?!?");
+                       assert(edge->list.next == NULL && edge->list.prev == NULL &&
+                               "New edge must not have list head initialized");
+
+                       msg = "adding";
+                       list_add(&edge->list, head);
 #ifdef DEBUG_libfirm
-                       assert(!edge->invalid && "Invalid edge encountered");
-#endif
+                       edge->edge_nr = ++last_edge_num;
+#endif /* DEBUG_libfirm */
+               }
+
+               edge_change_cnt(tgt, kind, +1);
+       } /* else */
 
-                       /* If the old target is not null, the edge is moved. */
-                       if(old_tgt) {
-                               msg = "redirecting";
-                               list_move(&edge->list, head);
-
-                               /* If the edge is a cf edge, move it from the successor list. */
-                               if(is_block_edge)
-                                       list_move(&block_edge->succ_list, succ_head);
-
-                               _get_irn_edge_info(old_tgt)->out_count -= 1;
-                       }
-
-                       /* The old target was null, thus, the edge is newly created. */
-                       else {
-                               msg = "adding";
-                               list_add(&edge->list, head);
-
-                               /*
-                                * If the edge is cf edge, enter it into the successor list
-                                * of the target node's block.
-                                */
-                               if(is_block_edge)
-                                       list_add(&block_edge->succ_list, succ_head);
-                       }
-
-                       _get_irn_edge_info(tgt)->out_count += 1;
-               } /* else */
+#ifndef DEBUG_libfirm
+       /* verify list heads */
+       if (edges_dbg) {
+               if (tgt)
+                       vrfy_list_head(tgt, kind);
+               if (old_tgt)
+                       vrfy_list_head(old_tgt, kind);
        }
+#endif
 
-       /* If the target and the old target are equal, nothing is done. */
-       DBG((dbg, LEVEL_5, "announce out edge: %n[%p] %d-> %n[%p](%n[%p]): %s\n",
-                               src, src, pos, tgt, tgt, old_tgt, old_tgt, msg));
+       DBG((dbg, LEVEL_5, "announce out edge: %+F %d-> %+F(%+F): %s\n", src, pos, tgt, old_tgt, msg));
 }
 
-void edges_node_deleted(ir_node *old, ir_graph *irg)
+void edges_notify_edge(ir_node *src, int pos, ir_node *tgt, ir_node *old_tgt, ir_graph *irg)
 {
-       if(edges_activated(irg)) {
-               int not_a_block = !is_Block(old);
-               ir_edge_t templ;
-               int i, n;
-
-               templ.src = old;
-               DBG((dbg, LEVEL_5, "node deleted: %n\n", old));
-
-               /* Change to get_irn_n */
-               for(i = -not_a_block, n = get_irn_arity(old); i < n; ++i) {
-                       ir_node *old_tgt = get_irn_n(old, i);
-                       DBG((dbg, LEVEL_5, "\tdelete to old target %n\n", old_tgt));
-                       edges_notify_edge(old, i, NULL, old_tgt, irg);
-               }
+       if (edges_activated_kind(irg, EDGE_KIND_NORMAL)) {
+               edges_notify_edge_kind(src, pos, tgt, old_tgt, EDGE_KIND_NORMAL, irg);
+       }
+
+       if (edges_activated_kind(irg, EDGE_KIND_BLOCK) && is_Block(src)) {
+               if (pos == -1) {
+                       /* a MacroBlock edge: ignore it here */
+               } else {
+                       ir_node *bl_old = old_tgt ? get_nodes_block(skip_Proj(old_tgt)) : NULL;
+                       ir_node *bl_tgt = NULL;
 
+                       if (tgt)
+                               bl_tgt = is_Bad(tgt) ? tgt : get_nodes_block(skip_Proj(tgt));
+
+                       edges_notify_edge_kind(src, pos, bl_tgt, bl_old, EDGE_KIND_BLOCK, irg);
+               }
        }
 }
 
-void edges_invalidate(ir_node *irn, ir_graph *irg)
+/**
+ * Delete all in edges of a given kind from the node old.
+ *
+ * @param old   the node
+ * @param kind  the kind of edges to remove
+ * @param irg   the irg of the old node
+ */
+static void edges_node_deleted_kind(ir_node *old, ir_edge_kind_t kind, ir_graph *irg)
 {
-       edges_node_deleted(irn, irg);
+       int i, n;
+
+       if (!edges_activated_kind(irg, kind))
+               return;
+
+       DBG((dbg, LEVEL_5, "node deleted (kind: %s): %+F\n", get_kind_str(kind), old));
+
+       foreach_tgt(old, i, n, kind) {
+               ir_node *old_tgt = get_n(old, i, kind);
+               edges_notify_edge_kind(old, i, NULL, old_tgt, kind, irg);
+       }
 }
 
-static void build_edges_walker(ir_node *irn, void *data)
-{
-       ir_graph *irg = data;
-       int not_a_block = !is_Block(irn);
-       int i, n;
+struct build_walker {
+       ir_graph       *irg;
+       ir_edge_kind_t kind;
+       bitset_t       *reachable;
+       unsigned       problem_found;
+};
+
+/**
+ * Post-Walker: notify all edges
+ */
+static void build_edges_walker(ir_node *irn, void *data) {
+       struct build_walker   *w = data;
+       int                   i, n;
+       ir_edge_kind_t        kind = w->kind;
+       ir_graph              *irg = w->irg;
+       get_edge_src_n_func_t *get_n;
+
+       if (! edges_activated_kind(irg, kind))
+               return;
 
-       for(i = -not_a_block, n = get_irn_arity(irn); i < n; ++i)
-               edges_notify_edge(irn, i, get_irn_n(irn, i), NULL, irg);
+       get_n = edge_kind_info[kind].get_n;
+       foreach_tgt(irn, i, n, kind) {
+               ir_node *pred = get_n(irn, i, kind);
+               edges_notify_edge_kind(irn, i, pred, NULL, kind, irg);
+       }
 }
 
-static void init_lh_walker(ir_node *irn, void *data)
-{
-       INIT_LIST_HEAD(_get_irn_outs_head(irn));
-       if(is_Block(irn))
-               INIT_LIST_HEAD(_get_block_succ_head(irn));
+/**
+ * Pre-Walker: initializes the list-heads and set the out-count
+ * of all nodes to 0.
+ */
+static void init_lh_walker(ir_node *irn, void *data) {
+       struct build_walker *w   = data;
+       ir_edge_kind_t      kind = w->kind;
+       INIT_LIST_HEAD(_get_irn_outs_head(irn, kind));
+       _get_irn_edge_info(irn, kind)->out_count = 0;
+}
+
+/**
+ * Visitor: initializes the list-heads and set the out-count
+ * of all nodes to 0 of nodes that are not seen so far.
+ */
+static void visitor(ir_node *irn, void *data) {
+       if (irn_not_visited(irn)) {
+               mark_irn_visited(irn);
+               init_lh_walker(irn, data);
+       }
 }
 
-void edges_activate(ir_graph *irg)
+/*
+ * Build the initial edge set.
+ * Beware, this is not a simple task because it suffers from two
+ * difficulties:
+ * - the anchor set allows access to Nodes that may not be reachable from
+ *   the End node
+ * - the identities add nodes to the "root set" that are not yet reachable
+ *   from End. However, after some transformations, the CSE may revival these
+ *   nodes
+ *
+ * These problems can be fixed using different strategies:
+ * - Add an age flag to every node. Whenever the edge of a node is older
+ *   then the current edge, invalidate the edges of this node.
+ *   While this would help for revivaled nodes, it increases memory and runtime.
+ * - Delete the identities set.
+ *   Solves the revival problem, but may increase the memory consumption, as
+ *   nodes cannot be revivaled at all.
+ * - Manually iterate over the identities root set. This did not consume more memory
+ *   but increase the computation time because the |identities| >= |V|
+ *
+ * Currently, we use the last option.
+ */
+void edges_activate_kind(ir_graph *irg, ir_edge_kind_t kind)
 {
-       irg_edge_info_t *info = _get_irg_edge_info(irg);
+       struct build_walker w;
+       irg_edge_info_t *info = _get_irg_edge_info(irg, kind);
+
+       w.irg  = irg;
+       w.kind = kind;
 
        info->activated = 1;
-       edges_init_graph(irg);
-       irg_walk_graph(irg, init_lh_walker, build_edges_walker, irg);
+       edges_init_graph_kind(irg, kind);
+       irg_walk_anchors(irg, init_lh_walker, build_edges_walker, &w);
+       visit_all_identities(irg, visitor, &w);
 }
 
-void edges_deactivate(ir_graph *irg)
+void edges_deactivate_kind(ir_graph *irg, ir_edge_kind_t kind)
 {
-       irg_edge_info_t *info = _get_irg_edge_info(irg);
+       irg_edge_info_t *info = _get_irg_edge_info(irg, kind);
 
        info->activated = 0;
-       if(info->edges) {
+       if (info->edges) {
                del_set(info->edges);
-    info->edges = NULL;
-  }
+               info->edges = NULL;
+       }
 }
 
-int (edges_activated)(const ir_graph *irg)
+int (edges_activated_kind)(const ir_graph *irg, ir_edge_kind_t kind)
 {
-       return _edges_activated(irg);
+       return _edges_activated_kind(irg, kind);
 }
 
 
 /**
  * Reroute all use-edges from a node to another.
  * @param from The node whose use-edges shall be withdrawn.
- * @param to The node to which all the use-edges of @p from shall be
- * sent to.
+ * @param to   The node to which all the use-edges of @p from shall be
+ *             sent to.
+ * @param irg  The graph.
  */
-void edges_reroute(ir_node *from, ir_node *to, ir_graph *irg)
+void edges_reroute_kind(ir_node *from, ir_node *to, ir_edge_kind_t kind, ir_graph *irg)
 {
-       if(edges_activated(irg)) {
-               struct list_head *head = _get_irn_outs_head(from);
+       set_edge_func_t *set_edge = edge_kind_info[kind].set_edge;
+
+       if(set_edge && edges_activated_kind(irg, kind)) {
+               struct list_head *head = _get_irn_outs_head(from, kind);
 
-               DBG((firm_dbg_register(DBG_EDGES), LEVEL_5,
-                                       "reroute from %n to %n\n", from, to));
+               DBG((dbg, LEVEL_5, "reroute from %+F to %+F\n", from, to));
 
-               while(head != head->next) {
+               while (head != head->next) {
                        ir_edge_t *edge = list_entry(head->next, ir_edge_t, list);
-                       // DBG((dbg, LEVEL_5, "\t%n %d\n", edge->src, edge->pos));
                        assert(edge->pos >= -1);
-                       set_irn_n(edge->src, edge->pos, to);
+                       set_edge(edge->src, edge->pos, to);
                }
        }
 }
 
 static void verify_set_presence(ir_node *irn, void *data)
 {
-       ir_graph *irg = data;
-       set *edges = _get_irg_edge_info(irg)->edges;
-       int not_a_block = !is_Block(irn);
+       struct build_walker *w     = data;
+       set                 *edges = _get_irg_edge_info(w->irg, w->kind)->edges;
        int i, n;
 
-       for(i = 0, n = get_irn_arity(irn) + not_a_block; i < n; ++i) {
-    ir_block_edge_t space;
-               ir_edge_t *templ = (ir_edge_t *) &space;
-               ir_edge_t *e;
-    size_t size = not_a_block ? sizeof(ir_edge_t) : sizeof(ir_block_edge_t);
+       foreach_tgt(irn, i, n, w->kind) {
+               ir_edge_t templ, *e;
 
-               templ->src = irn;
-               templ->pos = i - not_a_block;
+               templ.src = irn;
+               templ.pos = i;
 
-               e = set_find(edges, templ, size, edge_hash(templ));
-               if(e != NULL)
+               e = set_find(edges, &templ, EDGE_SIZE, edge_hash(&templ));
+               if(e != NULL) {
                        e->present = 1;
-               else
-                       DBG((dbg, LEVEL_DEFAULT, "edge %n,%d is missing\n", irn, templ->pos));
+               } else {
+                       w->problem_found = 1;
+#if 0
+                       ir_fprintf(stderr, "Edge Verifier: edge %+F,%d -> %+F (kind: \"%s\") is missing\n",
+                               irn, i, get_n(irn, i, w->kind), get_kind_str(w->kind));
+#endif
+               }
        }
 }
 
 static void verify_list_presence(ir_node *irn, void *data)
 {
-       const ir_edge_t *e;
+       struct build_walker *w = data;
+       const ir_edge_t     *e;
 
-       foreach_out_edge(irn, e) {
-               ir_node *tgt = get_irn_n(e->src, e->pos);
-               if(irn != tgt)
-                       DBG((dbg, LEVEL_DEFAULT, "edge %n,%d is no out edge of %n but of %n\n",
-                                       e->src, e->pos, irn, tgt));
-       }
+       bitset_set(w->reachable, get_irn_idx(irn));
+
+       /* check list heads */
+       vrfy_list_head(irn, w->kind);
+
+       foreach_out_edge_kind(irn, e, w->kind) {
+               ir_node *tgt;
+
+               if (w->kind == EDGE_KIND_NORMAL && get_irn_arity(e->src) <= e->pos) {
+                       w->problem_found = 1;
+#if 0
+                       ir_fprintf(stderr, "Edge Verifier: edge(%ld) %+F -> %+F recorded at src position %d, but src has arity %d\n",
+                               edge_get_id(e), e->src, irn, e->pos, get_irn_arity(e->src));
+#endif
+                       continue;
+               }
 
+               tgt = get_n(e->src, e->pos, w->kind);
+
+               if (irn != tgt) {
+                       w->problem_found = 1;
+#if 0
+                       ir_fprintf(stderr, "Edge Verifier: edge(%ld) %+F,%d (kind \"%s\") is no out edge of %+F but of %+F\n",
+                               edge_get_id(e), e->src, e->pos, get_kind_str(w->kind), irn, tgt);
+#endif
+               }
+       }
 }
 
-void edges_verify(ir_graph *irg)
+int edges_verify_kind(ir_graph *irg, ir_edge_kind_t kind)
 {
-       set *edges = _get_irg_edge_info(irg)->edges;
-       ir_edge_t *e;
+       struct build_walker w;
+       set                 *edges = _get_irg_edge_info(irg, kind)->edges;
+       ir_edge_t           *e;
+
+       w.irg           = irg;
+       w.kind          = kind;
+       w.reachable     = bitset_alloca(get_irg_last_idx(irg));
+       w.problem_found = 0;
 
        /* Clear the present bit in all edges available. */
-       for(e = set_first(edges); e; e = set_next(edges))
+       for (e = set_first(edges); e; e = set_next(edges))
                e->present = 0;
 
-       irg_walk_graph(irg, verify_set_presence, verify_list_presence, irg);
+       irg_walk_graph(irg, verify_set_presence, verify_list_presence, &w);
 
        /*
         * Dump all edges which are not invalid and not present.
         * These edges are superfluous and their presence in the
         * edge set is wrong.
         */
-       for(e = set_first(edges); e; e = set_next(edges)) {
-               if(!e->invalid && !e->present)
-                       DBG((dbg, LEVEL_DEFAULT, "edge %n,%d is superfluous\n", e->src, e->pos));
+       for (e = set_first(edges); e; e = set_next(edges)) {
+               if (! e->invalid && ! e->present && bitset_is_set(w.reachable, get_irn_idx(e->src))) {
+                       w.problem_found = 1;
+                       ir_fprintf(stderr, "Edge Verifier: edge(%ld) %+F,%d is superfluous\n", edge_get_id(e), e->src, e->pos);
+               }
        }
+
+       return w.problem_found;
 }
 
-void init_edges(void)
-{
-       dbg = firm_dbg_register(DBG_EDGES);
+#define IGNORE_NODE(irn) (is_Bad((irn)) || is_Block((irn)))
+
+/**
+ * Clear link field of all nodes.
+ */
+static void clear_links(ir_node *irn, void *env) {
+       struct build_walker *w  = env;
+       bitset_t            *bs;
+
+       if (IGNORE_NODE(irn)) {
+               set_irn_link(irn, NULL);
+               return;
+       }
+
+       bs = bitset_malloc(get_irg_last_idx(w->irg));
+       set_irn_link(irn, bs);
+}
+
+/**
+ * Increases count (stored in link field) for all operands of a node.
+ */
+static void count_user(ir_node *irn, void *env) {
+       int i;
+       int first;
+       (void) env;
+
+       first = -1;
+       for (i = get_irn_arity(irn) - 1; i >= first; --i) {
+               ir_node  *op = get_irn_n(irn, i);
+               bitset_t *bs = get_irn_link(op);
+
+               if (bs)
+                       bitset_set(bs, get_irn_idx(irn));
+       }
+}
+
+/**
+ * Verifies if collected count, number of edges in list and stored edge count are in sync.
+ */
+static void verify_edge_counter(ir_node *irn, void *env) {
+       struct build_walker    *w = env;
+       bitset_t               *bs;
+       int                    list_cnt;
+       int                    ref_cnt;
+       int                    edge_cnt;
+       unsigned long          idx;
+       const struct list_head *head;
+       const struct list_head *pos;
+
+       if (IGNORE_NODE(irn))
+               return;
+
+       bs       = get_irn_link(irn);
+       list_cnt = 0;
+       ref_cnt  = 0;
+       edge_cnt = _get_irn_edge_info(irn, EDGE_KIND_NORMAL)->out_count;
+       head     = _get_irn_outs_head(irn, EDGE_KIND_NORMAL);
+
+       /* We can iterate safely here, list heads have already been verified. */
+       list_for_each(pos, head) {
+               ++list_cnt;
+       }
+
+       /* check all nodes that reference us and count edges that point number
+        * of ins that actually point to us */
+       ref_cnt = 0;
+       bitset_foreach(bs, idx) {
+               int i, arity;
+               ir_node *src = get_idx_irn(w->irg, idx);
+
+               arity = get_irn_arity(src);
+               for (i = 0; i < arity; ++i) {
+                       ir_node *in = get_irn_n(src, i);
+                       if (in == irn)
+                               ++ref_cnt;
+               }
+       }
+
+       if (edge_cnt != list_cnt) {
+               w->problem_found = 1;
+               ir_fprintf(stderr, "Edge Verifier: edge count is %d, but %d edge(s) are recorded in list at %+F\n",
+                       edge_cnt, list_cnt, irn);
+       }
+
+       if (ref_cnt != list_cnt) {
+               w->problem_found = 1;
+               ir_fprintf(stderr, "Edge Verifier: %+F reachable by %d node(s), but the list contains %d edge(s)\n",
+                       irn, ref_cnt, list_cnt);
+
+               /* Matze: buggy if a node has multiple ins pointing at irn */
+#if 0
+               list_for_each(pos, head) {
+                       ir_edge_t *edge = list_entry(pos, ir_edge_t, list);
+                       bitset_flip(bs, get_irn_idx(edge->src));
+               }
+
+               if (ref_cnt < list_cnt)
+                       fprintf(stderr,"               following nodes are recorded in list, but not as user:\n");
+               else
+                       fprintf(stderr,"               following nodes are user, but not recorded in list:\n");
+
+               fprintf(stderr,"              ");
+               bitset_foreach(bs, idx) {
+                       ir_node *src = get_idx_irn(w->irg, idx);
+                       ir_fprintf(stderr, " %+F", src);
+               }
+               fprintf(stderr, "\n");
+#endif
+       }
+
+       bitset_free(bs);
+}
+
+/**
+ * Verifies the out edges of an irg.
+ */
+int edges_verify(ir_graph *irg) {
+       struct build_walker w;
+       int    problem_found = 0;
+
+       /* verify normal edges only */
+       problem_found  = edges_verify_kind(irg, EDGE_KIND_NORMAL);
+
+       w.irg           = irg;
+       w.kind          = EDGE_KIND_NORMAL;
+       w.problem_found = 0;
+
+       /* verify counter */
+       irg_walk_anchors(irg, clear_links, count_user, &w);
+       irg_walk_anchors(irg, NULL, verify_edge_counter, &w);
+
+       return problem_found ? 1 : w.problem_found;
+}
+
+void init_edges(void) {
+       FIRM_DBG_REGISTER(dbg, DBG_EDGES);
        /* firm_dbg_set_mask(dbg, -1); */
 }
 
+void edges_init_dbg(int do_dbg) {
+       edges_dbg = do_dbg;
+}
 
-const ir_edge_t *(get_irn_out_edge_first)(const ir_node *irn)
-{
-       return _get_irn_out_edge_first(irn);
+void edges_activate(ir_graph *irg) {
+       edges_activate_kind(irg, EDGE_KIND_NORMAL);
+       edges_activate_kind(irg, EDGE_KIND_BLOCK);
 }
 
-const ir_edge_t *(get_irn_out_edge_next)(const ir_node *irn, const ir_edge_t *last)
-{
+void edges_deactivate(ir_graph *irg) {
+       edges_deactivate_kind(irg, EDGE_KIND_NORMAL);
+       edges_deactivate_kind(irg, EDGE_KIND_BLOCK);
+}
+
+int edges_assure(ir_graph *irg) {
+       int activated = edges_activated(irg);
+
+       if (!activated)
+               edges_activate(irg);
+
+       return activated;
+}
+
+void edges_node_deleted(ir_node *irn, ir_graph *irg) {
+       edges_node_deleted_kind(irn, EDGE_KIND_NORMAL, irg);
+       edges_node_deleted_kind(irn, EDGE_KIND_BLOCK, irg);
+}
+
+
+const ir_edge_t *(get_irn_out_edge_first_kind)(const ir_node *irn, ir_edge_kind_t kind) {
+       return _get_irn_out_edge_first_kind(irn, kind);
+}
+
+const ir_edge_t *(get_irn_out_edge_next)(const ir_node *irn, const ir_edge_t *last) {
        return _get_irn_out_edge_next(irn, last);
 }
 
-ir_node *(get_edge_src_irn)(const ir_edge_t *edge)
-{
+ir_node *(get_edge_src_irn)(const ir_edge_t *edge) {
        return _get_edge_src_irn(edge);
 }
 
-int (get_edge_src_pos)(const ir_edge_t *edge)
-{
+int (get_edge_src_pos)(const ir_edge_t *edge) {
        return _get_edge_src_pos(edge);
 }
 
-int (get_irn_n_edges)(const ir_node *irn)
-{
-  return _get_irn_n_edges(irn);
+int (get_irn_n_edges_kind)(const ir_node *irn, ir_edge_kind_t kind) {
+       return _get_irn_n_edges_kind(irn, kind);
 }
 
+void dump_all_out_edges(ir_node *irn) {
+       int i;
+       for (i = 0; i < EDGE_KIND_LAST; ++i) {
+               const ir_edge_t *edge;
 
-#endif /* FIRM_EDGES_INPLACE */
+               printf("kind \"%s\"\n", get_kind_str(i));
+               foreach_out_edge_kind(irn, edge, i) {
+                       ir_printf("\t%+F(%d)\n", edge->src, edge->pos);
+               }
+       }
+}
+
+static void irg_block_edges_walk2(ir_node *bl,
+                                irg_walk_func *pre, irg_walk_func *post,
+                                void *env) {
+       const ir_edge_t *edge, *next;
+
+       if (Block_not_block_visited(bl)) {
+               mark_Block_block_visited(bl);
+
+               if (pre)
+                       pre(bl, env);
+
+               foreach_out_edge_kind_safe(bl, edge, next, EDGE_KIND_BLOCK) {
+                       /* find the corresponding successor block. */
+                       ir_node *pred = get_edge_src_irn(edge);
+                       irg_block_edges_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_block_edges_walk(ir_node *node,
+                          irg_walk_func *pre, irg_walk_func *post,
+                          void *env) {
+
+       assert(edges_activated(current_ir_graph));
+       assert(is_Block(node));
+
+       inc_irg_block_visited(current_ir_graph);
+       irg_block_edges_walk2(node, pre, post, env);
+}