cgraph.h (struct cgraph_edge): Add prev_caller and prev_callee fields.

2005-03-02  Richard Guenther  <rguenth@gcc.gnu.org>

	* cgraph.h (struct cgraph_edge): Add prev_caller and
	prev_callee fields.
	(cgraph_node_remove_callees): Export.
	* cgraph.c (cgraph_create_edge): Initialize prev_caller
	and prev_callee.
	(cgraph_edge_remove_callee): New function.
	(cgraph_edge_remove_caller): Likewise.
	(cgraph_remove_edge): Use.
	(cgraph_redirect_edge_callee): Likewise.
	(cgraph_node_remove_callees): New function.
	(cgraph_node_remove_callers): Likewise.
	(cgraph_remove_node): Use.
	* tree-optimize.c (tree_rest_of_compilation): Use
	cgraph_node_remove_callees instead of manual loop.
	* cgraphunit.c (cgraph_finalize_function): Likewise.
	(cgraph_expand_function): Likewise.
	(cgraph_remove_unreachable_nodes): Likewise.

From-SVN: r95777

5 files changed, 109 insertions, 34 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 46f4c11..12e9086 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,23 @@
+2005-03-02  Richard Guenther  <rguenth@gcc.gnu.org>
+
+	* cgraph.h (struct cgraph_edge): Add prev_caller and
+	prev_callee fields.
+	(cgraph_node_remove_callees): Export.
+	* cgraph.c (cgraph_create_edge): Initialize prev_caller
+	and prev_callee.
+	(cgraph_edge_remove_callee): New function.
+	(cgraph_edge_remove_caller): Likewise.
+	(cgraph_remove_edge): Use.
+	(cgraph_redirect_edge_callee): Likewise.
+	(cgraph_node_remove_callees): New function.
+	(cgraph_node_remove_callers): Likewise.
+	(cgraph_remove_node): Use.
+	* tree-optimize.c (tree_rest_of_compilation): Use
+	cgraph_node_remove_callees instead of manual loop.
+	* cgraphunit.c (cgraph_finalize_function): Likewise.
+	(cgraph_expand_function): Likewise.
+	(cgraph_remove_unreachable_nodes): Likewise.
+
 2005-03-02  Joseph S. Myers  <joseph@codesourcery.com>
 
 	PR c/8927
diff --git a/gcc/cgraph.c b/gcc/cgraph.c
index 7d1cca2..11953b4 100644
--- a/gcc/cgraph.c
+++ b/gcc/cgraph.c
@@ -96,6 +96,10 @@ The varpool data structure:
 #include "output.h"
 #include "intl.h"
 
+static void cgraph_node_remove_callers (struct cgraph_node *node);
+static inline void cgraph_edge_remove_caller (struct cgraph_edge *e);
+static inline void cgraph_edge_remove_callee (struct cgraph_edge *e);
+
 /* Hash table used to convert declarations into nodes.  */
 static GTY((param_is (struct cgraph_node))) htab_t cgraph_hash;
 
@@ -289,30 +293,55 @@ cgraph_create_edge (struct cgraph_node *caller, struct cgraph_node *callee,
   edge->caller = caller;
   edge->callee = callee;
   edge->call_expr = call_expr;
+  edge->prev_caller = NULL;
   edge->next_caller = callee->callers;
+  if (callee->callers)
+    callee->callers->prev_caller = edge;
+  edge->prev_callee = NULL;
   edge->next_callee = caller->callees;
+  if (caller->callees)
+    caller->callees->prev_callee = edge;
   caller->callees = edge;
   callee->callers = edge;
   return edge;
 }
 
-/* Remove the edge E the cgraph.  */
+/* Remove the edge E from the list of the callers of the callee.  */
+
+static inline void
+cgraph_edge_remove_callee (struct cgraph_edge *e)
+{
+  if (e->prev_caller)
+    e->prev_caller->next_caller = e->next_caller;
+  if (e->next_caller)
+    e->next_caller->prev_caller = e->prev_caller;
+  if (!e->prev_caller)
+    e->callee->callers = e->next_caller;
+}
+
+/* Remove the edge E from the list of the callees of the caller.  */
+
+static inline void
+cgraph_edge_remove_caller (struct cgraph_edge *e)
+{
+  if (e->prev_callee)
+    e->prev_callee->next_callee = e->next_callee;
+  if (e->next_callee)
+    e->next_callee->prev_callee = e->prev_callee;
+  if (!e->prev_callee)
+    e->caller->callees = e->next_callee;
+}
+
+/* Remove the edge E in the cgraph.  */
 
 void
 cgraph_remove_edge (struct cgraph_edge *e)
 {
-  struct cgraph_edge **edge, **edge2;
+  /* Remove from callers list of the callee.  */
+  cgraph_edge_remove_callee (e);
 
-  for (edge = &e->callee->callers; *edge && *edge != e;
-       edge = &((*edge)->next_caller))
-    continue;
-  gcc_assert (*edge);
-  *edge = (*edge)->next_caller;
-  for (edge2 = &e->caller->callees; *edge2 && *edge2 != e;
-       edge2 = &(*edge2)->next_callee)
-    continue;
-  gcc_assert (*edge2);
-  *edge2 = (*edge2)->next_callee;
+  /* Remove from callees list of the callers.  */
+  cgraph_edge_remove_caller (e);
 }
 
 /* Redirect callee of E to N.  The function does not update underlying
@@ -321,16 +350,46 @@ cgraph_remove_edge (struct cgraph_edge *e)
 void
 cgraph_redirect_edge_callee (struct cgraph_edge *e, struct cgraph_node *n)
 {
-  struct cgraph_edge **edge;
+  /* Remove from callers list of the current callee.  */
+  cgraph_edge_remove_callee (e);
 
-  for (edge = &e->callee->callers; *edge && *edge != e;
-       edge = &((*edge)->next_caller))
-    continue;
-  gcc_assert (*edge);
-  *edge = (*edge)->next_caller;
-  e->callee = n;
+  /* Insert to callers list of the new callee.  */
+  e->prev_caller = NULL;
+  if (n->callers)
+    n->callers->prev_caller = e;
   e->next_caller = n->callers;
   n->callers = e;
+  e->callee = n;
+}
+
+/* Remove all callees from the node.  */
+
+void
+cgraph_node_remove_callees (struct cgraph_node *node)
+{
+  struct cgraph_edge *e;
+
+  /* It is sufficient to remove the edges from the lists of callers of
+     the callees.  The callee list of the node can be zapped with one
+     assignment.  */
+  for (e = node->callees; e; e = e->next_callee)
+    cgraph_edge_remove_callee (e);
+  node->callees = NULL;
+}
+
+/* Remove all callers from the node.  */
+
+static void
+cgraph_node_remove_callers (struct cgraph_node *node)
+{
+  struct cgraph_edge *e;
+
+  /* It is sufficient to remove the edges from the lists of callees of
+     the callers.  The caller list of the node can be zapped with one
+     assignment.  */
+  for (e = node->callers; e; e = e->next_caller)
+    cgraph_edge_remove_caller (e);
+  node->callers = NULL;
 }
 
 /* Remove the node from cgraph.  */
@@ -341,10 +400,8 @@ cgraph_remove_node (struct cgraph_node *node)
   void **slot;
   bool check_dead = 1;
 
-  while (node->callers)
-    cgraph_remove_edge (node->callers);
-  while (node->callees)
-    cgraph_remove_edge (node->callees);
+  cgraph_node_remove_callers (node);
+  cgraph_node_remove_callees (node);
   while (node->nested)
     cgraph_remove_node (node->nested);
   if (node->origin)
diff --git a/gcc/cgraph.h b/gcc/cgraph.h
index ae902b2..b596a36 100644
--- a/gcc/cgraph.h
+++ b/gcc/cgraph.h
@@ -119,11 +119,13 @@ struct cgraph_node GTY((chain_next ("%h.next"), chain_prev ("%h.previous")))
   bool output;
 };
 
-struct cgraph_edge GTY((chain_next ("%h.next_caller")))
+struct cgraph_edge GTY((chain_next ("%h.next_caller"), chain_prev ("%h.prev_caller")))
 {
   struct cgraph_node *caller;
   struct cgraph_node *callee;
+  struct cgraph_edge *prev_caller;
   struct cgraph_edge *next_caller;
+  struct cgraph_edge *prev_callee;
   struct cgraph_edge *next_callee;
   tree call_expr;
   PTR GTY ((skip (""))) aux;
@@ -165,6 +167,7 @@ void dump_cgraph (FILE *);
 void dump_cgraph_node (FILE *, struct cgraph_node *);
 void cgraph_remove_edge (struct cgraph_edge *);
 void cgraph_remove_node (struct cgraph_node *);
+void cgraph_node_remove_callees (struct cgraph_node *node);
 struct cgraph_edge *cgraph_create_edge (struct cgraph_node *,
 					struct cgraph_node *,
 				        tree);
diff --git a/gcc/cgraphunit.c b/gcc/cgraphunit.c
index 3df79a4..1effef6 100644
--- a/gcc/cgraphunit.c
+++ b/gcc/cgraphunit.c
@@ -356,8 +356,7 @@ cgraph_finalize_function (tree decl, bool nested)
 	      cgraph_remove_node (n);
 	}
 
-      while (node->callees)
-	cgraph_remove_edge (node->callees);
+      cgraph_node_remove_callees (node);
 
       /* We may need to re-queue the node for assembling in case
          we already proceeded it and ignored as not needed.  */
@@ -843,8 +842,7 @@ cgraph_expand_function (struct cgraph_node *node)
       DECL_INITIAL (node->decl) = error_mark_node;
       /* Eliminate all call edges.  This is important so the call_expr no longer
 	 points to the dead function body.  */
-      while (node->callees)
-	cgraph_remove_edge (node->callees);
+      cgraph_node_remove_callees (node);
     }
 }
 
@@ -1006,8 +1004,7 @@ cgraph_remove_unreachable_nodes (void)
 		      DECL_STRUCT_FUNCTION (node->decl) = NULL;
 		      DECL_INITIAL (node->decl) = error_mark_node;
 		    }
-		  while (node->callees)
-		    cgraph_remove_edge (node->callees);
+		  cgraph_node_remove_callees (node);
 		  node->analyzed = false;
 		}
 	      else
diff --git a/gcc/tree-optimize.c b/gcc/tree-optimize.c
index f934c99..78d4ce5 100644
--- a/gcc/tree-optimize.c
+++ b/gcc/tree-optimize.c
@@ -656,8 +656,7 @@ tree_rest_of_compilation (tree fndecl)
 
   /* We are not going to maintain the cgraph edges up to date.
      Kill it so it won't confuse us.  */
-  while (node->callees)
-    cgraph_remove_edge (node->callees);
+  cgraph_node_remove_callees (node);
 
 
   /* Initialize the default bitmap obstack.  */
@@ -688,8 +687,7 @@ tree_rest_of_compilation (tree fndecl)
 	{
 	  struct cgraph_edge *e;
 
-	  while (node->callees)
-	    cgraph_remove_edge (node->callees);
+	  cgraph_node_remove_callees (node);
 	  node->callees = saved_node->callees;
 	  saved_node->callees = NULL;
 	  update_inlined_to_pointers (node, node);