Release cgraph_{node,edge} via ggc_free (PR ipa/89330).

2019-07-28  Martin Liska  <mliska@suse.cz>

	PR ipa/89330
	* cgraph.c (symbol_table::create_edge): Always allocate
	a cgraph_edge.
	(symbol_table::free_edge): Store summary_id to
	edge_released_summary_ids if != -1;
	* cgraph.h (NEXT_FREE_NODE): Remove.
	(SET_NEXT_FREE_NODE): Likewise.
	(NEXT_FREE_EDGE): Likewise.
	(symbol_table::release_symbol): Store summary_id to
	cgraph_released_summary_ids if != -1;
	(symbol_table::allocate_cgraph_symbol): Always allocate
	a cgraph_node.

From-SVN: r273857

gcc/ChangeLog

@@ -1,3 +1,18 @@
+2019-07-28  Martin Liska  <mliska@suse.cz>
+
+	PR ipa/89330
+	* cgraph.c (symbol_table::create_edge): Always allocate
+	a cgraph_edge.
+	(symbol_table::free_edge): Store summary_id to
+	edge_released_summary_ids if != -1;
+	* cgraph.h (NEXT_FREE_NODE): Remove.
+	(SET_NEXT_FREE_NODE): Likewise.
+	(NEXT_FREE_EDGE): Likewise.
+	(symbol_table::release_symbol): Store summary_id to
+	cgraph_released_summary_ids if != -1;
+	(symbol_table::allocate_cgraph_symbol): Always allocate
+	a cgraph_node.
+
 2019-07-28  Alan Modra  <amodra@gmail.com>
 
 	* gcc/config/rs6000/rs6000-call.c (rs6000_output_mi_thunk): Use

gcc/cgraph.c

@@ -846,17 +846,8 @@ symbol_table::create_edge (cgraph_node *caller, cgraph_node *callee,
       gcc_assert (is_gimple_call (call_stmt));
     }
 
-  if (free_edges)
-    {
-      edge = free_edges;
-      free_edges = NEXT_FREE_EDGE (edge);
-    }
-  else
-    {
-      edge = ggc_alloc<cgraph_edge> ();
-      edge->m_summary_id = -1;
-    }
-
+  edge = ggc_alloc<cgraph_edge> ();
+  edge->m_summary_id = -1;
   edges_count++;
 
   gcc_assert (++edges_max_uid != 0);
@@ -1013,16 +1004,13 @@ cgraph_edge::remove_caller (void)
 void
 symbol_table::free_edge (cgraph_edge *e)
 {
+  edges_count--;
+  if (e->m_summary_id != -1)
+    edge_released_summary_ids.safe_push (e->m_summary_id);
+
   if (e->indirect_info)
     ggc_free (e->indirect_info);
-
-  /* Clear out the edge so we do not dangle pointers.  */
-  int summary_id = e->m_summary_id;
-  memset (e, 0, sizeof (*e));
-  e->m_summary_id = summary_id;
-  NEXT_FREE_EDGE (e) = free_edges;
-  free_edges = e;
-  edges_count--;
+  ggc_free (e);
 }
 
 /* Remove the edge in the cgraph.  */

gcc/cgraph.h

@@ -2027,12 +2027,6 @@ is_a_helper <varpool_node *>::test (symtab_node *p)
   return p && p->type == SYMTAB_VARIABLE;
 }
 
-/* Macros to access the next item in the list of free cgraph nodes and
-   edges. */
-#define NEXT_FREE_NODE(NODE) dyn_cast<cgraph_node *> ((NODE)->next)
-#define SET_NEXT_FREE_NODE(NODE,NODE2) ((NODE))->next = NODE2
-#define NEXT_FREE_EDGE(EDGE) (EDGE)->prev_caller
-
 typedef void (*cgraph_edge_hook)(cgraph_edge *, void *);
 typedef void (*cgraph_node_hook)(cgraph_node *, void *);
 typedef void (*varpool_node_hook)(varpool_node *, void *);
@@ -2088,7 +2082,8 @@ public:
   friend struct cgraph_edge;
 
   symbol_table (): cgraph_max_uid (1), cgraph_max_summary_id (0),
-  edges_max_uid (1), edges_max_summary_id (0)
+  edges_max_uid (1), edges_max_summary_id (0),
+  cgraph_released_summary_ids (), edge_released_summary_ids ()
   {
   }
 
@@ -2297,14 +2292,22 @@ public:
   /* Assign a new summary ID for the callgraph NODE.  */
   inline int assign_summary_id (cgraph_node *node)
   {
-    node->m_summary_id = cgraph_max_summary_id++;
+    if (!cgraph_released_summary_ids.is_empty ())
+      node->m_summary_id = cgraph_released_summary_ids.pop ();
+    else
+      node->m_summary_id = cgraph_max_summary_id++;
+
     return node->m_summary_id;
   }
 
   /* Assign a new summary ID for the callgraph EDGE.  */
   inline int assign_summary_id (cgraph_edge *edge)
   {
-    edge->m_summary_id = edges_max_summary_id++;
+    if (!edge_released_summary_ids.is_empty ())
+      edge->m_summary_id = edge_released_summary_ids.pop ();
+    else
+      edge->m_summary_id = edges_max_summary_id++;
+
     return edge->m_summary_id;
   }
 
@@ -2320,14 +2323,15 @@ public:
   int edges_max_uid;
   int edges_max_summary_id;
 
+  /* Vector of released summary IDS for cgraph nodes.  */
+  vec<int> GTY ((skip)) cgraph_released_summary_ids;
+
+  /* Vector of released summary IDS for cgraph nodes.  */
+  vec<int> GTY ((skip)) edge_released_summary_ids;
+
   symtab_node* GTY(()) nodes;
   asm_node* GTY(()) asmnodes;
   asm_node* GTY(()) asm_last_node;
-  cgraph_node* GTY(()) free_nodes;
-
-  /* Head of a linked list of unused (freed) call graph edges.
-     Do not GTY((delete)) this list so UIDs gets reliably recycled.  */
-  cgraph_edge * GTY(()) free_edges;
 
   /* The order index of the next symtab node to be created.  This is
      used so that we can sort the cgraph nodes in order by when we saw
@@ -2687,15 +2691,9 @@ inline void
 symbol_table::release_symbol (cgraph_node *node)
 {
   cgraph_count--;
-
-  /* Clear out the node to NULL all pointers and add the node to the free
-     list.  */
-  int summary_id = node->m_summary_id;
-  memset (node, 0, sizeof (*node));
-  node->type = SYMTAB_FUNCTION;
-  node->m_summary_id = summary_id;
-  SET_NEXT_FREE_NODE (node, free_nodes);
-  free_nodes = node;
+  if (node->m_summary_id != -1)
+    cgraph_released_summary_ids.safe_push (node->m_summary_id);
+  ggc_free (node);
 }
 
 /* Allocate new callgraph node.  */
@@ -2705,17 +2703,9 @@ symbol_table::allocate_cgraph_symbol (void)
 {
   cgraph_node *node;
 
-  if (free_nodes)
-    {
-      node = free_nodes;
-      free_nodes = NEXT_FREE_NODE (node);
-    }
-  else
-    {
-      node = ggc_cleared_alloc<cgraph_node> ();
-      node->m_summary_id = -1;
-    }
-
+  node = ggc_cleared_alloc<cgraph_node> ();
+  node->type = SYMTAB_FUNCTION;
+  node->m_summary_id = -1;
   node->m_uid = cgraph_max_uid++;
   return node;
 }