re PR c++/12850 (memory consumption for heavy template instantiations tripled since 3.3)

	PR c++/12850
	* cgraph.c (cgraph_remove_node): Clear out saved/insns/arguments and
	initial pointers.
	* cgraphunit.c (cgraph_finalize_function): Clear out DECL_SAVED_INSNS
	for functions that will be only inlined.
	(cgraph_mark_function_to_output): Likewise.
	(cgraph_expand_function): Sanity check that DECL_DEFER_OUTPUT is clear;
	do not clear function body.
	* tree-optimize.c (clear_decl_rtl): Use decl_function_context.
	(tree_rest_of_compilation): Reorganize the logic releasing function
	body to use callgraph datastructure.

From-SVN: r76822

1 files changed, 9 insertions, 2 deletions

diff --git a/gcc/cgraphunit.c b/gcc/cgraphunit.c
index 3a7dcb3..f68bd2a 100644
--- a/gcc/cgraphunit.c
+++ b/gcc/cgraphunit.c
@@ -228,6 +228,11 @@ cgraph_finalize_function (tree decl, bool nested)
   /* If we've not yet emitted decl, tell the debug info about it.  */
   if (!TREE_ASM_WRITTEN (decl))
     (*debug_hooks->deferred_inline_function) (decl);
+
+  /* We will never really output the function body, clear the SAVED_INSNS array
+     early then.  */
+  if (DECL_EXTERNAL (decl))
+    DECL_SAVED_INSNS (decl) = NULL;
 }
 
 /* Walk tree and record all calls.  Called via walk_tree.  */
@@ -476,6 +481,8 @@ cgraph_mark_functions_to_output (void)
 	  && !TREE_ASM_WRITTEN (decl) && !node->origin
 	  && !DECL_EXTERNAL (decl))
 	node->output = 1;
+      else
+        DECL_SAVED_INSNS (decl) = NULL;
     }
 }
 
@@ -525,9 +532,9 @@ cgraph_expand_function (struct cgraph_node *node)
   /* Generate RTL for the body of DECL.  Nested functions are expanded
      via lang_expand_decl_stmt.  */
   (*lang_hooks.callgraph.expand_function) (decl);
+  if (DECL_DEFER_OUTPUT (decl))
+    abort ();
 
-  if (!cgraph_function_possibly_inlined_p (decl))
-    DECL_SAVED_TREE (decl) = NULL;
   current_function_decl = NULL;
 }