tree-ssanames.c (release_dead_ssa_names): Instead of ggc_freeing the names...

	* tree-ssanames.c (release_dead_ssa_names): Instead of ggc_freeing
	the names, just unlink the chain so we don't crash on dangling pointers
	to dead SSA names.

From-SVN: r120837

gcc/ChangeLog

 2007-01-16  Jan Hubicka  <jh@suse.cz>
 
+	* tree-ssanames.c (release_dead_ssa_names): Instead of ggc_freeing
+	the names, just unlink the chain so we don't crash on dangling pointers
+	to dead SSA names.
+
+2007-01-16  Jan Hubicka  <jh@suse.cz>
+
 	* cgraph.h (cgraph_decide_inlining_incrementally): Kill.
 	* tree-pass.h: Reorder to make IPA passes appear toegher.
 	(pass_early_inline, pass_inline_parameters, pass_apply_inline): Declare.

gcc/tree-ssanames.c

@@ -325,7 +325,12 @@ release_dead_ssa_names (void)
   for (t = FREE_SSANAMES (cfun); t; t = next)
     {
       next = TREE_CHAIN (t);
-      ggc_free (t);
+      /* Dangling pointers might make GGC to still see dead SSA names, so it is
+ 	 important to unlink the list and avoid GGC from seeing all subsequent
+	 SSA names.  In longer run we want to have all dangling pointers here
+	 removed (since they usually go trhough dead statements that consume
+	 considerable amounts of memory).  */
+      TREE_CHAIN (t) = NULL_TREE;
       n++;
     }
   FREE_SSANAMES (cfun) = NULL;