re PR c/56113 (out of memory when compiling a function with many goto labels (50k > ))

	PR middle-end/56113
	* fwprop.c (fwprop_init): Set up loops without CFG modifications.

From-SVN: r195632

gcc/ChangeLog

+2013-01-31  Steven Bosscher  <steven@gcc.gnu.org>
+
+	PR middle-end/56113
+	* fwprop.c (fwprop_init): Set up loops without CFG modifications.
+
 2013-01-31  Hiroyuki Ono  <hiroyuki.ono.jc@renesas.com>
 	    Nick Clifton  <nickc@redhat.com>
 

gcc/fwprop.c

@@ -1404,10 +1404,10 @@ fwprop_init (void)
   calculate_dominance_info (CDI_DOMINATORS);
 
   /* We do not always want to propagate into loops, so we have to find
-     loops and be careful about them.  But we have to call flow_loops_find
-     before df_analyze, because flow_loops_find may introduce new jump
-     insns (sadly) if we are not working in cfglayout mode.  */
-  loop_optimizer_init (0);
+     loops and be careful about them.  Avoid CFG modifications so that
+     we don't have to update dominance information afterwards for
+     build_single_def_use_links.  */
+  loop_optimizer_init (AVOID_CFG_MODIFICATIONS);
 
   build_single_def_use_links ();
   df_set_flags (DF_DEFER_INSN_RESCAN);