[backport r172004 to fix PR48444 regression from r171622 <mikpe@it.uu.se>]

gcc/

2011-04-05  Jeff Law  <law@redhat.com>

	* tree-ssa-threadupdate.c (determine_bb_domination_status): Always
	check if BB is a successor of LOOP->header and return
	NONDOMINATING if it is not, regardless of ENABLE_CHECKING.

--- gcc-4.7-20110402/gcc/tree-ssa-threadupdate.c.~1~	2011-03-30 00:49:00.000000000 +0200
+++ gcc-4.7-20110402/gcc/tree-ssa-threadupdate.c	2011-04-19 20:55:59.000000000 +0200
@@ -665,7 +665,6 @@ determine_bb_domination_status (struct l
   edge_iterator ei;
   edge e;
 
-#ifdef ENABLE_CHECKING
   /* This function assumes BB is a successor of LOOP->header.
      If that is not the case return DOMST_NONDOMINATING which
      is always safe.  */
@@ -684,7 +683,6 @@ determine_bb_domination_status (struct l
       if (!ok)
 	return DOMST_NONDOMINATING;
     }
-#endif
 
   if (bb == loop->latch)
     return DOMST_DOMINATING;