dbgcnt.def (dom_unreachable_edges): New debug counter.

	* dbgcnt.def (dom_unreachable_edges): New debug counter.
	* tree-ssa-dom.c: Include dbgcnt.h
	(dom_opt_dom_walker::before_dom_children): Handle the new counter.

From-SVN: r231896

gcc/ChangeLog

+2015-12-21  Jeff Law  <law@redhat.com>
+
+	* dbgcnt.def (dom_unreachable_edges): New debug counter.
+	* tree-ssa-dom.c: Include dbgcnt.h
+	(dom_opt_dom_walker::before_dom_children): Handle the new counter.
+
 2015-12-21  Andrew Pinski <apinski@cavium.com>
 
 	* config/aarch64/aarch64-option-extensions.def (LSE): Change

gcc/dbgcnt.def

@@ -192,3 +192,4 @@ DEBUG_COUNTER (treepre_insert)
 DEBUG_COUNTER (tree_sra)
 DEBUG_COUNTER (vect_loop)
 DEBUG_COUNTER (vect_slp)
+DEBUG_COUNTER (dom_unreachable_edges)

gcc/tree-ssa-dom.c

@@ -44,6 +44,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "tree-ssa-dom.h"
 #include "gimplify.h"
 #include "tree-cfgcleanup.h"
+#include "dbgcnt.h"
 
 /* This file implements optimizations on the dominator tree.  */
 
@@ -1369,6 +1370,9 @@ dom_opt_dom_walker::before_dom_children (basic_block bb)
   /* Now prepare to process dominated blocks.  */
   record_edge_info (bb);
   cprop_into_successor_phis (bb, m_const_and_copies);
+  if (taken_edge && !dbg_cnt (dom_unreachable_edges))
+    return NULL;
+
   return taken_edge;
 }