commit 992d281b2d1ba53a49198db44fee92a505e16f5d
Author: Jeff Law <law@tor.usersys.redhat.com>
Date:   Fri Oct 2 15:22:04 2015 -0400

    Re: [PATCH] Improve DOM's optimization of control statements
    
    	* tree-ssa-dom.c (optimize_stmt): Note when loop structures need
    	fixups.

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 3f7561a..e541df3 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2015-10-02  Jeff Law  <law@redhat.com>
+
+	* tree-ssa-dom.c (optimize_stmt): Note when loop structures need
+	fixups.
+
 2015-10-02  Uros Bizjak  <ubizjak@gmail.com>
 
 	* system.h (ROUND_UP): New macro definition.
diff --git a/gcc/tree-ssa-dom.c b/gcc/tree-ssa-dom.c
index a8b7038..d940816 100644
--- a/gcc/tree-ssa-dom.c
+++ b/gcc/tree-ssa-dom.c
@@ -1843,6 +1843,12 @@ optimize_stmt (basic_block bb, gimple_stmt_iterator si,
 	      /* Delete threads that start at BB.  */
 	      remove_jump_threads_starting_at (bb);
 
+	      /* If BB is in a loop, then removing an outgoing edge from BB
+		 may cause BB to move outside the loop, changes in the
+		 loop exit edges, etc.  So note that loops need fixing.  */
+	      if (bb_loop_depth (bb) > 0)
+		loops_state_set (LOOPS_NEED_FIXUP);
+
 	      /* Now clean up the control statement at the end of
 		 BB and remove unexecutable edges.  */
 	      remove_ctrl_stmt_and_useless_edges (bb, taken_edge->dest);