tree-ssa-threadbackward.c (pass_data_thread_jumps): Remove unconditional TODO_cleanup_cfg.

2016-08-11  Richard Biener  <rguenther@suse.de>

	* tree-ssa-threadbackward.c (pass_data_thread_jumps): Remove
	unconditional TODO_cleanup_cfg.
	(pass_thread_jumps::execute): Initialize loops, perform a CFG
	cleanup only if we threaded a jump.

	* gcc.dg/tree-ssa/ssa-dom-thread-7.c: Adjust.

From-SVN: r239355

gcc/ChangeLog

+2016-08-11  Richard Biener  <rguenther@suse.de>
+
+	* tree-ssa-threadbackward.c (pass_data_thread_jumps): Remove
+	unconditional TODO_cleanup_cfg.
+	(pass_thread_jumps::execute): Initialize loops, perform a CFG
+	cleanup only if we threaded a jump.
+
 2016-08-11  Alan Modra  <amodra@gmail.com>
 
 	PR target/71680

gcc/testsuite/ChangeLog

+2016-08-11  Richard Biener  <rguenther@suse.de>
+
+	* gcc.dg/tree-ssa/ssa-dom-thread-7.c: Adjust.
+
 2016-08-11  Alan Modra  <amodra@gmail.com>
 
 	* gcc.target/powerpc/pr71680.c: New.

gcc/testsuite/gcc.dg/tree-ssa/ssa-dom-thread-7.c

 /* { dg-do compile } */
-/* { dg-options "-O2 -fdump-tree-thread1-stats -fdump-tree-thread2-stats -fdump-tree-thread3-stats -fdump-tree-dom3-stats -fdump-tree-vrp2-stats -fno-guess-branch-probability" } */
+/* { dg-options "-O2 -fdump-tree-thread1-stats -fdump-tree-thread2-stats -fdump-tree-dom2-stats -fdump-tree-thread3-stats -fdump-tree-dom3-stats -fdump-tree-vrp2-stats -fno-guess-branch-probability" } */
 /* { dg-final { scan-tree-dump "Jumps threaded: 16"  "thread1" } } */
-/* { dg-final { scan-tree-dump "Jumps threaded: 6" "thread2" } } */
+/* { dg-final { scan-tree-dump "Jumps threaded: 9" "thread2" } } */
 /* { dg-final { scan-tree-dump "Jumps threaded: 3" "thread3" } } */
+/* { dg-final { scan-tree-dump-not "Jumps threaded"  "dom2" } } */
 /* { dg-final { scan-tree-dump-not "Jumps threaded"  "dom3" } } */
 /* { dg-final { scan-tree-dump-not "Jumps threaded"  "vrp2" } } */
 

gcc/tree-ssa-threadbackward.c

@@ -674,7 +674,7 @@ const pass_data pass_data_thread_jumps =
   0,
   0,
   0,
-  ( TODO_cleanup_cfg | TODO_update_ssa ),
+  TODO_update_ssa,
 };
 
 class pass_thread_jumps : public gimple_opt_pass
@@ -699,6 +699,8 @@ pass_thread_jumps::gate (function *fun ATTRIBUTE_UNUSED)
 unsigned int
 pass_thread_jumps::execute (function *fun)
 {
+  loop_optimizer_init (LOOPS_HAVE_PREHEADERS | LOOPS_HAVE_SIMPLE_LATCHES);
+
   /* Try to thread each block with more than one successor.  */
   basic_block bb;
   FOR_EACH_BB_FN (bb, fun)
@@ -706,8 +708,10 @@ pass_thread_jumps::execute (function *fun)
       if (EDGE_COUNT (bb->succs) > 1)
 	find_jump_threads_backwards (bb);
     }
-  thread_through_all_blocks (true);
-  return 0;
+  bool changed = thread_through_all_blocks (true);
+
+  loop_optimizer_finalize ();
+  return changed ? TODO_cleanup_cfg : 0;
 }
 
 }