tree-vrp.c (finalize_jump_threads): Do not care about dominance info.

	* tree-vrp.c (finalize_jump_threads): Do not care about dominance info.
	(execute_vrp): Preserve loops through jump threading.
	* tree-ssa-threadupdate.c (thread_single_edge,
	dbds_continue_enumeration_p, determine_bb_domination_status,
	thread_through_loop_header): New functions.
	(create_edge_and_update_destination_phis,
	create_edge_and_update_destination_phis): Set loops for the new blocks.
	(prune_undesirable_thread_requests): Removed.
	(redirect_edges): Do not pretend that redirect_edge_and_branch can
	create new blocks.
	(thread_block): Do not call prune_undesirable_thread_requests.
	Update loops.
	(mark_threaded_blocks): Select edges to thread here.
	(thread_through_all_blocks): Take may_peel_loop_headers argument.
	Thread edges through loop headers independently.
	* cfgloopmanip.c (create_preheader, mfb_keep_just): Export.
	* tree-pass.h (TODO_mark_first_instance): New.
	(first_pass_instance): Declare.
	* cfghooks.c (duplicate_block): Put the block to the original loop
	if copy is not specified.
	* tree-ssa-dom.c (tree_ssa_dominator_optimize): Preserve loops through
	jump threading.  Pass may_peel_loop_headers to
	thread_through_all_blocks according to first_pass_instance.
	* cfgloop.h (create_preheader): Declare.
	* tree-flow.h (thread_through_all_blocks): Declaration changed.
	* basic-block.h (mfb_keep_just, mfb_kj_edge): Declare.
	* passes.c (first_pass_instance): New variable.
	(next_pass_1): Set TODO_mark_first_instance.
	(execute_todo): Set first_pass_instance.

	* gcc.dg/tree-ssa/ssa-dom-thread-2.c: New test.
	* gcc.dg/vect/vect-102.c, gcc.dg/vect/vect-103.c,
	gcc.dg/vect/vect-104.c: Use more complex construction to prevent vectorizing.
	* gcc.dg/tree-ssa/pr21559.c: Update outcome.

From-SVN: r124786

1 files changed, 14 insertions, 17 deletions

diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index a9141d7..5f42ff6 100644
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -5865,13 +5865,7 @@ identify_jump_threads (void)
 static void
 finalize_jump_threads (void)
 {
-  bool cfg_altered = false;
-  cfg_altered = thread_through_all_blocks ();
-
-  /* If we threaded jumps, then we need to recompute the dominance
-     information.  */
-  if (cfg_altered)
-    free_dominance_info (CDI_DOMINATORS);
+  thread_through_all_blocks (false);
   VEC_free (tree, heap, stack);
 }
 
@@ -5990,22 +5984,19 @@ vrp_finalize (void)
 static unsigned int
 execute_vrp (void)
 {
-  insert_range_assertions ();
-
-  loop_optimizer_init (LOOPS_NORMAL);
+  loop_optimizer_init (LOOPS_NORMAL | LOOPS_HAVE_RECORDED_EXITS);
   if (current_loops)
-    scev_initialize ();
+    {
+      rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa);
+      scev_initialize ();
+    }
+
+  insert_range_assertions ();
 
   vrp_initialize ();
   ssa_propagate (vrp_visit_stmt, vrp_visit_phi_node);
   vrp_finalize ();
 
-  if (current_loops)
-    {
-      scev_finalize ();
-      loop_optimizer_finalize ();
-    }
-
   /* ASSERT_EXPRs must be removed before finalizing jump threads
      as finalizing jump threads calls the CFG cleanup code which
      does not properly handle ASSERT_EXPRs.  */
@@ -6019,6 +6010,12 @@ execute_vrp (void)
   update_ssa (TODO_update_ssa);
 
   finalize_jump_threads ();
+  if (current_loops)
+    {
+      scev_finalize ();
+      loop_optimizer_finalize ();
+    }
+
   return 0;
 }