* 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.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@124786 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 8 insertions, 2 deletions

diff --git a/gcc/cfghooks.c b/gcc/cfghooks.c
index f1103c15685..7f544c3ee3c 100644
--- a/gcc/cfghooks.c
+++ b/gcc/cfghooks.c
@@ -923,9 +923,15 @@ duplicate_block (basic_block bb, edge e, basic_block after)
   set_bb_original (new_bb, bb);
   set_bb_copy (bb, new_bb);
 
-  /* Add the new block to the prescribed loop.  */
+  /* Add the new block to the copy of the loop of BB, or directly to the loop
+     of BB if the loop is not being copied.  */
   if (current_loops != NULL)
-    add_bb_to_loop (new_bb, bb->loop_father->copy);
+    {
+      struct loop *cloop = bb->loop_father;
+      if (cloop->copy)
+	cloop = cloop->copy;
+      add_bb_to_loop (new_bb, cloop);
+    }
 
   return new_bb;
 }