2009-04-04 Richard Guenther <rguenther@suse.de>

	* Makefile.in (tree-ssa-copy.o): Add $(CFGLOOP_H) dependency.
	* tree-ssa-copy.c (init_copy_prop): Do not propagate through
	single-argument PHIs if we are in loop-closed SSA form.
	* tree-vect-loop-manip.c (slpeel_add_loop_guard): Pass extra guards
	for the pre-condition.
	(slpeel_tree_peel_loop_to_edge): Likewise.
	(vect_build_loop_niters): Take an optional sequence to append stmts.
	(vect_generate_tmps_on_preheader): Likewise.
	(vect_do_peeling_for_loop_bound): Take extra guards for the
	pre-condition.
	(vect_do_peeling_for_alignment): Adjust.  Unconditionally apply
	the cost model check.
	(vect_loop_versioning): Take stmt and stmt list to put pre-condition
	guards if we are going to peel.  Do not apply versioning in that
	case.
	* tree-vectorizer.h (vect_loop_versioning): Adjust declaration.
	(vect_do_peeling_for_loop_bound): Likewise.
	* tree-vect-loop.c (vect_transform_loop): If we are peeling for
	loop bound only record extra pre-conditions, do not apply loop
	versioning.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@145551 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 8 insertions, 1 deletions

diff --git a/gcc/tree-ssa-copy.c b/gcc/tree-ssa-copy.c
index a02aee0ca49..f582ed0f996 100644
--- a/gcc/tree-ssa-copy.c
+++ b/gcc/tree-ssa-copy.c
@@ -37,6 +37,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "tree-pass.h"
 #include "tree-ssa-propagate.h"
 #include "langhooks.h"
+#include "cfgloop.h"
 
 /* This file implements the copy propagation pass and provides a
    handful of interfaces for performing const/copy propagation and
@@ -885,7 +886,13 @@ init_copy_prop (void)
           tree def;
 
 	  def = gimple_phi_result (phi);
-	  if (!is_gimple_reg (def))
+	  if (!is_gimple_reg (def)
+	      /* In loop-closed SSA form do not copy-propagate through
+	         PHI nodes.  Technically this is only needed for loop
+		 exit PHIs, but this is difficult to query.  */
+	      || (current_loops
+		  && gimple_phi_num_args (phi) == 1
+		  && loops_state_satisfies_p (LOOP_CLOSED_SSA)))
             prop_set_simulate_again (phi, false);
 	  else
             prop_set_simulate_again (phi, true);