Do not bother with fake verifying of shared DRs

The following avoids comparing the shared DRs against their unmodified
copy for epilogues during loop transform since they are actually
modified by update_epilogue_loop_vinfo.  Avoid the pointless faking
of the original DRs there.

	* tree-vect-loop.cc (vect_transform_loop): Do not verify DRs
	have not been modified for epilogue loops.
	(update_epilogue_loop_vinfo): Do not copy modified DRs to
	the originals.

diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
index 80b5a0a326bd6003ebccffef1d9ce61ea5673276..9b4d200bb296957553c8528dfa01e47ea367a162 100644 (file)
--- a/gcc/tree-vect-loop.cc
+++ b/gcc/tree-vect-loop.cc
@@ -11318,9 +11318,6 @@ update_epilogue_loop_vinfo (class loop *epilogue, tree advance)
 
   /* Remember the advancement made.  */
   LOOP_VINFO_DRS_ADVANCED_BY (epilogue_vinfo) = advance;
-
-  epilogue_vinfo->shared->datarefs_copy.release ();
-  epilogue_vinfo->shared->save_datarefs ();
 }
 
 /*  When vectorizing early break statements instructions that happen before
@@ -11426,7 +11423,8 @@ vect_transform_loop (loop_vec_info loop_vinfo, gimple *loop_vectorized_call)
 
   DUMP_VECT_SCOPE ("vec_transform_loop");
 
-  loop_vinfo->shared->check_datarefs ();
+  if (! LOOP_VINFO_EPILOGUE_P (loop_vinfo))
+    loop_vinfo->shared->check_datarefs ();
 
   /* Use the more conservative vectorization threshold.  If the number
      of iterations is constant assume the cost check has been performed