tree-predcom: Do more unrolling if -fnoalias flag is set.gcc-8_2_0-amp-branch

1 files changed, 12 insertions, 1 deletions

diff --git a/gcc/tree-predcom.c b/gcc/tree-predcom.c
index 2bde732f8ad8..8524e4379be3 100644
--- a/gcc/tree-predcom.c
+++ b/gcc/tree-predcom.c
@@ -3170,6 +3170,15 @@ tree_predictive_commoning_loop (struct loop *loop)
   bool unroll = false, loop_closed_ssa = false;
   edge exit;
 
+  unroll_factor = 4;
+  unroll = can_unroll_loop_p (loop, unroll_factor, &desc);
+  exit = single_dom_exit (loop);
+
+  if (unroll && noalias != 0)
+    {
+      tree_unroll_loop (loop, unroll_factor, exit, &desc);
+    }
+
   if (dump_file && (dump_flags & TDF_DETAILS))
     fprintf (dump_file, "Processing loop %d\n",  loop->num);
 
@@ -3255,7 +3264,7 @@ tree_predictive_commoning_loop (struct loop *loop)
 
   /* Execute the predictive commoning transformations, and possibly unroll the
      loop.  */
-  if (unroll)
+  if (unroll && noalias == 0)
     {
       struct epcc_data dta;
 
@@ -3323,6 +3332,8 @@ tree_predictive_commoning (void)
       ret = TODO_cleanup_cfg;
     }
 
+  ret = TODO_cleanup_cfg;
+
   return ret;
 }