Introduce new command line flag -funroll-more.

This flag triggers more aggressive loop unrolling in tree-predcom.

Signed-off-by: Christoph Muellner <christoph.muellner@theobroma-systems.com>

2 files changed, 16 insertions, 1 deletions

diff --git a/gcc/common.opt b/gcc/common.opt
index abb50ad4fabb..01dc499b6716 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -2644,6 +2644,10 @@ fvectorize-more
 Common Report Var(flag_vectorize_more) Optimization
 Vectorize a bit more.
 
+funroll-more
+Common Report Var(flag_unroll_more) Optimization
+Unroll a bit more.
+
 funwind-tables
 Common Report Var(flag_unwind_tables) Optimization
 Just generate unwind tables for exception handling.
diff --git a/gcc/tree-predcom.c b/gcc/tree-predcom.c
index a2bb6763e524..67dc9d112cb0 100644
--- a/gcc/tree-predcom.c
+++ b/gcc/tree-predcom.c
@@ -2568,6 +2568,15 @@ tree_predictive_commoning_loop (struct loop *loop)
   edge exit;
   bitmap tmp_vars;
 
+  unroll_factor = 4;
+  unroll = can_unroll_loop_p (loop, unroll_factor, &desc);
+  exit = single_dom_exit (loop);
+
+  if (unroll && flag_unroll_more)
+    {
+      tree_unroll_loop (loop, unroll_factor, exit, &desc);
+    }
+
   if (dump_file && (dump_flags & TDF_DETAILS))
     fprintf (dump_file, "Processing loop %d\n",  loop->num);
 
@@ -2650,7 +2659,7 @@ tree_predictive_commoning_loop (struct loop *loop)
 
   /* Execute the predictive commoning transformations, and possibly unroll the
      loop.  */
-  if (unroll)
+  if (unroll && !flag_unroll_more)
     {
       struct epcc_data dta;
 
@@ -2716,6 +2725,8 @@ tree_predictive_commoning (void)
     }
   free_original_copy_tables ();
 
+  ret = TODO_cleanup_cfg;
+
   return ret;
 }