Fix profile update in unrolling

[Jan Hubicka]

hi,
this patch make unroller to update profile slightly beter by updating outgoing
probabilities when exit is proved to be taken.

Bootstrapped/regtested x86_64-linux, will commit it later today.

Honza

        * tree-ssa-loop-ivcanon.c (remove_exits_and_undefined_stmts): Update
        profile.
        (try_unroll_loop_completely): Fix reporting.
Index: tree-ssa-loop-ivcanon.c
===================================================================
--- tree-ssa-loop-ivcanon.c     (revision 249244)
+++ tree-ssa-loop-ivcanon.c     (working copy)
@@ -529,6 +529,8 @@ remove_exits_and_undefined_stmts (struct
            }
          if (!loop_exit_edge_p (loop, exit_edge))
            exit_edge = EDGE_SUCC (bb, 1);
+         exit_edge->probability = REG_BR_PROB_BASE;
+         exit_edge->count = exit_edge->src->count;
          gcc_checking_assert (loop_exit_edge_p (loop, exit_edge));
          gcond *cond_stmt = as_a <gcond *> (elt->stmt);
          if (exit_edge->flags & EDGE_TRUE_VALUE)
@@ -853,8 +855,9 @@ try_unroll_loop_completely (struct loop
                     loop->num);
          return false;
        }
-      dump_printf_loc (report_flags, locus,
-                       "loop turned into non-loop; it never loops.\n");
+      if (!n_unroll)
+        dump_printf_loc (report_flags, locus,
+                         "loop turned into non-loop; it never loops.\n");
 
       initialize_original_copy_tables ();
       auto_sbitmap wont_exit (n_unroll + 1);