Fix my change to unroll_loop_constant_iterations

[Jan Hubicka]

H,
I hope this change is responsible for today misoptimizations of SPEC at -O3.
While updating unroll_loop_constant_iterations and fighting with double_int
operations I made two trivial mistakes.

I am bootstrapping/regtesting the following and will commit it as obvious if
it passes.

Honza

        * loop-unroll.c (unroll_loop_constant_iterations): Fix previous patch.
Index: loop-unroll.c
===================================================================
--- loop-unroll.c       (revision 192239)
+++ loop-unroll.c       (working copy)
@@ -740,6 +740,7 @@ unroll_loop_constant_iterations (struct
            apply_opt_in_copies (opt_info, exit_mod + 1, false, false);
 
          desc->niter -= exit_mod + 1;
+         loop->nb_iterations_upper_bound -= double_int::from_uhwi (exit_mod + 
1);
          if (loop->any_estimate
              && double_int::from_uhwi (exit_mod + 1).ule
                   (loop->nb_iterations_estimate))
@@ -795,12 +796,12 @@ unroll_loop_constant_iterations (struct
 
   desc->niter /= max_unroll + 1;
   loop->nb_iterations_upper_bound
-    = loop->nb_iterations_upper_bound.udiv (double_int::from_uhwi (exit_mod
+    = loop->nb_iterations_upper_bound.udiv (double_int::from_uhwi (max_unroll
                                                                   + 1),
                                            FLOOR_DIV_EXPR);
   if (loop->any_estimate)
     loop->nb_iterations_estimate
-      = loop->nb_iterations_estimate.udiv (double_int::from_uhwi (exit_mod
+      = loop->nb_iterations_estimate.udiv (double_int::from_uhwi (max_unroll
                                                                  + 1),
                                           FLOOR_DIV_EXPR);
   desc->niter_expr = GEN_INT (desc->niter);