* xmenu.c (set_frame_menubar): Allocate smaller local vectors.

This also lets GCC 4.6.0 generate slightly better loop code.

2 files changed, 14 insertions, 10 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 86dec69e094..084f41fc974 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,8 @@
 2011-04-09  Paul Eggert  <eggert@cs.ucla.edu>
 
+        * xmenu.c (set_frame_menubar): Allocate smaller local vectors.
+        This also lets GCC 4.6.0 generate slightly better loop code.
+
         * callint.c (Fcall_interactively): <, not <=, for optimization.
         (Fcall_interactively): Count the number of arguments produced,
         not the number of arguments given.  This is simpler and lets GCC
diff --git a/src/xmenu.c b/src/xmenu.c
index dbf8145f737..b1f7dfb26bc 100644
--- a/src/xmenu.c
+++ b/src/xmenu.c
@@ -966,6 +966,7 @@ set_frame_menubar (FRAME_PTR f, int first_time, int deep_p)
       Lisp_Object *previous_items
         = (Lisp_Object *) alloca (previous_menu_items_used
                                   * sizeof (Lisp_Object));
+      EMACS_UINT subitems;
 
       /* If we are making a new widget, its contents are empty,
          do always reinitialize them.  */
@@ -1010,21 +1011,21 @@ set_frame_menubar (FRAME_PTR f, int first_time, int deep_p)
 
       menu_items = f->menu_bar_vector;
       menu_items_allocated = VECTORP (menu_items) ? ASIZE (menu_items) : 0;
-      submenu_start = (int *) alloca (XVECTOR (items)->size * sizeof (int *));
-      submenu_end = (int *) alloca (XVECTOR (items)->size * sizeof (int *));
-      submenu_n_panes = (int *) alloca (XVECTOR (items)->size * sizeof (int));
-      submenu_top_level_items
-        = (int *) alloca (XVECTOR (items)->size * sizeof (int *));
+      subitems = XVECTOR (items)->size / 4;
+      submenu_start = (int *) alloca (subitems * sizeof (int *));
+      submenu_end = (int *) alloca (subitems * sizeof (int *));
+      submenu_n_panes = (int *) alloca (subitems * sizeof (int));
+      submenu_top_level_items = (int *) alloca (subitems * sizeof (int *));
       init_menu_items ();
-      for (i = 0; i < XVECTOR (items)->size; i += 4)
+      for (i = 0; i < subitems; i++)
         {
           Lisp_Object key, string, maps;
 
           last_i = i;
 
-          key = XVECTOR (items)->contents[i];
-          string = XVECTOR (items)->contents[i + 1];
-          maps = XVECTOR (items)->contents[i + 2];
+          key = XVECTOR (items)->contents[4 * i];
+          string = XVECTOR (items)->contents[4 * i + 1];
+          maps = XVECTOR (items)->contents[4 * i + 2];
           if (NILP (string))
             break;
 
@@ -1051,7 +1052,7 @@ set_frame_menubar (FRAME_PTR f, int first_time, int deep_p)
       wv->help = Qnil;
       first_wv = wv;
 
-      for (i = 0; i < last_i; i += 4)
+      for (i = 0; i < last_i; i++)
         {
           menu_items_n_panes = submenu_n_panes[i];
           wv = digest_single_submenu (submenu_start[i], submenu_end[i],