[PATCH, rs6000] Change rs6000 into SWITCHABLE_TARGET

[Peter Bergner]

After Jakub changed i?386/x86_64 to use SWITCHABLE_TARGET, he asked me to
look at changing rs6000 too.  Here's the rs6000 patch, which is basically
identical to the i386.[hc] change Jakub made.  This passed bootstrap and
regtesting on powerpc64-linux with no regressions.  Ok for mainline?

Peter


        * config/rs6000/rs6000.h (SWITCHABLE_TARGET): Define.
        * config/rs6000/rs6000.c: Include target-globals.h.
        (rs6000_set_current_function): Instead of doing target_reinit
        unconditionally, use save_target_globals_default_opts and
        restore_target_globals.

Index: gcc/config/rs6000/rs6000.h
===================================================================
--- gcc/config/rs6000/rs6000.h  (revision 206526)
+++ gcc/config/rs6000/rs6000.h  (working copy)
@@ -892,6 +892,9 @@ enum data_align { align_abi, align_opt,
        && (ALIGN) < 32)                                                        
\
    || (VECTOR_MODE_P ((MODE)) && (((int)(ALIGN)) < VECTOR_ALIGN (MODE))))

+/* For switching between functions with different target attributes.  */
+#define SWITCHABLE_TARGET 1
+
 
 /* Standard register usage.  */

Index: gcc/config/rs6000/rs6000.c
===================================================================
--- gcc/config/rs6000/rs6000.c  (revision 206526)
+++ gcc/config/rs6000/rs6000.c  (working copy)
@@ -78,6 +78,7 @@
 #include "tree-vectorizer.h"
 #include "dumpfile.h"
 #include "cgraph.h"
+#include "target-globals.h"
 #if TARGET_XCOFF
 #include "xcoffout.h"  /* get declarations of xcoff_*_section_name */
 #endif
@@ -31199,16 +31200,25 @@ rs6000_set_current_function (tree fndecl
        {
          cl_target_option_restore (&global_options,
                                    TREE_TARGET_OPTION (new_tree));
-         target_reinit ();
+         if (TREE_TARGET_GLOBALS (new_tree))
+           restore_target_globals (TREE_TARGET_GLOBALS (new_tree));
+         else
+           TREE_TARGET_GLOBALS (new_tree)
+             = save_target_globals_default_opts ();
        }

       else if (old_tree)
        {
-         struct cl_target_option *def
-           = TREE_TARGET_OPTION (target_option_current_node);
-
-         cl_target_option_restore (&global_options, def);
-         target_reinit ();
+         new_tree = target_option_current_node;
+         cl_target_option_restore (&global_options,
+                                   TREE_TARGET_OPTION (new_tree));
+         if (TREE_TARGET_GLOBALS (new_tree))
+           restore_target_globals (TREE_TARGET_GLOBALS (new_tree));
+         else if (new_tree == target_option_default_node)
+           restore_target_globals (&default_target_globals);
+         else
+           TREE_TARGET_GLOBALS (new_tree)
+             = save_target_globals_default_opts ();
        }
     }
 }