commit f3c5c9df8bb5a26a7df65e7b68d9eb6f60eccb40
Author: Kyrylo Tkachov <kyrylo.tkachov@arm.com>
Date:   Thu May 7 14:06:04 2015 +0100

    [AArch64][7/N] Implement TARGET_SET_CURRENT_FUNCTION

diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 2891690..ff87631 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -73,6 +73,7 @@
 #include "tm-constrs.h"
 #include "sched-int.h"
 #include "cortex-a57-fma-steering.h"
+#include "target-globals.h"
 
 /* This file should be included last.  */
 #include "target-def.h"
@@ -7927,6 +7928,58 @@ aarch64_option_print (FILE *file, int indent, struct cl_target_option *ptr)
   aarch64_print_extension (file, isa_flags);
 }
 
+static GTY(()) tree aarch64_previous_fndecl;
+
+/* Implement TARGET_SET_CURRENT_FUNCTION.  Unpack the codegen decisions
+   like tuning and ISA features from the DECL_FUNCTION_SPECIFIC_TARGET
+   of the function, if such exists.  This function may be called multiple
+   times on a single function so use aarch64_previous_fndecl to avoid
+   setting up identical state.  */
+
+static void
+aarch64_set_current_function (tree fndecl)
+{
+  tree old_tree = (aarch64_previous_fndecl
+		   ? DECL_FUNCTION_SPECIFIC_TARGET (aarch64_previous_fndecl)
+		   : NULL_TREE);
+
+  tree new_tree = (fndecl
+		   ? DECL_FUNCTION_SPECIFIC_TARGET (fndecl)
+		   : NULL_TREE);
+
+
+  if (fndecl && fndecl != aarch64_previous_fndecl)
+    {
+      aarch64_previous_fndecl = fndecl;
+      if (old_tree == new_tree)
+	;
+
+      else if (new_tree && new_tree != target_option_default_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
+	    TREE_TARGET_GLOBALS (new_tree)
+	      = save_target_globals_default_opts ();
+	}
+
+      else if (old_tree && old_tree != target_option_default_node)
+	{
+	  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 ();
+	}
+    }
+}
 
 /* Return true if SYMBOL_REF X binds locally.  */
 
@@ -12399,6 +12452,9 @@ aarch64_unspec_may_trap_p (const_rtx x, unsigned flags)
 #undef TARGET_OPTION_PRINT
 #define TARGET_OPTION_PRINT aarch64_option_print
 
+#undef TARGET_SET_CURRENT_FUNCTION
+#define TARGET_SET_CURRENT_FUNCTION aarch64_set_current_function
+
 #undef TARGET_PASS_BY_REFERENCE
 #define TARGET_PASS_BY_REFERENCE aarch64_pass_by_reference
 
diff --git a/gcc/config/aarch64/aarch64.h b/gcc/config/aarch64/aarch64.h
index 6d792c4..2c1b6ce 100644
--- a/gcc/config/aarch64/aarch64.h
+++ b/gcc/config/aarch64/aarch64.h
@@ -920,6 +920,9 @@ do {									     \
 #define HARD_REGNO_CALL_PART_CLOBBERED(REGNO, MODE) \
 		(FP_REGNUM_P (REGNO) && GET_MODE_SIZE (MODE) > 8)
 
+#undef SWITCHABLE_TARGET
+#define SWITCHABLE_TARGET 1
+
 /* Check TLS Descriptors mechanism is selected.  */
 #define TARGET_TLS_DESC (aarch64_tls_dialect == TLS_DESCRIPTORS)