Index: config/i386/i386.c
===================================================================
--- config/i386/i386.c	(revision 227777)
+++ config/i386/i386.c	(working copy)
@@ -5080,12 +5080,14 @@ ix86_valid_target_attribute_tree (tree args,
       /* If we are using the default tune= or arch=, undo the string assigned,
 	 and use the default.  */
       if (option_strings[IX86_FUNCTION_SPECIFIC_ARCH])
-	opts->x_ix86_arch_string = option_strings[IX86_FUNCTION_SPECIFIC_ARCH];
+	opts->x_ix86_arch_string
+	  = xstrdup (option_strings[IX86_FUNCTION_SPECIFIC_ARCH]);
       else if (!orig_arch_specified)
 	opts->x_ix86_arch_string = NULL;
 
       if (option_strings[IX86_FUNCTION_SPECIFIC_TUNE])
-	opts->x_ix86_tune_string = option_strings[IX86_FUNCTION_SPECIFIC_TUNE];
+	opts->x_ix86_tune_string
+	  = xstrdup (option_strings[IX86_FUNCTION_SPECIFIC_TUNE]);
       else if (orig_tune_defaulted)
 	opts->x_ix86_tune_string = NULL;