Clean up attribute value comparison in lto-symtab.c.

2018-04-11  Martin Liska  <mliska@suse.cz>

	* lto-symtab.c (lto_symtab_merge_p): Use attribute_value_equal
	function.

From-SVN: r259312

gcc/lto/ChangeLog

+2018-04-11  Martin Liska  <mliska@suse.cz>
+
+	* lto-symtab.c (lto_symtab_merge_p): Use attribute_value_equal
+	function.
+
 2018-04-10  Martin Liska  <mliska@suse.cz>
 
 	PR lto/85248

gcc/lto/lto-symtab.c

@@ -580,9 +580,7 @@ lto_symtab_merge_p (tree prevailing, tree decl)
       tree prev_attr = lookup_attribute ("error", DECL_ATTRIBUTES (prevailing));
       tree attr = lookup_attribute ("error", DECL_ATTRIBUTES (decl));
       if ((prev_attr == NULL) != (attr == NULL)
-	  || (prev_attr
-	      && TREE_VALUE (TREE_VALUE (prev_attr))
-		 != TREE_VALUE (TREE_VALUE (attr))))
+	  || (prev_attr && !attribute_value_equal (prev_attr, attr)))
 	{
           if (symtab->dump_file)
 	    fprintf (symtab->dump_file, "Not merging decls; "
@@ -593,9 +591,7 @@ lto_symtab_merge_p (tree prevailing, tree decl)
       prev_attr = lookup_attribute ("warning", DECL_ATTRIBUTES (prevailing));
       attr = lookup_attribute ("warning", DECL_ATTRIBUTES (decl));
       if ((prev_attr == NULL) != (attr == NULL)
-	  || (prev_attr
-	      && TREE_VALUE (TREE_VALUE (prev_attr))
-		 != TREE_VALUE (TREE_VALUE (attr))))
+	  || (prev_attr && !attribute_value_equal (prev_attr, attr)))
 	{
           if (symtab->dump_file)
 	    fprintf (symtab->dump_file, "Not merging decls; "