--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/generic-match-head.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,70 @@
+/* Preamble and helpers for the autogenerated generic-match.c file.
+   Copyright (C) 2014-2017 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "backend.h"
+#include "target.h"
+#include "rtl.h"
+#include "tree.h"
+#include "gimple.h"
+#include "ssa.h"
+#include "cgraph.h"
+#include "fold-const.h"
+#include "stor-layout.h"
+#include "tree-dfa.h"
+#include "builtins.h"
+#include "case-cfn-macros.h"
+#include "gimplify.h"
+#include "optabs-tree.h"
+
+
+/* Routine to determine if the types T1 and T2 are effectively
+   the same for GENERIC.  If T1 or T2 is not a type, the test
+   applies to their TREE_TYPE.  */
+
+static inline bool
+types_match (tree t1, tree t2)
+{
+  if (!TYPE_P (t1))
+    t1 = TREE_TYPE (t1);
+  if (!TYPE_P (t2))
+    t2 = TREE_TYPE (t2);
+
+  return TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2);
+}
+
+/* Return if T has a single use.  For GENERIC, we assume this is
+   always true.  */
+
+static inline bool
+single_use (tree t ATTRIBUTE_UNUSED)
+{
+  return true;
+}
+
+/* Return true if math operations should be canonicalized,
+   e.g. sqrt(sqrt(x)) -> pow(x, 0.25).  */
+
+static inline bool
+canonicalize_math_p ()
+{
+  return true;
+}