--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/adjust-alignment.c	Mon May 25 07:50:57 2020 +0900
@@ -0,0 +1,85 @@
+/* Adjust alignment for local variable.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+   Contributed by Kito Cheng <kito.cheng@sifive.com>
+
+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 "tree.h"
+#include "tree-pass.h"
+#include "memmodel.h"
+#include "tm_p.h"
+
+namespace {
+
+const pass_data pass_data_adjust_alignment =
+{
+  GIMPLE_PASS, /* type */
+  "adjust_alignment", /* name */
+  OPTGROUP_NONE, /* optinfo_flags */
+  TV_NONE, /* tv_id */
+  0, /* properties_required */
+  0, /* properties_provided */
+  0, /* properties_destroyed */
+  0, /* todo_flags_start */
+  0, /* todo_flags_finish */
+};
+
+class pass_adjust_alignment : public gimple_opt_pass
+{
+public:
+  pass_adjust_alignment (gcc::context *ctxt)
+    : gimple_opt_pass (pass_data_adjust_alignment, ctxt)
+  {}
+
+  virtual unsigned int execute (function *);
+}; // class pass_adjust_alignment
+
+} // anon namespace
+
+/* Entry point to adjust_alignment pass.  */
+unsigned int
+pass_adjust_alignment::execute (function *fun)
+{
+  size_t i;
+  tree var;
+
+  FOR_EACH_LOCAL_DECL (fun, i, var)
+    {
+      /* Don't adjust aligment for static local var and hard register var.  */
+      if (is_global_var (var) || DECL_HARD_REGISTER (var))
+	continue;
+
+      unsigned align = LOCAL_DECL_ALIGNMENT (var);
+
+      /* Make sure alignment only increase.  */
+      gcc_assert (align >= DECL_ALIGN (var));
+
+      SET_DECL_ALIGN (var, align);
+    }
+  return 0;
+}
+
+gimple_opt_pass *
+make_pass_adjust_alignment (gcc::context *ctxt)
+{
+  return new pass_adjust_alignment (ctxt);
+}