--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/jit/docs/examples/tut03-sum-of-squares.cc	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,137 @@
+/* Usage example for libgccjit.so's C++ API
+   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 <libgccjit++.h>
+
+#include <stdlib.h>
+#include <stdio.h>
+
+void
+create_code (gccjit::context ctxt)
+{
+  /*
+    Simple sum-of-squares, to test conditionals and looping
+
+    int loop_test (int n)
+    {
+      int i;
+      int sum = 0;
+      for (i = 0; i < n ; i ++)
+      {
+	sum += i * i;
+      }
+      return sum;
+   */
+  gccjit::type the_type = ctxt.get_int_type <int> ();
+  gccjit::type return_type = the_type;
+
+  gccjit::param n = ctxt.new_param (the_type, "n");
+  std::vector<gccjit::param> params;
+  params.push_back (n);
+  gccjit::function func =
+    ctxt.new_function (GCC_JIT_FUNCTION_EXPORTED,
+                       return_type,
+                       "loop_test",
+                       params, 0);
+
+  /* Build locals:  */
+  gccjit::lvalue i = func.new_local (the_type, "i");
+  gccjit::lvalue sum = func.new_local (the_type, "sum");
+
+  gccjit::block b_initial = func.new_block ("initial");
+  gccjit::block b_loop_cond = func.new_block ("loop_cond");
+  gccjit::block b_loop_body = func.new_block ("loop_body");
+  gccjit::block b_after_loop = func.new_block ("after_loop");
+
+  /* sum = 0; */
+  b_initial.add_assignment (sum, ctxt.zero (the_type));
+
+  /* i = 0; */
+  b_initial.add_assignment (i, ctxt.zero (the_type));
+
+  b_initial.end_with_jump (b_loop_cond);
+
+  /* if (i >= n) */
+  b_loop_cond.end_with_conditional (
+    i >= n,
+    b_after_loop,
+    b_loop_body);
+
+  /* sum += i * i */
+  b_loop_body.add_assignment_op (sum,
+                                 GCC_JIT_BINARY_OP_PLUS,
+                                 i * i);
+
+  /* i++ */
+  b_loop_body.add_assignment_op (i,
+                                GCC_JIT_BINARY_OP_PLUS,
+                                ctxt.one (the_type));
+
+  b_loop_body.end_with_jump (b_loop_cond);
+
+  /* return sum */
+  b_after_loop.end_with_return (sum);
+}
+
+int
+main (int argc, char **argv)
+{
+  gccjit::context ctxt;
+  gcc_jit_result *result = NULL;
+
+  /* Get a "context" object for working with the library.  */
+  ctxt = gccjit::context::acquire ();
+
+  /* Set some options on the context.
+     Turn this on to see the code being generated, in assembler form.  */
+  ctxt.set_bool_option (GCC_JIT_BOOL_OPTION_DUMP_GENERATED_CODE,
+                        0);
+
+  /* Populate the context.  */
+  create_code (ctxt);
+
+  /* Compile the code.  */
+  result = ctxt.compile ();
+
+  ctxt.release ();
+
+  if (!result)
+    {
+      fprintf (stderr, "NULL result");
+      return 1;
+    }
+
+  /* Extract the generated code from "result".  */
+  typedef int (*loop_test_fn_type) (int);
+  loop_test_fn_type loop_test =
+    (loop_test_fn_type)gcc_jit_result_get_code (result, "loop_test");
+  if (!loop_test)
+    {
+      fprintf (stderr, "NULL loop_test");
+      gcc_jit_result_release (result);
+      return 1;
+    }
+
+  /* Run the generated code.  */
+  int val = loop_test (10);
+  printf("loop_test returned: %d\n", val);
+
+  gcc_jit_result_release (result);
+  return 0;
+}