--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/jit.dg/test-pr66700-observing-write-through-ptr.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,109 @@
+/* Test of PR jit/66700.  */
+
+#include <stdlib.h>
+#include <stdio.h>
+
+#include "libgccjit.h"
+
+#include "harness.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+  extern void
+  write_back_through_ptr (double *d);
+
+#ifdef __cplusplus
+}
+#endif
+
+void
+create_code (gcc_jit_context *ctxt, void *user_data)
+{
+  /* Let's try to inject the equivalent of:
+
+     double
+     test_caller_of_write_back_through_ptr (void)
+     {
+       double d;
+       d = 4.0;
+       write_back_through_ptr (&d);
+       return d;
+     }
+  */
+  gcc_jit_type *t_void =
+    gcc_jit_context_get_type (ctxt, GCC_JIT_TYPE_VOID);
+  gcc_jit_type *t_double =
+    gcc_jit_context_get_type (ctxt, GCC_JIT_TYPE_DOUBLE);
+  gcc_jit_type *t_ptr_to_double =
+    gcc_jit_type_get_pointer (t_double);
+
+  /* Declare the imported function.  */
+  gcc_jit_param *params[1];
+  params[0] =
+    gcc_jit_context_new_param (ctxt, NULL, t_ptr_to_double, "d");
+  gcc_jit_function *called_fn =
+    gcc_jit_context_new_function (ctxt, NULL,
+				  GCC_JIT_FUNCTION_IMPORTED,
+				  t_void,
+				  "write_back_through_ptr",
+				  1, params,
+				  0);
+
+  /* Build the test_fn.  */
+  gcc_jit_function *test_fn =
+    gcc_jit_context_new_function (ctxt, NULL,
+				  GCC_JIT_FUNCTION_EXPORTED,
+				  t_double,
+				  "test_caller_of_write_back_through_ptr",
+				  0, NULL,
+				  0);
+  gcc_jit_lvalue *d =
+    gcc_jit_function_new_local (test_fn, NULL, t_double, "d");
+
+  gcc_jit_block *block = gcc_jit_function_new_block (test_fn, NULL);
+
+  /* "d = 0.0" */
+  gcc_jit_block_add_assignment (
+    block, NULL, d,
+    gcc_jit_context_new_rvalue_from_int (ctxt, t_double, 4));
+
+  /* "write_back_through_ptr (&d);" */
+  gcc_jit_rvalue *args[1];
+  args[0] = gcc_jit_lvalue_get_address (d, NULL);
+  gcc_jit_block_add_eval (
+    block, NULL,
+    gcc_jit_context_new_call (ctxt,
+			      NULL,
+			      called_fn,
+			      1, args));
+  gcc_jit_block_end_with_return (block,
+				 NULL,
+				 gcc_jit_lvalue_as_rvalue (d));
+}
+
+extern void
+write_back_through_ptr (double *d)
+{
+  *d = 5.600000;
+}
+
+void
+verify_code (gcc_jit_context *ctxt, gcc_jit_result *result)
+{
+  typedef double (*fn_type) (void);
+  CHECK_NON_NULL (result);
+
+  fn_type test_caller_of_write_back_through_ptr =
+    (fn_type)gcc_jit_result_get_code (result,
+				      "test_caller_of_write_back_through_ptr");
+  CHECK_NON_NULL (test_caller_of_write_back_through_ptr);
+
+  /* Call the JIT-generated function.  */
+  double d = test_caller_of_write_back_through_ptr ();
+
+  /* Verify that it correctly called "write_back_through_ptr".  */
+  CHECK_VALUE (d, 5.600000);
+}
+