--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/c-c++-common/Wtautological-compare-8.c	Thu Feb 13 11:34:05 2020 +0900
@@ -0,0 +1,33 @@
+/* { dg-options "-Wtautological-compare" } */
+
+int foo;
+#define INCOMING_FRAME_SP_OFFSET foo
+#define DEFAULT_INCOMING_FRAME_SP_OFFSET INCOMING_FRAME_SP_OFFSET
+
+int test (void)
+{
+  if (DEFAULT_INCOMING_FRAME_SP_OFFSET != INCOMING_FRAME_SP_OFFSET) /* { dg-warning "self-comparison" "" { target c } } */
+    return 1;
+  else
+    return 0;
+}
+
+#define BYTES_BIG_ENDIAN foo
+#define WORDS_BIG_ENDIAN foo
+
+int test_2 (void)
+{
+  if (BYTES_BIG_ENDIAN != WORDS_BIG_ENDIAN) /* { dg-warning "self-comparison" "" { target c } } */
+    return 1;
+  else
+    return 0;
+}
+
+#define COND DEFAULT_INCOMING_FRAME_SP_OFFSET != INCOMING_FRAME_SP_OFFSET
+int test_3 (void)
+{
+  if (COND)
+    return 1;
+  else
+    return 0;
+}