--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/compare5.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,41 @@
+/* Test for a bogus warning on comparison between signed and unsigned.
+   Origin: Kaveh R. Ghazi <ghazi@caip.rutgers.edu> 8/21/2001.  */
+
+/* { dg-do compile } */
+/* { dg-options "-Wsign-compare" } */
+
+extern void bar(void);
+
+int foo(int x, int y, unsigned u)
+{
+  /* A *_DIV_EXPR is non-negative if both operands are.  */
+
+  if (u < ((x=-22)/33)) /* { dg-warning "different signedness" "DIV_EXPR" } */
+    return x;
+
+  if (u < ((x=22)/33))
+    return x;
+
+  if (u < ((x=22)/(y=33)))
+    return x;
+
+  if (u < (((x&0x10000)?128:64) / ((y&0x10000)?8:4)))
+    return x;
+
+
+  /* A *_MOD_EXPR is non-negative if the first operand is.  */
+
+  if (u < ((x=-22)%33)) /* { dg-warning "different signedness" "MOD_EXPR" } */
+    return x;
+
+  if (u < ((x=22)%-33))
+    return x;
+
+  if (u < ((x==y)%-33))
+    return x;
+
+  if (u < (((x=22)/33)%-33))
+    return x;
+
+  return 0;
+}