--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/cdce2.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,54 @@
+/* { dg-do  run  } */
+/* { dg-skip-if "doubles are floats" { "avr-*-*" } } */
+/* { dg-options "-O2 -fmath-errno -fdump-tree-cdce-details  -lm" } */
+/* { dg-final { scan-tree-dump  "cdce2.c:15: note: function call is shrink-wrapped into error conditions\." "cdce" } } */
+ 
+#include <stdlib.h>
+#include <math.h>
+#include <errno.h>
+int total_err_count = 0;
+double foo_opt (double y) __attribute__((noinline));
+double foo_opt (double y)
+{
+  double yy = 0;
+  errno = 0;
+  yy = log (y);
+  return 0;
+}
+
+double foo (double y) __attribute__((noinline));
+double foo (double y)
+{
+  double yy = 0;
+  errno = 0;
+  yy = log (y);
+  return yy;
+}
+
+int test (double (*fp) (double y))
+{
+  int i,x;
+  for (i = -100; i < 100; i++)
+    {  
+      fp (i);
+      if (errno)
+        total_err_count ++;
+    }
+
+  return total_err_count;
+}
+
+int main ()
+{
+  int en1, en2;
+  double yy;
+  total_err_count = 0;
+  en1 = test (foo_opt);
+  total_err_count = 0;
+  en2 = test (foo);
+
+  if (en1 != en2)
+    abort();
+
+  return 0;
+}