--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/pr55019.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,41 @@
+/* { dg-do run } */
+/* { dg-options "-O1 -funroll-loops" } */
+/* { dg-add-options ieee } */
+
+extern void exit (int);
+extern void abort (void);
+
+void
+compare (double a, double b)
+{
+  do
+    {
+      double s1 = __builtin_copysign ((double) 1.0, a);
+      double s2 = __builtin_copysign ((double) 1.0, b);
+
+      if (s1 != s2)
+        abort ();
+
+      if ((__builtin_isnan (a) != 0) != (__builtin_isnan (b) != 0))
+        abort ();
+
+      if ((a != b) != (__builtin_isnan (a) != 0))
+        abort ();
+    } while (0);
+}
+
+int
+main ()
+{
+  double a = 0.0;
+  double b = 0.0;
+  _Complex double cr = __builtin_complex (a, b);
+  static _Complex double cs = __builtin_complex (0.0, 0.0);
+
+  compare (__real__ cr, 0.0);
+  compare (__imag__ cr, 0.0);
+  compare (__real__ cs, 0.0);
+  compare (__imag__ cs, 0.0);
+
+  exit (0);
+}