--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/g++.dg/init/array51.C	Thu Feb 13 11:34:05 2020 +0900
@@ -0,0 +1,86 @@
+// PR c++/89833
+// Anal test to verify that arrays of null pointer to members are
+// treated as null regardless of the form of their initialization,
+// and have all bits set in their representation.
+// { dg-do run { target c++11 } }
+// { dg-options "-O2 -Wall" }
+
+#define NOIPA __attribute__ ((noipa))
+
+struct A { int i; };
+
+typedef int A::*pam_t;
+
+pam_t apam__[2] = { };
+pam_t apam0_[2] = { 0 };
+pam_t apam00[2] = { 0, 0 };
+
+struct B { pam_t a[2]; };
+
+NOIPA B f__   () { return B{ }; }
+NOIPA B f0_   () { return B{ 0 }; }
+NOIPA B f00   () { return B{ 0, 0 }; }
+
+const B c__{ };
+const B c0_{ 0 };
+const B c00{ 0, 0 };
+
+B b__{ };
+B b0_{ 0 };
+B b00{ 0, 0 };
+
+#define assert(expr)				\
+  (expr) ? (void)0 : __builtin_abort ()
+
+signed char allones[2 * sizeof (pam_t)];
+
+#define assert_rep(mp, n)			\
+  assert (!test_allones (mp, n))
+
+NOIPA void init_allones ()
+{
+  __builtin_memset (allones, -1, sizeof allones);
+}
+
+NOIPA int test_allones (const pam_t *p, unsigned n)
+{
+  return __builtin_memcmp (allones, p, sizeof *p * n);
+}
+
+int main ()
+{
+  init_allones ();
+
+  assert (apam__[0] == nullptr && apam__[1] == nullptr);
+  assert (apam0_[0] == nullptr && apam0_[1] == nullptr);
+  assert (apam00[0] == nullptr && apam00[1] == nullptr);
+
+  assert (f__ ().a[0] == nullptr && f__ ().a[1] == nullptr);
+  assert (f0_ ().a[0] == nullptr && f0_ ().a[1] == nullptr);
+  assert (f00 ().a[0] == nullptr && f00 ().a[1] == nullptr);
+
+  assert (b__.a[0] == nullptr && b__.a[1] == nullptr);
+  assert (b0_.a[0] == nullptr && b0_.a[1] == nullptr);
+  assert (b00.a[0] == nullptr && b00.a[1] == nullptr);
+
+  assert (c__.a[0] == nullptr && c__.a[1] == nullptr);
+  assert (c0_.a[0] == nullptr && c0_.a[1] == nullptr);
+  assert (c00.a[0] == nullptr && c00.a[1] == nullptr);
+
+  assert_rep (apam__, 2);
+  assert_rep (apam0_, 2);
+  assert_rep (apam00, 2);
+
+  assert_rep (f__ ().a, 2);
+  assert_rep (f0_ ().a, 2);
+  assert_rep (f0_ ().a, 2);
+  assert_rep (f00 ().a, 2);
+
+  assert_rep (b__.a, 2);
+  assert_rep (b0_.a, 2);
+  assert_rep (b00.a, 2);
+
+  assert_rep (c__.a, 2);
+  assert_rep (c0_.a, 2);
+  assert_rep (c00.a, 2);
+}