--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/c-c++-common/pr51628-9.c	Thu Feb 13 11:34:05 2020 +0900
@@ -0,0 +1,36 @@
+/* PR c/51628.  */
+/* { dg-do compile } */
+/* { dg-options "-O" } */
+
+struct pair_t
+{
+  int x;
+  int i[4];
+} __attribute__ ((packed));
+
+extern struct pair_t p;
+extern int *x;
+extern void bar (int *);
+
+int *addr = p.i;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* } .-1 } */
+
+int *
+foo (struct pair_t *p)
+{
+  int *p0, *p1;
+  p0 = p->i;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* } .-1 } */
+  bar (p0);
+  p1 = &p->i[1];
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* } .-1 } */
+  bar (p1);
+  bar (p->i);
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* } .-1 } */
+  bar (&p->i[2]);
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* } .-1 } */
+  x = p->i;
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* } .-1 } */
+  return &p->i[3];
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* } .-1 } */
+}