--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/c-c++-common/pr51628-28.c	Thu Feb 13 11:34:05 2020 +0900
@@ -0,0 +1,31 @@
+/* PR c/51628.  */
+/* { dg-do compile } */
+/* { dg-options "-O" } */
+
+struct A { 
+  int i;
+} __attribute__ ((packed));
+
+int *
+foo3 (struct A *p1, int *q1, int *q2, struct A *p2) 
+{
+  return (q1 
+	  ? &p1->i
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* } .-1 } */
+	  : (q2 ? &p2->i : q2));
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* } .-1 } */
+}
+
+int*
+foo4 (struct A *p1, int **q1, int *q2, int *q3, struct A *p2)
+{
+  return (q1
+	  ? (*q1 = q2, &p1->i)
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* } .-1 } */
+	  : (q2
+	     ? (*q1 = &p1->i,
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* } .-1 } */
+		*q2 = 2, &p2->i)
+/* { dg-warning "may result in an unaligned pointer value" "" { target *-*-* } .-1 } */
+	     : q2));
+}