--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/pr48784-2.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,19 @@
+/* { dg-do run } */
+/* { dg-require-effective-target size32plus } */
+/* { dg-options "-fno-strict-volatile-bitfields" } */
+
+extern void abort (void);
+
+#pragma pack(1)
+volatile struct S0 {
+   signed a : 7;
+   unsigned b : 28;  /* b can't be fetched with an aligned 32-bit access, */
+                     /* but it certainly can be fetched with an unaligned access */
+} g = {0,0xfffffff};
+
+int main() {
+  unsigned b = g.b;
+  if (b != 0xfffffff)
+    abort ();
+  return 0;
+}