--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/optimize-bswapsi-5.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,31 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target bswap32 } */
+/* { dg-options "-O2 -fdump-tree-bswap" } */
+/* { dg-additional-options "-march=z900" { target s390-*-* } } */
+
+struct L { unsigned int l[2]; };
+union U { double a; struct L l; } u;
+
+void
+foo (double a, struct L *p)
+{
+  u.a = a;
+  struct L l = u.l, m;
+  m.l[0] = (((l.l[1] & 0xff000000) >> 24)
+	    | ((l.l[1] & 0x00ff0000) >> 8)
+	    | ((l.l[1] & 0x0000ff00) << 8)
+	    | ((l.l[1] & 0x000000ff) << 24));
+  m.l[1] = (((l.l[0] & 0xff000000) >> 24)
+	    | ((l.l[0] & 0x00ff0000) >> 8)
+	    | ((l.l[0] & 0x0000ff00) << 8)
+	    | ((l.l[0] & 0x000000ff) << 24));
+  *p = m;
+}
+
+void
+bar (double a, struct L *p)
+{
+  foo (a, p);
+}
+
+/* { dg-final { scan-tree-dump-times "32 bit bswap implementation found at" 2 "bswap" } } */