diff --git a/gcc/testsuite/gcc.dg/fold-bswap-1.c b/gcc/testsuite/gcc.dg/fold-bswap-1.c
new file mode 100644
index 0000000..f14f731
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/fold-bswap-1.c
@@ -0,0 +1,22 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+
+unsigned int swap32(unsigned int x)
+{
+    unsigned int a = __builtin_bswap16(x);
+    x >>= 16;
+    a <<= 16;
+    return __builtin_bswap16(x) | a;
+}
+
+unsigned long swap64(unsigned long x)
+{
+    unsigned long a = __builtin_bswap32(x);
+    x >>= 32;
+    a <<= 32;
+    return __builtin_bswap32(x) | a;
+}
+
+/* { dg-final { scan-tree-dump-times "__builtin_bswap32" 1 "optimized" } } */
+/* { dg-final { scan-tree-dump-times "__builtin_bswap64" 1 "optimized" } } */
+