1 files changed, 28 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-18.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-18.c
new file mode 100644
index 000000000..392b1f6cf
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-18.c
@@ -0,0 +1,28 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-fre" } */
+
+struct a
+{
+  union
+  {
+    int a;
+    int b;
+  };
+  union
+  {
+    int c;
+    int d;
+  };
+};
+
+int f(struct a *c)
+{
+  int d = c->a;
+  c->c = 1;
+  return c->a + d;
+}
+
+/* We should have CSEd the load from c->a.  */
+
+/* { dg-final { scan-tree-dump-times "c_.*\\\.a" 1 "fre" } } */
+/* { dg-final { cleanup-tree-dump "fre" } } */