1 files changed, 29 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.dg/pr39343.c b/gcc/testsuite/gcc.dg/pr39343.c
new file mode 100644
index 000000000..70df59ef0
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr39343.c
@@ -0,0 +1,29 @@
+/* PR tree-optimization/39343 */
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+extern void abort (void);
+
+extern inline __attribute__ ((__always_inline__)) int
+foo (char *dest)
+{
+  return __builtin_object_size (dest, 1);
+}
+
+struct S
+{
+  union
+  {
+    struct { int a, b; char c, d; } f;
+    struct { struct { int a, b; char c, d[255]; } e; } g;
+  } u;
+};
+
+int
+main (void)
+{
+  struct S s;
+  if (foo (s.u.g.e.d) != 255)
+    abort ();
+  return 0;
+}