--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/pr29637.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,23 @@
+/* PR tree-optimization/29637 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -ftree-vectorize" } */
+
+typedef struct __attribute__ ((aligned (8)))
+{
+    short a, b, c, d;
+} A;
+
+typedef struct
+{
+  A a[24];
+} B;
+
+static const A b = { 0, 0, 1, -1 };
+
+void
+foo (B *x)
+{
+  int i;
+  for (i = 0; i <= 20; i += 4)
+    x->a[i] = b;
+}