diff --git a/gcc/fold-const.cc b/gcc/fold-const.cc
index 0578f42ac0c..6f73f648b70 100644
--- a/gcc/fold-const.cc
+++ b/gcc/fold-const.cc
@@ -13712,6 +13712,8 @@ fold_ternary_loc (location_t loc, enum tree_code code, tree type,
 	{
 	  unsigned HOST_WIDE_INT bitpos = tree_to_uhwi (op2);
 	  unsigned bitsize = TYPE_PRECISION (TREE_TYPE (arg1));
+	  if (BYTES_BIG_ENDIAN)
+	    bitpos = TYPE_PRECISION (type) - bitpos - bitsize;
 	  wide_int tem = (wi::to_wide (arg0)
 			  & wi::shifted_mask (bitpos, bitsize, true,
 					      TYPE_PRECISION (type)));
diff --git a/gcc/testsuite/gcc.dg/vect/pr116997.c b/gcc/testsuite/gcc.dg/vect/pr116997.c
new file mode 100644
index 00000000000..4563fc2bfb6
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/pr116997.c
@@ -0,0 +1,18 @@
+/* PR 116997.  */
+struct S0
+{
+  unsigned f0;
+  signed f2 : 11;
+  signed : 6;
+} GlobS, *Ptr = &GlobS;
+
+const struct S0 Initializer = {7, 3};
+
+int main (void)
+{
+  for (unsigned i = 0; i <= 2; i++)
+    *Ptr = Initializer;
+  if (GlobS.f2 != 3)
+    __builtin_abort ();
+  return 0;
+}