--- gcc/expr.c	(revision 314639)
+++ gcc/expr.c	(working copy)
@@ -8458,6 +8458,18 @@ expand_expr_real_1 (tree exp, rtx target
       return decl_rtl;
 
     case INTEGER_CST:
+      if (GET_MODE_BITSIZE (mode) > 2 * HOST_BITS_PER_WIDE_INT)
+	{
+	  /* FIXME: We can't generally represent wide integer constants,
+	     but GCC sometimes tries to initialise wide integer values (such
+	     as used by the ARM NEON support) with zero.  Handle that as a
+	     special case here.  */
+	  if (initializer_zerop (exp))
+	    return CONST0_RTX (mode);
+
+	  gcc_unreachable ();
+	}
+
       temp = immed_double_const (TREE_INT_CST_LOW (exp),
 				 TREE_INT_CST_HIGH (exp), mode);