--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/ada/libgnat/a-coprnu.ads	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,51 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                         GNAT LIBRARY COMPONENTS                          --
+--                                                                          --
+--         A D A . C O N T A I N E R S . P R I M E _ N U M B E R S          --
+--                                                                          --
+--                                 S p e c                                  --
+--                                                                          --
+--          Copyright (C) 2004-2017, Free Software Foundation, Inc.         --
+--                                                                          --
+-- GNAT is free software;  you can  redistribute it  and/or modify it under --
+-- terms of the  GNU General Public License as published  by the Free Soft- --
+-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
+-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
+-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
+-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
+--                                                                          --
+-- As a special exception under Section 7 of GPL version 3, you are granted --
+-- additional permissions described in the GCC Runtime Library Exception,   --
+-- version 3.1, as published by the Free Software Foundation.               --
+--                                                                          --
+-- You should have received a copy of the GNU General Public License and    --
+-- a copy of the GCC Runtime Library Exception along with this program;     --
+-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
+-- <http://www.gnu.org/licenses/>.                                          --
+--                                                                          --
+-- This unit was originally developed by Matthew J Heaney.                  --
+------------------------------------------------------------------------------
+
+--  This package declares the prime numbers array used to implement hashed
+--  containers. Bucket arrays are always allocated with a prime-number
+--  length (computed using To_Prime below), as this produces better scatter
+--  when hash values are folded.
+
+package Ada.Containers.Prime_Numbers is
+   pragma Pure;
+
+   type Primes_Type is array (Positive range <>) of Hash_Type;
+
+   Primes : constant Primes_Type :=
+     (53,         97,         193,       389,       769,
+      1543,       3079,       6151,      12289,     24593,
+      49157,      98317,      196613,    393241,    786433,
+      1572869,    3145739,    6291469,   12582917,  25165843,
+      50331653,   100663319,  201326611, 402653189, 805306457,
+      1610612741, 3221225473, 4294967291);
+
+   function To_Prime (Length : Count_Type) return Hash_Type;
+   --  Returns the smallest value in Primes not less than Length
+
+end Ada.Containers.Prime_Numbers;