--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/ada/libgnat/s-atopri.ads	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,180 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                         GNAT RUN-TIME COMPONENTS                         --
+--                                                                          --
+--               S Y S T E M . A T O M I C _ P R I M I T I V E S            --
+--                                                                          --
+--                                 S p e c                                  --
+--                                                                          --
+--              Copyright (C) 2012-2017, 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/>.                                          --
+--                                                                          --
+-- GNAT was originally developed  by the GNAT team at  New York University. --
+-- Extensive contributions were provided by Ada Core Technologies Inc.      --
+--                                                                          --
+------------------------------------------------------------------------------
+
+--  This package contains both atomic primitives defined from gcc built-in
+--  functions and operations used by the compiler to generate the lock-free
+--  implementation of protected objects.
+
+package System.Atomic_Primitives is
+   pragma Preelaborate;
+
+   type uint is mod 2 ** Long_Integer'Size;
+
+   type uint8  is mod 2**8
+     with Size => 8;
+
+   type uint16 is mod 2**16
+     with Size => 16;
+
+   type uint32 is mod 2**32
+     with Size => 32;
+
+   type uint64 is mod 2**64
+     with Size => 64;
+
+   Relaxed : constant := 0;
+   Consume : constant := 1;
+   Acquire : constant := 2;
+   Release : constant := 3;
+   Acq_Rel : constant := 4;
+   Seq_Cst : constant := 5;
+   Last    : constant := 6;
+
+   subtype Mem_Model is Integer range Relaxed .. Last;
+
+   ------------------------------------
+   -- GCC built-in atomic primitives --
+   ------------------------------------
+
+   function Atomic_Load_8
+     (Ptr   : Address;
+      Model : Mem_Model := Seq_Cst) return uint8;
+   pragma Import (Intrinsic, Atomic_Load_8, "__atomic_load_1");
+
+   function Atomic_Load_16
+     (Ptr   : Address;
+      Model : Mem_Model := Seq_Cst) return uint16;
+   pragma Import (Intrinsic, Atomic_Load_16, "__atomic_load_2");
+
+   function Atomic_Load_32
+     (Ptr   : Address;
+      Model : Mem_Model := Seq_Cst) return uint32;
+   pragma Import (Intrinsic, Atomic_Load_32, "__atomic_load_4");
+
+   function Atomic_Load_64
+     (Ptr   : Address;
+      Model : Mem_Model := Seq_Cst) return uint64;
+   pragma Import (Intrinsic, Atomic_Load_64, "__atomic_load_8");
+
+   function Sync_Compare_And_Swap_8
+     (Ptr      : Address;
+      Expected : uint8;
+      Desired  : uint8) return uint8;
+   pragma Import (Intrinsic,
+                  Sync_Compare_And_Swap_8,
+                  "__sync_val_compare_and_swap_1");
+
+   --  ??? Should use __atomic_compare_exchange_1 (doesn't work yet):
+   --  function Sync_Compare_And_Swap_8
+   --    (Ptr           : Address;
+   --     Expected      : Address;
+   --     Desired       : uint8;
+   --     Weak          : Boolean   := False;
+   --     Success_Model : Mem_Model := Seq_Cst;
+   --     Failure_Model : Mem_Model := Seq_Cst) return Boolean;
+   --  pragma Import (Intrinsic,
+   --                 Sync_Compare_And_Swap_8,
+   --                 "__atomic_compare_exchange_1");
+
+   function Sync_Compare_And_Swap_16
+     (Ptr      : Address;
+      Expected : uint16;
+      Desired  : uint16) return uint16;
+   pragma Import (Intrinsic,
+                  Sync_Compare_And_Swap_16,
+                  "__sync_val_compare_and_swap_2");
+
+   function Sync_Compare_And_Swap_32
+     (Ptr      : Address;
+      Expected : uint32;
+      Desired  : uint32) return uint32;
+   pragma Import (Intrinsic,
+                  Sync_Compare_And_Swap_32,
+                  "__sync_val_compare_and_swap_4");
+
+   function Sync_Compare_And_Swap_64
+     (Ptr      : Address;
+      Expected : uint64;
+      Desired  : uint64) return uint64;
+   pragma Import (Intrinsic,
+                  Sync_Compare_And_Swap_64,
+                  "__sync_val_compare_and_swap_8");
+
+   --------------------------
+   -- Lock-free operations --
+   --------------------------
+
+   --  The lock-free implementation uses two atomic instructions for the
+   --  expansion of protected operations:
+
+   --  * Lock_Free_Read_N atomically loads the value of the protected component
+   --    accessed by the current protected operation.
+
+   --  * Lock_Free_Try_Write_N tries to write the Desired value into Ptr only
+   --    if Expected and Desired mismatch.
+
+   function Lock_Free_Read_8 (Ptr : Address) return uint8;
+
+   function Lock_Free_Read_16 (Ptr : Address) return uint16;
+
+   function Lock_Free_Read_32 (Ptr : Address) return uint32;
+
+   function Lock_Free_Read_64 (Ptr : Address) return uint64;
+
+   function Lock_Free_Try_Write_8
+      (Ptr      : Address;
+       Expected : in out uint8;
+       Desired  : uint8) return Boolean;
+
+   function Lock_Free_Try_Write_16
+      (Ptr      : Address;
+       Expected : in out uint16;
+       Desired  : uint16) return Boolean;
+
+   function Lock_Free_Try_Write_32
+      (Ptr      : Address;
+       Expected : in out uint32;
+       Desired  : uint32) return Boolean;
+
+   function Lock_Free_Try_Write_64
+      (Ptr      : Address;
+       Expected : in out uint64;
+       Desired  : uint64) return Boolean;
+
+   pragma Inline (Lock_Free_Read_8);
+   pragma Inline (Lock_Free_Read_16);
+   pragma Inline (Lock_Free_Read_32);
+   pragma Inline (Lock_Free_Read_64);
+   pragma Inline (Lock_Free_Try_Write_8);
+   pragma Inline (Lock_Free_Try_Write_16);
+   pragma Inline (Lock_Free_Try_Write_32);
+   pragma Inline (Lock_Free_Try_Write_64);
+end System.Atomic_Primitives;