--- /dev/null
+// Low-level functions for atomic operations: S/390 version -*- C++ -*-
+
+// Copyright (C) 2001 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 2, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING. If not, write to the Free
+// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+// USA.
+
+// As a special exception, you may use this file as part of a free software
+// library without restriction. Specifically, if other files instantiate
+// templates or use macros or inline functions from this file, or you compile
+// this file and link it with other files to produce an executable, this
+// file does not by itself cause the resulting executable to be covered by
+// the GNU General Public License. This exception does not however
+// invalidate any other reasons why the executable file might be covered by
+// the GNU General Public License.
+
+#ifndef _BITS_ATOMICITY_H
+#define _BITS_ATOMICITY_H 1
+
+typedef int _Atomic_word;
+
+static inline _Atomic_word
+__attribute__ ((__unused__))
+__exchange_and_add (volatile _Atomic_word *__mem, int __val)
+{
+ register _Atomic_word __old_val, __new_val;
+
+ __asm__ __volatile__ (" l %0,0(%2)\n"
+ "0: lr %1,%0\n"
+ " ar %1,%3\n"
+ " cs %0,%1,0(%2)\n"
+ " jl 0b"
+ : "=&d" (__old_val), "=&d" (__new_val)
+ : "a" (__mem), "d" (__val) : "cc", "memory" );
+ return __old_val;
+}
+
+static inline void
+__attribute__ ((__unused__))
+__atomic_add (volatile _Atomic_word *__mem, int __val)
+{
+ __exchange_and_add (__mem, __val);
+}
+
+#endif /* atomicity.h */
+
+