freebsd-dev/contrib/libstdc++/config/cpu/alpha/atomicity.h

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// Low-level functions for atomic operations: Alpha version -*- C++ -*-
// Copyright (C) 1999, 2000, 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
/* @@@ With gas we can play nice .subsection games to get the
non-predicted branch pointing forward. But Digital assemblers
don't understand those directives. This isn't a terribly
important issue, so just ignore it. */
typedef int _Atomic_word;
static inline _Atomic_word
__attribute__ ((__unused__))
__exchange_and_add (volatile _Atomic_word* __mem, int __val)
{
register int __result, __tmp;
__asm__ __volatile__ (
"\n$Lxadd_%=:\n\t"
"ldl_l %0,%3\n\t"
"addl %0,%4,%1\n\t"
"stl_c %1,%2\n\t"
"beq %1,$Lxadd_%=\n\t"
"mb"
: "=&r"(__result), "=&r"(__tmp), "=m"(*__mem)
: "m" (*__mem), "r"(__val));
return __result;
}
static inline void
__attribute__ ((__unused__))
__atomic_add (volatile _Atomic_word* __mem, int __val)
{
register _Atomic_word __result;
__asm__ __volatile__ (
"\n$Ladd_%=:\n\t"
"ldl_l %0,%2\n\t"
"addl %0,%3,%0\n\t"
"stl_c %0,%1\n\t"
"beq %0,$Ladd_%=\n\t"
"mb"
: "=&r"(__result), "=m"(*__mem)
: "m" (*__mem), "r"(__val));
}
#endif /* atomicity.h */