91 lines
2.6 KiB
C++
91 lines
2.6 KiB
C++
/* Low-level functions for atomic operations. PA-RISC version. -*- C++ -*-
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Copyright 2002 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If not,
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write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#ifndef _BITS_ATOMICITY_H
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#define _BITS_ATOMICITY_H 1
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typedef int _Atomic_word;
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template <int __inst>
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struct __Atomicity_lock
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{
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static volatile int _S_atomicity_lock;
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};
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template <int __inst>
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volatile int
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__Atomicity_lock<__inst>::_S_atomicity_lock __attribute__ ((aligned (16))) = 1;
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/* Because of the lack of weak support when using the hpux
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som linker, we explicitly instantiate the atomicity lock
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in src/misc-inst.cc when _GLIBCPP_INST_ATOMICITY_LOCK
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is defined. */
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#ifndef _GLIBCPP_INST_ATOMICITY_LOCK
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template volatile int __Atomicity_lock<0>::_S_atomicity_lock;
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#endif
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static inline int
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__attribute__ ((__unused__))
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__exchange_and_add (volatile _Atomic_word* __mem, int __val)
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{
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_Atomic_word result;
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int tmp;
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volatile int& lock = __Atomicity_lock<0>::_S_atomicity_lock;
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__asm__ __volatile__ ("ldcw 0(%1),%0\n\t"
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"cmpib,<>,n 0,%0,.+20\n\t"
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"ldw 0(%1),%0\n\t"
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"cmpib,= 0,%0,.-4\n\t"
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"nop\n\t"
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"b,n .-20"
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: "=&r" (tmp)
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: "r" (&lock));
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result = *__mem;
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*__mem = result + __val;
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/* Reset lock with PA 2.0 "ordered" store. */
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__asm__ __volatile__ ("stw,ma %1,0(%0)"
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: : "r" (&lock), "r" (tmp) : "memory");
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return result;
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}
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static inline void
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__attribute__ ((__unused__))
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__atomic_add (_Atomic_word* __mem, int __val)
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{
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int tmp;
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volatile int& lock = __Atomicity_lock<0>::_S_atomicity_lock;
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__asm__ __volatile__ ("ldcw 0(%1),%0\n\t"
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"cmpib,<>,n 0,%0,.+20\n\t"
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"ldw 0(%1),%0\n\t"
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"cmpib,= 0,%0,.-4\n\t"
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"nop\n\t"
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"b,n .-20"
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: "=&r" (tmp)
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: "r" (&lock));
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*__mem += __val;
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/* Reset lock with PA 2.0 "ordered" store. */
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__asm__ __volatile__ ("stw,ma %1,0(%0)"
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: : "r" (&lock), "r" (tmp) : "memory");
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}
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#endif
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