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/* Copyright (C) 2003-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <errno.h>
#include "pthreadP.h"
int
pthread_spin_trylock (pthread_spinlock_t *lock)
{
unsigned int old;
int err = EBUSY;
asm ("1: lwarx %0,0,%2" MUTEX_HINT_ACQ "\n"
" cmpwi 0,%0,0\n"
" bne 2f\n"
" stwcx. %3,0,%2\n"
" bne- 1b\n"
" li %1,0\n"
__ARCH_ACQ_INSTR "\n"
"2: "
: "=&r" (old), "=&r" (err)
: "r" (lock), "r" (1), "1" (err)
: "cr0", "memory");
return err;
}
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