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/* Copyright (C) 2002-2014 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
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
<http://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include <lowlevellock.h>
#include <shlib-compat.h>
#include <pthread-errnos.h>
#include <structsem.h>
.text
.globl sem_post
.type sem_post,@function
.align 16
sem_post:
#if VALUE == 0
movl (%rdi), %eax
#else
movl VALUE(%rdi), %eax
#endif
0: cmpl $SEM_VALUE_MAX, %eax
je 3f
leal 1(%rax), %esi
LOCK
#if VALUE == 0
cmpxchgl %esi, (%rdi)
#else
cmpxchgl %esi, VALUE(%rdi)
#endif
jnz 0b
LP_OP(cmp) $0, NWAITERS(%rdi)
je 2f
movl $SYS_futex, %eax
movl $FUTEX_WAKE, %esi
orl PRIVATE(%rdi), %esi
movl $1, %edx
syscall
testq %rax, %rax
js 1f
2: xorl %eax, %eax
retq
1:
movl $EINVAL, %eax
jmp 4f
3:
movl $EOVERFLOW, %eax
4:
movq errno@gottpoff(%rip), %rdx
movl %eax, %fs:(%rdx)
orl $-1, %eax
retq
.size sem_post,.-sem_post
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