cosmopolitan/libc/nexgen32e/atomicislockfree.S

40 lines
2.3 KiB
ArmAsm

/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8 -*-│
vi: set et ft=asm ts=8 tw=8 fenc=utf-8 :vi
Copyright 2020 Justine Alexandra Roberts Tunney
This program 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; version 2 of the License. │
This program 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 program; if not, write to the Free Software │
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA
*/
#include "libc/macros.h"
/ Returns true if architecture guarantees atomicity.
/
/ @param rdi is byte width of type
/ @param rsi is optional pointer for alignment check
/ @see Intel's Six Thousand Page Manual V.3A §8.2.3.1
__atomic_is_lock_free:
.leafprologue
.profilable
xor %ecx,%ecx
pushpop 1,%rax
cmp $7,%rdi
cmova %ecx,%eax
dec %edi
and %edi,%esi
cmovnz %ecx,%eax
.leafepilogue
.endfn __atomic_is_lock_free,globl,hidden
.source __FILE__