glibc/sysdeps/sparc/cpu_relax.c

41 lines
1.2 KiB
C

/* CPU strand yielding for busy loops. Linux/sparc version.
Copyright (C) 2017-2024 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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 <sparc-ifunc.h>
#ifdef __sparc_v9__
static void
__cpu_relax_generic (void)
{
asm volatile ("rd %ccr, %g0;"
"rd %ccr, %g0;"
"rd %ccr, %g0");
}
static void
__cpu_relax_pause (void)
{
asm volatile ("wr %g0, 128, %asr27");
}
sparc_libc_ifunc (__cpu_relax,
hwcap & HWCAP_SPARC_PAUSE
? __cpu_relax_pause
: __cpu_relax_generic)
#endif