mirror of
https://sourceware.org/git/glibc.git
synced 2025-11-15 15:21:18 +03:00
324c088a18
The only usage was for pthread_spin_lock, introduced by 12d2dd7060,
as a way to optimize the code for certain architectures. Now that atomic
builtins are used by default, let the compiler use the best code sequence
for the atomic exchange.
Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
52 lines
1.8 KiB
C
52 lines
1.8 KiB
C
/* Low-level functions for atomic operations. RISC-V version.
|
|
Copyright (C) 2014-2025 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/>. */
|
|
|
|
#ifndef _LINUX_RISCV_BITS_ATOMIC_H
|
|
#define _LINUX_RISCV_BITS_ATOMIC_H 1
|
|
|
|
#ifdef __riscv_atomic
|
|
|
|
/* Miscellaneous. */
|
|
|
|
# define asm_amo(which, ordering, mem, value) ({ \
|
|
__atomic_check_size (mem); \
|
|
typeof (*mem) __tmp; \
|
|
if (sizeof (__tmp) == 4) \
|
|
asm volatile (which ".w" ordering "\t%0, %z2, %1" \
|
|
: "=r" (__tmp), "+A" (* (mem)) \
|
|
: "rJ" (value)); \
|
|
else if (sizeof (__tmp) == 8) \
|
|
asm volatile (which ".d" ordering "\t%0, %z2, %1" \
|
|
: "=r" (__tmp), "+A" (* (mem)) \
|
|
: "rJ" (value)); \
|
|
else \
|
|
abort (); \
|
|
__tmp; })
|
|
|
|
# define atomic_max(mem, value) asm_amo ("amomaxu", ".aq", mem, value)
|
|
# define atomic_min(mem, value) asm_amo ("amominu", ".aq", mem, value)
|
|
|
|
#else /* __riscv_atomic */
|
|
# error "ISAs that do not subsume the A extension are not supported"
|
|
#endif /* !__riscv_atomic */
|
|
|
|
/* Execute a PAUSE hint when spinning. */
|
|
#define atomic_spin_nop() __asm(".insn i 0x0f, 0, x0, x0, 0x010")
|
|
|
|
#endif /* bits/atomic.h */
|