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1//===-- Utilities for suspending threads ----------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef LLVM_LIBC_SRC___SUPPORT_THREADS_SLEEP_H10#define LLVM_LIBC_SRC___SUPPORT_THREADS_SLEEP_H11 12#include "src/__support/macros/attributes.h"13#include "src/__support/macros/config.h"14 15namespace LIBC_NAMESPACE_DECL {16 17/// Suspend the thread briefly to assist the thread scheduler during busy loops.18LIBC_INLINE void sleep_briefly() {19#if defined(LIBC_TARGET_ARCH_IS_NVPTX)20 if (__nvvm_reflect("__CUDA_ARCH") >= 700)21 LIBC_INLINE_ASM("nanosleep.u32 64;" ::: "memory");22#elif defined(LIBC_TARGET_ARCH_IS_AMDGPU)23 __builtin_amdgcn_s_sleep(2);24#elif defined(LIBC_TARGET_ARCH_IS_X86)25 __builtin_ia32_pause();26#elif defined(LIBC_TARGET_ARCH_IS_AARCH64) && __has_builtin(__builtin_arm_isb)27 __builtin_arm_isb(0xf);28#elif defined(LIBC_TARGET_ARCH_IS_AARCH64)29 asm volatile("isb\n" ::: "memory");30#else31 // Simply do nothing if sleeping isn't supported on this platform.32#endif33}34 35} // namespace LIBC_NAMESPACE_DECL36 37#endif // LLVM_LIBC_SRC___SUPPORT_THREADS_SLEEP_H38