17789fb66SJoseph Huber //===-- Utilities for suspending threads ----------------------------------===// 27789fb66SJoseph Huber // 37789fb66SJoseph Huber // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 47789fb66SJoseph Huber // See https://llvm.org/LICENSE.txt for license information. 57789fb66SJoseph Huber // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 67789fb66SJoseph Huber // 77789fb66SJoseph Huber //===----------------------------------------------------------------------===// 87789fb66SJoseph Huber 97789fb66SJoseph Huber #ifndef LLVM_LIBC_SRC___SUPPORT_THREADS_SLEEP_H 107789fb66SJoseph Huber #define LLVM_LIBC_SRC___SUPPORT_THREADS_SLEEP_H 117789fb66SJoseph Huber 127789fb66SJoseph Huber #include "src/__support/macros/attributes.h" 13*5ff3ff33SPetr Hosek #include "src/__support/macros/config.h" 147789fb66SJoseph Huber 15*5ff3ff33SPetr Hosek namespace LIBC_NAMESPACE_DECL { 167789fb66SJoseph Huber 177789fb66SJoseph Huber /// Suspend the thread briefly to assist the thread scheduler during busy loops. 187789fb66SJoseph Huber LIBC_INLINE void sleep_briefly() { 197789fb66SJoseph Huber #if defined(LIBC_TARGET_ARCH_IS_NVPTX) 207789fb66SJoseph Huber if (__nvvm_reflect("__CUDA_ARCH") >= 700) 217789fb66SJoseph Huber LIBC_INLINE_ASM("nanosleep.u32 64;" ::: "memory"); 227789fb66SJoseph Huber #elif defined(LIBC_TARGET_ARCH_IS_AMDGPU) 237789fb66SJoseph Huber __builtin_amdgcn_s_sleep(2); 247789fb66SJoseph Huber #elif defined(LIBC_TARGET_ARCH_IS_X86) 257789fb66SJoseph Huber __builtin_ia32_pause(); 261b26bb0dSSchrodinger ZHU Yifan #elif defined(LIBC_TARGET_ARCH_IS_AARCH64) && __has_builtin(__builtin_arm_isb) 277789fb66SJoseph Huber __builtin_arm_isb(0xf); 281b26bb0dSSchrodinger ZHU Yifan #elif defined(LIBC_TARGET_ARCH_IS_AARCH64) 291b26bb0dSSchrodinger ZHU Yifan asm volatile("isb\n" ::: "memory"); 307789fb66SJoseph Huber #else 317789fb66SJoseph Huber // Simply do nothing if sleeping isn't supported on this platform. 327789fb66SJoseph Huber #endif 337789fb66SJoseph Huber } 347789fb66SJoseph Huber 35*5ff3ff33SPetr Hosek } // namespace LIBC_NAMESPACE_DECL 367789fb66SJoseph Huber 377789fb66SJoseph Huber #endif // LLVM_LIBC_SRC___SUPPORT_THREADS_SLEEP_H 38