| 1 | //===-- Utilities for suspending threads ----------------------------------===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | |
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| 9 | #ifndef LLVM_LIBC_SRC___SUPPORT_THREADS_SLEEP_H |
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| 10 | #define LLVM_LIBC_SRC___SUPPORT_THREADS_SLEEP_H |
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| 11 | |
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| 12 | #include "src/__support/macros/attributes.h" |
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| 13 | |
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| 14 | namespace LIBC_NAMESPACE { |
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| 15 | |
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| 16 | /// Suspend the thread briefly to assist the thread scheduler during busy loops. |
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| 17 | LIBC_INLINE void sleep_briefly() { |
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| 18 | #if defined(LIBC_TARGET_ARCH_IS_NVPTX) |
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| 19 | if (__nvvm_reflect("__CUDA_ARCH" ) >= 700) |
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| 20 | LIBC_INLINE_ASM("nanosleep.u32 64;" ::: "memory" ); |
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| 21 | #elif defined(LIBC_TARGET_ARCH_IS_AMDGPU) |
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| 22 | __builtin_amdgcn_s_sleep(2); |
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| 23 | #elif defined(LIBC_TARGET_ARCH_IS_X86) |
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| 24 | __builtin_ia32_pause(); |
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| 25 | #elif defined(LIBC_TARGET_ARCH_IS_AARCH64) |
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| 26 | __builtin_arm_isb(0xf); |
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| 27 | #else |
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| 28 | // Simply do nothing if sleeping isn't supported on this platform. |
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| 29 | #endif |
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| 30 | } |
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| 31 | |
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| 32 | } // namespace LIBC_NAMESPACE |
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| 33 | |
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| 34 | #endif // LLVM_LIBC_SRC___SUPPORT_THREADS_SLEEP_H |
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| 35 | |
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