// -*- C++ -*- //===----------------------------------------------------------------------===// // // Part of libcu++, the C++ Standard Library for your entire system, // under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // SPDX-FileCopyrightText: Copyright (c) 2024 NVIDIA CORPORATION & AFFILIATES. // //===----------------------------------------------------------------------===// #ifndef _CUDA_PTX_BARRIER_EXPECT_TX_H_ #define _CUDA_PTX_BARRIER_EXPECT_TX_H_ #include #if defined(_CCCL_IMPLICIT_SYSTEM_HEADER_GCC) # pragma GCC system_header #elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_CLANG) # pragma clang system_header #elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_MSVC) # pragma system_header #endif // no system header #if _CCCL_HAS_CUDA_COMPILER() # if __cccl_ptx_isa >= 800 # include # include # include # include # include # include _LIBCUDACXX_BEGIN_NAMESPACE_CUDA_DEVICE extern "C" _CCCL_DEVICE void __cuda_ptx_barrier_expect_tx_is_not_supported_before_SM_90__(); _CCCL_DEVICE inline void barrier_expect_tx(barrier& __b, _CUDA_VSTD::ptrdiff_t __transaction_count_update) { _CCCL_ASSERT(__isShared(barrier_native_handle(__b)), "Barrier must be located in local shared memory."); _CCCL_ASSERT(__transaction_count_update >= 0, "Transaction count update must be non-negative."); // https://docs.nvidia.com/cuda/parallel-thread-execution/index.html#contents-of-the-mbarrier-object _CCCL_ASSERT(__transaction_count_update <= (1 << 20) - 1, "Transaction count update cannot exceed 2^20 - 1."); // We do not check for the statespace of the barrier here. This is // on purpose. This allows debugging tools like memcheck/racecheck // to detect that we are passing a pointer with the wrong state // space to mbarrier.arrive. If we checked for the state space here, // and __trap() if wrong, then those tools would not be able to help // us in release builds. In debug builds, the error would be caught // by the asserts at the top of this function. // On architectures pre-sm90, arrive_tx is not supported. NV_IF_ELSE_TARGET( NV_PROVIDES_SM_90, (auto __bh = __cvta_generic_to_shared(barrier_native_handle(__b)); asm("mbarrier.expect_tx.relaxed.cta.shared::cta.b64 [%0], %1;" : : "r"(static_cast<_CUDA_VSTD::uint32_t>(__bh)), "r"(static_cast<_CUDA_VSTD::uint32_t>(__transaction_count_update)) : "memory");), (__cuda_ptx_barrier_expect_tx_is_not_supported_before_SM_90__();)); } _LIBCUDACXX_END_NAMESPACE_CUDA_DEVICE # endif // __cccl_ptx_isa >= 800 #endif // _CCCL_CUDA_COMPILER #endif // _CUDA_PTX_BARRIER_EXPECT_TX_H_