BlockSharedMemDynUniformCudaHipBuiltIn.hpp

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/* Copyright 2022 Benjamin Worpitz, René Widera, Andrea Bocci, Bernhard Manfred Gruber
 * SPDX-License-Identifier: MPL-2.0
 */
 
#pragma once
 
#include "alpaka/block/shared/dyn/Traits.hpp"
#include "alpaka/core/BoostPredef.hpp"
#include "alpaka/core/Interface.hpp"
 
#include <cstddef>
#include <type_traits>
 
#if defined(ALPAKA_ACC_GPU_CUDA_ENABLED) || defined(ALPAKA_ACC_GPU_HIP_ENABLED)
 
namespace alpaka
{
    //! The GPU CUDA/HIP block shared memory allocator.
    class BlockSharedMemDynUniformCudaHipBuiltIn
        : public interface::Implements<ConceptBlockSharedDyn, BlockSharedMemDynUniformCudaHipBuiltIn>
    {
    };
 
#    if !defined(ALPAKA_HOST_ONLY)
 
#        if defined(ALPAKA_ACC_GPU_CUDA_ENABLED) && !BOOST_LANG_CUDA
#            error If ALPAKA_ACC_GPU_CUDA_ENABLED is set, the compiler has to support CUDA!
#        endif
 
#        if defined(ALPAKA_ACC_GPU_HIP_ENABLED) && !BOOST_LANG_HIP
#            error If ALPAKA_ACC_GPU_HIP_ENABLED is set, the compiler has to support HIP!
#        endif
 
    namespace trait
    {
        template<typename T>
        struct GetDynSharedMem<T, BlockSharedMemDynUniformCudaHipBuiltIn>
        {
            __device__ static auto getMem(BlockSharedMemDynUniformCudaHipBuiltIn const&) -> T*
            {
                // Because unaligned access to variables is not allowed in device code,
                // we use the widest possible alignment supported by CUDA types to have
                // all types aligned correctly.
                // See:
                //   - http://docs.nvidia.com/cuda/cuda-c-programming-guide/index.html#shared
                //   - http://docs.nvidia.com/cuda/cuda-c-programming-guide/index.html#vector-types
                extern __shared__ std::byte shMem alignas(std::max_align_t)[];
                return reinterpret_cast<T*>(shMem);
            }
        };
    } // namespace trait
 
#    endif
 
} // namespace alpaka
 
#endif