block_raking_layout.hpp

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#ifndef HIPCUB_ROCPRIM_BLOCK_BLOCK_RAKING_LAYOUT_HPP_
#define HIPCUB_ROCPRIM_BLOCK_BLOCK_RAKING_LAYOUT_HPP_

#include <type_traits>

#include "../../../config.hpp"

#include <rocprim/config.hpp>
#include <rocprim/detail/various.hpp>

BEGIN_HIPCUB_NAMESPACE

template<typename T, int BLOCK_THREADS, int ARCH = HIPCUB_ARCH /* ignored */
         >
struct BlockRakingLayout
{
    //---------------------------------------------------------------------
    // Constants and type definitions
    //---------------------------------------------------------------------

    enum
    {
        SHARED_ELEMENTS = BLOCK_THREADS,

        MAX_RAKING_THREADS = ::rocprim::detail::get_min_warp_size(
            static_cast<unsigned int>(BLOCK_THREADS), HIPCUB_DEVICE_WARP_THREADS),

        SEGMENT_LENGTH = (SHARED_ELEMENTS + MAX_RAKING_THREADS - 1) / MAX_RAKING_THREADS,

        RAKING_THREADS = (SHARED_ELEMENTS + SEGMENT_LENGTH - 1) / SEGMENT_LENGTH,

        USE_SEGMENT_PADDING = ((SEGMENT_LENGTH & 1) == 0) && (SEGMENT_LENGTH > 2),

        GRID_ELEMENTS = RAKING_THREADS * (SEGMENT_LENGTH + USE_SEGMENT_PADDING),

        UNGUARDED = (SHARED_ELEMENTS % RAKING_THREADS == 0),
    };

#ifndef DOXYGEN_SHOULD_SKIP_THIS    // Do not document

    struct __align__(16) _TempStorage
    {
        T buff[BlockRakingLayout::GRID_ELEMENTS];
    };

#endif

    struct TempStorage : Uninitialized<_TempStorage> {};

    static HIPCUB_DEVICE inline T* PlacementPtr(
        TempStorage &temp_storage,
        unsigned int linear_tid)
    {
        // Offset for partial
        unsigned int offset = linear_tid;

        // Add in one padding element for every segment
        if (USE_SEGMENT_PADDING > 0)
        {
            offset += offset / SEGMENT_LENGTH;
        }

        // Incorporating a block of padding partials every shared memory segment
        return temp_storage.Alias().buff + offset;
    }

    static HIPCUB_DEVICE inline T* RakingPtr(
        TempStorage &temp_storage,
        unsigned int linear_tid)
    {
        return temp_storage.Alias().buff + (linear_tid * (SEGMENT_LENGTH + USE_SEGMENT_PADDING));
    }
};

END_HIPCUB_NAMESPACE

#endif // HIPCUB_ROCPRIM_BLOCK_BLOCK_RAKING_LAYOUT_HPP_