src/core/NEON/kernels/arm_gemm/gemm_native.hpp

/*
 * Copyright (c) 2017-2018 ARM Limited.
 *
 * SPDX-License-Identifier: MIT
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
#pragma once

#include <stdio.h>

#include "arm_gemm.hpp"

#include "mergeresults.hpp"
#include "transform.hpp"

#ifdef CYCLE_PROFILING
#include "profiler.hpp"
#endif

namespace arm_gemm
{
// Implementation of the GemmCommon abstract class.
//
// This is implementation is for native GEMM with no transposition.
//
// By default the source data is used in-place, but if type conversion is
// needed we need to allocate working space (CURRENTLY NOT IMPLEMENTED).

template <typename strategy, typename To, typename Tr>
class GemmNative : public GemmCommon<To, Tr>
{
    typedef typename strategy::operand_type Toi;
    typedef typename strategy::result_type  Tri;

    const unsigned int _Msize;
    const unsigned int _Nsize;
    const unsigned int _Ksize;

    const unsigned int _nbatches;
    const unsigned int _nmultis;

    Tr _beta;

    const CPUInfo *const _ci;

    unsigned int k_block = 0;
    unsigned int n_block = 0;

public:
    GemmNative(GemmNative &) = delete;
    GemmNative &operator=(GemmNative &) = delete;

    GemmNative(const CPUInfo *ci, const unsigned int M, const unsigned int N, const unsigned int K, const unsigned int nbatches, const unsigned int nmultis, const Tr beta)
        : _Msize(M), _Nsize(N), _Ksize(K), _nbatches(nbatches), _nmultis(nmultis), _beta(beta), _ci(ci)
    {
        /* For now don't do any blocking. TODO: figure out if we should. */
        k_block = K;
        n_block = N;
    }

    // Window is number of out_height blocks
    unsigned int get_window_size() const override
    {
        return iceildiv(_Msize, strategy::out_height) * _nbatches * _nmultis;
    }

    // Actually execute the GEMM.
    void execute(unsigned int start, unsigned int end, int) override
    {
#ifdef CYCLE_PROFILING
        profiler prof;
#endif
        strategy           strat(_ci);
        const unsigned int window_per_batch = iceildiv(_Msize, strategy::out_height);
        const unsigned int window_per_multi = window_per_batch * _nbatches;

        const unsigned int first_multi = start / window_per_multi;
        const unsigned int last_multi  = end / window_per_multi;

        const unsigned int first_batch = (start - (first_multi * window_per_multi)) / window_per_batch;
        const unsigned int last_batch  = (end - (last_multi * window_per_multi)) / window_per_batch;

        const unsigned int first_row = ((start - (first_multi * window_per_multi)) % window_per_batch) * strategy::out_height;
        const unsigned int last_row  = ((end - (last_multi * window_per_multi)) % window_per_batch) * strategy::out_height;

        static_assert(std::is_same<To, Toi>::value, "gemm_native: Operand types must be the same.");
        static_assert(std::is_same<Tr, Tri>::value, "gemm_native: Result types must be the same.");

        for(unsigned int multi = first_multi; multi <= last_multi; multi++)
        {
            const unsigned int batch_0   = (multi == first_multi) ? first_batch : 0;
            const unsigned int batch_max = (multi == last_multi) ? last_batch : _nbatches - 1;

            for(unsigned int batch = batch_0; batch <= batch_max; batch++)
            {
                const unsigned int m_start = ((multi == first_multi) && (batch == first_batch)) ? first_row : 0;
                const unsigned int m_end   = ((multi == last_multi) && (batch == last_batch)) ? last_row : _Msize;

                for(unsigned int y0 = m_start; y0 < m_end; y0 += strategy::out_height)
                {
                    const unsigned int ymax = std::min(y0 + strategy::out_height, m_end);
#ifdef CYCLE_PROFILING
                    auto p = prof.ScopedProfiler(PROFILE_KERNEL, (ymax - y0) * _Nsize * _Ksize);
#endif

                    strat.kernel(this->_Aptr + (multi * this->_A_multi_stride) + (batch * this->_A_batch_stride) + (y0 * this->_lda), this->_lda,
                                 this->_Bptr + (multi * this->_B_multi_stride), this->_ldb,
                                 this->_Cptr + (multi * this->_C_multi_stride) + (batch * this->_C_batch_stride) + (y0 * this->_ldc), this->_ldc,
                                 _beta, (ymax - y0), _Nsize, _Ksize);
                }
            }
        }
    }
};

} // namespace arm_gemm