src/core/NEON/kernels/assembly/winograd.hpp

/*
 * Copyright (c) 2022 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 "src/cpu/kernels/assembly/arm_gemm.hpp"
#include <cstddef>

namespace arm_conv
{
struct Shape2D
{
    unsigned int rows, cols;
};

struct ConvolutionArgs
{
    unsigned int         n_batches;
    Shape2D              input_shape;
    unsigned int         n_input_channels;
    unsigned int         pad_top, pad_left;
    Shape2D              output_shape;
    unsigned int         n_output_channels;
    Shape2D              kernel_shape;
    arm_gemm::Activation activation;

    ConvolutionArgs(
        unsigned int   n_batches,
        const Shape2D &input_shape,
        unsigned int   n_input_channels,
        unsigned int pad_top, unsigned int pad_left,
        const Shape2D              &output_shape,
        unsigned int                n_output_channels,
        const Shape2D               kernel_shape,
        const arm_gemm::Activation &activation = {})
        : n_batches(n_batches), input_shape(input_shape), n_input_channels(n_input_channels), pad_top(pad_top), pad_left(pad_left), output_shape(output_shape), n_output_channels(n_output_channels),
          kernel_shape(kernel_shape), activation(activation)
    {
    }
};

namespace winograd
{
/* Constrain the selected Winograd implementation.
 */
struct WinogradConfig
{
    unsigned int output_rows = 0, output_cols = 0;
    std::string  input_transform_filter  = "";
    std::string  output_transform_filter = "";
    std::string  weight_transform_filter = "";
};

/* Struct describing (suggested) memory layout within the Winograd domain.
 */
struct WinogradDomainSpec
{
    size_t weight_matrix_size_bytes, input_matrix_size_bytes, output_matrix_size_bytes;

    size_t weight_ld_matrix, weight_ld_row;
    size_t input_ld_batch, input_ld_matrix, input_ld_row;
    size_t output_ld_batch, output_ld_matrix, output_ld_row;
};

class ITransformCommon
{
public:
    virtual ~ITransformCommon() = default;

    // Get the name of the transform
    virtual const std::string &get_name(void) const = 0;
};

namespace weight_transform
{
class ITransform : public ITransformCommon
{
public:
    ~ITransform() = default;

    virtual unsigned int get_kernel_rows(void) const = 0;
    virtual unsigned int get_kernel_cols(void) const = 0;

    virtual unsigned int get_transformed_tile_rows(void) const = 0;
    virtual unsigned int get_transformed_tile_cols(void) const = 0;

    void execute(
        const ConvolutionArgs &args,
        const void *inptr, size_t ld_in_row, size_t ld_in_col, size_t ld_input_channel,
        void *outptr, const WinogradDomainSpec &wds,
        unsigned int thread_id, unsigned int n_threads) const
    {
        this->execute(
            args, inptr, ld_in_row, ld_in_col, ld_input_channel,
            outptr, wds.weight_ld_matrix, wds.weight_ld_row,
            thread_id, n_threads);
    }

    virtual void execute(
        const ConvolutionArgs &args,
        const void *inptr, size_t ld_in_row, size_t ld_in_col, size_t ld_input_channel,
        void *outptr, size_t ld_out_matrix, size_t ld_out_row,
        unsigned int thread_id, unsigned int n_threads) const = 0;
};

} // namespace weight_transform

namespace input_transform
{
class ITransform : public ITransformCommon
{
public:
    ~ITransform() = default;

    virtual unsigned int get_input_rows(void) const = 0;
    virtual unsigned int get_input_cols(void) const = 0;

    virtual size_t get_working_space_size(
        const ConvolutionArgs &args,
        unsigned int           n_threads) const = 0;

    void execute(
        const ConvolutionArgs &args,
        const void *inptr, size_t ld_in_batch, size_t ld_in_row, size_t ld_in_col,
        void *outptr, const WinogradDomainSpec &wds,
        void *working_space, unsigned int thread_id, unsigned int n_threads) const
    {
        this->execute(
            args, inptr, ld_in_batch, ld_in_row, ld_in_col,
            outptr, wds.input_ld_batch, wds.input_ld_matrix, wds.input_ld_row,
            working_space, thread_id, n_threads);
    }

    virtual void execute(
        const ConvolutionArgs &args,
        const void *inptr, size_t ld_in_batch, size_t ld_in_row, size_t ld_in_col,
        void *outptr, size_t ld_out_batch, size_t ld_out_matrix, size_t ld_out_row,
        void *working_space, unsigned int thread_id, unsigned int n_threads) const = 0;
};

} // namespace input_transform

namespace output_transform
{
class ITransform : public ITransformCommon
{
public:
    ~ITransform() = default;

    virtual unsigned int get_input_rows(void) const = 0;
    virtual unsigned int get_input_cols(void) const = 0;

    virtual unsigned int get_output_rows(void) const = 0;
    virtual unsigned int get_output_cols(void) const = 0;

    virtual unsigned int get_kernel_rows(void) const = 0;
    virtual unsigned int get_kernel_cols(void) const = 0;

    virtual size_t get_working_space_size(
        const ConvolutionArgs &args,
        unsigned int           n_threads) const = 0;

    void execute(
        const ConvolutionArgs &args,
        const void *inptr, const WinogradDomainSpec &wds,
        const void *bias,
        void *outptr, size_t ld_out_batch, size_t ld_out_row, size_t ld_out_col,
        void *working_space, unsigned int thread_id, unsigned int n_threads) const
    {
        this->execute(
            args,
            inptr, wds.output_ld_batch, wds.output_ld_matrix, wds.output_ld_row,
            bias,
            outptr, ld_out_batch, ld_out_row, ld_out_col,
            working_space, thread_id, n_threads);
    }

    virtual void execute(
        const ConvolutionArgs &args,
        const void *inptr, size_t ld_in_batch, size_t ld_in_matrix, size_t ld_in_row,
        const void *bias,
        void *outptr, size_t ld_out_batch, size_t ld_out_row, size_t ld_out_col,
        void *working_space, unsigned int thread_id, unsigned int n_threads) const = 0;
};

} // namespace output_transform

struct WinogradImpl
{
    const output_transform::ITransform *output_transform = nullptr;
    const weight_transform::ITransform *weight_transform = nullptr;
    const input_transform::ITransform *input_transform  = nullptr;
    std::unique_ptr<arm_gemm::GemmArgs> gemm_args;
    WinogradDomainSpec                  winograd_spec;
};

/* Get pointers to Winograd transforms for the given convolution problem.
 *
 * Assigns to the pointers in the `dest` struct and returns true or false to
 * indicate whether the given problem can be executed or not.
 */
template <typename TIn, typename TWeight = TIn, typename TOut = TIn, typename TWinogradIn = TIn, typename TWinogradOut = TOut>
bool get_implementation(
    WinogradImpl &dest, // Destination for the selected implementation
    const CPUInfo *,
    const ConvolutionArgs &,
    int  max_threads,
    bool fast_mode,
    const WinogradConfig *,
    const arm_gemm::GemmConfig *);

} // namespace winograd
} // namespace arm_conv