// Copyright 2015 The Gemmlowp Authors. All Rights Reserved.

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//     http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

// compute.h: the central stage of the Gemm computation, operates

// on already-packed LHS and RHS blocks and calls the Gemm kernel

// to compute a block of the product.

#ifndef GEMMLOWP_INTERNAL_COMPUTE_H_

#define GEMMLOWP_INTERNAL_COMPUTE_H_

#include "block_params.h"

#include "kernel.h"

#include "pack.h"

namespace gemmlowp {

template <typename PackedLhs, typename PackedRhs, typename PackedResult>

class ComputeImpl {

  typedef typename PackedLhs::KernelSideFormat KernelLhsFormat;

  typedef typename PackedRhs::KernelSideFormat KernelRhsFormat;

  typedef KernelFormat<KernelLhsFormat, KernelRhsFormat> Format;

  const KernelBase& kernel_;

  const BlockParams& block_params_;

  PackedResult* const packed_result_;

  const PackedLhs& packed_lhs_;

  const PackedRhs& packed_rhs_;

 public:

  ComputeImpl(const KernelBase& _kernel, const BlockParams& _block_params,

              PackedResult* _packed_result, const PackedLhs& _packed_lhs,

              const PackedRhs& _packed_rhs)

      : kernel_(_kernel),

        block_params_(_block_params),

        packed_result_(_packed_result),

        packed_lhs_(_packed_lhs),

        packed_rhs_(_packed_rhs) {}

  void Compute(int depth) {

    depth = RoundUp<Format::kDepth>(depth);

    assert(depth <= block_params_.l2_depth);

    for (int d = 0; d < depth; d += block_params_.l1_depth) {

      int ds = std::min(block_params_.l1_depth, depth - d);

      for (int r = 0; r < block_params_.l2_rows; r += block_params_.l1_rows) {

        int rs = std::min(block_params_.l1_rows, block_params_.l2_rows - r);

        ComputeL1(r, rs, 0, block_params_.l2_cols, d, ds);

      }

    }

  }

 private:

  static void MarkPackedResultBlockAsInitialized(

      const MatrixMap<std::int32_t, MapOrder::ColMajor>& packed_result_block) {

#ifdef GEMMLOWP_MARK_MEMORY_AS_INITIALIZED

    for (int col = 0; col < packed_result_block.cols(); col++) {

      MarkMemoryAsInitialized(

          packed_result_block.data() + col * packed_result_block.cols_stride(),

          packed_result_block.rows());

    }

#else

    (void)packed_result_block;

#endif

  }

  void ComputeRun(int start_row, int start_col, int start_depth,

                  int depth) GEMMLOWP_NOINLINE {

    packed_lhs_.seek_run(start_row, start_depth);

    packed_rhs_.seek_run(start_col, start_depth);

    auto packed_result_block = packed_result_->Map().block(

        start_row, start_col, Format::kRows, Format::kCols);

    kernel_.Run(packed_result_block.data(), packed_result_block.rows_stride(),

                packed_result_block.cols_stride(), packed_lhs_.current_data(),

                packed_rhs_.current_data(), start_depth, depth);

    MarkPackedResultBlockAsInitialized(packed_result_block);

  }

  void ComputeL1(int start_row, int rows, int start_col, int cols,

                 int start_depth, int depth) {

    assert(rows % Format::kRows == 0);

    assert(cols % Format::kCols == 0);

    assert(depth % Format::kDepth == 0);

    for (int c = 0; c < cols; c += Format::kCols) {

      for (int r = 0; r < rows; r += Format::kRows) {

        ComputeRun(start_row + r, start_col + c, start_depth, depth);

      }

    }

  }

};

template <typename PackedLhs, typename PackedRhs, typename PackedResult>

void Compute(const KernelBase& kernel, const BlockParams& block_params,

             PackedResult* packed_result, const PackedLhs& packed_lhs,

             const PackedRhs& packed_rhs, int depth) {

  ScopedProfilingLabel label("compute");

  ComputeImpl<PackedLhs, PackedRhs, PackedResult> impl(

      kernel, block_params, packed_result, packed_lhs, packed_rhs);

  impl.Compute(depth);

}

}  // namespace gemmlowp

#endif  // GEMMLOWP_INTERNAL_COMPUTE_H_