text: /*
   * Copyright (c) 2019 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 <assert.h>
  
  #include <algorithm>
  
  #include "arm_gemm.hpp"
  #include "ndrange.hpp"
  #include "utils.hpp"
  
  #include "mergeresults.hpp"
  #include "transform.hpp"
  
  #ifdef CYCLE_PROFILING
  #include "profiler.hpp"
  #endif
  
  namespace arm_gemm {
  
  // Implementation of the GemmCommon abstract class.
  template<typename strategy, typename To, typename Tr>
  class GemmHybrid : public GemmCommon<To, Tr> {
      typedef typename strategy::operand_type Toi;
      typedef typename strategy::result_type Tri;
  
      /* const properties set by constructor */
      const CPUInfo * const _ci;
  
      const unsigned int _Msize;
      const unsigned int _Nsize;
      const unsigned int _Ksize;
  
      const unsigned int _nbatches;
      const unsigned int _nmulti;
  
      const bool _trB;
  
      const Tr _beta;
  
      /* Blocking info */
      const unsigned int _k_block;
      const unsigned int _n_block;
      const unsigned int _Mround;
  
      /* Pretransposed buffer. */
      const Toi *_B_transposed=nullptr;
  
      const NDRange<4> _window_range;
  
      static unsigned int compute_k_block(const GemmArgs<Tr> &args) {
          if (args._cfg && args._cfg->inner_block_size) {
              return args._cfg->inner_block_size;
          }
  
          const unsigned int L1_size = args._ci->get_L1_cache_size();
  
          // k_block: Find out how much of the larger array can be loaded into half the cache.
          // This should account for associative caches.
          unsigned int k_block = (L1_size / 2) / (sizeof(Toi) * (std::max(strategy::out_width(), strategy::out_height())));
  
          // Needs to be (at least a single) multiple of the K unroll level.
          k_block /= strategy::k_unroll();
          k_block = std::max(k_block, 1U) * strategy::k_unroll();
  
          // Now tune to presented problem size; this is how many blocks we need.
          unsigned int numk_blocks = iceildiv(args._Ksize, k_block);
  
          // So divide the space equally into that many blocks.
          k_block = iceildiv(args._Ksize, numk_blocks);
  
          // And round UP to the K unroll level required.
          k_block = roundup(k_block, strategy::k_unroll());
  
          return k_block;
      }
  
      static unsigned int compute_n_block(const GemmArgs<Tr> &args) {
          if (args._cfg && args._cfg->outer_block_size) {
              return args._cfg->outer_block_size;
          }
  
          const unsigned int k_block = compute_k_block(args);
          const unsigned int L2_size = args._ci->get_L2_cache_size();
  
          // n_block: Work out how many rows (of length k_block) will fit in the L2
          // Don't allocate more than 90% of the L2 to allow for overheads, and subtract off the L1 contents.
          unsigned int n_block = (((L2_size * 9) / 10) - (k_block * sizeof(Toi) * (strategy::out_width() + strategy::out_height()))) /
                                 (sizeof(Toi) * k_block);
  
          // Needs to be (at least a single) multiple of the kernel output width.
          n_block /= strategy::out_width();
          n_block = std::max(n_block, 1U) * strategy::out_width();
  
          // And tune to the presented problem size.
          unsigned int numblocks = iceildiv(args._Nsize, n_block);
          n_block = iceildiv(args._Nsize, numblocks);
          n_block = roundup(n_block, strategy::out_width());
  
          return n_block;
      }
  
  public:
      GemmHybrid(GemmHybrid &) = delete;
      GemmHybrid & operator= (GemmHybrid &) = delete;
  
      /* Constructor */
      GemmHybrid(const GemmArgs<Tr> &args)
              : _ci(args._ci), _Msize(args._Msize), _Nsize(args._Nsize), _Ksize(args._Ksize),
                _nbatches(args._nbatches), _nmulti(args._nmulti), _trB(args._trB), _beta(args._beta),
                _k_block(compute_k_block(args)), _n_block(compute_n_block(args)),
                _Mround(roundup(args._Msize, strategy::out_height())),
                _window_range(iceildiv(args._Msize, strategy::out_height()), _nbatches, iceildiv(_Nsize, _n_block), _nmulti) { }
  
      // Interface implementation - Compulsory functions
      unsigned int get_window_size() const override {
          return _window_range.total_size();
      }
  
      // This kernel can always be dynamically scheduled.
      bool supports_dynamic_scheduling() const override {
          return true;
      }
  
      // Execute
      void execute(unsigned int start, unsigned int end, int threadid) override {
  #ifdef CYCLE_PROFILING
          profiler prof;
  #endif
          strategy strat(_ci);
  
          /* Make sure we've been set up correctly. */
          assert(_B_transposed);
          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 now, each work item implies all the K for a given output
           * pixel (so we don't need to synchronize access to the output
           * array).  So separate the loop over K blocks here.  */
          for (unsigned int k0=0; k0<_Ksize; k0+=_k_block) {
              unsigned int kmax   = std::min(k0 + _k_block, _Ksize);
              unsigned int kern_k = roundup(kmax-k0, strategy::k_unroll());
  
              auto p = _window_range.iterator(start, end);
  
              if (p.done()) {
                  return;
              }
  
              do {
                  const unsigned int m_start = p.dim(0) * strategy::out_height();
                  const unsigned int m_end   = std::min(p.dim0_max() * strategy::out_height(), _Msize);
                  const unsigned int batch   = p.dim(1);
                  const unsigned int n0      = p.dim(2) * _n_block;
                  const unsigned int nmax    = std::min(n0 + _n_block, _Nsize);
                  const unsigned int multi   = p.dim(3);
  
                  const Toi *b_panel = _B_transposed +
                                       (multi * roundup(_Nsize, strategy::out_width()) * roundup(_Ksize, strategy::k_unroll())) +
                                       (k0 * roundup(_Nsize, strategy::out_width())) +
                                       (n0 * kern_k);
  
  #ifdef CYCLE_PROFILING
                  auto p = prof.ScopedProfiler(PROFILE_KERNEL, (m_end - m_start) * kern_k * roundup(nmax-n0, strategy::out_width()));
  #endif
  
                  strat.kernel(this->_Aptr + (multi * this->_A_multi_stride) + (batch * this->_A_batch_stride) + (m_start * this->_lda) + k0, this->_lda,
                               b_panel,
                               this->_Cptr + (multi * this->_C_multi_stride) + (batch * this->_C_batch_stride) + (m_start * this->_ldc) + n0, this->_ldc,
                               (k0 == 0) ? _beta : static_cast<Tr>(1),
                               (m_end - m_start), (nmax - n0), kern_k);
              } while (p.next_dim1());
          }
      }
  
      // Interface implementation - pretransposed
      bool B_is_pretransposed() const override {
          return true;
      }
  
      bool B_pretranspose_required() const override {
          return (_B_transposed==nullptr);
      }
  
      size_t get_B_pretransposed_array_size() const override {
          return roundup(_Nsize, strategy::out_width()) * roundup(_Ksize, strategy::k_unroll()) * _nmulti * sizeof(Toi);
      }
  
      void pretranspose_B_array(void *in_buffer, const To *B, const int ldb, const int B_multi_stride) override {
          Toi *buffer = reinterpret_cast<Toi *>(in_buffer);
          _B_transposed = buffer;
          strategy strat(_ci);
  
          for (unsigned int multi=0; multi<_nmulti; multi++) {
              for (unsigned int k0=0; k0<_Ksize; k0+=_k_block) {
                  const unsigned int kmax = std::min(k0 + _k_block, _Ksize);
                  const unsigned int k_size = roundup(kmax-k0, strategy::k_unroll());
  
                  for (unsigned int x0=0; x0<_Nsize; x0+=_n_block) {
                      const unsigned int xmax = std::min(x0+_n_block, _Nsize);
  
                      const unsigned int size = roundup(xmax-x0, strategy::out_width()) * k_size;
  
                      strat.transforms.PrepareB( buffer, B + (multi * B_multi_stride), ldb,
                                                 x0, xmax, k0, kmax, _trB);
  
                      buffer += size;
                  }
              }
          }
      }
  
      void set_pretransposed_B_data(void *in_buffer) override {
          _B_transposed = reinterpret_cast<Toi *>(in_buffer);
      }
  };
  
  } // namespace arm_gemm
  