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/*! \file
    \brief Defines abstractions for managing loading and storing fragments to shared memory in the
      efficient GEMM pipeline.
*/
#pragma once

#include <cutlass/gemm/gemm_shared_tile.h>

namespace cutlass {
namespace gemm {

////////////////////////////////////////////////////////////////////////////////////////////////////

template <
    /// The load iterator.
    typename Iterator_,
    /// The transformer to be applied after the data has been copied from shared memory.
    typename Transformer_ = Copy<typename Iterator_::Fragment> >

struct SharedLoadStream {
  /// The load iterator.
  typedef Iterator_ Iterator;
  /// The transformer.
  typedef Transformer_ Transformer;

  /// The fragment that is copied from shared memory.
  typedef typename Iterator::Fragment FetchedFragment;
  /// The fragment that is obtained after the transformation by the transformer.
  typedef typename Transformer::OutputFragment TransformedFragment;
  /// Make sure the fragments match.
  static_assert((platform::is_same<FetchedFragment, typename Transformer::InputFragment>::value),
                "");
  /// The output fragment.
  typedef TransformedFragment Fragment;

  /// The params.
  struct Params {
    /// The iterator params.
    typename Iterator::Params iterator;

    /// Setup the params.
    CUTLASS_HOST_DEVICE int initialize() { return iterator.initialize(); }
  };

  /// The storage in shared memory needed by that stream.
  typedef typename Iterator::Storage SharedStorage;

  /// Ctor.
  CUTLASS_DEVICE SharedLoadStream() {}

  /// Ctor.
  CUTLASS_DEVICE SharedLoadStream(Params const &params, SharedStorage &shared_storage) {
    this->initialize(params, shared_storage);
  }

  /// Initialize the stream.
  CUTLASS_DEVICE void initialize(Params const &params, SharedStorage &shared_storage) {
    // The iterator.
    iterator = Iterator(params.iterator, shared_storage);
    // The transformer.
    transformer = Transformer();
  }

  /// Load the data from shared memory to the fetch fragment.
  CUTLASS_DEVICE void copy(FetchedFragment &fetched) { shared_iterator_load(iterator, fetched); }

  /// Load the data from shared memory to the fetch fragment.
  CUTLASS_DEVICE void copy(int d, FetchedFragment &fetched) {
    shared_iterator_load(iterator, fetched, d);
  }

  /// Commit the data.
  CUTLASS_DEVICE void commit(FetchedFragment &fetched, TransformedFragment &transformed) {
    transformer.transform(fetched, transformed);
  }

  /// Increment the stage.
  CUTLASS_DEVICE void inc_stage() { iterator.inc_stage(); }

  /// The iterator.
  Iterator iterator;
  /// The transformer.
  Transformer transformer;
};

////////////////////////////////////////////////////////////////////////////////////////////////////

}  // namespace gemm
}  // namespace cutlass