EVOLUTION-MANAGER

Edit File: gather_functor.h

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
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distributed under the License is distributed on an "AS IS" BASIS,
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==============================================================================*/

#ifndef TENSORFLOW_CORE_KERNELS_GATHER_FUNCTOR_H_
#define TENSORFLOW_CORE_KERNELS_GATHER_FUNCTOR_H_

#include "third_party/eigen3/unsupported/Eigen/CXX11/Tensor"

#include "tensorflow/core/framework/bounds_check.h"
#include "tensorflow/core/framework/op_kernel.h"
#include "tensorflow/core/framework/tensor_types.h"
#include "tensorflow/core/framework/type_traits.h"
#include "tensorflow/core/framework/variant.h"
#include "tensorflow/core/platform/prefetch.h"
#include "tensorflow/core/platform/types.h"
#include "tensorflow/core/util/work_sharder.h"

namespace tensorflow {
typedef Eigen::ThreadPoolDevice CPUDevice;
typedef Eigen::GpuDevice GPUDevice;

namespace functor {

// Helper method to copy using memcpy.
template <typename T, typename Index, typename SliceIndex,
          SliceIndex static_slice_elems>
SliceIndex HandleCopies(OpKernelContext* ctx,
                        typename TTypes<T, 3>::ConstTensor params,
                        typename TTypes<Index>::ConstFlat indices,
                        SliceIndex slice_elems,
                        typename TTypes<T, 3>::Tensor out) {
  const SliceIndex indices_size = static_cast<SliceIndex>(indices.dimension(0));
  const SliceIndex batch_size = static_cast<SliceIndex>(params.dimension(0));
  const Index limit = static_cast<Index>(params.dimension(1));
  T* out_base = out.data();
  const T* params_base = params.data();
  if (static_slice_elems >= 0) {
    // Give compiler static knowledge of the number of elements/bytes
    slice_elems = static_slice_elems;
  }
  // Compute slice_bytes here so that static knowledge is available
  const size_t slice_bytes = slice_elems * sizeof(T);
  auto* worker_threads = ctx->device()->tensorflow_cpu_worker_threads();
  mutex mu;
  // Store the value of invalidate index for printing error information, it's a
  // shared variable.
  SliceIndex result = -1;
  auto work = [&](int64 start, int64 end) {
    SliceIndex batch_idx = static_cast<SliceIndex>(start / indices_size);
    SliceIndex indices_idx = static_cast<SliceIndex>(start % indices_size);
    SliceIndex batch_idx_end = static_cast<SliceIndex>(end / indices_size);
    SliceIndex indices_idx_end = static_cast<SliceIndex>(end % indices_size);

while ((batch_idx < batch_idx_end) ||
           (batch_idx == batch_idx_end && indices_idx < indices_idx_end)) {
      SliceIndex i_next = indices_idx + 1;
      SliceIndex b_next = batch_idx + 1;
      if ((batch_idx == batch_idx_end && i_next < indices_idx_end) ||
          (i_next < indices_size)) {
        port::prefetch<port::PREFETCH_HINT_T0>(
            &params(batch_idx, indices(i_next), 0));
        port::prefetch<port::PREFETCH_HINT_T0>(&out(batch_idx, i_next, 0));
        b_next = batch_idx;
      } else if (b_next <= batch_idx_end) {
        port::prefetch<port::PREFETCH_HINT_T0>(&params(b_next, indices(0), 0));
        port::prefetch<port::PREFETCH_HINT_T0>(&out(b_next, 0, 0));
        i_next = 0;
      }
      const Index index = internal::SubtleMustCopy(indices(indices_idx));
      if (!FastBoundsCheck(index, limit)) {
        mutex_lock l(mu);
        result = indices_idx;
        return;
      }
      // Copy using memcpy if possible, otherwise an Eigen loop
      // TODO(cwhipkey): avoid linking to framework to get Allocator (to improve
      // ahead-of-time compilation binary size).
      if (is_simple_type<T>::value) {
        // Avoid auto-promotion to Index from SliceIndex by casting.
        memcpy(
            out_base + (batch_idx * indices_size + indices_idx) * slice_elems,
            params_base + (batch_idx * static_cast<SliceIndex>(limit) +
                           static_cast<SliceIndex>(index)) *
                              slice_elems,
            slice_bytes);
      } else {
        // For non-"simple" types (e.g. strings).
        out.template chip<0>(batch_idx).template chip<0>(indices_idx) =
            params.template chip<0>(batch_idx).template chip<0>(index);
      }
      indices_idx = i_next;
      batch_idx = b_next;
    }
  };

Shard(worker_threads->num_threads, worker_threads->workers,
        batch_size * indices_size, slice_elems * sizeof(T), work);
  return result;
}

template <typename T, typename Index>
struct GatherFunctorCPU {
  int64 operator()(OpKernelContext* ctx,
                   typename TTypes<T, 3>::ConstTensor params,
                   typename TTypes<Index>::ConstFlat indices,
                   typename TTypes<T, 3>::Tensor out) {
    const int64 indices_size = indices.size();
    const int64 slice_size = out.dimension(2);
    int64 bad_i;

const int64 batch_size = params.dimension(0);

bool use_large = (slice_size > std::numeric_limits<int32>::max() ||
                      params.size() > std::numeric_limits<int32>::max() ||
                      indices_size > std::numeric_limits<int32>::max() ||
                      batch_size * indices_size * slice_size >
                          std::numeric_limits<int32>::max());
#define CALL(elems)                                                      \
  do {                                                                   \
    if (use_large) {                                                     \
      bad_i = HandleCopies<T, Index, int64, elems>(ctx, params, indices, \
                                                   slice_size, out);     \
    } else {                                                             \
      const int32 small_slice = static_cast<int32>(slice_size);          \
      bad_i = HandleCopies<T, Index, int32, elems>(ctx, params, indices, \
                                                   small_slice, out);    \
    }                                                                    \
  } while (0)

if (slice_size == 10)
      CALL(10);
    else if (slice_size == 20)
      CALL(20);
    else
      CALL(-1);
#undef CALL

return bad_i;
  }
};

template <typename Device, typename T, typename Index>
struct GatherFunctor {
  int64 operator()(OpKernelContext* ctx,
                   typename TTypes<T, 3>::ConstTensor params,
                   typename TTypes<Index>::ConstFlat indices,
                   typename TTypes<T, 3>::Tensor out);
};

template <typename T, typename Index>
struct GatherFunctor<CPUDevice, T, Index> {
  int64 operator()(OpKernelContext* ctx,
                   typename TTypes<T, 3>::ConstTensor params,
                   typename TTypes<Index>::ConstFlat indices,
                   typename TTypes<T, 3>::Tensor out) {
    return GatherFunctorCPU<T, Index>()(ctx, params, indices, out);
  }
};

template <typename Index>
struct GatherFunctor<GPUDevice, Variant, Index> {
  int64 operator()(OpKernelContext* ctx,
                   typename TTypes<Variant, 3>::ConstTensor params,
                   typename TTypes<Index>::ConstFlat indices,
                   typename TTypes<Variant, 3>::Tensor out) {
    return GatherFunctorCPU<Variant, Index>()(ctx, params, indices, out);
  }
};

}  // namespace functor
}  // namespace tensorflow

#endif  // TENSORFLOW_CORE_KERNELS_GATHER_FUNCTOR_H_