/* Copyright 2017 The TensorFlow 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.
==============================================================================*/
#ifndef TENSORFLOW_CONTRIB_LITE_KERNELS_KERNEL_UTIL_H_
#define TENSORFLOW_CONTRIB_LITE_KERNELS_KERNEL_UTIL_H_

#include "tensorflow/contrib/lite/builtin_op_data.h"
#include "tensorflow/contrib/lite/context.h"

namespace tflite {

inline int NumDimensions(const TfLiteTensor* t) { return t->dims->size; }
inline int SizeOfDimension(const TfLiteTensor* t, int dim) {
  return t->dims->data[dim];
}
inline TfLiteTensor* GetInput(TfLiteContext* context, TfLiteNode* node,
                              int index) {
  return &context->tensors[node->inputs->data[index]];
}
inline TfLiteTensor* GetOutput(TfLiteContext* context, TfLiteNode* node,
                               int index) {
  return &context->tensors[node->outputs->data[index]];
}
inline int NumInputs(const TfLiteNode* node) { return node->inputs->size; }
inline int NumOutputs(const TfLiteNode* node) { return node->outputs->size; }

inline int64_t NumElements(const TfLiteTensor* t) {
  int64_t count = 1;
  for (int i = 0; i < NumDimensions(t); ++i) {
    count *= SizeOfDimension(t, i);
  }
  return count;
}

inline TfLiteTensor* GetOptionalInputTensor(TfLiteContext* context,
                                            const TfLiteNode* node, int index) {
  const bool use_tensor = node->inputs->data[index] != kOptionalTensor;
  if (use_tensor) {
    return &context->tensors[node->inputs->data[index]];
  }
  return nullptr;
}

// Determines whether tensor is constant.
inline bool IsConstantTensor(TfLiteTensor* tensor) {
  return tensor->allocation_type == kTfLiteMmapRo;
}

// Determines whether tensor is dynamic. Note that a tensor can be non-const and
// not dynamic. This function specificially checks for a dynamic tensor.
inline bool IsDynamicTensor(TfLiteTensor* tensor) {
  return tensor->allocation_type == kTfLiteDynamic;
}

// Sets tensor to dynamic.
inline void SetTensorToDynamic(TfLiteTensor* tensor) {
  tensor->allocation_type = kTfLiteDynamic;
}

// Calculates the multiplication factor for a quantized convolution (or
// quantized depthwise convolution) involving the given tensors. Returns an
// error if the scales of the tensors are not compatible.
TfLiteStatus GetQuantizedConvolutionMultipler(
    TfLiteContext* context, TfLiteTensor* input, TfLiteTensor* filter,
    TfLiteTensor* bias, TfLiteTensor* output, double* multiplier);

// Calculates the useful range of an activation layer given its activation
// tensor.
void CalculateActivationRangeUint8(TfLiteFusedActivation activation,
                                   TfLiteTensor* output, int32_t* act_min,
                                   int32_t* act_max);
void CalculateActivationRangeFloat(TfLiteFusedActivation activation,
                                   float* activation_min,
                                   float* activation_max);

// Return true if the given tensors have the same shape.
bool HaveSameShapes(TfLiteTensor* input1, TfLiteTensor* input2);

// Calculate the output_shape that is necessary for element-wise operations
// with broadcasting involving the two input tensors.
TfLiteStatus CalculateShapeForBroadcast(TfLiteContext* context,
                                        TfLiteTensor* input1,
                                        TfLiteTensor* input2,
                                        TfLiteIntArray** output_shape);
}  // namespace tflite

#endif  // TENSORFLOW_CONTRIB_LITE_KERNELS_KERNEL_UTIL_H_
