1/* Copyright 2017 The TensorFlow Authors. All Rights Reserved.
2
3Licensed under the Apache License, Version 2.0 (the "License");
4you may not use this file except in compliance with the License.
5You may obtain a copy of the License at
6
7 http://www.apache.org/licenses/LICENSE-2.0
8
9Unless required by applicable law or agreed to in writing, software
10distributed under the License is distributed on an "AS IS" BASIS,
11WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12See the License for the specific language governing permissions and
13limitations under the License.
14==============================================================================*/
15#include <stdint.h>
16#include <string.h>
17
18#include "tensorflow/lite/c/common.h"
19#include "tensorflow/lite/kernels/internal/reference/reference_ops.h"
20#include "tensorflow/lite/kernels/internal/tensor.h"
21#include "tensorflow/lite/kernels/internal/tensor_ctypes.h"
22#include "tensorflow/lite/kernels/kernel_util.h"
23
24namespace tflite {
25namespace ops {
26namespace builtin {
27namespace expand_dims {
28
29// Input indices
30enum { kInput = 0, kAxis };
31
32namespace {
33TfLiteStatus ExpandTensorDim(TfLiteContext* context, const TfLiteTensor& input,
34 int axis, TfLiteTensor* output) {
35 const TfLiteIntArray& input_dims = *input.dims;
36 if (axis < 0) {
37 axis = input_dims.size + 1 + axis;
38 }
39 TF_LITE_ENSURE(context, axis <= input_dims.size);
40 TF_LITE_ENSURE(context, axis >= 0);
41
42 TfLiteIntArray* output_dims = TfLiteIntArrayCreate(input_dims.size + 1);
43 for (int i = 0; i < output_dims->size; ++i) {
44 if (i < axis) {
45 output_dims->data[i] = input_dims.data[i];
46 } else if (i == axis) {
47 output_dims->data[i] = 1;
48 } else {
49 output_dims->data[i] = input_dims.data[i - 1];
50 }
51 }
52
53 return context->ResizeTensor(context, output, output_dims);
54}
55
56TfLiteStatus GetAxisValueFromTensor(TfLiteContext* context,
57 const TfLiteTensor& axis, int* axis_value) {
58 TF_LITE_ENSURE_EQ(context, NumElements(&axis), 1);
59 switch (axis.type) {
60 case kTfLiteInt32:
61 *axis_value = *GetTensorData<int32_t>(&axis);
62 return kTfLiteOk;
63 case kTfLiteInt64:
64 *axis_value = *GetTensorData<int64_t>(&axis);
65 return kTfLiteOk;
66 default:
67 return kTfLiteError;
68 }
69}
70
71} // namespace
72
73TfLiteStatus Prepare(TfLiteContext* context, TfLiteNode* node) {
74 TF_LITE_ENSURE_EQ(context, NumInputs(node), 2);
75 TF_LITE_ENSURE_EQ(context, NumOutputs(node), 1);
76
77 const TfLiteTensor* input;
78 TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, kInput, &input));
79 const TfLiteTensor* axis;
80 TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, kAxis, &axis));
81 TfLiteTensor* output;
82 TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, 0, &output));
83
84 output->type = input->type;
85 TF_LITE_ENSURE_EQ(context, input->params.scale, output->params.scale);
86 TF_LITE_ENSURE_EQ(context, input->params.zero_point,
87 output->params.zero_point);
88 if (input->type == kTfLiteInt16) {
89 TF_LITE_ENSURE_EQ(context, input->params.zero_point, 0);
90 }
91
92 if (IsConstantTensor(axis)) {
93 int axis_value;
94 TF_LITE_ENSURE_OK(context,
95 GetAxisValueFromTensor(context, *axis, &axis_value));
96 return ExpandTensorDim(context, *input, axis_value, output);
97 }
98 SetTensorToDynamic(output);
99
100 return kTfLiteOk;
101}
102
103TfLiteStatus Eval(TfLiteContext* context, TfLiteNode* node) {
104 // Just copy input to output.
105 const TfLiteTensor* input;
106 TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, kInput, &input));
107 TfLiteTensor* output;
108 TF_LITE_ENSURE_OK(context, GetOutputSafe(context, node, 0, &output));
109 const TfLiteTensor* axis;
110 TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, kAxis, &axis));
111 if (IsDynamicTensor(output)) {
112 int axis_value;
113 TF_LITE_ENSURE_OK(context,
114 GetAxisValueFromTensor(context, *axis, &axis_value));
115 TF_LITE_ENSURE_OK(context,
116 ExpandTensorDim(context, *input, axis_value, output));
117 }
118 if (output->type == kTfLiteString) {
119 TfLiteTensorRealloc(input->bytes, output);
120 }
121 memcpy(output->data.raw, input->data.raw, input->bytes);
122 return kTfLiteOk;
123}
124
125} // namespace expand_dims
126TfLiteRegistration* Register_EXPAND_DIMS() {
127 static TfLiteRegistration r = {nullptr, nullptr, expand_dims::Prepare,
128 expand_dims::Eval};
129 return &r;
130}
131} // namespace builtin
132} // namespace ops
133} // namespace tflite
134