1 /* Copyright 2018 The TensorFlow Authors. All Rights Reserved.
2 
3 Licensed under the Apache License, Version 2.0 (the "License");
4 you may not use this file except in compliance with the License.
5 You may obtain a copy of the License at
6 
7     http://www.apache.org/licenses/LICENSE-2.0
8 
9 Unless required by applicable law or agreed to in writing, software
10 distributed under the License is distributed on an "AS IS" BASIS,
11 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 See the License for the specific language governing permissions and
13 limitations under the License.
14 ==============================================================================*/
15 #include <stddef.h>
16 #include <stdint.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 
24 namespace tflite {
25 namespace ops {
26 namespace builtin {
27 namespace select {
28 
29 constexpr int kInputTensorCondition = 0;
30 constexpr int kInputTensorX = 1;
31 constexpr int kInputTensorY = 2;
32 constexpr int kOutputTensor = 0;
33 
34 enum KernelType {
35   kVersionOne,
36   kVersionTwo,
37 };
38 
39 struct OpData {
40   bool requires_broadcast;
41   // True if input condition is scalar or input condition has rank one and
42   // matches the first dimension of other inputs.
43   bool has_low_rank_input_condition;
44 };
45 
SelectInit(TfLiteContext * context,const char * buffer,size_t length)46 void* SelectInit(TfLiteContext* context, const char* buffer, size_t length) {
47   auto* data = new OpData;
48   data->requires_broadcast = false;
49   data->has_low_rank_input_condition = false;
50   return data;
51 }
52 
SelectFree(TfLiteContext * context,void * buffer)53 void SelectFree(TfLiteContext* context, void* buffer) {
54   delete reinterpret_cast<OpData*>(buffer);
55 }
56 
57 template <KernelType kernel_type>
SelectPrepare(TfLiteContext * context,TfLiteNode * node)58 TfLiteStatus SelectPrepare(TfLiteContext* context, TfLiteNode* node) {
59   OpData* data = reinterpret_cast<OpData*>(node->user_data);
60 
61   TF_LITE_ENSURE_EQ(context, NumInputs(node), 3);
62   TF_LITE_ENSURE_EQ(context, NumOutputs(node), 1);
63 
64   const TfLiteTensor* input_condition;
65   TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, kInputTensorCondition,
66                                           &input_condition));
67   const TfLiteTensor* input_x;
68   TF_LITE_ENSURE_OK(context,
69                     GetInputSafe(context, node, kInputTensorX, &input_x));
70   const TfLiteTensor* input_y;
71   TF_LITE_ENSURE_OK(context,
72                     GetInputSafe(context, node, kInputTensorY, &input_y));
73   TfLiteTensor* output;
74   TF_LITE_ENSURE_OK(context,
75                     GetOutputSafe(context, node, kOutputTensor, &output));
76 
77   // Input must be bool.
78   TF_LITE_ENSURE_TYPES_EQ(context, input_condition->type, kTfLiteBool);
79   TF_LITE_ENSURE_TYPES_EQ(context, input_x->type, input_y->type);
80   output->type = input_x->type;
81 
82   bool same_shape = HaveSameShapes(input_condition, input_x) &&
83                     HaveSameShapes(input_x, input_y);
84   TfLiteIntArray* output_size;
85   if (!same_shape) {
86     switch (kernel_type) {
87       case kVersionOne: {
88         bool is_input_condition_scalar = NumDimensions(input_condition) == 0;
89         bool has_rank_one_input_condition =
90             NumDimensions(input_condition) == 1 &&
91             SizeOfDimension(input_condition, 0) == SizeOfDimension(input_x, 0);
92         data->has_low_rank_input_condition =
93             is_input_condition_scalar || has_rank_one_input_condition;
94         TF_LITE_ENSURE(context, data->has_low_rank_input_condition);
95 
96         output_size = TfLiteIntArrayCopy(input_x->dims);
97 
98         // Input tensors must have the same type and size
99         TF_LITE_ENSURE(context, HaveSameShapes(input_x, input_y));
100         break;
101       }
102       case kVersionTwo: {
103         TF_LITE_ENSURE_OK(context, CalculateShapeForBroadcast(
104                                        context, input_condition, input_x,
105                                        input_y, &output_size));
106         data->requires_broadcast = true;
107         break;
108       }
109       default:
110         return kTfLiteError;
111     }
112   } else {
113     output_size = TfLiteIntArrayCopy(input_x->dims);
114   }
115 
116   return context->ResizeTensor(context, output, output_size);
117 }
118 
SelectEval(TfLiteContext * context,TfLiteNode * node)119 TfLiteStatus SelectEval(TfLiteContext* context, TfLiteNode* node) {
120   OpData* data = reinterpret_cast<OpData*>(node->user_data);
121   const TfLiteTensor* input_condition;
122   TF_LITE_ENSURE_OK(context, GetInputSafe(context, node, kInputTensorCondition,
123                                           &input_condition));
124   const TfLiteTensor* input_x;
125   TF_LITE_ENSURE_OK(context,
126                     GetInputSafe(context, node, kInputTensorX, &input_x));
127   const TfLiteTensor* input_y;
128   TF_LITE_ENSURE_OK(context,
129                     GetInputSafe(context, node, kInputTensorY, &input_y));
130   TfLiteTensor* output;
131   TF_LITE_ENSURE_OK(context,
132                     GetOutputSafe(context, node, kOutputTensor, &output));
133 
134 #define TF_LITE_SELECT(type, op)                                           \
135   reference_ops::op(GetTensorShape(input_condition),                       \
136                     GetTensorData<bool>(input_condition),                  \
137                     GetTensorShape(input_x), GetTensorData<type>(input_x), \
138                     GetTensorShape(input_y), GetTensorData<type>(input_y), \
139                     GetTensorShape(output), GetTensorData<type>(output));
140 
141 #define TF_LITE_SWITCH(type, op)                                               \
142   switch (type) {                                                              \
143     break;                                                                     \
144     case kTfLiteBool:                                                          \
145       TF_LITE_SELECT(bool, op);                                                \
146       break;                                                                   \
147     case kTfLiteFloat32:                                                       \
148       TF_LITE_SELECT(float, op);                                               \
149       break;                                                                   \
150     case kTfLiteUInt8:                                                         \
151       TF_LITE_SELECT(uint8_t, op);                                             \
152       break;                                                                   \
153     case kTfLiteInt8:                                                          \
154       TF_LITE_SELECT(int8_t, op);                                              \
155       break;                                                                   \
156     case kTfLiteInt16:                                                         \
157       TF_LITE_SELECT(int16_t, op);                                             \
158       break;                                                                   \
159     case kTfLiteInt32:                                                         \
160       TF_LITE_SELECT(int32_t, op);                                             \
161       break;                                                                   \
162     case kTfLiteInt64:                                                         \
163       TF_LITE_SELECT(int64_t, op);                                             \
164       break;                                                                   \
165     default:                                                                   \
166       context->ReportError(context,                                            \
167                            "Does not support type other than bool|float|int, " \
168                            "got %d",                                           \
169                            type);                                              \
170       return kTfLiteError;                                                     \
171   }
172 
173   if (data->has_low_rank_input_condition) {
174     TF_LITE_SWITCH(input_x->type, RankOneSelect);
175   } else if (data->requires_broadcast) {
176     TF_LITE_SWITCH(input_x->type, BroadcastSelect4DSlow);
177   } else {
178     TF_LITE_SWITCH(input_x->type, Select);
179   }
180 
181 #undef TF_LITE_SELECT
182 #undef TF_LITE_SWITCH
183   return kTfLiteOk;
184 }
185 
186 }  // namespace select
187 
188 // Select op selects values of 'x' if the corresponding value of 'condition' is
189 // true or the value of 'y' if false. There are valid condition input sizes:
190 //
191 // 1. Either the same shape (in which case the select is elementwise), or
192 // 2. condition must be Rank 1 and match over the first dimension, or
193 // 3. condition is scalar
Register_SELECT()194 TfLiteRegistration* Register_SELECT() {
195   static TfLiteRegistration r = {select::SelectInit, select::SelectFree,
196                                  select::SelectPrepare<select::kVersionOne>,
197                                  select::SelectEval};
198   return &r;
199 }
200 
201 // SelectV2 op selects values of 'x' if the corresponding value of 'condition'
202 // is true or the value of 'y' if false. There are valid condition input sizes:
203 //
204 // 1. Either the same shape (in which case the select is elementwise), or
205 // 2. Broadcastable shapes between 'condition', 'x' and 'y'.
Register_SELECT_V2()206 TfLiteRegistration* Register_SELECT_V2() {
207   static TfLiteRegistration r = {select::SelectInit, select::SelectFree,
208                                  select::SelectPrepare<select::kVersionTwo>,
209                                  select::SelectEval};
210   return &r;
211 }
212 
213 }  // namespace builtin
214 }  // namespace ops
215 }  // namespace tflite
216