1 /*
2  * Copyright (C) 2019 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #define LOG_TAG "Operations"
18 
19 #include <algorithm>
20 #include <cmath>
21 #include <vector>
22 
23 #include "IndexedShapeWrapper.h"
24 #include "OperationResolver.h"
25 #include "OperationsUtils.h"
26 #include "Tracing.h"
27 
28 namespace android {
29 namespace nn {
30 namespace elu {
31 
32 constexpr uint32_t kNumInputs = 2;
33 constexpr uint32_t kInputTensor = 0;
34 constexpr uint32_t kAlphaScalar = 1;
35 
36 constexpr uint32_t kNumOutputs = 1;
37 constexpr uint32_t kOutputTensor = 0;
38 
39 namespace {
40 
41 template <typename T>
eluFloat(const T * inputData,const Shape & inputShape,const T alpha,T * outputData,const Shape & outputShape)42 bool eluFloat(const T* inputData, const Shape& inputShape, const T alpha, T* outputData,
43               const Shape& outputShape) {
44     NNTRACE_COMP("ELU");
45     int numElements = getNumberOfElements(inputShape);
46     for (int i = 0; i < numElements; ++i) {
47         float x = static_cast<float>(inputData[i]);
48         outputData[i] = static_cast<T>(std::max(0.f, x) + std::min(0.f, alpha * (std::exp(x) - 1)));
49     }
50     return true;
51 }
52 
53 }  // namespace
54 
validate(const IOperationValidationContext * context)55 Result<Version> validate(const IOperationValidationContext* context) {
56     NN_RET_CHECK_EQ(context->getNumInputs(), kNumInputs);
57     NN_RET_CHECK_EQ(context->getNumOutputs(), kNumOutputs);
58     auto inputType = context->getInputType(kInputTensor);
59     auto minSupportedVersion = Version::ANDROID_OC_MR1;
60     if (inputType == OperandType::TENSOR_FLOAT16 || inputType == OperandType::TENSOR_FLOAT32) {
61         minSupportedVersion = Version::ANDROID_R;
62     } else {
63         NN_RET_CHECK_FAIL() << "Unsupported tensor type for operation ELU";
64     }
65     auto scalarType =
66             inputType == OperandType::TENSOR_FLOAT16 ? OperandType::FLOAT16 : OperandType::FLOAT32;
67     NN_RET_CHECK(validateInputTypes(context, {inputType, scalarType}));
68     NN_RET_CHECK(validateOutputTypes(context, {inputType}));
69     return minSupportedVersion;
70 }
71 
prepare(IOperationExecutionContext * context)72 bool prepare(IOperationExecutionContext* context) {
73     Shape inputShape = context->getInputShape(kInputTensor);
74     return context->setOutputShape(kOutputTensor, inputShape);
75 }
76 
execute(IOperationExecutionContext * context)77 bool execute(IOperationExecutionContext* context) {
78     // Bypass execution in the case of zero-sized input.
79     if (getNumberOfElements(context->getOutputShape(kOutputTensor)) == 0) return true;
80     switch (context->getInputType(kInputTensor)) {
81         case OperandType::TENSOR_FLOAT16:
82             return eluFloat(context->getInputBuffer<_Float16>(kInputTensor),
83                             context->getInputShape(kInputTensor),
84                             context->getInputValue<_Float16>(kAlphaScalar),
85                             context->getOutputBuffer<_Float16>(kOutputTensor),
86                             context->getOutputShape(kOutputTensor));
87         case OperandType::TENSOR_FLOAT32:
88             return eluFloat(context->getInputBuffer<float>(kInputTensor),
89                             context->getInputShape(kInputTensor),
90                             context->getInputValue<float>(kAlphaScalar),
91                             context->getOutputBuffer<float>(kOutputTensor),
92                             context->getOutputShape(kOutputTensor));
93         default:
94             NN_RET_CHECK_FAIL() << "Unsupported tensor type for operation ELU";
95     }
96 }
97 
98 }  // namespace elu
99 
100 NN_REGISTER_OPERATION(ELU, "ELU", elu::validate, elu::prepare, elu::execute);
101 
102 }  // namespace nn
103 }  // namespace android
104