1 //
2 // Copyright © 2021-2023 Arm Ltd and Contributors. All rights reserved.
3 // SPDX-License-Identifier: MIT
4 //
5
6 #pragma once
7
8 #include "Optimization.hpp"
9
10 #include <armnnUtils/QuantizeHelper.hpp>
11
12 #include <armnn/utility/PolymorphicDowncast.hpp>
13 #include <armnnUtils/DataLayoutIndexed.hpp>
14
15 namespace armnn
16 {
17 namespace optimizations
18 {
19 namespace pad_fold
20 {
GetZeroElement(const TensorInfo & tensorInfo)21 inline float GetZeroElement(const TensorInfo& tensorInfo)
22 {
23 return static_cast<float>(tensorInfo.IsQuantized() ? tensorInfo.GetQuantizationOffset() : 0);
24 }
25
GetLowestElement(const TensorInfo & tensorInfo)26 inline float GetLowestElement(const TensorInfo& tensorInfo)
27 {
28 constexpr float negativeInfinity = -std::numeric_limits<float>::infinity();
29 const float scale = tensorInfo.GetQuantizationScale();
30 const int32_t offset = tensorInfo.GetQuantizationOffset();
31
32 switch (tensorInfo.GetDataType())
33 {
34 case DataType::Float16:
35 return armnnUtils::SelectiveQuantize<armnn::Half>(negativeInfinity, scale, offset);
36 case DataType::Float32:
37 return armnnUtils::SelectiveQuantize<float>(negativeInfinity, scale, offset);
38 case DataType::QAsymmU8:
39 return armnnUtils::SelectiveQuantize<uint8_t>(negativeInfinity, scale, offset);
40 case DataType::QSymmS16:
41 return armnnUtils::SelectiveQuantize<int16_t>(negativeInfinity, scale, offset);
42 case DataType::QSymmS8:
43 // Fall-through
44 case DataType::QAsymmS8:
45 return armnnUtils::SelectiveQuantize<int8_t>(negativeInfinity, scale, offset);
46 case DataType::BFloat16:
47 return armnnUtils::SelectiveQuantize<armnn::BFloat16>(negativeInfinity, scale, offset);
48 default:
49 {
50 ARMNN_ASSERT_MSG(false, "Unsupported DataType");
51 return NAN;
52 }
53 }
54 }
55
IsNeutralElement(const Convolution2dDescriptor &,const TensorInfo & tensorInfo,const float tensorValue)56 inline bool IsNeutralElement(const Convolution2dDescriptor&, const TensorInfo& tensorInfo, const float tensorValue)
57 {
58 return tensorValue == GetZeroElement(tensorInfo);
59 }
60
IsNeutralElement(const DepthwiseConvolution2dDescriptor &,const TensorInfo & tensorInfo,const float tensorValue)61 inline bool IsNeutralElement(const DepthwiseConvolution2dDescriptor&,
62 const TensorInfo& tensorInfo,
63 const float tensorValue)
64 {
65 return tensorValue == GetZeroElement(tensorInfo);
66 }
67
IsNeutralElement(const Pooling2dDescriptor & descriptor,const TensorInfo & tensorInfo,const float tensorValue)68 inline bool IsNeutralElement(
69 const Pooling2dDescriptor& descriptor, const TensorInfo& tensorInfo, const float tensorValue)
70 {
71 return (descriptor.m_PoolType == PoolingAlgorithm::Max)
72 ? tensorValue <= GetLowestElement(tensorInfo)
73 : tensorValue == GetZeroElement(tensorInfo);
74 }
75
IsPooling2dPadded(const Pooling2dDescriptor & poolDescriptor)76 inline bool IsPooling2dPadded(const Pooling2dDescriptor& poolDescriptor)
77 {
78 const auto poolingPadValues = std::make_tuple(poolDescriptor.m_PadLeft, poolDescriptor.m_PadRight,
79 poolDescriptor.m_PadTop, poolDescriptor.m_PadBottom);
80 if (poolingPadValues != std::make_tuple(0U, 0U, 0U, 0U))
81 {
82 return true;
83 }
84 return false;
85 }
86
87 template <typename Descriptor>
TryFoldPadIntoLayer2d(const PadDescriptor & padDescriptor,Descriptor & layerDescriptor,const TensorInfo & tensorInfo)88 bool TryFoldPadIntoLayer2d(
89 const PadDescriptor& padDescriptor, Descriptor& layerDescriptor, const TensorInfo& tensorInfo)
90 {
91 armnnUtils::DataLayoutIndexed layout = armnnUtils::DataLayoutIndexed(layerDescriptor.m_DataLayout);
92 constexpr unsigned int batchIndex = 0;
93
94 constexpr auto noPad = std::make_pair(0U, 0U);
95
96 if ((!IsNeutralElement(layerDescriptor, tensorInfo, padDescriptor.m_PadValue)) ||
97 (padDescriptor.m_PadList[batchIndex] != noPad) || (padDescriptor.m_PadList[layout.GetChannelsIndex()] != noPad))
98 {
99 return false;
100 }
101
102 const auto& padList = padDescriptor.m_PadList;
103
104 // In Convolution2dDescriptor/Pooling2dDescriptor, padLeft and padRight are defined as paddings
105 // on width dimension whereas padTop and padBottom - paddings on height dimension, so updating
106 // these according to data layout
107 layerDescriptor.m_PadLeft += padList[layout.GetWidthIndex()].first;
108 layerDescriptor.m_PadRight += padList[layout.GetWidthIndex()].second;
109 layerDescriptor.m_PadTop += padList[layout.GetHeightIndex()].first;
110 layerDescriptor.m_PadBottom += padList[layout.GetHeightIndex()].second;
111
112 return true;
113 }
114
TryFoldPadIntoLayer2d(const PadDescriptor & padDescriptor,Pooling2dDescriptor & poolDescriptor,const TensorInfo & tensorInfo,bool isBackendOptimization=false)115 inline bool TryFoldPadIntoLayer2d(const PadDescriptor& padDescriptor,
116 Pooling2dDescriptor& poolDescriptor,
117 const TensorInfo& tensorInfo,
118 bool isBackendOptimization = false)
119 {
120 // Cannot fold Average or L2 pooling if padding exists and the padding method is Exclude.
121 if (poolDescriptor.m_PoolType != PoolingAlgorithm::Max &&
122 IsPooling2dPadded(poolDescriptor) &&
123 poolDescriptor.m_PaddingMethod == PaddingMethod::Exclude)
124 {
125 return false;
126 }
127
128 // Cannot fold Average pooling if data type is quantized and layout is NHWC in Neon backend.
129 // Therefore, this specific case will become a backend specific optimization.
130 if (!isBackendOptimization &&
131 tensorInfo.IsQuantized() &&
132 poolDescriptor.m_PoolType == PoolingAlgorithm::Average &&
133 poolDescriptor.m_DataLayout == DataLayout::NHWC)
134 {
135 return false;
136 }
137
138 poolDescriptor.m_PaddingMethod = PaddingMethod::IgnoreValue;
139
140 return TryFoldPadIntoLayer2d<Pooling2dDescriptor>(padDescriptor, poolDescriptor, tensorInfo);
141 }
142
143 template <typename Layer2dT>
FoldPadIntoLayer2dImpl(Graph & graph,InputSlot & connection)144 Layer2dT* FoldPadIntoLayer2dImpl(Graph& graph, InputSlot& connection)
145 {
146 PadLayer& padLayer = *PolymorphicDowncast<PadLayer*>(&connection.GetConnectedOutputSlot()->GetOwningLayer());
147 Layer2dT& layer2d = *PolymorphicDowncast<Layer2dT*>(&connection.GetOwningLayer());
148
149 const PadDescriptor& padDescriptor = padLayer.GetParameters();
150 auto newLayer2dDescriptor = layer2d.GetParameters();
151
152 if (!TryFoldPadIntoLayer2d(padDescriptor, newLayer2dDescriptor, padLayer.GetOutputSlot().GetTensorInfo()))
153 {
154 return nullptr;
155 }
156
157 // Save original parent output slot of the pad layer
158 OutputSlot& parentSlot = *padLayer.GetInputSlot(0).GetConnectedOutputSlot();
159
160 // Insert new layer2d layer between the pad layer and its parent layer.
161 const std::string name = std::string("folded-") + padLayer.GetName() + "-into-" + layer2d.GetName();
162 auto& newLayer2d = *graph.InsertNewLayer<Layer2dT>(padLayer.GetInputSlot(0), newLayer2dDescriptor, name.c_str());
163
164 newLayer2d.GetOutputSlot().MoveAllConnections(parentSlot);
165 // Start at 1 to connect only weights and bias
166 for (unsigned int i = 1; i < layer2d.GetNumInputSlots(); ++i)
167 {
168 if (layer2d.GetInputSlot(i).GetConnectedOutputSlot() != nullptr)
169 {
170 Layer& tgtLayer = layer2d.GetInputSlot(i).GetConnectedOutputSlot()->GetOwningLayer();
171 // Remove old connection and connect to new layer2d
172 tgtLayer.GetOutputSlot(0).Disconnect(layer2d.GetInputSlot(i));
173 tgtLayer.GetOutputSlot(0).Connect(newLayer2d.GetInputSlot(i));
174 }
175 }
176
177 // Moves connections in old layer2d layer output to new layer.
178 // Old layer2d layer will be removed as it's left unconnected.
179 // Pad layer will be removed if left unconnected.
180 layer2d.GetOutputSlot().MoveAllConnections(newLayer2d.GetOutputSlot());
181
182 return &newLayer2d;
183 }
184
185 class FoldPadIntoConvolution2dImpl
186 {
187 public:
Run(Graph & graph,InputSlot & connection) const188 void Run(Graph& graph, InputSlot& connection) const
189 {
190 const auto newConv2dLayer = FoldPadIntoLayer2dImpl<Convolution2dLayer>(graph, connection);
191
192 if (newConv2dLayer != nullptr)
193 {
194 const auto conv2dLayer = PolymorphicDowncast<Convolution2dLayer*>(&connection.GetOwningLayer());
195 ARMNN_ASSERT_MSG(newConv2dLayer->GetInputSlot(1).GetConnection() != nullptr,
196 "FoldPadIntoConvolution2d: New convolution layer is missing connection to weights layer");
197
198 if (conv2dLayer->GetParameters().m_BiasEnabled)
199 {
200 ARMNN_ASSERT_MSG(newConv2dLayer->GetInputSlot(2).GetConnection() != nullptr,
201 "FoldPadIntoConvolution2d: New convolution layer is missing "
202 "connection to bias layer.");
203 }
204 }
205 }
206
207 protected:
208 FoldPadIntoConvolution2dImpl() = default;
209 ~FoldPadIntoConvolution2dImpl() = default;
210 };
211
212 class FoldPadIntoDepthwiseConvolution2dImpl
213 {
214 public:
Run(Graph & graph,InputSlot & connection) const215 void Run(Graph& graph, InputSlot& connection) const
216 {
217 const auto newConv2dLayer = FoldPadIntoLayer2dImpl<DepthwiseConvolution2dLayer>(graph, connection);
218
219 if (newConv2dLayer != nullptr)
220 {
221 const auto conv2dLayer = PolymorphicDowncast<DepthwiseConvolution2dLayer*>(&connection.GetOwningLayer());
222 ARMNN_ASSERT_MSG(newConv2dLayer->GetInputSlot(1).GetConnection() != nullptr,
223 "FoldPadIntoDepthwiseConvolution2d: New convolution layer is missing "
224 "connection to weights layer");
225
226 if (conv2dLayer->GetParameters().m_BiasEnabled)
227 {
228 ARMNN_ASSERT_MSG(newConv2dLayer->GetInputSlot(2).GetConnection() != nullptr,
229 "FoldPadIntoConvolution2d: New convolution layer is missing "
230 "connection to bias layer.");
231 }
232 }
233 }
234 protected:
235 FoldPadIntoDepthwiseConvolution2dImpl() = default;
236 ~FoldPadIntoDepthwiseConvolution2dImpl() = default;
237 };
238
239 class FoldPadIntoPooling2dImpl
240 {
241 public:
Run(Graph & graph,InputSlot & connection) const242 void Run(Graph& graph, InputSlot& connection) const
243 {
244 FoldPadIntoLayer2dImpl<Pooling2dLayer>(graph, connection);
245 }
246
247 protected:
248 FoldPadIntoPooling2dImpl() = default;
249 ~FoldPadIntoPooling2dImpl() = default;
250 };
251 } // namespace pad_fold
252
253 using FoldPadIntoConvolution2d =
254 OptimizeForExclusiveConnection<PadLayer, Convolution2dLayer, pad_fold::FoldPadIntoConvolution2dImpl>;
255 using FoldPadIntoDepthwiseConvolution2d =
256 OptimizeForExclusiveConnection <PadLayer,
257 DepthwiseConvolution2dLayer,
258 pad_fold::FoldPadIntoDepthwiseConvolution2dImpl>;
259 using FoldPadIntoPooling2d =
260 OptimizeForExclusiveConnection<PadLayer, Pooling2dLayer, pad_fold::FoldPadIntoPooling2dImpl>;
261
262 } // namespace optimizations
263 } // namespace armnn
264
265
266