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| 1 | +/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserve. |
| 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 "paddle/operators/lstm_op.h" |
| 16 | + |
| 17 | +namespace paddle { |
| 18 | +namespace operators { |
| 19 | + |
| 20 | +class LSTMOp : public framework::OperatorWithKernel { |
| 21 | + public: |
| 22 | + using framework::OperatorWithKernel::OperatorWithKernel; |
| 23 | + |
| 24 | + protected: |
| 25 | + void InferShape(framework::InferShapeContext* ctx) const override { |
| 26 | + PADDLE_ENFORCE(ctx->HasInput("Input"), |
| 27 | + "Input(Input) of LSTM should not be null."); |
| 28 | + PADDLE_ENFORCE(ctx->HasOutput("Hidden"), |
| 29 | + "Output(Hidden) of LSTM should not be null."); |
| 30 | + PADDLE_ENFORCE(ctx->HasOutput("Cell"), |
| 31 | + "Output(Cell) of LSTM should not be null."); |
| 32 | + |
| 33 | + auto x_dims = ctx->GetInputDim("Input"); |
| 34 | + PADDLE_ENFORCE_EQ(x_dims.size(), 2, "Input(X)'s rank must be 2."); |
| 35 | + |
| 36 | + if (ctx->HasInput("H0")) { |
| 37 | + PADDLE_ENFORCE(ctx->HasInput("C0"), |
| 38 | + "Input(Cell) and Input(Hidden) of LSTM should not " |
| 39 | + "be null at the same time."); |
| 40 | + auto h_dims = ctx->GetInputDim("H0"); |
| 41 | + auto c_dims = ctx->GetInputDim("C0"); |
| 42 | + PADDLE_ENFORCE(h_dims == c_dims, |
| 43 | + "The dimension of Input(H0) and Input(C0) " |
| 44 | + "should be the same."); |
| 45 | + } |
| 46 | + |
| 47 | + int frame_size = x_dims[1] / 4; |
| 48 | + auto w_dims = ctx->GetInputDim("Weight"); |
| 49 | + PADDLE_ENFORCE_EQ(w_dims.size(), 2, |
| 50 | + "The rank of Input(Weight) should be 2."); |
| 51 | + PADDLE_ENFORCE_EQ(w_dims[0], frame_size, |
| 52 | + "The first dimension of Input(Weight) " |
| 53 | + "should be %d.", |
| 54 | + frame_size); |
| 55 | + PADDLE_ENFORCE_EQ(w_dims[1], 4 * frame_size, |
| 56 | + "The second dimension of Input(Weight) " |
| 57 | + "should be 4 * %d.", |
| 58 | + frame_size); |
| 59 | + auto b_dims = ctx->GetInputDim("Bias"); |
| 60 | + PADDLE_ENFORCE_EQ(b_dims.size(), 2, "The rank of Input(Bias) should be 2."); |
| 61 | + PADDLE_ENFORCE_EQ(b_dims[0], 1, |
| 62 | + "The first dimension of Input(Bias) should be 1."); |
| 63 | + if (ctx->Attrs().Get<bool>("usePeepholes")) { |
| 64 | + PADDLE_ENFORCE_EQ(b_dims[1], 7 * frame_size, |
| 65 | + "The second dimension of Input(Bias) should be " |
| 66 | + "7 * %d if enable peepholes connection", |
| 67 | + frame_size); |
| 68 | + } else { |
| 69 | + PADDLE_ENFORCE_EQ(b_dims[1], 4 * frame_size, |
| 70 | + "The second dimension of Input(Bias) should be " |
| 71 | + "4 * %d if disable peepholes connection", |
| 72 | + frame_size); |
| 73 | + } |
| 74 | + ctx->SetOutputDim("Hidden", {x_dims[0], frame_size}); |
| 75 | + ctx->SetOutputDim("Cell", {x_dims[0], frame_size}); |
| 76 | + ctx->SetOutputDim("BatchGate", x_dims); |
| 77 | + ctx->ShareLoD("Input", "Hidden"); |
| 78 | + ctx->ShareLoD("Input", "Cell"); |
| 79 | + } |
| 80 | +}; |
| 81 | + |
| 82 | +class LSTMOpMaker : public framework::OpProtoAndCheckerMaker { |
| 83 | + public: |
| 84 | + LSTMOpMaker(framework::OpProto* proto, framework::OpAttrChecker* op_checker) |
| 85 | + : OpProtoAndCheckerMaker(proto, op_checker) { |
| 86 | + AddInput("Input", |
| 87 | + "(LoDTensor) the first input is a LodTensor, which support " |
| 88 | + "variable-time length input sequence. The underlying tensor in " |
| 89 | + "this LoDTensor is a matrix with shape (T X 4D), where, T is the " |
| 90 | + "total time steps in this mini-batch, D is the hidden size."); |
| 91 | + AddInput("H0", |
| 92 | + "(Tensor, optional) the initial hidden state is an optional " |
| 93 | + "input. This is a tensor with shape (N x D), where N is the " |
| 94 | + "batch size, D is the hidden size."); |
| 95 | + AddInput("C0", |
| 96 | + "(Tensor, optional) the initial cell state is an optional " |
| 97 | + "input. This is a tensor with shape (N x D), where N is the " |
| 98 | + "batch size. `H0` and `C0` can be NULL but only at the same time"); |
| 99 | + AddInput("Weight", |
| 100 | + "(Tensor) the learnable hidden-hidden weights." |
| 101 | + " - The shape is (D x 4D), where D is the hidden size. " |
| 102 | + " - Weight = {W_ch, W_ih, W_fh, W_oh}"); |
| 103 | + AddInput("Bias", |
| 104 | + "(Tensor) the learnable weights, which contains two parts: " |
| 105 | + "input-hidden bias weight and peephole connections weight if " |
| 106 | + "setting `usePeepholes` True. " |
| 107 | + "1. `usePeepholes = False` " |
| 108 | + " - The shape is (1 x 4D). " |
| 109 | + " - Bias = {b_c, b_i, b_f, b_o}." |
| 110 | + "2. `usePeepholes = True` " |
| 111 | + " - The shape is (1 x 7D). " |
| 112 | + " - Bias = {b_c, b_i, b_f, b_o, W_ic, W_fc, W_oc}."); |
| 113 | + AddOutput("BatchGate", |
| 114 | + "(LoDTensor) This LoDTensor contains input gate, forget gate " |
| 115 | + "and output gate after the nonlinear computation. This " |
| 116 | + "LoDTensor has the same shape with the reorganized input, which " |
| 117 | + "was also be called batch input. The LoD size is 2. The first " |
| 118 | + "LoD is the batch offsets and the second LoD contains the " |
| 119 | + "indexes, which denote the position of reorganized sequence " |
| 120 | + "in the raw input.") |
| 121 | + .AsIntermediate(); |
| 122 | + AddOutput("Hidden", |
| 123 | + "(LoDTensor) the hidden state lod tensor of LSTM operator. " |
| 124 | + "The shape and lod is the same with the `Input`."); |
| 125 | + AddOutput("Cell", |
| 126 | + "(LoDTensor) the cell state lod tensor of LSTM operator. " |
| 127 | + "The shape and lod is the same with the `Input`."); |
| 128 | + AddAttr<bool>("usePeepholes", |
| 129 | + "(bool, defalut: True) " |
| 130 | + "whether to enable diagonal/peephole connections.") |
| 131 | + .SetDefault(true); |
| 132 | + AddAttr<bool>("isReverse", |
| 133 | + "(bool, defalut: False) " |
| 134 | + "whether to compute reversed LSTM.") |
| 135 | + .SetDefault(false); |
| 136 | + AddAttr<std::string>( |
| 137 | + "gateActivation", |
| 138 | + "(string, default: sigmoid)" |
| 139 | + "The activation for input gate, forget gate and output " |
| 140 | + "gate, `sigmoid` by default.") |
| 141 | + .SetDefault("sigmoid"); |
| 142 | + AddAttr<std::string>("cellActivation", |
| 143 | + "(string, default: tanh)" |
| 144 | + "The activation for cell output, `tanh` by defalut.") |
| 145 | + .SetDefault("tanh"); |
| 146 | + AddAttr<std::string>("candidateActivation", |
| 147 | + "(string, default: tanh)" |
| 148 | + "The activation for candidate hidden state, " |
| 149 | + "`tanh` by default.") |
| 150 | + .SetDefault("tanh"); |
| 151 | + AddComment(R"DOC(Long-Short Term Memory (LSTM) Operator |
| 152 | +
|
| 153 | +The defalut implementation is diagonal/peephole connection [1], the formula is |
| 154 | +as follows |
| 155 | +
|
| 156 | + i_t = \sigma(W_{ix}x_{t} + W_{ih}h_{t-1} + W_{ic}c_{t-1} + b_i) |
| 157 | +
|
| 158 | + f_t = \sigma(W_{fx}x_{t} + W_{fh}h_{t-1} + W_{fc}c_{t-1} + b_f) |
| 159 | +
|
| 160 | + \tilde{c_t} = act_g(W_{cx}x_t + W_{ch}h_{t-1} + b_c) |
| 161 | +
|
| 162 | + o_t = \sigma(W_{ox}x_{t} + W_{oh}h_{t-1} + W_{oc}c_t + b_o) |
| 163 | +
|
| 164 | + c_t = f_t ⊙ c_{t-1} + i_t ⊙ \tilde{c_t} |
| 165 | +
|
| 166 | + h_t = o_t ⊙ act_h(c_t) |
| 167 | +
|
| 168 | +where the W terms denote weight matrices (e.g. \f$W_{xi}\f$ is the matrix |
| 169 | +of weights from the input gate to the input), \f$W_{ic}, W_{fc}, W_{oc}\f$ |
| 170 | +are diagonal weight matrices for peephole connections. In our implenmention, |
| 171 | +We use vectors to reprenset these diagonal weight matrices. The b terms |
| 172 | +denote bias vectors (\f$b_i\f$ is the input gate bias vector), \f$\sigma\f$ |
| 173 | +is the non-line actications, such as logistic sigmoid function, and |
| 174 | +\f$i, f, o\f$ and \f$c\f$ are respectively the input gate, forget gate, |
| 175 | +output gate and cell activation vectors, all of which are the same size as |
| 176 | +the cell output activation vector \f$h\f$. |
| 177 | +
|
| 178 | +The ⊙ is the element-wise product of the vectors, \f$act_g\f$ and \f$act_h\f$ |
| 179 | +are the cell input and cell output activation functions, `tanh` is usually |
| 180 | +used for them. \f$\tilde{c_t}\f$ is also called candidate hidden state, |
| 181 | +which is computed based on the current input and the previous hidden state. |
| 182 | +
|
| 183 | +Set `usePeepholes` False to disable peephole connection [2]. The formula |
| 184 | +is omitted here. |
| 185 | +
|
| 186 | +@note These \f$W_{xi}x_{t}, W_{xf}x_{t}, W_{xc}x_{t}, W_{xo}x_{t}\f$ |
| 187 | +operations on the input x_{t} were NOT included in this operator. |
| 188 | +Users can choose to use fully-connect operator before LSTM operator. |
| 189 | +
|
| 190 | +[1] Hasim Sak, Andrew Senior, and Francoise Beaufays. Long short-term memory |
| 191 | +recurrent neural network architectures for large scale acoustic modeling. |
| 192 | +INTERSPEECH, 2014. |
| 193 | +
|
| 194 | +[2] S. Hochreiter and J. Schmidhuber. Long Short-Term Memory. |
| 195 | +Neural Computation, 9(8):1735-1780, 1997. |
| 196 | +
|
| 197 | +)DOC"); |
| 198 | + } |
| 199 | +}; |
| 200 | + |
| 201 | +class LSTMGradOp : public framework::OperatorWithKernel { |
| 202 | + public: |
| 203 | + using framework::OperatorWithKernel::OperatorWithKernel; |
| 204 | + |
| 205 | + protected: |
| 206 | + void InferShape(framework::InferShapeContext* ctx) const override { |
| 207 | + PADDLE_ENFORCE(ctx->HasInput(framework::GradVarName("Hidden")), |
| 208 | + "Input(Hidden@GRAD) should not be null"); |
| 209 | + PADDLE_ENFORCE(ctx->HasInput(framework::GradVarName("Cell")), |
| 210 | + "Input(Cell@GRAD) should not be null"); |
| 211 | + ctx->SetOutputDim(framework::GradVarName("Weight"), |
| 212 | + ctx->GetInputDim("Weight")); |
| 213 | + ctx->SetOutputDim(framework::GradVarName("Bias"), ctx->GetInputDim("Bias")); |
| 214 | + } |
| 215 | +}; |
| 216 | + |
| 217 | +} // namespace operators |
| 218 | +} // namespace paddle |
| 219 | + |
| 220 | +namespace ops = paddle::operators; |
| 221 | +REGISTER_OP(lstm, ops::LSTMOp, ops::LSTMOpMaker, lstm_grad, ops::LSTMGradOp); |
| 222 | +REGISTER_OP_CPU_KERNEL(lstm, ops::LSTMKernel<paddle::platform::CPUPlace, float>, |
| 223 | + ops::LSTMKernel<paddle::platform::CPUPlace, double>); |
| 224 | +REGISTER_OP_CPU_KERNEL(lstm_grad, |
| 225 | + ops::LSTMGradKernel<paddle::platform::CPUPlace, float>, |
| 226 | + ops::LSTMGradKernel<paddle::platform::CPUPlace, double>); |
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