add unbind op (#23359)

* add unbind op
unbind(tensor, dim=0):
说明：移除指定维后，返回一组数组，包含了沿着指定维切片后的各个切片。

tensor(Tensor) -- 输入Tensor
dim(int) -- 删除的维度

示例：
 Input = [[1,2],
           [3,4],
           [5,6]]
  axis = 0
  Output[0] = [1,2]
  Output[1] = [3,4]
  Output[2] = [5,6]

paddle/fluid/operators/unbind_op.cc

+/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License. */
+
+#include "paddle/fluid/operators/unbind_op.h"
+#include <string>
+
+namespace paddle {
+namespace operators {
+using framework::Tensor;
+
+class UnbindOp : public framework::OperatorWithKernel {
+ public:
+  using framework::OperatorWithKernel::OperatorWithKernel;
+
+  void InferShape(framework::InferShapeContext *ctx) const override {
+    PADDLE_ENFORCE_EQ(
+        ctx->HasInput("X"), true,
+        platform::errors::NotFound("Input(X) of UnbindOp is not found."));
+    PADDLE_ENFORCE_GE(
+        ctx->Outputs("Out").size(), 1UL,
+        platform::errors::NotFound("Outputs(Out) of UnbindOp is not found."));
+    auto in_dims = ctx->GetInputDim("X");
+    auto outs_names = ctx->Outputs("Out");
+    int axis = ctx->Attrs().Get<int>("axis");
+    const size_t outs_number = outs_names.size();
+    auto out_dims = UnbindOutsDims(in_dims, axis);
+    std::vector<framework::DDim> outs_dims(outs_number, out_dims);
+    ctx->SetOutputsDim("Out", outs_dims);
+    for (size_t i = 0; i < outs_number; ++i) {
+      ctx->ShareLoD("X", "Out", 0, i);
+    }
+  }
+};
+
+class UnbindOpMaker : public framework::OpProtoAndCheckerMaker {
+ public:
+  void Make() override {
+    AddInput("X", "(Tensor) Input tensor of the split operator.");
+    AddOutput("Out", "(Tensor) Output tensors of the unbind operator.")
+        .AsDuplicable();
+    AddComment(R"DOC(
+Unbind operator
+
+Remove a tensor dimension.
+
+Example:
+  Input = [[1,2],
+           [3,4],
+           [5,6]]
+  axis = 0
+  Output[0] = [1,2]
+  Output[1] = [3,4]
+  Output[2] = [5,6]
+
+    )DOC");
+    AddAttr<int>("axis",
+                 "(int, default 0) "
+                 "dimension to remove.")
+        .SetDefault(0);
+  }
+};
+
+}  // namespace operators
+}  // namespace paddle
+
+namespace ops = paddle::operators;
+
+REGISTER_OPERATOR(unbind, ops::UnbindOp, ops::UnbindOpMaker,
+                  ops::UnbindGradMaker<paddle::framework::OpDesc>,
+                  ops::UnbindGradMaker<paddle::imperative::OpBase>);
+namespace plat = paddle::platform;
+REGISTER_OP_CPU_KERNEL(
+    unbind, ops::UnbindOpKernel<plat::CPUDeviceContext, double>,
+    ops::UnbindOpKernel<plat::CPUDeviceContext, float>,
+    ops::UnbindOpKernel<plat::CPUDeviceContext, int64_t>,
+    ops::UnbindOpKernel<plat::CPUDeviceContext, int>,
+    ops::UnbindOpKernel<plat::CPUDeviceContext, plat::float16>);

paddle/fluid/operators/unbind_op.cu.cc

+/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License. */
+
+#include "paddle/fluid/operators/unbind_op.h"
+namespace ops = paddle::operators;
+namespace plat = paddle::platform;
+REGISTER_OP_CUDA_KERNEL(
+    unbind, ops::UnbindOpKernel<plat::CUDADeviceContext, double>,
+    ops::UnbindOpKernel<plat::CUDADeviceContext, float>,
+    ops::UnbindOpKernel<plat::CUDADeviceContext, int64_t>,
+    ops::UnbindOpKernel<plat::CUDADeviceContext, int>,
+    ops::UnbindOpKernel<plat::CUDADeviceContext, plat::float16>);

paddle/fluid/operators/unbind_op.h

+/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License. */
+
+#pragma once
+
+#include <chrono>  // NOLINT
+#include <memory>
+#include <string>
+#include <vector>
+#include "paddle/fluid/framework/op_registry.h"
+#include "paddle/fluid/operators/math/concat_and_split.h"
+#include "paddle/fluid/operators/strided_memcpy.h"
+#include "paddle/fluid/operators/utils.h"
+
+namespace paddle {
+namespace operators {
+static inline framework::DDim UnbindOutsDims(const framework::DDim in_dims,
+                                             int axis) {
+  std::vector<int> out_dims;
+  axis = axis < 0 ? in_dims.size() + axis : axis;
+  for (int i = 0; i < in_dims.size(); i++) {
+    if (i != axis) out_dims.push_back(in_dims[i]);
+  }
+  return framework::make_ddim(out_dims);
+}
+template <typename DeviceContext, typename T>
+class UnbindOpKernel : public framework::OpKernel<T> {
+ public:
+  void Compute(const framework::ExecutionContext& ctx) const override {
+    auto* in = ctx.Input<framework::Tensor>("X");
+    auto outs = ctx.MultiOutput<framework::Tensor>("Out");
+    int axis = ctx.Attr<int>("axis");
+
+    auto in_dims = in->dims();
+
+    auto place = ctx.GetPlace();
+
+    axis = axis < 0 ? in_dims.size() + axis : axis;
+    std::vector<const framework::Tensor*> shape_refer;
+    for (size_t j = 0; j < outs.size(); ++j) {
+      outs[j]->mutable_data<T>(ctx.GetPlace());
+      shape_refer.emplace_back(outs[j]);
+    }
+
+    auto& dev_ctx = ctx.template device_context<DeviceContext>();
+    math::SplitFunctor<DeviceContext, T> functor;
+    functor(dev_ctx, *in, shape_refer, axis, &outs);
+  }
+};
+
+template <typename T>
+class UnbindGradMaker : public framework::SingleGradOpMaker<T> {
+ public:
+  using framework::SingleGradOpMaker<T>::SingleGradOpMaker;
+
+ protected:
+  void Apply(GradOpPtr<T> op) const override {
+    op->SetType("stack");
+    op->SetInput("X", this->OutputGrad("Out"));
+    op->SetOutput("Y", this->InputGrad("X"));
+    op->SetAttrMap(this->Attrs());
+  }
+};
+
+}  // namespace operators
+}  // namespace paddle

python/paddle/fluid/tests/unittests/test_unbind_op.py

+#   Copyright (c) 2018 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import print_function
+
+import unittest
+import numpy as np
+from op_test import OpTest
+import paddle.fluid as fluid
+from paddle.fluid import compiler, Program, program_guard, core
+
+
+class TestUnbindOp(OpTest):
+    def initParameters(self):
+        pass
+
+    def outReshape(self):
+        pass
+
+    def setAxis(self):
+        pass
+
+    def setUp(self):
+        self._set_op_type()
+        self.dtype = self.get_dtype()
+        self.axis = 0
+        self.num = 3
+        self.initParameters()
+        #x = np.random.random((3, 2, 2)).astype(self.dtype)
+        x = np.arange(12).reshape(3, 2, 2).astype(self.dtype)
+        self.out = np.split(x, self.num, self.axis)
+        self.outReshape()
+        self.inputs = {'X': x}
+        self.attrs = {'axis': self.axis}
+        self.setAxis()
+        self.outputs = {'Out': [('out%d' % i, self.out[i]) \
+            for i in range(len(self.out))]}
+
+    def get_dtype(self):
+        return "float64"
+
+    def _set_op_type(self):
+        self.op_type = "unbind"
+
+    def test_check_output(self):
+        self.check_output()
+
+    def test_check_grad(self):
+        self.check_grad(['X'], ['out0', 'out1', 'out2'])
+
+
+class TestUnbindOp1(TestUnbindOp):
+    def initParameters(self):
+        self.axis = 1
+        self.num = 2
+
+    def test_check_grad(self):
+        self.check_grad(['X'], ['out0', 'out1'])
+
+    def outReshape(self):
+        self.out[0] = self.out[0].reshape((3, 2))
+        self.out[1] = self.out[1].reshape((3, 2))
+
+
+class TestUnbindOp2(TestUnbindOp):
+    def initParameters(self):
+        self.axis = 2
+        self.num = 2
+
+    def test_check_grad(self):
+        self.check_grad(['X'], ['out0', 'out1'])
+
+    def outReshape(self):
+        self.out[0] = self.out[0].reshape((3, 2))
+        self.out[1] = self.out[1].reshape((3, 2))
+
+
+class TestUnbindOp3(TestUnbindOp):
+    def initParameters(self):
+        self.axis = 2
+        self.num = 2
+
+    def setAxis(self):
+        self.attrs = {'axis': -1}
+
+    def test_check_grad(self):
+        self.check_grad(['X'], ['out0', 'out1'])
+
+    def outReshape(self):
+        self.out[0] = self.out[0].reshape((3, 2))
+        self.out[1] = self.out[1].reshape((3, 2))
+
+
+class TestUnbindOp4(TestUnbindOp):
+    def initParameters(self):
+        self.axis = 1
+        self.num = 2
+
+    def setAxis(self):
+        self.attrs = {'axis': -2}
+
+    def test_check_grad(self):
+        self.check_grad(['X'], ['out0', 'out1'])
+
+    def outReshape(self):
+        self.out[0] = self.out[0].reshape((3, 2))
+        self.out[1] = self.out[1].reshape((3, 2))
+
+
+if __name__ == '__main__':
+    unittest.main()