Created by: zhiqiu

PR types

Others

PR changes

OPs

Describe

Add common unary op

Usage

For example, if we want to write a new operator, y = -(x). We can simply write like this,

class TestNegOpMaker : public framework::OpProtoAndCheckerMaker {
 public:
  void Make() override {
    AddInput("X", "input of test op");
    AddOutput("Out", "output of test op");
    AddComment("Out = -X");
  }
};

template <typename T>
class TestNegOpGradMaker : public framework::SingleGradOpMaker<T> {
 public:
  using framework::SingleGradOpMaker<T>::SingleGradOpMaker;

 protected:
  void Apply(GradOpPtr<T> op) const override {
    op->SetType(this->ForwardOpType() + "_grad");
    op->SetInput(framework::GradVarName("Out"), this->OutputGrad("Out"));
    op->SetOutput(framework::GradVarName("X"), this->InputGrad("X"));
    op->SetAttrMap(this->Attrs());
  }
};

}  // namespace operators
}  // namespace paddle

namespace ops = paddle::operators;
namespace functors = paddle::operators::functors;

REGISTER_OPERATOR(test_neg, ops::UnaryOp, ops::TestNegOpMaker,
                  ops::TestNegOpGradMaker<paddle::framework::OpDesc>,
                  ops::TestNegOpGradMaker<paddle::imperative::OpBase>);
REGISTER_OPERATOR(test_neg_grad, ops::UnaryGradOp);
REGISTER_OP_KERNEL_4(test_neg, ops::UnaryOpKernel, CPU, functors::Neg, int,
                     int64_t, float, double);
REGISTER_OP_KERNEL_4(test_neg_grad, ops::UnaryGradOpKernel, CPU, functors::Neg,
                     int, int64_t, float, double);

As the example shown, the implementation of neg op can be easy and simple enough.

Plus, if we want to implement another unary op, we only need to change the OpMaker, op_name, and functor.