Add register kernel functor and shrink reshape op

* Shrink reshape_op library size
* User can register a standard C++ functor as a op kernel

Author: reyoung

paddle/fluid/framework/op_registry.h

@@ -146,18 +146,15 @@ struct OpKernelRegistrarFunctorEx<PlaceType, true, I,
 template <typename PlaceType, size_t I, typename... DataTypeAndKernelType>
 struct OpKernelRegistrarFunctorEx<PlaceType, false, I,
                                   DataTypeAndKernelType...> {
-  using KERNEL_TYPE =
+  using Functor =
       typename std::tuple_element<I + 1,
                                   std::tuple<DataTypeAndKernelType...>>::type;
   using T =
       typename std::tuple_element<I,
                                   std::tuple<DataTypeAndKernelType...>>::type;
 
   void operator()(const char* op_type, const char* library_type) const {
-    RegisterKernelClass<PlaceType, T>(
-        op_type, library_type, [](const framework::ExecutionContext& ctx) {
-          KERNEL_TYPE().Compute(ctx);
-        });
+    RegisterKernelClass<PlaceType, T>(op_type, library_type, Functor());
 
     constexpr auto size =
         std::tuple_size<std::tuple<DataTypeAndKernelType...>>::value;
@@ -238,11 +235,11 @@ struct OpKernelRegistrarFunctorEx<PlaceType, false, I,
     return 0;                                                               \
   }
 
-#define REGISTER_OP_CUDA_KERNEL_EX(op_type, ...)                     \
-  REGISTER_OP_KERNEL_EX(p_type, CUDA, ::paddle::platform::CUDAPlace, \
+#define REGISTER_OP_CUDA_KERNEL_FUNCTOR(op_type, ...)                 \
+  REGISTER_OP_KERNEL_EX(op_type, CUDA, ::paddle::platform::CUDAPlace, \
                         __VA_ARGS__)
 
-#define REGISTER_OP_CPU_KERNEL_EX(op_type, ...) \
+#define REGISTER_OP_CPU_KERNEL_FUNCTOR(op_type, ...) \
   REGISTER_OP_KERNEL_EX(op_type, CPU, ::paddle::platform::CPUPlace, __VA_ARGS__)
 
 /**

paddle/fluid/operators/reshape_op.cc

@@ -107,7 +107,7 @@ class ReshapeGradOp : public framework::OperatorWithKernel {
   }
 };
 
-void ReshapeKernel::Compute(const framework::ExecutionContext &ctx) const {
+void ReshapeKernel::operator()(const framework::ExecutionContext &ctx) const {
   auto *out = ctx.Output<framework::LoDTensor>("Out");
   auto *in = ctx.Input<framework::LoDTensor>("X");
 
@@ -147,7 +147,7 @@ void ReshapeKernel::Compute(const framework::ExecutionContext &ctx) const {
     out->Resize(out_dims);
   }
 }
-void ReshapeGradKernelBase::Compute(
+void ReshapeGradKernel::operator()(
     const framework::ExecutionContext &ctx) const {
   auto *d_out = ctx.Input<framework::Tensor>(framework::GradVarName("Out"));
   auto *d_x = ctx.Output<framework::Tensor>(framework::GradVarName("X"));
@@ -172,10 +172,10 @@ namespace ops = paddle::operators;
 REGISTER_OPERATOR(reshape, ops::ReshapeOp, ops::ReshapeOpMaker,
                   paddle::framework::DefaultGradOpDescMaker<true>);
 REGISTER_OPERATOR(reshape_grad, ops::ReshapeGradOp);
-REGISTER_OP_CPU_KERNEL_EX(reshape, float, ops::ReshapeKernel, double,
-                          ops::ReshapeKernel, int, ops::ReshapeKernel, int64_t,
-                          ops::ReshapeKernel);
-REGISTER_OP_CPU_KERNEL(reshape_grad, ops::ReshapeGradKernel<float>,
-                       ops::ReshapeGradKernel<double>,
-                       ops::ReshapeGradKernel<int>,
-                       ops::ReshapeGradKernel<int64_t>);
+REGISTER_OP_CPU_KERNEL_FUNCTOR(reshape, float, ops::ReshapeKernel, double,
+                               ops::ReshapeKernel, int, ops::ReshapeKernel,
+                               int64_t, ops::ReshapeKernel);
+REGISTER_OP_CPU_KERNEL_FUNCTOR(reshape_grad, float, ops::ReshapeGradKernel,
+                               double, ops::ReshapeGradKernel, int,
+                               ops::ReshapeGradKernel, int64_t,
+                               ops::ReshapeGradKernel);

paddle/fluid/operators/reshape_op.cu.cc

@@ -14,11 +14,11 @@ limitations under the License. */
 
 #include "paddle/fluid/operators/reshape_op.h"
 namespace ops = paddle::operators;
-REGISTER_OP_CUDA_KERNEL_EX(reshape, float, ops::ReshapeKernel, double,
-                           ops::ReshapeKernel, int, ops::ReshapeKernel, int64_t,
-                           ops::ReshapeKernel);
-REGISTER_OP_CUDA_KERNEL(reshape_grad,
-                        paddle::operators::ReshapeGradKernel<float>,
-                        paddle::operators::ReshapeGradKernel<double>,
-                        paddle::operators::ReshapeGradKernel<int>,
-                        paddle::operators::ReshapeGradKernel<int64_t>);
+
+REGISTER_OP_CUDA_KERNEL_FUNCTOR(reshape, float, ops::ReshapeKernel, double,
+                                ops::ReshapeKernel, int, ops::ReshapeKernel,
+                                int64_t, ops::ReshapeKernel);
+REGISTER_OP_CUDA_KERNEL_FUNCTOR(reshape_grad, float, ops::ReshapeGradKernel,
+                                double, ops::ReshapeGradKernel, int,
+                                ops::ReshapeGradKernel, int64_t,
+                                ops::ReshapeGradKernel);

paddle/fluid/operators/reshape_op.h

@@ -118,21 +118,15 @@ class ReshapeOp : public framework::OperatorWithKernel {
   }
 };
 
-class ReshapeKernel : public framework::OpKernelBase {
+class ReshapeKernel {
  public:
-  void Compute(const framework::ExecutionContext &ctx) const final;
+  void operator()(const framework::ExecutionContext &ctx) const;
 };
 
-class ReshapeGradKernelBase : public framework::OpKernelBase {
+class ReshapeGradKernel {
  public:
-  void Compute(const framework::ExecutionContext &ctx) const;
+  void operator()(const framework::ExecutionContext &ctx) const;
 };
 
-template <typename T>
-class ReshapeGradKernel : public ReshapeGradKernelBase {
- public:
-  // Tell register element type.
-  using ELEMENT_TYPE = T;
-};
 }  // namespace operators
 }  // namespace paddle