diff --git a/paddle/operators/gru_op.h b/paddle/operators/gru_op.h
index c6228864d7ec042ff99e4521d1d707ba091e8ed5..b1957fb9ce6add8628cb206abf2c569d3f615c85 100644
--- a/paddle/operators/gru_op.h
+++ b/paddle/operators/gru_op.h
@@ -14,6 +14,7 @@ limitations under the License. */
 
 #pragma once
 
+#include "paddle/operators/math/detail/activation_functions.h"
 #include "paddle/operators/math/gru_compute.h"
 #include "paddle/operators/math/math_function.h"
 #include "paddle/operators/math/sequence2batch.h"
@@ -70,7 +71,7 @@ class GRUKernel : public framework::OpKernel<T> {
     }
 
     int frame_size = hidden_dims[1];
-    math::hl_gru_value<T> gru_value;
+    math::GRUMetaValue<T> gru_value;
     gru_value.gate_weight = const_cast<T*>(weight_data);
     gru_value.state_weight =
         const_cast<T*>(weight_data + 2 * frame_size * frame_size);
@@ -89,6 +90,10 @@ class GRUKernel : public framework::OpKernel<T> {
     }
     auto batch_starts = batch_gate->lod()[0];
     size_t num_batch = batch_starts.size() - 1;
+    auto active_node = math::detail::GetActivationType(
+        context.Attr<std::string>("activation"));
+    auto active_gate = math::detail::GetActivationType(
+        context.Attr<std::string>("gate_activation"));
     for (size_t n = 0; n < num_batch; n++) {
       int bstart = static_cast<int>(batch_starts[n]);
       int bend = static_cast<int>(batch_starts[n + 1]);
@@ -101,9 +106,8 @@ class GRUKernel : public framework::OpKernel<T> {
       gru_value.gate_value = gate_t.data<T>();
       gru_value.reset_output_value = reset_hidden_prev_t.data<T>();
       math::GRUUnitFunctor<DeviceContext, T>::compute(
-          dev_ctx, gru_value, frame_size, cur_batch_size,
-          math::ActiveType(context.Attr<std::string>("activation")),
-          math::ActiveType(context.Attr<std::string>("gate_activation")));
+          dev_ctx, gru_value, frame_size, cur_batch_size, active_node,
+          active_gate);
       gru_value.prev_out_value = gru_value.output_value;
     }
 
@@ -170,12 +174,12 @@ class GRUGradKernel : public framework::OpKernel<T> {
     batch_hidden_grad.set_lod(batch_hidden->lod());
     to_batch(dev_ctx, *hidden_grad, batch_hidden_grad, false, is_reverse);
 
-    math::hl_gru_value<T> gru_value;
+    math::GRUMetaValue<T> gru_value;
     gru_value.gate_weight = const_cast<T*>(weight_data);
     gru_value.state_weight =
         const_cast<T*>(weight_data + 2 * frame_size * frame_size);
 
-    math::hl_gru_grad<T> gru_grad;
+    math::GRUMetaGrad<T> gru_grad;
     if (weight_grad) {
       gru_grad.gate_weight_grad =
           weight_grad->mutable_data<T>(context.GetPlace());
@@ -189,6 +193,10 @@ class GRUGradKernel : public framework::OpKernel<T> {
 
     auto batch_starts = batch_hidden_grad.lod()[0];
     size_t num_batch = batch_starts.size() - 1;
+    auto active_node = math::detail::GetActivationType(
+        context.Attr<std::string>("activation"));
+    auto active_gate = math::detail::GetActivationType(
+        context.Attr<std::string>("gate_activation"));
     for (int n = static_cast<int>(num_batch) - 1; n >= 0; n--) {
       int bstart = static_cast<int>(batch_starts[n]);
       int bend = static_cast<int>(batch_starts[n + 1]);
@@ -219,9 +227,8 @@ class GRUGradKernel : public framework::OpKernel<T> {
       }
 
       math::GRUUnitGradFunctor<DeviceContext, T>::compute(
-          dev_ctx, gru_value, gru_grad, frame_size, cur_batch_size,
-          math::ActiveType(context.Attr<std::string>("activation")),
-          math::ActiveType(context.Attr<std::string>("gate_activation")));
+          dev_ctx, gru_value, gru_grad, frame_size, cur_batch_size, active_node,
+          active_gate);
     }
     if (input_grad) {
       input_grad->mutable_data<T>(context.GetPlace());
diff --git a/paddle/operators/math/detail/gru_cpu_kernel.h b/paddle/operators/math/detail/gru_cpu_kernel.h
index 4c67dec9cbeb48f400f79f5ed7ba3c939fa2540c..a61b232f4275d93cae1d9a71d49a779216c3555b 100644
--- a/paddle/operators/math/detail/gru_cpu_kernel.h
+++ b/paddle/operators/math/detail/gru_cpu_kernel.h
@@ -28,7 +28,7 @@ template <class OpResetOutput, typename T>
 void hl_naive_gru_forward_reset_output(OpResetOutput op_reset_output,
                                        T *gate_value, T *reset_output_value,
                                        T *prev_output_value, int frame_size,
-                                       activation_mode_t active_gate) {
+                                       ActivationType active_gate) {
   T r_value_update_gate;
   T r_value_reset_gate;
   T r_value_reset_output;
@@ -56,7 +56,7 @@ template <class OpFinalOutput, typename T>
 void hl_naive_gru_forward_final_output(OpFinalOutput op_final_output,
                                        T *gate_value, T *prev_output_value,
                                        T *output_value, int frame_size,
-                                       activation_mode_t active_node) {
+                                       ActivationType active_node) {
   T r_value_update_gate;
   T r_value_frame_state;
   T r_prev_out = 0;
@@ -83,7 +83,7 @@ template <class OpResetOutput, typename T>
 void hl_avx_gru_forward_reset_output(OpResetOutput op_reset_output,
                                      T *gate_value, T *reset_output_value,
                                      T *prev_output_value, int frame_size,
-                                     activation_mode_t active_gate) {
+                                     ActivationType active_gate) {
 #ifdef __AVX__
   __m256 r_value_update_gate;
   __m256 r_value_reset_gate;
@@ -113,7 +113,7 @@ template <class OpFinalOutput, typename T>
 void hl_avx_gru_forward_final_output(OpFinalOutput op_final_output,
                                      T *gate_value, T *prev_output_value,
                                      T *output_value, int frame_size,
-                                     activation_mode_t active_node) {
+                                     ActivationType active_node) {
 #ifdef __AVX__
   __m256 r_value_update_gate;
   __m256 r_value_frame_state;
@@ -140,9 +140,8 @@ void hl_avx_gru_forward_final_output(OpFinalOutput op_final_output,
 
 template <class OpResetOutput, typename T>
 inline void forward_reset_output(OpResetOutput op_reset_output,
-                                 hl_gru_value<T> value, int frame_size,
-                                 int batch_size,
-                                 activation_mode_t active_gate) {
+                                 GRUMetaValue<T> value, int frame_size,
+                                 int batch_size, ActivationType active_gate) {
   for (int b = 0; b < batch_size; b++) {
     if (OpResetOutput::avx && !(frame_size & (8 - 1)) && (sizeof(T) == 4)) {
       hl_avx_gru_forward_reset_output(
@@ -164,9 +163,8 @@ inline void forward_reset_output(OpResetOutput op_reset_output,
 
 template <class OpFinalOutput, typename T>
 inline void forward_final_output(OpFinalOutput op_final_output,
-                                 hl_gru_value<T> value, int frame_size,
-                                 int batch_size,
-                                 activation_mode_t active_node) {
+                                 GRUMetaValue<T> value, int frame_size,
+                                 int batch_size, ActivationType active_node) {
   for (int b = 0; b < batch_size; b++) {
     if (OpFinalOutput::avx && !(frame_size & (8 - 1)) && (sizeof(T) == 4)) {
       hl_avx_gru_forward_final_output(op_final_output, value.gate_value,
@@ -191,7 +189,7 @@ void hl_naive_gru_backward_state_grad(OpStateGrad op_state_grad, T *gate_value,
                                       T *gate_grad, T *prev_out_value,
                                       T *prev_out_grad, T *output_grad,
                                       int frame_size,
-                                      activation_mode_t active_node) {
+                                      ActivationType active_node) {
   T r_update_gate_value;
   T r_update_gate_grad;
   T r_frame_state_value;
@@ -232,7 +230,7 @@ void hl_naive_gru_backward_reset_grad(OpResetGrad op_reset_grad, T *gate_value,
                                       T *gate_grad, T *prev_out_value,
                                       T *prev_out_grad, T *reset_output_grad,
                                       int frame_size,
-                                      activation_mode_t active_gate) {
+                                      ActivationType active_gate) {
   T r_update_gate_value;
   T r_update_gate_grad;
   T r_reset_gate_value;
@@ -277,7 +275,7 @@ void hl_avx_gru_backward_state_grad(OpStateGrad op_state_grad, T *gate_value,
                                     T *gate_grad, T *prev_out_value,
                                     T *prev_out_grad, T *output_grad,
                                     int frame_size,
-                                    activation_mode_t active_node) {
+                                    ActivationType active_node) {
 #ifdef __AVX__
   __m256 r_update_gate_value;
   __m256 r_update_gate_grad;
@@ -320,7 +318,7 @@ void hl_avx_gru_backward_reset_grad(OpResetGrad op_reset_grad, T *gate_value,
                                     T *gate_grad, T *prev_out_value,
                                     T *prev_out_grad, T *reset_output_grad,
                                     int frame_size,
-                                    activation_mode_t active_gate) {
+                                    ActivationType active_gate) {
 #ifdef __AVX__
   __m256 r_update_gate_value;
   __m256 r_update_gate_grad;
@@ -364,9 +362,9 @@ void hl_avx_gru_backward_reset_grad(OpResetGrad op_reset_grad, T *gate_value,
 
 template <class OpStateGrad, typename T>
 inline void backward_state_grad(OpStateGrad op_state_grad,
-                                hl_gru_value<T> value, hl_gru_grad<T> grad,
+                                GRUMetaValue<T> value, GRUMetaGrad<T> grad,
                                 int frame_size, int batch_size,
-                                activation_mode_t active_node) {
+                                ActivationType active_node) {
   for (int b = 0; b < batch_size; b++) {
     if (OpStateGrad::avx && !(frame_size & (8 - 1)) && (sizeof(T) == 4)) {
       hl_avx_gru_backward_state_grad(
@@ -393,9 +391,9 @@ inline void backward_state_grad(OpStateGrad op_state_grad,
 
 template <class OpResetGrad, typename T>
 inline void backward_reset_grad(OpResetGrad op_reset_grad,
-                                hl_gru_value<T> value, hl_gru_grad<T> grad,
+                                GRUMetaValue<T> value, GRUMetaGrad<T> grad,
                                 int frame_size, int batch_size,
-                                activation_mode_t active_gate) {
+                                ActivationType active_gate) {
   for (int b = 0; b < batch_size; b++) {
     if (OpResetGrad::avx && !(frame_size & (8 - 1)) && (sizeof(T) == 4)) {
       hl_avx_gru_backward_reset_grad(
diff --git a/paddle/operators/math/detail/gru_gpu_kernel.h b/paddle/operators/math/detail/gru_gpu_kernel.h
index d2edcb7f258b387530799b967fc0fff61acc5b83..1783d46096858c874b27ce75760342082835b180 100644
--- a/paddle/operators/math/detail/gru_gpu_kernel.h
+++ b/paddle/operators/math/detail/gru_gpu_kernel.h
@@ -19,8 +19,6 @@ limitations under the License. */
 #include "paddle/platform/cuda_helper.h"
 #include "paddle/platform/device_context.h"
 
-#include <glog/logging.h>
-
 namespace paddle {
 namespace operators {
 namespace math {
@@ -35,7 +33,7 @@ __global__ void KeGruForwardResetOutput(OpResetOutput op_reset_output,
                                         T *gate_value, T *reset_output_value,
                                         T *prev_output_value, int frame_size,
                                         int batch_size,
-                                        activation_mode_t active_gate) {
+                                        ActivationType active_gate) {
   const int frame_idx = blockIdx.x * blockDim.x + threadIdx.x;
   if (frame_idx >= frame_size) return;
 
@@ -74,7 +72,7 @@ __global__ void KeGruForwardFinalOutput(OpFinalOutput op_final_output,
                                         T *gate_value, T *prev_output_value,
                                         T *output_value, int frame_size,
                                         int batch_size,
-                                        activation_mode_t active_node) {
+                                        ActivationType active_node) {
   const int frame_idx = blockIdx.x * blockDim.x + threadIdx.x;
   if (frame_idx >= frame_size) return;
   int batch_idx = 0;
@@ -111,7 +109,7 @@ __global__ void KeGruBackwardStateGrad(OpStateGrad op_state_grad, T *gate_value,
                                        T *gate_grad, T *prev_out_value,
                                        T *prev_out_grad, T *output_grad,
                                        int frame_size, int batch_size,
-                                       activation_mode_t active_node) {
+                                       ActivationType active_node) {
   const int frame_idx = blockIdx.x * blockDim.x + threadIdx.x;
   if (frame_idx >= frame_size) return;
   int batch_idx = 0;
@@ -159,7 +157,7 @@ __global__ void KeGruBackwardResetGrad(OpResetGrad op_reset_grad, T *gate_value,
                                        T *gate_grad, T *prev_out_value,
                                        T *prev_out_grad, T *reset_output_grad,
                                        int frame_size, int batch_size,
-                                       activation_mode_t active_gate) {
+                                       ActivationType active_gate) {
   const int frame_idx = blockIdx.x * blockDim.x + threadIdx.x;
   if (frame_idx >= frame_size) return;
   int batch_idx = 0;
diff --git a/paddle/operators/math/detail/gru_kernel.h b/paddle/operators/math/detail/gru_kernel.h
index acd84be01db9ddaf06d165d8be353b253f324dd2..4d8245cb5d03b33edbda5d8350be02b4fa87ab95 100644
--- a/paddle/operators/math/detail/gru_kernel.h
+++ b/paddle/operators/math/detail/gru_kernel.h
@@ -30,7 +30,7 @@ class gru_resetOutput {
  public:
   HOSTDEVICE void operator()(T &value_update_gate, T &value_reset_gate,
                              T &prev_out, T &value_reset_output,
-                             activation_mode_t act_gate) {
+                             ActivationType act_gate) {
     value_update_gate = activation(value_update_gate, act_gate);
     value_reset_gate = activation(value_reset_gate, act_gate);
     value_reset_output = prev_out * value_reset_gate;
@@ -43,7 +43,7 @@ class gru_resetOutput {
   HOSTDEVICE void operator()(__m256 &value_update_gate,
                              __m256 &value_reset_gate, __m256 &prev_out,
                              __m256 &value_reset_output,
-                             activation_mode_t act_gate) {
+                             ActivationType act_gate) {
     value_update_gate = activation(value_update_gate, act_gate);
     value_reset_gate = activation(value_reset_gate, act_gate);
     value_reset_output = _mm256_mul_ps(prev_out, value_reset_gate);
@@ -57,7 +57,7 @@ class gru_finalOutput {
  public:
   HOSTDEVICE void operator()(T &value_update_gate, T &value_frame_state,
                              T &prev_out, T &value_output,
-                             activation_mode_t act_input) {
+                             ActivationType act_input) {
     value_frame_state = activation(value_frame_state, act_input);
     value_output = prev_out - (value_update_gate * prev_out) +
                    (value_update_gate * value_frame_state);
@@ -69,8 +69,7 @@ class gru_finalOutput {
   static const bool avx = true;
   HOSTDEVICE void operator()(__m256 &value_update_gate,
                              __m256 &value_frame_state, __m256 &prev_out,
-                             __m256 &value_output,
-                             activation_mode_t act_input) {
+                             __m256 &value_output, ActivationType act_input) {
     value_frame_state = activation(value_frame_state, act_input);
     value_output = _mm256_add_ps(
         _mm256_sub_ps(prev_out, _mm256_mul_ps(value_update_gate, prev_out)),
@@ -89,7 +88,7 @@ class gru_stateGrad {
   HOSTDEVICE void operator()(T &value_update_gate, T &grad_update_gate,
                              T &value_frame_state, T &grad_frame_state,
                              T &value_prev_out, T &grad_prev_out,
-                             T &grad_output, activation_mode_t act_input) {
+                             T &grad_output, ActivationType act_input) {
     grad_update_gate = (grad_output * value_frame_state);
     grad_update_gate -= (grad_output * value_prev_out);
     grad_prev_out -= (grad_output * value_update_gate);
@@ -107,7 +106,7 @@ class gru_stateGrad {
                              __m256 &value_frame_state,
                              __m256 &grad_frame_state, __m256 &value_prev_out,
                              __m256 &grad_prev_out, __m256 &grad_output,
-                             activation_mode_t act_input) {
+                             ActivationType act_input) {
     grad_update_gate = _mm256_mul_ps(grad_output, value_frame_state);
     grad_update_gate = _mm256_sub_ps(
         grad_update_gate, _mm256_mul_ps(grad_output, value_prev_out));
@@ -128,7 +127,7 @@ class gru_resetGrad {
   HOSTDEVICE void operator()(T &value_update_gate, T &grad_update_gate,
                              T &value_reset_gate, T &grad_reset_gate,
                              T &value_prev_out, T &grad_prev_out,
-                             T &grad_reset_output, activation_mode_t act_gate) {
+                             T &grad_reset_output, ActivationType act_gate) {
     grad_reset_gate = (grad_reset_output * value_prev_out);
     grad_prev_out += (grad_reset_output * value_reset_gate);
     grad_update_gate =
@@ -144,7 +143,7 @@ class gru_resetGrad {
                              __m256 &grad_update_gate, __m256 &value_reset_gate,
                              __m256 &grad_reset_gate, __m256 &value_prev_out,
                              __m256 &grad_prev_out, __m256 &grad_reset_output,
-                             activation_mode_t act_gate) {
+                             ActivationType act_gate) {
     grad_reset_gate = _mm256_mul_ps(grad_reset_output, value_prev_out);
     grad_prev_out = _mm256_add_ps(
         grad_prev_out, _mm256_mul_ps(grad_reset_output, value_reset_gate));
diff --git a/paddle/operators/math/gru_compute.cc b/paddle/operators/math/gru_compute.cc
index d570c68cd458914c8951c4ce50a02e3c5b1acab0..101ab859624869bf34d171cd42d46d0c5bdac29c 100644
--- a/paddle/operators/math/gru_compute.cc
+++ b/paddle/operators/math/gru_compute.cc
@@ -21,9 +21,9 @@ namespace math {
 template <typename T>
 struct GRUUnitFunctor<platform::CPUDeviceContext, T> {
   static void compute(const platform::CPUDeviceContext &context,
-                      hl_gru_value<T> value, int frame_size, int batch_size,
-                      activation_mode_t active_node,
-                      activation_mode_t active_gate) {
+                      GRUMetaValue<T> value, int frame_size, int batch_size,
+                      const detail::ActivationType active_node,
+                      const detail::ActivationType active_gate) {
 #ifndef __NVCC__
     if (value.prev_out_value) {
       math::gemm<platform::CPUDeviceContext, T>(
@@ -51,10 +51,10 @@ struct GRUUnitFunctor<platform::CPUDeviceContext, T> {
 template <typename T>
 struct GRUUnitGradFunctor<platform::CPUDeviceContext, T> {
   static void compute(const platform::CPUDeviceContext &context,
-                      hl_gru_value<T> value, hl_gru_grad<T> grad,
+                      GRUMetaValue<T> value, GRUMetaGrad<T> grad,
                       int frame_size, int batch_size,
-                      activation_mode_t active_node,
-                      activation_mode_t active_gate) {
+                      const detail::ActivationType active_node,
+                      const detail::ActivationType active_gate) {
 #ifndef __NVCC__
     detail::backward_state_grad(detail::backward::gru_stateGrad<T>(), value,
                                 grad, frame_size, batch_size, active_node);
diff --git a/paddle/operators/math/gru_compute.cu b/paddle/operators/math/gru_compute.cu
index dd518cd1e4bea52f0d463150114feed3ceea0ccb..d5a0e630ea0eadea990988c3170395c842a91900 100644
--- a/paddle/operators/math/gru_compute.cu
+++ b/paddle/operators/math/gru_compute.cu
@@ -21,9 +21,9 @@ namespace math {
 template <typename T>
 struct GRUUnitFunctor<platform::CUDADeviceContext, T> {
   static void compute(const platform::CUDADeviceContext &context,
-                      hl_gru_value<T> value, int frame_size, int batch_size,
-                      activation_mode_t active_node,
-                      activation_mode_t active_gate) {
+                      GRUMetaValue<T> value, int frame_size, int batch_size,
+                      const detail::ActivationType active_node,
+                      const detail::ActivationType active_gate) {
     auto stream = context.stream();
     dim3 threads;
     dim3 grid;
@@ -88,10 +88,10 @@ struct GRUUnitFunctor<platform::CUDADeviceContext, T> {
 template <typename T>
 struct GRUUnitGradFunctor<platform::CUDADeviceContext, T> {
   static void compute(const platform::CUDADeviceContext &context,
-                      hl_gru_value<T> value, hl_gru_grad<T> grad,
+                      GRUMetaValue<T> value, GRUMetaGrad<T> grad,
                       int frame_size, int batch_size,
-                      activation_mode_t active_node,
-                      activation_mode_t active_gate) {
+                      const detail::ActivationType active_node,
+                      const detail::ActivationType active_gate) {
     auto stream = context.stream();
     dim3 threads;
     dim3 grid;
diff --git a/paddle/operators/math/gru_compute.h b/paddle/operators/math/gru_compute.h
index ca1343cb2c5c1eb8da92c2f06b25902c1c2fe8b3..bf69147b506661692a6d71823043cd3506ea8b5d 100644
--- a/paddle/operators/math/gru_compute.h
+++ b/paddle/operators/math/gru_compute.h
@@ -11,7 +11,7 @@ limitations under the License. */
 
 #pragma once
 
-#include "paddle/operators/math/lstm_compute.h"
+#include "paddle/operators/math/detail/activation_functions.h"
 #include "paddle/platform/device_context.h"
 #include "paddle/platform/enforce.h"
 
@@ -19,9 +19,8 @@ namespace paddle {
 namespace operators {
 namespace math {
 
-// TODO(guosheng): refine code style in gru_compute
 template <typename T>
-struct hl_gru_value {
+struct GRUMetaValue {
   T *gate_weight;
   T *state_weight;
   T *gate_value;
@@ -31,7 +30,7 @@ struct hl_gru_value {
 };
 
 template <typename T>
-struct hl_gru_grad {
+struct GRUMetaGrad {
   T *gate_weight_grad;
   T *state_weight_grad;
   T *gate_grad;
@@ -42,18 +41,18 @@ struct hl_gru_grad {
 
 template <typename DeviceContext, typename T>
 struct GRUUnitFunctor {
-  static void compute(const DeviceContext &context, hl_gru_value<T> value,
+  static void compute(const DeviceContext &context, GRUMetaValue<T> value,
                       int frame_size, int batch_size,
-                      activation_mode_t active_node,
-                      activation_mode_t active_gate);
+                      const detail::ActivationType active_node,
+                      const detail::ActivationType active_gate);
 };
 
 template <typename DeviceContext, typename T>
 struct GRUUnitGradFunctor {
-  static void compute(const DeviceContext &context, hl_gru_value<T> value,
-                      hl_gru_grad<T> grad, int frame_size, int batch_size,
-                      activation_mode_t active_node,
-                      activation_mode_t active_gate);
+  static void compute(const DeviceContext &context, GRUMetaValue<T> value,
+                      GRUMetaGrad<T> grad, int frame_size, int batch_size,
+                      const detail::ActivationType active_node,
+                      const detail::ActivationType active_gate);
 };
 
 }  // namespace math
diff --git a/paddle/operators/math/lstm_compute.h b/paddle/operators/math/lstm_compute.h
index 954762f92286fe13bd2c08ec03c3ac96bb663cca..e1ad6b64d201ef99d83eaa2a821356008dcc9c8e 100644
--- a/paddle/operators/math/lstm_compute.h
+++ b/paddle/operators/math/lstm_compute.h
@@ -22,14 +22,6 @@ namespace paddle {
 namespace operators {
 namespace math {
 
-typedef enum {
-  HL_ACTIVATION_SIGMOID = 0,
-  HL_ACTIVATION_RELU = 1,
-  HL_ACTIVATION_TANH = 2,
-  HL_ACTIVATION_LINEAR = 3,
-  HL_ACTIVATION_END
-} activation_mode_t;
-
 template <class T>
 struct LstmMetaValue {
   T *gate_value;
@@ -54,20 +46,6 @@ struct LstmMetaGrad {
   T *check_og_grad;
 };
 
-inline activation_mode_t ActiveType(const std::string &type) {
-  if (type == "sigmoid") {
-    return HL_ACTIVATION_SIGMOID;
-  } else if (type == "relu") {
-    return HL_ACTIVATION_RELU;
-  } else if (type == "tanh") {
-    return HL_ACTIVATION_TANH;
-  } else if (type == "linear" || type == "identity" || type == "") {
-    return HL_ACTIVATION_LINEAR;
-  } else {
-    PADDLE_THROW("Do not support activation type.");
-  }
-}
-
 template <typename DeviceContext, typename T>
 class LstmUnitFunctor {
  public: