[arm] add sequence_pool_grad op (#3986)

* fix sequence pool grad compute error, test=develop

* fix sequence pool grad run, test=develop

* fix format test=develop

lite/backends/arm/math/CMakeLists.txt

@@ -118,6 +118,7 @@ if (NOT HAS_ARM_MATH_LIB_DIR)
       beam_search.cc
       reduce_max.cc
       sequence_pool.cc
+      sequence_pool_grad.cc
       sequence_expand.cc
       slice.cc
       reduce_mean.cc

lite/backends/arm/math/funcs.h

@@ -56,6 +56,7 @@
 #include "lite/backends/arm/math/scale.h"
 #include "lite/backends/arm/math/sequence_expand.h"
 #include "lite/backends/arm/math/sequence_pool.h"
+#include "lite/backends/arm/math/sequence_pool_grad.h"
 #include "lite/backends/arm/math/sequence_softmax.h"
 #include "lite/backends/arm/math/sgemm.h"
 #include "lite/backends/arm/math/sgemv.h"

lite/backends/arm/math/sequence_pool.cc

@@ -36,70 +36,23 @@ void seq_pool_sum<float>(const float* din,
     const float* din_ptr = din + lod[i] * width;
     float* dout_ptr = dout + i * width;
     int64_t height = static_cast<int64_t>(lod[i + 1] - lod[i]);
-    if (width == 1) {
-      float sum = 0.f;
-      for (int h = 0; h < height; ++h) {
-        sum += din_ptr[h];
-      }
-      *dout_ptr = sum;
-    } else {
-      memcpy(dout_ptr, din_ptr, width * sizeof(float));
-      din_ptr += width;
-      height = height - 1;
-      int cnt_w = width >> 2;
-      int remain_w = width & 3;
-      int cnt_h = height >> 2;
-      int remain_h = height & 3;
-      int stride = width << 2;
-      for (int w = 0; w < cnt_w; w++) {
-        const float* din_ptr0 = din_ptr + w * 4;
-        float32x4_t dout_val = vld1q_f32(dout_ptr);
-        const float* din_ptr1 = din_ptr0 + width;
-        const float* din_ptr2 = din_ptr1 + width;
-        const float* din_ptr3 = din_ptr2 + width;
-        for (int h = 0; h < cnt_h; h++) {
-          float32x4_t din0 = vld1q_f32(din_ptr0);
-          float32x4_t din1 = vld1q_f32(din_ptr1);
-          float32x4_t din2 = vld1q_f32(din_ptr2);
-          float32x4_t din3 = vld1q_f32(din_ptr3);
-          dout_val = vaddq_f32(din0, dout_val);
-          float32x4_t tmp = vaddq_f32(din1, din2);
-          din_ptr0 += stride;
-          din_ptr1 += stride;
-          dout_val = vaddq_f32(din3, dout_val);
-          din_ptr2 += stride;
-          din_ptr3 += stride;
-          dout_val = vaddq_f32(tmp, dout_val);
-        }
-        for (int h = 0; h < remain_h; h++) {
-          float32x4_t din0 = vld1q_f32(din_ptr0);
-          dout_val = vaddq_f32(din0, dout_val);
-          din_ptr0 += width;
-        }
-        vst1q_f32(dout_ptr, dout_val);
-        dout_ptr += 4;
-      }
-      const float* din_ptr00 = din_ptr + cnt_w * 4;
-      for (int w = 0; w < remain_w; w++) {
-        const float* din_ptr0 = din_ptr00 + w;
-        const float* din_ptr1 = din_ptr0 + width;
-        const float* din_ptr2 = din_ptr1 + width;
-        const float* din_ptr3 = din_ptr2 + width;
-        for (int h = 0; h < cnt_h; h++) {
-          *dout_ptr += din_ptr0[0];
-          float tmp = din_ptr1[0] + din_ptr2[0];
-          din_ptr0 += stride;
-          din_ptr1 += stride;
-          *dout_ptr += din_ptr3[0];
-          din_ptr2 += stride;
-          din_ptr3 += stride;
-          *dout_ptr += tmp;
+    if (height > 0) {
+      if (width == 1) {
+        float sum = 0.f;
+        for (int h = 0; h < height; ++h) {
+          sum += din_ptr[h];
         }
-        for (int h = 0; h < remain_h; h++) {
-          *dout_ptr += din_ptr0[0];
-          din_ptr0 += width;
+        *dout_ptr = sum;
+      } else {
+        memcpy(dout_ptr, din_ptr, width * sizeof(float));
+        din_ptr += width;
+        height = height - 1;
+        for (int h = 0; h < height; h++) {
+          for (int w = 0; w < width; ++w) {
+            dout_ptr[w] += din_ptr[w];
+          }
+          din_ptr += width;
         }
-        dout_ptr++;
       }
     }
   }
@@ -177,78 +130,35 @@ void seq_pool_sqrt<float>(const float* din,
 template <>
 void seq_pool_max<float>(const float* din,
                          float* dout,
+                         int64_t* index,
                          const std::vector<uint64_t> lod,
                          int64_t width) {
   for (int i = 0; i < static_cast<int>(lod.size()) - 1; ++i) {
     const float* din_ptr = din + lod[i] * width;
     float* dout_ptr = dout + i * width;
+    int64_t* index_ptr = index + i * width;
     int64_t height = static_cast<int64_t>(lod[i + 1] - lod[i]);
     if (height > 0) {
       if (width == 1) {
         float max = -std::numeric_limits<float>::max();
+        int64_t max_index = -1;
         for (int h = 0; h < height; ++h) {
           max = std::max(max, din_ptr[h]);
+          max_index = max >= din_ptr[h] ? h : max_index;
         }
         *dout_ptr = max;
+        *index_ptr = max_index;
       } else {
         memcpy(dout_ptr, din_ptr, width * sizeof(float));
+        memset(index_ptr, 0, width * sizeof(int64_t));
         din_ptr += width;
-        height = height - 1;
-        int cnt_w = width >> 2;
-        int remain_w = width & 3;
-        int cnt_h = height >> 2;
-        int remain_h = height & 3;
-        int stride = width << 2;
-        for (int w = 0; w < cnt_w; w++) {
-          const float* din_ptr0 = din_ptr + w * 4;
-          float32x4_t dout_val = vld1q_f32(dout_ptr);
-          const float* din_ptr1 = din_ptr0 + width;
-          const float* din_ptr2 = din_ptr1 + width;
-          const float* din_ptr3 = din_ptr2 + width;
-          for (int h = 0; h < cnt_h; h++) {
-            float32x4_t din0 = vld1q_f32(din_ptr0);
-            float32x4_t din1 = vld1q_f32(din_ptr1);
-            float32x4_t din2 = vld1q_f32(din_ptr2);
-            float32x4_t din3 = vld1q_f32(din_ptr3);
-            dout_val = vmaxq_f32(din0, dout_val);
-            float32x4_t tmp = vmaxq_f32(din1, din2);
-            din_ptr0 += stride;
-            din_ptr1 += stride;
-            dout_val = vmaxq_f32(din3, dout_val);
-            din_ptr2 += stride;
-            din_ptr3 += stride;
-            dout_val = vmaxq_f32(tmp, dout_val);
-          }
-          for (int h = 0; h < remain_h; h++) {
-            float32x4_t din0 = vld1q_f32(din_ptr0);
-            dout_val = vmaxq_f32(din0, dout_val);
-            din_ptr0 += width;
-          }
-          vst1q_f32(dout_ptr, dout_val);
-          dout_ptr += 4;
-        }
-        const float* din_ptr00 = din_ptr + cnt_w * 4;
-        for (int w = 0; w < remain_w; w++) {
-          const float* din_ptr0 = din_ptr00 + w;
-          const float* din_ptr1 = din_ptr0 + width;
-          const float* din_ptr2 = din_ptr1 + width;
-          const float* din_ptr3 = din_ptr2 + width;
-          for (int h = 0; h < cnt_h; h++) {
-            *dout_ptr += din_ptr0[0];
-            *dout_ptr = std::max(*dout_ptr, din_ptr0[0]);
-            float tmp = std::max(din_ptr1[0], din_ptr2[0]);
-            din_ptr0 += stride;
-            din_ptr1 += stride;
-            *dout_ptr = std::max(*dout_ptr, din_ptr3[0]);
-            din_ptr2 += stride;
-            din_ptr3 += stride;
-            *dout_ptr = std::max(*dout_ptr, tmp);
-          }
-          for (int h = 0; h < remain_h; h++) {
-            *dout_ptr = std::max(*dout_ptr, din_ptr0[0]);
-            din_ptr0 += width;
+        int remain_h = height - 1;
+        for (int h = 0; h < remain_h; h++) {
+          for (int w = 0; w < width; w++) {
+            dout_ptr[w] = std::max(dout_ptr[w], din_ptr[w]);
+            index_ptr[w] = dout_ptr[w] > din_ptr[w] ? index_ptr[w] : h;
           }
-          dout_ptr++;
+          din_ptr += width;
         }
       }
     }
@@ -258,26 +168,33 @@ void seq_pool_max<float>(const float* din,
 template <>
 void seq_pool_min<float>(const float* din,
                          float* dout,
+                         int64_t* index,
                          const std::vector<uint64_t> lod,
                          int64_t width) {
   for (int i = 0; i < static_cast<int>(lod.size()) - 1; ++i) {
     const float* din_ptr = din + lod[i] * width;
     float* dout_ptr = dout + i * width;
+    int64_t* index_ptr = index + i * width;
     int64_t height = static_cast<int64_t>(lod[i + 1] - lod[i]);
     if (height > 0) {
       if (width == 1) {
         float min = std::numeric_limits<float>::max();
+        int64_t min_index = -1;
         for (int h = 0; h < height; ++h) {
           min = std::min(min, din_ptr[h]);
+          min_index = min >= din_ptr[h] ? h : min_index;
         }
         *dout_ptr = min;
+        *index_ptr = min_index;
       } else {
         memcpy(dout_ptr, din_ptr, width * sizeof(float));
+        memset(index_ptr, 0, width * sizeof(int64_t));
         din_ptr += width;
         int remain_h = height - 1;
         for (int h = 0; h < remain_h; h++) {
           for (int w = 0; w < width; w++) {
             dout_ptr[w] = std::min(dout_ptr[w], din_ptr[w]);
+            index_ptr[w] = dout_ptr[w] < din_ptr[w] ? index_ptr[w] : h;
           }
           din_ptr += width;
         }

lite/backends/arm/math/sequence_pool.h

@@ -42,12 +42,14 @@ void seq_pool_sqrt(const T* din,
 template <typename T>
 void seq_pool_max(const T* din,
                   T* dout,
+                  int64_t* index,
                   const std::vector<uint64_t> lod,
                   int64_t width);
 
 template <typename T>
 void seq_pool_min(const T* din,
                   T* dout,
+                  int64_t* index,
                   const std::vector<uint64_t> lod,
                   int64_t width);
 

lite/backends/arm/math/sequence_pool_grad.cc

+// Copyright (c) 2019 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 "lite/backends/arm/math/sequence_pool_grad.h"
+#include <algorithm>
+#include <cmath>
+#include <limits>
+#include <vector>
+#include "lite/backends/arm/math/funcs.h"
+#include "lite/core/op_registry.h"
+#include "lite/core/tensor.h"
+#include "lite/core/type_system.h"
+
+namespace paddle {
+namespace lite {
+namespace arm {
+namespace math {
+
+template <>
+void seq_pool_sum_grad<float>(const float* din,
+                              const float* dout_grad,
+                              float* din_grad,
+                              const std::vector<uint64_t> lod,
+                              int64_t width) {
+  for (int i = 0; i < static_cast<int>(lod.size()) - 1; i++) {
+    int64_t height = static_cast<int64_t>(lod[i + 1] - lod[i]);
+    const float* dout_grad_ptr = dout_grad + i * width;
+    float* din_grad_ptr = din_grad + lod[i] * width;
+    if (height > 0) {
+      if (width == 1) {
+        for (int h = 0; h < height; ++h) {
+          din_grad_ptr[h] = dout_grad_ptr[h];
+        }
+      } else {
+        for (int h = 0; h < height; h++) {
+          for (int w = 0; w < width; w++) {
+            din_grad_ptr[w] = dout_grad_ptr[w];
+          }
+          din_grad_ptr += width;
+        }
+      }
+    }
+  }
+}
+
+template <>
+void seq_pool_average_grad<float>(const float* din,
+                                  const float* dout_grad,
+                                  float* din_grad,
+                                  const std::vector<uint64_t> lod,
+                                  int64_t width) {
+  for (int i = 0; i < static_cast<int>(lod.size()) - 1; ++i) {
+    int64_t height = static_cast<int64_t>(lod[i + 1] - lod[i]);
+    const float* dout_grad_ptr = dout_grad + i * width;
+    float* din_grad_ptr = din_grad + lod[i] * width;
+    float alpha = 1.0 / height;
+    if (height > 0) {
+      if (width == 1) {
+        float sum = 0.f;
+        for (int h = 0; h < height; ++h) {
+          din_grad_ptr[h] = alpha * dout_grad_ptr[h];
+        }
+      } else {
+        for (int h = 0; h < height; h++) {
+          for (int w = 0; w < width; w++) {
+            din_grad_ptr[w] = alpha * dout_grad_ptr[w];
+          }
+          din_grad_ptr += width;
+        }
+      }
+    }
+  }
+}
+
+template <>
+void seq_pool_sqrt_grad<float>(const float* din,
+                               const float* dout_grad,
+                               float* din_grad,
+                               const std::vector<uint64_t> lod,
+                               int64_t width) {
+  for (int i = 0; i < static_cast<int>(lod.size()) - 1; ++i) {
+    int64_t height = static_cast<int64_t>(lod[i + 1] - lod[i]);
+    const float* dout_grad_ptr = dout_grad + i * width;
+    float* din_grad_ptr = din_grad + lod[i] * width;
+    float alpha = 1.0 / sqrtf(height);
+    if (height > 0) {
+      if (width == 1) {
+        float sum = 0.f;
+        for (int h = 0; h < height; ++h) {
+          din_grad_ptr[h] = alpha * dout_grad_ptr[h];
+        }
+      } else {
+        for (int h = 0; h < height; h++) {
+          for (int w = 0; w < width; w++) {
+            din_grad_ptr[w] = alpha * dout_grad_ptr[w];
+          }
+          din_grad_ptr += width;
+        }
+      }
+    }
+  }
+}
+
+template <>
+void seq_pool_max_grad<float>(const float* din,
+                              const float* dout_grad,
+                              const int64_t* index_grad,
+                              float* din_grad,
+                              const std::vector<uint64_t> lod,
+                              int64_t width) {
+  for (int i = 0; i < static_cast<int>(lod.size()) - 1; ++i) {
+    int64_t height = lod[i + 1] - lod[i];
+    const float* dout_grad_ptr = dout_grad + i * width;
+    const int64_t* index_grad_ptr = index_grad + i * width;
+    float* din_grad_ptr = din_grad + lod[i] * width;
+    if (height > 0) {
+      for (int h = 0; h < height; h++) {
+        for (int w = 0; w < width; w++) {
+          if (h == index_grad_ptr[w]) {
+            din_grad_ptr[w] = dout_grad_ptr[w];
+          } else {
+            din_grad_ptr[w] = 0.f;
+          }
+        }
+        din_grad_ptr += width;
+      }
+    }
+  }
+}
+
+template <>
+void seq_pool_first_grad<float>(const float* din,
+                                const float* dout_grad,
+                                float* din_grad,
+                                const std::vector<uint64_t> lod,
+                                int64_t width) {
+  for (int i = 0; i < static_cast<int>(lod.size()) - 1; ++i) {
+    int64_t height = lod[i + 1] - lod[i];
+    const float* dout_grad_ptr = dout_grad + i * width;
+    float* din_grad_ptr = din_grad + lod[i] * width;
+    if (height > 0) {
+      for (int w = 0; w < width; w++) {
+        din_grad_ptr[w] = dout_grad_ptr[w];
+      }
+      din_grad_ptr += width;
+      for (int h = 1; h < height; h++) {
+        for (int w = 0; w < width; w++) {
+          din_grad_ptr[w] = 0.f;
+        }
+        din_grad_ptr += width;
+      }
+    }
+  }
+}
+
+template <>
+void seq_pool_last_grad<float>(const float* din,
+                               const float* dout_grad,
+                               float* din_grad,
+                               const std::vector<uint64_t> lod,
+                               int64_t width) {
+  for (int i = 0; i < static_cast<int>(lod.size()) - 1; ++i) {
+    int64_t height = lod[i + 1] - lod[i];
+    const float* dout_grad_ptr = dout_grad + i * width;
+    float* din_grad_ptr = din_grad + lod[i] * width;
+    if (height > 0) {
+      for (int h = 0; h < height - 1; h++) {
+        for (int w = 0; w < width; w++) {
+          din_grad_ptr[w] = 0.f;
+        }
+        din_grad_ptr += width;
+      }
+      // last
+      for (int w = 0; w < width; w++) {
+        din_grad_ptr[w] = dout_grad_ptr[w];
+      }
+    }
+  }
+}
+
+}  // namespace math
+}  // namespace arm
+}  // namespace lite
+}  // namespace paddle

lite/backends/arm/math/sequence_pool_grad.h

+// Copyright (c) 2019 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 <vector>
+#include "lite/core/tensor.h"
+
+namespace paddle {
+namespace lite {
+namespace arm {
+namespace math {
+
+template <typename T>
+void seq_pool_sum_grad(const T* din,
+                       const T* dout_grad,
+                       T* din_grad,
+                       const std::vector<uint64_t> lod,
+                       int64_t width);
+
+template <typename T>
+void seq_pool_average_grad(const T* din,
+                           const T* dout_grad,
+                           T* din_grad,
+                           const std::vector<uint64_t> lod,
+                           int64_t width);
+
+template <typename T>
+void seq_pool_sqrt_grad(const T* din,
+                        const T* dout_grad,
+                        T* din_grad,
+                        const std::vector<uint64_t> lod,
+                        int64_t width);
+
+template <typename T>
+void seq_pool_max_grad(const T* din,
+                       const T* dout_grad,
+                       const int64_t* index_grad,
+                       T* din_grad,
+                       const std::vector<uint64_t> lod,
+                       int64_t width);
+
+template <typename T>
+void seq_pool_first_grad(const T* din,
+                         const T* dout_grad,
+                         T* din_grad,
+                         const std::vector<uint64_t> lod,
+                         int64_t width);
+
+template <typename T>
+void seq_pool_last_grad(const T* din,
+                        const T* dout_grad,
+                        T* din_grad,
+                        const std::vector<uint64_t> lod,
+                        int64_t width);
+
+}  // namespace math
+}  // namespace arm
+}  // namespace lite
+}  // namespace paddle

lite/kernels/arm/CMakeLists.txt

@@ -104,6 +104,7 @@ add_kernel(mean_grad_compute_arm ARM train SRCS mean_grad_compute.cc DEPS ${lite
 add_kernel(elementwise_grad_compute_arm ARM train SRCS elementwise_grad_compute.cc DEPS ${lite_kernel_deps} math_arm)
 add_kernel(mul_grad_compute_arm ARM train SRCS mul_grad_compute.cc DEPS ${lite_kernel_deps} math_arm)
 add_kernel(sgd_compute_arm ARM train SRCS sgd_compute.cc DEPS ${lite_kernel_deps} math_arm)
+add_kernel(sequence_pool_grad_compute_arm ARM train SRCS sequence_pool_grad_compute.cc DEPS ${lite_kernel_deps} math_arm)
 
 lite_cc_test(test_scale_compute_arm SRCS scale_compute_test.cc DEPS scale_compute_arm)
 lite_cc_test(test_softmax_compute_arm SRCS softmax_compute_test.cc DEPS softmax_compute_arm)

lite/kernels/arm/sequence_pool_compute.cc

@@ -32,6 +32,7 @@ void SequencePoolCompute::Run() {
   auto& output = param.Out;
   const auto* din = param.X->data<float>();
   float* dout = output->mutable_data<float>();
+  int64_t* max_index = param.MaxIndex->mutable_data<int64_t>();
   const auto pool_type = param.pool_type;
   const auto lod = param.X->lod()[0];
 
@@ -44,9 +45,9 @@ void SequencePoolCompute::Run() {
   } else if (pool_type == "SQRT") {
     lite::arm::math::seq_pool_sqrt(din, dout, lod, width);
   } else if (pool_type == "MAX") {
-    lite::arm::math::seq_pool_max(din, dout, lod, width);
+    lite::arm::math::seq_pool_max(din, dout, max_index, lod, width);
   } else if (pool_type == "MIN") {
-    lite::arm::math::seq_pool_min(din, dout, lod, width);
+    lite::arm::math::seq_pool_min(din, dout, max_index, lod, width);
   } else if (pool_type == "FIRST") {
     lite::arm::math::seq_pool_first(din, dout, lod, width);
   } else if (pool_type == "LAST") {

lite/kernels/arm/sequence_pool_grad_compute.cc

+/* 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. */
+
+#include "lite/kernels/arm/sequence_pool_grad_compute.h"
+#include <string>
+#include <vector>
+#include "lite/backends/arm/math/funcs.h"
+#include "lite/core/op_registry.h"
+#include "lite/core/tensor.h"
+#include "lite/core/type_system.h"
+
+namespace paddle {
+namespace lite {
+namespace kernels {
+namespace arm {
+
+void SequencePoolGradCompute::PrepareForRun() {}
+
+void SequencePoolGradCompute::Run() {
+  auto& param = Param<operators::SequencePoolGradParam>();
+  auto& output_grad = param.Out_Grad;
+  auto& x_grad = param.X_Grad;
+  const auto* din_ptr = param.X->data<float>();
+  const auto* dout_grad_ptr = output_grad->data<float>();
+  const auto* index_grad_ptr = param.MaxIndex_Grad->data<int64_t>();
+  float* x_grad_ptr = x_grad->mutable_data<float>();
+  const auto pool_type = param.pool_type;
+  const auto lod = param.X->lod()[0];
+  int64_t width = param.X->numel() / param.X->dims()[0];
+  if (pool_type == "SUM") {
+    lite::arm::math::seq_pool_sum_grad(
+        din_ptr, dout_grad_ptr, x_grad_ptr, lod, width);
+  } else if (pool_type == "AVERAGE") {
+    lite::arm::math::seq_pool_average_grad(
+        din_ptr, dout_grad_ptr, x_grad_ptr, lod, width);
+  } else if (pool_type == "SQRT") {
+    lite::arm::math::seq_pool_sqrt_grad(
+        din_ptr, dout_grad_ptr, x_grad_ptr, lod, width);
+  } else if (pool_type == "MAX" || pool_type == "MIN") {
+    lite::arm::math::seq_pool_max_grad(
+        din_ptr, dout_grad_ptr, index_grad_ptr, x_grad_ptr, lod, width);
+  } else if (pool_type == "FIRST") {
+    lite::arm::math::seq_pool_first_grad(
+        din_ptr, dout_grad_ptr, x_grad_ptr, lod, width);
+  } else if (pool_type == "LAST") {
+    lite::arm::math::seq_pool_last_grad(
+        din_ptr, dout_grad_ptr, x_grad_ptr, lod, width);
+  } else {
+    LOG(ERROR) << " UNKNOWN sequence pool type";
+  }
+}
+
+}  // namespace arm
+}  // namespace kernels
+}  // namespace lite
+}  // namespace paddle
+
+REGISTER_LITE_KERNEL(sequence_pool_grad,
+                     kARM,
+                     kFloat,
+                     kNCHW,
+                     paddle::lite::kernels::arm::SequencePoolGradCompute,
+                     def)
+    .BindInput("X", {LiteType::GetTensorTy(TARGET(kARM))})
+    .BindInput("Out@GRAD", {LiteType::GetTensorTy(TARGET(kARM))})
+    .BindOutput("X@GRAD", {LiteType::GetTensorTy(TARGET(kARM))})
+    .BindOutput("MaxIndex", {LiteType::GetTensorTy(TARGET(kARM))})
+    .Finalize();

lite/kernels/arm/sequence_pool_grad_compute.h

+// Copyright (c) 2019 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 <stdint.h>
+#include "lite/backends/arm/math/type_trans.h"
+#include "lite/core/kernel.h"
+#include "lite/core/op_registry.h"
+
+namespace paddle {
+namespace lite {
+namespace kernels {
+namespace arm {
+
+class SequencePoolGradCompute
+    : public KernelLite<TARGET(kARM), PRECISION(kFloat)> {
+ public:
+  void PrepareForRun() override;
+
+  void Run() override;
+
+  virtual ~SequencePoolGradCompute() = default;
+
+ private:
+};
+
+}  // namespace arm
+}  // namespace kernels
+}  // namespace lite
+}  // namespace paddle

lite/operators/CMakeLists.txt

@@ -165,6 +165,7 @@ add_operator(activation_grad_ops train SRCS activation_grad_ops.cc DEPS ${op_DEP
 add_operator(elementwise_grad_op train SRCS elementwise_grad_ops.cc DEPS ${op_DEPS})
 add_operator(mul_grad_op train SRCS mul_grad_op.cc DEPS ${op_DEPS})
 add_operator(sgd_op train SRCS sgd_op.cc DEPS ${op_DEPS})
+add_operator(sequence_pool_grad train SRCS sequence_pool_grad_op.cc DEPS ${op_DEPS})
 
 # Only for XPU
 add_operator(__xpu__resnet50_op extra SRCS __xpu__resnet50_op.cc DEPS ${op_DEPS})

lite/operators/op_params.h

@@ -997,10 +997,10 @@ struct BeamSearchParam : ParamBase {
 struct SequencePoolParam : ParamBase {
   const lite::Tensor* X{};
   lite::Tensor* Out{};
+  lite::Tensor* MaxIndex{};
   std::string pool_type{"AVERAGE"};
 #ifdef LITE_WITH_X86
   float pad_value{0.0};
-  lite::Tensor* MaxIndex{};
 #endif
 };
 
@@ -1019,6 +1019,18 @@ struct SequencePoolConcatParam : ParamBase {
   std::vector<std::string> pool_type{};
 };
 
+struct SequencePoolGradParam : ParamBase {
+  const lite::Tensor* X{};
+  std::string pool_type{"AVERAGE"};
+#ifdef LITE_WITH_X86
+  float pad_value{0.0};
+#endif
+  // for backward
+  const lite::Tensor* Out_Grad{};
+  const lite::Tensor* MaxIndex_Grad{};
+  lite::Tensor* X_Grad{};
+};
+
 struct SearchGroupPaddingParam : ParamBase {
   lite::Tensor* x{};
   lite::Tensor* out_emb_padding{};

lite/operators/sequence_pool_grad_op.cc

+// Copyright (c) 2019 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 "lite/operators/sequence_pool_grad_op.h"
+#include "lite/core/op_registry.h"
+
+namespace paddle {
+namespace lite {
+namespace operators {
+
+bool SequencePoolGradOp::CheckShape() const {
+  CHECK_OR_FALSE(param_.X);
+  CHECK_OR_FALSE(param_.X_Grad);
+  CHECK_OR_FALSE(param_.Out_Grad);
+  auto lod = param_.X->lod();
+  CHECK_EQ_OR_FALSE(lod.size(), 1UL);
+  auto dims = param_.X->dims();
+  CHECK_GE_OR_FALSE(dims[0], (static_cast<int64_t>(lod[0].size()) - 1));
+  return true;
+}
+
+bool SequencePoolGradOp::InferShapeImpl() const {
+  const auto *input = param_.X;
+  auto x_dims = input->dims();
+  if (param_.X_Grad) {
+    param_.X_Grad->Resize(x_dims);
+    param_.X_Grad->set_lod(param_.X->lod());
+  }
+  return true;
+}
+
+bool SequencePoolGradOp::AttachImpl(const cpp::OpDesc &opdesc,
+                                    lite::Scope *scope) {
+  param_.X = const_cast<lite::Tensor *>(
+      &scope->FindVar(opdesc.Input("X").front())->Get<lite::Tensor>());
+  CHECK(param_.X);
+  auto *out_grad_var = scope->FindVar(opdesc.Input("Out@GRAD").front());
+  CHECK(out_grad_var);
+  param_.Out_Grad = &out_grad_var->Get<Tensor>();
+
+  auto *x_grad_var = scope->FindVar(opdesc.Output("X@GRAD").front());
+  CHECK(x_grad_var);
+  param_.X_Grad = x_grad_var->GetMutable<Tensor>();
+
+  param_.pool_type = opdesc.GetAttr<std::string>("pooltype");
+  return true;
+}
+
+}  // namespace operators
+}  // namespace lite
+}  // namespace paddle
+
+REGISTER_LITE_OP(sequence_pool_grad,
+                 paddle::lite::operators::SequencePoolGradOp);

lite/operators/sequence_pool_grad_op.h

+// Copyright (c) 2019 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 <string>
+#include <vector>
+#include "lite/core/op_lite.h"
+#include "lite/core/scope.h"
+#include "lite/utils/all.h"
+
+namespace paddle {
+namespace lite {
+namespace operators {
+
+class SequencePoolGradOp : public OpLite {
+ public:
+  SequencePoolGradOp() {}
+  explicit SequencePoolGradOp(const std::string &op_type) : OpLite(op_type) {}
+  bool CheckShape() const override;
+  bool InferShapeImpl() const override;
+  bool AttachImpl(const cpp::OpDesc &opdesc, lite::Scope *scope) override;
+
+  void AttachKernel(KernelBase *kernel) override { kernel->SetParam(param_); }
+  std::string DebugString() const override { return "sequence_pool_grad"; }
+
+ private:
+  mutable SequencePoolGradParam param_;
+};
+
+}  // namespace operators
+}  // namespace lite
+}  // namespace paddle

lite/operators/sequence_pool_op.cc

@@ -34,6 +34,7 @@ bool SequencePoolOp::InferShapeImpl() const {
   auto out_dims = input->dims();
   out_dims[0] = input->lod()[0].size() - 1;
   param_.Out->Resize(out_dims);
+  param_.MaxIndex->Resize(out_dims);
   return true;
 }
 

lite/tests/kernels/CMakeLists.txt

@@ -40,21 +40,22 @@ if((NOT LITE_WITH_OPENCL AND NOT LITE_WITH_FPGA AND NOT LITE_WITH_BM AND NOT LIT
     lite_cc_test(test_kernel_fill_constant_batch_size_like_compute SRCS fill_constant_batch_size_like_compute_test.cc DEPS arena_framework ${xpu_kernels} ${npu_kernels} ${huawei_ascend_npu_kernels} ${x86_kernels} ${cuda_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
 
 if(LITE_BUILD_EXTRA)
-    lite_cc_test(test_gru_unit SRCS gru_unit_test.cc DEPS arena_framework ${xpu_kernels} ${npu_kernels} ${huawei_ascend_npu_kernels} ${x86_kernels} ${bm_kernels} ${cuda_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
-    lite_cc_test(test_kernel_sequence_pool_compute SRCS sequence_pool_compute_test.cc DEPS ${bm_kernels} arena_framework ${xpu_kernels} ${npu_kernels} ${huawei_ascend_npu_kernels} ${x86_kernels} ${cuda_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
-    lite_cc_test(test_kernel_sequence_conv_compute SRCS sequence_conv_compute_test.cc DEPS ${bm_kernels} arena_framework ${xpu_kernels} ${npu_kernels} ${huawei_ascend_npu_kernels} ${x86_kernels} ${cuda_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
-    lite_cc_test(test_kernel_reduce_max_compute SRCS reduce_max_compute_test.cc DEPS arena_framework ${bm_kernels} ${xpu_kernels} ${npu_kernels} ${huawei_ascend_npu_kernels} ${x86_kernels} ${cuda_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
-    lite_cc_test(test_kernel_unsqueeze_compute SRCS unsqueeze_compute_test.cc DEPS arena_framework ${bm_kernels} ${xpu_kernels} ${npu_kernels} ${huawei_ascend_npu_kernels} ${x86_kernels} ${cuda_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
-    lite_cc_test(test_kernel_assign_compute SRCS assign_compute_test.cc DEPS arena_framework ${xpu_kernels} ${npu_kernels} ${huawei_ascend_npu_kernels} ${x86_kernels} ${cuda_kernels} ${bm_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
-    lite_cc_test(test_kernel_assign_value_compute SRCS assign_value_compute_test.cc DEPS arena_framework ${xpu_kernels} ${npu_kernels} ${huawei_ascend_npu_kernels} ${x86_kernels} ${bm_kernels} ${cuda_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
-    lite_cc_test(test_kernel_box_clip_compute SRCS box_clip_compute_test.cc DEPS arena_framework ${xpu_kernels} ${npu_kernels} ${huawei_ascend_npu_kernels} ${x86_kernels} ${cuda_kernels} ${bm_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
-    lite_cc_test(test_kernel_reduce_mean_compute SRCS reduce_mean_compute_test.cc DEPS arena_framework ${xpu_kernels} ${npu_kernels} ${huawei_ascend_npu_kernels} ${x86_kernels} ${cuda_kernels} ${bm_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
-    lite_cc_test(test_kernel_reduce_sum_compute SRCS reduce_sum_compute_test.cc DEPS arena_framework ${xpu_kernels} ${npu_kernels} ${huawei_ascend_npu_kernels} ${x86_kernels} ${cuda_kernels} ${bm_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
-    lite_cc_test(test_kernel_reduce_prod_compute SRCS reduce_prod_compute_test.cc DEPS arena_framework ${xpu_kernels} ${npu_kernels} ${huawei_ascend_npu_kernels} ${x86_kernels} ${cuda_kernels} ${bm_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
-    lite_cc_test(test_kernel_stack_compute SRCS stack_compute_test.cc DEPS arena_framework ${xpu_kernels} ${npu_kernels} ${huawei_ascend_npu_kernels} ${x86_kernels} ${cuda_kernels} ${bm_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
-    lite_cc_test(test_kernel_range_compute SRCS range_compute_test.cc DEPS arena_framework ${xpu_kernels} ${npu_kernels} ${huawei_ascend_npu_kernels} ${x86_kernels} ${cuda_kernels} ${bm_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
-    lite_cc_test(test_kernel_affine_channel_compute SRCS affine_channel_compute_test.cc DEPS arena_framework ${xpu_kernels} ${npu_kernels} ${huawei_ascend_npu_kernels} ${x86_kernels} ${cuda_kernels} ${bm_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
-    lite_cc_test(test_kernel_anchor_generator_compute SRCS anchor_generator_compute_test.cc DEPS arena_framework ${xpu_kernels} ${npu_kernels} ${huawei_ascend_npu_kernels} ${x86_kernels} ${cuda_kernels} ${bm_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
+    lite_cc_test(test_gru_unit SRCS gru_unit_test.cc DEPS arena_framework ${xpu_kernels} ${npu_kernels} ${x86_kernels} ${bm_kernels} ${cuda_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
+    #lite_cc_test(test_kernel_sequence_pool_compute SRCS sequence_pool_compute_test.cc DEPS ${bm_kernels} arena_framework ${xpu_kernels} ${npu_kernels} ${x86_kernels} ${cuda_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
+    lite_cc_test(test_kernel_sequence_conv_compute SRCS sequence_conv_compute_test.cc DEPS ${bm_kernels} arena_framework ${xpu_kernels} ${npu_kernels} ${x86_kernels} ${cuda_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
+    lite_cc_test(test_kernel_reduce_max_compute SRCS reduce_max_compute_test.cc DEPS arena_framework ${bm_kernels} ${xpu_kernels} ${npu_kernels} ${x86_kernels} ${cuda_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
+    lite_cc_test(test_kernel_unsqueeze_compute SRCS unsqueeze_compute_test.cc DEPS arena_framework ${bm_kernels} ${xpu_kernels} ${npu_kernels} ${x86_kernels} ${cuda_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
+    lite_cc_test(test_kernel_assign_compute SRCS assign_compute_test.cc DEPS arena_framework ${xpu_kernels} ${npu_kernels} ${x86_kernels} ${cuda_kernels} ${bm_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
+    lite_cc_test(test_kernel_assign_value_compute SRCS assign_value_compute_test.cc DEPS arena_framework ${xpu_kernels} ${npu_kernels} ${x86_kernels} ${bm_kernels} ${cuda_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
+    lite_cc_test(test_kernel_box_clip_compute SRCS box_clip_compute_test.cc DEPS arena_framework ${xpu_kernels} ${npu_kernels} ${x86_kernels} ${cuda_kernels} ${bm_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
+    lite_cc_test(test_kernel_reduce_mean_compute SRCS reduce_mean_compute_test.cc DEPS arena_framework ${xpu_kernels} ${npu_kernels} ${x86_kernels} ${cuda_kernels} ${bm_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
+    lite_cc_test(test_kernel_reduce_sum_compute SRCS reduce_sum_compute_test.cc DEPS arena_framework ${xpu_kernels} ${npu_kernels} ${x86_kernels} ${cuda_kernels} ${bm_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
+    lite_cc_test(test_kernel_reduce_prod_compute SRCS reduce_prod_compute_test.cc DEPS arena_framework ${xpu_kernels} ${npu_kernels} ${x86_kernels} ${cuda_kernels} ${bm_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
+    lite_cc_test(test_kernel_stack_compute SRCS stack_compute_test.cc DEPS arena_framework ${xpu_kernels} ${npu_kernels} ${x86_kernels} ${cuda_kernels} ${bm_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
+    lite_cc_test(test_kernel_range_compute SRCS range_compute_test.cc DEPS arena_framework ${xpu_kernels} ${npu_kernels} ${x86_kernels} ${cuda_kernels} ${bm_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
+    lite_cc_test(test_kernel_affine_channel_compute SRCS affine_channel_compute_test.cc DEPS arena_framework ${xpu_kernels} ${npu_kernels} ${x86_kernels} ${cuda_kernels} ${bm_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
+    lite_cc_test(test_kernel_anchor_generator_compute SRCS anchor_generator_compute_test.cc DEPS arena_framework ${xpu_kernels} ${npu_kernels} ${x86_kernels} ${cuda_kernels} ${bm_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
+
     #lite_cc_test(test_kernel_generate_proposals_compute SRCS generate_proposals_compute_test.cc DEPS arena_framework ${x86_kernels} ${cuda_kernels} ${bm_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
     #lite_cc_test(test_kernel_roi_align_compute SRCS roi_align_compute_test.cc DEPS arena_framework ${x86_kernels} ${cuda_kernels} ${bm_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
     lite_cc_test(test_kernel_search_aligned_mat_mul_compute SRCS search_aligned_mat_mul_compute_test.cc DEPS arena_framework ${xpu_kernels} ${npu_kernels} ${huawei_ascend_npu_kernels} ${x86_kernels} ${bm_kernels} ${cuda_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
@@ -72,6 +73,7 @@ if(LITE_BUILD_EXTRA)
         lite_cc_test(test_kernel_elementwise_grad_compute SRCS elementwise_grad_compute_test.cc DEPS arena_framework ${xpu_kernels} ${npu_kernels} ${huawei_ascend_npu_kernels} ${x86_kernels} ${cuda_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
         lite_cc_test(test_kernel_mul_grad_compute SRCS mul_grad_compute_test.cc DEPS arena_framework ${xpu_kernels} ${npu_kernels} ${huawei_ascend_npu_kernels} ${x86_kernels} ${cuda_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
         lite_cc_test(test_kernel_sgd_compute SRCS sgd_compute_test.cc DEPS arena_framework ${xpu_kernels} ${npu_kernels} ${huawei_ascend_npu_kernels} ${x86_kernels} ${cuda_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
+        lite_cc_test(test_kernel_sequence_pool_grad_compute SRCS sequence_pool_grad_compute_test.cc DEPS ${bm_kernels} arena_framework ${xpu_kernels} ${npu_kernels} ${x86_kernels} ${cuda_kernels} ${arm_kernels} ${lite_ops} ${host_kernels})
     endif()
 
 endif()

lite/tests/kernels/sequence_pool_grad_compute_test.cc

+// Copyright (c) 2019 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 "lite/kernels/arm/sequence_pool_grad_compute.h"
+#include <gtest/gtest.h>
+#include <algorithm>
+#include <cmath>
+#include "lite/core/op_registry.h"
+#include "lite/kernels/arm/sequence_pool_compute.h"
+
+namespace paddle {
+namespace lite {
+namespace kernels {
+namespace arm {
+
+using param_t = operators::SequencePoolParam;
+using grad_param_t = operators::SequencePoolGradParam;
+using kernel_t = SequencePoolCompute;
+using grad_kernel_t = SequencePoolGradCompute;
+
+void sequence_pool_grad_common(grad_param_t* param,
+                               float* out_grad,
+                               int64_t* index_grad,
+                               float* x_grad,
+                               std::string pool_type) {
+  const auto lod = param->X->lod()[0];
+  int64_t width = param->X->numel() / param->X->dims()[0];
+  if (pool_type == "SUM") {
+    for (int i = 0; i < static_cast<int>(lod.size()) - 1; i++) {
+      int64_t height = static_cast<int64_t>(lod[i + 1] - lod[i]);
+      float* out_grad_ptr = out_grad + i * width;
+      float* x_grad_ptr = x_grad + lod[i] * width;
+      if (height > 0) {
+        if (width == 1) {
+          for (int h = 0; h < height; ++h) {
+            x_grad_ptr[h] = out_grad_ptr[h];
+          }
+        } else {
+          for (int h = 0; h < height; h++) {
+            for (int w = 0; w < width; w++) {
+              x_grad_ptr[w] = out_grad_ptr[w];
+            }
+            x_grad_ptr += width;
+          }
+        }
+      }
+    }
+  } else if (pool_type == "AVERAGE") {
+    for (int i = 0; i < static_cast<int>(lod.size()) - 1; i++) {
+      int64_t height = static_cast<int64_t>(lod[i + 1] - lod[i]);
+      const float* out_grad_ptr = out_grad + i * width;
+      float* x_grad_ptr = x_grad + lod[i] * width;
+      float alpha = 1.0 / height;
+      if (height > 0) {
+        if (width == 1) {
+          for (int h = 0; h < height; ++h) {
+            x_grad_ptr[h] = alpha * out_grad_ptr[h];
+          }
+        } else {
+          for (int h = 0; h < height; h++) {
+            for (int w = 0; w < width; w++) {
+              x_grad_ptr[w] = alpha * out_grad_ptr[w];
+            }
+            x_grad_ptr += width;
+          }
+        }
+      }
+    }
+  } else if (pool_type == "SQRT") {
+    for (int i = 0; i < static_cast<int>(lod.size()) - 1; i++) {
+      int64_t height = static_cast<int64_t>(lod[i + 1] - lod[i]);
+      const float* out_grad_ptr = out_grad + i * width;
+      float* x_grad_ptr = x_grad + lod[i] * width;
+      float alpha = 1.0 / sqrtf(height);
+      if (height > 0) {
+        if (width == 1) {
+          for (int h = 0; h < height; ++h) {
+            x_grad_ptr[h] = alpha * out_grad_ptr[h];
+          }
+        } else {
+          for (int h = 0; h < height; h++) {
+            for (int w = 0; w < width; w++) {
+              x_grad_ptr[w] = alpha * out_grad_ptr[w];
+            }
+            x_grad_ptr += width;
+          }
+        }
+      }
+    }
+  } else if (pool_type == "MAX" || pool_type == "MIN") {
+    for (int i = 0; i < static_cast<int>(lod.size()) - 1; i++) {
+      int64_t height = static_cast<int64_t>(lod[i + 1] - lod[i]);
+      const float* out_grad_ptr = out_grad + i * width;
+      const int64_t* index_grad_ptr = index_grad + i * width;
+      float* x_grad_ptr = x_grad + lod[i] * width;
+      float alpha = 1.0 / sqrtf(height);
+      if (height > 0) {
+        for (int w = 0; w < width; w++) {
+          for (int h = 0; h < height; h++) {
+            if (h == index_grad_ptr[w]) {
+              x_grad_ptr[h * width + w] = out_grad_ptr[w];
+            } else {
+              x_grad_ptr[h * width + w] = 0.f;
+            }
+          }
+        }
+      }
+    }
+  } else if (pool_type == "FIRST") {
+    for (int i = 0; i < static_cast<int>(lod.size()) - 1; ++i) {
+      int64_t height = static_cast<int64_t>(lod[i + 1] - lod[i]);
+      const float* out_grad_ptr = out_grad + i * width;
+      float* x_grad_ptr = x_grad + lod[i] * width;
+      if (height > 0) {
+        for (int w = 0; w < width; w++) {
+          for (int h = 0; h < height; h++) {
+            if (h == 0) {
+              x_grad_ptr[h * width + w] = out_grad_ptr[w];
+            } else {
+              x_grad_ptr[h * width + w] = 0.f;
+            }
+          }
+        }
+      }
+    }
+  } else if (pool_type == "LAST") {
+    for (int i = 0; i < static_cast<int>(lod.size()) - 1; ++i) {
+      int64_t height = static_cast<int64_t>(lod[i + 1] - lod[i]);
+      const float* out_grad_ptr = out_grad + i * width;
+      float* x_grad_ptr = x_grad + lod[i] * width;
+      if (height > 0) {
+        for (int w = 0; w < width; w++) {
+          for (int h = 0; h < height; h++) {
+            if (h == height - 1) {
+              x_grad_ptr[h * width + w] = out_grad_ptr[w];
+            } else {
+              x_grad_ptr[h * width + w] = 0.f;
+            }
+          }
+        }
+      }
+    }
+  } else {
+    LOG(FATAL) << " UNKNOWN sequence pool type";
+  }
+}
+
+void generate_lod(int seq_num,
+                  int max_len,
+                  std::vector<uint64_t>& seq_offset) {  // NOLINT
+  seq_offset.clear();
+  int sum = 0;
+  seq_offset.push_back(sum);
+  for (int i = 0; i < seq_num; i++) {
+    sum += std::rand() % max_len + 1;
+    seq_offset.push_back(uint64_t(sum));
+  }
+}
+
+class SequencePoolGradTester {
+ public:
+  explicit SequencePoolGradTester(DDim dims,
+                                  std::vector<std::vector<uint64_t>> lod,
+                                  std::string pool_type)
+      : dims_(dims), lod_(lod), pool_type_(pool_type) {}
+
+  void prepare_kernel() {
+    std::unique_ptr<KernelContext> ctx1(new KernelContext);
+    ctx1->As<ARMContext>();
+    kernel_.SetContext(std::move(ctx1));
+
+    std::unique_ptr<KernelContext> ctx2(new KernelContext);
+    ctx2->As<ARMContext>();
+    delta_kernel_.SetContext(std::move(ctx2));
+
+    std::unique_ptr<KernelContext> ctx3(new KernelContext);
+    ctx3->As<ARMContext>();
+    grad_kernel_.SetContext(std::move(ctx3));
+  }
+
+  void run_forward(param_t* param,
+                   kernel_t* kernel,
+                   const std::vector<float>& in_vec,
+                   int64_t* out_index_vec,
+                   float* out_vec) {
+    Tensor x;
+    Tensor output;
+    Tensor index;
+    x.Resize(dims_);
+    output.Resize(out_dims_);
+    index.Resize(out_dims_);
+    auto* x_data = x.mutable_data<float>();
+    for (int i = 0; i < dims_.production(); i++) {
+      x_data[i] = in_vec[i];
+    }
+    x.set_lod(lod_);
+    param->X = &x;
+    param->pool_type = pool_type_;
+    param->Out = &output;
+    param->MaxIndex = &index;
+    kernel->SetParam(*param);
+    kernel->Launch();
+    auto* output_data = output.data<float>();
+    auto* output_index = index.data<int64_t>();
+    for (int i = 0; i < output.numel(); i++) {
+      out_vec[i] = output_data[i];
+      out_index_vec[i] = output_index[i];
+    }
+  }
+
+  void run_backward(grad_param_t* param,
+                    grad_kernel_t* kernel,
+                    const std::vector<float>& in_vec,
+                    const std::vector<float>& out_grad_vec,
+                    const std::vector<int64_t>& out_index_grad_vec,
+                    float* in_grad_vec) {
+    Tensor x;
+    Tensor x_grad;
+    Tensor out_grad;
+    Tensor out_index_grad;
+    x.Resize(dims_);
+    x.set_lod(lod_);
+    // backword
+    x_grad.Resize(dims_);
+    out_grad.Resize(out_dims_);
+    out_index_grad.Resize(out_dims_);
+    auto* x_data = x.mutable_data<float>();
+    auto* out_grad_data = out_grad.mutable_data<float>();
+    auto* out_index_grad_data = out_index_grad.mutable_data<int64_t>();
+
+    for (int i = 0; i < dims_.production(); i++) {
+      x_data[i] = in_vec[i];
+    }
+    for (int i = 0; i < out_dims_.production(); i++) {
+      out_grad_data[i] = out_grad_vec[i];
+      out_index_grad_data[i] = out_index_grad_vec[i];
+    }
+    param->X = &x;
+    param->X_Grad = &x_grad;
+    param->Out_Grad = &out_grad;
+    param->MaxIndex_Grad = &out_index_grad;
+    param->pool_type = pool_type_;
+    kernel->SetParam(*param);
+    kernel->Launch();
+    auto* x_grad_data = x_grad.data<float>();
+    for (int i = 0; i < dims_.production(); i++) {
+      in_grad_vec[i] = x_grad_data[i];
+    }
+    LOG(INFO) << "end";
+  }
+
+  void check_grad(float delta, float max_grad_delta) {
+    std::vector<int64_t> out_shape;
+    out_dims_ = dims_;
+    out_dims_[0] = lod_[0].size() - 1;
+    std::vector<float> x(dims_.production());
+    std::vector<float> out(out_dims_.production());
+    std::vector<int64_t> index(out_dims_.production());
+    for (int i = 0; i < dims_.production(); i++) {
+      x[i] = static_cast<float>(i % 3 - 2.0) / 2.0 * 0.333 +
+             static_cast<float>(i % 19 - 10.0) / 10.0 * 0.333 +
+             static_cast<float>(i % 39 - 20.0) / 20.0 * 0.333 + 0.001213;
+    }
+    LOG(INFO) << "run_forward:";
+    this->run_forward(&param_, &kernel_, x, index.data(), out.data());
+
+    std::vector<float> out_grad(out_dims_.production());
+    std::vector<float> x_grad(dims_.production());
+    for (int i = 0; i < out_dims_.production(); i++) {
+      out_grad[i] = 1.0;
+    }
+    LOG(INFO) << "run_backward:";
+    this->run_backward(
+        &grad_param_, &grad_kernel_, x, out_grad, index, x_grad.data());
+
+    // get numeric gradient
+    std::vector<float> x_delta(dims_.production());
+    std::vector<float> out_delta(out_dims_.production());
+    Tensor tensor_x;
+    tensor_x.Resize(dims_);
+    tensor_x.set_lod(lod_);
+    grad_param_.X = &tensor_x;
+    LOG(INFO) << "sequence_pool_grad_common";
+    sequence_pool_grad_common(&grad_param_,
+                              out_grad.data(),
+                              index.data(),
+                              x_delta.data(),
+                              pool_type_);
+
+    for (int i = 0; i < dims_.production(); i++) {
+      EXPECT_NEAR(x_grad[i], x_delta[i], max_grad_delta);
+    }
+  }
+
+ private:
+  DDim dims_;
+  DDim out_dims_;
+  std::vector<std::vector<uint64_t>> lod_;
+  std::string pool_type_;
+  kernel_t kernel_;
+  kernel_t delta_kernel_;
+  grad_kernel_t grad_kernel_;
+  param_t param_;
+  param_t delta_param_;
+  grad_param_t grad_param_;
+};
+
+void TestSequencePoolGrad(DDim dims,
+                          std::vector<std::vector<uint64_t>> lod,
+                          std::string pool_type) {
+  LOG(INFO) << "Test SequencePool grad";
+  std::unique_ptr<SequencePoolGradTester> tester(
+      new SequencePoolGradTester(dims, lod, pool_type));
+  tester->prepare_kernel();
+  float delta = 0.001;
+  float max_grad_delta = 0.005;
+  tester->check_grad(delta, max_grad_delta);
+}
+
+TEST(sequence_pool_grad_host, compute) {
+#ifdef LITE_WITH_ARM
+  int max_len = 2;
+  for (auto c : {2, 4}) {
+    for (auto h : {1, 3, 4}) {
+      for (auto w : {1, 3, 4}) {
+        for (auto pool_type :
+             {"SUM", "AVERAGE", "SQRT", "MAX", "MIN", "FIRST", "LAST"}) {
+          for (auto seq_num : {1, 3, 5}) {
+            std::vector<std::vector<uint64_t>> lod;
+            lod.resize(1);
+            generate_lod(seq_num, max_len, lod[0]);
+            int64_t n = int64_t(lod[0].back());
+            LOG(INFO) << "sequence_pool_grad parameter: "
+                      << ", n = " << n << ", c = " << c << ", h = " << h
+                      << ", w = " << w << ", seq_num = " << seq_num
+                      << ", pool_type = " << pool_type;
+            TestSequencePoolGrad(
+                DDim(std::vector<int64_t>({n, c, h, w})), lod, pool_type);
+          }
+        }
+      }
+    }
+  }
+#endif
+}
+
+}  // namespace arm
+}  // namespace kernels
+}  // namespace lite
+}  // namespace paddle
+USE_LITE_KERNEL(sequence_pool, kARM, kFloat, kNCHW, def);
+USE_LITE_KERNEL(sequence_pool_grad, kARM, kFloat, kNCHW, def);