Merge pull request #4461 from chengduoZH/Add_maxpool_withIdx_only

Add max pool op (with index)

paddle/operators/CMakeLists.txt

@@ -55,12 +55,20 @@ function(op_library TARGET)
         set(pybind_flag 1)
     endif()
 
+    # pool_op contains several operators
     if ("${TARGET}" STREQUAL "pool_op")
         set(pybind_flag 1)
         # It's enough to just adding one operator to pybind
         file(APPEND ${pybind_file} "USE_OP(pool2d);\n")
     endif()
 
+    # pool_with_index_op contains several operators
+    if ("${TARGET}" STREQUAL "pool_with_index_op")
+        set(pybind_flag 1)
+        # It's enough to just adding one operator to pybind
+        file(APPEND ${pybind_file} "USE_OP(max_pool2d_with_index);\n")
+    endif()
+
     # activation_op contains several operators
     if ("${TARGET}" STREQUAL "activation_op")
         set(pybind_flag 1)

paddle/operators/math/pooling.cc

@@ -18,6 +18,11 @@ namespace paddle {
 namespace operators {
 namespace math {
 
+/*
+ * All tensors are in NCHW format.
+ * Ksize, strides, paddings are two elements. These two elements represent
+ * height and width, respectively.
+ */
 template <typename PoolProcess, typename T>
 class Pool2dFunctor<platform::CPUPlace, PoolProcess, T> {
  public:
@@ -73,6 +78,11 @@ class Pool2dFunctor<platform::CPUPlace, PoolProcess, T> {
   }
 };
 
+/*
+* All tensors are in NCHW format.
+* Ksize, strides, paddings are two elements. These two elements represent height
+* and width, respectively.
+*/
 template <typename PoolProcess, class T>
 class Pool2dGradFunctor<platform::CPUPlace, PoolProcess, T> {
  public:
@@ -135,6 +145,11 @@ class Pool2dGradFunctor<platform::CPUPlace, PoolProcess, T> {
   }
 };
 
+/*
+ * All tensors are in NCHW format.
+ * Ksize, strides, paddings are two elements. These two elements represent
+ * height and width, respectively.
+ */
 template <class T>
 class MaxPool2dGradFunctor<platform::CPUPlace, T> {
  public:
@@ -197,7 +212,7 @@ class MaxPool2dGradFunctor<platform::CPUPlace, T> {
 };
 
 template class MaxPool2dGradFunctor<platform::CPUPlace, float>;
-// template class MaxPool2dGradFunctor<platform::CPUPlace, double>;
+template class MaxPool2dGradFunctor<platform::CPUPlace, double>;
 
 template class Pool2dFunctor<platform::CPUPlace,
                              paddle::operators::math::MaxPool<float>, float>;
@@ -216,6 +231,11 @@ template class Pool2dGradFunctor<
 template class Pool2dGradFunctor<
     platform::CPUPlace, paddle::operators::math::AvgPoolGrad<double>, double>;
 
+/*
+ * All tensors are in NCDHW format.
+ * Ksize, strides, paddings are three elements. These three elements represent
+ * depth, height and width, respectively.
+ */
 template <typename PoolProcess, class T>
 class Pool3dFunctor<platform::CPUPlace, PoolProcess, T> {
  public:
@@ -286,6 +306,11 @@ class Pool3dFunctor<platform::CPUPlace, PoolProcess, T> {
   }
 };
 
+/*
+ * All tensors are in NCDHW format.
+ * Ksize, strides, paddings are three elements. These three elements represent
+ * depth, height and width, respectively.
+ */
 template <typename PoolProcess, class T>
 class Pool3dGradFunctor<platform::CPUPlace, PoolProcess, T> {
  public:
@@ -364,6 +389,11 @@ class Pool3dGradFunctor<platform::CPUPlace, PoolProcess, T> {
   }
 };
 
+/*
+ * All tensors are in NCDHW format.
+ * Ksize, strides, paddings are three elements. These three elements represent
+ * depth, height and width, respectively.
+ */
 template <class T>
 class MaxPool3dGradFunctor<platform::CPUPlace, T> {
  public:
@@ -440,7 +470,7 @@ class MaxPool3dGradFunctor<platform::CPUPlace, T> {
 };
 
 template class MaxPool3dGradFunctor<platform::CPUPlace, float>;
-// template class MaxPool3dGradFunctor<platform::CPUPlace, double>;
+template class MaxPool3dGradFunctor<platform::CPUPlace, double>;
 
 template class Pool3dFunctor<platform::CPUPlace,
                              paddle::operators::math::MaxPool<float>, float>;
@@ -458,6 +488,253 @@ template class Pool3dGradFunctor<
     platform::CPUPlace, paddle::operators::math::MaxPoolGrad<double>, double>;
 template class Pool3dGradFunctor<
     platform::CPUPlace, paddle::operators::math::AvgPoolGrad<double>, double>;
+
+/*
+ * All tensors are in NCHW format.
+ * Ksize, strides, paddings are two elements. These two elements represent
+ * height and width, respectively.
+ */
+template <typename T>
+class MaxPool2dWithIndexFunctor<platform::CPUPlace, T> {
+ public:
+  void operator()(const platform::DeviceContext& context,
+                  const framework::Tensor& input, framework::Tensor& output,
+                  framework::Tensor& mask, std::vector<int>& ksize,
+                  std::vector<int>& strides, std::vector<int>& paddings) {
+    const int batch_size = input.dims()[0];
+    const int input_height = input.dims()[2];
+    const int input_width = input.dims()[3];
+    const int output_channels = output.dims()[1];
+    const int output_height = output.dims()[2];
+    const int output_width = output.dims()[3];
+    const int ksize_height = ksize[0];
+    const int ksize_width = ksize[1];
+    const int stride_height = strides[0];
+    const int stride_width = strides[1];
+    const int padding_height = paddings[0];
+    const int padding_width = paddings[1];
+    const int input_stride = input_height * input_width;
+    const int output_stride = output_height * output_width;
+
+    const T* input_data = input.data<T>();
+    T* output_data = output.mutable_data<T>(context.GetPlace());
+    T* mask_data = mask.mutable_data<T>(context.GetPlace());
+
+    for (int i = 0; i < batch_size; i++) {
+      for (int c = 0; c < output_channels; ++c) {
+        for (int ph = 0; ph < output_height; ++ph) {
+          int hstart = ph * stride_height - padding_height;
+          int hend = std::min(hstart + ksize_height, input_height);
+          hstart = std::max(hstart, 0);
+          for (int pw = 0; pw < output_width; ++pw) {
+            int wstart = pw * stride_width - padding_width;
+            int wend = std::min(wstart + ksize_width, input_width);
+            wstart = std::max(wstart, 0);
+
+            T ele = static_cast<T>(-FLT_MAX);
+            int index = -1;
+            for (int h = hstart; h < hend; ++h) {
+              for (int w = wstart; w < wend; ++w) {
+                if (ele < input_data[h * input_width + w]) {
+                  ele = input_data[h * input_width + w];
+                  index = h * input_width + w;
+                }
+              }
+            }
+            output_data[ph * output_width + pw] = ele;
+            mask_data[ph * output_width + pw] = index;
+          }
+        }
+        // offset
+        input_data += input_stride;
+        output_data += output_stride;
+        mask_data += output_stride;
+      }
+    }
+  }
+};
+
+/*
+ * All tensors are in NCHW format.
+ * Ksize, strides, paddings are two elements. These two elements represent
+ * height and width, respectively.
+ */
+template <typename T>
+class MaxPool2dWithIndexGradFunctor<platform::CPUPlace, T> {
+ public:
+  void operator()(const platform::DeviceContext& context,
+                  framework::Tensor& input_grad,
+                  const framework::Tensor& output_grad,
+                  const framework::Tensor& mask, std::vector<int>& ksize,
+                  std::vector<int>& strides, std::vector<int>& paddings) {
+    const int batch_size = input_grad.dims()[0];
+    const int input_height = input_grad.dims()[2];
+    const int input_width = input_grad.dims()[3];
+    const int output_channels = output_grad.dims()[1];
+    const int output_height = output_grad.dims()[2];
+    const int output_width = output_grad.dims()[3];
+    const int input_stride = input_height * input_width;
+    const int output_stride = output_height * output_width;
+
+    const T* mask_data = mask.data<T>();
+    const T* output_grad_data = output_grad.data<T>();
+    T* input_grad_data = input_grad.mutable_data<T>(context.GetPlace());
+
+    for (int n = 0; n < batch_size; ++n) {
+      for (int c = 0; c < output_channels; ++c) {
+        for (int ph = 0; ph < output_height; ++ph) {
+          for (int pw = 0; pw < output_width; ++pw) {
+            const int output_idx = ph * output_width + pw;
+            const int input_idx = static_cast<int>(mask_data[output_idx]);
+            input_grad_data[input_idx] += output_grad_data[output_idx];
+          }
+        }
+        // offset
+        input_grad_data += input_stride;
+        output_grad_data += output_stride;
+        mask_data += output_stride;
+      }
+    }
+  }
+};
+
+template class MaxPool2dWithIndexFunctor<platform::CPUPlace, float>;
+template class MaxPool2dWithIndexGradFunctor<platform::CPUPlace, float>;
+template class MaxPool2dWithIndexFunctor<platform::CPUPlace, double>;
+template class MaxPool2dWithIndexGradFunctor<platform::CPUPlace, double>;
+
+/*
+ * All tensors are in NCDHW format.
+ * Ksize, strides, paddings are three elements. These three elements represent
+ * depth, height and width, respectively.
+ */
+template <typename T>
+class MaxPool3dWithIndexFunctor<platform::CPUPlace, T> {
+ public:
+  void operator()(const platform::DeviceContext& context,
+                  const framework::Tensor& input, framework::Tensor& output,
+                  framework::Tensor& mask, std::vector<int>& ksize,
+                  std::vector<int>& strides, std::vector<int>& paddings) {
+    const int batch_size = input.dims()[0];
+    const int input_depth = input.dims()[2];
+    const int input_height = input.dims()[3];
+    const int input_width = input.dims()[4];
+    const int output_channels = output.dims()[1];
+    const int output_depth = output.dims()[2];
+    const int output_height = output.dims()[3];
+    const int output_width = output.dims()[4];
+    const int ksize_depth = ksize[0];
+    const int ksize_height = ksize[1];
+    const int ksize_width = ksize[2];
+    const int stride_depth = strides[0];
+    const int stride_height = strides[1];
+    const int stride_width = strides[2];
+    const int padding_depth = paddings[0];
+    const int padding_height = paddings[1];
+    const int padding_width = paddings[2];
+    const int input_stride = input_depth * input_height * input_width;
+    const int output_stride = output_depth * output_height * output_width;
+
+    const T* input_data = input.data<T>();
+    T* output_data = output.mutable_data<T>(context.GetPlace());
+    T* mask_data = mask.mutable_data<T>(context.GetPlace());
+
+    for (int i = 0; i < batch_size; i++) {
+      for (int c = 0; c < output_channels; ++c) {
+        for (int pd = 0; pd < output_depth; ++pd) {
+          int dstart = pd * stride_depth - padding_depth;
+          int dend = std::min(dstart + ksize_depth, input_depth);
+          dstart = std::max(dstart, 0);
+          for (int ph = 0; ph < output_height; ++ph) {
+            int hstart = ph * stride_height - padding_height;
+            int hend = std::min(hstart + ksize_height, input_height);
+            hstart = std::max(hstart, 0);
+            for (int pw = 0; pw < output_width; ++pw) {
+              int wstart = pw * stride_width - padding_width;
+              int wend = std::min(wstart + ksize_width, input_width);
+              wstart = std::max(wstart, 0);
+
+              int output_idx = (pd * output_height + ph) * output_width + pw;
+              T ele = static_cast<T>(-FLT_MAX);
+              int index = -1;
+              for (int d = dstart; d < dend; ++d) {
+                for (int h = hstart; h < hend; ++h) {
+                  for (int w = wstart; w < wend; ++w) {
+                    int input_idx = (d * input_height + h) * input_width + w;
+                    if (ele < input_data[input_idx]) {
+                      index = input_idx;
+                      ele = input_data[input_idx];
+                    }
+                  }
+                }
+              }
+              output_data[output_idx] = ele;
+              mask_data[output_idx] = index;
+            }
+          }
+        }
+        // offset
+        input_data += input_stride;
+        output_data += output_stride;
+        mask_data += output_stride;
+      }
+    }
+  }
+};
+
+/*
+ * All tensors are in NCDHW format.
+ * Ksize, strides, paddings are three elements. These three elements represent
+ * depth, height and width, respectively.
+ */
+template <typename T>
+class MaxPool3dWithIndexGradFunctor<platform::CPUPlace, T> {
+ public:
+  void operator()(const platform::DeviceContext& context,
+                  framework::Tensor& input_grad,
+                  const framework::Tensor& output_grad,
+                  const framework::Tensor& mask, std::vector<int>& ksize,
+                  std::vector<int>& strides, std::vector<int>& paddings) {
+    const int batch_size = input_grad.dims()[0];
+    const int input_depth = input_grad.dims()[2];
+    const int input_height = input_grad.dims()[3];
+    const int input_width = input_grad.dims()[4];
+    const int output_channels = output_grad.dims()[1];
+    const int output_depth = output_grad.dims()[2];
+    const int output_height = output_grad.dims()[3];
+    const int output_width = output_grad.dims()[4];
+    const int input_stride = input_depth * input_height * input_width;
+    const int output_stride = output_depth * output_height * output_width;
+
+    const T* mask_data = mask.data<T>();
+    const T* output_grad_data = output_grad.data<T>();
+    T* input_grad_data = input_grad.mutable_data<T>(context.GetPlace());
+
+    for (int n = 0; n < batch_size; ++n) {
+      for (int c = 0; c < output_channels; ++c) {
+        for (int pd = 0; pd < output_depth; ++pd) {
+          for (int ph = 0; ph < output_height; ++ph) {
+            for (int pw = 0; pw < output_width; ++pw) {
+              const int output_idx =
+                  (pd * output_height + ph) * output_width + pw;
+              const int input_idx = static_cast<int>(mask_data[output_idx]);
+              input_grad_data[input_idx] += output_grad_data[output_idx];
+            }
+          }
+        }
+        // offset
+        input_grad_data += input_stride;
+        output_grad_data += output_stride;
+        mask_data += output_stride;
+      }
+    }
+  }
+};
+
+template class MaxPool3dWithIndexFunctor<platform::CPUPlace, float>;
+template class MaxPool3dWithIndexGradFunctor<platform::CPUPlace, float>;
+template class MaxPool3dWithIndexFunctor<platform::CPUPlace, double>;
+template class MaxPool3dWithIndexGradFunctor<platform::CPUPlace, double>;
 }  // namespace math
 }  // namespace operators
 }  // namespace paddle

paddle/operators/math/pooling.cu

@@ -144,11 +144,16 @@ __global__ void KernelMaxPool2DGrad(
 
     if (maxIndex != -1) {
       // atomic add
-      atomicAdd(input_grad + maxIndex, output_grad[index]);
+      platform::CudaAtomicAdd(input_grad + maxIndex, output_grad[index]);
     }
   }
 }
 
+/*
+ * All tensors are in NCHW format.
+ * Ksize, strides, paddings are two elements. These two elements represent
+ * height and width, respectively.
+ */
 template <typename PoolProcess, typename T>
 class Pool2dFunctor<platform::GPUPlace, PoolProcess, T> {
  public:
@@ -190,6 +195,11 @@ class Pool2dFunctor<platform::GPUPlace, PoolProcess, T> {
   }
 };
 
+/*
+ * All tensors are in NCHW format.
+ * Ksize, strides, paddings are two elements. These two elements represent
+ * height and width, respectively.
+ */
 template <typename PoolProcess, typename T>
 class Pool2dGradFunctor<platform::GPUPlace, PoolProcess, T> {
  public:
@@ -234,6 +244,11 @@ class Pool2dGradFunctor<platform::GPUPlace, PoolProcess, T> {
   }
 };
 
+/*
+ * All tensors are in NCHW format.
+ * Ksize, strides, paddings are two elements. These two elements represent
+ * height and width, respectively.
+ */
 template <typename T>
 class MaxPool2dGradFunctor<platform::GPUPlace, T> {
  public:
@@ -278,9 +293,7 @@ class MaxPool2dGradFunctor<platform::GPUPlace, T> {
 };
 
 template class MaxPool2dGradFunctor<platform::GPUPlace, float>;
-// template class MaxPool2dGradFunctor<platform::GPUPlace, double>; // The
-// 64-bit floating-point version of atomicAdd() is only supported by devices of
-// compute capability 6.x and higher.
+template class MaxPool2dGradFunctor<platform::GPUPlace, double>;
 
 template class Pool2dFunctor<platform::GPUPlace,
                              paddle::operators::math::MaxPool<float>, float>;
@@ -453,11 +466,16 @@ __global__ void KernelMaxPool3DGrad(
     }
     if (maxIdx != -1) {
       // atomic add
-      atomicAdd(input_grad + maxIdx, output_grad[index]);
+      platform::CudaAtomicAdd(input_grad + maxIdx, output_grad[index]);
     }
   }
 }
 
+/*
+ * All tensors are in NCDHW format.
+ * Ksize, strides, paddings are three elements. These three elements represent
+ * depth, height and width, respectively.
+ */
 template <typename PoolProcess, class T>
 class Pool3dFunctor<platform::GPUPlace, PoolProcess, T> {
  public:
@@ -506,6 +524,11 @@ class Pool3dFunctor<platform::GPUPlace, PoolProcess, T> {
   }
 };
 
+/*
+ * All tensors are in NCDHW format.
+ * Ksize, strides, paddings are three elements. These three elements represent
+ * depth, height and width, respectively.
+ */
 template <typename PoolProcess, class T>
 class Pool3dGradFunctor<platform::GPUPlace, PoolProcess, T> {
  public:
@@ -558,6 +581,11 @@ class Pool3dGradFunctor<platform::GPUPlace, PoolProcess, T> {
   }
 };
 
+/*
+ * All tensors are in NCDHW format.
+ * Ksize, strides, paddings are three elements. These three elements represent
+ * depth, height and width, respectively.
+ */
 template <class T>
 class MaxPool3dGradFunctor<platform::GPUPlace, T> {
  public:
@@ -609,9 +637,7 @@ class MaxPool3dGradFunctor<platform::GPUPlace, T> {
 };
 
 template class MaxPool3dGradFunctor<platform::GPUPlace, float>;
-// template class MaxPool3dGradFunctor<platform::GPUPlace, double>;  // The
-// 64-bit floating-point version of atomicAdd() is only supported by devices of
-// compute capability 6.x and higher.
+template class MaxPool3dGradFunctor<platform::GPUPlace, double>;
 
 template class Pool3dFunctor<platform::GPUPlace,
                              paddle::operators::math::MaxPool<float>, float>;
@@ -630,6 +656,404 @@ template class Pool3dGradFunctor<
 template class Pool3dGradFunctor<
     platform::GPUPlace, paddle::operators::math::AvgPoolGrad<double>, double>;
 
+template <typename T>
+__global__ void KernelMaxPool2dWithIdx(
+    const int nthreads, const T* input_data, T* output_data, T* mask_data,
+    const int channels, const int input_height, const int input_width,
+    const int output_height, const int output_width, const int ksize_height,
+    const int ksize_width, const int stride_height, const int stride_width,
+    const int padding_height, const int padding_width) {
+  for (int index = blockIdx.x * blockDim.x + threadIdx.x; index < nthreads;
+       index += blockDim.x * gridDim.x) {
+    int pw = index % output_width;
+    int ph = (index / output_width) % output_height;
+    int c = (index / output_width / output_height) % channels;
+    int batch_idx = index / output_width / output_height / channels;
+
+    int hstart = ph * stride_height - padding_height;
+    int hend = min(hstart + ksize_height, input_height);
+    hstart = max(hstart, 0);
+
+    int wstart = pw * stride_width - padding_width;
+    int wend = min(wstart + ksize_width, input_width);
+    wstart = max(wstart, 0);
+
+    input_data += (batch_idx * channels + c) * input_height * input_width;
+    T ele = -FLT_MAX;
+    int max_index = -1;
+    for (int h = hstart; h < hend; ++h) {
+      for (int w = wstart; w < wend; ++w) {
+        int input_index = h * input_width + w;
+        if (ele < input_data[input_index]) {
+          max_index = input_index;
+          ele = input_data[input_index];
+        }
+      }
+    }
+    output_data[index] = ele;
+    mask_data[index] = max_index;
+  }
+}
+
+template <typename T>
+__global__ void KernelMaxPool2DWithIdxGrad(
+    const int nthreads, T* input_grad, const T* output_grad, const T* mask_data,
+    const int channels, const int input_height, const int input_width,
+    const int output_height, const int output_width, const int ksize_height,
+    const int ksize_width, const int stride_height, const int stride_width,
+    const int padding_height, const int padding_width) {
+  for (int index = blockIdx.x * blockDim.x + threadIdx.x; index < nthreads;
+       index += blockDim.x * gridDim.x) {
+    int w_offset = index % input_width;
+    int h_offset = (index / input_width) % input_height;
+    int c_offset = (index / input_width / input_height) % channels;
+    int batch_idx = index / input_width / input_height / channels;
+
+    int ph_start =
+        (h_offset + padding_height < ksize_height)
+            ? 0
+            : (h_offset + padding_height - ksize_height) / stride_height + 1;
+    int pw_start =
+        (w_offset + padding_width < ksize_width)
+            ? 0
+            : (w_offset + padding_width - ksize_width) / stride_width + 1;
+    int ph_end =
+        min((h_offset + padding_height) / stride_height + 1, output_height);
+    int pw_end =
+        min((w_offset + padding_width) / stride_width + 1, output_width);
+
+    T gradient = 0;
+    int input_current_featuremap_idx = h_offset * input_width + w_offset;
+    int output_idx =
+        (batch_idx * channels + c_offset) * output_height * output_width;
+
+    mask_data += output_idx;
+    output_grad += output_idx;
+    for (int ph = ph_start; ph < ph_end; ++ph) {
+      for (int pw = pw_start; pw < pw_end; ++pw) {
+        if (mask_data[ph * output_width + pw] == input_current_featuremap_idx)
+          gradient += output_grad[ph * output_width + pw];
+      }
+    }
+    input_grad[index] = gradient;
+  }
+}
+
+/*
+ * All tensors are in NCHW format.
+ * Ksize, strides, paddings are two elements. These two elements represent
+ * height and width, respectively.
+ */
+template <typename T>
+class MaxPool2dWithIndexFunctor<platform::GPUPlace, T> {
+ public:
+  void operator()(const platform::DeviceContext& context,
+                  const framework::Tensor& input, framework::Tensor& output,
+                  framework::Tensor& mask, std::vector<int>& ksize,
+                  std::vector<int>& strides, std::vector<int>& paddings) {
+    const int batch_size = input.dims()[0];
+    const int input_channels = input.dims()[1];
+    const int input_height = input.dims()[2];
+    const int input_width = input.dims()[3];
+    const int output_channels = output.dims()[1];
+    const int output_height = output.dims()[2];
+    const int output_width = output.dims()[3];
+    const int ksize_height = ksize[0];
+    const int ksize_width = ksize[1];
+    const int stride_height = strides[0];
+    const int stride_width = strides[1];
+    const int padding_height = paddings[0];
+    const int padding_width = paddings[1];
+
+    const T* input_data = input.data<T>();
+    T* output_data = output.mutable_data<T>(context.GetPlace());
+    T* mask_data = mask.mutable_data<T>(context.GetPlace());
+
+    int nthreads = batch_size * output_channels * output_height * output_width;
+    int blocks = (nthreads + 1024 - 1) / 1024;
+    dim3 threads(1024, 1);
+    dim3 grid(blocks, 1);
+
+    KernelMaxPool2dWithIdx<
+        T><<<grid, threads, 0,
+             reinterpret_cast<const platform::CUDADeviceContext&>(context)
+                 .stream()>>>(nthreads, input_data, output_data, mask_data,
+                              input_channels, input_height, input_width,
+                              output_height, output_width, ksize_height,
+                              ksize_width, stride_height, stride_width,
+                              padding_height, padding_width);
+  }
+};
+
+/*
+ * All tensors are in NCHW format.
+ * Ksize, strides, paddings are two elements. These two elements represent
+ * height and width, respectively.
+ */
+template <typename T>
+class MaxPool2dWithIndexGradFunctor<platform::GPUPlace, T> {
+ public:
+  void operator()(const platform::DeviceContext& context,
+                  framework::Tensor& input_grad,
+                  const framework::Tensor& output_grad,
+                  const framework::Tensor& mask, std::vector<int>& ksize,
+                  std::vector<int>& strides, std::vector<int>& paddings) {
+    const int batch_size = input_grad.dims()[0];
+    const int input_channels = input_grad.dims()[1];
+    const int input_height = input_grad.dims()[2];
+    const int input_width = input_grad.dims()[3];
+    const int output_height = output_grad.dims()[2];
+    const int output_width = output_grad.dims()[3];
+    const int ksize_height = ksize[0];
+    const int ksize_width = ksize[1];
+    const int stride_height = strides[0];
+    const int stride_width = strides[1];
+    const int padding_height = paddings[0];
+    const int padding_width = paddings[1];
+
+    const T* mask_data = mask.data<T>();
+    const T* output_grad_data = output_grad.data<T>();
+    T* input_grad_data = input_grad.mutable_data<T>(context.GetPlace());
+
+    int nthreads = batch_size * input_channels * input_height * input_width;
+    int blocks = (nthreads + 1024 - 1) / 1024;
+    dim3 threads(1024, 1);
+    dim3 grid(blocks, 1);
+
+    KernelMaxPool2DWithIdxGrad<
+        T><<<grid, threads, 0,
+             reinterpret_cast<const platform::CUDADeviceContext&>(context)
+                 .stream()>>>(nthreads, input_grad_data, output_grad_data,
+                              mask_data, input_channels, input_height,
+                              input_width, output_height, output_width,
+                              ksize_height, ksize_width, stride_height,
+                              stride_width, padding_height, padding_width);
+  }
+};
+
+template class MaxPool2dWithIndexFunctor<platform::GPUPlace, float>;
+template class MaxPool2dWithIndexGradFunctor<platform::GPUPlace, float>;
+template class MaxPool2dWithIndexFunctor<platform::GPUPlace, double>;
+template class MaxPool2dWithIndexGradFunctor<platform::GPUPlace, double>;
+
+template <typename T>
+__global__ void KernelMaxPool3DWithIdx(
+    const int nthreads, const T* input_data, T* output_data, T* mask_data,
+    const int channels, const int input_depth, const int input_height,
+    const int input_width, const int output_depth, const int output_height,
+    const int output_width, const int ksize_depth, const int ksize_height,
+    const int ksize_width, const int stride_depth, const int stride_height,
+    const int stride_width, const int padding_depth, const int padding_height,
+    const int padding_width) {
+  for (int index = blockIdx.x * blockDim.x + threadIdx.x; index < nthreads;
+       index += blockDim.x * gridDim.x) {
+    int pw = index % output_width;
+    int ph = (index / output_width) % output_height;
+    int pd = (index / output_width / output_height) % output_depth;
+    int c = (index / output_width / output_height / output_depth) % channels;
+    int batch_idx =
+        index / output_width / output_height / output_depth / channels;
+
+    int dstart = pd * stride_depth - padding_depth;
+    int hstart = ph * stride_height - padding_height;
+    int wstart = pw * stride_width - padding_width;
+    int dend = min(dstart + ksize_depth, input_depth);
+    int hend = min(hstart + ksize_height, input_height);
+    int wend = min(wstart + ksize_width, input_width);
+    dstart = max(dstart, 0);
+    hstart = max(hstart, 0);
+    wstart = max(wstart, 0);
+
+    T ele = -FLT_MAX;
+    int max_index = -1;
+    input_data +=
+        (batch_idx * channels + c) * input_depth * input_height * input_width;
+
+    for (int d = dstart; d < dend; ++d) {
+      for (int h = hstart; h < hend; ++h) {
+        for (int w = wstart; w < wend; ++w) {
+          if (ele < input_data[(d * input_height + h) * input_width + w]) {
+            max_index = (d * input_height + h) * input_width + w;
+            ele = input_data[max_index];
+          }
+        }
+      }
+    }
+    output_data[index] = ele;
+    mask_data[index] = max_index;
+  }
+}
+
+template <typename T>
+__global__ void KernelMaxPool3DWithIdxGrad(
+    const int nthreads, T* input_grad, const T* output_grad, const T* mask,
+    const int channels, const int input_depth, const int input_height,
+    const int input_width, const int output_depth, const int output_height,
+    const int output_width, const int ksize_depth, const int ksize_height,
+    const int ksize_width, const int stride_depth, const int stride_height,
+    const int stride_width, const int padding_depth, const int padding_height,
+    const int padding_width) {
+  for (int index = blockIdx.x * blockDim.x + threadIdx.x; index < nthreads;
+       index += blockDim.x * gridDim.x) {
+    int w_offset = index % input_width;
+    int h_offset = (index / input_width) % input_height;
+    int d_offset = (index / input_width / input_height) % input_depth;
+    int c_offset =
+        (index / input_width / input_height / input_depth) % channels;
+    int batch_idx = index / input_width / input_height / input_depth / channels;
+
+    int pd_start =
+        (d_offset + padding_depth < ksize_depth)
+            ? 0
+            : (d_offset + padding_depth - ksize_depth) / stride_depth + 1;
+    int ph_start =
+        (h_offset + padding_height < ksize_height)
+            ? 0
+            : (h_offset + padding_height - ksize_height) / stride_height + 1;
+    int pw_start =
+        (w_offset + padding_width < ksize_width)
+            ? 0
+            : (w_offset + padding_width - ksize_width) / stride_width + 1;
+    int pd_end =
+        min((d_offset + padding_depth) / stride_depth + 1, output_depth);
+    int ph_end =
+        min((h_offset + padding_height) / stride_height + 1, output_height);
+    int pw_end =
+        min((w_offset + padding_width) / stride_width + 1, output_width);
+
+    T gradient = 0;
+    int input_current_feature_map_idx =
+        (d_offset * input_height + h_offset) * input_width + w_offset;
+    int output_idx = (batch_idx * channels + c_offset) * output_depth *
+                     output_height * output_width;
+    mask += output_idx;
+    output_grad += output_idx;
+
+    for (int pd = pd_start; pd < pd_end; ++pd) {
+      for (int ph = ph_start; ph < ph_end; ++ph) {
+        for (int pw = pw_start; pw < pw_end; ++pw) {
+          if (mask[(pd * output_height + ph) * output_width + pw] ==
+              input_current_feature_map_idx)
+            gradient +=
+                output_grad[(pd * output_height + ph) * output_width + pw];
+        }
+      }
+    }
+    input_grad[index] = gradient;
+  }
+}
+
+/*
+ * All tensors are in NCDHW format.
+ * Ksize, strides, paddings are three elements. These three elements represent
+ * depth, height and width, respectively.
+ */
+template <typename T>
+class MaxPool3dWithIndexFunctor<platform::GPUPlace, T> {
+ public:
+  void operator()(const platform::DeviceContext& context,
+                  const framework::Tensor& input, framework::Tensor& output,
+                  framework::Tensor& mask, std::vector<int>& ksize,
+                  std::vector<int>& strides, std::vector<int>& paddings) {
+    const int batch_size = input.dims()[0];
+    const int input_channels = input.dims()[1];
+    const int input_depth = input.dims()[2];
+    const int input_height = input.dims()[3];
+    const int input_width = input.dims()[4];
+    const int output_channels = output.dims()[1];
+    const int output_depth = output.dims()[2];
+    const int output_height = output.dims()[3];
+    const int output_width = output.dims()[4];
+    const int ksize_depth = ksize[0];
+    const int ksize_height = ksize[1];
+    const int ksize_width = ksize[2];
+    const int stride_depth = strides[0];
+    const int stride_height = strides[1];
+    const int stride_width = strides[2];
+    const int padding_depth = paddings[0];
+    const int padding_height = paddings[1];
+    const int padding_width = paddings[2];
+
+    const T* input_data = input.data<T>();
+    T* output_data = output.mutable_data<T>(context.GetPlace());
+    T* mask_data = mask.mutable_data<T>(context.GetPlace());
+
+    int nthreads = batch_size * output_channels * output_depth * output_height *
+                   output_width;
+    int blocks = (nthreads + 1024 - 1) / 1024;
+    dim3 threads(1024, 1);
+    dim3 grid(blocks, 1);
+
+    KernelMaxPool3DWithIdx<
+        T><<<grid, threads, 0,
+             reinterpret_cast<const platform::CUDADeviceContext&>(context)
+                 .stream()>>>(
+        nthreads, input_data, output_data, mask_data, input_channels,
+        input_depth, input_height, input_width, output_depth, output_height,
+        output_width, ksize_depth, ksize_height, ksize_width, stride_depth,
+        stride_height, stride_width, padding_depth, padding_height,
+        padding_width);
+  }
+};
+
+/*
+ * All tensors are in NCDHW format.
+ * Ksize, strides, paddings are three elements. These three elements represent
+ * depth, height and width, respectively.
+ */
+template <typename T>
+class MaxPool3dWithIndexGradFunctor<platform::GPUPlace, T> {
+ public:
+  void operator()(const platform::DeviceContext& context,
+                  framework::Tensor& input_grad,
+                  const framework::Tensor& output_grad,
+                  const framework::Tensor& mask, std::vector<int>& ksize,
+                  std::vector<int>& strides, std::vector<int>& paddings) {
+    const int batch_size = input_grad.dims()[0];
+    const int input_channels = input_grad.dims()[1];
+    const int input_depth = input_grad.dims()[2];
+    const int input_height = input_grad.dims()[3];
+    const int input_width = input_grad.dims()[4];
+    const int output_depth = output_grad.dims()[2];
+    const int output_height = output_grad.dims()[3];
+    const int output_width = output_grad.dims()[4];
+    const int ksize_depth = ksize[0];
+    const int ksize_height = ksize[1];
+    const int ksize_width = ksize[2];
+    const int stride_depth = strides[0];
+    const int stride_height = strides[1];
+    const int stride_width = strides[2];
+    const int padding_depth = paddings[0];
+    const int padding_height = paddings[1];
+    const int padding_width = paddings[2];
+
+    const T* output_grad_data = output_grad.data<T>();
+    const T* mask_data = mask.data<T>();
+    T* input_grad_data = input_grad.mutable_data<T>(context.GetPlace());
+
+    int nthreads =
+        batch_size * input_channels * input_depth * input_height * input_width;
+    int blocks = (nthreads + 1024 - 1) / 1024;
+    dim3 threads(1024, 1);
+    dim3 grid(blocks, 1);
+
+    KernelMaxPool3DWithIdxGrad<
+        T><<<grid, threads, 0,
+             reinterpret_cast<const platform::CUDADeviceContext&>(context)
+                 .stream()>>>(
+        nthreads, input_grad_data, output_grad_data, mask_data, input_channels,
+        input_depth, input_height, input_width, output_depth, output_height,
+        output_width, ksize_depth, ksize_height, ksize_width, stride_depth,
+        stride_height, stride_width, padding_depth, padding_height,
+        padding_width);
+  }
+};
+
+template class MaxPool3dWithIndexFunctor<platform::GPUPlace, float>;
+template class MaxPool3dWithIndexGradFunctor<platform::GPUPlace, float>;
+template class MaxPool3dWithIndexFunctor<platform::GPUPlace, double>;
+template class MaxPool3dWithIndexGradFunctor<platform::GPUPlace, double>;
+
 }  // namespace math
 }  // namespace operators
 }  // namespace paddle

paddle/operators/math/pooling.h

@@ -21,15 +21,27 @@ limitations under the License. */
 namespace paddle {
 namespace operators {
 namespace math {
-//////////////////////
-#define FLT_MAX __FLT_MAX__  //
 
+#define FLT_MAX \
+  __FLT_MAX__  // It might need to be placed in another file, but I'm still
+               // wondering where to put it.
+
+/*
+ * \brief Extracting simple operations from pooling.
+ *        Both MaxPool and AvgPool need "initial", "compute" and "finalize"
+ * operation.
+ *        MaxPool initializes temp variable to the negative maximum to find the
+ * maximum value in the pooling field.
+ *        AvgPool initializes temp variable to the zero to accumulate all values
+ * in pool pooling, and finally takes the average.
+ *        MaxPoolGrad and AvgPoolGrad are gradient operations respectively.
+ */
 template <class T>
 class MaxPool {
  public:
   DEVICE inline T initial() { return static_cast<T>(-FLT_MAX); }
   DEVICE inline void compute(T& y, const T& x) { y = y > x ? y : x; }
-  DEVICE inline void finalize(T& y, const T& poo_size) {}
+  DEVICE inline void finalize(T& y, const T& pool_field) {}
 };
 
 template <class T>
@@ -37,8 +49,9 @@ class AvgPool {
  public:
   DEVICE inline T initial() { return static_cast<T>(0); }
   DEVICE inline void compute(T& y, const T& x) { y += x; }
-  DEVICE inline void finalize(T& y, const T& poo_size) { y /= poo_size; }
+  DEVICE inline void finalize(T& y, const T& pool_field) { y /= pool_field; }
 };
+
 template <class T>
 class MaxPoolGrad {
  public:
@@ -57,6 +70,20 @@ class AvgPoolGrad {
   }
 };
 
+/*
+ * \brief Getting pooling results, and calculating gradient.
+ *
+ * In pool2d, all tensors are in NCHW format. Where N is batch size, C is the
+ * number of channels, H and W is the height and width of feature.
+ * In pool3d, all tensors are in NCDHW format. Where N is batch size, C is the
+ * number of channels, D, H and W is the depth, height and width of feature.
+ *
+ * In max pooling, it is possible that the pooling region has multiple maximum
+ * elements. In this case, we should compute the gradient of the first maximum
+ * element.
+ * This is different from average pooling. So we rewrite the max_pool_grad:
+ * MaxPool2dGradFunctor, MaxPool3dGradFunctor.
+ */
 template <typename Place, typename PoolProcess, typename T>
 class Pool2dFunctor {
  public:
@@ -117,6 +144,51 @@ class MaxPool3dGradFunctor {
                   std::vector<int>& strides, std::vector<int>& paddings);
 };
 
+/*
+ * \brief Getting max pooling results and corresponding max index, and
+ * calculating gradient.
+ * In up-sampling-pooling, it is necessary to know max element index.
+ * In pool2d, all tensors are in NCHW format. In pool3d, all tensors are in
+ * NCDHW format.
+ */
+template <typename Place, typename T>
+class MaxPool2dWithIndexFunctor {
+ public:
+  void operator()(const platform::DeviceContext& context,
+                  const framework::Tensor& input, framework::Tensor& output,
+                  framework::Tensor& mask, std::vector<int>& ksize,
+                  std::vector<int>& strides, std::vector<int>& paddings);
+};
+
+template <typename Place, typename T>
+class MaxPool2dWithIndexGradFunctor {
+ public:
+  void operator()(const platform::DeviceContext& context,
+                  framework::Tensor& input_grad,
+                  const framework::Tensor& output_grad,
+                  const framework::Tensor& mask, std::vector<int>& ksize,
+                  std::vector<int>& strides, std::vector<int>& paddings);
+};
+
+template <typename Place, typename T>
+class MaxPool3dWithIndexFunctor {
+ public:
+  void operator()(const platform::DeviceContext& context,
+                  const framework::Tensor& input, framework::Tensor& output,
+                  framework::Tensor& mask, std::vector<int>& ksize,
+                  std::vector<int>& strides, std::vector<int>& paddings);
+};
+
+template <typename Place, typename T>
+class MaxPool3dWithIndexGradFunctor {
+ public:
+  void operator()(const platform::DeviceContext& context,
+                  framework::Tensor& input_grad,
+                  const framework::Tensor& output_grad,
+                  const framework::Tensor& mask, std::vector<int>& ksize,
+                  std::vector<int>& strides, std::vector<int>& paddings);
+};
+
 }  // namespace math
 }  // namespace operators
 }  // namespace paddle

paddle/operators/pool_with_index_op.cc

+/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserve.
+
+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/operators/pool_with_index_op.h"
+
+namespace paddle {
+namespace operators {
+
+inline int OutputSizeMaxPool(int input_size, int filter_size, int padding,
+                             int stride) {
+  int output_size = (input_size - filter_size + 2 * padding) / stride + 1;
+  return output_size;
+}
+
+class MaxPoolWithIndexOp : public framework::OperatorWithKernel {
+ public:
+  using framework::OperatorWithKernel::OperatorWithKernel;
+
+ protected:
+  void InferShape(framework::InferShapeContextBase *ctx) const override {
+    PADDLE_ENFORCE(ctx->HasInput("X"),
+                   "X(Input) of Pooling should not be null.");
+    PADDLE_ENFORCE(ctx->HasOutput("Out"),
+                   "Out(Output) of Pooling should not be null.");
+    PADDLE_ENFORCE(ctx->HasOutput("Mask"),
+                   "Mask(Output) of Pooling should not be null.");
+
+    auto in_x_dims = ctx->GetInputDim("X");
+
+    std::vector<int> ksize = ctx->Attrs().Get<std::vector<int>>("ksize");
+    std::vector<int> strides = ctx->Attrs().Get<std::vector<int>>("strides");
+    std::vector<int> paddings = ctx->Attrs().Get<std::vector<int>>("paddings");
+
+    PADDLE_ENFORCE(in_x_dims.size() == 4 || in_x_dims.size() == 5,
+                   "Pooling intput should be 4-D or 5-D");
+
+    if (ctx->Attrs().Get<bool>("globalPooling")) {
+      ksize.resize(static_cast<size_t>(in_x_dims.size()) - 2);
+      for (size_t i = 0; i < ksize.size(); ++i)
+        ksize[i] = static_cast<int>(in_x_dims[i + 2]);
+    }
+
+    PADDLE_ENFORCE(in_x_dims.size() - ksize.size() == 2U,
+                   "Intput size and pooling size should be consistent.");
+    PADDLE_ENFORCE_EQ(ksize.size(), strides.size(),
+                      "Strides size and pooling size should be the same.");
+    PADDLE_ENFORCE_EQ(ksize.size(), paddings.size(),
+                      "Paddings size and pooling size should be the same.");
+
+    std::vector<int64_t> output_shape({in_x_dims[0], in_x_dims[1]});
+    for (size_t i = 0; i < ksize.size(); ++i) {
+      output_shape.push_back(OutputSizeMaxPool(in_x_dims[i + 2], ksize[i],
+                                               paddings[i], strides[i]));
+    }
+    ctx->SetOutputDim("Out", framework::make_ddim(output_shape));
+    ctx->SetOutputDim("Mask", framework::make_ddim(output_shape));
+  }
+};
+
+class MaxPoolWithIndexOpGrad : public framework::OperatorWithKernel {
+ public:
+  using framework::OperatorWithKernel::OperatorWithKernel;
+
+ protected:
+  void InferShape(framework::InferShapeContextBase *ctx) const override {
+    PADDLE_ENFORCE(ctx->HasInput("X"), "Input(X) must not be null.");
+    PADDLE_ENFORCE(ctx->HasOutput(framework::GradVarName("X")),
+                   "Input(X@GRAD) should not be null.");
+    ctx->SetOutputDim(framework::GradVarName("X"), ctx->GetInputDim("X"));
+  }
+};
+
+class MaxPool2dWithIndexOpMaker : public framework::OpProtoAndCheckerMaker {
+ public:
+  MaxPool2dWithIndexOpMaker(framework::OpProto *proto,
+                            framework::OpAttrChecker *op_checker)
+      : OpProtoAndCheckerMaker(proto, op_checker) {
+    AddInput(
+        "X",
+        "The input tensor of pooling operator. "
+        "The format of input tensor is NCHW. Where N is batch size, C is the "
+        "number of channels, H and W is the height and width of image.");
+    AddOutput("Out",
+              "The output tensor of pooling operator."
+              "The format of output tensor is also NCHW."
+              "Where N is batch size, C is "
+              "the number of channels, H and W is the height and "
+              "width of image.");
+    AddOutput("Mask",
+              "The Mask tensor of pooling operator."
+              "The format of output tensor is also NCHW."
+              "Where N is batch size, C is the number of channels, H and W "
+              "is the height and width of image."
+              "The value in it is the index in current feature map");
+
+    AddAttr<std::vector<int>>(
+        "ksize",
+        "The pooling size(height, width) of pooling operator."
+        "If globalPooling = true, ksize is ignored and need not be "
+        "specified.");  // TODO(Chengduo): Add checker. (Currently,
+                        // TypedAttrChecker don't support vector type.)
+    AddAttr<bool>(
+        "globalPooling",
+        "Whether to use the globalPooling."
+        "Bool constant equal to false or true."
+        "Default false."
+        "If globalPooling = true, ksize is ignored and need not be specified.")
+        .SetDefault(false);
+    AddAttr<std::vector<int>>("strides",
+                              "Strides(height, width) of pooling operator."
+                              "Default {1,1}.")
+        .SetDefault({1, 1});  // TODO(Chengduo): Add checker. (Currently,
+                              // TypedAttrChecker don't support vector type.)
+    AddAttr<std::vector<int>>("paddings",
+                              "Paddings(height, width) of pooling operator."
+                              "Default {0,0}.")
+        .SetDefault({0, 0});  // TODO(Chengduo): Add checker. (Currently,
+                              // TypedAttrChecker don't support vector type.)
+
+    AddComment(R"DOC(
+The maxPooling2d with index operation calculates the output and the mask
+based on the input and ksize, strides, paddings parameters. Input(X) and
+output(Out, Mask) are in NCHW format. Where N is batch size, C is the
+number of channels, H and W is the height and width of feature.
+Parameters(ksize, strides, paddings) are two elements.
+These two elements represent height and width, respectively.
+)DOC");
+  }
+};
+
+class MaxPool3dWithIndexOpMaker : public framework::OpProtoAndCheckerMaker {
+ public:
+  MaxPool3dWithIndexOpMaker(framework::OpProto *proto,
+                            framework::OpAttrChecker *op_checker)
+      : OpProtoAndCheckerMaker(proto, op_checker) {
+    AddInput(
+        "X",
+        "The input tensor of pooling operator. "
+        "The format of input tensor is NCDHW. Where N is batch size, C is "
+        "the number of channels, D, H and W is the depth, height and width of "
+        "image.");
+    AddOutput("Out",
+              "The output tensor of pooling operator."
+              "The format of output tensor is also NCDHW."
+              "Where N is batch size, C is "
+              "the number of channels, D, H and W is the depth, height and "
+              "width of image.");
+    AddOutput("Mask",
+              "The Mask tensor of pooling operator."
+              "The format of output tensor is also NCDHW."
+              "Where N is batch size, C is the number of channels, D, H and W "
+              "is the depth, height and width of image."
+              "The value in it is the index in current feature map");
+
+    AddAttr<std::vector<int>>(
+        "ksize",
+        "The pooling size(depth, height, width) of pooling operator."
+        "If globalPooling = true, ksize is ignored and need not be "
+        "specified.");  // TODO(Chengduo): Add checker. (Currently,
+                        // TypedAttrChecker don't support vector type.)
+    AddAttr<bool>(
+        "globalPooling",
+        "Whether to use the globalPooling."
+        "Bool constant equal to false or true."
+        "Default false."
+        "If globalPooling = true, ksize is ignored and need not be specified.")
+        .SetDefault(false);
+    AddAttr<std::vector<int>>(
+        "strides",
+        "Strides(depth, height, width) of pooling operator."
+        "Default {1,1,1}.")
+        .SetDefault({1, 1, 1});  // TODO(Chengduo): Add checker. (Currently,
+                                 // TypedAttrChecker don't support vector type.)
+    AddAttr<std::vector<int>>(
+        "paddings",
+        "Paddings(depth, height, width) of pooling operator."
+        "Default {0,0,0}.")
+        .SetDefault({0, 0, 0});  // TODO(Chengduo): Add checker. (Currently,
+                                 // TypedAttrChecker don't support vector type.)
+
+    AddComment(R"DOC(
+The maxpooling3d with index operation calculates the output and the mask
+based on the input and ksize, strides, paddings parameters.
+Input(X) and output(Out, Mask) are in NCDHW format. Where N is batch
+size, C is the number of channels, D, H and W is the depth, height and
+width of feature. Parameters(ksize, strides, paddings) are three elements.
+These three elements represent depth, height and width, respectively.
+)DOC");
+  }
+};
+
+}  // namespace operators
+}  // namespace paddle
+
+namespace ops = paddle::operators;
+
+REGISTER_OP(max_pool2d_with_index, ops::MaxPoolWithIndexOp,
+            ops::MaxPool2dWithIndexOpMaker, max_pool2d_with_index_grad,
+            ops::MaxPoolWithIndexOpGrad);
+
+REGISTER_OP_CPU_KERNEL(
+    max_pool2d_with_index,
+    ops::MaxPoolWithIndexKernel<paddle::platform::CPUPlace, float>);
+REGISTER_OP_CPU_KERNEL(
+    max_pool2d_with_index_grad,
+    ops::MaxPoolWithIndexGradKernel<paddle::platform::CPUPlace, float>)
+
+REGISTER_OP(max_pool3d_with_index, ops::MaxPoolWithIndexOp,
+            ops::MaxPool3dWithIndexOpMaker, max_pool3d_with_index_grad,
+            ops::MaxPoolWithIndexOpGrad);
+
+REGISTER_OP_CPU_KERNEL(
+    max_pool3d_with_index,
+    ops::MaxPoolWithIndexKernel<paddle::platform::CPUPlace, float>);
+REGISTER_OP_CPU_KERNEL(
+    max_pool3d_with_index_grad,
+    ops::MaxPoolWithIndexGradKernel<paddle::platform::CPUPlace, float>)

paddle/operators/pool_with_index_op.cu

+/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserve.
+
+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/operators/pool_with_index_op.h"
+
+namespace ops = paddle::operators;
+
+REGISTER_OP_GPU_KERNEL(
+    max_pool2d_with_index,
+    ops::MaxPoolWithIndexKernel<paddle::platform::GPUPlace, float>);
+REGISTER_OP_GPU_KERNEL(
+    max_pool2d_with_index_grad,
+    ops::MaxPoolWithIndexGradKernel<paddle::platform::GPUPlace, float>)
+
+REGISTER_OP_GPU_KERNEL(
+    max_pool3d_with_index,
+    ops::MaxPoolWithIndexKernel<paddle::platform::GPUPlace, float>);
+REGISTER_OP_GPU_KERNEL(
+    max_pool3d_with_index_grad,
+    ops::MaxPoolWithIndexGradKernel<paddle::platform::GPUPlace, float>)

paddle/operators/pool_with_index_op.h

+/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserve.
+
+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 "paddle/framework/eigen.h"
+#include "paddle/framework/op_registry.h"
+#include "paddle/operators/math/math_function.h"
+#include "paddle/operators/math/pooling.h"
+
+namespace paddle {
+namespace operators {
+
+using Tensor = framework::Tensor;
+
+template <typename Place, typename T>
+class MaxPoolWithIndexKernel : public framework::OpKernel<T> {
+ public:
+  void Compute(const framework::ExecutionContext& context) const override {
+    const Tensor* in_x = context.Input<Tensor>("X");
+    Tensor* out = context.Output<Tensor>("Out");
+    Tensor* mask = context.Output<Tensor>("Mask");
+
+    std::vector<int> ksize = context.Attr<std::vector<int>>("ksize");
+    std::vector<int> strides = context.Attr<std::vector<int>>("strides");
+    std::vector<int> paddings = context.Attr<std::vector<int>>("paddings");
+    if (context.Attr<bool>("globalPooling")) {
+      for (size_t i = 0; i < ksize.size(); ++i) {
+        ksize[i] = static_cast<int>(in_x->dims()[i + 2]);
+      }
+    }
+
+    switch (ksize.size()) {
+      case 2: {
+        paddle::operators::math::MaxPool2dWithIndexFunctor<Place, T>
+            pool2d_forward;
+        pool2d_forward(context.device_context(), *in_x, *out, *mask, ksize,
+                       strides, paddings);
+      } break;
+      case 3: {
+        paddle::operators::math::MaxPool3dWithIndexFunctor<Place, T>
+            pool3d_forward;
+        pool3d_forward(context.device_context(), *in_x, *out, *mask, ksize,
+                       strides, paddings);
+      } break;
+    }
+  }
+};
+
+template <typename Place, typename T>
+class MaxPoolWithIndexGradKernel : public framework::OpKernel<T> {
+ public:
+  void Compute(const framework::ExecutionContext& context) const override {
+    const Tensor* mask = context.Input<Tensor>("Mask");
+    const Tensor* out_grad =
+        context.Input<Tensor>(framework::GradVarName("Out"));
+    Tensor* in_x_grad = context.Output<Tensor>(framework::GradVarName("X"));
+
+    std::vector<int> ksize = context.Attr<std::vector<int>>("ksize");
+    std::vector<int> strides = context.Attr<std::vector<int>>("strides");
+    std::vector<int> paddings = context.Attr<std::vector<int>>("paddings");
+    if (context.Attr<bool>("globalPooling")) {
+      for (size_t i = 0; i < ksize.size(); ++i) {
+        ksize[i] = static_cast<int>(in_x_grad->dims()[i + 2]);
+      }
+    }
+
+    if (in_x_grad) {
+      in_x_grad->mutable_data<T>(context.GetPlace());
+      auto temp = framework::EigenVector<T>::Flatten(*in_x_grad);
+      temp.device(context.GetEigenDevice<Place>()) =
+          temp.constant(static_cast<T>(0));
+
+      switch (ksize.size()) {
+        case 2: {
+          paddle::operators::math::MaxPool2dWithIndexGradFunctor<Place, T>
+              pool2d_backward;
+          pool2d_backward(context.device_context(), *in_x_grad, *out_grad,
+                          *mask, ksize, strides, paddings);
+        } break;
+        case 3: {
+          paddle::operators::math::MaxPool3dWithIndexGradFunctor<Place, T>
+              pool3d_backward;
+          pool3d_backward(context.device_context(), *in_x_grad, *out_grad,
+                          *mask, ksize, strides, paddings);
+        } break;
+      }
+    }
+  }
+};
+}  // namespace operators
+}  // namespace paddle

python/paddle/v2/framework/tests/test_pool_max_op.py

+import unittest
+import numpy as np
+from op_test import OpTest
+
+
+def max_pool3D_forward_naive(x,
+                             ksize,
+                             strides,
+                             paddings=[0, 0, 0],
+                             global_pool=0):
+
+    N, C, D, H, W = x.shape
+    if global_pool == 1:
+        ksize = [D, H, W]
+    D_out = (D - ksize[0] + 2 * paddings[0]) / strides[0] + 1
+    H_out = (H - ksize[1] + 2 * paddings[1]) / strides[1] + 1
+    W_out = (W - ksize[2] + 2 * paddings[2]) / strides[2] + 1
+    out = np.zeros((N, C, D_out, H_out, W_out))
+    mask = np.zeros((N, C, D_out, H_out, W_out))
+    for k in xrange(D_out):
+        d_start = np.max((k * strides[0] - paddings[0], 0))
+        d_end = np.min((k * strides[0] + ksize[0] - paddings[0], D))
+        for i in xrange(H_out):
+            h_start = np.max((i * strides[0] - paddings[0], 0))
+            h_end = np.min((i * strides[0] + ksize[0] - paddings[0], H))
+            for j in xrange(W_out):
+                w_start = np.max((j * strides[1] - paddings[1], 0))
+                w_end = np.min((j * strides[1] + ksize[1] - paddings[1], W))
+                x_masked = x[:, :, d_start:d_end, h_start:h_end, w_start:w_end]
+
+                out[:, :, k, i, j] = np.max(x_masked, axis=(2, 3, 4))
+
+                for n in xrange(N):
+                    for c in xrange(C):
+                        arr = x_masked[n, c, :, :, :]
+                        index = np.where(arr == np.max(arr))
+                        sub_deep = index[0][0]
+                        sub_row = index[1][0]
+                        sub_col = index[2][0]
+                        index = ((d_start + sub_deep) * H +
+                                 (h_start + sub_row)) * W + w_start + sub_col
+                        mask[n, c, k, i, j] = index
+
+    return out, mask
+
+
+def max_pool2D_forward_naive(x, ksize, strides, paddings=[0, 0], global_pool=0):
+
+    N, C, H, W = x.shape
+    if global_pool == 1:
+        ksize = [H, W]
+    H_out = (H - ksize[0] + 2 * paddings[0]) / strides[0] + 1
+    W_out = (W - ksize[1] + 2 * paddings[1]) / strides[1] + 1
+    out = np.zeros((N, C, H_out, W_out))
+    mask = np.zeros((N, C, H_out, W_out))
+    for i in xrange(H_out):
+        for j in xrange(W_out):
+            r_start = np.max((i * strides[0] - paddings[0], 0))
+            r_end = np.min((i * strides[0] + ksize[0] - paddings[0], H))
+            c_start = np.max((j * strides[1] - paddings[1], 0))
+            c_end = np.min((j * strides[1] + ksize[1] - paddings[1], W))
+            x_masked = x[:, :, r_start:r_end, c_start:c_end]
+
+            out[:, :, i, j] = np.max(x_masked, axis=(2, 3))
+
+            for n in xrange(N):
+                for c in xrange(C):
+                    arr = x_masked[n, c, :, :]
+                    index = np.where(arr == np.max(arr))
+                    sub_row = index[0][0]
+                    sub_col = index[1][0]
+                    index = (r_start + sub_row) * W + c_start + sub_col
+                    mask[n, c, i, j] = index
+
+    return out, mask
+
+
+class TestMaxPoolWithIndex_Op(OpTest):
+    def setUp(self):
+        self.initTestCase()
+        input = np.random.random(self.shape).astype("float32")
+        output, mask = self.pool_forward_naive(input, self.ksize, self.strides,
+                                               self.paddings, self.global_pool)
+
+        self.attrs = {
+            'strides': self.strides,
+            'paddings': self.paddings,
+            'ksize': self.ksize,
+            'globalPooling': self.global_pool,
+        }
+
+        self.inputs = {'X': input}
+        self.outputs = {'Out': output, "Mask": mask}
+
+    def test_check_output(self):
+        self.check_output()
+
+    # def test_check_grad(self):
+    #     self.check_grad(set(['X']), ['Out'], max_relative_error=0.07)
+
+    def initTestCase(self):
+        self.global_pool = True
+        self.index = "max_pool3d_with_index"
+        self.op_type = "%s" % self.index
+        self.pool_forward_naive = max_pool3D_forward_naive
+        self.shape = [2, 3, 5, 5, 5]
+        self.ksize = [3, 3, 3]
+        self.strides = [1, 1, 1]
+        self.paddings = [1, 1, 1]
+
+
+class TestCase1(TestMaxPoolWithIndex_Op):
+    def initTestCase(self):
+        self.global_pool = True
+        self.op_type = "max_pool3d_with_index"
+        self.pool_forward_naive = max_pool3D_forward_naive
+        self.shape = [2, 3, 5, 5, 5]
+        self.ksize = [3, 3, 3]
+        self.strides = [1, 1, 1]
+        self.paddings = [1, 1, 1]
+
+
+class TestCase2(TestMaxPoolWithIndex_Op):
+    def initTestCase(self):
+        self.global_pool = False
+        self.op_type = "max_pool3d_with_index"
+        self.pool_forward_naive = max_pool3D_forward_naive
+        self.shape = [2, 3, 7, 7, 7]
+        self.ksize = [3, 3, 3]
+        self.strides = [1, 1, 1]
+        self.paddings = [1, 1, 1]
+
+
+class TestCase3(TestMaxPoolWithIndex_Op):
+    def initTestCase(self):
+        self.global_pool = False
+        self.op_type = "max_pool3d_with_index"
+        self.pool_forward_naive = max_pool3D_forward_naive
+        self.shape = [2, 3, 7, 7, 7]
+        self.ksize = [3, 3, 3]
+        self.strides = [2, 2, 2]
+        self.paddings = [0, 0, 0]
+
+
+class TestCase4(TestMaxPoolWithIndex_Op):
+    def initTestCase(self):
+        self.global_pool = True
+        self.op_type = "max_pool3d_with_index"
+        self.pool_forward_naive = max_pool3D_forward_naive
+        self.shape = [2, 3, 5, 5, 5]
+        self.ksize = [3, 3, 3]
+        self.strides = [1, 1, 1]
+        self.paddings = [1, 1, 1]
+
+
+class TestCase5(TestMaxPoolWithIndex_Op):
+    def initTestCase(self):
+        self.global_pool = True
+        self.op_type = "max_pool3d_with_index"
+        self.pool_forward_naive = max_pool3D_forward_naive
+        self.shape = [2, 3, 5, 5, 5]
+        self.ksize = [3, 3, 3]
+        self.strides = [2, 2, 2]
+        self.paddings = [0, 0, 0]
+
+
+class TestCase6(TestMaxPoolWithIndex_Op):
+    def initTestCase(self):
+        self.global_pool = False
+        self.op_type = "max_pool2d_with_index"
+        self.pool_forward_naive = max_pool2D_forward_naive
+        self.shape = [2, 3, 7, 7]
+        self.ksize = [3, 3]
+        self.strides = [1, 1]
+        self.paddings = [1, 1]
+
+
+class TestCase7(TestMaxPoolWithIndex_Op):
+    def initTestCase(self):
+        self.global_pool = False
+        self.op_type = "max_pool2d_with_index"
+        self.pool_forward_naive = max_pool2D_forward_naive
+        self.shape = [2, 3, 7, 7]
+        self.ksize = [3, 3]
+        self.strides = [2, 2]
+        self.paddings = [0, 0]
+
+
+class TestCase8(TestMaxPoolWithIndex_Op):
+    def initTestCase(self):
+        self.global_pool = True
+        self.op_type = "max_pool2d_with_index"
+        self.pool_forward_naive = max_pool2D_forward_naive
+        self.shape = [2, 3, 5, 5]
+        self.ksize = [3, 3]
+        self.strides = [1, 1]
+        self.paddings = [1, 1]
+
+
+class TestCase9(TestMaxPoolWithIndex_Op):
+    def initTestCase(self):
+        self.global_pool = True
+        self.op_type = "max_pool2d_with_index"
+        self.pool_forward_naive = max_pool2D_forward_naive
+        self.shape = [2, 3, 5, 5]
+        self.ksize = [3, 3]
+        self.strides = [2, 2]
+        self.paddings = [0, 0]
+
+
+if __name__ == '__main__':
+    unittest.main()