Implement max pooling layer

include/kernels/pooling.cuh

@@ -0,0 +1,30 @@
+#ifndef CUDANET_POOLING_H
+#define CUDANET_POOLING_H
+
+#include <cuda_runtime.h>
+
+namespace CUDANet::Kernels {
+
+__global__ void max_pooling(
+    const float* __restrict__ d_input,
+    float* __restrict__ d_output,
+    const int inputSize,
+    const int nChannels,
+    const int poolingSize,
+    const int stride,
+    const int paddingSize
+);
+
+__global__ void avg_pooling(
+    const float* __restrict__ d_input,
+    float* __restrict__ d_output,
+    const int inputSize,
+    const int nChannels,
+    const int poolingSize,
+    const int stride,
+    const int paddingSize
+);
+
+}  // namespace CUDANet::Kernels
+
+#endif // CUDANET_POOLING_H

include/layers/conv2d.cuh

@@ -25,16 +25,17 @@ class Conv2d : public WeightedLayer {
      * @param stride Convolution stride
      * @param numFilters Number of output filters
      * @param padding Padding type ('SAME' or 'VALID')
-     * @param activationType Activation function type ('RELU', 'SIGMOID', 'SOFTMAX' or 'NONE')
+     * @param activationType Activation function type ('RELU', 'SIGMOID',
+     * 'SOFTMAX' or 'NONE')
      */
     Conv2d(
-        int                    inputSize,
-        int                    inputChannels,
-        int                    kernelSize,
-        int                    stride,
-        int                    numFilters,
-        Layers::Padding        padding,
-        Layers::ActivationType activationType
+        int            inputSize,
+        int            inputChannels,
+        int            kernelSize,
+        int            stride,
+        int            numFilters,
+        Padding        padding,
+        ActivationType activationType
     );
 
     /**
@@ -107,7 +108,7 @@ class Conv2d : public WeightedLayer {
     float* d_biases;
 
     // Kernels
-    Layers::Activation activation;
+    Activation activation;
 
     /**
      * @brief Initialize weights of the convolutional layer with zeros

include/layers/max_pooling.cuh

@@ -0,0 +1,42 @@
+#ifndef CUDANET_MAX_POOLING_H
+#define CUDANET_MAX_POOLING_H
+
+#include <cuda_runtime.h>
+
+#include "layer.cuh"
+#include "activation.cuh"
+
+namespace CUDANet::Layers {
+
+class MaxPooling2D : public SequentialLayer {
+  public:
+    MaxPooling2D(
+        int            inputSize,
+        int            nChannels,
+        int            poolingSize,
+        int            stride,
+        Padding            padding,
+        ActivationType activationType
+    );
+    ~MaxPooling2D();
+
+    float* forward(const float* d_input);
+
+  private:
+    int inputSize;
+    int nChannels;
+    int poolingSize;
+    int stride;
+    int paddingSize;
+
+    int outputSize;
+    int gridSize;
+
+    float* d_output;
+
+    Activation activation;
+};
+
+}  // namespace CUDANet::Layers
+
+#endif  // CUDANET_MAX_POOLING_H