Restructure cuda backend

src/layers/add.cpp

@@ -0,0 +1,44 @@
+#include "add.hpp"
+
+#include <stddef.h>
+
+using namespace CUDANet::Layers;
+
+
+Add::Add(int inputSize)
+    : inputSize(inputSize) {
+
+    output = new float[inputSize];
+
+#ifdef USE_CUDA
+    initCUDA();
+#endif
+    
+}
+
+
+Add::~Add() {
+#ifdef USE_CUDA
+    delCUDA();
+#endif
+}
+
+
+float* Add::forward(const float* inputA, const float* inputB) {
+
+#ifdef USE_CUDA
+    return forwardCUDA(inputA, inputB);
+#else
+    return forwardCPU(inputA, inputB);
+#endif
+
+}
+
+float* Add::forwardCPU(const float* inputA, const float* inputB) {
+    for (size_t i = 0; i < inputSize; i++)
+    {
+        output[i] = inputA[i] + inputB[i];
+    }
+
+    return output;    
+}