Abstract activation and implement softmax

include/kernels/activation_functions.cuh

@@ -0,0 +1,74 @@
+#ifndef CUDANET_ACTIVATION_FUNCTIONS_H
+#define CUDANET_ACTIVATION_FUNCTIONS_H
+
+namespace CUDANet::Kernels {
+
+/**
+ * @brief Sigmoid activation function kernel
+ *
+ * @param src Pointer to the source array
+ * @param dst Pointer to the destination array
+ * @param len Length of the arrays
+ */
+__global__ void sigmoid(
+    const float* __restrict__ src,
+    float* __restrict__ dst,
+    const unsigned int len
+);
+
+/**
+ * @brief Relu activation function kernel
+ *
+ * @param src Pointer to the source array
+ * @param dst Pointer to the destination array
+ * @param len Length of the arrays
+ */
+__global__ void relu(
+    const float* __restrict__ src,
+    float* __restrict__ dst,
+    const unsigned int len
+);
+
+/**
+ * @brief Softmax activation exponentiation kernel
+ *
+ * @param src Pointer to the source array
+ * @param dst Pointer to the destination array
+ * @param len Length of the arrays
+ */
+__global__ void softmax_exp(
+    const float* __restrict__ src,
+    float* __restrict__ dst,
+    const unsigned int len
+);
+
+/**
+ * @brief 
+ * 
+ * @param d_vector Device pointer to vector
+ * @param d_output Device pointer to output vector
+ * @param w Length of the vector
+ */
+__global__ void softmax_sum(
+    const float* __restrict__ d_vector,
+    float* __restrict__ d_output,
+    const unsigned int w
+);
+
+/**
+ * @brief Softmax activation function kernel
+ *
+ * @param src Pointer to the source array
+ * @param dst Pointer to the destination array
+ * @param len Length of the arrays
+ */
+__global__ void softmax_div(
+    const float* __restrict__ src,
+    float* __restrict__ dst,
+    const float* __restrict__ sum,
+    const unsigned int len
+);
+
+}  // namespace CUDANet::Kernels
+
+#endif  // CUDANET_ACTIVATION_FUNCTIONS_H