Abstract activation and implement softmax

test/kernels/test_activation_functions.cu

@@ -0,0 +1,43 @@
+#include <cuda_runtime_api.h>
+#include <gtest/gtest.h>
+
+#include <iostream>
+
+#include "activation_functions.cuh"
+
+TEST(ActivationsTest, SigmoidSanityCheck) {
+
+    cudaError_t cudaStatus;
+
+    float input[3] = {-100.0f, 0.0f, 100.0f};
+
+    std::vector<float> expected_output = {0.0f, 0.5f, 1.0f};
+
+    float* d_input;
+    float* d_output;
+
+    cudaStatus = cudaMalloc((void**)&d_input, sizeof(float) * 3);
+    EXPECT_EQ(cudaStatus, cudaSuccess);
+
+    cudaStatus = cudaMalloc((void**)&d_output, sizeof(float) * 3);
+    EXPECT_EQ(cudaStatus, cudaSuccess);
+
+    cudaStatus = cudaMemcpy(d_input, input, sizeof(float) * 3, cudaMemcpyHostToDevice);
+    EXPECT_EQ(cudaStatus, cudaSuccess);
+
+    CUDANet::Kernels::sigmoid<<<1, 3>>>(d_input, d_output, 3);
+    cudaStatus = cudaDeviceSynchronize();
+    EXPECT_EQ(cudaStatus, cudaSuccess);
+
+    std::vector<float> output(3);
+
+    cudaStatus = cudaMemcpy(output.data(), d_output, sizeof(float) * 3, cudaMemcpyDeviceToHost);
+    EXPECT_EQ(cudaStatus, cudaSuccess);
+
+    for (int i = 0; i < 3; i++) {
+        EXPECT_NEAR(expected_output[i], output[i], 1e-5);
+    }
+
+    cudaFree(d_input);
+    cudaFree(d_output);
+}