Start implementing padding kernel

test/kernels/test_padding.cu

@@ -0,0 +1,82 @@
+#include <cuda_runtime_api.h>
+#include <gtest/gtest.h>
+
+#include <iostream>
+
+#include "padding.cuh"
+#include "test_cublas_fixture.cuh"
+
+class PaddingTest : public CublasTestFixture {
+  protected:
+    cudaError_t    cudaStatus;
+    cublasStatus_t cublasStatus;
+};
+
+TEST_F(PaddingTest, SimplePaddingTest) {
+    int w = 2;
+    int h = 3;
+    int n = 2;
+    int p = 1;
+
+    float* d_input;
+    float* d_padded;
+
+    int inputSize  = w * h * n;
+    int paddedSize = (w + 2 * p) * (h + 2 * p) * n;
+
+    cudaStatus = cudaMalloc((void**)&d_input, sizeof(float) * inputSize);
+    EXPECT_EQ(cudaStatus, cudaSuccess);
+
+    cudaStatus = cudaMalloc(
+        (void**)&d_padded, sizeof(float) * paddedSize
+    );
+    EXPECT_EQ(cudaStatus, cudaSuccess);
+
+    /*
+    Matrix channel 0:
+    0  1
+    2  3
+    4  5
+    Matrix channel 1:
+    6  7
+    8  9
+    10 11
+
+    Represented as column major vector:
+
+    0 2 4 1 3 5 6 8 10 7 9 11
+    */
+
+    std::vector<float> input = {0.0f, 2.0f, 4.0f,  1.0f, 3.0f, 5.0f,
+                                6.0f, 8.0f, 10.0f, 7.0f, 9.0f, 11.0f};
+
+    cublasStatus =
+        cublasSetVector(inputSize, sizeof(float), input.data(), 1, d_input, 1);
+    EXPECT_EQ(cublasStatus, CUBLAS_STATUS_SUCCESS);
+
+    pad_matrix_kernel<<<1, 1>>>(d_input, d_padded, w, h, n, p);
+    cudaStatus = cudaDeviceSynchronize();
+    EXPECT_EQ(cudaStatus, cudaSuccess);
+
+    std::vector<float> expectedOutput = {
+        0.0f, 0.0f, 0.0f, 0.0f,  0.0f, 0.0f, 0.0f, 2.0f, 4.0f,  0.0f,
+        0.0f, 1.0f, 3.0f, 5.0f,  0.0f, 0.0f, 0.0f, 0.0f, 0.0f,  0.0f,
+        0.0f, 0.0f, 0.0f, 0.0f,  0.0f, 0.0f, 6.0f, 8.0f, 10.0f, 0.0f,
+        0.0f, 7.0f, 9.0f, 11.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f,  0.0f
+    };
+
+    std::vector<float> output(paddedSize);
+    cublasStatus = cublasGetVector(
+        paddedSize, sizeof(float), d_padded, 1, output.data(), 1
+    );
+
+    std::cout << "Actual output: " << std::endl;
+    for (int i = 0; i < paddedSize; i++) {
+        std::cout << output[i] << " ";
+    }
+    std::cout << std::endl;
+
+    for (int i = 0; i < paddedSize; i++) {
+        EXPECT_NEAR(expectedOutput[i], output[i], 1e-5);
+    }
+}