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mpiHip/addVec.cpp

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+#include <mpi.h>
+#include <hip/hip_runtime.h>
+#include <iostream>
+
+// Kernel function to be executed on the GPU
+__global__ void vector_add(float* A, float* B, float* C, int N) {
+    int idx = blockIdx.x * blockDim.x + threadIdx.x;
+    if (idx < N) {
+        C[idx] = A[idx] + B[idx];
+    }
+}
+
+int main(int argc, char* argv[]) {
+    // Initialize MPI
+    MPI_Init(&argc, &argv);
+
+    int world_size;
+    MPI_Comm_size(MPI_COMM_WORLD, &world_size);
+
+    int world_rank;
+    MPI_Comm_rank(MPI_COMM_WORLD, &world_rank);
+
+    // Size of the vectors
+    int N = 1024;
+
+    // Allocate host memory
+    float *h_A = new float[N];
+    float *h_B = new float[N];
+    float *h_C = new float[N];
+
+    // Initialize vectors
+    for (int i = 0; i < N; ++i) {
+        h_A[i] = i;
+        h_B[i] = i * 2;
+    }
+
+    // Allocate device memory
+    float *d_A, *d_B, *d_C;
+    hipMalloc(&d_A, N * sizeof(float));
+    hipMalloc(&d_B, N * sizeof(float));
+    hipMalloc(&d_C, N * sizeof(float));
+
+    // Copy data from host to device
+    hipMemcpy(d_A, h_A, N * sizeof(float), hipMemcpyHostToDevice);
+    hipMemcpy(d_B, h_B, N * sizeof(float), hipMemcpyHostToDevice);
+
+    // Launch kernel
+    int threads_per_block = 256;
+    int blocks_per_grid = (N + threads_per_block - 1) / threads_per_block;
+    hipLaunchKernelGGL(vector_add, dim3(blocks_per_grid), dim3(threads_per_block), 0, 0, d_A, d_B, d_C, N);
+
+    // Copy result back to host
+    hipMemcpy(h_C, d_C, N * sizeof(float), hipMemcpyDeviceToHost);
+
+    // Each process prints its portion of the result
+    std::cout << "Process " << world_rank << " results: ";
+    for (int i = 0; i < N; ++i) {
+        std::cout << h_C[i] << " ";
+    }
+    std::cout << std::endl;
+
+    // Free device memory
+    hipFree(d_A);
+    hipFree(d_B);
+    hipFree(d_C);
+
+    // Free host memory
+    delete[] h_A;
+    delete[] h_B;
+    delete[] h_C;
+
+    // Finalize MPI
+    MPI_Finalize();
+
+    return 0;
+}