Main file - Exercise 5

Sheet5/mainEx5.cpp

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+// HOW TO COMPILE ON MACOS
+// export CPPFLAGS="-I/opt/homebrew/opt/libomp/include"
+// export LDFLAGS="-L/opt/homebrew/opt/libomp/lib"
+// clang++ -std=c++17 -O3 -Xpreprocessor -fopenmp $CPPFLAGS main.cpp bench_funcs.cpp $LDFLAGS -lomp -o Ex5
+// ./Ex5
+
+#include <iostream>
+#include <vector>
+#include <chrono>
+#include <omp.h>
+#include "bench_funcs.h"
+
+using namespace std;
+using namespace std::chrono;
+
+int main() {
+    size_t n = 200000;       // FEM system size
+    size_t maxit = 5000;
+    double omega = 1.0;
+    double tol = 1e-8;
+
+    // show threads
+    #pragma omp parallel
+    {
+        #pragma omp single
+        cout << "Using " << omp_get_num_threads() << " OpenMP threads\n";
+    }
+
+    CSR K;
+    vector<double> f, u;
+
+    cout << "\nBuilding FEM system (parallel)\n";
+    auto t0 = high_resolution_clock::now();
+    build_fem_system(n, K, f);
+    auto t1 = high_resolution_clock::now();
+    cout << "Assembly time = " << duration<double>(t1 - t0).count() << " s\n";
+
+    cout << "\nRunning Jacobi solver (parallel)\n";
+    t0 = high_resolution_clock::now();
+    jacobi_csr_parallel(K, f, u, maxit, omega, tol);
+    t1 = high_resolution_clock::now();
+
+    cout << "Jacobi time = " << duration<double>(t1 - t0).count() << " s\n";
+    cout << "Done\n";
+}