Adding simple OpenMP test

src/unit_tests/C++/apex_openmp.cpp

@@ -0,0 +1,67 @@
+#include <omp.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "apex.h"
+
+#define N 1024*1024
+#define MAX_THREADS 256
+
+#if defined(__GNUC__)
+#define ALIGNED_(x) __attribute__ ((aligned(x)))
+#else
+#define ALIGNED_(x) __declspec(align(x))
+#endif
+
+double no_sharing(double* x, double* y)
+{
+  double sum=0.0;
+  ALIGNED_(128) double sum_local[MAX_THREADS] = {0};
+  #pragma omp parallel
+  {
+   int me = omp_get_thread_num();
+
+   int i;
+   #pragma omp for
+   for (i = 0; i < N; i++) {
+     sum_local[me] = sum_local[me] + (x[i] * y[i]);
+   }
+
+   #pragma omp atomic
+   sum += sum_local[me];
+  }
+  return sum;
+}
+
+void my_init(double* x)
+{
+  double randval = 1.0 + (((double)(rand())) / RAND_MAX);
+  #pragma omp parallel
+  {
+   int i;
+   #pragma omp for
+   for (i = 0; i < N; i++) {
+     x[i] = randval;
+   }
+  }
+}
+
+int main(int argc, char** argv)
+{
+  APEX_UNUSED(argc);
+  APEX_UNUSED(argv);
+  static double x[N];
+  static double y[N];
+  printf("Initializing...\n"); fflush(stdout);
+  my_init(x);
+  my_init(y);
+
+  double result = 0.0;
+
+  printf("No Sharing...\n"); fflush(stdout);
+  result = no_sharing(x, y);
+  printf("Result: %f\n", result);
+
+  apex_finalize();
+  return 0;
+}