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Array Initialization

This program initializes the entries of a float-valued array.

#include <iostream.h>
const int N = 10;

float f (float i)  
{
  //evaluate polynomial 3xxx-7xx+2x+4 at x=i
  return 3*i*i*i - 7*i*i + 2*i + 4;
}

int main()
{
  //makes A[i] = f(i) and then outputs A[i]
  float A[N];

  parfor (int i=0; i<N; i++)
    A[i] = f((float)i);
  //implicit barrier

  for (int j=0; j<N; j++)
    cout << "A[" << j << "] is " << A[j] << endl;
  return 0;
}

Each element of the array A[] is evaluated and assigned a value by a different thread of control. This is an instance of safe sharing of mutable variables between concurrent threads of execution because each individual element of the array A[] is a different mutable variable, and single elements are not shared between iterations of the parfor loop.