UCI C Language Programming Worksheet

*In C Language*

A loop “runs efficiently in parallel” if execution time with P cores should be expected to be about 1/P times as long as with one core while leaving the effect of the loop unchanged.

Q1. Review the provided file parallel.c. For each for-loop (A-I), determine which of the following statements applies.

• The loop will run efficiently in parallel. It simply requires the statement #pragma omp parallel for.
• The loop requires modification or a more sophisticated pragma statement before it can run efficiently in parallel.
  • In this case, explain why statement A is not true.
  • If the loop-body requires significant changes for parallelization, describe the changes. The loop-body modifications may require some cleverness or math.
• The loop cannot be efficiently parallelized.
  • In this case, explain why the loop is a poor candidate for parallelization.