fibonacci_cutoff.c
8449e591e260master

fibonacci_cutoff.c
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			#include "timing.h"
			#include <stdio.h>
			#include <stdlib.h>
			#include <omp.h>

			long int fibonacci_seq(int n) {
			long int x, y;
			if (n < 2) {
			return n;
			} else {
			x = fibonacci_seq(n-1);
			y = fibonacci_seq(n-2);
			return (x+y);
			}
			}

			long int fibonacci(int n, int level, int cutoff) {
			long int x, y;
			if (n < 2) {
			return n;
			} else if (level < cutoff) {
			#pragma omp task shared(x)
			x = fibonacci(n-1, level+1, cutoff);
			#pragma omp task shared(y)
			y = fibonacci(n-2, level+1, cutoff);
			#pragma omp taskwait
			return (x+y);
			} else {
			x = fibonacci_seq(n - 1);
			y = fibonacci_seq(n - 2);
			return (x+y);
			}
			}


			int main() {
			int n = 42;
			int cutoff = 10;
			double t1, t2;
			long int fib = 0;

			t1 = second();
			#pragma omp parallel
			{
			#pragma omp single nowait
			{
			fib = fibonacci(n, 0, cutoff);
			}
			}

			t2 = second();

			printf("Fib(%d) = %ld (in %g [s])\n", n, fib, (t2-t1));

			return 0;
			}