primebenchmark.c

#include <stdio.h>
#include <stdint.h>
#include <inttypes.h>

int isPrime(int64_t);

int main(int argc, char *argv[]) {
  int64_t testPrime = 0xffffffffffffffc5LL;
  printf("%d", isPrime(testPrime));
  return 0; 
}

int isPrime(int64_t n){
	if (n%2==0) return n==2;
	if (n%3==0) return n==3;
	int d=5;
	while(d*d<=n){
		if(n%d==0) return 0;
		d+=2;
		if(n%d==0) return 0;
		d+=4;}
	return 1;}