![Java PrimeFinder Class
public class PrimeFinder {
private Integer max_prime;
public PrimeFinder(Integer max_prime) {
this.max_prime = max_prime;
}
public Integer find_primes() {
Integer num_primes_found = 0;
for (Integer n = 2; n <= max_prime; n++) {
Integer max_divisor = (int) sqrt(n);
Boolean is_prime = true;
for (Integer i = 2; i <= max_divisor; i++) {
if (n % i == 0) {
is_prime = false;
break;
}
}
if (is_prime) {
num_primes_found++;
}
}
return num_primes_found;
}
}
public static void main(String[] args) {
for (Integer iter = 0; iter < max_iter; iter++) {
//Start Timer
PrimeFinder primeFinder = new PrimeFinder(iter, max_prime);
num_primes_found = primeFinder.find_primes();
//End timer & Print
}](https://image.slidesharecdn.com/primeresultsobjects-191201184225/85/C-Java-JIT-Optimizations-Finding-Prime-Numbers-7-320.jpg)
C++ & Java JIT Optimizations: Finding Prime Numbers
- 1. Object Comparisons Finding Prime Numbers C++ & Java ADAM FELDSCHER I699 PERFORMANCE DESIGN PATTERNS II 10/16/2019
- 2. Modifications All tests are done for primes up to 10k, with 40 iterations 1k had too much noise Java and C++ Java Primitives vs Wrappers PrimeFinder Class Invoction New instance per each iteration Bring SQRT into for loop comparison Adding is_prime method
- 3. Algorithm (Java) for (int iter = 0; iter < max_iter; iter++) { // insert delays long start_time = System.nanoTime(); for (int n = 2; n <= max_prime; n++) {// 2 - 10k int max_divisor = (int) sqrt(n); boolean is_prime = true; for (int i = 2; i <= max_divisor; i++) {// check for divisors if (n % i == 0) { is_prime = false; break; } } if (is_prime) { num_primes_found++; // count primes } } long end_time = System.nanoTime(); // print things num_primes_found = 0; }
- 4. Java Consistency Check 0 1000000 2000000 3000000 4000000 5000000 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 Nanoseconds Iteration Java 10, 10k, normal consistency Run 1 Run 2
- 5. Java Primitives vs Wrappers
- 6. Java Primitives vs Wrappers (Integer) 0 5000000 10000000 15000000 20000000 25000000 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 Nanoseconds Iteration Java 10, 10k, Integer Primative Integer
- 7. Java PrimeFinder Class public class PrimeFinder { private Integer max_prime; public PrimeFinder(Integer max_prime) { this.max_prime = max_prime; } public Integer find_primes() { Integer num_primes_found = 0; for (Integer n = 2; n <= max_prime; n++) { Integer max_divisor = (int) sqrt(n); Boolean is_prime = true; for (Integer i = 2; i <= max_divisor; i++) { if (n % i == 0) { is_prime = false; break; } } if (is_prime) { num_primes_found++; } } return num_primes_found; } } public static void main(String[] args) { for (Integer iter = 0; iter < max_iter; iter++) { //Start Timer PrimeFinder primeFinder = new PrimeFinder(iter, max_prime); num_primes_found = primeFinder.find_primes(); //End timer & Print }
- 8. Java PrimeFinder Class 0 5000000 10000000 15000000 20000000 25000000 30000000 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 Nanoseconds Iteration Java 10, 10k, Primefinder Primative Class PrimeFinder
- 9. C++ PrimeFinder Class class PrimeFinder { private: int _max_prime; public: PrimeFinder(int max_prime); int find_primes(); }; PrimeFinder::PrimeFinder(int max_prime) { _max_prime = max_prime; } int PrimeFinder::find_primes() { int num_primes_found = 0; int n; for (n = 2; n <= _max_prime; n++) { int max_divisor = (int) sqrt(n); bool is_prime = true; int i; for (i = 2; i <= max_divisor; i++) { if (n % i == 0) { is_prime = false; break; } } if (is_prime) { num_primes_found++; } } return num_primes_found; }
- 10. C++ PrimeFinder Class 0 200000 400000 600000 800000 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 Nanoseconds Iteration C++ PrimeFinder C++ Primative C++ PrimeFinder
- 11. Java Prime Finder + SQRT
- 12. Java Prime Finder + SQRT 0 5000000 10000000 15000000 20000000 25000000 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 Nanoseconds Iteration Java 10, 10k, Primefinder Primative Class PrimeFinder SQRT
- 13. C++ PrimeFinder + SQRT 0 200000 400000 600000 800000 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 Nanoseconds Iteration C++ PrimeFinder SQRT C++ PrimeFinder C++ PrimeFinder SQRT
- 14. Java IsPrime Method public class PrimeFinder { private Boolean is_prime(Integer n) { Integer max_divisor = (int) sqrt(n); for (Integer i = 2; i <= max_divisor; i++) { if (n % i == 0) { return false; } } return true; } public Integer find_primes() { Integer num_primes_found = 0; for (Integer n = 2; n <= max_prime; n++) { if (is_prime(n)) { num_primes_found++; } } return num_primes_found; } }
- 15. Java IsPrime Method 0 5000000 10000000 15000000 20000000 25000000 30000000 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 Nanoseconds Iteration Java 10, 10k, Integer, PrimeFinder, IsPrime Primative Class PrimeFinder PrimeFinder IsPrime
- 16. C++ IsPrime Method bool PrimeFinder::is_prime(int n) { int max_divisor = (int) sqrt(n); for (int i = 2; i <= max_divisor; i++) { if (n % i == 0) { return false; } } return true; } int PrimeFinder::find_primes() { int num_primes_found = 0; int n; for (n = 2; n <= _max_prime; n++) { if (is_prime(n)) { num_primes_found++; } } return num_primes_found; }
- 17. C++ IsPrime Method 0 200000 400000 600000 800000 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 Nanoseconds Iteration C++ PrimeFinder isPrime C++ PrimeFinder C++ PrimeFinder isprime
- 18. Java 1K tests 0 1000000 2000000 3000000 4000000 5000000 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 Nanoseconds Iteration Java 10, 1k, Integer Primefinder Integer Class PrimeFinder
Editor's Notes
- #5: Retest in linux….
- #7: Significant! Scale difference from last
- #9: Surprising that there’s not more change
- #11: Gets entirely optimized out
- #13: Almost no impact
- #16: Some weirdness, not sure if it jits faster because there are smaller units, or if its just noise. JIT LOG
- #18: No change
- #19: 1k has more details but also more noise. Linux