C++ & Java JIT Optimizations: Finding Prime Numbers

C++ & Java JIT Optimizations: Finding Prime Numbers

• 1.
  Object Comparisons Finding PrimeNumbers C++ & Java ADAM FELDSCHER I699 PERFORMANCE DESIGN PATTERNS II 10/16/2019
• 2.
  Modifications  All testsare 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 (intiter = 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 13 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 vsWrappers
• 6.
  Java Primitives vsWrappers (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 publicclass 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 13 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 classPrimeFinder { 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 13 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 publicclass 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 13 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 boolPrimeFinder::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 13 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 13 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