gcd.java

package base;

public class GCD {

    public static long gcd(long a, long b) {
        while (a != b) {
            if (a < b) b -= a;
            else a -= b;
        }
        return a;
    }
    
}

repl

=> (crit/quick-bench (base.GCD/gcd 65678 5675684))
WARNING: Final GC required 29.3459828081481 % of runtime
Evaluation count : 3690984 in 6 samples of 615164 calls.
             Execution time mean : 321,007455 ns
    Execution time std-deviation : 245,404954 ns
   Execution time lower quantile : 151,285235 ns ( 2,5%)
   Execution time upper quantile : 633,579387 ns (97,5%)
                   Overhead used : 2,173030 ns
nil
=> (crit/quick-bench (-fast-gcd 65678 5675684))
WARNING: Final GC required 182.39447315166092 % of runtime
Evaluation count : 3743442 in 6 samples of 623907 calls.
             Execution time mean : 165,832780 ns
    Execution time std-deviation : 5,079956 ns
   Execution time lower quantile : 158,575288 ns ( 2,5%)
   Execution time upper quantile : 171,282710 ns (97,5%)
                   Overhead used : 2,173030 ns
nil
=> (defn -not-so-fast-gcd ^long [^long a ^long b]
     (if (== a b)
       a
       (if (> a b)
         (recur (- a b) b)
         (recur a (- b a)))))
#'user/-not-so-fast-gcd
=> (crit/quick-bench (-not-so-fast-gcd 65678 5675684))
WARNING: Final GC required 70.41637325295699 % of runtime
Evaluation count : 2502234 in 6 samples of 417039 calls.
             Execution time mean : 260,302822 ns
    Execution time std-deviation : 35,278050 ns
   Execution time lower quantile : 234,711291 ns ( 2,5%)
   Execution time upper quantile : 304,476349 ns (97,5%)
                   Overhead used : 2,173030 ns
nil