Измерение производительности javascript-функций

gistfile1.txt

function fib3(value){
if(value === 1) return 1
if(value === 2) return 1
if(value > 2) {
	return fib3(value - 1 ) +  fib3(value - 2)
	}
}
let t0 = performance.now();
result = fib3(30);
let t1 = performance.now();
console.log('Took', (t1 - t0).toFixed(4), 'milliseconds to generate:', result);

function fib(value) {
  function fib2(value, k, fk, fk1){
    if(k==value) return fk
    if(k < value){ 
    return fib2(value, k+1, fk+fk1, fk)
    }
  }
  if(value == 1) return 1;
  return fib2(value, 2, 1, 1);
}

t0 = performance.now();
result = fib(30);
t1 = performance.now();
console.log('Took', (t1 - t0).toFixed(4), 'milliseconds to generate:', result);