Run results for: divide by 2 vs multiply by 0.5

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_4 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.4 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 18

Operating system: iOS 18.4

Device Platform: Mobile

Date tested: one year ago

div by 2

20K/s

multiply by 0.5

19K/s

div by 2.0

13K/s

View exact numbers

Test name	Executions per second
✓ div by 2	19,729 Ops/sec
multiply by 0.5	18,710 Ops/sec
div by 2.0	13,234 Ops/sec

Script Preparation code:

const length = 100000;
const tmp_nums=[];
for (let i = 0; i < length; i++) {
  tmp_nums.push(Date.now() + Math.random());
}
nums = [...tmp_nums];
nums_len = length;

Tests:

div by 2
const length = nums_len; for (let i = 0; i < length; i++) { nums[i] /= 2; }
div by 2.0
const length = nums_len; for (let i = 0; i < length; i++) { nums[i] /= 2.0; }
multiply by 0.5
const length = nums_len; for (let i = 0; i < length; i++) { nums[i] *= 0.5; }