Prefix or Postfix increment? (v7)

Revision 7 of this benchmark created on

Description

So with recent JS runtimes, does using the prefix increment/decrement operators squeeze the usual performance droplet from loop index maintenance?

Preparation HTML

<script>
  var length = 500 * 1000;
  var data = new Array(length);
  var data2 = [];
  var index = data.length - 1;
  while (index--) {
    data[index] = 1;
    data2[index] = 1;
  }
</script>

Test runner

Ready to run.

Testing in
TestOps/sec
Suffix (reserved)
for (var index = 0, len = data.length; index < len; index++) {
 data[index]++;
 data[index]++;
 data[index]++;
 data[index]++;
 data[index]++;
}
ready
Prefix (reserved)
for (var index = 0, len = data.length; index < len; ++index) {
 ++data[index];
 ++data[index];
 ++data[index];
 ++data[index];
 ++data[index];
}
 
ready
Prefix ([])
for (var index = 0, len = data2.length; index < len; ++index) {
 ++data2[index];
 ++data2[index];
 ++data2[index];
 ++data2[index];
 ++data2[index];
}
ready
Suffix ([])
for (var index = 0, len = data2.length; index < len; index++) {
 data2[index]++;
 data2[index]++;
 data2[index]++;
 data2[index]++;
 data2[index]++;
}
ready

Revisions

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