Prefix or Postfix increment? (v15)

Revision 15 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 data = new Array(500 * 1000);
  var index = data.length-1;
do{
 data[index] = index;
}
while ( index-- );
</script>

Test runner

Ready to run.

Testing in
TestOps/sec
Suffix
for (var index = 0, len = data.length; index < len; index++) {
 data[index] = data[index] * 2;
}
ready
Prefix
for (var index = 0, len = data.length; index < len; ++index) {
 data[index] = data[index] * 2;
}
ready
Plus Equals
for (var index = 0, len = data.length; index < len; index+=1) {
 data[index] *= 2;
}
ready
Plus Equals fully-written
for (var index = 0, len = data.length; index < len; index=index+1) {
 data[index] = data[index] * 2;
}
ready
Decrement - Prefix
for (var i= data.length-1; i >= 0; --i) {
 data[i] *= 2;
}
ready
Decrement - Suffix
for (var i = data.length-1; i >= 0; i--) {
 data[i] *= 2;
}
ready

Revisions

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