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Normal loops vs bundle loops vs reverse loops

Benchmark created by EtnasSoft on October 4, 2011

Preparation HTML

<script>
  var x = 0,
      a = [1,1,2,3,5,8,13,21,34,55];
</script>

Test runner

Ready to run.

Test Ops/sec

Normal Loop

Testing in
Test	Ops/sec
Normal Loop	`for (var i = 0, l = a.length; i < l; i++){ x += a[i]; }; // cached length`	ready
Bundled Loop	`for (var i = -1, l = a.length; ++i < l;){ x += a[i]; }; // bundled condition (increment+test)`	ready
Reversed Loop	`for (var i = a.length; i--;){ x += a[i]; }; // reverse loop`	ready

for (var i = 0, l = a.length; i < l; i++){
  x += a[i];
}; // cached length

ready

Bundled Loop

for (var i = -1, l = a.length; ++i < l;){
  x += a[i];
}; // bundled condition (increment+test)

ready

Reversed Loop

for (var i = a.length; i--;){
  x += a[i];
}; // reverse loop

ready

Revisions

You can edit these tests or add more tests to this page by appending /edit to the URL.

Revision 1: published by EtnasSoft on October 4, 2011