title: basic operations cpu time cost
body: <p>I was wondering, how to optimize loops for systems with very limited resources. Let's say, if we have a basic <code>for</code> loop, like ( written in <code>javascript</code>):</p>
  
  <hr>
  
  <p><code>for(var i = someArr.length - 1; i &gt; -1; i--)
  {
  someArr[i]
  }</code></p>
  
  <hr>
  
  <p>I honestly don't know, isn't <code>!=</code> cheaper than <code>&gt;</code> ?</p>
  
  <p>I would be grateful for any resources covering computing cost in context of basic operators, like the aforementioned, <code>&gt;&gt;</code>, <code>~</code>, <code>!</code>, and so on.</p>