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copied!<p><strong>tl;dr</strong> IMHO, Avoiding exceptions for performance reasons hits both categories of premature and micro- optimizations. Don't do it.</p> <p>Ah, the religious war of exceptions.</p> <p>The various types of answers to this are usually:</p> <ul> <li>the usual mantra (a good one, IMHO): "use exceptions for exceptional situations" (IOW, not part of "normal" code paths). <ul> <li>If your normal user paths involved intentionally using exceptions as a control-flow mechanism, that's a smell.</li> </ul></li> <li>tons of detail, without really answering the original question <ul> <li>if you really want detail: </li> <li><a href="http://blogs.msdn.com/cbrumme/archive/2003/10/01/51524.aspx" rel="nofollow noreferrer">http://blogs.msdn.com/cbrumme/archive/2003/10/01/51524.aspx</a></li> <li><a href="http://blogs.msdn.com/ricom/archive/2006/09/14/754661.aspx" rel="nofollow noreferrer">http://blogs.msdn.com/ricom/archive/2006/09/14/754661.aspx</a></li> <li>etc.</li> </ul></li> <li>someone pointing at microbenchmarks showing that something like i/j with j == 0 is 10x slower catching div-by-zero than checking j == 0</li> <li>pragmatic answer of how to approach performance for apps in general <ul> <li>usually along the lines of:</li> <li>make perf goals for your scenarios (ideally working with customers)</li> <li>build it so it's maintainable, readable, and robust</li> <li>run it and check perf of goal scenarios</li> <li>if a set of scenarios aren't making goal, USE A PROFILER to tell you where your time is being spent and go from there.</li> <li>IOW, any perf changes, especially micro-optimizations like this, made without profiling data driving that decision, is typically a huge waste of time.</li> </ul></li> </ul> <p>Keep in mind that your perf wins will typically come from algorithmic changes (adding an index to a table to avoid table scans, moving something with large n from O(n^3) to O(n ln n), etc.).</p> <p>More fun links: </p> <ul> <li><a href="http://en.wikipedia.org/wiki/Program_optimization" rel="nofollow noreferrer">http://en.wikipedia.org/wiki/Program_optimization</a></li> <li><a href="http://www.flounder.com/optimization.htm" rel="nofollow noreferrer">http://www.flounder.com/optimization.htm</a></li> </ul>

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