<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On Aug 3, 2014, at 6:29 PM, Richard Cleis wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; font-family: 'Lucida Grande'; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; ">If I (define i->c integer->char), and use it in your test1, it becomes the slowest.<div>That might mean that the "unknown function" response from Dr F applies to your function, too.<br><div>In other words, I think this is another example of drawing ambiguous conclusions from tests that are too simple.</div><div>I gave up on benchmarks long ago, because there are too many people outsmarting too many other people. </div><div><br></div><div>Interesting, though (uh oh, I am getting sucked in): </div><div>In v5.3.1 all of your tests are the same speed.</div><div>I even added some tests that use 'currying' to perhaps prevent the conversion function from being "inspected" on every call, and those are the same speed, too.</div><div><br></div><div>So it seems that the outsmarting peeps who wrote v6.1 optimized your first test, somehow, to make it twice as fast when it uses a "known function".</div></div></span></blockquote><br></div><div><br></div><div>One major change in 6.1 is that local define no longer sets a function to "undefined" but instead uses a run-time check to catch bad uses. </div><div><br></div><div>Dybvig reported a long time ago that this could enable more flow-style optimizations because the compiler no longer needs to split values (check for undefined). </div><div><br></div><div>Enough about micro benchmarks, which really reveal little -- Matthias</div><div><br></div><br></body></html>