Norman Vine wrote: > However some code fragments run 100's or even 1000's of times per > iteration and these fragments should be studied on an individual basis > and not just automatically un-inlined because it is in 'vogue' :-)
It's even more complicated than that. If you call a function thousands of times in succession, then it almost always pays to inline it. If you call it the same number of times, but interspersed evenly with the rest of the code, inlining is only going to thrash the cache and hurt performance. I have nothing against re-inlining stuff once it's profiled and shown to have a performance benefit, but inlining by default because it "looks" faster is self-defeating. FWIW, my interest in un-inlining stuff has nothing to do with runtime performance at all. What I want to see is for FlightGear to compile in something under 20 minutes on my machine. Some parts are really just terribly slow to build. JSBSim and UIUC are big culprits here, but the WeatherCM stuff and the Main directory aren't far behind. I mean, think about it: this compilation, if run on a VAX 11/780, would take 13 days! FlightGear is a big program, granted. But is it big enough to justify two weeks of machine time to compile? Sure, programmers are writing bigger software these days, but not *that* much bigger. FlightGear strikes me as about the same level of complexity as the whole of 4BSD Unix. Naively, I'd want it to build in about the same time. I'm certain 4BSD didn't take two weeks to build. :) [I'm assuming that a VAX performs about the same as a 1 MHz Athlon here, which is roughtly in the ballpark.] Andy -- Andrew J. Ross NextBus Information Systems Senior Software Engineer Emeryville, CA [EMAIL PROTECTED] http://www.nextbus.com "Men go crazy in conflagrations. They only get better one by one." - Sting (misquoted) _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
