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"Dependent on" ???"Dependent on" ???Posted Feb 28, 2007 17:50 UTC (Wed) by nix (subscriber, #2304)In reply to: "Dependent on" ??? by k8to Parent article: Mitchell Baker and the Firefox Paradox (Inc)
With no -O flags at all I'd expect *huge* register pressure problems at all times! With -O2, well, even there the pressure is building up (although the problem is much less severe than with -O3).
I'm surprised to find problems on amd64. Raise a bug, maybe?
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"Dependent on" ??? Posted Feb 28, 2007 17:57 UTC (Wed) by k8to (subscriber, #15413) [Link] I suspect they know. It's getting better across 4.x as a whole. Also I'm really not excited about filing a bug "these 5 big applications that I don't really understand all do much better on gcc 3.x on i386 and amd64. Here's your several hundred thousand line testcase."
If I was the developer of them maybe, or if they were were more managably sized, or if I hadn't read through other bug entries where it's discussed that there are (supposedly) no automated performance regression tests at all.
I'm certainly not really intending my observations as complaints, it's just a matter of fact observation. I wish it wasn't so but it is, and I suspect half-assed bugs will only cost the project.
"Dependent on" ??? Posted Feb 28, 2007 22:13 UTC (Wed) by massimiliano (subscriber, #3048) [Link] Want to do a big favor to the gcc developers? Profile those applications, and find the hot spots that get significantly worse. Then, write small benchmarks with the same code, and test them to see that the slowdown is still there. Finally, open the bug with the small benchmarks :-) And if you do it, remember to send the samples to me as well (massi(at)ximan"dot"com)! I work on the Mono JIT, and am generally interested in performance tests...
"Dependent on" ??? Posted Feb 28, 2007 23:20 UTC (Wed) by nix (subscriber, #2304) [Link] Hell, if they're free software at least say what they are so someone elsewith more machine time than sense and heaps of old compiler versions scattered around can do the profiling :)
"Dependent on" ??? Posted Mar 1, 2007 12:09 UTC (Thu) by k8to (subscriber, #15413) [Link] Off the top, the n-queens "benchmark" shows a significant drop from 3.x to 4.x. http://www.arch.cs.titech.ac.jp/~kise/nq/index.htm
A larger one I care more about is UAE, the amiga emulator, without JIT. Both mainline and E-UAE from rcdrummond.net
"Dependent on" ??? Posted Mar 9, 2007 19:49 UTC (Fri) by anton (guest, #25547) [Link] Want to do a big favor to the gcc developers?And see it closed as invalid after an hour (less time than it took to do create the bug report). Given this reaction, I don't think the gcc developers consider such bug reports as favors, and it certainly has not inspired me to report other gcc bugs.
"Dependent on" ??? Posted Mar 9, 2007 20:52 UTC (Fri) by massimiliano (subscriber, #3048) [Link] And see it closed as invalid after an hour (less time than it took to do create the bug report). Interesting discussion in that bug :-)
Anyway, I wrote my suggestion without knowing how gcc development
actually works... I would welcome bugs like that opened for
the Mono JIT!
"Dependent on" ??? Posted Mar 10, 2007 1:42 UTC (Sat) by nix (subscriber, #2304) [Link] It seems that fixing this would be ridiculously difficult and not terriblybeneficial (how many programs have you seen that use computed goto? How much effort is it worth going to to speed it up?)
I'd have kept it open, too, but there is so much low-hanging optimization
GCC development actually works in much the same way everything else works
"Dependent on" ??? Posted Apr 7, 2007 20:29 UTC (Sat) by anton (guest, #25547) [Link] >how many programs have you seen that use computed goto? How>much effort is it worth going to to speed it up?
Many interpreters are using labels-as-values for a significant
>one-platform optimization bugs
As far as I understand the reply to the bug report, this bug affects
>A noninvasive patch would probably have made it...
They consider the bug "invalid", so they probably would not have
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