From mboxrd@z Thu Jan 1 00:00:00 1970 From: Doug Brown To: egcs@cygnus.com Cc: egcs@cygnus.com Subject: Re: Sun compares their compiler tools to GNU tools Date: Sat, 07 Nov 1998 09:09:00 -0000 Message-id: <36447DE7.3196D472@clark.net> References: <199811050703.XAA13088@Sunburn.Stanford.EDU> <19981106092642.26651.qmail@localhost.localdomain> X-SW-Source: 1998-11/msg00330.html And, of course, the Sun comparison completely ignores two chief advantages of gcc/egcs: portability to a wide range of platforms, and much greater ISO/IEC 14882 compliance. So if you're looking for a c++ compiler that only runs on Sun platforms, that doesn't support bool types, or namespaces, or a host of other ANSI standard features, and doesn't come bundled with STD/STL, but runs somewhat faster than a three-year old version of gcc in carefully selected tests using a statistically flawed testing procedure, then I guess Sun CC is the way to go! :-) Doug mal@bewoner.dma.be wrote: > Colin Douglas Howell writes: > > Sun has published a marketing comparison of their compiler suite, > > Visual WorkShop C++ 3.0, with the GNU compiler tools. See the URL: > > > > http://www.sun.com/workshop/visual/ > > > > The comparison includes performance test results on UltraSPARC. Of > > course, this is designed to sell Sun's compiler tools, and is thus > > rather biased. Also, their performance tests were done against old > > versions of gcc; they compare version 4.2 of their C, C++, and FORTRAN > > compilers with egcs 1.0.1 (and in one case with gcc 2.7.2.2). So the > > recent egcs optimizations and SPARC backend improvements are not > > tested. (On the other hand, Sun is currently beta-testing version 5.0 > > of their compilers.) > > > > I figured people might want to know what the competition is up to. Is > > anyone in a position to comment on the specific tests or do > > comparisons with the current egcs versions? > > > > Around here we have the SunSoft Visual Workshop and egcs. I'll add a > few comments on their text. > > In the introduction one of their points is "Specific code, such as C++ > exception handling, ran up to 10 times faster." If EH is on your > critical path, you have problems no compiler can solve. > > WRT the chapter on performance, 34% difference on specint is not all > that bad. Specfp that needs fortran is a known problem. g77 is still > not up to commercial standards wrt FORTRAN. On the other hand their > hint that the difference carries over to C because they share the same > backend is tenuous and doesn't show in their own data. > > Another distortion is their claim that they used the "enhanced version > of Cygnus' gcc, which is usually a version ahead of the freeware > version in terms of performance and functionality" while they were > using egcs which is a "freeware version". > > Their case study with Vividata gave numbers between 7 and 30% > difference on runs where the numbers represented the *best times* for > each compiler. This is methodologically unsound since you have to take > into account scheduling issues etc. They should take the means or > publish the whole data. Further for this case study they used gcc > 2.7.2.2 instead of egcs. > > Their most touted advantages are not compiler related. They hype their > Workshop integrated tools (of which an incredibly buggy version of > Xemacs 20.0 is the core ;-) ). There, the comparison is decidedly > unfair since they compare their debug session with tooltalk integrated > dbx and emacs to a command line gdb session. I personally find gud in > Xemacs more usable than the Sun stuff. And for some really complex > debugging sessions ddd is even better. > > Other tools include an enhanced performance profiler tcov and > automatic profile feedback-based optimisations. This is an area in > which egcs is lacking. > > They also have a class browser. Since OOBR is no longer distributed > with XEmacs there is also a lacune there. Although of our 8 developers > here nobody uses the thing. YMMV > > Their Runtime Checking can be done with a special malloc library and > things like efence are more advanced. It's something of a poor man's > Purify. > > Their appendix B claims to publish the full SPEC test results but > their is some error in it since they don't seem to publish the gcc > results. I also couldn't find which flags they were using since they > only publish the flags used for Sun cc. > > It would also be interesting to test the difference something like GNU > rope would make. > > Arguing about preferences between tools ends pretty fast in a > religious war but I find their comparison very flawed. > > > Also, this comparison is currently being discussed at slashdot.org, > > just in case anyone wants to add a voice of reason into that > > discussion. > > > > Life is too short to take up the task of inserting reason in > /. discussions. > > > -- > > Colin Douglas Howell Systems Administrator > > e-mail: howell@cs.stanford.edu Computer Facilities Group > > office: (650) 723-2491 Computer Science Department > > Stanford University