Re: Sun compares their compiler tools to GNU tools

[Doug Brown <dbrown at clark dot net>]

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
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