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Re: C++ compile time (again)


On Friday 13 June 2003 10:31 am, Steven Bosscher wrote:

> --enable-checking makes a very significant difference, so you're not
> making fair comparisons here.  Do you have the numbers with checking
> disabled?

If I have time over the weekend, I'll regenerate them. The comparison was more 
of mainline against tree-ssa, and that comparison _was_ fair.

> >Now, what troubles me (and Gerald, who has been pointing this out for
> >ages now) is that it seems as if these numbers don't change
> >anything. Everytime Gerald brings this up, answers are "Oh, yes, good
> >you remind us that there is C++ out there, we seem to have forgotten".
>
> That is not fair to, say, the CodeSourcery people.

That's correct. Their efforts are greatly appreciated.

Nevertheless, one can find mails every so often where people are surprised 
that C++ performance is so slow.

> If C speeds up, it usually helps _all_ languages, so speedin gup C is a
> good thing :-)

Maybe, or maybe not. It would be nice if we actually measured. The usual 
benchmark is bootstrap time, but that is 90% C and the C++ part is not 
representative for some C++ applications.


> Yes but how?   Is anyone testing/publishing C++ compile time performance
> on a regular basis?  There are three SPEC testers and an autocrasher,
> but there's not enough C++ in there, as we've seen many times now...

Then we need to add C++. I'm testing every night, but that's not 
representative since the code basis is changing (I test with gcc CVS and 
deal.II CVS) and the machine is not usually completely empty either). But if 
I can do it, it should be just as simple to add it to one of the SPEC 
testers.

W.

-------------------------------------------------------------------------
Wolfgang Bangerth              email:            bangerth@ices.utexas.edu
                               www: http://www.ices.utexas.edu/~bangerth/


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