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Re: GCC 4.1: Buildable on GHz machines only?


 I think Zack summarises very well here, the general consensus is that gcc is slow,
 now if gcc was faster, it would perhaps not be so bad to build java ?

 If we do a reasonable comparison of compile times against the intel compiler or
 the portland group or something similar we consistenly find that gcc is slower
 by a couple of times 1x - 3x, ( this is only my impression, not backed up by
 hard data but should be in the ballpark ).

 The real killer seems to be large memory usage, and I have a hard time believing that
 if you compile fx. 1 meg of source the compiler 'have' to use some 800 megs or 
 something as working memory. ( When speaking of the real killer here I mean for
 old systems ). With all the discussions on cache hit rate and similar criterions
 lately we can't forget that less data higher means hit rate.

 So I am of the opinion that we have to be aware of the problem, and the gcc list has
 a reputation for really ticking of people complaining on the slowness, look at the
 archives, this is something that comes up every two months and the it gets even
 slower. The regular arguments are:

 1. No it's not , ( slow that is ).
 2. It's your hardware/program
 3. All modern computers have a gig or RAM and then it's fast.
 4. I have a fast computer and am not interested.
 5. gcc does so much and and is so good that it's not strange that it takes time.
 6 .

  and so on ... please correlate to the whining on the mailing list archives.

 Anyhow, gcc need's to get faster, and it needs to use less memory, perhaps it
 shouldn't be a goal in itself, but it must be desirable, and 'on' the radar.

  The above are my opinions, feel free to disagree,

 / regards, Lars Segerlund.

On Wed, 27 Apr 2005 16:40:29 -0700
Zack Weinberg <zack@codesourcery.com> wrote:

> Daniel Berlin <dberlin@dberlin.org> writes:
> 
> > On Wed, 2005-04-27 at 15:13 -0700, Stan Shebs wrote:
> >> Steven Bosscher wrote:
> >> >If someone had cared about them, it would have been noticed
> >> >earlier.  But since _nobody_ has complained before you, I guess we
> >> >can conclude that by far the majority if GCC users are quite happy
> >> >with the cost assesments that were made.
> >> >
> >> No, there have been plenty of complaints, but the GCC mailing lists
> >> have, shall we say, a "reputation", and a great many users will not
> >> post to them,
> >
> > I've never in my life heard this from another mailing list, and i
> > contribute to a *great* many open source projects.
> 
> I have seen such complaints.  Not about bootstrap times, no, that only
> affects people who compile the compiler; but the more general case of
> 'gcc takes forever to compile this program' does appear on a regular
> basis.
> 
> I do also think that the amount of ridicule heaped on people who come
> to the gcc lists is, in general, too high.  People should not be
> ridiculed for complaining that the compiler is slow, even if they are
> insisting on using vintage hardware.  It is slow, even on fast
> hardware; it's just easier to see that on slow hardware.  Rather more
> importantly, people should not be ridiculed for submitting bug
> reports, even if they are wrong.  I suspect the bad public image that
> Stan refers to, has more to do with this than anything else.  To be
> fair, it can be hard to explain that someone is wrong without
> belittling them; but it is important to make the effort, particularly
> when the reason they are wrong is esoteric (e.g. any of the legion of
> counterintuitive things in the C standard).
> 
> Some people are worthy of ridicule; those who are trolling, or those
> who are persistently and wilfully clueless.  However, ridicule is
> *not* an effective way of making these people shut up and go away,
> which is the appropriate goal when dealing with them.  It can be fun
> to argue with them, but long argument threads are a drag on the
> mailing list, so we should not make a habit of it.  This is not
> alt.flame.
> 
> > The only person i see ridiculing people frequently happens to be
> > from @apple.com.
> 
> I can think of four people who regularly ridicule posters.  Only two
> of them are Apple employees.
> 
> zw


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