This is the mail archive of the mailing list for the GCC project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: GCC 4.1: Buildable on GHz machines only?

David Edelsohn wrote:
>>>>>>Matt Thomas writes:
> Matt> Regardless, GCC4.1 is a computational pig.
> 	If you are referring to the compiler itself, this has no basis in
> reality.  If you are referring to the entire compiler collection,
> including runtimes, you are not using a fair comparison or are making
> extreme statements without considering the cause.

When I see the native stage2 m68k compiler spend 30+ minutes compute bound
with no paging activity compiling a single source file, I believe
that is an accurate term.  Compiling stage3 on a 50MHz 68060 took 18 hours.
(That 30 minutes was for fold-const.c if you care to know).

At some points, I had no idea whether GCC had just gone into an infinite
loop due a bug or was actually doing what it was supposed to.

> 	GCC now supports C++, Fortran 90 and Java.  Those languages have
> extensive, complicated runtimes.  The GCC Java environment is becoming
> much more complete and standards compliant, which means adding more and
> more features.

That's all positive but if GCC also becomes too expensive to build then
all those extra features become worthless.  What is the slowest system
that GCC has been recently bootstrapped on?

> 	If your point is that fully supporting modern, richly featured
> languages results in a longer build process, that is correct.  Using
> disparaging terms like "pig" is missing the point.  As others have pointed
> out, if you do not want to build some languages and runtimes, you can
> disable them.  GCC is providing features that users want and that has a
> cost.

Yes they have a cost, but the cost is mitigated by running fast processors.
They are just so fast they can hide ineffiences and bloat.  We have seen
that for NetBSD and it's just as true for GCC or any other software.
These slower processor perform usefull feedback but only if a GCC bootstrap
is attempted on them on a semi-regular basis.

Am I the only person who has attempted to do a native bootstrap on a system
as slow as a M68k?  I thought about doing a bootstrap on a MicroSparc based
system but instead I decided to use a UltraSparcIIi system running with a
32bit kernel.
Matt Thomas                     email:
3am Software Foundry              www:
Cupertino, CA              disclaimer: I avow all knowledge of this message.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]