Re: Speeding up ggc-simple on stage1

[Alexandre Oliva <oliva at lsd dot ic dot unicamp dot br>]

On Jan 14, 2000, Jeffrey A Law <law@cygnus.com> wrote:

>> Nevertheless, `ps' says it's used just 54 minutes of CPU.  So it looks
>> like the system is thrashing, which is not that surprising, given that
>> it's got just 16MB of memory :-( :-(

> Yea, you're thrashing.  The only aspect of this change that might help that
> is a smaller call chain within the garbage collector.

Which, by some of those amazing coincidences that happen just once in
a millenium, is exactly what the patch is trying to accomplish :-) :-)

> Another way to test it would be to use ggc-simple on a more beefy box
> (there's a configure option to tweak the garbage collection selection).

Duh!  I should have called it a night long before having written that
message.  And it was already 9 in the morning! :-)

I'll do it right now, on a sparc (in which I expect a lot of
improvement) and a x86 (in which it probably wouldn't make much of a
difference, especially with optimization).

>> Should it be an optimized or unoptimized cc1?  Can it be cc1 from
>> stage1, built with gcc 2.95.2?

> Your choice.  If it's an improvement I'd expect it to show up regardless of
> those issues.

I had expected gcc -O2 would perform tail recursion optimization in
all those places.  Shouldn't it?

-- 
Alexandre Oliva http://www.ic.unicamp.br/~oliva IC-Unicamp, Bra[sz]il
oliva@{lsd.ic.unicamp.br,guarana.{org,com}} aoliva@{acm,computer}.org
oliva@{gnu.org,kaffe.org,{egcs,sourceware}.cygnus.com,samba.org}
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