Re: GCC Status Report (2004-09-13)

[Jan Hubicka <hubicka@ucw.cz>]

> Jeffrey A Law wrote:
> 
> >On Mon, 2004-09-13 at 17:05, Mark Mitchell wrote:
> >
> >September 19
> >
> >
> >* General compile-time performance improvements [Weinberg]
> >
> >Q. Presumably we can still also attack memory consumption
> >  issues as well.    Right?
> >
> >The reason I ask is I have the first in what I expect will
> >be a series of patches to start reducing memory consumption
> >and bring more sense to our data structures.
> > 
> >
> Yes.  We have a pretty good sense that reducing memory usage correlates 
> with reducing compile time, and, of course, people do not infinite RAM 
> anyhow, so this is a resource we should use prudently.  The biggest 
> caveat is the one you have been raising recently: that touching pages 
> merely for the purpose of marking memory as free is by no means always a 
> win.  But, if you can make data structures smaller in the first place, 
> and just allocate less along the way, that's going to help.
> 
> So, yes, this is OK -- but please do use your judgement about the 
> prudence of attempting major overhauls.  The smaller the change (whether 
> in terms of lines of code or in terms of conceptual complexity) the 
> better, naturally.

Thanks.
Just for a record - we consume roughly 4 times as much memory as 3.4 did
for common C sources.  Even tought we are down from 7 times we did week
ago, this is still major regression.

Honza