Re: GCC 3.3, GCC 3.4

[Michael Matz <matz at suse dot de>]

Hi,

On Thu, 30 Jan 2003, Michael S.Zick wrote:

> > where the real problems lie), the new GC default is going to reduce or
> > eliminate the impact of that improvement, an impact that would have been
> > noticeable had the GC defaults not been changed, and the improvement
> > is less likely to happen.
> >
> So, lets make part of the testing protocal: "disable GC"

What can be disabled easily is collecting and reclaiming GC memory.  What
can _not_ be done easily is to go back to a memory management like in
2.95.x or earlier.  But that would be needed to really calculate the cost
of GC, because collecting is only a part of the overhead.  The other part
comes from different layout of memory, and the resulting slowness is
distributed all over the compiler (so is not even measurable in one single
function suddenly taking much more time).  To this end we can't simply
"disable" GC.  One would need to rewrite the allocators too, but then have
the problem that noone is freeing memory explicitely anymore, which would
again be different to 2.95.x.


Ciao,
Michael.