Re: C++ compile and execution times

[Michael Matz <matz at suse dot de>]

Hi,

On 21 Nov 2002, Gabriel Dos Reis wrote:

> | Known problem.  Some sources have even higher additional costs.  This will
> | be fixed hopefully before 3.4.
>
> Is there any actual plan for that? I know there is a branch, but I
> didn't see any actual plan.

Unfortunately it's just in my head.  The current representation of the
conflict graph is highly suboptimal for splitting coalesced nodes.  Due to
that there are some hot fixes in it (to keep it correct), which basically
needs something like O(n^3) (worst case) per splitted node.  Those won't
be needed in the final version.  But even without that the underlying
representation is not very well fit for that kind of things, so I plan to
rewrite it into something using the usual conflict bitmaps, but helped by
some hash table for "difficult" edges (those which would need a reference
count).  Another problem is the scattering of information over different
data structures, which sometimes needs translation from one to the other
data set.  That also needs cleanup.

That having said some other people already asked for something like a web
page listing things we tried already, and things planned and such, for the
allocator.  I promised to write something over the next days ;-)


Ciao,
Michael.