Re: hard register reload patch

[Bernd Schmidt <bernds at pathia dot cygnus dot co dot uk>]

On Wed, 1 Dec 1999, Joern Rennecke wrote:

> >   > registers.  Joerns patch is a step in that direction (combine_reloads goes
> >   > away).
> > How related is this to your reload cleanup patch.  It sounds like the same
> > thing, and I've already agreed that we're going in the right direction.
> > Continuing down this road seems like a reasonable thing to do.
> 
> But that aspecty can't be simply broken out - combine_reload reuses hard
> registers that die.  If you remove it without a replacement, register pressure
> will increase, resulting in worse code and more reload aborts when it runs
> out of spill registers.
> 
> By patch replaces the functionality of combine_reloads because registers that
> die become available as spill registers, and the times they are not usable
> are encoded in the hard reloads.

It's possible that in the end we'll want to apply the whole patch (regardless
of what happens to sh.md).  I just haven't looked at it closely enough to
determine which parts are doing what.

Regarding combine_reloads: didn't you say once that the first part of it is
useless even now?  If so, let's delete it.

Bernd