Re: [new-ra] "#if DENIS"

[Michael Matz <matz at suse dot de>]

Hi,

On 15 Jul 2003, Denis Chertykov wrote:

> Yes. This can introduces a few passes of allocation, but I havn't seen
> more than two, and code quality will be higher than after reload pass.
> Michael ! reload isn't so fast as you think.

I don't think it's fast ;-)  But I know that two additional but needless
allocator rounds also aren't exactly fast.  Needless in the sense that
even without them reload wouldn't be needed (on my architecture).

> > I made the appropriate changes to recog.c.  While the new ra is running
> > spill pseudos are recognized as memory expressions (as offseted from the
> > frame or stack pointer, but with the real offset unknown).
>
> What happened if such pseudos will be colored ?

The same what happens when the normal pseudos are colored.  There is no
difference.

> To which color such pseudos will be colored ?

To one of those allowed by the constraints.

> How will allocator insert colored pseudo to insn (reload again can
> happened or special pass of allocation with pre-reload required) ?

I don't understand.  It's a simple normal reference to a pseudo register.
It just happens to be a place where also a mem would be generally accepted
(because that is what is checked by the changed validate_change),
therefore this particular reference can be changed into a hardreg, or a
stack reference without introducing reloads (modulo the problem that the
particular address might not be acceptable).


Ciao,
Michael.