Re: RFC: Optimization to write_register_bytes()

[Andrew Cagney <ac131313 at cygnus dot com>]

Fernando Nasser wrote:
> 
> Andrew Cagney wrote:
> >
> > Fernando Nasser wrote:
> > >
> > > We can save some time (and fix a problem I have) if we make a simple assumption in
> > > write_register_bytes().
> >
> > Would the problem go away if the problematic code didn't use
> > write_register_bytes?
> >
> 
> It would.  But this is exactly the only case where it's use is justifiable.
> These are registers that are aliased to a portion of another register.

Personally, I struggle to see any case where the use of
write_register_bytes() interface is justifiable.  It is part of one of
those (in hindsight) bits of very bad design.

> (The Pentium MMX registers are aliased to the mantissa of the floating point
> registers)

Can I guess that the bug is that there is no consistency between FP and
mmx registers and you're attempting to fix it by mapping the register
raw-size/offset of the mmx registers directly onto the FP registers?

	Andrew