Re: RFA: New builtin SIMD types

[Andrew Cagney <ac131313 at cygnus dot com>]

Jim Blandy wrote:
> 
> > BTW,
> >
> > I sometimes wonder if there should be a REGISTER_VIRTUAL_NAME() so that
> > the 1:1 between physical and virtual register names is broken.
> 
> Not sure what you mean.  Does REGISTER_NAME_ALIAS_HOOK do this?

Que? It isn't in the documenation ;-)

From memory, without looking at the code, no.  This just maps a register
name onto one of the existing registers.

Long ago GDB started out with the assumption that there were only raw
register values.  From there it evolved into an assumption that there
was a 1:1 mapping between virtual (user) and raw (target buffer)
registers. You end up going through hoops trying to convince gdb that a
raw register is made up of several virtual registers and vice versa.

I'm really wondering if there should be a clear separation between
virtual registers and the raw register buffer. The user sees virtual
registers, the arch code knows how to map between virtual registers and
the raw register buffer. The target knows how to stuff bytes into the
raw register buffer.

	enjoy,
		Andrew