Re: re-ordered i386 regcache

Daniel Jacobowitz
2003-04-29T15:25:35Z

On Tue, Apr 29, 2003 at 11:20:39AM -0400, Andrew Cagney wrote:
> >All three require a projection such that, assumed contigious, debug info
> >>registers project onto raw registers. Isn't this what i386 has?
> >
> >
> >I don't think so. All three need a view of registers slightly
> >different from the "normal" one, but they don't have "assumed
> >contiguous debug info registers". In fact in e500 they're assumed
> >not-contiguous.
>
> Please study the code. A 32 bit MIPS ABI on a 64 bit MIPS represents
> long long as two 32 bit sub-parts of two 64 bit registers; the two 32
> bit parts are assumed to be adjacent.
>
> The adjacent assumption will eventually be lifted, but that will be done
> by someone implementing something like location descriptions.

I posit that this is the exact same problem as the i386 is currently
facing.

Remember, location descriptions come from the debug reader, not from
the target. Where do you think these hypothetical descriptors to tell
us which two registers the long long value occupies will come from?
Current debug info won't give them to us.

--
Daniel Jacobowitz
MontaVista Software Debian GNU/Linux Developer