Re: [WIP/RFC] MIPS registers overhaul

Kevin Buettner
2003-05-21T18:32:43Z

On May 21, 12:58pm, Daniel Jacobowitz wrote:

> > From GDB's view point, the ISA is 64 bit.
> >
> > The fact that a specific remote debug agent choses to use 32 bit
> > registers is a limitation of that debug agent / kernel. An embedded
> > target, and I'm pretty sure IRIX 6.5, for instance, don't do that.
>
> No, from GDB's view point in this situation, the target ISA is _NOT_ 64
> bit. Nothing 64-bit is available, either to the inferior or to the
> debugger. Period.
>
> I would be a little surprised if IRIX didn't work that way too, but I
> don't have access to IRIX to poke around.

I too would be surprised. I should think that SGI would want to
ensure that legacy programs (i.e, those using the o32 ABI) behave the
same when run on 64-bit hardware as they do when run on 32-bit
hardware. One of the implications of this is that illegal
instructions in the 32-bit ISA should continue to be illegal when run
on the 64-bit hardware.

Kevin