[WIP/RFC] MIPS registers overhaul

[Kevin Buettner]

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