[rescue] OT: FeeCee rescue

[Joshua D. Boyd]

On Tue, Sep 30, 2003 at 10:53:33PM +0100, Mike Meredith wrote:
> On Tue, 30 Sep 2003 16:23:32 -0500, Joshua D. Boyd wrote:
> > W.r.t. register shortage.
> > 
> > I'm told that MIPSpro mainly only uses 4 out of the 32 registers a
> > MIPS chip has, except for special cases (which would be tight loops
> > that don't make function calls mainly).  
> 
> I don't know enough MIPS assembler to be able to tell for sure, but 'dis
> /usr/bin/ls' on an IRIX system seems to show more than 4 registers being
> used. Mind you limiting the number of registers you use allows you to
> call functions (which use a different set of registers) without worrying
> about your registers being scribbled on. And MIPSpro is quite probably
> capable of doing that kind of optimisation.

I'll have to look through it.  I was just operating on what I was told
by a former SGI engineer.

> > I'm beginning to wonder if lots of general purpose
> > registers is quite what its cracked up to be.
> 
> Registers are very fast memory ... the more very fast memory you have,
> the better. Aren't register windows used for fast context switching on
> SPARCs ?

Until you run out of windows.  They make it work quickly for them, but