[rescue] SS10/20 death

[Dave McGuire]

On February 5, Francisco Javier Mesa-Martinez wrote:
> > Have you ever enocuntered anyone using the windows for anything
> > other than function calls?
> > 
> > SPARC's register windows always seemed like one of the weird &
> > abandoned experiments in the crazy early days of the "RISC hype" before
> > a few years of actually producing machines made it obvious that the
> > wins of "RISC" amounted to: load/store arch & fixed length instructions.
> > (Which is why I still think Cray's machines qualify, all the way back
> > to the CDC-6600.)
> 
> Theoretically the Register windows are transparent to the programmer, and
> the assembler... so the machine will use them whether you want them or
> not. And I do not understand why Register windows will add complexity to
> context switches, if anything they aleviate the cost of context switches.
> I simply think of the register windows as just extra registers...

  What?  Do the instructions that move the current window pointer around
just "happen by magic" in your code? ;) If you don't want to use the
register windows, you don't have to.  Just don't move the current
window pointer from the base of the register bank and you'll only see
one "copy" of %g0-%g7, %o0-%o7, %l0-%l7, and %i0-%i7.  The SAVE and
RESTORE instructions bump that window pointer up and down.

     -Dave

-- 
Dave McGuire
St. Petersburg, FL         "Less talk.  More synthohol." --Lt. Worf