Re: Why Plan 9 C compilers don't have asm("")

[Rick Hohensee <humbubba@smarty.smart.net>]

>Cort Dougan writes:
> > I'm talking about _modern_ processors, not processors that dominate
>the
> > modern age.  This isn't x86.
>
>Linus mentioned Alpha specifically.  I don't see how any of the things
>he said were x86-centric in any way shape or form.
>
>All of his examples are entirely accurate on sparc64 for example, and
>to even moreso his Alpha commentary can nearly directly be applied to
>the MIPS.
>
>Calls suck ass, even on modern cpus.  I've seen several hundreds of
>

Modern? How many stacks?
There's a couple of Forth engines out there that pay the usual for a call
and get returns in zero time. Forth code, and Forth engine machine
instructions, have about twice as many calls as Linux code,
proportionately. Therefor, a return on some designs is one bit in every
instruction. Every instruction is "...and maybe do a return in parallel."
Forth engines don't have caches. They have on-chip stacks, or the Novix
has separate busses to the stacks. Both stacks, return and data. 

Forth chips aren't modern in the true-multi-user sense, but if an
individual were to design such a beast they could get several of them,
hundreds maybe, on FPGAs available now. Such things are coming, because a 
Forth chip IS something an individual can design.

Rick Hohensee
		www.clienux.com