[OpenBIOS] $find

[Stefan Reinauer]

* Segher Boessenkool <segher at chello.nl> [020627 01:48]:
> > for the first one we need to be able to get to a word's header when we
> > have the execution token (xt). This seems impossible at the moment as
> > we have a variable header length
> 
> Two easy solutions spring to mind:
> 
> 1) have the flag byte be the lasy byte in the header (it's the first
>    bybte right now);
> 2) have the flag byte have the high bit set always (so you can find it
>    easily).
> 
> I think I'll go with 1).
> 
> BTW, nothing requires SEE to accurately show the flags of a word ;)
 
SEE still needs the word's name, which is ugly to get when you have
the XT only. Even though we don't really need a fast SEE. With the word
I posted we have O(N) instead of O(1), but this is acceptable taking
into regard that SEE is only for debugging anyways and we have the
sources without SEE ;)

> There's no need for COMPILE-ONLY wrt FCode; the FCode loader can assume
> all FCode is legal FCode, the burden of checking is on the tokenizer.

b(;) is a COMPILE-ONLY/IMMEDIATE word. The evaluator gets B(;)'s FCode#
and fetches it's XT. But it of course needs to find out that this word
must not be compiled but executed, when in compile mode.
  
Stefan

-- 
The x86 isn't all that complex - it just doesn't make a lot of
sense.          -- Mike Johnson, Leader of 80x86 Design at AMD
	                          Microprocessor Report (1994)
-
To unsubscribe: send mail to majordomo at freiburg.linux.de
with 'unsubscribe openbios' in the body of the message
http://www.freiburg.linux.de/OpenBIOS/ - free your system..