To LUGNET HomepageTo LUGNET News HomepageTo LUGNET Guide Homepage
 Help on Searching
 
Post new message to lugnet.robotics.rcx.legosOpen lugnet.robotics.rcx.legos in your NNTP NewsreaderTo LUGNET News Traffic PageSign In (Members)
 Robotics / RCX / legOS / 3146
3145  |  3147
Subject: 
Re: command framing as seen from kernel/program.lrkey_handler
Newsgroups: 
lugnet.robotics.rcx.legos
Date: 
Sat, 1 Feb 2003 18:02:50 GMT
Viewed: 
7699 times
  
> > > ... brickos ...
> > Sorry to see the source less online than: http://lxr.linux.no/source/
> 
> Here's the link:
> http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/brickos/brickos/kernel/

Cool, thanks.  No grep, right?

> there's no fast way to execute
> log2() on the H8 (i.e. no O(1) solution)

Mmmmm.  I am curious, if that's ok.

To get log2(xx) in O(1) time we could fetch (p[xx & -xx]) i.e. fetch our choice
of the bytes at offset x 0 1 2 4 8 10 20 40 80 from some p we like.

Merely standard C can't easily express that old idea without misleading the
linker into wasting x81 - 9 bytes, which I gather would be considered expensive
on an H8?

Are Gnu-ism's banned from brickos, or can even Gnu C not express this idea?

> If I'm interpreting your shorthand correctly
> ...
> might be nicer if the remote handler got to decide
> whether it wanted to handle the message keys

Yes yes, thanks for understanding.

Cheers, Pat LaVarre



Message has 1 Reply:
  Re: command framing as seen from kernel/program.lrkey_handler
 
"Pat LaVarre" <ppaatt@aol.com> wrote in message news:H9n64q.B2p@lugnet.com... (...) I dunno, haven't found one yet, though. (...) choice (...) Touché. Yes, tables, overlooked that. (...) the (...) expensive (...) I think that smaller code size is (...) (24 years ago, 1-Feb-03, to lugnet.robotics.rcx.legos)

Message is in Reply To:
  Re: command framing as seen from kernel/program.lrkey_handler
 
(...) (URL) The missing (key & -key) might interest people who haven't used log2 & - to (...) number (...) and (...) log2(key (...) If I'm interpreting your shorthand correctly: there's no fast way to execute log2() on the H8 (i.e. no O(1) (...) (24 years ago, 1-Feb-03, to lugnet.robotics.rcx.legos)

5 Messages in This Thread:

Entire Thread on One Page:
Nested:  All | Brief | Compact | Dots
Linear:  All | Brief | Compact

This Message and its Replies on One Page:
Nested:  All | Brief | Compact | Dots
Linear:  All | Brief | Compact
    

©2005 LUGNET. All rights reserved. - hosted by steinbruch.info GbR