From: W B Hacker <wbh@conducive.org>
To: Fans of the OS Plan 9 from Bell Labs <9fans@cse.psu.edu>
Subject: Re: [9fans] speaking of kenc
Date: Sun, 6 May 2007 12:53:17 +0800 [thread overview]
Message-ID: <463D5F3D.5090405@conducive.org> (raw)
In-Reply-To: <d26945f76efbf070d2cc0131bc2fe7dd@coraid.com>
erik quanstrom wrote:
>> 1 and 3 are not really that different, so you're down to two examples.
>> C is OK for newer embedded systems (microcontrollers), older ones are
>> what they are and ASM may well be the way to go. But even there, ASM
>> is often just the lazy way rather than the more economical way.
>
> perhaps you haven't programmed many microcontrollers. usually the
> volumes are high and the per unit cost is very important so you end up
> with very simple parts with very little ram/flash. the one i worked on
> earlier this year had low speed usb interface, 2 gp registers, 256 bytes of ram
> and 4k of flash.
>
> i found it easy enough to program in assembly, but i don't think you'd
> get very far with c. i just don't think you could fit things into memory.
Well 'C compiler hosted on a larger machine, and with that one as a binary
target' will no doubt come back from someone. And that isn't wrong.
But unless it has to be done over and over in may ways, such a setup can take
longer to set up, test, and option for a given run than to JFDI the app in
machine code.
Less than 5K bytes total fits on a page or two of A4 in hex, or one modern LCD
display.
How 'lost' can you get in a teacup?
And how many op codes will you actually need to use from what must be a rather
small set anyway?
Bill
>
>> I have a feeling brucee will point out that the gain in efficiency in
>> using ASM is insufficient to justify the additional costs in
>> complexity and error potential.
>
> i don't understand the assumption that the only reason to use assembly is
> cycle efficiency.
Actually it often has *less* of that efficiency than a highly optimizing 'C' (or
'D') compiler. Especially if the coder is not well and truly au fait with a
specific CISC machine's op codes, architecture, cycle 'cost'.
>
> also, could you explain why this is "lazy"? or why assembly is more
> complicated?
>
"Tedious" might be more accurate than "complicated".
;-)
> clearly, an assembly is more difficult to wield than c. but you don't
> use them for the same thing.
>
Some of us try hard not to use either of them at all....
> this absolutist argument that c is teh bomb. asm suks is silly. it's like
> arguing bicycles and ferraris. which one you need (and which one gets
> you there faster) depends on what you're doing.
>
> - erik
>
ACK. Hong Kongs 100+ year-old tram system beats the modern underground on cost,
the undergrond beats a taxi on speed at rush hour, but not otherwise, buses have
a wider route choice than either, and the taxi *always* rules on assuredly
getting a place to sit down. IF you can get the taxi in the first place - which
is NOT assured.
'puters are not so different.
Glad to have choices, and we can never stop making them without giving up
*something* of value.
Bill
next prev parent reply other threads:[~2007-05-06 4:53 UTC|newest]
Thread overview: 149+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-04-27 3:08 erik quanstrom
2007-04-27 3:44 ` David Leimbach
2007-04-27 4:56 ` Bruce Ellis
2007-04-27 6:21 ` Skip Tavakkolian
2007-04-27 4:54 ` Joel C. Salomon
2007-04-27 4:58 ` Bruce Ellis
2007-04-27 11:00 ` Charles Forsyth
2007-04-27 13:49 ` David Leimbach
2007-04-27 16:23 ` Douglas A. Gwyn
2007-04-29 2:02 ` erik quanstrom
2007-04-29 2:55 ` Tim Wiess
2007-04-29 6:42 ` Uriel
2007-04-29 20:47 ` Charles Forsyth
2007-04-30 8:29 ` Douglas A. Gwyn
2007-04-30 13:08 ` Uriel
2007-05-01 0:22 ` erik quanstrom
2007-05-01 14:45 ` Jon Snader
2007-05-01 14:56 ` Devon H. O'Dell
2007-05-01 15:12 ` erik quanstrom
2007-05-01 15:29 ` Devon H. O'Dell
2007-05-01 21:32 ` Jon Snader
2007-05-02 0:04 ` Derek Fawcus
2007-05-02 8:44 ` Charles Forsyth
2007-05-01 15:51 ` Anthony Sorace
2007-05-02 8:32 ` Douglas A. Gwyn
2007-05-02 9:00 ` Steve Simon
2007-05-03 1:32 ` David Arnold
2007-05-03 3:39 ` Adrian Tritschler
2007-05-03 3:57 ` Paul Lalonde
2007-05-03 4:11 ` Federico Benavento
2007-05-03 13:34 ` Anthony Sorace
2007-05-03 22:04 ` LiteStar numnums
2007-05-04 1:45 ` Roman Shaposhnick
2007-05-04 1:51 ` Lyndon Nerenberg
2007-05-04 2:00 ` erik quanstrom
2007-05-04 2:08 ` Roman Shaposhnick
2007-05-04 2:12 ` Lyndon Nerenberg
2007-05-04 2:20 ` Roman Shaposhnick
2007-05-04 2:35 ` Lyndon Nerenberg
2007-05-04 6:53 ` Bruce Ellis
2007-05-05 4:49 ` Roman Shaposhnick
2007-05-05 5:11 ` Roman Shaposhnick
2007-05-05 5:14 ` Bruce Ellis
2007-05-05 18:52 ` erik quanstrom
2007-05-05 19:13 ` lucio
2007-05-05 23:09 ` Bruce Ellis
2007-05-06 1:24 ` Rogelio Serrano
2007-05-06 4:08 ` erik quanstrom
2007-05-06 4:53 ` W B Hacker [this message]
2007-05-06 5:01 ` lucio
2007-05-06 5:01 ` Rogelio Serrano
2007-05-06 5:07 ` Rogelio Serrano
2007-05-06 5:15 ` lucio
2007-05-06 5:37 ` Bruce Ellis
2007-05-06 6:30 ` Rogelio Serrano
2007-05-06 6:46 ` lucio
2007-05-06 6:49 ` lucio
2007-05-06 7:35 ` Rogelio Serrano
2007-05-06 6:51 ` W B Hacker
2007-05-06 10:25 ` Rogelio Serrano
2007-05-06 6:04 ` Skip Tavakkolian
2007-05-06 7:24 ` lucio
2007-05-06 11:47 ` Bruce Ellis
2007-05-07 1:55 ` Roman Shaposhnik
2007-05-06 5:12 ` lucio
2007-05-06 13:18 ` Richard Miller
2007-05-06 20:23 ` Roman Shaposhnik
2007-05-07 1:57 ` Roman Shaposhnik
2007-05-07 4:29 ` W B Hacker
2007-05-07 15:08 ` Tim Wiess
2007-05-06 5:15 ` W B Hacker
2007-05-06 7:43 ` Rogelio Serrano
2007-05-06 8:02 ` W B Hacker
2007-05-06 8:12 ` Rogelio Serrano
2007-05-06 9:00 ` W B Hacker
2007-05-06 8:03 ` lucio
2007-05-06 8:42 ` Rogelio Serrano
2007-05-06 10:20 ` matt
2007-05-06 10:29 ` Rogelio Serrano
2007-05-06 9:09 ` W B Hacker
2007-05-06 5:10 ` W B Hacker
2007-05-06 5:32 ` lucio
2007-05-06 6:18 ` Rogelio Serrano
2007-05-06 6:30 ` W B Hacker
2007-05-06 6:21 ` W B Hacker
2007-05-07 1:47 ` Roman Shaposhnik
2007-05-06 1:13 ` Rogelio Serrano
2007-05-06 3:31 ` W B Hacker
2007-05-06 4:10 ` erik quanstrom
2007-05-06 4:55 ` Rogelio Serrano
2007-05-06 5:10 ` lucio
2007-05-06 6:05 ` W B Hacker
2007-05-06 8:45 ` matt
2007-05-06 6:45 ` Rogelio Serrano
2007-05-06 6:52 ` lucio
2007-05-06 7:09 ` W B Hacker
2007-05-06 7:34 ` Rogelio Serrano
2007-05-06 7:49 ` W B Hacker
2007-05-06 7:54 ` lucio
2007-05-06 8:35 ` Rogelio Serrano
2007-05-06 7:40 ` lucio
2007-05-06 8:59 ` W B Hacker
2007-05-06 7:03 ` W B Hacker
2007-05-06 5:21 ` Bruce Ellis
2007-05-06 7:01 ` Rogelio Serrano
2007-05-05 5:30 ` lucio
2007-05-04 2:16 ` erik quanstrom
2007-05-04 9:24 ` C H Forsyth
2007-05-04 11:18 ` erik quanstrom
2007-05-04 16:19 ` Paul Lalonde
2007-05-04 21:58 ` Dave Eckhardt
2007-05-04 22:27 ` Paul Lalonde
2007-05-04 8:46 ` Douglas A. Gwyn
2007-05-05 4:47 ` Roman Shaposhnick
2007-05-02 8:33 ` Douglas A. Gwyn
2007-05-02 11:25 ` Jon Snader
2007-05-02 8:33 ` Douglas A. Gwyn
2007-05-02 11:30 ` erik quanstrom
2007-04-27 16:21 ` Douglas A. Gwyn
2007-04-27 11:12 ` Charles Forsyth
2007-04-27 11:46 ` erik quanstrom
2007-04-27 14:21 ` Joel C. Salomon
2007-04-27 14:26 ` erik quanstrom
2007-04-27 14:41 ` Rob Pike
2007-04-27 14:55 ` Joel C. Salomon
2007-04-27 15:24 ` erik quanstrom
2007-04-27 15:53 ` C H Forsyth
2007-04-28 9:09 ` ron minnich
2007-04-28 9:17 ` Lucio De Re
2007-04-28 13:48 ` Eric Van Hensbergen
2007-04-28 13:57 ` Lucio De Re
2007-04-28 14:15 ` LiteStar numnums
2007-04-28 21:21 ` Roman Shaposhnik
2007-04-28 21:54 ` ron minnich
2007-04-28 22:33 ` Steve Simon
2007-04-28 15:45 ` Charles Forsyth
2007-04-28 17:58 ` Rodrigo Miranda
2007-04-28 20:12 ` Eric Van Hensbergen
2007-04-28 21:10 ` Roman Shaposhnik
2007-04-28 18:15 ` Lluís Batlle i Rossell
2007-04-29 2:39 ` Joel C. Salomon
2007-04-29 12:41 ` erik quanstrom
2007-04-29 16:00 ` Joel C. Salomon
2007-04-28 21:24 ` Roman Shaposhnik
2007-05-06 12:36 erik quanstrom
2007-05-06 15:18 ` lucio
2007-05-06 16:23 ` W B Hacker
2007-05-06 17:53 ` Benn Newman
2007-05-06 17:56 ` Francisco J Ballesteros
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=463D5F3D.5090405@conducive.org \
--to=wbh@conducive.org \
--cc=9fans@cse.psu.edu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).