From: Andreas Ericsson <ae@op5.se>
To: Pierre Habouzit <madcoder@debian.org>,
Andreas Ericsson <ae@op5.se>,
Walter Bright <boost@digitalmars.com>,
git@vger.kernel.org
Subject: Re: [RFC] Convert builin-mailinfo.c to use The Better String Library.
Date: Sun, 09 Sep 2007 03:36:25 +0200 [thread overview]
Message-ID: <46E34E19.8050402@op5.se> (raw)
In-Reply-To: <20070909003718.GE13385@artemis.corp>
Pierre Habouzit wrote:
> On Sat, Sep 08, 2007 at 11:50:34PM +0000, Andreas Ericsson wrote:
>
>>>> You can tell C compilers to
>>>> check all array accesses, but that is a performance issue.
>>> Runtime checking of arrays in D is a performance issue too, so it is
>>> selectable via a command line switch.
>> Same as in C then.
>
> HAHAHAHAHAHA. Please, who do you try to convince here ? Except in the
> local scope, there is few differences between a foo* and a foo[] in C.
>
"Runtime checking of arrays is a performance issue." It's true whether it's
done manually by the coder or by the compiler. The difference is that in C,
you get to choose where it should be done.
>>> But more importantly,
>>> 2) For dynamically sized arrays, the dimension of the array is carried
>>> with the array, so loops automatically loop the correct number of times.
>>> No runtime check is necessary, and it's easier for the code reviewer to
>>> visually check the code for correctness.
>> But this introduces handy but, strictly speaking, unnecessary overhead
>> as well, meaning, in short; 'D is slower than C, but easier to write
>> code in'.
>
> That's BS. See the strbuf API I've been pushing recently ? It has
> simplified git's code a lot, because each time git had to deal with a
> growing string, it had to deal with at least three variables: the buffer
> pointer, the current occupied length, and its allocated size. That was
> three thing to have variable names for, and to pass to functions.
>
Yup. I applaud your efforts, but it does come with a slight overhead,
except where it replaces faulty code. In practice, it's probably better
to use the api for all the string-handling, as none of it is performance-
critical.
> Now instead, it's just one struct. D gives that gratis. There is no
> performance loss because you _need_ to do the same. How do you deal with
> dynamic arrays if you dont't store their lenght and size somewhere ? Or
> are you the kind of programmer that write:
>
> /* 640kb should be enough for everyone… */
> some_type *array = malloc(640 << 10);
>
No, but it would depend on what I am to do with it.
>
>> So in essence, it's a bit like Python, but a teensy bit faster and a
>> lot easier to shoot yourself in the foot with.
>
>> What was the niche you were going for when you thought up D? It can't
>> have been systems programming, because *any* extra baggage is baggage
>> one would like to get rid of. If it was application programming I fail
>> to see how one more language would help, as there will be portability
>> problems galore and it's still considerably slower to develop in than
>> fe Python, while at the same time being considerably easier to mess up
>> in.
>
> Right now I'm just laughing. There is for sure overheads in some
> places of D, but the example you take, and what you try to attack in D
> is definitely not where you lose any kind of performance. You could have
> attacked the GC instead (which is after all an easy classical target).
>
I was asking what role D was designed to fill. I didn't mean it as an
attack, but re-reading what I wrote earlier I see it came off a bit harsh.
> Just to evaluate the silliness of your arguments:
> * http://www.digitalmars.com/d/comparison.html so that you can tell
> what the D features really are,
You may notice that the feature-list is being provided by the creators
and marketeers of the D language. Walter Bright certainly seems like a
nice enough person, but it's possible it's a tad biased.
> * http://shootout.alioth.debian.org/gp4/benchmark.php?test=all&lang=all
> so that you can know what the D performance really is about. Of
> course those are only micro benchmarks, but well, python is "just"
> 15 times slower than D, and D seems to be 10% slower.
I get it to 7.7xC and 1.2xC, respectively, but whatever. It still means
performance-critical apps will be written in C, while
insert-script-language-of-choice will still be used for prototyping and
not-so performance-critical apps.
> Well then I'm
> okay with D, I'm ready to buy 10% faster CPUs and avoid a lot of
> painful debugging time. In my world, 10% faster hardware is cheaper
> by many orders of magnitude than skilled programmers, but YMMV.
>
I'm curious as to how many fewer bugs D developers write compared to C
programmers. I guess it's hard to do a fair test given the comparatively
shallow pool of D gurus around, but it'd still be interesting to see a
practical test. 20% increase in runtime is certainly acceptable for
never having to see a bug again, but is it acceptable for 10% fewer bugs?
Or 20% fewer?
--
Andreas Ericsson andreas.ericsson@op5.se
OP5 AB www.op5.se
Tel: +46 8-230225 Fax: +46 8-230231
next prev parent reply other threads:[~2007-09-09 1:39 UTC|newest]
Thread overview: 102+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-09-04 20:50 [RFC] Convert builin-mailinfo.c to use The Better String Library Lukas Sandström
2007-09-04 21:38 ` Alex Riesen
2007-09-04 23:01 ` Pierre Habouzit
2007-09-05 14:54 ` Kristian Høgsberg
2007-09-05 17:29 ` Matthieu Moy
2007-09-06 2:30 ` Miles Bader
2007-09-06 4:48 ` Dmitry Kakurin
2007-09-06 4:59 ` Shawn O. Pearce
2007-09-06 9:12 ` Andreas Ericsson
2007-09-06 9:35 ` Junio C Hamano
2007-09-06 10:21 ` Andreas Ericsson
2007-09-06 9:52 ` David Kastrup
2007-09-06 5:03 ` Miles Bader
2007-09-06 12:08 ` Johannes Schindelin
2007-09-06 17:50 ` Linus Torvalds
2007-09-07 0:21 ` Dmitry Kakurin
2007-09-07 0:38 ` Linus Torvalds
2007-09-07 1:08 ` Dmitry Kakurin
2007-09-07 1:27 ` Linus Torvalds
2007-09-07 3:09 ` Dmitry Kakurin
2007-09-07 5:48 ` David Symonds
2007-09-07 6:15 ` Theodore Tso
2007-09-20 14:06 ` Steven Burns
2007-09-20 14:56 ` Andreas Ericsson
2007-09-07 6:31 ` Andreas Ericsson
2007-09-07 22:17 ` Dmitry Kakurin
2007-09-07 22:28 ` David Kastrup
2007-09-08 0:37 ` Dmitry Kakurin
2007-09-08 6:25 ` David Kastrup
2007-09-09 0:29 ` Andreas Ericsson
2007-09-07 6:52 ` David Kastrup
2007-09-07 10:28 ` Johannes Schindelin
2007-09-07 10:26 ` Johannes Schindelin
2007-09-07 6:50 ` David Kastrup
2007-09-07 1:12 ` Linus Torvalds
2007-09-07 1:40 ` alan
2007-09-07 5:09 ` Walter Bright
2007-09-07 7:40 ` David Kastrup
2007-09-07 8:15 ` Walter Bright
2007-09-07 8:26 ` David Kastrup
2007-09-07 9:14 ` Walter Bright
2007-09-07 9:31 ` David Kastrup
2007-09-07 20:22 ` Walter Bright
2007-09-07 20:27 ` David Kastrup
2007-09-07 23:16 ` Walter Bright
2007-09-08 23:50 ` Andreas Ericsson
2007-09-09 0:37 ` Pierre Habouzit
2007-09-09 1:36 ` Andreas Ericsson [this message]
2007-09-07 11:36 ` Wincent Colaiuta
2007-09-07 9:41 ` Pierre Habouzit
2007-09-07 19:03 ` Walter Bright
2007-09-07 19:31 ` David Kastrup
2007-09-07 20:49 ` Walter Bright
2007-09-07 19:41 ` Pierre Habouzit
2007-09-07 19:51 ` David Kastrup
2007-09-07 19:59 ` Pierre Habouzit
2007-09-07 20:40 ` Walter Bright
2007-09-07 20:56 ` Pierre Habouzit
2007-09-07 22:54 ` Walter Bright
2007-09-08 0:56 ` John 'Z-Bo' Zabroski
2007-09-08 6:36 ` David Kastrup
2007-09-19 19:56 ` Steven Burns
2007-09-07 3:06 ` Wincent Colaiuta
2007-09-07 4:06 ` Paul Wankadia
2007-09-07 4:30 ` Nicolas Pitre
2007-09-07 9:19 ` Wincent Colaiuta
2007-09-07 6:25 ` Andreas Ericsson
2007-09-07 10:56 ` Johannes Schindelin
2007-09-07 11:54 ` Andreas Ericsson
2007-09-07 12:33 ` Wincent Colaiuta
2007-09-07 12:55 ` Karl Hasselström
2007-09-07 13:58 ` Andreas Ericsson
2007-09-07 14:13 ` Wincent Colaiuta
2007-09-09 0:09 ` Andreas Ericsson
2007-09-07 16:09 ` David Kastrup
2007-09-07 11:30 ` Wincent Colaiuta
2007-09-07 8:36 ` Walter Bright
2007-09-07 9:41 ` Andreas Ericsson
2007-09-07 19:23 ` Walter Bright
2007-09-07 19:40 ` David Kastrup
2007-09-09 0:25 ` Andreas Ericsson
2009-09-17 16:23 ` Bernd Jendrissek
2007-09-07 11:52 ` Wincent Colaiuta
2007-09-07 19:25 ` Walter Bright
2007-09-22 16:52 ` Steven Burns
2007-09-07 6:47 ` David Kastrup
2007-09-07 7:41 ` Andy Parkins
2007-09-07 8:08 ` David Kastrup
2007-09-07 10:21 ` Johannes Schindelin
2007-09-08 0:32 ` Dmitry Kakurin
2007-09-08 6:24 ` David Kastrup
2007-09-08 23:25 ` Alex Riesen
2007-09-24 13:41 ` figo
2007-09-24 13:57 ` David Kastrup
2007-09-25 19:19 ` Steven Burns
2007-09-25 19:55 ` David Kastrup
2012-05-22 18:30 ` Syed M Raihan
2010-06-10 19:12 ` Ian Molton
2010-06-11 12:23 ` Jakub Narebski
2010-06-11 13:33 ` Dario Rodriguez
2007-09-05 15:27 ` Kristian Høgsberg
2007-09-07 10:47 ` Lukas Sandström
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
List information: http://vger.kernel.org/majordomo-info.html
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=46E34E19.8050402@op5.se \
--to=ae@op5.se \
--cc=boost@digitalmars.com \
--cc=git@vger.kernel.org \
--cc=madcoder@debian.org \
/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.
Code repositories for project(s) associated with this public inbox
https://80x24.org/mirrors/git.git
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 read-only IMAP folder(s) and NNTP newsgroup(s).