• Andrei Alexandrescu (3/3) Dec 19 2012 Vote up!
• Joshua Niehus (6/8) Dec 20 2012 http://www.reddit.com/r/programming/comments/155ivw/three_optimization_t...
• bearophile (11/12) Dec 21 2012 I appreciate such slides and videos, thank you for sharing. But
• Peter Alexander (13/16) Dec 21 2012 I think the most interesting thing from that talk is when you
• Andrei Alexandrescu (4/22) Dec 21 2012 Text representation has its own advantages.
• Tove (5/12) Dec 24 2012 interesting, does it have to be base 10? would it not be feasible
• Max Samukha (7/10) Dec 21 2012 Nice talk. For anybody interested, PIC was made a bit faster by

Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> writes:

Vote up!

http://www.reddit.com/r/programming/comments/155ivw/three_optimization_tips_for_c_video/


Andrei

"Joshua Niehus" <jm.niehus gmail.com> writes:

On Thursday, 20 December 2012 at 05:29:46 UTC, Andrei 
Alexandrescu wrote:
 Vote up!

http://www.reddit.com/r/programming/comments/155ivw/three_optimization_tips_for_c_video/
 Andrei

Almost 2 years ago, I stumbled across your book at a Barnes&Nobel 
and began my journey with D. It turns out its an "unsigned" copy. 
  Any chance you'll sign it at the DConf?

"bearophile" <bearophileHUGS lycos.com> writes:

Andrei Alexandrescu:

 http://www.reddit.com/r/programming/comments/155ivw/three_optimization_tips_for_c_video/

I appreciate such slides and videos, thank you for sharing. But 
If possible I'd like a link to the slides in a place where I 
don't have to register to download them.

I have also just seen this other slides pack from Jordan DeLong, 
it is very interesting, it's about a topic that is usually 
regarded as one of the strongest points of functional languages 
(that is using types to "make illegal states unrepresentable"):

http://www.reddit.com/r/cpp/comments/1571m9/facebook_nyc_tech_talk_jordan_delong_using/

Bye,
bearophile

"Peter Alexander" <peter.alexander.au gmail.com> writes:

On Thursday, 20 December 2012 at 05:29:46 UTC, Andrei 
Alexandrescu wrote:
 Vote up!

 http://www.reddit.com/r/programming/comments/155ivw/three_optimization_tips_for_c_video/


 Andrei

I think the most interesting thing from that talk is when you 
said that Facebook's back end code is spending 15% of its time 
converting ints to strings.

I know you are looking at these small functions as simple 
examples of the optimisation tips you are giving, but I hope this 
isn't the kinds of optimisations you are doing at the Facebook. 
The problem isn't that the conversion is slow, the problem is 
that you are converting at all. Don't use text based formats for 
performance sensitive data!

Of course, maybe the 15% claim was pure exaggeration. I really 
hope that's the case.

Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> writes:

On 12/21/12 7:23 AM, Peter Alexander wrote:
 On Thursday, 20 December 2012 at 05:29:46 UTC, Andrei Alexandrescu wrote:
 Vote up!

 http://www.reddit.com/r/programming/comments/155ivw/three_optimization_tips_for_c_video/



 Andrei

 I think the most interesting thing from that talk is when you said that
 Facebook's back end code is spending 15% of its time converting ints to
 strings.

Not all back end code. Certain applications.

 I know you are looking at these small functions as simple examples of
 the optimisation tips you are giving, but I hope this isn't the kinds of
 optimisations you are doing at the Facebook. The problem isn't that the
 conversion is slow, the problem is that you are converting at all. Don't
 use text based formats for performance sensitive data!

 Of course, maybe the 15% claim was pure exaggeration. I really hope
 that's the case.

Text representation has its own advantages.


Andrei

"Tove" <tove fransson.se> writes:

On Friday, 21 December 2012 at 16:28:35 UTC, Andrei Alexandrescu 
wrote:
 use text based formats for performance sensitive data!

 Of course, maybe the 15% claim was pure exaggeration. I really 
 hope
 that's the case.

 Text representation has its own advantages.


 Andrei

interesting, does it have to be base 10? would it not be feasible 
to use hex strings in some scenarios? possible with bswap, or 
bitscan etc?

"Max Samukha" <maxsamukha gmail.com> writes:

On Thursday, 20 December 2012 at 05:29:46 UTC, Andrei 
Alexandrescu wrote:
 Vote up!

 http://www.reddit.com/r/programming/comments/155ivw/three_optimization_tips_for_c_video/


 Andrei

Nice talk. For anybody interested, PIC was made a bit faster by 
x64 due to introduction of RIP-relative addressing. Here is a 
concise and well-written article describing an x64 PIC 
implementation 
http://eli.thegreenplace.net/2011/11/11/position-independent-code-pic-in-shared-libraries-on-x64/.