Computer Chess Club Archives




Subject: Re: C and C++ --- NPS

Author: Matt Taylor

Date: 10:37:36 12/24/02

Go up one level in this thread

On December 24, 2002 at 05:16:37, Sune Fischer wrote:

>On December 23, 2002 at 21:29:08, Arshad F. Syed wrote:
>>Is there anyone here who has actually converted their C code to C++ while
>>keeping the NPS the same or even managed to improve upon it? Sune did mention
>>that he did so only at the cost of 15% degradation in speed. Why do people even
>>bother wasting their time with C++ for a chess program when it inevitably leads
>>to taking a hit in NPS? Regardless, of all the advice to simply inline the
>>functions, I have yet to see a living example of chess program code which
>>performed faster in C++.
>That problem is solved now, I just needed to inline a few functions and speed
>went back up.
>It's tiny things really, like I had a GenCastleMoves which was called from
>GenMoves. In GenCastleMoves I checked the flag first, most of the time this flag
>isn't set so castle is illegal and I can return, it's just a function call
>overhead for nothing.
>Actually I would like full inlining here, to have GenMoves and GetNextMove
>inlined in my Search. But if I understood things correctly, I would then need to
>have all the code in one huge file. I don't want that.

One of the weaknesses of C/C++ compilers in general is that the compiler can
only inline what it sees. It is interesting that, in VC 7, the linker can do
inlining. I was very pleased when I read that because it means I can practice
good design without having to expose unnecessary portions of my code for inline


This page took 0.01 seconds to execute

Last modified: Thu, 07 Jul 11 08:48:38 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.