From:	"Alexei A. Frounze" <dummy_addressee AT hotmail DOT com>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: compiler efficiency
Date:	Thu, 18 Jan 2001 01:28:23 -0500
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References:	<Pine DOT GSO DOT 4 DOT 21 DOT 0101172014390 DOT 7634-100000 AT sandman DOT ucdavis DOT edu>
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To:	djgpp AT delorie DOT com
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Reply-To:	djgpp AT delorie DOT com

Believe me GCC is quite good at optimization (well, when you helped it with
nice algorithm and source).
Around a year ago I had a bet in this NG that I can make a faster
implementation of my texture mapper in C+ASM mix rather than nearly plain C.
But in fact, eventually I got nearly the same thing when used 100% of GCC
capabilities and no extra ASM at all (well, probably just 1 or 2 ASM
instructions which is not a lot :). I was also wondered by the fact that GCC
beats Watcom. I've thought that Watcom is one of best C compilers before I
got GCC. But when I saw than my 3d-engine  comiled by Watcom is about twice
as slow as compiled by GCC...

:)

Happy coding with GCC!
--
Alexei A. Frounze
alexfru [AT] chat [DOT] ru
frounze [AT] ece [DOT] rochester [DOT] edu
http://alexfru.chat.ru
http://members.xoom.com/alexfru/
http://welcome.to/pmode/

"Mike Darrett" <ez073236 AT mailbox DOT ucdavis DOT edu> wrote in message
news:Pine DOT GSO DOT 4 DOT 21 DOT 0101172014390 DOT 7634-100000 AT sandman DOT ucdavis DOT edu...
> Hi guys,
>
> I was running some algorithm benchmarks on DJGPP vs Borland C++ 5.5, and
> was shocked to see that DJGPP outperformed Borland C++ on some stack
> tests. Using a linked list to simulate a stack, adding and removing 80,000
> entries took 1.8 seconds on my AMDK6-2 350, but took 2.5 seconds on
> Borland C++, compiled without the -tW option (since it is a console app).
>
> Any ideas? Is Borland C++ using thunking to access memory? Is DJGPP simply
> more efficient? Would like to get any input before I try optimizing the
> code any further.
>
> This was a homework assignment, but was meant only to test different
> algorithms vs each other, and not vs other compilers. The homework
> assignment can be seen
> at: http://wwwcsif.cs.ucdavis.edu/~davis/110/prog1.html
>
> Thanks,
>
> Mike Darrett
> mrdarrett AT ucdavis DOT edu
> http://mdarrett.freeyellow.com
>
> Get a free Windows C++ compiler! With STL, OpenGL and DirectX support.
> http://www.borland.com/bcppbuilder/freecompiler/
>
>

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