Danny Backx escreveu: > On Wed, 2007-09-19 at 17:51 +0200, pgeorges wrote: >>> Crosswords, compiled with cegcc, runs noticably slower than compiled >>> with the m$ compiler. Eric House also reported this. I've not >>> investigated this yet. We may have inefficiencies other than the code >>> generated by the compiler. Something with the coredll perhaps ? >>> >>> Danny >>> >> Is it possible to know in which cases the slowdowns are encountered ? >> CPU intensive code, I/O , system calls ? >> What is the amount of slow down ? 10 % , 50 % ? >> >> Pascal > > I don't have an eVC4 installed (only my children have Windows PC's) so I > have no simple way to do comparisons. > > Xwords shows a noticable difference if you get it to refresh its screen. > (It's a scrabble game application.) When compiled with cegcc, you can > see how it draws the game board - takes one or 1.5 seconds. With the > executable as you can download it from http://xwords.sf.net , the redraw > is instantaneous. > > So that example could lead you to the conclusion that it's either > graphics or system (DLL?) access. >
I doubt it. There shouldn't be any difference in calling system functions. It's just a bl anyway. Your example is about floating point arithmetic. Is Xwords doing it a lot? Pgeorges, is you chess engine doing a lot of fp math? We currently generate code that assumes that the device *does not* have an fpu. Also, we think our libgcc is not taking advantage of the: http://msdn2.microsoft.com/en-US/library/bb330866.aspx Which are probably pretty much optimized for the device they are running on by the manufacturer. If I was looking into this, I would learn which cpu I have, and which fpu I have if any, and then have gcc output insns for it. Something like -mfloat-abi=softfp for vfp, for example (you'll need to also specify a cpu that supports it like -mcpu=xscale). It may reveal interesting. Cheers, Pedro Alves ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Cegcc-devel mailing list Cegcc-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/cegcc-devel
