[fpc-devel] Benchmark for FreePascal

Marc Weustink marc.weustink at cuperus.nl
Wed Dec 14 18:33:41 CET 2005

Jonas Maebe wrote:
> On 10 dec 2005, at 22:09, darekM wrote:
>> I've see that reverse-complement benchmark <http:// 
>> shootout.alioth.debian.org/benchmark.php?test=revcomp&lang=all> for  
>> FPC is very slow. I discover, that problem is with readln, that  
>> function consume about 90% of time.
> In my test (Mac OS X/PPC, rtl and program compiled with register  
> variables, text buffer of 64kb) readln's overheid is negligible. The  
> large cost comes from writeln. The reason the C version is so much  
> faster is because its output is buffered as well. We automatically  
> flush the output after each writeln (i.e. after each writeln of 60  
> characters), while in C this only happens at the very end of the  
> program for 128kb of characters at a time.

Another speed improvement will be disabling IO checks for write, {$I-}

I normally wouldn't recomend doing so, but for this test it either 
passes or fails.


More information about the fpc-devel mailing list