On Wed, Oct 20, 2010 at 01:45, Michael Van Canneyt <mich...@freepascal.org> wrote:
> If you need more convincing: the contnrs unit contains 2 hash classes. > one based on ansistrings, one with pchars and shortstrings. The pchar > version is easily 20% faster. It comes from the compiler code and was > written specially by Peter Vreman. > > Try and improve that class with ansistrings. If you succeed, only then we > can start making a case for using them in the compiler. Ok, I went ahead and have taken look at the code. I assume you speak about TFPHashList vs TFPCustomHashTable. The classes are not really comparable, because they use quite different internal data structures. So instead I converted TFPHashList list to use ansistrings. Benchmarking included 3*10^6 calls to Add and Find methods with the arguments of various lengths. Average string length 5 characters: ShortString: 1.15 s AnsiString: 1.56 s Average string length 45 characters: ShortString: 12.0 s AnsiString: 3.2 s I agree that the first case is more relevant for the compiler, but still you can see that ShortStrings are clearly not always faster. -- Alexander S. Klenin _______________________________________________ fpc-devel maillist - fpc-devel@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-devel
