On Sat, 7 Oct 2006, Peter Vreman wrote:
> At 00:15 7-10-2006, you wrote: > > > >-----Original Message----- > >From: Michael Van Canneyt <[EMAIL PROTECTED]> > >To: FPC developers' list <fpc-devel@lists.freepascal.org> > >Date: Fri, 6 Oct 2006 22:01:55 +0200 (CEST) > >Subject: Re: [fpc-devel] rtti, arrays and performance > > > > > > > Did you see a change in performance ? Can you give an order of magnitude ? > > > > > > >For me Shark profiler shows that 60%-70% of time spent in fpc_finalize (this > >is on intel core duo, havn't measured on powerpc). After change it shown just > >a few percents (I do not remember exactly, and it's a little bit hard to > >measure exactly because this block is performd in a few seconds now). But > >it's just a mine specific case. I use dynamic arrays heavily there, too much, > >it would be better to use getmem there and then type cast it as pointer to > >array. Generally speaking I think that it's not a significant optimization > >for most of applications. Just it was easer for me to tweak rtl than to > >change my code :). But anyway - if I have array of integer with a hundreds > >thousand items call to finalize each item is not really good I think. What if > >user has record with array inside, and that record has some dynamic variable? > >as I understand fpc_finalize will try to finalize array too... And as I > >understand dynamic arrays always finalizing their items. > > > > > > > > I think it may be indeed a better idea to see whether the > > compiler can set a flag in the type info: > > > > > > If we change TTypeInfo to > > > > > > TTypeInfo = record > > > Kind : TTypeKind; > > > Finalize : Boolean; > > > Name : ShortString; > > > // here the type data follows as TTypeData record > > > end; > > > > > > Then there is no need for a recursive loop (the compiler has > > already done that...); > > > Only the Finalize field needs to be retrieved. Putting this field > > in the middle will > > > make sure 99,9% of all existing code will still work. > > > > > > >I don't know is this good - perhaps to not break other's code such attribute > >can be placed before type info record (at offset -1 or -4 from typeinfo > >pointer:)),so, if somebody relies on current typeinfo format his code will be > >not broken? > > If you relying on internal typeinfo your program already has a cross-platform > issue. So this is not an issue that we change the internal structure. Adding > the boolean is possible. But for the array finalize we also need an extra > function that will check if the array needs finalization before entering the > loop that calls Finalize(). The TypeInfo of the array should also be checked, simply, no ? Michael. _______________________________________________ fpc-devel maillist - fpc-devel@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-devel
