Hi, I specialized my generic abstract class in a different unit with this type: TRec = record A: Integer; B: Integer; end; (A is for sorting, B is for testing of stability, i.e. for MergeSort, TimSort) and compare function, declared with inline; directive: function MyComptFunc(const ARec, BRec: TRec): Integer; var i, aCnt: Integer; begin aCnt:=CFComplex; for i:=0 to aCnt do Result:=(BRec.A-ARec.A); inc(CFCnt); //InterlockedIncrement(CFCnt); end; The reason for this complex compare function is that it also measure number of comparisons and it can simulate more expensive comparisons (like sorting strings). For a while, I added this unit to the second "uses" section (implementation) of the other unit, which is impractical, but I had temporary access to the compare function. I tested again with ShellSort, sorting 2'000'000 values takes: 1380ms inlined 1515ms not inlined, ~9% slower 1430ms when compare func. is a parameter ~4% slower I pass variables by value. But you are right, when I shave the function like this: function MyComptFunc(const ARec, BRec: TRec): Integer; begin Result:=(BRec.A-ARec.A); end; the results are: 750ms inlined 950ms not inlined, ~21% slower 835ms when compare func. is a parameter ~10% slower so the gain of inlining is higher for sorting primitive types. V.______________________________________________________________
Od: "Flávio Etrusco via fpc-pascal" <fpc-pascal@lists.freepascal.org> Komu: "FPC-Pascal users discussions" <fpc-pascal@lists.freepascal.org> Datum: 18.11.2022 20:45 Předmět: Re: [fpc-pascal] How to inline CompareFunc to Sort method in generic abstract class
Em seg., 14 de nov. de 2022 15:26, Vojtěch Čihák via fpc-pascal <fpc-pascal@lists.freepascal.org <fpc-pascal@lists.freepascal.org>> escreveu:,What do you mean by "be inlined"? The 'inline' directive instructs the compiler (or is it the linker? 😬) to try copying the whole function inline, also avoiding the call (stack) setup; you can't do this for this for a general purpose method.I'm curious how you got that 6% figure, it seems rather large. Is this comparing the parameter vs virtual method approach or comparing a fully inline (no indirect call of any kind) sort function to some other option? Are you passing the variables by reference?Best regards,Flávio ---------- _______________________________________________ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal <https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal>
_______________________________________________ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
