Stefan Glienke

There are several factors - RTTI is one of them, another is generics, in combination they can be quite terrible. Example: A class is using a TList<something> as a field - TList<T> has RTTI enabled which causes all code for that TList<something> to reside inside the binary even though calls to Add, Delete and alike are inlined and go directly to those non generic TListHelper methods. Now multiply that with all lists and dictionaries in RTL/VCL and your code and you have the issue. Having said that - this is just one case which I was working on as author of a library that makes extensive use of generics and I don't want to be a big contributor to that issue. Putting {$WEAKLINKRTTI ON} into the project file can reduce the bloat a bit because this enables the linker to remove all methods that are not being used. An empty FMX application on Win32 is 8.5MB in release config and contains way over 2MB just from System.Generics.*. With that option you can at least reduce this to 7.4MB (numbers from Delphi 10.1). How that option affects your code depends on your code. During the development of Spring4D I rigorously have used {$RTTI EXPLICIT METHODS([]) PROPERTIES([]) FIELDS([])}{$ENDIF} in a lot of units to at least reduce any bloat from my code but without recompiling the RTL/VCL/FMX you cannot do that for the Delphi code.

A method is a routine (procedure/function) that is associated with an object. A class method would be a routine (procedure/function) that is associated with a class.

I don't see a class method in that code

@Kas Ob. Not strange at all (maybe a bit misleading UI I admit), what you download there is the source of a specific commit (the lastest master, which would not contain timsort btw, surprise) - repository size includes the entire history. If you want to not use git as intended then you need to switch to the branches tab and there select one of the download options.

@David Heffernan and me implemented one for Spring4D - you can already check it out in the develop branch

Lots of bogus and bias benchmarks

This feature is called CodeLens - if you fancy you can look on GitHub how its implemented in VSCode.

A string builder must be created and more importantly destroyed. Unless you are making this a custom managed record (which would be equally terrible for fluent API I guess - not tested yet) you would then need to explicitly call some Release/Free/whatever method on that record. If you were to make a fluent API on a record storing all the information those API methods must work with a reference type (such as the pointer to that record) but that makes this API a bit less convenient when you just want to store that result to a variable of that record type (would need an extra call or a deref after the last method call)

Fluent API with records containing managed fields (such as strings) unfortunately produces terrible code because the compiler produces an implicit variable for each method call.

I really lol'ed at that one - stockholm syndrome anyone?

The description is in the paper and the reference implementation in c is in the very links on that page. Attention though: there is xoroshiro and xoshiro in different variations.

Take a look into @Primož Gabrijelčič GpRandomGen.pas

Why are you running unit tests under the debugger if you are not interested in well actually debugging? If there are any unexpected exceptions the tests will be red and then you select those and start looking into the defects.

See my point is this - when a developer writes code like this: for i := 0 to list.Count - 1 do DoSomething(list[i]); it makes absolutely no sense that for every item access to perform the range check. Yes, I know you could use the for-in loop to avoid that but let's just see this as one example of "I have tested this code and I did not make an off by one error on the Count (like forgetting that -1) and let me just get the fastest possible code for my RELEASE build. Unfortunately unless you recompile the RTL/VCL/FMX/you name it yourself you have to stick with pointless sanity checks all over the place. No, I have not done any full application benchmark to actually measure the impact of the overall performance of all types of code that uses RTL lists but I think we can agree that even if the impact might be minor there is one. What I am talking here is the public API of my code that users can interact with and thus I have no control over them passing bad values hence I would like to perform sanity checks to make the code as robust as possible. But I also want the library code to be as fast as possible in a RELEASE configuration (I think this could also stir an argument on whether to turn range/overflow checking on or off then). I certainly don't want to add two levels of API here but make it behave reasonable under DEBUG and RELEASE. I am using these two words for the "tell me when I did a mistake and give me specific information about the mistake" and the "I tested all the code and don't have out of range cases, dont pollute all my code with useless sanity checks" cases.

And if you would use tinyint you could even save 3 byte per record 😉

tbh not having IDEFixPack being available is good in the long run - with the existence of it nobody (or very few) actually cared to report issues and put some pressure on Embarcadero to address these things. Now that there is no solution available the pressure on Embarcadero has raised and I can confirm that they are working on it - will they suddenly implement all fixes and optimizations from Andreas? No, but better they do slowly than relying on the third party no matter how incredible.

Disclaimer: This is microbenchmark area! Which is why I wrote "sometimes" - but it might be better to write this: if not precondition then raise_some_error; do_stuff into: if precondition then do Stuff else raise_some_error Of course there are other factors - but if we already talk about writing an index check as one instead of two cmp/jxx instructions we might as well talk about that.

If that would compile - and even if it would that would not prevent that set to be assigned [4] to.

Exactly what I have been doing recently during my refactoring - fun fact: sometimes you even want to rewrite that to avoid the conditional forward jump taken.

And I thought enums and the possibility to build sets of enums is one of those unique features in Delphi that many other languages such as C++ don't have hence you have to and/or with damn bitmasks....

Use Fixinsight. It catches those.

Give types a meaningful and obvious name. Then you don't have issues remembering them.

Those numbers make me assume that you ran in Debug config (i.e. without $O+).

Without going into more detailed analysis for now (maybe that's a good topic for a future blog post) I would say even though the older versions produced that extra temp variable and checking against that with the inlined code the main reason why both loops take different durations is due to being in one or two cachelines. We had the same situation some while ago in another thread when we measured different string handling routines. Some performed better or worse and then suddenly a small change changed the result significantly simply because the instructions emitted for the loop were located differently. Some stuff to read about Microbenchmarks: https://engineering.appfolio.com/appfolio-engineering/2019/1/7/microbenchmarks-vs-macrobenchmarks-ie-whats-a-microbenchmark

Classic measuring issues. I ran the same code in 10.4.1 and while it produces the same asm code the first loop ran slower for me (461 vs 232). I have seen this before and I guess its because the TStopwatch code is not yet in the cache for the first run - same is true for code to be measured. That is why for running good benchmarks you either run both in their own binary and not back to back in the same one - in order for them to be both affected by being a cold run or you simply run the benchmark once to warm up and then start measuring. There are more things to consider though but I won't go into detail here. Edit: compiled in 10.1 the second loop indeed runs slower for me as well. Unit1.pas.46: for i := 1 to loop do 005CE6D2 8B1D54C95D00 mov ebx,[$005dc954] 005CE6D8 85DB test ebx,ebx 005CE6DA 7E1A jle $005ce6f6 Unit1.pas.47: if (vSearchValue = '') and (vItemValue <> '') or (vItemValue = vSearchValue ) 005CE6DC 837DFC00 cmp dword ptr [ebp-$04],$00 005CE6E0 7506 jnz $005ce6e8 005CE6E2 837DF800 cmp dword ptr [ebp-$08],$00 005CE6E6 750B jnz $005ce6f3 005CE6E8 8B45F8 mov eax,[ebp-$08] 005CE6EB 8B55FC mov edx,[ebp-$04] 005CE6EE E8DDC2E3FF call @UStrEqual Unit1.pas.46: for i := 1 to loop do 005CE6F3 4B dec ebx 005CE6F4 75E6 jnz $005ce6dc vs Unit1.pas.53: for i := 1 to loop do 005CE74B 8B1D54C95D00 mov ebx,[$005dc954] 005CE751 85DB test ebx,ebx 005CE753 7E24 jle $005ce779 Unit1.pas.54: if IsSearchByValueFound_Inlined(vSearchValue, vItemValue) 005CE755 837DFC00 cmp dword ptr [ebp-$04],$00 005CE759 7506 jnz $005ce761 005CE75B 837DF800 cmp dword ptr [ebp-$08],$00 005CE75F 7511 jnz $005ce772 005CE761 8B45F8 mov eax,[ebp-$08] 005CE764 8B55FC mov edx,[ebp-$04] 005CE767 E864C2E3FF call @UStrEqual 005CE76C 7404 jz $005ce772 005CE76E 33C0 xor eax,eax 005CE770 EB02 jmp $005ce774 005CE772 B001 mov al,$01 005CE774 84C0 test al,al Unit1.pas.53: for i := 1 to loop do 005CE776 4B dec ebx 005CE777 75DC jnz $005ce755 So there is indeed a difference in the code which affects the performance which goes back to what I said before - the inliner not doing its best job - what you see here is that the compiler still generates that result variable and either sets it to true or to false and then checks that one. But the first loop is only faster because you don't do anything after the check. Edit: One more thing that is important when measuring stuff like this in comparison directly - cache lines. In my case the second loop is always faster in 10.4 even though both of them have the same code generated - and that is simply because the first loop spans two cachelines and the second one in only one - that is something you cannot influence easily and should not bother with but need to be kept in mind when doing measuring code like this.