Min & Max

[Attila Kovacs 629]

Am I the only one annoyed that these are in System.Math?

[Guest]

Perhaps, since you must have been born with this "gift" :)))    

 

Know that, since Delphi 2, Delphi already had problems with Min and Max procedure - at the time, Borland's manager, had switched roles, that is, Min did Max and Max did Min.

 

hug

[Attila Kovacs 629]

I have no idea what you are talking about. Those were MinValue and MaxValue. I'm really struggling to find any sense in any of your comments.

[Guest]

thanks for watch me! 

 

hug

[Guest]

did know that the "structures" seems dont have changed until today?

• same "DATA array"
• same > and < use

 

hug

[KodeZwerg 54]

30 minutes ago, Attila Kovacs said:

Am I the only one annoyed that these are in System.Math?

Without unit math use a custom one and you are not annoyed anymore 🙂

function myMin(const ValueA, ValueB: Integer): Integer;
begin
  if (ValueA <= ValueB) then
    Result := ValueA
    else
    Result := ValueB;
end;

function myMax(const ValueA, ValueB: Integer): Integer;
begin
  if (ValueA >= ValueB) then
    Result := ValueA
    else
    Result := ValueB;
end;

 

[Guest]

1 hour ago, Attila Kovacs said:

Am I the only one annoyed that these are in System.Math?

I'm with you 🙂 After a lot of times it's more like; "ah, that again".

[David Heffernan 2345]

Why does this bother you? Why don't you want to use System.Math?

[Guest]

It's simply because of being very very lazy.

Oops, sorry not my OP.

Edited March 23, 2021 by Guest

[Attila Kovacs 629]

35 minutes ago, Dany Marmur said:

"ah, that again".

_exactly_

 

32 minutes ago, David Heffernan said:

Why don't you want to use System.Math?

Because if someone sees it, he could think I can do math 🙂

[Fr0sT.Brutal 900]

Me too! Implemented my own routines for this

[Guest]

you have to complain about life because you need to breathe!

will understand such brilliant minds! 

 

hug

[Clément 148]

deleted

Edited March 23, 2021 by Clément

[Stefan Glienke 2002]

I am more annoyed with the unnecessary conditional jumps they generate and the fact they don't inline when using runtime packages

[Guest]

Yes, "functionalizing" these thingies needs all expressions to have to be evaluate-able.

So one still have to "fence" the minMaxIfThen(...). Makes it kind of a blow in the air.

[Vandrovnik 214]

30 minutes ago, Stefan Glienke said:

I am more annoyed with the unnecessary conditional jumps they generate and the fact they don't inline when using runtime packages

Is it possible to implement Min or Max without conditional jump?

[Stefan Glienke 2002]

37 minutes ago, Vandrovnik said:

Is it possible to implement Min or Max without conditional jump?

Not that I know of because the compiler unfortunately does not utilize the cmovxx instruction.

 

This has been reported already (I think there are other reports similar to this one): https://quality.embarcadero.com/browse/RSP-21955

 

Edit: Here is what clang and gcc generate: https://godbolt.org/z/4hnYrjYM6

 

And this is what Delphi generates:

 

 

Project1.dpr.16: Result := min(i, 42);
00408F94 83F82A           cmp eax,$2a
00408F97 7E05             jle $00408f9e
00408F99 B82A000000       mov eax,$0000002a
Project1.dpr.17: end;
00408F9E C3               ret 



Project1.dpr.16: Result := min(i, 42);
000000000040D4F0 83F92A           cmp ecx,$2a
000000000040D4F3 7F04             jnle Main + $9
000000000040D4F5 89C8             mov eax,ecx
000000000040D4F7 EB05             jmp Main + $E
000000000040D4F9 B82A000000       mov eax,$0000002a
Project1.dpr.17: end;
000000000040D4FE C3               ret

 

Yeah yeah branch predictors and all that - but if they are filled up with garbage conditional jumps like this they have less room for the important ones.

Edited March 23, 2021 by Stefan Glienke

[Vandrovnik 214]

19 minutes ago, Stefan Glienke said:

Not that I know of because the compiler unfortunately does not utilize the cmovxx instruction.

 

This has been reported already (I think there are other reports similar to this one): https://quality.embarcadero.com/browse/RSP-21955

Thanks, voted... My knowledge of assembler is frozen before Pentium instruction set...

[Vincent Parrett 750]

1 hour ago, Stefan Glienke said:

This has been reported already (I think there are other reports similar to this one): https://quality.embarcadero.com/browse/RSP-21955

 

Edit: Here is what clang and gcc generate: https://godbolt.org/z/4hnYrjYM6

 

And this is what Delphi generates:

Gotta support all those 386's that are still floating around 🙄 voted.

[Vandrovnik 214]

I have also found this comparing of the performance: https://github.com/xiadz/cmov

[Attila Kovacs 629]

@Vandrovnik Brutal. Voted too.

 

But I don't think they touch the compiler in the near future, however, I've noticed that reports regarding to the IDE are opened in a couple of workdays at the time and also being fixed. I'm surprisingly satisfied with that.

[mvanrijnen 123]

13 hours ago, Dany Marmur said:

Yes, "functionalizing" these thingies needs all expressions to have to be evaluate-able.

So one still have to "fence" the minMaxIfThen(...). Makes it kind of a blow in the air.

i have a minmax and maxmin function 🙂

 

[Guest]

7 hours ago, mvanrijnen said:

i have a minmax and maxmin function 🙂

Can you do this using your function?

 

var

  lSomeObject: TObject;

begin

  Result := MyInlineIfFunction(FValue, CConst, lSomeObject.Value);

end;

 

Assuming FValue is true, will you get the result of CConst or an AV/GPF?