[fpc-devel] Dangerous optimization in CASE..OF

[Ozz Nixon]

I have to ask why?

i is Int64 only, will always be int64 only, so all other comparisons are always skipped.

I could see this, inside a method with an untyped parameter:

procedure doSomething(myvar;out success:boolean);
Begin
   {… your if is comparisons …}
end;

This opens your method to be used for all types for param1.

Ozz

> On Apr 14, 2018, at 5:51 AM, Thorsten Engler <thorsten.engler at gmx.net> wrote:
> 
> I haven't checked out the changes you made to the compiler, so you might have already covered this, but while you are at it, you might want to just make this work for any ordinal type with a well-defined upper/lower bound (any type for which High()/Low() can be evaluated at compile time). So:
> 
> type
>  TSubRange=-5..5;
>  TEnum=(One, Two);
> 
> var
>  i: Int64;
> 
> begin
>  if i is TSubRange then
>    //...
>  If i is TEnum then
>    //...
>  If i is SmallInt then
>    //...
> 
> (same with "as").
> 
> 
> 
>> -----Original Message-----
>> From: fpc-devel <fpc-devel-bounces at lists.freepascal.org> On Behalf
>> Of Ondrej Pokorny
>> Sent: Saturday, 14 April 2018 19:03
>> To: fpc-devel at lists.freepascal.org
>> Subject: Re: [fpc-devel] Dangerous optimization in CASE..OF
>> 
>> On 14.04.2018 10:39, Thorsten Engler wrote:
>>> How about following the same schema as with classes?
>>> 
>>> If 1 is TMyEnum then
>>>   //use hard cast here
>> 
>> Yes, that is reasonable as well and it will be easier to implement
>> than the TryIntToEnum/IntToEnum intrinsics for me.
>> 
>> Ondrej
>> _______________________________________________
>> fpc-devel maillist  -  fpc-devel at lists.freepascal.org
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> 
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