[fpc-pascal] Floating point question

[Bernd Oppolzer]

Am 17.02.2024 um 16:38 schrieb Bernd Oppolzer:
>
> IMO, a compiler switch that gives all FP constants the best available 
> precision would solve the problem -
> BTW: WITHOUT forcing expressions where they appear to use this 
> precision, if the other parts of the expression
> have lower precision.
>
> In fact, when parsing and compiling the expressions, you always can 
> break the problem down to TWO operands
> that you have to consider, and if one of them is a literal constant, 
> it should not force the type of the operation to
> a higher precision ... that's what I would do.
>
>
Commenting on my own post (this time):

const xs : single = 1440.5;
       xd : double = 1440.5;
       xu = 1440.5;              /* double or single, depending on new 
option */
       z : single = 33.0;

y1 := xs / z;   { single precision }
y2 := xd / z;   { double precision }
y3 := xu / z;   { different result, depending on new option }
y4 := 1440.5 / z;   { single, because z dictates it, independent of 
option }
y5 := 1440.1 / z;   { IMO: single, because z dictates it, independent of 
option }
y6 := 1440.5 / 33.0;   { depending on new option }


This may be in contrast to what's today done in FPC,
but that's how I (personally) would like to have it done.
Maybe the behaviour without the new option set is the same as now.

Not sure about y5.

Kind regards

Bernd