[fpc-devel] Broken frac function in FPC3.1.1 / Windows x86_64

[Sven Barth]

Thorsten Engler <thorsten.engler at gmx.net> schrieb am Fr., 27. Apr. 2018,
18:48:

> For what it’s worth, Delphi simply decided to give up on doing it
> correctly and silently fail if the double is too large to fit in an Int64.
>
>
>
> WriteLn(Frac(1e15+0.5));
>
> WriteLn(Frac(1e16+0.5));
>
>
>
> When executed in 32bit code, returns:
>
>
>
> 5.00000000000000E-0001
>
> 5.00000000000000E-0001
>
>
>
> And when executed in 64bit code, returns:
>
>
>
> 5.00000000000000E-0001
>
> 0.00000000000000E+0000
>
>
>
> Whoever had the **brilliant** idea to deprecate the FPU in 64bit mode
> should be shoot and quartered, not necessarily in that order. 64bit code is
> basically useless if you want to do anything meaningful with floats that
> are larger than fits into an int64.
>

Ehm, what does the depreciation of the FPU have to do with that the floats
are too large for an Int64? Extended would only allow for even larger
values that would not fit. And all other functionality "simply" needs to be
implemented correctly using the "new" SSE functionality, which however is
not without its pitfalls as we have seen.

Regards,
Sven

>
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