Re: perl: 64-bit integers and long doubles
* Niko Tyni:
> I wasn't initially going for long doubles, but several upstream
> developers recommended that they be enabled together.
>
> http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2010-04/msg00773.html
This shows that long doubles are not backwards-compatible. 8-) The
root cause is that ** is a floating point operator, just like /. "use
integer" changes this, so I would say that this is just a user error.
> http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2010-04/msg00895.html
No matter how many bits you add, you can't change the fact that 0.1
cannot be represented exactly in binary floating point. And in
Debian's context, the argument goes in the other way: we'd have
NVs with 64, 80 and perhaps 96 and 128 bits, so we'd only see
accuracy issues on obscure architectures, making debugging much
harder.
> Given that we've already run into a dozen or so incompatibilities
> with just the CPAN modules, -Duselongdouble seems to be a pretty
> rare thing to do. I'm inclined to revert this setting.
That is, 64 bit NVs across all Debian architectures? That's good.
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