GDC/ARM: Help needed: Porting std.math.internal.gammafunction

[John Colvin via Digitalmars-d]

On Thursday, 3 July 2014 at 15:35:35 UTC, Johannes Pfau wrote:
> Hi,
>
> std.math.internal.gammafunction is the last module with failing
> unittest on ARM, simply because it assumes that reals are 
> always in
> x86 extended precision format which is obviously not true on 
> ARM.
>
> I haven't got the required (maths) knowledge to fix this, so 
> it'd be
> very appreciated if somebody could take a look.
>
> It's actually possible to easily test this on x86 with gdc: 
> Just install
> a recent gdc build and use the -mlong-double-64 command line 
> argument.
> More details and bug report here:
>
> https://issues.dlang.org/show_bug.cgi?id=13032

some trial and error suggests that gammaStirling needs it's 
threshold changing from 1024.0L to 143.0L when using 64bit reals 
to avoid overflow.