[Numpy-discussion] question about long doubles on ppc64el

[Matthew Brett]

Hi,

On Sun, Jan 15, 2017 at 10:00 PM, Thomas Caswell <tcaswell at gmail.com> wrote:
> Folks,
>
> Over at h5py we are trying to get a release out and have discovered (via
> debian) that on ppc64el there is an apparent disagreement between the size
> of a native long double according to hdf5 and numpy.
>
> For all of the gorey details see: https://github.com/h5py/h5py/issues/817 .
>
> In short, `np.longdouble` seems to be `np.float128` and according to the
> docs should map to the native 'long double'.  However, hdf5 provides a
> `H5T_NATIVE_LDOUBLE` which should also refer to the native 'long double',
> but seems to be a 64 bit float.
>
> Anyone on this list have a ppc64el machine (or experience with) that can
> provide some guidance here?

I know that long double on numpy for the PPC on Mac G4 (power64 arch)
is the twin double, as expected, so I'd be surprised if that wasn't
true for numpy on ppc64el .

Do you want a login for the G4 running Jessie?   If so, send me your
public key off-list?

Cheers,

Matthew