On Wed, Oct 06, 2021 at 10:17:44AM -0500, Segher Boessenkool wrote:
> On Wed, Oct 06, 2021 at 08:59:53AM +0200, Thomas Koenig wrote:
> > On 05.10.21 23:54, Segher Boessenkool wrote:
> > >>There is also the issue of binary data. If some user has written
> > >>out data in double double and wants to read it in as IEEE quad,
> > >>the results are going to be garbage. Another option for CONVERT
> > >>might be the solution to that, or, as you wrote, having a
> > >>REAL(KIND=15). It should be inaccessible via SELECTED_REAL_KIND,
> > >>though.
> > >
> > >That means flipping the default on all PowerPC to no longer be double-
> > >double. This means that you should have IEEE QP work everywhere, or the
> > >people who do need more than double precision will have no recourse.
> >
> > I think we can exclude big-endian POWER from this - they do not have
> > IEEE QP support, correct? So, exclude that from the SONAME change.
>
> Not correct, no. IEEE QP works fine in either endianness.
But only for Power8 or later, no? I guess the reason why le can switch
moreless easily (well, far from it, it is terribly hard anyway) is that
power8 is the oldest supported ISA for le, while be can't really assume
power8 or later.
Also, seems e.g. glibc support is there only for ppc64le and not be:
find . -name libm.abilist | xargs grep sinieee128
./sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libm.abilist:GLIBC_2.32
__asinieee128 F
./sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libm.abilist:GLIBC_2.32
__casinieee128 F
./sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libm.abilist:GLIBC_2.32
__csinieee128 F
./sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libm.abilist:GLIBC_2.32
__sinieee128 F
Jakub
