[Numpy-discussion] OS X PPC problem with Numpy 1.3.0b1
Charles R Harris
charlesr.harris@gmail....
Mon Mar 23 17:18:52 CDT 2009
On Mon, Mar 23, 2009 at 4:01 PM, Pauli Virtanen <pav@iki.fi> wrote:
> Mon, 23 Mar 2009 19:55:17 +0000, Pauli Virtanen wrote:
>
> > Mon, 23 Mar 2009 13:22:29 -0600, Charles R Harris wrote: [clip]
> >> PPC stores long doubles as two doubles. I don't recall exactly how the
> >> two are used, but the result is that the numbers aren't in the form you
> >> would expect. Long doubles on the PPC have always been iffy, so it is
> >> no surprise that machar fails. The failure on SPARC quad precision
> >> bothers me more.
> >
> > The test fails on SPARC, since we need one term more in the Horner
> > series to reach quad precision accuracy. I'll add that for long doubles.
>
> Another reason turned out to be that (1./6) is a double-precision
> constant, whereas the series of course needs an appropriate precision for
> each data type. Fixed in r6715, r6716.
>
Heh, I should have caught that too when I looked it over.
>
> I also skip the long double test if it seems that finfo(longdouble) is
> bogus.
>
> Backport?
>
I think so. It is a bug and the fix doesn't look complicated.
I don't much like all the ifdefs in the middle of the code, but if there is
a cleaner way to do it, it can wait.
Chuck
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