On Mon, Jun 25, 2018 at 09:53:17AM -0700, Carl Love wrote:
> On Mon, 2018-06-25 at 04:44 -0500, Segher Boessenkool wrote:
> > On Fri, Jun 22, 2018 at 02:55:44PM -0700, Carl Love wrote:
> > > --- a/gcc/testsuite/gcc.target/powerpc/divkc3-2.c
> > > +++ b/gcc/testsuite/gcc.target/powerpc/divkc3-2.c
> > > @@ -13,4 +13,5 @@ divide (cld_t *p, cld_t *q, cld_t *r)
> > > *p = *q / *r;
> > > }
> > >
> > > -/* { dg-final { scan-assembler "bl __divkc3" } } */
> > > +/* { dg-final { scan-assembler "bl __divkc3" { target { powerpc*-
> > > *-linux* } } } } */
> > > +/* { dg-final { scan-assembler "bl .__divdc3" { target { powerpc*-
> > > *-aix* } } } } */
> >
> > Should it be calling __divdc3 on AIX, is that correct?
>
> I was a bit surprised that it wasn't calling divkc3. I am guessing
> these are library routines we are calling? I couldn't find the source
> code for them and don't really know what the difference is between
> divkc3 and divdc3.
divkc3 is for KCmode, that is the complex mode for KFmode (128-bit IEEE).
divdc3 is for DCmode, that is the complex mode for DFmode (64-bit IEEE,
that is, "double").
I think this is the same as PR82625, for which I have a patch in testing.
> So, not sure why AIX and Linux are not calling the name for the
> function or if what is being called is functionally equivalent?
AIX uses 64-bit long double by default, and GCC has a bug with that and
-mabi=ieeelongdouble and __ieee128.
It thinks __ieee128 is the same as long double if it has -mabi=ieeelongdouble,
but that is not always true. So it ends up using the long double type for
__ieee128, but that is just double precision float in this case.
So, hang on :-)
Segher
