On Fri, Dec 01, 2017 at 05:53:55PM -0600, Segher Boessenkool wrote:
> On Fri, Dec 01, 2017 at 12:40:22AM -0500, Michael Meissner wrote:
> > After committing the previous patch, I noticed that it was now generating
> > warnings for __{mul,div}kc3_{sw,hw} not having a prototype that I hadn't
> > noticed during development of the patch. This is due to the fact that
> > before I
> > added the ifunc support, it was only compiling __{mul,div}kc3, and those
> > have
> > built-in declarations. I installed this patch as being obvious:
> >
> > 2017-11-30 Michael Meissner <meiss...@linux.vnet.ibm.com>
> >
> > * config/rs6000/_mulkc3.c (__mulkc3): Add forward declaration.
> > * config/rs6000/_divkc3.c (__divkc3): Likewise.
> >
> > Index: libgcc/config/rs6000/_divkc3.c
> > ===================================================================
> > --- libgcc/config/rs6000/_divkc3.c (revision 255288)
> > +++ libgcc/config/rs6000/_divkc3.c (working copy)
> > @@ -37,6 +37,8 @@ typedef __complex float KCtype __attribu
> > #define __divkc3 __divkc3_sw
> > #endif
> >
> > +extern KCtype __divkc3 (KFtype, KFtype, KFtype, KFtype);
> > +
> > KCtype
> > __divkc3 (KFtype a, KFtype b, KFtype c, KFtype d)
> > {
>
> How does this warn? -Wmissing-declarations? Should this declaration be
> in a header then?
The compiler creates the call to __mulkc3 and __divkc3, and internally it has
the appropriate prototype like it does for all built-in functions (in this
case, returning an _Float128 _Complex type, and taking 4 _Float128 arguments).
So before adding ifunc support, we never noticed it didn't have a prototype,
because the compiler already has a prototype.
With ifunc support, we now need to create two separate functions, __mulkc3_sw
and __mulkc3_hw, and make __multkc3 the ifunc resolver.
So there really isn't an include file that is appropriate to put the
definitions in. I could change it to use the soft-fp includes (including
quadmath-float128.h) if desired.
Did you want me to do that?
> A code comment explaining why you do a declaration for exactly the same
> thing as there is two lines later would help; otherwise people will try
> to delete it again :-)
--
Michael Meissner, IBM
IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA
email: meiss...@linux.vnet.ibm.com, phone: +1 (978) 899-4797
