Re: i386 and x86_64 fenv support

Corinna Vinschen <[email protected]> Tue, 27 Aug 2019 17:55:36 +0200
Newsgroups	gmane.comp.lib.newlib
Message-ID	<[email protected]>
On Aug 27 10:45, Joel Sherrill wrote:
> On Tue, Aug 27, 2019 at 10:39 AM Corinna Vinschen <[email protected]> wrote:
> >
> > On Aug 27 08:31, Joel Sherrill wrote:
> > > Hi
> > >
> > > Earlier we discussed moving the winsup fenv.h files to newlib. Splitting
> > > winsup/cygwin/include/fenv.h to create a sys/fenv.h looks easy enough.
> > > But I have some status and a question after tinkering with this code out
> > > of tree and compiling with the RTEMS i386 and x86_64
> > >
> > > It includes winsup.h and wincap.h but it doesn't need them.
> >
> > Yeah, that's kind of a boilerplate include in Cygwin code.  Just scratch
> > it, it can't be overly important for the fenv functionality.
> >
> > > [...]
> > > There are prototypes for fegetprec() and fesetprec(). I think the
> > > prototypes need to move to the shared fenv.h and commented
> > > stubs for the constants needs to be in the shared dummy sys/fenv.h.
> > > Does this sound right?
> >
> > As far as I can see, none of Linux or BSD have these functions.  It may
> > be the right thing to do to keep them local to Cygwin since they never
> > made it into a standard or one of the systems we're interested in here.
> >
> > Ideally they are never defined in a header, not even on Cygwin.  We only
> > have to keep exporting these symbols in Cygwin for backward compat.
> 
> OK. They will disappear from the machine .h files then if that's OK.

Sure!

> > > My remaining issue is that it appears that i386 and x86_64 will need to
> > > share the same files. Do I just copy the files to both machine directories?
> > > I don't know if newlib's build infrastructure supports putting it in one
> > > place and using it in another architecture.
> >
> > Shouldn't a symlink from x86_64/file to ../i386/file work?  git handles
> > symlinks just fine.
> 
> Didn't think of that. Sounds good to me.
> 
> How does a patch to winsup get handled? Given the fact I can't build it,
> should I just let you handle it after the patch is merged into newlib

Just create the patch, I pick up any problems.

> I'll keep plugging at this slowly.

Reply in PM.


Thanks,
Corinna

-- 
Corinna Vinschen
Cygwin Maintainer
Red Hat
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