__setfpucw in glibc 2.0.7

[Thorsten Kukuk]

On Sat, Jul 24, H.J. Lu wrote:

> > 
> > hjl@lucon.org (H.J. Lu) writes:
> > 
> > > __setfpucw is the only function available in glibc 2.0.7
> > > to control the FPU at the run-time. There is <fenv.h> in
> > > glibc 2.1. But it is not available in glibc 2.0. I believe
> > > we should export it in glibc 2.1.2.
> > 
> > No.  Nobody outside the libc should have used it.  This function is
> > not portable.  Therefore people should have used asms which at least
> > is portable on machines of the same architecure.
> > 
> 
> It is in glibc 2.0 and it is used by some programs. It
> doesn't make any senses to break existing binaries. At
> least, it should be global as the glibc 2.0 symbol
> and local as the glibc 2.1 symbol so that ld won't use
> it. People have been complaining about the Linux library
> upgrade. Why don't we try to avoid the binary incompatibility
> as much as we can?

As far as I know, on our 6 SuSE Linux 6.2 CDs is only one program
which uses __setfpucw. And for this I use the same workaround as
for the applixware binaries.

It would be really interesting to know how many programs are
affected. It looks for me we waste more time in discussing this
than we would need to fix this few programs.

  Thorsten
-- 
Thorsten Kukuk       http://www.suse.de/~kukuk/       kukuk@suse.de
SuSE GmbH            Schanzaeckerstr. 10            90443 Nuernberg
Linux is like a Vorlon.  It is incredibly powerful, gives terse,
cryptic answers and has a lot of things going on in the background.