On Fri, Oct 30, 2020 at 01:52:13PM -0500, Segher Boessenkool wrote:
> On Fri, Oct 30, 2020 at 01:21:34PM -0400, Michael Meissner wrote:
> > David reminded me that not all targets support GLIBC. This patch should
> > fix my
> > previous committed patch not to use TARGET_GLIBC_MAJOR or TARGET_GLIBC_MINOR
> > unless they are defined.
>
> > + This support is only in little endian GLIBC 2.32 or newer. */
> > +static bool
> > +glibc_supports_ieee_128bit (void)
> > +{
> > +#if defined (OPTION_GLIBC) \
> > + && defined (TARGET_GLIBC_MAJOR) \
> > + && defined (TARGET_GLIBC_MINOR)
> > +
> > + if (OPTION_GLIBC
> > + && !BYTES_BIG_ENDIAN
> > + && DEFAULT_ABI == ABI_ELFv2
> > + && ((TARGET_GLIBC_MAJOR * 1000) + TARGET_GLIBC_MINOR) >= 2032)
> > + return true;
> > +#endif /* GLIBC provided. */
> > +
> > + return false;
> > +}
> > +
>
> So this makes the compiler behave differently based on what the libc
> used at build time was (including its version). Can't we do better? :-(
Not really. We have exactly the same issue with __builtin_cpu_supports. At
the end of the day, you have to configure GCC with an appropriate GLIBC.
--
Michael Meissner, IBM
IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA
email: meiss...@linux.ibm.com, phone: +1 (978) 899-4797
