On Thu, 17 Dec 2020, Patrick Palka via Gcc-patches wrote:
> > >libstdc++-v3/ChangeLog:
> > >
> > > * config/abi/pre/gnu.ver: Add new exports.
> > > * include/std/charconv (to_chars): Declare the floating-point
> > > overloads for float, double and long double.
> > > * src/c++17/Makefile.am (sources): Add floating_to_chars.cc.
> > > * src/c++17/Makefile.in: Regenerate.
> > > * src/c++17/floating_to_chars.cc: New file.
> > > (to_chars): Define for float, double and long double.
> > > * testsuite/20_util/to_chars/long_double.cc: New test.
> >
> > Sorry it took so long to review, this is OK for trunk.
> >
> > The patch needs some minor changes to rebase it on the current trunk:
> > The linker script has additions since you send this patch, so the
> > context in the patch is wrong and it doesn't apply, and in <charconv>
> > the first line of context in the patch needs to have 'noexcept' added.
> > That rebase should be easy though.
> >
> > I'll look at adding __float128 support for powerpc64le.
>
> Thanks a lot. I committed the patch series just now, after rebasing
> and retesting on x86_64, aarch64 and ppc64le.
This breaks with the `vax-netbsdelf' target in GCC compilation:
.../libstdc++-v3/src/c++17/floating_to_chars.cc:126:38: error: static assertion
failed
126 | static_assert(__DBL_MANT_DIG__ == 53);
| ^
make[5]: *** [Makefile:577: floating_to_chars.lo] Error 1
So what's the fallback/alternative for non-IEEE-754 FP targets? Shouldn't
we call into libc (possibly with a warning attribute) for the formats we
don't have explicit handcoded support for?
Maciej
