https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82292
Michael Meissner <meissner at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2017-09-23
CC| |meissner at gcc dot gnu.org
Ever confirmed|0 |1
--- Comment #5 from Michael Meissner <meissner at gcc dot gnu.org> ---
In the GCC build, if you want to disable libquadmath completely, you need to
use both --disable-libquadmath and --disable-libquadmath-support. The
--disable-libquadmath option disables building the quadmath libraries, but it
doesn't disable the checks in libgfortran.
In GCC 7, __float128 was not the default. You didn't need an explicit
--disable-libquad math, because the quadmath library would notice that the
compiler didn't support the __float128 keyword.
As of September 9th, the trunk compiler now enables __float128 by default, and
libquad math normally builds. So, if you want to disable libquadmath and the
fortran support, you need both switches.
BTW, if you use --disable-libquamath without --disable-libquadmath-support on
the x86, it will not build the C++ libraries. Using both switches, will
disable both the libstdc++ and libgfortran support.
I have some patches that allow using --disable-libquadmath to automaically set
--disable-libquadmath-support which will allow the PowerPC to build, but the
x86 will still die in libstdc++, so I'm not sure how useful these patches are.
I would recommend dropping the --disable-quadmath configure option, and build
the quadmath libraries now.
