[Bug target/94630] General bug for changes needed to switch the powerpc64le-linux long double default

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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94630

--- Comment #9 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Michael Meissner <meissner@gcc.gnu.org>:

https://gcc.gnu.org/g:4c5d76a655b9abdacaa992ab1167b33d35c3ffe9

commit r12-3151-g4c5d76a655b9abdacaa992ab1167b33d35c3ffe9
Author: Michael Meissner <meissner@linux.ibm.com>
Date:   Wed Aug 25 19:25:12 2021 -0400

    Fix tests that require IBM 128-bit long double

    This patch adds 3 more selections to target-supports.exp to see if we can
    specify to use a particular long double format (IEEE 128-bit, IBM extended
    double, 64-bit), and the library support will track the changes for the
long
    double.  This is needed because two of the tests in the test suite use long
    double, and they are actually testing IBM extended double.

    This patch also forces the two tests that explicitly require long double
    to use the IBM double-double encoding to explicitly run the test.  This
    requires GLIBC 2.32 or greater in order to do the switch.

    I have run tests on a little endian power9 system with 3 compilers.  There
were
    no regressions with these patches, and the two tests in the following
patches
    now work if the default long double is not IBM 128-bit:

     * One compiler used the default IBM 128-bit format;
     * One compiler used the IEEE 128-bit format; (and)
     * One compiler used 64-bit long doubles.

    I have also tested compilers on a big endian power8 system with a compiler
    defaulting to power8 code generation and another with the default cpu
    set.  There were no regressions.

    2021-08-25  Michael Meissner  <meissner@linux.ibm.com>

    gcc/testsuite/
            PR target/94630
            * gcc.target/powerpc/pr70117.c: Specify that we need the long
double
            type to be IBM 128-bit.  Remove the code to use __ibm128.
            * c-c++-common/dfp/convert-bfp-11.c: Specify that we need the long
            double type to be IBM 128-bit.  Run the test at -O2 optimization.
            * lib/target-supports.exp (add_options_for_long_double_ibm128): New
            function.
            (check_effective_target_long_double_ibm128): New function.
            (add_options_for_long_double_ieee128): New function.
            (check_effective_target_long_double_ieee128): New function.
            (add_options_for_long_double_64bit): New function.
            (check_effective_target_long_double_64bit): New function.