[Bug tree-optimization/102571] FAIL: libgomp.c/../libgomp.c-c++-common/atomic-21.c execution test

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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102571

--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jakub Jelinek <jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:ba837323dbda2bca5a1c8a4c78092a88241dcfa3

commit r12-4207-gba837323dbda2bca5a1c8a4c78092a88241dcfa3
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Wed Oct 6 10:40:12 2021 +0200

    openmp: Optimize for OpenMP atomics
2x__builtin_clear_padding+__builtin_memcmp if possible

    For the few long double types that do have padding bits, e.g. on x86
    the clear_type_padding_in_mask computed mask is
    ff ff ff ff ff ff ff ff ff ff 00 00 for 32-bit and
    ff ff ff ff ff ff ff ff ff ff 00 00 00 00 00 00 for 64-bit.
    Instead of doing __builtin_clear_padding on both operands that will clear
the
    last 2 or 6 bytes and then memcmp on the whole 12/16 bytes, we can just
    memcmp 10 bytes.  The code also handles if the padding would be at the
start
    or both at the start and end, but everything on byte boundaries only and
    non-padding bits being contiguous.
    This works around a tree-ssa-dse.c bug (but we need to fix it anyway,
    as libstdc++ won't do this and as it can deal with arbitrary types, it even
    can't do that generally).

    2021-10-06  Jakub Jelinek  <jakub@redhat.com>

            PR tree-optimization/102571
            * c-omp.c (c_finish_omp_atomic): Optimize the case where type has
            padding, but the non-padding bits are contiguous set of bytes
            by adjusting the memcmp call arguments instead of emitting
            __builtin_clear_padding and then comparing all the type's bytes.