[Bug libstdc++/124657] New: experimental/simd/pr109261_constexpr_simd.cc fails to compile on x86_64 with -mlong-double-64

[aoliva at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124657

            Bug ID: 124657
           Summary: experimental/simd/pr109261_constexpr_simd.cc fails to
                    compile on x86_64 with -mlong-double-64
           Product: gcc
           Version: 16.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: aoliva at gcc dot gnu.org
                CC: mkretz at gcc dot gnu.org
  Target Milestone: ---

The immediate problem manifests as missing overloads for vector(2) long double,
because __v2df is a distinct type, but I guess we're missing something similar
to what maps long to int or long long to map long double vectors to double
vectors and vice-versa.

This might be present on ppc as well, since -mlong-double-64 needs similar
workarounds there.