[Bug libstdc++/87744] Some valid instantiations of linear_congruential_engine produce compiler errors when __int128 isn't available

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87744

--- Comment #15 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jonathan Wakely <r...@gcc.gnu.org>:

https://gcc.gnu.org/g:c9ce332b557bb95987d038d98ea929cdfd1eae1d

commit r14-8998-gc9ce332b557bb95987d038d98ea929cdfd1eae1d
Author: Jonathan Wakely <jwak...@redhat.com>
Date:   Wed Feb 7 11:31:10 2024 +0000

    libstdc++: Use 128-bit arithmetic for std::linear_congruential_engine
[PR87744]

    For 32-bit targets without __int128 we need to implement the LCG
    transition function by hand using 64-bit types.

    We can also slightly simplify the __mod function by using if-constexpr
    unconditionally, disabling -Wc++17-extensions warnings with diagnostic
    pragmas.

    libstdc++-v3/ChangeLog:

            PR libstdc++/87744
            * include/bits/random.h [!__SIZEOF_INT128__]
(_Select_uint_least_t):
            Define specialization for 64-bit generators with
            non-power-of-two modulus and large constants.
            (__mod): Use if constexpr unconditionally.
            * testsuite/26_numerics/random/pr60037-neg.cc: Adjust dg-error
            line number.
            * testsuite/26_numerics/random/linear_congruential_engine/87744.cc:
            New test.