[Bug c++/104722] Wrong std::accumulate result with -D_GLIBCXX_PARALLEL flag

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104722

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
See e.g. https://blog.tartanllama.xyz/accumulate-vs-reduce/ for more details.