i don't see corresponding email thread in gcc-patches, but since this commit: https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=251260
i see arm-* native compiler miscompile libstdc++, note that the cross compiler compiles it correctly. i guess it can be some latent bug that got uncovered, but it is reliably reproducible, i reported https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81982 those who run native arm gcc tests may see c++ execution tests timeout while spinning in __cxa_guard_acquire around a futex syscall. i'm still debugging it, but ideas and help is welcome.
