[Bug libgcc/71744] Concurrently throwing exceptions is not scalable

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71744

--- Comment #29 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Author: jakub
Date: Fri Sep 16 19:17:47 2016
New Revision: 240193

URL: https://gcc.gnu.org/viewcvs?rev=240193&root=gcc&view=rev
Log:
        PR libgcc/71744
        * unwind-dw2-fde.c (ATOMIC_FDE_FAST_PATH): Define if __register_frame*
        is not the primary registry and atomics are available.
        (any_objects_registered): New variable.
        (__register_frame_info_bases, __register_frame_info_table_bases):
        Atomically store 1 to any_objects_registered after registering first
        unwind info.
        (_Unwind_Find_FDE): Return early if any_objects_registered is 0.

Modified:
    trunk/libgcc/ChangeLog
    trunk/libgcc/unwind-dw2-fde.c