[Bug libstdc++/65913] [5 Regression] Linking failure without -latomic

["redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65913

--- Comment #9 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Author: redi
Date: Thu Oct  8 16:54:23 2015
New Revision: 228615

URL: https://gcc.gnu.org/viewcvs?rev=228615&root=gcc&view=rev
Log:
Backport PR libstdc++/65913 fix from mainline.

Handle alignment in __atomic_is_lock_free

gcc:

2015-09-17  Richard Henderson  <rth@redhat.com>

        PR libstdc++/65913
        * builtins.c (fold_builtin_atomic_always_lock_free): Handle fake
        pointers that encode the alignment of the object.

libstdc++-v3:

2015-09-17  Jonathan Wakely  <jwakely@redhat.com>

        PR libstdc++/65913
        * include/bits/atomic_base.h (__atomic_base<_TTp>::is_lock_free(),
        __atomic_base<_PTp*>::is_lock_free()): Call the built-in with the
        immediate pointer value, not a variable.
        * include/std/atomic (atomic<T>::is_lock_free()): Likewise.
        * testsuite/29_atomics/atomic/65913.cc: New.

Added:
    branches/gcc-5-branch/libstdc++-v3/testsuite/29_atomics/atomic/65913.cc
Modified:
    branches/gcc-5-branch/gcc/ChangeLog
    branches/gcc-5-branch/gcc/builtins.c
    branches/gcc-5-branch/libstdc++-v3/ChangeLog
    branches/gcc-5-branch/libstdc++-v3/include/bits/atomic_base.h
    branches/gcc-5-branch/libstdc++-v3/include/std/atomic