[Bug c++/60272] atomic<>::compare_exchange_weak has spurious store and can cause race conditions

[rth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60272

--- Comment #4 from Richard Henderson <rth at gcc dot gnu.org> ---
Author: rth
Date: Thu Feb 20 17:43:53 2014
New Revision: 207966

URL: http://gcc.gnu.org/viewcvs?rev=207966&root=gcc&view=rev
Log:
PR c++/60272

gcc/
    * builtins.c (expand_builtin_atomic_compare_exchange): Conditionalize
    on failure the store back into EXPECT.
libatomic/
    * cas_n.c (libat_compare_exchange): Conditionalize on failure
    the store back to EPTR.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/builtins.c
    trunk/libatomic/ChangeLog
    trunk/libatomic/cas_n.c