2011-11-07 Andrew MacLeod <amacleod@redhat.com>
libstdc++-v3
* include/bits/atomic_base.h (atomic_thread_fence): Call builtin.
(atomic_signal_fence): Call builtin.
(atomic_flag::test_and_set): Call __atomic_exchange when it is lockfree,
otherwise fall back to call __sync_lock_test_and_set.
(atomic_flag::clear): Call __atomic_store when it is lockfree,
otherwise fall back to call __sync_lock_release.
gcc
* doc/extend.texi: Docuemnt behaviour change for __atomic_exchange and
__atomic_store.
* optabs.c (expand_atomic_exchange): Expand to __sync_lock_test_and_set
only when originated from that builtin.
(expand_atomic_store): Expand to __sync_lock_release when originated
from that builtin.
* builtins.c (expand_builtin_sync_lock_test_and_set): Add flag that
expand_atomic_exchange call originated from here.
(expand_builtin_sync_lock_release): Add flag that expand_atomic_store
call originated from here.
(expand_builtin_atomic_exchange): Add origination flag.
(expand_builtin_atomic_store): Add origination flag.
* expr.h (expand_atomic_exchange, expand_atomic_store): Add boolean
parameters to indicate implementation fall back options.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@181111 138bc75d-0d04-0410-961f-82ee72b054a4