pa.md (UNSPEC_MEMORY_BARRIER): New unspec enum.

pa.md (UNSPEC_MEMORY_BARRIER): New unspec enum.

	gcc
	* config/pa/pa.md (UNSPEC_MEMORY_BARRIER): New unspec enum.
	Update comment for atomic instructions.
	(atomic_storeqi, atomic_storehi, atomic_storesi, atomic_storesf,
	atomic_loaddf, atomic_loaddf_1, atomic_storedf, atomic_storedf_1):
	Remove.
	(atomic_loaddi): Revise fence expansion to only emit fence prior to
	load for __ATOMIC_SEQ_CST model.
	(atomic_loaddi_1): Remove float register target.
	(atomic_storedi): Handle CONST_INT values.
	(atomic_storedi_1): Remove float register source.  Add special case
	for zero value.
	(memory_barrier): New expander and insn.

	libgcc
	* config/pa/linux-atomic.c: Update comment.
	(FETCH_AND_OP_2, OP_AND_FETCH_2, FETCH_AND_OP_WORD, OP_AND_FETCH_WORD,
	COMPARE_AND_SWAP_2, __sync_val_compare_and_swap_4,
	SYNC_LOCK_TEST_AND_SET_2, __sync_lock_test_and_set_4): Use
	__ATOMIC_RELAXED for atomic loads.
	(SYNC_LOCK_RELEASE_1): New define.  Use __sync_synchronize() and
	unordered store to release lock.
	(__sync_lock_release_8): Likewise.
	(SYNC_LOCK_RELEASE_2): Remove define.

From-SVN: r263488