arm.c (arm_emit_load_exclusive): Add acq parameter.

arm.c (arm_emit_load_exclusive): Add acq parameter.

2013-03-25  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>

	* config/arm/arm.c (arm_emit_load_exclusive): Add acq parameter.
	Emit load-acquire versions when acq is true.
	(arm_emit_store_exclusive): Add rel parameter.
	Emit store-release versions when rel is true.
	(arm_split_compare_and_swap): Use acquire-release instructions
	instead.
	of barriers when appropriate.
	(arm_split_atomic_op): Likewise.
	* config/arm/arm.h (TARGET_HAVE_LDACQ): New macro.
	* config/arm/unspecs.md (VUNSPEC_LAX): New unspec.
	(VUNSPEC_SLX): Likewise.
	(VUNSPEC_LDA): Likewise.
	(VUNSPEC_STL): Likewise.
	* config/arm/sync.md (atomic_load<mode>): New pattern.
	(atomic_store<mode>): Likewise.
	(arm_load_acquire_exclusive<mode>): Likewise.
	(arm_load_acquire_exclusivesi): Likewise.
	(arm_load_acquire_exclusivedi): Likewise.
	(arm_store_release_exclusive<mode>): Likewise.

From-SVN: r197046