[arm-embedded] Backport mainline r178852, r172697

[Joey Ye]

Backport mainline r178852, r172697 to ARM/embedded-4_6-branch

Committed.

2011-09-22  Joey Ye  <joey.ye@arm.com>

	Backport r178852 from mainline
	2011-09-14  Julian Brown  <julian@codesourcery.com>

	* config/arm/arm.c (arm_override_options): Add unaligned_access
	support.
	(arm_file_start): Emit attribute for unaligned access as
appropriate.
	* config/arm/arm.md (UNSPEC_UNALIGNED_LOAD)
	(UNSPEC_UNALIGNED_STORE): Add constants for unspecs.
	(insv, extzv): Add unaligned-access support.
	(extv): Change to expander. Likewise.
	(extzv_t1, extv_regsi): Add helpers.
	(unaligned_loadsi, unaligned_loadhis, unaligned_loadhiu)
	(unaligned_storesi, unaligned_storehi): New.
	(*extv_reg): New (previous extv implementation).
	* config/arm/arm.opt (munaligned_access): Add option.
	* config/arm/constraints.md (Uw): New constraint.
	* expmed.c (store_bit_field_1): Adjust bitfield numbering according
	to size of access, not size of unit, when BITS_BIG_ENDIAN !=
	BYTES_BIG_ENDIAN. Don't use bitfield accesses for
	volatile accesses when -fstrict-volatile-bitfields is in effect.
	(extract_bit_field_1): Likewise.

	Backport r172697 from mainline
	2011-04-19  Wei Guozhi  <carrot@google.com>

	PR target/47855
	* config/arm/arm-protos.h (thumb1_legitimate_address_p): New
prototype.
	* config/arm/arm.c (thumb1_legitimate_address_p): Remove the static
	linkage.
	* config/arm/constraints.md (Uu): New constraint.
	* config/arm/arm.md (*arm_movqi_insn): Compute attr "length".