re PR rtl-optimization/44194 (struct returned by value generates useless stores)

re PR rtl-optimization/44194 (struct returned by value generates useless stores)

	PR rtl-optimization/44194
	* calls.c (expand_call): In the PARALLEL case, copy the return value
	into pseudos instead of spilling it onto the stack.
	* emit-rtl.c (adjust_address_1): Rename ADJUST into ADJUST_ADDRESS and
	add new ADJUST_OBJECT parameter.
	If ADJUST_OBJECT is set, drop the underlying object if it cannot be
	proved that the adjusted memory access is still within its bounds.
	(adjust_automodify_address_1): Adjust call to adjust_address_1.
	(widen_memory_access): Likewise.
	* expmed.c (store_bit_field_1): Call adjust_bitfield_address instead
	of adjust_address.  Do not drop the underlying object of a MEM.
	(store_fixed_bit_field): Likewise.
	(extract_bit_field_1): Likewise.  Fix oversight in recursion.
	(extract_fixed_bit_field): Likewise.
	* expr.h (adjust_address_1): Adjust prototype.
	(adjust_address): Adjust call to adjust_address_1.
	(adjust_address_nv): Likewise.
	(adjust_bitfield_address): New macro.
	(adjust_bitfield_address_nv): Likewise.
	* expr.c (expand_assignment): Handle a PARALLEL in more cases.
	(store_expr): Likewise.
	(store_field): Likewise.

	* dse.c: Fix typos in the head comment.

From-SVN: r191302