re PR target/52080 (Stores to bitfields introduce a store-data-race on adjacent data)

re PR target/52080 (Stores to bitfields introduce a store-data-race on adjacent data)

2012-03-14  Richard Guenther  <rguenther@suse.de>

	* tree.h (DECL_BIT_FIELD_REPRESENTATIVE): New define.
	* stor-layout.c (start_bitfield_representative): New function.
	(finish_bitfield_representative): Likewise.
	(finish_bitfield_layout): Likewise.
	(finish_record_layout): Call finish_bitfield_layout.
	* tree.c (free_lang_data_in_decl): Only free DECL_QUALIFIER
	for QUAL_UNION_TYPE fields.
	* tree-streamer-in.c (lto_input_ts_field_decl_tree_pointers):
	Stream DECL_BIT_FIELD_REPRESENTATIVE.
	* tree-streamer-out.c (write_ts_field_decl_tree_pointers): Likewise.

	PR middle-end/52080
	PR middle-end/52097
	PR middle-end/48124
	* expr.c (get_bit_range): Unconditionally extract bitrange
	from DECL_BIT_FIELD_REPRESENTATIVE.
	(expand_assignment): Adjust call to get_bit_range.

	* gcc.dg/torture/pr48124-1.c: New testcase.
	* gcc.dg/torture/pr48124-2.c: Likewise.
	* gcc.dg/torture/pr48124-3.c: Likewise.
	* gcc.dg/torture/pr48124-4.c: Likewise.

From-SVN: r185379