PR rtl-optimization/42575
	* dce.c (word_dce_process_block): Renamed from byte_dce_process_block.
	Argument AU removed.  All callers changed.  Ignore artificial refs.
	Use return value of df_word_lr_simulate_defs to decide whether an insn
	is necessary.
	(fast_dce): Rename arg to WORD_LEVEL.
	(run_word_dce): Renamed from rest_of_handle_fast_byte_dce.  No longer
	static.
	(pass_fast_rtl_byte_dce): Delete.
	* dce.h (run_word_dce): Declare.
	* df-core.c (df_print_word_regset): Renamed from df_print_byteregset.
	All callers changed.  Simplify code to only deal with two-word regs.
	* df.h (DF_WORD_LR): Renamed from DF_BYTE_LR.
	(DF_WORD_LR_BB_INFO): Renamed from DF_BYTE_LR_BB_INFO.
	(DF_WORD_LR_IN): Renamed from DF_BYTE_LR_IN.
	(DF_WORD_LR_OUT): Renamed from DF_BYTE_LR_OUT.
	(struct df_word_lr_bb_info): Renamed from df_byte_lr_bb_info.
	(df_word_lr_mark_ref): Declare.
	(df_word_lr_add_problem, df_word_lr_mark_ref, df_word_lr_simulate_defs,
	df_word_lr_simulate_uses): Declare or rename from byte variants.
	(df_byte_lr_simulate_artificial_refs_at_top,
	df_byte_lr_simulate_artificial_refs_at_end, df_byte_lr_get_regno_start,
	df_byte_lr_get_regno_len, df_compute_accessed_bytes): Delete
	declarations.
	(df_word_lr_get_bb_info): Rename from df_byte_lr_get_bb_info.
	(enum df_mm): Delete.
	* df-byte-scan.c: Delete file.
	* df-problems.c (df_word_lr_problem_data): Renamed from
	df_byte_lr_problem_data, all members deleted except for
	WORD_LR_BITMAPS, which is renamed from BYTE_LR_BITMAPS.  Uses changed.
	(df_word_lr_expand_bitmap, df_byte_lr_simulate_artificial_refs_at_top,
	df_byte_lr_simulate_artificial_refs_at_end, df_byte_lr_get_regno_start,
	df_byte_lr_get_regno_len, df_byte_lr_check_regs,
	df_byte_lr_confluence_0): Delete functions.
	(df_word_lr_free_bb_info): Renamed from df_byte_lr_free_bb_info; all
	callers changed.
	(df_word_lr_alloc): Renamed from df_byte_lr_alloc; all callers changed.
	Don't initialize members that were deleted, don't try to discover data
	about registers.  Ignore hard regs.
	(df_word_lr_reset): Renamed from df_byte_lr_reset; all callers changed.
	(df_word_lr_mark_ref): New function.
	(df_word_lr_bb_local_compute): Renamed from
	df_byte_bb_lr_local_compute; all callers changed.  Use
	df_word_lr_mark_ref.  Assert that artificial refs don't include
	pseudos.  Ignore hard registers.
	(df_word_lr_local_compute): Renamed from df_byte_lr_local_compute.
	Assert that exit block uses don't contain pseudos.
	(df_word_lr_init): Renamed from df_byte_lr_init; all callers changed.
	(df_word_lr_confluence_n): Renamed from df_byte_lr_confluence_n; all
	callers changed.  Ignore hard regs.
	(df_word_lr_transfer_function): Renamed from
	df_byte_lr_transfer_function; all callers changed.
	(df_word_lr_free): Renamed from df_byte_lr_free; all callers changed.
	(df_word_lr_top_dump): Renamed from df_byte_lr_top_dump; all callers
	changed.
	(df_word_lr_bottom_dump): Renamed from df_byte_lr_bottom_dump; all
	callers changed.
	(problem_WORD_LR): Renamed from problem_BYTE_LR; uses changed;
	confluence operator 0 set to NULL.
	(df_word_lr_add_problem): Renamed from df_byte_lr_add_problem; all
	callers changed.
	(df_word_lr_simulate_defs): Renamed from df_byte_lr_simulate_defs.
	Return bool, true if bitmap changed or insn otherwise necessary.
	All callers changed.  Simplify using df_word_lr_mark_ref.
	(df_word_lr_simulate_uses): Renamed from df_byte_lr_simulate_uses;
	all callers changed.  Simplify using df_word_lr_mark_ref.
	* lower-subreg.c: Include "dce.h"
	(decompose_multiword_subregs): Call run_word_dce if df available.
	* Makefile.in (lower-subreg.o): Adjust dependencies.
	(df-byte-scan.o): Delete.
	* timevar.def (TV_DF_WORD_LR): Renamed from TV_DF_BYTE_LR.

From-SVN: r162678