re PR middle-end/54146 (Very slow compile with attribute((flatten)))

re PR middle-end/54146 (Very slow compile with attribute((flatten)))

	PR middle-end/54146
	* tree-ssa-loop-im.c (lim_bitmap_obstack): New bitmap_obstack.
	(memref_free): Don't free the bitmaps individually here.
	(mem_ref_alloc): Allocate the bitmaps on the new bitmap obstack.
	(analyze_memory_references): Likewise.
	(tree_ssa_lim_initialize): Initialize the new bitmap obstack.
	(tree_ssa_lim_finalize): Release it.
	* dse.c (dse_bitmap_obstack): New bitmap obstack.
	(dse_obstack): New obstack.
	(get_group_info): Allocate the bitmaps on the new bitmap obstack.
	(dse_step0): Allocate the scratch bitmap on reg_obstack.  Initialize
	the new bitmap obstack and normal obstack.  Use XNEWVEC for bb_table.
	(record_store): Allocate regs_set on reg_obstack.
	(dse_step1): Allocate regs_live on reg_obstack.
	(dse_step2_init): Allocate offset_map_n and offset_map_p on the new
	obstack.
	(dse_step3_scan): Allocate bitmaps on the new bitmap obstack.
	(dse_step3): Likewise.
	(dse_confluence_0): Likewise.
	(dse_confluence_n): Likewise.
	(dse_transfer_function): Likewise.
	(dse_step7): Destroy the new obstacks, and everything allocated on
	them, in one big sweep.
	(rest_of_handle_dse): Update.
	* cfgexpand.c (stack_var_bitmap_obstack): New bitmap obstack.
	(add_stack_var_conflict): Allocate bitmaps on it.
	(add_scope_conflicts_1): Likewise.
	(add_scope_conflicts): Likewise.
	(update_alias_info_with_stack_vars): Likewise.
	(init_vars_expansion): Move TREE_USED fiddling expand_used_vars.
	Initialize the new bitmap obstack.
	(fini_vars_expansion): Release it.
	(estimated_stack_frame_size): Use init_vars_expansion to set things up
	and always clean up at the end.
	(expand_used_vars): Do the TREE_USED trickery here.  Always call
	fini_vars_expansion.
	* tree-ssa-live.h (struct tree_live_info_d): Make livein and liveout
	arrays of bitmap_head to avoid one indirection per bitmap access.
	(live_on_entry, live_on_exit, live_var_map, live_merge_and_clear,
	make_live_on_entry): Update.
	* tree-ssa-live.c (partition_view_bitmap): Don't double-free 'used'.
	(liveness_bitmap_obstack): New bitmap obstack.
	(remove_unused_locals): Use it to allocate all bitmaps on.  Update
	for livein/liveout changes in tree-ssa-live.h.
	(delete_tree_live_info): Release the bitmap obstack.
	(loe_visit_block, live_worklist, set_var_live_on_entry,
	calculate_live_on_exit, dump_live_info): Update.
	(calculate_live_ranges): Initialize the bitmap.
	* tree-ssa-ter.c (ter_bitmap_obstack): New bitmap obstack.
	(new_temp_expr_table): Allocate bitmap on it.
	(make_dependent_on_partition, add_to_partition_kill_list,
	add_dependence, process_replaceable): Likewise.
	(find_replaceable_exprs): Initialize and release the new obstack here.
	* df-problems.c (df_lr_add_problem): Allocate persistent bitmap
	for out_of_date_transfer_functions on df_bitmap_obstack.
	(df_live_add_problem): Likewise.
	(df_chain_add_problem): Likewise.
	(df_word_lr_add_problem): Likewise.

From-SVN: r190475