haifa-sched.c: Include "hashtab.h"

	* haifa-sched.c: Include "hashtab.h"
	(sched_no_dce): New global variable.
	(INSN_EXACT_TICK, INSN_TICK_ESTIMATE, FEEDS_BACKTRACK_INSN,
	SHADOW_P): New macros.
	(last_clock_var, cycle_issued_insns): Move declarations.
	(must_backtrack): New static variable.
	(struct delay_pair): New structure.
	(delay_htab, delay_htab_i2): New static variables.
	(delay_hash_i1, delay_hash_i2, delay_i1_eq, delay_i2_eq,
	record_delay_slot_pair, pair_delay, add_delay_dependencies): New
	functions.
	(dep_cost_1): If delay pairs exist, try to look up the insns and
	use the correct pair delay if we find them.
	(rank-for_schedule): Tweak priority for insns that must be scheduled
	soon to avoid backtracking.
	(queue_insn): Detect conditions which force backtracking.
	(ready_add): Likewise.
	(struct sched_block_state): Add member shadows_only_p.
	(struct haifa_save_data): New structure.
	(backtrack_queue): New static variable.
	(mark_backtrack_feeds, copy_insn_list, save_backtrack_point,
	unschedule_insns_until, restore_last_backtrack_point,
	free_topmost_backtrack_point, free_backtrack_queue,
	estimate_insn_tick, estimate_shadow_tick): New functions.
	(prune_ready_list): New arg shadows_only_p.  All callers changed.
	If true, remove everything that isn't SHADOW_P.  Look up delay
	pairs and estimate ticks to avoid scheduling the first insn too
	early.
	(verify_shadows): New function.
	(schedule_block): Add machinery to enable backtracking.
	(sched_init): Take sched_no_dce into account when setting
	DF_LR_RUN_DCE.
	(free_delay_pairs): New function.
	(init_h_i_d): Initialize INSN_EXACT_TICK.
	* Makefile.in (haifa-sched.o): Add $(HASHTAB_H).
	* sched-deps.c (sd_unresolve_dep): New function.
	* sched-int.h (struct haifa_sched_info): New fields save_state
	and restore_state.
	(struct _haifa_insn_data): New fields exact_tick, tick_estimate,
	feeds_backtrack_insn and shadow_p.
	(DO_BACKTRACKING): New value in enum SCHED_FLAGS.
	(sched_no_dce): Declare variable.
	(record_delay_slot_pair, free_delay_pairs, add_delay_dependencies,
	sd_unresolve_dep): Declare functions.
	* modulo-sched.c (sms_sched_info): Clear the two new fields.
	* sched-rgn.c (rgn_const_sched_info): Likewise.
	* sel-sched-ir.c (sched_sel_haifa_sched_info): Likewise.
	* sched-ebb.c (save_ebb_state, restore_ebb_state): New functions.
	(ebb_sched_info): Add them for the two new fields.
	(add_deps_for_risky_insns): Call add_delay_dependencies.

From-SVN: r176255