haifa-sched.c (modulo_ii, [...]): New static variables.
* haifa-sched.c (modulo_ii, modulo_max_states, modulo_n_insns,
modulo_insns_scheduled, modulo_iter0_max_uid, modulo_backtracks_left,
modulo_last_stage): New static variables.
(set_modulo_params, discard_delay_pairs_above): New functions.
(struct delay_pair): New member stages.
(htab_i2_traverse, htab_i1_traverse): New static functions.
(record_delay_slot_pair): New arg stages. All callers changed.
Record it.
(pair_delay): Take stages into account.
(add_delay_dependencies): Don't do so for stage pairs.
(struct sched_block_state): New member modulo_epilogue.
(save_backtrack_point): Don't set SHADOW_P for stage pairs.
(unschedule_insns_until): Decrease modulo_insns_scheduled.
Set HARD_DEP without using or.
(resolve_dependencies): New static function.
(prune_ready_list): New arg modulo_epilogue_p. All callers changed.
If it is true, allow only insns with INSN_EXACT_TICK set.
(schedule_block): Return bool, always true for normal scheduling,
true or false depending on modulo scheduling success otherwise.
Add bookkeeping for modulo scheduling, and call resolve_dependencies
on everything left over after a modulo schedule.
(haifa_sched_init): Remove check_cfg call. Clear modulo_ii.
* sched-int.h (schedule_block, record_delay_slot_pair): Adjust
declarations.
(set_modulo_params, discard_delay_pairs_above): Declare.
* params.def (PARAM_MAX_MODULO_BACKTRACK_ATTEMPS): New.
* doc/invoke.texi (--param): Document it.