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.

From-SVN: r179383

gcc/ChangeLog

+2011-09-30  Bernd Schmidt  <bernds@codesourcery.com>
+
+	* 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.
+
 2011-09-30  Richard Guenther  <rguenther@suse.de>
 
 	PR middle-end/50574

gcc/config/c6x/c6x.c

@@ -4810,7 +4810,7 @@ split_delayed_branch (rtx insn)
   i1 = emit_insn_before (pat, insn);
   PATTERN (insn) = newpat;
   INSN_CODE (insn) = -1;
-  record_delay_slot_pair (i1, insn, 5);
+  record_delay_slot_pair (i1, insn, 5, 0);
 }
 
 /* Split every insn (i.e. jumps and calls) which can have delay slots into

gcc/doc/invoke.texi

@@ -8474,6 +8474,11 @@ before flushing the current state and starting over.  Large functions
 with few branches or calls can create excessively large lists which
 needlessly consume memory and resources.
 
+@item max-modulo-backtrack-attempts
+The maximum number of backtrack attempts the scheduler should make
+when modulo scheduling a loop.  Larger values can exponentially increase
+compile time.
+
 @item max-inline-insns-single
 Several parameters control the tree inliner used in gcc.
 This number sets the maximum number of instructions (counted in GCC's

gcc/params.def

@@ -165,6 +165,13 @@ DEFPARAM(PARAM_MAX_PENDING_LIST_LENGTH,
 	 "The maximum length of scheduling's pending operations list",
 	 32, 0, 0)
 
+/* This parameter limits the number of backtracking attempts when using the
+   haifa scheduler for modulo scheduling.  */
+DEFPARAM(PARAM_MAX_MODULO_BACKTRACK_ATTEMPTS,
+	 "max-modulo-backtrack-attempts",
+	 "The maximum number of backtrack attempts the scheduler should make when modulo scheduling a loop",
+	 40, 0, 0)
+
 DEFPARAM(PARAM_LARGE_FUNCTION_INSNS,
 	 "large-function-insns",
 	 "The size of function body to be considered large",

gcc/sched-int.h

@@ -1257,7 +1257,7 @@ extern int dep_cost (dep_t);
 extern int set_priorities (rtx, rtx);
 
 extern void sched_setup_bb_reg_pressure_info (basic_block, rtx);
-extern void schedule_block (basic_block *);
+extern bool schedule_block (basic_block *);
 
 extern int cycle_issued_insns;
 extern int issue_rate;
@@ -1330,7 +1330,9 @@ extern int current_blocks;
 extern int target_bb;
 extern bool sched_no_dce;
 
-extern void record_delay_slot_pair (rtx, rtx, int);
+extern void set_modulo_params (int, int, int, int);
+extern void record_delay_slot_pair (rtx, rtx, int, int);
+extern void discard_delay_pairs_above (int);
 extern void free_delay_pairs (void);
 extern void add_delay_dependencies (rtx);
 extern bool sched_is_disabled_for_current_region_p (void);