2 * Scheduling algorithms.
3 * Just a simple list scheduling algorithm is here.
5 * @author Sebastian Hack
24 #include "iredges_t.h"
29 #include "irprintf_t.h"
35 #include "besched_t.h"
38 #include "belistsched.h"
39 #include "beschedmris.h"
40 #include "beschedrss.h"
45 #include <libcore/lc_opts.h>
46 #include <libcore/lc_opts_enum.h>
48 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL);
50 #define BE_SCHED_NODE(irn) (be_is_Keep(irn) || be_is_CopyKeep(irn) || be_is_RegParams(irn))
53 BE_SCHED_SELECT_TRIVIAL = 0,
54 BE_SCHED_SELECT_REGPRESS = 1,
55 BE_SCHED_SELECT_MUCHNIK = 2,
56 BE_SCHED_SELECT_HEUR = 3,
57 BE_SCHED_SELECT_HMUCHNIK = 4,
58 BE_SCHED_SELECT_RANDOM = 5
62 BE_SCHED_PREP_NONE = 0,
63 BE_SCHED_PREP_MRIS = 2,
67 typedef struct _list_sched_options_t {
68 int select; /**< the node selector */
69 int prep; /**< schedule preparation */
70 } list_sched_options_t;
72 static list_sched_options_t list_sched_options = {
73 BE_SCHED_SELECT_HEUR, /* mueller heuristic selector */
74 BE_SCHED_PREP_NONE, /* no scheduling preparation */
77 /* schedule selector options. */
78 static const lc_opt_enum_int_items_t sched_select_items[] = {
79 { "trivial", BE_SCHED_SELECT_TRIVIAL },
80 { "random", BE_SCHED_SELECT_RANDOM },
81 { "regpress", BE_SCHED_SELECT_REGPRESS },
82 { "muchnik", BE_SCHED_SELECT_MUCHNIK },
83 { "heur", BE_SCHED_SELECT_HEUR },
84 { "hmuchnik", BE_SCHED_SELECT_HMUCHNIK },
88 /* schedule preparation options. */
89 static const lc_opt_enum_int_items_t sched_prep_items[] = {
90 { "none", BE_SCHED_PREP_NONE },
91 { "mris", BE_SCHED_PREP_MRIS },
92 { "rss", BE_SCHED_PREP_RSS },
96 static lc_opt_enum_int_var_t sched_select_var = {
97 &list_sched_options.select, sched_select_items
100 static lc_opt_enum_int_var_t sched_prep_var = {
101 &list_sched_options.prep, sched_prep_items
104 static const lc_opt_table_entry_t list_sched_option_table[] = {
105 LC_OPT_ENT_ENUM_PTR("prep", "schedule preparation", &sched_prep_var),
106 LC_OPT_ENT_ENUM_PTR("select", "node selector", &sched_select_var),
111 * All scheduling info needed per node.
113 typedef struct _sched_irn_t {
114 unsigned num_not_sched_user; /**< The number of not yet scheduled users of this node */
115 unsigned already_sched : 1; /**< Set if this node is already scheduled */
119 * Scheduling environment for the whole graph.
121 typedef struct _sched_env_t {
122 sched_irn_t *sched_info; /**< scheduling info per node */
123 const list_sched_selector_t *selector; /**< The node selector. */
124 const arch_env_t *arch_env; /**< The architecture environment. */
125 const ir_graph *irg; /**< The graph to schedule. */
126 void *selector_env; /**< A pointer to give to the selector. */
130 * Environment for a block scheduler.
132 typedef struct _block_sched_env_t {
133 sched_irn_t *sched_info; /**< scheduling info per node, copied from the global scheduler object */
134 ir_nodeset_t cands; /**< the set of candidates */
135 ir_node *block; /**< the current block */
136 sched_env_t *sched_env; /**< the scheduler environment */
137 ir_nodeset_t live; /**< simple liveness during scheduling */
138 const list_sched_selector_t *selector;
139 void *selector_block_env;
143 * Returns non-zero if the node is already scheduled
145 static INLINE int is_already_scheduled(block_sched_env_t *env, ir_node *n)
147 int idx = get_irn_idx(n);
149 assert(idx < ARR_LEN(env->sched_info));
150 return env->sched_info[idx].already_sched;
154 * Mark a node as already scheduled
156 static INLINE void mark_already_scheduled(block_sched_env_t *env, ir_node *n)
158 int idx = get_irn_idx(n);
160 assert(idx < ARR_LEN(env->sched_info));
161 env->sched_info[idx].already_sched = 1;
165 * Try to put a node in the ready set.
166 * @param env The block scheduler environment.
167 * @param pred The previous scheduled node.
168 * @param irn The node to make ready.
169 * @return 1, if the node could be made ready, 0 else.
171 static INLINE int make_ready(block_sched_env_t *env, ir_node *pred, ir_node *irn)
175 /* Blocks cannot be scheduled. */
176 if (is_Block(irn) || get_irn_n_edges(irn) == 0)
180 * Check, if the given ir node is in a different block as the
181 * currently scheduled one. If that is so, don't make the node ready.
183 if (env->block != get_nodes_block(irn))
186 for (i = 0, n = get_irn_ins_or_deps(irn); i < n; ++i) {
187 ir_node *op = get_irn_in_or_dep(irn, i);
189 /* if irn is an End we have keep-alives and op might be a block, skip that */
191 assert(get_irn_op(irn) == op_End);
195 /* If the operand is local to the scheduled block and not yet
196 * scheduled, this nodes cannot be made ready, so exit. */
197 if (! is_already_scheduled(env, op) && get_nodes_block(op) == env->block)
201 ir_nodeset_insert(&env->cands, irn);
203 /* Notify selector about the ready node. */
204 if (env->selector->node_ready)
205 env->selector->node_ready(env->selector_block_env, irn, pred);
207 DB((dbg, LEVEL_2, "\tmaking ready: %+F\n", irn));
213 * Try, to make all users of a node ready.
214 * In fact, a usage node can only be made ready, if all its operands
215 * have already been scheduled yet. This is checked by make_ready().
216 * @param env The block schedule environment.
217 * @param irn The node, which usages (successors) are to be made ready.
219 static INLINE void make_users_ready(block_sched_env_t *env, ir_node *irn)
221 const ir_edge_t *edge;
223 foreach_out_edge(irn, edge) {
224 ir_node *user = get_edge_src_irn(edge);
226 make_ready(env, irn, user);
229 foreach_out_edge_kind(irn, edge, EDGE_KIND_DEP) {
230 ir_node *user = get_edge_src_irn(edge);
232 make_ready(env, irn, user);
237 * Returns the number of not yet schedules users.
239 static INLINE int get_irn_not_sched_user(block_sched_env_t *env, ir_node *n) {
240 int idx = get_irn_idx(n);
242 assert(idx < ARR_LEN(env->sched_info));
243 return env->sched_info[idx].num_not_sched_user;
247 * Sets the number of not yet schedules users.
249 static INLINE void set_irn_not_sched_user(block_sched_env_t *env, ir_node *n, int num) {
250 int idx = get_irn_idx(n);
252 assert(idx < ARR_LEN(env->sched_info));
253 env->sched_info[idx].num_not_sched_user = num;
257 * Add @p num to the number of not yet schedules users and returns the result.
259 static INLINE int add_irn_not_sched_user(block_sched_env_t *env, ir_node *n, int num) {
260 int idx = get_irn_idx(n);
262 assert(idx < ARR_LEN(env->sched_info));
263 env->sched_info[idx].num_not_sched_user += num;
264 return env->sched_info[idx].num_not_sched_user;
268 * Returns the number of users of a node having mode datab.
270 static int get_num_successors(ir_node *irn) {
272 const ir_edge_t *edge;
274 if (get_irn_mode(irn) == mode_T) {
275 /* for mode_T nodes: count the users of all Projs */
276 foreach_out_edge(irn, edge) {
277 ir_node *proj = get_edge_src_irn(edge);
278 ir_mode *mode = get_irn_mode(proj);
281 sum += get_num_successors(proj);
282 else if (mode_is_datab(mode))
283 sum += get_irn_n_edges(proj);
287 /* do not count keep-alive edges */
288 foreach_out_edge(irn, edge) {
289 if (get_irn_opcode(get_edge_src_irn(edge)) != iro_End)
298 * Adds irn to @p live, updates all inputs that this user is scheduled
299 * and counts all of it's non scheduled users.
301 static void update_sched_liveness(block_sched_env_t *env, ir_node *irn) {
308 for (i = get_irn_ins_or_deps(irn) - 1; i >= 0; --i) {
309 ir_node *in = get_irn_in_or_dep(irn, i);
311 /* if in is a proj: update predecessor */
313 in = get_Proj_pred(in);
315 /* if in is still in the live set: reduce number of users by one */
316 if (ir_nodeset_contains(&env->live, in)) {
317 if (add_irn_not_sched_user(env, in, -1) <= 0)
318 ir_nodeset_remove(&env->live, in);
323 get_num_successors returns the number of all users. This includes
324 users in different blocks as well. As the each block is scheduled separately
325 the liveness info of those users will not be updated and so these
326 users will keep up the register pressure as it is desired.
328 i = get_num_successors(irn);
330 set_irn_not_sched_user(env, irn, i);
331 ir_nodeset_insert(&env->live, irn);
335 static INLINE int must_appear_in_schedule(const list_sched_selector_t *sel, void *block_env, const ir_node *irn)
339 if (get_irn_n_edges(irn) < 1)
342 if (sel->to_appear_in_schedule)
343 res = sel->to_appear_in_schedule(block_env, irn);
345 return res >= 0 ? res : ((to_appear_in_schedule(irn) || BE_SCHED_NODE(irn)) && ! is_Unknown(irn));
349 * Append an instruction to a schedule.
350 * @param env The block scheduling environment.
351 * @param irn The node to add to the schedule.
352 * @return The given node.
354 static ir_node *add_to_sched(block_sched_env_t *env, ir_node *irn)
356 /* If the node consumes/produces data, it is appended to the schedule
357 * list, otherwise, it is not put into the list */
358 if (must_appear_in_schedule(env->selector, env->selector_block_env, irn)) {
359 update_sched_liveness(env, irn);
360 sched_add_before(env->block, irn);
362 DBG((dbg, LEVEL_2, "\tadding %+F\n", irn));
365 /* notify the selector about the finally selected node. */
366 if (env->selector->node_selected)
367 env->selector->node_selected(env->selector_block_env, irn);
369 /* Insert the node in the set of all already scheduled nodes. */
370 mark_already_scheduled(env, irn);
372 /* Remove the node from the ready set */
373 ir_nodeset_remove(&env->cands, irn);
379 * Add the proj nodes of a tuple-mode irn to the schedule immediately
380 * after the tuple-moded irn. By pinning the projs after the irn, no
381 * other nodes can create a new lifetime between the tuple-moded irn and
382 * one of its projs. This should render a realistic image of a
383 * tuple-moded irn, which in fact models a node which defines multiple
386 * @param irn The tuple-moded irn.
388 static void add_tuple_projs(block_sched_env_t *env, ir_node *irn)
390 const ir_edge_t *edge;
392 assert(get_irn_mode(irn) == mode_T && "Mode of node must be tuple");
398 /* non-proj nodes can have dependency edges to tuple nodes. */
399 foreach_out_edge_kind(irn, edge, EDGE_KIND_DEP) {
400 ir_node *out = get_edge_src_irn(edge);
401 make_ready(env, irn, out);
404 /* schedule the normal projs */
405 foreach_out_edge(irn, edge) {
406 ir_node *out = get_edge_src_irn(edge);
408 assert(is_Proj(out) && "successor of a modeT node must be a proj");
410 if (get_irn_mode(out) == mode_T)
411 add_tuple_projs(env, out);
413 add_to_sched(env, out);
414 make_users_ready(env, out);
420 * Perform list scheduling on a block.
422 * Note, that the caller must compute a linked list of nodes in the block
423 * using the link field before calling this function.
425 * Also the outs must have been computed.
427 * @param block The block node.
428 * @param env Scheduling environment.
430 static void list_sched_block(ir_node *block, void *env_ptr)
432 sched_env_t *env = env_ptr;
433 const list_sched_selector_t *selector = env->selector;
434 ir_node *start_node = get_irg_start(get_irn_irg(block));
436 block_sched_env_t be;
437 const ir_edge_t *edge;
441 /* Initialize the block's list head that will hold the schedule. */
442 sched_init_block(block);
444 /* Initialize the block scheduling environment */
445 be.sched_info = env->sched_info;
447 ir_nodeset_init_size(&be.cands, get_irn_n_edges(block));
448 ir_nodeset_init_size(&be.live, get_irn_n_edges(block));
449 be.selector = selector;
452 DBG((dbg, LEVEL_1, "scheduling %+F\n", block));
454 if (selector->init_block)
455 be.selector_block_env = selector->init_block(env->selector_env, block);
457 /* Then one can add all nodes are ready to the set. */
458 foreach_out_edge(block, edge) {
459 ir_node *irn = get_edge_src_irn(edge);
461 /* Skip the end node because of keepalive edges. */
462 if (get_irn_opcode(irn) == iro_End)
465 if (get_irn_n_edges(irn) == 0)
470 Phi functions are scheduled immediately, since they only
471 transfer data flow from the predecessors to this block.
473 add_to_sched(&be, irn);
474 make_users_ready(&be, irn);
476 else if (irn == start_node) {
477 /* The start block will be scheduled as the first node */
478 add_to_sched(&be, irn);
479 add_tuple_projs(&be, irn);
482 /* Other nodes must have all operands in other blocks to be made
486 /* Check, if the operands of a node are not local to this block */
487 for (j = 0, m = get_irn_ins_or_deps(irn); j < m; ++j) {
488 ir_node *operand = get_irn_in_or_dep(irn, j);
490 if (get_nodes_block(operand) == block) {
495 /* live in values increase register pressure */
496 update_sched_liveness(&be, operand);
500 /* Make the node ready, if all operands live in a foreign block */
502 DBG((dbg, LEVEL_2, "\timmediately ready: %+F\n", irn));
503 make_ready(&be, NULL, irn);
508 /* Iterate over all remaining nodes */
509 while (ir_nodeset_size(&be.cands) > 0) {
510 ir_nodeset_iterator_t iter;
511 /* collect statistics about amount of ready nodes */
512 be_do_stat_sched_ready(block, &be.cands);
514 /* Keeps must be scheduled immediatly */
515 foreach_ir_nodeset(&be.cands, irn, iter) {
516 if (be_is_Keep(irn) || be_is_CopyKeep(irn) || is_Sync(irn)) {
522 /* Keeps must be immediately scheduled */
523 irn = be.selector->select(be.selector_block_env, &be.cands, &be.live);
526 DB((dbg, LEVEL_2, "\tpicked node %+F\n", irn));
528 /* Add the node to the schedule. */
529 add_to_sched(&be, irn);
531 if (get_irn_mode(irn) == mode_T)
532 add_tuple_projs(&be, irn);
534 make_users_ready(&be, irn);
536 /* remove the scheduled node from the ready list. */
537 ir_nodeset_remove(&be.cands, irn);
540 if (selector->finish_block)
541 selector->finish_block(be.selector_block_env);
543 ir_nodeset_destroy(&be.cands);
544 ir_nodeset_destroy(&be.live);
547 /* List schedule a graph. */
548 void list_sched(const be_irg_t *birg, be_options_t *be_opts)
550 const arch_env_t *arch_env = birg->main_env->arch_env;
551 ir_graph *irg = birg->irg;
555 mris_env_t *mris = NULL;
556 list_sched_selector_t sel;
558 /* Select a scheduler based on backend options */
559 switch (list_sched_options.select) {
560 case BE_SCHED_SELECT_TRIVIAL:
561 memcpy(&sel, trivial_selector, sizeof(sel));
563 case BE_SCHED_SELECT_RANDOM:
564 memcpy(&sel, random_selector, sizeof(sel));
566 case BE_SCHED_SELECT_REGPRESS:
567 memcpy(&sel, reg_pressure_selector, sizeof(sel));
569 case BE_SCHED_SELECT_MUCHNIK:
570 memcpy(&sel, muchnik_selector, sizeof(sel));
572 case BE_SCHED_SELECT_HEUR:
573 memcpy(&sel, heuristic_selector, sizeof(sel));
575 case BE_SCHED_SELECT_HMUCHNIK:
577 memcpy(&sel, trivial_selector, sizeof(sel));
581 /* Matze: This is very slow, we should avoid it to improve backend speed,
582 * we just have to make sure that we have no dangling out-edges at this
586 /* Assure, that we have no dangling out-edges to deleted stuff */
587 edges_deactivate(birg->irg);
588 edges_activate(birg->irg);
591 switch (list_sched_options.prep) {
592 case BE_SCHED_PREP_MRIS:
593 mris = be_sched_mris_preprocess(birg);
595 case BE_SCHED_PREP_RSS:
596 rss_schedule_preparation(birg);
602 num_nodes = get_irg_last_idx(irg);
604 /* initialize environment for list scheduler */
605 memset(&env, 0, sizeof(env));
606 env.selector = arch_env->isa->impl->get_list_sched_selector(arch_env->isa, &sel);
607 env.arch_env = arch_env;
609 env.sched_info = NEW_ARR_F(sched_irn_t, num_nodes);
611 memset(env.sched_info, 0, num_nodes * sizeof(env.sched_info[0]));
613 if (env.selector->init_graph)
614 env.selector_env = env.selector->init_graph(env.selector, arch_env, irg);
616 /* Schedule each single block. */
617 irg_block_walk_graph(irg, list_sched_block, NULL, &env);
619 if (env.selector->finish_graph)
620 env.selector->finish_graph(env.selector_env);
622 if (list_sched_options.prep == BE_SCHED_PREP_MRIS)
623 be_sched_mris_free(mris);
625 DEL_ARR_F(env.sched_info);
628 /* List schedule a block. */
629 void list_sched_single_block(const be_irg_t *birg, ir_node *block, be_options_t *be_opts)
631 const arch_env_t *arch_env = birg->main_env->arch_env;
632 ir_graph *irg = birg->irg;
636 list_sched_selector_t sel;
638 /* Select a scheduler based on backend options */
639 switch (list_sched_options.select) {
640 case BE_SCHED_SELECT_TRIVIAL:
641 memcpy(&sel, trivial_selector, sizeof(sel));
643 case BE_SCHED_SELECT_RANDOM:
644 memcpy(&sel, random_selector, sizeof(sel));
646 case BE_SCHED_SELECT_REGPRESS:
647 memcpy(&sel, reg_pressure_selector, sizeof(sel));
649 case BE_SCHED_SELECT_MUCHNIK:
650 memcpy(&sel, muchnik_selector, sizeof(sel));
652 case BE_SCHED_SELECT_HEUR:
653 memcpy(&sel, heuristic_selector, sizeof(sel));
655 case BE_SCHED_SELECT_HMUCHNIK:
657 memcpy(&sel, trivial_selector, sizeof(sel));
660 /* Assure, that the out edges are computed */
661 edges_deactivate(birg->irg);
662 edges_activate(birg->irg);
664 num_nodes = get_irg_last_idx(irg);
666 /* initialize environment for list scheduler */
667 memset(&env, 0, sizeof(env));
668 env.selector = arch_env->isa->impl->get_list_sched_selector(arch_env->isa, &sel);
669 env.arch_env = arch_env;
671 env.sched_info = NEW_ARR_F(sched_irn_t, num_nodes);
673 memset(env.sched_info, 0, num_nodes * sizeof(env.sched_info[0]));
675 if (env.selector->init_graph)
676 env.selector_env = env.selector->init_graph(env.selector, arch_env, irg);
678 /* Schedule block. */
679 list_sched_block(block, &env);
681 if (env.selector->finish_graph)
682 env.selector->finish_graph(env.selector_env);
684 DEL_ARR_F(env.sched_info);
688 * Register list scheduler options.
690 void be_init_listsched(void) {
691 lc_opt_entry_t *be_grp = lc_opt_get_grp(firm_opt_get_root(), "be");
692 lc_opt_entry_t *sched_grp = lc_opt_get_grp(be_grp, "listsched");
694 lc_opt_add_table(sched_grp, list_sched_option_table);
696 FIRM_DBG_REGISTER(dbg, "firm.be.sched");
699 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_listsched);