2 * Copyright (C) 1995-2007 University of Karlsruhe. All right reserved.
4 * This file is part of libFirm.
6 * This file may be distributed and/or modified under the terms of the
7 * GNU General Public License version 2 as published by the Free Software
8 * Foundation and appearing in the file LICENSE.GPL included in the
9 * packaging of this file.
11 * Licensees holding valid libFirm Professional Edition licenses may use
12 * this file in accordance with the libFirm Commercial License.
13 * Agreement provided with the Software.
15 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
16 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * @brief Simple copy minimization heuristics.
23 * @author Christian Wuerdig
27 * This is the C implementation of the mst algorithm
28 * originally written in Java by Sebastian Hack.
29 * (also known as "heur3" :)
30 * Performs simple copy minimization.
34 #endif /* HAVE_CONFIG_H */
41 #include "raw_bitset.h"
42 #include "irphase_t.h"
54 #include "becopyopt_t.h"
57 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
59 #define COL_COST_INFEASIBLE DBL_MAX
60 #define AFF_NEIGHBOUR_FIX_BENEFIT 128.0
61 #define NEIGHBOUR_CONSTR_COSTS 64.0
63 #define DBG_AFF_CHUNK(env, level, chunk) DEBUG_ONLY(do { if (firm_dbg_get_mask(dbg) & (level)) dbg_aff_chunk((env), (chunk)); } while(0))
64 #define DBG_COL_COST(env, level, cost) DEBUG_ONLY(do { if (firm_dbg_get_mask(dbg) & (level)) dbg_col_cost((env), (cost)); } while(0))
66 static int last_chunk_id = 0;
68 typedef struct _col_cost_t {
76 typedef struct _aff_chunk_t {
77 bitset_t *nodes; /**< A bitset containing all nodes inside this chunk. */
78 int weight; /**< The weight of this chunk. */
79 unsigned weight_consistent : 1; /**< Set if the weight is consistent. */
80 struct list_head list; /**< For linking into lists. */
81 int id; /**< For debugging: An identifier. */
87 typedef struct _aff_edge_t {
88 ir_node *src; /**< The source node. */
89 ir_node *tgt; /**< The target node. */
90 double weight; /**< The weight of this edge. */
93 /** Main coalescing environment. */
94 typedef struct _co_mst_env_t {
95 int n_regs; /**< number of regs in class */
96 int k; /**< number of non-ignore registers in class */
97 bitset_t *ignore_regs; /**< set containing all global ignore registers */
98 int *map_regs; /**< map the available colors to the available registers */
99 ir_phase ph; /**< phase object holding data for nodes */
100 pqueue *chunks; /**< priority queue for chunks */
101 struct list_head used_chunks; /**< The list of used chunks. */
102 struct list_head free_chunks; /**< The list of free chunks. */
103 be_ifg_t *ifg; /**< the interference graph */
104 const arch_env_t *aenv; /**< the arch environment */
105 copy_opt_t *co; /**< the copy opt object */
108 /* stores coalescing related information for a node */
109 typedef struct _co_mst_irn_t {
110 ir_node *irn; /**< the irn this information belongs to */
111 aff_chunk_t *chunk; /**< the chunk this irn belongs to */
112 bitset_t *adm_colors; /**< set of admissible colors for this irn */
113 ir_node **int_neighs; /**< array of all interfering neighbours (cached for speed reasons) */
114 int n_neighs; /**< length of the interfering neighbours array. */
115 int int_aff_neigh; /**< number of interfering affinity neighbours */
116 int col; /**< color currently assigned */
117 int init_col; /**< the initial color */
118 int tmp_col; /**< a temporary assigned color */
119 unsigned fixed : 1; /**< the color is fixed */
120 unsigned tmp_fixed : 1; /**< the color is temporary fixed */
123 #define get_co_mst_irn(mst_env, irn) (phase_get_or_set_irn_data(&(mst_env)->ph, (irn)))
125 typedef int decide_func_t(co_mst_irn_t *node, int col);
130 * Write a chunk to stderr for debugging.
132 static void dbg_aff_chunk(co_mst_env_t *env, aff_chunk_t *c) {
134 if (c->weight_consistent)
135 ir_fprintf(stderr, " $%d ", c->weight);
136 ir_fprintf(stderr, "{");
137 bitset_foreach(c->nodes, idx) {
138 ir_node *n = get_idx_irn(env->co->irg, idx);
139 ir_fprintf(stderr, " %+F,", n);
141 ir_fprintf(stderr, "}");
145 * Dump all admissible colors to stderr.
147 static void dbg_admissible_colors(co_mst_env_t *env, co_mst_irn_t *node) {
149 if (bitset_popcnt(node->adm_colors) < 1)
150 fprintf(stderr, "no admissible colors?!?");
152 bitset_foreach(node->adm_colors, idx)
153 fprintf(stderr, " %d", idx);
158 * Dump color-cost pairs to stderr.
160 static void dbg_col_cost(co_mst_env_t *env, col_cost_t *cost) {
162 for (i = 0; i < env->n_regs; ++i) {
163 if (cost[i].cost == COL_COST_INFEASIBLE)
164 fprintf(stderr, " (%d, INF)", cost[i].col);
166 fprintf(stderr, " (%d, %.1f)", cost[i].col, cost[i].cost);
170 #endif /* DEBUG_libfirm */
172 static INLINE int get_mst_irn_col(co_mst_irn_t *node) {
173 return node->tmp_fixed ? node->tmp_col : node->col;
177 * @return 1 if node @p node has color @p col, 0 otherwise.
179 static int decider_has_color(co_mst_irn_t *node, int col) {
180 return get_mst_irn_col(node) == col;
184 * @return 1 if node @p node has not color @p col, 0 otherwise.
186 static int decider_hasnot_color(co_mst_irn_t *node, int col) {
187 return get_mst_irn_col(node) != col;
191 * Always returns true.
193 static int decider_always_yes(co_mst_irn_t *node, int col) {
197 /** compares two affinity edges by its weight */
198 static int cmp_aff_edge(const void *a, const void *b) {
199 const aff_edge_t *e1 = a;
200 const aff_edge_t *e2 = b;
202 if (e2->weight == e1->weight) {
203 if (e2->src->node_idx == e1->src->node_idx)
204 return QSORT_CMP(e2->tgt->node_idx, e1->tgt->node_idx);
206 return QSORT_CMP(e2->src->node_idx, e1->src->node_idx);
208 /* sort in descending order */
209 return QSORT_CMP(e2->weight, e1->weight);
212 /** compares to color-cost pairs */
213 static int cmp_col_cost(const void *a, const void *b) {
214 const col_cost_t *c1 = a;
215 const col_cost_t *c2 = b;
217 return c1->cost < c2->cost ? -1 : 1;
221 * Creates a new affinity chunk
223 static INLINE aff_chunk_t *new_aff_chunk(co_mst_env_t *env) {
226 if (list_empty(&env->free_chunks)) {
227 struct obstack *obst = phase_obst(&env->ph);
229 c = obstack_alloc(obst, sizeof(*c));
230 c->nodes = bitset_irg_obstack_alloc(obst, env->co->irg);
231 INIT_LIST_HEAD(&c->list);
232 list_add(&c->list, &env->used_chunks);
234 c = list_entry(env->free_chunks.next, aff_chunk_t, list);
235 list_move(&c->list, &env->used_chunks);
236 bitset_clear_all(c->nodes);
239 c->weight_consistent = 0;
240 c->id = last_chunk_id++;
245 * Frees all memory allocated by an affinity chunk.
247 static INLINE void delete_aff_chunk(co_mst_env_t *env, aff_chunk_t *c) {
248 list_move(&c->list, &env->free_chunks);
252 * Adds a node to an affinity chunk
254 static INLINE void aff_chunk_add_node(aff_chunk_t *c, co_mst_irn_t *node) {
255 c->weight_consistent = 0;
257 bitset_set(c->nodes, get_irn_idx(node->irn));
261 * In case there is no phase information for irn, initialize it.
263 static void *co_mst_irn_init(ir_phase *ph, ir_node *irn, void *old) {
264 co_mst_irn_t *res = old ? old : phase_alloc(ph, sizeof(res[0]));
265 co_mst_env_t *env = ph->priv;
268 const arch_register_req_t *req;
269 void *nodes_it = be_ifg_nodes_iter_alloca(env->ifg);
278 res->int_neighs = NULL;
279 res->int_aff_neigh = 0;
280 res->col = arch_register_get_index(arch_get_irn_register(env->aenv, irn));
281 res->init_col = res->col;
283 DB((dbg, LEVEL_4, "Creating phase info for %+F\n", irn));
285 /* set admissible registers */
286 res->adm_colors = bitset_obstack_alloc(phase_obst(ph), env->n_regs);
288 /* Exclude colors not assignable to the irn */
289 req = arch_get_register_req(env->aenv, irn, -1);
290 if (arch_register_req_is(req, limited))
291 rbitset_copy_to_bitset(req->limited, res->adm_colors);
293 bitset_set_all(res->adm_colors);
295 /* exclude global ignore registers as well */
296 bitset_andnot(res->adm_colors, env->ignore_regs);
298 /* set the number of interfering affinity neighbours to -1, they are calculated later */
299 res->int_aff_neigh = -1;
301 /* build list of interfering neighbours */
303 be_ifg_foreach_neighbour(env->ifg, nodes_it, irn, neigh) {
304 obstack_ptr_grow(phase_obst(ph), neigh);
307 res->int_neighs = obstack_finish(phase_obst(ph));
314 * Check if affinity chunk @p chunk interferes with node @p irn.
316 static INLINE int aff_chunk_interferes(co_mst_env_t *env, aff_chunk_t *chunk, ir_node *irn) {
317 co_mst_irn_t *node = get_co_mst_irn(env, irn);
321 for (i = node->n_neighs - 1; i >= 0; --i) {
322 neigh = node->int_neighs[i];
323 if (! arch_irn_is(env->aenv, neigh, ignore) && bitset_is_set(chunk->nodes, get_irn_idx(neigh)))
331 * Check if there are interference edges from c1 to c2.
332 * @param env The global co_mst environment
334 * @param c2 Another chunk
335 * @return 1 if there are interferences between nodes of c1 and c2, 0 otherwise.
337 static INLINE int aff_chunks_interfere(co_mst_env_t *env, aff_chunk_t *c1, aff_chunk_t *c2) {
343 /* check if there is a node in c2 having an interfering neighbor in c1 */
344 bitset_foreach(c2->nodes, idx) {
345 ir_node *n = get_idx_irn(env->co->irg, idx);
347 if (aff_chunk_interferes(env, c1, n))
355 * Returns the affinity chunk of @p irn or creates a new
356 * one with @p irn as element if there is none assigned.
358 static INLINE aff_chunk_t *get_aff_chunk(co_mst_env_t *env, ir_node *irn) {
359 co_mst_irn_t *node = get_co_mst_irn(env, irn);
364 * Let chunk(src) absorb the nodes of chunk(tgt) (only possible when there
365 * are no interference edges from chunk(src) to chunk(tgt)).
366 * @return 1 if successful, 0 if not possible
368 static int aff_chunk_absorb(co_mst_env_t *env, ir_node *src, ir_node *tgt) {
369 aff_chunk_t *c1 = get_aff_chunk(env, src);
370 aff_chunk_t *c2 = get_aff_chunk(env, tgt);
373 DB((dbg, LEVEL_4, "Attempt to let c1 (id %d): ", c1 ? c1->id : -1));
375 DBG_AFF_CHUNK(env, LEVEL_4, c1);
377 DB((dbg, LEVEL_4, "{%+F}", src));
379 DB((dbg, LEVEL_4, "\n\tabsorb c2 (id %d): ", c2 ? c2->id : -1));
381 DBG_AFF_CHUNK(env, LEVEL_4, c2);
383 DB((dbg, LEVEL_4, "{%+F}", tgt));
385 DB((dbg, LEVEL_4, "\n"));
390 /* no chunk exists */
391 co_mst_irn_t *mirn = get_co_mst_irn(env, src);
394 for (i = mirn->n_neighs - 1; i >= 0; --i) {
395 if (mirn->int_neighs[i] == tgt)
399 /* create one containing both nodes */
400 c1 = new_aff_chunk(env);
401 aff_chunk_add_node(c1, get_co_mst_irn(env, src));
402 aff_chunk_add_node(c1, get_co_mst_irn(env, tgt));
406 /* c2 already exists */
407 if (! aff_chunk_interferes(env, c2, src)) {
408 aff_chunk_add_node(c2, get_co_mst_irn(env, src));
412 } else if (c2 == NULL) {
413 /* c1 already exists */
414 if (! aff_chunk_interferes(env, c1, tgt)) {
415 aff_chunk_add_node(c1, get_co_mst_irn(env, tgt));
418 } else if (c1 != c2 && ! aff_chunks_interfere(env, c1, c2)) {
421 bitset_or(c1->nodes, c2->nodes);
422 c1->weight_consistent = 0;
424 bitset_foreach(c2->nodes, idx) {
425 ir_node *n = get_idx_irn(env->co->irg, idx);
426 co_mst_irn_t *mn = get_co_mst_irn(env, n);
430 delete_aff_chunk(env, c2);
433 DB((dbg, LEVEL_4, " ... c1 interferes with c2, skipped\n"));
437 DB((dbg, LEVEL_4, " ... absorbed\n"));
442 * Assures that the weight of the given chunk is consistent.
444 static void aff_chunk_assure_weight(co_mst_env_t *env, aff_chunk_t *c) {
445 if (! c->weight_consistent) {
449 bitset_foreach(c->nodes, idx) {
450 ir_node *n = get_idx_irn(env->co->irg, idx);
451 affinity_node_t *an = get_affinity_info(env->co, n);
455 co_gs_foreach_neighb(an, neigh) {
456 ir_node *m = neigh->irn;
457 int m_idx = get_irn_idx(m);
459 /* skip ignore nodes */
460 if (arch_irn_is(env->aenv, m, ignore))
463 w += bitset_is_set(c->nodes, m_idx) ? neigh->costs : 0;
469 c->weight_consistent = 1;
474 * Count the number of interfering affinity neighbours
476 static int count_interfering_aff_neighs(co_mst_env_t *env, affinity_node_t *an) {
478 ir_node *irn = an->irn;
479 co_mst_irn_t *node = get_co_mst_irn(env, irn);
482 co_gs_foreach_neighb(an, neigh) {
483 ir_node *n = neigh->irn;
486 /* skip ignore nodes */
487 if (arch_irn_is(env->aenv, n, ignore))
490 /* check if n interfere with the affinity neighbours */
491 for (i = node->n_neighs - 1; i >= 0; --i) {
492 if (node->int_neighs[i] == n) {
503 * Build chunks of nodes connected by affinity edges.
504 * We start at the heaviest affinity edge.
505 * The chunks of the two edge-defining nodes will be
506 * merged if there are no interference edges from one
507 * chunk to the other.
509 static void build_affinity_chunks(co_mst_env_t *env) {
510 void *nodes_it = be_ifg_nodes_iter_alloca(env->ifg);
511 aff_edge_t *edges = NEW_ARR_F(aff_edge_t, 0);
514 aff_chunk_t *curr_chunk;
516 /* at first we create the affinity edge objects */
517 be_ifg_foreach_node(env->ifg, nodes_it, n) {
518 int n_idx = get_irn_idx(n);
522 /* skip ignore nodes */
523 if (arch_irn_is(env->aenv, n, ignore))
526 n1 = get_co_mst_irn(env, n);
527 an = get_affinity_info(env->co, n);
532 if (n1->int_aff_neigh < 0)
533 n1->int_aff_neigh = count_interfering_aff_neighs(env, an);
534 co_gs_foreach_neighb(an, neigh) {
535 ir_node *m = neigh->irn;
536 int m_idx = get_irn_idx(m);
538 /* record the edge in only one direction */
543 /* skip ignore nodes */
544 if (arch_irn_is(env->aenv, m, ignore))
550 n2 = get_co_mst_irn(env, m);
551 if (n2->int_aff_neigh < 0) {
552 affinity_node_t *am = get_affinity_info(env->co, m);
553 n2->int_aff_neigh = count_interfering_aff_neighs(env, am);
555 edge.weight = (double)neigh->costs / (double)(1 + n1->int_aff_neigh + n2->int_aff_neigh);
556 ARR_APP1(aff_edge_t, edges, edge);
562 /* now: sort edges and build the affinity chunks */
563 len = ARR_LEN(edges);
564 qsort(edges, len, sizeof(edges[0]), cmp_aff_edge);
565 for (i = 0; i < len; ++i) {
566 DBG((dbg, LEVEL_1, "edge (%u,%u) %f\n", edges[i].src->node_idx, edges[i].tgt->node_idx, edges[i].weight));
568 (void)aff_chunk_absorb(env, edges[i].src, edges[i].tgt);
571 /* now insert all chunks into a priority queue */
572 list_for_each_entry(aff_chunk_t, curr_chunk, &env->used_chunks, list) {
573 aff_chunk_assure_weight(env, curr_chunk);
575 DBG((dbg, LEVEL_1, "entry #%d", curr_chunk->id));
576 DBG_AFF_CHUNK(env, LEVEL_1, curr_chunk);
577 DBG((dbg, LEVEL_1, "\n"));
579 pqueue_put(env->chunks, curr_chunk, curr_chunk->weight);
581 foreach_phase_irn(&env->ph, n) {
582 co_mst_irn_t *mirn = get_co_mst_irn(env, n);
584 if (mirn->chunk == NULL) {
585 /* no chunk is allocated so far, do it now */
586 aff_chunk_t *curr_chunk = new_aff_chunk(env);
587 aff_chunk_add_node(curr_chunk, mirn);
589 aff_chunk_assure_weight(env, curr_chunk);
591 DBG((dbg, LEVEL_1, "entry #%d", curr_chunk->id));
592 DBG_AFF_CHUNK(env, LEVEL_1, curr_chunk);
593 DBG((dbg, LEVEL_1, "\n"));
595 pqueue_put(env->chunks, curr_chunk, curr_chunk->weight);
603 * Greedy collect affinity neighbours into thew new chunk @p chunk starting at node @p node.
605 static void expand_chunk_from(co_mst_env_t *env, co_mst_irn_t *node, bitset_t *visited,
606 aff_chunk_t *chunk, aff_chunk_t *orig_chunk, decide_func_t *decider, int col)
608 waitq *nodes = new_waitq();
610 DBG((dbg, LEVEL_1, "\nExpanding new chunk (id %d) from %+F:", chunk->id, node->irn));
612 /* init queue and chunk */
613 waitq_put(nodes, node);
614 bitset_set(visited, get_irn_idx(node->irn));
615 aff_chunk_add_node(chunk, node);
616 DB((dbg, LEVEL_1, " %+F", node->irn));
618 /* as long as there are nodes in the queue */
619 while (! waitq_empty(nodes)) {
620 co_mst_irn_t *n = waitq_get(nodes);
621 affinity_node_t *an = get_affinity_info(env->co, n->irn);
623 /* check all affinity neighbors */
626 co_gs_foreach_neighb(an, neigh) {
627 ir_node *m = neigh->irn;
628 int m_idx = get_irn_idx(m);
631 /* skip ignore nodes */
632 if (arch_irn_is(env->aenv, m, ignore))
635 n2 = get_co_mst_irn(env, m);
637 if (! bitset_is_set(visited, m_idx) &&
640 ! aff_chunk_interferes(env, chunk, m) &&
641 bitset_is_set(orig_chunk->nodes, m_idx))
644 following conditions are met:
645 - neighbour is not visited
646 - neighbour likes the color
647 - neighbour has not yet a fixed color
648 - the new chunk doesn't interfere with the neighbour
649 - neighbour belongs or belonged once to the original chunk
651 bitset_set(visited, m_idx);
652 aff_chunk_add_node(chunk, n2);
653 DB((dbg, LEVEL_1, " %+F", n2->irn));
654 /* enqueue for further search */
655 waitq_put(nodes, n2);
661 DB((dbg, LEVEL_1, "\n"));
667 * Fragment the given chunk into chunks having given color and not having given color.
669 static aff_chunk_t *fragment_chunk(co_mst_env_t *env, int col, aff_chunk_t *c, waitq *tmp) {
670 bitset_t *visited = bitset_irg_malloc(env->co->irg);
672 aff_chunk_t *best = NULL;
674 bitset_foreach(c->nodes, idx) {
677 aff_chunk_t *tmp_chunk;
678 decide_func_t *decider;
681 if (bitset_is_set(visited, idx))
684 irn = get_idx_irn(env->co->irg, idx);
685 node = get_co_mst_irn(env, irn);
687 if (get_mst_irn_col(node) == col) {
688 decider = decider_has_color;
692 decider = decider_hasnot_color;
696 /* create a new chunk starting at current node */
697 tmp_chunk = new_aff_chunk(env);
698 waitq_put(tmp, tmp_chunk);
699 expand_chunk_from(env, node, visited, tmp_chunk, c, decider, col);
700 assert(bitset_popcnt(tmp_chunk->nodes) > 0 && "No nodes added to chunk");
702 /* remember the local best */
703 aff_chunk_assure_weight(env, tmp_chunk);
704 if (check_for_best && (! best || best->weight < tmp_chunk->weight))
708 assert(best && "No chunk found?");
709 bitset_free(visited);
714 * Initializes an array of color-cost pairs.
715 * Sets forbidden colors to costs COL_COST_INFEASIBLE and all others to @p c.
717 static INLINE void col_cost_init(co_mst_env_t *env, col_cost_t *cost, double c) {
720 for (i = 0; i < env->n_regs; ++i) {
722 if (bitset_is_set(env->ignore_regs, i))
723 cost[i].cost = COL_COST_INFEASIBLE;
730 * Initializes an array of color-cost pairs.
731 * Sets all colors except color @p col to COL_COST_INFEASIBLE and @p col to 0.0
733 static INLINE void col_cost_init_single(co_mst_env_t *env, col_cost_t *cost, int col) {
734 assert(! bitset_is_set(env->ignore_regs, col) && "Attempt to use forbidden color.");
735 col_cost_init(env, cost, COL_COST_INFEASIBLE);
742 * Resets the temporary fixed color of all nodes within wait queue @p nodes.
743 * ATTENTION: the queue is empty after calling this function!
745 static INLINE void reject_coloring(waitq *nodes) {
746 while (! waitq_empty(nodes)) {
747 co_mst_irn_t *n = waitq_get(nodes);
753 * Determines the costs for each color if it would be assigned to node @p node.
755 static void determine_color_costs(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *costs) {
756 affinity_node_t *an = get_affinity_info(env->co, node->irn);
760 col_cost_init(env, costs, 0.0);
762 /* calculate (negative) costs for affinity neighbours */
764 co_gs_foreach_neighb(an, aff_neigh) {
765 ir_node *m = aff_neigh->irn;
769 /* skip ignore nodes */
770 if (arch_irn_is(env->aenv, m, ignore))
773 neigh = get_co_mst_irn(env, m);
774 c = (double)aff_neigh->costs;
776 /* calculate costs for fixed affinity neighbours */
777 if (neigh->tmp_fixed || neigh->fixed) {
778 int col = get_mst_irn_col(neigh);
779 costs[col].cost -= c * AFF_NEIGHBOUR_FIX_BENEFIT;
784 /* calculate (positive) costs for interfering neighbours */
785 for (i = 0; i < node->n_neighs; ++i) {
790 int_neigh = node->int_neighs[i];
792 /* skip ignore nodes */
793 if (arch_irn_is(env->aenv, int_neigh, ignore))
796 neigh = get_co_mst_irn(env, int_neigh);
797 col = get_mst_irn_col(neigh);
798 col_cnt = bitset_popcnt(neigh->adm_colors);
800 if (neigh->tmp_fixed || neigh->fixed) {
801 /* colors of fixed interfering neighbours are infeasible */
802 costs[col].cost = COL_COST_INFEASIBLE;
804 else if (col_cnt < env->k) {
805 /* calculate costs for constrained interfering neighbours */
806 double ratio = 1.0 - ((double)col_cnt / (double)env->k);
808 bitset_foreach_clear(neigh->adm_colors, idx) {
809 /* check only explicitly forbidden colors (skip global forbidden ones) */
810 if (! bitset_is_set(env->ignore_regs, idx)) {
811 costs[col].cost += ratio * NEIGHBOUR_CONSTR_COSTS;
817 /* set all not admissible colors to COL_COST_INFEASIBLE */
818 bitset_foreach_clear(node->adm_colors, idx)
819 costs[idx].cost = COL_COST_INFEASIBLE;
822 /* need forward declaration due to recursive call */
823 static int recolor_nodes(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *costs, waitq *changed_ones);
826 * Tries to change node to a color but @p explude_col.
827 * @return 1 if succeeded, 0 otherwise.
829 static int change_node_color_excluded(co_mst_env_t *env, co_mst_irn_t *node, int exclude_col, waitq *changed_ones) {
830 int col = get_mst_irn_col(node);
833 /* neighbours has already a different color -> good, temporary fix it */
834 if (col != exclude_col) {
837 waitq_put(changed_ones, node);
841 /* The node has the color it should not have _and_ has not been visited yet. */
842 if (! (node->tmp_fixed || node->fixed)) {
843 col_cost_t *costs = alloca(env->n_regs * sizeof(costs[0]));
845 /* Get the costs for giving the node a specific color. */
846 determine_color_costs(env, node, costs);
848 /* Since the node must not have the not_col, set the costs for that color to "infinity" */
849 costs[exclude_col].cost = COL_COST_INFEASIBLE;
851 /* sort the colors according costs, cheapest first. */
852 qsort(costs, env->n_regs, sizeof(costs[0]), cmp_col_cost);
854 /* Try recoloring the node using the color list. */
855 res = recolor_nodes(env, node, costs, changed_ones);
862 * Tries to bring node @p node to cheapest color and color all interfering neighbours with other colors.
863 * ATTENTION: Expect @p costs already sorted by increasing costs.
864 * @return 1 if coloring could be applied, 0 otherwise.
866 static int recolor_nodes(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *costs, waitq *changed_ones) {
868 waitq *local_changed = new_waitq();
869 waitq *tmp = new_waitq();
871 DBG((dbg, LEVEL_1, "\tRecoloring %+F with color-costs", node->irn));
872 DBG_COL_COST(env, LEVEL_1, costs);
873 DB((dbg, LEVEL_1, "\n"));
875 for (i = 0; i < env->n_regs; ++i) {
876 int tgt_col = costs[i].col;
880 /* If the costs for that color (and all successive) are infinite, bail out we won't make it anyway. */
881 if (costs[i].cost == COL_COST_INFEASIBLE) {
883 del_waitq(local_changed);
888 /* Set the new color of the node and mark the node as temporarily fixed. */
889 assert(! node->tmp_fixed && "Node must not have been temporary fixed.");
891 node->tmp_col = tgt_col;
893 assert(waitq_empty(local_changed) && "Node queue should be empty here.");
894 waitq_put(local_changed, node);
896 /* try to color all interfering neighbours with current color forbidden */
897 for (j = 0; j < node->n_neighs; ++j) {
901 neigh = node->int_neighs[j];
903 /* skip ignore nodes */
904 if (arch_irn_is(env->aenv, neigh, ignore))
907 nn = get_co_mst_irn(env, neigh);
910 Try to change the color of the neighbor and record all nodes which
911 get changed in the tmp list. Add this list to the "changed" list for
912 that color. If we did not succeed to change the color of the neighbor,
913 we bail out and try the next color.
915 if (get_mst_irn_col(nn) == tgt_col) {
916 /* try to color neighbour with tgt_col forbidden */
917 neigh_ok = change_node_color_excluded(env, nn, tgt_col, tmp);
919 /* join lists of changed nodes */
920 while (! waitq_empty(tmp))
921 waitq_put(local_changed, waitq_get(tmp));
929 We managed to assign the target color to all neighbors, so from the perspective
930 of the current node, every thing was ok and we can return safely.
933 /* append the local_changed ones to global ones */
934 while (! waitq_empty(local_changed))
935 waitq_put(changed_ones, waitq_get(local_changed));
936 del_waitq(local_changed);
941 /* coloring of neighbours failed, so we try next color */
942 reject_coloring(local_changed);
946 del_waitq(local_changed);
952 * Tries to bring node @p node and all it's neighbours to color @p tgt_col.
953 * @return 1 if color @p col could be applied, 0 otherwise
955 static int change_node_color(co_mst_env_t *env, co_mst_irn_t *node, int tgt_col, waitq *changed_ones) {
956 int col = get_mst_irn_col(node);
958 /* if node already has the target color -> good, temporary fix it */
959 if (col == tgt_col) {
960 DBG((dbg, LEVEL_4, "\t\tCNC: %+F has already color %d, fix temporary\n", node->irn, tgt_col));
961 if (! node->tmp_fixed) {
963 node->tmp_col = tgt_col;
964 waitq_put(changed_ones, node);
970 Node has not yet a fixed color and target color is admissible
971 -> try to recolor node and it's affinity neighbours
973 if (! (node->fixed || node->tmp_fixed) && bitset_is_set(node->adm_colors, tgt_col)) {
974 col_cost_t *costs = alloca(env->n_regs * sizeof(costs[0]));
977 col_cost_init_single(env, costs, tgt_col);
979 DBG((dbg, LEVEL_4, "\t\tCNC: Attempt to recolor %+F ===>>\n", node->irn));
980 res = recolor_nodes(env, node, costs, changed_ones);
981 DBG((dbg, LEVEL_4, "\t\tCNC: <<=== Recoloring of %+F %s\n", node->irn, res ? "succeeded" : "failed"));
987 if (firm_dbg_get_mask(dbg) & LEVEL_4) {
988 if (node->fixed || node->tmp_fixed)
989 DB((dbg, LEVEL_4, "\t\tCNC: %+F has already fixed color %d\n", node->irn, col));
991 DB((dbg, LEVEL_4, "\t\tCNC: color %d not admissible for %+F (", tgt_col, node->irn));
992 dbg_admissible_colors(env, node);
993 DB((dbg, LEVEL_4, ")\n"));
1002 * Tries to color an affinity chunk (or at least a part of it).
1003 * Inserts uncolored parts of the chunk as a new chunk into the priority queue.
1005 static void color_aff_chunk(co_mst_env_t *env, aff_chunk_t *c) {
1006 aff_chunk_t *best_chunk = NULL;
1007 int best_color = -1;
1008 waitq *changed_ones = new_waitq();
1009 waitq *tmp_chunks = new_waitq();
1013 DB((dbg, LEVEL_2, "fragmentizing chunk #%d", c->id));
1014 DBG_AFF_CHUNK(env, LEVEL_2, c);
1015 DB((dbg, LEVEL_2, "\n"));
1018 /* check which color is the "best" for the given chunk */
1019 for (col = 0; col < env->k; ++col) {
1020 int reg_col = env->map_regs[col];
1022 aff_chunk_t *local_best;
1024 DB((dbg, LEVEL_3, "\ttrying color %d\n", reg_col));
1026 /* try to bring all nodes of given chunk to the current color. */
1027 bitset_foreach(c->nodes, idx) {
1028 ir_node *irn = get_idx_irn(env->co->irg, idx);
1029 co_mst_irn_t *node = get_co_mst_irn(env, irn);
1031 assert(! node->fixed && "Node must not have a fixed color.");
1033 DB((dbg, LEVEL_4, "\t\tBringing %+F from color %d to color %d ...\n", irn, node->col, reg_col));
1034 one_good |= change_node_color(env, node, reg_col, changed_ones);
1035 DB((dbg, LEVEL_4, "\t\t... %+F attempt from %d to %d %s\n", irn, node->col, reg_col, one_good ? "succeeded" : "failed"));
1038 /* try next color when failed */
1042 /* fragment the chunk according to the coloring */
1043 local_best = fragment_chunk(env, reg_col, c, tmp_chunks);
1045 /* search the best of the good list
1046 and make it the new best if it is better than the current */
1048 aff_chunk_assure_weight(env, local_best);
1050 DB((dbg, LEVEL_4, "\t\tlocal best chunk (id %d) for color %d: ", local_best->id, reg_col));
1051 DBG_AFF_CHUNK(env, LEVEL_4, local_best);
1053 if (! best_chunk || best_chunk->weight < local_best->weight) {
1054 best_chunk = local_best;
1055 best_color = reg_col;
1056 DB((dbg, LEVEL_4, "\n\t\t... setting global best chunk (id %d), color %d\n", best_chunk->id, best_color));
1058 DB((dbg, LEVEL_4, "\n\t\t... omitting, global best is better\n"));
1062 /* reject the coloring and bring the coloring to the initial state */
1063 reject_coloring(changed_ones);
1066 /* free all intermediate created chunks except best one */
1067 while (! waitq_empty(tmp_chunks)) {
1068 aff_chunk_t *tmp = waitq_get(tmp_chunks);
1069 if (tmp != best_chunk)
1070 delete_aff_chunk(env, tmp);
1072 del_waitq(tmp_chunks);
1074 /* return if coloring failed */
1076 del_waitq(changed_ones);
1080 DB((dbg, LEVEL_2, "\tbest chunk #%d ", best_chunk->id));
1081 DBG_AFF_CHUNK(env, LEVEL_2, best_chunk);
1082 DB((dbg, LEVEL_2, "using color %d\n", best_color));
1084 /* get the best fragment from the best list and color it */
1085 bitset_foreach(best_chunk->nodes, idx) {
1086 ir_node *irn = get_idx_irn(env->co->irg, idx);
1087 co_mst_irn_t *node = get_co_mst_irn(env, irn);
1090 res = change_node_color(env, node, best_color, changed_ones);
1091 assert(res && "color manifesting failed");
1093 node->chunk = best_chunk;
1096 /* materialize colors on changed nodes */
1097 while (! waitq_empty(changed_ones)) {
1098 co_mst_irn_t *n = waitq_get(changed_ones);
1100 n->col = n->tmp_col;
1103 /* remove the nodes in best chunk from original chunk */
1104 bitset_andnot(c->nodes, best_chunk->nodes);
1106 /* we have to get the nodes back into the original chunk because they are scattered over temporary chunks */
1107 bitset_foreach(c->nodes, idx) {
1108 ir_node *n = get_idx_irn(env->co->irg, idx);
1109 co_mst_irn_t *nn = get_co_mst_irn(env, n);
1113 /* fragment the remaining chunk */
1114 visited = bitset_irg_malloc(env->co->irg);
1115 bitset_or(visited, best_chunk->nodes);
1116 bitset_foreach(c->nodes, idx) {
1117 if (! bitset_is_set(visited, idx)) {
1118 aff_chunk_t *new_chunk = new_aff_chunk(env);
1119 ir_node *irn = get_idx_irn(env->co->irg, idx);
1120 co_mst_irn_t *node = get_co_mst_irn(env, irn);
1122 expand_chunk_from(env, node, visited, new_chunk, c, decider_always_yes, 0);
1123 aff_chunk_assure_weight(env, new_chunk);
1124 pqueue_put(env->chunks, new_chunk, new_chunk->weight);
1128 /* clear obsolete chunks and free some memory */
1129 delete_aff_chunk(env, best_chunk);
1130 bitset_free(visited);
1131 del_waitq(changed_ones);
1135 * Main driver for mst safe coalescing algorithm.
1137 int co_solve_heuristic_mst(copy_opt_t *co)
1139 unsigned n_regs = co->cls->n_regs;
1140 bitset_t *ignore_regs = bitset_alloca(n_regs);
1141 unsigned k, idx, num;
1143 co_mst_env_t mst_env;
1146 phase_init(&mst_env.ph, "co_mst", co->irg, PHASE_DEFAULT_GROWTH, co_mst_irn_init, &mst_env);
1148 k = be_put_ignore_regs(co->cenv->birg, co->cls, ignore_regs);
1151 /* Create a color to register number map. In some architectures registers are ignore "in the middle"
1152 of the register set. */
1153 mst_env.map_regs = NEW_ARR_D(int, phase_obst(&mst_env.ph), k);
1154 for (idx = num = 0; idx < n_regs; ++idx) {
1155 if (bitset_is_set(ignore_regs, idx))
1157 mst_env.map_regs[num++] = idx;
1161 mst_env.n_regs = n_regs;
1163 mst_env.chunks = new_pqueue();
1165 mst_env.ignore_regs = ignore_regs;
1166 mst_env.ifg = co->cenv->ifg;
1167 mst_env.aenv = co->aenv;
1168 INIT_LIST_HEAD(&mst_env.used_chunks);
1169 INIT_LIST_HEAD(&mst_env.free_chunks);
1171 DBG((dbg, LEVEL_1, "==== Coloring %+F, class %s ====\n", co->irg, co->cls->name));
1173 /* build affinity chunks */
1174 build_affinity_chunks(&mst_env);
1176 /* color chunks as long as there are some */
1177 while (! pqueue_empty(mst_env.chunks)) {
1178 aff_chunk_t *chunk = pqueue_get(mst_env.chunks);
1180 color_aff_chunk(&mst_env, chunk);
1181 DB((dbg, LEVEL_4, "<<<====== Coloring chunk (%d) done\n", chunk->id));
1182 delete_aff_chunk(&mst_env, chunk);
1185 /* apply coloring */
1186 foreach_phase_irn(&mst_env.ph, irn) {
1187 co_mst_irn_t *mirn = get_co_mst_irn(&mst_env, irn);
1188 const arch_register_t *reg;
1190 if (arch_irn_is(mst_env.aenv, irn, ignore))
1193 assert(mirn->fixed && "Node should have fixed color");
1195 /* skip nodes where color hasn't changed */
1196 if (mirn->init_col == mirn->col)
1199 reg = arch_register_for_index(co->cls, mirn->col);
1200 arch_set_irn_register(co->aenv, irn, reg);
1201 DB((dbg, LEVEL_1, "%+F set color from %d to %d\n", irn, mirn->init_col, mirn->col));
1204 /* free allocated memory */
1205 del_pqueue(mst_env.chunks);
1206 phase_free(&mst_env.ph);
1211 void be_init_copyheur4(void) {
1212 FIRM_DBG_REGISTER(dbg, "firm.be.co.heur4");
1215 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_copyheur4);