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"
55 #include "becopyopt_t.h"
59 #define COL_COST_INFEASIBLE DBL_MAX
60 #define AFF_NEIGHBOUR_FIX_BENEFIT 128.0
61 #define NEIGHBOUR_CONSTR_COSTS 64.0
66 #define DBG_AFF_CHUNK(env, level, chunk) do { if (firm_dbg_get_mask(dbg) & (level)) dbg_aff_chunk((env), (chunk)); } while(0)
67 #define DBG_COL_COST(env, level, cost) do { if (firm_dbg_get_mask(dbg) & (level)) dbg_col_cost((env), (cost)); } while(0)
69 static firm_dbg_module_t *dbg = NULL;
73 #define DBG_AFF_CHUNK(env, level, chunk)
74 #define DBG_COL_COST(env, level, cost)
78 static int last_chunk_id = 0;
80 typedef struct _col_cost_t {
88 typedef struct _aff_chunk_t {
89 ir_node **n; /**< An ARR_F containing all nodes of the chunk. */
90 bitset_t *nodes; /**< A bitset containing all nodes inside this chunk. */
91 bitset_t *interfere; /**< A bitset containing all interfering neighbours of the nodes in this chunk. */
92 int weight; /**< Weight of this chunk */
93 unsigned weight_consistent : 1; /**< Set if the weight is consistent. */
94 unsigned deleted : 1; /**< Set if the was deleted. */
95 int id; /**< For debugging: An id of this chunk. */
101 typedef struct _aff_edge_t {
102 ir_node *src; /**< Source node. */
103 ir_node *tgt; /**< Target node. */
104 double weight; /**< The weight of this edge. */
107 /* main coalescing environment */
108 typedef struct _co_mst_env_t {
109 int n_regs; /**< number of regs in class */
110 int k; /**< number of non-ignore registers in class */
111 bitset_t *ignore_regs; /**< set containing all global ignore registers */
112 ir_phase ph; /**< phase object holding data for nodes */
113 pqueue *chunks; /**< priority queue for chunks */
114 pset *chunkset; /**< set holding all chunks */
115 be_ifg_t *ifg; /**< the interference graph */
116 const arch_env_t *aenv; /**< the arch environment */
117 copy_opt_t *co; /**< the copy opt object */
120 /* stores coalescing related information for a node */
121 typedef struct _co_mst_irn_t {
122 ir_node *irn; /**< the irn this information belongs to */
123 aff_chunk_t *chunk; /**< the chunk this irn belongs to */
124 bitset_t *adm_colors; /**< set of admissible colors for this irn */
125 ir_node **int_neighs; /**< array of all interfering neighbours (cached for speed reasons) */
126 int n_neighs; /**< length of the interfering neighbours array. */
127 int int_aff_neigh; /**< number of interfering affinity neighbours */
128 int col; /**< color currently assigned */
129 int init_col; /**< the initial color */
130 int tmp_col; /**< a temporary assigned color */
131 unsigned fixed : 1; /**< the color is fixed */
132 struct list_head list; /**< Queue for coloring undo. */
135 #define get_co_mst_irn(mst_env, irn) (phase_get_or_set_irn_data(&(mst_env)->ph, (irn)))
137 typedef int decide_func_t(const co_mst_irn_t *node, int col);
142 * Write a chunk to stderr for debugging.
144 static void dbg_aff_chunk(const co_mst_env_t *env, const aff_chunk_t *c) {
146 if (c->weight_consistent)
147 ir_fprintf(stderr, " $%d ", c->weight);
148 ir_fprintf(stderr, "{");
149 bitset_foreach(c->nodes, idx) {
150 ir_node *n = get_idx_irn(env->co->irg, idx);
151 ir_fprintf(stderr, " %+F,", n);
153 ir_fprintf(stderr, "}");
157 * Dump all admissible colors to stderr.
159 static void dbg_admissible_colors(const co_mst_env_t *env, const co_mst_irn_t *node) {
163 if (bitset_popcnt(node->adm_colors) < 1)
164 fprintf(stderr, "no admissible colors?!?");
166 bitset_foreach(node->adm_colors, idx)
167 fprintf(stderr, " %d", idx);
172 * Dump color-cost pairs to stderr.
174 static void dbg_col_cost(const co_mst_env_t *env, const col_cost_t *cost) {
176 for (i = 0; i < env->n_regs; ++i) {
177 if (cost[i].cost == COL_COST_INFEASIBLE)
178 fprintf(stderr, " (%d, INF)", cost[i].col);
180 fprintf(stderr, " (%d, %.1f)", cost[i].col, cost[i].cost);
184 #endif /* DEBUG_libfirm */
186 static INLINE int get_mst_irn_col(const co_mst_irn_t *node) {
187 return node->tmp_col >= 0 ? node->tmp_col : node->col;
191 * @return 1 if node @p node has color @p col, 0 otherwise.
193 static int decider_has_color(const co_mst_irn_t *node, int col) {
194 return get_mst_irn_col(node) == col;
198 * @return 1 if node @p node has not color @p col, 0 otherwise.
200 static int decider_hasnot_color(const co_mst_irn_t *node, int col) {
201 return get_mst_irn_col(node) != col;
205 * Always returns true.
207 static int decider_always_yes(const co_mst_irn_t *node, int col) {
213 /** compares two affinity edges by its weight */
214 static int cmp_aff_edge(const void *a, const void *b) {
215 const aff_edge_t *e1 = a;
216 const aff_edge_t *e2 = b;
218 if (e2->weight == e1->weight) {
219 if (e2->src->node_idx == e1->src->node_idx)
220 return QSORT_CMP(e2->tgt->node_idx, e1->tgt->node_idx);
222 return QSORT_CMP(e2->src->node_idx, e1->src->node_idx);
224 /* sort in descending order */
225 return QSORT_CMP(e2->weight, e1->weight);
228 /** compares to color-cost pairs */
229 static int cmp_col_cost(const void *a, const void *b) {
230 const col_cost_t *c1 = a;
231 const col_cost_t *c2 = b;
233 return c1->cost < c2->cost ? -1 : 1;
237 * Creates a new affinity chunk
239 static INLINE aff_chunk_t *new_aff_chunk(co_mst_env_t *env) {
240 aff_chunk_t *c = xmalloc(sizeof(*c));
242 c->weight_consistent = 0;
243 c->n = NEW_ARR_F(ir_node *, 0);
244 c->nodes = bitset_irg_malloc(env->co->irg);
245 c->interfere = bitset_irg_malloc(env->co->irg);
246 c->id = last_chunk_id++;
247 pset_insert(env->chunkset, c, c->id);
252 * Frees all memory allocated by an affinity chunk.
254 static INLINE void delete_aff_chunk(co_mst_env_t *env, aff_chunk_t *c) {
255 pset_remove(env->chunkset, c, c->id);
256 bitset_free(c->nodes);
257 bitset_free(c->interfere);
264 * Adds a node to an affinity chunk
266 static INLINE void aff_chunk_add_node(aff_chunk_t *c, co_mst_irn_t *node) {
269 if (bitset_is_set(c->nodes, get_irn_idx(node->irn)))
272 c->weight_consistent = 0;
274 bitset_set(c->nodes, get_irn_idx(node->irn));
276 ARR_APP1(ir_node *, c->n, node->irn);
278 for (i = node->n_neighs - 1; i >= 0; --i) {
279 ir_node *neigh = node->int_neighs[i];
280 bitset_set(c->interfere, get_irn_idx(neigh));
285 * In case there is no phase information for irn, initialize it.
287 static void *co_mst_irn_init(ir_phase *ph, ir_node *irn, void *old) {
288 co_mst_irn_t *res = old ? old : phase_alloc(ph, sizeof(res[0]));
289 co_mst_env_t *env = ph->priv;
292 const arch_register_req_t *req;
293 void *nodes_it = be_ifg_nodes_iter_alloca(env->ifg);
301 res->int_neighs = NULL;
302 res->int_aff_neigh = 0;
303 res->col = arch_register_get_index(arch_get_irn_register(env->aenv, irn));
304 res->init_col = res->col;
305 INIT_LIST_HEAD(&res->list);
307 DB((dbg, LEVEL_4, "Creating phase info for %+F\n", irn));
309 /* set admissible registers */
310 res->adm_colors = bitset_obstack_alloc(phase_obst(ph), env->n_regs);
312 /* Exclude colors not assignable to the irn */
313 req = arch_get_register_req(env->aenv, irn, -1);
314 if (arch_register_req_is(req, limited))
315 rbitset_copy_to_bitset(req->limited, res->adm_colors);
317 bitset_set_all(res->adm_colors);
319 /* exclude global ignore registers as well */
320 bitset_andnot(res->adm_colors, env->ignore_regs);
322 /* set the number of interfering affinity neighbours to -1, they are calculated later */
323 res->int_aff_neigh = -1;
325 /* build list of interfering neighbours */
327 be_ifg_foreach_neighbour(env->ifg, nodes_it, irn, neigh) {
328 if (! arch_irn_is(env->aenv, neigh, ignore)) {
329 obstack_ptr_grow(phase_obst(ph), neigh);
333 res->int_neighs = obstack_finish(phase_obst(ph));
340 * Check if affinity chunk @p chunk interferes with node @p irn.
342 static INLINE int aff_chunk_interferes(co_mst_env_t *env, const aff_chunk_t *chunk, ir_node *irn) {
344 return bitset_is_set(chunk->interfere, get_irn_idx(irn));
348 * Check if there are interference edges from c1 to c2.
349 * @param env The global co_mst environment
351 * @param c2 Another chunk
352 * @return 1 if there are interferences between nodes of c1 and c2, 0 otherwise.
354 static INLINE int aff_chunks_interfere(co_mst_env_t *env, const aff_chunk_t *c1, const aff_chunk_t *c2) {
360 /* check if there is a node in c2 having an interfering neighbor in c1 */
361 tmp = bitset_alloca(get_irg_last_idx(env->co->irg));
362 tmp = bitset_copy(tmp, c1->interfere);
363 tmp = bitset_and(tmp, c2->nodes);
365 return bitset_popcnt(tmp) > 0;
369 * Returns the affinity chunk of @p irn or creates a new
370 * one with @p irn as element if there is none assigned.
372 static INLINE aff_chunk_t *get_aff_chunk(co_mst_env_t *env, ir_node *irn) {
373 co_mst_irn_t *node = get_co_mst_irn(env, irn);
378 * Let chunk(src) absorb the nodes of chunk(tgt) (only possible when there
379 * are no interference edges from chunk(src) to chunk(tgt)).
380 * @return 1 if successful, 0 if not possible
382 static int aff_chunk_absorb(co_mst_env_t *env, ir_node *src, ir_node *tgt) {
383 aff_chunk_t *c1 = get_aff_chunk(env, src);
384 aff_chunk_t *c2 = get_aff_chunk(env, tgt);
387 DB((dbg, LEVEL_4, "Attempt to let c1 (id %d): ", c1 ? c1->id : -1));
389 DBG_AFF_CHUNK(env, LEVEL_4, c1);
391 DB((dbg, LEVEL_4, "{%+F}", src));
393 DB((dbg, LEVEL_4, "\n\tabsorb c2 (id %d): ", c2 ? c2->id : -1));
395 DBG_AFF_CHUNK(env, LEVEL_4, c2);
397 DB((dbg, LEVEL_4, "{%+F}", tgt));
399 DB((dbg, LEVEL_4, "\n"));
404 /* no chunk exists */
405 co_mst_irn_t *mirn = get_co_mst_irn(env, src);
408 for (i = mirn->n_neighs - 1; i >= 0; --i) {
409 if (mirn->int_neighs[i] == tgt)
413 /* create one containing both nodes */
414 c1 = new_aff_chunk(env);
415 aff_chunk_add_node(c1, get_co_mst_irn(env, src));
416 aff_chunk_add_node(c1, get_co_mst_irn(env, tgt));
420 /* c2 already exists */
421 if (! aff_chunk_interferes(env, c2, src)) {
422 aff_chunk_add_node(c2, get_co_mst_irn(env, src));
426 } else if (c2 == NULL) {
427 /* c1 already exists */
428 if (! aff_chunk_interferes(env, c1, tgt)) {
429 aff_chunk_add_node(c1, get_co_mst_irn(env, tgt));
432 } else if (c1 != c2 && ! aff_chunks_interfere(env, c1, c2)) {
435 for (idx = 0, len = ARR_LEN(c2->n); idx < len; ++idx) {
436 ir_node *n = c2->n[idx];
437 co_mst_irn_t *mn = get_co_mst_irn(env, n);
441 if (! bitset_is_set(c1->nodes, get_irn_idx(n)))
442 ARR_APP1(ir_node *, c1->n, n);
445 bitset_or(c1->nodes, c2->nodes);
446 bitset_or(c1->interfere, c2->interfere);
447 c1->weight_consistent = 0;
449 delete_aff_chunk(env, c2);
452 DB((dbg, LEVEL_4, " ... c1 interferes with c2, skipped\n"));
456 DB((dbg, LEVEL_4, " ... absorbed\n"));
461 * Assures that the weight of the given chunk is consistent.
463 static void aff_chunk_assure_weight(const co_mst_env_t *env, aff_chunk_t *c) {
464 if (! c->weight_consistent) {
468 for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
469 ir_node *n = c->n[idx];
470 const affinity_node_t *an = get_affinity_info(env->co, n);
474 co_gs_foreach_neighb(an, neigh) {
475 const ir_node *m = neigh->irn;
476 const int m_idx = get_irn_idx(m);
478 /* skip ignore nodes */
479 if (arch_irn_is(env->aenv, m, ignore))
482 w += bitset_is_set(c->nodes, m_idx) ? neigh->costs : 0;
488 c->weight_consistent = 1;
493 * Count the number of interfering affinity neighbours
495 static int count_interfering_aff_neighs(co_mst_env_t *env, const affinity_node_t *an) {
496 const neighb_t *neigh;
497 ir_node *irn = an->irn;
498 const co_mst_irn_t *node = get_co_mst_irn(env, irn);
501 co_gs_foreach_neighb(an, neigh) {
502 const ir_node *n = neigh->irn;
505 /* skip ignore nodes */
506 if (arch_irn_is(env->aenv, n, ignore))
509 /* check if the affinity neighbour interfere */
510 for (i = 0; i < node->n_neighs; ++i) {
511 if (node->int_neighs[i] == n) {
522 * Build chunks of nodes connected by affinity edges.
523 * We start at the heaviest affinity edge.
524 * The chunks of the two edge-defining nodes will be
525 * merged if there are no interference edges from one
526 * chunk to the other.
528 static void build_affinity_chunks(co_mst_env_t *env) {
529 void *nodes_it = be_ifg_nodes_iter_alloca(env->ifg);
530 aff_edge_t *edges = NEW_ARR_F(aff_edge_t, 0);
533 aff_chunk_t *curr_chunk;
535 /* at first we create the affinity edge objects */
536 be_ifg_foreach_node(env->ifg, nodes_it, n) {
537 int n_idx = get_irn_idx(n);
541 /* skip ignore nodes */
542 if (arch_irn_is(env->aenv, n, ignore))
545 n1 = get_co_mst_irn(env, n);
546 an = get_affinity_info(env->co, n);
551 if (n1->int_aff_neigh < 0)
552 n1->int_aff_neigh = count_interfering_aff_neighs(env, an);
554 /* build the affinity edges */
555 co_gs_foreach_neighb(an, neigh) {
556 ir_node *m = neigh->irn;
557 int m_idx = get_irn_idx(m);
559 /* record the edge in only one direction */
564 /* skip ignore nodes */
565 if (arch_irn_is(env->aenv, m, ignore))
571 n2 = get_co_mst_irn(env, m);
572 if (n2->int_aff_neigh < 0) {
573 affinity_node_t *am = get_affinity_info(env->co, m);
574 n2->int_aff_neigh = count_interfering_aff_neighs(env, am);
577 * these weights are pure hackery ;-).
578 * It's not chriswue's fault but mine.
580 edge.weight = (double)neigh->costs / (double)(1 + n1->int_aff_neigh + n2->int_aff_neigh);
581 ARR_APP1(aff_edge_t, edges, edge);
587 /* now: sort edges and build the affinity chunks */
588 len = ARR_LEN(edges);
589 qsort(edges, len, sizeof(edges[0]), cmp_aff_edge);
590 for (i = 0; i < len; ++i) {
591 DBG((dbg, LEVEL_1, "edge (%u,%u) %f\n", edges[i].src->node_idx, edges[i].tgt->node_idx, edges[i].weight));
593 (void)aff_chunk_absorb(env, edges[i].src, edges[i].tgt);
596 /* now insert all chunks into a priority queue */
597 foreach_pset(env->chunkset, curr_chunk) {
598 aff_chunk_assure_weight(env, curr_chunk);
600 DBG((dbg, LEVEL_1, "entry #%d", curr_chunk->id));
601 DBG_AFF_CHUNK(env, LEVEL_1, curr_chunk);
602 DBG((dbg, LEVEL_1, "\n"));
604 pqueue_put(env->chunks, curr_chunk, curr_chunk->weight);
606 foreach_phase_irn(&env->ph, n) {
607 co_mst_irn_t *mirn = get_co_mst_irn(env, n);
609 if (mirn->chunk == NULL) {
610 /* no chunk is allocated so far, do it now */
611 aff_chunk_t *curr_chunk = new_aff_chunk(env);
612 aff_chunk_add_node(curr_chunk, mirn);
614 aff_chunk_assure_weight(env, curr_chunk);
616 DBG((dbg, LEVEL_1, "entry #%d", curr_chunk->id));
617 DBG_AFF_CHUNK(env, LEVEL_1, curr_chunk);
618 DBG((dbg, LEVEL_1, "\n"));
620 pqueue_put(env->chunks, curr_chunk, curr_chunk->weight);
628 * Greedy collect affinity neighbours into thew new chunk @p chunk starting at node @p node.
630 static void expand_chunk_from(co_mst_env_t *env, co_mst_irn_t *node, bitset_t *visited,
631 aff_chunk_t *chunk, aff_chunk_t *orig_chunk, decide_func_t *decider, int col)
633 waitq *nodes = new_waitq();
635 DBG((dbg, LEVEL_1, "\n\tExpanding new chunk (#%d) from %+F, color %d:", chunk->id, node->irn, col));
637 /* init queue and chunk */
638 waitq_put(nodes, node);
639 bitset_set(visited, get_irn_idx(node->irn));
640 aff_chunk_add_node(chunk, node);
641 DB((dbg, LEVEL_1, " %+F", node->irn));
643 /* as long as there are nodes in the queue */
644 while (! waitq_empty(nodes)) {
645 co_mst_irn_t *n = waitq_get(nodes);
646 affinity_node_t *an = get_affinity_info(env->co, n->irn);
648 /* check all affinity neighbors */
651 co_gs_foreach_neighb(an, neigh) {
652 ir_node *m = neigh->irn;
653 int m_idx = get_irn_idx(m);
656 /* skip ignore nodes */
657 if (arch_irn_is(env->aenv, m, ignore))
660 n2 = get_co_mst_irn(env, m);
662 if (! bitset_is_set(visited, m_idx) &&
665 ! aff_chunk_interferes(env, chunk, m) &&
666 bitset_is_set(orig_chunk->nodes, m_idx))
669 following conditions are met:
670 - neighbour is not visited
671 - neighbour likes the color
672 - neighbour has not yet a fixed color
673 - the new chunk doesn't interfere with the neighbour
674 - neighbour belongs or belonged once to the original chunk
676 bitset_set(visited, m_idx);
677 aff_chunk_add_node(chunk, n2);
678 DB((dbg, LEVEL_1, " %+F", n2->irn));
679 /* enqueue for further search */
680 waitq_put(nodes, n2);
686 DB((dbg, LEVEL_1, "\n"));
692 * Fragment the given chunk into chunks having given color and not having given color.
694 static aff_chunk_t *fragment_chunk(co_mst_env_t *env, int col, aff_chunk_t *c, waitq *tmp) {
695 bitset_t *visited = bitset_irg_malloc(env->co->irg);
697 aff_chunk_t *best = NULL;
699 for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
702 aff_chunk_t *tmp_chunk;
703 decide_func_t *decider;
707 if (bitset_is_set(visited, get_irn_idx(irn)))
710 node = get_co_mst_irn(env, irn);
712 if (get_mst_irn_col(node) == col) {
713 decider = decider_has_color;
715 DBG((dbg, LEVEL_4, "\tcolor %d wanted", col));
718 decider = decider_hasnot_color;
720 DBG((dbg, LEVEL_4, "\tcolor %d forbidden", col));
723 /* create a new chunk starting at current node */
724 tmp_chunk = new_aff_chunk(env);
725 waitq_put(tmp, tmp_chunk);
726 expand_chunk_from(env, node, visited, tmp_chunk, c, decider, col);
727 assert(bitset_popcnt(tmp_chunk->nodes) > 0 && "No nodes added to chunk");
729 /* remember the local best */
730 aff_chunk_assure_weight(env, tmp_chunk);
731 if (check_for_best && (! best || best->weight < tmp_chunk->weight))
735 assert(best && "No chunk found?");
736 bitset_free(visited);
741 * Initializes an array of color-cost pairs.
742 * Sets forbidden colors to costs COL_COST_INFEASIBLE and all others to @p c.
744 static INLINE void col_cost_init(co_mst_env_t *env, col_cost_t *cost, double c) {
747 for (i = 0; i < env->n_regs; ++i) {
749 if (bitset_is_set(env->ignore_regs, i))
750 cost[i].cost = COL_COST_INFEASIBLE;
757 * Initializes an array of color-cost pairs.
758 * Sets all colors except color @p col to COL_COST_INFEASIBLE and @p col to 0.0
760 static INLINE void col_cost_init_single(co_mst_env_t *env, col_cost_t *cost, int col) {
761 assert(! bitset_is_set(env->ignore_regs, col) && "Attempt to use forbidden color.");
762 col_cost_init(env, cost, COL_COST_INFEASIBLE);
769 * Resets the temporary fixed color of all nodes within wait queue @p nodes.
770 * ATTENTION: the queue is empty after calling this function!
772 static INLINE void reject_coloring(struct list_head *nodes) {
773 co_mst_irn_t *n, *temp;
774 DB((dbg, LEVEL_4, "\treject coloring for"));
775 list_for_each_entry_safe(co_mst_irn_t, n, temp, nodes, list) {
776 DB((dbg, LEVEL_4, " %+F", n->irn));
777 assert(n->tmp_col >= 0);
779 list_del_init(&n->list);
781 DB((dbg, LEVEL_4, "\n"));
784 static INLINE void materialize_coloring(struct list_head *nodes) {
785 co_mst_irn_t *n, *temp;
786 list_for_each_entry_safe(co_mst_irn_t, n, temp, nodes, list) {
787 assert(n->tmp_col >= 0);
790 list_del_init(&n->list);
794 static INLINE void set_temp_color(co_mst_irn_t *node, int col, struct list_head *changed)
797 assert(!node->fixed);
798 assert(node->tmp_col < 0);
799 assert(node->list.next == &node->list && node->list.prev == &node->list);
801 list_add_tail(&node->list, changed);
805 static INLINE int is_loose(co_mst_irn_t *node)
807 return !node->fixed && node->tmp_col < 0;
811 * Determines the costs for each color if it would be assigned to node @p node.
813 static void determine_color_costs(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *costs) {
814 affinity_node_t *an = get_affinity_info(env->co, node->irn);
819 col_cost_init(env, costs, 0.0);
821 /* calculate (negative) costs for affinity neighbours */
823 co_gs_foreach_neighb(an, aff_neigh) {
824 ir_node *m = aff_neigh->irn;
828 /* skip ignore nodes */
829 if (arch_irn_is(env->aenv, m, ignore))
832 neigh = get_co_mst_irn(env, m);
833 c = (double)aff_neigh->costs;
835 /* calculate costs for fixed affinity neighbours */
836 if (!is_loose(neigh)) {
837 int col = get_mst_irn_col(neigh);
838 costs[col].cost -= c * AFF_NEIGHBOUR_FIX_BENEFIT;
843 /* calculate (positive) costs for interfering neighbours */
844 for (i = 0; i < node->n_neighs; ++i) {
849 int_neigh = node->int_neighs[i];
851 assert(!arch_irn_is(env->aenv, int_neigh, ignore));
853 neigh = get_co_mst_irn(env, int_neigh);
854 col = get_mst_irn_col(neigh);
855 col_cnt = bitset_popcnt(neigh->adm_colors);
857 if (!is_loose(neigh)) {
858 /* colors of fixed interfering neighbours are infeasible */
859 costs[col].cost = COL_COST_INFEASIBLE;
861 else if (col_cnt < env->k) {
862 /* calculate costs for constrained interfering neighbours */
863 double ratio = 1.0 - ((double)col_cnt / (double)env->k);
865 bitset_foreach_clear(neigh->adm_colors, idx) {
866 /* check only explicitly forbidden colors (skip global forbidden ones) */
867 if (! bitset_is_set(env->ignore_regs, idx)) {
868 costs[col].cost += ratio * NEIGHBOUR_CONSTR_COSTS;
873 DB((dbg, LEVEL_4, "\tneigh %+F, loose: %d, color: %d\n", int_neigh, is_loose(neigh), col));
876 /* set all not admissible colors to COL_COST_INFEASIBLE */
877 bitset_foreach_clear(node->adm_colors, idx)
878 costs[idx].cost = COL_COST_INFEASIBLE;
881 /* need forward declaration due to recursive call */
882 static int recolor_nodes(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *costs, struct list_head *changed_ones);
885 * Tries to change node to a color but @p explude_col.
886 * @return 1 if succeeded, 0 otherwise.
888 static int change_node_color_excluded(co_mst_env_t *env, co_mst_irn_t *node, int exclude_col, struct list_head *changed_ones) {
889 int col = get_mst_irn_col(node);
892 /* neighbours has already a different color -> good, temporary fix it */
893 if (col != exclude_col) {
895 set_temp_color(node, col, changed_ones);
899 /* The node has the color it should not have _and_ has not been visited yet. */
900 if (is_loose(node)) {
901 col_cost_t *costs = alloca(env->n_regs * sizeof(costs[0]));
903 /* Get the costs for giving the node a specific color. */
904 determine_color_costs(env, node, costs);
906 /* Since the node must not have the not_col, set the costs for that color to "infinity" */
907 costs[exclude_col].cost = COL_COST_INFEASIBLE;
909 /* sort the colors according costs, cheapest first. */
910 qsort(costs, env->n_regs, sizeof(costs[0]), cmp_col_cost);
912 /* Try recoloring the node using the color list. */
913 res = recolor_nodes(env, node, costs, changed_ones);
920 * Tries to bring node @p node to cheapest color and color all interfering neighbours with other colors.
921 * ATTENTION: Expect @p costs already sorted by increasing costs.
922 * @return 1 if coloring could be applied, 0 otherwise.
924 static int recolor_nodes(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *costs, struct list_head *changed_ones) {
926 struct list_head local_changed;
928 DBG((dbg, LEVEL_1, "\tRecoloring %+F with color-costs", node->irn));
929 DBG_COL_COST(env, LEVEL_1, costs);
930 DB((dbg, LEVEL_1, "\n"));
932 for (i = 0; i < env->n_regs; ++i) {
933 int tgt_col = costs[i].col;
937 /* If the costs for that color (and all successive) are infinite, bail out we won't make it anyway. */
938 if (costs[i].cost == COL_COST_INFEASIBLE) {
942 /* Set the new color of the node and mark the node as temporarily fixed. */
943 assert(node->tmp_col < 0 && "Node must not have been temporary fixed.");
944 INIT_LIST_HEAD(&local_changed);
945 set_temp_color(node, tgt_col, &local_changed);
946 DBG((dbg, LEVEL_4, "\tTemporary setting %+F to color %d\n", node->irn, tgt_col));
948 /* try to color all interfering neighbours with current color forbidden */
949 for (j = 0; j < node->n_neighs; ++j) {
953 neigh = node->int_neighs[j];
955 /* skip ignore nodes */
956 if (arch_irn_is(env->aenv, neigh, ignore))
959 nn = get_co_mst_irn(env, neigh);
960 DB((dbg, LEVEL_4, "\tHandling neighbour %+F, at position %d (fixed: %d, tmp_col: %d, col: %d)\n",
961 neigh, j, nn->fixed, nn->tmp_col, nn->col));
964 Try to change the color of the neighbor and record all nodes which
965 get changed in the tmp list. Add this list to the "changed" list for
966 that color. If we did not succeed to change the color of the neighbor,
967 we bail out and try the next color.
969 if (get_mst_irn_col(nn) == tgt_col) {
970 /* try to color neighbour with tgt_col forbidden */
971 neigh_ok = change_node_color_excluded(env, nn, tgt_col, &local_changed);
979 We managed to assign the target color to all neighbors, so from the perspective
980 of the current node, every thing was ok and we can return safely.
983 /* append the local_changed ones to global ones */
984 list_splice(&local_changed, changed_ones);
988 /* coloring of neighbours failed, so we try next color */
989 reject_coloring(&local_changed);
997 * Tries to bring node @p node and all it's neighbours to color @p tgt_col.
998 * @return 1 if color @p col could be applied, 0 otherwise
1000 static int change_node_color(co_mst_env_t *env, co_mst_irn_t *node, int tgt_col, struct list_head *changed_ones) {
1001 int col = get_mst_irn_col(node);
1003 /* if node already has the target color -> good, temporary fix it */
1004 if (col == tgt_col) {
1005 DBG((dbg, LEVEL_4, "\t\tCNC: %+F has already color %d, fix temporary\n", node->irn, tgt_col));
1007 set_temp_color(node, tgt_col, changed_ones);
1012 Node has not yet a fixed color and target color is admissible
1013 -> try to recolor node and it's affinity neighbours
1015 if (is_loose(node) && bitset_is_set(node->adm_colors, tgt_col)) {
1016 col_cost_t *costs = alloca(env->n_regs * sizeof(costs[0]));
1019 col_cost_init_single(env, costs, tgt_col);
1021 DBG((dbg, LEVEL_4, "\t\tCNC: Attempt to recolor %+F ===>>\n", node->irn));
1022 res = recolor_nodes(env, node, costs, changed_ones);
1023 DBG((dbg, LEVEL_4, "\t\tCNC: <<=== Recoloring of %+F %s\n", node->irn, res ? "succeeded" : "failed"));
1028 #ifdef DEBUG_libfirm
1029 if (firm_dbg_get_mask(dbg) & LEVEL_4) {
1030 if (!is_loose(node))
1031 DB((dbg, LEVEL_4, "\t\tCNC: %+F has already fixed color %d\n", node->irn, col));
1033 DB((dbg, LEVEL_4, "\t\tCNC: color %d not admissible for %+F (", tgt_col, node->irn));
1034 dbg_admissible_colors(env, node);
1035 DB((dbg, LEVEL_4, ")\n"));
1044 * Tries to color an affinity chunk (or at least a part of it).
1045 * Inserts uncolored parts of the chunk as a new chunk into the priority queue.
1047 static void color_aff_chunk(co_mst_env_t *env, aff_chunk_t *c) {
1048 aff_chunk_t *best_chunk = NULL;
1049 int best_color = -1;
1051 waitq *tmp_chunks = new_waitq();
1052 waitq *best_starts = NULL;
1055 struct list_head changed_ones;
1057 DB((dbg, LEVEL_2, "fragmentizing chunk #%d", c->id));
1058 DBG_AFF_CHUNK(env, LEVEL_2, c);
1059 DB((dbg, LEVEL_2, "\n"));
1062 /* check which color is the "best" for the given chunk.
1063 * if we found a color which was ok for all nodes, we take it
1064 * and do not look further. (see did_all flag usage below.)
1065 * If we have many colors which fit all nodes it is hard to decide
1066 * which one to take anyway.
1067 * TODO Sebastian: Perhaps we should at all nodes and figure out
1068 * a suitable color using costs as done above (determine_color_costs).
1070 for (col = 0; col < env->n_regs && !did_all; ++col) {
1072 waitq *good_starts = new_waitq();
1073 aff_chunk_t *local_best;
1075 /* skip ignore colors */
1076 if (bitset_is_set(env->ignore_regs, col))
1079 DB((dbg, LEVEL_3, "\ttrying color %d\n", col));
1081 /* suppose we can color all nodes to the same color */
1084 INIT_LIST_HEAD(&changed_ones);
1086 /* try to bring all nodes of given chunk to the current color. */
1087 for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
1088 ir_node *irn = c->n[idx];
1089 co_mst_irn_t *node = get_co_mst_irn(env, irn);
1092 assert(! node->fixed && "Node must not have a fixed color.");
1093 DB((dbg, LEVEL_4, "\t\tBringing %+F from color %d to color %d ...\n", irn, node->col, col));
1096 The order of the colored nodes is important, so we record the successfully
1097 colored ones in the order they appeared.
1099 good = change_node_color(env, node, col, &changed_ones);
1101 waitq_put(good_starts, node);
1107 DB((dbg, LEVEL_4, "\t\t... %+F attempt from %d to %d %s\n", irn, node->col, col, one_good ? "succeeded" : "failed"));
1110 /* try next color when failed */
1112 reject_coloring(&changed_ones);
1116 /* fragment the chunk according to the coloring */
1117 local_best = fragment_chunk(env, col, c, tmp_chunks);
1119 /* search the best of the good list
1120 and make it the new best if it is better than the current */
1122 aff_chunk_assure_weight(env, local_best);
1124 DB((dbg, LEVEL_4, "\t\tlocal best chunk (id %d) for color %d: ", local_best->id, col));
1125 DBG_AFF_CHUNK(env, LEVEL_4, local_best);
1127 if (! best_chunk || best_chunk->weight < local_best->weight) {
1128 best_chunk = local_best;
1131 del_waitq(best_starts);
1132 best_starts = good_starts;
1133 DB((dbg, LEVEL_4, "\n\t\t... setting global best chunk (id %d), color %d\n", best_chunk->id, best_color));
1135 DB((dbg, LEVEL_4, "\n\t\t... omitting, global best is better\n"));
1136 del_waitq(good_starts);
1140 del_waitq(good_starts);
1143 reject_coloring(&changed_ones);
1146 /* free all intermediate created chunks except best one */
1147 while (! waitq_empty(tmp_chunks)) {
1148 aff_chunk_t *tmp = waitq_get(tmp_chunks);
1149 if (tmp != best_chunk)
1150 delete_aff_chunk(env, tmp);
1152 del_waitq(tmp_chunks);
1154 /* return if coloring failed */
1157 del_waitq(best_starts);
1161 DB((dbg, LEVEL_2, "\tbest chunk #%d ", best_chunk->id));
1162 DBG_AFF_CHUNK(env, LEVEL_2, best_chunk);
1163 DB((dbg, LEVEL_2, "using color %d\n", best_color));
1165 INIT_LIST_HEAD(&changed_ones);
1166 for (idx = 0, len = ARR_LEN(best_chunk->n); idx < len; ++idx) {
1167 ir_node *irn = best_chunk->n[idx];
1168 co_mst_irn_t *node = get_co_mst_irn(env, irn);
1171 /* bring the node to the color. */
1172 DB((dbg, LEVEL_4, "\tManifesting color %d for %+F, chunk #%d\n", best_color, node->irn, best_chunk->id));
1173 INIT_LIST_HEAD(&changed_ones);
1174 res = change_node_color(env, node, best_color, &changed_ones);
1176 materialize_coloring(&changed_ones);
1181 /* remove the nodes in best chunk from original chunk */
1182 bitset_andnot(c->nodes, best_chunk->nodes);
1183 for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
1184 ir_node *irn = c->n[idx];
1186 if (bitset_is_set(best_chunk->nodes, get_irn_idx(irn))) {
1187 int last = ARR_LEN(c->n) - 1;
1189 c->n[idx] = c->n[last];
1190 ARR_SHRINKLEN(c->n, last);
1195 /* we have to get the nodes back into the original chunk because they are scattered over temporary chunks */
1196 for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
1197 ir_node *n = c->n[idx];
1198 co_mst_irn_t *nn = get_co_mst_irn(env, n);
1202 /* fragment the remaining chunk */
1203 visited = bitset_irg_malloc(env->co->irg);
1204 bitset_or(visited, best_chunk->nodes);
1205 for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
1206 ir_node *irn = c->n[idx];
1207 if (! bitset_is_set(visited, get_irn_idx(irn))) {
1208 aff_chunk_t *new_chunk = new_aff_chunk(env);
1209 co_mst_irn_t *node = get_co_mst_irn(env, irn);
1211 expand_chunk_from(env, node, visited, new_chunk, c, decider_always_yes, 0);
1212 aff_chunk_assure_weight(env, new_chunk);
1213 pqueue_put(env->chunks, new_chunk, new_chunk->weight);
1217 /* clear obsolete chunks and free some memory */
1218 delete_aff_chunk(env, best_chunk);
1219 bitset_free(visited);
1221 del_waitq(best_starts);
1225 * Main driver for mst safe coalescing algorithm.
1227 int co_solve_heuristic_mst(copy_opt_t *co) {
1228 unsigned n_regs = co->cls->n_regs;
1229 bitset_t *ignore_regs = bitset_alloca(n_regs);
1232 co_mst_env_t mst_env;
1235 phase_init(&mst_env.ph, "co_mst", co->irg, PHASE_DEFAULT_GROWTH, co_mst_irn_init, &mst_env);
1237 k = be_put_ignore_regs(co->cenv->birg, co->cls, ignore_regs);
1240 mst_env.n_regs = n_regs;
1242 mst_env.chunks = new_pqueue();
1244 mst_env.ignore_regs = ignore_regs;
1245 mst_env.ifg = co->cenv->ifg;
1246 mst_env.aenv = co->aenv;
1247 mst_env.chunkset = pset_new_ptr(512);
1249 DBG((dbg, LEVEL_1, "==== Coloring %+F, class %s ====\n", co->irg, co->cls->name));
1251 /* build affinity chunks */
1252 build_affinity_chunks(&mst_env);
1254 /* color chunks as long as there are some */
1255 while (! pqueue_empty(mst_env.chunks)) {
1256 aff_chunk_t *chunk = pqueue_get(mst_env.chunks);
1258 color_aff_chunk(&mst_env, chunk);
1259 DB((dbg, LEVEL_4, "<<<====== Coloring chunk (%d) done\n", chunk->id));
1260 delete_aff_chunk(&mst_env, chunk);
1263 /* apply coloring */
1264 foreach_phase_irn(&mst_env.ph, irn) {
1265 co_mst_irn_t *mirn = get_co_mst_irn(&mst_env, irn);
1266 const arch_register_t *reg;
1268 if (arch_irn_is(mst_env.aenv, irn, ignore))
1271 // assert(mirn->fixed && "Node should have fixed color");
1273 /* skip nodes where color hasn't changed */
1274 if (mirn->init_col == mirn->col)
1277 reg = arch_register_for_index(co->cls, mirn->col);
1278 arch_set_irn_register(co->aenv, irn, reg);
1279 DB((dbg, LEVEL_1, "%+F set color from %d to %d\n", irn, mirn->init_col, mirn->col));
1282 /* free allocated memory */
1283 del_pqueue(mst_env.chunks);
1284 phase_free(&mst_env.ph);
1285 del_pset(mst_env.chunkset);
1290 void be_init_copyheur4(void) {
1291 FIRM_DBG_REGISTER(dbg, "firm.be.co.heur4");
1294 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_copyheur4);