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"
53 #include "becopyopt_t.h"
56 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
58 #define COL_COST_INFEASIBLE DBL_MAX
59 #define AFF_NEIGHBOUR_FIX_BENEFIT 128.0
60 #define NEIGHBOUR_CONSTR_COSTS 64.0
62 #define DBG_AFF_CHUNK(env, level, chunk) DEBUG_ONLY(do { if (firm_dbg_get_mask(dbg) & (level)) dbg_aff_chunk((env), (chunk)); } while(0))
63 #define DBG_COL_COST(env, level, cost) DEBUG_ONLY(do { if (firm_dbg_get_mask(dbg) & (level)) dbg_col_cost((env), (cost)); } while(0))
65 static int last_chunk_id = 0;
67 typedef struct _col_cost_t {
75 typedef struct _aff_chunk_t {
76 bitset_t *nodes; /**< A bitset containing all nodes inside this chunk. */
77 int weight; /**< Weight of this chunk */
78 unsigned weight_consistent : 1; /**< Set if the weight is consistent. */
79 int id; /**< For debugging: An id of this chunk. */
85 typedef struct _aff_edge_t {
86 ir_node *src; /**< Source node. */
87 ir_node *tgt; /**< Target node. */
88 double weight; /**< The weight of this edge. */
91 /* main coalescing environment */
92 typedef struct _co_mst_env_t {
93 int n_regs; /**< number of regs in class */
94 int k; /**< number of non-ignore registers in class */
95 bitset_t *ignore_regs; /**< set containing all global ignore registers */
96 int *map_regs; /**< map the available colors to the available registers */
97 ir_phase ph; /**< phase object holding data for nodes */
98 pqueue *chunks; /**< priority queue for chunks */
99 pset_new_t chunkset; /**< set holding all chunks */
100 be_ifg_t *ifg; /**< the interference graph */
101 const arch_env_t *aenv; /**< the arch environment */
102 copy_opt_t *co; /**< the copy opt object */
105 /* stores coalescing related information for a node */
106 typedef struct _co_mst_irn_t {
107 ir_node *irn; /**< the irn this information belongs to */
108 aff_chunk_t *chunk; /**< the chunk this irn belongs to */
109 bitset_t *adm_colors; /**< set of admissible colors for this irn */
110 ir_node **int_neighs; /**< array of all interfering neighbours (cached for speed reasons) */
111 int n_neighs; /**< length of the interfering neighbours array. */
112 int int_aff_neigh; /**< number of interfering affinity neighbours */
113 int col; /**< color currently assigned */
114 int init_col; /**< the initial color */
115 int tmp_col; /**< a temporary assigned color */
116 unsigned fixed : 1; /**< the color is fixed */
117 unsigned tmp_fixed : 1; /**< the color is temporary fixed */
120 #define get_co_mst_irn(mst_env, irn) (phase_get_or_set_irn_data(&(mst_env)->ph, (irn)))
122 typedef int decide_func_t(co_mst_irn_t *node, int col);
127 * Write a chunk to stderr for debugging.
129 static void dbg_aff_chunk(co_mst_env_t *env, aff_chunk_t *c) {
131 if (c->weight_consistent)
132 ir_fprintf(stderr, " $%d ", c->weight);
133 ir_fprintf(stderr, "{");
134 bitset_foreach(c->nodes, idx) {
135 ir_node *n = get_idx_irn(env->co->irg, idx);
136 ir_fprintf(stderr, " %+F,", n);
138 ir_fprintf(stderr, "}");
142 * Dump all admissible colors to stderr.
144 static void dbg_admissible_colors(co_mst_env_t *env, co_mst_irn_t *node) {
146 if (bitset_popcnt(node->adm_colors) < 1)
147 fprintf(stderr, "no admissible colors?!?");
149 bitset_foreach(node->adm_colors, idx)
150 fprintf(stderr, " %d", idx);
155 * Dump color-cost pairs to stderr.
157 static void dbg_col_cost(co_mst_env_t *env, col_cost_t *cost) {
159 for (i = 0; i < env->n_regs; ++i) {
160 if (cost[i].cost == COL_COST_INFEASIBLE)
161 fprintf(stderr, " (%d, INF)", cost[i].col);
163 fprintf(stderr, " (%d, %.1f)", cost[i].col, cost[i].cost);
167 #endif /* DEBUG_libfirm */
169 static INLINE int get_mst_irn_col(co_mst_irn_t *node) {
170 return node->tmp_fixed ? node->tmp_col : node->col;
174 * @return 1 if node @p node has color @p col, 0 otherwise.
176 static int decider_has_color(co_mst_irn_t *node, int col) {
177 return get_mst_irn_col(node) == col;
181 * @return 1 if node @p node has not color @p col, 0 otherwise.
183 static int decider_hasnot_color(co_mst_irn_t *node, int col) {
184 return get_mst_irn_col(node) != col;
188 * Always returns true.
190 static int decider_always_yes(co_mst_irn_t *node, int col) {
194 /** compares two affinity edges by its weight */
195 static int cmp_aff_edge(const void *a, const void *b) {
196 const aff_edge_t *e1 = a;
197 const aff_edge_t *e2 = b;
199 if (e2->weight == e1->weight) {
200 if (e2->src->node_idx == e1->src->node_idx)
201 return QSORT_CMP(e2->tgt->node_idx, e1->tgt->node_idx);
203 return QSORT_CMP(e2->src->node_idx, e1->src->node_idx);
205 /* sort in descending order */
206 return QSORT_CMP(e2->weight, e1->weight);
209 /** compares to color-cost pairs */
210 static int cmp_col_cost(const void *a, const void *b) {
211 const col_cost_t *c1 = a;
212 const col_cost_t *c2 = b;
214 return c1->cost < c2->cost ? -1 : 1;
218 * Creates a new affinity chunk
220 static INLINE aff_chunk_t *new_aff_chunk(co_mst_env_t *env) {
221 aff_chunk_t *c = xmalloc(sizeof(*c));
223 c->weight_consistent = 0;
224 c->nodes = bitset_irg_malloc(env->co->irg);
225 c->id = last_chunk_id++;
226 pset_new_insert(&env->chunkset, c);
231 * Frees all memory allocated by an affinity chunk.
233 static INLINE void delete_aff_chunk(co_mst_env_t *env, aff_chunk_t *c) {
234 pset_new_remove(&env->chunkset, c);
235 bitset_free(c->nodes);
240 * Adds a node to an affinity chunk
242 static INLINE void aff_chunk_add_node(aff_chunk_t *c, co_mst_irn_t *node) {
243 c->weight_consistent = 0;
245 bitset_set(c->nodes, get_irn_idx(node->irn));
249 * In case there is no phase information for irn, initialize it.
251 static void *co_mst_irn_init(ir_phase *ph, ir_node *irn, void *old) {
252 co_mst_irn_t *res = old ? old : phase_alloc(ph, sizeof(res[0]));
253 co_mst_env_t *env = ph->priv;
256 const arch_register_req_t *req;
257 void *nodes_it = be_ifg_nodes_iter_alloca(env->ifg);
266 res->int_neighs = NULL;
267 res->int_aff_neigh = 0;
268 res->col = arch_register_get_index(arch_get_irn_register(env->aenv, irn));
269 res->init_col = res->col;
271 DB((dbg, LEVEL_4, "Creating phase info for %+F\n", irn));
273 /* set admissible registers */
274 res->adm_colors = bitset_obstack_alloc(phase_obst(ph), env->n_regs);
276 /* Exclude colors not assignable to the irn */
277 req = arch_get_register_req(env->aenv, irn, -1);
278 if (arch_register_req_is(req, limited))
279 rbitset_copy_to_bitset(req->limited, res->adm_colors);
281 bitset_set_all(res->adm_colors);
283 /* exclude global ignore registers as well */
284 bitset_andnot(res->adm_colors, env->ignore_regs);
286 /* set the number of interfering affinity neighbours to -1, they are calculated later */
287 res->int_aff_neigh = -1;
289 /* build list of interfering neighbours */
291 be_ifg_foreach_neighbour(env->ifg, nodes_it, irn, neigh) {
292 obstack_ptr_grow(phase_obst(ph), neigh);
295 res->int_neighs = obstack_finish(phase_obst(ph));
302 * Check if affinity chunk @p chunk interferes with node @p irn.
304 static INLINE int aff_chunk_interferes(co_mst_env_t *env, aff_chunk_t *chunk, ir_node *irn) {
305 co_mst_irn_t *node = get_co_mst_irn(env, irn);
309 for (i = 0; i < node->n_neighs; ++i) {
310 neigh = node->int_neighs[i];
311 if (! arch_irn_is(env->aenv, neigh, ignore) && bitset_is_set(chunk->nodes, get_irn_idx(neigh)))
319 * Check if there are interference edges from c1 to c2.
320 * @param env The global co_mst environment
322 * @param c2 Another chunk
323 * @return 1 if there are interferences between nodes of c1 and c2, 0 otherwise.
325 static INLINE int aff_chunks_interfere(co_mst_env_t *env, aff_chunk_t *c1, aff_chunk_t *c2) {
331 /* check if there is a node in c2 having an interfering neighbor in c1 */
332 bitset_foreach(c2->nodes, idx) {
333 ir_node *n = get_idx_irn(env->co->irg, idx);
335 if (aff_chunk_interferes(env, c1, n))
343 * Returns the affinity chunk of @p irn or creates a new
344 * one with @p irn as element if there is none assigned.
346 static INLINE aff_chunk_t *get_aff_chunk(co_mst_env_t *env, ir_node *irn) {
347 co_mst_irn_t *node = get_co_mst_irn(env, irn);
352 * Let chunk(src) absorb the nodes of chunk(tgt) (only possible when there
353 * are no interference edges from chunk(src) to chunk(tgt)).
354 * @return 1 if successful, 0 if not possible
356 static int aff_chunk_absorb(co_mst_env_t *env, ir_node *src, ir_node *tgt) {
357 aff_chunk_t *c1 = get_aff_chunk(env, src);
358 aff_chunk_t *c2 = get_aff_chunk(env, tgt);
361 DB((dbg, LEVEL_4, "Attempt to let c1 (id %d): ", c1 ? c1->id : -1));
363 DBG_AFF_CHUNK(env, LEVEL_4, c1);
365 DB((dbg, LEVEL_4, "{%+F}", src));
367 DB((dbg, LEVEL_4, "\n\tabsorb c2 (id %d): ", c2 ? c2->id : -1));
369 DBG_AFF_CHUNK(env, LEVEL_4, c2);
371 DB((dbg, LEVEL_4, "{%+F}", tgt));
373 DB((dbg, LEVEL_4, "\n"));
378 /* no chunk exists */
379 co_mst_irn_t *mirn = get_co_mst_irn(env, src);
382 for (i = mirn->n_neighs - 1; i >= 0; --i) {
383 if (mirn->int_neighs[i] == tgt)
387 /* create one containing both nodes */
388 c1 = new_aff_chunk(env);
389 aff_chunk_add_node(c1, get_co_mst_irn(env, src));
390 aff_chunk_add_node(c1, get_co_mst_irn(env, tgt));
394 /* c2 already exists */
395 if (! aff_chunk_interferes(env, c2, src)) {
396 aff_chunk_add_node(c2, get_co_mst_irn(env, src));
400 } else if (c2 == NULL) {
401 /* c1 already exists */
402 if (! aff_chunk_interferes(env, c1, tgt)) {
403 aff_chunk_add_node(c1, get_co_mst_irn(env, tgt));
406 } else if (c1 != c2 && ! aff_chunks_interfere(env, c1, c2)) {
409 bitset_or(c1->nodes, c2->nodes);
410 c1->weight_consistent = 0;
412 bitset_foreach(c2->nodes, idx) {
413 ir_node *n = get_idx_irn(env->co->irg, idx);
414 co_mst_irn_t *mn = get_co_mst_irn(env, n);
418 delete_aff_chunk(env, c2);
421 DB((dbg, LEVEL_4, " ... c1 interferes with c2, skipped\n"));
425 DB((dbg, LEVEL_4, " ... absorbed\n"));
430 * Assures that the weight of the given chunk is consistent.
432 static void aff_chunk_assure_weight(co_mst_env_t *env, aff_chunk_t *c) {
433 if (! c->weight_consistent) {
437 bitset_foreach(c->nodes, idx) {
438 ir_node *n = get_idx_irn(env->co->irg, idx);
439 affinity_node_t *an = get_affinity_info(env->co, n);
443 co_gs_foreach_neighb(an, neigh) {
444 ir_node *m = neigh->irn;
445 int m_idx = get_irn_idx(m);
447 /* skip ignore nodes */
448 if (arch_irn_is(env->aenv, m, ignore))
451 w += bitset_is_set(c->nodes, m_idx) ? neigh->costs : 0;
457 c->weight_consistent = 1;
462 * Count the number of interfering affinity neighbours
464 static int count_interfering_aff_neighs(co_mst_env_t *env, affinity_node_t *an) {
466 ir_node *irn = an->irn;
467 co_mst_irn_t *node = get_co_mst_irn(env, irn);
470 co_gs_foreach_neighb(an, neigh) {
471 ir_node *n = neigh->irn;
474 /* skip ignore nodes */
475 if (arch_irn_is(env->aenv, n, ignore))
478 /* check if the affinity neighbour interfere */
479 for (i = 0; i < node->n_neighs; ++i) {
480 if (node->int_neighs[i] == n) {
491 * Build chunks of nodes connected by affinity edges.
492 * We start at the heaviest affinity edge.
493 * The chunks of the two edge-defining nodes will be
494 * merged if there are no interference edges from one
495 * chunk to the other.
497 static void build_affinity_chunks(co_mst_env_t *env) {
498 void *nodes_it = be_ifg_nodes_iter_alloca(env->ifg);
499 aff_edge_t *edges = NEW_ARR_F(aff_edge_t, 0);
502 aff_chunk_t *curr_chunk;
503 pset_new_iterator_t iter;
505 /* at first we create the affinity edge objects */
506 be_ifg_foreach_node(env->ifg, nodes_it, n) {
507 int n_idx = get_irn_idx(n);
511 /* skip ignore nodes */
512 if (arch_irn_is(env->aenv, n, ignore))
515 n1 = get_co_mst_irn(env, n);
516 an = get_affinity_info(env->co, n);
521 if (n1->int_aff_neigh < 0)
522 n1->int_aff_neigh = count_interfering_aff_neighs(env, an);
523 co_gs_foreach_neighb(an, neigh) {
524 ir_node *m = neigh->irn;
525 int m_idx = get_irn_idx(m);
527 /* record the edge in only one direction */
532 /* skip ignore nodes */
533 if (arch_irn_is(env->aenv, m, ignore))
539 n2 = get_co_mst_irn(env, m);
540 if (n2->int_aff_neigh < 0) {
541 affinity_node_t *am = get_affinity_info(env->co, m);
542 n2->int_aff_neigh = count_interfering_aff_neighs(env, am);
544 edge.weight = (double)neigh->costs / (double)(1 + n1->int_aff_neigh + n2->int_aff_neigh);
545 ARR_APP1(aff_edge_t, edges, edge);
551 /* now: sort edges and build the affinity chunks */
552 len = ARR_LEN(edges);
553 qsort(edges, len, sizeof(edges[0]), cmp_aff_edge);
554 for (i = 0; i < len; ++i) {
555 DBG((dbg, LEVEL_1, "edge (%u,%u) %f\n", edges[i].src->node_idx, edges[i].tgt->node_idx, edges[i].weight));
557 (void)aff_chunk_absorb(env, edges[i].src, edges[i].tgt);
560 /* now insert all chunks into a priority queue */
561 foreach_pset_new(&env->chunkset, curr_chunk, iter) {
562 aff_chunk_assure_weight(env, curr_chunk);
564 DBG((dbg, LEVEL_1, "entry #%d", curr_chunk->id));
565 DBG_AFF_CHUNK(env, LEVEL_1, curr_chunk);
566 DBG((dbg, LEVEL_1, "\n"));
568 pqueue_put(env->chunks, curr_chunk, curr_chunk->weight);
570 foreach_phase_irn(&env->ph, n) {
571 co_mst_irn_t *mirn = get_co_mst_irn(env, n);
573 if (mirn->chunk == NULL) {
574 /* no chunk is allocated so far, do it now */
575 aff_chunk_t *curr_chunk = new_aff_chunk(env);
576 aff_chunk_add_node(curr_chunk, mirn);
578 aff_chunk_assure_weight(env, curr_chunk);
580 DBG((dbg, LEVEL_1, "entry #%d", curr_chunk->id));
581 DBG_AFF_CHUNK(env, LEVEL_1, curr_chunk);
582 DBG((dbg, LEVEL_1, "\n"));
584 pqueue_put(env->chunks, curr_chunk, curr_chunk->weight);
592 * Greedy collect affinity neighbours into thew new chunk @p chunk starting at node @p node.
594 static void expand_chunk_from(co_mst_env_t *env, co_mst_irn_t *node, bitset_t *visited,
595 aff_chunk_t *chunk, aff_chunk_t *orig_chunk, decide_func_t *decider, int col)
597 waitq *nodes = new_waitq();
599 DBG((dbg, LEVEL_1, "\nExpanding new chunk (id %d) from %+F:", chunk->id, node->irn));
601 /* init queue and chunk */
602 waitq_put(nodes, node);
603 bitset_set(visited, get_irn_idx(node->irn));
604 aff_chunk_add_node(chunk, node);
605 DB((dbg, LEVEL_1, " %+F", node->irn));
607 /* as long as there are nodes in the queue */
608 while (! waitq_empty(nodes)) {
609 co_mst_irn_t *n = waitq_get(nodes);
610 affinity_node_t *an = get_affinity_info(env->co, n->irn);
612 /* check all affinity neighbors */
615 co_gs_foreach_neighb(an, neigh) {
616 ir_node *m = neigh->irn;
617 int m_idx = get_irn_idx(m);
620 /* skip ignore nodes */
621 if (arch_irn_is(env->aenv, m, ignore))
624 n2 = get_co_mst_irn(env, m);
626 if (! bitset_is_set(visited, m_idx) &&
629 ! aff_chunk_interferes(env, chunk, m) &&
630 bitset_is_set(orig_chunk->nodes, m_idx))
633 following conditions are met:
634 - neighbour is not visited
635 - neighbour likes the color
636 - neighbour has not yet a fixed color
637 - the new chunk doesn't interfere with the neighbour
638 - neighbour belongs or belonged once to the original chunk
640 bitset_set(visited, m_idx);
641 aff_chunk_add_node(chunk, n2);
642 DB((dbg, LEVEL_1, " %+F", n2->irn));
643 /* enqueue for further search */
644 waitq_put(nodes, n2);
650 DB((dbg, LEVEL_1, "\n"));
656 * Fragment the given chunk into chunks having given color and not having given color.
658 static aff_chunk_t *fragment_chunk(co_mst_env_t *env, int col, aff_chunk_t *c, waitq *tmp) {
659 bitset_t *visited = bitset_irg_malloc(env->co->irg);
661 aff_chunk_t *best = NULL;
663 bitset_foreach(c->nodes, idx) {
666 aff_chunk_t *tmp_chunk;
667 decide_func_t *decider;
670 if (bitset_is_set(visited, idx))
673 irn = get_idx_irn(env->co->irg, idx);
674 node = get_co_mst_irn(env, irn);
676 if (get_mst_irn_col(node) == col) {
677 decider = decider_has_color;
681 decider = decider_hasnot_color;
685 /* create a new chunk starting at current node */
686 tmp_chunk = new_aff_chunk(env);
687 waitq_put(tmp, tmp_chunk);
688 expand_chunk_from(env, node, visited, tmp_chunk, c, decider, col);
689 assert(bitset_popcnt(tmp_chunk->nodes) > 0 && "No nodes added to chunk");
691 /* remember the local best */
692 aff_chunk_assure_weight(env, tmp_chunk);
693 if (check_for_best && (! best || best->weight < tmp_chunk->weight))
697 assert(best && "No chunk found?");
698 bitset_free(visited);
703 * Initializes an array of color-cost pairs.
704 * Sets forbidden colors to costs COL_COST_INFEASIBLE and all others to @p c.
706 static INLINE void col_cost_init(co_mst_env_t *env, col_cost_t *cost, double c) {
709 for (i = 0; i < env->n_regs; ++i) {
711 if (bitset_is_set(env->ignore_regs, i))
712 cost[i].cost = COL_COST_INFEASIBLE;
719 * Initializes an array of color-cost pairs.
720 * Sets all colors except color @p col to COL_COST_INFEASIBLE and @p col to 0.0
722 static INLINE void col_cost_init_single(co_mst_env_t *env, col_cost_t *cost, int col) {
723 assert(! bitset_is_set(env->ignore_regs, col) && "Attempt to use forbidden color.");
724 col_cost_init(env, cost, COL_COST_INFEASIBLE);
731 * Resets the temporary fixed color of all nodes within wait queue @p nodes.
732 * ATTENTION: the queue is empty after calling this function!
734 static INLINE void reject_coloring(waitq *nodes) {
735 while (! waitq_empty(nodes)) {
736 co_mst_irn_t *n = waitq_get(nodes);
742 * Determines the costs for each color if it would be assigned to node @p node.
744 static void determine_color_costs(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *costs) {
745 affinity_node_t *an = get_affinity_info(env->co, node->irn);
749 col_cost_init(env, costs, 0.0);
751 /* calculate (negative) costs for affinity neighbours */
753 co_gs_foreach_neighb(an, aff_neigh) {
754 ir_node *m = aff_neigh->irn;
758 /* skip ignore nodes */
759 if (arch_irn_is(env->aenv, m, ignore))
762 neigh = get_co_mst_irn(env, m);
763 c = (double)aff_neigh->costs;
765 /* calculate costs for fixed affinity neighbours */
766 if (neigh->tmp_fixed || neigh->fixed) {
767 int col = get_mst_irn_col(neigh);
768 costs[col].cost -= c * AFF_NEIGHBOUR_FIX_BENEFIT;
773 /* calculate (positive) costs for interfering neighbours */
774 for (i = 0; i < node->n_neighs; ++i) {
779 int_neigh = node->int_neighs[i];
781 /* skip ignore nodes */
782 if (arch_irn_is(env->aenv, int_neigh, ignore))
785 neigh = get_co_mst_irn(env, int_neigh);
786 col = get_mst_irn_col(neigh);
787 col_cnt = bitset_popcnt(neigh->adm_colors);
789 if (neigh->tmp_fixed || neigh->fixed) {
790 /* colors of fixed interfering neighbours are infeasible */
791 costs[col].cost = COL_COST_INFEASIBLE;
793 else if (col_cnt < env->k) {
794 /* calculate costs for constrained interfering neighbours */
795 double ratio = 1.0 - ((double)col_cnt / (double)env->k);
797 bitset_foreach_clear(neigh->adm_colors, idx) {
798 /* check only explicitly forbidden colors (skip global forbidden ones) */
799 if (! bitset_is_set(env->ignore_regs, idx)) {
800 costs[col].cost += ratio * NEIGHBOUR_CONSTR_COSTS;
806 /* set all not admissible colors to COL_COST_INFEASIBLE */
807 bitset_foreach_clear(node->adm_colors, idx)
808 costs[idx].cost = COL_COST_INFEASIBLE;
811 /* need forward declaration due to recursive call */
812 static int recolor_nodes(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *costs, waitq *changed_ones);
815 * Tries to change node to a color but @p explude_col.
816 * @return 1 if succeeded, 0 otherwise.
818 static int change_node_color_excluded(co_mst_env_t *env, co_mst_irn_t *node, int exclude_col, waitq *changed_ones) {
819 int col = get_mst_irn_col(node);
822 /* neighbours has already a different color -> good, temporary fix it */
823 if (col != exclude_col) {
826 waitq_put(changed_ones, node);
830 /* The node has the color it should not have _and_ has not been visited yet. */
831 if (! (node->tmp_fixed || node->fixed)) {
832 col_cost_t *costs = alloca(env->n_regs * sizeof(costs[0]));
834 /* Get the costs for giving the node a specific color. */
835 determine_color_costs(env, node, costs);
837 /* Since the node must not have the not_col, set the costs for that color to "infinity" */
838 costs[exclude_col].cost = COL_COST_INFEASIBLE;
840 /* sort the colors according costs, cheapest first. */
841 qsort(costs, env->n_regs, sizeof(costs[0]), cmp_col_cost);
843 /* Try recoloring the node using the color list. */
844 res = recolor_nodes(env, node, costs, changed_ones);
851 * Tries to bring node @p node to cheapest color and color all interfering neighbours with other colors.
852 * ATTENTION: Expect @p costs already sorted by increasing costs.
853 * @return 1 if coloring could be applied, 0 otherwise.
855 static int recolor_nodes(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *costs, waitq *changed_ones) {
857 waitq *local_changed = new_waitq();
858 waitq *tmp = new_waitq();
860 DBG((dbg, LEVEL_1, "\tRecoloring %+F with color-costs", node->irn));
861 DBG_COL_COST(env, LEVEL_1, costs);
862 DB((dbg, LEVEL_1, "\n"));
864 for (i = 0; i < env->n_regs; ++i) {
865 int tgt_col = costs[i].col;
869 /* If the costs for that color (and all successive) are infinite, bail out we won't make it anyway. */
870 if (costs[i].cost == COL_COST_INFEASIBLE) {
872 del_waitq(local_changed);
877 /* Set the new color of the node and mark the node as temporarily fixed. */
878 assert(! node->tmp_fixed && "Node must not have been temporary fixed.");
880 node->tmp_col = tgt_col;
882 assert(waitq_empty(local_changed) && "Node queue should be empty here.");
883 waitq_put(local_changed, node);
885 /* try to color all interfering neighbours with current color forbidden */
886 for (j = 0; j < node->n_neighs; ++j) {
890 neigh = node->int_neighs[j];
892 /* skip ignore nodes */
893 if (arch_irn_is(env->aenv, neigh, ignore))
896 nn = get_co_mst_irn(env, neigh);
899 Try to change the color of the neighbor and record all nodes which
900 get changed in the tmp list. Add this list to the "changed" list for
901 that color. If we did not succeed to change the color of the neighbor,
902 we bail out and try the next color.
904 if (get_mst_irn_col(nn) == tgt_col) {
905 /* try to color neighbour with tgt_col forbidden */
906 neigh_ok = change_node_color_excluded(env, nn, tgt_col, tmp);
908 /* join lists of changed nodes */
909 while (! waitq_empty(tmp))
910 waitq_put(local_changed, waitq_get(tmp));
918 We managed to assign the target color to all neighbors, so from the perspective
919 of the current node, every thing was ok and we can return safely.
922 /* append the local_changed ones to global ones */
923 while (! waitq_empty(local_changed))
924 waitq_put(changed_ones, waitq_get(local_changed));
925 del_waitq(local_changed);
930 /* coloring of neighbours failed, so we try next color */
931 reject_coloring(local_changed);
935 del_waitq(local_changed);
941 * Tries to bring node @p node and all it's neighbours to color @p tgt_col.
942 * @return 1 if color @p col could be applied, 0 otherwise
944 static int change_node_color(co_mst_env_t *env, co_mst_irn_t *node, int tgt_col, waitq *changed_ones) {
945 int col = get_mst_irn_col(node);
947 /* if node already has the target color -> good, temporary fix it */
948 if (col == tgt_col) {
949 DBG((dbg, LEVEL_4, "\t\tCNC: %+F has already color %d, fix temporary\n", node->irn, tgt_col));
950 if (! node->tmp_fixed) {
952 node->tmp_col = tgt_col;
953 waitq_put(changed_ones, node);
959 Node has not yet a fixed color and target color is admissible
960 -> try to recolor node and it's affinity neighbours
962 if (! (node->fixed || node->tmp_fixed) && bitset_is_set(node->adm_colors, tgt_col)) {
963 col_cost_t *costs = alloca(env->n_regs * sizeof(costs[0]));
966 col_cost_init_single(env, costs, tgt_col);
968 DBG((dbg, LEVEL_4, "\t\tCNC: Attempt to recolor %+F ===>>\n", node->irn));
969 res = recolor_nodes(env, node, costs, changed_ones);
970 DBG((dbg, LEVEL_4, "\t\tCNC: <<=== Recoloring of %+F %s\n", node->irn, res ? "succeeded" : "failed"));
976 if (firm_dbg_get_mask(dbg) & LEVEL_4) {
977 if (node->fixed || node->tmp_fixed)
978 DB((dbg, LEVEL_4, "\t\tCNC: %+F has already fixed color %d\n", node->irn, col));
980 DB((dbg, LEVEL_4, "\t\tCNC: color %d not admissible for %+F (", tgt_col, node->irn));
981 dbg_admissible_colors(env, node);
982 DB((dbg, LEVEL_4, ")\n"));
991 * Tries to color an affinity chunk (or at least a part of it).
992 * Inserts uncolored parts of the chunk as a new chunk into the priority queue.
994 static void color_aff_chunk(co_mst_env_t *env, aff_chunk_t *c) {
995 aff_chunk_t *best_chunk = NULL;
997 waitq *changed_ones = new_waitq();
998 waitq *tmp_chunks = new_waitq();
1002 DB((dbg, LEVEL_2, "fragmentizing chunk #%d", c->id));
1003 DBG_AFF_CHUNK(env, LEVEL_2, c);
1004 DB((dbg, LEVEL_2, "\n"));
1007 /* check which color is the "best" for the given chunk */
1008 for (col = 0; col < env->k; ++col) {
1009 int reg_col = env->map_regs[col];
1011 aff_chunk_t *local_best;
1013 DB((dbg, LEVEL_3, "\ttrying color %d\n", reg_col));
1015 /* try to bring all nodes of given chunk to the current color. */
1016 bitset_foreach(c->nodes, idx) {
1017 ir_node *irn = get_idx_irn(env->co->irg, idx);
1018 co_mst_irn_t *node = get_co_mst_irn(env, irn);
1020 assert(! node->fixed && "Node must not have a fixed color.");
1022 DB((dbg, LEVEL_4, "\t\tBringing %+F from color %d to color %d ...\n", irn, node->col, reg_col));
1023 one_good |= change_node_color(env, node, reg_col, changed_ones);
1024 DB((dbg, LEVEL_4, "\t\t... %+F attempt from %d to %d %s\n", irn, node->col, reg_col, one_good ? "succeeded" : "failed"));
1027 /* try next color when failed */
1031 /* fragment the chunk according to the coloring */
1032 local_best = fragment_chunk(env, reg_col, c, tmp_chunks);
1034 /* search the best of the good list
1035 and make it the new best if it is better than the current */
1037 aff_chunk_assure_weight(env, local_best);
1039 DB((dbg, LEVEL_4, "\t\tlocal best chunk (id %d) for color %d: ", local_best->id, reg_col));
1040 DBG_AFF_CHUNK(env, LEVEL_4, local_best);
1042 if (! best_chunk || best_chunk->weight < local_best->weight) {
1043 best_chunk = local_best;
1044 best_color = reg_col;
1045 DB((dbg, LEVEL_4, "\n\t\t... setting global best chunk (id %d), color %d\n", best_chunk->id, best_color));
1047 DB((dbg, LEVEL_4, "\n\t\t... omitting, global best is better\n"));
1051 /* reject the coloring and bring the coloring to the initial state */
1052 reject_coloring(changed_ones);
1055 /* free all intermediate created chunks except best one */
1056 while (! waitq_empty(tmp_chunks)) {
1057 aff_chunk_t *tmp = waitq_get(tmp_chunks);
1058 if (tmp != best_chunk)
1059 delete_aff_chunk(env, tmp);
1061 del_waitq(tmp_chunks);
1063 /* return if coloring failed */
1065 del_waitq(changed_ones);
1069 DB((dbg, LEVEL_2, "\tbest chunk #%d ", best_chunk->id));
1070 DBG_AFF_CHUNK(env, LEVEL_2, best_chunk);
1071 DB((dbg, LEVEL_2, "using color %d\n", best_color));
1073 /* get the best fragment from the best list and color it */
1074 bitset_foreach(best_chunk->nodes, idx) {
1075 ir_node *irn = get_idx_irn(env->co->irg, idx);
1076 co_mst_irn_t *node = get_co_mst_irn(env, irn);
1079 res = change_node_color(env, node, best_color, changed_ones);
1080 assert(res && "color manifesting failed");
1082 node->chunk = best_chunk;
1085 /* materialize colors on changed nodes */
1086 while (! waitq_empty(changed_ones)) {
1087 co_mst_irn_t *n = waitq_get(changed_ones);
1089 n->col = n->tmp_col;
1092 /* remove the nodes in best chunk from original chunk */
1093 bitset_andnot(c->nodes, best_chunk->nodes);
1095 /* we have to get the nodes back into the original chunk because they are scattered over temporary chunks */
1096 bitset_foreach(c->nodes, idx) {
1097 ir_node *n = get_idx_irn(env->co->irg, idx);
1098 co_mst_irn_t *nn = get_co_mst_irn(env, n);
1102 /* fragment the remaining chunk */
1103 visited = bitset_irg_malloc(env->co->irg);
1104 bitset_or(visited, best_chunk->nodes);
1105 bitset_foreach(c->nodes, idx) {
1106 if (! bitset_is_set(visited, idx)) {
1107 aff_chunk_t *new_chunk = new_aff_chunk(env);
1108 ir_node *irn = get_idx_irn(env->co->irg, idx);
1109 co_mst_irn_t *node = get_co_mst_irn(env, irn);
1111 expand_chunk_from(env, node, visited, new_chunk, c, decider_always_yes, 0);
1112 aff_chunk_assure_weight(env, new_chunk);
1113 pqueue_put(env->chunks, new_chunk, new_chunk->weight);
1117 /* clear obsolete chunks and free some memory */
1118 delete_aff_chunk(env, best_chunk);
1119 bitset_free(visited);
1120 del_waitq(changed_ones);
1124 * Main driver for mst safe coalescing algorithm.
1126 int co_solve_heuristic_mst(copy_opt_t *co)
1128 unsigned n_regs = co->cls->n_regs;
1129 bitset_t *ignore_regs = bitset_alloca(n_regs);
1130 unsigned k, idx, num;
1132 co_mst_env_t mst_env;
1135 phase_init(&mst_env.ph, "co_mst", co->irg, PHASE_DEFAULT_GROWTH, co_mst_irn_init, &mst_env);
1137 k = be_put_ignore_regs(co->cenv->birg, co->cls, ignore_regs);
1140 /* Create a color to register number map. In some architectures registers are ignore "in the middle"
1141 of the register set. */
1142 mst_env.map_regs = NEW_ARR_D(int, phase_obst(&mst_env.ph), k);
1143 for (idx = num = 0; idx < n_regs; ++idx) {
1144 if (bitset_is_set(ignore_regs, idx))
1146 mst_env.map_regs[num++] = idx;
1150 mst_env.n_regs = n_regs;
1152 mst_env.chunks = new_pqueue();
1154 mst_env.ignore_regs = ignore_regs;
1155 mst_env.ifg = co->cenv->ifg;
1156 mst_env.aenv = co->aenv;
1157 pset_new_init(&mst_env.chunkset);
1159 DBG((dbg, LEVEL_1, "==== Coloring %+F, class %s ====\n", co->irg, co->cls->name));
1161 /* build affinity chunks */
1162 build_affinity_chunks(&mst_env);
1164 /* color chunks as long as there are some */
1165 while (! pqueue_empty(mst_env.chunks)) {
1166 aff_chunk_t *chunk = pqueue_get(mst_env.chunks);
1168 color_aff_chunk(&mst_env, chunk);
1169 DB((dbg, LEVEL_4, "<<<====== Coloring chunk (%d) done\n", chunk->id));
1170 delete_aff_chunk(&mst_env, chunk);
1173 /* apply coloring */
1174 foreach_phase_irn(&mst_env.ph, irn) {
1175 co_mst_irn_t *mirn = get_co_mst_irn(&mst_env, irn);
1176 const arch_register_t *reg;
1178 if (arch_irn_is(mst_env.aenv, irn, ignore))
1181 assert(mirn->fixed && "Node should have fixed color");
1183 /* skip nodes where color hasn't changed */
1184 if (mirn->init_col == mirn->col)
1187 reg = arch_register_for_index(co->cls, mirn->col);
1188 arch_set_irn_register(co->aenv, irn, reg);
1189 DB((dbg, LEVEL_1, "%+F set color from %d to %d\n", irn, mirn->init_col, mirn->col));
1192 /* free allocated memory */
1193 del_pqueue(mst_env.chunks);
1194 phase_free(&mst_env.ph);
1195 pset_new_destroy(&mst_env.chunkset);
1200 void be_init_copyheur4(void) {
1201 FIRM_DBG_REGISTER(dbg, "firm.be.co.heur4");
1204 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_copyheur4);