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 bitset_t *interfere; /**< A bitset containing all interfering neighbours of the nodes in this chunk. */
79 int weight; /**< Weight of this chunk */
80 unsigned weight_consistent : 1; /**< Set if the weight is consistent. */
81 int id; /**< For debugging: An id of this chunk. */
87 typedef struct _aff_edge_t {
88 ir_node *src; /**< Source node. */
89 ir_node *tgt; /**< 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 ir_phase ph; /**< phase object holding data for nodes */
99 pqueue *chunks; /**< priority queue for chunks */
100 pset_new_t chunkset; /**< set holding all chunks */
101 be_ifg_t *ifg; /**< the interference graph */
102 const arch_env_t *aenv; /**< the arch environment */
103 copy_opt_t *co; /**< the copy opt object */
106 /* stores coalescing related information for a node */
107 typedef struct _co_mst_irn_t {
108 ir_node *irn; /**< the irn this information belongs to */
109 aff_chunk_t *chunk; /**< the chunk this irn belongs to */
110 bitset_t *adm_colors; /**< set of admissible colors for this irn */
111 ir_node **int_neighs; /**< array of all interfering neighbours (cached for speed reasons) */
112 int n_neighs; /**< length of the interfering neighbours array. */
113 int int_aff_neigh; /**< number of interfering affinity neighbours */
114 int col; /**< color currently assigned */
115 int init_col; /**< the initial color */
116 int tmp_col; /**< a temporary assigned color */
117 unsigned fixed : 1; /**< the color is fixed */
118 unsigned tmp_fixed : 1; /**< the color is temporary fixed */
121 #define get_co_mst_irn(mst_env, irn) (phase_get_or_set_irn_data(&(mst_env)->ph, (irn)))
123 typedef int decide_func_t(const co_mst_irn_t *node, int col);
128 * Write a chunk to stderr for debugging.
130 static void dbg_aff_chunk(const co_mst_env_t *env, const aff_chunk_t *c) {
132 if (c->weight_consistent)
133 ir_fprintf(stderr, " $%d ", c->weight);
134 ir_fprintf(stderr, "{");
135 bitset_foreach(c->nodes, idx) {
136 ir_node *n = get_idx_irn(env->co->irg, idx);
137 ir_fprintf(stderr, " %+F,", n);
139 ir_fprintf(stderr, "}");
143 * Dump all admissible colors to stderr.
145 static void dbg_admissible_colors(const co_mst_env_t *env, const co_mst_irn_t *node) {
147 if (bitset_popcnt(node->adm_colors) < 1)
148 fprintf(stderr, "no admissible colors?!?");
150 bitset_foreach(node->adm_colors, idx)
151 fprintf(stderr, " %d", idx);
156 * Dump color-cost pairs to stderr.
158 static void dbg_col_cost(const co_mst_env_t *env, const col_cost_t *cost) {
160 for (i = 0; i < env->n_regs; ++i) {
161 if (cost[i].cost == COL_COST_INFEASIBLE)
162 fprintf(stderr, " (%d, INF)", cost[i].col);
164 fprintf(stderr, " (%d, %.1f)", cost[i].col, cost[i].cost);
168 #endif /* DEBUG_libfirm */
170 static INLINE int get_mst_irn_col(const co_mst_irn_t *node) {
171 return node->tmp_fixed ? node->tmp_col : node->col;
175 * @return 1 if node @p node has color @p col, 0 otherwise.
177 static int decider_has_color(const co_mst_irn_t *node, int col) {
178 return get_mst_irn_col(node) == col;
182 * @return 1 if node @p node has not color @p col, 0 otherwise.
184 static int decider_hasnot_color(const co_mst_irn_t *node, int col) {
185 return get_mst_irn_col(node) != col;
189 * Always returns true.
191 static int decider_always_yes(const co_mst_irn_t *node, int col) {
195 /** compares two affinity edges by its weight */
196 static int cmp_aff_edge(const void *a, const void *b) {
197 const aff_edge_t *e1 = a;
198 const aff_edge_t *e2 = b;
200 if (e2->weight == e1->weight) {
201 if (e2->src->node_idx == e1->src->node_idx)
202 return QSORT_CMP(e2->tgt->node_idx, e1->tgt->node_idx);
204 return QSORT_CMP(e2->src->node_idx, e1->src->node_idx);
206 /* sort in descending order */
207 return QSORT_CMP(e2->weight, e1->weight);
210 /** compares to color-cost pairs */
211 static int cmp_col_cost(const void *a, const void *b) {
212 const col_cost_t *c1 = a;
213 const col_cost_t *c2 = b;
215 return c1->cost < c2->cost ? -1 : 1;
219 * Creates a new affinity chunk
221 static INLINE aff_chunk_t *new_aff_chunk(co_mst_env_t *env) {
222 aff_chunk_t *c = xmalloc(sizeof(*c));
224 c->weight_consistent = 0;
225 c->nodes = bitset_irg_malloc(env->co->irg);
226 c->interfere = bitset_irg_malloc(env->co->irg);
227 c->id = last_chunk_id++;
228 pset_new_insert(&env->chunkset, c);
233 * Frees all memory allocated by an affinity chunk.
235 static INLINE void delete_aff_chunk(co_mst_env_t *env, aff_chunk_t *c) {
236 pset_new_remove(&env->chunkset, c);
237 bitset_free(c->nodes);
238 bitset_free(c->interfere);
239 memset(c, 0, sizeof(*c));
244 * Adds a node to an affinity chunk
246 static INLINE void aff_chunk_add_node(aff_chunk_t *c, co_mst_irn_t *node) {
249 c->weight_consistent = 0;
251 bitset_set(c->nodes, get_irn_idx(node->irn));
253 for (i = node->n_neighs - 1; i >= 0; --i) {
254 ir_node *neigh = node->int_neighs[i];
255 bitset_set(c->interfere, get_irn_idx(neigh));
260 * In case there is no phase information for irn, initialize it.
262 static void *co_mst_irn_init(ir_phase *ph, ir_node *irn, void *old) {
263 co_mst_irn_t *res = old ? old : phase_alloc(ph, sizeof(res[0]));
264 co_mst_env_t *env = ph->priv;
267 const arch_register_req_t *req;
268 void *nodes_it = be_ifg_nodes_iter_alloca(env->ifg);
277 res->int_neighs = NULL;
278 res->int_aff_neigh = 0;
279 res->col = arch_register_get_index(arch_get_irn_register(env->aenv, irn));
280 res->init_col = res->col;
282 DB((dbg, LEVEL_4, "Creating phase info for %+F\n", irn));
284 /* set admissible registers */
285 res->adm_colors = bitset_obstack_alloc(phase_obst(ph), env->n_regs);
287 /* Exclude colors not assignable to the irn */
288 req = arch_get_register_req(env->aenv, irn, -1);
289 if (arch_register_req_is(req, limited))
290 rbitset_copy_to_bitset(req->limited, res->adm_colors);
292 bitset_set_all(res->adm_colors);
294 /* exclude global ignore registers as well */
295 bitset_andnot(res->adm_colors, env->ignore_regs);
297 /* set the number of interfering affinity neighbours to -1, they are calculated later */
298 res->int_aff_neigh = -1;
300 /* build list of interfering neighbours */
302 be_ifg_foreach_neighbour(env->ifg, nodes_it, irn, neigh) {
303 if (! arch_irn_is(env->aenv, neigh, ignore)) {
304 obstack_ptr_grow(phase_obst(ph), neigh);
308 res->int_neighs = obstack_finish(phase_obst(ph));
315 * Check if affinity chunk @p chunk interferes with node @p irn.
317 static INLINE int aff_chunk_interferes(co_mst_env_t *env, const aff_chunk_t *chunk, ir_node *irn) {
319 if (bitset_is_set(chunk->interfere, get_irn_idx(irn)))
322 const co_mst_irn_t *node = get_co_mst_irn(env, irn);
323 const ir_node *neigh;
326 for (i = 0; i < node->n_neighs; ++i) {
327 neigh = node->int_neighs[i];
328 if (! arch_irn_is(env->aenv, neigh, ignore) && bitset_is_set(chunk->nodes, get_irn_idx(neigh)))
336 * Check if there are interference edges from c1 to c2.
337 * @param env The global co_mst environment
339 * @param c2 Another chunk
340 * @return 1 if there are interferences between nodes of c1 and c2, 0 otherwise.
342 static INLINE int aff_chunks_interfere(co_mst_env_t *env, const aff_chunk_t *c1, const aff_chunk_t *c2) {
349 tmp = bitset_alloca(get_irg_last_idx(env->co->irg));
350 tmp = bitset_copy(tmp, c1->interfere);
351 tmp = bitset_and(tmp, c2->nodes);
352 if (bitset_popcnt(tmp) > 0)
355 /* check if there is a node in c2 having an interfering neighbor in c1 */
356 bitset_foreach(c2->nodes, idx) {
357 ir_node *n = get_idx_irn(env->co->irg, idx);
359 if (aff_chunk_interferes(env, c1, n))
367 * Returns the affinity chunk of @p irn or creates a new
368 * one with @p irn as element if there is none assigned.
370 static INLINE aff_chunk_t *get_aff_chunk(co_mst_env_t *env, ir_node *irn) {
371 co_mst_irn_t *node = get_co_mst_irn(env, irn);
376 * Let chunk(src) absorb the nodes of chunk(tgt) (only possible when there
377 * are no interference edges from chunk(src) to chunk(tgt)).
378 * @return 1 if successful, 0 if not possible
380 static int aff_chunk_absorb(co_mst_env_t *env, ir_node *src, ir_node *tgt) {
381 aff_chunk_t *c1 = get_aff_chunk(env, src);
382 aff_chunk_t *c2 = get_aff_chunk(env, tgt);
385 DB((dbg, LEVEL_4, "Attempt to let c1 (id %d): ", c1 ? c1->id : -1));
387 DBG_AFF_CHUNK(env, LEVEL_4, c1);
389 DB((dbg, LEVEL_4, "{%+F}", src));
391 DB((dbg, LEVEL_4, "\n\tabsorb c2 (id %d): ", c2 ? c2->id : -1));
393 DBG_AFF_CHUNK(env, LEVEL_4, c2);
395 DB((dbg, LEVEL_4, "{%+F}", tgt));
397 DB((dbg, LEVEL_4, "\n"));
402 /* no chunk exists */
403 co_mst_irn_t *mirn = get_co_mst_irn(env, src);
406 for (i = mirn->n_neighs - 1; i >= 0; --i) {
407 if (mirn->int_neighs[i] == tgt)
411 /* create one containing both nodes */
412 c1 = new_aff_chunk(env);
413 aff_chunk_add_node(c1, get_co_mst_irn(env, src));
414 aff_chunk_add_node(c1, get_co_mst_irn(env, tgt));
418 /* c2 already exists */
419 if (! aff_chunk_interferes(env, c2, src)) {
420 aff_chunk_add_node(c2, get_co_mst_irn(env, src));
424 } else if (c2 == NULL) {
425 /* c1 already exists */
426 if (! aff_chunk_interferes(env, c1, tgt)) {
427 aff_chunk_add_node(c1, get_co_mst_irn(env, tgt));
430 } else if (c1 != c2 && ! aff_chunks_interfere(env, c1, c2)) {
433 bitset_or(c1->nodes, c2->nodes);
434 bitset_or(c1->interfere, c2->interfere);
435 c1->weight_consistent = 0;
437 bitset_foreach(c2->nodes, idx) {
438 ir_node *n = get_idx_irn(env->co->irg, idx);
439 co_mst_irn_t *mn = get_co_mst_irn(env, n);
443 delete_aff_chunk(env, c2);
446 DB((dbg, LEVEL_4, " ... c1 interferes with c2, skipped\n"));
450 DB((dbg, LEVEL_4, " ... absorbed\n"));
455 * Assures that the weight of the given chunk is consistent.
457 static void aff_chunk_assure_weight(const co_mst_env_t *env, aff_chunk_t *c) {
458 if (! c->weight_consistent) {
462 bitset_foreach(c->nodes, idx) {
463 ir_node *n = get_idx_irn(env->co->irg, idx);
464 const affinity_node_t *an = get_affinity_info(env->co, n);
468 co_gs_foreach_neighb(an, neigh) {
469 const ir_node *m = neigh->irn;
470 const int m_idx = get_irn_idx(m);
472 /* skip ignore nodes */
473 if (arch_irn_is(env->aenv, m, ignore))
476 w += bitset_is_set(c->nodes, m_idx) ? neigh->costs : 0;
482 c->weight_consistent = 1;
487 * Count the number of interfering affinity neighbours
489 static int count_interfering_aff_neighs(co_mst_env_t *env, const affinity_node_t *an) {
490 const neighb_t *neigh;
491 ir_node *irn = an->irn;
492 const co_mst_irn_t *node = get_co_mst_irn(env, irn);
495 co_gs_foreach_neighb(an, neigh) {
496 const ir_node *n = neigh->irn;
499 /* skip ignore nodes */
500 if (arch_irn_is(env->aenv, n, ignore))
503 /* check if the affinity neighbour interfere */
504 for (i = 0; i < node->n_neighs; ++i) {
505 if (node->int_neighs[i] == n) {
516 * Build chunks of nodes connected by affinity edges.
517 * We start at the heaviest affinity edge.
518 * The chunks of the two edge-defining nodes will be
519 * merged if there are no interference edges from one
520 * chunk to the other.
522 static void build_affinity_chunks(co_mst_env_t *env) {
523 void *nodes_it = be_ifg_nodes_iter_alloca(env->ifg);
524 aff_edge_t *edges = NEW_ARR_F(aff_edge_t, 0);
527 aff_chunk_t *curr_chunk;
528 pset_new_iterator_t iter;
530 /* at first we create the affinity edge objects */
531 be_ifg_foreach_node(env->ifg, nodes_it, n) {
532 int n_idx = get_irn_idx(n);
536 /* skip ignore nodes */
537 if (arch_irn_is(env->aenv, n, ignore))
540 n1 = get_co_mst_irn(env, n);
541 an = get_affinity_info(env->co, n);
546 if (n1->int_aff_neigh < 0)
547 n1->int_aff_neigh = count_interfering_aff_neighs(env, an);
548 co_gs_foreach_neighb(an, neigh) {
549 ir_node *m = neigh->irn;
550 int m_idx = get_irn_idx(m);
552 /* record the edge in only one direction */
557 /* skip ignore nodes */
558 if (arch_irn_is(env->aenv, m, ignore))
564 n2 = get_co_mst_irn(env, m);
565 if (n2->int_aff_neigh < 0) {
566 affinity_node_t *am = get_affinity_info(env->co, m);
567 n2->int_aff_neigh = count_interfering_aff_neighs(env, am);
569 edge.weight = (double)neigh->costs / (double)(1 + n1->int_aff_neigh + n2->int_aff_neigh);
570 ARR_APP1(aff_edge_t, edges, edge);
576 /* now: sort edges and build the affinity chunks */
577 len = ARR_LEN(edges);
578 qsort(edges, len, sizeof(edges[0]), cmp_aff_edge);
579 for (i = 0; i < len; ++i) {
580 DBG((dbg, LEVEL_1, "edge (%u,%u) %f\n", edges[i].src->node_idx, edges[i].tgt->node_idx, edges[i].weight));
582 (void)aff_chunk_absorb(env, edges[i].src, edges[i].tgt);
585 /* now insert all chunks into a priority queue */
586 foreach_pset_new(&env->chunkset, curr_chunk, iter) {
587 aff_chunk_assure_weight(env, curr_chunk);
589 DBG((dbg, LEVEL_1, "entry #%d", curr_chunk->id));
590 DBG_AFF_CHUNK(env, LEVEL_1, curr_chunk);
591 DBG((dbg, LEVEL_1, "\n"));
593 pqueue_put(env->chunks, curr_chunk, curr_chunk->weight);
595 foreach_phase_irn(&env->ph, n) {
596 co_mst_irn_t *mirn = get_co_mst_irn(env, n);
598 if (mirn->chunk == NULL) {
599 /* no chunk is allocated so far, do it now */
600 aff_chunk_t *curr_chunk = new_aff_chunk(env);
601 aff_chunk_add_node(curr_chunk, mirn);
603 aff_chunk_assure_weight(env, curr_chunk);
605 DBG((dbg, LEVEL_1, "entry #%d", curr_chunk->id));
606 DBG_AFF_CHUNK(env, LEVEL_1, curr_chunk);
607 DBG((dbg, LEVEL_1, "\n"));
609 pqueue_put(env->chunks, curr_chunk, curr_chunk->weight);
617 * Greedy collect affinity neighbours into thew new chunk @p chunk starting at node @p node.
619 static void expand_chunk_from(co_mst_env_t *env, co_mst_irn_t *node, bitset_t *visited,
620 aff_chunk_t *chunk, aff_chunk_t *orig_chunk, decide_func_t *decider, int col)
622 waitq *nodes = new_waitq();
624 DBG((dbg, LEVEL_1, "\nExpanding new chunk (id %d) from %+F:", chunk->id, node->irn));
626 /* init queue and chunk */
627 waitq_put(nodes, node);
628 bitset_set(visited, get_irn_idx(node->irn));
629 aff_chunk_add_node(chunk, node);
630 DB((dbg, LEVEL_1, " %+F", node->irn));
632 /* as long as there are nodes in the queue */
633 while (! waitq_empty(nodes)) {
634 co_mst_irn_t *n = waitq_get(nodes);
635 affinity_node_t *an = get_affinity_info(env->co, n->irn);
637 /* check all affinity neighbors */
640 co_gs_foreach_neighb(an, neigh) {
641 ir_node *m = neigh->irn;
642 int m_idx = get_irn_idx(m);
645 /* skip ignore nodes */
646 if (arch_irn_is(env->aenv, m, ignore))
649 n2 = get_co_mst_irn(env, m);
651 if (! bitset_is_set(visited, m_idx) &&
654 ! aff_chunk_interferes(env, chunk, m) &&
655 bitset_is_set(orig_chunk->nodes, m_idx))
658 following conditions are met:
659 - neighbour is not visited
660 - neighbour likes the color
661 - neighbour has not yet a fixed color
662 - the new chunk doesn't interfere with the neighbour
663 - neighbour belongs or belonged once to the original chunk
665 bitset_set(visited, m_idx);
666 aff_chunk_add_node(chunk, n2);
667 DB((dbg, LEVEL_1, " %+F", n2->irn));
668 /* enqueue for further search */
669 waitq_put(nodes, n2);
675 DB((dbg, LEVEL_1, "\n"));
681 * Fragment the given chunk into chunks having given color and not having given color.
683 static aff_chunk_t *fragment_chunk(co_mst_env_t *env, int col, aff_chunk_t *c, waitq *tmp) {
684 bitset_t *visited = bitset_irg_malloc(env->co->irg);
686 aff_chunk_t *best = NULL;
688 bitset_foreach(c->nodes, idx) {
691 aff_chunk_t *tmp_chunk;
692 decide_func_t *decider;
695 if (bitset_is_set(visited, idx))
698 irn = get_idx_irn(env->co->irg, idx);
699 node = get_co_mst_irn(env, irn);
701 if (get_mst_irn_col(node) == col) {
702 decider = decider_has_color;
706 decider = decider_hasnot_color;
710 /* create a new chunk starting at current node */
711 tmp_chunk = new_aff_chunk(env);
712 waitq_put(tmp, tmp_chunk);
713 expand_chunk_from(env, node, visited, tmp_chunk, c, decider, col);
714 assert(bitset_popcnt(tmp_chunk->nodes) > 0 && "No nodes added to chunk");
716 /* remember the local best */
717 aff_chunk_assure_weight(env, tmp_chunk);
718 if (check_for_best && (! best || best->weight < tmp_chunk->weight))
722 assert(best && "No chunk found?");
723 bitset_free(visited);
728 * Initializes an array of color-cost pairs.
729 * Sets forbidden colors to costs COL_COST_INFEASIBLE and all others to @p c.
731 static INLINE void col_cost_init(co_mst_env_t *env, col_cost_t *cost, double c) {
734 for (i = 0; i < env->n_regs; ++i) {
736 if (bitset_is_set(env->ignore_regs, i))
737 cost[i].cost = COL_COST_INFEASIBLE;
744 * Initializes an array of color-cost pairs.
745 * Sets all colors except color @p col to COL_COST_INFEASIBLE and @p col to 0.0
747 static INLINE void col_cost_init_single(co_mst_env_t *env, col_cost_t *cost, int col) {
748 assert(! bitset_is_set(env->ignore_regs, col) && "Attempt to use forbidden color.");
749 col_cost_init(env, cost, COL_COST_INFEASIBLE);
756 * Resets the temporary fixed color of all nodes within wait queue @p nodes.
757 * ATTENTION: the queue is empty after calling this function!
759 static INLINE void reject_coloring(waitq *nodes) {
760 while (! waitq_empty(nodes)) {
761 co_mst_irn_t *n = waitq_get(nodes);
767 * Determines the costs for each color if it would be assigned to node @p node.
769 static void determine_color_costs(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *costs) {
770 affinity_node_t *an = get_affinity_info(env->co, node->irn);
774 col_cost_init(env, costs, 0.0);
776 /* calculate (negative) costs for affinity neighbours */
778 co_gs_foreach_neighb(an, aff_neigh) {
779 ir_node *m = aff_neigh->irn;
783 /* skip ignore nodes */
784 if (arch_irn_is(env->aenv, m, ignore))
787 neigh = get_co_mst_irn(env, m);
788 c = (double)aff_neigh->costs;
790 /* calculate costs for fixed affinity neighbours */
791 if (neigh->tmp_fixed || neigh->fixed) {
792 int col = get_mst_irn_col(neigh);
793 costs[col].cost -= c * AFF_NEIGHBOUR_FIX_BENEFIT;
798 /* calculate (positive) costs for interfering neighbours */
799 for (i = 0; i < node->n_neighs; ++i) {
804 int_neigh = node->int_neighs[i];
806 /* skip ignore nodes */
807 if (arch_irn_is(env->aenv, int_neigh, ignore))
810 neigh = get_co_mst_irn(env, int_neigh);
811 col = get_mst_irn_col(neigh);
812 col_cnt = bitset_popcnt(neigh->adm_colors);
814 if (neigh->tmp_fixed || neigh->fixed) {
815 /* colors of fixed interfering neighbours are infeasible */
816 costs[col].cost = COL_COST_INFEASIBLE;
818 else if (col_cnt < env->k) {
819 /* calculate costs for constrained interfering neighbours */
820 double ratio = 1.0 - ((double)col_cnt / (double)env->k);
822 bitset_foreach_clear(neigh->adm_colors, idx) {
823 /* check only explicitly forbidden colors (skip global forbidden ones) */
824 if (! bitset_is_set(env->ignore_regs, idx)) {
825 costs[col].cost += ratio * NEIGHBOUR_CONSTR_COSTS;
831 /* set all not admissible colors to COL_COST_INFEASIBLE */
832 bitset_foreach_clear(node->adm_colors, idx)
833 costs[idx].cost = COL_COST_INFEASIBLE;
836 /* need forward declaration due to recursive call */
837 static int recolor_nodes(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *costs, waitq *changed_ones);
840 * Tries to change node to a color but @p explude_col.
841 * @return 1 if succeeded, 0 otherwise.
843 static int change_node_color_excluded(co_mst_env_t *env, co_mst_irn_t *node, int exclude_col, waitq *changed_ones) {
844 int col = get_mst_irn_col(node);
847 /* neighbours has already a different color -> good, temporary fix it */
848 if (col != exclude_col) {
851 waitq_put(changed_ones, node);
855 /* The node has the color it should not have _and_ has not been visited yet. */
856 if (! (node->tmp_fixed || node->fixed)) {
857 col_cost_t *costs = alloca(env->n_regs * sizeof(costs[0]));
859 /* Get the costs for giving the node a specific color. */
860 determine_color_costs(env, node, costs);
862 /* Since the node must not have the not_col, set the costs for that color to "infinity" */
863 costs[exclude_col].cost = COL_COST_INFEASIBLE;
865 /* sort the colors according costs, cheapest first. */
866 qsort(costs, env->n_regs, sizeof(costs[0]), cmp_col_cost);
868 /* Try recoloring the node using the color list. */
869 res = recolor_nodes(env, node, costs, changed_ones);
876 * Tries to bring node @p node to cheapest color and color all interfering neighbours with other colors.
877 * ATTENTION: Expect @p costs already sorted by increasing costs.
878 * @return 1 if coloring could be applied, 0 otherwise.
880 static int recolor_nodes(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *costs, waitq *changed_ones) {
882 waitq *local_changed = new_waitq();
883 waitq *tmp = new_waitq();
885 DBG((dbg, LEVEL_1, "\tRecoloring %+F with color-costs", node->irn));
886 DBG_COL_COST(env, LEVEL_1, costs);
887 DB((dbg, LEVEL_1, "\n"));
889 for (i = 0; i < env->n_regs; ++i) {
890 int tgt_col = costs[i].col;
894 /* If the costs for that color (and all successive) are infinite, bail out we won't make it anyway. */
895 if (costs[i].cost == COL_COST_INFEASIBLE) {
897 del_waitq(local_changed);
902 /* Set the new color of the node and mark the node as temporarily fixed. */
903 assert(! node->tmp_fixed && "Node must not have been temporary fixed.");
905 node->tmp_col = tgt_col;
907 assert(waitq_empty(local_changed) && "Node queue should be empty here.");
908 waitq_put(local_changed, node);
910 /* try to color all interfering neighbours with current color forbidden */
911 for (j = 0; j < node->n_neighs; ++j) {
915 neigh = node->int_neighs[j];
917 /* skip ignore nodes */
918 if (arch_irn_is(env->aenv, neigh, ignore))
921 nn = get_co_mst_irn(env, neigh);
924 Try to change the color of the neighbor and record all nodes which
925 get changed in the tmp list. Add this list to the "changed" list for
926 that color. If we did not succeed to change the color of the neighbor,
927 we bail out and try the next color.
929 if (get_mst_irn_col(nn) == tgt_col) {
930 /* try to color neighbour with tgt_col forbidden */
931 neigh_ok = change_node_color_excluded(env, nn, tgt_col, tmp);
933 /* join lists of changed nodes */
934 while (! waitq_empty(tmp))
935 waitq_put(local_changed, waitq_get(tmp));
943 We managed to assign the target color to all neighbors, so from the perspective
944 of the current node, every thing was ok and we can return safely.
947 /* append the local_changed ones to global ones */
948 while (! waitq_empty(local_changed))
949 waitq_put(changed_ones, waitq_get(local_changed));
950 del_waitq(local_changed);
955 /* coloring of neighbours failed, so we try next color */
956 reject_coloring(local_changed);
960 del_waitq(local_changed);
966 * Tries to bring node @p node and all it's neighbours to color @p tgt_col.
967 * @return 1 if color @p col could be applied, 0 otherwise
969 static int change_node_color(co_mst_env_t *env, co_mst_irn_t *node, int tgt_col, waitq *changed_ones) {
970 int col = get_mst_irn_col(node);
972 /* if node already has the target color -> good, temporary fix it */
973 if (col == tgt_col) {
974 DBG((dbg, LEVEL_4, "\t\tCNC: %+F has already color %d, fix temporary\n", node->irn, tgt_col));
975 if (! node->tmp_fixed) {
977 node->tmp_col = tgt_col;
978 waitq_put(changed_ones, node);
984 Node has not yet a fixed color and target color is admissible
985 -> try to recolor node and it's affinity neighbours
987 if (! (node->fixed || node->tmp_fixed) && bitset_is_set(node->adm_colors, tgt_col)) {
988 col_cost_t *costs = alloca(env->n_regs * sizeof(costs[0]));
991 col_cost_init_single(env, costs, tgt_col);
993 DBG((dbg, LEVEL_4, "\t\tCNC: Attempt to recolor %+F ===>>\n", node->irn));
994 res = recolor_nodes(env, node, costs, changed_ones);
995 DBG((dbg, LEVEL_4, "\t\tCNC: <<=== Recoloring of %+F %s\n", node->irn, res ? "succeeded" : "failed"));
1001 if (firm_dbg_get_mask(dbg) & LEVEL_4) {
1002 if (node->fixed || node->tmp_fixed)
1003 DB((dbg, LEVEL_4, "\t\tCNC: %+F has already fixed color %d\n", node->irn, col));
1005 DB((dbg, LEVEL_4, "\t\tCNC: color %d not admissible for %+F (", tgt_col, node->irn));
1006 dbg_admissible_colors(env, node);
1007 DB((dbg, LEVEL_4, ")\n"));
1016 * Tries to color an affinity chunk (or at least a part of it).
1017 * Inserts uncolored parts of the chunk as a new chunk into the priority queue.
1019 static void color_aff_chunk(co_mst_env_t *env, aff_chunk_t *c) {
1020 aff_chunk_t *best_chunk = NULL;
1021 int best_color = -1;
1022 waitq *changed_ones = new_waitq();
1023 waitq *tmp_chunks = new_waitq();
1027 DB((dbg, LEVEL_2, "fragmentizing chunk #%d", c->id));
1028 DBG_AFF_CHUNK(env, LEVEL_2, c);
1029 DB((dbg, LEVEL_2, "\n"));
1032 /* check which color is the "best" for the given chunk */
1033 for (col = 0; col < env->n_regs; ++col) {
1035 aff_chunk_t *local_best;
1037 /* skip ignore colors */
1038 if (bitset_is_set(env->ignore_regs, col))
1041 DB((dbg, LEVEL_3, "\ttrying color %d\n", col));
1043 /* try to bring all nodes of given chunk to the current color. */
1044 bitset_foreach(c->nodes, idx) {
1045 ir_node *irn = get_idx_irn(env->co->irg, idx);
1046 co_mst_irn_t *node = get_co_mst_irn(env, irn);
1048 assert(! node->fixed && "Node must not have a fixed color.");
1050 DB((dbg, LEVEL_4, "\t\tBringing %+F from color %d to color %d ...\n", irn, node->col, col));
1051 one_good |= change_node_color(env, node, col, changed_ones);
1052 DB((dbg, LEVEL_4, "\t\t... %+F attempt from %d to %d %s\n", irn, node->col, col, one_good ? "succeeded" : "failed"));
1055 /* try next color when failed */
1059 /* fragment the chunk according to the coloring */
1060 local_best = fragment_chunk(env, col, c, tmp_chunks);
1062 /* search the best of the good list
1063 and make it the new best if it is better than the current */
1065 aff_chunk_assure_weight(env, local_best);
1067 DB((dbg, LEVEL_4, "\t\tlocal best chunk (id %d) for color %d: ", local_best->id, col));
1068 DBG_AFF_CHUNK(env, LEVEL_4, local_best);
1070 if (! best_chunk || best_chunk->weight < local_best->weight) {
1071 best_chunk = local_best;
1073 DB((dbg, LEVEL_4, "\n\t\t... setting global best chunk (id %d), color %d\n", best_chunk->id, best_color));
1075 DB((dbg, LEVEL_4, "\n\t\t... omitting, global best is better\n"));
1079 /* reject the coloring and bring the coloring to the initial state */
1080 reject_coloring(changed_ones);
1083 /* free all intermediate created chunks except best one */
1084 while (! waitq_empty(tmp_chunks)) {
1085 aff_chunk_t *tmp = waitq_get(tmp_chunks);
1086 if (tmp != best_chunk)
1087 delete_aff_chunk(env, tmp);
1089 del_waitq(tmp_chunks);
1091 /* return if coloring failed */
1093 del_waitq(changed_ones);
1097 DB((dbg, LEVEL_2, "\tbest chunk #%d ", best_chunk->id));
1098 DBG_AFF_CHUNK(env, LEVEL_2, best_chunk);
1099 DB((dbg, LEVEL_2, "using color %d\n", best_color));
1101 /* get the best fragment from the best list and color it */
1102 bitset_foreach(best_chunk->nodes, idx) {
1103 ir_node *irn = get_idx_irn(env->co->irg, idx);
1104 co_mst_irn_t *node = get_co_mst_irn(env, irn);
1107 res = change_node_color(env, node, best_color, changed_ones);
1109 panic("Color manifesting failed for %+F, color %d in chunk %d\n", irn, best_color, best_chunk->id);
1111 node->chunk = best_chunk;
1114 /* materialize colors on changed nodes */
1115 while (! waitq_empty(changed_ones)) {
1116 co_mst_irn_t *n = waitq_get(changed_ones);
1118 n->col = n->tmp_col;
1121 /* remove the nodes in best chunk from original chunk */
1122 bitset_andnot(c->nodes, best_chunk->nodes);
1124 /* we have to get the nodes back into the original chunk because they are scattered over temporary chunks */
1125 bitset_foreach(c->nodes, idx) {
1126 ir_node *n = get_idx_irn(env->co->irg, idx);
1127 co_mst_irn_t *nn = get_co_mst_irn(env, n);
1131 /* fragment the remaining chunk */
1132 visited = bitset_irg_malloc(env->co->irg);
1133 bitset_or(visited, best_chunk->nodes);
1134 bitset_foreach(c->nodes, idx) {
1135 if (! bitset_is_set(visited, idx)) {
1136 aff_chunk_t *new_chunk = new_aff_chunk(env);
1137 ir_node *irn = get_idx_irn(env->co->irg, idx);
1138 co_mst_irn_t *node = get_co_mst_irn(env, irn);
1140 expand_chunk_from(env, node, visited, new_chunk, c, decider_always_yes, 0);
1141 aff_chunk_assure_weight(env, new_chunk);
1142 pqueue_put(env->chunks, new_chunk, new_chunk->weight);
1146 /* clear obsolete chunks and free some memory */
1147 delete_aff_chunk(env, best_chunk);
1148 bitset_free(visited);
1149 del_waitq(changed_ones);
1153 * Main driver for mst safe coalescing algorithm.
1155 int co_solve_heuristic_mst(copy_opt_t *co) {
1156 unsigned n_regs = co->cls->n_regs;
1157 bitset_t *ignore_regs = bitset_alloca(n_regs);
1160 co_mst_env_t mst_env;
1163 phase_init(&mst_env.ph, "co_mst", co->irg, PHASE_DEFAULT_GROWTH, co_mst_irn_init, &mst_env);
1165 k = be_put_ignore_regs(co->cenv->birg, co->cls, ignore_regs);
1168 mst_env.n_regs = n_regs;
1170 mst_env.chunks = new_pqueue();
1172 mst_env.ignore_regs = ignore_regs;
1173 mst_env.ifg = co->cenv->ifg;
1174 mst_env.aenv = co->aenv;
1175 pset_new_init(&mst_env.chunkset);
1177 DBG((dbg, LEVEL_1, "==== Coloring %+F, class %s ====\n", co->irg, co->cls->name));
1179 /* build affinity chunks */
1180 build_affinity_chunks(&mst_env);
1182 /* color chunks as long as there are some */
1183 while (! pqueue_empty(mst_env.chunks)) {
1184 aff_chunk_t *chunk = pqueue_get(mst_env.chunks);
1186 color_aff_chunk(&mst_env, chunk);
1187 DB((dbg, LEVEL_4, "<<<====== Coloring chunk (%d) done\n", chunk->id));
1188 delete_aff_chunk(&mst_env, chunk);
1191 /* apply coloring */
1192 foreach_phase_irn(&mst_env.ph, irn) {
1193 co_mst_irn_t *mirn = get_co_mst_irn(&mst_env, irn);
1194 const arch_register_t *reg;
1196 if (arch_irn_is(mst_env.aenv, irn, ignore))
1199 assert(mirn->fixed && "Node should have fixed color");
1201 /* skip nodes where color hasn't changed */
1202 if (mirn->init_col == mirn->col)
1205 reg = arch_register_for_index(co->cls, mirn->col);
1206 arch_set_irn_register(co->aenv, irn, reg);
1207 DB((dbg, LEVEL_1, "%+F set color from %d to %d\n", irn, mirn->init_col, mirn->col));
1210 /* free allocated memory */
1211 del_pqueue(mst_env.chunks);
1212 phase_free(&mst_env.ph);
1213 pset_new_destroy(&mst_env.chunkset);
1218 void be_init_copyheur4(void) {
1219 FIRM_DBG_REGISTER(dbg, "firm.be.co.heur4");
1222 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_copyheur4);