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 ir_node **n; /**< An ARR_F containing all nodes of the chunk. */
78 bitset_t *nodes; /**< A bitset containing all nodes inside this chunk. */
79 bitset_t *interfere; /**< A bitset containing all interfering neighbours of the nodes in this chunk. */
80 int weight; /**< Weight of this chunk */
81 unsigned weight_consistent : 1; /**< Set if the weight is consistent. */
82 unsigned deleted : 1; /**< Set if the was deleted. */
83 int id; /**< For debugging: An id of this chunk. */
89 typedef struct _aff_edge_t {
90 ir_node *src; /**< Source node. */
91 ir_node *tgt; /**< Target node. */
92 double weight; /**< The weight of this edge. */
95 /* main coalescing environment */
96 typedef struct _co_mst_env_t {
97 int n_regs; /**< number of regs in class */
98 int k; /**< number of non-ignore registers in class */
99 bitset_t *ignore_regs; /**< set containing all global ignore registers */
100 ir_phase ph; /**< phase object holding data for nodes */
101 pqueue *chunks; /**< priority queue for chunks */
102 pset *chunkset; /**< set holding all chunks */
103 be_ifg_t *ifg; /**< the interference graph */
104 const arch_env_t *aenv; /**< the arch environment */
105 copy_opt_t *co; /**< the copy opt object */
108 /* stores coalescing related information for a node */
109 typedef struct _co_mst_irn_t {
110 ir_node *irn; /**< the irn this information belongs to */
111 aff_chunk_t *chunk; /**< the chunk this irn belongs to */
112 bitset_t *adm_colors; /**< set of admissible colors for this irn */
113 ir_node **int_neighs; /**< array of all interfering neighbours (cached for speed reasons) */
114 int n_neighs; /**< length of the interfering neighbours array. */
115 int int_aff_neigh; /**< number of interfering affinity neighbours */
116 int col; /**< color currently assigned */
117 int init_col; /**< the initial color */
118 int tmp_col; /**< a temporary assigned color */
119 unsigned fixed : 1; /**< the color is fixed */
120 unsigned tmp_fixed : 1; /**< the color is temporary fixed */
123 #define get_co_mst_irn(mst_env, irn) (phase_get_or_set_irn_data(&(mst_env)->ph, (irn)))
125 typedef int decide_func_t(const co_mst_irn_t *node, int col);
130 * Write a chunk to stderr for debugging.
132 static void dbg_aff_chunk(const co_mst_env_t *env, const aff_chunk_t *c) {
134 if (c->weight_consistent)
135 ir_fprintf(stderr, " $%d ", c->weight);
136 ir_fprintf(stderr, "{");
137 bitset_foreach(c->nodes, idx) {
138 ir_node *n = get_idx_irn(env->co->irg, idx);
139 ir_fprintf(stderr, " %+F,", n);
141 ir_fprintf(stderr, "}");
145 * Dump all admissible colors to stderr.
147 static void dbg_admissible_colors(const co_mst_env_t *env, const co_mst_irn_t *node) {
149 if (bitset_popcnt(node->adm_colors) < 1)
150 fprintf(stderr, "no admissible colors?!?");
152 bitset_foreach(node->adm_colors, idx)
153 fprintf(stderr, " %d", idx);
158 * Dump color-cost pairs to stderr.
160 static void dbg_col_cost(const co_mst_env_t *env, const col_cost_t *cost) {
162 for (i = 0; i < env->n_regs; ++i) {
163 if (cost[i].cost == COL_COST_INFEASIBLE)
164 fprintf(stderr, " (%d, INF)", cost[i].col);
166 fprintf(stderr, " (%d, %.1f)", cost[i].col, cost[i].cost);
170 #endif /* DEBUG_libfirm */
172 static INLINE int get_mst_irn_col(const co_mst_irn_t *node) {
173 return node->tmp_fixed ? node->tmp_col : node->col;
177 * @return 1 if node @p node has color @p col, 0 otherwise.
179 static int decider_has_color(const co_mst_irn_t *node, int col) {
180 return get_mst_irn_col(node) == col;
184 * @return 1 if node @p node has not color @p col, 0 otherwise.
186 static int decider_hasnot_color(const co_mst_irn_t *node, int col) {
187 return get_mst_irn_col(node) != col;
191 * Always returns true.
193 static int decider_always_yes(const co_mst_irn_t *node, int col) {
197 /** compares two affinity edges by its weight */
198 static int cmp_aff_edge(const void *a, const void *b) {
199 const aff_edge_t *e1 = a;
200 const aff_edge_t *e2 = b;
202 if (e2->weight == e1->weight) {
203 if (e2->src->node_idx == e1->src->node_idx)
204 return QSORT_CMP(e2->tgt->node_idx, e1->tgt->node_idx);
206 return QSORT_CMP(e2->src->node_idx, e1->src->node_idx);
208 /* sort in descending order */
209 return QSORT_CMP(e2->weight, e1->weight);
212 /** compares to color-cost pairs */
213 static int cmp_col_cost(const void *a, const void *b) {
214 const col_cost_t *c1 = a;
215 const col_cost_t *c2 = b;
217 return c1->cost < c2->cost ? -1 : 1;
221 * Creates a new affinity chunk
223 static INLINE aff_chunk_t *new_aff_chunk(co_mst_env_t *env) {
224 aff_chunk_t *c = xmalloc(sizeof(*c));
226 c->weight_consistent = 0;
227 c->n = NEW_ARR_F(ir_node *, 0);
228 c->nodes = bitset_irg_malloc(env->co->irg);
229 c->interfere = bitset_irg_malloc(env->co->irg);
230 c->id = last_chunk_id++;
231 pset_insert(env->chunkset, c, c->id);
236 * Frees all memory allocated by an affinity chunk.
238 static INLINE void delete_aff_chunk(co_mst_env_t *env, aff_chunk_t *c) {
239 pset_remove(env->chunkset, c, c->id);
240 bitset_free(c->nodes);
241 bitset_free(c->interfere);
248 * Adds a node to an affinity chunk
250 static INLINE void aff_chunk_add_node(aff_chunk_t *c, co_mst_irn_t *node) {
253 if (bitset_is_set(c->nodes, get_irn_idx(node->irn)))
256 c->weight_consistent = 0;
258 bitset_set(c->nodes, get_irn_idx(node->irn));
260 ARR_APP1(ir_node *, c->n, node->irn);
262 for (i = node->n_neighs - 1; i >= 0; --i) {
263 ir_node *neigh = node->int_neighs[i];
264 bitset_set(c->interfere, get_irn_idx(neigh));
269 * In case there is no phase information for irn, initialize it.
271 static void *co_mst_irn_init(ir_phase *ph, ir_node *irn, void *old) {
272 co_mst_irn_t *res = old ? old : phase_alloc(ph, sizeof(res[0]));
273 co_mst_env_t *env = ph->priv;
276 const arch_register_req_t *req;
277 void *nodes_it = be_ifg_nodes_iter_alloca(env->ifg);
286 res->int_neighs = NULL;
287 res->int_aff_neigh = 0;
288 res->col = arch_register_get_index(arch_get_irn_register(env->aenv, irn));
289 res->init_col = res->col;
291 DB((dbg, LEVEL_4, "Creating phase info for %+F\n", irn));
293 /* set admissible registers */
294 res->adm_colors = bitset_obstack_alloc(phase_obst(ph), env->n_regs);
296 /* Exclude colors not assignable to the irn */
297 req = arch_get_register_req(env->aenv, irn, -1);
298 if (arch_register_req_is(req, limited))
299 rbitset_copy_to_bitset(req->limited, res->adm_colors);
301 bitset_set_all(res->adm_colors);
303 /* exclude global ignore registers as well */
304 bitset_andnot(res->adm_colors, env->ignore_regs);
306 /* set the number of interfering affinity neighbours to -1, they are calculated later */
307 res->int_aff_neigh = -1;
309 /* build list of interfering neighbours */
311 be_ifg_foreach_neighbour(env->ifg, nodes_it, irn, neigh) {
312 if (! arch_irn_is(env->aenv, neigh, ignore)) {
313 obstack_ptr_grow(phase_obst(ph), neigh);
317 res->int_neighs = obstack_finish(phase_obst(ph));
324 * Check if affinity chunk @p chunk interferes with node @p irn.
326 static INLINE int aff_chunk_interferes(co_mst_env_t *env, const aff_chunk_t *chunk, ir_node *irn) {
327 return bitset_is_set(chunk->interfere, get_irn_idx(irn));
331 * Check if there are interference edges from c1 to c2.
332 * @param env The global co_mst environment
334 * @param c2 Another chunk
335 * @return 1 if there are interferences between nodes of c1 and c2, 0 otherwise.
337 static INLINE int aff_chunks_interfere(co_mst_env_t *env, const aff_chunk_t *c1, const aff_chunk_t *c2) {
343 /* check if there is a node in c2 having an interfering neighbor in c1 */
344 tmp = bitset_alloca(get_irg_last_idx(env->co->irg));
345 tmp = bitset_copy(tmp, c1->interfere);
346 tmp = bitset_and(tmp, c2->nodes);
348 return bitset_popcnt(tmp) > 0;
352 * Returns the affinity chunk of @p irn or creates a new
353 * one with @p irn as element if there is none assigned.
355 static INLINE aff_chunk_t *get_aff_chunk(co_mst_env_t *env, ir_node *irn) {
356 co_mst_irn_t *node = get_co_mst_irn(env, irn);
361 * Let chunk(src) absorb the nodes of chunk(tgt) (only possible when there
362 * are no interference edges from chunk(src) to chunk(tgt)).
363 * @return 1 if successful, 0 if not possible
365 static int aff_chunk_absorb(co_mst_env_t *env, ir_node *src, ir_node *tgt) {
366 aff_chunk_t *c1 = get_aff_chunk(env, src);
367 aff_chunk_t *c2 = get_aff_chunk(env, tgt);
370 DB((dbg, LEVEL_4, "Attempt to let c1 (id %d): ", c1 ? c1->id : -1));
372 DBG_AFF_CHUNK(env, LEVEL_4, c1);
374 DB((dbg, LEVEL_4, "{%+F}", src));
376 DB((dbg, LEVEL_4, "\n\tabsorb c2 (id %d): ", c2 ? c2->id : -1));
378 DBG_AFF_CHUNK(env, LEVEL_4, c2);
380 DB((dbg, LEVEL_4, "{%+F}", tgt));
382 DB((dbg, LEVEL_4, "\n"));
387 /* no chunk exists */
388 co_mst_irn_t *mirn = get_co_mst_irn(env, src);
391 for (i = mirn->n_neighs - 1; i >= 0; --i) {
392 if (mirn->int_neighs[i] == tgt)
396 /* create one containing both nodes */
397 c1 = new_aff_chunk(env);
398 aff_chunk_add_node(c1, get_co_mst_irn(env, src));
399 aff_chunk_add_node(c1, get_co_mst_irn(env, tgt));
403 /* c2 already exists */
404 if (! aff_chunk_interferes(env, c2, src)) {
405 aff_chunk_add_node(c2, get_co_mst_irn(env, src));
409 } else if (c2 == NULL) {
410 /* c1 already exists */
411 if (! aff_chunk_interferes(env, c1, tgt)) {
412 aff_chunk_add_node(c1, get_co_mst_irn(env, tgt));
415 } else if (c1 != c2 && ! aff_chunks_interfere(env, c1, c2)) {
418 for (idx = 0, len = ARR_LEN(c2->n); idx < len; ++idx) {
419 ir_node *n = c2->n[idx];
420 co_mst_irn_t *mn = get_co_mst_irn(env, n);
424 if (! bitset_is_set(c1->nodes, get_irn_idx(n)))
425 ARR_APP1(ir_node *, c1->n, n);
428 bitset_or(c1->nodes, c2->nodes);
429 bitset_or(c1->interfere, c2->interfere);
430 c1->weight_consistent = 0;
432 delete_aff_chunk(env, c2);
435 DB((dbg, LEVEL_4, " ... c1 interferes with c2, skipped\n"));
439 DB((dbg, LEVEL_4, " ... absorbed\n"));
444 * Assures that the weight of the given chunk is consistent.
446 static void aff_chunk_assure_weight(const co_mst_env_t *env, aff_chunk_t *c) {
447 if (! c->weight_consistent) {
451 for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
452 ir_node *n = c->n[idx];
453 const affinity_node_t *an = get_affinity_info(env->co, n);
457 co_gs_foreach_neighb(an, neigh) {
458 const ir_node *m = neigh->irn;
459 const int m_idx = get_irn_idx(m);
461 /* skip ignore nodes */
462 if (arch_irn_is(env->aenv, m, ignore))
465 w += bitset_is_set(c->nodes, m_idx) ? neigh->costs : 0;
471 c->weight_consistent = 1;
476 * Count the number of interfering affinity neighbours
478 static int count_interfering_aff_neighs(co_mst_env_t *env, const affinity_node_t *an) {
479 const neighb_t *neigh;
480 ir_node *irn = an->irn;
481 const co_mst_irn_t *node = get_co_mst_irn(env, irn);
484 co_gs_foreach_neighb(an, neigh) {
485 const ir_node *n = neigh->irn;
488 /* skip ignore nodes */
489 if (arch_irn_is(env->aenv, n, ignore))
492 /* check if the affinity neighbour interfere */
493 for (i = 0; i < node->n_neighs; ++i) {
494 if (node->int_neighs[i] == n) {
505 * Build chunks of nodes connected by affinity edges.
506 * We start at the heaviest affinity edge.
507 * The chunks of the two edge-defining nodes will be
508 * merged if there are no interference edges from one
509 * chunk to the other.
511 static void build_affinity_chunks(co_mst_env_t *env) {
512 void *nodes_it = be_ifg_nodes_iter_alloca(env->ifg);
513 aff_edge_t *edges = NEW_ARR_F(aff_edge_t, 0);
516 aff_chunk_t *curr_chunk;
518 /* at first we create the affinity edge objects */
519 be_ifg_foreach_node(env->ifg, nodes_it, n) {
520 int n_idx = get_irn_idx(n);
524 /* skip ignore nodes */
525 if (arch_irn_is(env->aenv, n, ignore))
528 n1 = get_co_mst_irn(env, n);
529 an = get_affinity_info(env->co, n);
534 if (n1->int_aff_neigh < 0)
535 n1->int_aff_neigh = count_interfering_aff_neighs(env, an);
537 /* build the affinity edges */
538 co_gs_foreach_neighb(an, neigh) {
539 ir_node *m = neigh->irn;
540 int m_idx = get_irn_idx(m);
542 /* record the edge in only one direction */
547 /* skip ignore nodes */
548 if (arch_irn_is(env->aenv, m, ignore))
554 n2 = get_co_mst_irn(env, m);
555 if (n2->int_aff_neigh < 0) {
556 affinity_node_t *am = get_affinity_info(env->co, m);
557 n2->int_aff_neigh = count_interfering_aff_neighs(env, am);
559 edge.weight = (double)neigh->costs / (double)(1 + n1->int_aff_neigh + n2->int_aff_neigh);
560 ARR_APP1(aff_edge_t, edges, edge);
566 /* now: sort edges and build the affinity chunks */
567 len = ARR_LEN(edges);
568 qsort(edges, len, sizeof(edges[0]), cmp_aff_edge);
569 for (i = 0; i < len; ++i) {
570 DBG((dbg, LEVEL_1, "edge (%u,%u) %f\n", edges[i].src->node_idx, edges[i].tgt->node_idx, edges[i].weight));
572 (void)aff_chunk_absorb(env, edges[i].src, edges[i].tgt);
575 /* now insert all chunks into a priority queue */
576 foreach_pset(env->chunkset, curr_chunk) {
577 aff_chunk_assure_weight(env, curr_chunk);
579 DBG((dbg, LEVEL_1, "entry #%d", curr_chunk->id));
580 DBG_AFF_CHUNK(env, LEVEL_1, curr_chunk);
581 DBG((dbg, LEVEL_1, "\n"));
583 pqueue_put(env->chunks, curr_chunk, curr_chunk->weight);
585 foreach_phase_irn(&env->ph, n) {
586 co_mst_irn_t *mirn = get_co_mst_irn(env, n);
588 if (mirn->chunk == NULL) {
589 /* no chunk is allocated so far, do it now */
590 aff_chunk_t *curr_chunk = new_aff_chunk(env);
591 aff_chunk_add_node(curr_chunk, mirn);
593 aff_chunk_assure_weight(env, curr_chunk);
595 DBG((dbg, LEVEL_1, "entry #%d", curr_chunk->id));
596 DBG_AFF_CHUNK(env, LEVEL_1, curr_chunk);
597 DBG((dbg, LEVEL_1, "\n"));
599 pqueue_put(env->chunks, curr_chunk, curr_chunk->weight);
607 * Greedy collect affinity neighbours into thew new chunk @p chunk starting at node @p node.
609 static void expand_chunk_from(co_mst_env_t *env, co_mst_irn_t *node, bitset_t *visited,
610 aff_chunk_t *chunk, aff_chunk_t *orig_chunk, decide_func_t *decider, int col)
612 waitq *nodes = new_waitq();
614 DBG((dbg, LEVEL_1, "\n\tExpanding new chunk (#%d) from %+F, color %d:", chunk->id, node->irn, col));
616 /* init queue and chunk */
617 waitq_put(nodes, node);
618 bitset_set(visited, get_irn_idx(node->irn));
619 aff_chunk_add_node(chunk, node);
620 DB((dbg, LEVEL_1, " %+F", node->irn));
622 /* as long as there are nodes in the queue */
623 while (! waitq_empty(nodes)) {
624 co_mst_irn_t *n = waitq_get(nodes);
625 affinity_node_t *an = get_affinity_info(env->co, n->irn);
627 /* check all affinity neighbors */
630 co_gs_foreach_neighb(an, neigh) {
631 ir_node *m = neigh->irn;
632 int m_idx = get_irn_idx(m);
635 /* skip ignore nodes */
636 if (arch_irn_is(env->aenv, m, ignore))
639 n2 = get_co_mst_irn(env, m);
641 if (! bitset_is_set(visited, m_idx) &&
644 ! aff_chunk_interferes(env, chunk, m) &&
645 bitset_is_set(orig_chunk->nodes, m_idx))
648 following conditions are met:
649 - neighbour is not visited
650 - neighbour likes the color
651 - neighbour has not yet a fixed color
652 - the new chunk doesn't interfere with the neighbour
653 - neighbour belongs or belonged once to the original chunk
655 bitset_set(visited, m_idx);
656 aff_chunk_add_node(chunk, n2);
657 DB((dbg, LEVEL_1, " %+F", n2->irn));
658 /* enqueue for further search */
659 waitq_put(nodes, n2);
665 DB((dbg, LEVEL_1, "\n"));
671 * Fragment the given chunk into chunks having given color and not having given color.
673 static aff_chunk_t *fragment_chunk(co_mst_env_t *env, int col, aff_chunk_t *c, waitq *tmp) {
674 bitset_t *visited = bitset_irg_malloc(env->co->irg);
676 aff_chunk_t *best = NULL;
678 for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
681 aff_chunk_t *tmp_chunk;
682 decide_func_t *decider;
686 if (bitset_is_set(visited, get_irn_idx(irn)))
689 node = get_co_mst_irn(env, irn);
691 if (get_mst_irn_col(node) == col) {
692 decider = decider_has_color;
694 DBG((dbg, LEVEL_4, "\tcolor %d wanted", col));
697 decider = decider_hasnot_color;
699 DBG((dbg, LEVEL_4, "\tcolor %d forbidden", col));
702 /* create a new chunk starting at current node */
703 tmp_chunk = new_aff_chunk(env);
704 waitq_put(tmp, tmp_chunk);
705 expand_chunk_from(env, node, visited, tmp_chunk, c, decider, col);
706 assert(bitset_popcnt(tmp_chunk->nodes) > 0 && "No nodes added to chunk");
708 /* remember the local best */
709 aff_chunk_assure_weight(env, tmp_chunk);
710 if (check_for_best && (! best || best->weight < tmp_chunk->weight))
714 assert(best && "No chunk found?");
715 bitset_free(visited);
720 * Initializes an array of color-cost pairs.
721 * Sets forbidden colors to costs COL_COST_INFEASIBLE and all others to @p c.
723 static INLINE void col_cost_init(co_mst_env_t *env, col_cost_t *cost, double c) {
726 for (i = 0; i < env->n_regs; ++i) {
728 if (bitset_is_set(env->ignore_regs, i))
729 cost[i].cost = COL_COST_INFEASIBLE;
736 * Initializes an array of color-cost pairs.
737 * Sets all colors except color @p col to COL_COST_INFEASIBLE and @p col to 0.0
739 static INLINE void col_cost_init_single(co_mst_env_t *env, col_cost_t *cost, int col) {
740 assert(! bitset_is_set(env->ignore_regs, col) && "Attempt to use forbidden color.");
741 col_cost_init(env, cost, COL_COST_INFEASIBLE);
748 * Resets the temporary fixed color of all nodes within wait queue @p nodes.
749 * ATTENTION: the queue is empty after calling this function!
751 static INLINE void reject_coloring(waitq *nodes) {
752 DB((dbg, LEVEL_4, "\treject coloring for"));
753 while (! waitq_empty(nodes)) {
754 co_mst_irn_t *n = waitq_get(nodes);
755 DB((dbg, LEVEL_4, " %+F", n->irn));
758 DB((dbg, LEVEL_4, "\n"));
762 * Determines the costs for each color if it would be assigned to node @p node.
764 static void determine_color_costs(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *costs) {
765 affinity_node_t *an = get_affinity_info(env->co, node->irn);
769 col_cost_init(env, costs, 0.0);
771 /* calculate (negative) costs for affinity neighbours */
773 co_gs_foreach_neighb(an, aff_neigh) {
774 ir_node *m = aff_neigh->irn;
778 /* skip ignore nodes */
779 if (arch_irn_is(env->aenv, m, ignore))
782 neigh = get_co_mst_irn(env, m);
783 c = (double)aff_neigh->costs;
785 /* calculate costs for fixed affinity neighbours */
786 if (neigh->tmp_fixed || neigh->fixed) {
787 int col = get_mst_irn_col(neigh);
788 costs[col].cost -= c * AFF_NEIGHBOUR_FIX_BENEFIT;
793 /* calculate (positive) costs for interfering neighbours */
794 for (i = 0; i < node->n_neighs; ++i) {
799 int_neigh = node->int_neighs[i];
801 /* skip ignore nodes */
802 if (arch_irn_is(env->aenv, int_neigh, ignore))
805 neigh = get_co_mst_irn(env, int_neigh);
806 col = get_mst_irn_col(neigh);
807 col_cnt = bitset_popcnt(neigh->adm_colors);
809 if (neigh->tmp_fixed || neigh->fixed) {
810 /* colors of fixed interfering neighbours are infeasible */
811 costs[col].cost = COL_COST_INFEASIBLE;
813 else if (col_cnt < env->k) {
814 /* calculate costs for constrained interfering neighbours */
815 double ratio = 1.0 - ((double)col_cnt / (double)env->k);
817 bitset_foreach_clear(neigh->adm_colors, idx) {
818 /* check only explicitly forbidden colors (skip global forbidden ones) */
819 if (! bitset_is_set(env->ignore_regs, idx)) {
820 costs[col].cost += ratio * NEIGHBOUR_CONSTR_COSTS;
826 /* set all not admissible colors to COL_COST_INFEASIBLE */
827 bitset_foreach_clear(node->adm_colors, idx)
828 costs[idx].cost = COL_COST_INFEASIBLE;
831 /* need forward declaration due to recursive call */
832 static int recolor_nodes(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *costs, waitq *changed_ones);
835 * Tries to change node to a color but @p explude_col.
836 * @return 1 if succeeded, 0 otherwise.
838 static int change_node_color_excluded(co_mst_env_t *env, co_mst_irn_t *node, int exclude_col, waitq *changed_ones) {
839 int col = get_mst_irn_col(node);
842 /* neighbours has already a different color -> good, temporary fix it */
843 if (col != exclude_col) {
846 waitq_put(changed_ones, node);
850 /* The node has the color it should not have _and_ has not been visited yet. */
851 if (! (node->tmp_fixed || node->fixed)) {
852 col_cost_t *costs = alloca(env->n_regs * sizeof(costs[0]));
854 /* Get the costs for giving the node a specific color. */
855 determine_color_costs(env, node, costs);
857 /* Since the node must not have the not_col, set the costs for that color to "infinity" */
858 costs[exclude_col].cost = COL_COST_INFEASIBLE;
860 /* sort the colors according costs, cheapest first. */
861 qsort(costs, env->n_regs, sizeof(costs[0]), cmp_col_cost);
863 /* Try recoloring the node using the color list. */
864 res = recolor_nodes(env, node, costs, changed_ones);
871 * Tries to bring node @p node to cheapest color and color all interfering neighbours with other colors.
872 * ATTENTION: Expect @p costs already sorted by increasing costs.
873 * @return 1 if coloring could be applied, 0 otherwise.
875 static int recolor_nodes(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *costs, waitq *changed_ones) {
877 waitq *local_changed = new_waitq();
878 waitq *tmp = new_waitq();
880 DBG((dbg, LEVEL_1, "\tRecoloring %+F with color-costs", node->irn));
881 DBG_COL_COST(env, LEVEL_1, costs);
882 DB((dbg, LEVEL_1, "\n"));
884 for (i = 0; i < env->n_regs; ++i) {
885 int tgt_col = costs[i].col;
889 /* If the costs for that color (and all successive) are infinite, bail out we won't make it anyway. */
890 if (costs[i].cost == COL_COST_INFEASIBLE) {
892 del_waitq(local_changed);
897 /* Set the new color of the node and mark the node as temporarily fixed. */
898 assert(! node->tmp_fixed && "Node must not have been temporary fixed.");
900 node->tmp_col = tgt_col;
901 DBG((dbg, LEVEL_4, "\tTemporary setting %+F to color %d\n", node->irn, tgt_col));
903 assert(waitq_empty(local_changed) && "Node queue should be empty here.");
904 waitq_put(local_changed, node);
906 /* try to color all interfering neighbours with current color forbidden */
907 for (j = 0; j < node->n_neighs; ++j) {
911 neigh = node->int_neighs[j];
913 /* skip ignore nodes */
914 if (arch_irn_is(env->aenv, neigh, ignore))
917 nn = get_co_mst_irn(env, neigh);
918 DB((dbg, LEVEL_4, "\tHandling neighbour %+F, at position %d (fixed: %d, tmp_fixed: %d, tmp_col: %d, col: %d)\n",
919 neigh, j, nn->fixed, nn->tmp_fixed, nn->tmp_col, nn->col));
922 Try to change the color of the neighbor and record all nodes which
923 get changed in the tmp list. Add this list to the "changed" list for
924 that color. If we did not succeed to change the color of the neighbor,
925 we bail out and try the next color.
927 if (get_mst_irn_col(nn) == tgt_col) {
928 /* try to color neighbour with tgt_col forbidden */
929 neigh_ok = change_node_color_excluded(env, nn, tgt_col, tmp);
931 /* join lists of changed nodes */
932 while (! waitq_empty(tmp))
933 waitq_put(local_changed, waitq_get(tmp));
941 We managed to assign the target color to all neighbors, so from the perspective
942 of the current node, every thing was ok and we can return safely.
945 /* append the local_changed ones to global ones */
946 while (! waitq_empty(local_changed))
947 waitq_put(changed_ones, waitq_get(local_changed));
948 del_waitq(local_changed);
953 /* coloring of neighbours failed, so we try next color */
954 reject_coloring(local_changed);
958 del_waitq(local_changed);
964 * Tries to bring node @p node and all it's neighbours to color @p tgt_col.
965 * @return 1 if color @p col could be applied, 0 otherwise
967 static int change_node_color(co_mst_env_t *env, co_mst_irn_t *node, int tgt_col, waitq *changed_ones) {
968 int col = get_mst_irn_col(node);
970 /* if node already has the target color -> good, temporary fix it */
971 if (col == tgt_col) {
972 DBG((dbg, LEVEL_4, "\t\tCNC: %+F has already color %d, fix temporary\n", node->irn, tgt_col));
973 if (! node->tmp_fixed) {
975 node->tmp_col = tgt_col;
976 waitq_put(changed_ones, node);
982 Node has not yet a fixed color and target color is admissible
983 -> try to recolor node and it's affinity neighbours
985 if (! (node->fixed || node->tmp_fixed) && bitset_is_set(node->adm_colors, tgt_col)) {
986 col_cost_t *costs = alloca(env->n_regs * sizeof(costs[0]));
989 col_cost_init_single(env, costs, tgt_col);
991 DBG((dbg, LEVEL_4, "\t\tCNC: Attempt to recolor %+F ===>>\n", node->irn));
992 res = recolor_nodes(env, node, costs, changed_ones);
993 DBG((dbg, LEVEL_4, "\t\tCNC: <<=== Recoloring of %+F %s\n", node->irn, res ? "succeeded" : "failed"));
999 if (firm_dbg_get_mask(dbg) & LEVEL_4) {
1000 if (node->fixed || node->tmp_fixed)
1001 DB((dbg, LEVEL_4, "\t\tCNC: %+F has already fixed color %d\n", node->irn, col));
1003 DB((dbg, LEVEL_4, "\t\tCNC: color %d not admissible for %+F (", tgt_col, node->irn));
1004 dbg_admissible_colors(env, node);
1005 DB((dbg, LEVEL_4, ")\n"));
1014 * Tries to color an affinity chunk (or at least a part of it).
1015 * Inserts uncolored parts of the chunk as a new chunk into the priority queue.
1017 static void color_aff_chunk(co_mst_env_t *env, aff_chunk_t *c) {
1018 aff_chunk_t *best_chunk = NULL;
1019 int best_color = -1;
1020 waitq *changed_ones = new_waitq();
1021 waitq *tmp_chunks = new_waitq();
1022 waitq *best_starts = NULL;
1026 DB((dbg, LEVEL_2, "fragmentizing chunk #%d", c->id));
1027 DBG_AFF_CHUNK(env, LEVEL_2, c);
1028 DB((dbg, LEVEL_2, "\n"));
1031 /* check which color is the "best" for the given chunk */
1032 for (col = 0; col < env->n_regs; ++col) {
1034 waitq *good_starts = new_waitq();
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 for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
1045 ir_node *irn = c->n[idx];
1046 co_mst_irn_t *node = get_co_mst_irn(env, irn);
1049 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));
1053 The order of the colored nodes is important, so we record the successfully
1054 colored ones in the order they appeared.
1056 good = change_node_color(env, node, col, changed_ones);
1058 waitq_put(good_starts, node);
1061 DB((dbg, LEVEL_4, "\t\t... %+F attempt from %d to %d %s\n", irn, node->col, col, one_good ? "succeeded" : "failed"));
1064 /* try next color when failed */
1068 /* fragment the chunk according to the coloring */
1069 local_best = fragment_chunk(env, col, c, tmp_chunks);
1071 /* search the best of the good list
1072 and make it the new best if it is better than the current */
1074 aff_chunk_assure_weight(env, local_best);
1076 DB((dbg, LEVEL_4, "\t\tlocal best chunk (id %d) for color %d: ", local_best->id, col));
1077 DBG_AFF_CHUNK(env, LEVEL_4, local_best);
1079 if (! best_chunk || best_chunk->weight < local_best->weight) {
1080 best_chunk = local_best;
1083 del_waitq(best_starts);
1084 best_starts = good_starts;
1085 DB((dbg, LEVEL_4, "\n\t\t... setting global best chunk (id %d), color %d\n", best_chunk->id, best_color));
1087 DB((dbg, LEVEL_4, "\n\t\t... omitting, global best is better\n"));
1088 del_waitq(good_starts);
1092 del_waitq(good_starts);
1095 /* reject the coloring and bring the coloring to the initial state */
1096 reject_coloring(changed_ones);
1099 /* free all intermediate created chunks except best one */
1100 while (! waitq_empty(tmp_chunks)) {
1101 aff_chunk_t *tmp = waitq_get(tmp_chunks);
1102 if (tmp != best_chunk)
1103 delete_aff_chunk(env, tmp);
1105 del_waitq(tmp_chunks);
1107 /* return if coloring failed */
1109 del_waitq(changed_ones);
1111 del_waitq(best_starts);
1115 DB((dbg, LEVEL_2, "\tbest chunk #%d ", best_chunk->id));
1116 DBG_AFF_CHUNK(env, LEVEL_2, best_chunk);
1117 DB((dbg, LEVEL_2, "using color %d\n", best_color));
1119 /* get the best fragment from the best list and color it */
1120 while (! waitq_empty(best_starts)) {
1121 co_mst_irn_t *node = waitq_get(best_starts);
1124 if (! bitset_is_set(best_chunk->nodes, get_irn_idx(node->irn)))
1127 res = change_node_color(env, node, best_color, changed_ones);
1129 panic("Color manifesting failed for %+F, color %d in chunk %d\n", node->irn, best_color, best_chunk->id);
1131 node->chunk = best_chunk;
1133 /* we colored the successful start nodes, now color the rest of the chunk */
1134 for (idx = 0, len = ARR_LEN(best_chunk->n); idx < len; ++idx) {
1135 ir_node *irn = best_chunk->n[idx];
1136 co_mst_irn_t *node = get_co_mst_irn(env, irn);
1139 res = change_node_color(env, node, best_color, changed_ones);
1141 panic("Color manifesting failed for %+F, color %d in chunk %d\n", irn, best_color, best_chunk->id);
1142 DB((dbg, LEVEL_4, "\tManifesting color %d for %+F, chunk #%d\n", best_color, irn, best_chunk->id));
1144 node->chunk = best_chunk;
1147 /* materialize colors on changed nodes */
1148 while (! waitq_empty(changed_ones)) {
1149 co_mst_irn_t *n = waitq_get(changed_ones);
1151 n->col = n->tmp_col;
1154 /* remove the nodes in best chunk from original chunk */
1155 bitset_andnot(c->nodes, best_chunk->nodes);
1156 for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
1157 ir_node *irn = c->n[idx];
1159 if (bitset_is_set(best_chunk->nodes, get_irn_idx(irn))) {
1160 int last = ARR_LEN(c->n) - 1;
1162 c->n[idx] = c->n[last];
1163 ARR_SHRINKLEN(c->n, last);
1168 /* we have to get the nodes back into the original chunk because they are scattered over temporary chunks */
1169 for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
1170 ir_node *n = c->n[idx];
1171 co_mst_irn_t *nn = get_co_mst_irn(env, n);
1175 /* fragment the remaining chunk */
1176 visited = bitset_irg_malloc(env->co->irg);
1177 bitset_or(visited, best_chunk->nodes);
1178 for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
1179 ir_node *irn = c->n[idx];
1180 if (! bitset_is_set(visited, get_irn_idx(irn))) {
1181 aff_chunk_t *new_chunk = new_aff_chunk(env);
1182 co_mst_irn_t *node = get_co_mst_irn(env, irn);
1184 expand_chunk_from(env, node, visited, new_chunk, c, decider_always_yes, 0);
1185 aff_chunk_assure_weight(env, new_chunk);
1186 pqueue_put(env->chunks, new_chunk, new_chunk->weight);
1190 /* clear obsolete chunks and free some memory */
1191 delete_aff_chunk(env, best_chunk);
1192 bitset_free(visited);
1193 del_waitq(changed_ones);
1195 del_waitq(best_starts);
1199 * Main driver for mst safe coalescing algorithm.
1201 int co_solve_heuristic_mst(copy_opt_t *co) {
1202 unsigned n_regs = co->cls->n_regs;
1203 bitset_t *ignore_regs = bitset_alloca(n_regs);
1206 co_mst_env_t mst_env;
1209 phase_init(&mst_env.ph, "co_mst", co->irg, PHASE_DEFAULT_GROWTH, co_mst_irn_init, &mst_env);
1211 k = be_put_ignore_regs(co->cenv->birg, co->cls, ignore_regs);
1214 mst_env.n_regs = n_regs;
1216 mst_env.chunks = new_pqueue();
1218 mst_env.ignore_regs = ignore_regs;
1219 mst_env.ifg = co->cenv->ifg;
1220 mst_env.aenv = co->aenv;
1221 mst_env.chunkset = pset_new_ptr(512);
1223 DBG((dbg, LEVEL_1, "==== Coloring %+F, class %s ====\n", co->irg, co->cls->name));
1225 /* build affinity chunks */
1226 build_affinity_chunks(&mst_env);
1228 /* color chunks as long as there are some */
1229 while (! pqueue_empty(mst_env.chunks)) {
1230 aff_chunk_t *chunk = pqueue_get(mst_env.chunks);
1232 color_aff_chunk(&mst_env, chunk);
1233 DB((dbg, LEVEL_4, "<<<====== Coloring chunk (%d) done\n", chunk->id));
1234 delete_aff_chunk(&mst_env, chunk);
1237 /* apply coloring */
1238 foreach_phase_irn(&mst_env.ph, irn) {
1239 co_mst_irn_t *mirn = get_co_mst_irn(&mst_env, irn);
1240 const arch_register_t *reg;
1242 if (arch_irn_is(mst_env.aenv, irn, ignore))
1245 assert(mirn->fixed && "Node should have fixed color");
1247 /* skip nodes where color hasn't changed */
1248 if (mirn->init_col == mirn->col)
1251 reg = arch_register_for_index(co->cls, mirn->col);
1252 arch_set_irn_register(co->aenv, irn, reg);
1253 DB((dbg, LEVEL_1, "%+F set color from %d to %d\n", irn, mirn->init_col, mirn->col));
1256 /* free allocated memory */
1257 del_pqueue(mst_env.chunks);
1258 phase_free(&mst_env.ph);
1259 del_pset(mst_env.chunkset);
1264 void be_init_copyheur4(void) {
1265 FIRM_DBG_REGISTER(dbg, "firm.be.co.heur4");
1268 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_copyheur4);