2 * Copyright (C) 1995-2011 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
26 * This is the C implementation of the mst algorithm
27 * originally written in Java by Sebastian Hack.
28 * (also known as "heur3" :)
29 * Performs simple copy minimization.
33 #define DISABLE_STATEV
40 #include "raw_bitset.h"
41 #include "irnodemap.h"
55 #include "becopyopt_t.h"
59 #define COL_COST_INFEASIBLE DBL_MAX
60 #define AFF_NEIGHBOUR_FIX_BENEFIT 128.0
61 #define NEIGHBOUR_CONSTR_COSTS 64.0
66 #define DBG_AFF_CHUNK(env, level, chunk) do { if (firm_dbg_get_mask(dbg) & (level)) dbg_aff_chunk((env), (chunk)); } while (0)
67 #define DBG_COL_COST(env, level, cost) do { if (firm_dbg_get_mask(dbg) & (level)) dbg_col_cost((env), (cost)); } while (0)
69 static firm_dbg_module_t *dbg = NULL;
73 #define DBG_AFF_CHUNK(env, level, chunk)
74 #define DBG_COL_COST(env, level, cost)
79 #define REAL(C) (C ## f)
81 static unsigned last_chunk_id = 0;
82 static int recolor_limit = 7;
83 static double dislike_influence = REAL(0.1);
85 typedef struct col_cost_t {
93 typedef struct aff_chunk_t {
94 const ir_node **n; /**< An ARR_F containing all nodes of the chunk. */
95 const ir_node **interfere; /**< An ARR_F containing all inference. */
96 int weight; /**< Weight of this chunk */
97 unsigned weight_consistent : 1; /**< Set if the weight is consistent. */
98 unsigned deleted : 1; /**< For debugging: Set if the was deleted. */
99 unsigned id; /**< An id of this chunk. */
102 col_cost_t color_affinity[1];
108 typedef struct aff_edge_t {
109 const ir_node *src; /**< Source node. */
110 const ir_node *tgt; /**< Target node. */
111 int weight; /**< The weight of this edge. */
114 /* main coalescing environment */
115 typedef struct co_mst_env_t {
116 int n_regs; /**< number of regs in class */
117 int k; /**< number of non-ignore registers in class */
118 bitset_t *allocatable_regs; /**< set containing all global ignore registers */
119 ir_nodemap map; /**< phase object holding data for nodes */
121 pqueue_t *chunks; /**< priority queue for chunks */
122 list_head chunklist; /**< list holding all chunks */
123 be_ifg_t *ifg; /**< the interference graph */
124 copy_opt_t *co; /**< the copy opt object */
125 unsigned chunk_visited;
126 col_cost_t **single_cols;
129 /* stores coalescing related information for a node */
130 typedef struct co_mst_irn_t {
131 const ir_node *irn; /**< the irn this information belongs to */
132 aff_chunk_t *chunk; /**< the chunk this irn belongs to */
133 bitset_t *adm_colors; /**< set of admissible colors for this irn */
134 ir_node **int_neighs; /**< array of all interfering neighbours (cached for speed reasons) */
135 int n_neighs; /**< length of the interfering neighbours array. */
136 int int_aff_neigh; /**< number of interfering affinity neighbours */
137 int col; /**< color currently assigned */
138 int init_col; /**< the initial color */
139 int tmp_col; /**< a temporary assigned color */
140 unsigned fixed : 1; /**< the color is fixed */
141 struct list_head list; /**< Queue for coloring undo. */
142 real_t constr_factor;
146 * In case there is no phase information for irn, initialize it.
148 static co_mst_irn_t *co_mst_irn_init(co_mst_env_t *env, const ir_node *irn)
150 co_mst_irn_t *res = OALLOC(&env->obst, co_mst_irn_t);
152 const arch_register_req_t *req;
153 neighbours_iter_t nodes_it;
161 res->int_neighs = NULL;
162 res->int_aff_neigh = 0;
163 res->col = arch_register_get_index(arch_get_irn_register(irn));
164 res->init_col = res->col;
165 INIT_LIST_HEAD(&res->list);
167 DB((dbg, LEVEL_4, "Creating phase info for %+F\n", irn));
169 /* set admissible registers */
170 res->adm_colors = bitset_obstack_alloc(&env->obst, env->n_regs);
172 /* Exclude colors not assignable to the irn */
173 req = arch_get_irn_register_req(irn);
174 if (arch_register_req_is(req, limited)) {
175 rbitset_copy_to_bitset(req->limited, res->adm_colors);
177 bitset_set_all(res->adm_colors);
180 /* exclude global ignore registers as well */
181 bitset_and(res->adm_colors, env->allocatable_regs);
183 /* compute the constraint factor */
184 res->constr_factor = (real_t) (1 + env->n_regs - bitset_popcount(res->adm_colors)) / env->n_regs;
186 /* set the number of interfering affinity neighbours to -1, they are calculated later */
187 res->int_aff_neigh = -1;
189 /* build list of interfering neighbours */
191 be_ifg_foreach_neighbour(env->ifg, &nodes_it, irn, neigh) {
192 if (!arch_irn_is_ignore(neigh)) {
193 obstack_ptr_grow(&env->obst, neigh);
197 res->int_neighs = (ir_node**)obstack_finish(&env->obst);
202 static co_mst_irn_t *get_co_mst_irn(co_mst_env_t *env, const ir_node *node)
204 co_mst_irn_t *res = (co_mst_irn_t*)ir_nodemap_get(&env->map, node);
206 res = co_mst_irn_init(env, node);
207 ir_nodemap_insert(&env->map, node, res);
212 typedef int decide_func_t(const co_mst_irn_t *node, int col);
217 * Write a chunk to stderr for debugging.
219 static void dbg_aff_chunk(const co_mst_env_t *env, const aff_chunk_t *c)
223 if (c->weight_consistent)
224 ir_fprintf(stderr, " $%d ", c->weight);
225 ir_fprintf(stderr, "{");
226 for (i = 0, l = ARR_LEN(c->n); i < l; ++i) {
227 const ir_node *n = c->n[i];
228 ir_fprintf(stderr, " %+F,", n);
230 ir_fprintf(stderr, "}");
234 * Dump all admissible colors to stderr.
236 static void dbg_admissible_colors(const co_mst_env_t *env, const co_mst_irn_t *node)
241 if (bitset_popcount(node->adm_colors) < 1)
242 fprintf(stderr, "no admissible colors?!?");
244 bitset_foreach(node->adm_colors, idx) {
245 ir_fprintf(stderr, " %zu", idx);
251 * Dump color-cost pairs to stderr.
253 static void dbg_col_cost(const co_mst_env_t *env, const col_cost_t *cost)
256 for (i = 0; i < env->n_regs; ++i)
257 fprintf(stderr, " (%d, %.4f)", cost[i].col, cost[i].cost);
260 #endif /* DEBUG_libfirm */
262 static inline int get_mst_irn_col(const co_mst_irn_t *node)
264 return node->tmp_col >= 0 ? node->tmp_col : node->col;
268 * @return 1 if node @p node has color @p col, 0 otherwise.
270 static int decider_has_color(const co_mst_irn_t *node, int col)
272 return get_mst_irn_col(node) == col;
276 * @return 1 if node @p node has not color @p col, 0 otherwise.
278 static int decider_hasnot_color(const co_mst_irn_t *node, int col)
280 return get_mst_irn_col(node) != col;
284 * Always returns true.
286 static int decider_always_yes(const co_mst_irn_t *node, int col)
293 /** compares two affinity edges by its weight */
294 static int cmp_aff_edge(const void *a, const void *b)
296 const aff_edge_t *e1 = (const aff_edge_t*)a;
297 const aff_edge_t *e2 = (const aff_edge_t*)b;
299 if (e2->weight == e1->weight) {
300 if (e2->src->node_idx == e1->src->node_idx)
301 return QSORT_CMP(e2->tgt->node_idx, e1->tgt->node_idx);
303 return QSORT_CMP(e2->src->node_idx, e1->src->node_idx);
305 /* sort in descending order */
306 return QSORT_CMP(e2->weight, e1->weight);
309 /** compares to color-cost pairs */
310 static __attribute__((unused)) int cmp_col_cost_lt(const void *a, const void *b)
312 const col_cost_t *c1 = (const col_cost_t*)a;
313 const col_cost_t *c2 = (const col_cost_t*)b;
314 real_t diff = c1->cost - c2->cost;
321 return QSORT_CMP(c1->col, c2->col);
324 static int cmp_col_cost_gt(const void *a, const void *b)
326 const col_cost_t *c1 = (const col_cost_t*)a;
327 const col_cost_t *c2 = (const col_cost_t*)b;
328 real_t diff = c2->cost - c1->cost;
335 return QSORT_CMP(c1->col, c2->col);
339 * Creates a new affinity chunk
341 static inline aff_chunk_t *new_aff_chunk(co_mst_env_t *env)
343 aff_chunk_t *c = XMALLOCF(aff_chunk_t, color_affinity, env->n_regs);
344 c->n = NEW_ARR_F(const ir_node *, 0);
345 c->interfere = NEW_ARR_F(const ir_node *, 0);
347 c->weight_consistent = 0;
349 c->id = ++last_chunk_id;
351 list_add(&c->list, &env->chunklist);
356 * Frees all memory allocated by an affinity chunk.
358 static inline void delete_aff_chunk(aff_chunk_t *c)
361 DEL_ARR_F(c->interfere);
368 * binary search of sorted nodes.
370 * @return the position where n is found in the array arr or ~pos
371 * if the nodes is not here.
373 static inline int nodes_bsearch(const ir_node **arr, const ir_node *n)
375 int hi = ARR_LEN(arr);
379 int md = lo + ((hi - lo) >> 1);
392 /** Check if a node n can be found inside arr. */
393 static int node_contains(const ir_node **arr, const ir_node *n)
395 int i = nodes_bsearch(arr, n);
400 * Insert a node into the sorted nodes list.
402 * @return 1 if the node was inserted, 0 else
404 static int nodes_insert(const ir_node ***arr, const ir_node *irn)
406 int idx = nodes_bsearch(*arr, irn);
409 int i, n = ARR_LEN(*arr);
412 ARR_APP1(const ir_node *, *arr, irn);
417 for (i = n - 1; i >= idx; --i)
426 * Adds a node to an affinity chunk
428 static inline void aff_chunk_add_node(aff_chunk_t *c, co_mst_irn_t *node)
432 if (! nodes_insert(&c->n, node->irn))
435 c->weight_consistent = 0;
438 for (i = node->n_neighs - 1; i >= 0; --i) {
439 ir_node *neigh = node->int_neighs[i];
440 nodes_insert(&c->interfere, neigh);
445 * Check if affinity chunk @p chunk interferes with node @p irn.
447 static inline int aff_chunk_interferes(const aff_chunk_t *chunk, const ir_node *irn)
449 return node_contains(chunk->interfere, irn);
453 * Check if there are interference edges from c1 to c2.
455 * @param c2 Another chunk
456 * @return 1 if there are interferences between nodes of c1 and c2, 0 otherwise.
458 static inline int aff_chunks_interfere(const aff_chunk_t *c1, const aff_chunk_t *c2)
465 /* check if there is a node in c2 having an interfering neighbor in c1 */
466 for (i = ARR_LEN(c2->n) - 1; i >= 0; --i) {
467 const ir_node *irn = c2->n[i];
469 if (node_contains(c1->interfere, irn))
476 * Returns the affinity chunk of @p irn or creates a new
477 * one with @p irn as element if there is none assigned.
479 static inline aff_chunk_t *get_aff_chunk(co_mst_env_t *env, const ir_node *irn)
481 co_mst_irn_t *node = get_co_mst_irn(env, irn);
486 * Let chunk(src) absorb the nodes of chunk(tgt) (only possible when there
487 * are no interference edges from chunk(src) to chunk(tgt)).
488 * @return 1 if successful, 0 if not possible
490 static int aff_chunk_absorb(co_mst_env_t *env, const ir_node *src, const ir_node *tgt)
492 aff_chunk_t *c1 = get_aff_chunk(env, src);
493 aff_chunk_t *c2 = get_aff_chunk(env, tgt);
496 DB((dbg, LEVEL_4, "Attempt to let c1 (id %u): ", c1 ? c1->id : 0));
498 DBG_AFF_CHUNK(env, LEVEL_4, c1);
500 DB((dbg, LEVEL_4, "{%+F}", src));
502 DB((dbg, LEVEL_4, "\n\tabsorb c2 (id %u): ", c2 ? c2->id : 0));
504 DBG_AFF_CHUNK(env, LEVEL_4, c2);
506 DB((dbg, LEVEL_4, "{%+F}", tgt));
508 DB((dbg, LEVEL_4, "\n"));
513 /* no chunk exists */
514 co_mst_irn_t *mirn = get_co_mst_irn(env, src);
517 for (i = mirn->n_neighs - 1; i >= 0; --i) {
518 if (mirn->int_neighs[i] == tgt)
522 /* create one containing both nodes */
523 c1 = new_aff_chunk(env);
524 aff_chunk_add_node(c1, get_co_mst_irn(env, src));
525 aff_chunk_add_node(c1, get_co_mst_irn(env, tgt));
529 /* c2 already exists */
530 if (! aff_chunk_interferes(c2, src)) {
531 aff_chunk_add_node(c2, get_co_mst_irn(env, src));
535 } else if (c2 == NULL) {
536 /* c1 already exists */
537 if (! aff_chunk_interferes(c1, tgt)) {
538 aff_chunk_add_node(c1, get_co_mst_irn(env, tgt));
541 } else if (c1 != c2 && ! aff_chunks_interfere(c1, c2)) {
544 for (idx = 0, len = ARR_LEN(c2->n); idx < len; ++idx)
545 aff_chunk_add_node(c1, get_co_mst_irn(env, c2->n[idx]));
547 for (idx = 0, len = ARR_LEN(c2->interfere); idx < len; ++idx) {
548 const ir_node *irn = c2->interfere[idx];
549 nodes_insert(&c1->interfere, irn);
552 c1->weight_consistent = 0;
554 delete_aff_chunk(c2);
557 DB((dbg, LEVEL_4, " ... c1 interferes with c2, skipped\n"));
561 DB((dbg, LEVEL_4, " ... absorbed\n"));
566 * Assures that the weight of the given chunk is consistent.
568 static void aff_chunk_assure_weight(co_mst_env_t *env, aff_chunk_t *c)
570 if (! c->weight_consistent) {
574 for (i = 0; i < env->n_regs; ++i) {
575 c->color_affinity[i].col = i;
576 c->color_affinity[i].cost = REAL(0.0);
579 for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
580 const ir_node *n = c->n[idx];
581 const affinity_node_t *an = get_affinity_info(env->co, n);
582 co_mst_irn_t *node = get_co_mst_irn(env, n);
585 if (node->constr_factor > REAL(0.0)) {
587 bitset_foreach (node->adm_colors, col)
588 c->color_affinity[col].cost += node->constr_factor;
593 co_gs_foreach_neighb(an, neigh) {
594 const ir_node *m = neigh->irn;
596 if (arch_irn_is_ignore(m))
599 w += node_contains(c->n, m) ? neigh->costs : 0;
604 for (i = 0; i < env->n_regs; ++i)
605 c->color_affinity[i].cost *= (REAL(1.0) / ARR_LEN(c->n));
608 // c->weight = bitset_popcount(c->nodes);
609 c->weight_consistent = 1;
614 * Count the number of interfering affinity neighbours
616 static int count_interfering_aff_neighs(co_mst_env_t *env, const affinity_node_t *an)
618 const neighb_t *neigh;
619 const ir_node *irn = an->irn;
620 const co_mst_irn_t *node = get_co_mst_irn(env, irn);
623 co_gs_foreach_neighb(an, neigh) {
624 const ir_node *n = neigh->irn;
627 if (arch_irn_is_ignore(n))
630 /* check if the affinity neighbour interfere */
631 for (i = 0; i < node->n_neighs; ++i) {
632 if (node->int_neighs[i] == n) {
643 * Build chunks of nodes connected by affinity edges.
644 * We start at the heaviest affinity edge.
645 * The chunks of the two edge-defining nodes will be
646 * merged if there are no interference edges from one
647 * chunk to the other.
649 static void build_affinity_chunks(co_mst_env_t *env)
651 nodes_iter_t nodes_it;
652 aff_edge_t *edges = NEW_ARR_F(aff_edge_t, 0);
655 aff_chunk_t *curr_chunk;
658 /* at first we create the affinity edge objects */
659 be_ifg_foreach_node(env->ifg, &nodes_it, n) {
660 int n_idx = get_irn_idx(n);
664 if (arch_irn_is_ignore(n))
667 n1 = get_co_mst_irn(env, n);
668 an = get_affinity_info(env->co, n);
673 if (n1->int_aff_neigh < 0)
674 n1->int_aff_neigh = count_interfering_aff_neighs(env, an);
676 /* build the affinity edges */
677 co_gs_foreach_neighb(an, neigh) {
678 const ir_node *m = neigh->irn;
679 int m_idx = get_irn_idx(m);
681 /* record the edge in only one direction */
686 /* skip ignore nodes */
687 if (arch_irn_is_ignore(m))
693 n2 = get_co_mst_irn(env, m);
694 if (n2->int_aff_neigh < 0) {
695 affinity_node_t *am = get_affinity_info(env->co, m);
696 n2->int_aff_neigh = count_interfering_aff_neighs(env, am);
699 * these weights are pure hackery ;-).
700 * It's not chriswue's fault but mine.
702 edge.weight = neigh->costs;
703 ARR_APP1(aff_edge_t, edges, edge);
709 /* now: sort edges and build the affinity chunks */
710 len = ARR_LEN(edges);
711 qsort(edges, len, sizeof(edges[0]), cmp_aff_edge);
712 for (i = 0; i < len; ++i) {
713 DBG((dbg, LEVEL_1, "edge (%u,%u) %f\n", edges[i].src->node_idx, edges[i].tgt->node_idx, edges[i].weight));
715 (void)aff_chunk_absorb(env, edges[i].src, edges[i].tgt);
718 /* now insert all chunks into a priority queue */
719 list_for_each_entry(aff_chunk_t, curr_chunk, &env->chunklist, list) {
720 aff_chunk_assure_weight(env, curr_chunk);
722 DBG((dbg, LEVEL_1, "entry #%u", curr_chunk->id));
723 DBG_AFF_CHUNK(env, LEVEL_1, curr_chunk);
724 DBG((dbg, LEVEL_1, "\n"));
726 pqueue_put(env->chunks, curr_chunk, curr_chunk->weight);
729 for (pn = 0; pn < ARR_LEN(env->map.data); ++pn) {
730 co_mst_irn_t *mirn = env->map.data[pn];
733 if (mirn->chunk != NULL)
736 /* no chunk is allocated so far, do it now */
737 aff_chunk_t *curr_chunk = new_aff_chunk(env);
738 aff_chunk_add_node(curr_chunk, mirn);
740 aff_chunk_assure_weight(env, curr_chunk);
742 DBG((dbg, LEVEL_1, "entry #%u", curr_chunk->id));
743 DBG_AFF_CHUNK(env, LEVEL_1, curr_chunk);
744 DBG((dbg, LEVEL_1, "\n"));
746 pqueue_put(env->chunks, curr_chunk, curr_chunk->weight);
752 static __attribute__((unused)) void chunk_order_nodes(co_mst_env_t *env, aff_chunk_t *chunk)
754 pqueue_t *grow = new_pqueue();
755 ir_node const *max_node = NULL;
759 for (i = ARR_LEN(chunk->n); i != 0;) {
760 const ir_node *irn = chunk->n[--i];
761 affinity_node_t *an = get_affinity_info(env->co, irn);
765 if (arch_irn_is_ignore(irn))
769 co_gs_foreach_neighb(an, neigh)
772 if (w > max_weight) {
780 bitset_t *visited = bitset_malloc(get_irg_last_idx(env->co->irg));
782 for (i = ARR_LEN(chunk->n); i != 0;)
783 bitset_set(visited, get_irn_idx(chunk->n[--i]));
785 pqueue_put(grow, (void *) max_node, max_weight);
786 bitset_clear(visited, get_irn_idx(max_node));
788 while (!pqueue_empty(grow)) {
789 ir_node *irn = (ir_node*)pqueue_pop_front(grow);
790 affinity_node_t *an = get_affinity_info(env->co, irn);
793 if (arch_irn_is_ignore(irn))
796 assert(i <= ARR_LEN(chunk->n));
801 /* build the affinity edges */
802 co_gs_foreach_neighb(an, neigh) {
803 co_mst_irn_t *node = get_co_mst_irn(env, neigh->irn);
805 if (bitset_is_set(visited, get_irn_idx(node->irn))) {
806 pqueue_put(grow, (void *) neigh->irn, neigh->costs);
807 bitset_clear(visited, get_irn_idx(node->irn));
813 bitset_free(visited);
818 * Greedy collect affinity neighbours into thew new chunk @p chunk starting at node @p node.
820 static void expand_chunk_from(co_mst_env_t *env, co_mst_irn_t *node, bitset_t *visited,
821 aff_chunk_t *chunk, aff_chunk_t *orig_chunk, decide_func_t *decider, int col)
823 waitq *nodes = new_waitq();
825 DBG((dbg, LEVEL_1, "\n\tExpanding new chunk (#%u) from %+F, color %d:", chunk->id, node->irn, col));
827 /* init queue and chunk */
828 waitq_put(nodes, node);
829 bitset_set(visited, get_irn_idx(node->irn));
830 aff_chunk_add_node(chunk, node);
831 DB((dbg, LEVEL_1, " %+F", node->irn));
833 /* as long as there are nodes in the queue */
834 while (! waitq_empty(nodes)) {
835 co_mst_irn_t *n = (co_mst_irn_t*)waitq_get(nodes);
836 affinity_node_t *an = get_affinity_info(env->co, n->irn);
838 /* check all affinity neighbors */
841 co_gs_foreach_neighb(an, neigh) {
842 const ir_node *m = neigh->irn;
843 int m_idx = get_irn_idx(m);
846 if (arch_irn_is_ignore(m))
849 n2 = get_co_mst_irn(env, m);
851 if (! bitset_is_set(visited, m_idx) &&
854 ! aff_chunk_interferes(chunk, m) &&
855 node_contains(orig_chunk->n, m))
858 following conditions are met:
859 - neighbour is not visited
860 - neighbour likes the color
861 - neighbour has not yet a fixed color
862 - the new chunk doesn't interfere with the neighbour
863 - neighbour belongs or belonged once to the original chunk
865 bitset_set(visited, m_idx);
866 aff_chunk_add_node(chunk, n2);
867 DB((dbg, LEVEL_1, " %+F", n2->irn));
868 /* enqueue for further search */
869 waitq_put(nodes, n2);
875 DB((dbg, LEVEL_1, "\n"));
881 * Fragment the given chunk into chunks having given color and not having given color.
883 static aff_chunk_t *fragment_chunk(co_mst_env_t *env, int col, aff_chunk_t *c, waitq *tmp)
885 bitset_t *visited = bitset_malloc(get_irg_last_idx(env->co->irg));
887 aff_chunk_t *best = NULL;
889 for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
892 aff_chunk_t *tmp_chunk;
893 decide_func_t *decider;
897 if (bitset_is_set(visited, get_irn_idx(irn)))
900 node = get_co_mst_irn(env, irn);
902 if (get_mst_irn_col(node) == col) {
903 decider = decider_has_color;
905 DBG((dbg, LEVEL_4, "\tcolor %d wanted\n", col));
908 decider = decider_hasnot_color;
910 DBG((dbg, LEVEL_4, "\tcolor %d forbidden\n", col));
913 /* create a new chunk starting at current node */
914 tmp_chunk = new_aff_chunk(env);
915 waitq_put(tmp, tmp_chunk);
916 expand_chunk_from(env, node, visited, tmp_chunk, c, decider, col);
917 assert(ARR_LEN(tmp_chunk->n) > 0 && "No nodes added to chunk");
919 /* remember the local best */
920 aff_chunk_assure_weight(env, tmp_chunk);
921 if (check_for_best && (! best || best->weight < tmp_chunk->weight))
925 assert(best && "No chunk found?");
926 bitset_free(visited);
931 * Resets the temporary fixed color of all nodes within wait queue @p nodes.
932 * ATTENTION: the queue is empty after calling this function!
934 static inline void reject_coloring(struct list_head *nodes)
936 co_mst_irn_t *n, *temp;
937 DB((dbg, LEVEL_4, "\treject coloring for"));
938 list_for_each_entry_safe(co_mst_irn_t, n, temp, nodes, list) {
939 DB((dbg, LEVEL_4, " %+F", n->irn));
940 assert(n->tmp_col >= 0);
942 list_del_init(&n->list);
944 DB((dbg, LEVEL_4, "\n"));
947 static inline void materialize_coloring(struct list_head *nodes)
949 co_mst_irn_t *n, *temp;
950 list_for_each_entry_safe(co_mst_irn_t, n, temp, nodes, list) {
951 assert(n->tmp_col >= 0);
954 list_del_init(&n->list);
958 static inline void set_temp_color(co_mst_irn_t *node, int col, struct list_head *changed)
961 assert(!node->fixed);
962 assert(node->tmp_col < 0);
963 assert(node->list.next == &node->list && node->list.prev == &node->list);
964 assert(bitset_is_set(node->adm_colors, col));
966 list_add_tail(&node->list, changed);
970 static inline int is_loose(co_mst_irn_t *node)
972 return !node->fixed && node->tmp_col < 0;
976 * Determines the costs for each color if it would be assigned to node @p node.
978 static void determine_color_costs(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *costs)
980 int *neigh_cols = ALLOCAN(int, env->n_regs);
985 for (i = 0; i < env->n_regs; ++i) {
988 costs[i].cost = bitset_is_set(node->adm_colors, i) ? node->constr_factor : REAL(0.0);
991 for (i = 0; i < node->n_neighs; ++i) {
992 co_mst_irn_t *n = get_co_mst_irn(env, node->int_neighs[i]);
993 int col = get_mst_irn_col(n);
998 costs[col].cost = REAL(0.0);
1002 coeff = REAL(1.0) / n_loose;
1003 for (i = 0; i < env->n_regs; ++i)
1004 costs[i].cost *= REAL(1.0) - coeff * neigh_cols[i];
1008 /* need forward declaration due to recursive call */
1009 static int recolor_nodes(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *costs, struct list_head *changed_ones, int depth, int *max_depth, int *trip);
1012 * Tries to change node to a color but @p explude_col.
1013 * @return 1 if succeeded, 0 otherwise.
1015 static int change_node_color_excluded(co_mst_env_t *env, co_mst_irn_t *node, int exclude_col, struct list_head *changed, int depth, int *max_depth, int *trip)
1017 int col = get_mst_irn_col(node);
1020 /* neighbours has already a different color -> good, temporary fix it */
1021 if (col != exclude_col) {
1023 set_temp_color(node, col, changed);
1027 /* The node has the color it should not have _and_ has not been visited yet. */
1028 if (is_loose(node)) {
1029 col_cost_t *costs = ALLOCAN(col_cost_t, env->n_regs);
1031 /* Get the costs for giving the node a specific color. */
1032 determine_color_costs(env, node, costs);
1034 /* Since the node must not have the not_col, set the costs for that color to "infinity" */
1035 costs[exclude_col].cost = REAL(0.0);
1037 /* sort the colors according costs, cheapest first. */
1038 qsort(costs, env->n_regs, sizeof(costs[0]), cmp_col_cost_gt);
1040 /* Try recoloring the node using the color list. */
1041 res = recolor_nodes(env, node, costs, changed, depth + 1, max_depth, trip);
1048 * Tries to bring node @p node to cheapest color and color all interfering neighbours with other colors.
1049 * ATTENTION: Expect @p costs already sorted by increasing costs.
1050 * @return 1 if coloring could be applied, 0 otherwise.
1052 static int recolor_nodes(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *costs, struct list_head *changed, int depth, int *max_depth, int *trip)
1055 struct list_head local_changed;
1058 if (depth > *max_depth)
1061 DBG((dbg, LEVEL_4, "\tRecoloring %+F with color-costs", node->irn));
1062 DBG_COL_COST(env, LEVEL_4, costs);
1063 DB((dbg, LEVEL_4, "\n"));
1065 if (depth >= recolor_limit) {
1066 DBG((dbg, LEVEL_4, "\tHit recolor limit\n"));
1070 for (i = 0; i < env->n_regs; ++i) {
1071 int tgt_col = costs[i].col;
1075 /* If the costs for that color (and all successive) are infinite, bail out we won't make it anyway. */
1076 if (costs[i].cost == REAL(0.0)) {
1077 DBG((dbg, LEVEL_4, "\tAll further colors forbidden\n"));
1081 /* Set the new color of the node and mark the node as temporarily fixed. */
1082 assert(node->tmp_col < 0 && "Node must not have been temporary fixed.");
1083 INIT_LIST_HEAD(&local_changed);
1084 set_temp_color(node, tgt_col, &local_changed);
1085 DBG((dbg, LEVEL_4, "\tTemporary setting %+F to color %d\n", node->irn, tgt_col));
1087 /* try to color all interfering neighbours with current color forbidden */
1088 for (j = 0; j < node->n_neighs; ++j) {
1092 neigh = node->int_neighs[j];
1094 if (arch_irn_is_ignore(neigh))
1097 nn = get_co_mst_irn(env, neigh);
1098 DB((dbg, LEVEL_4, "\tHandling neighbour %+F, at position %d (fixed: %d, tmp_col: %d, col: %d)\n",
1099 neigh, j, nn->fixed, nn->tmp_col, nn->col));
1102 Try to change the color of the neighbor and record all nodes which
1103 get changed in the tmp list. Add this list to the "changed" list for
1104 that color. If we did not succeed to change the color of the neighbor,
1105 we bail out and try the next color.
1107 if (get_mst_irn_col(nn) == tgt_col) {
1108 /* try to color neighbour with tgt_col forbidden */
1109 neigh_ok = change_node_color_excluded(env, nn, tgt_col, &local_changed, depth + 1, max_depth, trip);
1117 We managed to assign the target color to all neighbors, so from the perspective
1118 of the current node, every thing was ok and we can return safely.
1121 /* append the local_changed ones to global ones */
1122 list_splice(&local_changed, changed);
1126 /* coloring of neighbours failed, so we try next color */
1127 reject_coloring(&local_changed);
1131 DBG((dbg, LEVEL_4, "\tAll colors failed\n"));
1136 * Tries to bring node @p node and all its neighbours to color @p tgt_col.
1137 * @return 1 if color @p col could be applied, 0 otherwise
1139 static int change_node_color(co_mst_env_t *env, co_mst_irn_t *node, int tgt_col, struct list_head *changed)
1141 int col = get_mst_irn_col(node);
1143 /* if node already has the target color -> good, temporary fix it */
1144 if (col == tgt_col) {
1145 DBG((dbg, LEVEL_4, "\t\tCNC: %+F has already color %d, fix temporary\n", node->irn, tgt_col));
1147 set_temp_color(node, tgt_col, changed);
1152 Node has not yet a fixed color and target color is admissible
1153 -> try to recolor node and its affinity neighbours
1155 if (is_loose(node) && bitset_is_set(node->adm_colors, tgt_col)) {
1156 col_cost_t *costs = env->single_cols[tgt_col];
1157 int res, max_depth, trip;
1162 DBG((dbg, LEVEL_4, "\t\tCNC: Attempt to recolor %+F ===>>\n", node->irn));
1163 res = recolor_nodes(env, node, costs, changed, 0, &max_depth, &trip);
1164 DBG((dbg, LEVEL_4, "\t\tCNC: <<=== Recoloring of %+F %s\n", node->irn, res ? "succeeded" : "failed"));
1165 stat_ev_int("heur4_recolor_depth_max", max_depth);
1166 stat_ev_int("heur4_recolor_trip", trip);
1172 #ifdef DEBUG_libfirm
1173 if (firm_dbg_get_mask(dbg) & LEVEL_4) {
1174 if (!is_loose(node))
1175 DB((dbg, LEVEL_4, "\t\tCNC: %+F has already fixed color %d\n", node->irn, col));
1177 DB((dbg, LEVEL_4, "\t\tCNC: color %d not admissible for %+F (", tgt_col, node->irn));
1178 dbg_admissible_colors(env, node);
1179 DB((dbg, LEVEL_4, ")\n"));
1188 * Tries to color an affinity chunk (or at least a part of it).
1189 * Inserts uncolored parts of the chunk as a new chunk into the priority queue.
1191 static void color_aff_chunk(co_mst_env_t *env, aff_chunk_t *c)
1193 aff_chunk_t *best_chunk = NULL;
1194 int n_nodes = ARR_LEN(c->n);
1195 int best_color = -1;
1196 int n_int_chunks = 0;
1197 waitq *tmp_chunks = new_waitq();
1198 waitq *best_starts = NULL;
1199 col_cost_t *order = ALLOCANZ(col_cost_t, env->n_regs);
1206 struct list_head changed;
1208 DB((dbg, LEVEL_2, "fragmentizing chunk #%u", c->id));
1209 DBG_AFF_CHUNK(env, LEVEL_2, c);
1210 DB((dbg, LEVEL_2, "\n"));
1212 stat_ev_ctx_push_fmt("heur4_color_chunk", "%u", c->id);
1214 ++env->chunk_visited;
1216 /* compute color preference */
1217 for (pos = 0, len = ARR_LEN(c->interfere); pos < len; ++pos) {
1218 const ir_node *n = c->interfere[pos];
1219 co_mst_irn_t *node = get_co_mst_irn(env, n);
1220 aff_chunk_t *chunk = node->chunk;
1222 if (is_loose(node) && chunk && chunk->visited < env->chunk_visited) {
1223 assert(!chunk->deleted);
1224 chunk->visited = env->chunk_visited;
1227 aff_chunk_assure_weight(env, chunk);
1228 for (i = 0; i < env->n_regs; ++i)
1229 order[i].cost += chunk->color_affinity[i].cost;
1233 for (i = 0; i < env->n_regs; ++i) {
1234 real_t dislike = n_int_chunks > 0 ? REAL(1.0) - order[i].cost / n_int_chunks : REAL(0.0);
1236 order[i].cost = (REAL(1.0) - dislike_influence) * c->color_affinity[i].cost + dislike_influence * dislike;
1239 qsort(order, env->n_regs, sizeof(order[0]), cmp_col_cost_gt);
1241 DBG_COL_COST(env, LEVEL_2, order);
1242 DB((dbg, LEVEL_2, "\n"));
1244 /* check which color is the "best" for the given chunk.
1245 * if we found a color which was ok for all nodes, we take it
1246 * and do not look further. (see did_all flag usage below.)
1247 * If we have many colors which fit all nodes it is hard to decide
1248 * which one to take anyway.
1249 * TODO Sebastian: Perhaps we should at all nodes and figure out
1250 * a suitable color using costs as done above (determine_color_costs).
1252 for (i = 0; i < env->k; ++i) {
1253 int col = order[i].col;
1255 aff_chunk_t *local_best;
1258 /* skip ignore colors */
1259 if (!bitset_is_set(env->allocatable_regs, col))
1262 DB((dbg, LEVEL_2, "\ttrying color %d\n", col));
1265 good_starts = new_waitq();
1267 /* try to bring all nodes of given chunk to the current color. */
1268 for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
1269 const ir_node *irn = c->n[idx];
1270 co_mst_irn_t *node = get_co_mst_irn(env, irn);
1273 assert(! node->fixed && "Node must not have a fixed color.");
1274 DB((dbg, LEVEL_4, "\t\tBringing %+F from color %d to color %d ...\n", irn, node->col, col));
1277 The order of the colored nodes is important, so we record the successfully
1278 colored ones in the order they appeared.
1280 INIT_LIST_HEAD(&changed);
1282 good = change_node_color(env, node, col, &changed);
1283 stat_ev_tim_pop("heur4_recolor");
1285 waitq_put(good_starts, node);
1286 materialize_coloring(&changed);
1291 reject_coloring(&changed);
1293 n_succeeded += good;
1294 DB((dbg, LEVEL_4, "\t\t... %+F attempt from %d to %d %s\n", irn, node->col, col, good ? "succeeded" : "failed"));
1297 /* unfix all nodes */
1298 for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
1299 co_mst_irn_t *node = get_co_mst_irn(env, c->n[idx]);
1303 /* try next color when failed */
1304 if (n_succeeded == 0) {
1305 del_waitq(good_starts);
1309 /* fragment the chunk according to the coloring */
1310 local_best = fragment_chunk(env, col, c, tmp_chunks);
1312 /* search the best of the good list
1313 and make it the new best if it is better than the current */
1315 aff_chunk_assure_weight(env, local_best);
1317 DB((dbg, LEVEL_3, "\t\tlocal best chunk (id %u) for color %d: ", local_best->id, col));
1318 DBG_AFF_CHUNK(env, LEVEL_3, local_best);
1320 if (! best_chunk || best_chunk->weight < local_best->weight) {
1321 best_chunk = local_best;
1324 del_waitq(best_starts);
1325 best_starts = good_starts;
1326 DB((dbg, LEVEL_3, "\n\t\t... setting global best chunk (id %u), color %d\n", best_chunk->id, best_color));
1328 DB((dbg, LEVEL_3, "\n\t\t... omitting, global best is better\n"));
1329 del_waitq(good_starts);
1333 del_waitq(good_starts);
1336 /* if all nodes were recolored, bail out */
1337 if (n_succeeded == n_nodes)
1341 stat_ev_int("heur4_colors_tried", i);
1343 /* free all intermediate created chunks except best one */
1344 while (! waitq_empty(tmp_chunks)) {
1345 aff_chunk_t *tmp = (aff_chunk_t*)waitq_get(tmp_chunks);
1346 if (tmp != best_chunk)
1347 delete_aff_chunk(tmp);
1349 del_waitq(tmp_chunks);
1351 /* return if coloring failed */
1354 del_waitq(best_starts);
1358 DB((dbg, LEVEL_2, "\tbest chunk #%u ", best_chunk->id));
1359 DBG_AFF_CHUNK(env, LEVEL_2, best_chunk);
1360 DB((dbg, LEVEL_2, "using color %d\n", best_color));
1362 for (idx = 0, len = ARR_LEN(best_chunk->n); idx < len; ++idx) {
1363 const ir_node *irn = best_chunk->n[idx];
1364 co_mst_irn_t *node = get_co_mst_irn(env, irn);
1367 /* bring the node to the color. */
1368 DB((dbg, LEVEL_4, "\tManifesting color %d for %+F, chunk #%u\n", best_color, node->irn, best_chunk->id));
1369 INIT_LIST_HEAD(&changed);
1371 res = change_node_color(env, node, best_color, &changed);
1372 stat_ev_tim_pop("heur4_recolor");
1374 materialize_coloring(&changed);
1377 assert(list_empty(&changed));
1380 /* remove the nodes in best chunk from original chunk */
1381 len = ARR_LEN(best_chunk->n);
1382 for (idx = 0; idx < len; ++idx) {
1383 const ir_node *irn = best_chunk->n[idx];
1384 int pos = nodes_bsearch(c->n, irn);
1389 len = ARR_LEN(c->n);
1390 for (idx = nidx = 0; idx < len; ++idx) {
1391 const ir_node *irn = c->n[idx];
1397 ARR_SHRINKLEN(c->n, nidx);
1400 /* we have to get the nodes back into the original chunk because they are scattered over temporary chunks */
1401 for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
1402 const ir_node *n = c->n[idx];
1403 co_mst_irn_t *nn = get_co_mst_irn(env, n);
1407 /* fragment the remaining chunk */
1408 visited = bitset_malloc(get_irg_last_idx(env->co->irg));
1409 for (idx = 0, len = ARR_LEN(best_chunk->n); idx < len; ++idx)
1410 bitset_set(visited, get_irn_idx(best_chunk->n[idx]));
1412 for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
1413 const ir_node *irn = c->n[idx];
1414 if (! bitset_is_set(visited, get_irn_idx(irn))) {
1415 aff_chunk_t *new_chunk = new_aff_chunk(env);
1416 co_mst_irn_t *node = get_co_mst_irn(env, irn);
1418 expand_chunk_from(env, node, visited, new_chunk, c, decider_always_yes, 0);
1419 aff_chunk_assure_weight(env, new_chunk);
1420 pqueue_put(env->chunks, new_chunk, new_chunk->weight);
1424 for (idx = 0, len = ARR_LEN(best_chunk->n); idx < len; ++idx) {
1425 const ir_node *n = best_chunk->n[idx];
1426 co_mst_irn_t *nn = get_co_mst_irn(env, n);
1430 /* clear obsolete chunks and free some memory */
1431 delete_aff_chunk(best_chunk);
1432 bitset_free(visited);
1434 del_waitq(best_starts);
1436 stat_ev_ctx_pop("heur4_color_chunk");
1440 * Main driver for mst safe coalescing algorithm.
1442 static int co_solve_heuristic_mst(copy_opt_t *co)
1444 unsigned n_regs = co->cls->n_regs;
1445 bitset_t *allocatable_regs = bitset_alloca(n_regs);
1450 co_mst_env_t mst_env;
1457 ir_nodemap_init(&mst_env.map, co->irg);
1458 obstack_init(&mst_env.obst);
1460 be_put_allocatable_regs(co->cenv->irg, co->cls, allocatable_regs);
1461 k = bitset_popcount(allocatable_regs);
1463 mst_env.n_regs = n_regs;
1465 mst_env.chunks = new_pqueue();
1467 mst_env.allocatable_regs = allocatable_regs;
1468 mst_env.ifg = co->cenv->ifg;
1469 INIT_LIST_HEAD(&mst_env.chunklist);
1470 mst_env.chunk_visited = 0;
1471 mst_env.single_cols = OALLOCN(&mst_env.obst, col_cost_t*, n_regs);
1473 for (i = 0; i < n_regs; ++i) {
1474 col_cost_t *vec = OALLOCN(&mst_env.obst, col_cost_t, n_regs);
1476 mst_env.single_cols[i] = vec;
1477 for (j = 0; j < n_regs; ++j) {
1479 vec[j].cost = REAL(0.0);
1483 vec[0].cost = REAL(1.0);
1486 DBG((dbg, LEVEL_1, "==== Coloring %+F, class %s ====\n", co->irg, co->cls->name));
1488 /* build affinity chunks */
1490 build_affinity_chunks(&mst_env);
1491 stat_ev_tim_pop("heur4_initial_chunk");
1493 /* color chunks as long as there are some */
1494 while (! pqueue_empty(mst_env.chunks)) {
1495 aff_chunk_t *chunk = (aff_chunk_t*)pqueue_pop_front(mst_env.chunks);
1497 color_aff_chunk(&mst_env, chunk);
1498 DB((dbg, LEVEL_4, "<<<====== Coloring chunk (%u) done\n", chunk->id));
1499 delete_aff_chunk(chunk);
1502 /* apply coloring */
1503 for (pn = 0; pn < ARR_LEN(mst_env.map.data); ++pn) {
1504 co_mst_irn_t *mirn = mst_env.map.data[pn];
1505 const arch_register_t *reg;
1508 irn = get_idx_irn(co->irg, pn);
1509 if (arch_irn_is_ignore(irn))
1512 /* skip nodes where color hasn't changed */
1513 if (mirn->init_col == mirn->col)
1516 reg = arch_register_for_index(co->cls, mirn->col);
1517 arch_set_irn_register(irn, reg);
1518 DB((dbg, LEVEL_1, "%+F set color from %d to %d\n", irn, mirn->init_col, mirn->col));
1521 /* free allocated memory */
1522 del_pqueue(mst_env.chunks);
1523 obstack_free(&mst_env.obst, NULL);
1524 ir_nodemap_destroy(&mst_env.map);
1526 stat_ev_tim_pop("heur4_total");
1531 static const lc_opt_table_entry_t options[] = {
1532 LC_OPT_ENT_INT ("limit", "limit recoloring", &recolor_limit),
1533 LC_OPT_ENT_DBL ("di", "dislike influence", &dislike_influence),
1537 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_copyheur4)
1538 void be_init_copyheur4(void)
1540 lc_opt_entry_t *be_grp = lc_opt_get_grp(firm_opt_get_root(), "be");
1541 lc_opt_entry_t *ra_grp = lc_opt_get_grp(be_grp, "ra");
1542 lc_opt_entry_t *chordal_grp = lc_opt_get_grp(ra_grp, "chordal");
1543 lc_opt_entry_t *co_grp = lc_opt_get_grp(chordal_grp, "co");
1544 lc_opt_entry_t *heur4_grp = lc_opt_get_grp(co_grp, "heur4");
1546 static co_algo_info copyheur = {
1547 co_solve_heuristic_mst, 0
1550 lc_opt_add_table(heur4_grp, options);
1551 be_register_copyopt("heur4", ©heur);
1553 FIRM_DBG_REGISTER(dbg, "firm.be.co.heur4");