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 = ir_nodemap_get(co_mst_irn_t, &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)
240 if (bitset_popcount(node->adm_colors) < 1)
241 fprintf(stderr, "no admissible colors?!?");
243 bitset_foreach(node->adm_colors, idx) {
244 ir_fprintf(stderr, " %zu", idx);
250 * Dump color-cost pairs to stderr.
252 static void dbg_col_cost(const co_mst_env_t *env, const col_cost_t *cost)
255 for (i = 0; i < env->n_regs; ++i)
256 fprintf(stderr, " (%d, %.4f)", cost[i].col, cost[i].cost);
259 #endif /* DEBUG_libfirm */
261 static inline int get_mst_irn_col(const co_mst_irn_t *node)
263 return node->tmp_col >= 0 ? node->tmp_col : node->col;
267 * @return 1 if node @p node has color @p col, 0 otherwise.
269 static int decider_has_color(const co_mst_irn_t *node, int col)
271 return get_mst_irn_col(node) == col;
275 * @return 1 if node @p node has not color @p col, 0 otherwise.
277 static int decider_hasnot_color(const co_mst_irn_t *node, int col)
279 return get_mst_irn_col(node) != col;
283 * Always returns true.
285 static int decider_always_yes(const co_mst_irn_t *node, int col)
292 /** compares two affinity edges by its weight */
293 static int cmp_aff_edge(const void *a, const void *b)
295 const aff_edge_t *e1 = (const aff_edge_t*)a;
296 const aff_edge_t *e2 = (const aff_edge_t*)b;
298 if (e2->weight == e1->weight) {
299 if (e2->src->node_idx == e1->src->node_idx)
300 return QSORT_CMP(e2->tgt->node_idx, e1->tgt->node_idx);
302 return QSORT_CMP(e2->src->node_idx, e1->src->node_idx);
304 /* sort in descending order */
305 return QSORT_CMP(e2->weight, e1->weight);
308 /** compares to color-cost pairs */
309 static __attribute__((unused)) int cmp_col_cost_lt(const void *a, const void *b)
311 const col_cost_t *c1 = (const col_cost_t*)a;
312 const col_cost_t *c2 = (const col_cost_t*)b;
313 real_t diff = c1->cost - c2->cost;
320 return QSORT_CMP(c1->col, c2->col);
323 static int cmp_col_cost_gt(const void *a, const void *b)
325 const col_cost_t *c1 = (const col_cost_t*)a;
326 const col_cost_t *c2 = (const col_cost_t*)b;
327 real_t diff = c2->cost - c1->cost;
334 return QSORT_CMP(c1->col, c2->col);
338 * Creates a new affinity chunk
340 static inline aff_chunk_t *new_aff_chunk(co_mst_env_t *env)
342 aff_chunk_t *c = XMALLOCF(aff_chunk_t, color_affinity, env->n_regs);
343 c->n = NEW_ARR_F(const ir_node *, 0);
344 c->interfere = NEW_ARR_F(const ir_node *, 0);
346 c->weight_consistent = 0;
348 c->id = ++last_chunk_id;
350 list_add(&c->list, &env->chunklist);
355 * Frees all memory allocated by an affinity chunk.
357 static inline void delete_aff_chunk(aff_chunk_t *c)
360 DEL_ARR_F(c->interfere);
367 * binary search of sorted nodes.
369 * @return the position where n is found in the array arr or ~pos
370 * if the nodes is not here.
372 static inline int nodes_bsearch(const ir_node **arr, const ir_node *n)
374 int hi = ARR_LEN(arr);
378 int md = lo + ((hi - lo) >> 1);
391 /** Check if a node n can be found inside arr. */
392 static int node_contains(const ir_node **arr, const ir_node *n)
394 int i = nodes_bsearch(arr, n);
399 * Insert a node into the sorted nodes list.
401 * @return 1 if the node was inserted, 0 else
403 static int nodes_insert(const ir_node ***arr, const ir_node *irn)
405 int idx = nodes_bsearch(*arr, irn);
408 int i, n = ARR_LEN(*arr);
411 ARR_APP1(const ir_node *, *arr, irn);
416 for (i = n - 1; i >= idx; --i)
425 * Adds a node to an affinity chunk
427 static inline void aff_chunk_add_node(aff_chunk_t *c, co_mst_irn_t *node)
431 if (! nodes_insert(&c->n, node->irn))
434 c->weight_consistent = 0;
437 for (i = node->n_neighs - 1; i >= 0; --i) {
438 ir_node *neigh = node->int_neighs[i];
439 nodes_insert(&c->interfere, neigh);
444 * Check if affinity chunk @p chunk interferes with node @p irn.
446 static inline int aff_chunk_interferes(const aff_chunk_t *chunk, const ir_node *irn)
448 return node_contains(chunk->interfere, irn);
452 * Check if there are interference edges from c1 to c2.
454 * @param c2 Another chunk
455 * @return 1 if there are interferences between nodes of c1 and c2, 0 otherwise.
457 static inline int aff_chunks_interfere(const aff_chunk_t *c1, const aff_chunk_t *c2)
464 /* check if there is a node in c2 having an interfering neighbor in c1 */
465 for (i = ARR_LEN(c2->n) - 1; i >= 0; --i) {
466 const ir_node *irn = c2->n[i];
468 if (node_contains(c1->interfere, irn))
475 * Returns the affinity chunk of @p irn or creates a new
476 * one with @p irn as element if there is none assigned.
478 static inline aff_chunk_t *get_aff_chunk(co_mst_env_t *env, const ir_node *irn)
480 co_mst_irn_t *node = get_co_mst_irn(env, irn);
485 * Let chunk(src) absorb the nodes of chunk(tgt) (only possible when there
486 * are no interference edges from chunk(src) to chunk(tgt)).
487 * @return 1 if successful, 0 if not possible
489 static int aff_chunk_absorb(co_mst_env_t *env, const ir_node *src, const ir_node *tgt)
491 aff_chunk_t *c1 = get_aff_chunk(env, src);
492 aff_chunk_t *c2 = get_aff_chunk(env, tgt);
495 DB((dbg, LEVEL_4, "Attempt to let c1 (id %u): ", c1 ? c1->id : 0));
497 DBG_AFF_CHUNK(env, LEVEL_4, c1);
499 DB((dbg, LEVEL_4, "{%+F}", src));
501 DB((dbg, LEVEL_4, "\n\tabsorb c2 (id %u): ", c2 ? c2->id : 0));
503 DBG_AFF_CHUNK(env, LEVEL_4, c2);
505 DB((dbg, LEVEL_4, "{%+F}", tgt));
507 DB((dbg, LEVEL_4, "\n"));
512 /* no chunk exists */
513 co_mst_irn_t *mirn = get_co_mst_irn(env, src);
516 for (i = mirn->n_neighs - 1; i >= 0; --i) {
517 if (mirn->int_neighs[i] == tgt)
521 /* create one containing both nodes */
522 c1 = new_aff_chunk(env);
523 aff_chunk_add_node(c1, get_co_mst_irn(env, src));
524 aff_chunk_add_node(c1, get_co_mst_irn(env, tgt));
528 /* c2 already exists */
529 if (! aff_chunk_interferes(c2, src)) {
530 aff_chunk_add_node(c2, get_co_mst_irn(env, src));
534 } else if (c2 == NULL) {
535 /* c1 already exists */
536 if (! aff_chunk_interferes(c1, tgt)) {
537 aff_chunk_add_node(c1, get_co_mst_irn(env, tgt));
540 } else if (c1 != c2 && ! aff_chunks_interfere(c1, c2)) {
543 for (idx = 0, len = ARR_LEN(c2->n); idx < len; ++idx)
544 aff_chunk_add_node(c1, get_co_mst_irn(env, c2->n[idx]));
546 for (idx = 0, len = ARR_LEN(c2->interfere); idx < len; ++idx) {
547 const ir_node *irn = c2->interfere[idx];
548 nodes_insert(&c1->interfere, irn);
551 c1->weight_consistent = 0;
553 delete_aff_chunk(c2);
556 DB((dbg, LEVEL_4, " ... c1 interferes with c2, skipped\n"));
560 DB((dbg, LEVEL_4, " ... absorbed\n"));
565 * Assures that the weight of the given chunk is consistent.
567 static void aff_chunk_assure_weight(co_mst_env_t *env, aff_chunk_t *c)
569 if (! c->weight_consistent) {
573 for (i = 0; i < env->n_regs; ++i) {
574 c->color_affinity[i].col = i;
575 c->color_affinity[i].cost = REAL(0.0);
578 for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
579 const ir_node *n = c->n[idx];
580 const affinity_node_t *an = get_affinity_info(env->co, n);
581 co_mst_irn_t *node = get_co_mst_irn(env, n);
584 if (node->constr_factor > REAL(0.0)) {
585 bitset_foreach (node->adm_colors, col)
586 c->color_affinity[col].cost += node->constr_factor;
590 co_gs_foreach_neighb(an, neigh) {
591 const ir_node *m = neigh->irn;
593 if (arch_irn_is_ignore(m))
596 w += node_contains(c->n, m) ? neigh->costs : 0;
601 for (i = 0; i < env->n_regs; ++i)
602 c->color_affinity[i].cost *= (REAL(1.0) / ARR_LEN(c->n));
605 // c->weight = bitset_popcount(c->nodes);
606 c->weight_consistent = 1;
611 * Count the number of interfering affinity neighbours
613 static int count_interfering_aff_neighs(co_mst_env_t *env, const affinity_node_t *an)
615 const ir_node *irn = an->irn;
616 const co_mst_irn_t *node = get_co_mst_irn(env, irn);
619 co_gs_foreach_neighb(an, neigh) {
620 const ir_node *n = neigh->irn;
623 if (arch_irn_is_ignore(n))
626 /* check if the affinity neighbour interfere */
627 for (i = 0; i < node->n_neighs; ++i) {
628 if (node->int_neighs[i] == n) {
639 * Build chunks of nodes connected by affinity edges.
640 * We start at the heaviest affinity edge.
641 * The chunks of the two edge-defining nodes will be
642 * merged if there are no interference edges from one
643 * chunk to the other.
645 static void build_affinity_chunks(co_mst_env_t *env)
647 nodes_iter_t nodes_it;
648 aff_edge_t *edges = NEW_ARR_F(aff_edge_t, 0);
653 /* at first we create the affinity edge objects */
654 be_ifg_foreach_node(env->ifg, &nodes_it, n) {
655 int n_idx = get_irn_idx(n);
659 if (arch_irn_is_ignore(n))
662 n1 = get_co_mst_irn(env, n);
663 an = get_affinity_info(env->co, n);
666 if (n1->int_aff_neigh < 0)
667 n1->int_aff_neigh = count_interfering_aff_neighs(env, an);
669 /* build the affinity edges */
670 co_gs_foreach_neighb(an, neigh) {
671 const ir_node *m = neigh->irn;
672 int m_idx = get_irn_idx(m);
674 /* record the edge in only one direction */
679 /* skip ignore nodes */
680 if (arch_irn_is_ignore(m))
686 n2 = get_co_mst_irn(env, m);
687 if (n2->int_aff_neigh < 0) {
688 affinity_node_t *am = get_affinity_info(env->co, m);
689 n2->int_aff_neigh = count_interfering_aff_neighs(env, am);
692 * these weights are pure hackery ;-).
693 * It's not chriswue's fault but mine.
695 edge.weight = neigh->costs;
696 ARR_APP1(aff_edge_t, edges, edge);
702 /* now: sort edges and build the affinity chunks */
703 len = ARR_LEN(edges);
704 qsort(edges, len, sizeof(edges[0]), cmp_aff_edge);
705 for (i = 0; i < len; ++i) {
706 DBG((dbg, LEVEL_1, "edge (%u,%u) %f\n", edges[i].src->node_idx, edges[i].tgt->node_idx, edges[i].weight));
708 (void)aff_chunk_absorb(env, edges[i].src, edges[i].tgt);
711 /* now insert all chunks into a priority queue */
712 list_for_each_entry(aff_chunk_t, curr_chunk, &env->chunklist, list) {
713 aff_chunk_assure_weight(env, curr_chunk);
715 DBG((dbg, LEVEL_1, "entry #%u", curr_chunk->id));
716 DBG_AFF_CHUNK(env, LEVEL_1, curr_chunk);
717 DBG((dbg, LEVEL_1, "\n"));
719 pqueue_put(env->chunks, curr_chunk, curr_chunk->weight);
722 for (pn = 0; pn < ARR_LEN(env->map.data); ++pn) {
723 co_mst_irn_t *mirn = (co_mst_irn_t*)env->map.data[pn];
726 if (mirn->chunk != NULL)
729 /* no chunk is allocated so far, do it now */
730 aff_chunk_t *curr_chunk = new_aff_chunk(env);
731 aff_chunk_add_node(curr_chunk, mirn);
733 aff_chunk_assure_weight(env, curr_chunk);
735 DBG((dbg, LEVEL_1, "entry #%u", curr_chunk->id));
736 DBG_AFF_CHUNK(env, LEVEL_1, curr_chunk);
737 DBG((dbg, LEVEL_1, "\n"));
739 pqueue_put(env->chunks, curr_chunk, curr_chunk->weight);
745 static __attribute__((unused)) void chunk_order_nodes(co_mst_env_t *env, aff_chunk_t *chunk)
747 pqueue_t *grow = new_pqueue();
748 ir_node const *max_node = NULL;
752 for (i = ARR_LEN(chunk->n); i != 0;) {
753 const ir_node *irn = chunk->n[--i];
754 affinity_node_t *an = get_affinity_info(env->co, irn);
757 if (arch_irn_is_ignore(irn))
761 co_gs_foreach_neighb(an, neigh)
764 if (w > max_weight) {
772 bitset_t *visited = bitset_malloc(get_irg_last_idx(env->co->irg));
774 for (i = ARR_LEN(chunk->n); i != 0;)
775 bitset_set(visited, get_irn_idx(chunk->n[--i]));
777 pqueue_put(grow, (void *) max_node, max_weight);
778 bitset_clear(visited, get_irn_idx(max_node));
780 while (!pqueue_empty(grow)) {
781 ir_node *irn = (ir_node*)pqueue_pop_front(grow);
782 affinity_node_t *an = get_affinity_info(env->co, irn);
784 if (arch_irn_is_ignore(irn))
787 assert(i <= ARR_LEN(chunk->n));
792 /* build the affinity edges */
793 co_gs_foreach_neighb(an, neigh) {
794 co_mst_irn_t *node = get_co_mst_irn(env, neigh->irn);
796 if (bitset_is_set(visited, get_irn_idx(node->irn))) {
797 pqueue_put(grow, (void *) neigh->irn, neigh->costs);
798 bitset_clear(visited, get_irn_idx(node->irn));
804 bitset_free(visited);
809 * Greedy collect affinity neighbours into thew new chunk @p chunk starting at node @p node.
811 static void expand_chunk_from(co_mst_env_t *env, co_mst_irn_t *node, bitset_t *visited,
812 aff_chunk_t *chunk, aff_chunk_t *orig_chunk, decide_func_t *decider, int col)
814 waitq *nodes = new_waitq();
816 DBG((dbg, LEVEL_1, "\n\tExpanding new chunk (#%u) from %+F, color %d:", chunk->id, node->irn, col));
818 /* init queue and chunk */
819 waitq_put(nodes, node);
820 bitset_set(visited, get_irn_idx(node->irn));
821 aff_chunk_add_node(chunk, node);
822 DB((dbg, LEVEL_1, " %+F", node->irn));
824 /* as long as there are nodes in the queue */
825 while (! waitq_empty(nodes)) {
826 co_mst_irn_t *n = (co_mst_irn_t*)waitq_get(nodes);
827 affinity_node_t *an = get_affinity_info(env->co, n->irn);
829 /* check all affinity neighbors */
831 co_gs_foreach_neighb(an, neigh) {
832 const ir_node *m = neigh->irn;
833 int m_idx = get_irn_idx(m);
836 if (arch_irn_is_ignore(m))
839 n2 = get_co_mst_irn(env, m);
841 if (! bitset_is_set(visited, m_idx) &&
844 ! aff_chunk_interferes(chunk, m) &&
845 node_contains(orig_chunk->n, m))
848 following conditions are met:
849 - neighbour is not visited
850 - neighbour likes the color
851 - neighbour has not yet a fixed color
852 - the new chunk doesn't interfere with the neighbour
853 - neighbour belongs or belonged once to the original chunk
855 bitset_set(visited, m_idx);
856 aff_chunk_add_node(chunk, n2);
857 DB((dbg, LEVEL_1, " %+F", n2->irn));
858 /* enqueue for further search */
859 waitq_put(nodes, n2);
865 DB((dbg, LEVEL_1, "\n"));
871 * Fragment the given chunk into chunks having given color and not having given color.
873 static aff_chunk_t *fragment_chunk(co_mst_env_t *env, int col, aff_chunk_t *c, waitq *tmp)
875 bitset_t *visited = bitset_malloc(get_irg_last_idx(env->co->irg));
877 aff_chunk_t *best = NULL;
879 for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
882 aff_chunk_t *tmp_chunk;
883 decide_func_t *decider;
887 if (bitset_is_set(visited, get_irn_idx(irn)))
890 node = get_co_mst_irn(env, irn);
892 if (get_mst_irn_col(node) == col) {
893 decider = decider_has_color;
895 DBG((dbg, LEVEL_4, "\tcolor %d wanted\n", col));
898 decider = decider_hasnot_color;
900 DBG((dbg, LEVEL_4, "\tcolor %d forbidden\n", col));
903 /* create a new chunk starting at current node */
904 tmp_chunk = new_aff_chunk(env);
905 waitq_put(tmp, tmp_chunk);
906 expand_chunk_from(env, node, visited, tmp_chunk, c, decider, col);
907 assert(ARR_LEN(tmp_chunk->n) > 0 && "No nodes added to chunk");
909 /* remember the local best */
910 aff_chunk_assure_weight(env, tmp_chunk);
911 if (check_for_best && (! best || best->weight < tmp_chunk->weight))
915 assert(best && "No chunk found?");
916 bitset_free(visited);
921 * Resets the temporary fixed color of all nodes within wait queue @p nodes.
922 * ATTENTION: the queue is empty after calling this function!
924 static inline void reject_coloring(struct list_head *nodes)
926 DB((dbg, LEVEL_4, "\treject coloring for"));
927 list_for_each_entry_safe(co_mst_irn_t, n, temp, nodes, list) {
928 DB((dbg, LEVEL_4, " %+F", n->irn));
929 assert(n->tmp_col >= 0);
931 list_del_init(&n->list);
933 DB((dbg, LEVEL_4, "\n"));
936 static inline void materialize_coloring(struct list_head *nodes)
938 list_for_each_entry_safe(co_mst_irn_t, n, temp, nodes, list) {
939 assert(n->tmp_col >= 0);
942 list_del_init(&n->list);
946 static inline void set_temp_color(co_mst_irn_t *node, int col, struct list_head *changed)
949 assert(!node->fixed);
950 assert(node->tmp_col < 0);
951 assert(node->list.next == &node->list && node->list.prev == &node->list);
952 assert(bitset_is_set(node->adm_colors, col));
954 list_add_tail(&node->list, changed);
958 static inline int is_loose(co_mst_irn_t *node)
960 return !node->fixed && node->tmp_col < 0;
964 * Determines the costs for each color if it would be assigned to node @p node.
966 static void determine_color_costs(co_mst_env_t *env, co_mst_irn_t *node, col_cost_t *costs)
968 int *neigh_cols = ALLOCAN(int, env->n_regs);
973 for (i = 0; i < env->n_regs; ++i) {
976 costs[i].cost = bitset_is_set(node->adm_colors, i) ? node->constr_factor : REAL(0.0);
979 for (i = 0; i < node->n_neighs; ++i) {
980 co_mst_irn_t *n = get_co_mst_irn(env, node->int_neighs[i]);
981 int col = get_mst_irn_col(n);
986 costs[col].cost = REAL(0.0);
990 coeff = REAL(1.0) / n_loose;
991 for (i = 0; i < env->n_regs; ++i)
992 costs[i].cost *= REAL(1.0) - coeff * neigh_cols[i];
996 /* need forward declaration due to recursive call */
997 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);
1000 * Tries to change node to a color but @p explude_col.
1001 * @return 1 if succeeded, 0 otherwise.
1003 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)
1005 int col = get_mst_irn_col(node);
1008 /* neighbours has already a different color -> good, temporary fix it */
1009 if (col != exclude_col) {
1011 set_temp_color(node, col, changed);
1015 /* The node has the color it should not have _and_ has not been visited yet. */
1016 if (is_loose(node)) {
1017 col_cost_t *costs = ALLOCAN(col_cost_t, env->n_regs);
1019 /* Get the costs for giving the node a specific color. */
1020 determine_color_costs(env, node, costs);
1022 /* Since the node must not have the not_col, set the costs for that color to "infinity" */
1023 costs[exclude_col].cost = REAL(0.0);
1025 /* sort the colors according costs, cheapest first. */
1026 qsort(costs, env->n_regs, sizeof(costs[0]), cmp_col_cost_gt);
1028 /* Try recoloring the node using the color list. */
1029 res = recolor_nodes(env, node, costs, changed, depth + 1, max_depth, trip);
1036 * Tries to bring node @p node to cheapest color and color all interfering neighbours with other colors.
1037 * ATTENTION: Expect @p costs already sorted by increasing costs.
1038 * @return 1 if coloring could be applied, 0 otherwise.
1040 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)
1043 struct list_head local_changed;
1046 if (depth > *max_depth)
1049 DBG((dbg, LEVEL_4, "\tRecoloring %+F with color-costs", node->irn));
1050 DBG_COL_COST(env, LEVEL_4, costs);
1051 DB((dbg, LEVEL_4, "\n"));
1053 if (depth >= recolor_limit) {
1054 DBG((dbg, LEVEL_4, "\tHit recolor limit\n"));
1058 for (i = 0; i < env->n_regs; ++i) {
1059 int tgt_col = costs[i].col;
1063 /* If the costs for that color (and all successive) are infinite, bail out we won't make it anyway. */
1064 if (costs[i].cost == REAL(0.0)) {
1065 DBG((dbg, LEVEL_4, "\tAll further colors forbidden\n"));
1069 /* Set the new color of the node and mark the node as temporarily fixed. */
1070 assert(node->tmp_col < 0 && "Node must not have been temporary fixed.");
1071 INIT_LIST_HEAD(&local_changed);
1072 set_temp_color(node, tgt_col, &local_changed);
1073 DBG((dbg, LEVEL_4, "\tTemporary setting %+F to color %d\n", node->irn, tgt_col));
1075 /* try to color all interfering neighbours with current color forbidden */
1076 for (j = 0; j < node->n_neighs; ++j) {
1080 neigh = node->int_neighs[j];
1082 if (arch_irn_is_ignore(neigh))
1085 nn = get_co_mst_irn(env, neigh);
1086 DB((dbg, LEVEL_4, "\tHandling neighbour %+F, at position %d (fixed: %d, tmp_col: %d, col: %d)\n",
1087 neigh, j, nn->fixed, nn->tmp_col, nn->col));
1090 Try to change the color of the neighbor and record all nodes which
1091 get changed in the tmp list. Add this list to the "changed" list for
1092 that color. If we did not succeed to change the color of the neighbor,
1093 we bail out and try the next color.
1095 if (get_mst_irn_col(nn) == tgt_col) {
1096 /* try to color neighbour with tgt_col forbidden */
1097 neigh_ok = change_node_color_excluded(env, nn, tgt_col, &local_changed, depth + 1, max_depth, trip);
1105 We managed to assign the target color to all neighbors, so from the perspective
1106 of the current node, every thing was ok and we can return safely.
1109 /* append the local_changed ones to global ones */
1110 list_splice(&local_changed, changed);
1114 /* coloring of neighbours failed, so we try next color */
1115 reject_coloring(&local_changed);
1119 DBG((dbg, LEVEL_4, "\tAll colors failed\n"));
1124 * Tries to bring node @p node and all its neighbours to color @p tgt_col.
1125 * @return 1 if color @p col could be applied, 0 otherwise
1127 static int change_node_color(co_mst_env_t *env, co_mst_irn_t *node, int tgt_col, struct list_head *changed)
1129 int col = get_mst_irn_col(node);
1131 /* if node already has the target color -> good, temporary fix it */
1132 if (col == tgt_col) {
1133 DBG((dbg, LEVEL_4, "\t\tCNC: %+F has already color %d, fix temporary\n", node->irn, tgt_col));
1135 set_temp_color(node, tgt_col, changed);
1140 Node has not yet a fixed color and target color is admissible
1141 -> try to recolor node and its affinity neighbours
1143 if (is_loose(node) && bitset_is_set(node->adm_colors, tgt_col)) {
1144 col_cost_t *costs = env->single_cols[tgt_col];
1145 int res, max_depth, trip;
1150 DBG((dbg, LEVEL_4, "\t\tCNC: Attempt to recolor %+F ===>>\n", node->irn));
1151 res = recolor_nodes(env, node, costs, changed, 0, &max_depth, &trip);
1152 DBG((dbg, LEVEL_4, "\t\tCNC: <<=== Recoloring of %+F %s\n", node->irn, res ? "succeeded" : "failed"));
1153 stat_ev_int("heur4_recolor_depth_max", max_depth);
1154 stat_ev_int("heur4_recolor_trip", trip);
1160 #ifdef DEBUG_libfirm
1161 if (firm_dbg_get_mask(dbg) & LEVEL_4) {
1162 if (!is_loose(node))
1163 DB((dbg, LEVEL_4, "\t\tCNC: %+F has already fixed color %d\n", node->irn, col));
1165 DB((dbg, LEVEL_4, "\t\tCNC: color %d not admissible for %+F (", tgt_col, node->irn));
1166 dbg_admissible_colors(env, node);
1167 DB((dbg, LEVEL_4, ")\n"));
1176 * Tries to color an affinity chunk (or at least a part of it).
1177 * Inserts uncolored parts of the chunk as a new chunk into the priority queue.
1179 static void color_aff_chunk(co_mst_env_t *env, aff_chunk_t *c)
1181 aff_chunk_t *best_chunk = NULL;
1182 int n_nodes = ARR_LEN(c->n);
1183 int best_color = -1;
1184 int n_int_chunks = 0;
1185 waitq *tmp_chunks = new_waitq();
1186 waitq *best_starts = NULL;
1187 col_cost_t *order = ALLOCANZ(col_cost_t, env->n_regs);
1194 struct list_head changed;
1196 DB((dbg, LEVEL_2, "fragmentizing chunk #%u", c->id));
1197 DBG_AFF_CHUNK(env, LEVEL_2, c);
1198 DB((dbg, LEVEL_2, "\n"));
1200 stat_ev_ctx_push_fmt("heur4_color_chunk", "%u", c->id);
1202 ++env->chunk_visited;
1204 /* compute color preference */
1205 for (pos = 0, len = ARR_LEN(c->interfere); pos < len; ++pos) {
1206 const ir_node *n = c->interfere[pos];
1207 co_mst_irn_t *node = get_co_mst_irn(env, n);
1208 aff_chunk_t *chunk = node->chunk;
1210 if (is_loose(node) && chunk && chunk->visited < env->chunk_visited) {
1211 assert(!chunk->deleted);
1212 chunk->visited = env->chunk_visited;
1215 aff_chunk_assure_weight(env, chunk);
1216 for (i = 0; i < env->n_regs; ++i)
1217 order[i].cost += chunk->color_affinity[i].cost;
1221 for (i = 0; i < env->n_regs; ++i) {
1222 real_t dislike = n_int_chunks > 0 ? REAL(1.0) - order[i].cost / n_int_chunks : REAL(0.0);
1224 order[i].cost = (REAL(1.0) - dislike_influence) * c->color_affinity[i].cost + dislike_influence * dislike;
1227 qsort(order, env->n_regs, sizeof(order[0]), cmp_col_cost_gt);
1229 DBG_COL_COST(env, LEVEL_2, order);
1230 DB((dbg, LEVEL_2, "\n"));
1232 /* check which color is the "best" for the given chunk.
1233 * if we found a color which was ok for all nodes, we take it
1234 * and do not look further. (see did_all flag usage below.)
1235 * If we have many colors which fit all nodes it is hard to decide
1236 * which one to take anyway.
1237 * TODO Sebastian: Perhaps we should at all nodes and figure out
1238 * a suitable color using costs as done above (determine_color_costs).
1240 for (i = 0; i < env->k; ++i) {
1241 int col = order[i].col;
1243 aff_chunk_t *local_best;
1246 /* skip ignore colors */
1247 if (!bitset_is_set(env->allocatable_regs, col))
1250 DB((dbg, LEVEL_2, "\ttrying color %d\n", col));
1253 good_starts = new_waitq();
1255 /* try to bring all nodes of given chunk to the current color. */
1256 for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
1257 const ir_node *irn = c->n[idx];
1258 co_mst_irn_t *node = get_co_mst_irn(env, irn);
1261 assert(! node->fixed && "Node must not have a fixed color.");
1262 DB((dbg, LEVEL_4, "\t\tBringing %+F from color %d to color %d ...\n", irn, node->col, col));
1265 The order of the colored nodes is important, so we record the successfully
1266 colored ones in the order they appeared.
1268 INIT_LIST_HEAD(&changed);
1270 good = change_node_color(env, node, col, &changed);
1271 stat_ev_tim_pop("heur4_recolor");
1273 waitq_put(good_starts, node);
1274 materialize_coloring(&changed);
1279 reject_coloring(&changed);
1281 n_succeeded += good;
1282 DB((dbg, LEVEL_4, "\t\t... %+F attempt from %d to %d %s\n", irn, node->col, col, good ? "succeeded" : "failed"));
1285 /* unfix all nodes */
1286 for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
1287 co_mst_irn_t *node = get_co_mst_irn(env, c->n[idx]);
1291 /* try next color when failed */
1292 if (n_succeeded == 0) {
1293 del_waitq(good_starts);
1297 /* fragment the chunk according to the coloring */
1298 local_best = fragment_chunk(env, col, c, tmp_chunks);
1300 /* search the best of the good list
1301 and make it the new best if it is better than the current */
1303 aff_chunk_assure_weight(env, local_best);
1305 DB((dbg, LEVEL_3, "\t\tlocal best chunk (id %u) for color %d: ", local_best->id, col));
1306 DBG_AFF_CHUNK(env, LEVEL_3, local_best);
1308 if (! best_chunk || best_chunk->weight < local_best->weight) {
1309 best_chunk = local_best;
1312 del_waitq(best_starts);
1313 best_starts = good_starts;
1314 DB((dbg, LEVEL_3, "\n\t\t... setting global best chunk (id %u), color %d\n", best_chunk->id, best_color));
1316 DB((dbg, LEVEL_3, "\n\t\t... omitting, global best is better\n"));
1317 del_waitq(good_starts);
1321 del_waitq(good_starts);
1324 /* if all nodes were recolored, bail out */
1325 if (n_succeeded == n_nodes)
1329 stat_ev_int("heur4_colors_tried", i);
1331 /* free all intermediate created chunks except best one */
1332 while (! waitq_empty(tmp_chunks)) {
1333 aff_chunk_t *tmp = (aff_chunk_t*)waitq_get(tmp_chunks);
1334 if (tmp != best_chunk)
1335 delete_aff_chunk(tmp);
1337 del_waitq(tmp_chunks);
1339 /* return if coloring failed */
1342 del_waitq(best_starts);
1346 DB((dbg, LEVEL_2, "\tbest chunk #%u ", best_chunk->id));
1347 DBG_AFF_CHUNK(env, LEVEL_2, best_chunk);
1348 DB((dbg, LEVEL_2, "using color %d\n", best_color));
1350 for (idx = 0, len = ARR_LEN(best_chunk->n); idx < len; ++idx) {
1351 const ir_node *irn = best_chunk->n[idx];
1352 co_mst_irn_t *node = get_co_mst_irn(env, irn);
1355 /* bring the node to the color. */
1356 DB((dbg, LEVEL_4, "\tManifesting color %d for %+F, chunk #%u\n", best_color, node->irn, best_chunk->id));
1357 INIT_LIST_HEAD(&changed);
1359 res = change_node_color(env, node, best_color, &changed);
1360 stat_ev_tim_pop("heur4_recolor");
1362 materialize_coloring(&changed);
1365 assert(list_empty(&changed));
1368 /* remove the nodes in best chunk from original chunk */
1369 len = ARR_LEN(best_chunk->n);
1370 for (idx = 0; idx < len; ++idx) {
1371 const ir_node *irn = best_chunk->n[idx];
1372 int pos = nodes_bsearch(c->n, irn);
1377 len = ARR_LEN(c->n);
1378 for (idx = nidx = 0; idx < len; ++idx) {
1379 const ir_node *irn = c->n[idx];
1385 ARR_SHRINKLEN(c->n, nidx);
1388 /* we have to get the nodes back into the original chunk because they are scattered over temporary chunks */
1389 for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
1390 const ir_node *n = c->n[idx];
1391 co_mst_irn_t *nn = get_co_mst_irn(env, n);
1395 /* fragment the remaining chunk */
1396 visited = bitset_malloc(get_irg_last_idx(env->co->irg));
1397 for (idx = 0, len = ARR_LEN(best_chunk->n); idx < len; ++idx)
1398 bitset_set(visited, get_irn_idx(best_chunk->n[idx]));
1400 for (idx = 0, len = ARR_LEN(c->n); idx < len; ++idx) {
1401 const ir_node *irn = c->n[idx];
1402 if (! bitset_is_set(visited, get_irn_idx(irn))) {
1403 aff_chunk_t *new_chunk = new_aff_chunk(env);
1404 co_mst_irn_t *node = get_co_mst_irn(env, irn);
1406 expand_chunk_from(env, node, visited, new_chunk, c, decider_always_yes, 0);
1407 aff_chunk_assure_weight(env, new_chunk);
1408 pqueue_put(env->chunks, new_chunk, new_chunk->weight);
1412 for (idx = 0, len = ARR_LEN(best_chunk->n); idx < len; ++idx) {
1413 const ir_node *n = best_chunk->n[idx];
1414 co_mst_irn_t *nn = get_co_mst_irn(env, n);
1418 /* clear obsolete chunks and free some memory */
1419 delete_aff_chunk(best_chunk);
1420 bitset_free(visited);
1422 del_waitq(best_starts);
1424 stat_ev_ctx_pop("heur4_color_chunk");
1428 * Main driver for mst safe coalescing algorithm.
1430 static int co_solve_heuristic_mst(copy_opt_t *co)
1432 unsigned n_regs = co->cls->n_regs;
1433 bitset_t *allocatable_regs = bitset_alloca(n_regs);
1438 co_mst_env_t mst_env;
1445 ir_nodemap_init(&mst_env.map, co->irg);
1446 obstack_init(&mst_env.obst);
1448 be_put_allocatable_regs(co->cenv->irg, co->cls, allocatable_regs);
1449 k = bitset_popcount(allocatable_regs);
1451 mst_env.n_regs = n_regs;
1453 mst_env.chunks = new_pqueue();
1455 mst_env.allocatable_regs = allocatable_regs;
1456 mst_env.ifg = co->cenv->ifg;
1457 INIT_LIST_HEAD(&mst_env.chunklist);
1458 mst_env.chunk_visited = 0;
1459 mst_env.single_cols = OALLOCN(&mst_env.obst, col_cost_t*, n_regs);
1461 for (i = 0; i < n_regs; ++i) {
1462 col_cost_t *vec = OALLOCN(&mst_env.obst, col_cost_t, n_regs);
1464 mst_env.single_cols[i] = vec;
1465 for (j = 0; j < n_regs; ++j) {
1467 vec[j].cost = REAL(0.0);
1471 vec[0].cost = REAL(1.0);
1474 DBG((dbg, LEVEL_1, "==== Coloring %+F, class %s ====\n", co->irg, co->cls->name));
1476 /* build affinity chunks */
1478 build_affinity_chunks(&mst_env);
1479 stat_ev_tim_pop("heur4_initial_chunk");
1481 /* color chunks as long as there are some */
1482 while (! pqueue_empty(mst_env.chunks)) {
1483 aff_chunk_t *chunk = (aff_chunk_t*)pqueue_pop_front(mst_env.chunks);
1485 color_aff_chunk(&mst_env, chunk);
1486 DB((dbg, LEVEL_4, "<<<====== Coloring chunk (%u) done\n", chunk->id));
1487 delete_aff_chunk(chunk);
1490 /* apply coloring */
1491 for (pn = 0; pn < ARR_LEN(mst_env.map.data); ++pn) {
1492 co_mst_irn_t *mirn = (co_mst_irn_t*)mst_env.map.data[pn];
1493 const arch_register_t *reg;
1496 irn = get_idx_irn(co->irg, pn);
1497 if (arch_irn_is_ignore(irn))
1500 /* skip nodes where color hasn't changed */
1501 if (mirn->init_col == mirn->col)
1504 reg = arch_register_for_index(co->cls, mirn->col);
1505 arch_set_irn_register(irn, reg);
1506 DB((dbg, LEVEL_1, "%+F set color from %d to %d\n", irn, mirn->init_col, mirn->col));
1509 /* free allocated memory */
1510 del_pqueue(mst_env.chunks);
1511 obstack_free(&mst_env.obst, NULL);
1512 ir_nodemap_destroy(&mst_env.map);
1514 stat_ev_tim_pop("heur4_total");
1519 static const lc_opt_table_entry_t options[] = {
1520 LC_OPT_ENT_INT ("limit", "limit recoloring", &recolor_limit),
1521 LC_OPT_ENT_DBL ("di", "dislike influence", &dislike_influence),
1525 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_copyheur4)
1526 void be_init_copyheur4(void)
1528 lc_opt_entry_t *be_grp = lc_opt_get_grp(firm_opt_get_root(), "be");
1529 lc_opt_entry_t *ra_grp = lc_opt_get_grp(be_grp, "ra");
1530 lc_opt_entry_t *chordal_grp = lc_opt_get_grp(ra_grp, "chordal");
1531 lc_opt_entry_t *co_grp = lc_opt_get_grp(chordal_grp, "co");
1532 lc_opt_entry_t *heur4_grp = lc_opt_get_grp(co_grp, "heur4");
1534 static co_algo_info copyheur = {
1535 co_solve_heuristic_mst, 0
1538 lc_opt_add_table(heur4_grp, options);
1539 be_register_copyopt("heur4", ©heur);
1541 FIRM_DBG_REGISTER(dbg, "firm.be.co.heur4");