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 Combining congruent blocks
23 * @author Michael Beck
25 * This phase find congruent blocks.
26 * Two block are congruent, if they contains only equal calculations.
30 #include "iroptimize.h"
33 #include "irgraph_t.h"
44 /* define this for general block shaping: congruent blocks
45 are found not only before the end block but anywhere in the graph */
48 typedef struct partition_t partition_t;
49 typedef struct block_t block_t;
50 typedef struct node_t node_t;
51 typedef struct pair_t pair_t;
52 typedef struct phi_t phi_t;
53 typedef struct opcode_key_t opcode_key_t;
54 typedef struct listmap_entry_t listmap_entry_t;
55 typedef struct environment_t environment_t;
56 typedef struct pred_t pred_t;
58 /** An opcode map key. */
60 unsigned code; /**< The Firm opcode. */
61 ir_mode *mode; /**< The mode of all nodes in the partition. */
62 int arity; /**< The arity of this opcode (needed for Phi etc. */
64 long proj; /**< For Proj nodes, its proj number */
65 ir_entity *ent; /**< For Sel nodes, its entity */
66 ir_tarval *tv; /**< For Const nodes, its tarval */
67 symconst_symbol sym; /**< For SymConst nodes, its symbol .*/
68 void *addr; /**< Alias all addresses. */
69 int intVal; /**< For Conv/Div nodes: strict/remainderless. */
73 /** A partition contains all congruent blocks. */
75 list_head part_list; /**< Double linked list of partitions. */
76 list_head blocks; /**< List of blocks in this partition. */
77 unsigned n_blocks; /**< Number of block in this partition. */
78 ir_node *meet_block; /**< The control flow meet block of this partition. */
80 unsigned nr; /**< For debugging: number of this partition. */
86 list_head block_list; /**< Double linked list of block inside a partition. */
87 list_head nodes; /**< Wait-queue of nodes that must be checked for congruence. */
88 block_t *next; /**< Next block of a split list. */
89 ir_node *block; /**< Pointer to the associated IR-node block. */
90 ir_node **roots; /**< An array of all root nodes. */
91 node_t *cf_root; /**< The control flow root node of this block. */
92 pair_t *input_pairs; /**< The list of inputs to this block. */
93 phi_t *phis; /**< The list of Phis in this block. */
94 block_t *all_next; /**< Links all created blocks. */
95 int meet_input; /**< Input number of this block in the meet-block. */
100 list_head node_list; /**< Double linked list of block inside a partition. */
101 ir_node *node; /**< Pointer to the associated IR-node or NULL for block inputs. */
102 char is_input; /**< Set if this node is an input from other block. */
105 /** The environment. */
106 struct environment_t {
107 list_head partitions; /**< list of partitions. */
108 list_head ready; /**< list of ready partitions. */
109 set *opcode2id_map; /**< The opcodeMode->id map. */
110 ir_node **live_outs; /**< Live out only nodes. */
111 block_t *all_blocks; /**< List of all created blocks. */
112 struct obstack obst; /** obstack for temporary data */
115 /** A (node, input index) pair. */
117 pair_t *next; /**< Points to the next pair entry. */
118 ir_node *irn; /**< The IR-node. */
119 int index; /**< An input index. */
120 ir_node **ins; /**< A new in array once allocated. */
123 /** A Phi, inputs pair. */
125 phi_t *next; /**< Points to the next Phi pair entry. */
126 ir_node *phi; /**< The Phi node. */
127 ir_node **ins; /**< A new in array once allocated. */
130 /** Describes a predecessor input. */
132 ir_node *pred; /**< The predecessor. */
133 int index; /**< Its input index. */
137 * An entry in the list_map.
139 struct listmap_entry_t {
140 void *id; /**< The id. */
141 block_t *list; /**< The associated list for this id. */
142 listmap_entry_t *next; /**< Link to the next entry in the map. */
145 /** We must map id's to lists. */
146 typedef struct listmap_t {
147 set *map; /**< Map id's to listmap_entry_t's */
148 listmap_entry_t *values; /**< List of all values in the map. */
151 #define get_Block_entry(block) ((block_t *)get_irn_link(block))
153 /** The debug module handle. */
154 DEBUG_ONLY(static firm_dbg_module_t *dbg;)
156 /** Next partition number. */
157 DEBUG_ONLY(static unsigned part_nr = 0;)
161 * Dump partition to output.
163 static void dump_partition(const char *msg, const partition_t *part)
167 DB((dbg, LEVEL_2, " %s part%u (%u blocks) {\n ", msg, part->nr, part->n_blocks));
168 list_for_each_entry(block_t, block, &part->blocks, block_list) {
169 DB((dbg, LEVEL_2, "%s%+F", first ? "" : ", ", block->block));
172 DB((dbg, LEVEL_2, "\n }\n"));
173 } /* dump_partition */
178 static void dump_list(const char *msg, const block_t *block)
183 DB((dbg, LEVEL_3, " %s = {\n ", msg));
184 for (p = block; p != NULL; p = p->next) {
185 DB((dbg, LEVEL_3, "%s%+F", first ? "" : ", ", p->block));
188 DB((dbg, LEVEL_3, "\n }\n"));
191 #define dump_partition(msg, part)
192 #define dump_list(msg, block)
196 * Compare two pointer values of a listmap.
198 static int listmap_cmp_ptr(const void *elt, const void *key, size_t size)
200 const listmap_entry_t *e1 = (const listmap_entry_t*)elt;
201 const listmap_entry_t *e2 = (const listmap_entry_t*)key;
204 return e1->id != e2->id;
205 } /* listmap_cmp_ptr */
208 * Initializes a listmap.
210 * @param map the listmap
212 static void listmap_init(listmap_t *map)
214 map->map = new_set(listmap_cmp_ptr, 16);
219 * Terminates a listmap.
221 * @param map the listmap
223 static void listmap_term(listmap_t *map)
229 * Return the associated listmap entry for a given id.
231 * @param map the listmap
232 * @param id the id to search for
234 * @return the associated listmap entry for the given id
236 static listmap_entry_t *listmap_find(listmap_t *map, void *id)
238 listmap_entry_t key, *entry;
243 entry = set_insert(listmap_entry_t, map->map, &key, sizeof(key), hash_ptr(id));
245 if (entry->list == NULL) {
246 /* a new entry, put into the list */
247 entry->next = map->values;
254 * Calculate the hash value for an opcode map entry.
256 * @param entry an opcode map entry
258 * @return a hash value for the given opcode map entry
260 static unsigned opcode_hash(const opcode_key_t *entry)
262 /* assume long >= int */
263 return (unsigned)(PTR_TO_INT(entry->mode) * 9 + entry->code + entry->u.proj * 3 + hash_ptr(entry->u.addr) + entry->arity);
267 * Compare two entries in the opcode map.
269 static int cmp_opcode(const void *elt, const void *key, size_t size)
271 const opcode_key_t *o1 = (opcode_key_t*)elt;
272 const opcode_key_t *o2 = (opcode_key_t*)key;
275 return o1->code != o2->code || o1->mode != o2->mode ||
276 o1->arity != o2->arity ||
277 o1->u.proj != o2->u.proj || o1->u.addr != o2->u.addr;
281 * Creates a new empty partition and put in on the
284 * @param meet_block the control flow meet block of this partition
285 * @param env the environment
287 static partition_t *create_partition(ir_node *meet_block, environment_t *env)
289 partition_t *part = OALLOC(&env->obst, partition_t);
291 INIT_LIST_HEAD(&part->blocks);
292 part->meet_block = meet_block;
294 DEBUG_ONLY(part->nr = part_nr++;)
295 list_add_tail(&part->part_list, &env->partitions);
297 } /* create_partition */
300 * Allocate a new block in the given partition.
302 * @param block the IR-node
303 * @param meet_input Input number of this block in the meet-block
304 * @param partition the partition to add to
305 * @param env the environment
307 static block_t *create_block(ir_node *block, int meet_input, partition_t *partition, environment_t *env)
309 block_t *bl = OALLOC(&env->obst, block_t);
311 set_irn_link(block, bl);
313 INIT_LIST_HEAD(&bl->nodes);
316 bl->roots = NEW_ARR_F(ir_node *, 0);
318 bl->input_pairs = NULL;
320 bl->meet_input = meet_input;
322 /* put it into the list of partition blocks */
323 list_add_tail(&bl->block_list, &partition->blocks);
324 ++partition->n_blocks;
326 /* put in into the list of all blocks */
327 bl->all_next = env->all_blocks;
328 env->all_blocks = bl;
334 * Allocate a new node and add it to a blocks wait queue.
336 * @param irn the IR-node
337 * @param block the block to add to
338 * @param env the environment
340 static node_t *create_node(ir_node *irn, block_t *block, environment_t *env)
342 node_t *node = OALLOC(&env->obst, node_t);
347 list_add_tail(&node->node_list, &block->nodes);
353 * Add an input pair to a block.
355 * @param block the block
356 * @param irn the IR-node that has an block input
357 * @param idx the index of the block input in node's predecessors
358 * @param env the environment
360 static void add_pair(block_t *block, ir_node *irn, int idx, environment_t *env)
362 pair_t *pair = OALLOC(&env->obst, pair_t);
364 pair->next = block->input_pairs;
369 block->input_pairs = pair;
373 * Add a Phi to a block.
375 * @param block the block
376 * @param phi the Phi node
377 * @param env the environment
379 static void add_phi(block_t *block, ir_node *phi, environment_t *env)
381 phi_t *node = OALLOC(&env->obst, phi_t);
383 node->next = block->phis;
391 * Creates an opcode from a node.
393 static opcode_key_t *opcode(const node_t *node, environment_t *env)
395 opcode_key_t key, *entry;
396 ir_node *irn = node->node;
398 if (node->is_input) {
399 /* Node: as Block nodes are never propagated, it is safe to
400 use its code for "input" node */
401 key.code = iro_Block;
404 key.code = get_irn_opcode(irn);
405 key.arity = get_irn_arity(irn);
407 key.mode = get_irn_mode(node->node);
413 key.u.proj = get_Proj_proj(irn);
416 key.u.ent = get_Sel_entity(irn);
419 key.u.sym = get_SymConst_symbol(irn);
422 key.u.tv = get_Const_tarval(irn);
425 key.u.intVal = get_Conv_strict(irn);
428 key.mode = get_Load_mode(irn);
431 key.u.intVal = get_Div_no_remainder(irn);
434 key.u.intVal = get_Builtin_kind(irn);
440 entry = set_insert(opcode_key_t, env->opcode2id_map, &key, sizeof(key), opcode_hash(&key));
445 * Split a partition by a local list.
447 * @param Z partition to split
448 * @param g a (non-empty) block list
449 * @param env the environment
451 * @return a new partition containing the nodes of g
453 static partition_t *split(partition_t *Z, block_t *g, environment_t *env)
455 partition_t *Z_prime;
459 dump_partition("Splitting ", Z);
460 dump_list("by list ", g);
464 /* Remove g from Z. */
465 for (block = g; block != NULL; block = block->next) {
466 list_del(&block->block_list);
469 assert(n < Z->n_blocks);
472 /* Move g to a new partition, Z'. */
473 Z_prime = create_partition(Z->meet_block, env);
474 for (block = g; block != NULL; block = block->next) {
475 list_add_tail(&block->block_list, &Z_prime->blocks);
477 Z_prime->n_blocks = n;
479 dump_partition("Now ", Z);
480 dump_partition("Created new ", Z_prime);
485 * Return non-zero if pred should be tread as a input node.
487 static int is_input_node(ir_node *pred, ir_node *irn, int index)
489 /* for now, do NOT turn direct calls into indirect one */
492 if (! is_SymConst_addr_ent(pred))
497 } /* is_input_node */
500 * Propagate nodes on all wait queues of the given partition.
502 * @param part the partition
503 * @param env the environment
505 static void propagate_blocks(partition_t *part, environment_t *env)
507 block_t *ready_blocks = NULL;
508 unsigned n_ready = 0;
510 listmap_entry_t *iter;
512 DB((dbg, LEVEL_2, " Propagate blocks on part%u\n", part->nr));
514 /* Let map be an empty mapping from the range of Opcodes to (local) list of blocks. */
516 list_for_each_entry_safe(block_t, bl, next, &part->blocks, block_list) {
518 listmap_entry_t *entry;
521 if (list_empty(&bl->nodes)) {
522 bl->next = ready_blocks;
525 DB((dbg, LEVEL_2, " Block %+F completely processed\n", bl->block));
529 /* get the first node from the wait queue */
530 node = list_entry(bl->nodes.next, node_t, node_list);
531 list_del(&node->node_list);
533 /* put all not-visited predecessors to the wait queue */
534 if (! node->is_input) {
535 ir_node *irn = node->node;
538 DB((dbg, LEVEL_3, " propagate %+F\n", irn));
539 ir_normalize_node(node->node);
540 for (i = get_irn_arity(irn) - 1; i >= 0; --i) {
541 ir_node *pred = get_irn_n(irn, i);
542 ir_node *block = get_nodes_block(skip_Proj(pred));
545 if (block != bl->block) {
546 p_node = create_node(pred, bl, env);
547 if (is_input_node(pred, irn, i)) {
548 /* is a block live input */
549 p_node->is_input = 1;
551 add_pair(bl, irn, i, env);
552 } else if (is_Phi(pred)) {
553 /* update the Phi list */
554 add_phi(bl, pred, env);
556 } else if (! irn_visited_else_mark(pred)) {
557 /* not yet visited, ok */
558 p_node = create_node(pred, bl, env);
561 /* update the Phi list */
562 add_phi(bl, pred, env);
567 DB((dbg, LEVEL_3, " propagate Input %+F\n", node->node));
570 /* Add bl to map[opcode(n)]. */
571 id = opcode(node, env);
572 entry = listmap_find(&map, id);
573 bl->next = entry->list;
577 /* split out ready blocks */
581 if (n_ready < part->n_blocks)
582 Z = split(part, ready_blocks, env);
585 list_del(&Z->part_list);
587 if (Z->n_blocks > 1) {
588 DB((dbg, LEVEL_2, " Partition %u is ready\n", Z->nr));
589 list_add(&Z->part_list, &env->ready);
591 DB((dbg, LEVEL_2, " Partition %u contains only one block, killed\n", Z->nr));
595 /* for all sets S except one in the range of map do */
596 for (iter = map.values; iter != NULL; iter = iter->next) {
599 if (iter->next == NULL) {
600 /* this is the last entry, ignore */
605 /* Add SPLIT( X, S ) to P. */
609 } /* propagate_blocks */
612 * Propagate nodes on all wait queues.
614 * @param env the environment
616 static void propagate(environment_t *env)
618 list_for_each_entry_safe(partition_t, part, next, &env->partitions, part_list) {
619 if (part->n_blocks < 2) {
620 /* zero or one block left, kill this partition */
621 list_del(&part->part_list);
622 DB((dbg, LEVEL_2, " Partition %u contains less than 2 blocks, killed\n", part->nr));
624 propagate_blocks(part, env);
629 * Map a block to the phi[block->input] live-trough.
631 static void *live_throughs(const block_t *bl, const ir_node *phi)
633 ir_node *input = get_Phi_pred(phi, bl->meet_input);
635 /* If this input is inside our block, this
636 is a live-out and not a live trough.
637 Live-outs are tested inside propagate, so map all of
638 them to the "general" value NULL */
639 if (get_nodes_block(input) == bl->block)
642 } /* live_throughs */
645 * Split partition by live-outs and live-troughs.
647 * @param part the partition
648 * @param env the environment
650 static void propagate_blocks_live_troughs(partition_t *part, environment_t *env)
652 const ir_node *meet_block = part->meet_block;
654 listmap_entry_t *iter;
657 DB((dbg, LEVEL_2, " Propagate live-troughs on part%u\n", part->nr));
659 for (phi = get_Block_phis(meet_block); phi != NULL; phi = get_Phi_next(phi)) {
660 /* propagate on all Phis of the meet-block */
662 if (part->n_blocks < 2) {
663 /* zero or one block left, kill this partition */
664 list_del(&part->part_list);
665 DB((dbg, LEVEL_2, " Partition %u contains less than 2 blocks, killed\n", part->nr));
669 /* Let map be an empty mapping from the range of live-troughs to (local) list of blocks. */
671 list_for_each_entry_safe(block_t, bl, next, &part->blocks, block_list) {
673 listmap_entry_t *entry;
675 /* Add bl to map[live_trough(bl)]. */
676 id = (opcode_key_t*)live_throughs(bl, phi);
677 entry = listmap_find(&map, id);
678 bl->next = entry->list;
682 /* for all sets S except one in the range of map do */
683 for (iter = map.values; iter != NULL; iter = iter->next) {
686 if (iter->next == NULL) {
687 /* this is the last entry, ignore */
692 /* Add SPLIT( X, S ) to P. */
697 } /* propagate_blocks_live_troughs */
700 * Propagate live-troughs on all partitions on the partition list.
702 * @param env the environment
704 static void propagate_live_troughs(environment_t *env)
706 list_for_each_entry_safe(partition_t, part, next, &env->partitions, part_list) {
707 propagate_blocks_live_troughs(part, env);
709 } /* propagate_live_troughs */
712 * Apply analysis results by replacing all blocks of a partition
713 * by one representative.
715 * Route all inputs from all block of the partition to the one
717 * Enhance all existing Phis by combining them.
718 * Create new Phis for all previous input nodes.
720 * @param part the partition to process
722 static void apply(ir_graph *irg, partition_t *part)
724 block_t *repr = list_entry(part->blocks.next, block_t, block_list);
725 ir_node *block, *end, *meet_block, *p, *next;
726 ir_node **ins, **phi_ins;
727 phi_t *repr_phi, *phi;
728 pair_t *repr_pair, *pair;
729 int i, j, k, n, n_phis;
731 list_del(&repr->block_list);
733 /* prepare new in arrays for the block ... */
735 n = get_Block_n_cfgpreds(block);
736 ins = NEW_ARR_F(ir_node *, n);
738 for (i = 0; i < n; ++i) {
739 ins[i] = get_Block_cfgpred(block, i);
742 /* ... for all existing Phis ... */
743 for (repr_phi = repr->phis; repr_phi != NULL; repr_phi = repr_phi->next) {
744 repr_phi->ins = NEW_ARR_F(ir_node *, n);
746 for (i = 0; i < n; ++i)
747 repr_phi->ins[i] = get_Phi_pred(repr_phi->phi, i);
750 /* ... and all newly created Phis */
751 for (repr_pair = repr->input_pairs; repr_pair != NULL; repr_pair = repr_pair->next) {
752 ir_node *input = get_irn_n(repr_pair->irn, repr_pair->index);
754 repr_pair->ins = NEW_ARR_F(ir_node *, n);
755 for (i = 0; i < n; ++i)
756 repr_pair->ins[i] = input;
759 DB((dbg, LEVEL_1, "Replacing "));
761 /* collect new in arrays */
762 end = get_irg_end(irg);
763 list_for_each_entry(block_t, bl, &part->blocks, block_list) {
766 DB((dbg, LEVEL_1, "%+F, ", block));
768 /* first step: kill any keep-alive from this block */
769 for (i = get_End_n_keepalives(end) - 1; i >= 0; --i) {
770 ir_node *ka = get_End_keepalive(end, i);
774 remove_End_keepalive(end, ka);
776 if (get_nodes_block(ka) == block)
777 remove_End_keepalive(end, ka);
781 /* second step: update control flow */
782 n = get_Block_n_cfgpreds(block);
783 for (i = 0; i < n; ++i) {
784 ir_node *pred = get_Block_cfgpred(block, i);
785 ARR_APP1(ir_node *, ins, pred);
788 /* third step: update Phis */
789 for (repr_phi = repr->phis, phi = bl->phis;
791 repr_phi = repr_phi->next, phi = phi->next) {
792 for (i = 0; i < n; ++i) {
793 ir_node *pred = get_Phi_pred(phi->phi, i);
794 ARR_APP1(ir_node *, repr_phi->ins, pred);
798 /* fourth step: update inputs for new Phis */
799 for (repr_pair = repr->input_pairs, pair = bl->input_pairs;
801 repr_pair = repr_pair->next, pair = pair->next) {
802 ir_node *input = get_irn_n(pair->irn, pair->index);
804 for (i = 0; i < n; ++i)
805 ARR_APP1(ir_node *, repr_pair->ins, input);
809 DB((dbg, LEVEL_1, "by %+F\n", repr->block));
811 /* rewire block input ... */
815 * Some problem here. For:
816 * if (x) y = 1; else y = 2;
818 * the following code is constructed:
820 * b0: if (x) goto b1; else goto b1;
823 * However, both predecessors of b1 are b0, making the Phi
826 * We solve this by fixing critical edges.
828 for (i = 0; i < n; ++i) {
829 ir_node *pred = ins[i];
835 cfop = get_irn_op(skip_Proj(pred));
836 if (is_op_fragile(cfop)) {
837 /* ignore exception flow */
840 if (is_op_forking(cfop)) {
841 /* a critical edge */
842 ir_node *block = new_r_Block(irg, 1, &ins[i]);
843 ir_node *jmp = new_r_Jmp(block);
849 set_irn_in(block, n, ins);
852 /* ... existing Phis ... */
853 for (repr_phi = repr->phis; repr_phi != NULL; repr_phi = repr_phi->next) {
854 set_irn_in(repr_phi->phi, n, repr_phi->ins);
855 DEL_ARR_F(repr_phi->ins);
858 /* ... and all inputs by creating new Phis ... */
859 for (repr_pair = repr->input_pairs; repr_pair != NULL; repr_pair = repr_pair->next) {
860 ir_node *input = get_irn_n(repr_pair->irn, repr_pair->index);
861 ir_mode *mode = get_irn_mode(input);
862 ir_node *phi = new_r_Phi(block, n, repr_pair->ins, mode);
864 set_irn_n(repr_pair->irn, repr_pair->index, phi);
865 DEL_ARR_F(repr_pair->ins);
867 /* might be optimized away */
869 add_Block_phi(block, phi);
872 /* ... finally rewire the meet block and fix its Phi-nodes */
873 meet_block = part->meet_block;
874 n = get_Block_n_cfgpreds(meet_block);
876 ins = NEW_ARR_F(ir_node *, n);
879 for (p = get_Block_phis(meet_block); p != NULL; p = get_Phi_next(p)) {
883 phi_ins = NEW_ARR_F(ir_node *, n_phis * n);
885 for (i = j = 0; i < n; ++i) {
886 ir_node *pred = get_Block_cfgpred(meet_block, i);
888 list_for_each_entry(block_t, bl, &part->blocks, block_list) {
889 if (bl->cf_root->node == pred)
894 for (k = 0, p = get_Block_phis(meet_block); p != NULL; p = get_Phi_next(p), ++k) {
895 phi_ins[k * n + j] = get_Phi_pred(p, i);
905 for (k = 0, p = get_Block_phis(meet_block); p != NULL; p = next, ++k) {
906 next = get_Phi_next(p);
908 exchange(p, phi_ins[k * n]);
910 /* all Phis killed */
911 set_Block_phis(meet_block, NULL);
913 for (k = 0, p = get_Block_phis(meet_block); p != NULL; p = next, ++k) {
914 next = get_Phi_next(p);
916 set_irn_in(p, j, &phi_ins[k * n]);
921 /* fix inputs of the meet block */
922 set_irn_in(meet_block, j, ins);
927 * Create a partition for a the end block.
929 * @param end_block the end block
930 * @param env the environment
932 static void partition_for_end_block(ir_node *end_block, environment_t *env)
934 partition_t *part = create_partition(end_block, env);
938 /* collect normal blocks */
939 for (i = get_Block_n_cfgpreds(end_block) - 1; i >= 0; --i) {
940 ir_node *pred = get_Block_cfgpred(end_block, i);
945 mark_irn_visited(pred);
947 block = get_nodes_block(pred);
948 bl = create_block(block, i, part, env);
949 node = create_node(pred, bl, env);
954 /* collect all no-return blocks */
955 end = get_irg_end(get_irn_irg(end_block));
956 for (i = get_End_n_keepalives(end) - 1; i >= 0; --i) {
957 ir_node *ka = get_End_keepalive(end, i);
964 mark_irn_visited(ka);
967 block = get_nodes_block(ka);
968 bl = create_block(block, -1, part, env);
969 node = create_node(ka, bl, env);
974 dump_partition("Created", part);
975 } /* partition_for_end_block */
979 * Create a partition for a given meet block.
981 * @param block the meet block
982 * @param preds array of candidate predecessors
983 * @param n_preds number of elements in preds
984 * @param env the environment
986 static void partition_for_block(ir_node *block, pred_t preds[], int n_preds, environment_t *env)
988 partition_t *part = create_partition(block, env);
991 for (i = n_preds - 1; i >= 0; --i) {
992 ir_node *pred = preds[i].pred;
997 mark_irn_visited(pred);
999 block = get_nodes_block(pred);
1000 bl = create_block(block, preds[i].index, part, env);
1001 node = create_node(pred, bl, env);
1006 dump_partition("Created", part);
1007 } /* partition_for_block */
1010 * Walker: clear the links of all block phi lists and normal
1013 static void clear_phi_links(ir_node *irn, void *env)
1016 if (is_Block(irn)) {
1017 set_Block_phis(irn, NULL);
1018 set_irn_link(irn, NULL);
1020 } /* clear_phi_links */
1023 * Walker, detect live-out nodes.
1025 static void find_liveouts(ir_node *irn, void *ctx)
1027 environment_t *env = (environment_t*)ctx;
1028 ir_node **live_outs = env->live_outs;
1029 ir_node *this_block;
1035 /* ignore Keep-alives */
1039 this_block = get_nodes_block(irn);
1042 /* update the Phi list */
1043 add_Block_phi(this_block, irn);
1046 for (i = get_irn_arity(irn) - 1; i >= 0; --i) {
1047 ir_node *pred_block;
1048 ir_node *pred = get_irn_n(irn, i);
1049 int idx = get_irn_idx(pred);
1051 if (live_outs[idx] != NULL) {
1052 /* already marked as live-out */
1056 pred_block = get_nodes_block(pred);
1057 /* Phi nodes always refer to live-outs */
1058 if (is_Phi(irn) || this_block != pred_block) {
1059 /* pred is a live-out */
1060 live_outs[idx] = pred_block;
1063 } /* find_liveouts */
1066 * Check if the current block is the meet block of its predecessors.
1068 static void check_for_cf_meet(ir_node *block, void *ctx)
1070 environment_t *env = (environment_t*)ctx;
1074 if (block == get_irg_end_block(get_irn_irg(block))) {
1075 /* always create a partition for the end block */
1076 partition_for_end_block(block, env);
1080 n = get_Block_n_cfgpreds(block);
1082 /* Must have at least two predecessors */
1086 NEW_ARR_A(pred_t, preds, n);
1088 for (i = n - 1; i >= 0; --i) {
1089 ir_node *pred = get_Block_cfgpred(block, i);
1091 /* pred must be a direct jump to us */
1092 if (! is_Jmp(pred) && ! is_Raise(pred) && !is_Bad(pred))
1095 preds[k].pred = pred;
1101 partition_for_block(block, preds, k, env);
1102 } /* check_for_cf_meet */
1105 * Compare two nodes for root ordering.
1107 static int cmp_nodes(const void *a, const void *b)
1109 const ir_node *const *pa = (const ir_node*const*)a;
1110 const ir_node *const *pb = (const ir_node*const*)b;
1111 const ir_node *irn_a = *pa;
1112 const ir_node *irn_b = *pb;
1113 unsigned code_a = get_irn_opcode(irn_a);
1114 unsigned code_b = get_irn_opcode(irn_b);
1115 ir_mode *mode_a, *mode_b;
1116 unsigned idx_a, idx_b;
1118 /* try opcode first */
1119 if (code_a != code_b)
1120 return code_a - code_b;
1123 mode_a = get_irn_mode(irn_a);
1124 mode_b = get_irn_mode(irn_b);
1126 if (mode_a != mode_b)
1127 return mode_a < mode_b ? -1 : +1;
1129 /* last resort: index */
1130 idx_a = get_irn_idx(irn_a);
1131 idx_b = get_irn_idx(irn_b);
1133 return (idx_a > idx_b) - (idx_a < idx_b);
1137 * Add the roots to all blocks.
1139 static void add_roots(ir_graph *irg, environment_t *env)
1141 unsigned idx, n = get_irg_last_idx(irg);
1142 ir_node **live_outs = env->live_outs;
1145 for (idx = 0; idx < n; ++idx) {
1146 ir_node *block = live_outs[idx];
1148 if (block != NULL && is_Block(block)) {
1149 block_t *bl = get_Block_entry(block);
1152 ir_node *irn = get_idx_irn(irg, idx);
1154 if (!irn_visited_else_mark(irn)) {
1155 ARR_APP1(ir_node *, bl->roots, irn);
1161 * Now sort the roots to normalize them as good as possible.
1162 * Else, we will split identical blocks if we start which different roots.
1164 for (bl = env->all_blocks; bl != NULL; bl = bl->all_next) {
1165 size_t i, n = ARR_LEN(bl->roots);
1168 /* TODO: is this really needed? The roots are already in
1169 idx-order by construction, which might be good enough. */
1170 qsort(bl->roots, n, sizeof(bl->roots[0]), cmp_nodes);
1173 DB((dbg, LEVEL_2, " Adding Roots for block %+F\n ", bl->block));
1174 /* ok, add them sorted */
1175 for (i = 0; i < n; ++i) {
1176 DB((dbg, LEVEL_2, "%+F, ", bl->roots[i]));
1177 create_node(bl->roots[i], bl, env);
1179 DB((dbg, LEVEL_2, "\n"));
1180 DEL_ARR_F(bl->roots);
1184 #endif /* GENERAL_SHAPE */
1186 /* Combines congruent end blocks into one. */
1187 void shape_blocks(ir_graph *irg)
1193 /* register a debug mask */
1194 FIRM_DBG_REGISTER(dbg, "firm.opt.blocks");
1196 DEBUG_ONLY(part_nr = 0;)
1197 DB((dbg, LEVEL_1, "Shaping blocks for %+F\n", irg));
1199 /* works better, when returns are placed at the end of the blocks */
1200 normalize_n_returns(irg);
1202 obstack_init(&env.obst);
1203 INIT_LIST_HEAD(&env.partitions);
1204 INIT_LIST_HEAD(&env.ready);
1205 env.opcode2id_map = new_set(cmp_opcode, iro_Last * 4);
1207 n = get_irg_last_idx(irg);
1208 env.live_outs = NEW_ARR_F(ir_node *, n);
1209 memset(env.live_outs, 0, sizeof(*env.live_outs) * n);
1211 env.all_blocks = NULL;
1213 ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK | IR_RESOURCE_PHI_LIST);
1215 #ifdef GENERAL_SHAPE
1217 * Detect, which nodes are live-out only: these are the roots of our blocks.
1220 irg_walk_graph(irg, clear_phi_links, find_liveouts, &env);
1223 ir_reserve_resources(irg, IR_RESOURCE_IRN_VISITED);
1225 inc_irg_visited(irg);
1226 #ifdef GENERAL_SHAPE
1228 * Detect all control flow meets and create partitions.
1230 irg_block_walk_graph(irg, NULL, check_for_cf_meet, &env);
1232 /* add root nodes to the partition blocks */
1233 add_roots(irg, &env);
1235 partition_for_end_block(get_irg_end_block(irg), &env);
1238 propagate_live_troughs(&env);
1239 while (! list_empty(&env.partitions))
1242 res = !list_empty(&env.ready);
1243 //if (res) dump_ir_block_graph(irg, "-before");
1246 list_for_each_entry(partition_t, part, &env.ready, part_list) {
1247 dump_partition("Ready Partition", part);
1250 ir_free_resources(irg, IR_RESOURCE_IRN_VISITED | IR_RESOURCE_IRN_LINK | IR_RESOURCE_PHI_LIST);
1253 /* control flow changed */
1254 clear_irg_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_DOMINANCE);
1257 for (bl = env.all_blocks; bl != NULL; bl = bl->all_next) {
1258 DEL_ARR_F(bl->roots);
1261 DEL_ARR_F(env.live_outs);
1262 del_set(env.opcode2id_map);
1263 obstack_free(&env.obst, NULL);
1264 } /* shape_blocks */
1266 ir_graph_pass_t *shape_blocks_pass(const char *name)
1268 return def_graph_pass(name ? name : "shape_blocks", shape_blocks);
1269 } /* shape_blocks_pass */