2 * Copyright (C) 1995-2007 University of Karlsruhe. All right reserved.
4 * This file is part of libFirm.
6 * This file may be distributed and/or modified under the terms of the
7 * GNU General Public License version 2 as published by the Free Software
8 * Foundation and appearing in the file LICENSE.GPL included in the
9 * packaging of this file.
11 * Licensees holding valid libFirm Professional Edition licenses may use
12 * this file in accordance with the libFirm Commercial License.
13 * Agreement provided with the Software.
15 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
16 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * @brief Interblock liveness analysis.
23 * @author Sebastian Hack
32 #include "iredges_t.h"
34 #include "irprintf_t.h"
37 #include "irnodeset.h"
42 #include "besched_t.h"
45 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
47 #define LV_STD_SIZE 128
48 #define LV_USE_BINARY_SEARCH
49 #undef LV_INTESIVE_CHECKS
51 static INLINE int is_liveness_node(const ir_node *irn)
53 switch(get_irn_opcode(irn)) {
64 int (be_lv_next_irn)(const struct _be_lv_t *lv, const ir_node *bl, unsigned flags, int i)
66 return _be_lv_next_irn(lv, bl, flags, i);
69 const ir_node * (be_lv_get_irn)(const struct _be_lv_t *lv, const ir_node *bl, int i)
71 return _be_lv_get_irn(lv, bl, i);
74 int (be_is_live_in)(const be_lv_t *lv, const ir_node *block, const ir_node *irn)
76 return _be_is_live_xxx(lv, block, irn, be_lv_state_in);
79 int (be_is_live_out)(const be_lv_t *lv, const ir_node *block, const ir_node *irn)
81 return _be_is_live_xxx(lv, block, irn, be_lv_state_out);
84 int (be_is_live_end)(const be_lv_t *lv, const ir_node *block, const ir_node *irn)
86 return _be_is_live_xxx(lv, block, irn, be_lv_state_end);
90 #ifdef LV_USE_BINARY_SEARCH
91 static INLINE unsigned _be_liveness_bsearch(struct _be_lv_info_t *arr, unsigned idx)
93 struct _be_lv_info_t *payload = arr + 1;
95 unsigned n = arr[0].u.head.n_members;
104 if(idx < payload[0].u.node.idx)
107 if(idx > payload[n - 1].u.node.idx)
111 /* start a binary search for the requested node. */
113 int md = lo + ((hi - lo) >> 1);
114 unsigned md_idx = payload[md].u.node.idx;
118 else if(idx < md_idx)
122 assert(payload[res].u.node.idx == idx);
129 #ifdef LV_INTESIVE_CHECKS
132 for(i = res; i < n; ++i)
133 assert(payload[i].u.node.idx >= idx);
135 for(i = 0; i < res; ++i)
136 assert(payload[i].u.node.idx < idx);
146 * This function searches linearly for the node in the array.
148 static INLINE unsigned _be_liveness_bsearch(struct _be_lv_info_t *arr, unsigned idx) {
149 unsigned n = arr[0].u.head.n_members;
152 for(i = 0; i < n; ++i) {
153 if(arr[i + 1].u.node.idx == idx)
161 struct _be_lv_info_node_t *be_lv_get(const struct _be_lv_t *li, const ir_node *bl, const ir_node *irn)
163 struct _be_lv_info_t *irn_live = phase_get_irn_data(&li->ph, bl);
166 unsigned idx = get_irn_idx(irn);
168 /* Get the position of the index in the array. */
169 int pos = _be_liveness_bsearch(irn_live, idx);
171 /* Get the record in question. 1 must be added, since the first record contains information about the array and must be skipped. */
172 struct _be_lv_info_node_t *res = &irn_live[pos + 1].u.node;
174 /* Check, if the irn is in deed in the array. */
182 static struct _be_lv_info_node_t *be_lv_get_or_set(struct _be_lv_t *li, ir_node *bl, ir_node *irn)
184 struct _be_lv_info_t *irn_live = phase_get_or_set_irn_data(&li->ph, bl);
186 unsigned idx = get_irn_idx(irn);
188 /* Get the position of the index in the array. */
189 unsigned pos = _be_liveness_bsearch(irn_live, idx);
191 /* Get the record in question. 1 must be added, since the first record contains information about the array and must be skipped. */
192 struct _be_lv_info_node_t *res = &irn_live[pos + 1].u.node;
194 /* Check, if the irn is in deed in the array. */
195 if(res->idx != idx) {
196 struct _be_lv_info_t *payload;
197 unsigned n_members = irn_live[0].u.head.n_members;
198 unsigned n_size = irn_live[0].u.head.n_size;
201 if(n_members == n_size - 1) {
202 unsigned new_size = 2 * n_size * sizeof(irn_live[0]);
203 struct _be_lv_info_t *nw = phase_alloc(&li->ph, new_size);
204 memcpy(nw, irn_live, new_size);
205 nw[0].u.head.n_size = new_size;
207 phase_set_irn_data(&li->ph, irn, nw);
210 payload = &irn_live[1];
211 for(i = n_members; i > pos; --i) {
212 payload[i] = payload[i - 1];
215 ++irn_live[0].u.head.n_members;
217 res = &payload[pos].u.node;
222 #ifdef LV_INTESIVE_CHECKS
225 unsigned n = irn_live[0].u.head.n_members;
227 struct _be_lv_info_t *payload = &irn_live[1];
229 for(i = 0; i < n; ++i) {
230 assert(payload[i].u.node.idx >= last);
231 last = payload[i].u.node.idx;
240 * Removes a node from the list of live variables of a block.
241 * @return 1 if the node was live at that block, 0 if not.
243 static int be_lv_remove(struct _be_lv_t *li, ir_node *bl, ir_node *irn)
245 struct _be_lv_info_t *irn_live = phase_get_irn_data(&li->ph, bl);
248 unsigned n = irn_live[0].u.head.n_members;
249 unsigned idx = get_irn_idx(irn);
250 unsigned pos = _be_liveness_bsearch(irn_live, idx);
251 struct _be_lv_info_t *payload = irn_live + 1;
252 struct _be_lv_info_node_t *res = &payload[pos].u.node;
254 /* The node is in deed in the block's array. Let's remove it. */
255 if(res->idx == idx) {
258 for(i = pos + 1; i < n; ++i)
259 payload[i - 1] = payload[i];
261 payload[n - 1].u.node.idx = 0;
262 payload[n - 1].u.node.flags = 0;
264 --irn_live[0].u.head.n_members;
265 DBG((dbg, LEVEL_3, "\tdeleting %+F from %+F at pos %d\n", irn, bl, pos));
273 static void register_node(be_lv_t *lv, const ir_node *irn)
275 unsigned idx = get_irn_idx(irn);
276 if(idx >= bitset_size(lv->nodes)) {
277 bitset_t *nw = bitset_malloc(2 * idx);
278 bitset_copy(nw, lv->nodes);
279 bitset_free(lv->nodes);
283 bitset_set(lv->nodes, idx);
287 * Mark a node as live-in in a block.
289 static INLINE void mark_live_in(be_lv_t *lv, ir_node *block, ir_node *irn)
291 struct _be_lv_info_node_t *n = be_lv_get_or_set(lv, block, irn);
292 DBG((dbg, LEVEL_2, "marking %+F live in at %+F\n", irn, block));
293 n->flags |= be_lv_state_in;
294 register_node(lv, irn);
298 * Mark a node as live-out in a block.
300 static INLINE void mark_live_out(be_lv_t *lv, ir_node *block, ir_node *irn)
302 struct _be_lv_info_node_t *n = be_lv_get_or_set(lv, block, irn);
303 DBG((dbg, LEVEL_2, "marking %+F live out at %+F\n", irn, block));
304 n->flags |= be_lv_state_out | be_lv_state_end;
305 register_node(lv, irn);
309 * Mark a node as live-end in a block.
311 static INLINE void mark_live_end(be_lv_t *lv, ir_node *block, ir_node *irn)
313 struct _be_lv_info_node_t *n = be_lv_get_or_set(lv, block, irn);
314 DBG((dbg, LEVEL_2, "marking %+F live end at %+F\n", irn, block));
315 n->flags |= be_lv_state_end;
316 register_node(lv, irn);
320 * Mark a node (value) live out at a certain block. Do this also
321 * transitively, i.e. if the block is not the block of the value's
322 * definition, all predecessors are also marked live.
323 * @param def The node (value).
324 * @param block The block to mark the value live out of.
325 * @param visited A set were all visited blocks are recorded.
326 * @param is_true_out Is the node real out there or only live at the end
329 static void live_end_at_block(be_lv_t *lv, ir_node *def, ir_node *block, bitset_t *visited, int is_true_out)
331 mark_live_end(lv, block, def);
333 mark_live_out(lv, block, def);
335 if(!bitset_contains_irn(visited, block)) {
336 bitset_add_irn(visited, block);
339 * If this block is not the definition block, we have to go up
342 if(get_nodes_block(def) != block) {
345 mark_live_in(lv, block, def);
347 for(i = 0, n = get_Block_n_cfgpreds(block); i < n; ++i)
348 live_end_at_block(lv, def, get_Block_cfgpred_block(block, i), visited, 1);
354 struct _lv_walker_t {
360 * Liveness analysis for a value.
361 * This functions is meant to be called by a firm walker, to compute the
362 * set of all blocks a value is live in.
363 * @param irn The node (value).
364 * @param env Ignored.
366 static void liveness_for_node(ir_node *irn, void *data)
368 struct _lv_walker_t *walker = data;
369 be_lv_t *lv = walker->lv;
370 bitset_t *visited = walker->data;
371 const ir_edge_t *edge;
374 /* Don't compute liveness information for non-data nodes. */
375 if(!is_liveness_node(irn))
378 bitset_clear_all(visited);
379 def_block = get_nodes_block(irn);
381 /* Go over all uses of the value */
382 foreach_out_edge(irn, edge) {
383 ir_node *use = edge->src;
387 * If the usage is no data node, skip this use, since it does not
388 * affect the liveness of the node.
390 if(!is_liveness_node(use))
393 /* Get the block where the usage is in. */
394 use_block = get_nodes_block(use);
397 * If the use is a phi function, determine the corresponding block
398 * through which the value reaches the phi function and mark the
399 * value as live out of that block.
402 ir_node *pred_block = get_Block_cfgpred_block(use_block, edge->pos);
403 live_end_at_block(lv, irn, pred_block, visited, 0);
407 * Else, the value is live in at this block. Mark it and call live
408 * out on the predecessors.
410 else if(def_block != use_block) {
413 mark_live_in(lv, use_block, irn);
415 for(i = 0, n = get_Block_n_cfgpreds(use_block); i < n; ++i) {
416 ir_node *pred_block = get_Block_cfgpred_block(use_block, i);
417 live_end_at_block(lv, irn, pred_block, visited, 1);
423 static void lv_remove_irn_walker(ir_node *bl, void *data)
425 struct _lv_walker_t *w = data;
427 ir_node *irn = w->data;
428 be_lv_remove(lv, bl, irn);
431 static const char *lv_flags_to_str(unsigned flags)
433 static const char *states[] = {
444 return states[flags & 7];
447 static void lv_dump_block(void *context, FILE *f, const ir_node *bl)
450 be_lv_t *lv = context;
451 struct _be_lv_info_t *info = phase_get_irn_data(&lv->ph, bl);
453 fprintf(f, "liveness:\n");
455 unsigned n = info[0].u.head.n_members;
458 for(i = 0; i < n; ++i) {
459 struct _be_lv_info_node_t *n = &info[i+1].u.node;
460 ir_fprintf(f, "%s %+F\n", lv_flags_to_str(n->flags), get_idx_irn(lv->irg, n->idx));
466 static void *lv_phase_data_init(ir_phase *phase, ir_node *irn, void *old)
468 struct _be_lv_info_t *info = phase_alloc(phase, LV_STD_SIZE * sizeof(info[0]));
469 memset(info, 0, LV_STD_SIZE * sizeof(info[0]));
470 info[0].u.head.n_size = LV_STD_SIZE - 1;
474 static void compute_liveness(be_lv_t *lv)
476 struct _lv_walker_t w;
478 w.data = bitset_malloc(get_irg_last_idx(lv->irg));
479 irg_walk_graph(lv->irg, liveness_for_node, NULL, &w);
483 /* Compute the inter block liveness for a graph. */
484 be_lv_t *be_liveness(ir_graph *irg)
486 be_lv_t *lv = xmalloc(sizeof(lv[0]));
488 memset(lv, 0, sizeof(lv[0]));
490 lv->nodes = bitset_malloc(2 * get_irg_last_idx(irg));
491 lv->hook_info.context = lv;
492 lv->hook_info.hook._hook_node_info = lv_dump_block;
493 register_hook(hook_node_info, &lv->hook_info);
494 phase_init(&lv->ph, "liveness", irg, PHASE_DEFAULT_GROWTH, lv_phase_data_init, NULL);
495 compute_liveness(lv);
500 void be_liveness_recompute(be_lv_t *lv)
502 unsigned last_idx = get_irg_last_idx(lv->irg);
503 if(last_idx >= bitset_size(lv->nodes)) {
504 bitset_free(lv->nodes);
505 lv->nodes = bitset_malloc(last_idx * 2);
509 bitset_clear_all(lv->nodes);
512 phase_init(&lv->ph, "liveness", lv->irg, PHASE_DEFAULT_GROWTH, lv_phase_data_init, NULL);
513 compute_liveness(lv);
517 void be_liveness_free(be_lv_t *lv)
519 unregister_hook(hook_node_info, &lv->hook_info);
521 bitset_free(lv->nodes);
525 void be_liveness_remove(be_lv_t *lv, ir_node *irn)
527 unsigned idx = get_irn_idx(irn);
528 struct _lv_walker_t w;
531 * Removes a single irn from the liveness information.
532 * Since an irn can only be live at blocks dominated by the block of its
533 * definition, we only have to process that dominance subtree.
537 dom_tree_walk(get_nodes_block(irn), lv_remove_irn_walker, NULL, &w);
538 if(idx < bitset_size(lv->nodes))
539 bitset_clear(lv->nodes, idx);
542 void be_liveness_introduce(be_lv_t *lv, ir_node *irn)
544 struct _lv_walker_t w;
546 w.data = bitset_malloc(get_irg_last_idx(lv->irg));
547 liveness_for_node(irn, &w);
551 void be_liveness_update(be_lv_t *lv, ir_node *irn)
553 be_liveness_remove(lv, irn);
554 be_liveness_introduce(lv, irn);
557 static void lv_add_missing_walker(ir_node *irn, void *data)
559 struct _lv_walker_t *w = data;
560 if(!is_Block(irn) && !bitset_contains_irn(w->lv->nodes, irn)) {
561 liveness_for_node(irn, w);
565 void be_liveness_add_missing(be_lv_t *lv)
567 struct _lv_walker_t w;
569 w.data = bitset_malloc(get_irg_last_idx(lv->irg));
570 irg_walk_graph(lv->irg, lv_add_missing_walker, NULL, &w);
574 static void lv_check_walker(ir_node *bl, void *data)
576 struct _lv_walker_t *w = data;
578 be_lv_t *fresh = w->data;
580 struct _be_lv_info_t *curr = phase_get_irn_data(&lv->ph, bl);
581 struct _be_lv_info_t *fr = phase_get_irn_data(&fresh->ph, bl);
583 if(!fr && curr && curr[0].u.head.n_members > 0) {
586 ir_fprintf(stderr, "%+F liveness should be empty but current liveness contains:\n", bl);
587 for(i = 0; i < curr[0].u.head.n_members; ++i) {
588 ir_fprintf(stderr, "\t%+F\n", get_idx_irn(lv->irg, curr[1 + i].u.node.idx));
593 unsigned n_curr = curr[0].u.head.n_members;
594 unsigned n_fresh = fr[0].u.head.n_members;
598 if(n_curr != n_fresh) {
599 ir_fprintf(stderr, "%+F: liveness set sizes differ. curr %d, correct %d\n", bl, n_curr, n_fresh);
601 ir_fprintf(stderr, "current:\n");
602 for(i = 0; i < n_curr; ++i) {
603 struct _be_lv_info_node_t *n = &curr[1 + i].u.node;
604 ir_fprintf(stderr, "%+F %u %+F %s\n", bl, i, get_idx_irn(lv->irg, n->idx), lv_flags_to_str(n->flags));
607 ir_fprintf(stderr, "correct:\n");
608 for(i = 0; i < n_fresh; ++i) {
609 struct _be_lv_info_node_t *n = &fr[1 + i].u.node;
610 ir_fprintf(stderr, "%+F %u %+F %s\n", bl, i, get_idx_irn(lv->irg, n->idx), lv_flags_to_str(n->flags));
616 void be_liveness_check(be_lv_t *lv)
618 struct _lv_walker_t w;
619 be_lv_t *fresh = be_liveness(lv->irg);
623 irg_block_walk_graph(lv->irg, lv_check_walker, NULL, &w);
624 be_liveness_free(fresh);
628 static void lv_dump_block_walker(ir_node *irn, void *data)
630 struct _lv_walker_t *w = data;
632 lv_dump_block(w->lv, w->data, irn);
636 /* Dump the liveness information for a graph. */
637 void be_liveness_dump(const be_lv_t *lv, FILE *f)
639 struct _lv_walker_t w;
641 w.lv = (be_lv_t *) lv;
643 irg_block_walk_graph(lv->irg, lv_dump_block_walker, NULL, &w);
646 /* Dump the liveness information for a graph. */
647 void be_liveness_dumpto(const be_lv_t *lv, const char *cls_name)
651 ir_snprintf(buf, sizeof(buf), "%F_%s-live.txt", lv->irg, cls_name);
652 if((f = fopen(buf, "wt")) != NULL) {
653 be_liveness_dump(lv, f);
659 * Walker: checks the every predecessors of a node dominate
662 static void dom_check(ir_node *irn, void *data)
664 int *problem_found = data;
666 if(!is_Block(irn) && irn != get_irg_end(get_irn_irg(irn))) {
668 ir_node *bl = get_nodes_block(irn);
670 for(i = 0, n = get_irn_arity(irn); i < n; ++i) {
671 ir_node *op = get_irn_n(irn, i);
672 ir_node *def_bl = get_nodes_block(op);
673 ir_node *use_bl = bl;
676 use_bl = get_Block_cfgpred_block(bl, i);
678 if(get_irn_opcode(use_bl) != iro_Bad
679 && get_irn_opcode(def_bl) != iro_Bad
680 && !block_dominates(def_bl, use_bl)) {
681 ir_fprintf(stderr, "Verify warning: %+F in %+F must dominate %+F for user %+F (%s)\n", op, def_bl, use_bl, irn, get_irg_dump_name(get_irn_irg(op)));
688 /* Check, if the SSA dominance property is fulfilled. */
689 int be_check_dominance(ir_graph *irg)
691 int problem_found = 0;
694 irg_walk_graph(irg, dom_check, NULL, &problem_found);
696 return !problem_found;
699 pset *be_liveness_transfer(const arch_env_t *arch_env, const arch_register_class_t *cls, ir_node *irn, pset *live)
703 /* You should better break out of your loop when hitting the first phi function. */
704 assert(!is_Phi(irn) && "liveness_transfer produces invalid results for phi nodes");
706 if(arch_irn_consider_in_reg_alloc(arch_env, cls, irn)) {
707 ir_node *del = pset_remove_ptr(live, irn);
712 for(i = 0, n = get_irn_arity(irn); i < n; ++i) {
713 ir_node *op = get_irn_n(irn, i);
715 if(arch_irn_consider_in_reg_alloc(arch_env, cls, op))
716 pset_insert_ptr(live, op);
722 void be_liveness_transfer_ir_nodeset(const arch_env_t *arch_env,
723 const arch_register_class_t *cls,
724 ir_node *node, ir_nodeset_t *nodeset)
728 /* You should better break out of your loop when hitting the first phi
730 assert(!is_Phi(node) && "liveness_transfer produces invalid results for phi nodes");
732 if(arch_irn_consider_in_reg_alloc(arch_env, cls, node)) {
733 ir_nodeset_remove(nodeset, node);
736 arity = get_irn_arity(node);
737 for(i = 0; i < arity; ++i) {
738 ir_node *op = get_irn_n(node, i);
740 if(arch_irn_consider_in_reg_alloc(arch_env, cls, op))
741 ir_nodeset_insert(nodeset, op);
747 pset *be_liveness_end_of_block(const be_lv_t *lv, const arch_env_t *arch_env, const arch_register_class_t *cls, const ir_node *bl, pset *live)
750 be_lv_foreach(lv, bl, be_lv_state_end, i) {
751 ir_node *irn = be_lv_get_irn(lv, bl, i);
752 if(arch_irn_consider_in_reg_alloc(arch_env, cls, irn))
753 pset_insert_ptr(live, irn);
759 void be_liveness_end_of_block_ir_nodeset(const be_lv_t *lv,
760 const arch_env_t *arch_env,
761 const arch_register_class_t *cls,
762 const ir_node *block,
767 be_lv_foreach(lv, block, be_lv_state_end, i) {
768 ir_node *node = be_lv_get_irn(lv, block, i);
769 if(!arch_irn_consider_in_reg_alloc(arch_env, cls, node))
772 ir_nodeset_insert(live, node);
778 pset *be_liveness_nodes_live_at(const be_lv_t *lv, const arch_env_t *arch_env, const arch_register_class_t *cls, const ir_node *pos, pset *live)
780 const ir_node *bl = is_Block(pos) ? pos : get_nodes_block(pos);
783 be_liveness_end_of_block(lv, arch_env, cls, bl, live);
784 sched_foreach_reverse(bl, irn) {
786 * If we encounter the node we want to insert the Perm after,
787 * exit immediately, so that this node is still live
792 be_liveness_transfer(arch_env, cls, irn, live);
798 pset *be_liveness_nodes_live_at_input(const be_lv_t *lv, const arch_env_t *arch_env, const arch_register_class_t *cls, const ir_node *pos, pset *live)
800 const ir_node *bl = is_Block(pos) ? pos : get_nodes_block(pos);
803 be_liveness_end_of_block(lv, arch_env, cls, bl, live);
804 sched_foreach_reverse(bl, irn) {
805 be_liveness_transfer(arch_env, cls, irn, live);
813 static void collect_node(ir_node *irn, void *data)
815 struct obstack *obst = data;
816 obstack_ptr_grow(obst, irn);
819 void be_live_chk_compare(be_irg_t *birg)
821 ir_graph *irg = be_get_birg_irg(birg);
830 be_assure_liveness(birg);
831 be_assure_liveness_chk(birg);
832 lv = be_get_birg_liveness(birg);
833 lvc = be_get_birg_liveness_chk(birg);
837 irg_block_walk_graph(irg, collect_node, NULL, &obst);
838 obstack_ptr_grow(&obst, NULL);
839 blocks = obstack_finish(&obst);
841 irg_walk_graph(irg, collect_node, NULL, &obst);
842 obstack_ptr_grow(&obst, NULL);
843 nodes = obstack_finish(&obst);
845 for (i = 0; blocks[i]; ++i) {
846 ir_node *bl = blocks[i];
848 for (j = 0; nodes[j]; ++j) {
849 ir_node *irn = nodes[j];
850 if (!is_Block(irn)) {
851 int lvr_in = be_is_live_in (lv, bl, irn);
852 int lvr_out = be_is_live_out(lv, bl, irn);
853 int lvr_end = be_is_live_end(lv, bl, irn);
855 int lvc_in = lv_chk_bl_in (lvc, bl, irn);
856 int lvc_out = lv_chk_bl_out(lvc, bl, irn);
857 int lvc_end = lv_chk_bl_end(lvc, bl, irn);
859 if (lvr_in - lvc_in != 0)
860 ir_fprintf(stderr, "live in info for %+F at %+F differs: nml: %d, chk: %d\n", irn, bl, lvr_in, lvc_in);
862 if (lvr_end - lvc_end != 0)
863 ir_fprintf(stderr, "live end info for %+F at %+F differs: nml: %d, chk: %d\n", irn, bl, lvr_end, lvc_end);
865 if (lvr_out - lvc_out != 0)
866 ir_fprintf(stderr, "live out info for %+F at %+F differs: nml: %d, chk: %d\n", irn, bl, lvr_out, lvc_out);
872 obstack_free(&obst, NULL);
875 void be_init_live(void)
877 FIRM_DBG_REGISTER(dbg, "firm.be.liveness");
880 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_live);