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"
41 #include "besched_t.h"
44 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
46 #define LV_STD_SIZE 128
47 #define LV_USE_BINARY_SEARCH
48 #undef LV_INTESIVE_CHECKS
50 static INLINE int is_liveness_node(const ir_node *irn)
52 switch(get_irn_opcode(irn)) {
63 int (be_lv_next_irn)(const struct _be_lv_t *lv, const ir_node *bl, unsigned flags, int i)
65 return _be_lv_next_irn(lv, bl, flags, i);
68 const ir_node * (be_lv_get_irn)(const struct _be_lv_t *lv, const ir_node *bl, int i)
70 return _be_lv_get_irn(lv, bl, i);
73 int (be_is_live_in)(const be_lv_t *lv, const ir_node *block, const ir_node *irn)
75 return _be_is_live_xxx(lv, block, irn, be_lv_state_in);
78 int (be_is_live_out)(const be_lv_t *lv, const ir_node *block, const ir_node *irn)
80 return _be_is_live_xxx(lv, block, irn, be_lv_state_out);
83 int (be_is_live_end)(const be_lv_t *lv, const ir_node *block, const ir_node *irn)
85 return _be_is_live_xxx(lv, block, irn, be_lv_state_end);
89 #ifdef LV_USE_BINARY_SEARCH
90 static INLINE unsigned _be_liveness_bsearch(struct _be_lv_info_t *arr, unsigned idx)
92 struct _be_lv_info_t *payload = arr + 1;
94 unsigned n = arr[0].u.head.n_members;
103 if(idx < payload[0].u.node.idx)
106 if(idx > payload[n - 1].u.node.idx)
110 /* start a binary search for the requested node. */
112 int md = lo + ((hi - lo) >> 1);
113 unsigned md_idx = payload[md].u.node.idx;
117 else if(idx < md_idx)
121 assert(payload[res].u.node.idx == idx);
128 #ifdef LV_INTESIVE_CHECKS
131 for(i = res; i < n; ++i)
132 assert(payload[i].u.node.idx >= idx);
134 for(i = 0; i < res; ++i)
135 assert(payload[i].u.node.idx < idx);
145 * This function searches linearly for the node in the array.
147 static INLINE unsigned _be_liveness_bsearch(struct _be_lv_info_t *arr, unsigned idx) {
148 unsigned n = arr[0].u.head.n_members;
151 for(i = 0; i < n; ++i) {
152 if(arr[i + 1].u.node.idx == idx)
160 struct _be_lv_info_node_t *be_lv_get(const struct _be_lv_t *li, const ir_node *bl, const ir_node *irn)
162 struct _be_lv_info_t *irn_live = phase_get_irn_data(&li->ph, bl);
165 unsigned idx = get_irn_idx(irn);
167 /* Get the position of the index in the array. */
168 int pos = _be_liveness_bsearch(irn_live, idx);
170 /* Get the record in question. 1 must be added, since the first record contains information about the array and must be skipped. */
171 struct _be_lv_info_node_t *res = &irn_live[pos + 1].u.node;
173 /* Check, if the irn is in deed in the array. */
181 static struct _be_lv_info_node_t *be_lv_get_or_set(struct _be_lv_t *li, ir_node *bl, ir_node *irn)
183 struct _be_lv_info_t *irn_live = phase_get_or_set_irn_data(&li->ph, bl);
185 unsigned idx = get_irn_idx(irn);
187 /* Get the position of the index in the array. */
188 unsigned pos = _be_liveness_bsearch(irn_live, idx);
190 /* Get the record in question. 1 must be added, since the first record contains information about the array and must be skipped. */
191 struct _be_lv_info_node_t *res = &irn_live[pos + 1].u.node;
193 /* Check, if the irn is in deed in the array. */
194 if(res->idx != idx) {
195 struct _be_lv_info_t *payload;
196 unsigned n_members = irn_live[0].u.head.n_members;
197 unsigned n_size = irn_live[0].u.head.n_size;
200 if(n_members == n_size - 1) {
201 unsigned new_size = 2 * n_size * sizeof(irn_live[0]);
202 struct _be_lv_info_t *nw = phase_alloc(&li->ph, new_size);
203 memcpy(nw, irn_live, new_size);
204 nw[0].u.head.n_size = new_size;
206 phase_set_irn_data(&li->ph, irn, nw);
209 payload = &irn_live[1];
210 for(i = n_members; i > pos; --i) {
211 payload[i] = payload[i - 1];
214 ++irn_live[0].u.head.n_members;
216 res = &payload[pos].u.node;
221 #ifdef LV_INTESIVE_CHECKS
224 unsigned n = irn_live[0].u.head.n_members;
226 struct _be_lv_info_t *payload = &irn_live[1];
228 for(i = 0; i < n; ++i) {
229 assert(payload[i].u.node.idx >= last);
230 last = payload[i].u.node.idx;
239 * Removes a node from the list of live variables of a block.
240 * @return 1 if the node was live at that block, 0 if not.
242 static int be_lv_remove(struct _be_lv_t *li, ir_node *bl, ir_node *irn)
244 struct _be_lv_info_t *irn_live = phase_get_irn_data(&li->ph, bl);
247 unsigned n = irn_live[0].u.head.n_members;
248 unsigned idx = get_irn_idx(irn);
249 unsigned pos = _be_liveness_bsearch(irn_live, idx);
250 struct _be_lv_info_t *payload = irn_live + 1;
251 struct _be_lv_info_node_t *res = &payload[pos].u.node;
253 /* The node is in deed in the block's array. Let's remove it. */
254 if(res->idx == idx) {
257 for(i = pos + 1; i < n; ++i)
258 payload[i - 1] = payload[i];
260 payload[n - 1].u.node.idx = 0;
261 payload[n - 1].u.node.flags = 0;
263 --irn_live[0].u.head.n_members;
264 DBG((dbg, LEVEL_3, "\tdeleting %+F from %+F at pos %d\n", irn, bl, pos));
272 static void register_node(be_lv_t *lv, const ir_node *irn)
274 unsigned idx = get_irn_idx(irn);
275 if(idx >= bitset_size(lv->nodes)) {
276 bitset_t *nw = bitset_malloc(2 * idx);
277 bitset_copy(nw, lv->nodes);
278 bitset_free(lv->nodes);
282 bitset_set(lv->nodes, idx);
286 * Mark a node as live-in in a block.
288 static INLINE void mark_live_in(be_lv_t *lv, ir_node *block, ir_node *irn)
290 struct _be_lv_info_node_t *n = be_lv_get_or_set(lv, block, irn);
291 DBG((dbg, LEVEL_2, "marking %+F live in at %+F\n", irn, block));
292 n->flags |= be_lv_state_in;
293 register_node(lv, irn);
297 * Mark a node as live-out in a block.
299 static INLINE void mark_live_out(be_lv_t *lv, ir_node *block, ir_node *irn)
301 struct _be_lv_info_node_t *n = be_lv_get_or_set(lv, block, irn);
302 DBG((dbg, LEVEL_2, "marking %+F live out at %+F\n", irn, block));
303 n->flags |= be_lv_state_out | be_lv_state_end;
304 register_node(lv, irn);
308 * Mark a node as live-end in a block.
310 static INLINE void mark_live_end(be_lv_t *lv, ir_node *block, ir_node *irn)
312 struct _be_lv_info_node_t *n = be_lv_get_or_set(lv, block, irn);
313 DBG((dbg, LEVEL_2, "marking %+F live end at %+F\n", irn, block));
314 n->flags |= be_lv_state_end;
315 register_node(lv, irn);
319 * Mark a node (value) live out at a certain block. Do this also
320 * transitively, i.e. if the block is not the block of the value's
321 * definition, all predecessors are also marked live.
322 * @param def The node (value).
323 * @param block The block to mark the value live out of.
324 * @param visited A set were all visited blocks are recorded.
325 * @param is_true_out Is the node real out there or only live at the end
328 static void live_end_at_block(be_lv_t *lv, ir_node *def, ir_node *block, bitset_t *visited, int is_true_out)
330 mark_live_end(lv, block, def);
332 mark_live_out(lv, block, def);
334 if(!bitset_contains_irn(visited, block)) {
335 bitset_add_irn(visited, block);
338 * If this block is not the definition block, we have to go up
341 if(get_nodes_block(def) != block) {
344 mark_live_in(lv, block, def);
346 for(i = 0, n = get_Block_n_cfgpreds(block); i < n; ++i)
347 live_end_at_block(lv, def, get_Block_cfgpred_block(block, i), visited, 1);
353 struct _lv_walker_t {
359 * Liveness analysis for a value.
360 * This functions is meant to be called by a firm walker, to compute the
361 * set of all blocks a value is live in.
362 * @param irn The node (value).
363 * @param env Ignored.
365 static void liveness_for_node(ir_node *irn, void *data)
367 struct _lv_walker_t *walker = data;
368 be_lv_t *lv = walker->lv;
369 bitset_t *visited = walker->data;
370 const ir_edge_t *edge;
373 /* Don't compute liveness information for non-data nodes. */
374 if(!is_liveness_node(irn))
377 bitset_clear_all(visited);
378 def_block = get_nodes_block(irn);
380 /* Go over all uses of the value */
381 foreach_out_edge(irn, edge) {
382 ir_node *use = edge->src;
386 * If the usage is no data node, skip this use, since it does not
387 * affect the liveness of the node.
389 if(!is_liveness_node(use))
392 /* Get the block where the usage is in. */
393 use_block = get_nodes_block(use);
396 * If the use is a phi function, determine the corresponding block
397 * through which the value reaches the phi function and mark the
398 * value as live out of that block.
401 ir_node *pred_block = get_Block_cfgpred_block(use_block, edge->pos);
402 live_end_at_block(lv, irn, pred_block, visited, 0);
406 * Else, the value is live in at this block. Mark it and call live
407 * out on the predecessors.
409 else if(def_block != use_block) {
412 mark_live_in(lv, use_block, irn);
414 for(i = 0, n = get_Block_n_cfgpreds(use_block); i < n; ++i) {
415 ir_node *pred_block = get_Block_cfgpred_block(use_block, i);
416 live_end_at_block(lv, irn, pred_block, visited, 1);
422 static void lv_remove_irn_walker(ir_node *bl, void *data)
424 struct _lv_walker_t *w = data;
426 ir_node *irn = w->data;
427 be_lv_remove(lv, bl, irn);
430 static const char *lv_flags_to_str(unsigned flags)
432 static const char *states[] = {
443 return states[flags & 7];
446 static void lv_dump_block(void *context, FILE *f, const ir_node *bl)
449 be_lv_t *lv = context;
450 struct _be_lv_info_t *info = phase_get_irn_data(&lv->ph, bl);
452 fprintf(f, "liveness:\n");
454 unsigned n = info[0].u.head.n_members;
457 for(i = 0; i < n; ++i) {
458 struct _be_lv_info_node_t *n = &info[i+1].u.node;
459 ir_fprintf(f, "%s %+F\n", lv_flags_to_str(n->flags), get_idx_irn(lv->irg, n->idx));
465 static void *lv_phase_data_init(ir_phase *phase, ir_node *irn, void *old)
467 struct _be_lv_info_t *info = phase_alloc(phase, LV_STD_SIZE * sizeof(info[0]));
468 memset(info, 0, LV_STD_SIZE * sizeof(info[0]));
469 info[0].u.head.n_size = LV_STD_SIZE - 1;
473 static void compute_liveness(be_lv_t *lv)
475 struct _lv_walker_t w;
477 w.data = bitset_malloc(get_irg_last_idx(lv->irg));
478 irg_walk_graph(lv->irg, liveness_for_node, NULL, &w);
482 /* Compute the inter block liveness for a graph. */
483 be_lv_t *be_liveness(ir_graph *irg)
485 be_lv_t *lv = xmalloc(sizeof(lv[0]));
487 memset(lv, 0, sizeof(lv[0]));
489 lv->nodes = bitset_malloc(2 * get_irg_last_idx(irg));
490 lv->hook_info.context = lv;
491 lv->hook_info.hook._hook_node_info = lv_dump_block;
492 register_hook(hook_node_info, &lv->hook_info);
493 phase_init(&lv->ph, "liveness", irg, PHASE_DEFAULT_GROWTH, lv_phase_data_init, NULL);
494 compute_liveness(lv);
499 void be_liveness_recompute(be_lv_t *lv)
501 unsigned last_idx = get_irg_last_idx(lv->irg);
502 if(last_idx >= bitset_size(lv->nodes)) {
503 bitset_free(lv->nodes);
504 lv->nodes = bitset_malloc(last_idx * 2);
508 bitset_clear_all(lv->nodes);
511 phase_init(&lv->ph, "liveness", lv->irg, PHASE_DEFAULT_GROWTH, lv_phase_data_init, NULL);
512 compute_liveness(lv);
516 void be_liveness_free(be_lv_t *lv)
518 unregister_hook(hook_node_info, &lv->hook_info);
520 bitset_free(lv->nodes);
524 void be_liveness_remove(be_lv_t *lv, ir_node *irn)
526 unsigned idx = get_irn_idx(irn);
527 struct _lv_walker_t w;
530 * Removes a single irn from the liveness information.
531 * Since an irn can only be live at blocks dominated by the block of its
532 * definition, we only have to process that dominance subtree.
536 dom_tree_walk(get_nodes_block(irn), lv_remove_irn_walker, NULL, &w);
537 if(idx < bitset_size(lv->nodes))
538 bitset_clear(lv->nodes, idx);
541 void be_liveness_introduce(be_lv_t *lv, ir_node *irn)
543 struct _lv_walker_t w;
545 w.data = bitset_malloc(get_irg_last_idx(lv->irg));
546 liveness_for_node(irn, &w);
550 void be_liveness_update(be_lv_t *lv, ir_node *irn)
552 be_liveness_remove(lv, irn);
553 be_liveness_introduce(lv, irn);
556 static void lv_add_missing_walker(ir_node *irn, void *data)
558 struct _lv_walker_t *w = data;
559 if(!is_Block(irn) && !bitset_contains_irn(w->lv->nodes, irn)) {
560 liveness_for_node(irn, w);
564 void be_liveness_add_missing(be_lv_t *lv)
566 struct _lv_walker_t w;
568 w.data = bitset_malloc(get_irg_last_idx(lv->irg));
569 irg_walk_graph(lv->irg, lv_add_missing_walker, NULL, &w);
573 static void lv_check_walker(ir_node *bl, void *data)
575 struct _lv_walker_t *w = data;
577 be_lv_t *fresh = w->data;
579 struct _be_lv_info_t *curr = phase_get_irn_data(&lv->ph, bl);
580 struct _be_lv_info_t *fr = phase_get_irn_data(&fresh->ph, bl);
582 if(!fr && curr && curr[0].u.head.n_members > 0) {
585 ir_fprintf(stderr, "%+F liveness should be empty but current liveness contains:\n", bl);
586 for(i = 0; i < curr[0].u.head.n_members; ++i) {
587 ir_fprintf(stderr, "\t%+F\n", get_idx_irn(lv->irg, curr[1 + i].u.node.idx));
592 unsigned n_curr = curr[0].u.head.n_members;
593 unsigned n_fresh = fr[0].u.head.n_members;
597 if(n_curr != n_fresh) {
598 ir_fprintf(stderr, "%+F: liveness set sizes differ. curr %d, correct %d\n", bl, n_curr, n_fresh);
600 ir_fprintf(stderr, "current:\n");
601 for(i = 0; i < n_curr; ++i) {
602 struct _be_lv_info_node_t *n = &curr[1 + i].u.node;
603 ir_fprintf(stderr, "%+F %u %+F %s\n", bl, i, get_idx_irn(lv->irg, n->idx), lv_flags_to_str(n->flags));
606 ir_fprintf(stderr, "correct:\n");
607 for(i = 0; i < n_fresh; ++i) {
608 struct _be_lv_info_node_t *n = &fr[1 + i].u.node;
609 ir_fprintf(stderr, "%+F %u %+F %s\n", bl, i, get_idx_irn(lv->irg, n->idx), lv_flags_to_str(n->flags));
615 void be_liveness_check(be_lv_t *lv)
617 struct _lv_walker_t w;
618 be_lv_t *fresh = be_liveness(lv->irg);
622 irg_block_walk_graph(lv->irg, lv_check_walker, NULL, &w);
623 be_liveness_free(fresh);
627 static void lv_dump_block_walker(ir_node *irn, void *data)
629 struct _lv_walker_t *w = data;
631 lv_dump_block(w->lv, w->data, irn);
635 /* Dump the liveness information for a graph. */
636 void be_liveness_dump(const be_lv_t *lv, FILE *f)
638 struct _lv_walker_t w;
640 w.lv = (be_lv_t *) lv;
642 irg_block_walk_graph(lv->irg, lv_dump_block_walker, NULL, &w);
645 /* Dump the liveness information for a graph. */
646 void be_liveness_dumpto(const be_lv_t *lv, const char *cls_name)
650 ir_snprintf(buf, sizeof(buf), "%F_%s-live.txt", lv->irg, cls_name);
651 if((f = fopen(buf, "wt")) != NULL) {
652 be_liveness_dump(lv, f);
658 * Walker: checks the every predecessors of a node dominate
661 static void dom_check(ir_node *irn, void *data)
663 int *problem_found = data;
665 if(!is_Block(irn) && irn != get_irg_end(get_irn_irg(irn))) {
667 ir_node *bl = get_nodes_block(irn);
669 for(i = 0, n = get_irn_arity(irn); i < n; ++i) {
670 ir_node *op = get_irn_n(irn, i);
671 ir_node *def_bl = get_nodes_block(op);
672 ir_node *use_bl = bl;
675 use_bl = get_Block_cfgpred_block(bl, i);
677 if(get_irn_opcode(use_bl) != iro_Bad
678 && get_irn_opcode(def_bl) != iro_Bad
679 && !block_dominates(def_bl, use_bl)) {
680 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)));
687 /* Check, if the SSA dominance property is fulfilled. */
688 int be_check_dominance(ir_graph *irg)
690 int problem_found = 0;
693 irg_walk_graph(irg, dom_check, NULL, &problem_found);
695 return !problem_found;
698 pset *be_liveness_transfer(const arch_env_t *arch_env, const arch_register_class_t *cls, ir_node *irn, pset *live)
702 /* You should better break out of your loop when hitting the first phi function. */
703 assert(!is_Phi(irn) && "liveness_transfer produces invalid results for phi nodes");
705 if(arch_irn_consider_in_reg_alloc(arch_env, cls, irn)) {
706 ir_node *del = pset_remove_ptr(live, irn);
711 for(i = 0, n = get_irn_arity(irn); i < n; ++i) {
712 ir_node *op = get_irn_n(irn, i);
714 if(arch_irn_consider_in_reg_alloc(arch_env, cls, op))
715 pset_insert_ptr(live, op);
721 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)
724 be_lv_foreach(lv, bl, be_lv_state_end, i) {
725 ir_node *irn = be_lv_get_irn(lv, bl, i);
726 if(arch_irn_consider_in_reg_alloc(arch_env, cls, irn))
727 pset_insert_ptr(live, irn);
733 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)
735 const ir_node *bl = is_Block(pos) ? pos : get_nodes_block(pos);
738 be_liveness_end_of_block(lv, arch_env, cls, bl, live);
739 sched_foreach_reverse(bl, irn) {
741 * If we encounter the node we want to insert the Perm after,
742 * exit immediately, so that this node is still live
747 be_liveness_transfer(arch_env, cls, irn, live);
753 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)
755 const ir_node *bl = is_Block(pos) ? pos : get_nodes_block(pos);
758 be_liveness_end_of_block(lv, arch_env, cls, bl, live);
759 sched_foreach_reverse(bl, irn) {
760 be_liveness_transfer(arch_env, cls, irn, live);
768 static void collect_node(ir_node *irn, void *data)
770 struct obstack *obst = data;
771 obstack_ptr_grow(obst, irn);
774 void be_live_chk_compare(be_irg_t *birg)
776 ir_graph *irg = be_get_birg_irg(birg);
785 be_assure_liveness(birg);
786 be_assure_liveness_chk(birg);
787 lv = be_get_birg_liveness(birg);
788 lvc = be_get_birg_liveness_chk(birg);
792 irg_block_walk_graph(irg, collect_node, NULL, &obst);
793 obstack_ptr_grow(&obst, NULL);
794 blocks = obstack_finish(&obst);
796 irg_walk_graph(irg, collect_node, NULL, &obst);
797 obstack_ptr_grow(&obst, NULL);
798 nodes = obstack_finish(&obst);
800 for (i = 0; blocks[i]; ++i) {
801 ir_node *bl = blocks[i];
803 for (j = 0; nodes[j]; ++j) {
804 ir_node *irn = nodes[j];
805 if (!is_Block(irn)) {
806 int lvr_in = be_is_live_in (lv, bl, irn);
807 int lvr_out = be_is_live_out(lv, bl, irn);
808 int lvr_end = be_is_live_end(lv, bl, irn);
810 int lvc_in = lv_chk_bl_in (lvc, bl, irn);
811 int lvc_out = lv_chk_bl_out(lvc, bl, irn);
812 int lvc_end = lv_chk_bl_end(lvc, bl, irn);
814 if (lvr_in - lvc_in != 0)
815 ir_fprintf(stderr, "live in info for %+F at %+F differs: nml: %d, chk: %d\n", irn, bl, lvr_in, lvc_in);
817 if (lvr_end - lvc_end != 0)
818 ir_fprintf(stderr, "live end info for %+F at %+F differs: nml: %d, chk: %d\n", irn, bl, lvr_end, lvc_end);
820 if (lvr_out - lvc_out != 0)
821 ir_fprintf(stderr, "live out info for %+F at %+F differs: nml: %d, chk: %d\n", irn, bl, lvr_out, lvc_out);
827 obstack_free(&obst, NULL);
830 void be_init_live(void)
832 FIRM_DBG_REGISTER(dbg, "firm.be.liveness");
835 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_live);