27 #include "iredges_t.h"
29 #include "irprintf_t.h"
33 #include "bechordal_t.h"
35 #include "besched_t.h"
43 #define DBG_MODULE "firm.be.irgmod"
44 #define DBG_LEVEL SET_LEVEL_0
48 | _ \ ___ _ __ ___ (_)_ __ __ _ _ __ ___ ___
49 | | | |/ _ \| '_ ` _ \| | '_ \ / _` | '_ \ / __/ _ \
50 | |_| | (_) | | | | | | | | | | (_| | | | | (_| __/
51 |____/ \___/|_| |_| |_|_|_| |_|\__,_|_| |_|\___\___|
52 | ___| __ ___ _ __ | |_(_) ___ _ __ ___
53 | |_ | '__/ _ \| '_ \| __| |/ _ \ '__/ __|
54 | _|| | | (_) | | | | |_| | __/ | \__ \
55 |_| |_| \___/|_| |_|\__|_|\___|_| |___/
60 * The dominance frontier for a graph.
62 struct _be_dom_front_info_t {
63 pmap *df_map; /**< A map, mapping every block to a list of its dominance frontier blocks. */
64 struct obstack obst; /**< An obstack holding all the frontier data. */
68 * A wrapper for get_Block_idom.
69 * This function returns the block itself, if the block is the start
70 * block. Returning NULL would make any != comparison true which
71 * suggests, that the start block is dominated by some other node.
72 * @param bl The block.
73 * @return The immediate dominator of the block.
75 static INLINE ir_node *get_idom(ir_node *bl)
77 ir_node *idom = get_Block_idom(bl);
78 return idom == NULL ? bl : idom;
82 * Compute the dominance frontier for a given block.
84 * @param blk the block where the calculation starts
86 * @return the list of all blocks in the dominance frontier of blk
88 static ir_node **compute_df(ir_node *blk, be_dom_front_info_t *info)
91 const ir_edge_t *edge;
92 ir_node **df_list = NEW_ARR_F(ir_node *, 0);
96 /* Add local dominance frontiers */
97 foreach_block_succ(blk, edge) {
98 ir_node *y = edge->src;
100 if (get_idom(y) != blk) {
101 ARR_APP1(ir_node *, df_list, y);
106 * Go recursively down the dominance tree and add all blocks
107 * into the dominance frontiers of the children, which are not
108 * dominated by the given block.
110 for (c = get_Block_dominated_first(blk); c; c = get_Block_dominated_next(c)) {
112 ir_node **df_c_list = compute_df(c, info);
114 for (i = ARR_LEN(df_c_list) - 1; i >= 0; --i) {
115 ir_node *w = df_c_list[i];
116 if (get_idom(w) != blk)
117 ARR_APP1(ir_node *, df_list, w);
121 /* now copy the flexible array to the obstack */
122 len = ARR_LEN(df_list);
123 df = NEW_ARR_D(ir_node *, &info->obst, len);
124 memcpy(df, df_list, len * sizeof(df[0]));
127 pmap_insert(info->df_map, blk, df);
131 be_dom_front_info_t *be_compute_dominance_frontiers(ir_graph *irg)
133 be_dom_front_info_t *info = xmalloc(sizeof(*info));
136 obstack_init(&info->obst);
137 info->df_map = pmap_create();
139 (void)compute_df(get_irg_start_block(irg), info);
144 void be_free_dominance_frontiers(be_dom_front_info_t *info)
146 obstack_free(&info->obst, NULL);
147 pmap_destroy(info->df_map);
151 /* Get the dominance frontier of a block. */
152 ir_node **be_get_dominance_frontier(be_dom_front_info_t *info, ir_node *block)
154 return pmap_get(info->df_map, block);
157 static void determine_phi_blocks(pset *copies, pset *copy_blocks, pset *phi_blocks, be_dom_front_info_t *df_info)
160 waitq *worklist = new_waitq();
161 FIRM_DBG_REGISTER(firm_dbg_module_t *dbg, DBG_MODULE);
164 * Fill the worklist queue and the rest of the orig blocks array.
166 for (bl = pset_first(copy_blocks); bl; bl = pset_next(copy_blocks)) {
167 waitq_put(worklist, bl);
170 while (!pdeq_empty(worklist)) {
171 ir_node *bl = waitq_get(worklist);
172 ir_node **df = be_get_dominance_frontier(df_info, bl);
177 DBG((dbg, LEVEL_3, "dom front of %+F\n", bl));
179 for (i = ARR_LEN(df) - 1; i >= 0; --i)
180 DBG((dbg, LEVEL_3, "\t%+F\n", df[i]))
183 for (i = ARR_LEN(df) - 1; i >= 0; --i) {
185 if (!pset_find_ptr(phi_blocks, y)) {
186 pset_insert_ptr(phi_blocks, y);
189 * Clear the link field of a possible phi block, since
190 * the possibly created phi will be stored there. See,
193 set_irn_link(y, NULL);
195 if(!pset_find_ptr(copy_blocks, y))
196 waitq_put(worklist, y);
211 / ___|___ _ __ ___| |_ _ __ _ _ ___| |_(_) ___ _ __
212 | | / _ \| '_ \/ __| __| '__| | | |/ __| __| |/ _ \| '_ \
213 | |__| (_) | | | \__ \ |_| | | |_| | (__| |_| | (_) | | | |
214 \____\___/|_| |_|___/\__|_| \__,_|\___|\__|_|\___/|_| |_|
219 * Find the copy of the given original node whose value is 'active'
222 * The usage is given as a node and a position. Initially, the given operand
223 * points to a node for which copies were introduced. We have to find
224 * the valid copy for this usage. This is done by traversing the
225 * dominance tree upwards. If the usage is a phi function, we start
226 * traversing from the predecessor block which corresponds to the phi
229 * @param usage The node which uses the original node.
230 * @param pos The position of the argument which corresponds to the original node.
231 * @param copies A set containing all node which are copies from the original node.
232 * @param copy_blocks A set containing all basic block in which copies of the original node are located.
233 * @param phis A set where all created phis are recorded.
234 * @param phi_blocks A set of all blocks where Phis shall be inserted (iterated dominance frontier).
235 * @param mode The mode for the Phi if one has to be created.
236 * @return The valid copy for usage.
238 static ir_node *search_def(ir_node *usage, int pos, pset *copies, pset *copy_blocks, pset *phis, pset *phi_blocks, ir_mode *mode)
242 FIRM_DBG_REGISTER(firm_dbg_module_t *dbg, DBG_MODULE);
244 curr_bl = get_nodes_block(usage);
246 DBG((dbg, LEVEL_1, "Searching valid def for use %+F at pos %d\n", usage, pos));
248 * If the usage is in a phi node, search the copy in the
249 * predecessor denoted by pos.
252 curr_bl = get_Block_cfgpred_block(curr_bl, pos);
253 start_irn = sched_last(curr_bl);
255 start_irn = sched_prev(usage);
259 * Traverse the dominance tree upwards from the
260 * predecessor block of the usage.
262 while(curr_bl != NULL) {
266 * If this block contains a copy, search the block
267 * instruction by instruction. If nothing is found
268 * search for a not scheduled PhiM.
270 if(pset_find_ptr(copy_blocks, curr_bl)) {
273 /* Look at each instruction from last to first. */
274 sched_foreach_reverse_from(start_irn, irn) {
276 /* Take the first copy we find. */
277 if(pset_find_ptr(copies, irn))
281 for(phim = pset_first(copies); phim; phim = pset_next(copies)) {
282 if(!is_Phi(phim) || !(get_irn_mode(phim) == mode_M))
285 if(get_nodes_block(phim) == curr_bl) {
292 if(pset_find_ptr(phi_blocks, curr_bl)) {
293 ir_node *phi = get_irn_link(curr_bl);
296 int i, n_preds = get_irn_arity(curr_bl);
297 ir_graph *irg = get_irn_irg(curr_bl);
298 ir_node **ins = alloca(n_preds * sizeof(ins[0]));
300 for(i = 0; i < n_preds; ++i)
301 ins[i] = new_r_Bad(irg);
303 phi = new_r_Phi(irg, curr_bl, n_preds, ins, mode);
304 DBG((dbg, LEVEL_2, "\tcreating phi %+F in %+F\n", phi, curr_bl));
306 set_irn_link(curr_bl, phi);
308 sched_add_after(curr_bl, phi);
310 for(i = 0; i < n_preds; ++i) {
311 ir_node *arg = search_def(phi, i, copies, copy_blocks, phis, phi_blocks, mode);
315 ir_fprintf(stderr, "no definition found for %+F at position %d\nCopies: ", phi, i);
316 for(irn = pset_first(copies); irn; irn = pset_next(copies)) {
317 ir_fprintf(stderr, "%+F ", irn);
319 ir_fprintf(stderr, "\n\n");
320 assert(arg && "no definition found");
322 DBG((dbg, LEVEL_2, "\t\t%+F(%d) -> %+F\n", phi, i, arg));
323 set_irn_n(phi, i, arg);
327 pset_insert_ptr(phis, phi);
333 /* If were not done yet, look in the immediate dominator */
334 curr_bl = get_Block_idom(curr_bl);
336 start_irn = sched_last(curr_bl);
342 static void fix_usages(pset *copies, pset *copy_blocks, pset *phi_blocks, pset *phis, pset *ignore_uses)
353 FIRM_DBG_REGISTER(firm_dbg_module_t *dbg, DBG_MODULE);
358 * Put all outs into an array.
359 * This is necessary, since the outs would be modified while
360 * iterating on them what could bring the outs module in trouble.
362 for (irn = pset_first(copies); irn; irn = pset_next(copies)) {
363 const ir_edge_t *edge;
364 foreach_out_edge(irn, edge) {
365 if (!pset_find_ptr(ignore_uses, get_edge_src_irn(edge))) {
367 tmp.irn = get_edge_src_irn(edge);
368 tmp.pos = get_edge_src_pos(edge);
369 obstack_grow(&obst, &tmp, sizeof(tmp));
374 outs = obstack_finish(&obst);
377 * Search the valid def for each out and set it.
379 for(i = 0; i < n_outs; ++i) {
380 ir_node *irn = outs[i].irn;
381 int pos = outs[i].pos;
382 ir_mode *mode = get_irn_mode(get_irn_n(irn, pos));
386 def = search_def(irn, pos, copies, copy_blocks, phis, phi_blocks, mode);
387 DBG((dbg, LEVEL_2, "\t%+F(%d) -> %+F\n", irn, pos, def));
390 ir_fprintf(stderr, "no definition found for %+F at position %d\nCopies: ", irn, pos);
391 for(irn = pset_first(copies); irn; irn = pset_next(copies)) {
392 ir_fprintf(stderr, "%+F ", irn);
394 ir_fprintf(stderr, "\n\n");
395 assert(def && "no definition found");
397 set_irn_n(irn, pos, def);
400 obstack_free(&obst, NULL);
405 * Remove phis which are not necessary.
406 * During place_phi_functions() phi functions are put on the dominance
407 * frontiers blindly. However some of them will never be used (these
408 * have at least one predecessor which is NULL, see search_def() for
409 * this case). Since place_phi_functions() enters them into the
410 * schedule, we have to remove them from there.
412 * @param copies The set of all copies made (including the phi functions).
414 static void remove_odd_phis(pset *copies, pset *unused_copies)
418 for(irn = pset_first(copies); irn; irn = pset_next(copies)) {
423 assert(sched_is_scheduled(irn) && "phi must be scheduled");
424 for(i = 0, n = get_irn_arity(irn); i < n && !illegal; ++i)
425 illegal = get_irn_n(irn, i) == NULL;
428 for(i = 0, n = get_irn_arity(irn); i < n; ++i)
429 set_irn_n(irn, i, new_Bad());
435 for(irn = pset_first(unused_copies); irn; irn = pset_next(unused_copies)) {
436 for(i = 0, n = get_irn_arity(irn); i < n; ++i)
437 set_irn_n(irn, i, new_Bad());
443 void be_ssa_constr_phis_ignore(be_dom_front_info_t *info, be_lv_t *lv, int n, ir_node *nodes[], pset *phis, pset *ignore_uses)
445 pset *irns = pset_new_ptr(n);
448 for(i = 0; i < n; ++i)
449 pset_insert_ptr(irns, nodes[i]);
450 be_ssa_constr_set_phis_ignore(info, lv, irns, phis, ignore_uses);
454 void be_ssa_constr_ignore(be_dom_front_info_t *info, be_lv_t *lv, int n, ir_node *nodes[], pset *ignore_uses)
456 be_ssa_constr_phis_ignore(info, lv, n, nodes, NULL, ignore_uses);
459 void be_ssa_constr(be_dom_front_info_t *info, be_lv_t *lv, int n, ir_node *nodes[])
461 pset *empty_set = be_empty_set();
462 be_ssa_constr_ignore(info, lv, n, nodes, empty_set);
465 void be_ssa_constr_set_phis_ignore(be_dom_front_info_t *df, be_lv_t *lv, pset *nodes, pset *phis, pset *ignore_uses)
467 int n = pset_count(nodes);
468 pset *blocks = pset_new_ptr(n);
469 pset *phi_blocks = pset_new_ptr(n);
470 int save_optimize = get_optimize();
471 int save_normalize = get_opt_normalize();
472 int phis_set_created = 0;
473 FIRM_DBG_REGISTER(firm_dbg_module_t *dbg, DBG_MODULE);
477 /* We need to collect the phi functions to compute their liveness. */
479 phis_set_created = 1;
480 phis = pset_new_ptr_default();
483 DBG((dbg, LEVEL_1, "Introducing following copies for:\n"));
486 for(irn = pset_first(nodes); irn; irn = pset_next(nodes)) {
487 ir_node *bl = get_nodes_block(irn);
488 pset_insert_ptr(blocks, bl);
489 DBG((dbg, LEVEL_1, "\t%+F in %+F\n", irn, bl));
493 * Disable optimization so that the phi functions do not
497 set_opt_normalize(0);
500 * Place the phi functions and reroute the usages.
502 determine_phi_blocks(nodes, blocks, phi_blocks, df);
503 fix_usages(nodes, blocks, phi_blocks, phis, ignore_uses);
505 /* reset the optimizations */
506 set_optimize(save_optimize);
507 set_opt_normalize(save_normalize);
509 del_pset(phi_blocks);
512 /* Recompute the liveness (if wanted) of the original nodes, the copies and the inserted phis. */
515 foreach_pset(nodes, irn)
516 be_liveness_update(lv, irn);
518 foreach_pset(phis, irn)
519 be_liveness_introduce(lv, irn);
521 be_liveness_recompute(lv);
525 /* Free the phi set of we created it. */
531 void be_ssa_constr_set_phis(be_dom_front_info_t *df, be_lv_t *lv, pset *nodes, pset *phis)
533 pset *empty_set = be_empty_set();
534 be_ssa_constr_set_phis_ignore(df, lv, nodes, phis, empty_set);
537 void be_ssa_constr_set_ignore(be_dom_front_info_t *df, be_lv_t *lv, pset *nodes, pset *ignore_uses)
539 be_ssa_constr_set_phis_ignore(df, lv, nodes, NULL, ignore_uses);
542 void be_ssa_constr_set(be_dom_front_info_t *info, be_lv_t *lv, pset *nodes)
544 pset *empty_set = be_empty_set();
545 be_ssa_constr_set_ignore(info, lv, nodes, empty_set);
550 |_ _|_ __ ___ ___ _ __| |_ | _ \ ___ _ __ _ __ ___
551 | || '_ \/ __|/ _ \ '__| __| | |_) / _ \ '__| '_ ` _ \
552 | || | | \__ \ __/ | | |_ | __/ __/ | | | | | | |
553 |___|_| |_|___/\___|_| \__| |_| \___|_| |_| |_| |_|
557 ir_node *insert_Perm_after(const arch_env_t *arch_env,
559 const arch_register_class_t *cls,
560 be_dom_front_info_t *dom_front,
563 ir_node *bl = is_Block(pos) ? pos : get_nodes_block(pos);
564 ir_graph *irg = get_irn_irg(bl);
565 pset *live = pset_new_ptr_default();
566 FIRM_DBG_REGISTER(firm_dbg_module_t *dbg, "be.node");
568 ir_node *curr, *irn, *perm, **nodes;
571 DBG((dbg, LEVEL_1, "Insert Perm after: %+F\n", pos));
573 be_liveness_nodes_live_at(lv, arch_env, cls, pos, live);
575 n = pset_count(live);
582 nodes = xmalloc(n * sizeof(nodes[0]));
584 DBG((dbg, LEVEL_1, "live:\n"));
585 for(irn = pset_first(live), i = 0; irn; irn = pset_next(live), i++) {
586 DBG((dbg, LEVEL_1, "\t%+F\n", irn));
591 perm = be_new_Perm(cls, irg, bl, n, nodes);
592 sched_add_after(pos, perm);
596 for (i = 0; i < n; ++i) {
598 ir_node *perm_op = get_irn_n(perm, i);
599 const arch_register_t *reg = arch_get_irn_register(arch_env, perm_op);
601 ir_mode *mode = get_irn_mode(perm_op);
602 ir_node *proj = new_r_Proj(irg, bl, perm, mode, i);
603 arch_set_irn_register(arch_env, proj, reg);
605 sched_add_after(curr, proj);
611 be_ssa_constr(dom_front, lv, 2, copies);
617 struct _elr_closure_t {
619 const be_chordal_env_t *cenv;
622 static void elr_split_walker(ir_node *bl, void *data)
624 struct _elr_closure_t *c = data;
625 const be_chordal_env_t *cenv = c->cenv;
626 const arch_env_t *aenv = cenv->birg->main_env->arch_env;
627 be_lv_t *lv = cenv->birg->lv;
628 be_dom_front_info_t *dom_front = cenv->birg->dom_front;
632 be_insn_env_init(&ie, cenv->birg, cenv->cls, &c->obst);
634 for(insn = be_scan_insn(&ie, sched_first(bl)); !is_Block(insn->irn); insn = be_scan_insn(&ie, insn->next_insn)) {
635 ir_node *pred = sched_prev(insn->irn);
636 if(!is_Block(pred) && !is_Phi(insn->irn))
637 insert_Perm_after(aenv, lv, cenv->cls, dom_front, insn->irn);
641 void extreme_liverange_splitting(struct _be_chordal_env_t *cenv)
643 struct _elr_closure_t c;
644 be_lv_t *lv = cenv->birg->lv;
647 obstack_init(&c.obst);
648 be_liveness_recompute(lv);
649 irg_block_walk_graph(cenv->irg, elr_split_walker, NULL, &c);
650 be_liveness_recompute(lv);
651 obstack_free(&c.obst, NULL);
655 * Post-block-walker: Find blocks containing only one jump and
658 static void remove_empty_block(ir_node *block, void *data) {
659 const ir_edge_t *edge, *next;
662 ir_node *jump = NULL;
664 assert(is_Block(block));
666 if (get_Block_n_cfgpreds(block) != 1)
669 sched_foreach(block, node) {
673 /* we should never have 2 jumps in a block */
674 assert(0 && "We should never have 2 jumps in a block");
683 node = get_Block_cfgpred(block, 0);
684 foreach_out_edge_safe(jump, edge, next) {
685 ir_node *block = get_edge_src_irn(edge);
686 int pos = get_edge_src_pos(edge);
688 set_irn_n(block, pos, node);
691 set_Block_cfgpred(block, 0, new_Bad());
696 /* removes basic blocks that just contain a jump instruction */
697 int be_remove_empty_blocks(ir_graph *irg) {
700 irg_block_walk_graph(irg, remove_empty_block, NULL, &changed);
702 /* invalidate analysis info */
703 set_irg_doms_inconsistent(irg);
704 set_irg_extblk_inconsistent(irg);
705 set_irg_outs_inconsistent(irg);