2 * Author: Christian Wuerdig
4 * Copyright: (c) Universitaet Karlsruhe
5 * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
8 * Performs lowering of perm nodes and spill/reload optimization.
23 #include "besched_t.h"
25 #include "benodesets.h"
28 #include "iredges_t.h"
38 #undef KEEP_ALIVE_COPYKEEP_HACK
40 /* associates op with it's copy and CopyKeep */
42 ir_node *op; /* an irn which must be different */
43 pset *copies; /* all non-spillable copies of this irn */
44 const arch_register_class_t *cls;
47 /* environment for constraints */
52 DEBUG_ONLY(firm_dbg_module_t *dbg;)
55 /* lowering walker environment */
56 typedef struct _lower_env_t {
58 const arch_env_t *arch_env;
60 DEBUG_ONLY(firm_dbg_module_t *dbg_module;)
63 /* holds a perm register pair */
64 typedef struct _reg_pair_t {
65 const arch_register_t *in_reg; /**< a perm IN register */
66 ir_node *in_node; /**< the in node to which the register belongs */
68 const arch_register_t *out_reg; /**< a perm OUT register */
69 ir_node *out_node; /**< the out node to which the register belongs */
71 int checked; /**< indicates whether the pair was check for cycle or not */
74 typedef enum _perm_type_t {
81 /* structure to represent cycles or chains in a perm */
82 typedef struct _perm_cycle_t {
83 const arch_register_t **elems; /**< the registers in the cycle */
84 int n_elems; /**< number of elements in the cycle */
85 perm_type_t type; /**< type (CHAIN or CYCLE) */
88 /* Compare the two operands */
89 static int cmp_op_copy_assoc(const void *a, const void *b) {
90 const op_copy_assoc_t *op1 = a;
91 const op_copy_assoc_t *op2 = b;
93 return op1->op != op2->op;
96 /* Compare the in registers of two register pairs */
97 static int compare_reg_pair(const void *a, const void *b) {
98 const reg_pair_t *pair_a = a;
99 const reg_pair_t *pair_b = b;
101 if (pair_a->in_reg->index > pair_b->in_reg->index)
107 /* returns the number register pairs marked as checked */
108 static int get_n_checked_pairs(reg_pair_t *pairs, int n) {
109 int i, n_checked = 0;
111 for (i = 0; i < n; i++) {
112 if (pairs[i].checked)
120 * Gets the node corresponding to a register from an array of register pairs.
121 * NOTE: The given registers pairs and the register to look for must belong
122 * to the same register class.
124 * @param pairs The array of register pairs
125 * @param n The number of pairs
126 * @param reg The register to look for
127 * @param in_out 0 == look for IN register, 1 == look for OUT register
128 * @return The corresponding node or NULL if not found
130 static ir_node *get_node_for_register(reg_pair_t *pairs, int n, const arch_register_t *reg, int in_out) {
134 for (i = 0; i < n; i++) {
135 /* out register matches */
136 if (pairs[i].out_reg->index == reg->index)
137 return pairs[i].out_node;
141 for (i = 0; i < n; i++) {
142 /* in register matches */
143 if (pairs[i].in_reg->index == reg->index)
144 return pairs[i].in_node;
152 * Gets the index in the register pair array where the in/out register
153 * corresponds to reg_idx.
155 * @param pairs The array of register pairs
156 * @param n The number of pairs
157 * @param reg The register index to look for
158 * @param in_out 0 == look for IN register, 1 == look for OUT register
159 * @return The corresponding index in pairs or -1 if not found
161 static int get_pairidx_for_regidx(reg_pair_t *pairs, int n, int reg_idx, int in_out) {
165 for (i = 0; i < n; i++) {
166 /* out register matches */
167 if (pairs[i].out_reg->index == reg_idx)
172 for (i = 0; i < n; i++) {
173 /* in register matches */
174 if (pairs[i].in_reg->index == reg_idx)
183 * Gets an array of register pairs and tries to identify a cycle or chain starting
186 * @param cycle Variable to hold the cycle
187 * @param pairs Array of register pairs
188 * @param start Index to start
189 * @return The cycle or chain
191 static perm_cycle_t *get_perm_cycle(perm_cycle_t *cycle, reg_pair_t *pairs, int n, int start) {
192 int head = pairs[start].in_reg->index;
193 int cur_idx = pairs[start].out_reg->index;
194 int cur_pair_idx = start;
195 int n_pairs_done = get_n_checked_pairs(pairs, n);
197 perm_type_t cycle_tp = PERM_CYCLE;
199 /* We could be right in the middle of a chain, so we need to find the start */
200 while (head != cur_idx) {
201 /* goto previous register in cycle or chain */
202 cur_pair_idx = get_pairidx_for_regidx(pairs, n, head, 1);
204 if (cur_pair_idx < 0) {
205 cycle_tp = PERM_CHAIN;
209 head = pairs[cur_pair_idx].in_reg->index;
210 start = cur_pair_idx;
214 /* assume worst case: all remaining pairs build a cycle or chain */
215 cycle->elems = xcalloc((n - n_pairs_done) * 2, sizeof(cycle->elems[0]));
216 cycle->n_elems = 2; /* initial number of elements is 2 */
217 cycle->elems[0] = pairs[start].in_reg;
218 cycle->elems[1] = pairs[start].out_reg;
219 cycle->type = cycle_tp;
220 cur_idx = pairs[start].out_reg->index;
223 /* check for cycle or end of a chain */
224 while (cur_idx != head) {
225 /* goto next register in cycle or chain */
226 cur_pair_idx = get_pairidx_for_regidx(pairs, n, cur_idx, 0);
228 if (cur_pair_idx < 0)
231 cur_idx = pairs[cur_pair_idx].out_reg->index;
233 /* it's not the first element: insert it */
234 if (cur_idx != head) {
235 cycle->elems[idx++] = pairs[cur_pair_idx].out_reg;
239 /* we are there where we started -> CYCLE */
240 cycle->type = PERM_CYCLE;
244 /* mark all pairs having one in/out register with cycle in common as checked */
245 for (idx = 0; idx < cycle->n_elems; idx++) {
246 cur_pair_idx = get_pairidx_for_regidx(pairs, n, cycle->elems[idx]->index, 0);
248 if (cur_pair_idx >= 0)
249 pairs[cur_pair_idx].checked = 1;
251 cur_pair_idx = get_pairidx_for_regidx(pairs, n, cycle->elems[idx]->index, 1);
253 if (cur_pair_idx >= 0)
254 pairs[cur_pair_idx].checked = 1;
261 * Lowers a perm node. Resolves cycles and creates a bunch of
262 * copy and swap operations to permute registers.
263 * Note: The caller of this function has to make sure, that irn
266 * @param irn The perm node
267 * @param block The block the perm node belongs to
268 * @param walk_env The environment
270 static void lower_perm_node(ir_node *irn, void *walk_env) {
271 const arch_register_class_t *reg_class;
272 const arch_env_t *arch_env;
273 lower_env_t *env = walk_env;
276 int n, i, pn, do_copy, j, n_ops;
278 const ir_edge_t *edge;
280 ir_node *sched_point, *block, *in[2];
281 ir_node *arg1, *arg2, *res1, *res2;
282 ir_node *cpyxchg = NULL;
283 DEBUG_ONLY(firm_dbg_module_t *mod;)
285 arch_env = env->arch_env;
286 do_copy = env->do_copy;
287 DEBUG_ONLY(mod = env->dbg_module;)
288 block = get_nodes_block(irn);
291 Get the schedule predecessor node to the perm
292 NOTE: This works with auto-magic. If we insert the
293 new copy/exchange nodes after this node, everything
296 sched_point = sched_prev(irn);
297 DBG((mod, LEVEL_1, "sched point is %+F\n", sched_point));
298 assert(sched_point && "Perm is not scheduled or has no predecessor");
300 n = get_irn_arity(irn);
301 assert(n == get_irn_n_edges(irn) && "perm's in and out numbers different");
303 reg_class = arch_get_irn_register(arch_env, get_irn_n(irn, 0))->reg_class;
304 pairs = alloca(n * sizeof(pairs[0]));
306 /* build the list of register pairs (in, out) */
308 foreach_out_edge(irn, edge) {
309 pairs[i].out_node = get_edge_src_irn(edge);
310 pn = get_Proj_proj(pairs[i].out_node);
311 pairs[i].in_node = get_irn_n(irn, pn);
313 pairs[i].in_reg = arch_get_irn_register(arch_env, pairs[i].in_node);
314 pairs[i].out_reg = arch_get_irn_register(arch_env, pairs[i].out_node);
316 pairs[i].checked = 0;
320 /* sort the register pairs by the indices of the in registers */
321 qsort(pairs, n, sizeof(pairs[0]), compare_reg_pair);
323 /* Mark all equal pairs as checked, and exchange the OUT proj with
325 for (i = 0; i < n; i++) {
326 if (pairs[i].in_reg->index == pairs[i].out_reg->index) {
327 DBG((mod, LEVEL_1, "%+F removing equal perm register pair (%+F, %+F, %s)\n",
328 irn, pairs[i].in_node, pairs[i].out_node, pairs[i].out_reg->name));
330 /* We have to check for a special case:
331 The in-node could be a Proj from a Perm. In this case,
332 we need to correct the projnum */
333 if (be_is_Perm(pairs[i].in_node) && is_Proj(pairs[i].in_node)) {
334 set_Proj_proj(pairs[i].out_node, get_Proj_proj(pairs[i].in_node));
337 /* remove the proj from the schedule */
338 sched_remove(pairs[i].out_node);
340 /* reroute the edges from the proj to the argument */
341 exchange(pairs[i].out_node, pairs[i].in_node);
342 //edges_reroute(pairs[i].out_node, pairs[i].in_node, env->birg->irg);
343 //set_irn_n(pairs[i].out_node, 0, new_Bad());
345 pairs[i].checked = 1;
349 /* Set do_copy to 0 if it's on but we have no free register */
354 real_size = n - get_n_checked_pairs(pairs, n);
356 be_do_stat_perm(reg_class->name, reg_class->n_regs, irn, block, n, real_size);
358 /* check for cycles and chains */
359 while (get_n_checked_pairs(pairs, n) < n) {
362 /* go to the first not-checked pair */
363 while (pairs[i].checked) i++;
364 cycle = xcalloc(1, sizeof(*cycle));
365 cycle = get_perm_cycle(cycle, pairs, n, i);
367 DB((mod, LEVEL_1, "%+F: following %s created:\n ", irn, cycle->type == PERM_CHAIN ? "chain" : "cycle"));
368 for (j = 0; j < cycle->n_elems; j++) {
369 DB((mod, LEVEL_1, " %s", cycle->elems[j]->name));
371 DB((mod, LEVEL_1, "\n"));
374 We don't need to do anything if we have a Perm with two
375 elements which represents a cycle, because those nodes
376 already represent exchange nodes
378 if (n == 2 && cycle->type == PERM_CYCLE) {
384 //TODO: - iff PERM_CYCLE && do_copy -> determine free temp reg and insert copy to/from it before/after
385 // the copy cascade (this reduces the cycle into a chain)
387 /* build copy/swap nodes from back to front */
388 for (i = cycle->n_elems - 2; i >= 0; i--) {
389 arg1 = get_node_for_register(pairs, n, cycle->elems[i], 0);
390 arg2 = get_node_for_register(pairs, n, cycle->elems[i + 1], 0);
392 res1 = get_node_for_register(pairs, n, cycle->elems[i], 1);
393 res2 = get_node_for_register(pairs, n, cycle->elems[i + 1], 1);
395 If we have a cycle and don't copy: we need to create exchange nodes
396 NOTE: An exchange node is a perm node with 2 INs and 2 OUTs
397 IN_1 = in node with register i
398 IN_2 = in node with register i + 1
399 OUT_1 = out node with register i + 1
400 OUT_2 = out node with register i
402 if (cycle->type == PERM_CYCLE && !do_copy) {
406 /* At this point we have to handle the following problem: */
408 /* If we have a cycle with more than two elements, then */
409 /* this could correspond to the following Perm node: */
411 /* +----+ +----+ +----+ */
412 /* | r1 | | r2 | | r3 | */
413 /* +-+--+ +-+--+ +--+-+ */
416 /* +-+--------+---------+-+ */
418 /* +-+--------+---------+-+ */
421 /* +-+--+ +-+--+ +--+-+ */
422 /* |Proj| |Proj| |Proj| */
423 /* | r2 | | r3 | | r1 | */
424 /* +----+ +----+ +----+ */
426 /* This node is about to be split up into two 2x Perm's */
427 /* for which we need 4 Proj's and the one additional Proj */
428 /* of the first Perm has to be one IN of the second. So in */
429 /* general we need to create one additional Proj for each */
430 /* "middle" Perm and set this to one in node of the successor */
433 DBG((mod, LEVEL_1, "%+F creating exchange node (%+F, %s) and (%+F, %s) with\n",
434 irn, arg1, cycle->elems[i]->name, arg2, cycle->elems[i + 1]->name));
435 DBG((mod, LEVEL_1, "%+F (%+F, %s) and (%+F, %s)\n",
436 irn, res1, cycle->elems[i]->name, res2, cycle->elems[i + 1]->name));
438 cpyxchg = be_new_Perm(reg_class, env->birg->irg, block, 2, in);
442 /* cycle is not done yet */
443 int pidx = get_pairidx_for_regidx(pairs, n, cycle->elems[i]->index, 0);
445 /* create intermediate proj */
446 res1 = new_r_Proj(get_irn_irg(irn), block, cpyxchg, get_irn_mode(res1), 0);
448 /* set as in for next Perm */
449 pairs[pidx].in_node = res1;
457 set_Proj_pred(res2, cpyxchg);
458 set_Proj_proj(res2, 0);
459 set_Proj_pred(res1, cpyxchg);
460 set_Proj_proj(res1, 1);
462 sched_add_after(sched_point, res1);
463 sched_add_after(sched_point, res2);
465 arch_set_irn_register(arch_env, res2, cycle->elems[i + 1]);
466 arch_set_irn_register(arch_env, res1, cycle->elems[i]);
468 /* insert the copy/exchange node in schedule after the magic schedule node (see above) */
469 sched_add_after(sched_point, cpyxchg);
471 DBG((mod, LEVEL_1, "replacing %+F with %+F, placed new node after %+F\n", irn, cpyxchg, sched_point));
473 /* set the new scheduling point */
477 DBG((mod, LEVEL_1, "%+F creating copy node (%+F, %s) -> (%+F, %s)\n",
478 irn, arg1, cycle->elems[i]->name, res2, cycle->elems[i + 1]->name));
480 cpyxchg = be_new_Copy(reg_class, env->birg->irg, block, arg1);
481 arch_set_irn_register(arch_env, cpyxchg, cycle->elems[i + 1]);
484 /* remove the proj from the schedule */
487 /* exchange copy node and proj */
488 exchange(res2, cpyxchg);
490 /* insert the copy/exchange node in schedule after the magic schedule node (see above) */
491 sched_add_after(sched_point, cpyxchg);
493 /* set the new scheduling point */
494 sched_point = cpyxchg;
498 be_do_stat_permcycle(reg_class->name, irn, block, cycle->type == PERM_CHAIN, cycle->n_elems, n_ops);
500 free((void *) cycle->elems);
504 /* remove the perm from schedule */
513 static int get_n_out_edges(const ir_node *irn) {
514 const ir_edge_t *edge;
517 foreach_out_edge(irn, edge) {
524 static ir_node *belower_skip_proj(ir_node *irn) {
526 irn = get_Proj_pred(irn);
530 static ir_node *find_copy(constraint_env_t *env, ir_node *irn, ir_node *op) {
531 const arch_env_t *arch_env = env->birg->main_env->arch_env;
532 ir_node *block = get_nodes_block(irn);
535 for (cur_node = sched_prev(irn);
536 ! is_Block(cur_node) && be_is_Copy(cur_node) && get_nodes_block(cur_node) == block;
537 cur_node = sched_prev(cur_node))
539 if (be_get_Copy_op(cur_node) == op && arch_irn_is(arch_env, cur_node, dont_spill))
546 static void gen_assure_different_pattern(ir_node *irn, ir_node *other_different, constraint_env_t *env) {
547 be_irg_t *birg = env->birg;
548 pset *op_set = env->op_set;
549 const arch_env_t *arch_env = birg->main_env->arch_env;
550 ir_node *block = get_nodes_block(irn);
551 const arch_register_class_t *cls = arch_get_irn_reg_class(arch_env, other_different, -1);
552 ir_node *in[2], *keep, *cpy;
553 op_copy_assoc_t key, *entry;
554 DEBUG_ONLY(firm_dbg_module_t *mod = env->dbg;)
556 if (arch_irn_is(arch_env, other_different, ignore) || ! mode_is_datab(get_irn_mode(other_different))) {
557 DBG((mod, LEVEL_1, "ignore constraint for %+F because other_irn is ignore or not a datab node\n", irn));
561 /* Make a not spillable copy of the different node */
562 /* this is needed because the different irn could be */
563 /* in block far far away */
564 /* The copy is optimized later if not needed */
566 /* check if already exists such a copy in the schedule immediatly before */
567 cpy = find_copy(env, belower_skip_proj(irn), other_different);
569 cpy = be_new_Copy(cls, birg->irg, block, other_different);
570 be_node_set_flags(cpy, BE_OUT_POS(0), arch_irn_flags_dont_spill);
571 DBG((mod, LEVEL_1, "created non-spillable %+F for value %+F\n", cpy, other_different));
574 DBG((mod, LEVEL_1, "using already existing %+F for value %+F\n", cpy, other_different));
580 /* Add the Keep resp. CopyKeep and reroute the users */
581 /* of the other_different irn in case of CopyKeep. */
582 if (get_n_out_edges(other_different) == 0) {
583 keep = be_new_Keep(cls, birg->irg, block, 2, in);
586 keep = be_new_CopyKeep_single(cls, birg->irg, block, cpy, irn, get_irn_mode(other_different));
587 be_node_set_reg_class(keep, 1, cls);
590 DBG((mod, LEVEL_1, "created %+F(%+F, %+F)\n\n", keep, irn, cpy));
592 /* insert copy and keep into schedule */
593 assert(sched_is_scheduled(irn) && "need schedule to assure constraints");
594 if (! sched_is_scheduled(cpy))
595 sched_add_before(belower_skip_proj(irn), cpy);
596 sched_add_after(irn, keep);
598 /* insert the other different and it's copies into the set */
599 key.op = other_different;
601 entry = pset_find(op_set, &key, nodeset_hash(other_different));
604 entry = obstack_alloc(&env->obst, sizeof(*entry));
605 entry->copies = pset_new_ptr_default();
606 entry->op = other_different;
611 pset_insert_ptr(entry->copies, cpy);
613 /* insert keep in case of CopyKeep */
614 if (be_is_CopyKeep(keep))
615 pset_insert_ptr(entry->copies, keep);
617 pset_insert(op_set, entry, nodeset_hash(other_different));
621 * Checks if node has a should_be_different constraint in output
622 * and adds a Keep then to assure the constraint.
624 static void assure_different_constraints(ir_node *irn, constraint_env_t *env) {
625 const arch_register_req_t *req;
626 arch_register_req_t req_temp;
628 req = arch_get_register_req(env->birg->main_env->arch_env, &req_temp, irn, -1);
631 if (arch_register_req_is(req, should_be_different)) {
632 gen_assure_different_pattern(irn, req->other_different, env);
634 else if (arch_register_req_is(req, should_be_different_from_all)) {
635 int i, n = get_irn_arity(belower_skip_proj(irn));
636 for (i = 0; i < n; i++) {
637 gen_assure_different_pattern(irn, get_irn_n(belower_skip_proj(irn), i), env);
646 * Calls the functions to assure register constraints.
648 * @param irn The node to be checked for lowering
649 * @param walk_env The walker environment
651 static void assure_constraints_walker(ir_node *irn, void *walk_env) {
655 if (sched_is_scheduled(irn) && mode_is_datab(get_irn_mode(irn)))
656 assure_different_constraints(irn, walk_env);
662 * Melt all copykeeps pointing to the same node
663 * (or Projs of the same node), copying the same operand.
665 static void melt_copykeeps(constraint_env_t *cenv) {
666 op_copy_assoc_t *entry;
669 foreach_pset(cenv->op_set, entry) {
673 ir_node **ck_arr, **melt_arr;
677 /* collect all copykeeps */
679 foreach_pset(entry->copies, cp) {
680 if (be_is_CopyKeep(cp)) {
681 obstack_grow(&obst, &cp, sizeof(cp));
684 #ifdef KEEP_ALIVE_COPYKEEP_HACK
686 set_irn_mode(cp, mode_ANY);
689 #endif /* KEEP_ALIVE_COPYKEEP_HACK */
692 /* compare each copykeep with all other copykeeps */
693 ck_arr = (ir_node **)obstack_finish(&obst);
694 for (idx = 0; idx < num_ck; ++idx) {
695 ir_node *ref, *ref_mode_T;
701 ir_node *sched_pt = NULL;
705 ref_mode_T = skip_Proj(get_irn_n(ref, 1));
706 obstack_grow(&obst, &ref, sizeof(ref));
708 DBG((cenv->dbg, LEVEL_1, "Trying to melt %+F:\n", ref));
710 /* check for copykeeps pointing to the same mode_T node as the reference copykeep */
711 for (j = 0; j < num_ck; ++j) {
712 ir_node *cur_ck = ck_arr[j];
714 if (j != idx && cur_ck && skip_Proj(get_irn_n(cur_ck, 1)) == ref_mode_T) {
715 obstack_grow(&obst, &cur_ck, sizeof(cur_ck));
716 pset_remove_ptr(entry->copies, cur_ck);
717 DBG((cenv->dbg, LEVEL_1, "\t%+F\n", cur_ck));
720 sched_remove(cur_ck);
725 /* check, if we found some candidates for melting */
727 DBG((cenv->dbg, LEVEL_1, "\tno candidate found\n"));
731 pset_remove_ptr(entry->copies, ref);
734 melt_arr = (ir_node **)obstack_finish(&obst);
735 /* melt all found copykeeps */
736 NEW_ARR_A(ir_node *, new_ck_in, n_melt);
737 for (j = 0; j < n_melt; ++j) {
738 new_ck_in[j] = get_irn_n(melt_arr[j], 1);
740 /* now, we can kill the melted keep, except the */
741 /* ref one, we still need some information */
742 if (melt_arr[j] != ref)
743 be_kill_node(melt_arr[j]);
746 #ifdef KEEP_ALIVE_COPYKEEP_HACK
747 new_ck = be_new_CopyKeep(entry->cls, cenv->birg->irg, get_nodes_block(ref), be_get_CopyKeep_op(ref), n_melt, new_ck_in, mode_ANY);
750 new_ck = be_new_CopyKeep(entry->cls, cenv->birg->irg, get_nodes_block(ref), be_get_CopyKeep_op(ref), n_melt, new_ck_in, get_irn_mode(ref));
751 #endif /* KEEP_ALIVE_COPYKEEP_HACK */
753 /* set register class for all keeped inputs */
754 for (j = 1; j <= n_melt; ++j)
755 be_node_set_reg_class(new_ck, j, entry->cls);
757 pset_insert_ptr(entry->copies, new_ck);
759 /* find scheduling point */
760 if (get_irn_mode(ref_mode_T) == mode_T) {
761 /* walk along the Projs */
762 for (sched_pt = sched_next(ref_mode_T); is_Proj(sched_pt) || be_is_Keep(sched_pt) || be_is_CopyKeep(sched_pt); sched_pt = sched_next(sched_pt))
763 /* just walk along the schedule until a non-Proj/Keep/CopyKeep node is found*/ ;
766 sched_pt = ref_mode_T;
769 sched_add_before(sched_pt, new_ck);
770 DBG((cenv->dbg, LEVEL_1, "created %+F, scheduled before %+F\n", new_ck, sched_pt));
772 /* finally: kill the reference copykeep */
777 obstack_free(&obst, NULL);
782 * Walks over all nodes to assure register constraints.
784 * @param birg The birg structure containing the irg
786 void assure_constraints(be_irg_t *birg) {
787 constraint_env_t cenv;
788 op_copy_assoc_t *entry;
790 FIRM_DBG_REGISTER(firm_dbg_module_t *mod, "firm.be.lower.constr");
792 be_assure_dom_front(birg);
794 DEBUG_ONLY(cenv.dbg = mod;)
796 cenv.op_set = new_pset(cmp_op_copy_assoc, 16);
797 obstack_init(&cenv.obst);
799 irg_walk_blkwise_graph(birg->irg, NULL, assure_constraints_walker, &cenv);
801 /* melt copykeeps, pointing to projs of */
802 /* the same mode_T node and keeping the */
804 melt_copykeeps(&cenv);
807 foreach_pset(cenv.op_set, entry) {
811 n = pset_count(entry->copies);
812 nodes = alloca((n + 1) * sizeof(nodes[0]));
814 /* put the node in an array */
816 nodes[n++] = entry->op;
817 DBG((mod, LEVEL_1, "introduce copies for %+F ", entry->op));
819 /* collect all copies */
820 foreach_pset(entry->copies, cp) {
822 DB((mod, LEVEL_1, ", %+F ", cp));
825 DB((mod, LEVEL_1, "\n"));
827 /* introduce the copies for the operand and it's copies */
828 be_ssa_constr(birg->dom_front, NULL, n, nodes);
831 /* Could be that not all CopyKeeps are really needed, */
832 /* so we transform unnecessary ones into Keeps. */
833 foreach_pset(entry->copies, cp) {
834 if (be_is_CopyKeep(cp) && get_irn_n_edges(cp) < 1) {
836 int n = get_irn_arity(cp);
838 keep = be_new_Keep(arch_get_irn_reg_class(birg->main_env->arch_env, cp, -1),
839 birg->irg, get_nodes_block(cp), n, (ir_node **)&get_irn_in(cp)[1]);
840 sched_add_before(cp, keep);
842 /* Set all ins (including the block) of the CopyKeep BAD to keep the verifier happy. */
848 del_pset(entry->copies);
851 del_pset(cenv.op_set);
852 obstack_free(&cenv.obst, NULL);
858 * Calls the corresponding lowering function for the node.
860 * @param irn The node to be checked for lowering
861 * @param walk_env The walker environment
863 static void lower_nodes_after_ra_walker(ir_node *irn, void *walk_env) {
864 if (! is_Block(irn) && ! is_Proj(irn)) {
865 if (be_is_Perm(irn)) {
866 lower_perm_node(irn, walk_env);
874 * Walks over all blocks in an irg and performs lowering need to be
875 * done after register allocation (e.g. perm lowering).
877 * @param birg The birg object
878 * @param do_copy 1 == resolve cycles with a free reg if available
880 void lower_nodes_after_ra(be_irg_t *birg, int do_copy) {
884 env.arch_env = birg->main_env->arch_env;
885 env.do_copy = do_copy;
886 FIRM_DBG_REGISTER(env.dbg_module, "firm.be.lower");
888 irg_walk_blkwise_graph(birg->irg, NULL, lower_nodes_after_ra_walker, &env);