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 static void kill_node(ir_node *irn, int kill_block) {
89 int i, arity = get_irn_arity(irn);
90 ir_graph *irg = get_irn_irg(irn);
92 for (i = -1; i < arity; ++i) {
93 set_irn_n(irn, i, new_r_Bad(irg));
97 /* Compare the two operands */
98 static int cmp_op_copy_assoc(const void *a, const void *b) {
99 const op_copy_assoc_t *op1 = a;
100 const op_copy_assoc_t *op2 = b;
102 return op1->op != op2->op;
105 /* Compare the in registers of two register pairs */
106 static int compare_reg_pair(const void *a, const void *b) {
107 const reg_pair_t *pair_a = a;
108 const reg_pair_t *pair_b = b;
110 if (pair_a->in_reg->index > pair_b->in_reg->index)
116 /* returns the number register pairs marked as checked */
117 static int get_n_checked_pairs(reg_pair_t *pairs, int n) {
118 int i, n_checked = 0;
120 for (i = 0; i < n; i++) {
121 if (pairs[i].checked)
129 * Gets the node corresponding to a register from an array of register pairs.
130 * NOTE: The given registers pairs and the register to look for must belong
131 * to the same register class.
133 * @param pairs The array of register pairs
134 * @param n The number of pairs
135 * @param reg The register to look for
136 * @param in_out 0 == look for IN register, 1 == look for OUT register
137 * @return The corresponding node or NULL if not found
139 static ir_node *get_node_for_register(reg_pair_t *pairs, int n, const arch_register_t *reg, int in_out) {
143 for (i = 0; i < n; i++) {
144 /* out register matches */
145 if (pairs[i].out_reg->index == reg->index)
146 return pairs[i].out_node;
150 for (i = 0; i < n; i++) {
151 /* in register matches */
152 if (pairs[i].in_reg->index == reg->index)
153 return pairs[i].in_node;
161 * Gets the index in the register pair array where the in/out register
162 * corresponds to reg_idx.
164 * @param pairs The array of register pairs
165 * @param n The number of pairs
166 * @param reg The register index to look for
167 * @param in_out 0 == look for IN register, 1 == look for OUT register
168 * @return The corresponding index in pairs or -1 if not found
170 static int get_pairidx_for_regidx(reg_pair_t *pairs, int n, int reg_idx, int in_out) {
174 for (i = 0; i < n; i++) {
175 /* out register matches */
176 if (pairs[i].out_reg->index == reg_idx)
181 for (i = 0; i < n; i++) {
182 /* in register matches */
183 if (pairs[i].in_reg->index == reg_idx)
192 * Gets an array of register pairs and tries to identify a cycle or chain starting
195 * @param cycle Variable to hold the cycle
196 * @param pairs Array of register pairs
197 * @param start Index to start
198 * @return The cycle or chain
200 static perm_cycle_t *get_perm_cycle(perm_cycle_t *cycle, reg_pair_t *pairs, int n, int start) {
201 int head = pairs[start].in_reg->index;
202 int cur_idx = pairs[start].out_reg->index;
203 int cur_pair_idx = start;
204 int n_pairs_done = get_n_checked_pairs(pairs, n);
206 perm_type_t cycle_tp = PERM_CYCLE;
208 /* We could be right in the middle of a chain, so we need to find the start */
209 while (head != cur_idx) {
210 /* goto previous register in cycle or chain */
211 cur_pair_idx = get_pairidx_for_regidx(pairs, n, head, 1);
213 if (cur_pair_idx < 0) {
214 cycle_tp = PERM_CHAIN;
218 head = pairs[cur_pair_idx].in_reg->index;
219 start = cur_pair_idx;
223 /* assume worst case: all remaining pairs build a cycle or chain */
224 cycle->elems = xcalloc((n - n_pairs_done) * 2, sizeof(cycle->elems[0]));
225 cycle->n_elems = 2; /* initial number of elements is 2 */
226 cycle->elems[0] = pairs[start].in_reg;
227 cycle->elems[1] = pairs[start].out_reg;
228 cycle->type = cycle_tp;
229 cur_idx = pairs[start].out_reg->index;
232 /* check for cycle or end of a chain */
233 while (cur_idx != head) {
234 /* goto next register in cycle or chain */
235 cur_pair_idx = get_pairidx_for_regidx(pairs, n, cur_idx, 0);
237 if (cur_pair_idx < 0)
240 cur_idx = pairs[cur_pair_idx].out_reg->index;
242 /* it's not the first element: insert it */
243 if (cur_idx != head) {
244 cycle->elems[idx++] = pairs[cur_pair_idx].out_reg;
248 /* we are there where we started -> CYCLE */
249 cycle->type = PERM_CYCLE;
253 /* mark all pairs having one in/out register with cycle in common as checked */
254 for (idx = 0; idx < cycle->n_elems; idx++) {
255 cur_pair_idx = get_pairidx_for_regidx(pairs, n, cycle->elems[idx]->index, 0);
257 if (cur_pair_idx >= 0)
258 pairs[cur_pair_idx].checked = 1;
260 cur_pair_idx = get_pairidx_for_regidx(pairs, n, cycle->elems[idx]->index, 1);
262 if (cur_pair_idx >= 0)
263 pairs[cur_pair_idx].checked = 1;
270 * Lowers a perm node. Resolves cycles and creates a bunch of
271 * copy and swap operations to permute registers.
272 * Note: The caller of this function has to make sure, that irn
275 * @param irn The perm node
276 * @param block The block the perm node belongs to
277 * @param walk_env The environment
279 static void lower_perm_node(ir_node *irn, void *walk_env) {
280 const arch_register_class_t *reg_class;
281 const arch_env_t *arch_env;
282 lower_env_t *env = walk_env;
285 int n, i, pn, do_copy, j, n_ops;
287 const ir_edge_t *edge;
289 ir_node *sched_point, *block, *in[2];
290 ir_node *arg1, *arg2, *res1, *res2;
291 ir_node *cpyxchg = NULL;
292 DEBUG_ONLY(firm_dbg_module_t *mod;)
294 arch_env = env->arch_env;
295 do_copy = env->do_copy;
296 DEBUG_ONLY(mod = env->dbg_module;)
297 block = get_nodes_block(irn);
300 Get the schedule predecessor node to the perm
301 NOTE: This works with auto-magic. If we insert the
302 new copy/exchange nodes after this node, everything
305 sched_point = sched_prev(irn);
306 DBG((mod, LEVEL_1, "sched point is %+F\n", sched_point));
307 assert(sched_point && "Perm is not scheduled or has no predecessor");
309 n = get_irn_arity(irn);
310 assert(n == get_irn_n_edges(irn) && "perm's in and out numbers different");
312 reg_class = arch_get_irn_register(arch_env, get_irn_n(irn, 0))->reg_class;
313 pairs = alloca(n * sizeof(pairs[0]));
315 /* build the list of register pairs (in, out) */
317 foreach_out_edge(irn, edge) {
318 pairs[i].out_node = get_edge_src_irn(edge);
319 pn = get_Proj_proj(pairs[i].out_node);
320 pairs[i].in_node = get_irn_n(irn, pn);
322 pairs[i].in_reg = arch_get_irn_register(arch_env, pairs[i].in_node);
323 pairs[i].out_reg = arch_get_irn_register(arch_env, pairs[i].out_node);
325 pairs[i].checked = 0;
329 /* sort the register pairs by the indices of the in registers */
330 qsort(pairs, n, sizeof(pairs[0]), compare_reg_pair);
332 /* Mark all equal pairs as checked, and exchange the OUT proj with
334 for (i = 0; i < n; i++) {
335 if (pairs[i].in_reg->index == pairs[i].out_reg->index) {
336 DBG((mod, LEVEL_1, "%+F removing equal perm register pair (%+F, %+F, %s)\n",
337 irn, pairs[i].in_node, pairs[i].out_node, pairs[i].out_reg->name));
339 /* We have to check for a special case:
340 The in-node could be a Proj from a Perm. In this case,
341 we need to correct the projnum */
342 if (be_is_Perm(pairs[i].in_node) && is_Proj(pairs[i].in_node)) {
343 set_Proj_proj(pairs[i].out_node, get_Proj_proj(pairs[i].in_node));
346 /* remove the proj from the schedule */
347 sched_remove(pairs[i].out_node);
349 /* reroute the edges from the proj to the argument */
350 edges_reroute(pairs[i].out_node, pairs[i].in_node, env->birg->irg);
351 set_irn_n(pairs[i].out_node, 0, new_Bad());
353 pairs[i].checked = 1;
357 /* Set do_copy to 0 if it's on but we have no free register */
362 real_size = n - get_n_checked_pairs(pairs, n);
364 be_do_stat_perm(reg_class->name, reg_class->n_regs, irn, block, n, real_size);
366 /* check for cycles and chains */
367 while (get_n_checked_pairs(pairs, n) < n) {
370 /* go to the first not-checked pair */
371 while (pairs[i].checked) i++;
372 cycle = xcalloc(1, sizeof(*cycle));
373 cycle = get_perm_cycle(cycle, pairs, n, i);
375 DB((mod, LEVEL_1, "%+F: following %s created:\n ", irn, cycle->type == PERM_CHAIN ? "chain" : "cycle"));
376 for (j = 0; j < cycle->n_elems; j++) {
377 DB((mod, LEVEL_1, " %s", cycle->elems[j]->name));
379 DB((mod, LEVEL_1, "\n"));
382 We don't need to do anything if we have a Perm with two
383 elements which represents a cycle, because those nodes
384 already represent exchange nodes
386 if (n == 2 && cycle->type == PERM_CYCLE) {
392 //TODO: - iff PERM_CYCLE && do_copy -> determine free temp reg and insert copy to/from it before/after
393 // the copy cascade (this reduces the cycle into a chain)
395 /* build copy/swap nodes from back to front */
396 for (i = cycle->n_elems - 2; i >= 0; i--) {
397 arg1 = get_node_for_register(pairs, n, cycle->elems[i], 0);
398 arg2 = get_node_for_register(pairs, n, cycle->elems[i + 1], 0);
400 res1 = get_node_for_register(pairs, n, cycle->elems[i], 1);
401 res2 = get_node_for_register(pairs, n, cycle->elems[i + 1], 1);
403 If we have a cycle and don't copy: we need to create exchange nodes
404 NOTE: An exchange node is a perm node with 2 INs and 2 OUTs
405 IN_1 = in node with register i
406 IN_2 = in node with register i + 1
407 OUT_1 = out node with register i + 1
408 OUT_2 = out node with register i
410 if (cycle->type == PERM_CYCLE && !do_copy) {
414 /* At this point we have to handle the following problem: */
416 /* If we have a cycle with more than two elements, then */
417 /* this could correspond to the following Perm node: */
419 /* +----+ +----+ +----+ */
420 /* | r1 | | r2 | | r3 | */
421 /* +-+--+ +-+--+ +--+-+ */
424 /* +-+--------+---------+-+ */
426 /* +-+--------+---------+-+ */
429 /* +-+--+ +-+--+ +--+-+ */
430 /* |Proj| |Proj| |Proj| */
431 /* | r2 | | r3 | | r1 | */
432 /* +----+ +----+ +----+ */
434 /* This node is about to be split up into two 2x Perm's */
435 /* for which we need 4 Proj's and the one additional Proj */
436 /* of the first Perm has to be one IN of the second. So in */
437 /* general we need to create one additional Proj for each */
438 /* "middle" Perm and set this to one in node of the successor */
441 DBG((mod, LEVEL_1, "%+F creating exchange node (%+F, %s) and (%+F, %s) with\n",
442 irn, arg1, cycle->elems[i]->name, arg2, cycle->elems[i + 1]->name));
443 DBG((mod, LEVEL_1, "%+F (%+F, %s) and (%+F, %s)\n",
444 irn, res1, cycle->elems[i]->name, res2, cycle->elems[i + 1]->name));
446 cpyxchg = be_new_Perm(reg_class, env->birg->irg, block, 2, in);
450 /* cycle is not done yet */
451 int pidx = get_pairidx_for_regidx(pairs, n, cycle->elems[i]->index, 0);
453 /* create intermediate proj */
454 res1 = new_r_Proj(get_irn_irg(irn), block, cpyxchg, get_irn_mode(res1), 0);
456 /* set as in for next Perm */
457 pairs[pidx].in_node = res1;
465 set_Proj_pred(res2, cpyxchg);
466 set_Proj_proj(res2, 0);
467 set_Proj_pred(res1, cpyxchg);
468 set_Proj_proj(res1, 1);
470 sched_add_after(sched_point, res1);
471 sched_add_after(sched_point, res2);
473 arch_set_irn_register(arch_env, res2, cycle->elems[i + 1]);
474 arch_set_irn_register(arch_env, res1, cycle->elems[i]);
476 /* insert the copy/exchange node in schedule after the magic schedule node (see above) */
477 sched_add_after(sched_point, cpyxchg);
479 DBG((mod, LEVEL_1, "replacing %+F with %+F, placed new node after %+F\n", irn, cpyxchg, sched_point));
481 /* set the new scheduling point */
485 DBG((mod, LEVEL_1, "%+F creating copy node (%+F, %s) -> (%+F, %s)\n",
486 irn, arg1, cycle->elems[i]->name, res2, cycle->elems[i + 1]->name));
488 cpyxchg = be_new_Copy(reg_class, env->birg->irg, block, arg1);
489 arch_set_irn_register(arch_env, cpyxchg, cycle->elems[i + 1]);
492 /* remove the proj from the schedule */
495 /* exchange copy node and proj */
496 exchange(res2, cpyxchg);
498 /* insert the copy/exchange node in schedule after the magic schedule node (see above) */
499 sched_add_after(sched_point, cpyxchg);
501 /* set the new scheduling point */
502 sched_point = cpyxchg;
506 be_do_stat_permcycle(reg_class->name, irn, block, cycle->type == PERM_CHAIN, cycle->n_elems, n_ops);
508 free((void *) cycle->elems);
512 /* remove the perm from schedule */
521 static int get_n_out_edges(const ir_node *irn) {
522 const ir_edge_t *edge;
525 foreach_out_edge(irn, edge) {
532 static ir_node *belower_skip_proj(ir_node *irn) {
534 irn = get_Proj_pred(irn);
538 static ir_node *find_copy(constraint_env_t *env, ir_node *irn, ir_node *op) {
539 const arch_env_t *arch_env = env->birg->main_env->arch_env;
540 ir_node *block = get_nodes_block(irn);
543 for (cur_node = sched_prev(irn);
544 ! is_Block(cur_node) && be_is_Copy(cur_node) && get_nodes_block(cur_node) == block;
545 cur_node = sched_prev(cur_node))
547 if (be_get_Copy_op(cur_node) == op && arch_irn_is(arch_env, cur_node, dont_spill))
554 static void gen_assure_different_pattern(ir_node *irn, ir_node *other_different, constraint_env_t *env) {
555 be_irg_t *birg = env->birg;
556 pset *op_set = env->op_set;
557 const arch_env_t *arch_env = birg->main_env->arch_env;
558 ir_node *block = get_nodes_block(irn);
559 const arch_register_class_t *cls = arch_get_irn_reg_class(arch_env, other_different, -1);
560 ir_node *in[2], *keep, *cpy;
561 op_copy_assoc_t key, *entry;
562 DEBUG_ONLY(firm_dbg_module_t *mod = env->dbg;)
564 if (arch_irn_is(arch_env, other_different, ignore) || ! mode_is_datab(get_irn_mode(other_different))) {
565 DBG((mod, LEVEL_1, "ignore constraint for %+F because other_irn is ignore or not a datab node\n", irn));
569 /* Make a not spillable copy of the different node */
570 /* this is needed because the different irn could be */
571 /* in block far far away */
572 /* The copy is optimized later if not needed */
574 /* check if already exists such a copy in the schedule immediatly before */
575 cpy = find_copy(env, belower_skip_proj(irn), other_different);
577 cpy = be_new_Copy(cls, birg->irg, block, other_different);
578 be_node_set_flags(cpy, BE_OUT_POS(0), arch_irn_flags_dont_spill);
579 DBG((mod, LEVEL_1, "created non-spillable %+F for value %+F\n", cpy, other_different));
582 DBG((mod, LEVEL_1, "using already existing %+F for value %+F\n", cpy, other_different));
588 /* Add the Keep resp. CopyKeep and reroute the users */
589 /* of the other_different irn in case of CopyKeep. */
590 if (get_n_out_edges(other_different) == 0) {
591 keep = be_new_Keep(cls, birg->irg, block, 2, in);
594 keep = be_new_CopyKeep_single(cls, birg->irg, block, cpy, irn, get_irn_mode(other_different));
595 be_node_set_reg_class(keep, 1, cls);
598 DBG((mod, LEVEL_1, "created %+F(%+F, %+F)\n\n", keep, irn, cpy));
600 /* insert copy and keep into schedule */
601 assert(sched_is_scheduled(irn) && "need schedule to assure constraints");
602 if (! sched_is_scheduled(cpy))
603 sched_add_before(belower_skip_proj(irn), cpy);
604 sched_add_after(irn, keep);
606 /* insert the other different and it's copies into the set */
607 key.op = other_different;
609 entry = pset_find(op_set, &key, nodeset_hash(other_different));
612 entry = obstack_alloc(&env->obst, sizeof(*entry));
613 entry->copies = pset_new_ptr_default();
614 entry->op = other_different;
619 pset_insert_ptr(entry->copies, cpy);
621 /* insert keep in case of CopyKeep */
622 if (be_is_CopyKeep(keep))
623 pset_insert_ptr(entry->copies, keep);
625 pset_insert(op_set, entry, nodeset_hash(other_different));
629 * Checks if node has a should_be_different constraint in output
630 * and adds a Keep then to assure the constraint.
632 static void assure_different_constraints(ir_node *irn, constraint_env_t *env) {
633 const arch_register_req_t *req;
634 arch_register_req_t req_temp;
636 req = arch_get_register_req(env->birg->main_env->arch_env, &req_temp, irn, -1);
639 if (arch_register_req_is(req, should_be_different)) {
640 gen_assure_different_pattern(irn, req->other_different, env);
642 else if (arch_register_req_is(req, should_be_different_from_all)) {
643 int i, n = get_irn_arity(belower_skip_proj(irn));
644 for (i = 0; i < n; i++) {
645 gen_assure_different_pattern(irn, get_irn_n(belower_skip_proj(irn), i), env);
654 * Calls the functions to assure register constraints.
656 * @param irn The node to be checked for lowering
657 * @param walk_env The walker environment
659 static void assure_constraints_walker(ir_node *irn, void *walk_env) {
663 if (sched_is_scheduled(irn) && mode_is_datab(get_irn_mode(irn)))
664 assure_different_constraints(irn, walk_env);
670 * Melt all copykeeps pointing to the same node
671 * (or Projs of the same node), copying the same operand.
673 static void melt_copykeeps(constraint_env_t *cenv) {
674 op_copy_assoc_t *entry;
677 foreach_pset(cenv->op_set, entry) {
681 ir_node **ck_arr, **melt_arr;
685 /* collect all copykeeps */
687 foreach_pset(entry->copies, cp) {
688 if (be_is_CopyKeep(cp)) {
689 obstack_grow(&obst, &cp, sizeof(cp));
692 #ifdef KEEP_ALIVE_COPYKEEP_HACK
694 set_irn_mode(cp, mode_ANY);
697 #endif /* KEEP_ALIVE_COPYKEEP_HACK */
700 /* compare each copykeep with all other copykeeps */
701 ck_arr = (ir_node **)obstack_finish(&obst);
702 for (idx = 0; idx < num_ck; ++idx) {
703 ir_node *ref, *ref_mode_T;
709 ir_node *sched_pt = NULL;
713 ref_mode_T = skip_Proj(get_irn_n(ref, 1));
714 obstack_grow(&obst, &ref, sizeof(ref));
716 DBG((cenv->dbg, LEVEL_1, "Trying to melt %+F:\n", ref));
718 /* check for copykeeps pointing to the same mode_T node as the reference copykeep */
719 for (j = 0; j < num_ck; ++j) {
720 ir_node *cur_ck = ck_arr[j];
722 if (j != idx && cur_ck && skip_Proj(get_irn_n(cur_ck, 1)) == ref_mode_T) {
723 obstack_grow(&obst, &cur_ck, sizeof(cur_ck));
724 pset_remove_ptr(entry->copies, cur_ck);
725 DBG((cenv->dbg, LEVEL_1, "\t%+F\n", cur_ck));
728 sched_remove(cur_ck);
733 /* check, if we found some candidates for melting */
735 DBG((cenv->dbg, LEVEL_1, "\tno candidate found\n"));
739 pset_remove_ptr(entry->copies, ref);
742 melt_arr = (ir_node **)obstack_finish(&obst);
743 /* melt all found copykeeps */
744 NEW_ARR_A(ir_node *, new_ck_in, n_melt);
745 for (j = 0; j < n_melt; ++j) {
746 new_ck_in[j] = get_irn_n(melt_arr[j], 1);
748 /* now, we can kill the melted keep, except the */
749 /* ref one, we still need some information */
750 if (melt_arr[j] != ref)
751 kill_node(melt_arr[j], 0);
754 #ifdef KEEP_ALIVE_COPYKEEP_HACK
755 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);
758 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));
759 #endif /* KEEP_ALIVE_COPYKEEP_HACK */
761 /* set register class for all keeped inputs */
762 for (j = 1; j <= n_melt; ++j)
763 be_node_set_reg_class(new_ck, j, entry->cls);
765 pset_insert_ptr(entry->copies, new_ck);
767 /* find scheduling point */
768 if (get_irn_mode(ref_mode_T) == mode_T) {
769 /* walk along the Projs */
770 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))
771 /* just walk along the schedule until a non-Proj/Keep/CopyKeep node is found*/ ;
774 sched_pt = ref_mode_T;
777 sched_add_before(sched_pt, new_ck);
778 DBG((cenv->dbg, LEVEL_1, "created %+F, scheduled before %+F\n", new_ck, sched_pt));
780 /* finally: kill the reference copykeep */
785 obstack_free(&obst, NULL);
790 * Walks over all nodes to assure register constraints.
792 * @param birg The birg structure containing the irg
794 void assure_constraints(be_irg_t *birg) {
795 constraint_env_t cenv;
796 op_copy_assoc_t *entry;
798 FIRM_DBG_REGISTER(firm_dbg_module_t *mod, "firm.be.lower.constr");
800 be_assure_dom_front(birg);
802 DEBUG_ONLY(cenv.dbg = mod;)
804 cenv.op_set = new_pset(cmp_op_copy_assoc, 16);
805 obstack_init(&cenv.obst);
807 irg_walk_blkwise_graph(birg->irg, NULL, assure_constraints_walker, &cenv);
809 /* melt copykeeps, pointing to projs of */
810 /* the same mode_T node and keeping the */
812 melt_copykeeps(&cenv);
815 foreach_pset(cenv.op_set, entry) {
819 n = pset_count(entry->copies);
820 nodes = alloca((n + 1) * sizeof(nodes[0]));
822 /* put the node in an array */
824 nodes[n++] = entry->op;
825 DBG((mod, LEVEL_1, "introduce copies for %+F ", entry->op));
827 /* collect all copies */
828 foreach_pset(entry->copies, cp) {
830 DB((mod, LEVEL_1, ", %+F ", cp));
833 DB((mod, LEVEL_1, "\n"));
835 /* introduce the copies for the operand and it's copies */
836 be_ssa_constr(birg->dom_front, NULL, n, nodes);
839 /* Could be that not all CopyKeeps are really needed, */
840 /* so we transform unnecessary ones into Keeps. */
841 foreach_pset(entry->copies, cp) {
842 if (be_is_CopyKeep(cp) && get_irn_n_edges(cp) < 1) {
844 int n = get_irn_arity(cp);
846 keep = be_new_Keep(arch_get_irn_reg_class(birg->main_env->arch_env, cp, -1),
847 birg->irg, get_nodes_block(cp), n, (ir_node **)&get_irn_in(cp)[1]);
848 sched_add_before(cp, keep);
850 /* Set all ins (including the block) of the CopyKeep BAD to keep the verifier happy. */
856 del_pset(entry->copies);
859 del_pset(cenv.op_set);
860 obstack_free(&cenv.obst, NULL);
866 * Calls the corresponding lowering function for the node.
868 * @param irn The node to be checked for lowering
869 * @param walk_env The walker environment
871 static void lower_nodes_after_ra_walker(ir_node *irn, void *walk_env) {
872 if (! is_Block(irn) && ! is_Proj(irn)) {
873 if (be_is_Perm(irn)) {
874 lower_perm_node(irn, walk_env);
882 * Walks over all blocks in an irg and performs lowering need to be
883 * done after register allocation (e.g. perm lowering).
885 * @param birg The birg object
886 * @param do_copy 1 == resolve cycles with a free reg if available
888 void lower_nodes_after_ra(be_irg_t *birg, int do_copy) {
892 env.arch_env = birg->main_env->arch_env;
893 env.do_copy = do_copy;
894 FIRM_DBG_REGISTER(env.dbg_module, "firm.be.lower");
896 irg_walk_blkwise_graph(birg->irg, NULL, lower_nodes_after_ra_walker, &env);