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.
24 #include "besched_t.h"
26 #include "bessaconstr.h"
27 #include "irnodeset.h"
30 #include "iredges_t.h"
33 #undef KEEP_ALIVE_COPYKEEP_HACK
35 /* associates op with it's copy and CopyKeep */
37 ir_node *op; /* an irn which must be different */
38 ir_nodeset_t copies; /* all non-spillable copies of this irn */
39 const arch_register_class_t *cls;
42 /* environment for constraints */
47 DEBUG_ONLY(firm_dbg_module_t *dbg;)
50 /* lowering walker environment */
51 typedef struct _lower_env_t {
53 const arch_env_t *arch_env;
55 DEBUG_ONLY(firm_dbg_module_t *dbg_module;)
58 /* holds a perm register pair */
59 typedef struct _reg_pair_t {
60 const arch_register_t *in_reg; /**< a perm IN register */
61 ir_node *in_node; /**< the in node to which the register belongs */
63 const arch_register_t *out_reg; /**< a perm OUT register */
64 ir_node *out_node; /**< the out node to which the register belongs */
66 int checked; /**< indicates whether the pair was check for cycle or not */
69 typedef enum _perm_type_t {
76 /* structure to represent cycles or chains in a perm */
77 typedef struct _perm_cycle_t {
78 const arch_register_t **elems; /**< the registers in the cycle */
79 int n_elems; /**< number of elements in the cycle */
80 perm_type_t type; /**< type (CHAIN or CYCLE) */
83 /* Compare the two operands */
84 static int cmp_op_copy_assoc(const void *a, const void *b) {
85 const op_copy_assoc_t *op1 = a;
86 const op_copy_assoc_t *op2 = b;
88 return op1->op != op2->op;
91 /* Compare the in registers of two register pairs */
92 static int compare_reg_pair(const void *a, const void *b) {
93 const reg_pair_t *pair_a = a;
94 const reg_pair_t *pair_b = b;
96 if (pair_a->in_reg->index > pair_b->in_reg->index)
102 /* returns the number register pairs marked as checked */
103 static int get_n_checked_pairs(reg_pair_t *pairs, int n) {
104 int i, n_checked = 0;
106 for (i = 0; i < n; i++) {
107 if (pairs[i].checked)
115 * Gets the node corresponding to a register from an array of register pairs.
116 * NOTE: The given registers pairs and the register to look for must belong
117 * to the same register class.
119 * @param pairs The array of register pairs
120 * @param n The number of pairs
121 * @param reg The register to look for
122 * @param in_out 0 == look for IN register, 1 == look for OUT register
123 * @return The corresponding node or NULL if not found
125 static ir_node *get_node_for_register(reg_pair_t *pairs, int n, const arch_register_t *reg, int in_out) {
129 for (i = 0; i < n; i++) {
130 /* out register matches */
131 if (pairs[i].out_reg->index == reg->index)
132 return pairs[i].out_node;
136 for (i = 0; i < n; i++) {
137 /* in register matches */
138 if (pairs[i].in_reg->index == reg->index)
139 return pairs[i].in_node;
147 * Gets the index in the register pair array where the in/out register
148 * corresponds to reg_idx.
150 * @param pairs The array of register pairs
151 * @param n The number of pairs
152 * @param reg The register index to look for
153 * @param in_out 0 == look for IN register, 1 == look for OUT register
154 * @return The corresponding index in pairs or -1 if not found
156 static int get_pairidx_for_regidx(reg_pair_t *pairs, int n, int reg_idx, int in_out) {
160 for (i = 0; i < n; i++) {
161 /* out register matches */
162 if (pairs[i].out_reg->index == reg_idx)
167 for (i = 0; i < n; i++) {
168 /* in register matches */
169 if (pairs[i].in_reg->index == reg_idx)
178 * Gets an array of register pairs and tries to identify a cycle or chain starting
181 * @param cycle Variable to hold the cycle
182 * @param pairs Array of register pairs
183 * @param start Index to start
184 * @return The cycle or chain
186 static perm_cycle_t *get_perm_cycle(perm_cycle_t *cycle, reg_pair_t *pairs, int n, int start) {
187 int head = pairs[start].in_reg->index;
188 int cur_idx = pairs[start].out_reg->index;
189 int cur_pair_idx = start;
190 int n_pairs_done = get_n_checked_pairs(pairs, n);
192 perm_type_t cycle_tp = PERM_CYCLE;
194 /* We could be right in the middle of a chain, so we need to find the start */
195 while (head != cur_idx) {
196 /* goto previous register in cycle or chain */
197 cur_pair_idx = get_pairidx_for_regidx(pairs, n, head, 1);
199 if (cur_pair_idx < 0) {
200 cycle_tp = PERM_CHAIN;
204 head = pairs[cur_pair_idx].in_reg->index;
205 start = cur_pair_idx;
209 /* assume worst case: all remaining pairs build a cycle or chain */
210 cycle->elems = xcalloc((n - n_pairs_done) * 2, sizeof(cycle->elems[0]));
211 cycle->n_elems = 2; /* initial number of elements is 2 */
212 cycle->elems[0] = pairs[start].in_reg;
213 cycle->elems[1] = pairs[start].out_reg;
214 cycle->type = cycle_tp;
215 cur_idx = pairs[start].out_reg->index;
218 /* check for cycle or end of a chain */
219 while (cur_idx != head) {
220 /* goto next register in cycle or chain */
221 cur_pair_idx = get_pairidx_for_regidx(pairs, n, cur_idx, 0);
223 if (cur_pair_idx < 0)
226 cur_idx = pairs[cur_pair_idx].out_reg->index;
228 /* it's not the first element: insert it */
229 if (cur_idx != head) {
230 cycle->elems[idx++] = pairs[cur_pair_idx].out_reg;
234 /* we are there where we started -> CYCLE */
235 cycle->type = PERM_CYCLE;
239 /* mark all pairs having one in/out register with cycle in common as checked */
240 for (idx = 0; idx < cycle->n_elems; idx++) {
241 cur_pair_idx = get_pairidx_for_regidx(pairs, n, cycle->elems[idx]->index, 0);
243 if (cur_pair_idx >= 0)
244 pairs[cur_pair_idx].checked = 1;
246 cur_pair_idx = get_pairidx_for_regidx(pairs, n, cycle->elems[idx]->index, 1);
248 if (cur_pair_idx >= 0)
249 pairs[cur_pair_idx].checked = 1;
256 * Lowers a perm node. Resolves cycles and creates a bunch of
257 * copy and swap operations to permute registers.
258 * Note: The caller of this function has to make sure, that irn
261 * @param irn The perm node
262 * @param block The block the perm node belongs to
263 * @param walk_env The environment
265 static void lower_perm_node(ir_node *irn, void *walk_env) {
266 ir_graph *irg = get_irn_irg(irn);
267 const arch_register_class_t *reg_class;
268 const arch_env_t *arch_env;
269 lower_env_t *env = walk_env;
272 int n, i, pn, do_copy, j, n_ops;
274 const ir_edge_t *edge;
276 ir_node *sched_point, *block, *in[2];
277 ir_node *arg1, *arg2, *res1, *res2;
278 ir_node *cpyxchg = NULL;
279 DEBUG_ONLY(firm_dbg_module_t *mod;)
281 arch_env = env->arch_env;
282 do_copy = env->do_copy;
283 DEBUG_ONLY(mod = env->dbg_module;)
284 block = get_nodes_block(irn);
287 Get the schedule predecessor node to the perm
288 NOTE: This works with auto-magic. If we insert the
289 new copy/exchange nodes after this node, everything
292 sched_point = sched_prev(irn);
293 DBG((mod, LEVEL_1, "sched point is %+F\n", sched_point));
294 assert(sched_point && "Perm is not scheduled or has no predecessor");
296 n = get_irn_arity(irn);
297 assert(n == get_irn_n_edges(irn) && "perm's in and out numbers different");
299 reg_class = arch_get_irn_register(arch_env, get_irn_n(irn, 0))->reg_class;
300 pairs = alloca(n * sizeof(pairs[0]));
302 /* build the list of register pairs (in, out) */
304 foreach_out_edge(irn, edge) {
305 pairs[i].out_node = get_edge_src_irn(edge);
306 pn = get_Proj_proj(pairs[i].out_node);
307 pairs[i].in_node = get_irn_n(irn, pn);
309 pairs[i].in_reg = arch_get_irn_register(arch_env, pairs[i].in_node);
310 pairs[i].out_reg = arch_get_irn_register(arch_env, pairs[i].out_node);
312 pairs[i].checked = 0;
316 /* sort the register pairs by the indices of the in registers */
317 qsort(pairs, n, sizeof(pairs[0]), compare_reg_pair);
319 /* Mark all equal pairs as checked, and exchange the OUT proj with
321 for (i = 0; i < n; i++) {
322 if (pairs[i].in_reg->index == pairs[i].out_reg->index) {
323 DBG((mod, LEVEL_1, "%+F removing equal perm register pair (%+F, %+F, %s)\n",
324 irn, pairs[i].in_node, pairs[i].out_node, pairs[i].out_reg->name));
326 /* We have to check for a special case:
327 The in-node could be a Proj from a Perm. In this case,
328 we need to correct the projnum */
329 if (be_is_Perm(pairs[i].in_node) && is_Proj(pairs[i].in_node)) {
330 set_Proj_proj(pairs[i].out_node, get_Proj_proj(pairs[i].in_node));
333 /* remove the proj from the schedule */
334 sched_remove(pairs[i].out_node);
336 /* reroute the edges from the proj to the argument */
337 exchange(pairs[i].out_node, pairs[i].in_node);
338 //edges_reroute(pairs[i].out_node, pairs[i].in_node, env->birg->irg);
339 //set_irn_n(pairs[i].out_node, 0, new_Bad());
341 pairs[i].checked = 1;
345 /* Set do_copy to 0 if it's on but we have no free register */
350 real_size = n - get_n_checked_pairs(pairs, n);
352 be_do_stat_perm(reg_class->name, reg_class->n_regs, irn, block, n, real_size);
354 /* check for cycles and chains */
355 while (get_n_checked_pairs(pairs, n) < n) {
358 /* go to the first not-checked pair */
359 while (pairs[i].checked) i++;
360 cycle = xcalloc(1, sizeof(*cycle));
361 cycle = get_perm_cycle(cycle, pairs, n, i);
363 DB((mod, LEVEL_1, "%+F: following %s created:\n ", irn, cycle->type == PERM_CHAIN ? "chain" : "cycle"));
364 for (j = 0; j < cycle->n_elems; j++) {
365 DB((mod, LEVEL_1, " %s", cycle->elems[j]->name));
367 DB((mod, LEVEL_1, "\n"));
370 We don't need to do anything if we have a Perm with two
371 elements which represents a cycle, because those nodes
372 already represent exchange nodes
374 if (n == 2 && cycle->type == PERM_CYCLE) {
380 //TODO: - iff PERM_CYCLE && do_copy -> determine free temp reg and insert copy to/from it before/after
381 // the copy cascade (this reduces the cycle into a chain)
383 /* build copy/swap nodes from back to front */
384 for (i = cycle->n_elems - 2; i >= 0; i--) {
385 arg1 = get_node_for_register(pairs, n, cycle->elems[i], 0);
386 arg2 = get_node_for_register(pairs, n, cycle->elems[i + 1], 0);
388 res1 = get_node_for_register(pairs, n, cycle->elems[i], 1);
389 res2 = get_node_for_register(pairs, n, cycle->elems[i + 1], 1);
391 If we have a cycle and don't copy: we need to create exchange nodes
392 NOTE: An exchange node is a perm node with 2 INs and 2 OUTs
393 IN_1 = in node with register i
394 IN_2 = in node with register i + 1
395 OUT_1 = out node with register i + 1
396 OUT_2 = out node with register i
398 if (cycle->type == PERM_CYCLE && !do_copy) {
402 /* At this point we have to handle the following problem: */
404 /* If we have a cycle with more than two elements, then */
405 /* this could correspond to the following Perm node: */
407 /* +----+ +----+ +----+ */
408 /* | r1 | | r2 | | r3 | */
409 /* +-+--+ +-+--+ +--+-+ */
412 /* +-+--------+---------+-+ */
414 /* +-+--------+---------+-+ */
417 /* +-+--+ +-+--+ +--+-+ */
418 /* |Proj| |Proj| |Proj| */
419 /* | r2 | | r3 | | r1 | */
420 /* +----+ +----+ +----+ */
422 /* This node is about to be split up into two 2x Perm's */
423 /* for which we need 4 Proj's and the one additional Proj */
424 /* of the first Perm has to be one IN of the second. So in */
425 /* general we need to create one additional Proj for each */
426 /* "middle" Perm and set this to one in node of the successor */
429 DBG((mod, LEVEL_1, "%+F creating exchange node (%+F, %s) and (%+F, %s) with\n",
430 irn, arg1, cycle->elems[i]->name, arg2, cycle->elems[i + 1]->name));
431 DBG((mod, LEVEL_1, "%+F (%+F, %s) and (%+F, %s)\n",
432 irn, res1, cycle->elems[i]->name, res2, cycle->elems[i + 1]->name));
434 cpyxchg = be_new_Perm(reg_class, irg, block, 2, in);
438 /* cycle is not done yet */
439 int pidx = get_pairidx_for_regidx(pairs, n, cycle->elems[i]->index, 0);
441 /* create intermediate proj */
442 res1 = new_r_Proj(irg, block, cpyxchg, get_irn_mode(res1), 0);
444 /* set as in for next Perm */
445 pairs[pidx].in_node = res1;
453 set_Proj_pred(res2, cpyxchg);
454 set_Proj_proj(res2, 0);
455 set_Proj_pred(res1, cpyxchg);
456 set_Proj_proj(res1, 1);
458 sched_add_after(sched_point, res1);
459 sched_add_after(sched_point, res2);
461 arch_set_irn_register(arch_env, res2, cycle->elems[i + 1]);
462 arch_set_irn_register(arch_env, res1, cycle->elems[i]);
464 /* insert the copy/exchange node in schedule after the magic schedule node (see above) */
465 sched_add_after(sched_point, cpyxchg);
467 DBG((mod, LEVEL_1, "replacing %+F with %+F, placed new node after %+F\n", irn, cpyxchg, sched_point));
469 /* set the new scheduling point */
473 DBG((mod, LEVEL_1, "%+F creating copy node (%+F, %s) -> (%+F, %s)\n",
474 irn, arg1, cycle->elems[i]->name, res2, cycle->elems[i + 1]->name));
476 cpyxchg = be_new_Copy(reg_class, irg, block, arg1);
477 arch_set_irn_register(arch_env, cpyxchg, cycle->elems[i + 1]);
480 /* remove the proj from the schedule */
483 /* exchange copy node and proj */
484 exchange(res2, cpyxchg);
486 /* insert the copy/exchange node in schedule after the magic schedule node (see above) */
487 sched_add_after(sched_point, cpyxchg);
489 /* set the new scheduling point */
490 sched_point = cpyxchg;
494 be_do_stat_permcycle(reg_class->name, irn, block, cycle->type == PERM_CHAIN, cycle->n_elems, n_ops);
496 free((void *) cycle->elems);
500 /* remove the perm from schedule */
509 static int get_n_out_edges(const ir_node *irn) {
510 const ir_edge_t *edge;
513 foreach_out_edge(irn, edge) {
520 static INLINE ir_node *belower_skip_proj(ir_node *irn) {
522 irn = get_Proj_pred(irn);
526 static ir_node *find_copy(constraint_env_t *env, ir_node *irn, ir_node *op) {
527 const arch_env_t *arch_env = be_get_birg_arch_env(env->birg);
528 ir_node *block = get_nodes_block(irn);
531 for (cur_node = sched_prev(irn);
532 ! is_Block(cur_node) && be_is_Copy(cur_node) && get_nodes_block(cur_node) == block;
533 cur_node = sched_prev(cur_node))
535 if (be_get_Copy_op(cur_node) == op && arch_irn_is(arch_env, cur_node, dont_spill))
542 static void gen_assure_different_pattern(ir_node *irn, ir_node *other_different, constraint_env_t *env) {
543 be_irg_t *birg = env->birg;
544 ir_graph *irg = be_get_birg_irg(birg);
545 pset *op_set = env->op_set;
546 const arch_env_t *arch_env = be_get_birg_arch_env(birg);
547 ir_node *block = get_nodes_block(irn);
548 const arch_register_class_t *cls = arch_get_irn_reg_class(arch_env, other_different, -1);
549 ir_node *in[2], *keep, *cpy;
550 op_copy_assoc_t key, *entry;
551 DEBUG_ONLY(firm_dbg_module_t *mod = env->dbg;)
553 if (arch_irn_is(arch_env, other_different, ignore) || ! mode_is_datab(get_irn_mode(other_different))) {
554 DBG((mod, LEVEL_1, "ignore constraint for %+F because other_irn is ignore or not a datab node\n", irn));
558 /* Make a not spillable copy of the different node */
559 /* this is needed because the different irn could be */
560 /* in block far far away */
561 /* The copy is optimized later if not needed */
563 /* check if already exists such a copy in the schedule immediatly before */
564 cpy = find_copy(env, belower_skip_proj(irn), other_different);
566 cpy = be_new_Copy(cls, irg, block, other_different);
567 be_node_set_flags(cpy, BE_OUT_POS(0), arch_irn_flags_dont_spill);
568 DBG((mod, LEVEL_1, "created non-spillable %+F for value %+F\n", cpy, other_different));
571 DBG((mod, LEVEL_1, "using already existing %+F for value %+F\n", cpy, other_different));
577 /* Add the Keep resp. CopyKeep and reroute the users */
578 /* of the other_different irn in case of CopyKeep. */
579 if (get_n_out_edges(other_different) == 0) {
580 keep = be_new_Keep(cls, irg, block, 2, in);
583 keep = be_new_CopyKeep_single(cls, irg, block, cpy, irn, get_irn_mode(other_different));
584 be_node_set_reg_class(keep, 1, cls);
587 DBG((mod, LEVEL_1, "created %+F(%+F, %+F)\n\n", keep, irn, cpy));
589 /* insert copy and keep into schedule */
590 assert(sched_is_scheduled(irn) && "need schedule to assure constraints");
591 if (! sched_is_scheduled(cpy))
592 sched_add_before(belower_skip_proj(irn), cpy);
593 sched_add_after(irn, keep);
595 /* insert the other different and it's copies into the set */
596 key.op = other_different;
597 entry = pset_find(op_set, &key, nodeset_hash(other_different));
600 entry = obstack_alloc(&env->obst, sizeof(*entry));
601 ir_nodeset_init(&entry->copies);
602 entry->op = other_different;
607 ir_nodeset_insert(&entry->copies, cpy);
609 /* insert keep in case of CopyKeep */
610 if (be_is_CopyKeep(keep)) {
611 ir_nodeset_insert(&entry->copies, keep);
614 pset_insert(op_set, entry, nodeset_hash(other_different));
618 * Checks if node has a should_be_different constraint in output
619 * and adds a Keep then to assure the constraint.
621 static void assure_different_constraints(ir_node *irn, constraint_env_t *env) {
622 const arch_register_req_t *req;
623 const arch_env_t *arch_env = be_get_birg_arch_env(env->birg);
625 req = arch_get_register_req(arch_env, irn, -1);
627 if (arch_register_req_is(req, should_be_different)) {
628 ir_node *different_from = get_irn_n(belower_skip_proj(irn), req->other_different);
629 gen_assure_different_pattern(irn, different_from, env);
630 } else if (arch_register_req_is(req, should_be_different_from_all)) {
631 int i, n = get_irn_arity(belower_skip_proj(irn));
632 for (i = 0; i < n; i++) {
633 gen_assure_different_pattern(irn, get_irn_n(belower_skip_proj(irn), i), env);
641 * Calls the functions to assure register constraints.
643 * @param irn The node to be checked for lowering
644 * @param walk_env The walker environment
646 static void assure_constraints_walker(ir_node *irn, void *walk_env) {
650 if (sched_is_scheduled(irn) && mode_is_datab(get_irn_mode(irn)))
651 assure_different_constraints(irn, walk_env);
657 * Melt all copykeeps pointing to the same node
658 * (or Projs of the same node), copying the same operand.
660 static void melt_copykeeps(constraint_env_t *cenv) {
661 be_irg_t *birg = cenv->birg;
662 ir_graph *irg = be_get_birg_irg(birg);
663 op_copy_assoc_t *entry;
666 foreach_pset(cenv->op_set, entry) {
670 ir_nodeset_iterator_t iter;
671 ir_node **ck_arr, **melt_arr;
675 /* collect all copykeeps */
677 foreach_ir_nodeset(&entry->copies, cp, iter) {
678 if (be_is_CopyKeep(cp)) {
679 obstack_grow(&obst, &cp, sizeof(cp));
682 #ifdef KEEP_ALIVE_COPYKEEP_HACK
684 set_irn_mode(cp, mode_ANY);
687 #endif /* KEEP_ALIVE_COPYKEEP_HACK */
690 /* compare each copykeep with all other copykeeps */
691 ck_arr = (ir_node **)obstack_finish(&obst);
692 for (idx = 0; idx < num_ck; ++idx) {
693 ir_node *ref, *ref_mode_T;
699 ir_node *sched_pt = NULL;
703 ref_mode_T = skip_Proj(get_irn_n(ref, 1));
704 obstack_grow(&obst, &ref, sizeof(ref));
706 DBG((cenv->dbg, LEVEL_1, "Trying to melt %+F:\n", ref));
708 /* check for copykeeps pointing to the same mode_T node as the reference copykeep */
709 for (j = 0; j < num_ck; ++j) {
710 ir_node *cur_ck = ck_arr[j];
712 if (j != idx && cur_ck && skip_Proj(get_irn_n(cur_ck, 1)) == ref_mode_T) {
713 obstack_grow(&obst, &cur_ck, sizeof(cur_ck));
714 ir_nodeset_remove(&entry->copies, cur_ck);
715 DBG((cenv->dbg, LEVEL_1, "\t%+F\n", cur_ck));
718 sched_remove(cur_ck);
723 /* check, if we found some candidates for melting */
725 DBG((cenv->dbg, LEVEL_1, "\tno candidate found\n"));
729 ir_nodeset_remove(&entry->copies, ref);
732 melt_arr = (ir_node **)obstack_finish(&obst);
733 /* melt all found copykeeps */
734 NEW_ARR_A(ir_node *, new_ck_in, n_melt);
735 for (j = 0; j < n_melt; ++j) {
736 new_ck_in[j] = get_irn_n(melt_arr[j], 1);
738 /* now, we can kill the melted keep, except the */
739 /* ref one, we still need some information */
740 if (melt_arr[j] != ref)
741 be_kill_node(melt_arr[j]);
744 #ifdef KEEP_ALIVE_COPYKEEP_HACK
745 new_ck = be_new_CopyKeep(entry->cls, irg, get_nodes_block(ref), be_get_CopyKeep_op(ref), n_melt, new_ck_in, mode_ANY);
748 new_ck = be_new_CopyKeep(entry->cls, irg, get_nodes_block(ref), be_get_CopyKeep_op(ref), n_melt, new_ck_in, get_irn_mode(ref));
749 #endif /* KEEP_ALIVE_COPYKEEP_HACK */
751 /* set register class for all keeped inputs */
752 for (j = 1; j <= n_melt; ++j)
753 be_node_set_reg_class(new_ck, j, entry->cls);
755 ir_nodeset_insert(&entry->copies, new_ck);
757 /* find scheduling point */
758 if (get_irn_mode(ref_mode_T) == mode_T) {
759 /* walk along the Projs */
760 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))
761 /* just walk along the schedule until a non-Proj/Keep/CopyKeep node is found*/ ;
764 sched_pt = ref_mode_T;
767 sched_add_before(sched_pt, new_ck);
768 DBG((cenv->dbg, LEVEL_1, "created %+F, scheduled before %+F\n", new_ck, sched_pt));
770 /* finally: kill the reference copykeep */
775 obstack_free(&obst, NULL);
780 * Walks over all nodes to assure register constraints.
782 * @param birg The birg structure containing the irg
784 void assure_constraints(be_irg_t *birg) {
785 ir_graph *irg = be_get_birg_irg(birg);
786 const arch_env_t *arch_env = be_get_birg_arch_env(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(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) {
810 ir_nodeset_iterator_t iter;
811 be_ssa_construction_env_t senv;
813 n = ir_nodeset_size(&entry->copies);
814 nodes = alloca(n * sizeof(nodes[0]));
816 /* put the node in an array */
817 DBG((mod, LEVEL_1, "introduce copies for %+F ", entry->op));
819 /* collect all copies */
821 foreach_ir_nodeset(&entry->copies, cp, iter) {
823 DB((mod, LEVEL_1, ", %+F ", cp));
826 DB((mod, LEVEL_1, "\n"));
828 /* introduce the copies for the operand and it's copies */
829 be_ssa_construction_init(&senv, birg);
830 be_ssa_construction_add_copy(&senv, entry->op);
831 be_ssa_construction_add_copies(&senv, nodes, n);
832 be_ssa_construction_fix_users(&senv, entry->op);
833 be_ssa_construction_destroy(&senv);
835 /* Could be that not all CopyKeeps are really needed, */
836 /* so we transform unnecessary ones into Keeps. */
837 foreach_ir_nodeset(&entry->copies, cp, iter) {
838 if (be_is_CopyKeep(cp) && get_irn_n_edges(cp) < 1) {
840 int n = get_irn_arity(cp);
842 keep = be_new_Keep(arch_get_irn_reg_class(arch_env, cp, -1),
843 irg, get_nodes_block(cp), n, (ir_node **)&get_irn_in(cp)[1]);
844 sched_add_before(cp, keep);
846 /* Set all ins (including the block) of the CopyKeep BAD to keep the verifier happy. */
852 ir_nodeset_destroy(&entry->copies);
855 del_pset(cenv.op_set);
856 obstack_free(&cenv.obst, NULL);
857 be_invalidate_liveness(birg);
863 * Calls the corresponding lowering function for the node.
865 * @param irn The node to be checked for lowering
866 * @param walk_env The walker environment
868 static void lower_nodes_after_ra_walker(ir_node *irn, void *walk_env) {
869 if (! is_Block(irn) && ! is_Proj(irn)) {
870 if (be_is_Perm(irn)) {
871 lower_perm_node(irn, walk_env);
879 * Walks over all blocks in an irg and performs lowering need to be
880 * done after register allocation (e.g. perm lowering).
882 * @param birg The birg object
883 * @param do_copy 1 == resolve cycles with a free reg if available
885 void lower_nodes_after_ra(be_irg_t *birg, int do_copy) {
887 ir_graph *irg = be_get_birg_irg(birg);
890 env.arch_env = be_get_birg_arch_env(birg);
891 env.do_copy = do_copy;
892 FIRM_DBG_REGISTER(env.dbg_module, "firm.be.lower");
894 irg_walk_blkwise_graph(irg, NULL, lower_nodes_after_ra_walker, &env);