2 * Copyright (C) 1995-2008 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 New approach to allocation and copy coalescing
23 * @author Matthias Braun
27 * ... WE NEED A NAME FOR THIS ...
29 * Only a proof of concept at this moment...
31 * The idea is to allocate registers in 2 passes:
32 * 1. A first pass to determine "preferred" registers for live-ranges. This
33 * calculates for each register and each live-range a value indicating
34 * the usefulness. (You can roughly think of the value as the negative
35 * costs needed for copies when the value is in the specific registers...)
37 * 2. Walk blocks and assigns registers in a greedy fashion. Preferring
38 * registers with high preferences. When register constraints are not met,
39 * add copies and split live-ranges.
42 * - make use of free registers in the permute_values code
43 * - think about a smarter sequence of visiting the blocks. Sorted by
44 * execfreq might be good, or looptree from inner to outermost loops going
45 * over blocks in a reverse postorder
46 * - propagate preferences through Phis
58 #include "iredges_t.h"
59 #include "irgraph_t.h"
64 #include "raw_bitset.h"
65 #include "unionfind.h"
67 #include "hungarian.h"
70 #include "bechordal_t.h"
79 #include "bespillutil.h"
83 #define USE_FACTOR 1.0f
84 #define DEF_FACTOR 1.0f
85 #define NEIGHBOR_FACTOR 0.2f
86 #define AFF_SHOULD_BE_SAME 0.5f
88 #define SPLIT_DELTA 1.0f
90 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
92 static struct obstack obst;
93 static be_irg_t *birg;
95 static const arch_register_class_t *cls;
96 static const arch_register_req_t *default_cls_req;
98 static const ir_exec_freq *execfreqs;
99 static unsigned n_regs;
100 static unsigned *normal_regs;
101 static int *congruence_classes;
102 static ir_node **block_order;
103 static int n_block_order;
105 /** currently active assignments (while processing a basic block)
106 * maps registers to values(their current copies) */
107 static ir_node **assignments;
110 * allocation information: last_uses, register preferences
111 * the information is per firm-node.
113 struct allocation_info_t {
114 unsigned last_uses; /**< bitset indicating last uses (input pos) */
115 ir_node *current_value; /**< copy of the value that should be used */
116 ir_node *original_value; /**< for copies point to original value */
117 float prefs[0]; /**< register preferences */
119 typedef struct allocation_info_t allocation_info_t;
121 /** helper datastructure used when sorting register preferences */
126 typedef struct reg_pref_t reg_pref_t;
128 /** per basic-block information */
129 struct block_info_t {
130 bool processed; /**< indicate wether block is processed */
131 ir_node *assignments[0]; /**< register assignments at end of block */
133 typedef struct block_info_t block_info_t;
136 * Get the allocation info for a node.
137 * The info is allocated on the first visit of a node.
139 static allocation_info_t *get_allocation_info(ir_node *node)
141 allocation_info_t *info = get_irn_link(node);
143 info = OALLOCFZ(&obst, allocation_info_t, prefs, n_regs);
144 info->current_value = node;
145 info->original_value = node;
146 set_irn_link(node, info);
153 * Get allocation information for a basic block
155 static block_info_t *get_block_info(ir_node *block)
157 block_info_t *info = get_irn_link(block);
159 assert(is_Block(block));
161 info = OALLOCFZ(&obst, block_info_t, assignments, n_regs);
162 set_irn_link(block, info);
169 * Get default register requirement for the current register class
171 static const arch_register_req_t *get_default_req_current_cls(void)
173 if (default_cls_req == NULL) {
174 struct obstack *obst = get_irg_obstack(irg);
175 arch_register_req_t *req = OALLOCZ(obst, arch_register_req_t);
177 req->type = arch_register_req_type_normal;
180 default_cls_req = req;
182 return default_cls_req;
186 * Link the allocation info of a node to a copy.
187 * Afterwards, both nodes uses the same allocation info.
188 * Copy must not have an allocation info assigned yet.
190 * @param copy the node that gets the allocation info assigned
191 * @param value the original node
193 static void mark_as_copy_of(ir_node *copy, ir_node *value)
196 allocation_info_t *info = get_allocation_info(value);
197 allocation_info_t *copy_info = get_allocation_info(copy);
199 /* find original value */
200 original = info->original_value;
201 if (original != value) {
202 info = get_allocation_info(original);
205 assert(info->original_value == original);
206 info->current_value = copy;
208 /* the copy should not be linked to something else yet */
209 assert(copy_info->original_value == copy);
210 copy_info->original_value = original;
212 /* copy over allocation preferences */
213 memcpy(copy_info->prefs, info->prefs, n_regs * sizeof(copy_info->prefs[0]));
217 * Calculate the penalties for every register on a node and its live neighbors.
219 * @param live_nodes the set of live nodes at the current position, may be NULL
220 * @param penalty the penalty to subtract from
221 * @param limited a raw bitset containing the limited set for the node
222 * @param node the node
224 static void give_penalties_for_limits(const ir_nodeset_t *live_nodes,
225 float penalty, const unsigned* limited,
228 ir_nodeset_iterator_t iter;
230 allocation_info_t *info = get_allocation_info(node);
233 /* give penalty for all forbidden regs */
234 for (r = 0; r < n_regs; ++r) {
235 if (rbitset_is_set(limited, r))
238 info->prefs[r] -= penalty;
241 /* all other live values should get a penalty for allowed regs */
242 if (live_nodes == NULL)
245 /* TODO: reduce penalty if there are multiple allowed registers... */
246 penalty *= NEIGHBOR_FACTOR;
247 foreach_ir_nodeset(live_nodes, neighbor, iter) {
248 allocation_info_t *neighbor_info;
250 /* TODO: if op is used on multiple inputs we might not do a
252 if (neighbor == node)
255 neighbor_info = get_allocation_info(neighbor);
256 for (r = 0; r < n_regs; ++r) {
257 if (!rbitset_is_set(limited, r))
260 neighbor_info->prefs[r] -= penalty;
266 * Calculate the preferences of a definition for the current register class.
267 * If the definition uses a limited set of registers, reduce the preferences
268 * for the limited register on the node and its neighbors.
270 * @param live_nodes the set of live nodes at the current node
271 * @param weight the weight
272 * @param node the current node
274 static void check_defs(const ir_nodeset_t *live_nodes, float weight,
277 const arch_register_req_t *req;
279 if (get_irn_mode(node) == mode_T) {
280 const ir_edge_t *edge;
281 foreach_out_edge(node, edge) {
282 ir_node *proj = get_edge_src_irn(edge);
283 check_defs(live_nodes, weight, proj);
288 if (!arch_irn_consider_in_reg_alloc(cls, node))
291 req = arch_get_register_req_out(node);
292 if (req->type & arch_register_req_type_limited) {
293 const unsigned *limited = req->limited;
294 float penalty = weight * DEF_FACTOR;
295 give_penalties_for_limits(live_nodes, penalty, limited, node);
298 if (req->type & arch_register_req_type_should_be_same) {
299 ir_node *insn = skip_Proj(node);
300 allocation_info_t *info = get_allocation_info(node);
301 int arity = get_irn_arity(insn);
304 float factor = 1.0f / rbitset_popcnt(&req->other_same, arity);
305 for (i = 0; i < arity; ++i) {
308 allocation_info_t *op_info;
310 if (!rbitset_is_set(&req->other_same, i))
313 op = get_irn_n(insn, i);
315 /* if we the value at the should_be_same input doesn't die at the
316 * node, then it is no use to propagate the constraints (since a
317 * copy will emerge anyway) */
318 if (ir_nodeset_contains(live_nodes, op))
321 op_info = get_allocation_info(op);
322 for (r = 0; r < n_regs; ++r) {
323 op_info->prefs[r] += info->prefs[r] * factor;
330 * Walker: Runs an a block calculates the preferences for any
331 * node and every register from the considered register class.
333 static void analyze_block(ir_node *block, void *data)
335 float weight = get_block_execfreq(execfreqs, block);
336 ir_nodeset_t live_nodes;
340 ir_nodeset_init(&live_nodes);
341 be_liveness_end_of_block(lv, cls, block, &live_nodes);
343 sched_foreach_reverse(block, node) {
344 allocation_info_t *info;
351 check_defs(&live_nodes, weight, node);
354 arity = get_irn_arity(node);
356 /* the allocation info node currently only uses 1 unsigned value
357 to mark last used inputs. So we will fail for a node with more than
359 if (arity >= (int) sizeof(unsigned) * 8) {
360 panic("Node with more than %d inputs not supported yet",
361 (int) sizeof(unsigned) * 8);
364 info = get_allocation_info(node);
365 for (i = 0; i < arity; ++i) {
366 ir_node *op = get_irn_n(node, i);
367 if (!arch_irn_consider_in_reg_alloc(cls, op))
370 /* last usage of a value? */
371 if (!ir_nodeset_contains(&live_nodes, op)) {
372 rbitset_set(&info->last_uses, i);
376 be_liveness_transfer(cls, node, &live_nodes);
378 /* update weights based on usage constraints */
379 for (i = 0; i < arity; ++i) {
380 const arch_register_req_t *req;
381 const unsigned *limited;
382 ir_node *op = get_irn_n(node, i);
384 if (!arch_irn_consider_in_reg_alloc(cls, op))
387 req = arch_get_register_req(node, i);
388 if (!(req->type & arch_register_req_type_limited))
391 limited = req->limited;
392 give_penalties_for_limits(&live_nodes, weight * USE_FACTOR, limited,
397 ir_nodeset_destroy(&live_nodes);
400 static void congruence_def(ir_nodeset_t *live_nodes, ir_node *node)
402 if (get_irn_mode(node) == mode_T) {
403 const ir_edge_t *edge;
404 foreach_out_edge(node, edge) {
405 ir_node *def = get_edge_src_irn(edge);
406 congruence_def(live_nodes, def);
411 if (!arch_irn_consider_in_reg_alloc(cls, node))
414 /* should be same constraint? */
415 const arch_register_req_t *req = arch_get_register_req_out(node);
416 if (req->type & arch_register_req_type_should_be_same) {
417 ir_node *insn = skip_Proj(node);
418 int arity = get_irn_arity(insn);
420 unsigned node_idx = get_irn_idx(node);
421 node_idx = uf_find(congruence_classes, node_idx);
423 for (i = 0; i < arity; ++i) {
427 ir_nodeset_iterator_t iter;
429 if (!rbitset_is_set(&req->other_same, i))
432 op = get_irn_n(insn, i);
433 op_idx = get_irn_idx(op);
434 op_idx = uf_find(congruence_classes, op_idx);
436 /* do we interfere with the value */
437 bool interferes = false;
438 foreach_ir_nodeset(live_nodes, live, iter) {
439 int lv_idx = get_irn_idx(live);
440 lv_idx = uf_find(congruence_classes, lv_idx);
441 if (lv_idx == op_idx) {
446 /* don't put in same affinity class if we interfere */
450 node_idx = uf_union(congruence_classes, node_idx, op_idx);
451 DB((dbg, LEVEL_3, "Merge %+F and %+F congruence classes\n",
453 /* one should_be_same is enough... */
459 static void create_congurence_class(ir_node *block, void *data)
461 ir_nodeset_t live_nodes;
465 ir_nodeset_init(&live_nodes);
466 be_liveness_end_of_block(lv, cls, block, &live_nodes);
468 /* check should be same constraints */
469 sched_foreach_reverse(block, node) {
473 congruence_def(&live_nodes, node);
474 be_liveness_transfer(cls, node, &live_nodes);
477 /* check phi congruence classes */
478 sched_foreach_reverse_from(node, node) {
482 assert(is_Phi(node));
484 if (!arch_irn_consider_in_reg_alloc(cls, node))
487 node_idx = get_irn_idx(node);
488 node_idx = uf_find(congruence_classes, node_idx);
490 arity = get_irn_arity(node);
491 for (i = 0; i < arity; ++i) {
492 ir_nodeset_iterator_t iter;
495 ir_node *op = get_Phi_pred(node, i);
496 int op_idx = get_irn_idx(op);
497 op_idx = uf_find(congruence_classes, op_idx);
499 /* do we interfere with the value */
500 bool interferes = false;
501 foreach_ir_nodeset(&live_nodes, live, iter) {
502 int lv_idx = get_irn_idx(live);
503 lv_idx = uf_find(congruence_classes, lv_idx);
504 if (lv_idx == op_idx) {
509 /* don't put in same affinity class if we interfere */
512 /* any other phi has the same input? */
513 sched_foreach(block, phi) {
518 if (!arch_irn_consider_in_reg_alloc(cls, phi))
520 oop = get_Phi_pred(phi, i);
523 oop_idx = get_irn_idx(oop);
524 oop_idx = uf_find(congruence_classes, oop_idx);
525 if (oop_idx == op_idx) {
533 node_idx = uf_union(congruence_classes, node_idx, op_idx);
534 DB((dbg, LEVEL_3, "Merge %+F and %+F congruence classes\n",
540 static void merge_congruence_prefs(ir_node *node, void *data)
542 allocation_info_t *info;
543 allocation_info_t *head_info;
544 unsigned node_idx = get_irn_idx(node);
545 unsigned node_set = uf_find(congruence_classes, node_idx);
550 /* head of congruence class or not in any class */
551 if (node_set == node_idx)
554 if (!arch_irn_consider_in_reg_alloc(cls, node))
557 head_info = get_allocation_info(get_idx_irn(irg, node_set));
558 info = get_allocation_info(node);
560 for (r = 0; r < n_regs; ++r) {
561 head_info->prefs[r] += info->prefs[r];
565 static void set_congruence_prefs(ir_node *node, void *data)
567 allocation_info_t *info;
568 allocation_info_t *head_info;
569 unsigned node_idx = get_irn_idx(node);
570 unsigned node_set = uf_find(congruence_classes, node_idx);
574 /* head of congruence class or not in any class */
575 if (node_set == node_idx)
578 if (!arch_irn_consider_in_reg_alloc(cls, node))
581 head_info = get_allocation_info(get_idx_irn(irg, node_set));
582 info = get_allocation_info(node);
584 memcpy(info->prefs, head_info->prefs, n_regs * sizeof(info->prefs[0]));
587 static void combine_congruence_classes(void)
589 size_t n = get_irg_last_idx(irg);
590 congruence_classes = XMALLOCN(int, n);
591 uf_init(congruence_classes, n);
593 /* create congruence classes */
594 irg_block_walk_graph(irg, create_congurence_class, NULL, NULL);
595 /* merge preferences */
596 irg_walk_graph(irg, merge_congruence_prefs, NULL, NULL);
597 irg_walk_graph(irg, set_congruence_prefs, NULL, NULL);
605 * Assign register reg to the given node.
607 * @param node the node
608 * @param reg the register
610 static void use_reg(ir_node *node, const arch_register_t *reg)
612 unsigned r = arch_register_get_index(reg);
613 assignments[r] = node;
614 arch_set_irn_register(node, reg);
617 static void free_reg_of_value(ir_node *node)
619 const arch_register_t *reg;
622 if (!arch_irn_consider_in_reg_alloc(cls, node))
625 reg = arch_get_irn_register(node);
626 r = arch_register_get_index(reg);
627 /* assignment->value may be NULL if a value is used at 2 inputs
628 so it gets freed twice. */
629 assert(assignments[r] == node || assignments[r] == NULL);
630 assignments[r] = NULL;
634 * Compare two register preferences in decreasing order.
636 static int compare_reg_pref(const void *e1, const void *e2)
638 const reg_pref_t *rp1 = (const reg_pref_t*) e1;
639 const reg_pref_t *rp2 = (const reg_pref_t*) e2;
640 if (rp1->pref < rp2->pref)
642 if (rp1->pref > rp2->pref)
647 static void fill_sort_candidates(reg_pref_t *regprefs,
648 const allocation_info_t *info)
652 for (r = 0; r < n_regs; ++r) {
653 float pref = info->prefs[r];
655 regprefs[r].pref = pref;
657 /* TODO: use a stable sort here to avoid unnecessary register jumping */
658 qsort(regprefs, n_regs, sizeof(regprefs[0]), compare_reg_pref);
661 static bool try_optimistic_split(ir_node *to_split, ir_node *before,
662 float pref, float pref_delta,
663 unsigned *output_regs)
665 const arch_register_t *reg;
666 ir_node *original_insn;
671 allocation_info_t *info = get_allocation_info(to_split);
674 float split_threshold;
678 /* stupid hack: don't optimisticallt split don't spill nodes...
679 * (so we don't split away the values produced because of
680 * must_be_different constraints) */
681 original_insn = skip_Proj(info->original_value);
682 if (arch_irn_get_flags(original_insn) & arch_irn_flags_dont_spill)
685 /* find the best free position where we could move to */
686 prefs = ALLOCAN(reg_pref_t, n_regs);
687 fill_sort_candidates(prefs, info);
688 for (i = 0; i < n_regs; ++i) {
690 if (!rbitset_is_set(normal_regs, r))
692 if (rbitset_is_set(output_regs, r))
694 if (assignments[r] == NULL)
700 /* TODO: use execfreq somehow... */
701 block = get_nodes_block(before);
702 delta = pref_delta + prefs[i].pref;
703 split_threshold = get_block_execfreq(execfreqs, block) * SPLIT_DELTA;
704 if (delta < split_threshold) {
705 DB((dbg, LEVEL_3, "Not doing optimistical split, win %f too low\n",
710 reg = arch_register_for_index(cls, r);
711 copy = be_new_Copy(cls, block, to_split);
712 mark_as_copy_of(copy, to_split);
713 free_reg_of_value(to_split);
715 sched_add_before(before, copy);
718 "Optimistic live-range split %+F move %+F -> %s before %+F (win %f)\n",
719 copy, to_split, reg->name, before, delta));
724 * Determine and assign a register for node @p node
726 static void assign_reg(const ir_node *block, ir_node *node,
727 unsigned *output_regs)
729 const arch_register_t *reg;
730 allocation_info_t *info;
731 const arch_register_req_t *req;
732 reg_pref_t *reg_prefs;
735 const unsigned *allowed_regs;
738 assert(arch_irn_consider_in_reg_alloc(cls, node));
740 /* preassigned register? */
741 reg = arch_get_irn_register(node);
743 DB((dbg, LEVEL_2, "Preassignment %+F -> %s\n", node, reg->name));
748 /* give should_be_same boni */
749 info = get_allocation_info(node);
750 req = arch_get_register_req_out(node);
752 in_node = skip_Proj(node);
753 if (req->type & arch_register_req_type_should_be_same) {
754 float weight = get_block_execfreq(execfreqs, block);
755 int arity = get_irn_arity(in_node);
758 assert(arity <= (int) sizeof(req->other_same) * 8);
759 for (i = 0; i < arity; ++i) {
761 const arch_register_t *reg;
763 if (!rbitset_is_set(&req->other_same, i))
766 in = get_irn_n(in_node, i);
767 reg = arch_get_irn_register(in);
769 r = arch_register_get_index(reg);
771 /* if the value didn't die here then we should not propagate the
772 * should_be_same info */
773 if (assignments[r] == in)
776 info->prefs[r] += weight * AFF_SHOULD_BE_SAME;
780 /* create list of register candidates and sort by their preference */
781 DB((dbg, LEVEL_2, "Candidates for %+F:", node));
782 reg_prefs = alloca(n_regs * sizeof(reg_prefs[0]));
783 fill_sort_candidates(reg_prefs, info);
784 for (i = 0; i < n_regs; ++i) {
785 unsigned num = reg_prefs[i].num;
786 const arch_register_t *reg;
788 if (!rbitset_is_set(normal_regs, num))
791 reg = arch_register_for_index(cls, num);
792 DB((dbg, LEVEL_2, " %s(%f)", reg->name, reg_prefs[i].pref));
794 DB((dbg, LEVEL_2, "\n"));
796 allowed_regs = normal_regs;
797 if (req->type & arch_register_req_type_limited) {
798 allowed_regs = req->limited;
801 for (i = 0; i < n_regs; ++i) {
802 r = reg_prefs[i].num;
803 if (!rbitset_is_set(allowed_regs, r))
805 if (assignments[r] == NULL)
808 float pref = reg_prefs[i].pref;
809 float delta = i+1 < n_regs ? pref - reg_prefs[i+1].pref : 0;
810 ir_node *before = skip_Proj(node);
811 bool res = try_optimistic_split(assignments[r], before,
819 panic("No register left for %+F\n", node);
822 reg = arch_register_for_index(cls, r);
823 DB((dbg, LEVEL_2, "Assign %+F -> %s\n", node, reg->name));
828 * Add an permutation in front of a node and change the assignments
829 * due to this permutation.
831 * To understand this imagine a permutation like this:
841 * First we count how many destinations a single value has. At the same time
842 * we can be sure that each destination register has at most 1 source register
843 * (it can have 0 which means we don't care what value is in it).
844 * We ignore all fullfilled permuations (like 7->7)
845 * In a first pass we create as much copy instructions as possible as they
846 * are generally cheaper than exchanges. We do this by counting into how many
847 * destinations a register has to be copied (in the example it's 2 for register
848 * 3, or 1 for the registers 1,2,4 and 7).
849 * We can then create a copy into every destination register when the usecount
850 * of that register is 0 (= noone else needs the value in the register).
852 * After this step we should have cycles left. We implement a cyclic permutation
853 * of n registers with n-1 transpositions.
855 * @param live_nodes the set of live nodes, updated due to live range split
856 * @param before the node before we add the permutation
857 * @param permutation the permutation array indices are the destination
858 * registers, the values in the array are the source
861 static void permute_values(ir_nodeset_t *live_nodes, ir_node *before,
862 unsigned *permutation)
864 unsigned *n_used = ALLOCANZ(unsigned, n_regs);
868 /* determine how often each source register needs to be read */
869 for (r = 0; r < n_regs; ++r) {
870 unsigned old_reg = permutation[r];
873 value = assignments[old_reg];
875 /* nothing to do here, reg is not live. Mark it as fixpoint
876 * so we ignore it in the next steps */
884 block = get_nodes_block(before);
886 /* step1: create copies where immediately possible */
887 for (r = 0; r < n_regs; /* empty */) {
890 const arch_register_t *reg;
891 unsigned old_r = permutation[r];
893 /* - no need to do anything for fixed points.
894 - we can't copy if the value in the dest reg is still needed */
895 if (old_r == r || n_used[r] > 0) {
901 src = assignments[old_r];
902 copy = be_new_Copy(cls, block, src);
903 sched_add_before(before, copy);
904 reg = arch_register_for_index(cls, r);
905 DB((dbg, LEVEL_2, "Copy %+F (from %+F, before %+F) -> %s\n",
906 copy, src, before, reg->name));
907 mark_as_copy_of(copy, src);
910 if (live_nodes != NULL) {
911 ir_nodeset_insert(live_nodes, copy);
914 /* old register has 1 user less, permutation is resolved */
915 assert(arch_register_get_index(arch_get_irn_register(src)) == old_r);
918 assert(n_used[old_r] > 0);
920 if (n_used[old_r] == 0) {
921 if (live_nodes != NULL) {
922 ir_nodeset_remove(live_nodes, src);
924 free_reg_of_value(src);
927 /* advance or jump back (if this copy enabled another copy) */
928 if (old_r < r && n_used[old_r] == 0) {
935 /* at this point we only have "cycles" left which we have to resolve with
937 * TODO: if we have free registers left, then we should really use copy
938 * instructions for any cycle longer than 2 registers...
939 * (this is probably architecture dependent, there might be archs where
940 * copies are preferable even for 2-cycles) */
942 /* create perms with the rest */
943 for (r = 0; r < n_regs; /* empty */) {
944 const arch_register_t *reg;
945 unsigned old_r = permutation[r];
957 /* we shouldn't have copies from 1 value to multiple destinations left*/
958 assert(n_used[old_r] == 1);
960 /* exchange old_r and r2; after that old_r is a fixed point */
961 r2 = permutation[old_r];
963 in[0] = assignments[r2];
964 in[1] = assignments[old_r];
965 perm = be_new_Perm(cls, block, 2, in);
966 sched_add_before(before, perm);
967 DB((dbg, LEVEL_2, "Perm %+F (perm %+F,%+F, before %+F)\n",
968 perm, in[0], in[1], before));
970 proj0 = new_r_Proj(block, perm, get_irn_mode(in[0]), 0);
971 mark_as_copy_of(proj0, in[0]);
972 reg = arch_register_for_index(cls, old_r);
975 proj1 = new_r_Proj(block, perm, get_irn_mode(in[1]), 1);
976 mark_as_copy_of(proj1, in[1]);
977 reg = arch_register_for_index(cls, r2);
980 /* 1 value is now in the correct register */
981 permutation[old_r] = old_r;
982 /* the source of r changed to r2 */
985 /* if we have reached a fixpoint update data structures */
986 if (live_nodes != NULL) {
987 ir_nodeset_remove(live_nodes, in[0]);
988 ir_nodeset_remove(live_nodes, in[1]);
989 ir_nodeset_remove(live_nodes, proj0);
990 ir_nodeset_insert(live_nodes, proj1);
995 /* now we should only have fixpoints left */
996 for (r = 0; r < n_regs; ++r) {
997 assert(permutation[r] == r);
1003 * Free regs for values last used.
1005 * @param live_nodes set of live nodes, will be updated
1006 * @param node the node to consider
1008 static void free_last_uses(ir_nodeset_t *live_nodes, ir_node *node)
1010 allocation_info_t *info = get_allocation_info(node);
1011 const unsigned *last_uses = &info->last_uses;
1012 int arity = get_irn_arity(node);
1015 for (i = 0; i < arity; ++i) {
1018 /* check if one operand is the last use */
1019 if (!rbitset_is_set(last_uses, i))
1022 op = get_irn_n(node, i);
1023 free_reg_of_value(op);
1024 ir_nodeset_remove(live_nodes, op);
1029 * change inputs of a node to the current value (copies/perms)
1031 static void rewire_inputs(ir_node *node)
1034 int arity = get_irn_arity(node);
1036 for (i = 0; i < arity; ++i) {
1037 ir_node *op = get_irn_n(node, i);
1038 allocation_info_t *info;
1040 if (!arch_irn_consider_in_reg_alloc(cls, op))
1043 info = get_allocation_info(op);
1044 info = get_allocation_info(info->original_value);
1045 if (info->current_value != op) {
1046 set_irn_n(node, i, info->current_value);
1052 * Create a bitset of registers occupied with value living through an
1055 static void determine_live_through_regs(unsigned *bitset, ir_node *node)
1057 const allocation_info_t *info = get_allocation_info(node);
1062 /* mark all used registers as potentially live-through */
1063 for (r = 0; r < n_regs; ++r) {
1064 if (assignments[r] == NULL)
1066 if (!rbitset_is_set(normal_regs, r))
1069 rbitset_set(bitset, r);
1072 /* remove registers of value dying at the instruction */
1073 arity = get_irn_arity(node);
1074 for (i = 0; i < arity; ++i) {
1076 const arch_register_t *reg;
1078 if (!rbitset_is_set(&info->last_uses, i))
1081 op = get_irn_n(node, i);
1082 reg = arch_get_irn_register(op);
1083 rbitset_clear(bitset, arch_register_get_index(reg));
1088 * Enforce constraints at a node by live range splits.
1090 * @param live_nodes the set of live nodes, might be changed
1091 * @param node the current node
1093 static void enforce_constraints(ir_nodeset_t *live_nodes, ir_node *node,
1094 unsigned *output_regs)
1096 int arity = get_irn_arity(node);
1098 hungarian_problem_t *bp;
1100 unsigned *assignment;
1102 /* construct a list of register occupied by live-through values */
1103 unsigned *live_through_regs = NULL;
1105 /* see if any use constraints are not met */
1107 for (i = 0; i < arity; ++i) {
1108 ir_node *op = get_irn_n(node, i);
1109 const arch_register_t *reg;
1110 const arch_register_req_t *req;
1111 const unsigned *limited;
1114 if (!arch_irn_consider_in_reg_alloc(cls, op))
1117 /* are there any limitations for the i'th operand? */
1118 req = arch_get_register_req(node, i);
1119 if (!(req->type & arch_register_req_type_limited))
1122 limited = req->limited;
1123 reg = arch_get_irn_register(op);
1124 r = arch_register_get_index(reg);
1125 if (!rbitset_is_set(limited, r)) {
1126 /* found an assignment outside the limited set */
1132 /* is any of the live-throughs using a constrained output register? */
1133 if (get_irn_mode(node) == mode_T) {
1134 const ir_edge_t *edge;
1136 foreach_out_edge(node, edge) {
1137 ir_node *proj = get_edge_src_irn(edge);
1138 const arch_register_req_t *req;
1140 if (!arch_irn_consider_in_reg_alloc(cls, proj))
1143 req = arch_get_register_req_out(proj);
1144 if (!(req->type & arch_register_req_type_limited))
1147 if (live_through_regs == NULL) {
1148 rbitset_alloca(live_through_regs, n_regs);
1149 determine_live_through_regs(live_through_regs, node);
1152 rbitset_or(output_regs, req->limited, n_regs);
1153 if (rbitsets_have_common(req->limited, live_through_regs, n_regs)) {
1158 if (arch_irn_consider_in_reg_alloc(cls, node)) {
1159 const arch_register_req_t *req = arch_get_register_req_out(node);
1160 if (req->type & arch_register_req_type_limited) {
1161 rbitset_alloca(live_through_regs, n_regs);
1162 determine_live_through_regs(live_through_regs, node);
1163 if (rbitsets_have_common(req->limited, live_through_regs, n_regs)) {
1165 rbitset_or(output_regs, req->limited, n_regs);
1174 /* create these arrays if we haven't yet */
1175 if (live_through_regs == NULL) {
1176 rbitset_alloca(live_through_regs, n_regs);
1179 /* at this point we have to construct a bipartite matching problem to see
1180 * which values should go to which registers
1181 * Note: We're building the matrix in "reverse" - source registers are
1182 * right, destinations left because this will produce the solution
1183 * in the format required for permute_values.
1185 bp = hungarian_new(n_regs, n_regs, HUNGARIAN_MATCH_PERFECT);
1187 /* add all combinations, then remove not allowed ones */
1188 for (l = 0; l < n_regs; ++l) {
1189 if (!rbitset_is_set(normal_regs, l)) {
1190 hungarian_add(bp, l, l, 1);
1194 for (r = 0; r < n_regs; ++r) {
1195 if (!rbitset_is_set(normal_regs, r))
1197 /* livethrough values may not use constrainted output registers */
1198 if (rbitset_is_set(live_through_regs, l)
1199 && rbitset_is_set(output_regs, r))
1202 hungarian_add(bp, r, l, l == r ? 9 : 8);
1206 for (i = 0; i < arity; ++i) {
1207 ir_node *op = get_irn_n(node, i);
1208 const arch_register_t *reg;
1209 const arch_register_req_t *req;
1210 const unsigned *limited;
1211 unsigned current_reg;
1213 if (!arch_irn_consider_in_reg_alloc(cls, op))
1216 req = arch_get_register_req(node, i);
1217 if (!(req->type & arch_register_req_type_limited))
1220 limited = req->limited;
1221 reg = arch_get_irn_register(op);
1222 current_reg = arch_register_get_index(reg);
1223 for (r = 0; r < n_regs; ++r) {
1224 if (rbitset_is_set(limited, r))
1226 hungarian_remv(bp, r, current_reg);
1230 //hungarian_print_cost_matrix(bp, 1);
1231 hungarian_prepare_cost_matrix(bp, HUNGARIAN_MODE_MAXIMIZE_UTIL);
1233 assignment = ALLOCAN(unsigned, n_regs);
1234 res = hungarian_solve(bp, (int*) assignment, NULL, 0);
1238 fprintf(stderr, "Swap result:");
1239 for (i = 0; i < (int) n_regs; ++i) {
1240 fprintf(stderr, " %d", assignment[i]);
1242 fprintf(stderr, "\n");
1247 permute_values(live_nodes, node, assignment);
1250 /** test wether a node @p n is a copy of the value of node @p of */
1251 static bool is_copy_of(ir_node *value, ir_node *test_value)
1253 allocation_info_t *test_info;
1254 allocation_info_t *info;
1256 if (value == test_value)
1259 info = get_allocation_info(value);
1260 test_info = get_allocation_info(test_value);
1261 return test_info->original_value == info->original_value;
1265 * find a value in the end-assignment of a basic block
1266 * @returns the index into the assignment array if found
1269 static int find_value_in_block_info(block_info_t *info, ir_node *value)
1272 ir_node **assignments = info->assignments;
1273 for (r = 0; r < n_regs; ++r) {
1274 ir_node *a_value = assignments[r];
1276 if (a_value == NULL)
1278 if (is_copy_of(a_value, value))
1286 * Create the necessary permutations at the end of a basic block to fullfill
1287 * the register assignment for phi-nodes in the next block
1289 static void add_phi_permutations(ir_node *block, int p)
1292 unsigned *permutation;
1293 ir_node **old_assignments;
1294 bool need_permutation;
1296 ir_node *pred = get_Block_cfgpred_block(block, p);
1298 block_info_t *pred_info = get_block_info(pred);
1300 /* predecessor not processed yet? nothing to do */
1301 if (!pred_info->processed)
1304 permutation = ALLOCAN(unsigned, n_regs);
1305 for (r = 0; r < n_regs; ++r) {
1309 /* check phi nodes */
1310 need_permutation = false;
1311 node = sched_first(block);
1312 for ( ; is_Phi(node); node = sched_next(node)) {
1313 const arch_register_t *reg;
1318 if (!arch_irn_consider_in_reg_alloc(cls, node))
1321 op = get_Phi_pred(node, p);
1322 if (!arch_irn_consider_in_reg_alloc(cls, op))
1325 a = find_value_in_block_info(pred_info, op);
1328 reg = arch_get_irn_register(node);
1329 regn = arch_register_get_index(reg);
1331 permutation[regn] = a;
1332 need_permutation = true;
1336 if (need_permutation) {
1337 /* permute values at end of predecessor */
1338 old_assignments = assignments;
1339 assignments = pred_info->assignments;
1340 permute_values(NULL, be_get_end_of_block_insertion_point(pred),
1342 assignments = old_assignments;
1345 /* change phi nodes to use the copied values */
1346 node = sched_first(block);
1347 for ( ; is_Phi(node); node = sched_next(node)) {
1351 if (!arch_irn_consider_in_reg_alloc(cls, node))
1354 op = get_Phi_pred(node, p);
1355 /* no need to do anything for Unknown inputs */
1356 if (!arch_irn_consider_in_reg_alloc(cls, op))
1359 /* we have permuted all values into the correct registers so we can
1360 simply query which value occupies the phis register in the
1362 a = arch_register_get_index(arch_get_irn_register(node));
1363 op = pred_info->assignments[a];
1364 set_Phi_pred(node, p, op);
1369 * Set preferences for a phis register based on the registers used on the
1372 static void adapt_phi_prefs(ir_node *phi)
1375 int arity = get_irn_arity(phi);
1376 ir_node *block = get_nodes_block(phi);
1377 allocation_info_t *info = get_allocation_info(phi);
1379 for (i = 0; i < arity; ++i) {
1380 ir_node *op = get_irn_n(phi, i);
1381 const arch_register_t *reg = arch_get_irn_register(op);
1382 ir_node *pred_block;
1383 block_info_t *pred_block_info;
1389 /* we only give the bonus if the predecessor already has registers
1390 * assigned, otherwise we only see a dummy value
1391 * and any conclusions about its register are useless */
1392 pred_block = get_Block_cfgpred_block(block, i);
1393 pred_block_info = get_block_info(pred_block);
1394 if (!pred_block_info->processed)
1397 /* give bonus for already assigned register */
1398 weight = get_block_execfreq(execfreqs, pred_block);
1399 r = arch_register_get_index(reg);
1400 info->prefs[r] += weight * AFF_PHI;
1405 * After a phi has been assigned a register propagate preference inputs
1406 * to the phi inputs.
1408 static void propagate_phi_register(ir_node *phi, unsigned r)
1411 ir_node *block = get_nodes_block(phi);
1412 int arity = get_irn_arity(phi);
1414 for (i = 0; i < arity; ++i) {
1415 ir_node *op = get_Phi_pred(phi, i);
1416 allocation_info_t *info = get_allocation_info(op);
1417 ir_node *pred_block = get_Block_cfgpred_block(block, i);
1419 = get_block_execfreq(execfreqs, pred_block) * AFF_PHI;
1421 if (info->prefs[r] >= weight)
1424 /* promote the prefered register */
1425 info->prefs[r] = AFF_PHI * weight;
1427 propagate_phi_register(op, r);
1431 static void assign_phi_registers(ir_node *block)
1438 hungarian_problem_t *bp;
1440 /* count phi nodes */
1441 sched_foreach(block, node) {
1444 if (!arch_irn_consider_in_reg_alloc(cls, node))
1452 /* build a bipartite matching problem for all phi nodes */
1453 bp = hungarian_new(n_phis, n_regs, HUNGARIAN_MATCH_PERFECT);
1455 sched_foreach(block, node) {
1458 allocation_info_t *info;
1461 if (!arch_irn_consider_in_reg_alloc(cls, node))
1464 /* give boni for predecessor colorings */
1465 adapt_phi_prefs(node);
1466 /* add stuff to bipartite problem */
1467 info = get_allocation_info(node);
1468 DB((dbg, LEVEL_3, "Prefs for %+F: ", node));
1469 for (r = 0; r < n_regs; ++r) {
1472 if (!rbitset_is_set(normal_regs, r))
1475 costs = info->prefs[r];
1476 costs = costs < 0 ? -logf(-costs+1) : logf(costs+1);
1479 hungarian_add(bp, n, r, costs);
1480 DB((dbg, LEVEL_3, " %s(%f)", arch_register_for_index(cls, r)->name,
1483 DB((dbg, LEVEL_3, "\n"));
1487 //hungarian_print_cost_matrix(bp, 7);
1488 hungarian_prepare_cost_matrix(bp, HUNGARIAN_MODE_MAXIMIZE_UTIL);
1490 assignment = ALLOCAN(int, n_regs);
1491 res = hungarian_solve(bp, assignment, NULL, 0);
1496 sched_foreach(block, node) {
1498 const arch_register_t *reg;
1502 if (!arch_irn_consider_in_reg_alloc(cls, node))
1505 r = assignment[n++];
1506 assert(rbitset_is_set(normal_regs, r));
1507 reg = arch_register_for_index(cls, r);
1508 DB((dbg, LEVEL_2, "Assign %+F -> %s\n", node, reg->name));
1511 /* adapt preferences for phi inputs */
1512 propagate_phi_register(node, r);
1517 * Walker: assign registers to all nodes of a block that
1518 * need registers from the currently considered register class.
1520 static void allocate_coalesce_block(ir_node *block, void *data)
1523 ir_nodeset_t live_nodes;
1524 ir_nodeset_iterator_t iter;
1527 block_info_t *block_info;
1528 block_info_t **pred_block_infos;
1530 unsigned *output_regs; /**< collects registers which must not
1531 be used for optimistic splits */
1534 DB((dbg, LEVEL_2, "* Block %+F\n", block));
1536 /* clear assignments */
1537 block_info = get_block_info(block);
1538 assignments = block_info->assignments;
1540 ir_nodeset_init(&live_nodes);
1542 /* gather regalloc infos of predecessor blocks */
1543 n_preds = get_Block_n_cfgpreds(block);
1544 pred_block_infos = ALLOCAN(block_info_t*, n_preds);
1545 for (i = 0; i < n_preds; ++i) {
1546 ir_node *pred = get_Block_cfgpred_block(block, i);
1547 block_info_t *pred_info = get_block_info(pred);
1548 pred_block_infos[i] = pred_info;
1551 phi_ins = ALLOCAN(ir_node*, n_preds);
1553 /* collect live-in nodes and preassigned values */
1554 be_lv_foreach(lv, block, be_lv_state_in, i) {
1555 const arch_register_t *reg;
1557 bool need_phi = false;
1559 node = be_lv_get_irn(lv, block, i);
1560 if (!arch_irn_consider_in_reg_alloc(cls, node))
1563 /* check all predecessors for this value, if it is not everywhere the
1564 same or unknown then we have to construct a phi
1565 (we collect the potential phi inputs here) */
1566 for (p = 0; p < n_preds; ++p) {
1567 block_info_t *pred_info = pred_block_infos[p];
1569 if (!pred_info->processed) {
1570 /* use node for now, it will get fixed later */
1574 int a = find_value_in_block_info(pred_info, node);
1576 /* must live out of predecessor */
1578 phi_ins[p] = pred_info->assignments[a];
1579 /* different value from last time? then we need a phi */
1580 if (p > 0 && phi_ins[p-1] != phi_ins[p]) {
1587 ir_mode *mode = get_irn_mode(node);
1588 const arch_register_req_t *req = get_default_req_current_cls();
1592 phi = new_r_Phi(block, n_preds, phi_ins, mode);
1593 be_set_phi_reg_req(phi, req);
1595 DB((dbg, LEVEL_3, "Create Phi %+F (for %+F) -", phi, node));
1596 #ifdef DEBUG_libfirm
1597 for (i = 0; i < n_preds; ++i) {
1598 DB((dbg, LEVEL_3, " %+F", phi_ins[i]));
1600 DB((dbg, LEVEL_3, "\n"));
1602 mark_as_copy_of(phi, node);
1603 sched_add_after(block, phi);
1607 allocation_info_t *info = get_allocation_info(node);
1608 info->current_value = phi_ins[0];
1610 /* Grab 1 of the inputs we constructed (might not be the same as
1611 * "node" as we could see the same copy of the value in all
1616 /* if the node already has a register assigned use it */
1617 reg = arch_get_irn_register(node);
1619 /* TODO: consult pred-block infos here. The value could be copied
1620 away in some/all predecessor blocks. We need to construct
1621 phi-nodes in this case.
1622 We even need to construct some Phi_0 like constructs in cases
1623 where the predecessor allocation is not determined yet. */
1627 /* remember that this node is live at the beginning of the block */
1628 ir_nodeset_insert(&live_nodes, node);
1631 rbitset_alloca(output_regs, n_regs);
1633 /* handle phis... */
1634 assign_phi_registers(block);
1636 /* assign regs for live-in values */
1637 foreach_ir_nodeset(&live_nodes, node, iter) {
1638 const arch_register_t *reg = arch_get_irn_register(node);
1642 assign_reg(block, node, output_regs);
1643 /* shouldn't happen if we color in dominance order */
1644 assert (!is_Phi(node));
1647 /* assign instructions in the block */
1648 sched_foreach(block, node) {
1651 /* phis are already assigned */
1655 rewire_inputs(node);
1657 /* enforce use constraints */
1658 rbitset_clear_all(output_regs, n_regs);
1659 enforce_constraints(&live_nodes, node, output_regs);
1660 /* we may not use registers occupied here for optimistic splits */
1661 for (r = 0; r < n_regs; ++r) {
1662 if (assignments[r] != NULL)
1663 rbitset_set(output_regs, r);
1666 rewire_inputs(node);
1668 /* free registers of values last used at this instruction */
1669 free_last_uses(&live_nodes, node);
1671 /* assign output registers */
1672 /* TODO: 2 phases: first: pre-assigned ones, 2nd real regs */
1673 if (get_irn_mode(node) == mode_T) {
1674 const ir_edge_t *edge;
1675 foreach_out_edge(node, edge) {
1676 ir_node *proj = get_edge_src_irn(edge);
1677 if (!arch_irn_consider_in_reg_alloc(cls, proj))
1679 assign_reg(block, proj, output_regs);
1681 } else if (arch_irn_consider_in_reg_alloc(cls, node)) {
1682 assign_reg(block, node, output_regs);
1686 ir_nodeset_destroy(&live_nodes);
1689 block_info->processed = true;
1691 /* permute values at end of predecessor blocks in case of phi-nodes */
1694 for (p = 0; p < n_preds; ++p) {
1695 add_phi_permutations(block, p);
1699 /* if we have exactly 1 successor then we might be able to produce phi
1701 if (get_irn_n_edges_kind(block, EDGE_KIND_BLOCK) == 1) {
1702 const ir_edge_t *edge
1703 = get_irn_out_edge_first_kind(block, EDGE_KIND_BLOCK);
1704 ir_node *succ = get_edge_src_irn(edge);
1705 int p = get_edge_src_pos(edge);
1706 block_info_t *succ_info = get_block_info(succ);
1708 if (succ_info->processed) {
1709 add_phi_permutations(succ, p);
1714 typedef struct block_costs_t block_costs_t;
1715 struct block_costs_t {
1716 float costs; /**< costs of the block */
1717 int dfs_num; /**< depth first search number (to detect backedges) */
1720 static int cmp_block_costs(const void *d1, const void *d2)
1722 const ir_node * const *block1 = d1;
1723 const ir_node * const *block2 = d2;
1724 const block_costs_t *info1 = get_irn_link(*block1);
1725 const block_costs_t *info2 = get_irn_link(*block2);
1726 return QSORT_CMP(info2->costs, info1->costs);
1729 static void determine_block_order(void)
1732 ir_node **blocklist = be_get_cfgpostorder(irg);
1733 int n_blocks = ARR_LEN(blocklist);
1736 /* clear block links... */
1737 for (i = 0; i < n_blocks; ++i) {
1738 ir_node *block = blocklist[i];
1739 set_irn_link(block, NULL);
1742 /* walk blocks in reverse postorder, the costs for each block are the
1743 * sum of the costs of its predecessors (excluding the costs on backedges
1744 * which we can't determine) */
1745 for (i = n_blocks-1; i >= 0; --i) {
1746 block_costs_t *cost_info;
1747 ir_node *block = blocklist[i];
1749 float execfreq = get_block_execfreq(execfreqs, block);
1750 float costs = execfreq;
1751 int n_cfgpreds = get_Block_n_cfgpreds(block);
1753 for (p = 0; p < n_cfgpreds; ++p) {
1754 ir_node *pred_block = get_Block_cfgpred_block(block, p);
1755 block_costs_t *pred_costs = get_irn_link(pred_block);
1756 /* we don't have any info for backedges */
1757 if (pred_costs == NULL)
1759 costs += pred_costs->costs;
1762 cost_info = OALLOCZ(&obst, block_costs_t);
1763 cost_info->costs = costs;
1764 cost_info->dfs_num = dfs_num++;
1765 set_irn_link(block, cost_info);
1768 /* sort array by block costs */
1769 qsort(blocklist, n_blocks, sizeof(blocklist[0]), cmp_block_costs);
1771 ir_reserve_resources(irg, IR_RESOURCE_BLOCK_VISITED);
1772 inc_irg_block_visited(irg);
1774 pdeq *worklist = new_pdeq();
1775 ir_node **order = XMALLOCN(ir_node*, n_blocks);
1777 for (i = 0; i < n_blocks; ++i) {
1778 ir_node *block = blocklist[i];
1779 if (Block_block_visited(block))
1782 /* continually add predecessors with highest costs to worklist
1783 * (without using backedges) */
1785 block_costs_t *info = get_irn_link(block);
1786 ir_node *best_pred = NULL;
1787 float best_costs = -1;
1788 int n_cfgpred = get_Block_n_cfgpreds(block);
1791 pdeq_putr(worklist, block);
1792 mark_Block_block_visited(block);
1793 for (i = 0; i < n_cfgpred; ++i) {
1794 ir_node *pred_block = get_Block_cfgpred_block(block, i);
1795 block_costs_t *pred_info = get_irn_link(pred_block);
1797 /* ignore backedges */
1798 if (pred_info->dfs_num > info->dfs_num)
1801 if (info->costs > best_costs) {
1802 best_costs = info->costs;
1803 best_pred = pred_block;
1807 } while(block != NULL && !Block_block_visited(block));
1809 /* now put all nodes in the worklist in our final order */
1810 while (!pdeq_empty(worklist)) {
1811 ir_node *pblock = pdeq_getr(worklist);
1812 assert(order_p < n_blocks);
1813 order[order_p++] = pblock;
1816 assert(order_p == n_blocks);
1819 ir_free_resources(irg, IR_RESOURCE_BLOCK_VISITED);
1821 DEL_ARR_F(blocklist);
1823 obstack_free(&obst, NULL);
1824 obstack_init(&obst);
1826 block_order = order;
1827 n_block_order = n_blocks;
1831 * Run the register allocator for the current register class.
1833 static void be_straight_alloc_cls(void)
1837 lv = be_assure_liveness(birg);
1838 be_liveness_assure_sets(lv);
1839 be_liveness_assure_chk(lv);
1841 ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
1843 DB((dbg, LEVEL_2, "=== Allocating registers of %s ===\n", cls->name));
1845 be_clear_links(irg);
1846 irg_block_walk_graph(irg, NULL, analyze_block, NULL);
1847 combine_congruence_classes();
1849 for (i = 0; i < n_block_order; ++i) {
1850 ir_node *block = block_order[i];
1851 allocate_coalesce_block(block, NULL);
1854 ir_free_resources(irg, IR_RESOURCE_IRN_LINK);
1857 static void dump(int mask, ir_graph *irg, const char *suffix,
1858 void (*dumper)(ir_graph *, const char *))
1860 if(birg->main_env->options->dump_flags & mask)
1861 be_dump(irg, suffix, dumper);
1865 * Run the spiller on the current graph.
1867 static void spill(void)
1869 /* make sure all nodes show their real register pressure */
1870 BE_TIMER_PUSH(t_ra_constr);
1871 be_pre_spill_prepare_constr(birg, cls);
1872 BE_TIMER_POP(t_ra_constr);
1874 dump(DUMP_RA, irg, "-spillprepare", dump_ir_block_graph_sched);
1877 BE_TIMER_PUSH(t_ra_spill);
1878 be_do_spill(birg, cls);
1879 BE_TIMER_POP(t_ra_spill);
1881 BE_TIMER_PUSH(t_ra_spill_apply);
1882 check_for_memory_operands(irg);
1883 BE_TIMER_POP(t_ra_spill_apply);
1885 dump(DUMP_RA, irg, "-spill", dump_ir_block_graph_sched);
1889 * The straight register allocator for a whole procedure.
1891 static void be_straight_alloc(be_irg_t *new_birg)
1893 const arch_env_t *arch_env = new_birg->main_env->arch_env;
1894 int n_cls = arch_env_get_n_reg_class(arch_env);
1897 obstack_init(&obst);
1900 irg = be_get_birg_irg(birg);
1901 execfreqs = birg->exec_freq;
1903 /* determine a good coloring order */
1904 determine_block_order();
1906 for (c = 0; c < n_cls; ++c) {
1907 cls = arch_env_get_reg_class(arch_env, c);
1908 default_cls_req = NULL;
1909 if (arch_register_class_flags(cls) & arch_register_class_flag_manual_ra)
1912 stat_ev_ctx_push_str("regcls", cls->name);
1914 n_regs = arch_register_class_n_regs(cls);
1915 normal_regs = rbitset_malloc(n_regs);
1916 be_abi_set_non_ignore_regs(birg->abi, cls, normal_regs);
1920 /* verify schedule and register pressure */
1921 BE_TIMER_PUSH(t_verify);
1922 if (birg->main_env->options->vrfy_option == BE_VRFY_WARN) {
1923 be_verify_schedule(birg);
1924 be_verify_register_pressure(birg, cls, irg);
1925 } else if (birg->main_env->options->vrfy_option == BE_VRFY_ASSERT) {
1926 assert(be_verify_schedule(birg) && "Schedule verification failed");
1927 assert(be_verify_register_pressure(birg, cls, irg)
1928 && "Register pressure verification failed");
1930 BE_TIMER_POP(t_verify);
1932 BE_TIMER_PUSH(t_ra_color);
1933 be_straight_alloc_cls();
1934 BE_TIMER_POP(t_ra_color);
1936 /* we most probably constructed new Phis so liveness info is invalid
1938 /* TODO: test liveness_introduce */
1939 be_liveness_invalidate(lv);
1942 stat_ev_ctx_pop("regcls");
1945 BE_TIMER_PUSH(t_ra_spill_apply);
1946 be_abi_fix_stack_nodes(birg->abi);
1947 BE_TIMER_POP(t_ra_spill_apply);
1949 BE_TIMER_PUSH(t_verify);
1950 if (birg->main_env->options->vrfy_option == BE_VRFY_WARN) {
1951 be_verify_register_allocation(birg);
1952 } else if (birg->main_env->options->vrfy_option == BE_VRFY_ASSERT) {
1953 assert(be_verify_register_allocation(birg)
1954 && "Register allocation invalid");
1956 BE_TIMER_POP(t_verify);
1958 obstack_free(&obst, NULL);
1962 * Initializes this module.
1964 void be_init_straight_alloc(void)
1966 static be_ra_t be_ra_straight = {
1970 FIRM_DBG_REGISTER(dbg, "firm.be.straightalloc");
1972 be_register_allocator("straight", &be_ra_straight);
1975 BE_REGISTER_MODULE_CONSTRUCTOR(be_init_straight_alloc);