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1 /* Assign reload pseudos.
2 Copyright (C) 2010-2021 Free Software Foundation, Inc.
3 Contributed by Vladimir Makarov <vmakarov@redhat.com>.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
10 version.
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
22 /* This file's main objective is to assign hard registers to reload
23 pseudos. It also tries to allocate hard registers to other
24 pseudos, but at a lower priority than the reload pseudos. The pass
25 does not transform the RTL.
27 We must allocate a hard register to every reload pseudo. We try to
28 increase the chances of finding a viable allocation by assigning
29 the pseudos in order of fewest available hard registers first. If
30 we still fail to find a hard register, we spill other (non-reload)
31 pseudos in order to make room.
33 find_hard_regno_for finds hard registers for allocation without
34 spilling. spill_for does the same with spilling. Both functions
35 use a cost model to determine the most profitable choice of hard
36 and spill registers.
38 Once we have finished allocating reload pseudos, we also try to
39 assign registers to other (non-reload) pseudos. This is useful if
40 hard registers were freed up by the spilling just described.
42 We try to assign hard registers by collecting pseudos into threads.
43 These threads contain reload and inheritance pseudos that are
44 connected by copies (move insns). Doing this improves the chances
45 of pseudos in the thread getting the same hard register and, as a
46 result, of allowing some move insns to be deleted.
48 When we assign a hard register to a pseudo, we decrease the cost of
49 using the same hard register for pseudos that are connected by
50 copies.
52 If two hard registers have the same frequency-derived cost, we
53 prefer hard registers with higher priorities. The mapping of
54 registers to priorities is controlled by the register_priority
55 target hook. For example, x86-64 has a few register priorities:
56 hard registers with and without REX prefixes have different
57 priorities. This permits us to generate smaller code as insns
58 without REX prefixes are shorter.
60 If a few hard registers are still equally good for the assignment,
61 we choose the least used hard register. It is called leveling and
62 may be profitable for some targets.
64 Only insns with changed allocation pseudos are processed on the
65 next constraint pass.
67 The pseudo live-ranges are used to find conflicting pseudos.
69 For understanding the code, it is important to keep in mind that
70 inheritance, split, and reload pseudos created since last
71 constraint pass have regno >= lra_constraint_new_regno_start.
72 Inheritance and split pseudos created on any pass are in the
73 corresponding bitmaps. Inheritance and split pseudos since the
74 last constraint pass have also the corresponding non-negative
75 restore_regno. */
77 #include "config.h"
78 #include "system.h"
79 #include "coretypes.h"
80 #include "backend.h"
81 #include "target.h"
82 #include "rtl.h"
83 #include "tree.h"
84 #include "predict.h"
85 #include "df.h"
86 #include "memmodel.h"
87 #include "tm_p.h"
88 #include "insn-config.h"
89 #include "regs.h"
90 #include "ira.h"
91 #include "recog.h"
92 #include "rtl-error.h"
93 #include "sparseset.h"
94 #include "lra.h"
95 #include "lra-int.h"
96 #include "function-abi.h"
98 /* Current iteration number of the pass and current iteration number
99 of the pass after the latest spill pass when any former reload
100 pseudo was spilled. */
101 int lra_assignment_iter;
102 int lra_assignment_iter_after_spill;
104 /* Flag of spilling former reload pseudos on this pass. */
105 static bool former_reload_pseudo_spill_p;
107 /* Array containing corresponding values of function
108 lra_get_allocno_class. It is used to speed up the code. */
109 static enum reg_class *regno_allocno_class_array;
111 /* Array containing lengths of pseudo live ranges. It is used to
112 speed up the code. */
113 static int *regno_live_length;
115 /* Information about the thread to which a pseudo belongs. Threads are
116 a set of connected reload and inheritance pseudos with the same set of
117 available hard registers. Lone registers belong to their own threads. */
118 struct regno_assign_info
120 /* First/next pseudo of the same thread. */
121 int first, next;
122 /* Frequency of the thread (execution frequency of only reload
123 pseudos in the thread when the thread contains a reload pseudo).
124 Defined only for the first thread pseudo. */
125 int freq;
128 /* Map regno to the corresponding regno assignment info. */
129 static struct regno_assign_info *regno_assign_info;
131 /* All inherited, subreg or optional pseudos created before last spill
132 sub-pass. Such pseudos are permitted to get memory instead of hard
133 regs. */
134 static bitmap_head non_reload_pseudos;
136 /* Process a pseudo copy with execution frequency COPY_FREQ connecting
137 REGNO1 and REGNO2 to form threads. */
138 static void
139 process_copy_to_form_thread (int regno1, int regno2, int copy_freq)
141 int last, regno1_first, regno2_first;
143 lra_assert (regno1 >= lra_constraint_new_regno_start
144 && regno2 >= lra_constraint_new_regno_start);
145 regno1_first = regno_assign_info[regno1].first;
146 regno2_first = regno_assign_info[regno2].first;
147 if (regno1_first != regno2_first)
149 for (last = regno2_first;
150 regno_assign_info[last].next >= 0;
151 last = regno_assign_info[last].next)
152 regno_assign_info[last].first = regno1_first;
153 regno_assign_info[last].first = regno1_first;
154 regno_assign_info[last].next = regno_assign_info[regno1_first].next;
155 regno_assign_info[regno1_first].next = regno2_first;
156 regno_assign_info[regno1_first].freq
157 += regno_assign_info[regno2_first].freq;
159 regno_assign_info[regno1_first].freq -= 2 * copy_freq;
160 lra_assert (regno_assign_info[regno1_first].freq >= 0);
163 /* Initialize REGNO_ASSIGN_INFO and form threads. */
164 static void
165 init_regno_assign_info (void)
167 int i, regno1, regno2, max_regno = max_reg_num ();
168 lra_copy_t cp;
170 regno_assign_info = XNEWVEC (struct regno_assign_info, max_regno);
171 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
173 regno_assign_info[i].first = i;
174 regno_assign_info[i].next = -1;
175 regno_assign_info[i].freq = lra_reg_info[i].freq;
177 /* Form the threads. */
178 for (i = 0; (cp = lra_get_copy (i)) != NULL; i++)
179 if ((regno1 = cp->regno1) >= lra_constraint_new_regno_start
180 && (regno2 = cp->regno2) >= lra_constraint_new_regno_start
181 && reg_renumber[regno1] < 0 && lra_reg_info[regno1].nrefs != 0
182 && reg_renumber[regno2] < 0 && lra_reg_info[regno2].nrefs != 0
183 && (ira_class_hard_regs_num[regno_allocno_class_array[regno1]]
184 == ira_class_hard_regs_num[regno_allocno_class_array[regno2]]))
185 process_copy_to_form_thread (regno1, regno2, cp->freq);
188 /* Free REGNO_ASSIGN_INFO. */
189 static void
190 finish_regno_assign_info (void)
192 free (regno_assign_info);
195 /* The function is used to sort *reload* and *inheritance* pseudos to
196 try to assign them hard registers. We put pseudos from the same
197 thread always nearby. */
198 static int
199 reload_pseudo_compare_func (const void *v1p, const void *v2p)
201 int r1 = *(const int *) v1p, r2 = *(const int *) v2p;
202 enum reg_class cl1 = regno_allocno_class_array[r1];
203 enum reg_class cl2 = regno_allocno_class_array[r2];
204 int diff;
206 lra_assert (r1 >= lra_constraint_new_regno_start
207 && r2 >= lra_constraint_new_regno_start);
209 /* Prefer to assign reload registers with smaller classes first to
210 guarantee assignment to all reload registers. */
211 if ((diff = (ira_class_hard_regs_num[cl1]
212 - ira_class_hard_regs_num[cl2])) != 0)
213 return diff;
214 /* Allocate bigger pseudos first to avoid register file
215 fragmentation. */
216 if ((diff
217 = (ira_reg_class_max_nregs[cl2][lra_reg_info[r2].biggest_mode]
218 - ira_reg_class_max_nregs[cl1][lra_reg_info[r1].biggest_mode])) != 0)
219 return diff;
220 if ((diff = (regno_assign_info[regno_assign_info[r2].first].freq
221 - regno_assign_info[regno_assign_info[r1].first].freq)) != 0)
222 return diff;
223 /* Put pseudos from the thread nearby. */
224 if ((diff = regno_assign_info[r1].first - regno_assign_info[r2].first) != 0)
225 return diff;
226 /* Prefer pseudos with longer live ranges. It sets up better
227 prefered hard registers for the thread pseudos and decreases
228 register-register moves between the thread pseudos. */
229 if ((diff = regno_live_length[r2] - regno_live_length[r1]) != 0)
230 return diff;
231 /* If regs are equally good, sort by their numbers, so that the
232 results of qsort leave nothing to chance. */
233 return r1 - r2;
236 /* The function is used to sort *non-reload* pseudos to try to assign
237 them hard registers. The order calculation is simpler than in the
238 previous function and based on the pseudo frequency usage. */
239 static int
240 pseudo_compare_func (const void *v1p, const void *v2p)
242 int r1 = *(const int *) v1p, r2 = *(const int *) v2p;
243 int diff;
245 /* Assign hard reg to static chain pointer first pseudo when
246 non-local goto is used. */
247 if ((diff = (non_spilled_static_chain_regno_p (r2)
248 - non_spilled_static_chain_regno_p (r1))) != 0)
249 return diff;
251 /* Prefer to assign more frequently used registers first. */
252 if ((diff = lra_reg_info[r2].freq - lra_reg_info[r1].freq) != 0)
253 return diff;
255 /* If regs are equally good, sort by their numbers, so that the
256 results of qsort leave nothing to chance. */
257 return r1 - r2;
260 /* Arrays of size LRA_LIVE_MAX_POINT mapping a program point to the
261 pseudo live ranges with given start point. We insert only live
262 ranges of pseudos interesting for assignment purposes. They are
263 reload pseudos and pseudos assigned to hard registers. */
264 static lra_live_range_t *start_point_ranges;
266 /* Used as a flag that a live range is not inserted in the start point
267 chain. */
268 static struct lra_live_range not_in_chain_mark;
270 /* Create and set up START_POINT_RANGES. */
271 static void
272 create_live_range_start_chains (void)
274 int i, max_regno;
275 lra_live_range_t r;
277 start_point_ranges = XCNEWVEC (lra_live_range_t, lra_live_max_point);
278 max_regno = max_reg_num ();
279 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
280 if (i >= lra_constraint_new_regno_start || reg_renumber[i] >= 0)
282 for (r = lra_reg_info[i].live_ranges; r != NULL; r = r->next)
284 r->start_next = start_point_ranges[r->start];
285 start_point_ranges[r->start] = r;
288 else
290 for (r = lra_reg_info[i].live_ranges; r != NULL; r = r->next)
291 r->start_next = &not_in_chain_mark;
295 /* Insert live ranges of pseudo REGNO into start chains if they are
296 not there yet. */
297 static void
298 insert_in_live_range_start_chain (int regno)
300 lra_live_range_t r = lra_reg_info[regno].live_ranges;
302 if (r->start_next != &not_in_chain_mark)
303 return;
304 for (; r != NULL; r = r->next)
306 r->start_next = start_point_ranges[r->start];
307 start_point_ranges[r->start] = r;
311 /* Free START_POINT_RANGES. */
312 static void
313 finish_live_range_start_chains (void)
315 gcc_assert (start_point_ranges != NULL);
316 free (start_point_ranges);
317 start_point_ranges = NULL;
320 /* Map: program point -> bitmap of all pseudos living at the point and
321 assigned to hard registers. */
322 static bitmap_head *live_hard_reg_pseudos;
323 static bitmap_obstack live_hard_reg_pseudos_bitmap_obstack;
325 /* reg_renumber corresponding to pseudos marked in
326 live_hard_reg_pseudos. reg_renumber might be not matched to
327 live_hard_reg_pseudos but live_pseudos_reg_renumber always reflects
328 live_hard_reg_pseudos. */
329 static int *live_pseudos_reg_renumber;
331 /* Sparseset used to calculate living hard reg pseudos for some program
332 point range. */
333 static sparseset live_range_hard_reg_pseudos;
335 /* Sparseset used to calculate living reload/inheritance pseudos for
336 some program point range. */
337 static sparseset live_range_reload_inheritance_pseudos;
339 /* Allocate and initialize the data about living pseudos at program
340 points. */
341 static void
342 init_lives (void)
344 int i, max_regno = max_reg_num ();
346 live_range_hard_reg_pseudos = sparseset_alloc (max_regno);
347 live_range_reload_inheritance_pseudos = sparseset_alloc (max_regno);
348 live_hard_reg_pseudos = XNEWVEC (bitmap_head, lra_live_max_point);
349 bitmap_obstack_initialize (&live_hard_reg_pseudos_bitmap_obstack);
350 for (i = 0; i < lra_live_max_point; i++)
351 bitmap_initialize (&live_hard_reg_pseudos[i],
352 &live_hard_reg_pseudos_bitmap_obstack);
353 live_pseudos_reg_renumber = XNEWVEC (int, max_regno);
354 for (i = 0; i < max_regno; i++)
355 live_pseudos_reg_renumber[i] = -1;
358 /* Free the data about living pseudos at program points. */
359 static void
360 finish_lives (void)
362 sparseset_free (live_range_hard_reg_pseudos);
363 sparseset_free (live_range_reload_inheritance_pseudos);
364 free (live_hard_reg_pseudos);
365 bitmap_obstack_release (&live_hard_reg_pseudos_bitmap_obstack);
366 free (live_pseudos_reg_renumber);
369 /* Update the LIVE_HARD_REG_PSEUDOS and LIVE_PSEUDOS_REG_RENUMBER
370 entries for pseudo REGNO. Assume that the register has been
371 spilled if FREE_P, otherwise assume that it has been assigned
372 reg_renumber[REGNO] (if >= 0). We also insert the pseudo live
373 ranges in the start chains when it is assumed to be assigned to a
374 hard register because we use the chains of pseudos assigned to hard
375 registers during allocation. */
376 static void
377 update_lives (int regno, bool free_p)
379 int p;
380 lra_live_range_t r;
382 if (reg_renumber[regno] < 0)
383 return;
384 live_pseudos_reg_renumber[regno] = free_p ? -1 : reg_renumber[regno];
385 for (r = lra_reg_info[regno].live_ranges; r != NULL; r = r->next)
387 for (p = r->start; p <= r->finish; p++)
388 if (free_p)
389 bitmap_clear_bit (&live_hard_reg_pseudos[p], regno);
390 else
392 bitmap_set_bit (&live_hard_reg_pseudos[p], regno);
393 insert_in_live_range_start_chain (regno);
398 /* Sparseset used to calculate reload pseudos conflicting with a given
399 pseudo when we are trying to find a hard register for the given
400 pseudo. */
401 static sparseset conflict_reload_and_inheritance_pseudos;
403 /* Map: program point -> bitmap of all reload and inheritance pseudos
404 living at the point. */
405 static bitmap_head *live_reload_and_inheritance_pseudos;
406 static bitmap_obstack live_reload_and_inheritance_pseudos_bitmap_obstack;
408 /* Allocate and initialize data about living reload pseudos at any
409 given program point. */
410 static void
411 init_live_reload_and_inheritance_pseudos (void)
413 int i, p, max_regno = max_reg_num ();
414 lra_live_range_t r;
416 conflict_reload_and_inheritance_pseudos = sparseset_alloc (max_regno);
417 live_reload_and_inheritance_pseudos = XNEWVEC (bitmap_head, lra_live_max_point);
418 bitmap_obstack_initialize (&live_reload_and_inheritance_pseudos_bitmap_obstack);
419 for (p = 0; p < lra_live_max_point; p++)
420 bitmap_initialize (&live_reload_and_inheritance_pseudos[p],
421 &live_reload_and_inheritance_pseudos_bitmap_obstack);
422 for (i = lra_constraint_new_regno_start; i < max_regno; i++)
424 for (r = lra_reg_info[i].live_ranges; r != NULL; r = r->next)
425 for (p = r->start; p <= r->finish; p++)
426 bitmap_set_bit (&live_reload_and_inheritance_pseudos[p], i);
430 /* Finalize data about living reload pseudos at any given program
431 point. */
432 static void
433 finish_live_reload_and_inheritance_pseudos (void)
435 sparseset_free (conflict_reload_and_inheritance_pseudos);
436 free (live_reload_and_inheritance_pseudos);
437 bitmap_obstack_release (&live_reload_and_inheritance_pseudos_bitmap_obstack);
440 /* The value used to check that cost of given hard reg is really
441 defined currently. */
442 static int curr_hard_regno_costs_check = 0;
443 /* Array used to check that cost of the corresponding hard reg (the
444 array element index) is really defined currently. */
445 static int hard_regno_costs_check[FIRST_PSEUDO_REGISTER];
446 /* The current costs of allocation of hard regs. Defined only if the
447 value of the corresponding element of the previous array is equal to
448 CURR_HARD_REGNO_COSTS_CHECK. */
449 static int hard_regno_costs[FIRST_PSEUDO_REGISTER];
451 /* Adjust cost of HARD_REGNO by INCR. Reset the cost first if it is
452 not defined yet. */
453 static inline void
454 adjust_hard_regno_cost (int hard_regno, int incr)
456 if (hard_regno_costs_check[hard_regno] != curr_hard_regno_costs_check)
457 hard_regno_costs[hard_regno] = 0;
458 hard_regno_costs_check[hard_regno] = curr_hard_regno_costs_check;
459 hard_regno_costs[hard_regno] += incr;
462 /* Try to find a free hard register for pseudo REGNO. Return the
463 hard register on success and set *COST to the cost of using
464 that register. (If several registers have equal cost, the one with
465 the highest priority wins.) Return -1 on failure.
467 If FIRST_P, return the first available hard reg ignoring other
468 criteria, e.g. allocation cost. This approach results in less hard
469 reg pool fragmentation and permit to allocate hard regs to reload
470 pseudos in complicated situations where pseudo sizes are different.
472 If TRY_ONLY_HARD_REGNO >= 0, consider only that hard register,
473 otherwise consider all hard registers in REGNO's class.
475 If REGNO_SET is not empty, only hard registers from the set are
476 considered. */
477 static int
478 find_hard_regno_for_1 (int regno, int *cost, int try_only_hard_regno,
479 bool first_p, HARD_REG_SET regno_set)
481 HARD_REG_SET conflict_set;
482 int best_cost = INT_MAX, best_priority = INT_MIN, best_usage = INT_MAX;
483 lra_live_range_t r;
484 int p, i, j, rclass_size, best_hard_regno, priority, hard_regno;
485 int hr, conflict_hr, nregs;
486 machine_mode biggest_mode;
487 unsigned int k, conflict_regno;
488 poly_int64 offset;
489 int val, biggest_nregs, nregs_diff;
490 enum reg_class rclass;
491 bitmap_iterator bi;
492 bool *rclass_intersect_p;
493 HARD_REG_SET impossible_start_hard_regs, available_regs;
495 if (hard_reg_set_empty_p (regno_set))
496 conflict_set = lra_no_alloc_regs;
497 else
498 conflict_set = ~regno_set | lra_no_alloc_regs;
499 rclass = regno_allocno_class_array[regno];
500 rclass_intersect_p = ira_reg_classes_intersect_p[rclass];
501 curr_hard_regno_costs_check++;
502 sparseset_clear (conflict_reload_and_inheritance_pseudos);
503 sparseset_clear (live_range_hard_reg_pseudos);
504 conflict_set |= lra_reg_info[regno].conflict_hard_regs;
505 biggest_mode = lra_reg_info[regno].biggest_mode;
506 for (r = lra_reg_info[regno].live_ranges; r != NULL; r = r->next)
508 EXECUTE_IF_SET_IN_BITMAP (&live_hard_reg_pseudos[r->start], 0, k, bi)
509 if (rclass_intersect_p[regno_allocno_class_array[k]])
510 sparseset_set_bit (live_range_hard_reg_pseudos, k);
511 EXECUTE_IF_SET_IN_BITMAP (&live_reload_and_inheritance_pseudos[r->start],
512 0, k, bi)
513 if (lra_reg_info[k].preferred_hard_regno1 >= 0
514 && live_pseudos_reg_renumber[k] < 0
515 && rclass_intersect_p[regno_allocno_class_array[k]])
516 sparseset_set_bit (conflict_reload_and_inheritance_pseudos, k);
517 for (p = r->start + 1; p <= r->finish; p++)
519 lra_live_range_t r2;
521 for (r2 = start_point_ranges[p];
522 r2 != NULL;
523 r2 = r2->start_next)
525 if (r2->regno >= lra_constraint_new_regno_start
526 && lra_reg_info[r2->regno].preferred_hard_regno1 >= 0
527 && live_pseudos_reg_renumber[r2->regno] < 0
528 && rclass_intersect_p[regno_allocno_class_array[r2->regno]])
529 sparseset_set_bit (conflict_reload_and_inheritance_pseudos,
530 r2->regno);
531 if (live_pseudos_reg_renumber[r2->regno] >= 0
532 && rclass_intersect_p[regno_allocno_class_array[r2->regno]])
533 sparseset_set_bit (live_range_hard_reg_pseudos, r2->regno);
537 if ((hard_regno = lra_reg_info[regno].preferred_hard_regno1) >= 0)
539 adjust_hard_regno_cost
540 (hard_regno, -lra_reg_info[regno].preferred_hard_regno_profit1);
541 if ((hard_regno = lra_reg_info[regno].preferred_hard_regno2) >= 0)
542 adjust_hard_regno_cost
543 (hard_regno, -lra_reg_info[regno].preferred_hard_regno_profit2);
545 #ifdef STACK_REGS
546 if (lra_reg_info[regno].no_stack_p)
547 for (i = FIRST_STACK_REG; i <= LAST_STACK_REG; i++)
548 SET_HARD_REG_BIT (conflict_set, i);
549 #endif
550 sparseset_clear_bit (conflict_reload_and_inheritance_pseudos, regno);
551 val = lra_reg_info[regno].val;
552 offset = lra_reg_info[regno].offset;
553 CLEAR_HARD_REG_SET (impossible_start_hard_regs);
554 EXECUTE_IF_SET_IN_SPARSESET (live_range_hard_reg_pseudos, conflict_regno)
556 conflict_hr = live_pseudos_reg_renumber[conflict_regno];
557 if (lra_reg_val_equal_p (conflict_regno, val, offset))
559 conflict_hr = live_pseudos_reg_renumber[conflict_regno];
560 nregs = hard_regno_nregs (conflict_hr,
561 lra_reg_info[conflict_regno].biggest_mode);
562 /* Remember about multi-register pseudos. For example, 2
563 hard register pseudos can start on the same hard register
564 but cannot start on HR and HR+1/HR-1. */
565 for (hr = conflict_hr + 1;
566 hr < FIRST_PSEUDO_REGISTER && hr < conflict_hr + nregs;
567 hr++)
568 SET_HARD_REG_BIT (impossible_start_hard_regs, hr);
569 for (hr = conflict_hr - 1;
570 hr >= 0 && (int) end_hard_regno (biggest_mode, hr) > conflict_hr;
571 hr--)
572 SET_HARD_REG_BIT (impossible_start_hard_regs, hr);
574 else
576 machine_mode biggest_conflict_mode
577 = lra_reg_info[conflict_regno].biggest_mode;
578 int biggest_conflict_nregs
579 = hard_regno_nregs (conflict_hr, biggest_conflict_mode);
581 nregs_diff
582 = (biggest_conflict_nregs
583 - hard_regno_nregs (conflict_hr,
584 PSEUDO_REGNO_MODE (conflict_regno)));
585 add_to_hard_reg_set (&conflict_set,
586 biggest_conflict_mode,
587 conflict_hr
588 - (WORDS_BIG_ENDIAN ? nregs_diff : 0));
589 if (hard_reg_set_subset_p (reg_class_contents[rclass],
590 conflict_set))
591 return -1;
594 EXECUTE_IF_SET_IN_SPARSESET (conflict_reload_and_inheritance_pseudos,
595 conflict_regno)
596 if (!lra_reg_val_equal_p (conflict_regno, val, offset))
598 lra_assert (live_pseudos_reg_renumber[conflict_regno] < 0);
599 if ((hard_regno
600 = lra_reg_info[conflict_regno].preferred_hard_regno1) >= 0)
602 adjust_hard_regno_cost
603 (hard_regno,
604 lra_reg_info[conflict_regno].preferred_hard_regno_profit1);
605 if ((hard_regno
606 = lra_reg_info[conflict_regno].preferred_hard_regno2) >= 0)
607 adjust_hard_regno_cost
608 (hard_regno,
609 lra_reg_info[conflict_regno].preferred_hard_regno_profit2);
612 /* Make sure that all registers in a multi-word pseudo belong to the
613 required class. */
614 conflict_set |= ~reg_class_contents[rclass];
615 lra_assert (rclass != NO_REGS);
616 rclass_size = ira_class_hard_regs_num[rclass];
617 best_hard_regno = -1;
618 hard_regno = ira_class_hard_regs[rclass][0];
619 biggest_nregs = hard_regno_nregs (hard_regno, biggest_mode);
620 nregs_diff = (biggest_nregs
621 - hard_regno_nregs (hard_regno, PSEUDO_REGNO_MODE (regno)));
622 available_regs = reg_class_contents[rclass] & ~lra_no_alloc_regs;
623 for (i = 0; i < rclass_size; i++)
625 if (try_only_hard_regno >= 0)
626 hard_regno = try_only_hard_regno;
627 else
628 hard_regno = ira_class_hard_regs[rclass][i];
629 if (! overlaps_hard_reg_set_p (conflict_set,
630 PSEUDO_REGNO_MODE (regno), hard_regno)
631 && targetm.hard_regno_mode_ok (hard_regno,
632 PSEUDO_REGNO_MODE (regno))
633 /* We cannot use prohibited_class_mode_regs for all classes
634 because it is not defined for all classes. */
635 && (ira_allocno_class_translate[rclass] != rclass
636 || ! TEST_HARD_REG_BIT (ira_prohibited_class_mode_regs
637 [rclass][PSEUDO_REGNO_MODE (regno)],
638 hard_regno))
639 && ! TEST_HARD_REG_BIT (impossible_start_hard_regs, hard_regno)
640 && (nregs_diff == 0
641 || (WORDS_BIG_ENDIAN
642 ? (hard_regno - nregs_diff >= 0
643 && TEST_HARD_REG_BIT (available_regs,
644 hard_regno - nregs_diff))
645 : TEST_HARD_REG_BIT (available_regs,
646 hard_regno + nregs_diff))))
648 if (hard_regno_costs_check[hard_regno]
649 != curr_hard_regno_costs_check)
651 hard_regno_costs_check[hard_regno] = curr_hard_regno_costs_check;
652 hard_regno_costs[hard_regno] = 0;
654 for (j = 0;
655 j < hard_regno_nregs (hard_regno, PSEUDO_REGNO_MODE (regno));
656 j++)
657 if (! crtl->abi->clobbers_full_reg_p (hard_regno + j)
658 && ! df_regs_ever_live_p (hard_regno + j))
659 /* It needs save restore. */
660 hard_regno_costs[hard_regno]
661 += (2
662 * REG_FREQ_FROM_BB (ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb)
663 + 1);
664 priority = targetm.register_priority (hard_regno);
665 if (best_hard_regno < 0 || hard_regno_costs[hard_regno] < best_cost
666 || (hard_regno_costs[hard_regno] == best_cost
667 && (priority > best_priority
668 || (targetm.register_usage_leveling_p ()
669 && priority == best_priority
670 && best_usage > lra_hard_reg_usage[hard_regno]))))
672 best_hard_regno = hard_regno;
673 best_cost = hard_regno_costs[hard_regno];
674 best_priority = priority;
675 best_usage = lra_hard_reg_usage[hard_regno];
678 if (try_only_hard_regno >= 0 || (first_p && best_hard_regno >= 0))
679 break;
681 if (best_hard_regno >= 0)
682 *cost = best_cost - lra_reg_info[regno].freq;
683 return best_hard_regno;
686 /* A wrapper for find_hard_regno_for_1 (see comments for that function
687 description). This function tries to find a hard register for
688 preferred class first if it is worth. */
689 static int
690 find_hard_regno_for (int regno, int *cost, int try_only_hard_regno, bool first_p)
692 int hard_regno;
693 HARD_REG_SET regno_set;
695 /* Only original pseudos can have a different preferred class. */
696 if (try_only_hard_regno < 0 && regno < lra_new_regno_start)
698 enum reg_class pref_class = reg_preferred_class (regno);
700 if (regno_allocno_class_array[regno] != pref_class)
702 hard_regno = find_hard_regno_for_1 (regno, cost, -1, first_p,
703 reg_class_contents[pref_class]);
704 if (hard_regno >= 0)
705 return hard_regno;
708 CLEAR_HARD_REG_SET (regno_set);
709 return find_hard_regno_for_1 (regno, cost, try_only_hard_regno, first_p,
710 regno_set);
713 /* Current value used for checking elements in
714 update_hard_regno_preference_check. */
715 static int curr_update_hard_regno_preference_check;
716 /* If an element value is equal to the above variable value, then the
717 corresponding regno has been processed for preference
718 propagation. */
719 static int *update_hard_regno_preference_check;
721 /* Update the preference for using HARD_REGNO for pseudos that are
722 connected directly or indirectly with REGNO. Apply divisor DIV
723 to any preference adjustments.
725 The more indirectly a pseudo is connected, the smaller its effect
726 should be. We therefore increase DIV on each "hop". */
727 static void
728 update_hard_regno_preference (int regno, int hard_regno, int div)
730 int another_regno, cost;
731 lra_copy_t cp, next_cp;
733 /* Search depth 5 seems to be enough. */
734 if (div > (1 << 5))
735 return;
736 for (cp = lra_reg_info[regno].copies; cp != NULL; cp = next_cp)
738 if (cp->regno1 == regno)
740 next_cp = cp->regno1_next;
741 another_regno = cp->regno2;
743 else if (cp->regno2 == regno)
745 next_cp = cp->regno2_next;
746 another_regno = cp->regno1;
748 else
749 gcc_unreachable ();
750 if (reg_renumber[another_regno] < 0
751 && (update_hard_regno_preference_check[another_regno]
752 != curr_update_hard_regno_preference_check))
754 update_hard_regno_preference_check[another_regno]
755 = curr_update_hard_regno_preference_check;
756 cost = cp->freq < div ? 1 : cp->freq / div;
757 lra_setup_reload_pseudo_preferenced_hard_reg
758 (another_regno, hard_regno, cost);
759 update_hard_regno_preference (another_regno, hard_regno, div * 2);
764 /* Return prefix title for pseudo REGNO. */
765 static const char *
766 pseudo_prefix_title (int regno)
768 return
769 (regno < lra_constraint_new_regno_start ? ""
770 : bitmap_bit_p (&lra_inheritance_pseudos, regno) ? "inheritance "
771 : bitmap_bit_p (&lra_split_regs, regno) ? "split "
772 : bitmap_bit_p (&lra_optional_reload_pseudos, regno) ? "optional reload "
773 : bitmap_bit_p (&lra_subreg_reload_pseudos, regno) ? "subreg reload "
774 : "reload ");
777 /* Update REG_RENUMBER and other pseudo preferences by assignment of
778 HARD_REGNO to pseudo REGNO and print about it if PRINT_P. */
779 void
780 lra_setup_reg_renumber (int regno, int hard_regno, bool print_p)
782 int i, hr;
784 /* We cannot just reassign hard register. */
785 lra_assert (hard_regno < 0 || reg_renumber[regno] < 0);
786 if ((hr = hard_regno) < 0)
787 hr = reg_renumber[regno];
788 reg_renumber[regno] = hard_regno;
789 lra_assert (hr >= 0);
790 for (i = 0; i < hard_regno_nregs (hr, PSEUDO_REGNO_MODE (regno)); i++)
791 if (hard_regno < 0)
792 lra_hard_reg_usage[hr + i] -= lra_reg_info[regno].freq;
793 else
794 lra_hard_reg_usage[hr + i] += lra_reg_info[regno].freq;
795 if (print_p && lra_dump_file != NULL)
796 fprintf (lra_dump_file, " Assign %d to %sr%d (freq=%d)\n",
797 reg_renumber[regno], pseudo_prefix_title (regno),
798 regno, lra_reg_info[regno].freq);
799 if (hard_regno >= 0)
801 curr_update_hard_regno_preference_check++;
802 update_hard_regno_preference (regno, hard_regno, 1);
806 /* Pseudos which occur in insns containing a particular pseudo. */
807 static bitmap_head insn_conflict_pseudos;
809 /* Bitmaps used to contain spill pseudos for given pseudo hard regno
810 and best spill pseudos for given pseudo (and best hard regno). */
811 static bitmap_head spill_pseudos_bitmap, best_spill_pseudos_bitmap;
813 /* Current pseudo check for validity of elements in
814 TRY_HARD_REG_PSEUDOS. */
815 static int curr_pseudo_check;
816 /* Array used for validity of elements in TRY_HARD_REG_PSEUDOS. */
817 static int try_hard_reg_pseudos_check[FIRST_PSEUDO_REGISTER];
818 /* Pseudos who hold given hard register at the considered points. */
819 static bitmap_head try_hard_reg_pseudos[FIRST_PSEUDO_REGISTER];
821 /* Set up try_hard_reg_pseudos for given program point P and class
822 RCLASS. Those are pseudos living at P and assigned to a hard
823 register of RCLASS. In other words, those are pseudos which can be
824 spilled to assign a hard register of RCLASS to a pseudo living at
825 P. */
826 static void
827 setup_try_hard_regno_pseudos (int p, enum reg_class rclass)
829 int i, hard_regno;
830 machine_mode mode;
831 unsigned int spill_regno;
832 bitmap_iterator bi;
834 /* Find what pseudos could be spilled. */
835 EXECUTE_IF_SET_IN_BITMAP (&live_hard_reg_pseudos[p], 0, spill_regno, bi)
837 mode = PSEUDO_REGNO_MODE (spill_regno);
838 hard_regno = live_pseudos_reg_renumber[spill_regno];
839 if (overlaps_hard_reg_set_p (reg_class_contents[rclass],
840 mode, hard_regno))
842 for (i = hard_regno_nregs (hard_regno, mode) - 1; i >= 0; i--)
844 if (try_hard_reg_pseudos_check[hard_regno + i]
845 != curr_pseudo_check)
847 try_hard_reg_pseudos_check[hard_regno + i]
848 = curr_pseudo_check;
849 bitmap_clear (&try_hard_reg_pseudos[hard_regno + i]);
851 bitmap_set_bit (&try_hard_reg_pseudos[hard_regno + i],
852 spill_regno);
858 /* Assign temporarily HARD_REGNO to pseudo REGNO. Temporary
859 assignment means that we might undo the data change. */
860 static void
861 assign_temporarily (int regno, int hard_regno)
863 int p;
864 lra_live_range_t r;
866 for (r = lra_reg_info[regno].live_ranges; r != NULL; r = r->next)
868 for (p = r->start; p <= r->finish; p++)
869 if (hard_regno < 0)
870 bitmap_clear_bit (&live_hard_reg_pseudos[p], regno);
871 else
873 bitmap_set_bit (&live_hard_reg_pseudos[p], regno);
874 insert_in_live_range_start_chain (regno);
877 live_pseudos_reg_renumber[regno] = hard_regno;
880 /* Return true iff there is a reason why pseudo SPILL_REGNO should not
881 be spilled. */
882 static bool
883 must_not_spill_p (unsigned spill_regno)
885 if ((pic_offset_table_rtx != NULL
886 && spill_regno == REGNO (pic_offset_table_rtx))
887 || ((int) spill_regno >= lra_constraint_new_regno_start
888 && ! bitmap_bit_p (&lra_inheritance_pseudos, spill_regno)
889 && ! bitmap_bit_p (&lra_split_regs, spill_regno)
890 && ! bitmap_bit_p (&lra_subreg_reload_pseudos, spill_regno)
891 && ! bitmap_bit_p (&lra_optional_reload_pseudos, spill_regno)))
892 return true;
893 /* A reload pseudo that requires a singleton register class should
894 not be spilled.
895 FIXME: this mitigates the issue on certain i386 patterns, but
896 does not solve the general case where existing reloads fully
897 cover a limited register class. */
898 if (!bitmap_bit_p (&non_reload_pseudos, spill_regno)
899 && reg_class_size [reg_preferred_class (spill_regno)] == 1
900 && reg_alternate_class (spill_regno) == NO_REGS)
901 return true;
902 return false;
905 /* Array used for sorting reload pseudos for subsequent allocation
906 after spilling some pseudo. */
907 static int *sorted_reload_pseudos;
909 /* Spill some pseudos for a reload pseudo REGNO and return hard
910 register which should be used for pseudo after spilling. The
911 function adds spilled pseudos to SPILLED_PSEUDO_BITMAP. When we
912 choose hard register (and pseudos occupying the hard registers and
913 to be spilled), we take into account not only how REGNO will
914 benefit from the spills but also how other reload pseudos not yet
915 assigned to hard registers benefit from the spills too. In very
916 rare cases, the function can fail and return -1.
918 If FIRST_P, return the first available hard reg ignoring other
919 criteria, e.g. allocation cost and cost of spilling non-reload
920 pseudos. This approach results in less hard reg pool fragmentation
921 and permit to allocate hard regs to reload pseudos in complicated
922 situations where pseudo sizes are different. */
923 static int
924 spill_for (int regno, bitmap spilled_pseudo_bitmap, bool first_p)
926 int i, j, n, p, hard_regno, best_hard_regno, cost, best_cost, rclass_size;
927 int reload_hard_regno, reload_cost;
928 bool static_p, best_static_p;
929 machine_mode mode;
930 enum reg_class rclass;
931 unsigned int spill_regno, reload_regno, uid;
932 int insn_pseudos_num, best_insn_pseudos_num;
933 int bad_spills_num, smallest_bad_spills_num;
934 lra_live_range_t r;
935 bitmap_iterator bi;
937 rclass = regno_allocno_class_array[regno];
938 lra_assert (reg_renumber[regno] < 0 && rclass != NO_REGS);
939 bitmap_clear (&insn_conflict_pseudos);
940 bitmap_clear (&best_spill_pseudos_bitmap);
941 EXECUTE_IF_SET_IN_BITMAP (&lra_reg_info[regno].insn_bitmap, 0, uid, bi)
943 struct lra_insn_reg *ir;
945 for (ir = lra_get_insn_regs (uid); ir != NULL; ir = ir->next)
946 if (ir->regno >= FIRST_PSEUDO_REGISTER)
947 bitmap_set_bit (&insn_conflict_pseudos, ir->regno);
949 best_hard_regno = -1;
950 best_cost = INT_MAX;
951 best_static_p = TRUE;
952 best_insn_pseudos_num = INT_MAX;
953 smallest_bad_spills_num = INT_MAX;
954 rclass_size = ira_class_hard_regs_num[rclass];
955 mode = PSEUDO_REGNO_MODE (regno);
956 /* Invalidate try_hard_reg_pseudos elements. */
957 curr_pseudo_check++;
958 for (r = lra_reg_info[regno].live_ranges; r != NULL; r = r->next)
959 for (p = r->start; p <= r->finish; p++)
960 setup_try_hard_regno_pseudos (p, rclass);
961 for (i = 0; i < rclass_size; i++)
963 hard_regno = ira_class_hard_regs[rclass][i];
964 bitmap_clear (&spill_pseudos_bitmap);
965 for (j = hard_regno_nregs (hard_regno, mode) - 1; j >= 0; j--)
967 if (hard_regno + j >= FIRST_PSEUDO_REGISTER)
968 break;
969 if (try_hard_reg_pseudos_check[hard_regno + j] != curr_pseudo_check)
970 continue;
971 lra_assert (!bitmap_empty_p (&try_hard_reg_pseudos[hard_regno + j]));
972 bitmap_ior_into (&spill_pseudos_bitmap,
973 &try_hard_reg_pseudos[hard_regno + j]);
975 /* Spill pseudos. */
976 static_p = false;
977 EXECUTE_IF_SET_IN_BITMAP (&spill_pseudos_bitmap, 0, spill_regno, bi)
978 if (must_not_spill_p (spill_regno))
979 goto fail;
980 else if (non_spilled_static_chain_regno_p (spill_regno))
981 static_p = true;
982 insn_pseudos_num = 0;
983 bad_spills_num = 0;
984 if (lra_dump_file != NULL)
985 fprintf (lra_dump_file, " Trying %d:", hard_regno);
986 sparseset_clear (live_range_reload_inheritance_pseudos);
987 EXECUTE_IF_SET_IN_BITMAP (&spill_pseudos_bitmap, 0, spill_regno, bi)
989 if (bitmap_bit_p (&insn_conflict_pseudos, spill_regno))
990 insn_pseudos_num++;
991 if (spill_regno >= (unsigned int) lra_bad_spill_regno_start)
992 bad_spills_num++;
993 for (r = lra_reg_info[spill_regno].live_ranges;
994 r != NULL;
995 r = r->next)
997 for (p = r->start; p <= r->finish; p++)
999 lra_live_range_t r2;
1001 for (r2 = start_point_ranges[p];
1002 r2 != NULL;
1003 r2 = r2->start_next)
1004 if (r2->regno >= lra_constraint_new_regno_start)
1005 sparseset_set_bit (live_range_reload_inheritance_pseudos,
1006 r2->regno);
1010 n = 0;
1011 if (sparseset_cardinality (live_range_reload_inheritance_pseudos)
1012 <= (unsigned)param_lra_max_considered_reload_pseudos)
1013 EXECUTE_IF_SET_IN_SPARSESET (live_range_reload_inheritance_pseudos,
1014 reload_regno)
1015 if ((int) reload_regno != regno
1016 && (ira_reg_classes_intersect_p
1017 [rclass][regno_allocno_class_array[reload_regno]])
1018 && live_pseudos_reg_renumber[reload_regno] < 0
1019 && find_hard_regno_for (reload_regno, &cost, -1, first_p) < 0)
1020 sorted_reload_pseudos[n++] = reload_regno;
1021 EXECUTE_IF_SET_IN_BITMAP (&spill_pseudos_bitmap, 0, spill_regno, bi)
1023 update_lives (spill_regno, true);
1024 if (lra_dump_file != NULL)
1025 fprintf (lra_dump_file, " spill %d(freq=%d)",
1026 spill_regno, lra_reg_info[spill_regno].freq);
1028 hard_regno = find_hard_regno_for (regno, &cost, -1, first_p);
1029 if (hard_regno >= 0)
1031 assign_temporarily (regno, hard_regno);
1032 qsort (sorted_reload_pseudos, n, sizeof (int),
1033 reload_pseudo_compare_func);
1034 for (j = 0; j < n; j++)
1036 reload_regno = sorted_reload_pseudos[j];
1037 lra_assert (live_pseudos_reg_renumber[reload_regno] < 0);
1038 if ((reload_hard_regno
1039 = find_hard_regno_for (reload_regno,
1040 &reload_cost, -1, first_p)) >= 0)
1042 if (lra_dump_file != NULL)
1043 fprintf (lra_dump_file, " assign %d(cost=%d)",
1044 reload_regno, reload_cost);
1045 assign_temporarily (reload_regno, reload_hard_regno);
1046 cost += reload_cost;
1049 EXECUTE_IF_SET_IN_BITMAP (&spill_pseudos_bitmap, 0, spill_regno, bi)
1051 rtx_insn_list *x;
1053 cost += lra_reg_info[spill_regno].freq;
1054 if (ira_reg_equiv[spill_regno].memory != NULL
1055 || ira_reg_equiv[spill_regno].constant != NULL)
1056 for (x = ira_reg_equiv[spill_regno].init_insns;
1057 x != NULL;
1058 x = x->next ())
1059 cost -= REG_FREQ_FROM_BB (BLOCK_FOR_INSN (x->insn ()));
1061 /* Avoid spilling static chain pointer pseudo when non-local
1062 goto is used. */
1063 if ((! static_p && best_static_p)
1064 || (static_p == best_static_p
1065 && (best_insn_pseudos_num > insn_pseudos_num
1066 || (best_insn_pseudos_num == insn_pseudos_num
1067 && (bad_spills_num < smallest_bad_spills_num
1068 || (bad_spills_num == smallest_bad_spills_num
1069 && best_cost > cost))))))
1071 best_insn_pseudos_num = insn_pseudos_num;
1072 smallest_bad_spills_num = bad_spills_num;
1073 best_static_p = static_p;
1074 best_cost = cost;
1075 best_hard_regno = hard_regno;
1076 bitmap_copy (&best_spill_pseudos_bitmap, &spill_pseudos_bitmap);
1077 if (lra_dump_file != NULL)
1078 fprintf (lra_dump_file,
1079 " Now best %d(cost=%d, bad_spills=%d, insn_pseudos=%d)\n",
1080 hard_regno, cost, bad_spills_num, insn_pseudos_num);
1082 assign_temporarily (regno, -1);
1083 for (j = 0; j < n; j++)
1085 reload_regno = sorted_reload_pseudos[j];
1086 if (live_pseudos_reg_renumber[reload_regno] >= 0)
1087 assign_temporarily (reload_regno, -1);
1090 if (lra_dump_file != NULL)
1091 fprintf (lra_dump_file, "\n");
1092 /* Restore the live hard reg pseudo info for spilled pseudos. */
1093 EXECUTE_IF_SET_IN_BITMAP (&spill_pseudos_bitmap, 0, spill_regno, bi)
1094 update_lives (spill_regno, false);
1095 fail:
1098 /* Spill: */
1099 EXECUTE_IF_SET_IN_BITMAP (&best_spill_pseudos_bitmap, 0, spill_regno, bi)
1101 if ((int) spill_regno >= lra_constraint_new_regno_start)
1102 former_reload_pseudo_spill_p = true;
1103 if (lra_dump_file != NULL)
1104 fprintf (lra_dump_file, " Spill %sr%d(hr=%d, freq=%d) for r%d\n",
1105 pseudo_prefix_title (spill_regno),
1106 spill_regno, reg_renumber[spill_regno],
1107 lra_reg_info[spill_regno].freq, regno);
1108 update_lives (spill_regno, true);
1109 lra_setup_reg_renumber (spill_regno, -1, false);
1111 bitmap_ior_into (spilled_pseudo_bitmap, &best_spill_pseudos_bitmap);
1112 return best_hard_regno;
1115 /* Assign HARD_REGNO to REGNO. */
1116 static void
1117 assign_hard_regno (int hard_regno, int regno)
1119 int i;
1121 lra_assert (hard_regno >= 0);
1122 lra_setup_reg_renumber (regno, hard_regno, true);
1123 update_lives (regno, false);
1124 for (i = 0;
1125 i < hard_regno_nregs (hard_regno, lra_reg_info[regno].biggest_mode);
1126 i++)
1127 df_set_regs_ever_live (hard_regno + i, true);
1130 /* Array used for sorting different pseudos. */
1131 static int *sorted_pseudos;
1133 /* The constraints pass is allowed to create equivalences between
1134 pseudos that make the current allocation "incorrect" (in the sense
1135 that pseudos are assigned to hard registers from their own conflict
1136 sets). The global variable check_and_force_assignment_correctness_p says
1137 whether this might have happened.
1139 Process pseudos assigned to hard registers (less frequently used
1140 first), spill if a conflict is found, and mark the spilled pseudos
1141 in SPILLED_PSEUDO_BITMAP. Set up LIVE_HARD_REG_PSEUDOS from
1142 pseudos, assigned to hard registers. */
1143 static void
1144 setup_live_pseudos_and_spill_after_risky_transforms (bitmap
1145 spilled_pseudo_bitmap)
1147 int p, i, j, n, regno, hard_regno, biggest_nregs, nregs_diff;
1148 unsigned int k, conflict_regno;
1149 poly_int64 offset;
1150 int val;
1151 HARD_REG_SET conflict_set;
1152 machine_mode mode, biggest_mode;
1153 lra_live_range_t r;
1154 bitmap_iterator bi;
1155 int max_regno = max_reg_num ();
1157 if (! check_and_force_assignment_correctness_p)
1159 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
1160 if (reg_renumber[i] >= 0 && lra_reg_info[i].nrefs > 0)
1161 update_lives (i, false);
1162 return;
1164 for (n = 0, i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
1165 if ((pic_offset_table_rtx == NULL_RTX
1166 || i != (int) REGNO (pic_offset_table_rtx))
1167 && (hard_regno = reg_renumber[i]) >= 0 && lra_reg_info[i].nrefs > 0)
1169 biggest_mode = lra_reg_info[i].biggest_mode;
1170 biggest_nregs = hard_regno_nregs (hard_regno, biggest_mode);
1171 nregs_diff = (biggest_nregs
1172 - hard_regno_nregs (hard_regno, PSEUDO_REGNO_MODE (i)));
1173 enum reg_class rclass = lra_get_allocno_class (i);
1175 if ((WORDS_BIG_ENDIAN
1176 && (hard_regno - nregs_diff < 0
1177 || !TEST_HARD_REG_BIT (reg_class_contents[rclass],
1178 hard_regno - nregs_diff)))
1179 || (!WORDS_BIG_ENDIAN
1180 && (hard_regno + nregs_diff >= FIRST_PSEUDO_REGISTER
1181 || !TEST_HARD_REG_BIT (reg_class_contents[rclass],
1182 hard_regno + nregs_diff))))
1184 /* Hard registers of paradoxical sub-registers are out of
1185 range of pseudo register class. Spill the pseudo. */
1186 reg_renumber[i] = -1;
1187 continue;
1189 sorted_pseudos[n++] = i;
1191 qsort (sorted_pseudos, n, sizeof (int), pseudo_compare_func);
1192 if (pic_offset_table_rtx != NULL_RTX
1193 && (regno = REGNO (pic_offset_table_rtx)) >= FIRST_PSEUDO_REGISTER
1194 && reg_renumber[regno] >= 0 && lra_reg_info[regno].nrefs > 0)
1195 sorted_pseudos[n++] = regno;
1196 for (i = n - 1; i >= 0; i--)
1198 regno = sorted_pseudos[i];
1199 hard_regno = reg_renumber[regno];
1200 lra_assert (hard_regno >= 0);
1201 mode = lra_reg_info[regno].biggest_mode;
1202 sparseset_clear (live_range_hard_reg_pseudos);
1203 for (r = lra_reg_info[regno].live_ranges; r != NULL; r = r->next)
1205 EXECUTE_IF_SET_IN_BITMAP (&live_hard_reg_pseudos[r->start], 0, k, bi)
1206 sparseset_set_bit (live_range_hard_reg_pseudos, k);
1207 for (p = r->start + 1; p <= r->finish; p++)
1209 lra_live_range_t r2;
1211 for (r2 = start_point_ranges[p];
1212 r2 != NULL;
1213 r2 = r2->start_next)
1214 if (live_pseudos_reg_renumber[r2->regno] >= 0)
1215 sparseset_set_bit (live_range_hard_reg_pseudos, r2->regno);
1218 conflict_set = lra_no_alloc_regs;
1219 conflict_set |= lra_reg_info[regno].conflict_hard_regs;
1220 val = lra_reg_info[regno].val;
1221 offset = lra_reg_info[regno].offset;
1222 EXECUTE_IF_SET_IN_SPARSESET (live_range_hard_reg_pseudos, conflict_regno)
1223 if (!lra_reg_val_equal_p (conflict_regno, val, offset)
1224 /* If it is multi-register pseudos they should start on
1225 the same hard register. */
1226 || hard_regno != reg_renumber[conflict_regno])
1228 int conflict_hard_regno = reg_renumber[conflict_regno];
1230 biggest_mode = lra_reg_info[conflict_regno].biggest_mode;
1231 biggest_nregs = hard_regno_nregs (conflict_hard_regno,
1232 biggest_mode);
1233 nregs_diff
1234 = (biggest_nregs
1235 - hard_regno_nregs (conflict_hard_regno,
1236 PSEUDO_REGNO_MODE (conflict_regno)));
1237 add_to_hard_reg_set (&conflict_set,
1238 biggest_mode,
1239 conflict_hard_regno
1240 - (WORDS_BIG_ENDIAN ? nregs_diff : 0));
1242 if (! overlaps_hard_reg_set_p (conflict_set, mode, hard_regno))
1244 update_lives (regno, false);
1245 continue;
1247 bitmap_set_bit (spilled_pseudo_bitmap, regno);
1248 for (j = 0;
1249 j < hard_regno_nregs (hard_regno, PSEUDO_REGNO_MODE (regno));
1250 j++)
1251 lra_hard_reg_usage[hard_regno + j] -= lra_reg_info[regno].freq;
1252 reg_renumber[regno] = -1;
1253 if (regno >= lra_constraint_new_regno_start)
1254 former_reload_pseudo_spill_p = true;
1255 if (lra_dump_file != NULL)
1256 fprintf (lra_dump_file, " Spill r%d after risky transformations\n",
1257 regno);
1261 /* Improve allocation by assigning the same hard regno of inheritance
1262 pseudos to the connected pseudos. We need this because inheritance
1263 pseudos are allocated after reload pseudos in the thread and when
1264 we assign a hard register to a reload pseudo we don't know yet that
1265 the connected inheritance pseudos can get the same hard register.
1266 Add pseudos with changed allocation to bitmap CHANGED_PSEUDOS. */
1267 static void
1268 improve_inheritance (bitmap changed_pseudos)
1270 unsigned int k;
1271 int regno, another_regno, hard_regno, another_hard_regno, cost, i, n;
1272 lra_copy_t cp, next_cp;
1273 bitmap_iterator bi;
1275 if (lra_inheritance_iter > LRA_MAX_INHERITANCE_PASSES)
1276 return;
1277 n = 0;
1278 EXECUTE_IF_SET_IN_BITMAP (&lra_inheritance_pseudos, 0, k, bi)
1279 if (reg_renumber[k] >= 0 && lra_reg_info[k].nrefs != 0)
1280 sorted_pseudos[n++] = k;
1281 qsort (sorted_pseudos, n, sizeof (int), pseudo_compare_func);
1282 for (i = 0; i < n; i++)
1284 regno = sorted_pseudos[i];
1285 hard_regno = reg_renumber[regno];
1286 lra_assert (hard_regno >= 0);
1287 for (cp = lra_reg_info[regno].copies; cp != NULL; cp = next_cp)
1289 if (cp->regno1 == regno)
1291 next_cp = cp->regno1_next;
1292 another_regno = cp->regno2;
1294 else if (cp->regno2 == regno)
1296 next_cp = cp->regno2_next;
1297 another_regno = cp->regno1;
1299 else
1300 gcc_unreachable ();
1301 /* Don't change reload pseudo allocation. It might have
1302 this allocation for a purpose and changing it can result
1303 in LRA cycling. */
1304 if ((another_regno < lra_constraint_new_regno_start
1305 || bitmap_bit_p (&lra_inheritance_pseudos, another_regno))
1306 && (another_hard_regno = reg_renumber[another_regno]) >= 0
1307 && another_hard_regno != hard_regno)
1309 if (lra_dump_file != NULL)
1310 fprintf
1311 (lra_dump_file,
1312 " Improving inheritance for %d(%d) and %d(%d)...\n",
1313 regno, hard_regno, another_regno, another_hard_regno);
1314 update_lives (another_regno, true);
1315 lra_setup_reg_renumber (another_regno, -1, false);
1316 if (hard_regno == find_hard_regno_for (another_regno, &cost,
1317 hard_regno, false))
1318 assign_hard_regno (hard_regno, another_regno);
1319 else
1320 assign_hard_regno (another_hard_regno, another_regno);
1321 bitmap_set_bit (changed_pseudos, another_regno);
1328 /* Bitmap finally containing all pseudos spilled on this assignment
1329 pass. */
1330 static bitmap_head all_spilled_pseudos;
1331 /* All pseudos whose allocation was changed. */
1332 static bitmap_head changed_pseudo_bitmap;
1335 /* Add to LIVE_RANGE_HARD_REG_PSEUDOS all pseudos conflicting with
1336 REGNO and whose hard regs can be assigned to REGNO. */
1337 static void
1338 find_all_spills_for (int regno)
1340 int p;
1341 lra_live_range_t r;
1342 unsigned int k;
1343 bitmap_iterator bi;
1344 enum reg_class rclass;
1345 bool *rclass_intersect_p;
1347 rclass = regno_allocno_class_array[regno];
1348 rclass_intersect_p = ira_reg_classes_intersect_p[rclass];
1349 for (r = lra_reg_info[regno].live_ranges; r != NULL; r = r->next)
1351 EXECUTE_IF_SET_IN_BITMAP (&live_hard_reg_pseudos[r->start], 0, k, bi)
1352 if (rclass_intersect_p[regno_allocno_class_array[k]])
1353 sparseset_set_bit (live_range_hard_reg_pseudos, k);
1354 for (p = r->start + 1; p <= r->finish; p++)
1356 lra_live_range_t r2;
1358 for (r2 = start_point_ranges[p];
1359 r2 != NULL;
1360 r2 = r2->start_next)
1362 if (live_pseudos_reg_renumber[r2->regno] >= 0
1363 && ! sparseset_bit_p (live_range_hard_reg_pseudos, r2->regno)
1364 && rclass_intersect_p[regno_allocno_class_array[r2->regno]]
1365 && ((int) r2->regno < lra_constraint_new_regno_start
1366 || bitmap_bit_p (&lra_inheritance_pseudos, r2->regno)
1367 || bitmap_bit_p (&lra_split_regs, r2->regno)
1368 || bitmap_bit_p (&lra_optional_reload_pseudos, r2->regno)
1369 /* There is no sense to consider another reload
1370 pseudo if it has the same class. */
1371 || regno_allocno_class_array[r2->regno] != rclass))
1372 sparseset_set_bit (live_range_hard_reg_pseudos, r2->regno);
1378 /* Assign hard registers to reload pseudos and other pseudos. Return
1379 true if we was not able to assign hard registers to all reload
1380 pseudos. */
1381 static bool
1382 assign_by_spills (void)
1384 int i, n, nfails, iter, regno, regno2, hard_regno, cost;
1385 rtx restore_rtx;
1386 bitmap_head changed_insns, do_not_assign_nonreload_pseudos;
1387 unsigned int u, conflict_regno;
1388 bitmap_iterator bi;
1389 bool reload_p, fails_p = false;
1390 int max_regno = max_reg_num ();
1392 for (n = 0, i = lra_constraint_new_regno_start; i < max_regno; i++)
1393 if (reg_renumber[i] < 0 && lra_reg_info[i].nrefs != 0
1394 && regno_allocno_class_array[i] != NO_REGS)
1395 sorted_pseudos[n++] = i;
1396 bitmap_initialize (&insn_conflict_pseudos, &reg_obstack);
1397 bitmap_initialize (&spill_pseudos_bitmap, &reg_obstack);
1398 bitmap_initialize (&best_spill_pseudos_bitmap, &reg_obstack);
1399 update_hard_regno_preference_check = XCNEWVEC (int, max_regno);
1400 curr_update_hard_regno_preference_check = 0;
1401 memset (try_hard_reg_pseudos_check, 0, sizeof (try_hard_reg_pseudos_check));
1402 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1403 bitmap_initialize (&try_hard_reg_pseudos[i], &reg_obstack);
1404 curr_pseudo_check = 0;
1405 bitmap_initialize (&changed_insns, &reg_obstack);
1406 bitmap_initialize (&non_reload_pseudos, &reg_obstack);
1407 bitmap_ior (&non_reload_pseudos, &lra_inheritance_pseudos, &lra_split_regs);
1408 bitmap_ior_into (&non_reload_pseudos, &lra_subreg_reload_pseudos);
1409 bitmap_ior_into (&non_reload_pseudos, &lra_optional_reload_pseudos);
1410 for (iter = 0; iter <= 1; iter++)
1412 qsort (sorted_pseudos, n, sizeof (int), reload_pseudo_compare_func);
1413 nfails = 0;
1414 for (i = 0; i < n; i++)
1416 regno = sorted_pseudos[i];
1417 if (reg_renumber[regno] >= 0)
1418 continue;
1419 if (lra_dump_file != NULL)
1420 fprintf (lra_dump_file, " Assigning to %d "
1421 "(cl=%s, orig=%d, freq=%d, tfirst=%d, tfreq=%d)...\n",
1422 regno, reg_class_names[regno_allocno_class_array[regno]],
1423 ORIGINAL_REGNO (regno_reg_rtx[regno]),
1424 lra_reg_info[regno].freq, regno_assign_info[regno].first,
1425 regno_assign_info[regno_assign_info[regno].first].freq);
1426 hard_regno = find_hard_regno_for (regno, &cost, -1, iter == 1);
1427 reload_p = ! bitmap_bit_p (&non_reload_pseudos, regno);
1428 if (hard_regno < 0 && reload_p)
1429 hard_regno = spill_for (regno, &all_spilled_pseudos, iter == 1);
1430 if (hard_regno < 0)
1432 if (reload_p) {
1433 /* Put unassigned reload pseudo first in the
1434 array. */
1435 regno2 = sorted_pseudos[nfails];
1436 sorted_pseudos[nfails++] = regno;
1437 sorted_pseudos[i] = regno2;
1440 else
1442 /* This register might have been spilled by the previous
1443 pass. Indicate that it is no longer spilled. */
1444 bitmap_clear_bit (&all_spilled_pseudos, regno);
1445 assign_hard_regno (hard_regno, regno);
1446 if (! reload_p)
1447 /* As non-reload pseudo assignment is changed we
1448 should reconsider insns referring for the
1449 pseudo. */
1450 bitmap_set_bit (&changed_pseudo_bitmap, regno);
1453 if (nfails == 0 || iter > 0)
1455 fails_p = nfails != 0;
1456 break;
1458 /* This is a very rare event. We cannot assign a hard register
1459 to reload pseudo because the hard register was assigned to
1460 another reload pseudo on a previous assignment pass. For x86
1461 example, on the 1st pass we assigned CX (although another
1462 hard register could be used for this) to reload pseudo in an
1463 insn, on the 2nd pass we need CX (and only this) hard
1464 register for a new reload pseudo in the same insn. Another
1465 possible situation may occur in assigning to multi-regs
1466 reload pseudos when hard regs pool is too fragmented even
1467 after spilling non-reload pseudos.
1469 We should do something radical here to succeed. Here we
1470 spill *all* conflicting pseudos and reassign them. */
1471 if (lra_dump_file != NULL)
1472 fprintf (lra_dump_file, " 2nd iter for reload pseudo assignments:\n");
1473 sparseset_clear (live_range_hard_reg_pseudos);
1474 for (i = 0; i < nfails; i++)
1476 if (lra_dump_file != NULL)
1477 fprintf (lra_dump_file, " Reload r%d assignment failure\n",
1478 sorted_pseudos[i]);
1479 find_all_spills_for (sorted_pseudos[i]);
1481 EXECUTE_IF_SET_IN_SPARSESET (live_range_hard_reg_pseudos, conflict_regno)
1483 if ((int) conflict_regno >= lra_constraint_new_regno_start)
1485 sorted_pseudos[nfails++] = conflict_regno;
1486 former_reload_pseudo_spill_p = true;
1488 else
1489 /* It is better to do reloads before spilling as after the
1490 spill-subpass we will reload memory instead of pseudos
1491 and this will make reusing reload pseudos more
1492 complicated. Going directly to the spill pass in such
1493 case might result in worse code performance or even LRA
1494 cycling if we have few registers. */
1495 bitmap_set_bit (&all_spilled_pseudos, conflict_regno);
1496 if (lra_dump_file != NULL)
1497 fprintf (lra_dump_file, " Spill %s r%d(hr=%d, freq=%d)\n",
1498 pseudo_prefix_title (conflict_regno), conflict_regno,
1499 reg_renumber[conflict_regno],
1500 lra_reg_info[conflict_regno].freq);
1501 update_lives (conflict_regno, true);
1502 lra_setup_reg_renumber (conflict_regno, -1, false);
1504 if (n < nfails)
1505 n = nfails;
1507 improve_inheritance (&changed_pseudo_bitmap);
1508 bitmap_clear (&non_reload_pseudos);
1509 bitmap_clear (&changed_insns);
1510 if (! lra_simple_p)
1512 /* We should not assign to original pseudos of inheritance
1513 pseudos or split pseudos if any its inheritance pseudo did
1514 not get hard register or any its split pseudo was not split
1515 because undo inheritance/split pass will extend live range of
1516 such inheritance or split pseudos. */
1517 bitmap_initialize (&do_not_assign_nonreload_pseudos, &reg_obstack);
1518 EXECUTE_IF_SET_IN_BITMAP (&lra_inheritance_pseudos, 0, u, bi)
1519 if ((restore_rtx = lra_reg_info[u].restore_rtx) != NULL_RTX
1520 && REG_P (restore_rtx)
1521 && reg_renumber[u] < 0
1522 && bitmap_bit_p (&lra_inheritance_pseudos, u))
1523 bitmap_set_bit (&do_not_assign_nonreload_pseudos, REGNO (restore_rtx));
1524 EXECUTE_IF_SET_IN_BITMAP (&lra_split_regs, 0, u, bi)
1525 if ((restore_rtx = lra_reg_info[u].restore_rtx) != NULL_RTX
1526 && reg_renumber[u] >= 0)
1528 lra_assert (REG_P (restore_rtx));
1529 bitmap_set_bit (&do_not_assign_nonreload_pseudos, REGNO (restore_rtx));
1531 for (n = 0, i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
1532 if (((i < lra_constraint_new_regno_start
1533 && ! bitmap_bit_p (&do_not_assign_nonreload_pseudos, i))
1534 || (bitmap_bit_p (&lra_inheritance_pseudos, i)
1535 && lra_reg_info[i].restore_rtx != NULL_RTX)
1536 || (bitmap_bit_p (&lra_split_regs, i)
1537 && lra_reg_info[i].restore_rtx != NULL_RTX)
1538 || bitmap_bit_p (&lra_subreg_reload_pseudos, i)
1539 || bitmap_bit_p (&lra_optional_reload_pseudos, i))
1540 && reg_renumber[i] < 0 && lra_reg_info[i].nrefs != 0
1541 && regno_allocno_class_array[i] != NO_REGS)
1542 sorted_pseudos[n++] = i;
1543 bitmap_clear (&do_not_assign_nonreload_pseudos);
1544 if (n != 0 && lra_dump_file != NULL)
1545 fprintf (lra_dump_file, " Reassigning non-reload pseudos\n");
1546 qsort (sorted_pseudos, n, sizeof (int), pseudo_compare_func);
1547 for (i = 0; i < n; i++)
1549 regno = sorted_pseudos[i];
1550 hard_regno = find_hard_regno_for (regno, &cost, -1, false);
1551 if (hard_regno >= 0)
1553 assign_hard_regno (hard_regno, regno);
1554 /* We change allocation for non-reload pseudo on this
1555 iteration -- mark the pseudo for invalidation of used
1556 alternatives of insns containing the pseudo. */
1557 bitmap_set_bit (&changed_pseudo_bitmap, regno);
1559 else
1561 enum reg_class rclass = lra_get_allocno_class (regno);
1562 enum reg_class spill_class;
1564 if (targetm.spill_class == NULL
1565 || lra_reg_info[regno].restore_rtx == NULL_RTX
1566 || ! bitmap_bit_p (&lra_inheritance_pseudos, regno)
1567 || (spill_class
1568 = ((enum reg_class)
1569 targetm.spill_class
1570 ((reg_class_t) rclass,
1571 PSEUDO_REGNO_MODE (regno)))) == NO_REGS)
1572 continue;
1573 regno_allocno_class_array[regno] = spill_class;
1574 hard_regno = find_hard_regno_for (regno, &cost, -1, false);
1575 if (hard_regno < 0)
1576 regno_allocno_class_array[regno] = rclass;
1577 else
1579 setup_reg_classes
1580 (regno, spill_class, spill_class, spill_class);
1581 assign_hard_regno (hard_regno, regno);
1582 bitmap_set_bit (&changed_pseudo_bitmap, regno);
1587 free (update_hard_regno_preference_check);
1588 bitmap_clear (&best_spill_pseudos_bitmap);
1589 bitmap_clear (&spill_pseudos_bitmap);
1590 bitmap_clear (&insn_conflict_pseudos);
1591 return fails_p;
1594 /* Entry function to assign hard registers to new reload pseudos
1595 starting with LRA_CONSTRAINT_NEW_REGNO_START (by possible spilling
1596 of old pseudos) and possibly to the old pseudos. The function adds
1597 what insns to process for the next constraint pass. Those are all
1598 insns who contains non-reload and non-inheritance pseudos with
1599 changed allocation.
1601 Return true if we did not spill any non-reload and non-inheritance
1602 pseudos. Set up FAILS_P if we failed to assign hard registers to
1603 all reload pseudos. */
1604 bool
1605 lra_assign (bool &fails_p)
1607 int i;
1608 unsigned int u;
1609 bitmap_iterator bi;
1610 bitmap_head insns_to_process;
1611 bool no_spills_p;
1612 int max_regno = max_reg_num ();
1614 timevar_push (TV_LRA_ASSIGN);
1615 lra_assignment_iter++;
1616 if (lra_dump_file != NULL)
1617 fprintf (lra_dump_file, "\n********** Assignment #%d: **********\n\n",
1618 lra_assignment_iter);
1619 init_lives ();
1620 sorted_pseudos = XNEWVEC (int, max_regno);
1621 sorted_reload_pseudos = XNEWVEC (int, max_regno);
1622 regno_allocno_class_array = XNEWVEC (enum reg_class, max_regno);
1623 regno_live_length = XNEWVEC (int, max_regno);
1624 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
1626 int l;
1627 lra_live_range_t r;
1629 regno_allocno_class_array[i] = lra_get_allocno_class (i);
1630 for (l = 0, r = lra_reg_info[i].live_ranges; r != NULL; r = r->next)
1631 l += r->finish - r->start + 1;
1632 regno_live_length[i] = l;
1634 former_reload_pseudo_spill_p = false;
1635 init_regno_assign_info ();
1636 bitmap_initialize (&all_spilled_pseudos, &reg_obstack);
1637 create_live_range_start_chains ();
1638 setup_live_pseudos_and_spill_after_risky_transforms (&all_spilled_pseudos);
1639 if (! lra_hard_reg_split_p && ! lra_asm_error_p && flag_checking)
1640 /* Check correctness of allocation but only when there are no hard reg
1641 splits and asm errors as in the case of errors explicit insns involving
1642 hard regs are added or the asm is removed and this can result in
1643 incorrect allocation. */
1644 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
1645 if (lra_reg_info[i].nrefs != 0
1646 && reg_renumber[i] >= 0
1647 && overlaps_hard_reg_set_p (lra_reg_info[i].conflict_hard_regs,
1648 PSEUDO_REGNO_MODE (i), reg_renumber[i]))
1649 gcc_unreachable ();
1650 /* Setup insns to process on the next constraint pass. */
1651 bitmap_initialize (&changed_pseudo_bitmap, &reg_obstack);
1652 init_live_reload_and_inheritance_pseudos ();
1653 fails_p = assign_by_spills ();
1654 finish_live_reload_and_inheritance_pseudos ();
1655 bitmap_ior_into (&changed_pseudo_bitmap, &all_spilled_pseudos);
1656 no_spills_p = true;
1657 EXECUTE_IF_SET_IN_BITMAP (&all_spilled_pseudos, 0, u, bi)
1658 /* We ignore spilled pseudos created on last inheritance pass
1659 because they will be removed. */
1660 if (lra_reg_info[u].restore_rtx == NULL_RTX)
1662 no_spills_p = false;
1663 break;
1665 finish_live_range_start_chains ();
1666 bitmap_clear (&all_spilled_pseudos);
1667 bitmap_initialize (&insns_to_process, &reg_obstack);
1668 EXECUTE_IF_SET_IN_BITMAP (&changed_pseudo_bitmap, 0, u, bi)
1669 bitmap_ior_into (&insns_to_process, &lra_reg_info[u].insn_bitmap);
1670 bitmap_clear (&changed_pseudo_bitmap);
1671 EXECUTE_IF_SET_IN_BITMAP (&insns_to_process, 0, u, bi)
1673 lra_push_insn_by_uid (u);
1674 /* Invalidate alternatives for insn should be processed. */
1675 lra_set_used_insn_alternative_by_uid (u, -1);
1677 bitmap_clear (&insns_to_process);
1678 finish_regno_assign_info ();
1679 free (regno_live_length);
1680 free (regno_allocno_class_array);
1681 free (sorted_pseudos);
1682 free (sorted_reload_pseudos);
1683 finish_lives ();
1684 timevar_pop (TV_LRA_ASSIGN);
1685 if (former_reload_pseudo_spill_p)
1686 lra_assignment_iter_after_spill++;
1687 /* This is conditional on flag_checking because valid code can take
1688 more than this maximum number of iteration, but at the same time
1689 the test can uncover errors in machine descriptions. */
1690 if (flag_checking
1691 && (lra_assignment_iter_after_spill
1692 > LRA_MAX_ASSIGNMENT_ITERATION_NUMBER))
1693 internal_error
1694 ("maximum number of LRA assignment passes is achieved (%d)",
1695 LRA_MAX_ASSIGNMENT_ITERATION_NUMBER);
1696 /* Reset the assignment correctness flag: */
1697 check_and_force_assignment_correctness_p = false;
1698 return no_spills_p;
1701 /* Find start and finish insns for reload pseudo REGNO. Return true
1702 if we managed to find the expected insns. Return false,
1703 otherwise. */
1704 static bool
1705 find_reload_regno_insns (int regno, rtx_insn * &start, rtx_insn * &finish)
1707 unsigned int uid;
1708 bitmap_iterator bi;
1709 int n = 0;
1710 rtx_insn *prev_insn, *next_insn;
1711 rtx_insn *start_insn = NULL, *first_insn = NULL, *second_insn = NULL;
1713 EXECUTE_IF_SET_IN_BITMAP (&lra_reg_info[regno].insn_bitmap, 0, uid, bi)
1715 if (start_insn == NULL)
1716 start_insn = lra_insn_recog_data[uid]->insn;
1717 n++;
1719 /* For reload pseudo we should have at most 3 insns referring for
1720 it: input/output reload insns and the original insn. */
1721 if (n > 3)
1722 return false;
1723 if (n > 1)
1725 for (prev_insn = PREV_INSN (start_insn),
1726 next_insn = NEXT_INSN (start_insn);
1727 n != 1 && (prev_insn != NULL || next_insn != NULL); )
1729 if (prev_insn != NULL && first_insn == NULL)
1731 if (! bitmap_bit_p (&lra_reg_info[regno].insn_bitmap,
1732 INSN_UID (prev_insn)))
1733 prev_insn = PREV_INSN (prev_insn);
1734 else
1736 first_insn = prev_insn;
1737 n--;
1740 if (next_insn != NULL && second_insn == NULL)
1742 if (! bitmap_bit_p (&lra_reg_info[regno].insn_bitmap,
1743 INSN_UID (next_insn)))
1744 next_insn = NEXT_INSN (next_insn);
1745 else
1747 second_insn = next_insn;
1748 n--;
1752 if (n > 1)
1753 return false;
1755 start = first_insn != NULL ? first_insn : start_insn;
1756 finish = second_insn != NULL ? second_insn : start_insn;
1757 return true;
1760 /* Process reload pseudos which did not get a hard reg, split a hard
1761 reg live range in live range of a reload pseudo, and then return
1762 TRUE. If we did not split a hard reg live range, report an error,
1763 and return FALSE. */
1764 bool
1765 lra_split_hard_reg_for (void)
1767 int i, regno;
1768 rtx_insn *insn, *first, *last;
1769 unsigned int u;
1770 bitmap_iterator bi;
1771 enum reg_class rclass;
1772 int max_regno = max_reg_num ();
1773 /* We did not assign hard regs to reload pseudos after two
1774 iterations. Either it's an asm and something is wrong with the
1775 constraints, or we have run out of spill registers; error out in
1776 either case. */
1777 bool asm_p = false;
1778 bitmap_head failed_reload_insns, failed_reload_pseudos;
1780 if (lra_dump_file != NULL)
1781 fprintf (lra_dump_file,
1782 "\n****** Splitting a hard reg after assignment #%d: ******\n\n",
1783 lra_assignment_iter);
1784 bitmap_initialize (&failed_reload_pseudos, &reg_obstack);
1785 bitmap_initialize (&non_reload_pseudos, &reg_obstack);
1786 bitmap_ior (&non_reload_pseudos, &lra_inheritance_pseudos, &lra_split_regs);
1787 bitmap_ior_into (&non_reload_pseudos, &lra_subreg_reload_pseudos);
1788 bitmap_ior_into (&non_reload_pseudos, &lra_optional_reload_pseudos);
1789 for (i = lra_constraint_new_regno_start; i < max_regno; i++)
1790 if (reg_renumber[i] < 0 && lra_reg_info[i].nrefs != 0
1791 && (rclass = lra_get_allocno_class (i)) != NO_REGS
1792 && ! bitmap_bit_p (&non_reload_pseudos, i))
1794 if (! find_reload_regno_insns (i, first, last))
1795 continue;
1796 if (BLOCK_FOR_INSN (first) == BLOCK_FOR_INSN (last)
1797 && spill_hard_reg_in_range (i, rclass, first, last))
1799 bitmap_clear (&failed_reload_pseudos);
1800 return true;
1802 bitmap_set_bit (&failed_reload_pseudos, i);
1804 bitmap_clear (&non_reload_pseudos);
1805 bitmap_initialize (&failed_reload_insns, &reg_obstack);
1806 EXECUTE_IF_SET_IN_BITMAP (&failed_reload_pseudos, 0, u, bi)
1808 regno = u;
1809 bitmap_ior_into (&failed_reload_insns,
1810 &lra_reg_info[regno].insn_bitmap);
1811 lra_setup_reg_renumber
1812 (regno, ira_class_hard_regs[lra_get_allocno_class (regno)][0], false);
1814 EXECUTE_IF_SET_IN_BITMAP (&failed_reload_insns, 0, u, bi)
1816 insn = lra_insn_recog_data[u]->insn;
1817 if (asm_noperands (PATTERN (insn)) >= 0)
1819 lra_asm_error_p = asm_p = true;
1820 error_for_asm (insn,
1821 "%<asm%> operand has impossible constraints");
1822 /* Avoid further trouble with this insn. */
1823 if (JUMP_P (insn))
1825 ira_nullify_asm_goto (insn);
1826 lra_update_insn_regno_info (insn);
1828 else
1830 PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx);
1831 lra_set_insn_deleted (insn);
1834 else if (!asm_p)
1836 error ("unable to find a register to spill");
1837 fatal_insn ("this is the insn:", insn);
1840 bitmap_clear (&failed_reload_pseudos);
1841 bitmap_clear (&failed_reload_insns);
1842 return false;