xref: /netbsd-src/external/gpl3/gcc.old/dist/gcc/lra-assigns.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /* Assign reload pseudos.
2    Copyright (C) 2010-2015 Free Software Foundation, Inc.
3    Contributed by Vladimir Makarov <vmakarov@redhat.com>.
4 
5 This file is part of GCC.
6 
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.
11 
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.
16 
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/>.	 */
20 
21 
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.
26 
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.
32 
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.
37 
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.
41 
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.
47 
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.
51 
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.
59 
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.
63 
64    Only insns with changed allocation pseudos are processed on the
65    next constraint pass.
66 
67    The pseudo live-ranges are used to find conflicting pseudos.
68 
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.  */
76 
77 #include "config.h"
78 #include "system.h"
79 #include "coretypes.h"
80 #include "tm.h"
81 #include "hard-reg-set.h"
82 #include "rtl.h"
83 #include "rtl-error.h"
84 #include "tm_p.h"
85 #include "target.h"
86 #include "insn-config.h"
87 #include "recog.h"
88 #include "output.h"
89 #include "regs.h"
90 #include "hashtab.h"
91 #include "hash-set.h"
92 #include "vec.h"
93 #include "machmode.h"
94 #include "input.h"
95 #include "function.h"
96 #include "symtab.h"
97 #include "flags.h"
98 #include "statistics.h"
99 #include "double-int.h"
100 #include "real.h"
101 #include "fixed-value.h"
102 #include "alias.h"
103 #include "wide-int.h"
104 #include "inchash.h"
105 #include "tree.h"
106 #include "expmed.h"
107 #include "dojump.h"
108 #include "explow.h"
109 #include "calls.h"
110 #include "emit-rtl.h"
111 #include "varasm.h"
112 #include "stmt.h"
113 #include "expr.h"
114 #include "predict.h"
115 #include "dominance.h"
116 #include "cfg.h"
117 #include "basic-block.h"
118 #include "except.h"
119 #include "df.h"
120 #include "ira.h"
121 #include "sparseset.h"
122 #include "params.h"
123 #include "lra-int.h"
124 
125 /* Current iteration number of the pass and current iteration number
126    of the pass after the latest spill pass when any former reload
127    pseudo was spilled.  */
128 int lra_assignment_iter;
129 int lra_assignment_iter_after_spill;
130 
131 /* Flag of spilling former reload pseudos on this pass.  */
132 static bool former_reload_pseudo_spill_p;
133 
134 /* Array containing corresponding values of function
135    lra_get_allocno_class.  It is used to speed up the code.  */
136 static enum reg_class *regno_allocno_class_array;
137 
138 /* Information about the thread to which a pseudo belongs.  Threads are
139    a set of connected reload and inheritance pseudos with the same set of
140    available hard registers.  Lone registers belong to their own threads.  */
141 struct regno_assign_info
142 {
143   /* First/next pseudo of the same thread.  */
144   int first, next;
145   /* Frequency of the thread (execution frequency of only reload
146      pseudos in the thread when the thread contains a reload pseudo).
147      Defined only for the first thread pseudo.	*/
148   int freq;
149 };
150 
151 /* Map regno to the corresponding regno assignment info.  */
152 static struct regno_assign_info *regno_assign_info;
153 
154 /* All inherited, subreg or optional pseudos created before last spill
155    sub-pass.  Such pseudos are permitted to get memory instead of hard
156    regs.  */
157 static bitmap_head non_reload_pseudos;
158 
159 /* Process a pseudo copy with execution frequency COPY_FREQ connecting
160    REGNO1 and REGNO2 to form threads.  */
161 static void
162 process_copy_to_form_thread (int regno1, int regno2, int copy_freq)
163 {
164   int last, regno1_first, regno2_first;
165 
166   lra_assert (regno1 >= lra_constraint_new_regno_start
167 	      && regno2 >= lra_constraint_new_regno_start);
168   regno1_first = regno_assign_info[regno1].first;
169   regno2_first = regno_assign_info[regno2].first;
170   if (regno1_first != regno2_first)
171     {
172       for (last = regno2_first;
173 	   regno_assign_info[last].next >= 0;
174 	   last = regno_assign_info[last].next)
175 	regno_assign_info[last].first = regno1_first;
176       regno_assign_info[last].first = regno1_first;
177       regno_assign_info[last].next = regno_assign_info[regno1_first].next;
178       regno_assign_info[regno1_first].next = regno2_first;
179       regno_assign_info[regno1_first].freq
180 	+= regno_assign_info[regno2_first].freq;
181     }
182   regno_assign_info[regno1_first].freq -= 2 * copy_freq;
183   lra_assert (regno_assign_info[regno1_first].freq >= 0);
184 }
185 
186 /* Initialize REGNO_ASSIGN_INFO and form threads.  */
187 static void
188 init_regno_assign_info (void)
189 {
190   int i, regno1, regno2, max_regno = max_reg_num ();
191   lra_copy_t cp;
192 
193   regno_assign_info = XNEWVEC (struct regno_assign_info, max_regno);
194   for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
195     {
196       regno_assign_info[i].first = i;
197       regno_assign_info[i].next = -1;
198       regno_assign_info[i].freq = lra_reg_info[i].freq;
199     }
200   /* Form the threads.	*/
201   for (i = 0; (cp = lra_get_copy (i)) != NULL; i++)
202     if ((regno1 = cp->regno1) >= lra_constraint_new_regno_start
203 	&& (regno2 = cp->regno2) >= lra_constraint_new_regno_start
204 	&& reg_renumber[regno1] < 0 && lra_reg_info[regno1].nrefs != 0
205 	&& reg_renumber[regno2] < 0 && lra_reg_info[regno2].nrefs != 0
206 	&& (ira_class_hard_regs_num[regno_allocno_class_array[regno1]]
207 	    == ira_class_hard_regs_num[regno_allocno_class_array[regno2]]))
208       process_copy_to_form_thread (regno1, regno2, cp->freq);
209 }
210 
211 /* Free REGNO_ASSIGN_INFO.  */
212 static void
213 finish_regno_assign_info (void)
214 {
215   free (regno_assign_info);
216 }
217 
218 /* The function is used to sort *reload* and *inheritance* pseudos to
219    try to assign them hard registers.  We put pseudos from the same
220    thread always nearby.  */
221 static int
222 reload_pseudo_compare_func (const void *v1p, const void *v2p)
223 {
224   int r1 = *(const int *) v1p, r2 = *(const int *) v2p;
225   enum reg_class cl1 = regno_allocno_class_array[r1];
226   enum reg_class cl2 = regno_allocno_class_array[r2];
227   int diff;
228 
229   lra_assert (r1 >= lra_constraint_new_regno_start
230 	      && r2 >= lra_constraint_new_regno_start);
231 
232   /* Prefer to assign reload registers with smaller classes first to
233      guarantee assignment to all reload registers.  */
234   if ((diff = (ira_class_hard_regs_num[cl1]
235 	       - ira_class_hard_regs_num[cl2])) != 0)
236     return diff;
237   if ((diff
238        = (ira_reg_class_max_nregs[cl2][lra_reg_info[r2].biggest_mode]
239 	  - ira_reg_class_max_nregs[cl1][lra_reg_info[r1].biggest_mode])) != 0
240       /* The code below executes rarely as nregs == 1 in most cases.
241 	 So we should not worry about using faster data structures to
242 	 check reload pseudos.  */
243       && ! bitmap_bit_p (&non_reload_pseudos, r1)
244       && ! bitmap_bit_p (&non_reload_pseudos, r2))
245     return diff;
246   if ((diff = (regno_assign_info[regno_assign_info[r2].first].freq
247 	       - regno_assign_info[regno_assign_info[r1].first].freq)) != 0)
248     return diff;
249   /* Allocate bigger pseudos first to avoid register file
250      fragmentation.  */
251   if ((diff
252        = (ira_reg_class_max_nregs[cl2][lra_reg_info[r2].biggest_mode]
253 	  - ira_reg_class_max_nregs[cl1][lra_reg_info[r1].biggest_mode])) != 0)
254     return diff;
255   /* Put pseudos from the thread nearby.  */
256   if ((diff = regno_assign_info[r1].first - regno_assign_info[r2].first) != 0)
257     return diff;
258   /* If regs are equally good, sort by their numbers, so that the
259      results of qsort leave nothing to chance.	*/
260   return r1 - r2;
261 }
262 
263 /* The function is used to sort *non-reload* pseudos to try to assign
264    them hard registers.	 The order calculation is simpler than in the
265    previous function and based on the pseudo frequency usage.  */
266 static int
267 pseudo_compare_func (const void *v1p, const void *v2p)
268 {
269   int r1 = *(const int *) v1p, r2 = *(const int *) v2p;
270   int diff;
271 
272   /* Prefer to assign more frequently used registers first.  */
273   if ((diff = lra_reg_info[r2].freq - lra_reg_info[r1].freq) != 0)
274     return diff;
275 
276   /* If regs are equally good, sort by their numbers, so that the
277      results of qsort leave nothing to chance.	*/
278   return r1 - r2;
279 }
280 
281 /* Arrays of size LRA_LIVE_MAX_POINT mapping a program point to the
282    pseudo live ranges with given start point.  We insert only live
283    ranges of pseudos interesting for assignment purposes.  They are
284    reload pseudos and pseudos assigned to hard registers.  */
285 static lra_live_range_t *start_point_ranges;
286 
287 /* Used as a flag that a live range is not inserted in the start point
288    chain.  */
289 static struct lra_live_range not_in_chain_mark;
290 
291 /* Create and set up START_POINT_RANGES.  */
292 static void
293 create_live_range_start_chains (void)
294 {
295   int i, max_regno;
296   lra_live_range_t r;
297 
298   start_point_ranges = XCNEWVEC (lra_live_range_t, lra_live_max_point);
299   max_regno = max_reg_num ();
300   for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
301     if (i >= lra_constraint_new_regno_start || reg_renumber[i] >= 0)
302       {
303 	for (r = lra_reg_info[i].live_ranges; r != NULL; r = r->next)
304 	  {
305 	    r->start_next = start_point_ranges[r->start];
306 	    start_point_ranges[r->start] = r;
307 	  }
308       }
309     else
310       {
311 	for (r = lra_reg_info[i].live_ranges; r != NULL; r = r->next)
312 	  r->start_next = &not_in_chain_mark;
313       }
314 }
315 
316 /* Insert live ranges of pseudo REGNO into start chains if they are
317    not there yet.  */
318 static void
319 insert_in_live_range_start_chain (int regno)
320 {
321   lra_live_range_t r = lra_reg_info[regno].live_ranges;
322 
323   if (r->start_next != &not_in_chain_mark)
324     return;
325   for (; r != NULL; r = r->next)
326     {
327       r->start_next = start_point_ranges[r->start];
328       start_point_ranges[r->start] = r;
329     }
330 }
331 
332 /* Free START_POINT_RANGES.  */
333 static void
334 finish_live_range_start_chains (void)
335 {
336   gcc_assert (start_point_ranges != NULL);
337   free (start_point_ranges);
338   start_point_ranges = NULL;
339 }
340 
341 /* Map: program point -> bitmap of all pseudos living at the point and
342    assigned to hard registers.	*/
343 static bitmap_head *live_hard_reg_pseudos;
344 static bitmap_obstack live_hard_reg_pseudos_bitmap_obstack;
345 
346 /* reg_renumber corresponding to pseudos marked in
347    live_hard_reg_pseudos.  reg_renumber might be not matched to
348    live_hard_reg_pseudos but live_pseudos_reg_renumber always reflects
349    live_hard_reg_pseudos.  */
350 static int *live_pseudos_reg_renumber;
351 
352 /* Sparseset used to calculate living hard reg pseudos for some program
353    point range.	 */
354 static sparseset live_range_hard_reg_pseudos;
355 
356 /* Sparseset used to calculate living reload/inheritance pseudos for
357    some program point range.  */
358 static sparseset live_range_reload_inheritance_pseudos;
359 
360 /* Allocate and initialize the data about living pseudos at program
361    points.  */
362 static void
363 init_lives (void)
364 {
365   int i, max_regno = max_reg_num ();
366 
367   live_range_hard_reg_pseudos = sparseset_alloc (max_regno);
368   live_range_reload_inheritance_pseudos = sparseset_alloc (max_regno);
369   live_hard_reg_pseudos = XNEWVEC (bitmap_head, lra_live_max_point);
370   bitmap_obstack_initialize (&live_hard_reg_pseudos_bitmap_obstack);
371   for (i = 0; i < lra_live_max_point; i++)
372     bitmap_initialize (&live_hard_reg_pseudos[i],
373 		       &live_hard_reg_pseudos_bitmap_obstack);
374   live_pseudos_reg_renumber = XNEWVEC (int, max_regno);
375   for (i = 0; i < max_regno; i++)
376     live_pseudos_reg_renumber[i] = -1;
377 }
378 
379 /* Free the data about living pseudos at program points.  */
380 static void
381 finish_lives (void)
382 {
383   sparseset_free (live_range_hard_reg_pseudos);
384   sparseset_free (live_range_reload_inheritance_pseudos);
385   free (live_hard_reg_pseudos);
386   bitmap_obstack_release (&live_hard_reg_pseudos_bitmap_obstack);
387   free (live_pseudos_reg_renumber);
388 }
389 
390 /* Update the LIVE_HARD_REG_PSEUDOS and LIVE_PSEUDOS_REG_RENUMBER
391    entries for pseudo REGNO.  Assume that the register has been
392    spilled if FREE_P, otherwise assume that it has been assigned
393    reg_renumber[REGNO] (if >= 0).  We also insert the pseudo live
394    ranges in the start chains when it is assumed to be assigned to a
395    hard register because we use the chains of pseudos assigned to hard
396    registers during allocation.  */
397 static void
398 update_lives (int regno, bool free_p)
399 {
400   int p;
401   lra_live_range_t r;
402 
403   if (reg_renumber[regno] < 0)
404     return;
405   live_pseudos_reg_renumber[regno] = free_p ? -1 : reg_renumber[regno];
406   for (r = lra_reg_info[regno].live_ranges; r != NULL; r = r->next)
407     {
408       for (p = r->start; p <= r->finish; p++)
409 	if (free_p)
410 	  bitmap_clear_bit (&live_hard_reg_pseudos[p], regno);
411 	else
412 	  {
413 	    bitmap_set_bit (&live_hard_reg_pseudos[p], regno);
414 	    insert_in_live_range_start_chain (regno);
415 	  }
416     }
417 }
418 
419 /* Sparseset used to calculate reload pseudos conflicting with a given
420    pseudo when we are trying to find a hard register for the given
421    pseudo.  */
422 static sparseset conflict_reload_and_inheritance_pseudos;
423 
424 /* Map: program point -> bitmap of all reload and inheritance pseudos
425    living at the point.	 */
426 static bitmap_head *live_reload_and_inheritance_pseudos;
427 static bitmap_obstack live_reload_and_inheritance_pseudos_bitmap_obstack;
428 
429 /* Allocate and initialize data about living reload pseudos at any
430    given program point.  */
431 static void
432 init_live_reload_and_inheritance_pseudos (void)
433 {
434   int i, p, max_regno = max_reg_num ();
435   lra_live_range_t r;
436 
437   conflict_reload_and_inheritance_pseudos = sparseset_alloc (max_regno);
438   live_reload_and_inheritance_pseudos = XNEWVEC (bitmap_head, lra_live_max_point);
439   bitmap_obstack_initialize (&live_reload_and_inheritance_pseudos_bitmap_obstack);
440   for (p = 0; p < lra_live_max_point; p++)
441     bitmap_initialize (&live_reload_and_inheritance_pseudos[p],
442 		       &live_reload_and_inheritance_pseudos_bitmap_obstack);
443   for (i = lra_constraint_new_regno_start; i < max_regno; i++)
444     {
445       for (r = lra_reg_info[i].live_ranges; r != NULL; r = r->next)
446 	for (p = r->start; p <= r->finish; p++)
447 	  bitmap_set_bit (&live_reload_and_inheritance_pseudos[p], i);
448     }
449 }
450 
451 /* Finalize data about living reload pseudos at any given program
452    point.  */
453 static void
454 finish_live_reload_and_inheritance_pseudos (void)
455 {
456   sparseset_free (conflict_reload_and_inheritance_pseudos);
457   free (live_reload_and_inheritance_pseudos);
458   bitmap_obstack_release (&live_reload_and_inheritance_pseudos_bitmap_obstack);
459 }
460 
461 /* The value used to check that cost of given hard reg is really
462    defined currently.  */
463 static int curr_hard_regno_costs_check = 0;
464 /* Array used to check that cost of the corresponding hard reg (the
465    array element index) is really defined currently.  */
466 static int hard_regno_costs_check[FIRST_PSEUDO_REGISTER];
467 /* The current costs of allocation of hard regs.  Defined only if the
468    value of the corresponding element of the previous array is equal to
469    CURR_HARD_REGNO_COSTS_CHECK.	 */
470 static int hard_regno_costs[FIRST_PSEUDO_REGISTER];
471 
472 /* Adjust cost of HARD_REGNO by INCR.  Reset the cost first if it is
473    not defined yet.  */
474 static inline void
475 adjust_hard_regno_cost (int hard_regno, int incr)
476 {
477   if (hard_regno_costs_check[hard_regno] != curr_hard_regno_costs_check)
478     hard_regno_costs[hard_regno] = 0;
479   hard_regno_costs_check[hard_regno] = curr_hard_regno_costs_check;
480   hard_regno_costs[hard_regno] += incr;
481 }
482 
483 /* Try to find a free hard register for pseudo REGNO.  Return the
484    hard register on success and set *COST to the cost of using
485    that register.  (If several registers have equal cost, the one with
486    the highest priority wins.)  Return -1 on failure.
487 
488    If FIRST_P, return the first available hard reg ignoring other
489    criteria, e.g. allocation cost.  This approach results in less hard
490    reg pool fragmentation and permit to allocate hard regs to reload
491    pseudos in complicated situations where pseudo sizes are different.
492 
493    If TRY_ONLY_HARD_REGNO >= 0, consider only that hard register,
494    otherwise consider all hard registers in REGNO's class.
495 
496    If REGNO_SET is not empty, only hard registers from the set are
497    considered.  */
498 static int
499 find_hard_regno_for_1 (int regno, int *cost, int try_only_hard_regno,
500 		       bool first_p, HARD_REG_SET regno_set)
501 {
502   HARD_REG_SET conflict_set;
503   int best_cost = INT_MAX, best_priority = INT_MIN, best_usage = INT_MAX;
504   lra_live_range_t r;
505   int p, i, j, rclass_size, best_hard_regno, priority, hard_regno;
506   int hr, conflict_hr, nregs;
507   machine_mode biggest_mode;
508   unsigned int k, conflict_regno;
509   int offset, val, biggest_nregs, nregs_diff;
510   enum reg_class rclass;
511   bitmap_iterator bi;
512   bool *rclass_intersect_p;
513   HARD_REG_SET impossible_start_hard_regs, available_regs;
514 
515   if (hard_reg_set_empty_p (regno_set))
516     COPY_HARD_REG_SET (conflict_set, lra_no_alloc_regs);
517   else
518     {
519       COMPL_HARD_REG_SET (conflict_set, regno_set);
520       IOR_HARD_REG_SET (conflict_set, lra_no_alloc_regs);
521     }
522   rclass = regno_allocno_class_array[regno];
523   rclass_intersect_p = ira_reg_classes_intersect_p[rclass];
524   curr_hard_regno_costs_check++;
525   sparseset_clear (conflict_reload_and_inheritance_pseudos);
526   sparseset_clear (live_range_hard_reg_pseudos);
527   IOR_HARD_REG_SET (conflict_set, lra_reg_info[regno].conflict_hard_regs);
528   biggest_mode = lra_reg_info[regno].biggest_mode;
529   for (r = lra_reg_info[regno].live_ranges; r != NULL; r = r->next)
530     {
531       EXECUTE_IF_SET_IN_BITMAP (&live_hard_reg_pseudos[r->start], 0, k, bi)
532 	if (rclass_intersect_p[regno_allocno_class_array[k]])
533 	  sparseset_set_bit (live_range_hard_reg_pseudos, k);
534       EXECUTE_IF_SET_IN_BITMAP (&live_reload_and_inheritance_pseudos[r->start],
535 				0, k, bi)
536 	if (lra_reg_info[k].preferred_hard_regno1 >= 0
537 	    && live_pseudos_reg_renumber[k] < 0
538 	    && rclass_intersect_p[regno_allocno_class_array[k]])
539 	  sparseset_set_bit (conflict_reload_and_inheritance_pseudos, k);
540       for (p = r->start + 1; p <= r->finish; p++)
541 	{
542 	  lra_live_range_t r2;
543 
544 	  for (r2 = start_point_ranges[p];
545 	       r2 != NULL;
546 	       r2 = r2->start_next)
547 	    {
548 	      if (r2->regno >= lra_constraint_new_regno_start
549 		  && lra_reg_info[r2->regno].preferred_hard_regno1 >= 0
550 		  && live_pseudos_reg_renumber[r2->regno] < 0
551 		  && rclass_intersect_p[regno_allocno_class_array[r2->regno]])
552 		sparseset_set_bit (conflict_reload_and_inheritance_pseudos,
553 				   r2->regno);
554 	      if (live_pseudos_reg_renumber[r2->regno] >= 0
555 		  && rclass_intersect_p[regno_allocno_class_array[r2->regno]])
556 		sparseset_set_bit (live_range_hard_reg_pseudos, r2->regno);
557 	    }
558 	}
559     }
560   if ((hard_regno = lra_reg_info[regno].preferred_hard_regno1) >= 0)
561     {
562       adjust_hard_regno_cost
563 	(hard_regno, -lra_reg_info[regno].preferred_hard_regno_profit1);
564       if ((hard_regno = lra_reg_info[regno].preferred_hard_regno2) >= 0)
565 	adjust_hard_regno_cost
566 	  (hard_regno, -lra_reg_info[regno].preferred_hard_regno_profit2);
567     }
568 #ifdef STACK_REGS
569   if (lra_reg_info[regno].no_stack_p)
570     for (i = FIRST_STACK_REG; i <= LAST_STACK_REG; i++)
571       SET_HARD_REG_BIT (conflict_set, i);
572 #endif
573   sparseset_clear_bit (conflict_reload_and_inheritance_pseudos, regno);
574   val = lra_reg_info[regno].val;
575   offset = lra_reg_info[regno].offset;
576   CLEAR_HARD_REG_SET (impossible_start_hard_regs);
577   EXECUTE_IF_SET_IN_SPARSESET (live_range_hard_reg_pseudos, conflict_regno)
578     if (lra_reg_val_equal_p (conflict_regno, val, offset))
579       {
580 	conflict_hr = live_pseudos_reg_renumber[conflict_regno];
581 	nregs = (hard_regno_nregs[conflict_hr]
582 		 [lra_reg_info[conflict_regno].biggest_mode]);
583 	/* Remember about multi-register pseudos.  For example, 2 hard
584 	   register pseudos can start on the same hard register but can
585 	   not start on HR and HR+1/HR-1.  */
586 	for (hr = conflict_hr + 1;
587 	     hr < FIRST_PSEUDO_REGISTER && hr < conflict_hr + nregs;
588 	     hr++)
589 	  SET_HARD_REG_BIT (impossible_start_hard_regs, hr);
590 	for (hr = conflict_hr - 1;
591 	     hr >= 0 && hr + hard_regno_nregs[hr][biggest_mode] > conflict_hr;
592 	     hr--)
593 	  SET_HARD_REG_BIT (impossible_start_hard_regs, hr);
594       }
595     else
596       {
597 	add_to_hard_reg_set (&conflict_set,
598 			     lra_reg_info[conflict_regno].biggest_mode,
599 			     live_pseudos_reg_renumber[conflict_regno]);
600 	if (hard_reg_set_subset_p (reg_class_contents[rclass],
601 				   conflict_set))
602 	  return -1;
603       }
604   EXECUTE_IF_SET_IN_SPARSESET (conflict_reload_and_inheritance_pseudos,
605 			       conflict_regno)
606     if (!lra_reg_val_equal_p (conflict_regno, val, offset))
607       {
608 	lra_assert (live_pseudos_reg_renumber[conflict_regno] < 0);
609 	if ((hard_regno
610 	     = lra_reg_info[conflict_regno].preferred_hard_regno1) >= 0)
611 	  {
612 	    adjust_hard_regno_cost
613 	      (hard_regno,
614 	       lra_reg_info[conflict_regno].preferred_hard_regno_profit1);
615 	    if ((hard_regno
616 		 = lra_reg_info[conflict_regno].preferred_hard_regno2) >= 0)
617 	      adjust_hard_regno_cost
618 		(hard_regno,
619 		 lra_reg_info[conflict_regno].preferred_hard_regno_profit2);
620 	  }
621       }
622   /* Make sure that all registers in a multi-word pseudo belong to the
623      required class.  */
624   IOR_COMPL_HARD_REG_SET (conflict_set, reg_class_contents[rclass]);
625   lra_assert (rclass != NO_REGS);
626   rclass_size = ira_class_hard_regs_num[rclass];
627   best_hard_regno = -1;
628   hard_regno = ira_class_hard_regs[rclass][0];
629   biggest_nregs = hard_regno_nregs[hard_regno][biggest_mode];
630   nregs_diff = (biggest_nregs
631 		- hard_regno_nregs[hard_regno][PSEUDO_REGNO_MODE (regno)]);
632   COPY_HARD_REG_SET (available_regs, reg_class_contents[rclass]);
633   AND_COMPL_HARD_REG_SET (available_regs, lra_no_alloc_regs);
634   for (i = 0; i < rclass_size; i++)
635     {
636       if (try_only_hard_regno >= 0)
637 	hard_regno = try_only_hard_regno;
638       else
639 	hard_regno = ira_class_hard_regs[rclass][i];
640       if (! overlaps_hard_reg_set_p (conflict_set,
641 				     PSEUDO_REGNO_MODE (regno), hard_regno)
642 	  /* We can not use prohibited_class_mode_regs because it is
643 	     not defined for all classes.  */
644 	  && HARD_REGNO_MODE_OK (hard_regno, PSEUDO_REGNO_MODE (regno))
645 	  && ! TEST_HARD_REG_BIT (impossible_start_hard_regs, hard_regno)
646 	  && (nregs_diff == 0
647 	      || (WORDS_BIG_ENDIAN
648 		  ? (hard_regno - nregs_diff >= 0
649 		     && TEST_HARD_REG_BIT (available_regs,
650 					   hard_regno - nregs_diff))
651 		  : TEST_HARD_REG_BIT (available_regs,
652 				       hard_regno + nregs_diff))))
653 	{
654 	  if (hard_regno_costs_check[hard_regno]
655 	      != curr_hard_regno_costs_check)
656 	    {
657 	      hard_regno_costs_check[hard_regno] = curr_hard_regno_costs_check;
658 	      hard_regno_costs[hard_regno] = 0;
659 	    }
660 	  for (j = 0;
661 	       j < hard_regno_nregs[hard_regno][PSEUDO_REGNO_MODE (regno)];
662 	       j++)
663 	    if (! TEST_HARD_REG_BIT (call_used_reg_set, hard_regno + j)
664 		&& ! df_regs_ever_live_p (hard_regno + j))
665 	      /* It needs save restore.	 */
666 	      hard_regno_costs[hard_regno]
667 		+= (2
668 		    * REG_FREQ_FROM_BB (ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb)
669 		    + 1);
670 	  priority = targetm.register_priority (hard_regno);
671 	  if (best_hard_regno < 0 || hard_regno_costs[hard_regno] < best_cost
672 	      || (hard_regno_costs[hard_regno] == best_cost
673 		  && (priority > best_priority
674 		      || (targetm.register_usage_leveling_p ()
675 			  && priority == best_priority
676 			  && best_usage > lra_hard_reg_usage[hard_regno]))))
677 	    {
678 	      best_hard_regno = hard_regno;
679 	      best_cost = hard_regno_costs[hard_regno];
680 	      best_priority = priority;
681 	      best_usage = lra_hard_reg_usage[hard_regno];
682 	    }
683 	}
684       if (try_only_hard_regno >= 0 || (first_p && best_hard_regno >= 0))
685 	break;
686     }
687   if (best_hard_regno >= 0)
688     *cost = best_cost - lra_reg_info[regno].freq;
689   return best_hard_regno;
690 }
691 
692 /* A wrapper for find_hard_regno_for_1 (see comments for that function
693    description).  This function tries to find a hard register for
694    preferred class first if it is worth.  */
695 static int
696 find_hard_regno_for (int regno, int *cost, int try_only_hard_regno, bool first_p)
697 {
698   int hard_regno;
699   HARD_REG_SET regno_set;
700 
701   /* Only original pseudos can have a different preferred class.  */
702   if (try_only_hard_regno < 0 && regno < lra_new_regno_start)
703     {
704       enum reg_class pref_class = reg_preferred_class (regno);
705 
706       if (regno_allocno_class_array[regno] != pref_class)
707 	{
708 	  hard_regno = find_hard_regno_for_1 (regno, cost, -1, first_p,
709 					      reg_class_contents[pref_class]);
710 	  if (hard_regno >= 0)
711 	    return hard_regno;
712 	}
713     }
714   CLEAR_HARD_REG_SET (regno_set);
715   return find_hard_regno_for_1 (regno, cost, try_only_hard_regno, first_p,
716 				regno_set);
717 }
718 
719 /* Current value used for checking elements in
720    update_hard_regno_preference_check.	*/
721 static int curr_update_hard_regno_preference_check;
722 /* If an element value is equal to the above variable value, then the
723    corresponding regno has been processed for preference
724    propagation.	 */
725 static int *update_hard_regno_preference_check;
726 
727 /* Update the preference for using HARD_REGNO for pseudos that are
728    connected directly or indirectly with REGNO.  Apply divisor DIV
729    to any preference adjustments.
730 
731    The more indirectly a pseudo is connected, the smaller its effect
732    should be.  We therefore increase DIV on each "hop".  */
733 static void
734 update_hard_regno_preference (int regno, int hard_regno, int div)
735 {
736   int another_regno, cost;
737   lra_copy_t cp, next_cp;
738 
739   /* Search depth 5 seems to be enough.	 */
740   if (div > (1 << 5))
741     return;
742   for (cp = lra_reg_info[regno].copies; cp != NULL; cp = next_cp)
743     {
744       if (cp->regno1 == regno)
745 	{
746 	  next_cp = cp->regno1_next;
747 	  another_regno = cp->regno2;
748 	}
749       else if (cp->regno2 == regno)
750 	{
751 	  next_cp = cp->regno2_next;
752 	  another_regno = cp->regno1;
753 	}
754       else
755 	gcc_unreachable ();
756       if (reg_renumber[another_regno] < 0
757 	  && (update_hard_regno_preference_check[another_regno]
758 	      != curr_update_hard_regno_preference_check))
759 	{
760 	  update_hard_regno_preference_check[another_regno]
761 	    = curr_update_hard_regno_preference_check;
762 	  cost = cp->freq < div ? 1 : cp->freq / div;
763 	  lra_setup_reload_pseudo_preferenced_hard_reg
764 	    (another_regno, hard_regno, cost);
765 	  update_hard_regno_preference (another_regno, hard_regno, div * 2);
766 	}
767     }
768 }
769 
770 /* Return prefix title for pseudo REGNO.  */
771 static const char *
772 pseudo_prefix_title (int regno)
773 {
774   return
775     (regno < lra_constraint_new_regno_start ? ""
776      : bitmap_bit_p (&lra_inheritance_pseudos, regno) ? "inheritance "
777      : bitmap_bit_p (&lra_split_regs, regno) ? "split "
778      : bitmap_bit_p (&lra_optional_reload_pseudos, regno) ? "optional reload "
779      : bitmap_bit_p (&lra_subreg_reload_pseudos, regno) ? "subreg reload "
780      : "reload ");
781 }
782 
783 /* Update REG_RENUMBER and other pseudo preferences by assignment of
784    HARD_REGNO to pseudo REGNO and print about it if PRINT_P.  */
785 void
786 lra_setup_reg_renumber (int regno, int hard_regno, bool print_p)
787 {
788   int i, hr;
789 
790   /* We can not just reassign hard register.  */
791   lra_assert (hard_regno < 0 || reg_renumber[regno] < 0);
792   if ((hr = hard_regno) < 0)
793     hr = reg_renumber[regno];
794   reg_renumber[regno] = hard_regno;
795   lra_assert (hr >= 0);
796   for (i = 0; i < hard_regno_nregs[hr][PSEUDO_REGNO_MODE (regno)]; i++)
797     if (hard_regno < 0)
798       lra_hard_reg_usage[hr + i] -= lra_reg_info[regno].freq;
799     else
800       lra_hard_reg_usage[hr + i] += lra_reg_info[regno].freq;
801   if (print_p && lra_dump_file != NULL)
802     fprintf (lra_dump_file, "	   Assign %d to %sr%d (freq=%d)\n",
803 	     reg_renumber[regno], pseudo_prefix_title (regno),
804 	     regno, lra_reg_info[regno].freq);
805   if (hard_regno >= 0)
806     {
807       curr_update_hard_regno_preference_check++;
808       update_hard_regno_preference (regno, hard_regno, 1);
809     }
810 }
811 
812 /* Pseudos which occur in insns containing a particular pseudo.  */
813 static bitmap_head insn_conflict_pseudos;
814 
815 /* Bitmaps used to contain spill pseudos for given pseudo hard regno
816    and best spill pseudos for given pseudo (and best hard regno).  */
817 static bitmap_head spill_pseudos_bitmap, best_spill_pseudos_bitmap;
818 
819 /* Current pseudo check for validity of elements in
820    TRY_HARD_REG_PSEUDOS.  */
821 static int curr_pseudo_check;
822 /* Array used for validity of elements in TRY_HARD_REG_PSEUDOS.	 */
823 static int try_hard_reg_pseudos_check[FIRST_PSEUDO_REGISTER];
824 /* Pseudos who hold given hard register at the considered points.  */
825 static bitmap_head try_hard_reg_pseudos[FIRST_PSEUDO_REGISTER];
826 
827 /* Set up try_hard_reg_pseudos for given program point P and class
828    RCLASS.  Those are pseudos living at P and assigned to a hard
829    register of RCLASS.	In other words, those are pseudos which can be
830    spilled to assign a hard register of RCLASS to a pseudo living at
831    P.  */
832 static void
833 setup_try_hard_regno_pseudos (int p, enum reg_class rclass)
834 {
835   int i, hard_regno;
836   machine_mode mode;
837   unsigned int spill_regno;
838   bitmap_iterator bi;
839 
840   /* Find what pseudos could be spilled.  */
841   EXECUTE_IF_SET_IN_BITMAP (&live_hard_reg_pseudos[p], 0, spill_regno, bi)
842     {
843       mode = PSEUDO_REGNO_MODE (spill_regno);
844       hard_regno = live_pseudos_reg_renumber[spill_regno];
845       if (overlaps_hard_reg_set_p (reg_class_contents[rclass],
846 				   mode, hard_regno))
847 	{
848 	  for (i = hard_regno_nregs[hard_regno][mode] - 1; i >= 0; i--)
849 	    {
850 	      if (try_hard_reg_pseudos_check[hard_regno + i]
851 		  != curr_pseudo_check)
852 		{
853 		  try_hard_reg_pseudos_check[hard_regno + i]
854 		    = curr_pseudo_check;
855 		  bitmap_clear (&try_hard_reg_pseudos[hard_regno + i]);
856 		}
857 	      bitmap_set_bit (&try_hard_reg_pseudos[hard_regno + i],
858 			      spill_regno);
859 	    }
860 	}
861     }
862 }
863 
864 /* Assign temporarily HARD_REGNO to pseudo REGNO.  Temporary
865    assignment means that we might undo the data change.	 */
866 static void
867 assign_temporarily (int regno, int hard_regno)
868 {
869   int p;
870   lra_live_range_t r;
871 
872   for (r = lra_reg_info[regno].live_ranges; r != NULL; r = r->next)
873     {
874       for (p = r->start; p <= r->finish; p++)
875 	if (hard_regno < 0)
876 	  bitmap_clear_bit (&live_hard_reg_pseudos[p], regno);
877 	else
878 	  {
879 	    bitmap_set_bit (&live_hard_reg_pseudos[p], regno);
880 	    insert_in_live_range_start_chain (regno);
881 	  }
882     }
883   live_pseudos_reg_renumber[regno] = hard_regno;
884 }
885 
886 /* Array used for sorting reload pseudos for subsequent allocation
887    after spilling some pseudo.	*/
888 static int *sorted_reload_pseudos;
889 
890 /* Spill some pseudos for a reload pseudo REGNO and return hard
891    register which should be used for pseudo after spilling.  The
892    function adds spilled pseudos to SPILLED_PSEUDO_BITMAP.  When we
893    choose hard register (and pseudos occupying the hard registers and
894    to be spilled), we take into account not only how REGNO will
895    benefit from the spills but also how other reload pseudos not yet
896    assigned to hard registers benefit from the spills too.  In very
897    rare cases, the function can fail and return -1.
898 
899    If FIRST_P, return the first available hard reg ignoring other
900    criteria, e.g. allocation cost and cost of spilling non-reload
901    pseudos.  This approach results in less hard reg pool fragmentation
902    and permit to allocate hard regs to reload pseudos in complicated
903    situations where pseudo sizes are different.  */
904 static int
905 spill_for (int regno, bitmap spilled_pseudo_bitmap, bool first_p)
906 {
907   int i, j, n, p, hard_regno, best_hard_regno, cost, best_cost, rclass_size;
908   int reload_hard_regno, reload_cost;
909   machine_mode mode;
910   enum reg_class rclass;
911   unsigned int spill_regno, reload_regno, uid;
912   int insn_pseudos_num, best_insn_pseudos_num;
913   int bad_spills_num, smallest_bad_spills_num;
914   lra_live_range_t r;
915   bitmap_iterator bi;
916 
917   rclass = regno_allocno_class_array[regno];
918   lra_assert (reg_renumber[regno] < 0 && rclass != NO_REGS);
919   bitmap_clear (&insn_conflict_pseudos);
920   bitmap_clear (&best_spill_pseudos_bitmap);
921   EXECUTE_IF_SET_IN_BITMAP (&lra_reg_info[regno].insn_bitmap, 0, uid, bi)
922     {
923       struct lra_insn_reg *ir;
924 
925       for (ir = lra_get_insn_regs (uid); ir != NULL; ir = ir->next)
926 	if (ir->regno >= FIRST_PSEUDO_REGISTER)
927 	  bitmap_set_bit (&insn_conflict_pseudos, ir->regno);
928     }
929   best_hard_regno = -1;
930   best_cost = INT_MAX;
931   best_insn_pseudos_num = INT_MAX;
932   smallest_bad_spills_num = INT_MAX;
933   rclass_size = ira_class_hard_regs_num[rclass];
934   mode = PSEUDO_REGNO_MODE (regno);
935   /* Invalidate try_hard_reg_pseudos elements.  */
936   curr_pseudo_check++;
937   for (r = lra_reg_info[regno].live_ranges; r != NULL; r = r->next)
938     for (p = r->start; p <= r->finish; p++)
939       setup_try_hard_regno_pseudos (p, rclass);
940   for (i = 0; i < rclass_size; i++)
941     {
942       hard_regno = ira_class_hard_regs[rclass][i];
943       bitmap_clear (&spill_pseudos_bitmap);
944       for (j = hard_regno_nregs[hard_regno][mode] - 1; j >= 0; j--)
945 	{
946 	  if (try_hard_reg_pseudos_check[hard_regno + j] != curr_pseudo_check)
947 	    continue;
948 	  lra_assert (!bitmap_empty_p (&try_hard_reg_pseudos[hard_regno + j]));
949 	  bitmap_ior_into (&spill_pseudos_bitmap,
950 			   &try_hard_reg_pseudos[hard_regno + j]);
951 	}
952       /* Spill pseudos.	 */
953       EXECUTE_IF_SET_IN_BITMAP (&spill_pseudos_bitmap, 0, spill_regno, bi)
954 	if ((pic_offset_table_rtx != NULL
955 	     && spill_regno == REGNO (pic_offset_table_rtx))
956 	    || ((int) spill_regno >= lra_constraint_new_regno_start
957 		&& ! bitmap_bit_p (&lra_inheritance_pseudos, spill_regno)
958 		&& ! bitmap_bit_p (&lra_split_regs, spill_regno)
959 		&& ! bitmap_bit_p (&lra_subreg_reload_pseudos, spill_regno)
960 		&& ! bitmap_bit_p (&lra_optional_reload_pseudos, spill_regno)))
961 	  goto fail;
962       insn_pseudos_num = 0;
963       bad_spills_num = 0;
964       if (lra_dump_file != NULL)
965 	fprintf (lra_dump_file, "	 Trying %d:", hard_regno);
966       sparseset_clear (live_range_reload_inheritance_pseudos);
967       EXECUTE_IF_SET_IN_BITMAP (&spill_pseudos_bitmap, 0, spill_regno, bi)
968 	{
969 	  if (bitmap_bit_p (&insn_conflict_pseudos, spill_regno))
970 	    insn_pseudos_num++;
971 	  if (spill_regno >= (unsigned int) lra_bad_spill_regno_start)
972 	    bad_spills_num++;
973 	  for (r = lra_reg_info[spill_regno].live_ranges;
974 	       r != NULL;
975 	       r = r->next)
976 	    {
977 	      for (p = r->start; p <= r->finish; p++)
978 		{
979 		  lra_live_range_t r2;
980 
981 		  for (r2 = start_point_ranges[p];
982 		       r2 != NULL;
983 		       r2 = r2->start_next)
984 		    if (r2->regno >= lra_constraint_new_regno_start)
985 		      sparseset_set_bit (live_range_reload_inheritance_pseudos,
986 					 r2->regno);
987 		}
988 	    }
989 	}
990       n = 0;
991       if (sparseset_cardinality (live_range_reload_inheritance_pseudos)
992 	  <= (unsigned)LRA_MAX_CONSIDERED_RELOAD_PSEUDOS)
993 	EXECUTE_IF_SET_IN_SPARSESET (live_range_reload_inheritance_pseudos,
994 				     reload_regno)
995 	  if ((int) reload_regno != regno
996 	      && (ira_reg_classes_intersect_p
997 		  [rclass][regno_allocno_class_array[reload_regno]])
998 	      && live_pseudos_reg_renumber[reload_regno] < 0
999 	      && find_hard_regno_for (reload_regno, &cost, -1, first_p) < 0)
1000 	    sorted_reload_pseudos[n++] = reload_regno;
1001       EXECUTE_IF_SET_IN_BITMAP (&spill_pseudos_bitmap, 0, spill_regno, bi)
1002 	{
1003 	  update_lives (spill_regno, true);
1004 	  if (lra_dump_file != NULL)
1005 	    fprintf (lra_dump_file, " spill %d(freq=%d)",
1006 		     spill_regno, lra_reg_info[spill_regno].freq);
1007 	}
1008       hard_regno = find_hard_regno_for (regno, &cost, -1, first_p);
1009       if (hard_regno >= 0)
1010 	{
1011 	  assign_temporarily (regno, hard_regno);
1012 	  qsort (sorted_reload_pseudos, n, sizeof (int),
1013 		 reload_pseudo_compare_func);
1014 	  for (j = 0; j < n; j++)
1015 	    {
1016 	      reload_regno = sorted_reload_pseudos[j];
1017 	      lra_assert (live_pseudos_reg_renumber[reload_regno] < 0);
1018 	      if ((reload_hard_regno
1019 		   = find_hard_regno_for (reload_regno,
1020 					  &reload_cost, -1, first_p)) >= 0)
1021 		{
1022 		  if (lra_dump_file != NULL)
1023 		    fprintf (lra_dump_file, " assign %d(cost=%d)",
1024 			     reload_regno, reload_cost);
1025 		  assign_temporarily (reload_regno, reload_hard_regno);
1026 		  cost += reload_cost;
1027 		}
1028 	    }
1029 	  EXECUTE_IF_SET_IN_BITMAP (&spill_pseudos_bitmap, 0, spill_regno, bi)
1030 	    {
1031 	      rtx_insn_list *x;
1032 
1033 	      cost += lra_reg_info[spill_regno].freq;
1034 	      if (ira_reg_equiv[spill_regno].memory != NULL
1035 		  || ira_reg_equiv[spill_regno].constant != NULL)
1036 		for (x = ira_reg_equiv[spill_regno].init_insns;
1037 		     x != NULL;
1038 		     x = x->next ())
1039 		  cost -= REG_FREQ_FROM_BB (BLOCK_FOR_INSN (x->insn ()));
1040 	    }
1041 	  if (best_insn_pseudos_num > insn_pseudos_num
1042 	      || (best_insn_pseudos_num == insn_pseudos_num
1043 		  && (bad_spills_num < smallest_bad_spills_num
1044 		      || (bad_spills_num == smallest_bad_spills_num
1045 			  && best_cost > cost))))
1046 	    {
1047 	      best_insn_pseudos_num = insn_pseudos_num;
1048 	      smallest_bad_spills_num = bad_spills_num;
1049 	      best_cost = cost;
1050 	      best_hard_regno = hard_regno;
1051 	      bitmap_copy (&best_spill_pseudos_bitmap, &spill_pseudos_bitmap);
1052 	      if (lra_dump_file != NULL)
1053 		fprintf (lra_dump_file,
1054 			 "	 Now best %d(cost=%d, bad_spills=%d, insn_pseudos=%d)\n",
1055 			 hard_regno, cost, bad_spills_num, insn_pseudos_num);
1056 	    }
1057 	  assign_temporarily (regno, -1);
1058 	  for (j = 0; j < n; j++)
1059 	    {
1060 	      reload_regno = sorted_reload_pseudos[j];
1061 	      if (live_pseudos_reg_renumber[reload_regno] >= 0)
1062 		assign_temporarily (reload_regno, -1);
1063 	    }
1064 	}
1065       if (lra_dump_file != NULL)
1066 	fprintf (lra_dump_file, "\n");
1067       /* Restore the live hard reg pseudo info for spilled pseudos.  */
1068       EXECUTE_IF_SET_IN_BITMAP (&spill_pseudos_bitmap, 0, spill_regno, bi)
1069 	update_lives (spill_regno, false);
1070     fail:
1071       ;
1072     }
1073   /* Spill: */
1074   EXECUTE_IF_SET_IN_BITMAP (&best_spill_pseudos_bitmap, 0, spill_regno, bi)
1075     {
1076       if ((int) spill_regno >= lra_constraint_new_regno_start)
1077 	former_reload_pseudo_spill_p = true;
1078       if (lra_dump_file != NULL)
1079 	fprintf (lra_dump_file, "      Spill %sr%d(hr=%d, freq=%d) for r%d\n",
1080 		 pseudo_prefix_title (spill_regno),
1081 		 spill_regno, reg_renumber[spill_regno],
1082 		 lra_reg_info[spill_regno].freq, regno);
1083       update_lives (spill_regno, true);
1084       lra_setup_reg_renumber (spill_regno, -1, false);
1085     }
1086   bitmap_ior_into (spilled_pseudo_bitmap, &best_spill_pseudos_bitmap);
1087   return best_hard_regno;
1088 }
1089 
1090 /* Assign HARD_REGNO to REGNO.	*/
1091 static void
1092 assign_hard_regno (int hard_regno, int regno)
1093 {
1094   int i;
1095 
1096   lra_assert (hard_regno >= 0);
1097   lra_setup_reg_renumber (regno, hard_regno, true);
1098   update_lives (regno, false);
1099   for (i = 0;
1100        i < hard_regno_nregs[hard_regno][lra_reg_info[regno].biggest_mode];
1101        i++)
1102     df_set_regs_ever_live (hard_regno + i, true);
1103 }
1104 
1105 /* Array used for sorting different pseudos.  */
1106 static int *sorted_pseudos;
1107 
1108 /* The constraints pass is allowed to create equivalences between
1109    pseudos that make the current allocation "incorrect" (in the sense
1110    that pseudos are assigned to hard registers from their own conflict
1111    sets).  The global variable lra_risky_transformations_p says
1112    whether this might have happened.
1113 
1114    Process pseudos assigned to hard registers (less frequently used
1115    first), spill if a conflict is found, and mark the spilled pseudos
1116    in SPILLED_PSEUDO_BITMAP.  Set up LIVE_HARD_REG_PSEUDOS from
1117    pseudos, assigned to hard registers.	 */
1118 static void
1119 setup_live_pseudos_and_spill_after_risky_transforms (bitmap
1120 						     spilled_pseudo_bitmap)
1121 {
1122   int p, i, j, n, regno, hard_regno;
1123   unsigned int k, conflict_regno;
1124   int val, offset;
1125   HARD_REG_SET conflict_set;
1126   machine_mode mode;
1127   lra_live_range_t r;
1128   bitmap_iterator bi;
1129   int max_regno = max_reg_num ();
1130 
1131   if (! lra_risky_transformations_p)
1132     {
1133       for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
1134 	if (reg_renumber[i] >= 0 && lra_reg_info[i].nrefs > 0)
1135 	  update_lives (i, false);
1136       return;
1137     }
1138   for (n = 0, i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
1139     if ((pic_offset_table_rtx == NULL_RTX
1140 	 || i != (int) REGNO (pic_offset_table_rtx))
1141 	&& reg_renumber[i] >= 0 && lra_reg_info[i].nrefs > 0)
1142       sorted_pseudos[n++] = i;
1143   qsort (sorted_pseudos, n, sizeof (int), pseudo_compare_func);
1144   if (pic_offset_table_rtx != NULL_RTX
1145       && (regno = REGNO (pic_offset_table_rtx)) >= FIRST_PSEUDO_REGISTER
1146       && reg_renumber[regno] >= 0 && lra_reg_info[regno].nrefs > 0)
1147     sorted_pseudos[n++] = regno;
1148   for (i = n - 1; i >= 0; i--)
1149     {
1150       regno = sorted_pseudos[i];
1151       hard_regno = reg_renumber[regno];
1152       lra_assert (hard_regno >= 0);
1153       mode = lra_reg_info[regno].biggest_mode;
1154       sparseset_clear (live_range_hard_reg_pseudos);
1155       for (r = lra_reg_info[regno].live_ranges; r != NULL; r = r->next)
1156 	{
1157 	  EXECUTE_IF_SET_IN_BITMAP (&live_hard_reg_pseudos[r->start], 0, k, bi)
1158 	    sparseset_set_bit (live_range_hard_reg_pseudos, k);
1159 	  for (p = r->start + 1; p <= r->finish; p++)
1160 	    {
1161 	      lra_live_range_t r2;
1162 
1163 	      for (r2 = start_point_ranges[p];
1164 		   r2 != NULL;
1165 		   r2 = r2->start_next)
1166 		if (live_pseudos_reg_renumber[r2->regno] >= 0)
1167 		  sparseset_set_bit (live_range_hard_reg_pseudos, r2->regno);
1168 	    }
1169 	}
1170       COPY_HARD_REG_SET (conflict_set, lra_no_alloc_regs);
1171       IOR_HARD_REG_SET (conflict_set, lra_reg_info[regno].conflict_hard_regs);
1172       val = lra_reg_info[regno].val;
1173       offset = lra_reg_info[regno].offset;
1174       EXECUTE_IF_SET_IN_SPARSESET (live_range_hard_reg_pseudos, conflict_regno)
1175 	if (!lra_reg_val_equal_p (conflict_regno, val, offset)
1176 	    /* If it is multi-register pseudos they should start on
1177 	       the same hard register.	*/
1178 	    || hard_regno != reg_renumber[conflict_regno])
1179 	  add_to_hard_reg_set (&conflict_set,
1180 			       lra_reg_info[conflict_regno].biggest_mode,
1181 			       reg_renumber[conflict_regno]);
1182       if (! overlaps_hard_reg_set_p (conflict_set, mode, hard_regno))
1183 	{
1184 	  update_lives (regno, false);
1185 	  continue;
1186 	}
1187       bitmap_set_bit (spilled_pseudo_bitmap, regno);
1188       for (j = 0;
1189 	   j < hard_regno_nregs[hard_regno][PSEUDO_REGNO_MODE (regno)];
1190 	   j++)
1191 	lra_hard_reg_usage[hard_regno + j] -= lra_reg_info[regno].freq;
1192       reg_renumber[regno] = -1;
1193       if (regno >= lra_constraint_new_regno_start)
1194 	former_reload_pseudo_spill_p = true;
1195       if (lra_dump_file != NULL)
1196 	fprintf (lra_dump_file, "    Spill r%d after risky transformations\n",
1197 		 regno);
1198     }
1199 }
1200 
1201 /* Improve allocation by assigning the same hard regno of inheritance
1202    pseudos to the connected pseudos.  We need this because inheritance
1203    pseudos are allocated after reload pseudos in the thread and when
1204    we assign a hard register to a reload pseudo we don't know yet that
1205    the connected inheritance pseudos can get the same hard register.
1206    Add pseudos with changed allocation to bitmap CHANGED_PSEUDOS.  */
1207 static void
1208 improve_inheritance (bitmap changed_pseudos)
1209 {
1210   unsigned int k;
1211   int regno, another_regno, hard_regno, another_hard_regno, cost, i, n;
1212   lra_copy_t cp, next_cp;
1213   bitmap_iterator bi;
1214 
1215   if (lra_inheritance_iter > LRA_MAX_INHERITANCE_PASSES)
1216     return;
1217   n = 0;
1218   EXECUTE_IF_SET_IN_BITMAP (&lra_inheritance_pseudos, 0, k, bi)
1219     if (reg_renumber[k] >= 0 && lra_reg_info[k].nrefs != 0)
1220       sorted_pseudos[n++] = k;
1221   qsort (sorted_pseudos, n, sizeof (int), pseudo_compare_func);
1222   for (i = 0; i < n; i++)
1223     {
1224       regno = sorted_pseudos[i];
1225       hard_regno = reg_renumber[regno];
1226       lra_assert (hard_regno >= 0);
1227       for (cp = lra_reg_info[regno].copies; cp != NULL; cp = next_cp)
1228 	{
1229 	  if (cp->regno1 == regno)
1230 	    {
1231 	      next_cp = cp->regno1_next;
1232 	      another_regno = cp->regno2;
1233 	    }
1234 	  else if (cp->regno2 == regno)
1235 	    {
1236 	      next_cp = cp->regno2_next;
1237 	      another_regno = cp->regno1;
1238 	    }
1239 	  else
1240 	    gcc_unreachable ();
1241 	  /* Don't change reload pseudo allocation.  It might have
1242 	     this allocation for a purpose and changing it can result
1243 	     in LRA cycling.  */
1244 	  if ((another_regno < lra_constraint_new_regno_start
1245 	       || bitmap_bit_p (&lra_inheritance_pseudos, another_regno))
1246 	      && (another_hard_regno = reg_renumber[another_regno]) >= 0
1247 	      && another_hard_regno != hard_regno)
1248 	    {
1249 	      if (lra_dump_file != NULL)
1250 		fprintf
1251 		  (lra_dump_file,
1252 		   "	Improving inheritance for %d(%d) and %d(%d)...\n",
1253 		   regno, hard_regno, another_regno, another_hard_regno);
1254 	      update_lives (another_regno, true);
1255 	      lra_setup_reg_renumber (another_regno, -1, false);
1256 	      if (hard_regno == find_hard_regno_for (another_regno, &cost,
1257 						     hard_regno, false))
1258 		assign_hard_regno (hard_regno, another_regno);
1259 	      else
1260 		assign_hard_regno (another_hard_regno, another_regno);
1261 	      bitmap_set_bit (changed_pseudos, another_regno);
1262 	    }
1263 	}
1264     }
1265 }
1266 
1267 
1268 /* Bitmap finally containing all pseudos spilled on this assignment
1269    pass.  */
1270 static bitmap_head all_spilled_pseudos;
1271 /* All pseudos whose allocation was changed.  */
1272 static bitmap_head changed_pseudo_bitmap;
1273 
1274 
1275 /* Add to LIVE_RANGE_HARD_REG_PSEUDOS all pseudos conflicting with
1276    REGNO and whose hard regs can be assigned to REGNO.  */
1277 static void
1278 find_all_spills_for (int regno)
1279 {
1280   int p;
1281   lra_live_range_t r;
1282   unsigned int k;
1283   bitmap_iterator bi;
1284   enum reg_class rclass;
1285   bool *rclass_intersect_p;
1286 
1287   rclass = regno_allocno_class_array[regno];
1288   rclass_intersect_p = ira_reg_classes_intersect_p[rclass];
1289   for (r = lra_reg_info[regno].live_ranges; r != NULL; r = r->next)
1290     {
1291       EXECUTE_IF_SET_IN_BITMAP (&live_hard_reg_pseudos[r->start], 0, k, bi)
1292 	if (rclass_intersect_p[regno_allocno_class_array[k]])
1293 	  sparseset_set_bit (live_range_hard_reg_pseudos, k);
1294       for (p = r->start + 1; p <= r->finish; p++)
1295 	{
1296 	  lra_live_range_t r2;
1297 
1298 	  for (r2 = start_point_ranges[p];
1299 	       r2 != NULL;
1300 	       r2 = r2->start_next)
1301 	    {
1302 	      if (live_pseudos_reg_renumber[r2->regno] >= 0
1303 		  && rclass_intersect_p[regno_allocno_class_array[r2->regno]])
1304 		sparseset_set_bit (live_range_hard_reg_pseudos, r2->regno);
1305 	    }
1306 	}
1307     }
1308 }
1309 
1310 /* Assign hard registers to reload pseudos and other pseudos.  */
1311 static void
1312 assign_by_spills (void)
1313 {
1314   int i, n, nfails, iter, regno, hard_regno, cost, restore_regno;
1315   rtx_insn *insn;
1316   bitmap_head changed_insns, do_not_assign_nonreload_pseudos;
1317   unsigned int u, conflict_regno;
1318   bitmap_iterator bi;
1319   bool reload_p;
1320   int max_regno = max_reg_num ();
1321 
1322   for (n = 0, i = lra_constraint_new_regno_start; i < max_regno; i++)
1323     if (reg_renumber[i] < 0 && lra_reg_info[i].nrefs != 0
1324 	&& regno_allocno_class_array[i] != NO_REGS)
1325       sorted_pseudos[n++] = i;
1326   bitmap_initialize (&insn_conflict_pseudos, &reg_obstack);
1327   bitmap_initialize (&spill_pseudos_bitmap, &reg_obstack);
1328   bitmap_initialize (&best_spill_pseudos_bitmap, &reg_obstack);
1329   update_hard_regno_preference_check = XCNEWVEC (int, max_regno);
1330   curr_update_hard_regno_preference_check = 0;
1331   memset (try_hard_reg_pseudos_check, 0, sizeof (try_hard_reg_pseudos_check));
1332   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1333     bitmap_initialize (&try_hard_reg_pseudos[i], &reg_obstack);
1334   curr_pseudo_check = 0;
1335   bitmap_initialize (&changed_insns, &reg_obstack);
1336   bitmap_initialize (&non_reload_pseudos, &reg_obstack);
1337   bitmap_ior (&non_reload_pseudos, &lra_inheritance_pseudos, &lra_split_regs);
1338   bitmap_ior_into (&non_reload_pseudos, &lra_subreg_reload_pseudos);
1339   bitmap_ior_into (&non_reload_pseudos, &lra_optional_reload_pseudos);
1340   for (iter = 0; iter <= 1; iter++)
1341     {
1342       qsort (sorted_pseudos, n, sizeof (int), reload_pseudo_compare_func);
1343       nfails = 0;
1344       for (i = 0; i < n; i++)
1345 	{
1346 	  regno = sorted_pseudos[i];
1347 	  if (lra_dump_file != NULL)
1348 	    fprintf (lra_dump_file, "	 Assigning to %d "
1349 		     "(cl=%s, orig=%d, freq=%d, tfirst=%d, tfreq=%d)...\n",
1350 		     regno, reg_class_names[regno_allocno_class_array[regno]],
1351 		     ORIGINAL_REGNO (regno_reg_rtx[regno]),
1352 		     lra_reg_info[regno].freq, regno_assign_info[regno].first,
1353 		     regno_assign_info[regno_assign_info[regno].first].freq);
1354 	  hard_regno = find_hard_regno_for (regno, &cost, -1, iter == 1);
1355 	  reload_p = ! bitmap_bit_p (&non_reload_pseudos, regno);
1356 	  if (hard_regno < 0 && reload_p)
1357 	    hard_regno = spill_for (regno, &all_spilled_pseudos, iter == 1);
1358 	  if (hard_regno < 0)
1359 	    {
1360 	      if (reload_p)
1361 		sorted_pseudos[nfails++] = regno;
1362 	    }
1363 	  else
1364 	    {
1365 	      /* This register might have been spilled by the previous
1366 		 pass.  Indicate that it is no longer spilled.  */
1367 	      bitmap_clear_bit (&all_spilled_pseudos, regno);
1368 	      assign_hard_regno (hard_regno, regno);
1369 	      if (! reload_p)
1370 		/* As non-reload pseudo assignment is changed we
1371 		   should reconsider insns referring for the
1372 		   pseudo.  */
1373 		bitmap_set_bit (&changed_pseudo_bitmap, regno);
1374 	    }
1375 	}
1376       if (nfails == 0)
1377 	break;
1378       if (iter > 0)
1379 	{
1380 	  /* We did not assign hard regs to reload pseudos after two iterations.
1381 	     Either it's an asm and something is wrong with the constraints, or
1382 	     we have run out of spill registers; error out in either case.  */
1383 	  bool asm_p = false;
1384 	  bitmap_head failed_reload_insns;
1385 
1386 	  bitmap_initialize (&failed_reload_insns, &reg_obstack);
1387 	  for (i = 0; i < nfails; i++)
1388 	    {
1389 	      regno = sorted_pseudos[i];
1390 	      bitmap_ior_into (&failed_reload_insns,
1391 			       &lra_reg_info[regno].insn_bitmap);
1392 	      /* Assign an arbitrary hard register of regno class to
1393 		 avoid further trouble with this insn.  */
1394 	      bitmap_clear_bit (&all_spilled_pseudos, regno);
1395 	      assign_hard_regno
1396 		(ira_class_hard_regs[regno_allocno_class_array[regno]][0],
1397 		 regno);
1398 	    }
1399 	  EXECUTE_IF_SET_IN_BITMAP (&failed_reload_insns, 0, u, bi)
1400 	    {
1401 	      insn = lra_insn_recog_data[u]->insn;
1402 	      if (asm_noperands (PATTERN (insn)) >= 0)
1403 		{
1404 		  asm_p = true;
1405 		  error_for_asm (insn,
1406 				 "%<asm%> operand has impossible constraints");
1407 		  /* Avoid further trouble with this insn.
1408 		     For asm goto, instead of fixing up all the edges
1409 		     just clear the template and clear input operands
1410 		     (asm goto doesn't have any output operands).  */
1411 		  if (JUMP_P (insn))
1412 		    {
1413 		      rtx asm_op = extract_asm_operands (PATTERN (insn));
1414 		      ASM_OPERANDS_TEMPLATE (asm_op) = ggc_strdup ("");
1415 		      ASM_OPERANDS_INPUT_VEC (asm_op) = rtvec_alloc (0);
1416 		      ASM_OPERANDS_INPUT_CONSTRAINT_VEC (asm_op) = rtvec_alloc (0);
1417 		      lra_update_insn_regno_info (insn);
1418 		    }
1419 		  else
1420 		    {
1421 		      PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx);
1422 		      lra_set_insn_deleted (insn);
1423 		    }
1424 		}
1425 	      else if (!asm_p)
1426 		{
1427 		  error ("unable to find a register to spill");
1428 		  fatal_insn ("this is the insn:", insn);
1429 		}
1430 	    }
1431 	  break;
1432 	}
1433       /* This is a very rare event.  We can not assign a hard register
1434 	 to reload pseudo because the hard register was assigned to
1435 	 another reload pseudo on a previous assignment pass.  For x86
1436 	 example, on the 1st pass we assigned CX (although another
1437 	 hard register could be used for this) to reload pseudo in an
1438 	 insn, on the 2nd pass we need CX (and only this) hard
1439 	 register for a new reload pseudo in the same insn.  Another
1440 	 possible situation may occur in assigning to multi-regs
1441 	 reload pseudos when hard regs pool is too fragmented even
1442 	 after spilling non-reload pseudos.
1443 
1444 	 We should do something radical here to succeed.  Here we
1445 	 spill *all* conflicting pseudos and reassign them.  */
1446       if (lra_dump_file != NULL)
1447 	fprintf (lra_dump_file, "  2nd iter for reload pseudo assignments:\n");
1448       sparseset_clear (live_range_hard_reg_pseudos);
1449       for (i = 0; i < nfails; i++)
1450 	{
1451 	  if (lra_dump_file != NULL)
1452 	    fprintf (lra_dump_file, "	 Reload r%d assignment failure\n",
1453 		     sorted_pseudos[i]);
1454 	  find_all_spills_for (sorted_pseudos[i]);
1455 	}
1456       EXECUTE_IF_SET_IN_SPARSESET (live_range_hard_reg_pseudos, conflict_regno)
1457 	{
1458 	  if ((int) conflict_regno >= lra_constraint_new_regno_start)
1459 	    {
1460 	      sorted_pseudos[nfails++] = conflict_regno;
1461 	      former_reload_pseudo_spill_p = true;
1462 	    }
1463 	  if (lra_dump_file != NULL)
1464 	    fprintf (lra_dump_file, "	  Spill %s r%d(hr=%d, freq=%d)\n",
1465 		     pseudo_prefix_title (conflict_regno), conflict_regno,
1466 		     reg_renumber[conflict_regno],
1467 		     lra_reg_info[conflict_regno].freq);
1468 	  update_lives (conflict_regno, true);
1469 	  lra_setup_reg_renumber (conflict_regno, -1, false);
1470 	}
1471       n = nfails;
1472     }
1473   improve_inheritance (&changed_pseudo_bitmap);
1474   bitmap_clear (&non_reload_pseudos);
1475   bitmap_clear (&changed_insns);
1476   if (! lra_simple_p)
1477     {
1478       /* We should not assign to original pseudos of inheritance
1479 	 pseudos or split pseudos if any its inheritance pseudo did
1480 	 not get hard register or any its split pseudo was not split
1481 	 because undo inheritance/split pass will extend live range of
1482 	 such inheritance or split pseudos.  */
1483       bitmap_initialize (&do_not_assign_nonreload_pseudos, &reg_obstack);
1484       EXECUTE_IF_SET_IN_BITMAP (&lra_inheritance_pseudos, 0, u, bi)
1485 	if ((restore_regno = lra_reg_info[u].restore_regno) >= 0
1486 	    && reg_renumber[u] < 0
1487 	    && bitmap_bit_p (&lra_inheritance_pseudos, u))
1488 	  bitmap_set_bit (&do_not_assign_nonreload_pseudos, restore_regno);
1489       EXECUTE_IF_SET_IN_BITMAP (&lra_split_regs, 0, u, bi)
1490 	if ((restore_regno = lra_reg_info[u].restore_regno) >= 0
1491 	    && reg_renumber[u] >= 0)
1492 	  bitmap_set_bit (&do_not_assign_nonreload_pseudos, restore_regno);
1493       for (n = 0, i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
1494 	if (((i < lra_constraint_new_regno_start
1495 	      && ! bitmap_bit_p (&do_not_assign_nonreload_pseudos, i))
1496 	     || (bitmap_bit_p (&lra_inheritance_pseudos, i)
1497 		 && lra_reg_info[i].restore_regno >= 0)
1498 	     || (bitmap_bit_p (&lra_split_regs, i)
1499 		 && lra_reg_info[i].restore_regno >= 0)
1500 	     || bitmap_bit_p (&lra_subreg_reload_pseudos, i)
1501 	     || bitmap_bit_p (&lra_optional_reload_pseudos, i))
1502 	    && reg_renumber[i] < 0 && lra_reg_info[i].nrefs != 0
1503 	    && regno_allocno_class_array[i] != NO_REGS)
1504 	  sorted_pseudos[n++] = i;
1505       bitmap_clear (&do_not_assign_nonreload_pseudos);
1506       if (n != 0 && lra_dump_file != NULL)
1507 	fprintf (lra_dump_file, "  Reassigning non-reload pseudos\n");
1508       qsort (sorted_pseudos, n, sizeof (int), pseudo_compare_func);
1509       for (i = 0; i < n; i++)
1510 	{
1511 	  regno = sorted_pseudos[i];
1512 	  hard_regno = find_hard_regno_for (regno, &cost, -1, false);
1513 	  if (hard_regno >= 0)
1514 	    {
1515 	      assign_hard_regno (hard_regno, regno);
1516 	      /* We change allocation for non-reload pseudo on this
1517 		 iteration -- mark the pseudo for invalidation of used
1518 		 alternatives of insns containing the pseudo.  */
1519 	      bitmap_set_bit (&changed_pseudo_bitmap, regno);
1520 	    }
1521 	  else
1522 	    {
1523 	      enum reg_class rclass = lra_get_allocno_class (regno);
1524 	      enum reg_class spill_class;
1525 
1526 	      if (targetm.spill_class == NULL
1527 		  || lra_reg_info[regno].restore_regno < 0
1528 		  || ! bitmap_bit_p (&lra_inheritance_pseudos, regno)
1529 		  || (spill_class
1530 		      = ((enum reg_class)
1531 			 targetm.spill_class
1532 			 ((reg_class_t) rclass,
1533 			  PSEUDO_REGNO_MODE (regno)))) == NO_REGS)
1534 		continue;
1535 	      regno_allocno_class_array[regno] = spill_class;
1536 	      hard_regno = find_hard_regno_for (regno, &cost, -1, false);
1537 	      if (hard_regno < 0)
1538 		regno_allocno_class_array[regno] = rclass;
1539 	      else
1540 		{
1541 		  setup_reg_classes
1542 		    (regno, spill_class, spill_class, spill_class);
1543 		  assign_hard_regno (hard_regno, regno);
1544 		  bitmap_set_bit (&changed_pseudo_bitmap, regno);
1545 		}
1546 	    }
1547 	}
1548     }
1549   free (update_hard_regno_preference_check);
1550   bitmap_clear (&best_spill_pseudos_bitmap);
1551   bitmap_clear (&spill_pseudos_bitmap);
1552   bitmap_clear (&insn_conflict_pseudos);
1553 }
1554 
1555 
1556 /* Entry function to assign hard registers to new reload pseudos
1557    starting with LRA_CONSTRAINT_NEW_REGNO_START (by possible spilling
1558    of old pseudos) and possibly to the old pseudos.  The function adds
1559    what insns to process for the next constraint pass.	Those are all
1560    insns who contains non-reload and non-inheritance pseudos with
1561    changed allocation.
1562 
1563    Return true if we did not spill any non-reload and non-inheritance
1564    pseudos.  */
1565 bool
1566 lra_assign (void)
1567 {
1568   int i;
1569   unsigned int u;
1570   bitmap_iterator bi;
1571   bitmap_head insns_to_process;
1572   bool no_spills_p;
1573   int max_regno = max_reg_num ();
1574 
1575   timevar_push (TV_LRA_ASSIGN);
1576   lra_assignment_iter++;
1577   if (lra_dump_file != NULL)
1578     fprintf (lra_dump_file, "\n********** Assignment #%d: **********\n\n",
1579 	     lra_assignment_iter);
1580   init_lives ();
1581   sorted_pseudos = XNEWVEC (int, max_regno);
1582   sorted_reload_pseudos = XNEWVEC (int, max_regno);
1583   regno_allocno_class_array = XNEWVEC (enum reg_class, max_regno);
1584   for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
1585     regno_allocno_class_array[i] = lra_get_allocno_class (i);
1586   former_reload_pseudo_spill_p = false;
1587   init_regno_assign_info ();
1588   bitmap_initialize (&all_spilled_pseudos, &reg_obstack);
1589   create_live_range_start_chains ();
1590   setup_live_pseudos_and_spill_after_risky_transforms (&all_spilled_pseudos);
1591 #ifdef ENABLE_CHECKING
1592   if (!flag_ipa_ra)
1593     for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
1594       if (lra_reg_info[i].nrefs != 0 && reg_renumber[i] >= 0
1595 	  && lra_reg_info[i].call_p
1596 	  && overlaps_hard_reg_set_p (call_used_reg_set,
1597 				      PSEUDO_REGNO_MODE (i), reg_renumber[i]))
1598 	gcc_unreachable ();
1599 #endif
1600   /* Setup insns to process on the next constraint pass.  */
1601   bitmap_initialize (&changed_pseudo_bitmap, &reg_obstack);
1602   init_live_reload_and_inheritance_pseudos ();
1603   assign_by_spills ();
1604   finish_live_reload_and_inheritance_pseudos ();
1605   bitmap_ior_into (&changed_pseudo_bitmap, &all_spilled_pseudos);
1606   no_spills_p = true;
1607   EXECUTE_IF_SET_IN_BITMAP (&all_spilled_pseudos, 0, u, bi)
1608     /* We ignore spilled pseudos created on last inheritance pass
1609        because they will be removed.  */
1610     if (lra_reg_info[u].restore_regno < 0)
1611       {
1612 	no_spills_p = false;
1613 	break;
1614       }
1615   finish_live_range_start_chains ();
1616   bitmap_clear (&all_spilled_pseudos);
1617   bitmap_initialize (&insns_to_process, &reg_obstack);
1618   EXECUTE_IF_SET_IN_BITMAP (&changed_pseudo_bitmap, 0, u, bi)
1619     bitmap_ior_into (&insns_to_process, &lra_reg_info[u].insn_bitmap);
1620   bitmap_clear (&changed_pseudo_bitmap);
1621   EXECUTE_IF_SET_IN_BITMAP (&insns_to_process, 0, u, bi)
1622     {
1623       lra_push_insn_by_uid (u);
1624       /* Invalidate alternatives for insn should be processed.	*/
1625       lra_set_used_insn_alternative_by_uid (u, -1);
1626     }
1627   bitmap_clear (&insns_to_process);
1628   finish_regno_assign_info ();
1629   free (regno_allocno_class_array);
1630   free (sorted_pseudos);
1631   free (sorted_reload_pseudos);
1632   finish_lives ();
1633   timevar_pop (TV_LRA_ASSIGN);
1634   if (former_reload_pseudo_spill_p)
1635     lra_assignment_iter_after_spill++;
1636   if (lra_assignment_iter_after_spill > LRA_MAX_ASSIGNMENT_ITERATION_NUMBER)
1637     internal_error
1638       ("Maximum number of LRA assignment passes is achieved (%d)\n",
1639        LRA_MAX_ASSIGNMENT_ITERATION_NUMBER);
1640   return no_spills_p;
1641 }
1642