1 /* IRA hard register and memory cost calculation for allocnos or pseudos.
2 Copyright (C) 2006-2018 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 #include "config.h"
22 #include "system.h"
23 #include "coretypes.h"
24 #include "backend.h"
25 #include "target.h"
26 #include "rtl.h"
27 #include "tree.h"
28 #include "predict.h"
29 #include "memmodel.h"
30 #include "tm_p.h"
31 #include "insn-config.h"
32 #include "regs.h"
33 #include "ira.h"
34 #include "ira-int.h"
35 #include "addresses.h"
36 #include "reload.h"
37
38 /* The flags is set up every time when we calculate pseudo register
39 classes through function ira_set_pseudo_classes. */
40 static bool pseudo_classes_defined_p = false;
41
42 /* TRUE if we work with allocnos. Otherwise we work with pseudos. */
43 static bool allocno_p;
44
45 /* Number of elements in array `costs'. */
46 static int cost_elements_num;
47
48 /* The `costs' struct records the cost of using hard registers of each
49 class considered for the calculation and of using memory for each
50 allocno or pseudo. */
51 struct costs
52 {
53 int mem_cost;
54 /* Costs for register classes start here. We process only some
55 allocno classes. */
56 int cost[1];
57 };
58
59 #define max_struct_costs_size \
60 (this_target_ira_int->x_max_struct_costs_size)
61 #define init_cost \
62 (this_target_ira_int->x_init_cost)
63 #define temp_costs \
64 (this_target_ira_int->x_temp_costs)
65 #define op_costs \
66 (this_target_ira_int->x_op_costs)
67 #define this_op_costs \
68 (this_target_ira_int->x_this_op_costs)
69
70 /* Costs of each class for each allocno or pseudo. */
71 static struct costs *costs;
72
73 /* Accumulated costs of each class for each allocno. */
74 static struct costs *total_allocno_costs;
75
76 /* It is the current size of struct costs. */
77 static size_t struct_costs_size;
78
79 /* Return pointer to structure containing costs of allocno or pseudo
80 with given NUM in array ARR. */
81 #define COSTS(arr, num) \
82 ((struct costs *) ((char *) (arr) + (num) * struct_costs_size))
83
84 /* Return index in COSTS when processing reg with REGNO. */
85 #define COST_INDEX(regno) (allocno_p \
86 ? ALLOCNO_NUM (ira_curr_regno_allocno_map[regno]) \
87 : (int) regno)
88
89 /* Record register class preferences of each allocno or pseudo. Null
90 value means no preferences. It happens on the 1st iteration of the
91 cost calculation. */
92 static enum reg_class *pref;
93
94 /* Allocated buffers for pref. */
95 static enum reg_class *pref_buffer;
96
97 /* Record allocno class of each allocno with the same regno. */
98 static enum reg_class *regno_aclass;
99
100 /* Record cost gains for not allocating a register with an invariant
101 equivalence. */
102 static int *regno_equiv_gains;
103
104 /* Execution frequency of the current insn. */
105 static int frequency;
106
107
108
109 /* Info about reg classes whose costs are calculated for a pseudo. */
110 struct cost_classes
111 {
112 /* Number of the cost classes in the subsequent array. */
113 int num;
114 /* Container of the cost classes. */
115 enum reg_class classes[N_REG_CLASSES];
116 /* Map reg class -> index of the reg class in the previous array.
117 -1 if it is not a cost class. */
118 int index[N_REG_CLASSES];
119 /* Map hard regno index of first class in array CLASSES containing
120 the hard regno, -1 otherwise. */
121 int hard_regno_index[FIRST_PSEUDO_REGISTER];
122 };
123
124 /* Types of pointers to the structure above. */
125 typedef struct cost_classes *cost_classes_t;
126 typedef const struct cost_classes *const_cost_classes_t;
127
128 /* Info about cost classes for each pseudo. */
129 static cost_classes_t *regno_cost_classes;
130
131 /* Helper for cost_classes hashing. */
132
133 struct cost_classes_hasher : pointer_hash <cost_classes>
134 {
135 static inline hashval_t hash (const cost_classes *);
136 static inline bool equal (const cost_classes *, const cost_classes *);
137 static inline void remove (cost_classes *);
138 };
139
140 /* Returns hash value for cost classes info HV. */
141 inline hashval_t
hash(const cost_classes * hv)142 cost_classes_hasher::hash (const cost_classes *hv)
143 {
144 return iterative_hash (&hv->classes, sizeof (enum reg_class) * hv->num, 0);
145 }
146
147 /* Compares cost classes info HV1 and HV2. */
148 inline bool
equal(const cost_classes * hv1,const cost_classes * hv2)149 cost_classes_hasher::equal (const cost_classes *hv1, const cost_classes *hv2)
150 {
151 return (hv1->num == hv2->num
152 && memcmp (hv1->classes, hv2->classes,
153 sizeof (enum reg_class) * hv1->num) == 0);
154 }
155
156 /* Delete cost classes info V from the hash table. */
157 inline void
remove(cost_classes * v)158 cost_classes_hasher::remove (cost_classes *v)
159 {
160 ira_free (v);
161 }
162
163 /* Hash table of unique cost classes. */
164 static hash_table<cost_classes_hasher> *cost_classes_htab;
165
166 /* Map allocno class -> cost classes for pseudo of given allocno
167 class. */
168 static cost_classes_t cost_classes_aclass_cache[N_REG_CLASSES];
169
170 /* Map mode -> cost classes for pseudo of give mode. */
171 static cost_classes_t cost_classes_mode_cache[MAX_MACHINE_MODE];
172
173 /* Cost classes that include all classes in ira_important_classes. */
174 static cost_classes all_cost_classes;
175
176 /* Use the array of classes in CLASSES_PTR to fill out the rest of
177 the structure. */
178 static void
complete_cost_classes(cost_classes_t classes_ptr)179 complete_cost_classes (cost_classes_t classes_ptr)
180 {
181 for (int i = 0; i < N_REG_CLASSES; i++)
182 classes_ptr->index[i] = -1;
183 for (int i = 0; i < FIRST_PSEUDO_REGISTER; i++)
184 classes_ptr->hard_regno_index[i] = -1;
185 for (int i = 0; i < classes_ptr->num; i++)
186 {
187 enum reg_class cl = classes_ptr->classes[i];
188 classes_ptr->index[cl] = i;
189 for (int j = ira_class_hard_regs_num[cl] - 1; j >= 0; j--)
190 {
191 unsigned int hard_regno = ira_class_hard_regs[cl][j];
192 if (classes_ptr->hard_regno_index[hard_regno] < 0)
193 classes_ptr->hard_regno_index[hard_regno] = i;
194 }
195 }
196 }
197
198 /* Initialize info about the cost classes for each pseudo. */
199 static void
initiate_regno_cost_classes(void)200 initiate_regno_cost_classes (void)
201 {
202 int size = sizeof (cost_classes_t) * max_reg_num ();
203
204 regno_cost_classes = (cost_classes_t *) ira_allocate (size);
205 memset (regno_cost_classes, 0, size);
206 memset (cost_classes_aclass_cache, 0,
207 sizeof (cost_classes_t) * N_REG_CLASSES);
208 memset (cost_classes_mode_cache, 0,
209 sizeof (cost_classes_t) * MAX_MACHINE_MODE);
210 cost_classes_htab = new hash_table<cost_classes_hasher> (200);
211 all_cost_classes.num = ira_important_classes_num;
212 for (int i = 0; i < ira_important_classes_num; i++)
213 all_cost_classes.classes[i] = ira_important_classes[i];
214 complete_cost_classes (&all_cost_classes);
215 }
216
217 /* Create new cost classes from cost classes FROM and set up members
218 index and hard_regno_index. Return the new classes. The function
219 implements some common code of two functions
220 setup_regno_cost_classes_by_aclass and
221 setup_regno_cost_classes_by_mode. */
222 static cost_classes_t
setup_cost_classes(cost_classes_t from)223 setup_cost_classes (cost_classes_t from)
224 {
225 cost_classes_t classes_ptr;
226
227 classes_ptr = (cost_classes_t) ira_allocate (sizeof (struct cost_classes));
228 classes_ptr->num = from->num;
229 for (int i = 0; i < from->num; i++)
230 classes_ptr->classes[i] = from->classes[i];
231 complete_cost_classes (classes_ptr);
232 return classes_ptr;
233 }
234
235 /* Return a version of FULL that only considers registers in REGS that are
236 valid for mode MODE. Both FULL and the returned class are globally
237 allocated. */
238 static cost_classes_t
restrict_cost_classes(cost_classes_t full,machine_mode mode,const HARD_REG_SET & regs)239 restrict_cost_classes (cost_classes_t full, machine_mode mode,
240 const HARD_REG_SET ®s)
241 {
242 static struct cost_classes narrow;
243 int map[N_REG_CLASSES];
244 narrow.num = 0;
245 for (int i = 0; i < full->num; i++)
246 {
247 /* Assume that we'll drop the class. */
248 map[i] = -1;
249
250 /* Ignore classes that are too small for the mode. */
251 enum reg_class cl = full->classes[i];
252 if (!contains_reg_of_mode[cl][mode])
253 continue;
254
255 /* Calculate the set of registers in CL that belong to REGS and
256 are valid for MODE. */
257 HARD_REG_SET valid_for_cl;
258 COPY_HARD_REG_SET (valid_for_cl, reg_class_contents[cl]);
259 AND_HARD_REG_SET (valid_for_cl, regs);
260 AND_COMPL_HARD_REG_SET (valid_for_cl,
261 ira_prohibited_class_mode_regs[cl][mode]);
262 AND_COMPL_HARD_REG_SET (valid_for_cl, ira_no_alloc_regs);
263 if (hard_reg_set_empty_p (valid_for_cl))
264 continue;
265
266 /* Don't use this class if the set of valid registers is a subset
267 of an existing class. For example, suppose we have two classes
268 GR_REGS and FR_REGS and a union class GR_AND_FR_REGS. Suppose
269 that the mode changes allowed by FR_REGS are not as general as
270 the mode changes allowed by GR_REGS.
271
272 In this situation, the mode changes for GR_AND_FR_REGS could
273 either be seen as the union or the intersection of the mode
274 changes allowed by the two subclasses. The justification for
275 the union-based definition would be that, if you want a mode
276 change that's only allowed by GR_REGS, you can pick a register
277 from the GR_REGS subclass. The justification for the
278 intersection-based definition would be that every register
279 from the class would allow the mode change.
280
281 However, if we have a register that needs to be in GR_REGS,
282 using GR_AND_FR_REGS with the intersection-based definition
283 would be too pessimistic, since it would bring in restrictions
284 that only apply to FR_REGS. Conversely, if we have a register
285 that needs to be in FR_REGS, using GR_AND_FR_REGS with the
286 union-based definition would lose the extra restrictions
287 placed on FR_REGS. GR_AND_FR_REGS is therefore only useful
288 for cases where GR_REGS and FP_REGS are both valid. */
289 int pos;
290 for (pos = 0; pos < narrow.num; ++pos)
291 {
292 enum reg_class cl2 = narrow.classes[pos];
293 if (hard_reg_set_subset_p (valid_for_cl, reg_class_contents[cl2]))
294 break;
295 }
296 map[i] = pos;
297 if (pos == narrow.num)
298 {
299 /* If several classes are equivalent, prefer to use the one
300 that was chosen as the allocno class. */
301 enum reg_class cl2 = ira_allocno_class_translate[cl];
302 if (ira_class_hard_regs_num[cl] == ira_class_hard_regs_num[cl2])
303 cl = cl2;
304 narrow.classes[narrow.num++] = cl;
305 }
306 }
307 if (narrow.num == full->num)
308 return full;
309
310 cost_classes **slot = cost_classes_htab->find_slot (&narrow, INSERT);
311 if (*slot == NULL)
312 {
313 cost_classes_t classes = setup_cost_classes (&narrow);
314 /* Map equivalent classes to the representative that we chose above. */
315 for (int i = 0; i < ira_important_classes_num; i++)
316 {
317 enum reg_class cl = ira_important_classes[i];
318 int index = full->index[cl];
319 if (index >= 0)
320 classes->index[cl] = map[index];
321 }
322 *slot = classes;
323 }
324 return *slot;
325 }
326
327 /* Setup cost classes for pseudo REGNO whose allocno class is ACLASS.
328 This function is used when we know an initial approximation of
329 allocno class of the pseudo already, e.g. on the second iteration
330 of class cost calculation or after class cost calculation in
331 register-pressure sensitive insn scheduling or register-pressure
332 sensitive loop-invariant motion. */
333 static void
setup_regno_cost_classes_by_aclass(int regno,enum reg_class aclass)334 setup_regno_cost_classes_by_aclass (int regno, enum reg_class aclass)
335 {
336 static struct cost_classes classes;
337 cost_classes_t classes_ptr;
338 enum reg_class cl;
339 int i;
340 cost_classes **slot;
341 HARD_REG_SET temp, temp2;
342 bool exclude_p;
343
344 if ((classes_ptr = cost_classes_aclass_cache[aclass]) == NULL)
345 {
346 COPY_HARD_REG_SET (temp, reg_class_contents[aclass]);
347 AND_COMPL_HARD_REG_SET (temp, ira_no_alloc_regs);
348 /* We exclude classes from consideration which are subsets of
349 ACLASS only if ACLASS is an uniform class. */
350 exclude_p = ira_uniform_class_p[aclass];
351 classes.num = 0;
352 for (i = 0; i < ira_important_classes_num; i++)
353 {
354 cl = ira_important_classes[i];
355 if (exclude_p)
356 {
357 /* Exclude non-uniform classes which are subsets of
358 ACLASS. */
359 COPY_HARD_REG_SET (temp2, reg_class_contents[cl]);
360 AND_COMPL_HARD_REG_SET (temp2, ira_no_alloc_regs);
361 if (hard_reg_set_subset_p (temp2, temp) && cl != aclass)
362 continue;
363 }
364 classes.classes[classes.num++] = cl;
365 }
366 slot = cost_classes_htab->find_slot (&classes, INSERT);
367 if (*slot == NULL)
368 {
369 classes_ptr = setup_cost_classes (&classes);
370 *slot = classes_ptr;
371 }
372 classes_ptr = cost_classes_aclass_cache[aclass] = (cost_classes_t) *slot;
373 }
374 if (regno_reg_rtx[regno] != NULL_RTX)
375 {
376 /* Restrict the classes to those that are valid for REGNO's mode
377 (which might for example exclude singleton classes if the mode
378 requires two registers). Also restrict the classes to those that
379 are valid for subregs of REGNO. */
380 const HARD_REG_SET *valid_regs = valid_mode_changes_for_regno (regno);
381 if (!valid_regs)
382 valid_regs = ®_class_contents[ALL_REGS];
383 classes_ptr = restrict_cost_classes (classes_ptr,
384 PSEUDO_REGNO_MODE (regno),
385 *valid_regs);
386 }
387 regno_cost_classes[regno] = classes_ptr;
388 }
389
390 /* Setup cost classes for pseudo REGNO with MODE. Usage of MODE can
391 decrease number of cost classes for the pseudo, if hard registers
392 of some important classes can not hold a value of MODE. So the
393 pseudo can not get hard register of some important classes and cost
394 calculation for such important classes is only wasting CPU
395 time. */
396 static void
setup_regno_cost_classes_by_mode(int regno,machine_mode mode)397 setup_regno_cost_classes_by_mode (int regno, machine_mode mode)
398 {
399 if (const HARD_REG_SET *valid_regs = valid_mode_changes_for_regno (regno))
400 regno_cost_classes[regno] = restrict_cost_classes (&all_cost_classes,
401 mode, *valid_regs);
402 else
403 {
404 if (cost_classes_mode_cache[mode] == NULL)
405 cost_classes_mode_cache[mode]
406 = restrict_cost_classes (&all_cost_classes, mode,
407 reg_class_contents[ALL_REGS]);
408 regno_cost_classes[regno] = cost_classes_mode_cache[mode];
409 }
410 }
411
412 /* Finalize info about the cost classes for each pseudo. */
413 static void
finish_regno_cost_classes(void)414 finish_regno_cost_classes (void)
415 {
416 ira_free (regno_cost_classes);
417 delete cost_classes_htab;
418 cost_classes_htab = NULL;
419 }
420
421
422
423 /* Compute the cost of loading X into (if TO_P is TRUE) or from (if
424 TO_P is FALSE) a register of class RCLASS in mode MODE. X must not
425 be a pseudo register. */
426 static int
copy_cost(rtx x,machine_mode mode,reg_class_t rclass,bool to_p,secondary_reload_info * prev_sri)427 copy_cost (rtx x, machine_mode mode, reg_class_t rclass, bool to_p,
428 secondary_reload_info *prev_sri)
429 {
430 secondary_reload_info sri;
431 reg_class_t secondary_class = NO_REGS;
432
433 /* If X is a SCRATCH, there is actually nothing to move since we are
434 assuming optimal allocation. */
435 if (GET_CODE (x) == SCRATCH)
436 return 0;
437
438 /* Get the class we will actually use for a reload. */
439 rclass = targetm.preferred_reload_class (x, rclass);
440
441 /* If we need a secondary reload for an intermediate, the cost is
442 that to load the input into the intermediate register, then to
443 copy it. */
444 sri.prev_sri = prev_sri;
445 sri.extra_cost = 0;
446 /* PR 68770: Secondary reload might examine the t_icode field. */
447 sri.t_icode = CODE_FOR_nothing;
448
449 secondary_class = targetm.secondary_reload (to_p, x, rclass, mode, &sri);
450
451 if (secondary_class != NO_REGS)
452 {
453 ira_init_register_move_cost_if_necessary (mode);
454 return (ira_register_move_cost[mode][(int) secondary_class][(int) rclass]
455 + sri.extra_cost
456 + copy_cost (x, mode, secondary_class, to_p, &sri));
457 }
458
459 /* For memory, use the memory move cost, for (hard) registers, use
460 the cost to move between the register classes, and use 2 for
461 everything else (constants). */
462 if (MEM_P (x) || rclass == NO_REGS)
463 return sri.extra_cost
464 + ira_memory_move_cost[mode][(int) rclass][to_p != 0];
465 else if (REG_P (x))
466 {
467 reg_class_t x_class = REGNO_REG_CLASS (REGNO (x));
468
469 ira_init_register_move_cost_if_necessary (mode);
470 return (sri.extra_cost
471 + ira_register_move_cost[mode][(int) x_class][(int) rclass]);
472 }
473 else
474 /* If this is a constant, we may eventually want to call rtx_cost
475 here. */
476 return sri.extra_cost + COSTS_N_INSNS (1);
477 }
478
479
480
481 /* Record the cost of using memory or hard registers of various
482 classes for the operands in INSN.
483
484 N_ALTS is the number of alternatives.
485 N_OPS is the number of operands.
486 OPS is an array of the operands.
487 MODES are the modes of the operands, in case any are VOIDmode.
488 CONSTRAINTS are the constraints to use for the operands. This array
489 is modified by this procedure.
490
491 This procedure works alternative by alternative. For each
492 alternative we assume that we will be able to allocate all allocnos
493 to their ideal register class and calculate the cost of using that
494 alternative. Then we compute, for each operand that is a
495 pseudo-register, the cost of having the allocno allocated to each
496 register class and using it in that alternative. To this cost is
497 added the cost of the alternative.
498
499 The cost of each class for this insn is its lowest cost among all
500 the alternatives. */
501 static void
record_reg_classes(int n_alts,int n_ops,rtx * ops,machine_mode * modes,const char ** constraints,rtx_insn * insn,enum reg_class * pref)502 record_reg_classes (int n_alts, int n_ops, rtx *ops,
503 machine_mode *modes, const char **constraints,
504 rtx_insn *insn, enum reg_class *pref)
505 {
506 int alt;
507 int i, j, k;
508 int insn_allows_mem[MAX_RECOG_OPERANDS];
509 move_table *move_in_cost, *move_out_cost;
510 short (*mem_cost)[2];
511
512 for (i = 0; i < n_ops; i++)
513 insn_allows_mem[i] = 0;
514
515 /* Process each alternative, each time minimizing an operand's cost
516 with the cost for each operand in that alternative. */
517 alternative_mask preferred = get_preferred_alternatives (insn);
518 for (alt = 0; alt < n_alts; alt++)
519 {
520 enum reg_class classes[MAX_RECOG_OPERANDS];
521 int allows_mem[MAX_RECOG_OPERANDS];
522 enum reg_class rclass;
523 int alt_fail = 0;
524 int alt_cost = 0, op_cost_add;
525
526 if (!TEST_BIT (preferred, alt))
527 {
528 for (i = 0; i < recog_data.n_operands; i++)
529 constraints[i] = skip_alternative (constraints[i]);
530
531 continue;
532 }
533
534 for (i = 0; i < n_ops; i++)
535 {
536 unsigned char c;
537 const char *p = constraints[i];
538 rtx op = ops[i];
539 machine_mode mode = modes[i];
540 int allows_addr = 0;
541 int win = 0;
542
543 /* Initially show we know nothing about the register class. */
544 classes[i] = NO_REGS;
545 allows_mem[i] = 0;
546
547 /* If this operand has no constraints at all, we can
548 conclude nothing about it since anything is valid. */
549 if (*p == 0)
550 {
551 if (REG_P (op) && REGNO (op) >= FIRST_PSEUDO_REGISTER)
552 memset (this_op_costs[i], 0, struct_costs_size);
553 continue;
554 }
555
556 /* If this alternative is only relevant when this operand
557 matches a previous operand, we do different things
558 depending on whether this operand is a allocno-reg or not.
559 We must process any modifiers for the operand before we
560 can make this test. */
561 while (*p == '%' || *p == '=' || *p == '+' || *p == '&')
562 p++;
563
564 if (p[0] >= '0' && p[0] <= '0' + i)
565 {
566 /* Copy class and whether memory is allowed from the
567 matching alternative. Then perform any needed cost
568 computations and/or adjustments. */
569 j = p[0] - '0';
570 classes[i] = classes[j];
571 allows_mem[i] = allows_mem[j];
572 if (allows_mem[i])
573 insn_allows_mem[i] = 1;
574
575 if (! REG_P (op) || REGNO (op) < FIRST_PSEUDO_REGISTER)
576 {
577 /* If this matches the other operand, we have no
578 added cost and we win. */
579 if (rtx_equal_p (ops[j], op))
580 win = 1;
581 /* If we can put the other operand into a register,
582 add to the cost of this alternative the cost to
583 copy this operand to the register used for the
584 other operand. */
585 else if (classes[j] != NO_REGS)
586 {
587 alt_cost += copy_cost (op, mode, classes[j], 1, NULL);
588 win = 1;
589 }
590 }
591 else if (! REG_P (ops[j])
592 || REGNO (ops[j]) < FIRST_PSEUDO_REGISTER)
593 {
594 /* This op is an allocno but the one it matches is
595 not. */
596
597 /* If we can't put the other operand into a
598 register, this alternative can't be used. */
599
600 if (classes[j] == NO_REGS)
601 alt_fail = 1;
602 /* Otherwise, add to the cost of this alternative
603 the cost to copy the other operand to the hard
604 register used for this operand. */
605 else
606 alt_cost += copy_cost (ops[j], mode, classes[j], 1, NULL);
607 }
608 else
609 {
610 /* The costs of this operand are not the same as the
611 other operand since move costs are not symmetric.
612 Moreover, if we cannot tie them, this alternative
613 needs to do a copy, which is one insn. */
614 struct costs *pp = this_op_costs[i];
615 int *pp_costs = pp->cost;
616 cost_classes_t cost_classes_ptr
617 = regno_cost_classes[REGNO (op)];
618 enum reg_class *cost_classes = cost_classes_ptr->classes;
619 bool in_p = recog_data.operand_type[i] != OP_OUT;
620 bool out_p = recog_data.operand_type[i] != OP_IN;
621 enum reg_class op_class = classes[i];
622
623 ira_init_register_move_cost_if_necessary (mode);
624 if (! in_p)
625 {
626 ira_assert (out_p);
627 if (op_class == NO_REGS)
628 {
629 mem_cost = ira_memory_move_cost[mode];
630 for (k = cost_classes_ptr->num - 1; k >= 0; k--)
631 {
632 rclass = cost_classes[k];
633 pp_costs[k] = mem_cost[rclass][0] * frequency;
634 }
635 }
636 else
637 {
638 move_out_cost = ira_may_move_out_cost[mode];
639 for (k = cost_classes_ptr->num - 1; k >= 0; k--)
640 {
641 rclass = cost_classes[k];
642 pp_costs[k]
643 = move_out_cost[op_class][rclass] * frequency;
644 }
645 }
646 }
647 else if (! out_p)
648 {
649 ira_assert (in_p);
650 if (op_class == NO_REGS)
651 {
652 mem_cost = ira_memory_move_cost[mode];
653 for (k = cost_classes_ptr->num - 1; k >= 0; k--)
654 {
655 rclass = cost_classes[k];
656 pp_costs[k] = mem_cost[rclass][1] * frequency;
657 }
658 }
659 else
660 {
661 move_in_cost = ira_may_move_in_cost[mode];
662 for (k = cost_classes_ptr->num - 1; k >= 0; k--)
663 {
664 rclass = cost_classes[k];
665 pp_costs[k]
666 = move_in_cost[rclass][op_class] * frequency;
667 }
668 }
669 }
670 else
671 {
672 if (op_class == NO_REGS)
673 {
674 mem_cost = ira_memory_move_cost[mode];
675 for (k = cost_classes_ptr->num - 1; k >= 0; k--)
676 {
677 rclass = cost_classes[k];
678 pp_costs[k] = ((mem_cost[rclass][0]
679 + mem_cost[rclass][1])
680 * frequency);
681 }
682 }
683 else
684 {
685 move_in_cost = ira_may_move_in_cost[mode];
686 move_out_cost = ira_may_move_out_cost[mode];
687 for (k = cost_classes_ptr->num - 1; k >= 0; k--)
688 {
689 rclass = cost_classes[k];
690 pp_costs[k] = ((move_in_cost[rclass][op_class]
691 + move_out_cost[op_class][rclass])
692 * frequency);
693 }
694 }
695 }
696
697 /* If the alternative actually allows memory, make
698 things a bit cheaper since we won't need an extra
699 insn to load it. */
700 pp->mem_cost
701 = ((out_p ? ira_memory_move_cost[mode][op_class][0] : 0)
702 + (in_p ? ira_memory_move_cost[mode][op_class][1] : 0)
703 - allows_mem[i]) * frequency;
704
705 /* If we have assigned a class to this allocno in
706 our first pass, add a cost to this alternative
707 corresponding to what we would add if this
708 allocno were not in the appropriate class. */
709 if (pref)
710 {
711 enum reg_class pref_class = pref[COST_INDEX (REGNO (op))];
712
713 if (pref_class == NO_REGS)
714 alt_cost
715 += ((out_p
716 ? ira_memory_move_cost[mode][op_class][0] : 0)
717 + (in_p
718 ? ira_memory_move_cost[mode][op_class][1]
719 : 0));
720 else if (ira_reg_class_intersect
721 [pref_class][op_class] == NO_REGS)
722 alt_cost
723 += ira_register_move_cost[mode][pref_class][op_class];
724 }
725 if (REGNO (ops[i]) != REGNO (ops[j])
726 && ! find_reg_note (insn, REG_DEAD, op))
727 alt_cost += 2;
728
729 p++;
730 }
731 }
732
733 /* Scan all the constraint letters. See if the operand
734 matches any of the constraints. Collect the valid
735 register classes and see if this operand accepts
736 memory. */
737 while ((c = *p))
738 {
739 switch (c)
740 {
741 case '*':
742 /* Ignore the next letter for this pass. */
743 c = *++p;
744 break;
745
746 case '^':
747 alt_cost += 2;
748 break;
749
750 case '?':
751 alt_cost += 2;
752 break;
753
754 case 'g':
755 if (MEM_P (op)
756 || (CONSTANT_P (op)
757 && (! flag_pic || LEGITIMATE_PIC_OPERAND_P (op))))
758 win = 1;
759 insn_allows_mem[i] = allows_mem[i] = 1;
760 classes[i] = ira_reg_class_subunion[classes[i]][GENERAL_REGS];
761 break;
762
763 default:
764 enum constraint_num cn = lookup_constraint (p);
765 enum reg_class cl;
766 switch (get_constraint_type (cn))
767 {
768 case CT_REGISTER:
769 cl = reg_class_for_constraint (cn);
770 if (cl != NO_REGS)
771 classes[i] = ira_reg_class_subunion[classes[i]][cl];
772 break;
773
774 case CT_CONST_INT:
775 if (CONST_INT_P (op)
776 && insn_const_int_ok_for_constraint (INTVAL (op), cn))
777 win = 1;
778 break;
779
780 case CT_MEMORY:
781 /* Every MEM can be reloaded to fit. */
782 insn_allows_mem[i] = allows_mem[i] = 1;
783 if (MEM_P (op))
784 win = 1;
785 break;
786
787 case CT_SPECIAL_MEMORY:
788 insn_allows_mem[i] = allows_mem[i] = 1;
789 if (MEM_P (op) && constraint_satisfied_p (op, cn))
790 win = 1;
791 break;
792
793 case CT_ADDRESS:
794 /* Every address can be reloaded to fit. */
795 allows_addr = 1;
796 if (address_operand (op, GET_MODE (op))
797 || constraint_satisfied_p (op, cn))
798 win = 1;
799 /* We know this operand is an address, so we
800 want it to be allocated to a hard register
801 that can be the base of an address,
802 i.e. BASE_REG_CLASS. */
803 classes[i]
804 = ira_reg_class_subunion[classes[i]]
805 [base_reg_class (VOIDmode, ADDR_SPACE_GENERIC,
806 ADDRESS, SCRATCH)];
807 break;
808
809 case CT_FIXED_FORM:
810 if (constraint_satisfied_p (op, cn))
811 win = 1;
812 break;
813 }
814 break;
815 }
816 p += CONSTRAINT_LEN (c, p);
817 if (c == ',')
818 break;
819 }
820
821 constraints[i] = p;
822
823 if (alt_fail)
824 break;
825
826 /* How we account for this operand now depends on whether it
827 is a pseudo register or not. If it is, we first check if
828 any register classes are valid. If not, we ignore this
829 alternative, since we want to assume that all allocnos get
830 allocated for register preferencing. If some register
831 class is valid, compute the costs of moving the allocno
832 into that class. */
833 if (REG_P (op) && REGNO (op) >= FIRST_PSEUDO_REGISTER)
834 {
835 if (classes[i] == NO_REGS && ! allows_mem[i])
836 {
837 /* We must always fail if the operand is a REG, but
838 we did not find a suitable class and memory is
839 not allowed.
840
841 Otherwise we may perform an uninitialized read
842 from this_op_costs after the `continue' statement
843 below. */
844 alt_fail = 1;
845 }
846 else
847 {
848 unsigned int regno = REGNO (op);
849 struct costs *pp = this_op_costs[i];
850 int *pp_costs = pp->cost;
851 cost_classes_t cost_classes_ptr = regno_cost_classes[regno];
852 enum reg_class *cost_classes = cost_classes_ptr->classes;
853 bool in_p = recog_data.operand_type[i] != OP_OUT;
854 bool out_p = recog_data.operand_type[i] != OP_IN;
855 enum reg_class op_class = classes[i];
856
857 ira_init_register_move_cost_if_necessary (mode);
858 if (! in_p)
859 {
860 ira_assert (out_p);
861 if (op_class == NO_REGS)
862 {
863 mem_cost = ira_memory_move_cost[mode];
864 for (k = cost_classes_ptr->num - 1; k >= 0; k--)
865 {
866 rclass = cost_classes[k];
867 pp_costs[k] = mem_cost[rclass][0] * frequency;
868 }
869 }
870 else
871 {
872 move_out_cost = ira_may_move_out_cost[mode];
873 for (k = cost_classes_ptr->num - 1; k >= 0; k--)
874 {
875 rclass = cost_classes[k];
876 pp_costs[k]
877 = move_out_cost[op_class][rclass] * frequency;
878 }
879 }
880 }
881 else if (! out_p)
882 {
883 ira_assert (in_p);
884 if (op_class == NO_REGS)
885 {
886 mem_cost = ira_memory_move_cost[mode];
887 for (k = cost_classes_ptr->num - 1; k >= 0; k--)
888 {
889 rclass = cost_classes[k];
890 pp_costs[k] = mem_cost[rclass][1] * frequency;
891 }
892 }
893 else
894 {
895 move_in_cost = ira_may_move_in_cost[mode];
896 for (k = cost_classes_ptr->num - 1; k >= 0; k--)
897 {
898 rclass = cost_classes[k];
899 pp_costs[k]
900 = move_in_cost[rclass][op_class] * frequency;
901 }
902 }
903 }
904 else
905 {
906 if (op_class == NO_REGS)
907 {
908 mem_cost = ira_memory_move_cost[mode];
909 for (k = cost_classes_ptr->num - 1; k >= 0; k--)
910 {
911 rclass = cost_classes[k];
912 pp_costs[k] = ((mem_cost[rclass][0]
913 + mem_cost[rclass][1])
914 * frequency);
915 }
916 }
917 else
918 {
919 move_in_cost = ira_may_move_in_cost[mode];
920 move_out_cost = ira_may_move_out_cost[mode];
921 for (k = cost_classes_ptr->num - 1; k >= 0; k--)
922 {
923 rclass = cost_classes[k];
924 pp_costs[k] = ((move_in_cost[rclass][op_class]
925 + move_out_cost[op_class][rclass])
926 * frequency);
927 }
928 }
929 }
930
931 if (op_class == NO_REGS)
932 /* Although we don't need insn to reload from
933 memory, still accessing memory is usually more
934 expensive than a register. */
935 pp->mem_cost = frequency;
936 else
937 /* If the alternative actually allows memory, make
938 things a bit cheaper since we won't need an
939 extra insn to load it. */
940 pp->mem_cost
941 = ((out_p ? ira_memory_move_cost[mode][op_class][0] : 0)
942 + (in_p ? ira_memory_move_cost[mode][op_class][1] : 0)
943 - allows_mem[i]) * frequency;
944 /* If we have assigned a class to this allocno in
945 our first pass, add a cost to this alternative
946 corresponding to what we would add if this
947 allocno were not in the appropriate class. */
948 if (pref)
949 {
950 enum reg_class pref_class = pref[COST_INDEX (REGNO (op))];
951
952 if (pref_class == NO_REGS)
953 {
954 if (op_class != NO_REGS)
955 alt_cost
956 += ((out_p
957 ? ira_memory_move_cost[mode][op_class][0]
958 : 0)
959 + (in_p
960 ? ira_memory_move_cost[mode][op_class][1]
961 : 0));
962 }
963 else if (op_class == NO_REGS)
964 alt_cost
965 += ((out_p
966 ? ira_memory_move_cost[mode][pref_class][1]
967 : 0)
968 + (in_p
969 ? ira_memory_move_cost[mode][pref_class][0]
970 : 0));
971 else if (ira_reg_class_intersect[pref_class][op_class]
972 == NO_REGS)
973 alt_cost += (ira_register_move_cost
974 [mode][pref_class][op_class]);
975 }
976 }
977 }
978
979 /* Otherwise, if this alternative wins, either because we
980 have already determined that or if we have a hard
981 register of the proper class, there is no cost for this
982 alternative. */
983 else if (win || (REG_P (op)
984 && reg_fits_class_p (op, classes[i],
985 0, GET_MODE (op))))
986 ;
987
988 /* If registers are valid, the cost of this alternative
989 includes copying the object to and/or from a
990 register. */
991 else if (classes[i] != NO_REGS)
992 {
993 if (recog_data.operand_type[i] != OP_OUT)
994 alt_cost += copy_cost (op, mode, classes[i], 1, NULL);
995
996 if (recog_data.operand_type[i] != OP_IN)
997 alt_cost += copy_cost (op, mode, classes[i], 0, NULL);
998 }
999 /* The only other way this alternative can be used is if
1000 this is a constant that could be placed into memory. */
1001 else if (CONSTANT_P (op) && (allows_addr || allows_mem[i]))
1002 alt_cost += ira_memory_move_cost[mode][classes[i]][1];
1003 else
1004 alt_fail = 1;
1005
1006 if (alt_fail)
1007 break;
1008 }
1009
1010 if (alt_fail)
1011 {
1012 /* The loop above might have exited early once the failure
1013 was seen. Skip over the constraints for the remaining
1014 operands. */
1015 i += 1;
1016 for (; i < n_ops; ++i)
1017 constraints[i] = skip_alternative (constraints[i]);
1018 continue;
1019 }
1020
1021 op_cost_add = alt_cost * frequency;
1022 /* Finally, update the costs with the information we've
1023 calculated about this alternative. */
1024 for (i = 0; i < n_ops; i++)
1025 if (REG_P (ops[i]) && REGNO (ops[i]) >= FIRST_PSEUDO_REGISTER)
1026 {
1027 struct costs *pp = op_costs[i], *qq = this_op_costs[i];
1028 int *pp_costs = pp->cost, *qq_costs = qq->cost;
1029 int scale = 1 + (recog_data.operand_type[i] == OP_INOUT);
1030 cost_classes_t cost_classes_ptr
1031 = regno_cost_classes[REGNO (ops[i])];
1032
1033 pp->mem_cost = MIN (pp->mem_cost,
1034 (qq->mem_cost + op_cost_add) * scale);
1035
1036 for (k = cost_classes_ptr->num - 1; k >= 0; k--)
1037 pp_costs[k]
1038 = MIN (pp_costs[k], (qq_costs[k] + op_cost_add) * scale);
1039 }
1040 }
1041
1042 if (allocno_p)
1043 for (i = 0; i < n_ops; i++)
1044 {
1045 ira_allocno_t a;
1046 rtx op = ops[i];
1047
1048 if (! REG_P (op) || REGNO (op) < FIRST_PSEUDO_REGISTER)
1049 continue;
1050 a = ira_curr_regno_allocno_map [REGNO (op)];
1051 if (! ALLOCNO_BAD_SPILL_P (a) && insn_allows_mem[i] == 0)
1052 ALLOCNO_BAD_SPILL_P (a) = true;
1053 }
1054
1055 }
1056
1057
1058
1059 /* Wrapper around REGNO_OK_FOR_INDEX_P, to allow pseudo registers. */
1060 static inline bool
ok_for_index_p_nonstrict(rtx reg)1061 ok_for_index_p_nonstrict (rtx reg)
1062 {
1063 unsigned regno = REGNO (reg);
1064
1065 return regno >= FIRST_PSEUDO_REGISTER || REGNO_OK_FOR_INDEX_P (regno);
1066 }
1067
1068 /* A version of regno_ok_for_base_p for use here, when all
1069 pseudo-registers should count as OK. Arguments as for
1070 regno_ok_for_base_p. */
1071 static inline bool
ok_for_base_p_nonstrict(rtx reg,machine_mode mode,addr_space_t as,enum rtx_code outer_code,enum rtx_code index_code)1072 ok_for_base_p_nonstrict (rtx reg, machine_mode mode, addr_space_t as,
1073 enum rtx_code outer_code, enum rtx_code index_code)
1074 {
1075 unsigned regno = REGNO (reg);
1076
1077 if (regno >= FIRST_PSEUDO_REGISTER)
1078 return true;
1079 return ok_for_base_p_1 (regno, mode, as, outer_code, index_code);
1080 }
1081
1082 /* Record the pseudo registers we must reload into hard registers in a
1083 subexpression of a memory address, X.
1084
1085 If CONTEXT is 0, we are looking at the base part of an address,
1086 otherwise we are looking at the index part.
1087
1088 MODE and AS are the mode and address space of the memory reference;
1089 OUTER_CODE and INDEX_CODE give the context that the rtx appears in.
1090 These four arguments are passed down to base_reg_class.
1091
1092 SCALE is twice the amount to multiply the cost by (it is twice so
1093 we can represent half-cost adjustments). */
1094 static void
record_address_regs(machine_mode mode,addr_space_t as,rtx x,int context,enum rtx_code outer_code,enum rtx_code index_code,int scale)1095 record_address_regs (machine_mode mode, addr_space_t as, rtx x,
1096 int context, enum rtx_code outer_code,
1097 enum rtx_code index_code, int scale)
1098 {
1099 enum rtx_code code = GET_CODE (x);
1100 enum reg_class rclass;
1101
1102 if (context == 1)
1103 rclass = INDEX_REG_CLASS;
1104 else
1105 rclass = base_reg_class (mode, as, outer_code, index_code);
1106
1107 switch (code)
1108 {
1109 case CONST_INT:
1110 case CONST:
1111 case CC0:
1112 case PC:
1113 case SYMBOL_REF:
1114 case LABEL_REF:
1115 return;
1116
1117 case PLUS:
1118 /* When we have an address that is a sum, we must determine
1119 whether registers are "base" or "index" regs. If there is a
1120 sum of two registers, we must choose one to be the "base".
1121 Luckily, we can use the REG_POINTER to make a good choice
1122 most of the time. We only need to do this on machines that
1123 can have two registers in an address and where the base and
1124 index register classes are different.
1125
1126 ??? This code used to set REGNO_POINTER_FLAG in some cases,
1127 but that seems bogus since it should only be set when we are
1128 sure the register is being used as a pointer. */
1129 {
1130 rtx arg0 = XEXP (x, 0);
1131 rtx arg1 = XEXP (x, 1);
1132 enum rtx_code code0 = GET_CODE (arg0);
1133 enum rtx_code code1 = GET_CODE (arg1);
1134
1135 /* Look inside subregs. */
1136 if (code0 == SUBREG)
1137 arg0 = SUBREG_REG (arg0), code0 = GET_CODE (arg0);
1138 if (code1 == SUBREG)
1139 arg1 = SUBREG_REG (arg1), code1 = GET_CODE (arg1);
1140
1141 /* If index registers do not appear, or coincide with base registers,
1142 just record registers in any non-constant operands. We
1143 assume here, as well as in the tests below, that all
1144 addresses are in canonical form. */
1145 if (MAX_REGS_PER_ADDRESS == 1
1146 || INDEX_REG_CLASS == base_reg_class (VOIDmode, as, PLUS, SCRATCH))
1147 {
1148 record_address_regs (mode, as, arg0, context, PLUS, code1, scale);
1149 if (! CONSTANT_P (arg1))
1150 record_address_regs (mode, as, arg1, context, PLUS, code0, scale);
1151 }
1152
1153 /* If the second operand is a constant integer, it doesn't
1154 change what class the first operand must be. */
1155 else if (CONST_SCALAR_INT_P (arg1))
1156 record_address_regs (mode, as, arg0, context, PLUS, code1, scale);
1157 /* If the second operand is a symbolic constant, the first
1158 operand must be an index register. */
1159 else if (code1 == SYMBOL_REF || code1 == CONST || code1 == LABEL_REF)
1160 record_address_regs (mode, as, arg0, 1, PLUS, code1, scale);
1161 /* If both operands are registers but one is already a hard
1162 register of index or reg-base class, give the other the
1163 class that the hard register is not. */
1164 else if (code0 == REG && code1 == REG
1165 && REGNO (arg0) < FIRST_PSEUDO_REGISTER
1166 && (ok_for_base_p_nonstrict (arg0, mode, as, PLUS, REG)
1167 || ok_for_index_p_nonstrict (arg0)))
1168 record_address_regs (mode, as, arg1,
1169 ok_for_base_p_nonstrict (arg0, mode, as,
1170 PLUS, REG) ? 1 : 0,
1171 PLUS, REG, scale);
1172 else if (code0 == REG && code1 == REG
1173 && REGNO (arg1) < FIRST_PSEUDO_REGISTER
1174 && (ok_for_base_p_nonstrict (arg1, mode, as, PLUS, REG)
1175 || ok_for_index_p_nonstrict (arg1)))
1176 record_address_regs (mode, as, arg0,
1177 ok_for_base_p_nonstrict (arg1, mode, as,
1178 PLUS, REG) ? 1 : 0,
1179 PLUS, REG, scale);
1180 /* If one operand is known to be a pointer, it must be the
1181 base with the other operand the index. Likewise if the
1182 other operand is a MULT. */
1183 else if ((code0 == REG && REG_POINTER (arg0)) || code1 == MULT)
1184 {
1185 record_address_regs (mode, as, arg0, 0, PLUS, code1, scale);
1186 record_address_regs (mode, as, arg1, 1, PLUS, code0, scale);
1187 }
1188 else if ((code1 == REG && REG_POINTER (arg1)) || code0 == MULT)
1189 {
1190 record_address_regs (mode, as, arg0, 1, PLUS, code1, scale);
1191 record_address_regs (mode, as, arg1, 0, PLUS, code0, scale);
1192 }
1193 /* Otherwise, count equal chances that each might be a base or
1194 index register. This case should be rare. */
1195 else
1196 {
1197 record_address_regs (mode, as, arg0, 0, PLUS, code1, scale / 2);
1198 record_address_regs (mode, as, arg0, 1, PLUS, code1, scale / 2);
1199 record_address_regs (mode, as, arg1, 0, PLUS, code0, scale / 2);
1200 record_address_regs (mode, as, arg1, 1, PLUS, code0, scale / 2);
1201 }
1202 }
1203 break;
1204
1205 /* Double the importance of an allocno that is incremented or
1206 decremented, since it would take two extra insns if it ends
1207 up in the wrong place. */
1208 case POST_MODIFY:
1209 case PRE_MODIFY:
1210 record_address_regs (mode, as, XEXP (x, 0), 0, code,
1211 GET_CODE (XEXP (XEXP (x, 1), 1)), 2 * scale);
1212 if (REG_P (XEXP (XEXP (x, 1), 1)))
1213 record_address_regs (mode, as, XEXP (XEXP (x, 1), 1), 1, code, REG,
1214 2 * scale);
1215 break;
1216
1217 case POST_INC:
1218 case PRE_INC:
1219 case POST_DEC:
1220 case PRE_DEC:
1221 /* Double the importance of an allocno that is incremented or
1222 decremented, since it would take two extra insns if it ends
1223 up in the wrong place. */
1224 record_address_regs (mode, as, XEXP (x, 0), 0, code, SCRATCH, 2 * scale);
1225 break;
1226
1227 case REG:
1228 {
1229 struct costs *pp;
1230 int *pp_costs;
1231 enum reg_class i;
1232 int k, regno, add_cost;
1233 cost_classes_t cost_classes_ptr;
1234 enum reg_class *cost_classes;
1235 move_table *move_in_cost;
1236
1237 if (REGNO (x) < FIRST_PSEUDO_REGISTER)
1238 break;
1239
1240 regno = REGNO (x);
1241 if (allocno_p)
1242 ALLOCNO_BAD_SPILL_P (ira_curr_regno_allocno_map[regno]) = true;
1243 pp = COSTS (costs, COST_INDEX (regno));
1244 add_cost = (ira_memory_move_cost[Pmode][rclass][1] * scale) / 2;
1245 if (INT_MAX - add_cost < pp->mem_cost)
1246 pp->mem_cost = INT_MAX;
1247 else
1248 pp->mem_cost += add_cost;
1249 cost_classes_ptr = regno_cost_classes[regno];
1250 cost_classes = cost_classes_ptr->classes;
1251 pp_costs = pp->cost;
1252 ira_init_register_move_cost_if_necessary (Pmode);
1253 move_in_cost = ira_may_move_in_cost[Pmode];
1254 for (k = cost_classes_ptr->num - 1; k >= 0; k--)
1255 {
1256 i = cost_classes[k];
1257 add_cost = (move_in_cost[i][rclass] * scale) / 2;
1258 if (INT_MAX - add_cost < pp_costs[k])
1259 pp_costs[k] = INT_MAX;
1260 else
1261 pp_costs[k] += add_cost;
1262 }
1263 }
1264 break;
1265
1266 default:
1267 {
1268 const char *fmt = GET_RTX_FORMAT (code);
1269 int i;
1270 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
1271 if (fmt[i] == 'e')
1272 record_address_regs (mode, as, XEXP (x, i), context, code, SCRATCH,
1273 scale);
1274 }
1275 }
1276 }
1277
1278
1279
1280 /* Calculate the costs of insn operands. */
1281 static void
record_operand_costs(rtx_insn * insn,enum reg_class * pref)1282 record_operand_costs (rtx_insn *insn, enum reg_class *pref)
1283 {
1284 const char *constraints[MAX_RECOG_OPERANDS];
1285 machine_mode modes[MAX_RECOG_OPERANDS];
1286 rtx ops[MAX_RECOG_OPERANDS];
1287 rtx set;
1288 int i;
1289
1290 for (i = 0; i < recog_data.n_operands; i++)
1291 {
1292 constraints[i] = recog_data.constraints[i];
1293 modes[i] = recog_data.operand_mode[i];
1294 }
1295
1296 /* If we get here, we are set up to record the costs of all the
1297 operands for this insn. Start by initializing the costs. Then
1298 handle any address registers. Finally record the desired classes
1299 for any allocnos, doing it twice if some pair of operands are
1300 commutative. */
1301 for (i = 0; i < recog_data.n_operands; i++)
1302 {
1303 memcpy (op_costs[i], init_cost, struct_costs_size);
1304
1305 ops[i] = recog_data.operand[i];
1306 if (GET_CODE (recog_data.operand[i]) == SUBREG)
1307 recog_data.operand[i] = SUBREG_REG (recog_data.operand[i]);
1308
1309 if (MEM_P (recog_data.operand[i]))
1310 record_address_regs (GET_MODE (recog_data.operand[i]),
1311 MEM_ADDR_SPACE (recog_data.operand[i]),
1312 XEXP (recog_data.operand[i], 0),
1313 0, MEM, SCRATCH, frequency * 2);
1314 else if (constraints[i][0] == 'p'
1315 || (insn_extra_address_constraint
1316 (lookup_constraint (constraints[i]))))
1317 record_address_regs (VOIDmode, ADDR_SPACE_GENERIC,
1318 recog_data.operand[i], 0, ADDRESS, SCRATCH,
1319 frequency * 2);
1320 }
1321
1322 /* Check for commutative in a separate loop so everything will have
1323 been initialized. We must do this even if one operand is a
1324 constant--see addsi3 in m68k.md. */
1325 for (i = 0; i < (int) recog_data.n_operands - 1; i++)
1326 if (constraints[i][0] == '%')
1327 {
1328 const char *xconstraints[MAX_RECOG_OPERANDS];
1329 int j;
1330
1331 /* Handle commutative operands by swapping the constraints.
1332 We assume the modes are the same. */
1333 for (j = 0; j < recog_data.n_operands; j++)
1334 xconstraints[j] = constraints[j];
1335
1336 xconstraints[i] = constraints[i+1];
1337 xconstraints[i+1] = constraints[i];
1338 record_reg_classes (recog_data.n_alternatives, recog_data.n_operands,
1339 recog_data.operand, modes,
1340 xconstraints, insn, pref);
1341 }
1342 record_reg_classes (recog_data.n_alternatives, recog_data.n_operands,
1343 recog_data.operand, modes,
1344 constraints, insn, pref);
1345
1346 /* If this insn is a single set copying operand 1 to operand 0 and
1347 one operand is an allocno with the other a hard reg or an allocno
1348 that prefers a hard register that is in its own register class
1349 then we may want to adjust the cost of that register class to -1.
1350
1351 Avoid the adjustment if the source does not die to avoid
1352 stressing of register allocator by preferencing two colliding
1353 registers into single class.
1354
1355 Also avoid the adjustment if a copy between hard registers of the
1356 class is expensive (ten times the cost of a default copy is
1357 considered arbitrarily expensive). This avoids losing when the
1358 preferred class is very expensive as the source of a copy
1359 instruction. */
1360 if ((set = single_set (insn)) != NULL_RTX
1361 /* In rare cases the single set insn might have less 2 operands
1362 as the source can be a fixed special reg. */
1363 && recog_data.n_operands > 1
1364 && ops[0] == SET_DEST (set) && ops[1] == SET_SRC (set))
1365 {
1366 int regno, other_regno;
1367 rtx dest = SET_DEST (set);
1368 rtx src = SET_SRC (set);
1369
1370 if (GET_CODE (dest) == SUBREG
1371 && known_eq (GET_MODE_SIZE (GET_MODE (dest)),
1372 GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest)))))
1373 dest = SUBREG_REG (dest);
1374 if (GET_CODE (src) == SUBREG
1375 && known_eq (GET_MODE_SIZE (GET_MODE (src)),
1376 GET_MODE_SIZE (GET_MODE (SUBREG_REG (src)))))
1377 src = SUBREG_REG (src);
1378 if (REG_P (src) && REG_P (dest)
1379 && find_regno_note (insn, REG_DEAD, REGNO (src))
1380 && (((regno = REGNO (src)) >= FIRST_PSEUDO_REGISTER
1381 && (other_regno = REGNO (dest)) < FIRST_PSEUDO_REGISTER)
1382 || ((regno = REGNO (dest)) >= FIRST_PSEUDO_REGISTER
1383 && (other_regno = REGNO (src)) < FIRST_PSEUDO_REGISTER)))
1384 {
1385 machine_mode mode = GET_MODE (src);
1386 cost_classes_t cost_classes_ptr = regno_cost_classes[regno];
1387 enum reg_class *cost_classes = cost_classes_ptr->classes;
1388 reg_class_t rclass;
1389 int k;
1390
1391 i = regno == (int) REGNO (src) ? 1 : 0;
1392 for (k = cost_classes_ptr->num - 1; k >= 0; k--)
1393 {
1394 rclass = cost_classes[k];
1395 if (TEST_HARD_REG_BIT (reg_class_contents[rclass], other_regno)
1396 && (reg_class_size[(int) rclass]
1397 == ira_reg_class_max_nregs [(int) rclass][(int) mode]))
1398 {
1399 if (reg_class_size[rclass] == 1)
1400 op_costs[i]->cost[k] = -frequency;
1401 else if (in_hard_reg_set_p (reg_class_contents[rclass],
1402 mode, other_regno))
1403 op_costs[i]->cost[k] = -frequency;
1404 }
1405 }
1406 }
1407 }
1408 }
1409
1410
1411
1412 /* Process one insn INSN. Scan it and record each time it would save
1413 code to put a certain allocnos in a certain class. Return the last
1414 insn processed, so that the scan can be continued from there. */
1415 static rtx_insn *
scan_one_insn(rtx_insn * insn)1416 scan_one_insn (rtx_insn *insn)
1417 {
1418 enum rtx_code pat_code;
1419 rtx set, note;
1420 int i, k;
1421 bool counted_mem;
1422
1423 if (!NONDEBUG_INSN_P (insn))
1424 return insn;
1425
1426 pat_code = GET_CODE (PATTERN (insn));
1427 if (pat_code == ASM_INPUT)
1428 return insn;
1429
1430 /* If INSN is a USE/CLOBBER of a pseudo in a mode M then go ahead
1431 and initialize the register move costs of mode M.
1432
1433 The pseudo may be related to another pseudo via a copy (implicit or
1434 explicit) and if there are no mode M uses/sets of the original
1435 pseudo, then we may leave the register move costs uninitialized for
1436 mode M. */
1437 if (pat_code == USE || pat_code == CLOBBER)
1438 {
1439 rtx x = XEXP (PATTERN (insn), 0);
1440 if (GET_CODE (x) == REG
1441 && REGNO (x) >= FIRST_PSEUDO_REGISTER
1442 && have_regs_of_mode[GET_MODE (x)])
1443 ira_init_register_move_cost_if_necessary (GET_MODE (x));
1444 return insn;
1445 }
1446
1447 counted_mem = false;
1448 set = single_set (insn);
1449 extract_insn (insn);
1450
1451 /* If this insn loads a parameter from its stack slot, then it
1452 represents a savings, rather than a cost, if the parameter is
1453 stored in memory. Record this fact.
1454
1455 Similarly if we're loading other constants from memory (constant
1456 pool, TOC references, small data areas, etc) and this is the only
1457 assignment to the destination pseudo.
1458
1459 Don't do this if SET_SRC (set) isn't a general operand, if it is
1460 a memory requiring special instructions to load it, decreasing
1461 mem_cost might result in it being loaded using the specialized
1462 instruction into a register, then stored into stack and loaded
1463 again from the stack. See PR52208.
1464
1465 Don't do this if SET_SRC (set) has side effect. See PR56124. */
1466 if (set != 0 && REG_P (SET_DEST (set)) && MEM_P (SET_SRC (set))
1467 && (note = find_reg_note (insn, REG_EQUIV, NULL_RTX)) != NULL_RTX
1468 && ((MEM_P (XEXP (note, 0))
1469 && !side_effects_p (SET_SRC (set)))
1470 || (CONSTANT_P (XEXP (note, 0))
1471 && targetm.legitimate_constant_p (GET_MODE (SET_DEST (set)),
1472 XEXP (note, 0))
1473 && REG_N_SETS (REGNO (SET_DEST (set))) == 1))
1474 && general_operand (SET_SRC (set), GET_MODE (SET_SRC (set)))
1475 /* LRA does not use equiv with a symbol for PIC code. */
1476 && (! ira_use_lra_p || ! pic_offset_table_rtx
1477 || ! contains_symbol_ref_p (XEXP (note, 0))))
1478 {
1479 enum reg_class cl = GENERAL_REGS;
1480 rtx reg = SET_DEST (set);
1481 int num = COST_INDEX (REGNO (reg));
1482
1483 COSTS (costs, num)->mem_cost
1484 -= ira_memory_move_cost[GET_MODE (reg)][cl][1] * frequency;
1485 record_address_regs (GET_MODE (SET_SRC (set)),
1486 MEM_ADDR_SPACE (SET_SRC (set)),
1487 XEXP (SET_SRC (set), 0), 0, MEM, SCRATCH,
1488 frequency * 2);
1489 counted_mem = true;
1490 }
1491
1492 record_operand_costs (insn, pref);
1493
1494 /* Now add the cost for each operand to the total costs for its
1495 allocno. */
1496 for (i = 0; i < recog_data.n_operands; i++)
1497 if (REG_P (recog_data.operand[i])
1498 && REGNO (recog_data.operand[i]) >= FIRST_PSEUDO_REGISTER)
1499 {
1500 int regno = REGNO (recog_data.operand[i]);
1501 struct costs *p = COSTS (costs, COST_INDEX (regno));
1502 struct costs *q = op_costs[i];
1503 int *p_costs = p->cost, *q_costs = q->cost;
1504 cost_classes_t cost_classes_ptr = regno_cost_classes[regno];
1505 int add_cost;
1506
1507 /* If the already accounted for the memory "cost" above, don't
1508 do so again. */
1509 if (!counted_mem)
1510 {
1511 add_cost = q->mem_cost;
1512 if (add_cost > 0 && INT_MAX - add_cost < p->mem_cost)
1513 p->mem_cost = INT_MAX;
1514 else
1515 p->mem_cost += add_cost;
1516 }
1517 for (k = cost_classes_ptr->num - 1; k >= 0; k--)
1518 {
1519 add_cost = q_costs[k];
1520 if (add_cost > 0 && INT_MAX - add_cost < p_costs[k])
1521 p_costs[k] = INT_MAX;
1522 else
1523 p_costs[k] += add_cost;
1524 }
1525 }
1526
1527 return insn;
1528 }
1529
1530
1531
1532 /* Print allocnos costs to file F. */
1533 static void
print_allocno_costs(FILE * f)1534 print_allocno_costs (FILE *f)
1535 {
1536 int k;
1537 ira_allocno_t a;
1538 ira_allocno_iterator ai;
1539
1540 ira_assert (allocno_p);
1541 fprintf (f, "\n");
1542 FOR_EACH_ALLOCNO (a, ai)
1543 {
1544 int i, rclass;
1545 basic_block bb;
1546 int regno = ALLOCNO_REGNO (a);
1547 cost_classes_t cost_classes_ptr = regno_cost_classes[regno];
1548 enum reg_class *cost_classes = cost_classes_ptr->classes;
1549
1550 i = ALLOCNO_NUM (a);
1551 fprintf (f, " a%d(r%d,", i, regno);
1552 if ((bb = ALLOCNO_LOOP_TREE_NODE (a)->bb) != NULL)
1553 fprintf (f, "b%d", bb->index);
1554 else
1555 fprintf (f, "l%d", ALLOCNO_LOOP_TREE_NODE (a)->loop_num);
1556 fprintf (f, ") costs:");
1557 for (k = 0; k < cost_classes_ptr->num; k++)
1558 {
1559 rclass = cost_classes[k];
1560 fprintf (f, " %s:%d", reg_class_names[rclass],
1561 COSTS (costs, i)->cost[k]);
1562 if (flag_ira_region == IRA_REGION_ALL
1563 || flag_ira_region == IRA_REGION_MIXED)
1564 fprintf (f, ",%d", COSTS (total_allocno_costs, i)->cost[k]);
1565 }
1566 fprintf (f, " MEM:%i", COSTS (costs, i)->mem_cost);
1567 if (flag_ira_region == IRA_REGION_ALL
1568 || flag_ira_region == IRA_REGION_MIXED)
1569 fprintf (f, ",%d", COSTS (total_allocno_costs, i)->mem_cost);
1570 fprintf (f, "\n");
1571 }
1572 }
1573
1574 /* Print pseudo costs to file F. */
1575 static void
print_pseudo_costs(FILE * f)1576 print_pseudo_costs (FILE *f)
1577 {
1578 int regno, k;
1579 int rclass;
1580 cost_classes_t cost_classes_ptr;
1581 enum reg_class *cost_classes;
1582
1583 ira_assert (! allocno_p);
1584 fprintf (f, "\n");
1585 for (regno = max_reg_num () - 1; regno >= FIRST_PSEUDO_REGISTER; regno--)
1586 {
1587 if (REG_N_REFS (regno) <= 0)
1588 continue;
1589 cost_classes_ptr = regno_cost_classes[regno];
1590 cost_classes = cost_classes_ptr->classes;
1591 fprintf (f, " r%d costs:", regno);
1592 for (k = 0; k < cost_classes_ptr->num; k++)
1593 {
1594 rclass = cost_classes[k];
1595 fprintf (f, " %s:%d", reg_class_names[rclass],
1596 COSTS (costs, regno)->cost[k]);
1597 }
1598 fprintf (f, " MEM:%i\n", COSTS (costs, regno)->mem_cost);
1599 }
1600 }
1601
1602 /* Traverse the BB represented by LOOP_TREE_NODE to update the allocno
1603 costs. */
1604 static void
process_bb_for_costs(basic_block bb)1605 process_bb_for_costs (basic_block bb)
1606 {
1607 rtx_insn *insn;
1608
1609 frequency = REG_FREQ_FROM_BB (bb);
1610 if (frequency == 0)
1611 frequency = 1;
1612 FOR_BB_INSNS (bb, insn)
1613 insn = scan_one_insn (insn);
1614 }
1615
1616 /* Traverse the BB represented by LOOP_TREE_NODE to update the allocno
1617 costs. */
1618 static void
process_bb_node_for_costs(ira_loop_tree_node_t loop_tree_node)1619 process_bb_node_for_costs (ira_loop_tree_node_t loop_tree_node)
1620 {
1621 basic_block bb;
1622
1623 bb = loop_tree_node->bb;
1624 if (bb != NULL)
1625 process_bb_for_costs (bb);
1626 }
1627
1628 /* Find costs of register classes and memory for allocnos or pseudos
1629 and their best costs. Set up preferred, alternative and allocno
1630 classes for pseudos. */
1631 static void
find_costs_and_classes(FILE * dump_file)1632 find_costs_and_classes (FILE *dump_file)
1633 {
1634 int i, k, start, max_cost_classes_num;
1635 int pass;
1636 basic_block bb;
1637 enum reg_class *regno_best_class, new_class;
1638
1639 init_recog ();
1640 regno_best_class
1641 = (enum reg_class *) ira_allocate (max_reg_num ()
1642 * sizeof (enum reg_class));
1643 for (i = max_reg_num () - 1; i >= FIRST_PSEUDO_REGISTER; i--)
1644 regno_best_class[i] = NO_REGS;
1645 if (!resize_reg_info () && allocno_p
1646 && pseudo_classes_defined_p && flag_expensive_optimizations)
1647 {
1648 ira_allocno_t a;
1649 ira_allocno_iterator ai;
1650
1651 pref = pref_buffer;
1652 max_cost_classes_num = 1;
1653 FOR_EACH_ALLOCNO (a, ai)
1654 {
1655 pref[ALLOCNO_NUM (a)] = reg_preferred_class (ALLOCNO_REGNO (a));
1656 setup_regno_cost_classes_by_aclass
1657 (ALLOCNO_REGNO (a), pref[ALLOCNO_NUM (a)]);
1658 max_cost_classes_num
1659 = MAX (max_cost_classes_num,
1660 regno_cost_classes[ALLOCNO_REGNO (a)]->num);
1661 }
1662 start = 1;
1663 }
1664 else
1665 {
1666 pref = NULL;
1667 max_cost_classes_num = ira_important_classes_num;
1668 for (i = max_reg_num () - 1; i >= FIRST_PSEUDO_REGISTER; i--)
1669 if (regno_reg_rtx[i] != NULL_RTX)
1670 setup_regno_cost_classes_by_mode (i, PSEUDO_REGNO_MODE (i));
1671 else
1672 setup_regno_cost_classes_by_aclass (i, ALL_REGS);
1673 start = 0;
1674 }
1675 if (allocno_p)
1676 /* Clear the flag for the next compiled function. */
1677 pseudo_classes_defined_p = false;
1678 /* Normally we scan the insns once and determine the best class to
1679 use for each allocno. However, if -fexpensive-optimizations are
1680 on, we do so twice, the second time using the tentative best
1681 classes to guide the selection. */
1682 for (pass = start; pass <= flag_expensive_optimizations; pass++)
1683 {
1684 if ((!allocno_p || internal_flag_ira_verbose > 0) && dump_file)
1685 fprintf (dump_file,
1686 "\nPass %i for finding pseudo/allocno costs\n\n", pass);
1687
1688 if (pass != start)
1689 {
1690 max_cost_classes_num = 1;
1691 for (i = max_reg_num () - 1; i >= FIRST_PSEUDO_REGISTER; i--)
1692 {
1693 setup_regno_cost_classes_by_aclass (i, regno_best_class[i]);
1694 max_cost_classes_num
1695 = MAX (max_cost_classes_num, regno_cost_classes[i]->num);
1696 }
1697 }
1698
1699 struct_costs_size
1700 = sizeof (struct costs) + sizeof (int) * (max_cost_classes_num - 1);
1701 /* Zero out our accumulation of the cost of each class for each
1702 allocno. */
1703 memset (costs, 0, cost_elements_num * struct_costs_size);
1704
1705 if (allocno_p)
1706 {
1707 /* Scan the instructions and record each time it would save code
1708 to put a certain allocno in a certain class. */
1709 ira_traverse_loop_tree (true, ira_loop_tree_root,
1710 process_bb_node_for_costs, NULL);
1711
1712 memcpy (total_allocno_costs, costs,
1713 max_struct_costs_size * ira_allocnos_num);
1714 }
1715 else
1716 {
1717 basic_block bb;
1718
1719 FOR_EACH_BB_FN (bb, cfun)
1720 process_bb_for_costs (bb);
1721 }
1722
1723 if (pass == 0)
1724 pref = pref_buffer;
1725
1726 /* Now for each allocno look at how desirable each class is and
1727 find which class is preferred. */
1728 for (i = max_reg_num () - 1; i >= FIRST_PSEUDO_REGISTER; i--)
1729 {
1730 ira_allocno_t a, parent_a;
1731 int rclass, a_num, parent_a_num, add_cost;
1732 ira_loop_tree_node_t parent;
1733 int best_cost, allocno_cost;
1734 enum reg_class best, alt_class;
1735 cost_classes_t cost_classes_ptr = regno_cost_classes[i];
1736 enum reg_class *cost_classes;
1737 int *i_costs = temp_costs->cost;
1738 int i_mem_cost;
1739 int equiv_savings = regno_equiv_gains[i];
1740
1741 if (! allocno_p)
1742 {
1743 if (regno_reg_rtx[i] == NULL_RTX)
1744 continue;
1745 memcpy (temp_costs, COSTS (costs, i), struct_costs_size);
1746 i_mem_cost = temp_costs->mem_cost;
1747 cost_classes = cost_classes_ptr->classes;
1748 }
1749 else
1750 {
1751 if (ira_regno_allocno_map[i] == NULL)
1752 continue;
1753 memset (temp_costs, 0, struct_costs_size);
1754 i_mem_cost = 0;
1755 cost_classes = cost_classes_ptr->classes;
1756 /* Find cost of all allocnos with the same regno. */
1757 for (a = ira_regno_allocno_map[i];
1758 a != NULL;
1759 a = ALLOCNO_NEXT_REGNO_ALLOCNO (a))
1760 {
1761 int *a_costs, *p_costs;
1762
1763 a_num = ALLOCNO_NUM (a);
1764 if ((flag_ira_region == IRA_REGION_ALL
1765 || flag_ira_region == IRA_REGION_MIXED)
1766 && (parent = ALLOCNO_LOOP_TREE_NODE (a)->parent) != NULL
1767 && (parent_a = parent->regno_allocno_map[i]) != NULL
1768 /* There are no caps yet. */
1769 && bitmap_bit_p (ALLOCNO_LOOP_TREE_NODE
1770 (a)->border_allocnos,
1771 ALLOCNO_NUM (a)))
1772 {
1773 /* Propagate costs to upper levels in the region
1774 tree. */
1775 parent_a_num = ALLOCNO_NUM (parent_a);
1776 a_costs = COSTS (total_allocno_costs, a_num)->cost;
1777 p_costs = COSTS (total_allocno_costs, parent_a_num)->cost;
1778 for (k = cost_classes_ptr->num - 1; k >= 0; k--)
1779 {
1780 add_cost = a_costs[k];
1781 if (add_cost > 0 && INT_MAX - add_cost < p_costs[k])
1782 p_costs[k] = INT_MAX;
1783 else
1784 p_costs[k] += add_cost;
1785 }
1786 add_cost = COSTS (total_allocno_costs, a_num)->mem_cost;
1787 if (add_cost > 0
1788 && (INT_MAX - add_cost
1789 < COSTS (total_allocno_costs,
1790 parent_a_num)->mem_cost))
1791 COSTS (total_allocno_costs, parent_a_num)->mem_cost
1792 = INT_MAX;
1793 else
1794 COSTS (total_allocno_costs, parent_a_num)->mem_cost
1795 += add_cost;
1796
1797 if (i >= first_moveable_pseudo && i < last_moveable_pseudo)
1798 COSTS (total_allocno_costs, parent_a_num)->mem_cost = 0;
1799 }
1800 a_costs = COSTS (costs, a_num)->cost;
1801 for (k = cost_classes_ptr->num - 1; k >= 0; k--)
1802 {
1803 add_cost = a_costs[k];
1804 if (add_cost > 0 && INT_MAX - add_cost < i_costs[k])
1805 i_costs[k] = INT_MAX;
1806 else
1807 i_costs[k] += add_cost;
1808 }
1809 add_cost = COSTS (costs, a_num)->mem_cost;
1810 if (add_cost > 0 && INT_MAX - add_cost < i_mem_cost)
1811 i_mem_cost = INT_MAX;
1812 else
1813 i_mem_cost += add_cost;
1814 }
1815 }
1816 if (i >= first_moveable_pseudo && i < last_moveable_pseudo)
1817 i_mem_cost = 0;
1818 else if (equiv_savings < 0)
1819 i_mem_cost = -equiv_savings;
1820 else if (equiv_savings > 0)
1821 {
1822 i_mem_cost = 0;
1823 for (k = cost_classes_ptr->num - 1; k >= 0; k--)
1824 i_costs[k] += equiv_savings;
1825 }
1826
1827 best_cost = (1 << (HOST_BITS_PER_INT - 2)) - 1;
1828 best = ALL_REGS;
1829 alt_class = NO_REGS;
1830 /* Find best common class for all allocnos with the same
1831 regno. */
1832 for (k = 0; k < cost_classes_ptr->num; k++)
1833 {
1834 rclass = cost_classes[k];
1835 if (i_costs[k] < best_cost)
1836 {
1837 best_cost = i_costs[k];
1838 best = (enum reg_class) rclass;
1839 }
1840 else if (i_costs[k] == best_cost)
1841 best = ira_reg_class_subunion[best][rclass];
1842 if (pass == flag_expensive_optimizations
1843 /* We still prefer registers to memory even at this
1844 stage if their costs are the same. We will make
1845 a final decision during assigning hard registers
1846 when we have all info including more accurate
1847 costs which might be affected by assigning hard
1848 registers to other pseudos because the pseudos
1849 involved in moves can be coalesced. */
1850 && i_costs[k] <= i_mem_cost
1851 && (reg_class_size[reg_class_subunion[alt_class][rclass]]
1852 > reg_class_size[alt_class]))
1853 alt_class = reg_class_subunion[alt_class][rclass];
1854 }
1855 alt_class = ira_allocno_class_translate[alt_class];
1856 if (best_cost > i_mem_cost
1857 && ! non_spilled_static_chain_regno_p (i))
1858 regno_aclass[i] = NO_REGS;
1859 else if (!optimize && !targetm.class_likely_spilled_p (best))
1860 /* Registers in the alternative class are likely to need
1861 longer or slower sequences than registers in the best class.
1862 When optimizing we make some effort to use the best class
1863 over the alternative class where possible, but at -O0 we
1864 effectively give the alternative class equal weight.
1865 We then run the risk of using slower alternative registers
1866 when plenty of registers from the best class are still free.
1867 This is especially true because live ranges tend to be very
1868 short in -O0 code and so register pressure tends to be low.
1869
1870 Avoid that by ignoring the alternative class if the best
1871 class has plenty of registers.
1872
1873 The union class arrays give important classes and only
1874 part of it are allocno classes. So translate them into
1875 allocno classes. */
1876 regno_aclass[i] = ira_allocno_class_translate[best];
1877 else
1878 {
1879 /* Make the common class the biggest class of best and
1880 alt_class. Translate the common class into an
1881 allocno class too. */
1882 regno_aclass[i] = (ira_allocno_class_translate
1883 [ira_reg_class_superunion[best][alt_class]]);
1884 ira_assert (regno_aclass[i] != NO_REGS
1885 && ira_reg_allocno_class_p[regno_aclass[i]]);
1886 }
1887 if ((new_class
1888 = (reg_class) (targetm.ira_change_pseudo_allocno_class
1889 (i, regno_aclass[i], best))) != regno_aclass[i])
1890 {
1891 regno_aclass[i] = new_class;
1892 if (hard_reg_set_subset_p (reg_class_contents[new_class],
1893 reg_class_contents[best]))
1894 best = new_class;
1895 if (hard_reg_set_subset_p (reg_class_contents[new_class],
1896 reg_class_contents[alt_class]))
1897 alt_class = new_class;
1898 }
1899 if (pass == flag_expensive_optimizations)
1900 {
1901 if (best_cost > i_mem_cost
1902 /* Do not assign NO_REGS to static chain pointer
1903 pseudo when non-local goto is used. */
1904 && ! non_spilled_static_chain_regno_p (i))
1905 best = alt_class = NO_REGS;
1906 else if (best == alt_class)
1907 alt_class = NO_REGS;
1908 setup_reg_classes (i, best, alt_class, regno_aclass[i]);
1909 if ((!allocno_p || internal_flag_ira_verbose > 2)
1910 && dump_file != NULL)
1911 fprintf (dump_file,
1912 " r%d: preferred %s, alternative %s, allocno %s\n",
1913 i, reg_class_names[best], reg_class_names[alt_class],
1914 reg_class_names[regno_aclass[i]]);
1915 }
1916 regno_best_class[i] = best;
1917 if (! allocno_p)
1918 {
1919 pref[i] = (best_cost > i_mem_cost
1920 && ! non_spilled_static_chain_regno_p (i)
1921 ? NO_REGS : best);
1922 continue;
1923 }
1924 for (a = ira_regno_allocno_map[i];
1925 a != NULL;
1926 a = ALLOCNO_NEXT_REGNO_ALLOCNO (a))
1927 {
1928 enum reg_class aclass = regno_aclass[i];
1929 int a_num = ALLOCNO_NUM (a);
1930 int *total_a_costs = COSTS (total_allocno_costs, a_num)->cost;
1931 int *a_costs = COSTS (costs, a_num)->cost;
1932
1933 if (aclass == NO_REGS)
1934 best = NO_REGS;
1935 else
1936 {
1937 /* Finding best class which is subset of the common
1938 class. */
1939 best_cost = (1 << (HOST_BITS_PER_INT - 2)) - 1;
1940 allocno_cost = best_cost;
1941 best = ALL_REGS;
1942 for (k = 0; k < cost_classes_ptr->num; k++)
1943 {
1944 rclass = cost_classes[k];
1945 if (! ira_class_subset_p[rclass][aclass])
1946 continue;
1947 if (total_a_costs[k] < best_cost)
1948 {
1949 best_cost = total_a_costs[k];
1950 allocno_cost = a_costs[k];
1951 best = (enum reg_class) rclass;
1952 }
1953 else if (total_a_costs[k] == best_cost)
1954 {
1955 best = ira_reg_class_subunion[best][rclass];
1956 allocno_cost = MAX (allocno_cost, a_costs[k]);
1957 }
1958 }
1959 ALLOCNO_CLASS_COST (a) = allocno_cost;
1960 }
1961 if (internal_flag_ira_verbose > 2 && dump_file != NULL
1962 && (pass == 0 || pref[a_num] != best))
1963 {
1964 fprintf (dump_file, " a%d (r%d,", a_num, i);
1965 if ((bb = ALLOCNO_LOOP_TREE_NODE (a)->bb) != NULL)
1966 fprintf (dump_file, "b%d", bb->index);
1967 else
1968 fprintf (dump_file, "l%d",
1969 ALLOCNO_LOOP_TREE_NODE (a)->loop_num);
1970 fprintf (dump_file, ") best %s, allocno %s\n",
1971 reg_class_names[best],
1972 reg_class_names[aclass]);
1973 }
1974 pref[a_num] = best;
1975 if (pass == flag_expensive_optimizations && best != aclass
1976 && ira_class_hard_regs_num[best] > 0
1977 && (ira_reg_class_max_nregs[best][ALLOCNO_MODE (a)]
1978 >= ira_class_hard_regs_num[best]))
1979 {
1980 int ind = cost_classes_ptr->index[aclass];
1981
1982 ira_assert (ind >= 0);
1983 ira_init_register_move_cost_if_necessary (ALLOCNO_MODE (a));
1984 ira_add_allocno_pref (a, ira_class_hard_regs[best][0],
1985 (a_costs[ind] - ALLOCNO_CLASS_COST (a))
1986 / (ira_register_move_cost
1987 [ALLOCNO_MODE (a)][best][aclass]));
1988 for (k = 0; k < cost_classes_ptr->num; k++)
1989 if (ira_class_subset_p[cost_classes[k]][best])
1990 a_costs[k] = a_costs[ind];
1991 }
1992 }
1993 }
1994
1995 if (internal_flag_ira_verbose > 4 && dump_file)
1996 {
1997 if (allocno_p)
1998 print_allocno_costs (dump_file);
1999 else
2000 print_pseudo_costs (dump_file);
2001 fprintf (dump_file,"\n");
2002 }
2003 }
2004 ira_free (regno_best_class);
2005 }
2006
2007
2008
2009 /* Process moves involving hard regs to modify allocno hard register
2010 costs. We can do this only after determining allocno class. If a
2011 hard register forms a register class, then moves with the hard
2012 register are already taken into account in class costs for the
2013 allocno. */
2014 static void
process_bb_node_for_hard_reg_moves(ira_loop_tree_node_t loop_tree_node)2015 process_bb_node_for_hard_reg_moves (ira_loop_tree_node_t loop_tree_node)
2016 {
2017 int i, freq, src_regno, dst_regno, hard_regno, a_regno;
2018 bool to_p;
2019 ira_allocno_t a, curr_a;
2020 ira_loop_tree_node_t curr_loop_tree_node;
2021 enum reg_class rclass;
2022 basic_block bb;
2023 rtx_insn *insn;
2024 rtx set, src, dst;
2025
2026 bb = loop_tree_node->bb;
2027 if (bb == NULL)
2028 return;
2029 freq = REG_FREQ_FROM_BB (bb);
2030 if (freq == 0)
2031 freq = 1;
2032 FOR_BB_INSNS (bb, insn)
2033 {
2034 if (!NONDEBUG_INSN_P (insn))
2035 continue;
2036 set = single_set (insn);
2037 if (set == NULL_RTX)
2038 continue;
2039 dst = SET_DEST (set);
2040 src = SET_SRC (set);
2041 if (! REG_P (dst) || ! REG_P (src))
2042 continue;
2043 dst_regno = REGNO (dst);
2044 src_regno = REGNO (src);
2045 if (dst_regno >= FIRST_PSEUDO_REGISTER
2046 && src_regno < FIRST_PSEUDO_REGISTER)
2047 {
2048 hard_regno = src_regno;
2049 a = ira_curr_regno_allocno_map[dst_regno];
2050 to_p = true;
2051 }
2052 else if (src_regno >= FIRST_PSEUDO_REGISTER
2053 && dst_regno < FIRST_PSEUDO_REGISTER)
2054 {
2055 hard_regno = dst_regno;
2056 a = ira_curr_regno_allocno_map[src_regno];
2057 to_p = false;
2058 }
2059 else
2060 continue;
2061 rclass = ALLOCNO_CLASS (a);
2062 if (! TEST_HARD_REG_BIT (reg_class_contents[rclass], hard_regno))
2063 continue;
2064 i = ira_class_hard_reg_index[rclass][hard_regno];
2065 if (i < 0)
2066 continue;
2067 a_regno = ALLOCNO_REGNO (a);
2068 for (curr_loop_tree_node = ALLOCNO_LOOP_TREE_NODE (a);
2069 curr_loop_tree_node != NULL;
2070 curr_loop_tree_node = curr_loop_tree_node->parent)
2071 if ((curr_a = curr_loop_tree_node->regno_allocno_map[a_regno]) != NULL)
2072 ira_add_allocno_pref (curr_a, hard_regno, freq);
2073 {
2074 int cost;
2075 enum reg_class hard_reg_class;
2076 machine_mode mode;
2077
2078 mode = ALLOCNO_MODE (a);
2079 hard_reg_class = REGNO_REG_CLASS (hard_regno);
2080 ira_init_register_move_cost_if_necessary (mode);
2081 cost = (to_p ? ira_register_move_cost[mode][hard_reg_class][rclass]
2082 : ira_register_move_cost[mode][rclass][hard_reg_class]) * freq;
2083 ira_allocate_and_set_costs (&ALLOCNO_HARD_REG_COSTS (a), rclass,
2084 ALLOCNO_CLASS_COST (a));
2085 ira_allocate_and_set_costs (&ALLOCNO_CONFLICT_HARD_REG_COSTS (a),
2086 rclass, 0);
2087 ALLOCNO_HARD_REG_COSTS (a)[i] -= cost;
2088 ALLOCNO_CONFLICT_HARD_REG_COSTS (a)[i] -= cost;
2089 ALLOCNO_CLASS_COST (a) = MIN (ALLOCNO_CLASS_COST (a),
2090 ALLOCNO_HARD_REG_COSTS (a)[i]);
2091 }
2092 }
2093 }
2094
2095 /* After we find hard register and memory costs for allocnos, define
2096 its class and modify hard register cost because insns moving
2097 allocno to/from hard registers. */
2098 static void
setup_allocno_class_and_costs(void)2099 setup_allocno_class_and_costs (void)
2100 {
2101 int i, j, n, regno, hard_regno, num;
2102 int *reg_costs;
2103 enum reg_class aclass, rclass;
2104 ira_allocno_t a;
2105 ira_allocno_iterator ai;
2106 cost_classes_t cost_classes_ptr;
2107
2108 ira_assert (allocno_p);
2109 FOR_EACH_ALLOCNO (a, ai)
2110 {
2111 i = ALLOCNO_NUM (a);
2112 regno = ALLOCNO_REGNO (a);
2113 aclass = regno_aclass[regno];
2114 cost_classes_ptr = regno_cost_classes[regno];
2115 ira_assert (pref[i] == NO_REGS || aclass != NO_REGS);
2116 ALLOCNO_MEMORY_COST (a) = COSTS (costs, i)->mem_cost;
2117 ira_set_allocno_class (a, aclass);
2118 if (aclass == NO_REGS)
2119 continue;
2120 if (optimize && ALLOCNO_CLASS (a) != pref[i])
2121 {
2122 n = ira_class_hard_regs_num[aclass];
2123 ALLOCNO_HARD_REG_COSTS (a)
2124 = reg_costs = ira_allocate_cost_vector (aclass);
2125 for (j = n - 1; j >= 0; j--)
2126 {
2127 hard_regno = ira_class_hard_regs[aclass][j];
2128 if (TEST_HARD_REG_BIT (reg_class_contents[pref[i]], hard_regno))
2129 reg_costs[j] = ALLOCNO_CLASS_COST (a);
2130 else
2131 {
2132 rclass = REGNO_REG_CLASS (hard_regno);
2133 num = cost_classes_ptr->index[rclass];
2134 if (num < 0)
2135 {
2136 num = cost_classes_ptr->hard_regno_index[hard_regno];
2137 ira_assert (num >= 0);
2138 }
2139 reg_costs[j] = COSTS (costs, i)->cost[num];
2140 }
2141 }
2142 }
2143 }
2144 if (optimize)
2145 ira_traverse_loop_tree (true, ira_loop_tree_root,
2146 process_bb_node_for_hard_reg_moves, NULL);
2147 }
2148
2149
2150
2151 /* Function called once during compiler work. */
2152 void
ira_init_costs_once(void)2153 ira_init_costs_once (void)
2154 {
2155 int i;
2156
2157 init_cost = NULL;
2158 for (i = 0; i < MAX_RECOG_OPERANDS; i++)
2159 {
2160 op_costs[i] = NULL;
2161 this_op_costs[i] = NULL;
2162 }
2163 temp_costs = NULL;
2164 }
2165
2166 /* Free allocated temporary cost vectors. */
2167 void
free_ira_costs()2168 target_ira_int::free_ira_costs ()
2169 {
2170 int i;
2171
2172 free (x_init_cost);
2173 x_init_cost = NULL;
2174 for (i = 0; i < MAX_RECOG_OPERANDS; i++)
2175 {
2176 free (x_op_costs[i]);
2177 free (x_this_op_costs[i]);
2178 x_op_costs[i] = x_this_op_costs[i] = NULL;
2179 }
2180 free (x_temp_costs);
2181 x_temp_costs = NULL;
2182 }
2183
2184 /* This is called each time register related information is
2185 changed. */
2186 void
ira_init_costs(void)2187 ira_init_costs (void)
2188 {
2189 int i;
2190
2191 this_target_ira_int->free_ira_costs ();
2192 max_struct_costs_size
2193 = sizeof (struct costs) + sizeof (int) * (ira_important_classes_num - 1);
2194 /* Don't use ira_allocate because vectors live through several IRA
2195 calls. */
2196 init_cost = (struct costs *) xmalloc (max_struct_costs_size);
2197 init_cost->mem_cost = 1000000;
2198 for (i = 0; i < ira_important_classes_num; i++)
2199 init_cost->cost[i] = 1000000;
2200 for (i = 0; i < MAX_RECOG_OPERANDS; i++)
2201 {
2202 op_costs[i] = (struct costs *) xmalloc (max_struct_costs_size);
2203 this_op_costs[i] = (struct costs *) xmalloc (max_struct_costs_size);
2204 }
2205 temp_costs = (struct costs *) xmalloc (max_struct_costs_size);
2206 }
2207
2208
2209
2210 /* Common initialization function for ira_costs and
2211 ira_set_pseudo_classes. */
2212 static void
init_costs(void)2213 init_costs (void)
2214 {
2215 init_subregs_of_mode ();
2216 costs = (struct costs *) ira_allocate (max_struct_costs_size
2217 * cost_elements_num);
2218 pref_buffer = (enum reg_class *) ira_allocate (sizeof (enum reg_class)
2219 * cost_elements_num);
2220 regno_aclass = (enum reg_class *) ira_allocate (sizeof (enum reg_class)
2221 * max_reg_num ());
2222 regno_equiv_gains = (int *) ira_allocate (sizeof (int) * max_reg_num ());
2223 memset (regno_equiv_gains, 0, sizeof (int) * max_reg_num ());
2224 }
2225
2226 /* Common finalization function for ira_costs and
2227 ira_set_pseudo_classes. */
2228 static void
finish_costs(void)2229 finish_costs (void)
2230 {
2231 finish_subregs_of_mode ();
2232 ira_free (regno_equiv_gains);
2233 ira_free (regno_aclass);
2234 ira_free (pref_buffer);
2235 ira_free (costs);
2236 }
2237
2238 /* Entry function which defines register class, memory and hard
2239 register costs for each allocno. */
2240 void
ira_costs(void)2241 ira_costs (void)
2242 {
2243 allocno_p = true;
2244 cost_elements_num = ira_allocnos_num;
2245 init_costs ();
2246 total_allocno_costs = (struct costs *) ira_allocate (max_struct_costs_size
2247 * ira_allocnos_num);
2248 initiate_regno_cost_classes ();
2249 calculate_elim_costs_all_insns ();
2250 find_costs_and_classes (ira_dump_file);
2251 setup_allocno_class_and_costs ();
2252 finish_regno_cost_classes ();
2253 finish_costs ();
2254 ira_free (total_allocno_costs);
2255 }
2256
2257 /* Entry function which defines classes for pseudos.
2258 Set pseudo_classes_defined_p only if DEFINE_PSEUDO_CLASSES is true. */
2259 void
ira_set_pseudo_classes(bool define_pseudo_classes,FILE * dump_file)2260 ira_set_pseudo_classes (bool define_pseudo_classes, FILE *dump_file)
2261 {
2262 allocno_p = false;
2263 internal_flag_ira_verbose = flag_ira_verbose;
2264 cost_elements_num = max_reg_num ();
2265 init_costs ();
2266 initiate_regno_cost_classes ();
2267 find_costs_and_classes (dump_file);
2268 finish_regno_cost_classes ();
2269 if (define_pseudo_classes)
2270 pseudo_classes_defined_p = true;
2271
2272 finish_costs ();
2273 }
2274
2275
2276
2277 /* Change hard register costs for allocnos which lives through
2278 function calls. This is called only when we found all intersected
2279 calls during building allocno live ranges. */
2280 void
ira_tune_allocno_costs(void)2281 ira_tune_allocno_costs (void)
2282 {
2283 int j, n, regno;
2284 int cost, min_cost, *reg_costs;
2285 enum reg_class aclass, rclass;
2286 machine_mode mode;
2287 ira_allocno_t a;
2288 ira_allocno_iterator ai;
2289 ira_allocno_object_iterator oi;
2290 ira_object_t obj;
2291 bool skip_p;
2292 HARD_REG_SET *crossed_calls_clobber_regs;
2293
2294 FOR_EACH_ALLOCNO (a, ai)
2295 {
2296 aclass = ALLOCNO_CLASS (a);
2297 if (aclass == NO_REGS)
2298 continue;
2299 mode = ALLOCNO_MODE (a);
2300 n = ira_class_hard_regs_num[aclass];
2301 min_cost = INT_MAX;
2302 if (ALLOCNO_CALLS_CROSSED_NUM (a)
2303 != ALLOCNO_CHEAP_CALLS_CROSSED_NUM (a))
2304 {
2305 ira_allocate_and_set_costs
2306 (&ALLOCNO_HARD_REG_COSTS (a), aclass,
2307 ALLOCNO_CLASS_COST (a));
2308 reg_costs = ALLOCNO_HARD_REG_COSTS (a);
2309 for (j = n - 1; j >= 0; j--)
2310 {
2311 regno = ira_class_hard_regs[aclass][j];
2312 skip_p = false;
2313 FOR_EACH_ALLOCNO_OBJECT (a, obj, oi)
2314 {
2315 if (ira_hard_reg_set_intersection_p (regno, mode,
2316 OBJECT_CONFLICT_HARD_REGS
2317 (obj)))
2318 {
2319 skip_p = true;
2320 break;
2321 }
2322 }
2323 if (skip_p)
2324 continue;
2325 rclass = REGNO_REG_CLASS (regno);
2326 cost = 0;
2327 crossed_calls_clobber_regs
2328 = &(ALLOCNO_CROSSED_CALLS_CLOBBERED_REGS (a));
2329 if (ira_hard_reg_set_intersection_p (regno, mode,
2330 *crossed_calls_clobber_regs)
2331 && (ira_hard_reg_set_intersection_p (regno, mode,
2332 call_used_reg_set)
2333 || targetm.hard_regno_call_part_clobbered (regno,
2334 mode)))
2335 cost += (ALLOCNO_CALL_FREQ (a)
2336 * (ira_memory_move_cost[mode][rclass][0]
2337 + ira_memory_move_cost[mode][rclass][1]));
2338 #ifdef IRA_HARD_REGNO_ADD_COST_MULTIPLIER
2339 cost += ((ira_memory_move_cost[mode][rclass][0]
2340 + ira_memory_move_cost[mode][rclass][1])
2341 * ALLOCNO_FREQ (a)
2342 * IRA_HARD_REGNO_ADD_COST_MULTIPLIER (regno) / 2);
2343 #endif
2344 if (INT_MAX - cost < reg_costs[j])
2345 reg_costs[j] = INT_MAX;
2346 else
2347 reg_costs[j] += cost;
2348 if (min_cost > reg_costs[j])
2349 min_cost = reg_costs[j];
2350 }
2351 }
2352 if (min_cost != INT_MAX)
2353 ALLOCNO_CLASS_COST (a) = min_cost;
2354
2355 /* Some targets allow pseudos to be allocated to unaligned sequences
2356 of hard registers. However, selecting an unaligned sequence can
2357 unnecessarily restrict later allocations. So increase the cost of
2358 unaligned hard regs to encourage the use of aligned hard regs. */
2359 {
2360 const int nregs = ira_reg_class_max_nregs[aclass][ALLOCNO_MODE (a)];
2361
2362 if (nregs > 1)
2363 {
2364 ira_allocate_and_set_costs
2365 (&ALLOCNO_HARD_REG_COSTS (a), aclass, ALLOCNO_CLASS_COST (a));
2366 reg_costs = ALLOCNO_HARD_REG_COSTS (a);
2367 for (j = n - 1; j >= 0; j--)
2368 {
2369 regno = ira_non_ordered_class_hard_regs[aclass][j];
2370 if ((regno % nregs) != 0)
2371 {
2372 int index = ira_class_hard_reg_index[aclass][regno];
2373 ira_assert (index != -1);
2374 reg_costs[index] += ALLOCNO_FREQ (a);
2375 }
2376 }
2377 }
2378 }
2379 }
2380 }
2381
2382 /* Add COST to the estimated gain for eliminating REGNO with its
2383 equivalence. If COST is zero, record that no such elimination is
2384 possible. */
2385
2386 void
ira_adjust_equiv_reg_cost(unsigned regno,int cost)2387 ira_adjust_equiv_reg_cost (unsigned regno, int cost)
2388 {
2389 if (cost == 0)
2390 regno_equiv_gains[regno] = 0;
2391 else
2392 regno_equiv_gains[regno] += cost;
2393 }
2394
2395 void
ira_costs_c_finalize(void)2396 ira_costs_c_finalize (void)
2397 {
2398 this_target_ira_int->free_ira_costs ();
2399 }
2400