* lib/ubsan-dg.exp (check_effective_target_fsanitize_undefined):
[official-gcc.git] / gcc / lra-spills.c
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1 /* Change pseudos by memory.
2 Copyright (C) 2010-2014 Free Software Foundation, Inc.
3 Contributed by Vladimir Makarov <vmakarov@redhat.com>.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
10 version.
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
22 /* This file contains code for a pass to change spilled pseudos into
23 memory.
25 The pass creates necessary stack slots and assigns spilled pseudos
26 to the stack slots in following way:
28 for all spilled pseudos P most frequently used first do
29 for all stack slots S do
30 if P doesn't conflict with pseudos assigned to S then
31 assign S to P and goto to the next pseudo process
32 end
33 end
34 create new stack slot S and assign P to S
35 end
37 The actual algorithm is bit more complicated because of different
38 pseudo sizes.
40 After that the code changes spilled pseudos (except ones created
41 from scratches) by corresponding stack slot memory in RTL.
43 If at least one stack slot was created, we need to run more passes
44 because we have new addresses which should be checked and because
45 the old address displacements might change and address constraints
46 (or insn memory constraints) might not be satisfied any more.
48 For some targets, the pass can spill some pseudos into hard
49 registers of different class (usually into vector registers)
50 instead of spilling them into memory if it is possible and
51 profitable. Spilling GENERAL_REGS pseudo into SSE registers for
52 Intel Corei7 is an example of such optimization. And this is
53 actually recommended by Intel optimization guide.
55 The file also contains code for final change of pseudos on hard
56 regs correspondingly assigned to them. */
58 #include "config.h"
59 #include "system.h"
60 #include "coretypes.h"
61 #include "tm.h"
62 #include "rtl.h"
63 #include "tm_p.h"
64 #include "insn-config.h"
65 #include "recog.h"
66 #include "output.h"
67 #include "regs.h"
68 #include "hard-reg-set.h"
69 #include "flags.h"
70 #include "hashtab.h"
71 #include "hash-set.h"
72 #include "vec.h"
73 #include "machmode.h"
74 #include "input.h"
75 #include "function.h"
76 #include "expr.h"
77 #include "predict.h"
78 #include "dominance.h"
79 #include "cfg.h"
80 #include "cfgrtl.h"
81 #include "basic-block.h"
82 #include "except.h"
83 #include "timevar.h"
84 #include "target.h"
85 #include "lra-int.h"
86 #include "ira.h"
87 #include "df.h"
90 /* Max regno at the start of the pass. */
91 static int regs_num;
93 /* Map spilled regno -> hard regno used instead of memory for
94 spilling. */
95 static rtx *spill_hard_reg;
97 /* The structure describes stack slot of a spilled pseudo. */
98 struct pseudo_slot
100 /* Number (0, 1, ...) of the stack slot to which given pseudo
101 belongs. */
102 int slot_num;
103 /* First or next slot with the same slot number. */
104 struct pseudo_slot *next, *first;
105 /* Memory representing the spilled pseudo. */
106 rtx mem;
109 /* The stack slots for each spilled pseudo. Indexed by regnos. */
110 static struct pseudo_slot *pseudo_slots;
112 /* The structure describes a register or a stack slot which can be
113 used for several spilled pseudos. */
114 struct slot
116 /* First pseudo with given stack slot. */
117 int regno;
118 /* Hard reg into which the slot pseudos are spilled. The value is
119 negative for pseudos spilled into memory. */
120 int hard_regno;
121 /* Memory representing the all stack slot. It can be different from
122 memory representing a pseudo belonging to give stack slot because
123 pseudo can be placed in a part of the corresponding stack slot.
124 The value is NULL for pseudos spilled into a hard reg. */
125 rtx mem;
126 /* Combined live ranges of all pseudos belonging to given slot. It
127 is used to figure out that a new spilled pseudo can use given
128 stack slot. */
129 lra_live_range_t live_ranges;
132 /* Array containing info about the stack slots. The array element is
133 indexed by the stack slot number in the range [0..slots_num). */
134 static struct slot *slots;
135 /* The number of the stack slots currently existing. */
136 static int slots_num;
138 /* Set up memory of the spilled pseudo I. The function can allocate
139 the corresponding stack slot if it is not done yet. */
140 static void
141 assign_mem_slot (int i)
143 rtx x = NULL_RTX;
144 machine_mode mode = GET_MODE (regno_reg_rtx[i]);
145 unsigned int inherent_size = PSEUDO_REGNO_BYTES (i);
146 unsigned int inherent_align = GET_MODE_ALIGNMENT (mode);
147 unsigned int max_ref_width = GET_MODE_SIZE (lra_reg_info[i].biggest_mode);
148 unsigned int total_size = MAX (inherent_size, max_ref_width);
149 unsigned int min_align = max_ref_width * BITS_PER_UNIT;
150 int adjust = 0;
152 lra_assert (regno_reg_rtx[i] != NULL_RTX && REG_P (regno_reg_rtx[i])
153 && lra_reg_info[i].nrefs != 0 && reg_renumber[i] < 0);
155 x = slots[pseudo_slots[i].slot_num].mem;
157 /* We can use a slot already allocated because it is guaranteed the
158 slot provides both enough inherent space and enough total
159 space. */
160 if (x)
162 /* Each pseudo has an inherent size which comes from its own mode,
163 and a total size which provides room for paradoxical subregs
164 which refer to the pseudo reg in wider modes. We allocate a new
165 slot, making sure that it has enough inherent space and total
166 space. */
167 else
169 rtx stack_slot;
171 /* No known place to spill from => no slot to reuse. */
172 x = assign_stack_local (mode, total_size,
173 min_align > inherent_align
174 || total_size > inherent_size ? -1 : 0);
175 stack_slot = x;
176 /* Cancel the big-endian correction done in assign_stack_local.
177 Get the address of the beginning of the slot. This is so we
178 can do a big-endian correction unconditionally below. */
179 if (BYTES_BIG_ENDIAN)
181 adjust = inherent_size - total_size;
182 if (adjust)
183 stack_slot
184 = adjust_address_nv (x,
185 mode_for_size (total_size * BITS_PER_UNIT,
186 MODE_INT, 1),
187 adjust);
189 slots[pseudo_slots[i].slot_num].mem = stack_slot;
192 /* On a big endian machine, the "address" of the slot is the address
193 of the low part that fits its inherent mode. */
194 if (BYTES_BIG_ENDIAN && inherent_size < total_size)
195 adjust += (total_size - inherent_size);
197 x = adjust_address_nv (x, GET_MODE (regno_reg_rtx[i]), adjust);
199 /* Set all of the memory attributes as appropriate for a spill. */
200 set_mem_attrs_for_spill (x);
201 pseudo_slots[i].mem = x;
204 /* Sort pseudos according their usage frequencies. */
205 static int
206 regno_freq_compare (const void *v1p, const void *v2p)
208 const int regno1 = *(const int *) v1p;
209 const int regno2 = *(const int *) v2p;
210 int diff;
212 if ((diff = lra_reg_info[regno2].freq - lra_reg_info[regno1].freq) != 0)
213 return diff;
214 return regno1 - regno2;
217 /* Redefine STACK_GROWS_DOWNWARD in terms of 0 or 1. */
218 #ifdef STACK_GROWS_DOWNWARD
219 # undef STACK_GROWS_DOWNWARD
220 # define STACK_GROWS_DOWNWARD 1
221 #else
222 # define STACK_GROWS_DOWNWARD 0
223 #endif
225 /* Sort pseudos according to their slots, putting the slots in the order
226 that they should be allocated. Slots with lower numbers have the highest
227 priority and should get the smallest displacement from the stack or
228 frame pointer (whichever is being used).
230 The first allocated slot is always closest to the frame pointer,
231 so prefer lower slot numbers when frame_pointer_needed. If the stack
232 and frame grow in the same direction, then the first allocated slot is
233 always closest to the initial stack pointer and furthest away from the
234 final stack pointer, so allocate higher numbers first when using the
235 stack pointer in that case. The reverse is true if the stack and
236 frame grow in opposite directions. */
237 static int
238 pseudo_reg_slot_compare (const void *v1p, const void *v2p)
240 const int regno1 = *(const int *) v1p;
241 const int regno2 = *(const int *) v2p;
242 int diff, slot_num1, slot_num2;
243 int total_size1, total_size2;
245 slot_num1 = pseudo_slots[regno1].slot_num;
246 slot_num2 = pseudo_slots[regno2].slot_num;
247 if ((diff = slot_num1 - slot_num2) != 0)
248 return (frame_pointer_needed
249 || (!FRAME_GROWS_DOWNWARD) == STACK_GROWS_DOWNWARD ? diff : -diff);
250 total_size1 = GET_MODE_SIZE (lra_reg_info[regno1].biggest_mode);
251 total_size2 = GET_MODE_SIZE (lra_reg_info[regno2].biggest_mode);
252 if ((diff = total_size2 - total_size1) != 0)
253 return diff;
254 return regno1 - regno2;
257 /* Assign spill hard registers to N pseudos in PSEUDO_REGNOS which is
258 sorted in order of highest frequency first. Put the pseudos which
259 did not get a spill hard register at the beginning of array
260 PSEUDO_REGNOS. Return the number of such pseudos. */
261 static int
262 assign_spill_hard_regs (int *pseudo_regnos, int n)
264 int i, k, p, regno, res, spill_class_size, hard_regno, nr;
265 enum reg_class rclass, spill_class;
266 machine_mode mode;
267 lra_live_range_t r;
268 rtx_insn *insn;
269 rtx set;
270 basic_block bb;
271 HARD_REG_SET conflict_hard_regs;
272 bitmap_head ok_insn_bitmap;
273 bitmap setjump_crosses = regstat_get_setjmp_crosses ();
274 /* Hard registers which can not be used for any purpose at given
275 program point because they are unallocatable or already allocated
276 for other pseudos. */
277 HARD_REG_SET *reserved_hard_regs;
279 if (! lra_reg_spill_p)
280 return n;
281 /* Set up reserved hard regs for every program point. */
282 reserved_hard_regs = XNEWVEC (HARD_REG_SET, lra_live_max_point);
283 for (p = 0; p < lra_live_max_point; p++)
284 COPY_HARD_REG_SET (reserved_hard_regs[p], lra_no_alloc_regs);
285 for (i = FIRST_PSEUDO_REGISTER; i < regs_num; i++)
286 if (lra_reg_info[i].nrefs != 0
287 && (hard_regno = lra_get_regno_hard_regno (i)) >= 0)
288 for (r = lra_reg_info[i].live_ranges; r != NULL; r = r->next)
289 for (p = r->start; p <= r->finish; p++)
290 add_to_hard_reg_set (&reserved_hard_regs[p],
291 lra_reg_info[i].biggest_mode, hard_regno);
292 bitmap_initialize (&ok_insn_bitmap, &reg_obstack);
293 FOR_EACH_BB_FN (bb, cfun)
294 FOR_BB_INSNS (bb, insn)
295 if (DEBUG_INSN_P (insn)
296 || ((set = single_set (insn)) != NULL_RTX
297 && REG_P (SET_SRC (set)) && REG_P (SET_DEST (set))))
298 bitmap_set_bit (&ok_insn_bitmap, INSN_UID (insn));
299 for (res = i = 0; i < n; i++)
301 regno = pseudo_regnos[i];
302 rclass = lra_get_allocno_class (regno);
303 if (bitmap_bit_p (setjump_crosses, regno)
304 || (spill_class
305 = ((enum reg_class)
306 targetm.spill_class ((reg_class_t) rclass,
307 PSEUDO_REGNO_MODE (regno)))) == NO_REGS
308 || bitmap_intersect_compl_p (&lra_reg_info[regno].insn_bitmap,
309 &ok_insn_bitmap))
311 pseudo_regnos[res++] = regno;
312 continue;
314 lra_assert (spill_class != NO_REGS);
315 COPY_HARD_REG_SET (conflict_hard_regs,
316 lra_reg_info[regno].conflict_hard_regs);
317 for (r = lra_reg_info[regno].live_ranges; r != NULL; r = r->next)
318 for (p = r->start; p <= r->finish; p++)
319 IOR_HARD_REG_SET (conflict_hard_regs, reserved_hard_regs[p]);
320 spill_class_size = ira_class_hard_regs_num[spill_class];
321 mode = lra_reg_info[regno].biggest_mode;
322 for (k = 0; k < spill_class_size; k++)
324 hard_regno = ira_class_hard_regs[spill_class][k];
325 if (! overlaps_hard_reg_set_p (conflict_hard_regs, mode, hard_regno))
326 break;
328 if (k >= spill_class_size)
330 /* There is no available regs -- assign memory later. */
331 pseudo_regnos[res++] = regno;
332 continue;
334 if (lra_dump_file != NULL)
335 fprintf (lra_dump_file, " Spill r%d into hr%d\n", regno, hard_regno);
336 /* Update reserved_hard_regs. */
337 for (r = lra_reg_info[regno].live_ranges; r != NULL; r = r->next)
338 for (p = r->start; p <= r->finish; p++)
339 add_to_hard_reg_set (&reserved_hard_regs[p],
340 lra_reg_info[regno].biggest_mode, hard_regno);
341 spill_hard_reg[regno]
342 = gen_raw_REG (PSEUDO_REGNO_MODE (regno), hard_regno);
343 for (nr = 0;
344 nr < hard_regno_nregs[hard_regno][lra_reg_info[regno].biggest_mode];
345 nr++)
346 /* Just loop. */
347 df_set_regs_ever_live (hard_regno + nr, true);
349 bitmap_clear (&ok_insn_bitmap);
350 free (reserved_hard_regs);
351 return res;
354 /* Add pseudo REGNO to slot SLOT_NUM. */
355 static void
356 add_pseudo_to_slot (int regno, int slot_num)
358 struct pseudo_slot *first;
360 if (slots[slot_num].regno < 0)
362 /* It is the first pseudo in the slot. */
363 slots[slot_num].regno = regno;
364 pseudo_slots[regno].first = &pseudo_slots[regno];
365 pseudo_slots[regno].next = NULL;
367 else
369 first = pseudo_slots[regno].first = &pseudo_slots[slots[slot_num].regno];
370 pseudo_slots[regno].next = first->next;
371 first->next = &pseudo_slots[regno];
373 pseudo_slots[regno].mem = NULL_RTX;
374 pseudo_slots[regno].slot_num = slot_num;
375 slots[slot_num].live_ranges
376 = lra_merge_live_ranges (slots[slot_num].live_ranges,
377 lra_copy_live_range_list
378 (lra_reg_info[regno].live_ranges));
381 /* Assign stack slot numbers to pseudos in array PSEUDO_REGNOS of
382 length N. Sort pseudos in PSEUDO_REGNOS for subsequent assigning
383 memory stack slots. */
384 static void
385 assign_stack_slot_num_and_sort_pseudos (int *pseudo_regnos, int n)
387 int i, j, regno;
389 slots_num = 0;
390 /* Assign stack slot numbers to spilled pseudos, use smaller numbers
391 for most frequently used pseudos. */
392 for (i = 0; i < n; i++)
394 regno = pseudo_regnos[i];
395 if (! flag_ira_share_spill_slots)
396 j = slots_num;
397 else
399 for (j = 0; j < slots_num; j++)
400 if (slots[j].hard_regno < 0
401 && ! (lra_intersected_live_ranges_p
402 (slots[j].live_ranges,
403 lra_reg_info[regno].live_ranges)))
404 break;
406 if (j >= slots_num)
408 /* New slot. */
409 slots[j].live_ranges = NULL;
410 slots[j].regno = slots[j].hard_regno = -1;
411 slots[j].mem = NULL_RTX;
412 slots_num++;
414 add_pseudo_to_slot (regno, j);
416 /* Sort regnos according to their slot numbers. */
417 qsort (pseudo_regnos, n, sizeof (int), pseudo_reg_slot_compare);
420 /* Recursively process LOC in INSN and change spilled pseudos to the
421 corresponding memory or spilled hard reg. Ignore spilled pseudos
422 created from the scratches. */
423 static void
424 remove_pseudos (rtx *loc, rtx_insn *insn)
426 int i;
427 rtx hard_reg;
428 const char *fmt;
429 enum rtx_code code;
431 if (*loc == NULL_RTX)
432 return;
433 code = GET_CODE (*loc);
434 if (code == REG && (i = REGNO (*loc)) >= FIRST_PSEUDO_REGISTER
435 && lra_get_regno_hard_regno (i) < 0
436 /* We do not want to assign memory for former scratches because
437 it might result in an address reload for some targets. In
438 any case we transform such pseudos not getting hard registers
439 into scratches back. */
440 && ! lra_former_scratch_p (i))
442 if ((hard_reg = spill_hard_reg[i]) != NULL_RTX)
443 *loc = copy_rtx (hard_reg);
444 else
446 rtx x = lra_eliminate_regs_1 (insn, pseudo_slots[i].mem,
447 GET_MODE (pseudo_slots[i].mem),
448 0, false, false, true);
449 *loc = x != pseudo_slots[i].mem ? x : copy_rtx (x);
451 return;
454 fmt = GET_RTX_FORMAT (code);
455 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
457 if (fmt[i] == 'e')
458 remove_pseudos (&XEXP (*loc, i), insn);
459 else if (fmt[i] == 'E')
461 int j;
463 for (j = XVECLEN (*loc, i) - 1; j >= 0; j--)
464 remove_pseudos (&XVECEXP (*loc, i, j), insn);
469 /* Convert spilled pseudos into their stack slots or spill hard regs,
470 put insns to process on the constraint stack (that is all insns in
471 which pseudos were changed to memory or spill hard regs). */
472 static void
473 spill_pseudos (void)
475 basic_block bb;
476 rtx_insn *insn;
477 int i;
478 bitmap_head spilled_pseudos, changed_insns;
480 bitmap_initialize (&spilled_pseudos, &reg_obstack);
481 bitmap_initialize (&changed_insns, &reg_obstack);
482 for (i = FIRST_PSEUDO_REGISTER; i < regs_num; i++)
484 if (lra_reg_info[i].nrefs != 0 && lra_get_regno_hard_regno (i) < 0
485 && ! lra_former_scratch_p (i))
487 bitmap_set_bit (&spilled_pseudos, i);
488 bitmap_ior_into (&changed_insns, &lra_reg_info[i].insn_bitmap);
491 FOR_EACH_BB_FN (bb, cfun)
493 FOR_BB_INSNS (bb, insn)
494 if (bitmap_bit_p (&changed_insns, INSN_UID (insn)))
496 rtx *link_loc, link;
497 remove_pseudos (&PATTERN (insn), insn);
498 if (CALL_P (insn))
499 remove_pseudos (&CALL_INSN_FUNCTION_USAGE (insn), insn);
500 for (link_loc = &REG_NOTES (insn);
501 (link = *link_loc) != NULL_RTX;
502 link_loc = &XEXP (link, 1))
504 switch (REG_NOTE_KIND (link))
506 case REG_FRAME_RELATED_EXPR:
507 case REG_CFA_DEF_CFA:
508 case REG_CFA_ADJUST_CFA:
509 case REG_CFA_OFFSET:
510 case REG_CFA_REGISTER:
511 case REG_CFA_EXPRESSION:
512 case REG_CFA_RESTORE:
513 case REG_CFA_SET_VDRAP:
514 remove_pseudos (&XEXP (link, 0), insn);
515 break;
516 default:
517 break;
520 if (lra_dump_file != NULL)
521 fprintf (lra_dump_file,
522 "Changing spilled pseudos to memory in insn #%u\n",
523 INSN_UID (insn));
524 lra_push_insn (insn);
525 if (lra_reg_spill_p || targetm.different_addr_displacement_p ())
526 lra_set_used_insn_alternative (insn, -1);
528 else if (CALL_P (insn))
529 /* Presence of any pseudo in CALL_INSN_FUNCTION_USAGE does
530 not affect value of insn_bitmap of the corresponding
531 lra_reg_info. That is because we don't need to reload
532 pseudos in CALL_INSN_FUNCTION_USAGEs. So if we process
533 only insns in the insn_bitmap of given pseudo here, we
534 can miss the pseudo in some
535 CALL_INSN_FUNCTION_USAGEs. */
536 remove_pseudos (&CALL_INSN_FUNCTION_USAGE (insn), insn);
537 bitmap_and_compl_into (df_get_live_in (bb), &spilled_pseudos);
538 bitmap_and_compl_into (df_get_live_out (bb), &spilled_pseudos);
540 bitmap_clear (&spilled_pseudos);
541 bitmap_clear (&changed_insns);
544 /* Return true if we need to change some pseudos into memory. */
545 bool
546 lra_need_for_spills_p (void)
548 int i; max_regno = max_reg_num ();
550 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
551 if (lra_reg_info[i].nrefs != 0 && lra_get_regno_hard_regno (i) < 0
552 && ! lra_former_scratch_p (i))
553 return true;
554 return false;
557 /* Change spilled pseudos into memory or spill hard regs. Put changed
558 insns on the constraint stack (these insns will be considered on
559 the next constraint pass). The changed insns are all insns in
560 which pseudos were changed. */
561 void
562 lra_spill (void)
564 int i, n, curr_regno;
565 int *pseudo_regnos;
567 regs_num = max_reg_num ();
568 spill_hard_reg = XNEWVEC (rtx, regs_num);
569 pseudo_regnos = XNEWVEC (int, regs_num);
570 for (n = 0, i = FIRST_PSEUDO_REGISTER; i < regs_num; i++)
571 if (lra_reg_info[i].nrefs != 0 && lra_get_regno_hard_regno (i) < 0
572 /* We do not want to assign memory for former scratches. */
573 && ! lra_former_scratch_p (i))
575 spill_hard_reg[i] = NULL_RTX;
576 pseudo_regnos[n++] = i;
578 lra_assert (n > 0);
579 pseudo_slots = XNEWVEC (struct pseudo_slot, regs_num);
580 slots = XNEWVEC (struct slot, regs_num);
581 /* Sort regnos according their usage frequencies. */
582 qsort (pseudo_regnos, n, sizeof (int), regno_freq_compare);
583 n = assign_spill_hard_regs (pseudo_regnos, n);
584 assign_stack_slot_num_and_sort_pseudos (pseudo_regnos, n);
585 for (i = 0; i < n; i++)
586 if (pseudo_slots[pseudo_regnos[i]].mem == NULL_RTX)
587 assign_mem_slot (pseudo_regnos[i]);
588 if (n > 0 && crtl->stack_alignment_needed)
589 /* If we have a stack frame, we must align it now. The stack size
590 may be a part of the offset computation for register
591 elimination. */
592 assign_stack_local (BLKmode, 0, crtl->stack_alignment_needed);
593 if (lra_dump_file != NULL)
595 for (i = 0; i < slots_num; i++)
597 fprintf (lra_dump_file, " Slot %d regnos (width = %d):", i,
598 GET_MODE_SIZE (GET_MODE (slots[i].mem)));
599 for (curr_regno = slots[i].regno;;
600 curr_regno = pseudo_slots[curr_regno].next - pseudo_slots)
602 fprintf (lra_dump_file, " %d", curr_regno);
603 if (pseudo_slots[curr_regno].next == NULL)
604 break;
606 fprintf (lra_dump_file, "\n");
609 spill_pseudos ();
610 free (slots);
611 free (pseudo_slots);
612 free (pseudo_regnos);
613 free (spill_hard_reg);
616 /* Apply alter_subreg for subregs of regs in *LOC. Use FINAL_P for
617 alter_subreg calls. Return true if any subreg of reg is
618 processed. */
619 static bool
620 alter_subregs (rtx *loc, bool final_p)
622 int i;
623 rtx x = *loc;
624 bool res;
625 const char *fmt;
626 enum rtx_code code;
628 if (x == NULL_RTX)
629 return false;
630 code = GET_CODE (x);
631 if (code == SUBREG && REG_P (SUBREG_REG (x)))
633 lra_assert (REGNO (SUBREG_REG (x)) < FIRST_PSEUDO_REGISTER);
634 alter_subreg (loc, final_p);
635 return true;
637 fmt = GET_RTX_FORMAT (code);
638 res = false;
639 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
641 if (fmt[i] == 'e')
643 if (alter_subregs (&XEXP (x, i), final_p))
644 res = true;
646 else if (fmt[i] == 'E')
648 int j;
650 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
651 if (alter_subregs (&XVECEXP (x, i, j), final_p))
652 res = true;
655 return res;
658 /* Return true if REGNO is used for return in the current
659 function. */
660 static bool
661 return_regno_p (unsigned int regno)
663 rtx outgoing = crtl->return_rtx;
665 if (! outgoing)
666 return false;
668 if (REG_P (outgoing))
669 return REGNO (outgoing) == regno;
670 else if (GET_CODE (outgoing) == PARALLEL)
672 int i;
674 for (i = 0; i < XVECLEN (outgoing, 0); i++)
676 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
678 if (REG_P (x) && REGNO (x) == regno)
679 return true;
682 return false;
685 /* Final change of pseudos got hard registers into the corresponding
686 hard registers and removing temporary clobbers. */
687 void
688 lra_final_code_change (void)
690 int i, hard_regno;
691 basic_block bb;
692 rtx_insn *insn, *curr;
693 int max_regno = max_reg_num ();
695 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
696 if (lra_reg_info[i].nrefs != 0
697 && (hard_regno = lra_get_regno_hard_regno (i)) >= 0)
698 SET_REGNO (regno_reg_rtx[i], hard_regno);
699 FOR_EACH_BB_FN (bb, cfun)
700 FOR_BB_INSNS_SAFE (bb, insn, curr)
701 if (INSN_P (insn))
703 rtx pat = PATTERN (insn);
705 if (GET_CODE (pat) == CLOBBER && LRA_TEMP_CLOBBER_P (pat))
707 /* Remove clobbers temporarily created in LRA. We don't
708 need them anymore and don't want to waste compiler
709 time processing them in a few subsequent passes. */
710 lra_invalidate_insn_data (insn);
711 delete_insn (insn);
712 continue;
715 /* IRA can generate move insns involving pseudos. It is
716 better remove them earlier to speed up compiler a bit.
717 It is also better to do it here as they might not pass
718 final RTL check in LRA, (e.g. insn moving a control
719 register into itself). So remove an useless move insn
720 unless next insn is USE marking the return reg (we should
721 save this as some subsequent optimizations assume that
722 such original insns are saved). */
723 if (NONJUMP_INSN_P (insn) && GET_CODE (pat) == SET
724 && REG_P (SET_SRC (pat)) && REG_P (SET_DEST (pat))
725 && REGNO (SET_SRC (pat)) == REGNO (SET_DEST (pat))
726 && ! return_regno_p (REGNO (SET_SRC (pat))))
728 lra_invalidate_insn_data (insn);
729 delete_insn (insn);
730 continue;
733 lra_insn_recog_data_t id = lra_get_insn_recog_data (insn);
734 struct lra_static_insn_data *static_id = id->insn_static_data;
735 bool insn_change_p = false;
737 for (i = id->insn_static_data->n_operands - 1; i >= 0; i--)
738 if ((DEBUG_INSN_P (insn) || ! static_id->operand[i].is_operator)
739 && alter_subregs (id->operand_loc[i], ! DEBUG_INSN_P (insn)))
741 lra_update_dup (id, i);
742 insn_change_p = true;
744 if (insn_change_p)
745 lra_update_operator_dups (id);