Merge branch 'vendor/GCC47'
[dragonfly.git] / contrib / gcc-4.7 / gcc / regcprop.c
CommitLineData
e4b17023
JM
1/* Copy propagation on hard registers for the GNU compiler.
2 Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
3 2010 Free Software Foundation, Inc.
4
5 This file is part of GCC.
6
7 GCC is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
10 any later version.
11
12 GCC is distributed in the hope that it will be useful, but WITHOUT
13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
15 License 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 "tm.h"
25#include "rtl.h"
26#include "tm_p.h"
27#include "insn-config.h"
28#include "regs.h"
29#include "addresses.h"
30#include "hard-reg-set.h"
31#include "basic-block.h"
32#include "reload.h"
33#include "output.h"
34#include "function.h"
35#include "recog.h"
36#include "flags.h"
37#include "diagnostic-core.h"
38#include "obstack.h"
39#include "timevar.h"
40#include "tree-pass.h"
41#include "df.h"
42
43/* The following code does forward propagation of hard register copies.
44 The object is to eliminate as many dependencies as possible, so that
45 we have the most scheduling freedom. As a side effect, we also clean
46 up some silly register allocation decisions made by reload. This
47 code may be obsoleted by a new register allocator. */
48
49/* DEBUG_INSNs aren't changed right away, as doing so might extend the
50 lifetime of a register and get the DEBUG_INSN subsequently reset.
51 So they are queued instead, and updated only when the register is
52 used in some subsequent real insn before it is set. */
53struct queued_debug_insn_change
54{
55 struct queued_debug_insn_change *next;
56 rtx insn;
57 rtx *loc;
58 rtx new_rtx;
59};
60
61/* For each register, we have a list of registers that contain the same
62 value. The OLDEST_REGNO field points to the head of the list, and
63 the NEXT_REGNO field runs through the list. The MODE field indicates
64 what mode the data is known to be in; this field is VOIDmode when the
65 register is not known to contain valid data. */
66
67struct value_data_entry
68{
69 enum machine_mode mode;
70 unsigned int oldest_regno;
71 unsigned int next_regno;
72 struct queued_debug_insn_change *debug_insn_changes;
73};
74
75struct value_data
76{
77 struct value_data_entry e[FIRST_PSEUDO_REGISTER];
78 unsigned int max_value_regs;
79 unsigned int n_debug_insn_changes;
80};
81
82static alloc_pool debug_insn_changes_pool;
83
84static void kill_value_one_regno (unsigned, struct value_data *);
85static void kill_value_regno (unsigned, unsigned, struct value_data *);
86static void kill_value (rtx, struct value_data *);
87static void set_value_regno (unsigned, enum machine_mode, struct value_data *);
88static void init_value_data (struct value_data *);
89static void kill_clobbered_value (rtx, const_rtx, void *);
90static void kill_set_value (rtx, const_rtx, void *);
91static int kill_autoinc_value (rtx *, void *);
92static void copy_value (rtx, rtx, struct value_data *);
93static bool mode_change_ok (enum machine_mode, enum machine_mode,
94 unsigned int);
95static rtx maybe_mode_change (enum machine_mode, enum machine_mode,
96 enum machine_mode, unsigned int, unsigned int);
97static rtx find_oldest_value_reg (enum reg_class, rtx, struct value_data *);
98static bool replace_oldest_value_reg (rtx *, enum reg_class, rtx,
99 struct value_data *);
100static bool replace_oldest_value_addr (rtx *, enum reg_class,
101 enum machine_mode, addr_space_t, rtx,
102 struct value_data *);
103static bool replace_oldest_value_mem (rtx, rtx, struct value_data *);
104static bool copyprop_hardreg_forward_1 (basic_block, struct value_data *);
105extern void debug_value_data (struct value_data *);
106#ifdef ENABLE_CHECKING
107static void validate_value_data (struct value_data *);
108#endif
109
110/* Free all queued updates for DEBUG_INSNs that change some reg to
111 register REGNO. */
112
113static void
114free_debug_insn_changes (struct value_data *vd, unsigned int regno)
115{
116 struct queued_debug_insn_change *cur, *next;
117 for (cur = vd->e[regno].debug_insn_changes; cur; cur = next)
118 {
119 next = cur->next;
120 --vd->n_debug_insn_changes;
121 pool_free (debug_insn_changes_pool, cur);
122 }
123 vd->e[regno].debug_insn_changes = NULL;
124}
125
126/* Kill register REGNO. This involves removing it from any value
127 lists, and resetting the value mode to VOIDmode. This is only a
128 helper function; it does not handle any hard registers overlapping
129 with REGNO. */
130
131static void
132kill_value_one_regno (unsigned int regno, struct value_data *vd)
133{
134 unsigned int i, next;
135
136 if (vd->e[regno].oldest_regno != regno)
137 {
138 for (i = vd->e[regno].oldest_regno;
139 vd->e[i].next_regno != regno;
140 i = vd->e[i].next_regno)
141 continue;
142 vd->e[i].next_regno = vd->e[regno].next_regno;
143 }
144 else if ((next = vd->e[regno].next_regno) != INVALID_REGNUM)
145 {
146 for (i = next; i != INVALID_REGNUM; i = vd->e[i].next_regno)
147 vd->e[i].oldest_regno = next;
148 }
149
150 vd->e[regno].mode = VOIDmode;
151 vd->e[regno].oldest_regno = regno;
152 vd->e[regno].next_regno = INVALID_REGNUM;
153 if (vd->e[regno].debug_insn_changes)
154 free_debug_insn_changes (vd, regno);
155
156#ifdef ENABLE_CHECKING
157 validate_value_data (vd);
158#endif
159}
160
161/* Kill the value in register REGNO for NREGS, and any other registers
162 whose values overlap. */
163
164static void
165kill_value_regno (unsigned int regno, unsigned int nregs,
166 struct value_data *vd)
167{
168 unsigned int j;
169
170 /* Kill the value we're told to kill. */
171 for (j = 0; j < nregs; ++j)
172 kill_value_one_regno (regno + j, vd);
173
174 /* Kill everything that overlapped what we're told to kill. */
175 if (regno < vd->max_value_regs)
176 j = 0;
177 else
178 j = regno - vd->max_value_regs;
179 for (; j < regno; ++j)
180 {
181 unsigned int i, n;
182 if (vd->e[j].mode == VOIDmode)
183 continue;
184 n = hard_regno_nregs[j][vd->e[j].mode];
185 if (j + n > regno)
186 for (i = 0; i < n; ++i)
187 kill_value_one_regno (j + i, vd);
188 }
189}
190
191/* Kill X. This is a convenience function wrapping kill_value_regno
192 so that we mind the mode the register is in. */
193
194static void
195kill_value (rtx x, struct value_data *vd)
196{
197 rtx orig_rtx = x;
198
199 if (GET_CODE (x) == SUBREG)
200 {
201 x = simplify_subreg (GET_MODE (x), SUBREG_REG (x),
202 GET_MODE (SUBREG_REG (x)), SUBREG_BYTE (x));
203 if (x == NULL_RTX)
204 x = SUBREG_REG (orig_rtx);
205 }
206 if (REG_P (x))
207 {
208 unsigned int regno = REGNO (x);
209 unsigned int n = hard_regno_nregs[regno][GET_MODE (x)];
210
211 kill_value_regno (regno, n, vd);
212 }
213}
214
215/* Remember that REGNO is valid in MODE. */
216
217static void
218set_value_regno (unsigned int regno, enum machine_mode mode,
219 struct value_data *vd)
220{
221 unsigned int nregs;
222
223 vd->e[regno].mode = mode;
224
225 nregs = hard_regno_nregs[regno][mode];
226 if (nregs > vd->max_value_regs)
227 vd->max_value_regs = nregs;
228}
229
230/* Initialize VD such that there are no known relationships between regs. */
231
232static void
233init_value_data (struct value_data *vd)
234{
235 int i;
236 for (i = 0; i < FIRST_PSEUDO_REGISTER; ++i)
237 {
238 vd->e[i].mode = VOIDmode;
239 vd->e[i].oldest_regno = i;
240 vd->e[i].next_regno = INVALID_REGNUM;
241 vd->e[i].debug_insn_changes = NULL;
242 }
243 vd->max_value_regs = 0;
244 vd->n_debug_insn_changes = 0;
245}
246
247/* Called through note_stores. If X is clobbered, kill its value. */
248
249static void
250kill_clobbered_value (rtx x, const_rtx set, void *data)
251{
252 struct value_data *const vd = (struct value_data *) data;
253 if (GET_CODE (set) == CLOBBER)
254 kill_value (x, vd);
255}
256
257/* Called through note_stores. If X is set, not clobbered, kill its
258 current value and install it as the root of its own value list. */
259
260static void
261kill_set_value (rtx x, const_rtx set, void *data)
262{
263 struct value_data *const vd = (struct value_data *) data;
264 if (GET_CODE (set) != CLOBBER)
265 {
266 kill_value (x, vd);
267 if (REG_P (x))
268 set_value_regno (REGNO (x), GET_MODE (x), vd);
269 }
270}
271
272/* Called through for_each_rtx. Kill any register used as the base of an
273 auto-increment expression, and install that register as the root of its
274 own value list. */
275
276static int
277kill_autoinc_value (rtx *px, void *data)
278{
279 rtx x = *px;
280 struct value_data *const vd = (struct value_data *) data;
281
282 if (GET_RTX_CLASS (GET_CODE (x)) == RTX_AUTOINC)
283 {
284 x = XEXP (x, 0);
285 kill_value (x, vd);
286 set_value_regno (REGNO (x), GET_MODE (x), vd);
287 return -1;
288 }
289
290 return 0;
291}
292
293/* Assert that SRC has been copied to DEST. Adjust the data structures
294 to reflect that SRC contains an older copy of the shared value. */
295
296static void
297copy_value (rtx dest, rtx src, struct value_data *vd)
298{
299 unsigned int dr = REGNO (dest);
300 unsigned int sr = REGNO (src);
301 unsigned int dn, sn;
302 unsigned int i;
303
304 /* ??? At present, it's possible to see noop sets. It'd be nice if
305 this were cleaned up beforehand... */
306 if (sr == dr)
307 return;
308
309 /* Do not propagate copies to the stack pointer, as that can leave
310 memory accesses with no scheduling dependency on the stack update. */
311 if (dr == STACK_POINTER_REGNUM)
312 return;
313
314 /* Likewise with the frame pointer, if we're using one. */
315 if (frame_pointer_needed && dr == HARD_FRAME_POINTER_REGNUM)
316 return;
317
318 /* Do not propagate copies to fixed or global registers, patterns
319 can be relying to see particular fixed register or users can
320 expect the chosen global register in asm. */
321 if (fixed_regs[dr] || global_regs[dr])
322 return;
323
324 /* If SRC and DEST overlap, don't record anything. */
325 dn = hard_regno_nregs[dr][GET_MODE (dest)];
326 sn = hard_regno_nregs[sr][GET_MODE (dest)];
327 if ((dr > sr && dr < sr + sn)
328 || (sr > dr && sr < dr + dn))
329 return;
330
331 /* If SRC had no assigned mode (i.e. we didn't know it was live)
332 assign it now and assume the value came from an input argument
333 or somesuch. */
334 if (vd->e[sr].mode == VOIDmode)
335 set_value_regno (sr, vd->e[dr].mode, vd);
336
337 /* If we are narrowing the input to a smaller number of hard regs,
338 and it is in big endian, we are really extracting a high part.
339 Since we generally associate a low part of a value with the value itself,
340 we must not do the same for the high part.
341 Note we can still get low parts for the same mode combination through
342 a two-step copy involving differently sized hard regs.
343 Assume hard regs fr* are 32 bits bits each, while r* are 64 bits each:
344 (set (reg:DI r0) (reg:DI fr0))
345 (set (reg:SI fr2) (reg:SI r0))
346 loads the low part of (reg:DI fr0) - i.e. fr1 - into fr2, while:
347 (set (reg:SI fr2) (reg:SI fr0))
348 loads the high part of (reg:DI fr0) into fr2.
349
350 We can't properly represent the latter case in our tables, so don't
351 record anything then. */
352 else if (sn < (unsigned int) hard_regno_nregs[sr][vd->e[sr].mode]
353 && (GET_MODE_SIZE (vd->e[sr].mode) > UNITS_PER_WORD
354 ? WORDS_BIG_ENDIAN : BYTES_BIG_ENDIAN))
355 return;
356
357 /* If SRC had been assigned a mode narrower than the copy, we can't
358 link DEST into the chain, because not all of the pieces of the
359 copy came from oldest_regno. */
360 else if (sn > (unsigned int) hard_regno_nregs[sr][vd->e[sr].mode])
361 return;
362
363 /* Link DR at the end of the value chain used by SR. */
364
365 vd->e[dr].oldest_regno = vd->e[sr].oldest_regno;
366
367 for (i = sr; vd->e[i].next_regno != INVALID_REGNUM; i = vd->e[i].next_regno)
368 continue;
369 vd->e[i].next_regno = dr;
370
371#ifdef ENABLE_CHECKING
372 validate_value_data (vd);
373#endif
374}
375
376/* Return true if a mode change from ORIG to NEW is allowed for REGNO. */
377
378static bool
379mode_change_ok (enum machine_mode orig_mode, enum machine_mode new_mode,
380 unsigned int regno ATTRIBUTE_UNUSED)
381{
382 if (GET_MODE_SIZE (orig_mode) < GET_MODE_SIZE (new_mode))
383 return false;
384
385#ifdef CANNOT_CHANGE_MODE_CLASS
386 return !REG_CANNOT_CHANGE_MODE_P (regno, orig_mode, new_mode);
387#endif
388
389 return true;
390}
391
392/* Register REGNO was originally set in ORIG_MODE. It - or a copy of it -
393 was copied in COPY_MODE to COPY_REGNO, and then COPY_REGNO was accessed
394 in NEW_MODE.
395 Return a NEW_MODE rtx for REGNO if that's OK, otherwise return NULL_RTX. */
396
397static rtx
398maybe_mode_change (enum machine_mode orig_mode, enum machine_mode copy_mode,
399 enum machine_mode new_mode, unsigned int regno,
400 unsigned int copy_regno ATTRIBUTE_UNUSED)
401{
402 if (GET_MODE_SIZE (copy_mode) < GET_MODE_SIZE (orig_mode)
403 && GET_MODE_SIZE (copy_mode) < GET_MODE_SIZE (new_mode))
404 return NULL_RTX;
405
406 if (orig_mode == new_mode)
407 return gen_rtx_raw_REG (new_mode, regno);
408 else if (mode_change_ok (orig_mode, new_mode, regno))
409 {
410 int copy_nregs = hard_regno_nregs[copy_regno][copy_mode];
411 int use_nregs = hard_regno_nregs[copy_regno][new_mode];
412 int copy_offset
413 = GET_MODE_SIZE (copy_mode) / copy_nregs * (copy_nregs - use_nregs);
414 int offset
415 = GET_MODE_SIZE (orig_mode) - GET_MODE_SIZE (new_mode) - copy_offset;
416 int byteoffset = offset % UNITS_PER_WORD;
417 int wordoffset = offset - byteoffset;
418
419 offset = ((WORDS_BIG_ENDIAN ? wordoffset : 0)
420 + (BYTES_BIG_ENDIAN ? byteoffset : 0));
421 regno += subreg_regno_offset (regno, orig_mode, offset, new_mode);
422 if (HARD_REGNO_MODE_OK (regno, new_mode))
423 return gen_rtx_raw_REG (new_mode, regno);
424 }
425 return NULL_RTX;
426}
427
428/* Find the oldest copy of the value contained in REGNO that is in
429 register class CL and has mode MODE. If found, return an rtx
430 of that oldest register, otherwise return NULL. */
431
432static rtx
433find_oldest_value_reg (enum reg_class cl, rtx reg, struct value_data *vd)
434{
435 unsigned int regno = REGNO (reg);
436 enum machine_mode mode = GET_MODE (reg);
437 unsigned int i;
438
439 /* If we are accessing REG in some mode other that what we set it in,
440 make sure that the replacement is valid. In particular, consider
441 (set (reg:DI r11) (...))
442 (set (reg:SI r9) (reg:SI r11))
443 (set (reg:SI r10) (...))
444 (set (...) (reg:DI r9))
445 Replacing r9 with r11 is invalid. */
446 if (mode != vd->e[regno].mode)
447 {
448 if (hard_regno_nregs[regno][mode]
449 > hard_regno_nregs[regno][vd->e[regno].mode])
450 return NULL_RTX;
451 }
452
453 for (i = vd->e[regno].oldest_regno; i != regno; i = vd->e[i].next_regno)
454 {
455 enum machine_mode oldmode = vd->e[i].mode;
456 rtx new_rtx;
457
458 if (!in_hard_reg_set_p (reg_class_contents[cl], mode, i))
459 continue;
460
461 new_rtx = maybe_mode_change (oldmode, vd->e[regno].mode, mode, i, regno);
462 if (new_rtx)
463 {
464 ORIGINAL_REGNO (new_rtx) = ORIGINAL_REGNO (reg);
465 REG_ATTRS (new_rtx) = REG_ATTRS (reg);
466 REG_POINTER (new_rtx) = REG_POINTER (reg);
467 return new_rtx;
468 }
469 }
470
471 return NULL_RTX;
472}
473
474/* If possible, replace the register at *LOC with the oldest register
475 in register class CL. Return true if successfully replaced. */
476
477static bool
478replace_oldest_value_reg (rtx *loc, enum reg_class cl, rtx insn,
479 struct value_data *vd)
480{
481 rtx new_rtx = find_oldest_value_reg (cl, *loc, vd);
482 if (new_rtx)
483 {
484 if (DEBUG_INSN_P (insn))
485 {
486 struct queued_debug_insn_change *change;
487
488 if (dump_file)
489 fprintf (dump_file, "debug_insn %u: queued replacing reg %u with %u\n",
490 INSN_UID (insn), REGNO (*loc), REGNO (new_rtx));
491
492 change = (struct queued_debug_insn_change *)
493 pool_alloc (debug_insn_changes_pool);
494 change->next = vd->e[REGNO (new_rtx)].debug_insn_changes;
495 change->insn = insn;
496 change->loc = loc;
497 change->new_rtx = new_rtx;
498 vd->e[REGNO (new_rtx)].debug_insn_changes = change;
499 ++vd->n_debug_insn_changes;
500 return true;
501 }
502 if (dump_file)
503 fprintf (dump_file, "insn %u: replaced reg %u with %u\n",
504 INSN_UID (insn), REGNO (*loc), REGNO (new_rtx));
505
506 validate_change (insn, loc, new_rtx, 1);
507 return true;
508 }
509 return false;
510}
511
512/* Similar to replace_oldest_value_reg, but *LOC contains an address.
513 Adapted from find_reloads_address_1. CL is INDEX_REG_CLASS or
514 BASE_REG_CLASS depending on how the register is being considered. */
515
516static bool
517replace_oldest_value_addr (rtx *loc, enum reg_class cl,
518 enum machine_mode mode, addr_space_t as,
519 rtx insn, struct value_data *vd)
520{
521 rtx x = *loc;
522 RTX_CODE code = GET_CODE (x);
523 const char *fmt;
524 int i, j;
525 bool changed = false;
526
527 switch (code)
528 {
529 case PLUS:
530 if (DEBUG_INSN_P (insn))
531 break;
532
533 {
534 rtx orig_op0 = XEXP (x, 0);
535 rtx orig_op1 = XEXP (x, 1);
536 RTX_CODE code0 = GET_CODE (orig_op0);
537 RTX_CODE code1 = GET_CODE (orig_op1);
538 rtx op0 = orig_op0;
539 rtx op1 = orig_op1;
540 rtx *locI = NULL;
541 rtx *locB = NULL;
542 enum rtx_code index_code = SCRATCH;
543
544 if (GET_CODE (op0) == SUBREG)
545 {
546 op0 = SUBREG_REG (op0);
547 code0 = GET_CODE (op0);
548 }
549
550 if (GET_CODE (op1) == SUBREG)
551 {
552 op1 = SUBREG_REG (op1);
553 code1 = GET_CODE (op1);
554 }
555
556 if (code0 == MULT || code0 == SIGN_EXTEND || code0 == TRUNCATE
557 || code0 == ZERO_EXTEND || code1 == MEM)
558 {
559 locI = &XEXP (x, 0);
560 locB = &XEXP (x, 1);
561 index_code = GET_CODE (*locI);
562 }
563 else if (code1 == MULT || code1 == SIGN_EXTEND || code1 == TRUNCATE
564 || code1 == ZERO_EXTEND || code0 == MEM)
565 {
566 locI = &XEXP (x, 1);
567 locB = &XEXP (x, 0);
568 index_code = GET_CODE (*locI);
569 }
570 else if (code0 == CONST_INT || code0 == CONST
571 || code0 == SYMBOL_REF || code0 == LABEL_REF)
572 {
573 locB = &XEXP (x, 1);
574 index_code = GET_CODE (XEXP (x, 0));
575 }
576 else if (code1 == CONST_INT || code1 == CONST
577 || code1 == SYMBOL_REF || code1 == LABEL_REF)
578 {
579 locB = &XEXP (x, 0);
580 index_code = GET_CODE (XEXP (x, 1));
581 }
582 else if (code0 == REG && code1 == REG)
583 {
584 int index_op;
585 unsigned regno0 = REGNO (op0), regno1 = REGNO (op1);
586
587 if (REGNO_OK_FOR_INDEX_P (regno1)
588 && regno_ok_for_base_p (regno0, mode, as, PLUS, REG))
589 index_op = 1;
590 else if (REGNO_OK_FOR_INDEX_P (regno0)
591 && regno_ok_for_base_p (regno1, mode, as, PLUS, REG))
592 index_op = 0;
593 else if (regno_ok_for_base_p (regno0, mode, as, PLUS, REG)
594 || REGNO_OK_FOR_INDEX_P (regno1))
595 index_op = 1;
596 else if (regno_ok_for_base_p (regno1, mode, as, PLUS, REG))
597 index_op = 0;
598 else
599 index_op = 1;
600
601 locI = &XEXP (x, index_op);
602 locB = &XEXP (x, !index_op);
603 index_code = GET_CODE (*locI);
604 }
605 else if (code0 == REG)
606 {
607 locI = &XEXP (x, 0);
608 locB = &XEXP (x, 1);
609 index_code = GET_CODE (*locI);
610 }
611 else if (code1 == REG)
612 {
613 locI = &XEXP (x, 1);
614 locB = &XEXP (x, 0);
615 index_code = GET_CODE (*locI);
616 }
617
618 if (locI)
619 changed |= replace_oldest_value_addr (locI, INDEX_REG_CLASS,
620 mode, as, insn, vd);
621 if (locB)
622 changed |= replace_oldest_value_addr (locB,
623 base_reg_class (mode, as, PLUS,
624 index_code),
625 mode, as, insn, vd);
626 return changed;
627 }
628
629 case POST_INC:
630 case POST_DEC:
631 case POST_MODIFY:
632 case PRE_INC:
633 case PRE_DEC:
634 case PRE_MODIFY:
635 return false;
636
637 case MEM:
638 return replace_oldest_value_mem (x, insn, vd);
639
640 case REG:
641 return replace_oldest_value_reg (loc, cl, insn, vd);
642
643 default:
644 break;
645 }
646
647 fmt = GET_RTX_FORMAT (code);
648 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
649 {
650 if (fmt[i] == 'e')
651 changed |= replace_oldest_value_addr (&XEXP (x, i), cl, mode, as,
652 insn, vd);
653 else if (fmt[i] == 'E')
654 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
655 changed |= replace_oldest_value_addr (&XVECEXP (x, i, j), cl,
656 mode, as, insn, vd);
657 }
658
659 return changed;
660}
661
662/* Similar to replace_oldest_value_reg, but X contains a memory. */
663
664static bool
665replace_oldest_value_mem (rtx x, rtx insn, struct value_data *vd)
666{
667 enum reg_class cl;
668
669 if (DEBUG_INSN_P (insn))
670 cl = ALL_REGS;
671 else
672 cl = base_reg_class (GET_MODE (x), MEM_ADDR_SPACE (x), MEM, SCRATCH);
673
674 return replace_oldest_value_addr (&XEXP (x, 0), cl,
675 GET_MODE (x), MEM_ADDR_SPACE (x),
676 insn, vd);
677}
678
679/* Apply all queued updates for DEBUG_INSNs that change some reg to
680 register REGNO. */
681
682static void
683apply_debug_insn_changes (struct value_data *vd, unsigned int regno)
684{
685 struct queued_debug_insn_change *change;
686 rtx last_insn = vd->e[regno].debug_insn_changes->insn;
687
688 for (change = vd->e[regno].debug_insn_changes;
689 change;
690 change = change->next)
691 {
692 if (last_insn != change->insn)
693 {
694 apply_change_group ();
695 last_insn = change->insn;
696 }
697 validate_change (change->insn, change->loc, change->new_rtx, 1);
698 }
699 apply_change_group ();
700}
701
702/* Called via for_each_rtx, for all used registers in a real
703 insn apply DEBUG_INSN changes that change registers to the
704 used register. */
705
706static int
707cprop_find_used_regs_1 (rtx *loc, void *data)
708{
709 if (REG_P (*loc))
710 {
711 struct value_data *vd = (struct value_data *) data;
712 if (vd->e[REGNO (*loc)].debug_insn_changes)
713 {
714 apply_debug_insn_changes (vd, REGNO (*loc));
715 free_debug_insn_changes (vd, REGNO (*loc));
716 }
717 }
718 return 0;
719}
720
721/* Called via note_uses, for all used registers in a real insn
722 apply DEBUG_INSN changes that change registers to the used
723 registers. */
724
725static void
726cprop_find_used_regs (rtx *loc, void *vd)
727{
728 for_each_rtx (loc, cprop_find_used_regs_1, vd);
729}
730
731/* Perform the forward copy propagation on basic block BB. */
732
733static bool
734copyprop_hardreg_forward_1 (basic_block bb, struct value_data *vd)
735{
736 bool anything_changed = false;
737 rtx insn;
738
739 for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn))
740 {
741 int n_ops, i, alt, predicated;
742 bool is_asm, any_replacements;
743 rtx set;
95d28233 744 rtx link;
e4b17023
JM
745 bool replaced[MAX_RECOG_OPERANDS];
746 bool changed = false;
747
748 if (!NONDEBUG_INSN_P (insn))
749 {
750 if (DEBUG_INSN_P (insn))
751 {
752 rtx loc = INSN_VAR_LOCATION_LOC (insn);
753 if (!VAR_LOC_UNKNOWN_P (loc))
754 replace_oldest_value_addr (&INSN_VAR_LOCATION_LOC (insn),
755 ALL_REGS, GET_MODE (loc),
756 ADDR_SPACE_GENERIC, insn, vd);
757 }
758
759 if (insn == BB_END (bb))
760 break;
761 else
762 continue;
763 }
764
765 set = single_set (insn);
766 extract_insn (insn);
767 if (! constrain_operands (1))
768 fatal_insn_not_found (insn);
769 preprocess_constraints ();
770 alt = which_alternative;
771 n_ops = recog_data.n_operands;
772 is_asm = asm_noperands (PATTERN (insn)) >= 0;
773
774 /* Simplify the code below by rewriting things to reflect
775 matching constraints. Also promote OP_OUT to OP_INOUT
776 in predicated instructions. */
777
778 predicated = GET_CODE (PATTERN (insn)) == COND_EXEC;
779 for (i = 0; i < n_ops; ++i)
780 {
781 int matches = recog_op_alt[i][alt].matches;
782 if (matches >= 0)
783 recog_op_alt[i][alt].cl = recog_op_alt[matches][alt].cl;
784 if (matches >= 0 || recog_op_alt[i][alt].matched >= 0
785 || (predicated && recog_data.operand_type[i] == OP_OUT))
786 recog_data.operand_type[i] = OP_INOUT;
787 }
788
789 /* Apply changes to earlier DEBUG_INSNs if possible. */
790 if (vd->n_debug_insn_changes)
791 note_uses (&PATTERN (insn), cprop_find_used_regs, vd);
792
793 /* For each earlyclobber operand, zap the value data. */
794 for (i = 0; i < n_ops; i++)
795 if (recog_op_alt[i][alt].earlyclobber)
796 kill_value (recog_data.operand[i], vd);
797
798 /* Within asms, a clobber cannot overlap inputs or outputs.
799 I wouldn't think this were true for regular insns, but
800 scan_rtx treats them like that... */
801 note_stores (PATTERN (insn), kill_clobbered_value, vd);
802
803 /* Kill all auto-incremented values. */
804 /* ??? REG_INC is useless, since stack pushes aren't done that way. */
805 for_each_rtx (&PATTERN (insn), kill_autoinc_value, vd);
806
807 /* Kill all early-clobbered operands. */
808 for (i = 0; i < n_ops; i++)
809 if (recog_op_alt[i][alt].earlyclobber)
810 kill_value (recog_data.operand[i], vd);
811
95d28233
JM
812 /* If we have dead sets in the insn, then we need to note these as we
813 would clobbers. */
814 for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
815 {
816 if (REG_NOTE_KIND (link) == REG_UNUSED)
817 {
818 kill_value (XEXP (link, 0), vd);
819 /* Furthermore, if the insn looked like a single-set,
820 but the dead store kills the source value of that
821 set, then we can no-longer use the plain move
822 special case below. */
823 if (set
824 && reg_overlap_mentioned_p (XEXP (link, 0), SET_SRC (set)))
825 set = NULL;
826 }
827 }
828
e4b17023
JM
829 /* Special-case plain move instructions, since we may well
830 be able to do the move from a different register class. */
831 if (set && REG_P (SET_SRC (set)))
832 {
833 rtx src = SET_SRC (set);
834 unsigned int regno = REGNO (src);
835 enum machine_mode mode = GET_MODE (src);
836 unsigned int i;
837 rtx new_rtx;
838
839 /* If we are accessing SRC in some mode other that what we
840 set it in, make sure that the replacement is valid. */
841 if (mode != vd->e[regno].mode)
842 {
843 if (hard_regno_nregs[regno][mode]
844 > hard_regno_nregs[regno][vd->e[regno].mode])
845 goto no_move_special_case;
846
847 /* And likewise, if we are narrowing on big endian the transformation
848 is also invalid. */
849 if (hard_regno_nregs[regno][mode]
850 < hard_regno_nregs[regno][vd->e[regno].mode]
851 && (GET_MODE_SIZE (vd->e[regno].mode) > UNITS_PER_WORD
852 ? WORDS_BIG_ENDIAN : BYTES_BIG_ENDIAN))
853 goto no_move_special_case;
854 }
855
856 /* If the destination is also a register, try to find a source
857 register in the same class. */
858 if (REG_P (SET_DEST (set)))
859 {
860 new_rtx = find_oldest_value_reg (REGNO_REG_CLASS (regno), src, vd);
861 if (new_rtx && validate_change (insn, &SET_SRC (set), new_rtx, 0))
862 {
863 if (dump_file)
864 fprintf (dump_file,
865 "insn %u: replaced reg %u with %u\n",
866 INSN_UID (insn), regno, REGNO (new_rtx));
867 changed = true;
868 goto did_replacement;
869 }
870 /* We need to re-extract as validate_change clobbers
871 recog_data. */
872 extract_insn (insn);
873 if (! constrain_operands (1))
874 fatal_insn_not_found (insn);
875 preprocess_constraints ();
876 }
877
878 /* Otherwise, try all valid registers and see if its valid. */
879 for (i = vd->e[regno].oldest_regno; i != regno;
880 i = vd->e[i].next_regno)
881 {
882 new_rtx = maybe_mode_change (vd->e[i].mode, vd->e[regno].mode,
883 mode, i, regno);
884 if (new_rtx != NULL_RTX)
885 {
886 if (validate_change (insn, &SET_SRC (set), new_rtx, 0))
887 {
888 ORIGINAL_REGNO (new_rtx) = ORIGINAL_REGNO (src);
889 REG_ATTRS (new_rtx) = REG_ATTRS (src);
890 REG_POINTER (new_rtx) = REG_POINTER (src);
891 if (dump_file)
892 fprintf (dump_file,
893 "insn %u: replaced reg %u with %u\n",
894 INSN_UID (insn), regno, REGNO (new_rtx));
895 changed = true;
896 goto did_replacement;
897 }
898 /* We need to re-extract as validate_change clobbers
899 recog_data. */
900 extract_insn (insn);
901 if (! constrain_operands (1))
902 fatal_insn_not_found (insn);
903 preprocess_constraints ();
904 }
905 }
906 }
907 no_move_special_case:
908
909 any_replacements = false;
910
911 /* For each input operand, replace a hard register with the
912 eldest live copy that's in an appropriate register class. */
913 for (i = 0; i < n_ops; i++)
914 {
915 replaced[i] = false;
916
917 /* Don't scan match_operand here, since we've no reg class
918 information to pass down. Any operands that we could
919 substitute in will be represented elsewhere. */
920 if (recog_data.constraints[i][0] == '\0')
921 continue;
922
923 /* Don't replace in asms intentionally referencing hard regs. */
924 if (is_asm && REG_P (recog_data.operand[i])
925 && (REGNO (recog_data.operand[i])
926 == ORIGINAL_REGNO (recog_data.operand[i])))
927 continue;
928
929 if (recog_data.operand_type[i] == OP_IN)
930 {
931 if (recog_op_alt[i][alt].is_address)
932 replaced[i]
933 = replace_oldest_value_addr (recog_data.operand_loc[i],
934 recog_op_alt[i][alt].cl,
935 VOIDmode, ADDR_SPACE_GENERIC,
936 insn, vd);
937 else if (REG_P (recog_data.operand[i]))
938 replaced[i]
939 = replace_oldest_value_reg (recog_data.operand_loc[i],
940 recog_op_alt[i][alt].cl,
941 insn, vd);
942 else if (MEM_P (recog_data.operand[i]))
943 replaced[i] = replace_oldest_value_mem (recog_data.operand[i],
944 insn, vd);
945 }
946 else if (MEM_P (recog_data.operand[i]))
947 replaced[i] = replace_oldest_value_mem (recog_data.operand[i],
948 insn, vd);
949
950 /* If we performed any replacement, update match_dups. */
951 if (replaced[i])
952 {
953 int j;
954 rtx new_rtx;
955
956 new_rtx = *recog_data.operand_loc[i];
957 recog_data.operand[i] = new_rtx;
958 for (j = 0; j < recog_data.n_dups; j++)
959 if (recog_data.dup_num[j] == i)
960 validate_unshare_change (insn, recog_data.dup_loc[j], new_rtx, 1);
961
962 any_replacements = true;
963 }
964 }
965
966 if (any_replacements)
967 {
968 if (! apply_change_group ())
969 {
970 for (i = 0; i < n_ops; i++)
971 if (replaced[i])
972 {
973 rtx old = *recog_data.operand_loc[i];
974 recog_data.operand[i] = old;
975 }
976
977 if (dump_file)
978 fprintf (dump_file,
979 "insn %u: reg replacements not verified\n",
980 INSN_UID (insn));
981 }
982 else
983 changed = true;
984 }
985
986 did_replacement:
987 if (changed)
988 {
989 anything_changed = true;
990
991 /* If something changed, perhaps further changes to earlier
992 DEBUG_INSNs can be applied. */
993 if (vd->n_debug_insn_changes)
994 note_uses (&PATTERN (insn), cprop_find_used_regs, vd);
995 }
996
997 /* Clobber call-clobbered registers. */
998 if (CALL_P (insn))
999 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1000 if (TEST_HARD_REG_BIT (regs_invalidated_by_call, i))
1001 kill_value_regno (i, 1, vd);
1002
1003 /* Notice stores. */
1004 note_stores (PATTERN (insn), kill_set_value, vd);
1005
1006 /* Notice copies. */
1007 if (set && REG_P (SET_DEST (set)) && REG_P (SET_SRC (set)))
1008 copy_value (SET_DEST (set), SET_SRC (set), vd);
1009
1010 if (insn == BB_END (bb))
1011 break;
1012 }
1013
1014 return anything_changed;
1015}
1016
1017/* Main entry point for the forward copy propagation optimization. */
1018
1019static unsigned int
1020copyprop_hardreg_forward (void)
1021{
1022 struct value_data *all_vd;
1023 basic_block bb;
1024 sbitmap visited;
1025 bool analyze_called = false;
1026
1027 all_vd = XNEWVEC (struct value_data, last_basic_block);
1028
1029 visited = sbitmap_alloc (last_basic_block);
1030 sbitmap_zero (visited);
1031
1032 if (MAY_HAVE_DEBUG_INSNS)
1033 debug_insn_changes_pool
1034 = create_alloc_pool ("debug insn changes pool",
1035 sizeof (struct queued_debug_insn_change), 256);
1036
1037 FOR_EACH_BB (bb)
1038 {
1039 SET_BIT (visited, bb->index);
1040
1041 /* If a block has a single predecessor, that we've already
1042 processed, begin with the value data that was live at
1043 the end of the predecessor block. */
1044 /* ??? Ought to use more intelligent queuing of blocks. */
1045 if (single_pred_p (bb)
1046 && TEST_BIT (visited, single_pred (bb)->index)
1047 && ! (single_pred_edge (bb)->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)))
1048 {
1049 all_vd[bb->index] = all_vd[single_pred (bb)->index];
1050 if (all_vd[bb->index].n_debug_insn_changes)
1051 {
1052 unsigned int regno;
1053
1054 for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
1055 {
1056 if (all_vd[bb->index].e[regno].debug_insn_changes)
1057 {
1058 all_vd[bb->index].e[regno].debug_insn_changes = NULL;
1059 if (--all_vd[bb->index].n_debug_insn_changes == 0)
1060 break;
1061 }
1062 }
1063 }
1064 }
1065 else
1066 init_value_data (all_vd + bb->index);
1067
1068 copyprop_hardreg_forward_1 (bb, all_vd + bb->index);
1069 }
1070
1071 if (MAY_HAVE_DEBUG_INSNS)
1072 {
1073 FOR_EACH_BB (bb)
1074 if (TEST_BIT (visited, bb->index)
1075 && all_vd[bb->index].n_debug_insn_changes)
1076 {
1077 unsigned int regno;
1078 bitmap live;
1079
1080 if (!analyze_called)
1081 {
1082 df_analyze ();
1083 analyze_called = true;
1084 }
1085 live = df_get_live_out (bb);
1086 for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
1087 if (all_vd[bb->index].e[regno].debug_insn_changes)
1088 {
1089 if (REGNO_REG_SET_P (live, regno))
1090 apply_debug_insn_changes (all_vd + bb->index, regno);
1091 if (all_vd[bb->index].n_debug_insn_changes == 0)
1092 break;
1093 }
1094 }
1095
1096 free_alloc_pool (debug_insn_changes_pool);
1097 }
1098
1099 sbitmap_free (visited);
1100 free (all_vd);
1101 return 0;
1102}
1103
1104/* Dump the value chain data to stderr. */
1105
1106DEBUG_FUNCTION void
1107debug_value_data (struct value_data *vd)
1108{
1109 HARD_REG_SET set;
1110 unsigned int i, j;
1111
1112 CLEAR_HARD_REG_SET (set);
1113
1114 for (i = 0; i < FIRST_PSEUDO_REGISTER; ++i)
1115 if (vd->e[i].oldest_regno == i)
1116 {
1117 if (vd->e[i].mode == VOIDmode)
1118 {
1119 if (vd->e[i].next_regno != INVALID_REGNUM)
1120 fprintf (stderr, "[%u] Bad next_regno for empty chain (%u)\n",
1121 i, vd->e[i].next_regno);
1122 continue;
1123 }
1124
1125 SET_HARD_REG_BIT (set, i);
1126 fprintf (stderr, "[%u %s] ", i, GET_MODE_NAME (vd->e[i].mode));
1127
1128 for (j = vd->e[i].next_regno;
1129 j != INVALID_REGNUM;
1130 j = vd->e[j].next_regno)
1131 {
1132 if (TEST_HARD_REG_BIT (set, j))
1133 {
1134 fprintf (stderr, "[%u] Loop in regno chain\n", j);
1135 return;
1136 }
1137
1138 if (vd->e[j].oldest_regno != i)
1139 {
1140 fprintf (stderr, "[%u] Bad oldest_regno (%u)\n",
1141 j, vd->e[j].oldest_regno);
1142 return;
1143 }
1144 SET_HARD_REG_BIT (set, j);
1145 fprintf (stderr, "[%u %s] ", j, GET_MODE_NAME (vd->e[j].mode));
1146 }
1147 fputc ('\n', stderr);
1148 }
1149
1150 for (i = 0; i < FIRST_PSEUDO_REGISTER; ++i)
1151 if (! TEST_HARD_REG_BIT (set, i)
1152 && (vd->e[i].mode != VOIDmode
1153 || vd->e[i].oldest_regno != i
1154 || vd->e[i].next_regno != INVALID_REGNUM))
1155 fprintf (stderr, "[%u] Non-empty reg in chain (%s %u %i)\n",
1156 i, GET_MODE_NAME (vd->e[i].mode), vd->e[i].oldest_regno,
1157 vd->e[i].next_regno);
1158}
1159
1160#ifdef ENABLE_CHECKING
1161static void
1162validate_value_data (struct value_data *vd)
1163{
1164 HARD_REG_SET set;
1165 unsigned int i, j;
1166
1167 CLEAR_HARD_REG_SET (set);
1168
1169 for (i = 0; i < FIRST_PSEUDO_REGISTER; ++i)
1170 if (vd->e[i].oldest_regno == i)
1171 {
1172 if (vd->e[i].mode == VOIDmode)
1173 {
1174 if (vd->e[i].next_regno != INVALID_REGNUM)
1175 internal_error ("validate_value_data: [%u] Bad next_regno for empty chain (%u)",
1176 i, vd->e[i].next_regno);
1177 continue;
1178 }
1179
1180 SET_HARD_REG_BIT (set, i);
1181
1182 for (j = vd->e[i].next_regno;
1183 j != INVALID_REGNUM;
1184 j = vd->e[j].next_regno)
1185 {
1186 if (TEST_HARD_REG_BIT (set, j))
1187 internal_error ("validate_value_data: Loop in regno chain (%u)",
1188 j);
1189 if (vd->e[j].oldest_regno != i)
1190 internal_error ("validate_value_data: [%u] Bad oldest_regno (%u)",
1191 j, vd->e[j].oldest_regno);
1192
1193 SET_HARD_REG_BIT (set, j);
1194 }
1195 }
1196
1197 for (i = 0; i < FIRST_PSEUDO_REGISTER; ++i)
1198 if (! TEST_HARD_REG_BIT (set, i)
1199 && (vd->e[i].mode != VOIDmode
1200 || vd->e[i].oldest_regno != i
1201 || vd->e[i].next_regno != INVALID_REGNUM))
1202 internal_error ("validate_value_data: [%u] Non-empty reg in chain (%s %u %i)",
1203 i, GET_MODE_NAME (vd->e[i].mode), vd->e[i].oldest_regno,
1204 vd->e[i].next_regno);
1205}
1206#endif
1207\f
1208static bool
1209gate_handle_cprop (void)
1210{
1211 return (optimize > 0 && (flag_cprop_registers));
1212}
1213
1214
1215struct rtl_opt_pass pass_cprop_hardreg =
1216{
1217 {
1218 RTL_PASS,
1219 "cprop_hardreg", /* name */
1220 gate_handle_cprop, /* gate */
1221 copyprop_hardreg_forward, /* execute */
1222 NULL, /* sub */
1223 NULL, /* next */
1224 0, /* static_pass_number */
1225 TV_CPROP_REGISTERS, /* tv_id */
1226 0, /* properties_required */
1227 0, /* properties_provided */
1228 0, /* properties_destroyed */
1229 0, /* todo_flags_start */
1230 TODO_df_finish
1231 | TODO_verify_rtl_sharing /* todo_flags_finish */
1232 }
1233};