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cb20f7e8 | 1 | /* RTL-level loop invariant motion. |
4d779342 | 2 | Copyright (C) 2004, 2005, 2006 Free Software Foundation, Inc. |
cb20f7e8 | 3 | |
5e962776 | 4 | This file is part of GCC. |
cb20f7e8 | 5 | |
5e962776 ZD |
6 | GCC is free software; you can redistribute it and/or modify it |
7 | under the terms of the GNU General Public License as published by the | |
8 | Free Software Foundation; either version 2, or (at your option) any | |
9 | later version. | |
cb20f7e8 | 10 | |
5e962776 ZD |
11 | GCC is distributed in the hope that it will be useful, but WITHOUT |
12 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
13 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
14 | for more details. | |
cb20f7e8 | 15 | |
5e962776 ZD |
16 | You should have received a copy of the GNU General Public License |
17 | along with GCC; see the file COPYING. If not, write to the Free | |
366ccddb KC |
18 | Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA |
19 | 02110-1301, USA. */ | |
5e962776 ZD |
20 | |
21 | /* This implements the loop invariant motion pass. It is very simple | |
cb20f7e8 ZD |
22 | (no calls, libcalls, etc.). This should be sufficient to cleanup things |
23 | like address arithmetics -- other more complicated invariants should be | |
5e962776 | 24 | eliminated on tree level either in tree-ssa-loop-im.c or in tree-ssa-pre.c. |
cb20f7e8 | 25 | |
5e962776 ZD |
26 | We proceed loop by loop -- it is simpler than trying to handle things |
27 | globally and should not lose much. First we inspect all sets inside loop | |
28 | and create a dependency graph on insns (saying "to move this insn, you must | |
29 | also move the following insns"). | |
30 | ||
31 | We then need to determine what to move. We estimate the number of registers | |
32 | used and move as many invariants as possible while we still have enough free | |
33 | registers. We prefer the expensive invariants. | |
cb20f7e8 | 34 | |
5e962776 ZD |
35 | Then we move the selected invariants out of the loop, creating a new |
36 | temporaries for them if necessary. */ | |
37 | ||
38 | #include "config.h" | |
39 | #include "system.h" | |
40 | #include "coretypes.h" | |
41 | #include "tm.h" | |
42 | #include "rtl.h" | |
3912d291 | 43 | #include "tm_p.h" |
5e962776 | 44 | #include "hard-reg-set.h" |
7932a3db | 45 | #include "obstack.h" |
5e962776 ZD |
46 | #include "basic-block.h" |
47 | #include "cfgloop.h" | |
48 | #include "expr.h" | |
1052bd54 | 49 | #include "recog.h" |
5e962776 ZD |
50 | #include "output.h" |
51 | #include "function.h" | |
52 | #include "flags.h" | |
53 | #include "df.h" | |
1052bd54 | 54 | #include "hashtab.h" |
5e962776 ZD |
55 | |
56 | /* The data stored for the loop. */ | |
57 | ||
58 | struct loop_data | |
59 | { | |
60 | struct loop *outermost_exit; /* The outermost exit of the loop. */ | |
61 | bool has_call; /* True if the loop contains a call. */ | |
62 | }; | |
63 | ||
64 | #define LOOP_DATA(LOOP) ((struct loop_data *) (LOOP)->aux) | |
65 | ||
66 | /* The description of an use. */ | |
67 | ||
68 | struct use | |
69 | { | |
70 | rtx *pos; /* Position of the use. */ | |
71 | rtx insn; /* The insn in that the use occurs. */ | |
72 | ||
73 | struct use *next; /* Next use in the list. */ | |
74 | }; | |
75 | ||
76 | /* The description of a def. */ | |
77 | ||
78 | struct def | |
79 | { | |
80 | struct use *uses; /* The list of uses that are uniquely reached | |
81 | by it. */ | |
82 | unsigned n_uses; /* Number of such uses. */ | |
83 | unsigned invno; /* The corresponding invariant. */ | |
84 | }; | |
85 | ||
86 | /* The data stored for each invariant. */ | |
87 | ||
88 | struct invariant | |
89 | { | |
90 | /* The number of the invariant. */ | |
91 | unsigned invno; | |
92 | ||
1052bd54 ZD |
93 | /* The number of the invariant with the same value. */ |
94 | unsigned eqto; | |
95 | ||
96 | /* If we moved the invariant out of the loop, the register that contains its | |
97 | value. */ | |
98 | rtx reg; | |
5e962776 ZD |
99 | |
100 | /* The definition of the invariant. */ | |
101 | struct def *def; | |
102 | ||
103 | /* The insn in that it is defined. */ | |
104 | rtx insn; | |
105 | ||
106 | /* Whether it is always executed. */ | |
107 | bool always_executed; | |
108 | ||
109 | /* Whether to move the invariant. */ | |
110 | bool move; | |
111 | ||
cb20f7e8 | 112 | /* Cost of the invariant. */ |
5e962776 ZD |
113 | unsigned cost; |
114 | ||
115 | /* The invariants it depends on. */ | |
116 | bitmap depends_on; | |
117 | ||
118 | /* Used for detecting already visited invariants during determining | |
119 | costs of movements. */ | |
120 | unsigned stamp; | |
121 | }; | |
122 | ||
1052bd54 ZD |
123 | /* Entry for hash table of invariant expressions. */ |
124 | ||
125 | struct invariant_expr_entry | |
126 | { | |
127 | /* The invariant. */ | |
128 | struct invariant *inv; | |
129 | ||
130 | /* Its value. */ | |
131 | rtx expr; | |
132 | ||
133 | /* Its mode. */ | |
134 | enum machine_mode mode; | |
135 | ||
136 | /* Its hash. */ | |
137 | hashval_t hash; | |
138 | }; | |
139 | ||
5e962776 ZD |
140 | /* The actual stamp for marking already visited invariants during determining |
141 | costs of movements. */ | |
142 | ||
143 | static unsigned actual_stamp; | |
144 | ||
edd954e6 KH |
145 | typedef struct invariant *invariant_p; |
146 | ||
147 | DEF_VEC_P(invariant_p); | |
148 | DEF_VEC_ALLOC_P(invariant_p, heap); | |
149 | ||
5e962776 ZD |
150 | /* The invariants. */ |
151 | ||
edd954e6 | 152 | static VEC(invariant_p,heap) *invariants; |
5e962776 | 153 | |
cb20f7e8 ZD |
154 | /* The dataflow object. */ |
155 | ||
4d779342 | 156 | static struct df *df = NULL; |
cb20f7e8 | 157 | |
5e962776 ZD |
158 | /* Test for possibility of invariantness of X. */ |
159 | ||
160 | static bool | |
161 | check_maybe_invariant (rtx x) | |
162 | { | |
163 | enum rtx_code code = GET_CODE (x); | |
164 | int i, j; | |
165 | const char *fmt; | |
166 | ||
167 | switch (code) | |
168 | { | |
169 | case CONST_INT: | |
170 | case CONST_DOUBLE: | |
171 | case SYMBOL_REF: | |
172 | case CONST: | |
173 | case LABEL_REF: | |
174 | return true; | |
175 | ||
176 | case PC: | |
177 | case CC0: | |
178 | case UNSPEC_VOLATILE: | |
179 | case CALL: | |
180 | return false; | |
181 | ||
182 | case REG: | |
183 | return true; | |
184 | ||
185 | case MEM: | |
186 | /* Load/store motion is done elsewhere. ??? Perhaps also add it here? | |
187 | It should not be hard, and might be faster than "elsewhere". */ | |
188 | ||
189 | /* Just handle the most trivial case where we load from an unchanging | |
190 | location (most importantly, pic tables). */ | |
389fdba0 | 191 | if (MEM_READONLY_P (x)) |
5e962776 ZD |
192 | break; |
193 | ||
194 | return false; | |
195 | ||
196 | case ASM_OPERANDS: | |
197 | /* Don't mess with insns declared volatile. */ | |
198 | if (MEM_VOLATILE_P (x)) | |
199 | return false; | |
200 | break; | |
201 | ||
202 | default: | |
203 | break; | |
204 | } | |
205 | ||
206 | fmt = GET_RTX_FORMAT (code); | |
207 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
208 | { | |
209 | if (fmt[i] == 'e') | |
210 | { | |
211 | if (!check_maybe_invariant (XEXP (x, i))) | |
212 | return false; | |
213 | } | |
214 | else if (fmt[i] == 'E') | |
215 | { | |
216 | for (j = 0; j < XVECLEN (x, i); j++) | |
217 | if (!check_maybe_invariant (XVECEXP (x, i, j))) | |
218 | return false; | |
219 | } | |
220 | } | |
221 | ||
222 | return true; | |
223 | } | |
224 | ||
1052bd54 ZD |
225 | /* Returns the invariant definition for USE, or NULL if USE is not |
226 | invariant. */ | |
227 | ||
228 | static struct invariant * | |
4d779342 | 229 | invariant_for_use (struct df_ref *use) |
1052bd54 ZD |
230 | { |
231 | struct df_link *defs; | |
4d779342 | 232 | struct df_ref *def; |
1052bd54 ZD |
233 | basic_block bb = BLOCK_FOR_INSN (use->insn), def_bb; |
234 | ||
235 | defs = DF_REF_CHAIN (use); | |
236 | if (!defs || defs->next) | |
237 | return NULL; | |
238 | def = defs->ref; | |
239 | if (!DF_REF_DATA (def)) | |
240 | return NULL; | |
241 | ||
242 | def_bb = DF_REF_BB (def); | |
243 | if (!dominated_by_p (CDI_DOMINATORS, bb, def_bb)) | |
244 | return NULL; | |
245 | return DF_REF_DATA (def); | |
246 | } | |
247 | ||
248 | /* Computes hash value for invariant expression X in INSN. */ | |
249 | ||
250 | static hashval_t | |
251 | hash_invariant_expr_1 (rtx insn, rtx x) | |
252 | { | |
253 | enum rtx_code code = GET_CODE (x); | |
254 | int i, j; | |
255 | const char *fmt; | |
256 | hashval_t val = code; | |
257 | int do_not_record_p; | |
4d779342 | 258 | struct df_ref *use; |
1052bd54 ZD |
259 | struct invariant *inv; |
260 | ||
261 | switch (code) | |
262 | { | |
263 | case CONST_INT: | |
264 | case CONST_DOUBLE: | |
265 | case SYMBOL_REF: | |
266 | case CONST: | |
267 | case LABEL_REF: | |
268 | return hash_rtx (x, GET_MODE (x), &do_not_record_p, NULL, false); | |
269 | ||
270 | case REG: | |
271 | use = df_find_use (df, insn, x); | |
272 | if (!use) | |
273 | return hash_rtx (x, GET_MODE (x), &do_not_record_p, NULL, false); | |
274 | inv = invariant_for_use (use); | |
275 | if (!inv) | |
276 | return hash_rtx (x, GET_MODE (x), &do_not_record_p, NULL, false); | |
277 | ||
278 | gcc_assert (inv->eqto != ~0u); | |
279 | return inv->eqto; | |
280 | ||
281 | default: | |
282 | break; | |
283 | } | |
284 | ||
285 | fmt = GET_RTX_FORMAT (code); | |
286 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
287 | { | |
288 | if (fmt[i] == 'e') | |
289 | val ^= hash_invariant_expr_1 (insn, XEXP (x, i)); | |
290 | else if (fmt[i] == 'E') | |
291 | { | |
292 | for (j = 0; j < XVECLEN (x, i); j++) | |
293 | val ^= hash_invariant_expr_1 (insn, XVECEXP (x, i, j)); | |
294 | } | |
295 | } | |
296 | ||
297 | return val; | |
298 | } | |
299 | ||
300 | /* Returns true if the invariant expressions E1 and E2 used in insns INSN1 | |
301 | and INSN2 have always the same value. */ | |
302 | ||
303 | static bool | |
304 | invariant_expr_equal_p (rtx insn1, rtx e1, rtx insn2, rtx e2) | |
305 | { | |
306 | enum rtx_code code = GET_CODE (e1); | |
307 | int i, j; | |
308 | const char *fmt; | |
4d779342 | 309 | struct df_ref *use1, *use2; |
1052bd54 ZD |
310 | struct invariant *inv1 = NULL, *inv2 = NULL; |
311 | rtx sub1, sub2; | |
312 | ||
313 | /* If mode of only one of the operands is VOIDmode, it is not equivalent to | |
314 | the other one. If both are VOIDmode, we rely on the caller of this | |
315 | function to verify that their modes are the same. */ | |
316 | if (code != GET_CODE (e2) || GET_MODE (e1) != GET_MODE (e2)) | |
317 | return false; | |
318 | ||
319 | switch (code) | |
320 | { | |
321 | case CONST_INT: | |
322 | case CONST_DOUBLE: | |
323 | case SYMBOL_REF: | |
324 | case CONST: | |
325 | case LABEL_REF: | |
326 | return rtx_equal_p (e1, e2); | |
327 | ||
328 | case REG: | |
329 | use1 = df_find_use (df, insn1, e1); | |
330 | use2 = df_find_use (df, insn2, e2); | |
331 | if (use1) | |
332 | inv1 = invariant_for_use (use1); | |
333 | if (use2) | |
334 | inv2 = invariant_for_use (use2); | |
335 | ||
336 | if (!inv1 && !inv2) | |
337 | return rtx_equal_p (e1, e2); | |
338 | ||
339 | if (!inv1 || !inv2) | |
340 | return false; | |
341 | ||
342 | gcc_assert (inv1->eqto != ~0u); | |
343 | gcc_assert (inv2->eqto != ~0u); | |
344 | return inv1->eqto == inv2->eqto; | |
345 | ||
346 | default: | |
347 | break; | |
348 | } | |
349 | ||
350 | fmt = GET_RTX_FORMAT (code); | |
351 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
352 | { | |
353 | if (fmt[i] == 'e') | |
354 | { | |
355 | sub1 = XEXP (e1, i); | |
356 | sub2 = XEXP (e2, i); | |
357 | ||
358 | if (!invariant_expr_equal_p (insn1, sub1, insn2, sub2)) | |
359 | return false; | |
360 | } | |
361 | ||
362 | else if (fmt[i] == 'E') | |
363 | { | |
364 | if (XVECLEN (e1, i) != XVECLEN (e2, i)) | |
365 | return false; | |
366 | ||
367 | for (j = 0; j < XVECLEN (e1, i); j++) | |
368 | { | |
369 | sub1 = XVECEXP (e1, i, j); | |
370 | sub2 = XVECEXP (e2, i, j); | |
371 | ||
372 | if (!invariant_expr_equal_p (insn1, sub1, insn2, sub2)) | |
373 | return false; | |
374 | } | |
375 | } | |
376 | } | |
377 | ||
378 | return true; | |
379 | } | |
380 | ||
381 | /* Returns hash value for invariant expression entry E. */ | |
382 | ||
383 | static hashval_t | |
384 | hash_invariant_expr (const void *e) | |
385 | { | |
386 | const struct invariant_expr_entry *entry = e; | |
387 | ||
388 | return entry->hash; | |
389 | } | |
390 | ||
391 | /* Compares invariant expression entries E1 and E2. */ | |
392 | ||
393 | static int | |
394 | eq_invariant_expr (const void *e1, const void *e2) | |
395 | { | |
396 | const struct invariant_expr_entry *entry1 = e1; | |
397 | const struct invariant_expr_entry *entry2 = e2; | |
398 | ||
399 | if (entry1->mode != entry2->mode) | |
400 | return 0; | |
401 | ||
402 | return invariant_expr_equal_p (entry1->inv->insn, entry1->expr, | |
403 | entry2->inv->insn, entry2->expr); | |
404 | } | |
405 | ||
406 | /* Checks whether invariant with value EXPR in machine mode MODE is | |
407 | recorded in EQ. If this is the case, return the invariant. Otherwise | |
408 | insert INV to the table for this expression and return INV. */ | |
409 | ||
410 | static struct invariant * | |
411 | find_or_insert_inv (htab_t eq, rtx expr, enum machine_mode mode, | |
412 | struct invariant *inv) | |
413 | { | |
414 | hashval_t hash = hash_invariant_expr_1 (inv->insn, expr); | |
415 | struct invariant_expr_entry *entry; | |
416 | struct invariant_expr_entry pentry; | |
417 | PTR *slot; | |
418 | ||
419 | pentry.expr = expr; | |
420 | pentry.inv = inv; | |
421 | pentry.mode = mode; | |
422 | slot = htab_find_slot_with_hash (eq, &pentry, hash, INSERT); | |
423 | entry = *slot; | |
424 | ||
425 | if (entry) | |
426 | return entry->inv; | |
427 | ||
5ed6ace5 | 428 | entry = XNEW (struct invariant_expr_entry); |
1052bd54 ZD |
429 | entry->inv = inv; |
430 | entry->expr = expr; | |
431 | entry->mode = mode; | |
432 | entry->hash = hash; | |
433 | *slot = entry; | |
434 | ||
435 | return inv; | |
436 | } | |
437 | ||
438 | /* Finds invariants identical to INV and records the equivalence. EQ is the | |
439 | hash table of the invariants. */ | |
440 | ||
441 | static void | |
442 | find_identical_invariants (htab_t eq, struct invariant *inv) | |
443 | { | |
444 | unsigned depno; | |
445 | bitmap_iterator bi; | |
446 | struct invariant *dep; | |
447 | rtx expr, set; | |
448 | enum machine_mode mode; | |
449 | ||
450 | if (inv->eqto != ~0u) | |
451 | return; | |
452 | ||
453 | EXECUTE_IF_SET_IN_BITMAP (inv->depends_on, 0, depno, bi) | |
454 | { | |
455 | dep = VEC_index (invariant_p, invariants, depno); | |
456 | find_identical_invariants (eq, dep); | |
457 | } | |
458 | ||
459 | set = single_set (inv->insn); | |
460 | expr = SET_SRC (set); | |
461 | mode = GET_MODE (expr); | |
462 | if (mode == VOIDmode) | |
463 | mode = GET_MODE (SET_DEST (set)); | |
464 | inv->eqto = find_or_insert_inv (eq, expr, mode, inv)->invno; | |
465 | ||
466 | if (dump_file && inv->eqto != inv->invno) | |
467 | fprintf (dump_file, | |
468 | "Invariant %d is equivalent to invariant %d.\n ", | |
469 | inv->invno, inv->eqto); | |
470 | } | |
471 | ||
472 | /* Find invariants with the same value and record the equivalences. */ | |
473 | ||
474 | static void | |
475 | merge_identical_invariants (void) | |
476 | { | |
477 | unsigned i; | |
478 | struct invariant *inv; | |
479 | htab_t eq = htab_create (VEC_length (invariant_p, invariants), | |
480 | hash_invariant_expr, eq_invariant_expr, free); | |
481 | ||
482 | for (i = 0; VEC_iterate (invariant_p, invariants, i, inv); i++) | |
483 | find_identical_invariants (eq, inv); | |
484 | ||
485 | htab_delete (eq); | |
486 | } | |
487 | ||
5e962776 ZD |
488 | /* Determines the basic blocks inside LOOP that are always executed and |
489 | stores their bitmap to ALWAYS_REACHED. MAY_EXIT is a bitmap of | |
490 | basic blocks that may either exit the loop, or contain the call that | |
491 | does not have to return. BODY is body of the loop obtained by | |
492 | get_loop_body_in_dom_order. */ | |
493 | ||
494 | static void | |
495 | compute_always_reached (struct loop *loop, basic_block *body, | |
496 | bitmap may_exit, bitmap always_reached) | |
497 | { | |
498 | unsigned i; | |
499 | ||
500 | for (i = 0; i < loop->num_nodes; i++) | |
501 | { | |
502 | if (dominated_by_p (CDI_DOMINATORS, loop->latch, body[i])) | |
503 | bitmap_set_bit (always_reached, i); | |
504 | ||
505 | if (bitmap_bit_p (may_exit, i)) | |
506 | return; | |
507 | } | |
508 | } | |
509 | ||
510 | /* Finds exits out of the LOOP with body BODY. Marks blocks in that we may | |
511 | exit the loop by cfg edge to HAS_EXIT and MAY_EXIT. In MAY_EXIT | |
512 | additionally mark blocks that may exit due to a call. */ | |
513 | ||
514 | static void | |
515 | find_exits (struct loop *loop, basic_block *body, | |
516 | bitmap may_exit, bitmap has_exit) | |
517 | { | |
518 | unsigned i; | |
628f6a4e | 519 | edge_iterator ei; |
5e962776 ZD |
520 | edge e; |
521 | struct loop *outermost_exit = loop, *aexit; | |
522 | bool has_call = false; | |
523 | rtx insn; | |
524 | ||
525 | for (i = 0; i < loop->num_nodes; i++) | |
526 | { | |
527 | if (body[i]->loop_father == loop) | |
528 | { | |
529 | FOR_BB_INSNS (body[i], insn) | |
530 | { | |
4b4bf941 | 531 | if (CALL_P (insn) |
5e962776 ZD |
532 | && !CONST_OR_PURE_CALL_P (insn)) |
533 | { | |
534 | has_call = true; | |
535 | bitmap_set_bit (may_exit, i); | |
536 | break; | |
537 | } | |
538 | } | |
539 | ||
628f6a4e | 540 | FOR_EACH_EDGE (e, ei, body[i]->succs) |
5e962776 ZD |
541 | { |
542 | if (flow_bb_inside_loop_p (loop, e->dest)) | |
543 | continue; | |
544 | ||
545 | bitmap_set_bit (may_exit, i); | |
546 | bitmap_set_bit (has_exit, i); | |
547 | outermost_exit = find_common_loop (outermost_exit, | |
548 | e->dest->loop_father); | |
549 | } | |
550 | continue; | |
551 | } | |
cb20f7e8 | 552 | |
5e962776 ZD |
553 | /* Use the data stored for the subloop to decide whether we may exit |
554 | through it. It is sufficient to do this for header of the loop, | |
555 | as other basic blocks inside it must be dominated by it. */ | |
556 | if (body[i]->loop_father->header != body[i]) | |
557 | continue; | |
558 | ||
559 | if (LOOP_DATA (body[i]->loop_father)->has_call) | |
560 | { | |
561 | has_call = true; | |
562 | bitmap_set_bit (may_exit, i); | |
563 | } | |
564 | aexit = LOOP_DATA (body[i]->loop_father)->outermost_exit; | |
565 | if (aexit != loop) | |
566 | { | |
567 | bitmap_set_bit (may_exit, i); | |
568 | bitmap_set_bit (has_exit, i); | |
569 | ||
570 | if (flow_loop_nested_p (aexit, outermost_exit)) | |
571 | outermost_exit = aexit; | |
572 | } | |
573 | } | |
574 | ||
575 | loop->aux = xcalloc (1, sizeof (struct loop_data)); | |
576 | LOOP_DATA (loop)->outermost_exit = outermost_exit; | |
577 | LOOP_DATA (loop)->has_call = has_call; | |
578 | } | |
579 | ||
580 | /* Check whether we may assign a value to X from a register. */ | |
581 | ||
582 | static bool | |
583 | may_assign_reg_p (rtx x) | |
584 | { | |
a7f4ccb1 SB |
585 | return (can_copy_p (GET_MODE (x)) |
586 | && (!REG_P (x) | |
587 | || !HARD_REGISTER_P (x) | |
588 | || REGNO_REG_CLASS (REGNO (x)) != NO_REGS)); | |
5e962776 ZD |
589 | } |
590 | ||
cb20f7e8 ZD |
591 | /* Finds definitions that may correspond to invariants in LOOP with body |
592 | BODY. */ | |
5e962776 ZD |
593 | |
594 | static void | |
cb20f7e8 | 595 | find_defs (struct loop *loop, basic_block *body) |
5e962776 ZD |
596 | { |
597 | unsigned i; | |
8bdbfff5 | 598 | bitmap blocks = BITMAP_ALLOC (NULL); |
5e962776 ZD |
599 | |
600 | for (i = 0; i < loop->num_nodes; i++) | |
601 | bitmap_set_bit (blocks, body[i]->index); | |
602 | ||
4d779342 DB |
603 | df_set_blocks (df, blocks); |
604 | df_analyze (df); | |
8bdbfff5 | 605 | BITMAP_FREE (blocks); |
5e962776 ZD |
606 | } |
607 | ||
608 | /* Creates a new invariant for definition DEF in INSN, depending on invariants | |
609 | in DEPENDS_ON. ALWAYS_EXECUTED is true if the insn is always executed, | |
1052bd54 ZD |
610 | unless the program ends due to a function call. The newly created invariant |
611 | is returned. */ | |
5e962776 | 612 | |
1052bd54 | 613 | static struct invariant * |
5e962776 ZD |
614 | create_new_invariant (struct def *def, rtx insn, bitmap depends_on, |
615 | bool always_executed) | |
616 | { | |
5ed6ace5 | 617 | struct invariant *inv = XNEW (struct invariant); |
5e962776 ZD |
618 | rtx set = single_set (insn); |
619 | ||
620 | inv->def = def; | |
621 | inv->always_executed = always_executed; | |
622 | inv->depends_on = depends_on; | |
623 | ||
624 | /* If the set is simple, usually by moving it we move the whole store out of | |
625 | the loop. Otherwise we save only cost of the computation. */ | |
626 | if (def) | |
627 | inv->cost = rtx_cost (set, SET); | |
628 | else | |
629 | inv->cost = rtx_cost (SET_SRC (set), SET); | |
630 | ||
631 | inv->move = false; | |
1052bd54 | 632 | inv->reg = NULL_RTX; |
5e962776 ZD |
633 | inv->stamp = 0; |
634 | inv->insn = insn; | |
635 | ||
edd954e6 | 636 | inv->invno = VEC_length (invariant_p, invariants); |
1052bd54 | 637 | inv->eqto = ~0u; |
5e962776 ZD |
638 | if (def) |
639 | def->invno = inv->invno; | |
edd954e6 | 640 | VEC_safe_push (invariant_p, heap, invariants, inv); |
5e962776 ZD |
641 | |
642 | if (dump_file) | |
643 | { | |
644 | fprintf (dump_file, | |
645 | "Set in insn %d is invariant (%d), cost %d, depends on ", | |
646 | INSN_UID (insn), inv->invno, inv->cost); | |
647 | dump_bitmap (dump_file, inv->depends_on); | |
648 | } | |
1052bd54 ZD |
649 | |
650 | return inv; | |
5e962776 ZD |
651 | } |
652 | ||
653 | /* Record USE at DEF. */ | |
654 | ||
655 | static void | |
656 | record_use (struct def *def, rtx *use, rtx insn) | |
657 | { | |
5ed6ace5 | 658 | struct use *u = XNEW (struct use); |
5e962776 ZD |
659 | |
660 | if (GET_CODE (*use) == SUBREG) | |
661 | use = &SUBREG_REG (*use); | |
b5e624c6 | 662 | gcc_assert (REG_P (*use)); |
5e962776 ZD |
663 | |
664 | u->pos = use; | |
665 | u->insn = insn; | |
666 | u->next = def->uses; | |
667 | def->uses = u; | |
668 | def->n_uses++; | |
669 | } | |
670 | ||
671 | /* Finds the invariants INSN depends on and store them to the DEPENDS_ON | |
cb20f7e8 | 672 | bitmap. */ |
5e962776 ZD |
673 | |
674 | static bool | |
cb20f7e8 | 675 | check_dependencies (rtx insn, bitmap depends_on) |
5e962776 | 676 | { |
4d779342 DB |
677 | struct df_link *defs; |
678 | struct df_ref *use, *def; | |
5e962776 ZD |
679 | basic_block bb = BLOCK_FOR_INSN (insn), def_bb; |
680 | struct def *def_data; | |
1052bd54 ZD |
681 | struct invariant *inv; |
682 | ||
4d779342 | 683 | for (use = DF_INSN_GET (df, insn)->uses; use; use = use->next_ref) |
5e962776 | 684 | { |
5e962776 ZD |
685 | defs = DF_REF_CHAIN (use); |
686 | if (!defs) | |
687 | continue; | |
688 | ||
689 | if (defs->next) | |
690 | return false; | |
691 | ||
692 | def = defs->ref; | |
1052bd54 ZD |
693 | inv = DF_REF_DATA (def); |
694 | if (!inv) | |
5e962776 ZD |
695 | return false; |
696 | ||
1052bd54 ZD |
697 | def_data = inv->def; |
698 | gcc_assert (def_data != NULL); | |
699 | ||
5e962776 | 700 | def_bb = DF_REF_BB (def); |
1052bd54 ZD |
701 | /* Note that in case bb == def_bb, we know that the definition dominates |
702 | insn, because def has DF_REF_DATA defined and we process the insns | |
703 | in the basic block bb sequentially. */ | |
5e962776 ZD |
704 | if (!dominated_by_p (CDI_DOMINATORS, bb, def_bb)) |
705 | return false; | |
706 | ||
707 | bitmap_set_bit (depends_on, def_data->invno); | |
708 | } | |
709 | ||
710 | return true; | |
711 | } | |
712 | ||
713 | /* Finds invariant in INSN. ALWAYS_REACHED is true if the insn is always | |
714 | executed. ALWAYS_EXECUTED is true if the insn is always executed, | |
cb20f7e8 | 715 | unless the program ends due to a function call. */ |
5e962776 ZD |
716 | |
717 | static void | |
cb20f7e8 | 718 | find_invariant_insn (rtx insn, bool always_reached, bool always_executed) |
5e962776 | 719 | { |
4d779342 | 720 | struct df_ref *ref; |
5e962776 ZD |
721 | struct def *def; |
722 | bitmap depends_on; | |
723 | rtx set, dest; | |
724 | bool simple = true; | |
1052bd54 | 725 | struct invariant *inv; |
5e962776 ZD |
726 | |
727 | /* Until we get rid of LIBCALLS. */ | |
728 | if (find_reg_note (insn, REG_RETVAL, NULL_RTX) | |
729 | || find_reg_note (insn, REG_LIBCALL, NULL_RTX) | |
730 | || find_reg_note (insn, REG_NO_CONFLICT, NULL_RTX)) | |
731 | return; | |
1052bd54 | 732 | |
00f70f98 ZD |
733 | #ifdef HAVE_cc0 |
734 | /* We can't move a CC0 setter without the user. */ | |
735 | if (sets_cc0_p (insn)) | |
736 | return; | |
737 | #endif | |
738 | ||
5e962776 ZD |
739 | set = single_set (insn); |
740 | if (!set) | |
741 | return; | |
742 | dest = SET_DEST (set); | |
743 | ||
2ca202e7 | 744 | if (!REG_P (dest) |
5e962776 ZD |
745 | || HARD_REGISTER_P (dest)) |
746 | simple = false; | |
747 | ||
a7f4ccb1 SB |
748 | if (!may_assign_reg_p (SET_DEST (set)) |
749 | || !check_maybe_invariant (SET_SRC (set))) | |
5e962776 ZD |
750 | return; |
751 | ||
752 | if (may_trap_p (PATTERN (insn))) | |
753 | { | |
754 | if (!always_reached) | |
755 | return; | |
756 | ||
757 | /* Unless the exceptions are handled, the behavior is undefined | |
758 | if the trap occurs. */ | |
759 | if (flag_non_call_exceptions) | |
760 | return; | |
761 | } | |
762 | ||
8bdbfff5 | 763 | depends_on = BITMAP_ALLOC (NULL); |
cb20f7e8 | 764 | if (!check_dependencies (insn, depends_on)) |
5e962776 | 765 | { |
8bdbfff5 | 766 | BITMAP_FREE (depends_on); |
5e962776 ZD |
767 | return; |
768 | } | |
769 | ||
770 | if (simple) | |
5ed6ace5 | 771 | def = XCNEW (struct def); |
5e962776 ZD |
772 | else |
773 | def = NULL; | |
774 | ||
1052bd54 ZD |
775 | inv = create_new_invariant (def, insn, depends_on, always_executed); |
776 | ||
777 | if (simple) | |
778 | { | |
779 | ref = df_find_def (df, insn, dest); | |
780 | DF_REF_DATA (ref) = inv; | |
781 | } | |
5e962776 ZD |
782 | } |
783 | ||
cb20f7e8 | 784 | /* Record registers used in INSN that have a unique invariant definition. */ |
5e962776 ZD |
785 | |
786 | static void | |
cb20f7e8 | 787 | record_uses (rtx insn) |
5e962776 | 788 | { |
4d779342 | 789 | struct df_ref *use; |
1052bd54 ZD |
790 | struct invariant *inv; |
791 | ||
4d779342 | 792 | for (use = DF_INSN_GET (df, insn)->uses; use; use = use->next_ref) |
5e962776 | 793 | { |
1052bd54 ZD |
794 | inv = invariant_for_use (use); |
795 | if (inv) | |
796 | record_use (inv->def, DF_REF_LOC (use), DF_REF_INSN (use)); | |
5e962776 ZD |
797 | } |
798 | } | |
799 | ||
800 | /* Finds invariants in INSN. ALWAYS_REACHED is true if the insn is always | |
801 | executed. ALWAYS_EXECUTED is true if the insn is always executed, | |
cb20f7e8 | 802 | unless the program ends due to a function call. */ |
5e962776 ZD |
803 | |
804 | static void | |
cb20f7e8 | 805 | find_invariants_insn (rtx insn, bool always_reached, bool always_executed) |
5e962776 | 806 | { |
cb20f7e8 ZD |
807 | find_invariant_insn (insn, always_reached, always_executed); |
808 | record_uses (insn); | |
5e962776 ZD |
809 | } |
810 | ||
811 | /* Finds invariants in basic block BB. ALWAYS_REACHED is true if the | |
812 | basic block is always executed. ALWAYS_EXECUTED is true if the basic | |
813 | block is always executed, unless the program ends due to a function | |
cb20f7e8 | 814 | call. */ |
5e962776 ZD |
815 | |
816 | static void | |
cb20f7e8 | 817 | find_invariants_bb (basic_block bb, bool always_reached, bool always_executed) |
5e962776 ZD |
818 | { |
819 | rtx insn; | |
820 | ||
821 | FOR_BB_INSNS (bb, insn) | |
822 | { | |
823 | if (!INSN_P (insn)) | |
824 | continue; | |
825 | ||
cb20f7e8 | 826 | find_invariants_insn (insn, always_reached, always_executed); |
5e962776 ZD |
827 | |
828 | if (always_reached | |
4b4bf941 | 829 | && CALL_P (insn) |
5e962776 ZD |
830 | && !CONST_OR_PURE_CALL_P (insn)) |
831 | always_reached = false; | |
832 | } | |
833 | } | |
834 | ||
835 | /* Finds invariants in LOOP with body BODY. ALWAYS_REACHED is the bitmap of | |
836 | basic blocks in BODY that are always executed. ALWAYS_EXECUTED is the | |
837 | bitmap of basic blocks in BODY that are always executed unless the program | |
cb20f7e8 | 838 | ends due to a function call. */ |
5e962776 ZD |
839 | |
840 | static void | |
841 | find_invariants_body (struct loop *loop, basic_block *body, | |
cb20f7e8 | 842 | bitmap always_reached, bitmap always_executed) |
5e962776 ZD |
843 | { |
844 | unsigned i; | |
845 | ||
846 | for (i = 0; i < loop->num_nodes; i++) | |
847 | find_invariants_bb (body[i], | |
848 | bitmap_bit_p (always_reached, i), | |
cb20f7e8 | 849 | bitmap_bit_p (always_executed, i)); |
5e962776 ZD |
850 | } |
851 | ||
cb20f7e8 | 852 | /* Finds invariants in LOOP. */ |
5e962776 ZD |
853 | |
854 | static void | |
cb20f7e8 | 855 | find_invariants (struct loop *loop) |
5e962776 | 856 | { |
8bdbfff5 NS |
857 | bitmap may_exit = BITMAP_ALLOC (NULL); |
858 | bitmap always_reached = BITMAP_ALLOC (NULL); | |
859 | bitmap has_exit = BITMAP_ALLOC (NULL); | |
860 | bitmap always_executed = BITMAP_ALLOC (NULL); | |
5e962776 ZD |
861 | basic_block *body = get_loop_body_in_dom_order (loop); |
862 | ||
863 | find_exits (loop, body, may_exit, has_exit); | |
864 | compute_always_reached (loop, body, may_exit, always_reached); | |
865 | compute_always_reached (loop, body, has_exit, always_executed); | |
866 | ||
cb20f7e8 ZD |
867 | find_defs (loop, body); |
868 | find_invariants_body (loop, body, always_reached, always_executed); | |
1052bd54 | 869 | merge_identical_invariants (); |
5e962776 | 870 | |
8bdbfff5 NS |
871 | BITMAP_FREE (always_reached); |
872 | BITMAP_FREE (always_executed); | |
873 | BITMAP_FREE (may_exit); | |
874 | BITMAP_FREE (has_exit); | |
5e962776 ZD |
875 | free (body); |
876 | } | |
877 | ||
878 | /* Frees a list of uses USE. */ | |
879 | ||
880 | static void | |
881 | free_use_list (struct use *use) | |
882 | { | |
883 | struct use *next; | |
884 | ||
885 | for (; use; use = next) | |
886 | { | |
887 | next = use->next; | |
888 | free (use); | |
889 | } | |
890 | } | |
891 | ||
892 | /* Calculates cost and number of registers needed for moving invariant INV | |
893 | out of the loop and stores them to *COST and *REGS_NEEDED. */ | |
894 | ||
895 | static void | |
896 | get_inv_cost (struct invariant *inv, int *comp_cost, unsigned *regs_needed) | |
897 | { | |
898 | int acomp_cost; | |
899 | unsigned aregs_needed; | |
900 | unsigned depno; | |
901 | struct invariant *dep; | |
87c476a2 | 902 | bitmap_iterator bi; |
5e962776 | 903 | |
1052bd54 ZD |
904 | /* Find the representative of the class of the equivalent invariants. */ |
905 | inv = VEC_index (invariant_p, invariants, inv->eqto); | |
906 | ||
5e962776 ZD |
907 | *comp_cost = 0; |
908 | *regs_needed = 0; | |
909 | if (inv->move | |
910 | || inv->stamp == actual_stamp) | |
911 | return; | |
912 | inv->stamp = actual_stamp; | |
913 | ||
914 | (*regs_needed)++; | |
915 | (*comp_cost) += inv->cost; | |
916 | ||
87c476a2 | 917 | EXECUTE_IF_SET_IN_BITMAP (inv->depends_on, 0, depno, bi) |
5e962776 | 918 | { |
edd954e6 | 919 | dep = VEC_index (invariant_p, invariants, depno); |
5e962776 ZD |
920 | |
921 | get_inv_cost (dep, &acomp_cost, &aregs_needed); | |
922 | ||
923 | if (aregs_needed | |
924 | /* We need to check always_executed, since if the original value of | |
925 | the invariant may be preserved, we may need to keep it in a | |
926 | separate register. TODO check whether the register has an | |
927 | use outside of the loop. */ | |
928 | && dep->always_executed | |
929 | && !dep->def->uses->next) | |
930 | { | |
931 | /* If this is a single use, after moving the dependency we will not | |
932 | need a new register. */ | |
933 | aregs_needed--; | |
934 | } | |
935 | ||
936 | (*regs_needed) += aregs_needed; | |
937 | (*comp_cost) += acomp_cost; | |
87c476a2 | 938 | } |
5e962776 ZD |
939 | } |
940 | ||
941 | /* Calculates gain for eliminating invariant INV. REGS_USED is the number | |
942 | of registers used in the loop, N_INV_USES is the number of uses of | |
943 | invariants, NEW_REGS is the number of new variables already added due to | |
944 | the invariant motion. The number of registers needed for it is stored in | |
945 | *REGS_NEEDED. */ | |
946 | ||
947 | static int | |
948 | gain_for_invariant (struct invariant *inv, unsigned *regs_needed, | |
949 | unsigned new_regs, unsigned regs_used, unsigned n_inv_uses) | |
950 | { | |
951 | int comp_cost, size_cost; | |
952 | ||
953 | get_inv_cost (inv, &comp_cost, regs_needed); | |
954 | actual_stamp++; | |
955 | ||
956 | size_cost = (global_cost_for_size (new_regs + *regs_needed, | |
957 | regs_used, n_inv_uses) | |
958 | - global_cost_for_size (new_regs, regs_used, n_inv_uses)); | |
959 | ||
960 | return comp_cost - size_cost; | |
961 | } | |
962 | ||
963 | /* Finds invariant with best gain for moving. Returns the gain, stores | |
964 | the invariant in *BEST and number of registers needed for it to | |
965 | *REGS_NEEDED. REGS_USED is the number of registers used in | |
966 | the loop, N_INV_USES is the number of uses of invariants. NEW_REGS | |
967 | is the number of new variables already added due to invariant motion. */ | |
968 | ||
969 | static int | |
970 | best_gain_for_invariant (struct invariant **best, unsigned *regs_needed, | |
971 | unsigned new_regs, unsigned regs_used, | |
972 | unsigned n_inv_uses) | |
973 | { | |
974 | struct invariant *inv; | |
975 | int gain = 0, again; | |
976 | unsigned aregs_needed, invno; | |
977 | ||
edd954e6 | 978 | for (invno = 0; VEC_iterate (invariant_p, invariants, invno, inv); invno++) |
5e962776 | 979 | { |
5e962776 ZD |
980 | if (inv->move) |
981 | continue; | |
982 | ||
1052bd54 ZD |
983 | /* Only consider the "representatives" of equivalent invariants. */ |
984 | if (inv->eqto != inv->invno) | |
985 | continue; | |
986 | ||
5e962776 ZD |
987 | again = gain_for_invariant (inv, &aregs_needed, |
988 | new_regs, regs_used, n_inv_uses); | |
989 | if (again > gain) | |
990 | { | |
991 | gain = again; | |
992 | *best = inv; | |
993 | *regs_needed = aregs_needed; | |
994 | } | |
995 | } | |
996 | ||
997 | return gain; | |
998 | } | |
999 | ||
1000 | /* Marks invariant INVNO and all its dependencies for moving. */ | |
1001 | ||
1002 | static void | |
1003 | set_move_mark (unsigned invno) | |
1004 | { | |
edd954e6 | 1005 | struct invariant *inv = VEC_index (invariant_p, invariants, invno); |
87c476a2 | 1006 | bitmap_iterator bi; |
5e962776 | 1007 | |
1052bd54 ZD |
1008 | /* Find the representative of the class of the equivalent invariants. */ |
1009 | inv = VEC_index (invariant_p, invariants, inv->eqto); | |
1010 | ||
5e962776 ZD |
1011 | if (inv->move) |
1012 | return; | |
1013 | inv->move = true; | |
1014 | ||
1015 | if (dump_file) | |
1016 | fprintf (dump_file, "Decided to move invariant %d\n", invno); | |
1017 | ||
87c476a2 ZD |
1018 | EXECUTE_IF_SET_IN_BITMAP (inv->depends_on, 0, invno, bi) |
1019 | { | |
1020 | set_move_mark (invno); | |
1021 | } | |
5e962776 ZD |
1022 | } |
1023 | ||
cb20f7e8 | 1024 | /* Determines which invariants to move. */ |
5e962776 ZD |
1025 | |
1026 | static void | |
cb20f7e8 | 1027 | find_invariants_to_move (void) |
5e962776 ZD |
1028 | { |
1029 | unsigned i, regs_used, n_inv_uses, regs_needed = 0, new_regs; | |
1030 | struct invariant *inv = NULL; | |
4d779342 | 1031 | unsigned int n_regs = DF_REG_SIZE (df); |
5e962776 | 1032 | |
edd954e6 | 1033 | if (!VEC_length (invariant_p, invariants)) |
5e962776 ZD |
1034 | return; |
1035 | ||
1036 | /* Now something slightly more involved. First estimate the number of used | |
1037 | registers. */ | |
1038 | n_inv_uses = 0; | |
1039 | ||
1040 | /* We do not really do a good job in this estimation; put some initial bound | |
1041 | here to stand for induction variables etc. that we do not detect. */ | |
1042 | regs_used = 2; | |
1043 | ||
4d779342 | 1044 | for (i = 0; i < n_regs; i++) |
5e962776 ZD |
1045 | { |
1046 | if (!DF_REGNO_FIRST_DEF (df, i) && DF_REGNO_LAST_USE (df, i)) | |
1047 | { | |
1048 | /* This is a value that is used but not changed inside loop. */ | |
1049 | regs_used++; | |
1050 | } | |
1051 | } | |
1052 | ||
edd954e6 | 1053 | for (i = 0; VEC_iterate (invariant_p, invariants, i, inv); i++) |
5e962776 | 1054 | { |
5e962776 ZD |
1055 | if (inv->def) |
1056 | n_inv_uses += inv->def->n_uses; | |
1057 | } | |
1058 | ||
1059 | new_regs = 0; | |
1060 | while (best_gain_for_invariant (&inv, ®s_needed, | |
1061 | new_regs, regs_used, n_inv_uses) > 0) | |
1062 | { | |
1063 | set_move_mark (inv->invno); | |
1064 | new_regs += regs_needed; | |
1065 | } | |
1066 | } | |
1067 | ||
cb20f7e8 | 1068 | /* Move invariant INVNO out of the LOOP. */ |
5e962776 ZD |
1069 | |
1070 | static void | |
cb20f7e8 | 1071 | move_invariant_reg (struct loop *loop, unsigned invno) |
5e962776 | 1072 | { |
edd954e6 | 1073 | struct invariant *inv = VEC_index (invariant_p, invariants, invno); |
1052bd54 | 1074 | struct invariant *repr = VEC_index (invariant_p, invariants, inv->eqto); |
5e962776 ZD |
1075 | unsigned i; |
1076 | basic_block preheader = loop_preheader_edge (loop)->src; | |
1077 | rtx reg, set; | |
1078 | struct use *use; | |
87c476a2 | 1079 | bitmap_iterator bi; |
5e962776 | 1080 | |
1052bd54 ZD |
1081 | if (inv->reg |
1082 | || !repr->move) | |
5e962776 | 1083 | return; |
5e962776 | 1084 | |
1052bd54 ZD |
1085 | /* If this is a representative of the class of equivalent invariants, |
1086 | really move the invariant. Otherwise just replace its use with | |
1087 | the register used for the representative. */ | |
1088 | if (inv == repr) | |
5e962776 | 1089 | { |
1052bd54 | 1090 | if (inv->depends_on) |
5e962776 | 1091 | { |
1052bd54 ZD |
1092 | EXECUTE_IF_SET_IN_BITMAP (inv->depends_on, 0, i, bi) |
1093 | { | |
1094 | move_invariant_reg (loop, i); | |
1095 | } | |
87c476a2 | 1096 | } |
5e962776 | 1097 | |
1052bd54 ZD |
1098 | /* Move the set out of the loop. If the set is always executed (we could |
1099 | omit this condition if we know that the register is unused outside of the | |
1100 | loop, but it does not seem worth finding out) and it has no uses that | |
1101 | would not be dominated by it, we may just move it (TODO). Otherwise we | |
1102 | need to create a temporary register. */ | |
1103 | set = single_set (inv->insn); | |
1104 | reg = gen_reg_rtx (GET_MODE (SET_DEST (set))); | |
4d779342 | 1105 | emit_insn_after (gen_move_insn (SET_DEST (set), reg), inv->insn); |
1052bd54 ZD |
1106 | |
1107 | /* If the SET_DEST of the invariant insn is a reg, we can just move | |
1108 | the insn out of the loop. Otherwise, we have to use gen_move_insn | |
1109 | to let emit_move_insn produce a valid instruction stream. */ | |
1110 | if (REG_P (SET_DEST (set))) | |
1111 | { | |
1112 | SET_DEST (set) = reg; | |
1113 | reorder_insns (inv->insn, inv->insn, BB_END (preheader)); | |
1052bd54 ZD |
1114 | } |
1115 | else | |
1116 | { | |
4d779342 DB |
1117 | emit_insn_after (gen_move_insn (reg, SET_SRC (set)), BB_END (preheader)); |
1118 | delete_insn (inv->insn); | |
1052bd54 | 1119 | } |
b644b211 SB |
1120 | } |
1121 | else | |
1122 | { | |
1052bd54 ZD |
1123 | move_invariant_reg (loop, repr->invno); |
1124 | reg = repr->reg; | |
1125 | set = single_set (inv->insn); | |
4d779342 DB |
1126 | emit_insn_after (gen_move_insn (SET_DEST (set), reg), inv->insn); |
1127 | delete_insn (inv->insn); | |
b644b211 | 1128 | } |
5e962776 | 1129 | |
1052bd54 ZD |
1130 | inv->reg = reg; |
1131 | ||
5e962776 ZD |
1132 | /* Replace the uses we know to be dominated. It saves work for copy |
1133 | propagation, and also it is necessary so that dependent invariants | |
1134 | are computed right. */ | |
1135 | if (inv->def) | |
1136 | { | |
1137 | for (use = inv->def->uses; use; use = use->next) | |
4d779342 | 1138 | *use->pos = reg; |
5e962776 ZD |
1139 | } |
1140 | } | |
1141 | ||
1142 | /* Move selected invariant out of the LOOP. Newly created regs are marked | |
cb20f7e8 | 1143 | in TEMPORARY_REGS. */ |
5e962776 ZD |
1144 | |
1145 | static void | |
cb20f7e8 | 1146 | move_invariants (struct loop *loop) |
5e962776 ZD |
1147 | { |
1148 | struct invariant *inv; | |
1149 | unsigned i; | |
1150 | ||
edd954e6 | 1151 | for (i = 0; VEC_iterate (invariant_p, invariants, i, inv); i++) |
1052bd54 | 1152 | move_invariant_reg (loop, i); |
5e962776 ZD |
1153 | } |
1154 | ||
1155 | /* Initializes invariant motion data. */ | |
1156 | ||
1157 | static void | |
1158 | init_inv_motion_data (void) | |
1159 | { | |
1160 | actual_stamp = 1; | |
1161 | ||
edd954e6 | 1162 | invariants = VEC_alloc (invariant_p, heap, 100); |
5e962776 ZD |
1163 | } |
1164 | ||
cb20f7e8 | 1165 | /* Frees the data allocated by invariant motion. */ |
5e962776 ZD |
1166 | |
1167 | static void | |
cb20f7e8 | 1168 | free_inv_motion_data (void) |
5e962776 ZD |
1169 | { |
1170 | unsigned i; | |
1171 | struct def *def; | |
1172 | struct invariant *inv; | |
1173 | ||
4d779342 | 1174 | for (i = 0; i < DF_DEFS_SIZE (df); i++) |
5e962776 | 1175 | { |
4d779342 DB |
1176 | struct df_ref * ref = DF_DEFS_GET (df, i); |
1177 | if (!ref) | |
5e962776 ZD |
1178 | continue; |
1179 | ||
4d779342 | 1180 | inv = DF_REF_DATA (ref); |
1052bd54 | 1181 | if (!inv) |
5e962776 | 1182 | continue; |
4d779342 | 1183 | |
1052bd54 ZD |
1184 | def = inv->def; |
1185 | gcc_assert (def != NULL); | |
5e962776 ZD |
1186 | |
1187 | free_use_list (def->uses); | |
1188 | free (def); | |
4d779342 | 1189 | DF_REF_DATA (ref) = NULL; |
5e962776 ZD |
1190 | } |
1191 | ||
edd954e6 | 1192 | for (i = 0; VEC_iterate (invariant_p, invariants, i, inv); i++) |
5e962776 | 1193 | { |
8bdbfff5 | 1194 | BITMAP_FREE (inv->depends_on); |
5e962776 ZD |
1195 | free (inv); |
1196 | } | |
edd954e6 | 1197 | VEC_free (invariant_p, heap, invariants); |
5e962776 ZD |
1198 | } |
1199 | ||
cb20f7e8 | 1200 | /* Move the invariants out of the LOOP. */ |
5e962776 ZD |
1201 | |
1202 | static void | |
cb20f7e8 | 1203 | move_single_loop_invariants (struct loop *loop) |
5e962776 ZD |
1204 | { |
1205 | init_inv_motion_data (); | |
1206 | ||
cb20f7e8 ZD |
1207 | find_invariants (loop); |
1208 | find_invariants_to_move (); | |
1209 | move_invariants (loop); | |
5e962776 | 1210 | |
cb20f7e8 | 1211 | free_inv_motion_data (); |
5e962776 ZD |
1212 | } |
1213 | ||
1214 | /* Releases the auxiliary data for LOOP. */ | |
1215 | ||
1216 | static void | |
1217 | free_loop_data (struct loop *loop) | |
1218 | { | |
1219 | struct loop_data *data = LOOP_DATA (loop); | |
1220 | ||
1221 | free (data); | |
1222 | loop->aux = NULL; | |
1223 | } | |
1224 | ||
1225 | /* Move the invariants out of the LOOPS. */ | |
1226 | ||
1227 | void | |
1228 | move_loop_invariants (struct loops *loops) | |
1229 | { | |
1230 | struct loop *loop; | |
1231 | unsigned i; | |
cb20f7e8 | 1232 | |
4d779342 DB |
1233 | df = df_init (DF_HARD_REGS | DF_EQUIV_NOTES); |
1234 | df_chain_add_problem (df, DF_UD_CHAIN); | |
1235 | ||
5e962776 ZD |
1236 | /* Process the loops, innermost first. */ |
1237 | loop = loops->tree_root; | |
1238 | while (loop->inner) | |
1239 | loop = loop->inner; | |
1240 | ||
1241 | while (loop != loops->tree_root) | |
1242 | { | |
cb20f7e8 | 1243 | move_single_loop_invariants (loop); |
5e962776 ZD |
1244 | |
1245 | if (loop->next) | |
1246 | { | |
1247 | loop = loop->next; | |
1248 | while (loop->inner) | |
1249 | loop = loop->inner; | |
1250 | } | |
1251 | else | |
1252 | loop = loop->outer; | |
1253 | } | |
1254 | ||
1255 | for (i = 1; i < loops->num; i++) | |
1256 | if (loops->parray[i]) | |
1257 | free_loop_data (loops->parray[i]); | |
1258 | ||
1259 | df_finish (df); | |
d7712dda | 1260 | df = NULL; |
a7f4ccb1 SB |
1261 | |
1262 | #ifdef ENABLE_CHECKING | |
1263 | verify_flow_info (); | |
1264 | #endif | |
5e962776 | 1265 | } |