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2c88418c | 1 | /* Analyze RTL for C-Compiler |
c166a311 | 2 | Copyright (C) 1987, 1988, 1991, 1992 Free Software Foundation, Inc. |
2c88418c RS |
3 | |
4 | This file is part of GNU CC. | |
5 | ||
6 | GNU CC is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 2, or (at your option) | |
9 | any later version. | |
10 | ||
11 | GNU CC is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with GNU CC; see the file COPYING. If not, write to | |
18 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
19 | ||
20 | ||
21 | #include "config.h" | |
22 | #include "rtl.h" | |
23 | ||
24 | void note_stores (); | |
25 | int reg_set_p (); | |
26 | ||
27 | /* Bit flags that specify the machine subtype we are compiling for. | |
28 | Bits are tested using macros TARGET_... defined in the tm.h file | |
29 | and set by `-m...' switches. Must be defined in rtlanal.c. */ | |
30 | ||
31 | int target_flags; | |
32 | \f | |
33 | /* Return 1 if the value of X is unstable | |
34 | (would be different at a different point in the program). | |
35 | The frame pointer, arg pointer, etc. are considered stable | |
36 | (within one function) and so is anything marked `unchanging'. */ | |
37 | ||
38 | int | |
39 | rtx_unstable_p (x) | |
40 | rtx x; | |
41 | { | |
42 | register RTX_CODE code = GET_CODE (x); | |
43 | register int i; | |
44 | register char *fmt; | |
45 | ||
46 | if (code == MEM) | |
47 | return ! RTX_UNCHANGING_P (x); | |
48 | ||
49 | if (code == QUEUED) | |
50 | return 1; | |
51 | ||
52 | if (code == CONST || code == CONST_INT) | |
53 | return 0; | |
54 | ||
55 | if (code == REG) | |
56 | return ! (REGNO (x) == FRAME_POINTER_REGNUM | |
57 | || REGNO (x) == ARG_POINTER_REGNUM | |
58 | || RTX_UNCHANGING_P (x)); | |
59 | ||
60 | fmt = GET_RTX_FORMAT (code); | |
61 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
62 | if (fmt[i] == 'e') | |
63 | if (rtx_unstable_p (XEXP (x, i))) | |
64 | return 1; | |
65 | return 0; | |
66 | } | |
67 | ||
68 | /* Return 1 if X has a value that can vary even between two | |
69 | executions of the program. 0 means X can be compared reliably | |
70 | against certain constants or near-constants. | |
71 | The frame pointer and the arg pointer are considered constant. */ | |
72 | ||
73 | int | |
74 | rtx_varies_p (x) | |
75 | rtx x; | |
76 | { | |
77 | register RTX_CODE code = GET_CODE (x); | |
78 | register int i; | |
79 | register char *fmt; | |
80 | ||
81 | switch (code) | |
82 | { | |
83 | case MEM: | |
84 | case QUEUED: | |
85 | return 1; | |
86 | ||
87 | case CONST: | |
88 | case CONST_INT: | |
89 | case CONST_DOUBLE: | |
90 | case SYMBOL_REF: | |
91 | case LABEL_REF: | |
92 | return 0; | |
93 | ||
94 | case REG: | |
95 | /* Note that we have to test for the actual rtx used for the frame | |
96 | and arg pointers and not just the register number in case we have | |
97 | eliminated the frame and/or arg pointer and are using it | |
98 | for pseudos. */ | |
99 | return ! (x == frame_pointer_rtx || x == arg_pointer_rtx); | |
100 | ||
101 | case LO_SUM: | |
102 | /* The operand 0 of a LO_SUM is considered constant | |
103 | (in fact is it related specifically to operand 1). */ | |
104 | return rtx_varies_p (XEXP (x, 1)); | |
105 | } | |
106 | ||
107 | fmt = GET_RTX_FORMAT (code); | |
108 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
109 | if (fmt[i] == 'e') | |
110 | if (rtx_varies_p (XEXP (x, i))) | |
111 | return 1; | |
112 | return 0; | |
113 | } | |
114 | ||
115 | /* Return 0 if the use of X as an address in a MEM can cause a trap. */ | |
116 | ||
117 | int | |
118 | rtx_addr_can_trap_p (x) | |
119 | register rtx x; | |
120 | { | |
121 | register enum rtx_code code = GET_CODE (x); | |
122 | ||
123 | switch (code) | |
124 | { | |
125 | case SYMBOL_REF: | |
126 | case LABEL_REF: | |
127 | /* SYMBOL_REF is problematic due to the possible presence of | |
128 | a #pragma weak, but to say that loads from symbols can trap is | |
129 | *very* costly. It's not at all clear what's best here. For | |
130 | now, we ignore the impact of #pragma weak. */ | |
131 | return 0; | |
132 | ||
133 | case REG: | |
134 | /* As in rtx_varies_p, we have to use the actual rtx, not reg number. */ | |
135 | return ! (x == frame_pointer_rtx || x == stack_pointer_rtx | |
136 | || x == arg_pointer_rtx); | |
137 | ||
138 | case CONST: | |
139 | return rtx_addr_can_trap_p (XEXP (x, 0)); | |
140 | ||
141 | case PLUS: | |
142 | /* An address is assumed not to trap if it is an address that can't | |
143 | trap plus a constant integer. */ | |
144 | return (rtx_addr_can_trap_p (XEXP (x, 0)) | |
145 | || GET_CODE (XEXP (x, 1)) != CONST_INT); | |
146 | ||
147 | case LO_SUM: | |
148 | return rtx_addr_can_trap_p (XEXP (x, 1)); | |
149 | } | |
150 | ||
151 | /* If it isn't one of the case above, it can cause a trap. */ | |
152 | return 1; | |
153 | } | |
154 | ||
155 | /* Return 1 if X refers to a memory location whose address | |
156 | cannot be compared reliably with constant addresses, | |
157 | or if X refers to a BLKmode memory object. */ | |
158 | ||
159 | int | |
160 | rtx_addr_varies_p (x) | |
161 | rtx x; | |
162 | { | |
163 | register enum rtx_code code; | |
164 | register int i; | |
165 | register char *fmt; | |
166 | ||
167 | if (x == 0) | |
168 | return 0; | |
169 | ||
170 | code = GET_CODE (x); | |
171 | if (code == MEM) | |
172 | return GET_MODE (x) == BLKmode || rtx_varies_p (XEXP (x, 0)); | |
173 | ||
174 | fmt = GET_RTX_FORMAT (code); | |
175 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
176 | if (fmt[i] == 'e') | |
177 | if (rtx_addr_varies_p (XEXP (x, i))) | |
178 | return 1; | |
179 | return 0; | |
180 | } | |
181 | \f | |
182 | /* Return the value of the integer term in X, if one is apparent; | |
183 | otherwise return 0. | |
184 | Only obvious integer terms are detected. | |
185 | This is used in cse.c with the `related_value' field.*/ | |
186 | ||
c166a311 | 187 | HOST_WIDE_INT |
2c88418c RS |
188 | get_integer_term (x) |
189 | rtx x; | |
190 | { | |
191 | if (GET_CODE (x) == CONST) | |
192 | x = XEXP (x, 0); | |
193 | ||
194 | if (GET_CODE (x) == MINUS | |
195 | && GET_CODE (XEXP (x, 1)) == CONST_INT) | |
196 | return - INTVAL (XEXP (x, 1)); | |
197 | if (GET_CODE (x) == PLUS | |
198 | && GET_CODE (XEXP (x, 1)) == CONST_INT) | |
199 | return INTVAL (XEXP (x, 1)); | |
200 | return 0; | |
201 | } | |
202 | ||
203 | /* If X is a constant, return the value sans apparent integer term; | |
204 | otherwise return 0. | |
205 | Only obvious integer terms are detected. */ | |
206 | ||
207 | rtx | |
208 | get_related_value (x) | |
209 | rtx x; | |
210 | { | |
211 | if (GET_CODE (x) != CONST) | |
212 | return 0; | |
213 | x = XEXP (x, 0); | |
214 | if (GET_CODE (x) == PLUS | |
215 | && GET_CODE (XEXP (x, 1)) == CONST_INT) | |
216 | return XEXP (x, 0); | |
217 | else if (GET_CODE (x) == MINUS | |
218 | && GET_CODE (XEXP (x, 1)) == CONST_INT) | |
219 | return XEXP (x, 0); | |
220 | return 0; | |
221 | } | |
222 | \f | |
223 | /* Nonzero if register REG appears somewhere within IN. | |
224 | Also works if REG is not a register; in this case it checks | |
225 | for a subexpression of IN that is Lisp "equal" to REG. */ | |
226 | ||
227 | int | |
228 | reg_mentioned_p (reg, in) | |
229 | register rtx reg, in; | |
230 | { | |
231 | register char *fmt; | |
232 | register int i; | |
233 | register enum rtx_code code; | |
234 | ||
235 | if (in == 0) | |
236 | return 0; | |
237 | ||
238 | if (reg == in) | |
239 | return 1; | |
240 | ||
241 | if (GET_CODE (in) == LABEL_REF) | |
242 | return reg == XEXP (in, 0); | |
243 | ||
244 | code = GET_CODE (in); | |
245 | ||
246 | switch (code) | |
247 | { | |
248 | /* Compare registers by number. */ | |
249 | case REG: | |
250 | return GET_CODE (reg) == REG && REGNO (in) == REGNO (reg); | |
251 | ||
252 | /* These codes have no constituent expressions | |
253 | and are unique. */ | |
254 | case SCRATCH: | |
255 | case CC0: | |
256 | case PC: | |
257 | return 0; | |
258 | ||
259 | case CONST_INT: | |
260 | return GET_CODE (reg) == CONST_INT && INTVAL (in) == INTVAL (reg); | |
261 | ||
262 | case CONST_DOUBLE: | |
263 | /* These are kept unique for a given value. */ | |
264 | return 0; | |
265 | } | |
266 | ||
267 | if (GET_CODE (reg) == code && rtx_equal_p (reg, in)) | |
268 | return 1; | |
269 | ||
270 | fmt = GET_RTX_FORMAT (code); | |
271 | ||
272 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
273 | { | |
274 | if (fmt[i] == 'E') | |
275 | { | |
276 | register int j; | |
277 | for (j = XVECLEN (in, i) - 1; j >= 0; j--) | |
278 | if (reg_mentioned_p (reg, XVECEXP (in, i, j))) | |
279 | return 1; | |
280 | } | |
281 | else if (fmt[i] == 'e' | |
282 | && reg_mentioned_p (reg, XEXP (in, i))) | |
283 | return 1; | |
284 | } | |
285 | return 0; | |
286 | } | |
287 | \f | |
288 | /* Return 1 if in between BEG and END, exclusive of BEG and END, there is | |
289 | no CODE_LABEL insn. */ | |
290 | ||
291 | int | |
292 | no_labels_between_p (beg, end) | |
293 | rtx beg, end; | |
294 | { | |
295 | register rtx p; | |
296 | for (p = NEXT_INSN (beg); p != end; p = NEXT_INSN (p)) | |
297 | if (GET_CODE (p) == CODE_LABEL) | |
298 | return 0; | |
299 | return 1; | |
300 | } | |
301 | ||
302 | /* Nonzero if register REG is used in an insn between | |
303 | FROM_INSN and TO_INSN (exclusive of those two). */ | |
304 | ||
305 | int | |
306 | reg_used_between_p (reg, from_insn, to_insn) | |
307 | rtx reg, from_insn, to_insn; | |
308 | { | |
309 | register rtx insn; | |
310 | ||
311 | if (from_insn == to_insn) | |
312 | return 0; | |
313 | ||
314 | for (insn = NEXT_INSN (from_insn); insn != to_insn; insn = NEXT_INSN (insn)) | |
315 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
316 | && reg_overlap_mentioned_p (reg, PATTERN (insn))) | |
317 | return 1; | |
318 | return 0; | |
319 | } | |
320 | \f | |
321 | /* Nonzero if the old value of X, a register, is referenced in BODY. If X | |
322 | is entirely replaced by a new value and the only use is as a SET_DEST, | |
323 | we do not consider it a reference. */ | |
324 | ||
325 | int | |
326 | reg_referenced_p (x, body) | |
327 | rtx x; | |
328 | rtx body; | |
329 | { | |
330 | int i; | |
331 | ||
332 | switch (GET_CODE (body)) | |
333 | { | |
334 | case SET: | |
335 | if (reg_overlap_mentioned_p (x, SET_SRC (body))) | |
336 | return 1; | |
337 | ||
338 | /* If the destination is anything other than CC0, PC, a REG or a SUBREG | |
339 | of a REG that occupies all of the REG, the insn references X if | |
340 | it is mentioned in the destination. */ | |
341 | if (GET_CODE (SET_DEST (body)) != CC0 | |
342 | && GET_CODE (SET_DEST (body)) != PC | |
343 | && GET_CODE (SET_DEST (body)) != REG | |
344 | && ! (GET_CODE (SET_DEST (body)) == SUBREG | |
345 | && GET_CODE (SUBREG_REG (SET_DEST (body))) == REG | |
346 | && (((GET_MODE_SIZE (GET_MODE (SUBREG_REG (SET_DEST (body)))) | |
347 | + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD) | |
348 | == ((GET_MODE_SIZE (GET_MODE (SET_DEST (body))) | |
349 | + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD))) | |
350 | && reg_overlap_mentioned_p (x, SET_DEST (body))) | |
351 | return 1; | |
352 | break; | |
353 | ||
354 | case ASM_OPERANDS: | |
355 | for (i = ASM_OPERANDS_INPUT_LENGTH (body) - 1; i >= 0; i--) | |
356 | if (reg_overlap_mentioned_p (x, ASM_OPERANDS_INPUT (body, i))) | |
357 | return 1; | |
358 | break; | |
359 | ||
360 | case CALL: | |
361 | case USE: | |
362 | return reg_overlap_mentioned_p (x, body); | |
363 | ||
364 | case TRAP_IF: | |
365 | return reg_overlap_mentioned_p (x, TRAP_CONDITION (body)); | |
366 | ||
2ac4fed0 RK |
367 | case UNSPEC: |
368 | case UNSPEC_VOLATILE: | |
2c88418c RS |
369 | case PARALLEL: |
370 | for (i = XVECLEN (body, 0) - 1; i >= 0; i--) | |
371 | if (reg_referenced_p (x, XVECEXP (body, 0, i))) | |
372 | return 1; | |
373 | break; | |
374 | } | |
375 | ||
376 | return 0; | |
377 | } | |
378 | ||
379 | /* Nonzero if register REG is referenced in an insn between | |
380 | FROM_INSN and TO_INSN (exclusive of those two). Sets of REG do | |
381 | not count. */ | |
382 | ||
383 | int | |
384 | reg_referenced_between_p (reg, from_insn, to_insn) | |
385 | rtx reg, from_insn, to_insn; | |
386 | { | |
387 | register rtx insn; | |
388 | ||
389 | if (from_insn == to_insn) | |
390 | return 0; | |
391 | ||
392 | for (insn = NEXT_INSN (from_insn); insn != to_insn; insn = NEXT_INSN (insn)) | |
393 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
394 | && reg_referenced_p (reg, PATTERN (insn))) | |
395 | return 1; | |
396 | return 0; | |
397 | } | |
398 | \f | |
399 | /* Nonzero if register REG is set or clobbered in an insn between | |
400 | FROM_INSN and TO_INSN (exclusive of those two). */ | |
401 | ||
402 | int | |
403 | reg_set_between_p (reg, from_insn, to_insn) | |
404 | rtx reg, from_insn, to_insn; | |
405 | { | |
406 | register rtx insn; | |
407 | ||
408 | if (from_insn == to_insn) | |
409 | return 0; | |
410 | ||
411 | for (insn = NEXT_INSN (from_insn); insn != to_insn; insn = NEXT_INSN (insn)) | |
412 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
84607dc1 | 413 | && reg_set_p (reg, insn)) |
2c88418c RS |
414 | return 1; |
415 | return 0; | |
416 | } | |
417 | ||
418 | /* Internals of reg_set_between_p. */ | |
419 | ||
420 | static rtx reg_set_reg; | |
421 | static int reg_set_flag; | |
422 | ||
423 | void | |
424 | reg_set_p_1 (x) | |
425 | rtx x; | |
426 | { | |
427 | /* We don't want to return 1 if X is a MEM that contains a register | |
428 | within REG_SET_REG. */ | |
429 | ||
430 | if ((GET_CODE (x) != MEM) | |
431 | && reg_overlap_mentioned_p (reg_set_reg, x)) | |
432 | reg_set_flag = 1; | |
433 | } | |
434 | ||
435 | int | |
436 | reg_set_p (reg, insn) | |
437 | rtx reg, insn; | |
438 | { | |
439 | rtx body = insn; | |
440 | ||
441 | /* We can be passed an insn or part of one. If we are passed an insn, | |
442 | check if a side-effect of the insn clobbers REG. */ | |
443 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') | |
444 | { | |
445 | if (FIND_REG_INC_NOTE (insn, reg) | |
446 | || (GET_CODE (insn) == CALL_INSN | |
447 | /* We'd like to test call_used_regs here, but rtlanal.c can't | |
448 | reference that variable due to its use in genattrtab. So | |
449 | we'll just be more conservative. */ | |
450 | && ((GET_CODE (reg) == REG | |
451 | && REGNO (reg) < FIRST_PSEUDO_REGISTER) | |
452 | || GET_CODE (reg) == MEM))) | |
453 | return 1; | |
454 | ||
455 | body = PATTERN (insn); | |
456 | } | |
457 | ||
458 | reg_set_reg = reg; | |
459 | reg_set_flag = 0; | |
460 | note_stores (body, reg_set_p_1); | |
461 | return reg_set_flag; | |
462 | } | |
463 | ||
464 | /* Similar to reg_set_between_p, but check all registers in X. Return 0 | |
465 | only if none of them are modified between START and END. Return 1 if | |
466 | X contains a MEM; this routine does not perform any memory aliasing. */ | |
467 | ||
468 | int | |
469 | modified_between_p (x, start, end) | |
470 | rtx x; | |
471 | rtx start, end; | |
472 | { | |
473 | enum rtx_code code = GET_CODE (x); | |
474 | char *fmt; | |
475 | int i; | |
476 | ||
477 | switch (code) | |
478 | { | |
479 | case CONST_INT: | |
480 | case CONST_DOUBLE: | |
481 | case CONST: | |
482 | case SYMBOL_REF: | |
483 | case LABEL_REF: | |
484 | return 0; | |
485 | ||
486 | case PC: | |
487 | case CC0: | |
488 | return 1; | |
489 | ||
490 | case MEM: | |
491 | /* If the memory is not constant, assume it is modified. If it is | |
492 | constant, we still have to check the address. */ | |
493 | if (! RTX_UNCHANGING_P (x)) | |
494 | return 1; | |
495 | break; | |
496 | ||
497 | case REG: | |
498 | return reg_set_between_p (x, start, end); | |
499 | } | |
500 | ||
501 | fmt = GET_RTX_FORMAT (code); | |
502 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
503 | if (fmt[i] == 'e' | |
504 | && modified_between_p (XEXP (x, i), start, end)) | |
505 | return 1; | |
506 | ||
507 | return 0; | |
508 | } | |
509 | \f | |
510 | /* Given an INSN, return a SET expression if this insn has only a single SET. | |
511 | It may also have CLOBBERs, USEs, or SET whose output | |
512 | will not be used, which we ignore. */ | |
513 | ||
514 | rtx | |
515 | single_set (insn) | |
516 | rtx insn; | |
517 | { | |
518 | rtx set; | |
519 | int i; | |
520 | ||
521 | if (GET_RTX_CLASS (GET_CODE (insn)) != 'i') | |
522 | return 0; | |
523 | ||
524 | if (GET_CODE (PATTERN (insn)) == SET) | |
525 | return PATTERN (insn); | |
526 | ||
527 | else if (GET_CODE (PATTERN (insn)) == PARALLEL) | |
528 | { | |
529 | for (i = 0, set = 0; i < XVECLEN (PATTERN (insn), 0); i++) | |
530 | if (GET_CODE (XVECEXP (PATTERN (insn), 0, i)) == SET | |
fb3ef382 RS |
531 | && (! find_reg_note (insn, REG_UNUSED, |
532 | SET_DEST (XVECEXP (PATTERN (insn), 0, i))) | |
533 | || side_effects_p (XVECEXP (PATTERN (insn), 0, i)))) | |
2c88418c RS |
534 | { |
535 | if (set) | |
536 | return 0; | |
537 | else | |
538 | set = XVECEXP (PATTERN (insn), 0, i); | |
539 | } | |
540 | return set; | |
541 | } | |
542 | ||
543 | return 0; | |
544 | } | |
545 | \f | |
546 | /* Return the last thing that X was assigned from before *PINSN. Verify that | |
547 | the object is not modified up to VALID_TO. If it was, if we hit | |
548 | a partial assignment to X, or hit a CODE_LABEL first, return X. If we | |
549 | found an assignment, update *PINSN to point to it. */ | |
550 | ||
551 | rtx | |
552 | find_last_value (x, pinsn, valid_to) | |
553 | rtx x; | |
554 | rtx *pinsn; | |
555 | rtx valid_to; | |
556 | { | |
557 | rtx p; | |
558 | ||
559 | for (p = PREV_INSN (*pinsn); p && GET_CODE (p) != CODE_LABEL; | |
560 | p = PREV_INSN (p)) | |
561 | if (GET_RTX_CLASS (GET_CODE (p)) == 'i') | |
562 | { | |
563 | rtx set = single_set (p); | |
c166a311 | 564 | rtx note = find_reg_note (p, REG_EQUAL, NULL_RTX); |
2c88418c RS |
565 | |
566 | if (set && rtx_equal_p (x, SET_DEST (set))) | |
567 | { | |
568 | rtx src = SET_SRC (set); | |
569 | ||
570 | if (note && GET_CODE (XEXP (note, 0)) != EXPR_LIST) | |
571 | src = XEXP (note, 0); | |
572 | ||
573 | if (! modified_between_p (src, PREV_INSN (p), valid_to) | |
574 | /* Reject hard registers because we don't usually want | |
575 | to use them; we'd rather use a pseudo. */ | |
576 | && ! (GET_CODE (src) == REG | |
577 | && REGNO (src) < FIRST_PSEUDO_REGISTER)) | |
578 | { | |
579 | *pinsn = p; | |
580 | return src; | |
581 | } | |
582 | } | |
583 | ||
584 | /* If set in non-simple way, we don't have a value. */ | |
585 | if (reg_set_p (x, p)) | |
586 | break; | |
587 | } | |
588 | ||
589 | return x; | |
590 | } | |
591 | \f | |
592 | /* Return nonzero if register in range [REGNO, ENDREGNO) | |
593 | appears either explicitly or implicitly in X | |
594 | other than being stored into. | |
595 | ||
596 | References contained within the substructure at LOC do not count. | |
597 | LOC may be zero, meaning don't ignore anything. */ | |
598 | ||
599 | int | |
600 | refers_to_regno_p (regno, endregno, x, loc) | |
601 | int regno, endregno; | |
602 | rtx x; | |
603 | rtx *loc; | |
604 | { | |
605 | register int i; | |
606 | register RTX_CODE code; | |
607 | register char *fmt; | |
608 | ||
609 | repeat: | |
610 | /* The contents of a REG_NONNEG note is always zero, so we must come here | |
611 | upon repeat in case the last REG_NOTE is a REG_NONNEG note. */ | |
612 | if (x == 0) | |
613 | return 0; | |
614 | ||
615 | code = GET_CODE (x); | |
616 | ||
617 | switch (code) | |
618 | { | |
619 | case REG: | |
620 | i = REGNO (x); | |
621 | return (endregno > i | |
622 | && regno < i + (i < FIRST_PSEUDO_REGISTER | |
623 | ? HARD_REGNO_NREGS (i, GET_MODE (x)) | |
624 | : 1)); | |
625 | ||
626 | case SUBREG: | |
627 | /* If this is a SUBREG of a hard reg, we can see exactly which | |
628 | registers are being modified. Otherwise, handle normally. */ | |
629 | if (GET_CODE (SUBREG_REG (x)) == REG | |
630 | && REGNO (SUBREG_REG (x)) < FIRST_PSEUDO_REGISTER) | |
631 | { | |
632 | int inner_regno = REGNO (SUBREG_REG (x)) + SUBREG_WORD (x); | |
633 | int inner_endregno | |
634 | = inner_regno + (inner_regno < FIRST_PSEUDO_REGISTER | |
635 | ? HARD_REGNO_NREGS (regno, GET_MODE (x)) : 1); | |
636 | ||
637 | return endregno > inner_regno && regno < inner_endregno; | |
638 | } | |
639 | break; | |
640 | ||
641 | case CLOBBER: | |
642 | case SET: | |
643 | if (&SET_DEST (x) != loc | |
644 | /* Note setting a SUBREG counts as referring to the REG it is in for | |
645 | a pseudo but not for hard registers since we can | |
646 | treat each word individually. */ | |
647 | && ((GET_CODE (SET_DEST (x)) == SUBREG | |
648 | && loc != &SUBREG_REG (SET_DEST (x)) | |
649 | && GET_CODE (SUBREG_REG (SET_DEST (x))) == REG | |
650 | && REGNO (SUBREG_REG (SET_DEST (x))) >= FIRST_PSEUDO_REGISTER | |
651 | && refers_to_regno_p (regno, endregno, | |
652 | SUBREG_REG (SET_DEST (x)), loc)) | |
653 | || (GET_CODE (SET_DEST (x)) != REG | |
654 | && refers_to_regno_p (regno, endregno, SET_DEST (x), loc)))) | |
655 | return 1; | |
656 | ||
657 | if (code == CLOBBER || loc == &SET_SRC (x)) | |
658 | return 0; | |
659 | x = SET_SRC (x); | |
660 | goto repeat; | |
661 | } | |
662 | ||
663 | /* X does not match, so try its subexpressions. */ | |
664 | ||
665 | fmt = GET_RTX_FORMAT (code); | |
666 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
667 | { | |
668 | if (fmt[i] == 'e' && loc != &XEXP (x, i)) | |
669 | { | |
670 | if (i == 0) | |
671 | { | |
672 | x = XEXP (x, 0); | |
673 | goto repeat; | |
674 | } | |
675 | else | |
676 | if (refers_to_regno_p (regno, endregno, XEXP (x, i), loc)) | |
677 | return 1; | |
678 | } | |
679 | else if (fmt[i] == 'E') | |
680 | { | |
681 | register int j; | |
682 | for (j = XVECLEN (x, i) - 1; j >=0; j--) | |
683 | if (loc != &XVECEXP (x, i, j) | |
684 | && refers_to_regno_p (regno, endregno, XVECEXP (x, i, j), loc)) | |
685 | return 1; | |
686 | } | |
687 | } | |
688 | return 0; | |
689 | } | |
690 | ||
691 | /* Nonzero if modifying X will affect IN. If X is a register or a SUBREG, | |
692 | we check if any register number in X conflicts with the relevant register | |
693 | numbers. If X is a constant, return 0. If X is a MEM, return 1 iff IN | |
694 | contains a MEM (we don't bother checking for memory addresses that can't | |
695 | conflict because we expect this to be a rare case. */ | |
696 | ||
697 | int | |
698 | reg_overlap_mentioned_p (x, in) | |
699 | rtx x, in; | |
700 | { | |
701 | int regno, endregno; | |
702 | ||
703 | if (GET_CODE (x) == SUBREG) | |
704 | { | |
705 | regno = REGNO (SUBREG_REG (x)); | |
706 | if (regno < FIRST_PSEUDO_REGISTER) | |
707 | regno += SUBREG_WORD (x); | |
708 | } | |
709 | else if (GET_CODE (x) == REG) | |
710 | regno = REGNO (x); | |
711 | else if (CONSTANT_P (x)) | |
712 | return 0; | |
713 | else if (GET_CODE (x) == MEM) | |
714 | { | |
715 | char *fmt; | |
716 | int i; | |
717 | ||
718 | if (GET_CODE (in) == MEM) | |
719 | return 1; | |
720 | ||
721 | fmt = GET_RTX_FORMAT (GET_CODE (in)); | |
722 | ||
723 | for (i = GET_RTX_LENGTH (GET_CODE (in)) - 1; i >= 0; i--) | |
724 | if (fmt[i] == 'e' && reg_overlap_mentioned_p (x, XEXP (in, i))) | |
725 | return 1; | |
726 | ||
727 | return 0; | |
728 | } | |
729 | else if (GET_CODE (x) == SCRATCH || GET_CODE (x) == PC | |
730 | || GET_CODE (x) == CC0) | |
731 | return reg_mentioned_p (x, in); | |
732 | else | |
733 | abort (); | |
734 | ||
735 | endregno = regno + (regno < FIRST_PSEUDO_REGISTER | |
736 | ? HARD_REGNO_NREGS (regno, GET_MODE (x)) : 1); | |
737 | ||
c166a311 | 738 | return refers_to_regno_p (regno, endregno, in, NULL_PTR); |
2c88418c RS |
739 | } |
740 | \f | |
741 | /* Used for communications between the next few functions. */ | |
742 | ||
743 | static int reg_set_last_unknown; | |
744 | static rtx reg_set_last_value; | |
745 | static int reg_set_last_first_regno, reg_set_last_last_regno; | |
746 | ||
747 | /* Called via note_stores from reg_set_last. */ | |
748 | ||
749 | static void | |
750 | reg_set_last_1 (x, pat) | |
751 | rtx x; | |
752 | rtx pat; | |
753 | { | |
754 | int first, last; | |
755 | ||
756 | /* If X is not a register, or is not one in the range we care | |
757 | about, ignore. */ | |
758 | if (GET_CODE (x) != REG) | |
759 | return; | |
760 | ||
761 | first = REGNO (x); | |
762 | last = first + (first < FIRST_PSEUDO_REGISTER | |
763 | ? HARD_REGNO_NREGS (first, GET_MODE (x)) : 1); | |
764 | ||
765 | if (first >= reg_set_last_last_regno | |
766 | || last <= reg_set_last_first_regno) | |
767 | return; | |
768 | ||
769 | /* If this is a CLOBBER or is some complex LHS, or doesn't modify | |
770 | exactly the registers we care about, show we don't know the value. */ | |
771 | if (GET_CODE (pat) == CLOBBER || SET_DEST (pat) != x | |
772 | || first != reg_set_last_first_regno | |
773 | || last != reg_set_last_last_regno) | |
774 | reg_set_last_unknown = 1; | |
775 | else | |
776 | reg_set_last_value = SET_SRC (pat); | |
777 | } | |
778 | ||
779 | /* Return the last value to which REG was set prior to INSN. If we can't | |
780 | find it easily, return 0. | |
781 | ||
4d9d7d9d RK |
782 | We only return a REG, SUBREG, or constant because it is too hard to |
783 | check if a MEM remains unchanged. */ | |
2c88418c RS |
784 | |
785 | rtx | |
786 | reg_set_last (x, insn) | |
787 | rtx x; | |
788 | rtx insn; | |
789 | { | |
790 | rtx orig_insn = insn; | |
791 | ||
792 | reg_set_last_first_regno = REGNO (x); | |
793 | ||
794 | reg_set_last_last_regno | |
795 | = reg_set_last_first_regno | |
796 | + (reg_set_last_first_regno < FIRST_PSEUDO_REGISTER | |
797 | ? HARD_REGNO_NREGS (reg_set_last_first_regno, GET_MODE (x)) : 1); | |
798 | ||
799 | reg_set_last_unknown = 0; | |
800 | reg_set_last_value = 0; | |
801 | ||
802 | /* Scan backwards until reg_set_last_1 changed one of the above flags. | |
803 | Stop when we reach a label or X is a hard reg and we reach a | |
804 | CALL_INSN (if reg_set_last_last_regno is a hard reg). | |
805 | ||
806 | If we find a set of X, ensure that its SET_SRC remains unchanged. */ | |
807 | ||
808 | for (; | |
809 | insn && GET_CODE (insn) != CODE_LABEL | |
810 | && ! (GET_CODE (insn) == CALL_INSN | |
811 | && reg_set_last_last_regno <= FIRST_PSEUDO_REGISTER); | |
812 | insn = PREV_INSN (insn)) | |
813 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') | |
814 | { | |
815 | note_stores (PATTERN (insn), reg_set_last_1); | |
816 | if (reg_set_last_unknown) | |
817 | return 0; | |
818 | else if (reg_set_last_value) | |
819 | { | |
820 | if (CONSTANT_P (reg_set_last_value) | |
4d9d7d9d RK |
821 | || ((GET_CODE (reg_set_last_value) == REG |
822 | || GET_CODE (reg_set_last_value) == SUBREG) | |
2c88418c RS |
823 | && ! reg_set_between_p (reg_set_last_value, |
824 | NEXT_INSN (insn), orig_insn))) | |
825 | return reg_set_last_value; | |
826 | else | |
827 | return 0; | |
828 | } | |
829 | } | |
830 | ||
831 | return 0; | |
832 | } | |
833 | \f | |
834 | /* This is 1 until after reload pass. */ | |
835 | int rtx_equal_function_value_matters; | |
836 | ||
837 | /* Return 1 if X and Y are identical-looking rtx's. | |
838 | This is the Lisp function EQUAL for rtx arguments. */ | |
839 | ||
840 | int | |
841 | rtx_equal_p (x, y) | |
842 | rtx x, y; | |
843 | { | |
844 | register int i; | |
845 | register int j; | |
846 | register enum rtx_code code; | |
847 | register char *fmt; | |
848 | ||
849 | if (x == y) | |
850 | return 1; | |
851 | if (x == 0 || y == 0) | |
852 | return 0; | |
853 | ||
854 | code = GET_CODE (x); | |
855 | /* Rtx's of different codes cannot be equal. */ | |
856 | if (code != GET_CODE (y)) | |
857 | return 0; | |
858 | ||
859 | /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. | |
860 | (REG:SI x) and (REG:HI x) are NOT equivalent. */ | |
861 | ||
862 | if (GET_MODE (x) != GET_MODE (y)) | |
863 | return 0; | |
864 | ||
865 | /* REG, LABEL_REF, and SYMBOL_REF can be compared nonrecursively. */ | |
866 | ||
867 | if (code == REG) | |
868 | /* Until rtl generation is complete, don't consider a reference to the | |
869 | return register of the current function the same as the return from a | |
870 | called function. This eases the job of function integration. Once the | |
871 | distinction is no longer needed, they can be considered equivalent. */ | |
872 | return (REGNO (x) == REGNO (y) | |
873 | && (! rtx_equal_function_value_matters | |
874 | || REG_FUNCTION_VALUE_P (x) == REG_FUNCTION_VALUE_P (y))); | |
875 | else if (code == LABEL_REF) | |
876 | return XEXP (x, 0) == XEXP (y, 0); | |
877 | else if (code == SYMBOL_REF) | |
878 | return XSTR (x, 0) == XSTR (y, 0); | |
879 | else if (code == SCRATCH || code == CONST_DOUBLE) | |
880 | return 0; | |
881 | ||
882 | /* Compare the elements. If any pair of corresponding elements | |
883 | fail to match, return 0 for the whole things. */ | |
884 | ||
885 | fmt = GET_RTX_FORMAT (code); | |
886 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
887 | { | |
888 | switch (fmt[i]) | |
889 | { | |
c166a311 CH |
890 | case 'w': |
891 | if (XWINT (x, i) != XWINT (y, i)) | |
892 | return 0; | |
893 | break; | |
894 | ||
2c88418c RS |
895 | case 'n': |
896 | case 'i': | |
897 | if (XINT (x, i) != XINT (y, i)) | |
898 | return 0; | |
899 | break; | |
900 | ||
901 | case 'V': | |
902 | case 'E': | |
903 | /* Two vectors must have the same length. */ | |
904 | if (XVECLEN (x, i) != XVECLEN (y, i)) | |
905 | return 0; | |
906 | ||
907 | /* And the corresponding elements must match. */ | |
908 | for (j = 0; j < XVECLEN (x, i); j++) | |
909 | if (rtx_equal_p (XVECEXP (x, i, j), XVECEXP (y, i, j)) == 0) | |
910 | return 0; | |
911 | break; | |
912 | ||
913 | case 'e': | |
914 | if (rtx_equal_p (XEXP (x, i), XEXP (y, i)) == 0) | |
915 | return 0; | |
916 | break; | |
917 | ||
918 | case 'S': | |
919 | case 's': | |
920 | if (strcmp (XSTR (x, i), XSTR (y, i))) | |
921 | return 0; | |
922 | break; | |
923 | ||
924 | case 'u': | |
925 | /* These are just backpointers, so they don't matter. */ | |
926 | break; | |
927 | ||
928 | case '0': | |
929 | break; | |
930 | ||
931 | /* It is believed that rtx's at this level will never | |
932 | contain anything but integers and other rtx's, | |
933 | except for within LABEL_REFs and SYMBOL_REFs. */ | |
934 | default: | |
935 | abort (); | |
936 | } | |
937 | } | |
938 | return 1; | |
939 | } | |
940 | \f | |
941 | /* Call FUN on each register or MEM that is stored into or clobbered by X. | |
942 | (X would be the pattern of an insn). | |
943 | FUN receives two arguments: | |
944 | the REG, MEM, CC0 or PC being stored in or clobbered, | |
945 | the SET or CLOBBER rtx that does the store. | |
946 | ||
947 | If the item being stored in or clobbered is a SUBREG of a hard register, | |
948 | the SUBREG will be passed. */ | |
949 | ||
950 | void | |
951 | note_stores (x, fun) | |
952 | register rtx x; | |
953 | void (*fun) (); | |
954 | { | |
955 | if ((GET_CODE (x) == SET || GET_CODE (x) == CLOBBER)) | |
956 | { | |
957 | register rtx dest = SET_DEST (x); | |
958 | while ((GET_CODE (dest) == SUBREG | |
959 | && (GET_CODE (SUBREG_REG (dest)) != REG | |
960 | || REGNO (SUBREG_REG (dest)) >= FIRST_PSEUDO_REGISTER)) | |
961 | || GET_CODE (dest) == ZERO_EXTRACT | |
962 | || GET_CODE (dest) == SIGN_EXTRACT | |
963 | || GET_CODE (dest) == STRICT_LOW_PART) | |
964 | dest = XEXP (dest, 0); | |
965 | (*fun) (dest, x); | |
966 | } | |
967 | else if (GET_CODE (x) == PARALLEL) | |
968 | { | |
969 | register int i; | |
970 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) | |
971 | { | |
972 | register rtx y = XVECEXP (x, 0, i); | |
973 | if (GET_CODE (y) == SET || GET_CODE (y) == CLOBBER) | |
974 | { | |
975 | register rtx dest = SET_DEST (y); | |
976 | while ((GET_CODE (dest) == SUBREG | |
977 | && (GET_CODE (SUBREG_REG (dest)) != REG | |
978 | || (REGNO (SUBREG_REG (dest)) | |
979 | >= FIRST_PSEUDO_REGISTER))) | |
980 | || GET_CODE (dest) == ZERO_EXTRACT | |
981 | || GET_CODE (dest) == SIGN_EXTRACT | |
982 | || GET_CODE (dest) == STRICT_LOW_PART) | |
983 | dest = XEXP (dest, 0); | |
984 | (*fun) (dest, y); | |
985 | } | |
986 | } | |
987 | } | |
988 | } | |
989 | \f | |
990 | /* Return nonzero if X's old contents don't survive after INSN. | |
991 | This will be true if X is (cc0) or if X is a register and | |
992 | X dies in INSN or because INSN entirely sets X. | |
993 | ||
994 | "Entirely set" means set directly and not through a SUBREG, | |
995 | ZERO_EXTRACT or SIGN_EXTRACT, so no trace of the old contents remains. | |
996 | Likewise, REG_INC does not count. | |
997 | ||
998 | REG may be a hard or pseudo reg. Renumbering is not taken into account, | |
999 | but for this use that makes no difference, since regs don't overlap | |
1000 | during their lifetimes. Therefore, this function may be used | |
1001 | at any time after deaths have been computed (in flow.c). | |
1002 | ||
1003 | If REG is a hard reg that occupies multiple machine registers, this | |
1004 | function will only return 1 if each of those registers will be replaced | |
1005 | by INSN. */ | |
1006 | ||
1007 | int | |
1008 | dead_or_set_p (insn, x) | |
1009 | rtx insn; | |
1010 | rtx x; | |
1011 | { | |
1012 | register int regno, last_regno; | |
1013 | register int i; | |
1014 | ||
1015 | /* Can't use cc0_rtx below since this file is used by genattrtab.c. */ | |
1016 | if (GET_CODE (x) == CC0) | |
1017 | return 1; | |
1018 | ||
1019 | if (GET_CODE (x) != REG) | |
1020 | abort (); | |
1021 | ||
1022 | regno = REGNO (x); | |
1023 | last_regno = (regno >= FIRST_PSEUDO_REGISTER ? regno | |
1024 | : regno + HARD_REGNO_NREGS (regno, GET_MODE (x)) - 1); | |
1025 | ||
1026 | for (i = regno; i <= last_regno; i++) | |
1027 | if (! dead_or_set_regno_p (insn, i)) | |
1028 | return 0; | |
1029 | ||
1030 | return 1; | |
1031 | } | |
1032 | ||
1033 | /* Utility function for dead_or_set_p to check an individual register. Also | |
1034 | called from flow.c. */ | |
1035 | ||
1036 | int | |
1037 | dead_or_set_regno_p (insn, test_regno) | |
1038 | rtx insn; | |
1039 | int test_regno; | |
1040 | { | |
1041 | int regno, endregno; | |
1042 | rtx link; | |
1043 | ||
1044 | /* See if there is a death note for something that includes TEST_REGNO. */ | |
1045 | for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) | |
1046 | { | |
1047 | if (REG_NOTE_KIND (link) != REG_DEAD || GET_CODE (XEXP (link, 0)) != REG) | |
1048 | continue; | |
1049 | ||
1050 | regno = REGNO (XEXP (link, 0)); | |
1051 | endregno = (regno >= FIRST_PSEUDO_REGISTER ? regno + 1 | |
1052 | : regno + HARD_REGNO_NREGS (regno, | |
1053 | GET_MODE (XEXP (link, 0)))); | |
1054 | ||
1055 | if (test_regno >= regno && test_regno < endregno) | |
1056 | return 1; | |
1057 | } | |
1058 | ||
1059 | if (GET_CODE (PATTERN (insn)) == SET) | |
1060 | { | |
1061 | rtx dest = SET_DEST (PATTERN (insn)); | |
1062 | ||
1063 | /* A value is totally replaced if it is the destination or the | |
1064 | destination is a SUBREG of REGNO that does not change the number of | |
1065 | words in it. */ | |
1066 | if (GET_CODE (dest) == SUBREG | |
1067 | && (((GET_MODE_SIZE (GET_MODE (dest)) | |
1068 | + UNITS_PER_WORD - 1) / UNITS_PER_WORD) | |
1069 | == ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest))) | |
1070 | + UNITS_PER_WORD - 1) / UNITS_PER_WORD))) | |
1071 | dest = SUBREG_REG (dest); | |
1072 | ||
1073 | if (GET_CODE (dest) != REG) | |
1074 | return 0; | |
1075 | ||
1076 | regno = REGNO (dest); | |
1077 | endregno = (regno >= FIRST_PSEUDO_REGISTER ? regno + 1 | |
1078 | : regno + HARD_REGNO_NREGS (regno, GET_MODE (dest))); | |
1079 | ||
1080 | return (test_regno >= regno && test_regno < endregno); | |
1081 | } | |
1082 | else if (GET_CODE (PATTERN (insn)) == PARALLEL) | |
1083 | { | |
1084 | register int i; | |
1085 | ||
1086 | for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--) | |
1087 | { | |
1088 | rtx body = XVECEXP (PATTERN (insn), 0, i); | |
1089 | ||
1090 | if (GET_CODE (body) == SET || GET_CODE (body) == CLOBBER) | |
1091 | { | |
1092 | rtx dest = SET_DEST (body); | |
1093 | ||
1094 | if (GET_CODE (dest) == SUBREG | |
1095 | && (((GET_MODE_SIZE (GET_MODE (dest)) | |
1096 | + UNITS_PER_WORD - 1) / UNITS_PER_WORD) | |
1097 | == ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest))) | |
1098 | + UNITS_PER_WORD - 1) / UNITS_PER_WORD))) | |
1099 | dest = SUBREG_REG (dest); | |
1100 | ||
1101 | if (GET_CODE (dest) != REG) | |
1102 | continue; | |
1103 | ||
1104 | regno = REGNO (dest); | |
1105 | endregno = (regno >= FIRST_PSEUDO_REGISTER ? regno + 1 | |
1106 | : regno + HARD_REGNO_NREGS (regno, GET_MODE (dest))); | |
1107 | ||
1108 | if (test_regno >= regno && test_regno < endregno) | |
1109 | return 1; | |
1110 | } | |
1111 | } | |
1112 | } | |
1113 | ||
1114 | return 0; | |
1115 | } | |
1116 | ||
1117 | /* Return the reg-note of kind KIND in insn INSN, if there is one. | |
1118 | If DATUM is nonzero, look for one whose datum is DATUM. */ | |
1119 | ||
1120 | rtx | |
1121 | find_reg_note (insn, kind, datum) | |
1122 | rtx insn; | |
1123 | enum reg_note kind; | |
1124 | rtx datum; | |
1125 | { | |
1126 | register rtx link; | |
1127 | ||
1128 | for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) | |
1129 | if (REG_NOTE_KIND (link) == kind | |
1130 | && (datum == 0 || datum == XEXP (link, 0))) | |
1131 | return link; | |
1132 | return 0; | |
1133 | } | |
1134 | ||
1135 | /* Return the reg-note of kind KIND in insn INSN which applies to register | |
1136 | number REGNO, if any. Return 0 if there is no such reg-note. */ | |
1137 | ||
1138 | rtx | |
1139 | find_regno_note (insn, kind, regno) | |
1140 | rtx insn; | |
1141 | enum reg_note kind; | |
1142 | int regno; | |
1143 | { | |
1144 | register rtx link; | |
1145 | ||
1146 | for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) | |
1147 | if (REG_NOTE_KIND (link) == kind | |
1148 | /* Verify that it is a register, so that scratch and MEM won't cause a | |
1149 | problem here. */ | |
1150 | && GET_CODE (XEXP (link, 0)) == REG | |
1151 | && REGNO (XEXP (link, 0)) == regno) | |
1152 | return link; | |
1153 | return 0; | |
1154 | } | |
1155 | \f | |
1156 | /* Remove register note NOTE from the REG_NOTES of INSN. */ | |
1157 | ||
1158 | void | |
1159 | remove_note (insn, note) | |
1160 | register rtx note; | |
1161 | register rtx insn; | |
1162 | { | |
1163 | register rtx link; | |
1164 | ||
1165 | if (REG_NOTES (insn) == note) | |
1166 | { | |
1167 | REG_NOTES (insn) = XEXP (note, 1); | |
1168 | return; | |
1169 | } | |
1170 | ||
1171 | for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) | |
1172 | if (XEXP (link, 1) == note) | |
1173 | { | |
1174 | XEXP (link, 1) = XEXP (note, 1); | |
1175 | return; | |
1176 | } | |
1177 | ||
1178 | abort (); | |
1179 | } | |
1180 | \f | |
1181 | /* Nonzero if X contains any volatile memory references | |
2ac4fed0 | 1182 | UNSPEC_VOLATILE operations or volatile ASM_OPERANDS expressions. */ |
2c88418c RS |
1183 | |
1184 | int | |
1185 | volatile_refs_p (x) | |
1186 | rtx x; | |
1187 | { | |
1188 | register RTX_CODE code; | |
1189 | ||
1190 | code = GET_CODE (x); | |
1191 | switch (code) | |
1192 | { | |
1193 | case LABEL_REF: | |
1194 | case SYMBOL_REF: | |
1195 | case CONST_INT: | |
1196 | case CONST: | |
1197 | case CONST_DOUBLE: | |
1198 | case CC0: | |
1199 | case PC: | |
1200 | case REG: | |
1201 | case SCRATCH: | |
1202 | case CLOBBER: | |
1203 | case ASM_INPUT: | |
1204 | case ADDR_VEC: | |
1205 | case ADDR_DIFF_VEC: | |
1206 | return 0; | |
1207 | ||
1208 | case CALL: | |
2ac4fed0 | 1209 | case UNSPEC_VOLATILE: |
2c88418c RS |
1210 | /* case TRAP_IF: This isn't clear yet. */ |
1211 | return 1; | |
1212 | ||
1213 | case MEM: | |
1214 | case ASM_OPERANDS: | |
1215 | if (MEM_VOLATILE_P (x)) | |
1216 | return 1; | |
1217 | } | |
1218 | ||
1219 | /* Recursively scan the operands of this expression. */ | |
1220 | ||
1221 | { | |
1222 | register char *fmt = GET_RTX_FORMAT (code); | |
1223 | register int i; | |
1224 | ||
1225 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
1226 | { | |
1227 | if (fmt[i] == 'e') | |
1228 | { | |
1229 | if (volatile_refs_p (XEXP (x, i))) | |
1230 | return 1; | |
1231 | } | |
1232 | if (fmt[i] == 'E') | |
1233 | { | |
1234 | register int j; | |
1235 | for (j = 0; j < XVECLEN (x, i); j++) | |
1236 | if (volatile_refs_p (XVECEXP (x, i, j))) | |
1237 | return 1; | |
1238 | } | |
1239 | } | |
1240 | } | |
1241 | return 0; | |
1242 | } | |
1243 | ||
1244 | /* Similar to above, except that it also rejects register pre- and post- | |
1245 | incrementing. */ | |
1246 | ||
1247 | int | |
1248 | side_effects_p (x) | |
1249 | rtx x; | |
1250 | { | |
1251 | register RTX_CODE code; | |
1252 | ||
1253 | code = GET_CODE (x); | |
1254 | switch (code) | |
1255 | { | |
1256 | case LABEL_REF: | |
1257 | case SYMBOL_REF: | |
1258 | case CONST_INT: | |
1259 | case CONST: | |
1260 | case CONST_DOUBLE: | |
1261 | case CC0: | |
1262 | case PC: | |
1263 | case REG: | |
1264 | case SCRATCH: | |
1265 | case ASM_INPUT: | |
1266 | case ADDR_VEC: | |
1267 | case ADDR_DIFF_VEC: | |
1268 | return 0; | |
1269 | ||
1270 | case CLOBBER: | |
1271 | /* Reject CLOBBER with a non-VOID mode. These are made by combine.c | |
1272 | when some combination can't be done. If we see one, don't think | |
1273 | that we can simplify the expression. */ | |
1274 | return (GET_MODE (x) != VOIDmode); | |
1275 | ||
1276 | case PRE_INC: | |
1277 | case PRE_DEC: | |
1278 | case POST_INC: | |
1279 | case POST_DEC: | |
1280 | case CALL: | |
2ac4fed0 | 1281 | case UNSPEC_VOLATILE: |
2c88418c RS |
1282 | /* case TRAP_IF: This isn't clear yet. */ |
1283 | return 1; | |
1284 | ||
1285 | case MEM: | |
1286 | case ASM_OPERANDS: | |
1287 | if (MEM_VOLATILE_P (x)) | |
1288 | return 1; | |
1289 | } | |
1290 | ||
1291 | /* Recursively scan the operands of this expression. */ | |
1292 | ||
1293 | { | |
1294 | register char *fmt = GET_RTX_FORMAT (code); | |
1295 | register int i; | |
1296 | ||
1297 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
1298 | { | |
1299 | if (fmt[i] == 'e') | |
1300 | { | |
1301 | if (side_effects_p (XEXP (x, i))) | |
1302 | return 1; | |
1303 | } | |
1304 | if (fmt[i] == 'E') | |
1305 | { | |
1306 | register int j; | |
1307 | for (j = 0; j < XVECLEN (x, i); j++) | |
1308 | if (side_effects_p (XVECEXP (x, i, j))) | |
1309 | return 1; | |
1310 | } | |
1311 | } | |
1312 | } | |
1313 | return 0; | |
1314 | } | |
1315 | \f | |
1316 | /* Return nonzero if evaluating rtx X might cause a trap. */ | |
1317 | ||
1318 | int | |
1319 | may_trap_p (x) | |
1320 | rtx x; | |
1321 | { | |
1322 | int i; | |
1323 | enum rtx_code code; | |
1324 | char *fmt; | |
1325 | ||
1326 | if (x == 0) | |
1327 | return 0; | |
1328 | code = GET_CODE (x); | |
1329 | switch (code) | |
1330 | { | |
1331 | /* Handle these cases quickly. */ | |
1332 | case CONST_INT: | |
1333 | case CONST_DOUBLE: | |
1334 | case SYMBOL_REF: | |
1335 | case LABEL_REF: | |
1336 | case CONST: | |
1337 | case PC: | |
1338 | case CC0: | |
1339 | case REG: | |
1340 | case SCRATCH: | |
1341 | return 0; | |
1342 | ||
1343 | /* Conditional trap can trap! */ | |
2ac4fed0 | 1344 | case UNSPEC_VOLATILE: |
2c88418c RS |
1345 | case TRAP_IF: |
1346 | return 1; | |
1347 | ||
1348 | /* Memory ref can trap unless it's a static var or a stack slot. */ | |
1349 | case MEM: | |
1350 | return rtx_addr_can_trap_p (XEXP (x, 0)); | |
1351 | ||
1352 | /* Division by a non-constant might trap. */ | |
1353 | case DIV: | |
1354 | case MOD: | |
1355 | case UDIV: | |
1356 | case UMOD: | |
1357 | if (! CONSTANT_P (XEXP (x, 1))) | |
1358 | return 1; | |
1359 | /* This was const0_rtx, but by not using that, | |
1360 | we can link this file into other programs. */ | |
1361 | if (GET_CODE (XEXP (x, 1)) == CONST_INT && INTVAL (XEXP (x, 1)) == 0) | |
1362 | return 1; | |
1363 | default: | |
1364 | /* Any floating arithmetic may trap. */ | |
1365 | if (GET_MODE_CLASS (GET_MODE (x)) == MODE_FLOAT) | |
1366 | return 1; | |
1367 | } | |
1368 | ||
1369 | fmt = GET_RTX_FORMAT (code); | |
1370 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
1371 | { | |
1372 | if (fmt[i] == 'e') | |
1373 | { | |
1374 | if (may_trap_p (XEXP (x, i))) | |
1375 | return 1; | |
1376 | } | |
1377 | else if (fmt[i] == 'E') | |
1378 | { | |
1379 | register int j; | |
1380 | for (j = 0; j < XVECLEN (x, i); j++) | |
1381 | if (may_trap_p (XVECEXP (x, i, j))) | |
1382 | return 1; | |
1383 | } | |
1384 | } | |
1385 | return 0; | |
1386 | } | |
1387 | \f | |
1388 | /* Return nonzero if X contains a comparison that is not either EQ or NE, | |
1389 | i.e., an inequality. */ | |
1390 | ||
1391 | int | |
1392 | inequality_comparisons_p (x) | |
1393 | rtx x; | |
1394 | { | |
1395 | register char *fmt; | |
1396 | register int len, i; | |
1397 | register enum rtx_code code = GET_CODE (x); | |
1398 | ||
1399 | switch (code) | |
1400 | { | |
1401 | case REG: | |
1402 | case SCRATCH: | |
1403 | case PC: | |
1404 | case CC0: | |
1405 | case CONST_INT: | |
1406 | case CONST_DOUBLE: | |
1407 | case CONST: | |
1408 | case LABEL_REF: | |
1409 | case SYMBOL_REF: | |
1410 | return 0; | |
1411 | ||
1412 | case LT: | |
1413 | case LTU: | |
1414 | case GT: | |
1415 | case GTU: | |
1416 | case LE: | |
1417 | case LEU: | |
1418 | case GE: | |
1419 | case GEU: | |
1420 | return 1; | |
1421 | } | |
1422 | ||
1423 | len = GET_RTX_LENGTH (code); | |
1424 | fmt = GET_RTX_FORMAT (code); | |
1425 | ||
1426 | for (i = 0; i < len; i++) | |
1427 | { | |
1428 | if (fmt[i] == 'e') | |
1429 | { | |
1430 | if (inequality_comparisons_p (XEXP (x, i))) | |
1431 | return 1; | |
1432 | } | |
1433 | else if (fmt[i] == 'E') | |
1434 | { | |
1435 | register int j; | |
1436 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
1437 | if (inequality_comparisons_p (XVECEXP (x, i, j))) | |
1438 | return 1; | |
1439 | } | |
1440 | } | |
1441 | ||
1442 | return 0; | |
1443 | } | |
1444 | \f | |
1445 | /* Replace any occurrence of FROM in X with TO. | |
1446 | ||
1447 | Note that copying is not done so X must not be shared unless all copies | |
1448 | are to be modified. */ | |
1449 | ||
1450 | rtx | |
1451 | replace_rtx (x, from, to) | |
1452 | rtx x, from, to; | |
1453 | { | |
1454 | register int i, j; | |
1455 | register char *fmt; | |
1456 | ||
1457 | if (x == from) | |
1458 | return to; | |
1459 | ||
1460 | /* Allow this function to make replacements in EXPR_LISTs. */ | |
1461 | if (x == 0) | |
1462 | return 0; | |
1463 | ||
1464 | fmt = GET_RTX_FORMAT (GET_CODE (x)); | |
1465 | for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0; i--) | |
1466 | { | |
1467 | if (fmt[i] == 'e') | |
1468 | XEXP (x, i) = replace_rtx (XEXP (x, i), from, to); | |
1469 | else if (fmt[i] == 'E') | |
1470 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
1471 | XVECEXP (x, i, j) = replace_rtx (XVECEXP (x, i, j), from, to); | |
1472 | } | |
1473 | ||
1474 | return x; | |
1475 | } | |
1476 | \f | |
1477 | /* Throughout the rtx X, replace many registers according to REG_MAP. | |
1478 | Return the replacement for X (which may be X with altered contents). | |
1479 | REG_MAP[R] is the replacement for register R, or 0 for don't replace. | |
1480 | NREGS is the length of REG_MAP; regs >= NREGS are not mapped. | |
1481 | ||
1482 | We only support REG_MAP entries of REG or SUBREG. Also, hard registers | |
1483 | should not be mapped to pseudos or vice versa since validate_change | |
1484 | is not called. | |
1485 | ||
1486 | If REPLACE_DEST is 1, replacements are also done in destinations; | |
1487 | otherwise, only sources are replaced. */ | |
1488 | ||
1489 | rtx | |
1490 | replace_regs (x, reg_map, nregs, replace_dest) | |
1491 | rtx x; | |
1492 | rtx *reg_map; | |
1493 | int nregs; | |
1494 | int replace_dest; | |
1495 | { | |
1496 | register enum rtx_code code; | |
1497 | register int i; | |
1498 | register char *fmt; | |
1499 | ||
1500 | if (x == 0) | |
1501 | return x; | |
1502 | ||
1503 | code = GET_CODE (x); | |
1504 | switch (code) | |
1505 | { | |
1506 | case SCRATCH: | |
1507 | case PC: | |
1508 | case CC0: | |
1509 | case CONST_INT: | |
1510 | case CONST_DOUBLE: | |
1511 | case CONST: | |
1512 | case SYMBOL_REF: | |
1513 | case LABEL_REF: | |
1514 | return x; | |
1515 | ||
1516 | case REG: | |
1517 | /* Verify that the register has an entry before trying to access it. */ | |
1518 | if (REGNO (x) < nregs && reg_map[REGNO (x)] != 0) | |
1519 | return reg_map[REGNO (x)]; | |
1520 | return x; | |
1521 | ||
1522 | case SUBREG: | |
1523 | /* Prevent making nested SUBREGs. */ | |
1524 | if (GET_CODE (SUBREG_REG (x)) == REG && REGNO (SUBREG_REG (x)) < nregs | |
1525 | && reg_map[REGNO (SUBREG_REG (x))] != 0 | |
1526 | && GET_CODE (reg_map[REGNO (SUBREG_REG (x))]) == SUBREG) | |
1527 | { | |
1528 | rtx map_val = reg_map[REGNO (SUBREG_REG (x))]; | |
1529 | rtx map_inner = SUBREG_REG (map_val); | |
1530 | ||
1531 | if (GET_MODE (x) == GET_MODE (map_inner)) | |
1532 | return map_inner; | |
1533 | else | |
1534 | { | |
1535 | /* We cannot call gen_rtx here since we may be linked with | |
1536 | genattrtab.c. */ | |
1537 | /* Let's try clobbering the incoming SUBREG and see | |
1538 | if this is really safe. */ | |
1539 | SUBREG_REG (x) = map_inner; | |
1540 | SUBREG_WORD (x) += SUBREG_WORD (map_val); | |
1541 | return x; | |
1542 | #if 0 | |
1543 | rtx new = rtx_alloc (SUBREG); | |
1544 | PUT_MODE (new, GET_MODE (x)); | |
1545 | SUBREG_REG (new) = map_inner; | |
1546 | SUBREG_WORD (new) = SUBREG_WORD (x) + SUBREG_WORD (map_val); | |
1547 | #endif | |
1548 | } | |
1549 | } | |
1550 | break; | |
1551 | ||
1552 | case SET: | |
1553 | if (replace_dest) | |
1554 | SET_DEST (x) = replace_regs (SET_DEST (x), reg_map, nregs, 0); | |
1555 | ||
1556 | else if (GET_CODE (SET_DEST (x)) == MEM | |
1557 | || GET_CODE (SET_DEST (x)) == STRICT_LOW_PART) | |
1558 | /* Even if we are not to replace destinations, replace register if it | |
1559 | is CONTAINED in destination (destination is memory or | |
1560 | STRICT_LOW_PART). */ | |
1561 | XEXP (SET_DEST (x), 0) = replace_regs (XEXP (SET_DEST (x), 0), | |
1562 | reg_map, nregs, 0); | |
1563 | else if (GET_CODE (SET_DEST (x)) == ZERO_EXTRACT) | |
1564 | /* Similarly, for ZERO_EXTRACT we replace all operands. */ | |
1565 | break; | |
1566 | ||
1567 | SET_SRC (x) = replace_regs (SET_SRC (x), reg_map, nregs, 0); | |
1568 | return x; | |
1569 | } | |
1570 | ||
1571 | fmt = GET_RTX_FORMAT (code); | |
1572 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
1573 | { | |
1574 | if (fmt[i] == 'e') | |
1575 | XEXP (x, i) = replace_regs (XEXP (x, i), reg_map, nregs, replace_dest); | |
1576 | if (fmt[i] == 'E') | |
1577 | { | |
1578 | register int j; | |
1579 | for (j = 0; j < XVECLEN (x, i); j++) | |
1580 | XVECEXP (x, i, j) = replace_regs (XVECEXP (x, i, j), reg_map, | |
1581 | nregs, replace_dest); | |
1582 | } | |
1583 | } | |
1584 | return x; | |
1585 | } |