var-tracking.c (unshare_variable): Force initialized to be VAR_INIT_STATUS_INITIALIZE...
[gcc.git] / gcc / rtl.c
1 /* RTL utility routines.
2 Copyright (C) 1987, 1988, 1991, 1994, 1997, 1998, 1999, 2000, 2001, 2002,
3 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
4
5 This file is part of GCC.
6
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
10 version.
11
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
20
21 /* This file is compiled twice: once for the generator programs
22 once for the compiler. */
23 #ifdef GENERATOR_FILE
24 #include "bconfig.h"
25 #else
26 #include "config.h"
27 #endif
28
29 #include "system.h"
30 #include "coretypes.h"
31 #include "tm.h"
32 #include "rtl.h"
33 #include "real.h"
34 #include "ggc.h"
35 #ifdef GENERATOR_FILE
36 # include "errors.h"
37 #else
38 # include "toplev.h"
39 #endif
40
41 \f
42 /* Indexed by rtx code, gives number of operands for an rtx with that code.
43 Does NOT include rtx header data (code and links). */
44
45 #define DEF_RTL_EXPR(ENUM, NAME, FORMAT, CLASS) sizeof FORMAT - 1 ,
46
47 const unsigned char rtx_length[NUM_RTX_CODE] = {
48 #include "rtl.def"
49 };
50
51 #undef DEF_RTL_EXPR
52
53 /* Indexed by rtx code, gives the name of that kind of rtx, as a C string. */
54
55 #define DEF_RTL_EXPR(ENUM, NAME, FORMAT, CLASS) NAME ,
56
57 const char * const rtx_name[NUM_RTX_CODE] = {
58 #include "rtl.def" /* rtl expressions are documented here */
59 };
60
61 #undef DEF_RTL_EXPR
62
63 /* Indexed by rtx code, gives a sequence of operand-types for
64 rtx's of that code. The sequence is a C string in which
65 each character describes one operand. */
66
67 const char * const rtx_format[NUM_RTX_CODE] = {
68 /* "*" undefined.
69 can cause a warning message
70 "0" field is unused (or used in a phase-dependent manner)
71 prints nothing
72 "i" an integer
73 prints the integer
74 "n" like "i", but prints entries from `note_insn_name'
75 "w" an integer of width HOST_BITS_PER_WIDE_INT
76 prints the integer
77 "s" a pointer to a string
78 prints the string
79 "S" like "s", but optional:
80 the containing rtx may end before this operand
81 "T" like "s", but treated specially by the RTL reader;
82 only found in machine description patterns.
83 "e" a pointer to an rtl expression
84 prints the expression
85 "E" a pointer to a vector that points to a number of rtl expressions
86 prints a list of the rtl expressions
87 "V" like "E", but optional:
88 the containing rtx may end before this operand
89 "u" a pointer to another insn
90 prints the uid of the insn.
91 "b" is a pointer to a bitmap header.
92 "B" is a basic block pointer.
93 "t" is a tree pointer. */
94
95 #define DEF_RTL_EXPR(ENUM, NAME, FORMAT, CLASS) FORMAT ,
96 #include "rtl.def" /* rtl expressions are defined here */
97 #undef DEF_RTL_EXPR
98 };
99
100 /* Indexed by rtx code, gives a character representing the "class" of
101 that rtx code. See rtl.def for documentation on the defined classes. */
102
103 const enum rtx_class rtx_class[NUM_RTX_CODE] = {
104 #define DEF_RTL_EXPR(ENUM, NAME, FORMAT, CLASS) CLASS,
105 #include "rtl.def" /* rtl expressions are defined here */
106 #undef DEF_RTL_EXPR
107 };
108
109 /* Indexed by rtx code, gives the size of the rtx in bytes. */
110
111 const unsigned char rtx_code_size[NUM_RTX_CODE] = {
112 #define DEF_RTL_EXPR(ENUM, NAME, FORMAT, CLASS) \
113 ((ENUM) == CONST_INT || (ENUM) == CONST_DOUBLE || (ENUM) == CONST_FIXED\
114 ? RTX_HDR_SIZE + (sizeof FORMAT - 1) * sizeof (HOST_WIDE_INT) \
115 : RTX_HDR_SIZE + (sizeof FORMAT - 1) * sizeof (rtunion)),
116
117 #include "rtl.def"
118 #undef DEF_RTL_EXPR
119 };
120
121 /* Names for kinds of NOTEs and REG_NOTEs. */
122
123 const char * const note_insn_name[NOTE_INSN_MAX] =
124 {
125 #define DEF_INSN_NOTE(NAME) #NAME,
126 #include "insn-notes.def"
127 #undef DEF_INSN_NOTE
128 };
129
130 const char * const reg_note_name[REG_NOTE_MAX] =
131 {
132 #define DEF_REG_NOTE(NAME) #NAME,
133 #include "reg-notes.def"
134 #undef DEF_REG_NOTE
135 };
136
137 #ifdef GATHER_STATISTICS
138 static int rtx_alloc_counts[(int) LAST_AND_UNUSED_RTX_CODE];
139 static int rtx_alloc_sizes[(int) LAST_AND_UNUSED_RTX_CODE];
140 static int rtvec_alloc_counts;
141 static int rtvec_alloc_sizes;
142 #endif
143
144 \f
145 /* Allocate an rtx vector of N elements.
146 Store the length, and initialize all elements to zero. */
147
148 rtvec
149 rtvec_alloc (int n)
150 {
151 rtvec rt;
152
153 rt = ggc_alloc_rtvec (n);
154 /* Clear out the vector. */
155 memset (&rt->elem[0], 0, n * sizeof (rtx));
156
157 PUT_NUM_ELEM (rt, n);
158
159 #ifdef GATHER_STATISTICS
160 rtvec_alloc_counts++;
161 rtvec_alloc_sizes += n * sizeof (rtx);
162 #endif
163
164 return rt;
165 }
166
167 /* Return the number of bytes occupied by rtx value X. */
168
169 unsigned int
170 rtx_size (const_rtx x)
171 {
172 if (GET_CODE (x) == SYMBOL_REF && SYMBOL_REF_HAS_BLOCK_INFO_P (x))
173 return RTX_HDR_SIZE + sizeof (struct block_symbol);
174 return RTX_CODE_SIZE (GET_CODE (x));
175 }
176
177 /* Allocate an rtx of code CODE. The CODE is stored in the rtx;
178 all the rest is initialized to zero. */
179
180 rtx
181 rtx_alloc_stat (RTX_CODE code MEM_STAT_DECL)
182 {
183 rtx rt;
184
185 rt = (rtx) ggc_alloc_zone_pass_stat (RTX_CODE_SIZE (code), &rtl_zone);
186
187 /* We want to clear everything up to the FLD array. Normally, this
188 is one int, but we don't want to assume that and it isn't very
189 portable anyway; this is. */
190
191 memset (rt, 0, RTX_HDR_SIZE);
192 PUT_CODE (rt, code);
193
194 #ifdef GATHER_STATISTICS
195 rtx_alloc_counts[code]++;
196 rtx_alloc_sizes[code] += RTX_CODE_SIZE (code);
197 #endif
198
199 return rt;
200 }
201
202 \f
203 /* Return true if ORIG is a sharable CONST. */
204
205 bool
206 shared_const_p (const_rtx orig)
207 {
208 gcc_assert (GET_CODE (orig) == CONST);
209
210 /* CONST can be shared if it contains a SYMBOL_REF. If it contains
211 a LABEL_REF, it isn't sharable. */
212 return (GET_CODE (XEXP (orig, 0)) == PLUS
213 && GET_CODE (XEXP (XEXP (orig, 0), 0)) == SYMBOL_REF
214 && CONST_INT_P(XEXP (XEXP (orig, 0), 1)));
215 }
216
217
218 /* Create a new copy of an rtx.
219 Recursively copies the operands of the rtx,
220 except for those few rtx codes that are sharable. */
221
222 rtx
223 copy_rtx (rtx orig)
224 {
225 rtx copy;
226 int i, j;
227 RTX_CODE code;
228 const char *format_ptr;
229
230 code = GET_CODE (orig);
231
232 switch (code)
233 {
234 case REG:
235 case CONST_INT:
236 case CONST_DOUBLE:
237 case CONST_FIXED:
238 case CONST_VECTOR:
239 case SYMBOL_REF:
240 case CODE_LABEL:
241 case PC:
242 case CC0:
243 case SCRATCH:
244 /* SCRATCH must be shared because they represent distinct values. */
245 return orig;
246 case CLOBBER:
247 if (REG_P (XEXP (orig, 0)) && REGNO (XEXP (orig, 0)) < FIRST_PSEUDO_REGISTER)
248 return orig;
249 break;
250
251 case CONST:
252 if (shared_const_p (orig))
253 return orig;
254 break;
255
256 /* A MEM with a constant address is not sharable. The problem is that
257 the constant address may need to be reloaded. If the mem is shared,
258 then reloading one copy of this mem will cause all copies to appear
259 to have been reloaded. */
260
261 default:
262 break;
263 }
264
265 /* Copy the various flags, fields, and other information. We assume
266 that all fields need copying, and then clear the fields that should
267 not be copied. That is the sensible default behavior, and forces
268 us to explicitly document why we are *not* copying a flag. */
269 copy = shallow_copy_rtx (orig);
270
271 /* We do not copy the USED flag, which is used as a mark bit during
272 walks over the RTL. */
273 RTX_FLAG (copy, used) = 0;
274
275 /* We do not copy FRAME_RELATED for INSNs. */
276 if (INSN_P (orig))
277 RTX_FLAG (copy, frame_related) = 0;
278 RTX_FLAG (copy, jump) = RTX_FLAG (orig, jump);
279 RTX_FLAG (copy, call) = RTX_FLAG (orig, call);
280
281 format_ptr = GET_RTX_FORMAT (GET_CODE (copy));
282
283 for (i = 0; i < GET_RTX_LENGTH (GET_CODE (copy)); i++)
284 switch (*format_ptr++)
285 {
286 case 'e':
287 if (XEXP (orig, i) != NULL)
288 XEXP (copy, i) = copy_rtx (XEXP (orig, i));
289 break;
290
291 case 'E':
292 case 'V':
293 if (XVEC (orig, i) != NULL)
294 {
295 XVEC (copy, i) = rtvec_alloc (XVECLEN (orig, i));
296 for (j = 0; j < XVECLEN (copy, i); j++)
297 XVECEXP (copy, i, j) = copy_rtx (XVECEXP (orig, i, j));
298 }
299 break;
300
301 case 't':
302 case 'w':
303 case 'i':
304 case 's':
305 case 'S':
306 case 'T':
307 case 'u':
308 case 'B':
309 case '0':
310 /* These are left unchanged. */
311 break;
312
313 default:
314 gcc_unreachable ();
315 }
316 return copy;
317 }
318
319 /* Create a new copy of an rtx. Only copy just one level. */
320
321 rtx
322 shallow_copy_rtx_stat (const_rtx orig MEM_STAT_DECL)
323 {
324 const unsigned int size = rtx_size (orig);
325 rtx const copy = (rtx) ggc_alloc_zone_pass_stat (size, &rtl_zone);
326 return (rtx) memcpy (copy, orig, size);
327 }
328 \f
329 /* Nonzero when we are generating CONCATs. */
330 int generating_concat_p;
331
332 /* Nonzero when we are expanding trees to RTL. */
333 int currently_expanding_to_rtl;
334
335 \f
336
337 /* Same as rtx_equal_p, but call CB on each pair of rtx if CB is not NULL.
338 When the callback returns true, we continue with the new pair.
339 Whenever changing this function check if rtx_equal_p below doesn't need
340 changing as well. */
341
342 int
343 rtx_equal_p_cb (const_rtx x, const_rtx y, rtx_equal_p_callback_function cb)
344 {
345 int i;
346 int j;
347 enum rtx_code code;
348 const char *fmt;
349 rtx nx, ny;
350
351 if (x == y)
352 return 1;
353 if (x == 0 || y == 0)
354 return 0;
355
356 /* Invoke the callback first. */
357 if (cb != NULL
358 && ((*cb) (&x, &y, &nx, &ny)))
359 return rtx_equal_p_cb (nx, ny, cb);
360
361 code = GET_CODE (x);
362 /* Rtx's of different codes cannot be equal. */
363 if (code != GET_CODE (y))
364 return 0;
365
366 /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent.
367 (REG:SI x) and (REG:HI x) are NOT equivalent. */
368
369 if (GET_MODE (x) != GET_MODE (y))
370 return 0;
371
372 /* Some RTL can be compared nonrecursively. */
373 switch (code)
374 {
375 case REG:
376 return (REGNO (x) == REGNO (y));
377
378 case LABEL_REF:
379 return XEXP (x, 0) == XEXP (y, 0);
380
381 case SYMBOL_REF:
382 return XSTR (x, 0) == XSTR (y, 0);
383
384 case SCRATCH:
385 case CONST_DOUBLE:
386 case CONST_INT:
387 case CONST_FIXED:
388 return 0;
389
390 default:
391 break;
392 }
393
394 /* Compare the elements. If any pair of corresponding elements
395 fail to match, return 0 for the whole thing. */
396
397 fmt = GET_RTX_FORMAT (code);
398 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
399 {
400 switch (fmt[i])
401 {
402 case 'w':
403 if (XWINT (x, i) != XWINT (y, i))
404 return 0;
405 break;
406
407 case 'n':
408 case 'i':
409 if (XINT (x, i) != XINT (y, i))
410 return 0;
411 break;
412
413 case 'V':
414 case 'E':
415 /* Two vectors must have the same length. */
416 if (XVECLEN (x, i) != XVECLEN (y, i))
417 return 0;
418
419 /* And the corresponding elements must match. */
420 for (j = 0; j < XVECLEN (x, i); j++)
421 if (rtx_equal_p_cb (XVECEXP (x, i, j),
422 XVECEXP (y, i, j), cb) == 0)
423 return 0;
424 break;
425
426 case 'e':
427 if (rtx_equal_p_cb (XEXP (x, i), XEXP (y, i), cb) == 0)
428 return 0;
429 break;
430
431 case 'S':
432 case 's':
433 if ((XSTR (x, i) || XSTR (y, i))
434 && (! XSTR (x, i) || ! XSTR (y, i)
435 || strcmp (XSTR (x, i), XSTR (y, i))))
436 return 0;
437 break;
438
439 case 'u':
440 /* These are just backpointers, so they don't matter. */
441 break;
442
443 case '0':
444 case 't':
445 break;
446
447 /* It is believed that rtx's at this level will never
448 contain anything but integers and other rtx's,
449 except for within LABEL_REFs and SYMBOL_REFs. */
450 default:
451 gcc_unreachable ();
452 }
453 }
454 return 1;
455 }
456
457 /* Return 1 if X and Y are identical-looking rtx's.
458 This is the Lisp function EQUAL for rtx arguments.
459 Whenever changing this function check if rtx_equal_p_cb above doesn't need
460 changing as well. */
461
462 int
463 rtx_equal_p (const_rtx x, const_rtx y)
464 {
465 int i;
466 int j;
467 enum rtx_code code;
468 const char *fmt;
469
470 if (x == y)
471 return 1;
472 if (x == 0 || y == 0)
473 return 0;
474
475 code = GET_CODE (x);
476 /* Rtx's of different codes cannot be equal. */
477 if (code != GET_CODE (y))
478 return 0;
479
480 /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent.
481 (REG:SI x) and (REG:HI x) are NOT equivalent. */
482
483 if (GET_MODE (x) != GET_MODE (y))
484 return 0;
485
486 /* Some RTL can be compared nonrecursively. */
487 switch (code)
488 {
489 case REG:
490 return (REGNO (x) == REGNO (y));
491
492 case LABEL_REF:
493 return XEXP (x, 0) == XEXP (y, 0);
494
495 case SYMBOL_REF:
496 return XSTR (x, 0) == XSTR (y, 0);
497
498 case SCRATCH:
499 case CONST_DOUBLE:
500 case CONST_INT:
501 case CONST_FIXED:
502 return 0;
503
504 default:
505 break;
506 }
507
508 /* Compare the elements. If any pair of corresponding elements
509 fail to match, return 0 for the whole thing. */
510
511 fmt = GET_RTX_FORMAT (code);
512 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
513 {
514 switch (fmt[i])
515 {
516 case 'w':
517 if (XWINT (x, i) != XWINT (y, i))
518 return 0;
519 break;
520
521 case 'n':
522 case 'i':
523 if (XINT (x, i) != XINT (y, i))
524 return 0;
525 break;
526
527 case 'V':
528 case 'E':
529 /* Two vectors must have the same length. */
530 if (XVECLEN (x, i) != XVECLEN (y, i))
531 return 0;
532
533 /* And the corresponding elements must match. */
534 for (j = 0; j < XVECLEN (x, i); j++)
535 if (rtx_equal_p (XVECEXP (x, i, j), XVECEXP (y, i, j)) == 0)
536 return 0;
537 break;
538
539 case 'e':
540 if (rtx_equal_p (XEXP (x, i), XEXP (y, i)) == 0)
541 return 0;
542 break;
543
544 case 'S':
545 case 's':
546 if ((XSTR (x, i) || XSTR (y, i))
547 && (! XSTR (x, i) || ! XSTR (y, i)
548 || strcmp (XSTR (x, i), XSTR (y, i))))
549 return 0;
550 break;
551
552 case 'u':
553 /* These are just backpointers, so they don't matter. */
554 break;
555
556 case '0':
557 case 't':
558 break;
559
560 /* It is believed that rtx's at this level will never
561 contain anything but integers and other rtx's,
562 except for within LABEL_REFs and SYMBOL_REFs. */
563 default:
564 gcc_unreachable ();
565 }
566 }
567 return 1;
568 }
569
570 void
571 dump_rtx_statistics (void)
572 {
573 #ifdef GATHER_STATISTICS
574 int i;
575 int total_counts = 0;
576 int total_sizes = 0;
577 fprintf (stderr, "\nRTX Kind Count Bytes\n");
578 fprintf (stderr, "---------------------------------------\n");
579 for (i = 0; i < LAST_AND_UNUSED_RTX_CODE; i++)
580 if (rtx_alloc_counts[i])
581 {
582 fprintf (stderr, "%-20s %7d %10d\n", GET_RTX_NAME (i),
583 rtx_alloc_counts[i], rtx_alloc_sizes[i]);
584 total_counts += rtx_alloc_counts[i];
585 total_sizes += rtx_alloc_sizes[i];
586 }
587 if (rtvec_alloc_counts)
588 {
589 fprintf (stderr, "%-20s %7d %10d\n", "rtvec",
590 rtvec_alloc_counts, rtvec_alloc_sizes);
591 total_counts += rtvec_alloc_counts;
592 total_sizes += rtvec_alloc_sizes;
593 }
594 fprintf (stderr, "---------------------------------------\n");
595 fprintf (stderr, "%-20s %7d %10d\n",
596 "Total", total_counts, total_sizes);
597 fprintf (stderr, "---------------------------------------\n");
598 #endif
599 }
600 \f
601 #if defined ENABLE_RTL_CHECKING && (GCC_VERSION >= 2007)
602 void
603 rtl_check_failed_bounds (const_rtx r, int n, const char *file, int line,
604 const char *func)
605 {
606 internal_error
607 ("RTL check: access of elt %d of '%s' with last elt %d in %s, at %s:%d",
608 n, GET_RTX_NAME (GET_CODE (r)), GET_RTX_LENGTH (GET_CODE (r)) - 1,
609 func, trim_filename (file), line);
610 }
611
612 void
613 rtl_check_failed_type1 (const_rtx r, int n, int c1, const char *file, int line,
614 const char *func)
615 {
616 internal_error
617 ("RTL check: expected elt %d type '%c', have '%c' (rtx %s) in %s, at %s:%d",
618 n, c1, GET_RTX_FORMAT (GET_CODE (r))[n], GET_RTX_NAME (GET_CODE (r)),
619 func, trim_filename (file), line);
620 }
621
622 void
623 rtl_check_failed_type2 (const_rtx r, int n, int c1, int c2, const char *file,
624 int line, const char *func)
625 {
626 internal_error
627 ("RTL check: expected elt %d type '%c' or '%c', have '%c' (rtx %s) in %s, at %s:%d",
628 n, c1, c2, GET_RTX_FORMAT (GET_CODE (r))[n], GET_RTX_NAME (GET_CODE (r)),
629 func, trim_filename (file), line);
630 }
631
632 void
633 rtl_check_failed_code1 (const_rtx r, enum rtx_code code, const char *file,
634 int line, const char *func)
635 {
636 internal_error ("RTL check: expected code '%s', have '%s' in %s, at %s:%d",
637 GET_RTX_NAME (code), GET_RTX_NAME (GET_CODE (r)), func,
638 trim_filename (file), line);
639 }
640
641 void
642 rtl_check_failed_code2 (const_rtx r, enum rtx_code code1, enum rtx_code code2,
643 const char *file, int line, const char *func)
644 {
645 internal_error
646 ("RTL check: expected code '%s' or '%s', have '%s' in %s, at %s:%d",
647 GET_RTX_NAME (code1), GET_RTX_NAME (code2), GET_RTX_NAME (GET_CODE (r)),
648 func, trim_filename (file), line);
649 }
650
651 void
652 rtl_check_failed_code_mode (const_rtx r, enum rtx_code code, enum machine_mode mode,
653 bool not_mode, const char *file, int line,
654 const char *func)
655 {
656 internal_error ((not_mode
657 ? ("RTL check: expected code '%s' and not mode '%s', "
658 "have code '%s' and mode '%s' in %s, at %s:%d")
659 : ("RTL check: expected code '%s' and mode '%s', "
660 "have code '%s' and mode '%s' in %s, at %s:%d")),
661 GET_RTX_NAME (code), GET_MODE_NAME (mode),
662 GET_RTX_NAME (GET_CODE (r)), GET_MODE_NAME (GET_MODE (r)),
663 func, trim_filename (file), line);
664 }
665
666 /* Report that line LINE of FILE tried to access the block symbol fields
667 of a non-block symbol. FUNC is the function that contains the line. */
668
669 void
670 rtl_check_failed_block_symbol (const char *file, int line, const char *func)
671 {
672 internal_error
673 ("RTL check: attempt to treat non-block symbol as a block symbol "
674 "in %s, at %s:%d", func, trim_filename (file), line);
675 }
676
677 /* XXX Maybe print the vector? */
678 void
679 rtvec_check_failed_bounds (const_rtvec r, int n, const char *file, int line,
680 const char *func)
681 {
682 internal_error
683 ("RTL check: access of elt %d of vector with last elt %d in %s, at %s:%d",
684 n, GET_NUM_ELEM (r) - 1, func, trim_filename (file), line);
685 }
686 #endif /* ENABLE_RTL_CHECKING */
687
688 #if defined ENABLE_RTL_FLAG_CHECKING
689 void
690 rtl_check_failed_flag (const char *name, const_rtx r, const char *file,
691 int line, const char *func)
692 {
693 internal_error
694 ("RTL flag check: %s used with unexpected rtx code '%s' in %s, at %s:%d",
695 name, GET_RTX_NAME (GET_CODE (r)), func, trim_filename (file), line);
696 }
697 #endif /* ENABLE_RTL_FLAG_CHECKING */