1 /* Data flow functions for trees.
2 Copyright (C) 2001-2018 Free Software Foundation, Inc.
3 Contributed by Diego Novillo <dnovillo@redhat.com>
4
5 This file is part of GCC.
6
7 GCC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
10 any later version.
11
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
20
21 #include "config.h"
22 #include "system.h"
23 #include "coretypes.h"
24 #include "backend.h"
25 #include "rtl.h"
26 #include "tree.h"
27 #include "gimple.h"
28 #include "tree-pass.h"
29 #include "ssa.h"
30 #include "tree-pretty-print.h"
31 #include "fold-const.h"
32 #include "stor-layout.h"
33 #include "langhooks.h"
34 #include "gimple-iterator.h"
35 #include "gimple-walk.h"
36 #include "tree-dfa.h"
37
38 /* Build and maintain data flow information for trees. */
39
40 /* Counters used to display DFA and SSA statistics. */
41 struct dfa_stats_d
42 {
43 long num_defs;
44 long num_uses;
45 long num_phis;
46 long num_phi_args;
47 size_t max_num_phi_args;
48 long num_vdefs;
49 long num_vuses;
50 };
51
52
53 /* Local functions. */
54 static void collect_dfa_stats (struct dfa_stats_d *);
55
56
57 /*---------------------------------------------------------------------------
58 Dataflow analysis (DFA) routines
59 ---------------------------------------------------------------------------*/
60
61 /* Renumber all of the gimple stmt uids. */
62
63 void
renumber_gimple_stmt_uids(void)64 renumber_gimple_stmt_uids (void)
65 {
66 basic_block bb;
67
68 set_gimple_stmt_max_uid (cfun, 0);
69 FOR_ALL_BB_FN (bb, cfun)
70 {
71 gimple_stmt_iterator bsi;
72 for (bsi = gsi_start_phis (bb); !gsi_end_p (bsi); gsi_next (&bsi))
73 {
74 gimple *stmt = gsi_stmt (bsi);
75 gimple_set_uid (stmt, inc_gimple_stmt_max_uid (cfun));
76 }
77 for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
78 {
79 gimple *stmt = gsi_stmt (bsi);
80 gimple_set_uid (stmt, inc_gimple_stmt_max_uid (cfun));
81 }
82 }
83 }
84
85 /* Like renumber_gimple_stmt_uids, but only do work on the basic blocks
86 in BLOCKS, of which there are N_BLOCKS. Also renumbers PHIs. */
87
88 void
renumber_gimple_stmt_uids_in_blocks(basic_block * blocks,int n_blocks)89 renumber_gimple_stmt_uids_in_blocks (basic_block *blocks, int n_blocks)
90 {
91 int i;
92
93 set_gimple_stmt_max_uid (cfun, 0);
94 for (i = 0; i < n_blocks; i++)
95 {
96 basic_block bb = blocks[i];
97 gimple_stmt_iterator bsi;
98 for (bsi = gsi_start_phis (bb); !gsi_end_p (bsi); gsi_next (&bsi))
99 {
100 gimple *stmt = gsi_stmt (bsi);
101 gimple_set_uid (stmt, inc_gimple_stmt_max_uid (cfun));
102 }
103 for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
104 {
105 gimple *stmt = gsi_stmt (bsi);
106 gimple_set_uid (stmt, inc_gimple_stmt_max_uid (cfun));
107 }
108 }
109 }
110
111
112
113 /*---------------------------------------------------------------------------
114 Debugging functions
115 ---------------------------------------------------------------------------*/
116
117 /* Dump variable VAR and its may-aliases to FILE. */
118
119 void
dump_variable(FILE * file,tree var)120 dump_variable (FILE *file, tree var)
121 {
122 if (TREE_CODE (var) == SSA_NAME)
123 {
124 if (POINTER_TYPE_P (TREE_TYPE (var)))
125 dump_points_to_info_for (file, var);
126 var = SSA_NAME_VAR (var);
127 }
128
129 if (var == NULL_TREE)
130 {
131 fprintf (file, "<nil>");
132 return;
133 }
134
135 print_generic_expr (file, var, dump_flags);
136
137 fprintf (file, ", UID D.%u", (unsigned) DECL_UID (var));
138 if (DECL_PT_UID (var) != DECL_UID (var))
139 fprintf (file, ", PT-UID D.%u", (unsigned) DECL_PT_UID (var));
140
141 fprintf (file, ", ");
142 print_generic_expr (file, TREE_TYPE (var), dump_flags);
143
144 if (TREE_ADDRESSABLE (var))
145 fprintf (file, ", is addressable");
146
147 if (is_global_var (var))
148 fprintf (file, ", is global");
149
150 if (TREE_THIS_VOLATILE (var))
151 fprintf (file, ", is volatile");
152
153 if (cfun && ssa_default_def (cfun, var))
154 {
155 fprintf (file, ", default def: ");
156 print_generic_expr (file, ssa_default_def (cfun, var), dump_flags);
157 }
158
159 if (DECL_INITIAL (var))
160 {
161 fprintf (file, ", initial: ");
162 print_generic_expr (file, DECL_INITIAL (var), dump_flags);
163 }
164
165 fprintf (file, "\n");
166 }
167
168
169 /* Dump variable VAR and its may-aliases to stderr. */
170
171 DEBUG_FUNCTION void
debug_variable(tree var)172 debug_variable (tree var)
173 {
174 dump_variable (stderr, var);
175 }
176
177
178 /* Dump various DFA statistics to FILE. */
179
180 void
dump_dfa_stats(FILE * file)181 dump_dfa_stats (FILE *file)
182 {
183 struct dfa_stats_d dfa_stats;
184
185 unsigned long size, total = 0;
186 const char * const fmt_str = "%-30s%-13s%12s\n";
187 const char * const fmt_str_1 = "%-30s%13lu%11lu%c\n";
188 const char * const fmt_str_3 = "%-43s%11lu%c\n";
189 const char *funcname
190 = lang_hooks.decl_printable_name (current_function_decl, 2);
191
192 collect_dfa_stats (&dfa_stats);
193
194 fprintf (file, "\nDFA Statistics for %s\n\n", funcname);
195
196 fprintf (file, "---------------------------------------------------------\n");
197 fprintf (file, fmt_str, "", " Number of ", "Memory");
198 fprintf (file, fmt_str, "", " instances ", "used ");
199 fprintf (file, "---------------------------------------------------------\n");
200
201 size = dfa_stats.num_uses * sizeof (tree *);
202 total += size;
203 fprintf (file, fmt_str_1, "USE operands", dfa_stats.num_uses,
204 SCALE (size), LABEL (size));
205
206 size = dfa_stats.num_defs * sizeof (tree *);
207 total += size;
208 fprintf (file, fmt_str_1, "DEF operands", dfa_stats.num_defs,
209 SCALE (size), LABEL (size));
210
211 size = dfa_stats.num_vuses * sizeof (tree *);
212 total += size;
213 fprintf (file, fmt_str_1, "VUSE operands", dfa_stats.num_vuses,
214 SCALE (size), LABEL (size));
215
216 size = dfa_stats.num_vdefs * sizeof (tree *);
217 total += size;
218 fprintf (file, fmt_str_1, "VDEF operands", dfa_stats.num_vdefs,
219 SCALE (size), LABEL (size));
220
221 size = dfa_stats.num_phis * sizeof (struct gphi);
222 total += size;
223 fprintf (file, fmt_str_1, "PHI nodes", dfa_stats.num_phis,
224 SCALE (size), LABEL (size));
225
226 size = dfa_stats.num_phi_args * sizeof (struct phi_arg_d);
227 total += size;
228 fprintf (file, fmt_str_1, "PHI arguments", dfa_stats.num_phi_args,
229 SCALE (size), LABEL (size));
230
231 fprintf (file, "---------------------------------------------------------\n");
232 fprintf (file, fmt_str_3, "Total memory used by DFA/SSA data", SCALE (total),
233 LABEL (total));
234 fprintf (file, "---------------------------------------------------------\n");
235 fprintf (file, "\n");
236
237 if (dfa_stats.num_phis)
238 fprintf (file, "Average number of arguments per PHI node: %.1f (max: %ld)\n",
239 (float) dfa_stats.num_phi_args / (float) dfa_stats.num_phis,
240 (long) dfa_stats.max_num_phi_args);
241
242 fprintf (file, "\n");
243 }
244
245
246 /* Dump DFA statistics on stderr. */
247
248 DEBUG_FUNCTION void
debug_dfa_stats(void)249 debug_dfa_stats (void)
250 {
251 dump_dfa_stats (stderr);
252 }
253
254
255 /* Collect DFA statistics and store them in the structure pointed to by
256 DFA_STATS_P. */
257
258 static void
collect_dfa_stats(struct dfa_stats_d * dfa_stats_p ATTRIBUTE_UNUSED)259 collect_dfa_stats (struct dfa_stats_d *dfa_stats_p ATTRIBUTE_UNUSED)
260 {
261 basic_block bb;
262
263 gcc_assert (dfa_stats_p);
264
265 memset ((void *)dfa_stats_p, 0, sizeof (struct dfa_stats_d));
266
267 /* Walk all the statements in the function counting references. */
268 FOR_EACH_BB_FN (bb, cfun)
269 {
270 for (gphi_iterator si = gsi_start_phis (bb); !gsi_end_p (si);
271 gsi_next (&si))
272 {
273 gphi *phi = si.phi ();
274 dfa_stats_p->num_phis++;
275 dfa_stats_p->num_phi_args += gimple_phi_num_args (phi);
276 if (gimple_phi_num_args (phi) > dfa_stats_p->max_num_phi_args)
277 dfa_stats_p->max_num_phi_args = gimple_phi_num_args (phi);
278 }
279
280 for (gimple_stmt_iterator si = gsi_start_bb (bb); !gsi_end_p (si);
281 gsi_next (&si))
282 {
283 gimple *stmt = gsi_stmt (si);
284 dfa_stats_p->num_defs += NUM_SSA_OPERANDS (stmt, SSA_OP_DEF);
285 dfa_stats_p->num_uses += NUM_SSA_OPERANDS (stmt, SSA_OP_USE);
286 dfa_stats_p->num_vdefs += gimple_vdef (stmt) ? 1 : 0;
287 dfa_stats_p->num_vuses += gimple_vuse (stmt) ? 1 : 0;
288 }
289 }
290 }
291
292
293 /*---------------------------------------------------------------------------
294 Miscellaneous helpers
295 ---------------------------------------------------------------------------*/
296
297 /* Lookup VAR UID in the default_defs hashtable and return the associated
298 variable. */
299
300 tree
ssa_default_def(struct function * fn,tree var)301 ssa_default_def (struct function *fn, tree var)
302 {
303 struct tree_decl_minimal ind;
304 struct tree_ssa_name in;
305 gcc_assert (VAR_P (var)
306 || TREE_CODE (var) == PARM_DECL
307 || TREE_CODE (var) == RESULT_DECL);
308
309 /* Always NULL_TREE for rtl function dumps. */
310 if (!fn->gimple_df)
311 return NULL_TREE;
312
313 in.var = (tree)&ind;
314 ind.uid = DECL_UID (var);
315 return DEFAULT_DEFS (fn)->find_with_hash ((tree)&in, DECL_UID (var));
316 }
317
318 /* Insert the pair VAR's UID, DEF into the default_defs hashtable
319 of function FN. */
320
321 void
set_ssa_default_def(struct function * fn,tree var,tree def)322 set_ssa_default_def (struct function *fn, tree var, tree def)
323 {
324 struct tree_decl_minimal ind;
325 struct tree_ssa_name in;
326
327 gcc_assert (VAR_P (var)
328 || TREE_CODE (var) == PARM_DECL
329 || TREE_CODE (var) == RESULT_DECL);
330 in.var = (tree)&ind;
331 ind.uid = DECL_UID (var);
332 if (!def)
333 {
334 tree *loc = DEFAULT_DEFS (fn)->find_slot_with_hash ((tree)&in,
335 DECL_UID (var),
336 NO_INSERT);
337 if (loc)
338 {
339 SSA_NAME_IS_DEFAULT_DEF (*(tree *)loc) = false;
340 DEFAULT_DEFS (fn)->clear_slot (loc);
341 }
342 return;
343 }
344 gcc_assert (TREE_CODE (def) == SSA_NAME && SSA_NAME_VAR (def) == var);
345 tree *loc = DEFAULT_DEFS (fn)->find_slot_with_hash ((tree)&in,
346 DECL_UID (var), INSERT);
347
348 /* Default definition might be changed by tail call optimization. */
349 if (*loc)
350 SSA_NAME_IS_DEFAULT_DEF (*loc) = false;
351
352 /* Mark DEF as the default definition for VAR. */
353 *loc = def;
354 SSA_NAME_IS_DEFAULT_DEF (def) = true;
355 }
356
357 /* Retrieve or create a default definition for VAR. */
358
359 tree
get_or_create_ssa_default_def(struct function * fn,tree var)360 get_or_create_ssa_default_def (struct function *fn, tree var)
361 {
362 tree ddef = ssa_default_def (fn, var);
363 if (ddef == NULL_TREE)
364 {
365 ddef = make_ssa_name_fn (fn, var, gimple_build_nop ());
366 set_ssa_default_def (fn, var, ddef);
367 }
368 return ddef;
369 }
370
371
372 /* If EXP is a handled component reference for a structure, return the
373 base variable. The access range is delimited by bit positions *POFFSET and
374 *POFFSET + *PMAX_SIZE. The access size is *PSIZE bits. If either
375 *PSIZE or *PMAX_SIZE is -1, they could not be determined. If *PSIZE
376 and *PMAX_SIZE are equal, the access is non-variable. If *PREVERSE is
377 true, the storage order of the reference is reversed. */
378
379 tree
get_ref_base_and_extent(tree exp,poly_int64_pod * poffset,poly_int64_pod * psize,poly_int64_pod * pmax_size,bool * preverse)380 get_ref_base_and_extent (tree exp, poly_int64_pod *poffset,
381 poly_int64_pod *psize,
382 poly_int64_pod *pmax_size,
383 bool *preverse)
384 {
385 poly_offset_int bitsize = -1;
386 poly_offset_int maxsize;
387 tree size_tree = NULL_TREE;
388 poly_offset_int bit_offset = 0;
389 bool seen_variable_array_ref = false;
390
391 /* First get the final access size and the storage order from just the
392 outermost expression. */
393 if (TREE_CODE (exp) == COMPONENT_REF)
394 size_tree = DECL_SIZE (TREE_OPERAND (exp, 1));
395 else if (TREE_CODE (exp) == BIT_FIELD_REF)
396 size_tree = TREE_OPERAND (exp, 1);
397 else if (!VOID_TYPE_P (TREE_TYPE (exp)))
398 {
399 machine_mode mode = TYPE_MODE (TREE_TYPE (exp));
400 if (mode == BLKmode)
401 size_tree = TYPE_SIZE (TREE_TYPE (exp));
402 else
403 bitsize = GET_MODE_BITSIZE (mode);
404 }
405 if (size_tree != NULL_TREE
406 && poly_int_tree_p (size_tree))
407 bitsize = wi::to_poly_offset (size_tree);
408
409 *preverse = reverse_storage_order_for_component_p (exp);
410
411 /* Initially, maxsize is the same as the accessed element size.
412 In the following it will only grow (or become -1). */
413 maxsize = bitsize;
414
415 /* Compute cumulative bit-offset for nested component-refs and array-refs,
416 and find the ultimate containing object. */
417 while (1)
418 {
419 switch (TREE_CODE (exp))
420 {
421 case BIT_FIELD_REF:
422 bit_offset += wi::to_poly_offset (TREE_OPERAND (exp, 2));
423 break;
424
425 case COMPONENT_REF:
426 {
427 tree field = TREE_OPERAND (exp, 1);
428 tree this_offset = component_ref_field_offset (exp);
429
430 if (this_offset && poly_int_tree_p (this_offset))
431 {
432 poly_offset_int woffset = (wi::to_poly_offset (this_offset)
433 << LOG2_BITS_PER_UNIT);
434 woffset += wi::to_offset (DECL_FIELD_BIT_OFFSET (field));
435 bit_offset += woffset;
436
437 /* If we had seen a variable array ref already and we just
438 referenced the last field of a struct or a union member
439 then we have to adjust maxsize by the padding at the end
440 of our field. */
441 if (seen_variable_array_ref)
442 {
443 tree stype = TREE_TYPE (TREE_OPERAND (exp, 0));
444 tree next = DECL_CHAIN (field);
445 while (next && TREE_CODE (next) != FIELD_DECL)
446 next = DECL_CHAIN (next);
447 if (!next
448 || TREE_CODE (stype) != RECORD_TYPE)
449 {
450 tree fsize = DECL_SIZE_UNIT (field);
451 tree ssize = TYPE_SIZE_UNIT (stype);
452 if (fsize == NULL
453 || !poly_int_tree_p (fsize)
454 || ssize == NULL
455 || !poly_int_tree_p (ssize))
456 maxsize = -1;
457 else if (known_size_p (maxsize))
458 {
459 poly_offset_int tem
460 = (wi::to_poly_offset (ssize)
461 - wi::to_poly_offset (fsize));
462 tem <<= LOG2_BITS_PER_UNIT;
463 tem -= woffset;
464 maxsize += tem;
465 }
466 }
467 /* An component ref with an adjacent field up in the
468 structure hierarchy constrains the size of any variable
469 array ref lower in the access hierarchy. */
470 else
471 seen_variable_array_ref = false;
472 }
473 }
474 else
475 {
476 tree csize = TYPE_SIZE (TREE_TYPE (TREE_OPERAND (exp, 0)));
477 /* We need to adjust maxsize to the whole structure bitsize.
478 But we can subtract any constant offset seen so far,
479 because that would get us out of the structure otherwise. */
480 if (known_size_p (maxsize)
481 && csize
482 && poly_int_tree_p (csize))
483 maxsize = wi::to_poly_offset (csize) - bit_offset;
484 else
485 maxsize = -1;
486 }
487 }
488 break;
489
490 case ARRAY_REF:
491 case ARRAY_RANGE_REF:
492 {
493 tree index = TREE_OPERAND (exp, 1);
494 tree low_bound, unit_size;
495
496 /* If the resulting bit-offset is constant, track it. */
497 if (poly_int_tree_p (index)
498 && (low_bound = array_ref_low_bound (exp),
499 poly_int_tree_p (low_bound))
500 && (unit_size = array_ref_element_size (exp),
501 TREE_CODE (unit_size) == INTEGER_CST))
502 {
503 poly_offset_int woffset
504 = wi::sext (wi::to_poly_offset (index)
505 - wi::to_poly_offset (low_bound),
506 TYPE_PRECISION (TREE_TYPE (index)));
507 woffset *= wi::to_offset (unit_size);
508 woffset <<= LOG2_BITS_PER_UNIT;
509 bit_offset += woffset;
510
511 /* An array ref with a constant index up in the structure
512 hierarchy will constrain the size of any variable array ref
513 lower in the access hierarchy. */
514 seen_variable_array_ref = false;
515 }
516 else
517 {
518 tree asize = TYPE_SIZE (TREE_TYPE (TREE_OPERAND (exp, 0)));
519 /* We need to adjust maxsize to the whole array bitsize.
520 But we can subtract any constant offset seen so far,
521 because that would get us outside of the array otherwise. */
522 if (known_size_p (maxsize)
523 && asize
524 && poly_int_tree_p (asize))
525 maxsize = wi::to_poly_offset (asize) - bit_offset;
526 else
527 maxsize = -1;
528
529 /* Remember that we have seen an array ref with a variable
530 index. */
531 seen_variable_array_ref = true;
532 }
533 }
534 break;
535
536 case REALPART_EXPR:
537 break;
538
539 case IMAGPART_EXPR:
540 bit_offset += bitsize;
541 break;
542
543 case VIEW_CONVERT_EXPR:
544 break;
545
546 case TARGET_MEM_REF:
547 /* Via the variable index or index2 we can reach the
548 whole object. Still hand back the decl here. */
549 if (TREE_CODE (TMR_BASE (exp)) == ADDR_EXPR
550 && (TMR_INDEX (exp) || TMR_INDEX2 (exp)))
551 {
552 exp = TREE_OPERAND (TMR_BASE (exp), 0);
553 bit_offset = 0;
554 maxsize = -1;
555 goto done;
556 }
557 /* Fallthru. */
558 case MEM_REF:
559 /* We need to deal with variable arrays ending structures such as
560 struct { int length; int a[1]; } x; x.a[d]
561 struct { struct { int a; int b; } a[1]; } x; x.a[d].a
562 struct { struct { int a[1]; } a[1]; } x; x.a[0][d], x.a[d][0]
563 struct { int len; union { int a[1]; struct X x; } u; } x; x.u.a[d]
564 where we do not know maxsize for variable index accesses to
565 the array. The simplest way to conservatively deal with this
566 is to punt in the case that offset + maxsize reaches the
567 base type boundary. This needs to include possible trailing
568 padding that is there for alignment purposes. */
569 if (seen_variable_array_ref
570 && known_size_p (maxsize)
571 && (TYPE_SIZE (TREE_TYPE (exp)) == NULL_TREE
572 || !poly_int_tree_p (TYPE_SIZE (TREE_TYPE (exp)))
573 || (maybe_eq
574 (bit_offset + maxsize,
575 wi::to_poly_offset (TYPE_SIZE (TREE_TYPE (exp)))))))
576 maxsize = -1;
577
578 /* Hand back the decl for MEM[&decl, off]. */
579 if (TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR)
580 {
581 if (integer_zerop (TREE_OPERAND (exp, 1)))
582 exp = TREE_OPERAND (TREE_OPERAND (exp, 0), 0);
583 else
584 {
585 poly_offset_int off = mem_ref_offset (exp);
586 off <<= LOG2_BITS_PER_UNIT;
587 off += bit_offset;
588 poly_int64 off_hwi;
589 if (off.to_shwi (&off_hwi))
590 {
591 bit_offset = off_hwi;
592 exp = TREE_OPERAND (TREE_OPERAND (exp, 0), 0);
593 }
594 }
595 }
596 goto done;
597
598 default:
599 goto done;
600 }
601
602 exp = TREE_OPERAND (exp, 0);
603 }
604
605 done:
606 if (!bitsize.to_shwi (psize) || maybe_lt (*psize, 0))
607 {
608 *poffset = 0;
609 *psize = -1;
610 *pmax_size = -1;
611
612 return exp;
613 }
614
615 /* ??? Due to negative offsets in ARRAY_REF we can end up with
616 negative bit_offset here. We might want to store a zero offset
617 in this case. */
618 if (!bit_offset.to_shwi (poffset))
619 {
620 *poffset = 0;
621 *pmax_size = -1;
622
623 return exp;
624 }
625
626 /* In case of a decl or constant base object we can do better. */
627
628 if (DECL_P (exp))
629 {
630 if (VAR_P (exp)
631 && ((flag_unconstrained_commons && DECL_COMMON (exp))
632 || (DECL_EXTERNAL (exp) && seen_variable_array_ref)))
633 {
634 tree sz_tree = TYPE_SIZE (TREE_TYPE (exp));
635 /* If size is unknown, or we have read to the end, assume there
636 may be more to the structure than we are told. */
637 if (TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE
638 || (seen_variable_array_ref
639 && (sz_tree == NULL_TREE
640 || !poly_int_tree_p (sz_tree)
641 || maybe_eq (bit_offset + maxsize,
642 wi::to_poly_offset (sz_tree)))))
643 maxsize = -1;
644 }
645 /* If maxsize is unknown adjust it according to the size of the
646 base decl. */
647 else if (!known_size_p (maxsize)
648 && DECL_SIZE (exp)
649 && poly_int_tree_p (DECL_SIZE (exp)))
650 maxsize = wi::to_poly_offset (DECL_SIZE (exp)) - bit_offset;
651 }
652 else if (CONSTANT_CLASS_P (exp))
653 {
654 /* If maxsize is unknown adjust it according to the size of the
655 base type constant. */
656 if (!known_size_p (maxsize)
657 && TYPE_SIZE (TREE_TYPE (exp))
658 && poly_int_tree_p (TYPE_SIZE (TREE_TYPE (exp))))
659 maxsize = (wi::to_poly_offset (TYPE_SIZE (TREE_TYPE (exp)))
660 - bit_offset);
661 }
662
663 if (!maxsize.to_shwi (pmax_size)
664 || maybe_lt (*pmax_size, 0)
665 || !endpoint_representable_p (*poffset, *pmax_size))
666 *pmax_size = -1;
667
668 /* Punt if *POFFSET + *PSIZE overflows in HOST_WIDE_INT, the callers don't
669 check for such overflows individually and assume it works. */
670 if (!endpoint_representable_p (*poffset, *psize))
671 {
672 *poffset = 0;
673 *psize = -1;
674 *pmax_size = -1;
675
676 return exp;
677 }
678
679 return exp;
680 }
681
682 /* Like get_ref_base_and_extent, but for cases in which we only care
683 about constant-width accesses at constant offsets. Return null
684 if the access is anything else. */
685
686 tree
get_ref_base_and_extent_hwi(tree exp,HOST_WIDE_INT * poffset,HOST_WIDE_INT * psize,bool * preverse)687 get_ref_base_and_extent_hwi (tree exp, HOST_WIDE_INT *poffset,
688 HOST_WIDE_INT *psize, bool *preverse)
689 {
690 poly_int64 offset, size, max_size;
691 HOST_WIDE_INT const_offset, const_size;
692 bool reverse;
693 tree decl = get_ref_base_and_extent (exp, &offset, &size, &max_size,
694 &reverse);
695 if (!offset.is_constant (&const_offset)
696 || !size.is_constant (&const_size)
697 || const_offset < 0
698 || !known_size_p (max_size)
699 || maybe_ne (max_size, const_size))
700 return NULL_TREE;
701
702 *poffset = const_offset;
703 *psize = const_size;
704 *preverse = reverse;
705 return decl;
706 }
707
708 /* Returns the base object and a constant BITS_PER_UNIT offset in *POFFSET that
709 denotes the starting address of the memory access EXP.
710 Returns NULL_TREE if the offset is not constant or any component
711 is not BITS_PER_UNIT-aligned.
712 VALUEIZE if non-NULL is used to valueize SSA names. It should return
713 its argument or a constant if the argument is known to be constant. */
714
715 tree
get_addr_base_and_unit_offset_1(tree exp,poly_int64_pod * poffset,tree (* valueize)(tree))716 get_addr_base_and_unit_offset_1 (tree exp, poly_int64_pod *poffset,
717 tree (*valueize) (tree))
718 {
719 poly_int64 byte_offset = 0;
720
721 /* Compute cumulative byte-offset for nested component-refs and array-refs,
722 and find the ultimate containing object. */
723 while (1)
724 {
725 switch (TREE_CODE (exp))
726 {
727 case BIT_FIELD_REF:
728 {
729 poly_int64 this_byte_offset;
730 poly_uint64 this_bit_offset;
731 if (!poly_int_tree_p (TREE_OPERAND (exp, 2), &this_bit_offset)
732 || !multiple_p (this_bit_offset, BITS_PER_UNIT,
733 &this_byte_offset))
734 return NULL_TREE;
735 byte_offset += this_byte_offset;
736 }
737 break;
738
739 case COMPONENT_REF:
740 {
741 tree field = TREE_OPERAND (exp, 1);
742 tree this_offset = component_ref_field_offset (exp);
743 poly_int64 hthis_offset;
744
745 if (!this_offset
746 || !poly_int_tree_p (this_offset, &hthis_offset)
747 || (TREE_INT_CST_LOW (DECL_FIELD_BIT_OFFSET (field))
748 % BITS_PER_UNIT))
749 return NULL_TREE;
750
751 hthis_offset += (TREE_INT_CST_LOW (DECL_FIELD_BIT_OFFSET (field))
752 / BITS_PER_UNIT);
753 byte_offset += hthis_offset;
754 }
755 break;
756
757 case ARRAY_REF:
758 case ARRAY_RANGE_REF:
759 {
760 tree index = TREE_OPERAND (exp, 1);
761 tree low_bound, unit_size;
762
763 if (valueize
764 && TREE_CODE (index) == SSA_NAME)
765 index = (*valueize) (index);
766
767 /* If the resulting bit-offset is constant, track it. */
768 if (poly_int_tree_p (index)
769 && (low_bound = array_ref_low_bound (exp),
770 poly_int_tree_p (low_bound))
771 && (unit_size = array_ref_element_size (exp),
772 TREE_CODE (unit_size) == INTEGER_CST))
773 {
774 poly_offset_int woffset
775 = wi::sext (wi::to_poly_offset (index)
776 - wi::to_poly_offset (low_bound),
777 TYPE_PRECISION (TREE_TYPE (index)));
778 woffset *= wi::to_offset (unit_size);
779 byte_offset += woffset.force_shwi ();
780 }
781 else
782 return NULL_TREE;
783 }
784 break;
785
786 case REALPART_EXPR:
787 break;
788
789 case IMAGPART_EXPR:
790 byte_offset += TREE_INT_CST_LOW (TYPE_SIZE_UNIT (TREE_TYPE (exp)));
791 break;
792
793 case VIEW_CONVERT_EXPR:
794 break;
795
796 case MEM_REF:
797 {
798 tree base = TREE_OPERAND (exp, 0);
799 if (valueize
800 && TREE_CODE (base) == SSA_NAME)
801 base = (*valueize) (base);
802
803 /* Hand back the decl for MEM[&decl, off]. */
804 if (TREE_CODE (base) == ADDR_EXPR)
805 {
806 if (!integer_zerop (TREE_OPERAND (exp, 1)))
807 {
808 poly_offset_int off = mem_ref_offset (exp);
809 byte_offset += off.force_shwi ();
810 }
811 exp = TREE_OPERAND (base, 0);
812 }
813 goto done;
814 }
815
816 case TARGET_MEM_REF:
817 {
818 tree base = TREE_OPERAND (exp, 0);
819 if (valueize
820 && TREE_CODE (base) == SSA_NAME)
821 base = (*valueize) (base);
822
823 /* Hand back the decl for MEM[&decl, off]. */
824 if (TREE_CODE (base) == ADDR_EXPR)
825 {
826 if (TMR_INDEX (exp) || TMR_INDEX2 (exp))
827 return NULL_TREE;
828 if (!integer_zerop (TMR_OFFSET (exp)))
829 {
830 poly_offset_int off = mem_ref_offset (exp);
831 byte_offset += off.force_shwi ();
832 }
833 exp = TREE_OPERAND (base, 0);
834 }
835 goto done;
836 }
837
838 default:
839 goto done;
840 }
841
842 exp = TREE_OPERAND (exp, 0);
843 }
844 done:
845
846 *poffset = byte_offset;
847 return exp;
848 }
849
850 /* Returns the base object and a constant BITS_PER_UNIT offset in *POFFSET that
851 denotes the starting address of the memory access EXP.
852 Returns NULL_TREE if the offset is not constant or any component
853 is not BITS_PER_UNIT-aligned. */
854
855 tree
get_addr_base_and_unit_offset(tree exp,poly_int64_pod * poffset)856 get_addr_base_and_unit_offset (tree exp, poly_int64_pod *poffset)
857 {
858 return get_addr_base_and_unit_offset_1 (exp, poffset, NULL);
859 }
860
861 /* Returns true if STMT references an SSA_NAME that has
862 SSA_NAME_OCCURS_IN_ABNORMAL_PHI set, otherwise false. */
863
864 bool
stmt_references_abnormal_ssa_name(gimple * stmt)865 stmt_references_abnormal_ssa_name (gimple *stmt)
866 {
867 ssa_op_iter oi;
868 use_operand_p use_p;
869
870 FOR_EACH_SSA_USE_OPERAND (use_p, stmt, oi, SSA_OP_USE)
871 {
872 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (USE_FROM_PTR (use_p)))
873 return true;
874 }
875
876 return false;
877 }
878
879 /* If STMT takes any abnormal PHI values as input, replace them with
880 local copies. */
881
882 void
replace_abnormal_ssa_names(gimple * stmt)883 replace_abnormal_ssa_names (gimple *stmt)
884 {
885 ssa_op_iter oi;
886 use_operand_p use_p;
887
888 FOR_EACH_SSA_USE_OPERAND (use_p, stmt, oi, SSA_OP_USE)
889 {
890 tree op = USE_FROM_PTR (use_p);
891 if (TREE_CODE (op) == SSA_NAME && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (op))
892 {
893 gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
894 tree new_name = make_ssa_name (TREE_TYPE (op));
895 gassign *assign = gimple_build_assign (new_name, op);
896 gsi_insert_before (&gsi, assign, GSI_SAME_STMT);
897 SET_USE (use_p, new_name);
898 }
899 }
900 }
901
902 /* Pair of tree and a sorting index, for dump_enumerated_decls. */
903 struct GTY(()) numbered_tree
904 {
905 tree t;
906 int num;
907 };
908
909
910 /* Compare two declarations references by their DECL_UID / sequence number.
911 Called via qsort. */
912
913 static int
compare_decls_by_uid(const void * pa,const void * pb)914 compare_decls_by_uid (const void *pa, const void *pb)
915 {
916 const numbered_tree *nt_a = ((const numbered_tree *)pa);
917 const numbered_tree *nt_b = ((const numbered_tree *)pb);
918
919 if (DECL_UID (nt_a->t) != DECL_UID (nt_b->t))
920 return DECL_UID (nt_a->t) - DECL_UID (nt_b->t);
921 return nt_a->num - nt_b->num;
922 }
923
924 /* Called via walk_gimple_stmt / walk_gimple_op by dump_enumerated_decls. */
925 static tree
dump_enumerated_decls_push(tree * tp,int * walk_subtrees,void * data)926 dump_enumerated_decls_push (tree *tp, int *walk_subtrees, void *data)
927 {
928 struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
929 vec<numbered_tree> *list = (vec<numbered_tree> *) wi->info;
930 numbered_tree nt;
931
932 if (!DECL_P (*tp))
933 return NULL_TREE;
934 nt.t = *tp;
935 nt.num = list->length ();
936 list->safe_push (nt);
937 *walk_subtrees = 0;
938 return NULL_TREE;
939 }
940
941 /* Find all the declarations used by the current function, sort them by uid,
942 and emit the sorted list. Each declaration is tagged with a sequence
943 number indicating when it was found during statement / tree walking,
944 so that TDF_NOUID comparisons of anonymous declarations are still
945 meaningful. Where a declaration was encountered more than once, we
946 emit only the sequence number of the first encounter.
947 FILE is the dump file where to output the list and FLAGS is as in
948 print_generic_expr. */
949 void
dump_enumerated_decls(FILE * file,dump_flags_t flags)950 dump_enumerated_decls (FILE *file, dump_flags_t flags)
951 {
952 basic_block bb;
953 struct walk_stmt_info wi;
954 auto_vec<numbered_tree, 40> decl_list;
955
956 memset (&wi, '\0', sizeof (wi));
957 wi.info = (void *) &decl_list;
958 FOR_EACH_BB_FN (bb, cfun)
959 {
960 gimple_stmt_iterator gsi;
961
962 for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
963 if (!is_gimple_debug (gsi_stmt (gsi)))
964 walk_gimple_stmt (&gsi, NULL, dump_enumerated_decls_push, &wi);
965 }
966 decl_list.qsort (compare_decls_by_uid);
967 if (decl_list.length ())
968 {
969 unsigned ix;
970 numbered_tree *ntp;
971 tree last = NULL_TREE;
972
973 fprintf (file, "Declarations used by %s, sorted by DECL_UID:\n",
974 current_function_name ());
975 FOR_EACH_VEC_ELT (decl_list, ix, ntp)
976 {
977 if (ntp->t == last)
978 continue;
979 fprintf (file, "%d: ", ntp->num);
980 print_generic_decl (file, ntp->t, flags);
981 fprintf (file, "\n");
982 last = ntp->t;
983 }
984 }
985 }
986