PR libstdc++/70940 make pmr::resource_adaptor return aligned memory
[official-gcc.git] / gcc / tree-ssanames.c
blob6cce43be593fcb3b64a98a357eca36e0fbd2a614
1 /* Generic routines for manipulating SSA_NAME expressions
2 Copyright (C) 2003-2018 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC 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 3, or (at your option)
9 any later version.
11 GCC 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.
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
20 #include "config.h"
21 #include "system.h"
22 #include "coretypes.h"
23 #include "backend.h"
24 #include "tree.h"
25 #include "gimple.h"
26 #include "tree-pass.h"
27 #include "ssa.h"
28 #include "gimple-iterator.h"
29 #include "stor-layout.h"
30 #include "tree-into-ssa.h"
31 #include "tree-ssa.h"
32 #include "cfgloop.h"
33 #include "tree-scalar-evolution.h"
35 /* Rewriting a function into SSA form can create a huge number of SSA_NAMEs,
36 many of which may be thrown away shortly after their creation if jumps
37 were threaded through PHI nodes.
39 While our garbage collection mechanisms will handle this situation, it
40 is extremely wasteful to create nodes and throw them away, especially
41 when the nodes can be reused.
43 For PR 8361, we can significantly reduce the number of nodes allocated
44 and thus the total amount of memory allocated by managing SSA_NAMEs a
45 little. This additionally helps reduce the amount of work done by the
46 garbage collector. Similar results have been seen on a wider variety
47 of tests (such as the compiler itself).
49 Right now we maintain our free list on a per-function basis. It may
50 or may not make sense to maintain the free list for the duration of
51 a compilation unit.
53 External code should rely solely upon HIGHEST_SSA_VERSION and the
54 externally defined functions. External code should not know about
55 the details of the free list management.
57 External code should also not assume the version number on nodes is
58 monotonically increasing. We reuse the version number when we
59 reuse an SSA_NAME expression. This helps keep arrays and bitmaps
60 more compact. */
63 /* Version numbers with special meanings. We start allocating new version
64 numbers after the special ones. */
65 #define UNUSED_NAME_VERSION 0
67 unsigned int ssa_name_nodes_reused;
68 unsigned int ssa_name_nodes_created;
70 #define FREE_SSANAMES(fun) (fun)->gimple_df->free_ssanames
71 #define FREE_SSANAMES_QUEUE(fun) (fun)->gimple_df->free_ssanames_queue
74 /* Initialize management of SSA_NAMEs to default SIZE. If SIZE is
75 zero use default. */
77 void
78 init_ssanames (struct function *fn, int size)
80 if (size < 50)
81 size = 50;
83 vec_alloc (SSANAMES (fn), size);
85 /* Version 0 is special, so reserve the first slot in the table. Though
86 currently unused, we may use version 0 in alias analysis as part of
87 the heuristics used to group aliases when the alias sets are too
88 large.
90 We use vec::quick_push here because we know that SSA_NAMES has at
91 least 50 elements reserved in it. */
92 SSANAMES (fn)->quick_push (NULL_TREE);
93 FREE_SSANAMES (fn) = NULL;
94 FREE_SSANAMES_QUEUE (fn) = NULL;
96 fn->gimple_df->ssa_renaming_needed = 0;
97 fn->gimple_df->rename_vops = 0;
100 /* Finalize management of SSA_NAMEs. */
102 void
103 fini_ssanames (struct function *fn)
105 vec_free (SSANAMES (fn));
106 vec_free (FREE_SSANAMES (fn));
107 vec_free (FREE_SSANAMES_QUEUE (fn));
110 /* Dump some simple statistics regarding the re-use of SSA_NAME nodes. */
112 void
113 ssanames_print_statistics (void)
115 fprintf (stderr, "SSA_NAME nodes allocated: %u\n", ssa_name_nodes_created);
116 fprintf (stderr, "SSA_NAME nodes reused: %u\n", ssa_name_nodes_reused);
119 /* Verify the state of the SSA_NAME lists.
121 There must be no duplicates on the free list.
122 Every name on the free list must be marked as on the free list.
123 Any name on the free list must not appear in the IL.
124 No names can be leaked. */
126 DEBUG_FUNCTION void
127 verify_ssaname_freelists (struct function *fun)
129 if (!gimple_in_ssa_p (fun))
130 return;
132 auto_bitmap names_in_il;
134 /* Walk the entire IL noting every SSA_NAME we see. */
135 basic_block bb;
136 FOR_EACH_BB_FN (bb, fun)
138 tree t;
139 /* First note the result and arguments of PHI nodes. */
140 for (gphi_iterator gsi = gsi_start_phis (bb);
141 !gsi_end_p (gsi);
142 gsi_next (&gsi))
144 gphi *phi = gsi.phi ();
145 t = gimple_phi_result (phi);
146 bitmap_set_bit (names_in_il, SSA_NAME_VERSION (t));
148 for (unsigned int i = 0; i < gimple_phi_num_args (phi); i++)
150 t = gimple_phi_arg_def (phi, i);
151 if (TREE_CODE (t) == SSA_NAME)
152 bitmap_set_bit (names_in_il, SSA_NAME_VERSION (t));
156 /* Then note the operands of each statement. */
157 for (gimple_stmt_iterator gsi = gsi_start_bb (bb);
158 !gsi_end_p (gsi);
159 gsi_next (&gsi))
161 ssa_op_iter iter;
162 gimple *stmt = gsi_stmt (gsi);
163 FOR_EACH_SSA_TREE_OPERAND (t, stmt, iter, SSA_OP_ALL_OPERANDS)
164 bitmap_set_bit (names_in_il, SSA_NAME_VERSION (t));
168 /* Now walk the free list noting what we find there and verifying
169 there are no duplicates. */
170 auto_bitmap names_in_freelists;
171 if (FREE_SSANAMES (fun))
173 for (unsigned int i = 0; i < FREE_SSANAMES (fun)->length (); i++)
175 tree t = (*FREE_SSANAMES (fun))[i];
177 /* Verify that the name is marked as being in the free list. */
178 gcc_assert (SSA_NAME_IN_FREE_LIST (t));
180 /* Verify the name has not already appeared in the free list and
181 note it in the list of names found in the free list. */
182 gcc_assert (!bitmap_bit_p (names_in_freelists, SSA_NAME_VERSION (t)));
183 bitmap_set_bit (names_in_freelists, SSA_NAME_VERSION (t));
187 /* Similarly for the names in the pending free list. */
188 if (FREE_SSANAMES_QUEUE (fun))
190 for (unsigned int i = 0; i < FREE_SSANAMES_QUEUE (fun)->length (); i++)
192 tree t = (*FREE_SSANAMES_QUEUE (fun))[i];
194 /* Verify that the name is marked as being in the free list. */
195 gcc_assert (SSA_NAME_IN_FREE_LIST (t));
197 /* Verify the name has not already appeared in the free list and
198 note it in the list of names found in the free list. */
199 gcc_assert (!bitmap_bit_p (names_in_freelists, SSA_NAME_VERSION (t)));
200 bitmap_set_bit (names_in_freelists, SSA_NAME_VERSION (t));
204 /* If any name appears in both the IL and the freelists, then
205 something horrible has happened. */
206 bool intersect_p = bitmap_intersect_p (names_in_il, names_in_freelists);
207 gcc_assert (!intersect_p);
209 /* Names can be queued up for release if there is an ssa update
210 pending. Pretend we saw them in the IL. */
211 if (names_to_release)
212 bitmap_ior_into (names_in_il, names_to_release);
214 /* Function splitting can "lose" SSA_NAMEs in an effort to ensure that
215 debug/non-debug compilations have the same SSA_NAMEs. So for each
216 lost SSA_NAME, see if it's likely one from that wart. These will always
217 be marked as default definitions. So we loosely assume that anything
218 marked as a default definition isn't leaked by pretending they are
219 in the IL. */
220 for (unsigned int i = UNUSED_NAME_VERSION + 1; i < num_ssa_names; i++)
221 if (ssa_name (i) && SSA_NAME_IS_DEFAULT_DEF (ssa_name (i)))
222 bitmap_set_bit (names_in_il, i);
224 unsigned int i;
225 bitmap_iterator bi;
226 auto_bitmap all_names;
227 bitmap_set_range (all_names, UNUSED_NAME_VERSION + 1, num_ssa_names - 1);
228 bitmap_ior_into (names_in_il, names_in_freelists);
230 /* Any name not mentioned in the IL and not in the feelists
231 has been leaked. */
232 EXECUTE_IF_AND_COMPL_IN_BITMAP(all_names, names_in_il,
233 UNUSED_NAME_VERSION + 1, i, bi)
234 gcc_assert (!ssa_name (i));
237 /* Move all SSA_NAMEs from FREE_SSA_NAMES_QUEUE to FREE_SSA_NAMES.
239 We do not, but should have a mode to verify the state of the SSA_NAMEs
240 lists. In particular at this point every name must be in the IL,
241 on the free list or in the queue. Anything else is an error. */
243 void
244 flush_ssaname_freelist (void)
246 /* If there were any SSA names released reset the SCEV cache. */
247 if (! vec_safe_is_empty (FREE_SSANAMES_QUEUE (cfun)))
248 scev_reset_htab ();
249 vec_safe_splice (FREE_SSANAMES (cfun), FREE_SSANAMES_QUEUE (cfun));
250 vec_safe_truncate (FREE_SSANAMES_QUEUE (cfun), 0);
253 /* Return an SSA_NAME node for variable VAR defined in statement STMT
254 in function FN. STMT may be an empty statement for artificial
255 references (e.g., default definitions created when a variable is
256 used without a preceding definition). If VERISON is not zero then
257 allocate the SSA name with that version. */
259 tree
260 make_ssa_name_fn (struct function *fn, tree var, gimple *stmt,
261 unsigned int version)
263 tree t;
264 use_operand_p imm;
266 gcc_assert (VAR_P (var)
267 || TREE_CODE (var) == PARM_DECL
268 || TREE_CODE (var) == RESULT_DECL
269 || (TYPE_P (var) && is_gimple_reg_type (var)));
271 /* Get the specified SSA name version. */
272 if (version != 0)
274 t = make_node (SSA_NAME);
275 SSA_NAME_VERSION (t) = version;
276 if (version >= SSANAMES (fn)->length ())
277 vec_safe_grow_cleared (SSANAMES (fn), version + 1);
278 gcc_assert ((*SSANAMES (fn))[version] == NULL);
279 (*SSANAMES (fn))[version] = t;
280 ssa_name_nodes_created++;
282 /* If our free list has an element, then use it. */
283 else if (!vec_safe_is_empty (FREE_SSANAMES (fn)))
285 t = FREE_SSANAMES (fn)->pop ();
286 ssa_name_nodes_reused++;
288 /* The node was cleared out when we put it on the free list, so
289 there is no need to do so again here. */
290 gcc_assert ((*SSANAMES (fn))[SSA_NAME_VERSION (t)] == NULL);
291 (*SSANAMES (fn))[SSA_NAME_VERSION (t)] = t;
293 else
295 t = make_node (SSA_NAME);
296 SSA_NAME_VERSION (t) = SSANAMES (fn)->length ();
297 vec_safe_push (SSANAMES (fn), t);
298 ssa_name_nodes_created++;
301 if (TYPE_P (var))
303 TREE_TYPE (t) = TYPE_MAIN_VARIANT (var);
304 SET_SSA_NAME_VAR_OR_IDENTIFIER (t, NULL_TREE);
306 else
308 TREE_TYPE (t) = TREE_TYPE (var);
309 SET_SSA_NAME_VAR_OR_IDENTIFIER (t, var);
311 SSA_NAME_DEF_STMT (t) = stmt;
312 if (POINTER_TYPE_P (TREE_TYPE (t)))
313 SSA_NAME_PTR_INFO (t) = NULL;
314 else
315 SSA_NAME_RANGE_INFO (t) = NULL;
317 SSA_NAME_IN_FREE_LIST (t) = 0;
318 SSA_NAME_IS_DEFAULT_DEF (t) = 0;
319 imm = &(SSA_NAME_IMM_USE_NODE (t));
320 imm->use = NULL;
321 imm->prev = imm;
322 imm->next = imm;
323 imm->loc.ssa_name = t;
325 return t;
328 /* Helper function for set_range_info.
330 Store range information RANGE_TYPE, MIN, and MAX to tree ssa_name
331 NAME. */
333 void
334 set_range_info_raw (tree name, enum value_range_type range_type,
335 const wide_int_ref &min, const wide_int_ref &max)
337 gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name)));
338 gcc_assert (range_type == VR_RANGE || range_type == VR_ANTI_RANGE);
339 range_info_def *ri = SSA_NAME_RANGE_INFO (name);
340 unsigned int precision = TYPE_PRECISION (TREE_TYPE (name));
342 /* Allocate if not available. */
343 if (ri == NULL)
345 size_t size = (sizeof (range_info_def)
346 + trailing_wide_ints <3>::extra_size (precision));
347 ri = static_cast<range_info_def *> (ggc_internal_alloc (size));
348 ri->ints.set_precision (precision);
349 SSA_NAME_RANGE_INFO (name) = ri;
350 ri->set_nonzero_bits (wi::shwi (-1, precision));
353 /* Record the range type. */
354 if (SSA_NAME_RANGE_TYPE (name) != range_type)
355 SSA_NAME_ANTI_RANGE_P (name) = (range_type == VR_ANTI_RANGE);
357 /* Set the values. */
358 ri->set_min (min);
359 ri->set_max (max);
361 /* If it is a range, try to improve nonzero_bits from the min/max. */
362 if (range_type == VR_RANGE)
364 wide_int xorv = ri->get_min () ^ ri->get_max ();
365 if (xorv != 0)
366 xorv = wi::mask (precision - wi::clz (xorv), false, precision);
367 ri->set_nonzero_bits (ri->get_nonzero_bits () & (ri->get_min () | xorv));
371 /* Store range information RANGE_TYPE, MIN, and MAX to tree ssa_name
372 NAME while making sure we don't store useless range info. */
374 void
375 set_range_info (tree name, enum value_range_type range_type,
376 const wide_int_ref &min, const wide_int_ref &max)
378 gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name)));
380 /* A range of the entire domain is really no range at all. */
381 tree type = TREE_TYPE (name);
382 if (min == wi::min_value (TYPE_PRECISION (type), TYPE_SIGN (type))
383 && max == wi::max_value (TYPE_PRECISION (type), TYPE_SIGN (type)))
385 range_info_def *ri = SSA_NAME_RANGE_INFO (name);
386 if (ri == NULL)
387 return;
388 if (ri->get_nonzero_bits () == -1)
390 ggc_free (ri);
391 SSA_NAME_RANGE_INFO (name) = NULL;
392 return;
396 set_range_info_raw (name, range_type, min, max);
400 /* Gets range information MIN, MAX and returns enum value_range_type
401 corresponding to tree ssa_name NAME. enum value_range_type returned
402 is used to determine if MIN and MAX are valid values. */
404 enum value_range_type
405 get_range_info (const_tree name, wide_int *min, wide_int *max)
407 gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name)));
408 gcc_assert (min && max);
409 range_info_def *ri = SSA_NAME_RANGE_INFO (name);
411 /* Return VR_VARYING for SSA_NAMEs with NULL RANGE_INFO or SSA_NAMEs
412 with integral types width > 2 * HOST_BITS_PER_WIDE_INT precision. */
413 if (!ri || (GET_MODE_PRECISION (SCALAR_INT_TYPE_MODE (TREE_TYPE (name)))
414 > 2 * HOST_BITS_PER_WIDE_INT))
415 return VR_VARYING;
417 *min = ri->get_min ();
418 *max = ri->get_max ();
419 return SSA_NAME_RANGE_TYPE (name);
422 /* Set nonnull attribute to pointer NAME. */
424 void
425 set_ptr_nonnull (tree name)
427 gcc_assert (POINTER_TYPE_P (TREE_TYPE (name)));
428 struct ptr_info_def *pi = get_ptr_info (name);
429 pi->pt.null = 0;
432 /* Return nonnull attribute of pointer NAME. */
433 bool
434 get_ptr_nonnull (const_tree name)
436 gcc_assert (POINTER_TYPE_P (TREE_TYPE (name)));
437 struct ptr_info_def *pi = SSA_NAME_PTR_INFO (name);
438 if (pi == NULL)
439 return false;
440 /* TODO Now pt->null is conservatively set to true in PTA
441 analysis. vrp is the only pass (including ipa-vrp)
442 that clears pt.null via set_ptr_nonull when it knows
443 for sure. PTA will preserves the pt.null value set by VRP.
445 When PTA analysis is improved, pt.anything, pt.nonlocal
446 and pt.escaped may also has to be considered before
447 deciding that pointer cannot point to NULL. */
448 return !pi->pt.null;
451 /* Change non-zero bits bitmask of NAME. */
453 void
454 set_nonzero_bits (tree name, const wide_int_ref &mask)
456 gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name)));
457 if (SSA_NAME_RANGE_INFO (name) == NULL)
459 if (mask == -1)
460 return;
461 set_range_info_raw (name, VR_RANGE,
462 wi::to_wide (TYPE_MIN_VALUE (TREE_TYPE (name))),
463 wi::to_wide (TYPE_MAX_VALUE (TREE_TYPE (name))));
465 range_info_def *ri = SSA_NAME_RANGE_INFO (name);
466 ri->set_nonzero_bits (mask);
469 /* Return a widest_int with potentially non-zero bits in SSA_NAME
470 NAME, the constant for INTEGER_CST, or -1 if unknown. */
472 wide_int
473 get_nonzero_bits (const_tree name)
475 if (TREE_CODE (name) == INTEGER_CST)
476 return wi::to_wide (name);
478 /* Use element_precision instead of TYPE_PRECISION so complex and
479 vector types get a non-zero precision. */
480 unsigned int precision = element_precision (TREE_TYPE (name));
481 if (POINTER_TYPE_P (TREE_TYPE (name)))
483 struct ptr_info_def *pi = SSA_NAME_PTR_INFO (name);
484 if (pi && pi->align)
485 return wi::shwi (-(HOST_WIDE_INT) pi->align
486 | (HOST_WIDE_INT) pi->misalign, precision);
487 return wi::shwi (-1, precision);
490 range_info_def *ri = SSA_NAME_RANGE_INFO (name);
491 if (!ri)
492 return wi::shwi (-1, precision);
494 return ri->get_nonzero_bits ();
497 /* Return TRUE is OP, an SSA_NAME has a range of values [0..1], false
498 otherwise.
500 This can be because it is a boolean type, any unsigned integral
501 type with a single bit of precision, or has known range of [0..1]
502 via VRP analysis. */
504 bool
505 ssa_name_has_boolean_range (tree op)
507 gcc_assert (TREE_CODE (op) == SSA_NAME);
509 /* Boolean types always have a range [0..1]. */
510 if (TREE_CODE (TREE_TYPE (op)) == BOOLEAN_TYPE)
511 return true;
513 /* An integral type with a single bit of precision. */
514 if (INTEGRAL_TYPE_P (TREE_TYPE (op))
515 && TYPE_UNSIGNED (TREE_TYPE (op))
516 && TYPE_PRECISION (TREE_TYPE (op)) == 1)
517 return true;
519 /* An integral type with more precision, but the object
520 only takes on values [0..1] as determined by VRP
521 analysis. */
522 if (INTEGRAL_TYPE_P (TREE_TYPE (op))
523 && (TYPE_PRECISION (TREE_TYPE (op)) > 1)
524 && wi::eq_p (get_nonzero_bits (op), 1))
525 return true;
527 return false;
530 /* We no longer need the SSA_NAME expression VAR, release it so that
531 it may be reused.
533 Note it is assumed that no calls to make_ssa_name will be made
534 until all uses of the ssa name are released and that the only
535 use of the SSA_NAME expression is to check its SSA_NAME_VAR. All
536 other fields must be assumed clobbered. */
538 void
539 release_ssa_name_fn (struct function *fn, tree var)
541 if (!var)
542 return;
544 /* Never release the default definition for a symbol. It's a
545 special SSA name that should always exist once it's created. */
546 if (SSA_NAME_IS_DEFAULT_DEF (var))
547 return;
549 /* If VAR has been registered for SSA updating, don't remove it.
550 After update_ssa has run, the name will be released. */
551 if (name_registered_for_update_p (var))
553 release_ssa_name_after_update_ssa (var);
554 return;
557 /* release_ssa_name can be called multiple times on a single SSA_NAME.
558 However, it should only end up on our free list one time. We
559 keep a status bit in the SSA_NAME node itself to indicate it has
560 been put on the free list.
562 Note that once on the freelist you can not reference the SSA_NAME's
563 defining statement. */
564 if (! SSA_NAME_IN_FREE_LIST (var))
566 tree saved_ssa_name_var = SSA_NAME_VAR (var);
567 int saved_ssa_name_version = SSA_NAME_VERSION (var);
568 use_operand_p imm = &(SSA_NAME_IMM_USE_NODE (var));
570 if (MAY_HAVE_DEBUG_BIND_STMTS)
571 insert_debug_temp_for_var_def (NULL, var);
573 if (flag_checking)
574 verify_imm_links (stderr, var);
575 while (imm->next != imm)
576 delink_imm_use (imm->next);
578 (*SSANAMES (fn))[SSA_NAME_VERSION (var)] = NULL_TREE;
579 memset (var, 0, tree_size (var));
581 imm->prev = imm;
582 imm->next = imm;
583 imm->loc.ssa_name = var;
585 /* First put back the right tree node so that the tree checking
586 macros do not complain. */
587 TREE_SET_CODE (var, SSA_NAME);
589 /* Restore the version number. */
590 SSA_NAME_VERSION (var) = saved_ssa_name_version;
592 /* Hopefully this can go away once we have the new incremental
593 SSA updating code installed. */
594 SET_SSA_NAME_VAR_OR_IDENTIFIER (var, saved_ssa_name_var);
596 /* Note this SSA_NAME is now in the first list. */
597 SSA_NAME_IN_FREE_LIST (var) = 1;
599 /* And finally queue it so that it will be put on the free list. */
600 vec_safe_push (FREE_SSANAMES_QUEUE (fn), var);
604 /* If the alignment of the pointer described by PI is known, return true and
605 store the alignment and the deviation from it into *ALIGNP and *MISALIGNP
606 respectively. Otherwise return false. */
608 bool
609 get_ptr_info_alignment (struct ptr_info_def *pi, unsigned int *alignp,
610 unsigned int *misalignp)
612 if (pi->align)
614 *alignp = pi->align;
615 *misalignp = pi->misalign;
616 return true;
618 else
619 return false;
622 /* State that the pointer described by PI has unknown alignment. */
624 void
625 mark_ptr_info_alignment_unknown (struct ptr_info_def *pi)
627 pi->align = 0;
628 pi->misalign = 0;
631 /* Store the power-of-two byte alignment and the deviation from that
632 alignment of pointer described by PI to ALIOGN and MISALIGN
633 respectively. */
635 void
636 set_ptr_info_alignment (struct ptr_info_def *pi, unsigned int align,
637 unsigned int misalign)
639 gcc_checking_assert (align != 0);
640 gcc_assert ((align & (align - 1)) == 0);
641 gcc_assert ((misalign & ~(align - 1)) == 0);
643 pi->align = align;
644 pi->misalign = misalign;
647 /* If pointer described by PI has known alignment, increase its known
648 misalignment by INCREMENT modulo its current alignment. */
650 void
651 adjust_ptr_info_misalignment (struct ptr_info_def *pi, poly_uint64 increment)
653 if (pi->align != 0)
655 increment += pi->misalign;
656 if (!known_misalignment (increment, pi->align, &pi->misalign))
658 pi->align = known_alignment (increment);
659 pi->misalign = 0;
664 /* Return the alias information associated with pointer T. It creates a
665 new instance if none existed. */
667 struct ptr_info_def *
668 get_ptr_info (tree t)
670 struct ptr_info_def *pi;
672 gcc_assert (POINTER_TYPE_P (TREE_TYPE (t)));
674 pi = SSA_NAME_PTR_INFO (t);
675 if (pi == NULL)
677 pi = ggc_cleared_alloc<ptr_info_def> ();
678 pt_solution_reset (&pi->pt);
679 mark_ptr_info_alignment_unknown (pi);
680 SSA_NAME_PTR_INFO (t) = pi;
683 return pi;
687 /* Creates a new SSA name using the template NAME tobe defined by
688 statement STMT in function FN. */
690 tree
691 copy_ssa_name_fn (struct function *fn, tree name, gimple *stmt)
693 tree new_name;
695 if (SSA_NAME_VAR (name))
696 new_name = make_ssa_name_fn (fn, SSA_NAME_VAR (name), stmt);
697 else
699 new_name = make_ssa_name_fn (fn, TREE_TYPE (name), stmt);
700 SET_SSA_NAME_VAR_OR_IDENTIFIER (new_name, SSA_NAME_IDENTIFIER (name));
703 return new_name;
707 /* Creates a duplicate of the ptr_info_def at PTR_INFO for use by
708 the SSA name NAME. */
710 void
711 duplicate_ssa_name_ptr_info (tree name, struct ptr_info_def *ptr_info)
713 struct ptr_info_def *new_ptr_info;
715 gcc_assert (POINTER_TYPE_P (TREE_TYPE (name)));
716 gcc_assert (!SSA_NAME_PTR_INFO (name));
718 if (!ptr_info)
719 return;
721 new_ptr_info = ggc_alloc<ptr_info_def> ();
722 *new_ptr_info = *ptr_info;
724 SSA_NAME_PTR_INFO (name) = new_ptr_info;
727 /* Creates a duplicate of the range_info_def at RANGE_INFO of type
728 RANGE_TYPE for use by the SSA name NAME. */
729 void
730 duplicate_ssa_name_range_info (tree name, enum value_range_type range_type,
731 struct range_info_def *range_info)
733 struct range_info_def *new_range_info;
735 gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name)));
736 gcc_assert (!SSA_NAME_RANGE_INFO (name));
738 if (!range_info)
739 return;
741 unsigned int precision = TYPE_PRECISION (TREE_TYPE (name));
742 size_t size = (sizeof (range_info_def)
743 + trailing_wide_ints <3>::extra_size (precision));
744 new_range_info = static_cast<range_info_def *> (ggc_internal_alloc (size));
745 memcpy (new_range_info, range_info, size);
747 gcc_assert (range_type == VR_RANGE || range_type == VR_ANTI_RANGE);
748 SSA_NAME_ANTI_RANGE_P (name) = (range_type == VR_ANTI_RANGE);
749 SSA_NAME_RANGE_INFO (name) = new_range_info;
754 /* Creates a duplicate of a ssa name NAME tobe defined by statement STMT
755 in function FN. */
757 tree
758 duplicate_ssa_name_fn (struct function *fn, tree name, gimple *stmt)
760 tree new_name = copy_ssa_name_fn (fn, name, stmt);
761 if (POINTER_TYPE_P (TREE_TYPE (name)))
763 struct ptr_info_def *old_ptr_info = SSA_NAME_PTR_INFO (name);
765 if (old_ptr_info)
766 duplicate_ssa_name_ptr_info (new_name, old_ptr_info);
768 else
770 struct range_info_def *old_range_info = SSA_NAME_RANGE_INFO (name);
772 if (old_range_info)
773 duplicate_ssa_name_range_info (new_name, SSA_NAME_RANGE_TYPE (name),
774 old_range_info);
777 return new_name;
781 /* Reset all flow sensitive data on NAME such as range-info, nonzero
782 bits and alignment. */
784 void
785 reset_flow_sensitive_info (tree name)
787 if (POINTER_TYPE_P (TREE_TYPE (name)))
789 /* points-to info is not flow-sensitive. */
790 if (SSA_NAME_PTR_INFO (name))
791 mark_ptr_info_alignment_unknown (SSA_NAME_PTR_INFO (name));
793 else
794 SSA_NAME_RANGE_INFO (name) = NULL;
797 /* Clear all flow sensitive data from all statements and PHI definitions
798 in BB. */
800 void
801 reset_flow_sensitive_info_in_bb (basic_block bb)
803 for (gimple_stmt_iterator gsi = gsi_start_bb (bb); !gsi_end_p (gsi);
804 gsi_next (&gsi))
806 gimple *stmt = gsi_stmt (gsi);
807 ssa_op_iter i;
808 tree op;
809 FOR_EACH_SSA_TREE_OPERAND (op, stmt, i, SSA_OP_DEF)
810 reset_flow_sensitive_info (op);
813 for (gphi_iterator gsi = gsi_start_phis (bb); !gsi_end_p (gsi);
814 gsi_next (&gsi))
816 tree phi_def = gimple_phi_result (gsi.phi ());
817 reset_flow_sensitive_info (phi_def);
821 /* Release all the SSA_NAMEs created by STMT. */
823 void
824 release_defs (gimple *stmt)
826 tree def;
827 ssa_op_iter iter;
829 FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS)
830 if (TREE_CODE (def) == SSA_NAME)
831 release_ssa_name (def);
835 /* Replace the symbol associated with SSA_NAME with SYM. */
837 void
838 replace_ssa_name_symbol (tree ssa_name, tree sym)
840 SET_SSA_NAME_VAR_OR_IDENTIFIER (ssa_name, sym);
841 TREE_TYPE (ssa_name) = TREE_TYPE (sym);
844 /* Release the vector of free SSA_NAMEs and compact the vector of SSA_NAMEs
845 that are live. */
847 static void
848 release_free_names_and_compact_live_names (function *fun)
850 unsigned i, j;
851 int n = vec_safe_length (FREE_SSANAMES (fun));
853 /* Now release the freelist. */
854 vec_free (FREE_SSANAMES (fun));
856 /* And compact the SSA number space. We make sure to not change the
857 relative order of SSA versions. */
858 for (i = 1, j = 1; i < fun->gimple_df->ssa_names->length (); ++i)
860 tree name = ssa_name (i);
861 if (name)
863 if (i != j)
865 SSA_NAME_VERSION (name) = j;
866 (*fun->gimple_df->ssa_names)[j] = name;
868 j++;
871 fun->gimple_df->ssa_names->truncate (j);
873 statistics_counter_event (fun, "SSA names released", n);
874 statistics_counter_event (fun, "SSA name holes removed", i - j);
875 if (dump_file)
876 fprintf (dump_file, "Released %i names, %.2f%%, removed %i holes\n",
877 n, n * 100.0 / num_ssa_names, i - j);
880 /* Return SSA names that are unused to GGC memory and compact the SSA
881 version namespace. This is used to keep footprint of compiler during
882 interprocedural optimization. */
884 namespace {
886 const pass_data pass_data_release_ssa_names =
888 GIMPLE_PASS, /* type */
889 "release_ssa", /* name */
890 OPTGROUP_NONE, /* optinfo_flags */
891 TV_TREE_SSA_OTHER, /* tv_id */
892 PROP_ssa, /* properties_required */
893 0, /* properties_provided */
894 0, /* properties_destroyed */
895 TODO_remove_unused_locals, /* todo_flags_start */
896 0, /* todo_flags_finish */
899 class pass_release_ssa_names : public gimple_opt_pass
901 public:
902 pass_release_ssa_names (gcc::context *ctxt)
903 : gimple_opt_pass (pass_data_release_ssa_names, ctxt)
906 /* opt_pass methods: */
907 virtual unsigned int execute (function *);
909 }; // class pass_release_ssa_names
911 unsigned int
912 pass_release_ssa_names::execute (function *fun)
914 release_free_names_and_compact_live_names (fun);
915 return 0;
918 } // anon namespace
920 gimple_opt_pass *
921 make_pass_release_ssa_names (gcc::context *ctxt)
923 return new pass_release_ssa_names (ctxt);