1 /* Generic routines for manipulating SSA_NAME expressions
2 Copyright (C) 2003-2021 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)
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/>. */
22 #include "coretypes.h"
26 #include "tree-pass.h"
28 #include "gimple-iterator.h"
29 #include "stor-layout.h"
30 #include "tree-into-ssa.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
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
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
78 init_ssanames (struct function
*fn
, int size
)
81 vec_alloc (SSANAMES (fn
), 50);
83 vec_safe_reserve (SSANAMES (fn
), size
, true);
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
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. */
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. */
113 ssanames_print_statistics (void)
115 fprintf (stderr
, "%-32s" PRsa (11) "\n", "SSA_NAME nodes allocated:",
116 SIZE_AMOUNT (ssa_name_nodes_created
));
117 fprintf (stderr
, "%-32s" PRsa (11) "\n", "SSA_NAME nodes reused:",
118 SIZE_AMOUNT (ssa_name_nodes_reused
));
121 /* Verify the state of the SSA_NAME lists.
123 There must be no duplicates on the free list.
124 Every name on the free list must be marked as on the free list.
125 Any name on the free list must not appear in the IL.
126 No names can be leaked. */
129 verify_ssaname_freelists (struct function
*fun
)
131 if (!gimple_in_ssa_p (fun
))
134 auto_bitmap names_in_il
;
136 /* Walk the entire IL noting every SSA_NAME we see. */
138 FOR_EACH_BB_FN (bb
, fun
)
141 /* First note the result and arguments of PHI nodes. */
142 for (gphi_iterator gsi
= gsi_start_phis (bb
);
146 gphi
*phi
= gsi
.phi ();
147 t
= gimple_phi_result (phi
);
148 bitmap_set_bit (names_in_il
, SSA_NAME_VERSION (t
));
150 for (unsigned int i
= 0; i
< gimple_phi_num_args (phi
); i
++)
152 t
= gimple_phi_arg_def (phi
, i
);
153 if (TREE_CODE (t
) == SSA_NAME
)
154 bitmap_set_bit (names_in_il
, SSA_NAME_VERSION (t
));
158 /* Then note the operands of each statement. */
159 for (gimple_stmt_iterator gsi
= gsi_start_bb (bb
);
164 gimple
*stmt
= gsi_stmt (gsi
);
165 FOR_EACH_SSA_TREE_OPERAND (t
, stmt
, iter
, SSA_OP_ALL_OPERANDS
)
166 bitmap_set_bit (names_in_il
, SSA_NAME_VERSION (t
));
170 /* Now walk the free list noting what we find there and verifying
171 there are no duplicates. */
172 auto_bitmap names_in_freelists
;
173 if (FREE_SSANAMES (fun
))
175 for (unsigned int i
= 0; i
< FREE_SSANAMES (fun
)->length (); i
++)
177 tree t
= (*FREE_SSANAMES (fun
))[i
];
179 /* Verify that the name is marked as being in the free list. */
180 gcc_assert (SSA_NAME_IN_FREE_LIST (t
));
182 /* Verify the name has not already appeared in the free list and
183 note it in the list of names found in the free list. */
184 gcc_assert (!bitmap_bit_p (names_in_freelists
, SSA_NAME_VERSION (t
)));
185 bitmap_set_bit (names_in_freelists
, SSA_NAME_VERSION (t
));
189 /* Similarly for the names in the pending free list. */
190 if (FREE_SSANAMES_QUEUE (fun
))
192 for (unsigned int i
= 0; i
< FREE_SSANAMES_QUEUE (fun
)->length (); i
++)
194 tree t
= (*FREE_SSANAMES_QUEUE (fun
))[i
];
196 /* Verify that the name is marked as being in the free list. */
197 gcc_assert (SSA_NAME_IN_FREE_LIST (t
));
199 /* Verify the name has not already appeared in the free list and
200 note it in the list of names found in the free list. */
201 gcc_assert (!bitmap_bit_p (names_in_freelists
, SSA_NAME_VERSION (t
)));
202 bitmap_set_bit (names_in_freelists
, SSA_NAME_VERSION (t
));
206 /* If any name appears in both the IL and the freelists, then
207 something horrible has happened. */
208 bool intersect_p
= bitmap_intersect_p (names_in_il
, names_in_freelists
);
209 gcc_assert (!intersect_p
);
211 /* Names can be queued up for release if there is an ssa update
212 pending. Pretend we saw them in the IL. */
213 if (names_to_release
)
214 bitmap_ior_into (names_in_il
, names_to_release
);
216 /* Function splitting can "lose" SSA_NAMEs in an effort to ensure that
217 debug/non-debug compilations have the same SSA_NAMEs. So for each
218 lost SSA_NAME, see if it's likely one from that wart. These will always
219 be marked as default definitions. So we loosely assume that anything
220 marked as a default definition isn't leaked by pretending they are
222 for (unsigned int i
= UNUSED_NAME_VERSION
+ 1; i
< num_ssa_names
; i
++)
223 if (ssa_name (i
) && SSA_NAME_IS_DEFAULT_DEF (ssa_name (i
)))
224 bitmap_set_bit (names_in_il
, i
);
228 auto_bitmap all_names
;
229 bitmap_set_range (all_names
, UNUSED_NAME_VERSION
+ 1, num_ssa_names
- 1);
230 bitmap_ior_into (names_in_il
, names_in_freelists
);
232 /* Any name not mentioned in the IL and not in the feelists
234 EXECUTE_IF_AND_COMPL_IN_BITMAP(all_names
, names_in_il
,
235 UNUSED_NAME_VERSION
+ 1, i
, bi
)
236 gcc_assert (!ssa_name (i
));
239 /* Move all SSA_NAMEs from FREE_SSA_NAMES_QUEUE to FREE_SSA_NAMES.
241 We do not, but should have a mode to verify the state of the SSA_NAMEs
242 lists. In particular at this point every name must be in the IL,
243 on the free list or in the queue. Anything else is an error. */
246 flush_ssaname_freelist (void)
248 /* If there were any SSA names released reset the SCEV cache. */
249 if (! vec_safe_is_empty (FREE_SSANAMES_QUEUE (cfun
)))
251 vec_safe_splice (FREE_SSANAMES (cfun
), FREE_SSANAMES_QUEUE (cfun
));
252 vec_safe_truncate (FREE_SSANAMES_QUEUE (cfun
), 0);
255 /* Initialize SSA_NAME_IMM_USE_NODE of a SSA NAME. */
258 init_ssa_name_imm_use (tree name
)
261 imm
= &(SSA_NAME_IMM_USE_NODE (name
));
265 imm
->loc
.ssa_name
= name
;
268 /* Return an SSA_NAME node for variable VAR defined in statement STMT
269 in function FN. STMT may be an empty statement for artificial
270 references (e.g., default definitions created when a variable is
271 used without a preceding definition). If VERISON is not zero then
272 allocate the SSA name with that version. */
275 make_ssa_name_fn (struct function
*fn
, tree var
, gimple
*stmt
,
276 unsigned int version
)
279 gcc_assert (VAR_P (var
)
280 || TREE_CODE (var
) == PARM_DECL
281 || TREE_CODE (var
) == RESULT_DECL
282 || (TYPE_P (var
) && is_gimple_reg_type (var
)));
284 /* Get the specified SSA name version. */
287 t
= make_node (SSA_NAME
);
288 SSA_NAME_VERSION (t
) = version
;
289 if (version
>= SSANAMES (fn
)->length ())
290 vec_safe_grow_cleared (SSANAMES (fn
), version
+ 1, true);
291 gcc_assert ((*SSANAMES (fn
))[version
] == NULL
);
292 (*SSANAMES (fn
))[version
] = t
;
293 ssa_name_nodes_created
++;
295 /* If our free list has an element, then use it. */
296 else if (!vec_safe_is_empty (FREE_SSANAMES (fn
)))
298 t
= FREE_SSANAMES (fn
)->pop ();
299 ssa_name_nodes_reused
++;
301 /* The node was cleared out when we put it on the free list, so
302 there is no need to do so again here. */
303 gcc_assert ((*SSANAMES (fn
))[SSA_NAME_VERSION (t
)] == NULL
);
304 (*SSANAMES (fn
))[SSA_NAME_VERSION (t
)] = t
;
308 t
= make_node (SSA_NAME
);
309 SSA_NAME_VERSION (t
) = SSANAMES (fn
)->length ();
310 vec_safe_push (SSANAMES (fn
), t
);
311 ssa_name_nodes_created
++;
316 TREE_TYPE (t
) = TYPE_MAIN_VARIANT (var
);
317 SET_SSA_NAME_VAR_OR_IDENTIFIER (t
, NULL_TREE
);
321 TREE_TYPE (t
) = TREE_TYPE (var
);
322 SET_SSA_NAME_VAR_OR_IDENTIFIER (t
, var
);
324 SSA_NAME_DEF_STMT (t
) = stmt
;
325 if (POINTER_TYPE_P (TREE_TYPE (t
)))
326 SSA_NAME_PTR_INFO (t
) = NULL
;
328 SSA_NAME_RANGE_INFO (t
) = NULL
;
330 SSA_NAME_IN_FREE_LIST (t
) = 0;
331 SSA_NAME_IS_DEFAULT_DEF (t
) = 0;
332 init_ssa_name_imm_use (t
);
337 /* Helper function for set_range_info.
339 Store range information RANGE_TYPE, MIN, and MAX to tree ssa_name
343 set_range_info_raw (tree name
, enum value_range_kind range_type
,
344 const wide_int_ref
&min
, const wide_int_ref
&max
)
346 gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name
)));
347 gcc_assert (range_type
== VR_RANGE
|| range_type
== VR_ANTI_RANGE
);
348 range_info_def
*ri
= SSA_NAME_RANGE_INFO (name
);
349 unsigned int precision
= TYPE_PRECISION (TREE_TYPE (name
));
351 /* Allocate if not available. */
354 size_t size
= (sizeof (range_info_def
)
355 + trailing_wide_ints
<3>::extra_size (precision
));
356 ri
= static_cast<range_info_def
*> (ggc_internal_alloc (size
));
357 ri
->ints
.set_precision (precision
);
358 SSA_NAME_RANGE_INFO (name
) = ri
;
359 ri
->set_nonzero_bits (wi::shwi (-1, precision
));
362 /* Record the range type. */
363 if (SSA_NAME_RANGE_TYPE (name
) != range_type
)
364 SSA_NAME_ANTI_RANGE_P (name
) = (range_type
== VR_ANTI_RANGE
);
366 /* Set the values. */
370 /* If it is a range, try to improve nonzero_bits from the min/max. */
371 if (range_type
== VR_RANGE
)
373 wide_int xorv
= ri
->get_min () ^ ri
->get_max ();
375 xorv
= wi::mask (precision
- wi::clz (xorv
), false, precision
);
376 ri
->set_nonzero_bits (ri
->get_nonzero_bits () & (ri
->get_min () | xorv
));
380 /* Store range information RANGE_TYPE, MIN, and MAX to tree ssa_name
381 NAME while making sure we don't store useless range info. */
384 set_range_info (tree name
, enum value_range_kind range_type
,
385 const wide_int_ref
&min
, const wide_int_ref
&max
)
387 gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name
)));
389 /* A range of the entire domain is really no range at all. */
390 tree type
= TREE_TYPE (name
);
391 if (min
== wi::min_value (TYPE_PRECISION (type
), TYPE_SIGN (type
))
392 && max
== wi::max_value (TYPE_PRECISION (type
), TYPE_SIGN (type
)))
394 range_info_def
*ri
= SSA_NAME_RANGE_INFO (name
);
397 if (ri
->get_nonzero_bits () == -1)
400 SSA_NAME_RANGE_INFO (name
) = NULL
;
405 set_range_info_raw (name
, range_type
, min
, max
);
408 /* Store range information for NAME from a value_range. */
411 set_range_info (tree name
, const value_range
&vr
)
413 wide_int min
= wi::to_wide (vr
.min ());
414 wide_int max
= wi::to_wide (vr
.max ());
415 set_range_info (name
, vr
.kind (), min
, max
);
418 /* Gets range information MIN, MAX and returns enum value_range_kind
419 corresponding to tree ssa_name NAME. enum value_range_kind returned
420 is used to determine if MIN and MAX are valid values. */
422 enum value_range_kind
423 get_range_info (const_tree expr
, wide_int
*min
, wide_int
*max
)
425 gcc_assert (!POINTER_TYPE_P (TREE_TYPE (expr
)));
426 gcc_assert (min
&& max
);
427 if (TREE_CODE (expr
) == INTEGER_CST
)
429 *min
= wi::to_wide (expr
);
433 if (TREE_CODE (expr
) != SSA_NAME
)
436 range_info_def
*ri
= SSA_NAME_RANGE_INFO (expr
);
438 /* Return VR_VARYING for SSA_NAMEs with NULL RANGE_INFO or SSA_NAMEs
439 with integral types width > 2 * HOST_BITS_PER_WIDE_INT precision. */
440 if (!ri
|| (GET_MODE_PRECISION (SCALAR_INT_TYPE_MODE (TREE_TYPE (expr
)))
441 > 2 * HOST_BITS_PER_WIDE_INT
))
444 *min
= ri
->get_min ();
445 *max
= ri
->get_max ();
446 return SSA_NAME_RANGE_TYPE (expr
);
449 /* Gets range information corresponding to ssa_name NAME and stores it
450 in a value_range VR. Returns the value_range_kind. */
452 enum value_range_kind
453 get_range_info (const_tree name
, irange
&vr
)
457 enum value_range_kind kind
= get_range_info (name
, &wmin
, &wmax
);
459 if (kind
== VR_VARYING
)
460 vr
.set_varying (TREE_TYPE (name
));
461 else if (kind
== VR_UNDEFINED
)
465 min
= wide_int_to_tree (TREE_TYPE (name
), wmin
);
466 max
= wide_int_to_tree (TREE_TYPE (name
), wmax
);
467 vr
.set (min
, max
, kind
);
472 /* Set nonnull attribute to pointer NAME. */
475 set_ptr_nonnull (tree name
)
477 gcc_assert (POINTER_TYPE_P (TREE_TYPE (name
)));
478 struct ptr_info_def
*pi
= get_ptr_info (name
);
482 /* Return nonnull attribute of pointer NAME. */
484 get_ptr_nonnull (const_tree name
)
486 gcc_assert (POINTER_TYPE_P (TREE_TYPE (name
)));
487 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (name
);
490 /* TODO Now pt->null is conservatively set to true in PTA
491 analysis. vrp is the only pass (including ipa-vrp)
492 that clears pt.null via set_ptr_nonull when it knows
493 for sure. PTA will preserves the pt.null value set by VRP.
495 When PTA analysis is improved, pt.anything, pt.nonlocal
496 and pt.escaped may also has to be considered before
497 deciding that pointer cannot point to NULL. */
501 /* Change non-zero bits bitmask of NAME. */
504 set_nonzero_bits (tree name
, const wide_int_ref
&mask
)
506 gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name
)));
507 if (SSA_NAME_RANGE_INFO (name
) == NULL
)
511 set_range_info_raw (name
, VR_RANGE
,
512 wi::to_wide (TYPE_MIN_VALUE (TREE_TYPE (name
))),
513 wi::to_wide (TYPE_MAX_VALUE (TREE_TYPE (name
))));
515 range_info_def
*ri
= SSA_NAME_RANGE_INFO (name
);
516 ri
->set_nonzero_bits (mask
);
519 /* Return a widest_int with potentially non-zero bits in SSA_NAME
520 NAME, the constant for INTEGER_CST, or -1 if unknown. */
523 get_nonzero_bits (const_tree name
)
525 if (TREE_CODE (name
) == INTEGER_CST
)
526 return wi::to_wide (name
);
528 /* Use element_precision instead of TYPE_PRECISION so complex and
529 vector types get a non-zero precision. */
530 unsigned int precision
= element_precision (TREE_TYPE (name
));
531 if (POINTER_TYPE_P (TREE_TYPE (name
)))
533 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (name
);
535 return wi::shwi (-(HOST_WIDE_INT
) pi
->align
536 | (HOST_WIDE_INT
) pi
->misalign
, precision
);
537 return wi::shwi (-1, precision
);
540 range_info_def
*ri
= SSA_NAME_RANGE_INFO (name
);
542 return wi::shwi (-1, precision
);
544 return ri
->get_nonzero_bits ();
547 /* Return TRUE is OP, an SSA_NAME has a range of values [0..1], false
550 This can be because it is a boolean type, any unsigned integral
551 type with a single bit of precision, or has known range of [0..1]
555 ssa_name_has_boolean_range (tree op
)
557 gcc_assert (TREE_CODE (op
) == SSA_NAME
);
559 /* Boolean types always have a range [0..1]. */
560 if (TREE_CODE (TREE_TYPE (op
)) == BOOLEAN_TYPE
)
563 /* An integral type with a single bit of precision. */
564 if (INTEGRAL_TYPE_P (TREE_TYPE (op
))
565 && TYPE_UNSIGNED (TREE_TYPE (op
))
566 && TYPE_PRECISION (TREE_TYPE (op
)) == 1)
569 /* An integral type with more precision, but the object
570 only takes on values [0..1] as determined by VRP
572 if (INTEGRAL_TYPE_P (TREE_TYPE (op
))
573 && (TYPE_PRECISION (TREE_TYPE (op
)) > 1)
574 && wi::eq_p (get_nonzero_bits (op
), 1))
580 /* We no longer need the SSA_NAME expression VAR, release it so that
583 Note it is assumed that no calls to make_ssa_name will be made
584 until all uses of the ssa name are released and that the only
585 use of the SSA_NAME expression is to check its SSA_NAME_VAR. All
586 other fields must be assumed clobbered. */
589 release_ssa_name_fn (struct function
*fn
, tree var
)
594 /* Never release the default definition for a symbol. It's a
595 special SSA name that should always exist once it's created. */
596 if (SSA_NAME_IS_DEFAULT_DEF (var
))
599 /* If VAR has been registered for SSA updating, don't remove it.
600 After update_ssa has run, the name will be released. */
601 if (name_registered_for_update_p (var
))
603 release_ssa_name_after_update_ssa (var
);
607 /* release_ssa_name can be called multiple times on a single SSA_NAME.
608 However, it should only end up on our free list one time. We
609 keep a status bit in the SSA_NAME node itself to indicate it has
610 been put on the free list.
612 Note that once on the freelist you cannot reference the SSA_NAME's
613 defining statement. */
614 if (! SSA_NAME_IN_FREE_LIST (var
))
616 int saved_ssa_name_version
= SSA_NAME_VERSION (var
);
617 use_operand_p imm
= &(SSA_NAME_IMM_USE_NODE (var
));
619 if (MAY_HAVE_DEBUG_BIND_STMTS
)
620 insert_debug_temp_for_var_def (NULL
, var
);
623 verify_imm_links (stderr
, var
);
624 while (imm
->next
!= imm
)
625 delink_imm_use (imm
->next
);
627 (*SSANAMES (fn
))[SSA_NAME_VERSION (var
)] = NULL_TREE
;
628 memset (var
, 0, tree_size (var
));
632 imm
->loc
.ssa_name
= var
;
634 /* First put back the right tree node so that the tree checking
635 macros do not complain. */
636 TREE_SET_CODE (var
, SSA_NAME
);
638 /* Restore the version number. */
639 SSA_NAME_VERSION (var
) = saved_ssa_name_version
;
641 /* Note this SSA_NAME is now in the first list. */
642 SSA_NAME_IN_FREE_LIST (var
) = 1;
644 /* Put in a non-NULL TREE_TYPE so dumping code will not ICE
645 if it happens to come along a released SSA name and tries
646 to inspect its type. */
647 TREE_TYPE (var
) = error_mark_node
;
649 /* And finally queue it so that it will be put on the free list. */
650 vec_safe_push (FREE_SSANAMES_QUEUE (fn
), var
);
654 /* If the alignment of the pointer described by PI is known, return true and
655 store the alignment and the deviation from it into *ALIGNP and *MISALIGNP
656 respectively. Otherwise return false. */
659 get_ptr_info_alignment (struct ptr_info_def
*pi
, unsigned int *alignp
,
660 unsigned int *misalignp
)
665 *misalignp
= pi
->misalign
;
672 /* State that the pointer described by PI has unknown alignment. */
675 mark_ptr_info_alignment_unknown (struct ptr_info_def
*pi
)
681 /* Store the power-of-two byte alignment and the deviation from that
682 alignment of pointer described by PI to ALIOGN and MISALIGN
686 set_ptr_info_alignment (struct ptr_info_def
*pi
, unsigned int align
,
687 unsigned int misalign
)
689 gcc_checking_assert (align
!= 0);
690 gcc_assert ((align
& (align
- 1)) == 0);
691 gcc_assert ((misalign
& ~(align
- 1)) == 0);
694 pi
->misalign
= misalign
;
697 /* If pointer described by PI has known alignment, increase its known
698 misalignment by INCREMENT modulo its current alignment. */
701 adjust_ptr_info_misalignment (struct ptr_info_def
*pi
, poly_uint64 increment
)
705 increment
+= pi
->misalign
;
706 if (!known_misalignment (increment
, pi
->align
, &pi
->misalign
))
708 pi
->align
= known_alignment (increment
);
714 /* Return the alias information associated with pointer T. It creates a
715 new instance if none existed. */
717 struct ptr_info_def
*
718 get_ptr_info (tree t
)
720 struct ptr_info_def
*pi
;
722 gcc_assert (POINTER_TYPE_P (TREE_TYPE (t
)));
724 pi
= SSA_NAME_PTR_INFO (t
);
727 pi
= ggc_cleared_alloc
<ptr_info_def
> ();
728 pt_solution_reset (&pi
->pt
);
729 mark_ptr_info_alignment_unknown (pi
);
730 SSA_NAME_PTR_INFO (t
) = pi
;
737 /* Creates a new SSA name using the template NAME tobe defined by
738 statement STMT in function FN. */
741 copy_ssa_name_fn (struct function
*fn
, tree name
, gimple
*stmt
)
745 if (SSA_NAME_VAR (name
))
746 new_name
= make_ssa_name_fn (fn
, SSA_NAME_VAR (name
), stmt
);
749 new_name
= make_ssa_name_fn (fn
, TREE_TYPE (name
), stmt
);
750 SET_SSA_NAME_VAR_OR_IDENTIFIER (new_name
, SSA_NAME_IDENTIFIER (name
));
757 /* Creates a duplicate of the ptr_info_def at PTR_INFO for use by
758 the SSA name NAME. */
761 duplicate_ssa_name_ptr_info (tree name
, struct ptr_info_def
*ptr_info
)
763 struct ptr_info_def
*new_ptr_info
;
765 gcc_assert (POINTER_TYPE_P (TREE_TYPE (name
)));
766 gcc_assert (!SSA_NAME_PTR_INFO (name
));
771 new_ptr_info
= ggc_alloc
<ptr_info_def
> ();
772 *new_ptr_info
= *ptr_info
;
774 SSA_NAME_PTR_INFO (name
) = new_ptr_info
;
777 /* Creates a duplicate of the range_info_def at RANGE_INFO of type
778 RANGE_TYPE for use by the SSA name NAME. */
780 duplicate_ssa_name_range_info (tree name
, enum value_range_kind range_type
,
781 struct range_info_def
*range_info
)
783 struct range_info_def
*new_range_info
;
785 gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name
)));
786 gcc_assert (!SSA_NAME_RANGE_INFO (name
));
791 unsigned int precision
= TYPE_PRECISION (TREE_TYPE (name
));
792 size_t size
= (sizeof (range_info_def
)
793 + trailing_wide_ints
<3>::extra_size (precision
));
794 new_range_info
= static_cast<range_info_def
*> (ggc_internal_alloc (size
));
795 memcpy (new_range_info
, range_info
, size
);
797 gcc_assert (range_type
== VR_RANGE
|| range_type
== VR_ANTI_RANGE
);
798 SSA_NAME_ANTI_RANGE_P (name
) = (range_type
== VR_ANTI_RANGE
);
799 SSA_NAME_RANGE_INFO (name
) = new_range_info
;
804 /* Creates a duplicate of a ssa name NAME tobe defined by statement STMT
808 duplicate_ssa_name_fn (struct function
*fn
, tree name
, gimple
*stmt
)
810 tree new_name
= copy_ssa_name_fn (fn
, name
, stmt
);
811 if (POINTER_TYPE_P (TREE_TYPE (name
)))
813 struct ptr_info_def
*old_ptr_info
= SSA_NAME_PTR_INFO (name
);
816 duplicate_ssa_name_ptr_info (new_name
, old_ptr_info
);
820 struct range_info_def
*old_range_info
= SSA_NAME_RANGE_INFO (name
);
823 duplicate_ssa_name_range_info (new_name
, SSA_NAME_RANGE_TYPE (name
),
831 /* Reset all flow sensitive data on NAME such as range-info, nonzero
832 bits and alignment. */
835 reset_flow_sensitive_info (tree name
)
837 if (POINTER_TYPE_P (TREE_TYPE (name
)))
839 /* points-to info is not flow-sensitive. */
840 if (SSA_NAME_PTR_INFO (name
))
842 /* [E]VRP can derive context sensitive alignment info and
843 non-nullness properties. We must reset both. */
844 mark_ptr_info_alignment_unknown (SSA_NAME_PTR_INFO (name
));
845 SSA_NAME_PTR_INFO (name
)->pt
.null
= 1;
849 SSA_NAME_RANGE_INFO (name
) = NULL
;
852 /* Clear all flow sensitive data from all statements and PHI definitions
856 reset_flow_sensitive_info_in_bb (basic_block bb
)
858 for (gimple_stmt_iterator gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
);
861 gimple
*stmt
= gsi_stmt (gsi
);
864 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, i
, SSA_OP_DEF
)
865 reset_flow_sensitive_info (op
);
868 for (gphi_iterator gsi
= gsi_start_phis (bb
); !gsi_end_p (gsi
);
871 tree phi_def
= gimple_phi_result (gsi
.phi ());
872 reset_flow_sensitive_info (phi_def
);
876 /* Release all the SSA_NAMEs created by STMT. */
879 release_defs (gimple
*stmt
)
884 FOR_EACH_SSA_TREE_OPERAND (def
, stmt
, iter
, SSA_OP_ALL_DEFS
)
885 if (TREE_CODE (def
) == SSA_NAME
)
886 release_ssa_name (def
);
890 /* Replace the symbol associated with SSA_NAME with SYM. */
893 replace_ssa_name_symbol (tree ssa_name
, tree sym
)
895 SET_SSA_NAME_VAR_OR_IDENTIFIER (ssa_name
, sym
);
896 TREE_TYPE (ssa_name
) = TREE_TYPE (sym
);
899 /* Release the vector of free SSA_NAMEs and compact the vector of SSA_NAMEs
903 release_free_names_and_compact_live_names (function
*fun
)
906 int n
= vec_safe_length (FREE_SSANAMES (fun
));
908 /* Now release the freelist. */
909 vec_free (FREE_SSANAMES (fun
));
911 /* And compact the SSA number space. We make sure to not change the
912 relative order of SSA versions. */
913 for (i
= 1, j
= 1; i
< fun
->gimple_df
->ssa_names
->length (); ++i
)
915 tree name
= ssa_name (i
);
920 SSA_NAME_VERSION (name
) = j
;
921 (*fun
->gimple_df
->ssa_names
)[j
] = name
;
926 fun
->gimple_df
->ssa_names
->truncate (j
);
928 statistics_counter_event (fun
, "SSA names released", n
);
929 statistics_counter_event (fun
, "SSA name holes removed", i
- j
);
931 fprintf (dump_file
, "Released %i names, %.2f%%, removed %i holes\n",
932 n
, n
* 100.0 / num_ssa_names
, i
- j
);
935 /* Return SSA names that are unused to GGC memory and compact the SSA
936 version namespace. This is used to keep footprint of compiler during
937 interprocedural optimization. */
941 const pass_data pass_data_release_ssa_names
=
943 GIMPLE_PASS
, /* type */
944 "release_ssa", /* name */
945 OPTGROUP_NONE
, /* optinfo_flags */
946 TV_TREE_SSA_OTHER
, /* tv_id */
947 PROP_ssa
, /* properties_required */
948 0, /* properties_provided */
949 0, /* properties_destroyed */
950 TODO_remove_unused_locals
, /* todo_flags_start */
951 0, /* todo_flags_finish */
954 class pass_release_ssa_names
: public gimple_opt_pass
957 pass_release_ssa_names (gcc::context
*ctxt
)
958 : gimple_opt_pass (pass_data_release_ssa_names
, ctxt
)
961 /* opt_pass methods: */
962 virtual unsigned int execute (function
*);
964 }; // class pass_release_ssa_names
967 pass_release_ssa_names::execute (function
*fun
)
969 release_free_names_and_compact_live_names (fun
);
976 make_pass_release_ssa_names (gcc::context
*ctxt
)
978 return new pass_release_ssa_names (ctxt
);