1 /* Generic routines for manipulating SSA_NAME expressions
2 Copyright (C) 2003-2019 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
)
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
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 /* Return an SSA_NAME node for variable VAR defined in statement STMT
256 in function FN. STMT may be an empty statement for artificial
257 references (e.g., default definitions created when a variable is
258 used without a preceding definition). If VERISON is not zero then
259 allocate the SSA name with that version. */
262 make_ssa_name_fn (struct function
*fn
, tree var
, gimple
*stmt
,
263 unsigned int version
)
268 gcc_assert (VAR_P (var
)
269 || TREE_CODE (var
) == PARM_DECL
270 || TREE_CODE (var
) == RESULT_DECL
271 || (TYPE_P (var
) && is_gimple_reg_type (var
)));
273 /* Get the specified SSA name version. */
276 t
= make_node (SSA_NAME
);
277 SSA_NAME_VERSION (t
) = version
;
278 if (version
>= SSANAMES (fn
)->length ())
279 vec_safe_grow_cleared (SSANAMES (fn
), version
+ 1);
280 gcc_assert ((*SSANAMES (fn
))[version
] == NULL
);
281 (*SSANAMES (fn
))[version
] = t
;
282 ssa_name_nodes_created
++;
284 /* If our free list has an element, then use it. */
285 else if (!vec_safe_is_empty (FREE_SSANAMES (fn
)))
287 t
= FREE_SSANAMES (fn
)->pop ();
288 ssa_name_nodes_reused
++;
290 /* The node was cleared out when we put it on the free list, so
291 there is no need to do so again here. */
292 gcc_assert ((*SSANAMES (fn
))[SSA_NAME_VERSION (t
)] == NULL
);
293 (*SSANAMES (fn
))[SSA_NAME_VERSION (t
)] = t
;
297 t
= make_node (SSA_NAME
);
298 SSA_NAME_VERSION (t
) = SSANAMES (fn
)->length ();
299 vec_safe_push (SSANAMES (fn
), t
);
300 ssa_name_nodes_created
++;
305 TREE_TYPE (t
) = TYPE_MAIN_VARIANT (var
);
306 SET_SSA_NAME_VAR_OR_IDENTIFIER (t
, NULL_TREE
);
310 TREE_TYPE (t
) = TREE_TYPE (var
);
311 SET_SSA_NAME_VAR_OR_IDENTIFIER (t
, var
);
313 SSA_NAME_DEF_STMT (t
) = stmt
;
314 if (POINTER_TYPE_P (TREE_TYPE (t
)))
315 SSA_NAME_PTR_INFO (t
) = NULL
;
317 SSA_NAME_RANGE_INFO (t
) = NULL
;
319 SSA_NAME_IN_FREE_LIST (t
) = 0;
320 SSA_NAME_IS_DEFAULT_DEF (t
) = 0;
321 imm
= &(SSA_NAME_IMM_USE_NODE (t
));
325 imm
->loc
.ssa_name
= t
;
330 /* Helper function for set_range_info.
332 Store range information RANGE_TYPE, MIN, and MAX to tree ssa_name
336 set_range_info_raw (tree name
, enum value_range_kind range_type
,
337 const wide_int_ref
&min
, const wide_int_ref
&max
)
339 gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name
)));
340 gcc_assert (range_type
== VR_RANGE
|| range_type
== VR_ANTI_RANGE
);
341 range_info_def
*ri
= SSA_NAME_RANGE_INFO (name
);
342 unsigned int precision
= TYPE_PRECISION (TREE_TYPE (name
));
344 /* Allocate if not available. */
347 size_t size
= (sizeof (range_info_def
)
348 + trailing_wide_ints
<3>::extra_size (precision
));
349 ri
= static_cast<range_info_def
*> (ggc_internal_alloc (size
));
350 ri
->ints
.set_precision (precision
);
351 SSA_NAME_RANGE_INFO (name
) = ri
;
352 ri
->set_nonzero_bits (wi::shwi (-1, precision
));
355 /* Record the range type. */
356 if (SSA_NAME_RANGE_TYPE (name
) != range_type
)
357 SSA_NAME_ANTI_RANGE_P (name
) = (range_type
== VR_ANTI_RANGE
);
359 /* Set the values. */
363 /* If it is a range, try to improve nonzero_bits from the min/max. */
364 if (range_type
== VR_RANGE
)
366 wide_int xorv
= ri
->get_min () ^ ri
->get_max ();
368 xorv
= wi::mask (precision
- wi::clz (xorv
), false, precision
);
369 ri
->set_nonzero_bits (ri
->get_nonzero_bits () & (ri
->get_min () | xorv
));
373 /* Store range information RANGE_TYPE, MIN, and MAX to tree ssa_name
374 NAME while making sure we don't store useless range info. */
377 set_range_info (tree name
, enum value_range_kind range_type
,
378 const wide_int_ref
&min
, const wide_int_ref
&max
)
380 gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name
)));
382 /* A range of the entire domain is really no range at all. */
383 tree type
= TREE_TYPE (name
);
384 if (min
== wi::min_value (TYPE_PRECISION (type
), TYPE_SIGN (type
))
385 && max
== wi::max_value (TYPE_PRECISION (type
), TYPE_SIGN (type
)))
387 range_info_def
*ri
= SSA_NAME_RANGE_INFO (name
);
390 if (ri
->get_nonzero_bits () == -1)
393 SSA_NAME_RANGE_INFO (name
) = NULL
;
398 set_range_info_raw (name
, range_type
, min
, max
);
401 /* Store range information for NAME from a value_range. */
404 set_range_info (tree name
, const value_range_base
&vr
)
406 wide_int min
= wi::to_wide (vr
.min ());
407 wide_int max
= wi::to_wide (vr
.max ());
408 set_range_info (name
, vr
.kind (), min
, max
);
411 /* Gets range information MIN, MAX and returns enum value_range_kind
412 corresponding to tree ssa_name NAME. enum value_range_kind returned
413 is used to determine if MIN and MAX are valid values. */
415 enum value_range_kind
416 get_range_info (const_tree name
, wide_int
*min
, wide_int
*max
)
418 gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name
)));
419 gcc_assert (min
&& max
);
420 range_info_def
*ri
= SSA_NAME_RANGE_INFO (name
);
422 /* Return VR_VARYING for SSA_NAMEs with NULL RANGE_INFO or SSA_NAMEs
423 with integral types width > 2 * HOST_BITS_PER_WIDE_INT precision. */
424 if (!ri
|| (GET_MODE_PRECISION (SCALAR_INT_TYPE_MODE (TREE_TYPE (name
)))
425 > 2 * HOST_BITS_PER_WIDE_INT
))
428 *min
= ri
->get_min ();
429 *max
= ri
->get_max ();
430 return SSA_NAME_RANGE_TYPE (name
);
433 /* Gets range information corresponding to ssa_name NAME and stores it
434 in a value_range VR. Returns the value_range_kind. */
436 enum value_range_kind
437 get_range_info (const_tree name
, value_range_base
&vr
)
441 enum value_range_kind kind
= get_range_info (name
, &wmin
, &wmax
);
443 if (kind
== VR_VARYING
)
444 vr
.set_varying (TREE_TYPE (name
));
445 else if (kind
== VR_UNDEFINED
)
449 min
= wide_int_to_tree (TREE_TYPE (name
), wmin
);
450 max
= wide_int_to_tree (TREE_TYPE (name
), wmax
);
451 vr
.set (kind
, min
, max
);
456 /* Set nonnull attribute to pointer NAME. */
459 set_ptr_nonnull (tree name
)
461 gcc_assert (POINTER_TYPE_P (TREE_TYPE (name
)));
462 struct ptr_info_def
*pi
= get_ptr_info (name
);
466 /* Return nonnull attribute of pointer NAME. */
468 get_ptr_nonnull (const_tree name
)
470 gcc_assert (POINTER_TYPE_P (TREE_TYPE (name
)));
471 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (name
);
474 /* TODO Now pt->null is conservatively set to true in PTA
475 analysis. vrp is the only pass (including ipa-vrp)
476 that clears pt.null via set_ptr_nonull when it knows
477 for sure. PTA will preserves the pt.null value set by VRP.
479 When PTA analysis is improved, pt.anything, pt.nonlocal
480 and pt.escaped may also has to be considered before
481 deciding that pointer cannot point to NULL. */
485 /* Change non-zero bits bitmask of NAME. */
488 set_nonzero_bits (tree name
, const wide_int_ref
&mask
)
490 gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name
)));
491 if (SSA_NAME_RANGE_INFO (name
) == NULL
)
495 set_range_info_raw (name
, VR_RANGE
,
496 wi::to_wide (TYPE_MIN_VALUE (TREE_TYPE (name
))),
497 wi::to_wide (TYPE_MAX_VALUE (TREE_TYPE (name
))));
499 range_info_def
*ri
= SSA_NAME_RANGE_INFO (name
);
500 ri
->set_nonzero_bits (mask
);
503 /* Return a widest_int with potentially non-zero bits in SSA_NAME
504 NAME, the constant for INTEGER_CST, or -1 if unknown. */
507 get_nonzero_bits (const_tree name
)
509 if (TREE_CODE (name
) == INTEGER_CST
)
510 return wi::to_wide (name
);
512 /* Use element_precision instead of TYPE_PRECISION so complex and
513 vector types get a non-zero precision. */
514 unsigned int precision
= element_precision (TREE_TYPE (name
));
515 if (POINTER_TYPE_P (TREE_TYPE (name
)))
517 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (name
);
519 return wi::shwi (-(HOST_WIDE_INT
) pi
->align
520 | (HOST_WIDE_INT
) pi
->misalign
, precision
);
521 return wi::shwi (-1, precision
);
524 range_info_def
*ri
= SSA_NAME_RANGE_INFO (name
);
526 return wi::shwi (-1, precision
);
528 return ri
->get_nonzero_bits ();
531 /* Return TRUE is OP, an SSA_NAME has a range of values [0..1], false
534 This can be because it is a boolean type, any unsigned integral
535 type with a single bit of precision, or has known range of [0..1]
539 ssa_name_has_boolean_range (tree op
)
541 gcc_assert (TREE_CODE (op
) == SSA_NAME
);
543 /* Boolean types always have a range [0..1]. */
544 if (TREE_CODE (TREE_TYPE (op
)) == BOOLEAN_TYPE
)
547 /* An integral type with a single bit of precision. */
548 if (INTEGRAL_TYPE_P (TREE_TYPE (op
))
549 && TYPE_UNSIGNED (TREE_TYPE (op
))
550 && TYPE_PRECISION (TREE_TYPE (op
)) == 1)
553 /* An integral type with more precision, but the object
554 only takes on values [0..1] as determined by VRP
556 if (INTEGRAL_TYPE_P (TREE_TYPE (op
))
557 && (TYPE_PRECISION (TREE_TYPE (op
)) > 1)
558 && wi::eq_p (get_nonzero_bits (op
), 1))
564 /* We no longer need the SSA_NAME expression VAR, release it so that
567 Note it is assumed that no calls to make_ssa_name will be made
568 until all uses of the ssa name are released and that the only
569 use of the SSA_NAME expression is to check its SSA_NAME_VAR. All
570 other fields must be assumed clobbered. */
573 release_ssa_name_fn (struct function
*fn
, tree var
)
578 /* Never release the default definition for a symbol. It's a
579 special SSA name that should always exist once it's created. */
580 if (SSA_NAME_IS_DEFAULT_DEF (var
))
583 /* If VAR has been registered for SSA updating, don't remove it.
584 After update_ssa has run, the name will be released. */
585 if (name_registered_for_update_p (var
))
587 release_ssa_name_after_update_ssa (var
);
591 /* release_ssa_name can be called multiple times on a single SSA_NAME.
592 However, it should only end up on our free list one time. We
593 keep a status bit in the SSA_NAME node itself to indicate it has
594 been put on the free list.
596 Note that once on the freelist you cannot reference the SSA_NAME's
597 defining statement. */
598 if (! SSA_NAME_IN_FREE_LIST (var
))
600 int saved_ssa_name_version
= SSA_NAME_VERSION (var
);
601 use_operand_p imm
= &(SSA_NAME_IMM_USE_NODE (var
));
603 if (MAY_HAVE_DEBUG_BIND_STMTS
)
604 insert_debug_temp_for_var_def (NULL
, var
);
607 verify_imm_links (stderr
, var
);
608 while (imm
->next
!= imm
)
609 delink_imm_use (imm
->next
);
611 (*SSANAMES (fn
))[SSA_NAME_VERSION (var
)] = NULL_TREE
;
612 memset (var
, 0, tree_size (var
));
616 imm
->loc
.ssa_name
= var
;
618 /* First put back the right tree node so that the tree checking
619 macros do not complain. */
620 TREE_SET_CODE (var
, SSA_NAME
);
622 /* Restore the version number. */
623 SSA_NAME_VERSION (var
) = saved_ssa_name_version
;
625 /* Note this SSA_NAME is now in the first list. */
626 SSA_NAME_IN_FREE_LIST (var
) = 1;
628 /* Put in a non-NULL TREE_TYPE so dumping code will not ICE
629 if it happens to come along a released SSA name and tries
630 to inspect its type. */
631 TREE_TYPE (var
) = error_mark_node
;
633 /* And finally queue it so that it will be put on the free list. */
634 vec_safe_push (FREE_SSANAMES_QUEUE (fn
), var
);
638 /* If the alignment of the pointer described by PI is known, return true and
639 store the alignment and the deviation from it into *ALIGNP and *MISALIGNP
640 respectively. Otherwise return false. */
643 get_ptr_info_alignment (struct ptr_info_def
*pi
, unsigned int *alignp
,
644 unsigned int *misalignp
)
649 *misalignp
= pi
->misalign
;
656 /* State that the pointer described by PI has unknown alignment. */
659 mark_ptr_info_alignment_unknown (struct ptr_info_def
*pi
)
665 /* Store the power-of-two byte alignment and the deviation from that
666 alignment of pointer described by PI to ALIOGN and MISALIGN
670 set_ptr_info_alignment (struct ptr_info_def
*pi
, unsigned int align
,
671 unsigned int misalign
)
673 gcc_checking_assert (align
!= 0);
674 gcc_assert ((align
& (align
- 1)) == 0);
675 gcc_assert ((misalign
& ~(align
- 1)) == 0);
678 pi
->misalign
= misalign
;
681 /* If pointer described by PI has known alignment, increase its known
682 misalignment by INCREMENT modulo its current alignment. */
685 adjust_ptr_info_misalignment (struct ptr_info_def
*pi
, poly_uint64 increment
)
689 increment
+= pi
->misalign
;
690 if (!known_misalignment (increment
, pi
->align
, &pi
->misalign
))
692 pi
->align
= known_alignment (increment
);
698 /* Return the alias information associated with pointer T. It creates a
699 new instance if none existed. */
701 struct ptr_info_def
*
702 get_ptr_info (tree t
)
704 struct ptr_info_def
*pi
;
706 gcc_assert (POINTER_TYPE_P (TREE_TYPE (t
)));
708 pi
= SSA_NAME_PTR_INFO (t
);
711 pi
= ggc_cleared_alloc
<ptr_info_def
> ();
712 pt_solution_reset (&pi
->pt
);
713 mark_ptr_info_alignment_unknown (pi
);
714 SSA_NAME_PTR_INFO (t
) = pi
;
721 /* Creates a new SSA name using the template NAME tobe defined by
722 statement STMT in function FN. */
725 copy_ssa_name_fn (struct function
*fn
, tree name
, gimple
*stmt
)
729 if (SSA_NAME_VAR (name
))
730 new_name
= make_ssa_name_fn (fn
, SSA_NAME_VAR (name
), stmt
);
733 new_name
= make_ssa_name_fn (fn
, TREE_TYPE (name
), stmt
);
734 SET_SSA_NAME_VAR_OR_IDENTIFIER (new_name
, SSA_NAME_IDENTIFIER (name
));
741 /* Creates a duplicate of the ptr_info_def at PTR_INFO for use by
742 the SSA name NAME. */
745 duplicate_ssa_name_ptr_info (tree name
, struct ptr_info_def
*ptr_info
)
747 struct ptr_info_def
*new_ptr_info
;
749 gcc_assert (POINTER_TYPE_P (TREE_TYPE (name
)));
750 gcc_assert (!SSA_NAME_PTR_INFO (name
));
755 new_ptr_info
= ggc_alloc
<ptr_info_def
> ();
756 *new_ptr_info
= *ptr_info
;
758 SSA_NAME_PTR_INFO (name
) = new_ptr_info
;
761 /* Creates a duplicate of the range_info_def at RANGE_INFO of type
762 RANGE_TYPE for use by the SSA name NAME. */
764 duplicate_ssa_name_range_info (tree name
, enum value_range_kind range_type
,
765 struct range_info_def
*range_info
)
767 struct range_info_def
*new_range_info
;
769 gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name
)));
770 gcc_assert (!SSA_NAME_RANGE_INFO (name
));
775 unsigned int precision
= TYPE_PRECISION (TREE_TYPE (name
));
776 size_t size
= (sizeof (range_info_def
)
777 + trailing_wide_ints
<3>::extra_size (precision
));
778 new_range_info
= static_cast<range_info_def
*> (ggc_internal_alloc (size
));
779 memcpy (new_range_info
, range_info
, size
);
781 gcc_assert (range_type
== VR_RANGE
|| range_type
== VR_ANTI_RANGE
);
782 SSA_NAME_ANTI_RANGE_P (name
) = (range_type
== VR_ANTI_RANGE
);
783 SSA_NAME_RANGE_INFO (name
) = new_range_info
;
788 /* Creates a duplicate of a ssa name NAME tobe defined by statement STMT
792 duplicate_ssa_name_fn (struct function
*fn
, tree name
, gimple
*stmt
)
794 tree new_name
= copy_ssa_name_fn (fn
, name
, stmt
);
795 if (POINTER_TYPE_P (TREE_TYPE (name
)))
797 struct ptr_info_def
*old_ptr_info
= SSA_NAME_PTR_INFO (name
);
800 duplicate_ssa_name_ptr_info (new_name
, old_ptr_info
);
804 struct range_info_def
*old_range_info
= SSA_NAME_RANGE_INFO (name
);
807 duplicate_ssa_name_range_info (new_name
, SSA_NAME_RANGE_TYPE (name
),
815 /* Reset all flow sensitive data on NAME such as range-info, nonzero
816 bits and alignment. */
819 reset_flow_sensitive_info (tree name
)
821 if (POINTER_TYPE_P (TREE_TYPE (name
)))
823 /* points-to info is not flow-sensitive. */
824 if (SSA_NAME_PTR_INFO (name
))
826 /* [E]VRP can derive context sensitive alignment info and
827 non-nullness properties. We must reset both. */
828 mark_ptr_info_alignment_unknown (SSA_NAME_PTR_INFO (name
));
829 SSA_NAME_PTR_INFO (name
)->pt
.null
= 1;
833 SSA_NAME_RANGE_INFO (name
) = NULL
;
836 /* Clear all flow sensitive data from all statements and PHI definitions
840 reset_flow_sensitive_info_in_bb (basic_block bb
)
842 for (gimple_stmt_iterator gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
);
845 gimple
*stmt
= gsi_stmt (gsi
);
848 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, i
, SSA_OP_DEF
)
849 reset_flow_sensitive_info (op
);
852 for (gphi_iterator gsi
= gsi_start_phis (bb
); !gsi_end_p (gsi
);
855 tree phi_def
= gimple_phi_result (gsi
.phi ());
856 reset_flow_sensitive_info (phi_def
);
860 /* Release all the SSA_NAMEs created by STMT. */
863 release_defs (gimple
*stmt
)
868 FOR_EACH_SSA_TREE_OPERAND (def
, stmt
, iter
, SSA_OP_ALL_DEFS
)
869 if (TREE_CODE (def
) == SSA_NAME
)
870 release_ssa_name (def
);
874 /* Replace the symbol associated with SSA_NAME with SYM. */
877 replace_ssa_name_symbol (tree ssa_name
, tree sym
)
879 SET_SSA_NAME_VAR_OR_IDENTIFIER (ssa_name
, sym
);
880 TREE_TYPE (ssa_name
) = TREE_TYPE (sym
);
883 /* Release the vector of free SSA_NAMEs and compact the vector of SSA_NAMEs
887 release_free_names_and_compact_live_names (function
*fun
)
890 int n
= vec_safe_length (FREE_SSANAMES (fun
));
892 /* Now release the freelist. */
893 vec_free (FREE_SSANAMES (fun
));
895 /* And compact the SSA number space. We make sure to not change the
896 relative order of SSA versions. */
897 for (i
= 1, j
= 1; i
< fun
->gimple_df
->ssa_names
->length (); ++i
)
899 tree name
= ssa_name (i
);
904 SSA_NAME_VERSION (name
) = j
;
905 (*fun
->gimple_df
->ssa_names
)[j
] = name
;
910 fun
->gimple_df
->ssa_names
->truncate (j
);
912 statistics_counter_event (fun
, "SSA names released", n
);
913 statistics_counter_event (fun
, "SSA name holes removed", i
- j
);
915 fprintf (dump_file
, "Released %i names, %.2f%%, removed %i holes\n",
916 n
, n
* 100.0 / num_ssa_names
, i
- j
);
919 /* Return SSA names that are unused to GGC memory and compact the SSA
920 version namespace. This is used to keep footprint of compiler during
921 interprocedural optimization. */
925 const pass_data pass_data_release_ssa_names
=
927 GIMPLE_PASS
, /* type */
928 "release_ssa", /* name */
929 OPTGROUP_NONE
, /* optinfo_flags */
930 TV_TREE_SSA_OTHER
, /* tv_id */
931 PROP_ssa
, /* properties_required */
932 0, /* properties_provided */
933 0, /* properties_destroyed */
934 TODO_remove_unused_locals
, /* todo_flags_start */
935 0, /* todo_flags_finish */
938 class pass_release_ssa_names
: public gimple_opt_pass
941 pass_release_ssa_names (gcc::context
*ctxt
)
942 : gimple_opt_pass (pass_data_release_ssa_names
, ctxt
)
945 /* opt_pass methods: */
946 virtual unsigned int execute (function
*);
948 }; // class pass_release_ssa_names
951 pass_release_ssa_names::execute (function
*fun
)
953 release_free_names_and_compact_live_names (fun
);
960 make_pass_release_ssa_names (gcc::context
*ctxt
)
962 return new pass_release_ssa_names (ctxt
);