1 /* Generic routines for manipulating SSA_NAME expressions
2 Copyright (C) 2003-2017 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 /* Rewriting a function into SSA form can create a huge number of SSA_NAMEs,
34 many of which may be thrown away shortly after their creation if jumps
35 were threaded through PHI nodes.
37 While our garbage collection mechanisms will handle this situation, it
38 is extremely wasteful to create nodes and throw them away, especially
39 when the nodes can be reused.
41 For PR 8361, we can significantly reduce the number of nodes allocated
42 and thus the total amount of memory allocated by managing SSA_NAMEs a
43 little. This additionally helps reduce the amount of work done by the
44 garbage collector. Similar results have been seen on a wider variety
45 of tests (such as the compiler itself).
47 Right now we maintain our free list on a per-function basis. It may
48 or may not make sense to maintain the free list for the duration of
51 External code should rely solely upon HIGHEST_SSA_VERSION and the
52 externally defined functions. External code should not know about
53 the details of the free list management.
55 External code should also not assume the version number on nodes is
56 monotonically increasing. We reuse the version number when we
57 reuse an SSA_NAME expression. This helps keep arrays and bitmaps
61 /* Version numbers with special meanings. We start allocating new version
62 numbers after the special ones. */
63 #define UNUSED_NAME_VERSION 0
65 unsigned int ssa_name_nodes_reused
;
66 unsigned int ssa_name_nodes_created
;
68 #define FREE_SSANAMES(fun) (fun)->gimple_df->free_ssanames
69 #define FREE_SSANAMES_QUEUE(fun) (fun)->gimple_df->free_ssanames_queue
72 /* Initialize management of SSA_NAMEs to default SIZE. If SIZE is
76 init_ssanames (struct function
*fn
, int size
)
81 vec_alloc (SSANAMES (fn
), size
);
83 /* Version 0 is special, so reserve the first slot in the table. Though
84 currently unused, we may use version 0 in alias analysis as part of
85 the heuristics used to group aliases when the alias sets are too
88 We use vec::quick_push here because we know that SSA_NAMES has at
89 least 50 elements reserved in it. */
90 SSANAMES (fn
)->quick_push (NULL_TREE
);
91 FREE_SSANAMES (fn
) = NULL
;
92 FREE_SSANAMES_QUEUE (fn
) = NULL
;
94 fn
->gimple_df
->ssa_renaming_needed
= 0;
95 fn
->gimple_df
->rename_vops
= 0;
98 /* Finalize management of SSA_NAMEs. */
101 fini_ssanames (struct function
*fn
)
103 vec_free (SSANAMES (fn
));
104 vec_free (FREE_SSANAMES (fn
));
105 vec_free (FREE_SSANAMES_QUEUE (fn
));
108 /* Dump some simple statistics regarding the re-use of SSA_NAME nodes. */
111 ssanames_print_statistics (void)
113 fprintf (stderr
, "SSA_NAME nodes allocated: %u\n", ssa_name_nodes_created
);
114 fprintf (stderr
, "SSA_NAME nodes reused: %u\n", ssa_name_nodes_reused
);
117 /* Verify the state of the SSA_NAME lists.
119 There must be no duplicates on the free list.
120 Every name on the free list must be marked as on the free list.
121 Any name on the free list must not appear in the IL.
122 No names can be leaked. */
125 verify_ssaname_freelists (struct function
*fun
)
127 if (!gimple_in_ssa_p (fun
))
130 auto_bitmap names_in_il
;
132 /* Walk the entire IL noting every SSA_NAME we see. */
134 FOR_EACH_BB_FN (bb
, fun
)
137 /* First note the result and arguments of PHI nodes. */
138 for (gphi_iterator gsi
= gsi_start_phis (bb
);
142 gphi
*phi
= gsi
.phi ();
143 t
= gimple_phi_result (phi
);
144 bitmap_set_bit (names_in_il
, SSA_NAME_VERSION (t
));
146 for (unsigned int i
= 0; i
< gimple_phi_num_args (phi
); i
++)
148 t
= gimple_phi_arg_def (phi
, i
);
149 if (TREE_CODE (t
) == SSA_NAME
)
150 bitmap_set_bit (names_in_il
, SSA_NAME_VERSION (t
));
154 /* Then note the operands of each statement. */
155 for (gimple_stmt_iterator gsi
= gsi_start_bb (bb
);
160 gimple
*stmt
= gsi_stmt (gsi
);
161 FOR_EACH_SSA_TREE_OPERAND (t
, stmt
, iter
, SSA_OP_ALL_OPERANDS
)
162 bitmap_set_bit (names_in_il
, SSA_NAME_VERSION (t
));
166 /* Now walk the free list noting what we find there and verifying
167 there are no duplicates. */
168 auto_bitmap names_in_freelists
;
169 if (FREE_SSANAMES (fun
))
171 for (unsigned int i
= 0; i
< FREE_SSANAMES (fun
)->length (); i
++)
173 tree t
= (*FREE_SSANAMES (fun
))[i
];
175 /* Verify that the name is marked as being in the free list. */
176 gcc_assert (SSA_NAME_IN_FREE_LIST (t
));
178 /* Verify the name has not already appeared in the free list and
179 note it in the list of names found in the free list. */
180 gcc_assert (!bitmap_bit_p (names_in_freelists
, SSA_NAME_VERSION (t
)));
181 bitmap_set_bit (names_in_freelists
, SSA_NAME_VERSION (t
));
185 /* Similarly for the names in the pending free list. */
186 if (FREE_SSANAMES_QUEUE (fun
))
188 for (unsigned int i
= 0; i
< FREE_SSANAMES_QUEUE (fun
)->length (); i
++)
190 tree t
= (*FREE_SSANAMES_QUEUE (fun
))[i
];
192 /* Verify that the name is marked as being in the free list. */
193 gcc_assert (SSA_NAME_IN_FREE_LIST (t
));
195 /* Verify the name has not already appeared in the free list and
196 note it in the list of names found in the free list. */
197 gcc_assert (!bitmap_bit_p (names_in_freelists
, SSA_NAME_VERSION (t
)));
198 bitmap_set_bit (names_in_freelists
, SSA_NAME_VERSION (t
));
202 /* If any name appears in both the IL and the freelists, then
203 something horrible has happened. */
204 bool intersect_p
= bitmap_intersect_p (names_in_il
, names_in_freelists
);
205 gcc_assert (!intersect_p
);
207 /* Names can be queued up for release if there is an ssa update
208 pending. Pretend we saw them in the IL. */
209 if (names_to_release
)
210 bitmap_ior_into (names_in_il
, names_to_release
);
212 /* Function splitting can "lose" SSA_NAMEs in an effort to ensure that
213 debug/non-debug compilations have the same SSA_NAMEs. So for each
214 lost SSA_NAME, see if it's likely one from that wart. These will always
215 be marked as default definitions. So we loosely assume that anything
216 marked as a default definition isn't leaked by pretending they are
218 for (unsigned int i
= UNUSED_NAME_VERSION
+ 1; i
< num_ssa_names
; i
++)
219 if (ssa_name (i
) && SSA_NAME_IS_DEFAULT_DEF (ssa_name (i
)))
220 bitmap_set_bit (names_in_il
, i
);
224 auto_bitmap all_names
;
225 bitmap_set_range (all_names
, UNUSED_NAME_VERSION
+ 1, num_ssa_names
- 1);
226 bitmap_ior_into (names_in_il
, names_in_freelists
);
228 /* Any name not mentioned in the IL and not in the feelists
230 EXECUTE_IF_AND_COMPL_IN_BITMAP(all_names
, names_in_il
,
231 UNUSED_NAME_VERSION
+ 1, i
, bi
)
232 gcc_assert (!ssa_name (i
));
235 /* Move all SSA_NAMEs from FREE_SSA_NAMES_QUEUE to FREE_SSA_NAMES.
237 We do not, but should have a mode to verify the state of the SSA_NAMEs
238 lists. In particular at this point every name must be in the IL,
239 on the free list or in the queue. Anything else is an error. */
242 flush_ssaname_freelist (void)
244 vec_safe_splice (FREE_SSANAMES (cfun
), FREE_SSANAMES_QUEUE (cfun
));
245 vec_safe_truncate (FREE_SSANAMES_QUEUE (cfun
), 0);
248 /* Return an SSA_NAME node for variable VAR defined in statement STMT
249 in function FN. STMT may be an empty statement for artificial
250 references (e.g., default definitions created when a variable is
251 used without a preceding definition). If VERISON is not zero then
252 allocate the SSA name with that version. */
255 make_ssa_name_fn (struct function
*fn
, tree var
, gimple
*stmt
,
256 unsigned int version
)
261 gcc_assert (VAR_P (var
)
262 || TREE_CODE (var
) == PARM_DECL
263 || TREE_CODE (var
) == RESULT_DECL
264 || (TYPE_P (var
) && is_gimple_reg_type (var
)));
266 /* Get the specified SSA name version. */
269 t
= make_node (SSA_NAME
);
270 SSA_NAME_VERSION (t
) = version
;
271 if (version
>= SSANAMES (fn
)->length ())
272 vec_safe_grow_cleared (SSANAMES (fn
), version
+ 1);
273 gcc_assert ((*SSANAMES (fn
))[version
] == NULL
);
274 (*SSANAMES (fn
))[version
] = t
;
275 ssa_name_nodes_created
++;
277 /* If our free list has an element, then use it. */
278 else if (!vec_safe_is_empty (FREE_SSANAMES (fn
)))
280 t
= FREE_SSANAMES (fn
)->pop ();
281 ssa_name_nodes_reused
++;
283 /* The node was cleared out when we put it on the free list, so
284 there is no need to do so again here. */
285 gcc_assert ((*SSANAMES (fn
))[SSA_NAME_VERSION (t
)] == NULL
);
286 (*SSANAMES (fn
))[SSA_NAME_VERSION (t
)] = t
;
290 t
= make_node (SSA_NAME
);
291 SSA_NAME_VERSION (t
) = SSANAMES (fn
)->length ();
292 vec_safe_push (SSANAMES (fn
), t
);
293 ssa_name_nodes_created
++;
298 TREE_TYPE (t
) = TYPE_MAIN_VARIANT (var
);
299 SET_SSA_NAME_VAR_OR_IDENTIFIER (t
, NULL_TREE
);
303 TREE_TYPE (t
) = TREE_TYPE (var
);
304 SET_SSA_NAME_VAR_OR_IDENTIFIER (t
, var
);
306 SSA_NAME_DEF_STMT (t
) = stmt
;
307 if (POINTER_TYPE_P (TREE_TYPE (t
)))
308 SSA_NAME_PTR_INFO (t
) = NULL
;
310 SSA_NAME_RANGE_INFO (t
) = NULL
;
312 SSA_NAME_IN_FREE_LIST (t
) = 0;
313 SSA_NAME_IS_DEFAULT_DEF (t
) = 0;
314 imm
= &(SSA_NAME_IMM_USE_NODE (t
));
318 imm
->loc
.ssa_name
= t
;
323 /* Store range information RANGE_TYPE, MIN, and MAX to tree ssa_name NAME. */
326 set_range_info (tree name
, enum value_range_type range_type
,
327 const wide_int_ref
&min
, const wide_int_ref
&max
)
329 gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name
)));
330 gcc_assert (range_type
== VR_RANGE
|| range_type
== VR_ANTI_RANGE
);
331 range_info_def
*ri
= SSA_NAME_RANGE_INFO (name
);
332 unsigned int precision
= TYPE_PRECISION (TREE_TYPE (name
));
334 /* Allocate if not available. */
337 size_t size
= (sizeof (range_info_def
)
338 + trailing_wide_ints
<3>::extra_size (precision
));
339 ri
= static_cast<range_info_def
*> (ggc_internal_alloc (size
));
340 ri
->ints
.set_precision (precision
);
341 SSA_NAME_RANGE_INFO (name
) = ri
;
342 ri
->set_nonzero_bits (wi::shwi (-1, precision
));
345 /* Record the range type. */
346 if (SSA_NAME_RANGE_TYPE (name
) != range_type
)
347 SSA_NAME_ANTI_RANGE_P (name
) = (range_type
== VR_ANTI_RANGE
);
349 /* Set the values. */
353 /* If it is a range, try to improve nonzero_bits from the min/max. */
354 if (range_type
== VR_RANGE
)
356 wide_int xorv
= ri
->get_min () ^ ri
->get_max ();
358 xorv
= wi::mask (precision
- wi::clz (xorv
), false, precision
);
359 ri
->set_nonzero_bits (ri
->get_nonzero_bits () & (ri
->get_min () | xorv
));
364 /* Gets range information MIN, MAX and returns enum value_range_type
365 corresponding to tree ssa_name NAME. enum value_range_type returned
366 is used to determine if MIN and MAX are valid values. */
368 enum value_range_type
369 get_range_info (const_tree name
, wide_int
*min
, wide_int
*max
)
371 gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name
)));
372 gcc_assert (min
&& max
);
373 range_info_def
*ri
= SSA_NAME_RANGE_INFO (name
);
375 /* Return VR_VARYING for SSA_NAMEs with NULL RANGE_INFO or SSA_NAMEs
376 with integral types width > 2 * HOST_BITS_PER_WIDE_INT precision. */
377 if (!ri
|| (GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (name
)))
378 > 2 * HOST_BITS_PER_WIDE_INT
))
381 *min
= ri
->get_min ();
382 *max
= ri
->get_max ();
383 return SSA_NAME_RANGE_TYPE (name
);
386 /* Set nonnull attribute to pointer NAME. */
389 set_ptr_nonnull (tree name
)
391 gcc_assert (POINTER_TYPE_P (TREE_TYPE (name
)));
392 struct ptr_info_def
*pi
= get_ptr_info (name
);
396 /* Return nonnull attribute of pointer NAME. */
398 get_ptr_nonnull (const_tree name
)
400 gcc_assert (POINTER_TYPE_P (TREE_TYPE (name
)));
401 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (name
);
404 /* TODO Now pt->null is conservatively set to true in PTA
405 analysis. vrp is the only pass (including ipa-vrp)
406 that clears pt.null via set_ptr_nonull when it knows
407 for sure. PTA will preserves the pt.null value set by VRP.
409 When PTA analysis is improved, pt.anything, pt.nonlocal
410 and pt.escaped may also has to be considered before
411 deciding that pointer cannot point to NULL. */
415 /* Change non-zero bits bitmask of NAME. */
418 set_nonzero_bits (tree name
, const wide_int_ref
&mask
)
420 gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name
)));
421 if (SSA_NAME_RANGE_INFO (name
) == NULL
)
422 set_range_info (name
, VR_RANGE
,
423 TYPE_MIN_VALUE (TREE_TYPE (name
)),
424 TYPE_MAX_VALUE (TREE_TYPE (name
)));
425 range_info_def
*ri
= SSA_NAME_RANGE_INFO (name
);
426 ri
->set_nonzero_bits (mask
);
429 /* Return a widest_int with potentially non-zero bits in SSA_NAME
430 NAME, the constant for INTEGER_CST, or -1 if unknown. */
433 get_nonzero_bits (const_tree name
)
435 if (TREE_CODE (name
) == INTEGER_CST
)
438 unsigned int precision
= TYPE_PRECISION (TREE_TYPE (name
));
439 if (POINTER_TYPE_P (TREE_TYPE (name
)))
441 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (name
);
443 return wi::shwi (-(HOST_WIDE_INT
) pi
->align
444 | (HOST_WIDE_INT
) pi
->misalign
, precision
);
445 return wi::shwi (-1, precision
);
448 range_info_def
*ri
= SSA_NAME_RANGE_INFO (name
);
450 return wi::shwi (-1, precision
);
452 return ri
->get_nonzero_bits ();
455 /* Return TRUE is OP, an SSA_NAME has a range of values [0..1], false
458 This can be because it is a boolean type, any unsigned integral
459 type with a single bit of precision, or has known range of [0..1]
463 ssa_name_has_boolean_range (tree op
)
465 gcc_assert (TREE_CODE (op
) == SSA_NAME
);
467 /* Boolean types always have a range [0..1]. */
468 if (TREE_CODE (TREE_TYPE (op
)) == BOOLEAN_TYPE
)
471 /* An integral type with a single bit of precision. */
472 if (INTEGRAL_TYPE_P (TREE_TYPE (op
))
473 && TYPE_UNSIGNED (TREE_TYPE (op
))
474 && TYPE_PRECISION (TREE_TYPE (op
)) == 1)
477 /* An integral type with more precision, but the object
478 only takes on values [0..1] as determined by VRP
480 if (INTEGRAL_TYPE_P (TREE_TYPE (op
))
481 && (TYPE_PRECISION (TREE_TYPE (op
)) > 1)
482 && wi::eq_p (get_nonzero_bits (op
), 1))
488 /* We no longer need the SSA_NAME expression VAR, release it so that
491 Note it is assumed that no calls to make_ssa_name will be made
492 until all uses of the ssa name are released and that the only
493 use of the SSA_NAME expression is to check its SSA_NAME_VAR. All
494 other fields must be assumed clobbered. */
497 release_ssa_name_fn (struct function
*fn
, tree var
)
502 /* Never release the default definition for a symbol. It's a
503 special SSA name that should always exist once it's created. */
504 if (SSA_NAME_IS_DEFAULT_DEF (var
))
507 /* If VAR has been registered for SSA updating, don't remove it.
508 After update_ssa has run, the name will be released. */
509 if (name_registered_for_update_p (var
))
511 release_ssa_name_after_update_ssa (var
);
515 /* release_ssa_name can be called multiple times on a single SSA_NAME.
516 However, it should only end up on our free list one time. We
517 keep a status bit in the SSA_NAME node itself to indicate it has
518 been put on the free list.
520 Note that once on the freelist you can not reference the SSA_NAME's
521 defining statement. */
522 if (! SSA_NAME_IN_FREE_LIST (var
))
524 tree saved_ssa_name_var
= SSA_NAME_VAR (var
);
525 int saved_ssa_name_version
= SSA_NAME_VERSION (var
);
526 use_operand_p imm
= &(SSA_NAME_IMM_USE_NODE (var
));
528 if (MAY_HAVE_DEBUG_STMTS
)
529 insert_debug_temp_for_var_def (NULL
, var
);
532 verify_imm_links (stderr
, var
);
533 while (imm
->next
!= imm
)
534 delink_imm_use (imm
->next
);
536 (*SSANAMES (fn
))[SSA_NAME_VERSION (var
)] = NULL_TREE
;
537 memset (var
, 0, tree_size (var
));
541 imm
->loc
.ssa_name
= var
;
543 /* First put back the right tree node so that the tree checking
544 macros do not complain. */
545 TREE_SET_CODE (var
, SSA_NAME
);
547 /* Restore the version number. */
548 SSA_NAME_VERSION (var
) = saved_ssa_name_version
;
550 /* Hopefully this can go away once we have the new incremental
551 SSA updating code installed. */
552 SET_SSA_NAME_VAR_OR_IDENTIFIER (var
, saved_ssa_name_var
);
554 /* Note this SSA_NAME is now in the first list. */
555 SSA_NAME_IN_FREE_LIST (var
) = 1;
557 /* And finally queue it so that it will be put on the free list. */
558 vec_safe_push (FREE_SSANAMES_QUEUE (fn
), var
);
562 /* If the alignment of the pointer described by PI is known, return true and
563 store the alignment and the deviation from it into *ALIGNP and *MISALIGNP
564 respectively. Otherwise return false. */
567 get_ptr_info_alignment (struct ptr_info_def
*pi
, unsigned int *alignp
,
568 unsigned int *misalignp
)
573 *misalignp
= pi
->misalign
;
580 /* State that the pointer described by PI has unknown alignment. */
583 mark_ptr_info_alignment_unknown (struct ptr_info_def
*pi
)
589 /* Store the power-of-two byte alignment and the deviation from that
590 alignment of pointer described by PI to ALIOGN and MISALIGN
594 set_ptr_info_alignment (struct ptr_info_def
*pi
, unsigned int align
,
595 unsigned int misalign
)
597 gcc_checking_assert (align
!= 0);
598 gcc_assert ((align
& (align
- 1)) == 0);
599 gcc_assert ((misalign
& ~(align
- 1)) == 0);
602 pi
->misalign
= misalign
;
605 /* If pointer described by PI has known alignment, increase its known
606 misalignment by INCREMENT modulo its current alignment. */
609 adjust_ptr_info_misalignment (struct ptr_info_def
*pi
,
610 unsigned int increment
)
614 pi
->misalign
+= increment
;
615 pi
->misalign
&= (pi
->align
- 1);
619 /* Return the alias information associated with pointer T. It creates a
620 new instance if none existed. */
622 struct ptr_info_def
*
623 get_ptr_info (tree t
)
625 struct ptr_info_def
*pi
;
627 gcc_assert (POINTER_TYPE_P (TREE_TYPE (t
)));
629 pi
= SSA_NAME_PTR_INFO (t
);
632 pi
= ggc_cleared_alloc
<ptr_info_def
> ();
633 pt_solution_reset (&pi
->pt
);
634 mark_ptr_info_alignment_unknown (pi
);
635 SSA_NAME_PTR_INFO (t
) = pi
;
642 /* Creates a new SSA name using the template NAME tobe defined by
643 statement STMT in function FN. */
646 copy_ssa_name_fn (struct function
*fn
, tree name
, gimple
*stmt
)
650 if (SSA_NAME_VAR (name
))
651 new_name
= make_ssa_name_fn (fn
, SSA_NAME_VAR (name
), stmt
);
654 new_name
= make_ssa_name_fn (fn
, TREE_TYPE (name
), stmt
);
655 SET_SSA_NAME_VAR_OR_IDENTIFIER (new_name
, SSA_NAME_IDENTIFIER (name
));
662 /* Creates a duplicate of the ptr_info_def at PTR_INFO for use by
663 the SSA name NAME. */
666 duplicate_ssa_name_ptr_info (tree name
, struct ptr_info_def
*ptr_info
)
668 struct ptr_info_def
*new_ptr_info
;
670 gcc_assert (POINTER_TYPE_P (TREE_TYPE (name
)));
671 gcc_assert (!SSA_NAME_PTR_INFO (name
));
676 new_ptr_info
= ggc_alloc
<ptr_info_def
> ();
677 *new_ptr_info
= *ptr_info
;
679 SSA_NAME_PTR_INFO (name
) = new_ptr_info
;
682 /* Creates a duplicate of the range_info_def at RANGE_INFO of type
683 RANGE_TYPE for use by the SSA name NAME. */
685 duplicate_ssa_name_range_info (tree name
, enum value_range_type range_type
,
686 struct range_info_def
*range_info
)
688 struct range_info_def
*new_range_info
;
690 gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name
)));
691 gcc_assert (!SSA_NAME_RANGE_INFO (name
));
696 unsigned int precision
= TYPE_PRECISION (TREE_TYPE (name
));
697 size_t size
= (sizeof (range_info_def
)
698 + trailing_wide_ints
<3>::extra_size (precision
));
699 new_range_info
= static_cast<range_info_def
*> (ggc_internal_alloc (size
));
700 memcpy (new_range_info
, range_info
, size
);
702 gcc_assert (range_type
== VR_RANGE
|| range_type
== VR_ANTI_RANGE
);
703 SSA_NAME_ANTI_RANGE_P (name
) = (range_type
== VR_ANTI_RANGE
);
704 SSA_NAME_RANGE_INFO (name
) = new_range_info
;
709 /* Creates a duplicate of a ssa name NAME tobe defined by statement STMT
713 duplicate_ssa_name_fn (struct function
*fn
, tree name
, gimple
*stmt
)
715 tree new_name
= copy_ssa_name_fn (fn
, name
, stmt
);
716 if (POINTER_TYPE_P (TREE_TYPE (name
)))
718 struct ptr_info_def
*old_ptr_info
= SSA_NAME_PTR_INFO (name
);
721 duplicate_ssa_name_ptr_info (new_name
, old_ptr_info
);
725 struct range_info_def
*old_range_info
= SSA_NAME_RANGE_INFO (name
);
728 duplicate_ssa_name_range_info (new_name
, SSA_NAME_RANGE_TYPE (name
),
736 /* Reset all flow sensitive data on NAME such as range-info, nonzero
737 bits and alignment. */
740 reset_flow_sensitive_info (tree name
)
742 if (POINTER_TYPE_P (TREE_TYPE (name
)))
744 /* points-to info is not flow-sensitive. */
745 if (SSA_NAME_PTR_INFO (name
))
746 mark_ptr_info_alignment_unknown (SSA_NAME_PTR_INFO (name
));
749 SSA_NAME_RANGE_INFO (name
) = NULL
;
752 /* Clear all flow sensitive data from all statements and PHI definitions
756 reset_flow_sensitive_info_in_bb (basic_block bb
)
758 for (gimple_stmt_iterator gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
);
761 gimple
*stmt
= gsi_stmt (gsi
);
764 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, i
, SSA_OP_DEF
)
765 reset_flow_sensitive_info (op
);
768 for (gphi_iterator gsi
= gsi_start_phis (bb
); !gsi_end_p (gsi
);
771 tree phi_def
= gimple_phi_result (gsi
.phi ());
772 reset_flow_sensitive_info (phi_def
);
776 /* Release all the SSA_NAMEs created by STMT. */
779 release_defs (gimple
*stmt
)
784 FOR_EACH_SSA_TREE_OPERAND (def
, stmt
, iter
, SSA_OP_ALL_DEFS
)
785 if (TREE_CODE (def
) == SSA_NAME
)
786 release_ssa_name (def
);
790 /* Replace the symbol associated with SSA_NAME with SYM. */
793 replace_ssa_name_symbol (tree ssa_name
, tree sym
)
795 SET_SSA_NAME_VAR_OR_IDENTIFIER (ssa_name
, sym
);
796 TREE_TYPE (ssa_name
) = TREE_TYPE (sym
);
799 /* Release the vector of free SSA_NAMEs and compact the vector of SSA_NAMEs
803 release_free_names_and_compact_live_names (function
*fun
)
806 int n
= vec_safe_length (FREE_SSANAMES (fun
));
808 /* Now release the freelist. */
809 vec_free (FREE_SSANAMES (fun
));
811 /* And compact the SSA number space. We make sure to not change the
812 relative order of SSA versions. */
813 for (i
= 1, j
= 1; i
< fun
->gimple_df
->ssa_names
->length (); ++i
)
815 tree name
= ssa_name (i
);
820 SSA_NAME_VERSION (name
) = j
;
821 (*fun
->gimple_df
->ssa_names
)[j
] = name
;
826 fun
->gimple_df
->ssa_names
->truncate (j
);
828 statistics_counter_event (fun
, "SSA names released", n
);
829 statistics_counter_event (fun
, "SSA name holes removed", i
- j
);
831 fprintf (dump_file
, "Released %i names, %.2f%%, removed %i holes\n",
832 n
, n
* 100.0 / num_ssa_names
, i
- j
);
835 /* Return SSA names that are unused to GGC memory and compact the SSA
836 version namespace. This is used to keep footprint of compiler during
837 interprocedural optimization. */
841 const pass_data pass_data_release_ssa_names
=
843 GIMPLE_PASS
, /* type */
844 "release_ssa", /* name */
845 OPTGROUP_NONE
, /* optinfo_flags */
846 TV_TREE_SSA_OTHER
, /* tv_id */
847 PROP_ssa
, /* properties_required */
848 0, /* properties_provided */
849 0, /* properties_destroyed */
850 TODO_remove_unused_locals
, /* todo_flags_start */
851 0, /* todo_flags_finish */
854 class pass_release_ssa_names
: public gimple_opt_pass
857 pass_release_ssa_names (gcc::context
*ctxt
)
858 : gimple_opt_pass (pass_data_release_ssa_names
, ctxt
)
861 /* opt_pass methods: */
862 virtual unsigned int execute (function
*);
864 }; // class pass_release_ssa_names
867 pass_release_ssa_names::execute (function
*fun
)
869 release_free_names_and_compact_live_names (fun
);
876 make_pass_release_ssa_names (gcc::context
*ctxt
)
878 return new pass_release_ssa_names (ctxt
);