1 /* Generic routines for manipulating SSA_NAME expressions
2 Copyright (C) 2003-2015 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 /* Do nothing if we are in RTL format. */
129 FOR_EACH_BB_FN (bb
, fun
)
131 if (bb
->flags
& BB_RTL
)
135 bitmap names_in_il
= BITMAP_ALLOC (NULL
);
137 /* 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 if (TREE_CODE (t
) == SSA_NAME
)
167 bitmap_set_bit (names_in_il
, SSA_NAME_VERSION (t
));
171 /* Now walk the free list noting what we find there and verifying
172 there are no duplicates. */
173 bitmap names_in_freelists
= BITMAP_ALLOC (NULL
);
174 if (FREE_SSANAMES (fun
))
176 for (unsigned int i
= 0; i
< FREE_SSANAMES (fun
)->length (); i
++)
178 tree t
= (*FREE_SSANAMES (fun
))[i
];
180 /* Verify that the name is marked as being in the free list. */
181 gcc_assert (SSA_NAME_IN_FREE_LIST (t
));
183 /* Verify the name has not already appeared in the free list and
184 note it in the list of names found in the free list. */
185 gcc_assert (!bitmap_bit_p (names_in_freelists
, SSA_NAME_VERSION (t
)));
186 bitmap_set_bit (names_in_freelists
, SSA_NAME_VERSION (t
));
190 /* Similarly for the names in the pending free list. */
191 if (FREE_SSANAMES_QUEUE (fun
))
193 for (unsigned int i
= 0; i
< FREE_SSANAMES_QUEUE (fun
)->length (); i
++)
195 tree t
= (*FREE_SSANAMES_QUEUE (fun
))[i
];
197 /* Verify that the name is marked as being in the free list. */
198 gcc_assert (SSA_NAME_IN_FREE_LIST (t
));
200 /* Verify the name has not already appeared in the free list and
201 note it in the list of names found in the free list. */
202 gcc_assert (!bitmap_bit_p (names_in_freelists
, SSA_NAME_VERSION (t
)));
203 bitmap_set_bit (names_in_freelists
, SSA_NAME_VERSION (t
));
207 /* If any name appears in both the IL and the freelists, then
208 something horrible has happened. */
209 bool intersect_p
= bitmap_intersect_p (names_in_il
, names_in_freelists
);
210 gcc_assert (!intersect_p
);
212 /* Names can be queued up for release if there is an ssa update
213 pending. Pretend we saw them in the IL. */
214 if (names_to_release
)
215 bitmap_ior_into (names_in_il
, names_to_release
);
217 /* Function splitting can "lose" SSA_NAMEs in an effort to ensure that
218 debug/non-debug compilations have the same SSA_NAMEs. So for each
219 lost SSA_NAME, see if it's likely one from that wart. These will always
220 be marked as default definitions. So we loosely assume that anything
221 marked as a default definition isn't leaked by pretening they are
223 for (unsigned int i
= UNUSED_NAME_VERSION
+ 1; i
< num_ssa_names
; i
++)
224 if (ssa_name (i
) && SSA_NAME_IS_DEFAULT_DEF (ssa_name (i
)))
225 bitmap_set_bit (names_in_il
, i
);
229 bitmap all_names
= BITMAP_ALLOC (NULL
);
230 bitmap_set_range (all_names
, UNUSED_NAME_VERSION
+ 1, num_ssa_names
- 1);
231 bitmap_ior_into (names_in_il
, names_in_freelists
);
233 /* Any name not mentioned in the IL and not in the feelists
235 EXECUTE_IF_AND_COMPL_IN_BITMAP(all_names
, names_in_il
,
236 UNUSED_NAME_VERSION
+ 1, i
, bi
)
237 gcc_assert (!ssa_name (i
));
239 BITMAP_FREE (all_names
);
240 BITMAP_FREE (names_in_freelists
);
241 BITMAP_FREE (names_in_il
);
244 /* Move all SSA_NAMEs from FREE_SSA_NAMES_QUEUE to FREE_SSA_NAMES.
246 We do not, but should have a mode to verify the state of the SSA_NAMEs
247 lists. In particular at this point every name must be in the IL,
248 on the free list or in the queue. Anything else is an error. */
251 flush_ssaname_freelist (void)
253 vec_safe_splice (FREE_SSANAMES (cfun
), FREE_SSANAMES_QUEUE (cfun
));
254 vec_safe_truncate (FREE_SSANAMES_QUEUE (cfun
), 0);
257 /* Return an SSA_NAME node for variable VAR defined in statement STMT
258 in function FN. STMT may be an empty statement for artificial
259 references (e.g., default definitions created when a variable is
260 used without a preceding definition). */
263 make_ssa_name_fn (struct function
*fn
, tree var
, gimple
*stmt
)
268 gcc_assert (TREE_CODE (var
) == VAR_DECL
269 || TREE_CODE (var
) == PARM_DECL
270 || TREE_CODE (var
) == RESULT_DECL
271 || (TYPE_P (var
) && is_gimple_reg_type (var
)));
273 /* If our free list has an element, then use it. */
274 if (!vec_safe_is_empty (FREE_SSANAMES (fn
)))
276 t
= FREE_SSANAMES (fn
)->pop ();
277 ssa_name_nodes_reused
++;
279 /* The node was cleared out when we put it on the free list, so
280 there is no need to do so again here. */
281 gcc_assert ((*SSANAMES (fn
))[SSA_NAME_VERSION (t
)] == NULL
);
282 (*SSANAMES (fn
))[SSA_NAME_VERSION (t
)] = t
;
286 t
= make_node (SSA_NAME
);
287 SSA_NAME_VERSION (t
) = SSANAMES (fn
)->length ();
288 vec_safe_push (SSANAMES (fn
), t
);
289 ssa_name_nodes_created
++;
295 SET_SSA_NAME_VAR_OR_IDENTIFIER (t
, NULL_TREE
);
299 TREE_TYPE (t
) = TREE_TYPE (var
);
300 SET_SSA_NAME_VAR_OR_IDENTIFIER (t
, var
);
302 SSA_NAME_DEF_STMT (t
) = stmt
;
303 if (POINTER_TYPE_P (TREE_TYPE (t
)))
304 SSA_NAME_PTR_INFO (t
) = NULL
;
306 SSA_NAME_RANGE_INFO (t
) = NULL
;
308 SSA_NAME_IN_FREE_LIST (t
) = 0;
309 SSA_NAME_IS_DEFAULT_DEF (t
) = 0;
310 imm
= &(SSA_NAME_IMM_USE_NODE (t
));
314 imm
->loc
.ssa_name
= t
;
319 /* Store range information RANGE_TYPE, MIN, and MAX to tree ssa_name NAME. */
322 set_range_info (tree name
, enum value_range_type range_type
,
323 const wide_int_ref
&min
, const wide_int_ref
&max
)
325 gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name
)));
326 gcc_assert (range_type
== VR_RANGE
|| range_type
== VR_ANTI_RANGE
);
327 range_info_def
*ri
= SSA_NAME_RANGE_INFO (name
);
328 unsigned int precision
= TYPE_PRECISION (TREE_TYPE (name
));
330 /* Allocate if not available. */
333 size_t size
= (sizeof (range_info_def
)
334 + trailing_wide_ints
<3>::extra_size (precision
));
335 ri
= static_cast<range_info_def
*> (ggc_internal_alloc (size
));
336 ri
->ints
.set_precision (precision
);
337 SSA_NAME_RANGE_INFO (name
) = ri
;
338 ri
->set_nonzero_bits (wi::shwi (-1, precision
));
341 /* Record the range type. */
342 if (SSA_NAME_RANGE_TYPE (name
) != range_type
)
343 SSA_NAME_ANTI_RANGE_P (name
) = (range_type
== VR_ANTI_RANGE
);
345 /* Set the values. */
349 /* If it is a range, try to improve nonzero_bits from the min/max. */
350 if (range_type
== VR_RANGE
)
352 wide_int xorv
= ri
->get_min () ^ ri
->get_max ();
354 xorv
= wi::mask (precision
- wi::clz (xorv
), false, precision
);
355 ri
->set_nonzero_bits (ri
->get_nonzero_bits () & (ri
->get_min () | xorv
));
360 /* Gets range information MIN, MAX and returns enum value_range_type
361 corresponding to tree ssa_name NAME. enum value_range_type returned
362 is used to determine if MIN and MAX are valid values. */
364 enum value_range_type
365 get_range_info (const_tree name
, wide_int
*min
, wide_int
*max
)
367 gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name
)));
368 gcc_assert (min
&& max
);
369 range_info_def
*ri
= SSA_NAME_RANGE_INFO (name
);
371 /* Return VR_VARYING for SSA_NAMEs with NULL RANGE_INFO or SSA_NAMEs
372 with integral types width > 2 * HOST_BITS_PER_WIDE_INT precision. */
373 if (!ri
|| (GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (name
)))
374 > 2 * HOST_BITS_PER_WIDE_INT
))
377 *min
= ri
->get_min ();
378 *max
= ri
->get_max ();
379 return SSA_NAME_RANGE_TYPE (name
);
382 /* Change non-zero bits bitmask of NAME. */
385 set_nonzero_bits (tree name
, const wide_int_ref
&mask
)
387 gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name
)));
388 if (SSA_NAME_RANGE_INFO (name
) == NULL
)
389 set_range_info (name
, VR_RANGE
,
390 TYPE_MIN_VALUE (TREE_TYPE (name
)),
391 TYPE_MAX_VALUE (TREE_TYPE (name
)));
392 range_info_def
*ri
= SSA_NAME_RANGE_INFO (name
);
393 ri
->set_nonzero_bits (mask
);
396 /* Return a widest_int with potentially non-zero bits in SSA_NAME
397 NAME, or -1 if unknown. */
400 get_nonzero_bits (const_tree name
)
402 unsigned int precision
= TYPE_PRECISION (TREE_TYPE (name
));
403 if (POINTER_TYPE_P (TREE_TYPE (name
)))
405 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (name
);
407 return wi::shwi (-(HOST_WIDE_INT
) pi
->align
408 | (HOST_WIDE_INT
) pi
->misalign
, precision
);
409 return wi::shwi (-1, precision
);
412 range_info_def
*ri
= SSA_NAME_RANGE_INFO (name
);
414 return wi::shwi (-1, precision
);
416 return ri
->get_nonzero_bits ();
419 /* We no longer need the SSA_NAME expression VAR, release it so that
422 Note it is assumed that no calls to make_ssa_name will be made
423 until all uses of the ssa name are released and that the only
424 use of the SSA_NAME expression is to check its SSA_NAME_VAR. All
425 other fields must be assumed clobbered. */
428 release_ssa_name_fn (struct function
*fn
, tree var
)
433 /* Never release the default definition for a symbol. It's a
434 special SSA name that should always exist once it's created. */
435 if (SSA_NAME_IS_DEFAULT_DEF (var
))
438 /* If VAR has been registered for SSA updating, don't remove it.
439 After update_ssa has run, the name will be released. */
440 if (name_registered_for_update_p (var
))
442 release_ssa_name_after_update_ssa (var
);
446 /* release_ssa_name can be called multiple times on a single SSA_NAME.
447 However, it should only end up on our free list one time. We
448 keep a status bit in the SSA_NAME node itself to indicate it has
449 been put on the free list.
451 Note that once on the freelist you can not reference the SSA_NAME's
452 defining statement. */
453 if (! SSA_NAME_IN_FREE_LIST (var
))
455 tree saved_ssa_name_var
= SSA_NAME_VAR (var
);
456 int saved_ssa_name_version
= SSA_NAME_VERSION (var
);
457 use_operand_p imm
= &(SSA_NAME_IMM_USE_NODE (var
));
459 if (MAY_HAVE_DEBUG_STMTS
)
460 insert_debug_temp_for_var_def (NULL
, var
);
463 verify_imm_links (stderr
, var
);
464 while (imm
->next
!= imm
)
465 delink_imm_use (imm
->next
);
467 (*SSANAMES (fn
))[SSA_NAME_VERSION (var
)] = NULL_TREE
;
468 memset (var
, 0, tree_size (var
));
472 imm
->loc
.ssa_name
= var
;
474 /* First put back the right tree node so that the tree checking
475 macros do not complain. */
476 TREE_SET_CODE (var
, SSA_NAME
);
478 /* Restore the version number. */
479 SSA_NAME_VERSION (var
) = saved_ssa_name_version
;
481 /* Hopefully this can go away once we have the new incremental
482 SSA updating code installed. */
483 SET_SSA_NAME_VAR_OR_IDENTIFIER (var
, saved_ssa_name_var
);
485 /* Note this SSA_NAME is now in the first list. */
486 SSA_NAME_IN_FREE_LIST (var
) = 1;
488 /* And finally queue it so that it will be put on the free list. */
489 vec_safe_push (FREE_SSANAMES_QUEUE (fn
), var
);
493 /* If the alignment of the pointer described by PI is known, return true and
494 store the alignment and the deviation from it into *ALIGNP and *MISALIGNP
495 respectively. Otherwise return false. */
498 get_ptr_info_alignment (struct ptr_info_def
*pi
, unsigned int *alignp
,
499 unsigned int *misalignp
)
504 *misalignp
= pi
->misalign
;
511 /* State that the pointer described by PI has unknown alignment. */
514 mark_ptr_info_alignment_unknown (struct ptr_info_def
*pi
)
520 /* Store the power-of-two byte alignment and the deviation from that
521 alignment of pointer described by PI to ALIOGN and MISALIGN
525 set_ptr_info_alignment (struct ptr_info_def
*pi
, unsigned int align
,
526 unsigned int misalign
)
528 gcc_checking_assert (align
!= 0);
529 gcc_assert ((align
& (align
- 1)) == 0);
530 gcc_assert ((misalign
& ~(align
- 1)) == 0);
533 pi
->misalign
= misalign
;
536 /* If pointer described by PI has known alignment, increase its known
537 misalignment by INCREMENT modulo its current alignment. */
540 adjust_ptr_info_misalignment (struct ptr_info_def
*pi
,
541 unsigned int increment
)
545 pi
->misalign
+= increment
;
546 pi
->misalign
&= (pi
->align
- 1);
550 /* Return the alias information associated with pointer T. It creates a
551 new instance if none existed. */
553 struct ptr_info_def
*
554 get_ptr_info (tree t
)
556 struct ptr_info_def
*pi
;
558 gcc_assert (POINTER_TYPE_P (TREE_TYPE (t
)));
560 pi
= SSA_NAME_PTR_INFO (t
);
563 pi
= ggc_cleared_alloc
<ptr_info_def
> ();
564 pt_solution_reset (&pi
->pt
);
565 mark_ptr_info_alignment_unknown (pi
);
566 SSA_NAME_PTR_INFO (t
) = pi
;
573 /* Creates a new SSA name using the template NAME tobe defined by
574 statement STMT in function FN. */
577 copy_ssa_name_fn (struct function
*fn
, tree name
, gimple
*stmt
)
581 if (SSA_NAME_VAR (name
))
582 new_name
= make_ssa_name_fn (fn
, SSA_NAME_VAR (name
), stmt
);
585 new_name
= make_ssa_name_fn (fn
, TREE_TYPE (name
), stmt
);
586 SET_SSA_NAME_VAR_OR_IDENTIFIER (new_name
, SSA_NAME_IDENTIFIER (name
));
593 /* Creates a duplicate of the ptr_info_def at PTR_INFO for use by
594 the SSA name NAME. */
597 duplicate_ssa_name_ptr_info (tree name
, struct ptr_info_def
*ptr_info
)
599 struct ptr_info_def
*new_ptr_info
;
601 gcc_assert (POINTER_TYPE_P (TREE_TYPE (name
)));
602 gcc_assert (!SSA_NAME_PTR_INFO (name
));
607 new_ptr_info
= ggc_alloc
<ptr_info_def
> ();
608 *new_ptr_info
= *ptr_info
;
610 SSA_NAME_PTR_INFO (name
) = new_ptr_info
;
613 /* Creates a duplicate of the range_info_def at RANGE_INFO of type
614 RANGE_TYPE for use by the SSA name NAME. */
616 duplicate_ssa_name_range_info (tree name
, enum value_range_type range_type
,
617 struct range_info_def
*range_info
)
619 struct range_info_def
*new_range_info
;
621 gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name
)));
622 gcc_assert (!SSA_NAME_RANGE_INFO (name
));
627 unsigned int precision
= TYPE_PRECISION (TREE_TYPE (name
));
628 size_t size
= (sizeof (range_info_def
)
629 + trailing_wide_ints
<3>::extra_size (precision
));
630 new_range_info
= static_cast<range_info_def
*> (ggc_internal_alloc (size
));
631 memcpy (new_range_info
, range_info
, size
);
633 gcc_assert (range_type
== VR_RANGE
|| range_type
== VR_ANTI_RANGE
);
634 SSA_NAME_ANTI_RANGE_P (name
) = (range_type
== VR_ANTI_RANGE
);
635 SSA_NAME_RANGE_INFO (name
) = new_range_info
;
640 /* Creates a duplicate of a ssa name NAME tobe defined by statement STMT
644 duplicate_ssa_name_fn (struct function
*fn
, tree name
, gimple
*stmt
)
646 tree new_name
= copy_ssa_name_fn (fn
, name
, stmt
);
647 if (POINTER_TYPE_P (TREE_TYPE (name
)))
649 struct ptr_info_def
*old_ptr_info
= SSA_NAME_PTR_INFO (name
);
652 duplicate_ssa_name_ptr_info (new_name
, old_ptr_info
);
656 struct range_info_def
*old_range_info
= SSA_NAME_RANGE_INFO (name
);
659 duplicate_ssa_name_range_info (new_name
, SSA_NAME_RANGE_TYPE (name
),
667 /* Reset all flow sensitive data on NAME such as range-info, nonzero
668 bits and alignment. */
671 reset_flow_sensitive_info (tree name
)
673 if (POINTER_TYPE_P (TREE_TYPE (name
)))
675 /* points-to info is not flow-sensitive. */
676 if (SSA_NAME_PTR_INFO (name
))
677 mark_ptr_info_alignment_unknown (SSA_NAME_PTR_INFO (name
));
680 SSA_NAME_RANGE_INFO (name
) = NULL
;
683 /* Clear all flow sensitive data from all statements and PHI definitions
687 reset_flow_sensitive_info_in_bb (basic_block bb
)
689 for (gimple_stmt_iterator gsi
= gsi_start_bb (bb
); !gsi_end_p (gsi
);
692 gimple
*stmt
= gsi_stmt (gsi
);
695 FOR_EACH_SSA_TREE_OPERAND (op
, stmt
, i
, SSA_OP_DEF
)
696 reset_flow_sensitive_info (op
);
699 for (gphi_iterator gsi
= gsi_start_phis (bb
); !gsi_end_p (gsi
);
702 tree phi_def
= gimple_phi_result (gsi
.phi ());
703 reset_flow_sensitive_info (phi_def
);
707 /* Release all the SSA_NAMEs created by STMT. */
710 release_defs (gimple
*stmt
)
715 /* Make sure that we are in SSA. Otherwise, operand cache may point
717 gcc_assert (gimple_in_ssa_p (cfun
));
719 FOR_EACH_SSA_TREE_OPERAND (def
, stmt
, iter
, SSA_OP_ALL_DEFS
)
720 if (TREE_CODE (def
) == SSA_NAME
)
721 release_ssa_name (def
);
725 /* Replace the symbol associated with SSA_NAME with SYM. */
728 replace_ssa_name_symbol (tree ssa_name
, tree sym
)
730 SET_SSA_NAME_VAR_OR_IDENTIFIER (ssa_name
, sym
);
731 TREE_TYPE (ssa_name
) = TREE_TYPE (sym
);
734 /* Release the vector of free SSA_NAMEs and compact the the
735 vector of SSA_NAMEs that are live. */
738 release_free_names_and_compact_live_names (function
*fun
)
741 int n
= vec_safe_length (FREE_SSANAMES (fun
));
743 /* Now release the freelist. */
744 vec_free (FREE_SSANAMES (fun
));
746 /* And compact the SSA number space. We make sure to not change the
747 relative order of SSA versions. */
748 for (i
= 1, j
= 1; i
< fun
->gimple_df
->ssa_names
->length (); ++i
)
750 tree name
= ssa_name (i
);
755 SSA_NAME_VERSION (name
) = j
;
756 (*fun
->gimple_df
->ssa_names
)[j
] = name
;
761 fun
->gimple_df
->ssa_names
->truncate (j
);
763 statistics_counter_event (fun
, "SSA names released", n
);
764 statistics_counter_event (fun
, "SSA name holes removed", i
- j
);
766 fprintf (dump_file
, "Released %i names, %.2f%%, removed %i holes\n",
767 n
, n
* 100.0 / num_ssa_names
, i
- j
);
770 /* Return SSA names that are unused to GGC memory and compact the SSA
771 version namespace. This is used to keep footprint of compiler during
772 interprocedural optimization. */
776 const pass_data pass_data_release_ssa_names
=
778 GIMPLE_PASS
, /* type */
779 "release_ssa", /* name */
780 OPTGROUP_NONE
, /* optinfo_flags */
781 TV_TREE_SSA_OTHER
, /* tv_id */
782 PROP_ssa
, /* properties_required */
783 0, /* properties_provided */
784 0, /* properties_destroyed */
785 TODO_remove_unused_locals
, /* todo_flags_start */
786 0, /* todo_flags_finish */
789 class pass_release_ssa_names
: public gimple_opt_pass
792 pass_release_ssa_names (gcc::context
*ctxt
)
793 : gimple_opt_pass (pass_data_release_ssa_names
, ctxt
)
796 /* opt_pass methods: */
797 virtual unsigned int execute (function
*);
799 }; // class pass_release_ssa_names
802 pass_release_ssa_names::execute (function
*fun
)
804 release_free_names_and_compact_live_names (fun
);
811 make_pass_release_ssa_names (gcc::context
*ctxt
)
813 return new pass_release_ssa_names (ctxt
);