Makefile.in (OBJC-common): Add tree-ssa-threadupdate.c
[gcc.git] / gcc / tree-flow.h
1 /* Data and Control Flow Analysis for Trees.
2 Copyright (C) 2001, 2003, 2004 Free Software Foundation, Inc.
3 Contributed by Diego Novillo <dnovillo@redhat.com>
4
5 This file is part of GCC.
6
7 GCC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
10 any later version.
11
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to
19 the Free Software Foundation, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
21
22 #ifndef _TREE_FLOW_H
23 #define _TREE_FLOW_H 1
24
25 #include "bitmap.h"
26 #include "hard-reg-set.h"
27 #include "basic-block.h"
28 #include "hashtab.h"
29 #include "tree-gimple.h"
30 #include "tree-ssa-operands.h"
31
32 /* Forward declare structures for the garbage collector GTY markers. */
33 #ifndef GCC_BASIC_BLOCK_H
34 struct edge_def;
35 typedef struct edge_def *edge;
36 struct basic_block_def;
37 typedef struct basic_block_def *basic_block;
38 #endif
39
40 /*---------------------------------------------------------------------------
41 Attributes for SSA_NAMEs.
42
43 NOTE: These structures are stored in struct tree_ssa_name
44 but are only used by the tree optimizers, so it makes better sense
45 to declare them here to avoid recompiling unrelated files when
46 making changes.
47 ---------------------------------------------------------------------------*/
48
49 /* Aliasing information for SSA_NAMEs representing pointer variables. */
50 struct ptr_info_def GTY(())
51 {
52 /* Nonzero if points-to analysis couldn't determine where this pointer
53 is pointing to. */
54 unsigned int pt_anything : 1;
55
56 /* Nonzero if this pointer is the result of a call to malloc. */
57 unsigned int pt_malloc : 1;
58
59 /* Nonzero if the value of this pointer escapes the current function. */
60 unsigned int value_escapes_p : 1;
61
62 /* Nonzero if this pointer is dereferenced. */
63 unsigned int is_dereferenced : 1;
64
65 /* Set of variables that this pointer may point to. */
66 bitmap pt_vars;
67
68 /* If this pointer has been dereferenced, and points-to information is
69 more precise than type-based aliasing, indirect references to this
70 pointer will be represented by this memory tag, instead of the type
71 tag computed by TBAA. */
72 tree name_mem_tag;
73 };
74
75
76 /*---------------------------------------------------------------------------
77 Tree annotations stored in tree_common.ann
78 ---------------------------------------------------------------------------*/
79 enum tree_ann_type { TREE_ANN_COMMON, VAR_ANN, STMT_ANN };
80
81 struct tree_ann_common_d GTY(())
82 {
83 /* Annotation type. */
84 enum tree_ann_type type;
85
86 /* Auxiliary info specific to a pass. At all times, this
87 should either point to valid data or be NULL. */
88 PTR GTY ((skip (""))) aux;
89
90 /* The value handle for this expression. Used by GVN-PRE. */
91 tree GTY((skip)) value_handle;
92 };
93
94 /* It is advantageous to avoid things like life analysis for variables which
95 do not need PHI nodes. This enum describes whether or not a particular
96 variable may need a PHI node. */
97
98 enum need_phi_state {
99 /* This is the default. If we are still in this state after finding
100 all the definition and use sites, then we will assume the variable
101 needs PHI nodes. This is probably an overly conservative assumption. */
102 NEED_PHI_STATE_UNKNOWN,
103
104 /* This state indicates that we have seen one or more sets of the
105 variable in a single basic block and that the sets dominate all
106 uses seen so far. If after finding all definition and use sites
107 we are still in this state, then the variable does not need any
108 PHI nodes. */
109 NEED_PHI_STATE_NO,
110
111 /* This state indicates that we have either seen multiple definitions of
112 the variable in multiple blocks, or that we encountered a use in a
113 block that was not dominated by the block containing the set(s) of
114 this variable. This variable is assumed to need PHI nodes. */
115 NEED_PHI_STATE_MAYBE
116 };
117
118
119 /* When computing aliasing information, we represent the memory pointed-to
120 by pointers with artificial variables called "memory tags" (MT). There
121 are two kinds of tags: type and name. Type tags (TMT) are used in
122 type-based alias analysis, they represent all the pointed-to locations
123 and variables of the same alias set class. Name tags (NMT) are used in
124 flow-sensitive points-to alias analysis, they represent the variables
125 and memory locations pointed-to by a specific SSA_NAME pointer. */
126 enum mem_tag_kind {
127 /* This variable is not a memory tag. */
128 NOT_A_TAG,
129
130 /* This variable is a type memory tag (TMT). */
131 TYPE_TAG,
132
133 /* This variable is a name memory tag (NMT). */
134 NAME_TAG
135 };
136
137 struct var_ann_d GTY(())
138 {
139 struct tree_ann_common_d common;
140
141 /* Used by the out of SSA pass to determine whether this variable has
142 been seen yet or not. */
143 unsigned out_of_ssa_tag : 1;
144
145 /* Used when building root_var structures in tree_ssa_live.[ch]. */
146 unsigned root_var_processed : 1;
147
148 /* If nonzero, this variable is a memory tag. */
149 ENUM_BITFIELD (mem_tag_kind) mem_tag_kind : 2;
150
151 /* Nonzero if this variable is an alias tag that represents references to
152 other variables (i.e., this variable appears in the MAY_ALIASES array
153 of other variables). */
154 unsigned is_alias_tag : 1;
155
156 /* Nonzero if this variable was used after SSA optimizations were
157 applied. We set this when translating out of SSA form. */
158 unsigned used : 1;
159
160 /* This field indicates whether or not the variable may need PHI nodes.
161 See the enum's definition for more detailed information about the
162 states. */
163 ENUM_BITFIELD (need_phi_state) need_phi_state : 2;
164
165 /* An artificial variable representing the memory location pointed-to by
166 all the pointers that TBAA (type-based alias analysis) considers
167 to be aliased. If the variable is not a pointer or if it is never
168 dereferenced, this must be NULL. */
169 tree type_mem_tag;
170
171 /* Variables that may alias this variable. */
172 varray_type may_aliases;
173
174 /* Unique ID of this variable. */
175 size_t uid;
176
177 /* Used when going out of SSA form to indicate which partition this
178 variable represents storage for. */
179 unsigned partition;
180
181 /* Used by the root-var object in tree-ssa-live.[ch]. */
182 unsigned root_index;
183
184 /* Default definition for this symbol. If this field is not NULL, it
185 means that the first reference to this variable in the function is a
186 USE or a VUSE. In those cases, the SSA renamer creates an SSA name
187 for this variable with an empty defining statement. */
188 tree default_def;
189
190 /* During into-ssa and the dominator optimizer, this field holds the
191 current version of this variable (an SSA_NAME).
192
193 This was previously two varrays (one in into-ssa the other in the
194 dominator optimizer). That is wasteful, particularly since the
195 dominator optimizer calls into-ssa resulting in having two varrays
196 live at the same time and this can happen for each call to the
197 dominator optimizer. */
198 tree current_def;
199 };
200
201
202 struct dataflow_d GTY(())
203 {
204 /* Immediate uses. This is a list of all the statements and PHI nodes
205 that are immediately reached by the definitions made in this
206 statement. */
207 varray_type immediate_uses;
208
209 /* Use this array for very small numbers of uses instead of the varray. */
210 tree uses[2];
211
212 /* Reached uses. This is a list of all the possible program statements
213 that may be reached directly or indirectly by definitions made in this
214 statement. Notice that this is a superset of IMMEDIATE_USES.
215 For instance, given the following piece of code:
216
217 1 a1 = 10;
218 2 if (a1 > 3)
219 3 a2 = a1 + 5;
220 4 a3 = PHI (a1, a2)
221 5 b1 = a3 - 2;
222
223 IMMEDIATE_USES for statement #1 are all those statements that use a1
224 directly (i.e., #2, #3 and #4). REACHED_USES for statement #1 also
225 includes statement #5 because 'a1' could reach 'a3' via the PHI node
226 at statement #4. The set of REACHED_USES is then the transitive
227 closure over all the PHI nodes in the IMMEDIATE_USES set. */
228
229 /* Reaching definitions. Similarly to REACHED_USES, the set
230 REACHING_DEFS is the set of all the statements that make definitions
231 that may reach this statement. Notice that we don't need to have a
232 similar entry for immediate definitions, as these are represented by
233 the SSA_NAME nodes themselves (each SSA_NAME node contains a pointer
234 to the statement that makes that definition). */
235 };
236
237 typedef struct dataflow_d *dataflow_t;
238
239
240 struct stmt_ann_d GTY(())
241 {
242 struct tree_ann_common_d common;
243
244 /* Nonzero if the statement has been modified (meaning that the operands
245 need to be scanned again). */
246 unsigned modified : 1;
247
248 /* Nonzero if the statement is in the CCP worklist and has not been
249 "cancelled". If we ever need to use this bit outside CCP, then
250 it should be renamed. */
251 unsigned in_ccp_worklist: 1;
252
253 /* Nonzero if the statement makes aliased loads. */
254 unsigned makes_aliased_loads : 1;
255
256 /* Nonzero if the statement makes aliased stores. */
257 unsigned makes_aliased_stores : 1;
258
259 /* Nonzero if the statement makes references to volatile storage. */
260 unsigned has_volatile_ops : 1;
261
262 /* Nonzero if the statement makes a function call that may clobber global
263 and local addressable variables. */
264 unsigned makes_clobbering_call : 1;
265
266 /* Basic block that contains this statement. */
267 basic_block GTY ((skip (""))) bb;
268
269 /* Statement operands. */
270 struct def_optype_d * GTY (()) def_ops;
271 struct use_optype_d * GTY (()) use_ops;
272
273 /* Virtual operands (V_MAY_DEF, VUSE, and V_MUST_DEF). */
274 struct v_may_def_optype_d * GTY (()) v_may_def_ops;
275 struct vuse_optype_d * GTY (()) vuse_ops;
276 struct v_must_def_optype_d * GTY (()) v_must_def_ops;
277
278 /* Dataflow information. */
279 dataflow_t df;
280
281 /* Set of variables that have had their address taken in the statement. */
282 bitmap addresses_taken;
283
284 /* Unique identifier for this statement. These ID's are to be created
285 by each pass on an as-needed basis in any order convenient for the
286 pass which needs statement UIDs. */
287 unsigned int uid;
288 };
289
290 union tree_ann_d GTY((desc ("ann_type ((tree_ann_t)&%h)")))
291 {
292 struct tree_ann_common_d GTY((tag ("TREE_ANN_COMMON"))) common;
293 struct var_ann_d GTY((tag ("VAR_ANN"))) decl;
294 struct stmt_ann_d GTY((tag ("STMT_ANN"))) stmt;
295 };
296
297 typedef union tree_ann_d *tree_ann_t;
298 typedef struct var_ann_d *var_ann_t;
299 typedef struct stmt_ann_d *stmt_ann_t;
300
301 static inline tree_ann_t tree_ann (tree);
302 static inline tree_ann_t get_tree_ann (tree);
303 static inline var_ann_t var_ann (tree);
304 static inline var_ann_t get_var_ann (tree);
305 static inline stmt_ann_t stmt_ann (tree);
306 static inline stmt_ann_t get_stmt_ann (tree);
307 static inline enum tree_ann_type ann_type (tree_ann_t);
308 static inline basic_block bb_for_stmt (tree);
309 extern void set_bb_for_stmt (tree, basic_block);
310 static inline void modify_stmt (tree);
311 static inline void unmodify_stmt (tree);
312 static inline bool stmt_modified_p (tree);
313 static inline varray_type may_aliases (tree);
314 static inline int get_lineno (tree);
315 static inline const char *get_filename (tree);
316 static inline bool is_exec_stmt (tree);
317 static inline bool is_label_stmt (tree);
318 static inline v_may_def_optype get_v_may_def_ops (stmt_ann_t);
319 static inline vuse_optype get_vuse_ops (stmt_ann_t);
320 static inline use_optype get_use_ops (stmt_ann_t);
321 static inline def_optype get_def_ops (stmt_ann_t);
322 static inline bitmap addresses_taken (tree);
323 static inline int num_immediate_uses (dataflow_t);
324 static inline tree immediate_use (dataflow_t, int);
325 static inline dataflow_t get_immediate_uses (tree);
326 static inline void set_default_def (tree, tree);
327 static inline tree default_def (tree);
328
329 /*---------------------------------------------------------------------------
330 Structure representing predictions in tree level.
331 ---------------------------------------------------------------------------*/
332 struct edge_prediction GTY((chain_next ("%h.next")))
333 {
334 struct edge_prediction *next;
335 edge edge;
336 enum br_predictor predictor;
337 int probability;
338 };
339
340 /*---------------------------------------------------------------------------
341 Block annotations stored in basic_block.tree_annotations
342 ---------------------------------------------------------------------------*/
343 struct bb_ann_d GTY(())
344 {
345 /* Chain of PHI nodes for this block. */
346 tree phi_nodes;
347
348 /* Number of predecessors for this block. This is only valid during
349 SSA rewriting. It is not maintained after conversion into SSA form. */
350 int num_preds;
351
352 /* Nonzero if this block is forwardable during cfg cleanups. This is also
353 used to detect loops during cfg cleanups. */
354 unsigned forwardable: 1;
355
356 /* Nonzero if this block contains an escape point (see is_escape_site). */
357 unsigned has_escape_site : 1;
358
359 /* Nonzero if one or more incoming edges to this block should be threaded
360 to an outgoing edge of this block. */
361 unsigned incoming_edge_threaded : 1;
362
363 struct edge_prediction *predictions;
364 };
365
366 typedef struct bb_ann_d *bb_ann_t;
367
368 /* Accessors for basic block annotations. */
369 static inline bb_ann_t bb_ann (basic_block);
370 static inline tree phi_nodes (basic_block);
371 static inline void set_phi_nodes (basic_block, tree);
372
373 /*---------------------------------------------------------------------------
374 Global declarations
375 ---------------------------------------------------------------------------*/
376 /* Array of all variables referenced in the function. */
377 extern GTY(()) varray_type referenced_vars;
378
379 #define num_referenced_vars VARRAY_ACTIVE_SIZE (referenced_vars)
380 #define referenced_var(i) VARRAY_TREE (referenced_vars, i)
381
382 /* Array of all SSA_NAMEs used in the function. */
383 extern GTY(()) varray_type ssa_names;
384
385 #define num_ssa_names VARRAY_ACTIVE_SIZE (ssa_names)
386 #define ssa_name(i) VARRAY_TREE (ssa_names, i)
387
388 /* Artificial variable used to model the effects of function calls. */
389 extern GTY(()) tree global_var;
390
391 /* Call clobbered variables in the function. If bit I is set, then
392 REFERENCED_VARS (I) is call-clobbered. */
393 extern bitmap call_clobbered_vars;
394
395 /* Addressable variables in the function. If bit I is set, then
396 REFERENCED_VARS (I) has had its address taken. */
397 extern bitmap addressable_vars;
398
399 /* 'true' after aliases have been computed (see compute_may_aliases). */
400 extern bool aliases_computed_p;
401
402 /* Macros for showing usage statistics. */
403 #define SCALE(x) ((unsigned long) ((x) < 1024*10 \
404 ? (x) \
405 : ((x) < 1024*1024*10 \
406 ? (x) / 1024 \
407 : (x) / (1024*1024))))
408
409 #define LABEL(x) ((x) < 1024*10 ? 'b' : ((x) < 1024*1024*10 ? 'k' : 'M'))
410
411 #define PERCENT(x,y) ((float)(x) * 100.0 / (float)(y))
412
413
414 /*---------------------------------------------------------------------------
415 Block iterators
416 ---------------------------------------------------------------------------*/
417
418 typedef struct {
419 tree_stmt_iterator tsi;
420 basic_block bb;
421 } block_stmt_iterator;
422
423 static inline block_stmt_iterator bsi_start (basic_block);
424 static inline block_stmt_iterator bsi_last (basic_block);
425 static inline block_stmt_iterator bsi_after_labels (basic_block);
426 static inline bool bsi_end_p (block_stmt_iterator);
427 static inline void bsi_next (block_stmt_iterator *);
428 static inline void bsi_prev (block_stmt_iterator *);
429 static inline tree bsi_stmt (block_stmt_iterator);
430 static inline tree * bsi_stmt_ptr (block_stmt_iterator);
431
432 extern void bsi_remove (block_stmt_iterator *);
433 extern void bsi_move_before (block_stmt_iterator *, block_stmt_iterator *);
434 extern void bsi_move_after (block_stmt_iterator *, block_stmt_iterator *);
435 extern void bsi_move_to_bb_end (block_stmt_iterator *, basic_block);
436
437 enum bsi_iterator_update
438 {
439 /* Note that these are intentionally in the same order as TSI_FOO. They
440 mean exactly the same as their TSI_* counterparts. */
441 BSI_NEW_STMT,
442 BSI_SAME_STMT,
443 BSI_CHAIN_START,
444 BSI_CHAIN_END,
445 BSI_CONTINUE_LINKING
446 };
447
448 extern void bsi_insert_before (block_stmt_iterator *, tree,
449 enum bsi_iterator_update);
450 extern void bsi_insert_after (block_stmt_iterator *, tree,
451 enum bsi_iterator_update);
452
453 extern void bsi_replace (const block_stmt_iterator *, tree, bool);
454
455 /*---------------------------------------------------------------------------
456 Function prototypes
457 ---------------------------------------------------------------------------*/
458 /* In tree-cfg.c */
459
460 /* Location to track pending stmt for edge insertion. */
461 #define PENDING_STMT(e) ((e)->insns.t)
462
463 extern void delete_tree_cfg_annotations (void);
464 extern void disband_implicit_edges (void);
465 extern bool stmt_ends_bb_p (tree);
466 extern bool is_ctrl_stmt (tree);
467 extern bool is_ctrl_altering_stmt (tree);
468 extern bool computed_goto_p (tree);
469 extern bool simple_goto_p (tree);
470 extern void tree_dump_bb (basic_block, FILE *, int);
471 extern void debug_tree_bb (basic_block);
472 extern basic_block debug_tree_bb_n (int);
473 extern void dump_tree_cfg (FILE *, int);
474 extern void debug_tree_cfg (int);
475 extern void dump_cfg_stats (FILE *);
476 extern void debug_cfg_stats (void);
477 extern void debug_loop_ir (void);
478 extern void print_loop_ir (FILE *);
479 extern void cleanup_dead_labels (void);
480 extern void group_case_labels (void);
481 extern bool cleanup_tree_cfg (void);
482 extern tree first_stmt (basic_block);
483 extern tree last_stmt (basic_block);
484 extern tree *last_stmt_ptr (basic_block);
485 extern tree last_and_only_stmt (basic_block);
486 extern edge find_taken_edge (basic_block, tree);
487 extern void cfg_remove_useless_stmts (void);
488 extern edge thread_edge (edge, basic_block);
489 extern basic_block label_to_block (tree);
490 extern void tree_optimize_tail_calls (bool, enum tree_dump_index);
491 extern edge tree_block_forwards_to (basic_block bb);
492 extern void bsi_insert_on_edge (edge, tree);
493 extern void bsi_commit_edge_inserts (int *);
494 extern void notice_special_calls (tree);
495 extern void clear_special_calls (void);
496 extern void compute_dominance_frontiers (bitmap *);
497 extern void verify_stmts (void);
498 extern tree tree_block_label (basic_block bb);
499 extern void extract_true_false_edges_from_block (basic_block, edge *, edge *);
500 extern bool tree_purge_dead_eh_edges (basic_block);
501 extern bool tree_purge_all_dead_eh_edges (bitmap);
502 extern tree gimplify_val (block_stmt_iterator *, tree, tree);
503 extern tree gimplify_build1 (block_stmt_iterator *, enum tree_code,
504 tree, tree);
505 extern tree gimplify_build2 (block_stmt_iterator *, enum tree_code,
506 tree, tree, tree);
507 extern tree gimplify_build3 (block_stmt_iterator *, enum tree_code,
508 tree, tree, tree, tree);
509
510 /* In tree-pretty-print.c. */
511 extern void dump_generic_bb (FILE *, basic_block, int, int);
512
513 /* In tree-dfa.c */
514 extern var_ann_t create_var_ann (tree);
515 extern stmt_ann_t create_stmt_ann (tree);
516 extern tree_ann_t create_tree_ann (tree);
517 extern tree create_phi_node (tree, basic_block);
518 extern void add_phi_arg (tree *, tree, edge);
519 extern void remove_phi_arg (tree, basic_block);
520 extern void remove_phi_arg_num (tree, int);
521 extern void remove_phi_node (tree, tree, basic_block);
522 extern void remove_all_phi_nodes_for (bitmap);
523 extern void dump_dfa_stats (FILE *);
524 extern void debug_dfa_stats (void);
525 extern void debug_referenced_vars (void);
526 extern void dump_referenced_vars (FILE *);
527 extern void dump_variable (FILE *, tree);
528 extern void debug_variable (tree);
529 extern void dump_immediate_uses (FILE *);
530 extern void debug_immediate_uses (void);
531 extern void dump_immediate_uses_for (FILE *, tree);
532 extern void debug_immediate_uses_for (tree);
533 extern void compute_immediate_uses (int, bool (*)(tree));
534 extern void free_df (void);
535 extern tree get_virtual_var (tree);
536 extern void add_referenced_tmp_var (tree var);
537 extern void mark_new_vars_to_rename (tree, bitmap);
538 extern void redirect_immediate_uses (tree, tree);
539 extern tree make_rename_temp (tree, const char *);
540
541 /* Flags used when computing reaching definitions and reached uses. */
542 #define TDFA_USE_OPS 1 << 0
543 #define TDFA_USE_VOPS 1 << 1
544
545 /* In gimple-low.c */
546 struct lower_data;
547 extern void lower_stmt_body (tree, struct lower_data *);
548 extern void record_vars (tree);
549 extern bool block_may_fallthru (tree block);
550
551 /* In tree-ssa-alias.c */
552 extern void dump_may_aliases_for (FILE *, tree);
553 extern void debug_may_aliases_for (tree);
554 extern void dump_alias_info (FILE *);
555 extern void debug_alias_info (void);
556 extern void dump_points_to_info (FILE *);
557 extern void debug_points_to_info (void);
558 extern void dump_points_to_info_for (FILE *, tree);
559 extern void debug_points_to_info_for (tree);
560 extern bool may_be_aliased (tree);
561
562 /* Call-back function for walk_use_def_chains(). At each reaching
563 definition, a function with this prototype is called. */
564 typedef bool (*walk_use_def_chains_fn) (tree, tree, void *);
565
566 /* In tree-ssa.c */
567 extern void init_tree_ssa (void);
568 extern void dump_reaching_defs (FILE *);
569 extern void debug_reaching_defs (void);
570 extern void dump_tree_ssa (FILE *);
571 extern void debug_tree_ssa (void);
572 extern void debug_def_blocks (void);
573 extern void dump_tree_ssa_stats (FILE *);
574 extern void debug_tree_ssa_stats (void);
575 extern void ssa_remove_edge (edge);
576 extern edge ssa_redirect_edge (edge, basic_block);
577 extern bool tree_ssa_useless_type_conversion (tree);
578 extern bool tree_ssa_useless_type_conversion_1 (tree, tree);
579 extern void verify_ssa (void);
580 extern void delete_tree_ssa (void);
581 extern void register_new_def (tree, varray_type *);
582 extern void walk_use_def_chains (tree, walk_use_def_chains_fn, void *, bool);
583 extern void kill_redundant_phi_nodes (void);
584
585 /* In tree-into-ssa.c */
586 extern void rewrite_into_ssa (bool);
587 extern void rewrite_ssa_into_ssa (void);
588
589 void compute_global_livein (bitmap, bitmap);
590 tree duplicate_ssa_name (tree, tree);
591
592 /* In tree-ssa-ccp.c */
593 bool fold_stmt (tree *);
594 tree widen_bitfield (tree, tree, tree);
595
596 /* In tree-ssa-dom.c */
597 extern void dump_dominator_optimization_stats (FILE *);
598 extern void debug_dominator_optimization_stats (void);
599
600 /* In tree-ssa-copy.c */
601 extern void propagate_value (use_operand_p, tree);
602 extern void propagate_tree_value (tree *, tree);
603 extern void replace_exp (use_operand_p, tree);
604 extern bool may_propagate_copy (tree, tree);
605
606 /* Description of number of iterations of a loop. All the expressions inside
607 the structure can be evaluated at the end of the loop's preheader
608 (and due to ssa form, also anywhere inside the body of the loop). */
609
610 struct tree_niter_desc
611 {
612 tree assumptions; /* The boolean expression. If this expression evalutes
613 to false, then the other fields in this structure
614 should not be used; there is no guarantee that they
615 will be correct. */
616 tree may_be_zero; /* The booleand expression. If it evaluates to true,
617 the loop will exit in the first iteration (i.e.
618 its latch will not be executed), even if the niter
619 field says otherwise. */
620 tree niter; /* The expression giving the number of iterations of
621 a loop (provided that assumptions == true and
622 may_be_zero == false), more precisely the number
623 of executions of the latch of the loop. */
624 tree additional_info; /* The boolean expression. Sometimes we use additional
625 knowledge to simplify the other expressions
626 contained in this structure (for example the
627 knowledge about value ranges of operands on entry to
628 the loop). If this is a case, conjunction of such
629 condition is stored in this field, so that we do not
630 lose the information: for example if may_be_zero
631 is (n <= 0) and niter is (unsigned) n, we know
632 that the number of iterations is at most
633 MAX_SIGNED_INT. However if the (n <= 0) assumption
634 is eliminated (by looking at the guard on entry of
635 the loop), then the information would be lost. */
636 };
637
638 /* In tree-ssa-loop*.c */
639
640 void tree_ssa_lim (struct loops *);
641
642 void number_of_iterations_cond (tree, tree, tree, enum tree_code, tree, tree,
643 struct tree_niter_desc *);
644 bool number_of_iterations_exit (struct loop *, edge,
645 struct tree_niter_desc *niter);
646 tree loop_niter_by_eval (struct loop *, edge);
647 tree find_loop_niter_by_eval (struct loop *, edge *);
648 void estimate_numbers_of_iterations (struct loops *);
649 tree can_count_iv_in_wider_type (struct loop *, tree, tree, tree, tree);
650 void free_numbers_of_iterations_estimates (struct loops *);
651 void rewrite_into_loop_closed_ssa (void);
652 void verify_loop_closed_ssa (void);
653 void loop_commit_inserts (void);
654 bool for_each_index (tree *, bool (*) (tree, tree *, void *), void *);
655
656 /* In tree-flow-inline.h */
657 static inline int phi_arg_from_edge (tree, edge);
658 static inline bool is_call_clobbered (tree);
659 static inline void mark_call_clobbered (tree);
660 static inline void set_is_used (tree);
661
662 /* In tree-eh.c */
663 extern void make_eh_edges (tree);
664 extern bool tree_could_trap_p (tree);
665 extern bool tree_could_throw_p (tree);
666 extern bool tree_can_throw_internal (tree);
667 extern bool tree_can_throw_external (tree);
668 extern int lookup_stmt_eh_region (tree);
669 extern void add_stmt_to_eh_region (tree, int);
670 extern bool remove_stmt_from_eh_region (tree);
671 extern bool maybe_clean_eh_stmt (tree);
672
673 /* In tree-ssa-pre.c */
674 void add_to_value (tree, tree);
675 void debug_value_expressions (tree);
676 void print_value_expressions (FILE *, tree);
677
678
679 /* In tree-vn.c */
680 bool expressions_equal_p (tree, tree);
681 tree get_value_handle (tree);
682 hashval_t vn_compute (tree, hashval_t, vuse_optype);
683 tree vn_lookup_or_add (tree, vuse_optype);
684 void vn_add (tree, tree, vuse_optype);
685 tree vn_lookup (tree, vuse_optype);
686 void vn_init (void);
687 void vn_delete (void);
688
689
690 /* In tree-sra.c */
691 void insert_edge_copies (tree stmt, basic_block bb);
692
693 #include "tree-flow-inline.h"
694
695 #endif /* _TREE_FLOW_H */