1/* Data and Control Flow Analysis for Trees.
2   Copyright (C) 2001, 2003, 2004, 2005 Free Software Foundation, Inc.
3   Contributed by Diego Novillo <dnovillo@redhat.com>
4
5This file is part of GCC.
6
7GCC is free software; you can redistribute it and/or modify
8it under the terms of the GNU General Public License as published by
9the Free Software Foundation; either version 2, or (at your option)
10any later version.
11
12GCC is distributed in the hope that it will be useful,
13but WITHOUT ANY WARRANTY; without even the implied warranty of
14MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15GNU General Public License for more details.
16
17You should have received a copy of the GNU General Public License
18along with GCC; see the file COPYING.  If not, write to
19the Free Software Foundation, 51 Franklin Street, Fifth Floor,
20Boston, MA 02110-1301, 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#include "cgraph.h"
32#include "ipa-reference.h"
33
34/* Forward declare structures for the garbage collector GTY markers.  */
35#ifndef GCC_BASIC_BLOCK_H
36struct edge_def;
37typedef struct edge_def *edge;
38struct basic_block_def;
39typedef struct basic_block_def *basic_block;
40#endif
41
42/* True if the code is in ssa form.  */
43extern bool in_ssa_p;
44
45typedef struct
46{
47  htab_t htab;
48  PTR *slot;
49  PTR *limit;
50} htab_iterator;
51
52/* Iterate through the elements of hashtable HTAB, using htab_iterator ITER,
53   storing each element in RESULT, which is of type TYPE.  */
54#define FOR_EACH_HTAB_ELEMENT(HTAB, RESULT, TYPE, ITER) \
55  for (RESULT = (TYPE) first_htab_element (&(ITER), (HTAB)); \
56	!end_htab_p (&(ITER)); \
57	RESULT = (TYPE) next_htab_element (&(ITER)))
58
59/*---------------------------------------------------------------------------
60		      Attributes for SSA_NAMEs.
61
62  NOTE: These structures are stored in struct tree_ssa_name
63  but are only used by the tree optimizers, so it makes better sense
64  to declare them here to avoid recompiling unrelated files when
65  making changes.
66---------------------------------------------------------------------------*/
67
68/* Aliasing information for SSA_NAMEs representing pointer variables.  */
69struct ptr_info_def GTY(())
70{
71  /* Nonzero if points-to analysis couldn't determine where this pointer
72     is pointing to.  */
73  unsigned int pt_anything : 1;
74
75  /* Nonzero if the value of this pointer escapes the current function.  */
76  unsigned int value_escapes_p : 1;
77
78  /* Nonzero if this pointer is dereferenced.  */
79  unsigned int is_dereferenced : 1;
80
81  /* Nonzero if this pointer points to a global variable.  */
82  unsigned int pt_global_mem : 1;
83
84  /* Nonzero if this pointer points to NULL.  */
85  unsigned int pt_null : 1;
86
87  /* Set of variables that this pointer may point to.  */
88  bitmap pt_vars;
89
90  /* If this pointer has been dereferenced, and points-to information is
91     more precise than type-based aliasing, indirect references to this
92     pointer will be represented by this memory tag, instead of the type
93     tag computed by TBAA.  */
94  tree name_mem_tag;
95};
96
97
98/*---------------------------------------------------------------------------
99		   Tree annotations stored in tree_common.ann
100---------------------------------------------------------------------------*/
101enum tree_ann_type { TREE_ANN_COMMON, VAR_ANN, STMT_ANN };
102
103struct tree_ann_common_d GTY(())
104{
105  /* Annotation type.  */
106  enum tree_ann_type type;
107
108 /* Auxiliary info specific to a pass.  At all times, this
109    should either point to valid data or be NULL.  */
110  PTR GTY ((skip (""))) aux;
111
112  /* The value handle for this expression.  Used by GVN-PRE.  */
113  tree GTY((skip)) value_handle;
114};
115
116/* It is advantageous to avoid things like life analysis for variables which
117   do not need PHI nodes.  This enum describes whether or not a particular
118   variable may need a PHI node.  */
119
120enum need_phi_state {
121  /* This is the default.  If we are still in this state after finding
122     all the definition and use sites, then we will assume the variable
123     needs PHI nodes.  This is probably an overly conservative assumption.  */
124  NEED_PHI_STATE_UNKNOWN,
125
126  /* This state indicates that we have seen one or more sets of the
127     variable in a single basic block and that the sets dominate all
128     uses seen so far.  If after finding all definition and use sites
129     we are still in this state, then the variable does not need any
130     PHI nodes.  */
131  NEED_PHI_STATE_NO,
132
133  /* This state indicates that we have either seen multiple definitions of
134     the variable in multiple blocks, or that we encountered a use in a
135     block that was not dominated by the block containing the set(s) of
136     this variable.  This variable is assumed to need PHI nodes.  */
137  NEED_PHI_STATE_MAYBE
138};
139
140
141/* When computing aliasing information, we represent the memory pointed-to
142   by pointers with artificial variables called "memory tags" (MT).  There
143   are two kinds of tags: type and name.  Type tags (TMT) are used in
144   type-based alias analysis, they represent all the pointed-to locations
145   and variables of the same alias set class.  Name tags (NMT) are used in
146   flow-sensitive points-to alias analysis, they represent the variables
147   and memory locations pointed-to by a specific SSA_NAME pointer.  */
148enum mem_tag_kind {
149  /* This variable is not a memory tag.  */
150  NOT_A_TAG,
151
152  /* This variable is a type memory tag (TMT).  */
153  TYPE_TAG,
154
155  /* This variable is a name memory tag (NMT).  */
156  NAME_TAG,
157
158  /* This variable represents a structure field.  */
159  STRUCT_FIELD
160};
161
162struct subvar;
163typedef struct subvar *subvar_t;
164
165/* This structure represents a fake sub-variable for a structure field.  */
166struct subvar GTY(())
167{
168  /* Fake variable.  */
169  tree var;
170
171  /* Offset inside structure.  */
172  unsigned HOST_WIDE_INT offset;
173
174  /* Size of the field.  */
175  unsigned HOST_WIDE_INT size;
176
177  /* Next subvar for this structure.  */
178  subvar_t next;
179};
180
181struct var_ann_d GTY(())
182{
183  struct tree_ann_common_d common;
184
185  /* Used by the out of SSA pass to determine whether this variable has
186     been seen yet or not.  */
187  unsigned out_of_ssa_tag : 1;
188
189  /* Used when building root_var structures in tree_ssa_live.[ch].  */
190  unsigned root_var_processed : 1;
191
192  /* If nonzero, this variable is a memory tag.  */
193  ENUM_BITFIELD (mem_tag_kind) mem_tag_kind : 2;
194
195  /* Nonzero if this variable is an alias tag that represents references to
196     other variables (i.e., this variable appears in the MAY_ALIASES array
197     of other variables).  */
198  unsigned is_alias_tag : 1;
199
200  /* Nonzero if this variable was used after SSA optimizations were
201     applied.  We set this when translating out of SSA form.  */
202  unsigned used : 1;
203
204  /* This field indicates whether or not the variable may need PHI nodes.
205     See the enum's definition for more detailed information about the
206     states.  */
207  ENUM_BITFIELD (need_phi_state) need_phi_state : 2;
208
209  /* Used during operand processing to determine if this variable is already
210     in the vuse list.  */
211  unsigned in_vuse_list : 1;
212
213  /* Used during operand processing to determine if this variable is already
214     in the v_may_def list.  */
215  unsigned in_v_may_def_list : 1;
216
217  /* An artificial variable representing the memory location pointed-to by
218     all the pointers that TBAA (type-based alias analysis) considers
219     to be aliased.  If the variable is not a pointer or if it is never
220     dereferenced, this must be NULL.  */
221  tree type_mem_tag;
222
223  /* Variables that may alias this variable.  */
224  varray_type may_aliases;
225
226  /* Used when going out of SSA form to indicate which partition this
227     variable represents storage for.  */
228  unsigned partition;
229
230  /* Used by the root-var object in tree-ssa-live.[ch].  */
231  unsigned root_index;
232
233  /* Default definition for this symbol.  If this field is not NULL, it
234     means that the first reference to this variable in the function is a
235     USE or a VUSE.  In those cases, the SSA renamer creates an SSA name
236     for this variable with an empty defining statement.  */
237  tree default_def;
238
239  /* During into-ssa and the dominator optimizer, this field holds the
240     current version of this variable (an SSA_NAME).  */
241  tree current_def;
242
243  /* Pointer to the structure that contains the sets of global
244     variables modified by function calls.  This field is only used
245     for FUNCTION_DECLs.  */
246  ipa_reference_vars_info_t GTY ((skip)) reference_vars_info;
247
248  /* If this variable is a structure, this fields holds a list of
249     symbols representing each of the fields of the structure.  */
250  subvar_t subvars;
251};
252
253
254typedef struct immediate_use_iterator_d
255{
256  ssa_use_operand_t *imm_use;
257  ssa_use_operand_t *end_p;
258  ssa_use_operand_t iter_node;
259} imm_use_iterator;
260
261
262/* Use this iterator when simply looking at stmts.  Adding, deleting or
263   modifying stmts will cause this iterator to malfunction.  */
264
265#define FOR_EACH_IMM_USE_FAST(DEST, ITER, SSAVAR)			\
266  for ((DEST) = first_readonly_imm_use (&(ITER), (SSAVAR));	\
267       !end_readonly_imm_use_p (&(ITER));			\
268       (DEST) = next_readonly_imm_use (&(ITER)))
269
270
271#define FOR_EACH_IMM_USE_SAFE(DEST, ITER, SSAVAR)		\
272  for ((DEST) = first_safe_imm_use (&(ITER), (SSAVAR));		\
273       !end_safe_imm_use_p (&(ITER));				\
274       (DEST) = next_safe_imm_use (&(ITER)))
275
276#define BREAK_FROM_SAFE_IMM_USE(ITER)				\
277   {								\
278     end_safe_imm_use_traverse (&(ITER));			\
279     break;							\
280   }
281
282struct stmt_ann_d GTY(())
283{
284  struct tree_ann_common_d common;
285
286  /* Nonzero if the statement has been modified (meaning that the operands
287     need to be scanned again).  */
288  unsigned modified : 1;
289
290  /* Nonzero if the statement makes aliased loads.  */
291  unsigned makes_aliased_loads : 1;
292
293  /* Nonzero if the statement makes aliased stores.  */
294  unsigned makes_aliased_stores : 1;
295
296  /* Nonzero if the statement makes references to volatile storage.  */
297  unsigned has_volatile_ops : 1;
298
299  /* Nonzero if the statement makes a function call that may clobber global
300     and local addressable variables.  */
301  unsigned makes_clobbering_call : 1;
302
303  /* Basic block that contains this statement.  */
304  basic_block bb;
305
306  /* Operand cache for stmt.  */
307  struct stmt_operands_d GTY ((skip (""))) operands;
308
309  /* Set of variables that have had their address taken in the statement.  */
310  bitmap addresses_taken;
311
312  /* Unique identifier for this statement.  These ID's are to be created
313     by each pass on an as-needed basis in any order convenient for the
314     pass which needs statement UIDs.  */
315  unsigned int uid;
316
317  /* Linked list of histograms for value-based profiling.  This is really a
318     struct histogram_value*.  We use void* to avoid having to export that
319     everywhere, and to avoid having to put it in GC memory.  */
320
321  void * GTY ((skip (""))) histograms;
322};
323
324union tree_ann_d GTY((desc ("ann_type ((tree_ann_t)&%h)")))
325{
326  struct tree_ann_common_d GTY((tag ("TREE_ANN_COMMON"))) common;
327  struct var_ann_d GTY((tag ("VAR_ANN"))) decl;
328  struct stmt_ann_d GTY((tag ("STMT_ANN"))) stmt;
329};
330
331extern GTY(()) VEC(tree,gc) *modified_noreturn_calls;
332
333typedef union tree_ann_d *tree_ann_t;
334typedef struct var_ann_d *var_ann_t;
335typedef struct stmt_ann_d *stmt_ann_t;
336
337static inline tree_ann_t tree_ann (tree);
338static inline tree_ann_t get_tree_ann (tree);
339static inline var_ann_t var_ann (tree);
340static inline var_ann_t get_var_ann (tree);
341static inline stmt_ann_t stmt_ann (tree);
342static inline stmt_ann_t get_stmt_ann (tree);
343static inline enum tree_ann_type ann_type (tree_ann_t);
344static inline basic_block bb_for_stmt (tree);
345extern void set_bb_for_stmt (tree, basic_block);
346static inline bool noreturn_call_p (tree);
347static inline void update_stmt (tree);
348static inline bool stmt_modified_p (tree);
349static inline varray_type may_aliases (tree);
350static inline int get_lineno (tree);
351static inline const char *get_filename (tree);
352static inline bool is_exec_stmt (tree);
353static inline bool is_label_stmt (tree);
354static inline bitmap addresses_taken (tree);
355static inline void set_default_def (tree, tree);
356static inline tree default_def (tree);
357
358/*---------------------------------------------------------------------------
359                  Structure representing predictions in tree level.
360---------------------------------------------------------------------------*/
361struct edge_prediction GTY((chain_next ("%h.next")))
362{
363  struct edge_prediction *next;
364  edge edge;
365  enum br_predictor predictor;
366  int probability;
367};
368
369/* Accessors for basic block annotations.  */
370static inline tree phi_nodes (basic_block);
371static inline void set_phi_nodes (basic_block, tree);
372
373/*---------------------------------------------------------------------------
374			      Global declarations
375---------------------------------------------------------------------------*/
376struct int_tree_map GTY(())
377{
378
379  unsigned int uid;
380  tree to;
381};
382
383extern unsigned int int_tree_map_hash (const void *);
384extern int int_tree_map_eq (const void *, const void *);
385
386typedef struct
387{
388  htab_iterator hti;
389} referenced_var_iterator;
390
391
392/* This macro loops over all the referenced vars, one at a time, putting the
393   current var in VAR.  Note:  You are not allowed to add referenced variables
394   to the hashtable while using this macro.  Doing so may cause it to behave
395   erratically.  */
396
397#define FOR_EACH_REFERENCED_VAR(VAR, ITER) \
398  for ((VAR) = first_referenced_var (&(ITER)); \
399       !end_referenced_vars_p (&(ITER)); \
400       (VAR) = next_referenced_var (&(ITER)))
401
402
403typedef struct
404{
405  int i;
406} safe_referenced_var_iterator;
407
408/* This macro loops over all the referenced vars, one at a time, putting the
409   current var in VAR.  You are allowed to add referenced variables during the
410   execution of this macro, however, the macro will not iterate over them.  It
411   requires a temporary vector of trees, VEC, whose lifetime is controlled by
412   the caller.  The purpose of the vector is to temporarily store the
413   referenced_variables hashtable so that adding referenced variables does not
414   affect the hashtable.  */
415
416#define FOR_EACH_REFERENCED_VAR_SAFE(VAR, VEC, ITER) \
417  for ((ITER).i = 0, fill_referenced_var_vec (&(VEC)); \
418       VEC_iterate (tree, (VEC), (ITER).i, (VAR)); \
419       (ITER).i++)
420
421/* Array of all variables referenced in the function.  */
422extern GTY((param_is (struct int_tree_map))) htab_t referenced_vars;
423
424extern tree referenced_var_lookup (unsigned int);
425extern tree referenced_var_lookup_if_exists (unsigned int);
426#define num_referenced_vars htab_elements (referenced_vars)
427#define referenced_var(i) referenced_var_lookup (i)
428
429/* Array of all SSA_NAMEs used in the function.  */
430extern GTY(()) VEC(tree,gc) *ssa_names;
431
432#define num_ssa_names (VEC_length (tree, ssa_names))
433#define ssa_name(i) (VEC_index (tree, ssa_names, (i)))
434
435/* Artificial variable used to model the effects of function calls.  */
436extern GTY(()) tree global_var;
437
438/* Call clobbered variables in the function.  If bit I is set, then
439   REFERENCED_VARS (I) is call-clobbered.  */
440extern bitmap call_clobbered_vars;
441
442/* Addressable variables in the function.  If bit I is set, then
443   REFERENCED_VARS (I) has had its address taken.  */
444extern bitmap addressable_vars;
445
446/* 'true' after aliases have been computed (see compute_may_aliases).  */
447extern bool aliases_computed_p;
448
449/* Macros for showing usage statistics.  */
450#define SCALE(x) ((unsigned long) ((x) < 1024*10	\
451		  ? (x)					\
452		  : ((x) < 1024*1024*10			\
453		     ? (x) / 1024			\
454		     : (x) / (1024*1024))))
455
456#define LABEL(x) ((x) < 1024*10 ? 'b' : ((x) < 1024*1024*10 ? 'k' : 'M'))
457
458#define PERCENT(x,y) ((float)(x) * 100.0 / (float)(y))
459
460/*---------------------------------------------------------------------------
461			      Block iterators
462---------------------------------------------------------------------------*/
463
464typedef struct {
465  tree_stmt_iterator tsi;
466  basic_block bb;
467} block_stmt_iterator;
468
469static inline block_stmt_iterator bsi_start (basic_block);
470static inline block_stmt_iterator bsi_last (basic_block);
471static inline block_stmt_iterator bsi_after_labels (basic_block);
472block_stmt_iterator bsi_for_stmt (tree);
473static inline bool bsi_end_p (block_stmt_iterator);
474static inline void bsi_next (block_stmt_iterator *);
475static inline void bsi_prev (block_stmt_iterator *);
476static inline tree bsi_stmt (block_stmt_iterator);
477static inline tree * bsi_stmt_ptr (block_stmt_iterator);
478
479extern void bsi_remove (block_stmt_iterator *);
480extern void bsi_move_before (block_stmt_iterator *, block_stmt_iterator *);
481extern void bsi_move_after (block_stmt_iterator *, block_stmt_iterator *);
482extern void bsi_move_to_bb_end (block_stmt_iterator *, basic_block);
483
484enum bsi_iterator_update
485{
486  /* Note that these are intentionally in the same order as TSI_FOO.  They
487     mean exactly the same as their TSI_* counterparts.  */
488  BSI_NEW_STMT,
489  BSI_SAME_STMT,
490  BSI_CHAIN_START,
491  BSI_CHAIN_END,
492  BSI_CONTINUE_LINKING
493};
494
495extern void bsi_insert_before (block_stmt_iterator *, tree,
496			       enum bsi_iterator_update);
497extern void bsi_insert_after (block_stmt_iterator *, tree,
498			      enum bsi_iterator_update);
499
500extern void bsi_replace (const block_stmt_iterator *, tree, bool);
501
502/*---------------------------------------------------------------------------
503			      Function prototypes
504---------------------------------------------------------------------------*/
505/* In tree-cfg.c  */
506
507/* Location to track pending stmt for edge insertion.  */
508#define PENDING_STMT(e)	((e)->insns.t)
509
510extern void delete_tree_cfg_annotations (void);
511extern void disband_implicit_edges (void);
512extern bool stmt_ends_bb_p (tree);
513extern bool is_ctrl_stmt (tree);
514extern bool is_ctrl_altering_stmt (tree);
515extern bool computed_goto_p (tree);
516extern bool simple_goto_p (tree);
517extern basic_block single_noncomplex_succ (basic_block bb);
518extern void tree_dump_bb (basic_block, FILE *, int);
519extern void debug_tree_bb (basic_block);
520extern basic_block debug_tree_bb_n (int);
521extern void dump_tree_cfg (FILE *, int);
522extern void debug_tree_cfg (int);
523extern void dump_cfg_stats (FILE *);
524extern void debug_cfg_stats (void);
525extern void debug_loop_ir (void);
526extern void print_loop_ir (FILE *);
527extern void cleanup_dead_labels (void);
528extern void group_case_labels (void);
529extern tree first_stmt (basic_block);
530extern tree last_stmt (basic_block);
531extern tree *last_stmt_ptr (basic_block);
532extern tree last_and_only_stmt (basic_block);
533extern edge find_taken_edge (basic_block, tree);
534extern basic_block label_to_block_fn (struct function *, tree);
535#define label_to_block(t) (label_to_block_fn (cfun, t))
536extern void bsi_insert_on_edge (edge, tree);
537extern basic_block bsi_insert_on_edge_immediate (edge, tree);
538extern void bsi_commit_one_edge_insert (edge, basic_block *);
539extern void bsi_commit_edge_inserts (void);
540extern void notice_special_calls (tree);
541extern void clear_special_calls (void);
542extern void verify_stmts (void);
543extern tree tree_block_label (basic_block);
544extern void extract_true_false_edges_from_block (basic_block, edge *, edge *);
545extern bool tree_duplicate_sese_region (edge, edge, basic_block *, unsigned,
546					basic_block *);
547extern void add_phi_args_after_copy_bb (basic_block);
548extern void add_phi_args_after_copy (basic_block *, unsigned);
549extern bool tree_purge_dead_eh_edges (basic_block);
550extern bool tree_purge_all_dead_eh_edges (bitmap);
551extern tree gimplify_val (block_stmt_iterator *, tree, tree);
552extern tree gimplify_build1 (block_stmt_iterator *, enum tree_code,
553			     tree, tree);
554extern tree gimplify_build2 (block_stmt_iterator *, enum tree_code,
555			     tree, tree, tree);
556extern tree gimplify_build3 (block_stmt_iterator *, enum tree_code,
557			     tree, tree, tree, tree);
558extern void init_empty_tree_cfg (void);
559extern void fold_cond_expr_cond (void);
560extern void replace_uses_by (tree, tree);
561extern void start_recording_case_labels (void);
562extern void end_recording_case_labels (void);
563
564/* In tree-cfgcleanup.c  */
565extern bool cleanup_tree_cfg (void);
566extern void cleanup_tree_cfg_loop (void);
567
568/* In tree-pretty-print.c.  */
569extern void dump_generic_bb (FILE *, basic_block, int, int);
570
571/* In tree-dfa.c  */
572extern var_ann_t create_var_ann (tree);
573extern stmt_ann_t create_stmt_ann (tree);
574extern tree_ann_t create_tree_ann (tree);
575extern void dump_dfa_stats (FILE *);
576extern void debug_dfa_stats (void);
577extern void debug_referenced_vars (void);
578extern void dump_referenced_vars (FILE *);
579extern void dump_variable (FILE *, tree);
580extern void debug_variable (tree);
581extern void dump_subvars_for (FILE *, tree);
582extern void debug_subvars_for (tree);
583extern tree get_virtual_var (tree);
584extern void add_referenced_tmp_var (tree);
585extern void mark_new_vars_to_rename (tree);
586extern void find_new_referenced_vars (tree *);
587
588extern tree make_rename_temp (tree, const char *);
589
590/* In tree-phinodes.c  */
591extern void reserve_phi_args_for_new_edge (basic_block);
592extern tree create_phi_node (tree, basic_block);
593extern void add_phi_arg (tree, tree, edge);
594extern void remove_phi_args (edge);
595extern void remove_phi_node (tree, tree);
596extern tree phi_reverse (tree);
597
598/* In gimple-low.c  */
599extern void record_vars (tree);
600extern bool block_may_fallthru (tree block);
601
602/* In tree-ssa-alias.c  */
603extern void dump_may_aliases_for (FILE *, tree);
604extern void debug_may_aliases_for (tree);
605extern void dump_alias_info (FILE *);
606extern void debug_alias_info (void);
607extern void dump_points_to_info (FILE *);
608extern void debug_points_to_info (void);
609extern void dump_points_to_info_for (FILE *, tree);
610extern void debug_points_to_info_for (tree);
611extern bool may_be_aliased (tree);
612extern bool is_aliased_with (tree, tree);
613extern bool may_aliases_intersect (tree, tree);
614extern struct ptr_info_def *get_ptr_info (tree);
615extern void add_type_alias (tree, tree);
616extern void new_type_alias (tree, tree);
617extern void count_uses_and_derefs (tree, tree, unsigned *, unsigned *, bool *);
618static inline subvar_t get_subvars_for_var (tree);
619static inline tree get_subvar_at (tree, unsigned HOST_WIDE_INT);
620static inline bool ref_contains_array_ref (tree);
621static inline bool array_ref_contains_indirect_ref (tree);
622extern tree okay_component_ref_for_subvars (tree, unsigned HOST_WIDE_INT *,
623					    unsigned HOST_WIDE_INT *);
624static inline bool var_can_have_subvars (tree);
625static inline bool overlap_subvar (unsigned HOST_WIDE_INT,
626				   unsigned HOST_WIDE_INT,
627				   subvar_t, bool *);
628
629/* Call-back function for walk_use_def_chains().  At each reaching
630   definition, a function with this prototype is called.  */
631typedef bool (*walk_use_def_chains_fn) (tree, tree, void *);
632
633
634/* In tree-ssa.c  */
635extern void init_tree_ssa (void);
636extern edge ssa_redirect_edge (edge, basic_block);
637extern void flush_pending_stmts (edge);
638extern bool tree_ssa_useless_type_conversion (tree);
639extern bool tree_ssa_useless_type_conversion_1 (tree, tree);
640extern void verify_ssa (bool);
641extern void delete_tree_ssa (void);
642extern void register_new_def (tree, VEC(tree,heap) **);
643extern void walk_use_def_chains (tree, walk_use_def_chains_fn, void *, bool);
644extern bool stmt_references_memory_p (tree);
645
646/* In tree-into-ssa.c  */
647void update_ssa (unsigned);
648void delete_update_ssa (void);
649void register_new_name_mapping (tree, tree);
650tree create_new_def_for (tree, tree, def_operand_p);
651bool need_ssa_update_p (void);
652bool name_registered_for_update_p (tree);
653bitmap ssa_names_to_replace (void);
654void release_ssa_name_after_update_ssa (tree name);
655void compute_global_livein (bitmap, bitmap);
656tree duplicate_ssa_name (tree, tree);
657void mark_sym_for_renaming (tree);
658void mark_set_for_renaming (bitmap);
659tree get_current_def (tree);
660void set_current_def (tree, tree);
661
662/* In tree-ssa-ccp.c  */
663bool fold_stmt (tree *);
664bool fold_stmt_inplace (tree);
665tree widen_bitfield (tree, tree, tree);
666
667/* In tree-vrp.c  */
668tree vrp_evaluate_conditional (tree, bool);
669void simplify_stmt_using_ranges (tree);
670
671/* In tree-ssa-dom.c  */
672extern void dump_dominator_optimization_stats (FILE *);
673extern void debug_dominator_optimization_stats (void);
674int loop_depth_of_name (tree);
675
676/* In tree-ssa-copy.c  */
677extern void merge_alias_info (tree, tree);
678extern void propagate_value (use_operand_p, tree);
679extern void propagate_tree_value (tree *, tree);
680extern void replace_exp (use_operand_p, tree);
681extern bool may_propagate_copy (tree, tree);
682extern bool may_propagate_copy_into_asm (tree);
683
684/* Description of number of iterations of a loop.  All the expressions inside
685   the structure can be evaluated at the end of the loop's preheader
686   (and due to ssa form, also anywhere inside the body of the loop).  */
687
688struct tree_niter_desc
689{
690  tree assumptions;	/* The boolean expression.  If this expression evaluates
691			   to false, then the other fields in this structure
692			   should not be used; there is no guarantee that they
693			   will be correct.  */
694  tree may_be_zero;	/* The boolean expression.  If it evaluates to true,
695			   the loop will exit in the first iteration (i.e.
696			   its latch will not be executed), even if the niter
697			   field says otherwise.  */
698  tree niter;		/* The expression giving the number of iterations of
699			   a loop (provided that assumptions == true and
700			   may_be_zero == false), more precisely the number
701			   of executions of the latch of the loop.  */
702  tree additional_info;	/* The boolean expression.  Sometimes we use additional
703			   knowledge to simplify the other expressions
704			   contained in this structure (for example the
705			   knowledge about value ranges of operands on entry to
706			   the loop).  If this is a case, conjunction of such
707			   condition is stored in this field, so that we do not
708			   lose the information: for example if may_be_zero
709			   is (n <= 0) and niter is (unsigned) n, we know
710			   that the number of iterations is at most
711			   MAX_SIGNED_INT.  However if the (n <= 0) assumption
712			   is eliminated (by looking at the guard on entry of
713			   the loop), then the information would be lost.  */
714};
715
716/* In tree-vectorizer.c */
717void vectorize_loops (struct loops *);
718
719/* In tree-ssa-phiopt.c */
720bool empty_block_p (basic_block);
721
722/* In tree-ssa-loop*.c  */
723
724void tree_ssa_lim (struct loops *);
725void tree_ssa_unswitch_loops (struct loops *);
726void canonicalize_induction_variables (struct loops *);
727void tree_unroll_loops_completely (struct loops *, bool);
728void remove_empty_loops (struct loops *);
729void tree_ssa_iv_optimize (struct loops *);
730
731bool number_of_iterations_exit (struct loop *, edge,
732				struct tree_niter_desc *niter, bool);
733tree find_loop_niter (struct loop *, edge *);
734tree loop_niter_by_eval (struct loop *, edge);
735tree find_loop_niter_by_eval (struct loop *, edge *);
736void estimate_numbers_of_iterations (struct loops *);
737bool scev_probably_wraps_p (tree, tree, tree, struct loop *, bool);
738bool convert_affine_scev (struct loop *, tree, tree *, tree *, tree, bool);
739
740bool nowrap_type_p (tree);
741enum ev_direction {EV_DIR_GROWS, EV_DIR_DECREASES, EV_DIR_UNKNOWN};
742enum ev_direction scev_direction (tree);
743
744void free_numbers_of_iterations_estimates (struct loops *);
745void free_numbers_of_iterations_estimates_loop (struct loop *);
746void rewrite_into_loop_closed_ssa (bitmap, unsigned);
747void verify_loop_closed_ssa (void);
748void loop_commit_inserts (void);
749bool for_each_index (tree *, bool (*) (tree, tree *, void *), void *);
750void create_iv (tree, tree, tree, struct loop *, block_stmt_iterator *, bool,
751		tree *, tree *);
752void split_loop_exit_edge (edge);
753void compute_phi_arg_on_exit (edge, tree, tree);
754unsigned force_expr_to_var_cost (tree);
755basic_block bsi_insert_on_edge_immediate_loop (edge, tree);
756void standard_iv_increment_position (struct loop *, block_stmt_iterator *,
757				     bool *);
758basic_block ip_end_pos (struct loop *);
759basic_block ip_normal_pos (struct loop *);
760bool tree_duplicate_loop_to_header_edge (struct loop *, edge, struct loops *,
761					 unsigned int, sbitmap,
762					 edge, edge *,
763					 unsigned int *, int);
764struct loop *tree_ssa_loop_version (struct loops *, struct loop *, tree,
765				    basic_block *);
766tree expand_simple_operations (tree);
767void substitute_in_loop_info (struct loop *, tree, tree);
768edge single_dom_exit (struct loop *);
769bool contains_abnormal_ssa_name_p (tree);
770
771/* In tree-ssa-loop-im.c  */
772/* The possibilities of statement movement.  */
773
774enum move_pos
775  {
776    MOVE_IMPOSSIBLE,		/* No movement -- side effect expression.  */
777    MOVE_PRESERVE_EXECUTION,	/* Must not cause the non-executed statement
778				   become executed -- memory accesses, ... */
779    MOVE_POSSIBLE		/* Unlimited movement.  */
780  };
781extern enum move_pos movement_possibility (tree);
782
783/* In tree-flow-inline.h  */
784static inline bool is_call_clobbered (tree);
785static inline void mark_call_clobbered (tree);
786static inline void set_is_used (tree);
787static inline bool unmodifiable_var_p (tree);
788
789/* In tree-eh.c  */
790extern void make_eh_edges (tree);
791extern bool tree_could_trap_p (tree);
792extern bool tree_could_throw_p (tree);
793extern bool tree_can_throw_internal (tree);
794extern bool tree_can_throw_external (tree);
795extern int lookup_stmt_eh_region (tree);
796extern void add_stmt_to_eh_region (tree, int);
797extern bool remove_stmt_from_eh_region (tree);
798extern bool maybe_clean_or_replace_eh_stmt (tree, tree);
799
800/* In tree-ssa-pre.c  */
801void add_to_value (tree, tree);
802void debug_value_expressions (tree);
803void print_value_expressions (FILE *, tree);
804
805
806/* In tree-vn.c  */
807bool expressions_equal_p (tree, tree);
808tree get_value_handle (tree);
809hashval_t vn_compute (tree, hashval_t, tree);
810tree vn_lookup_or_add (tree, tree);
811void vn_add (tree, tree, tree);
812tree vn_lookup (tree, tree);
813void vn_init (void);
814void vn_delete (void);
815
816/* In tree-ssa-sink.c  */
817bool is_hidden_global_store (tree);
818
819/* In tree-sra.c  */
820void insert_edge_copies (tree, basic_block);
821void sra_insert_before (block_stmt_iterator *, tree);
822void sra_insert_after (block_stmt_iterator *, tree);
823void sra_init_cache (void);
824bool sra_type_can_be_decomposed_p (tree);
825
826/* In tree-loop-linear.c  */
827extern void linear_transform_loops (struct loops *);
828
829/* In tree-ssa-loop-ivopts.c  */
830bool expr_invariant_in_loop_p (struct loop *, tree);
831bool multiplier_allowed_in_address_p (HOST_WIDE_INT);
832unsigned multiply_by_cost (HOST_WIDE_INT, enum machine_mode);
833
834/* In tree-ssa-threadupdate.c.  */
835extern bool thread_through_all_blocks (bitmap);
836
837/* In gimplify.c  */
838tree force_gimple_operand (tree, tree *, bool, tree);
839tree force_gimple_operand_bsi (block_stmt_iterator *, tree, bool, tree);
840
841/* In tree-ssa-structalias.c */
842bool find_what_p_points_to (tree);
843
844/* In tree-ssa-address.c  */
845
846/* Affine combination of trees.  We keep track of at most MAX_AFF_ELTS elements
847   to make things simpler; this is sufficient in most cases.  */
848
849#define MAX_AFF_ELTS 8
850
851struct affine_tree_combination
852{
853  /* Type of the result of the combination.  */
854  tree type;
855
856  /* Mask modulo that the operations are performed.  */
857  unsigned HOST_WIDE_INT mask;
858
859  /* Constant offset.  */
860  unsigned HOST_WIDE_INT offset;
861
862  /* Number of elements of the combination.  */
863  unsigned n;
864
865  /* Elements and their coefficients.  */
866  tree elts[MAX_AFF_ELTS];
867  unsigned HOST_WIDE_INT coefs[MAX_AFF_ELTS];
868
869  /* Remainder of the expression.  */
870  tree rest;
871};
872
873/* Description of a memory address.  */
874
875struct mem_address
876{
877  tree symbol, base, index, step, offset;
878};
879
880tree create_mem_ref (block_stmt_iterator *, tree,
881		     struct affine_tree_combination *);
882rtx addr_for_mem_ref (struct mem_address *, bool);
883void get_address_description (tree, struct mem_address *);
884tree maybe_fold_tmr (tree);
885/* This structure is simply used during pushing fields onto the fieldstack
886   to track the offset of the field, since bitpos_of_field gives it relative
887   to its immediate containing type, and we want it relative to the ultimate
888   containing object.  */
889
890struct fieldoff
891{
892  tree field;
893  HOST_WIDE_INT offset;
894};
895typedef struct fieldoff fieldoff_s;
896
897DEF_VEC_O(fieldoff_s);
898DEF_VEC_ALLOC_O(fieldoff_s,heap);
899int push_fields_onto_fieldstack (tree, VEC(fieldoff_s,heap) **,
900				 HOST_WIDE_INT, bool *);
901void sort_fieldstack (VEC(fieldoff_s,heap) *);
902
903void init_alias_heapvars (void);
904void delete_alias_heapvars (void);
905
906#include "tree-flow-inline.h"
907
908#endif /* _TREE_FLOW_H  */
909