1/* Data and Control Flow Analysis for Trees.
2   Copyright (C) 2001, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
3   Free Software Foundation, Inc.
4   Contributed by Diego Novillo <dnovillo@redhat.com>
5
6This file is part of GCC.
7
8GCC is free software; you can redistribute it and/or modify
9it under the terms of the GNU General Public License as published by
10the Free Software Foundation; either version 3, or (at your option)
11any later version.
12
13GCC is distributed in the hope that it will be useful,
14but WITHOUT ANY WARRANTY; without even the implied warranty of
15MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16GNU General Public License for more details.
17
18You should have received a copy of the GNU General Public License
19along with GCC; see the file COPYING3.  If not see
20<http://www.gnu.org/licenses/>.  */
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 "gimple.h"
30#include "tree-ssa-operands.h"
31#include "cgraph.h"
32#include "ipa-reference.h"
33#include "tree-ssa-alias.h"
34
35
36/* Gimple dataflow datastructure. All publicly available fields shall have
37   gimple_ accessor defined in tree-flow-inline.h, all publicly modifiable
38   fields should have gimple_set accessor.  */
39struct GTY(()) gimple_df {
40  /* Array of all variables referenced in the function.  */
41  htab_t GTY((param_is (union tree_node))) referenced_vars;
42
43  /* A vector of all the noreturn calls passed to modify_stmt.
44     cleanup_control_flow uses it to detect cases where a mid-block
45     indirect call has been turned into a noreturn call.  When this
46     happens, all the instructions after the call are no longer
47     reachable and must be deleted as dead.  */
48  VEC(gimple,gc) *modified_noreturn_calls;
49
50  /* Array of all SSA_NAMEs used in the function.  */
51  VEC(tree,gc) *ssa_names;
52
53  /* Artificial variable used for the virtual operand FUD chain.  */
54  tree vop;
55
56  /* The PTA solution for the ESCAPED artificial variable.  */
57  struct pt_solution escaped;
58
59  /* The PTA solution for the CALLUSED artificial variable.  */
60  struct pt_solution callused;
61
62  /* A map of decls to artificial ssa-names that point to the partition
63     of the decl.  */
64  struct pointer_map_t * GTY((skip(""))) decls_to_pointers;
65
66  /* Free list of SSA_NAMEs.  */
67  tree free_ssanames;
68
69  /* Hashtable holding definition for symbol.  If this field is not NULL, it
70     means that the first reference to this variable in the function is a
71     USE or a VUSE.  In those cases, the SSA renamer creates an SSA name
72     for this variable with an empty defining statement.  */
73  htab_t GTY((param_is (union tree_node))) default_defs;
74
75  /* Symbols whose SSA form needs to be updated or created for the first
76     time.  */
77  bitmap syms_to_rename;
78
79  /* True if the code is in ssa form.  */
80  unsigned int in_ssa_p : 1;
81
82  struct ssa_operands ssa_operands;
83};
84
85/* Accessors for internal use only.  Generic code should use abstraction
86   provided by tree-flow-inline.h or specific modules.  */
87#define FREE_SSANAMES(fun) (fun)->gimple_df->free_ssanames
88#define SSANAMES(fun) (fun)->gimple_df->ssa_names
89#define MODIFIED_NORETURN_CALLS(fun) (fun)->gimple_df->modified_noreturn_calls
90#define DEFAULT_DEFS(fun) (fun)->gimple_df->default_defs
91#define SYMS_TO_RENAME(fun) (fun)->gimple_df->syms_to_rename
92
93typedef struct
94{
95  htab_t htab;
96  PTR *slot;
97  PTR *limit;
98} htab_iterator;
99
100/* Iterate through the elements of hashtable HTAB, using htab_iterator ITER,
101   storing each element in RESULT, which is of type TYPE.  */
102#define FOR_EACH_HTAB_ELEMENT(HTAB, RESULT, TYPE, ITER) \
103  for (RESULT = (TYPE) first_htab_element (&(ITER), (HTAB)); \
104	!end_htab_p (&(ITER)); \
105	RESULT = (TYPE) next_htab_element (&(ITER)))
106
107/*---------------------------------------------------------------------------
108		      Attributes for SSA_NAMEs.
109
110  NOTE: These structures are stored in struct tree_ssa_name
111  but are only used by the tree optimizers, so it makes better sense
112  to declare them here to avoid recompiling unrelated files when
113  making changes.
114---------------------------------------------------------------------------*/
115
116/* Aliasing information for SSA_NAMEs representing pointer variables.  */
117struct GTY(()) ptr_info_def
118{
119  /* The points-to solution, TBAA-pruned if the pointer is dereferenced.  */
120  struct pt_solution pt;
121};
122
123
124/* It is advantageous to avoid things like life analysis for variables which
125   do not need PHI nodes.  This enum describes whether or not a particular
126   variable may need a PHI node.  */
127
128enum need_phi_state {
129  /* This is the default.  If we are still in this state after finding
130     all the definition and use sites, then we will assume the variable
131     needs PHI nodes.  This is probably an overly conservative assumption.  */
132  NEED_PHI_STATE_UNKNOWN,
133
134  /* This state indicates that we have seen one or more sets of the
135     variable in a single basic block and that the sets dominate all
136     uses seen so far.  If after finding all definition and use sites
137     we are still in this state, then the variable does not need any
138     PHI nodes.  */
139  NEED_PHI_STATE_NO,
140
141  /* This state indicates that we have either seen multiple definitions of
142     the variable in multiple blocks, or that we encountered a use in a
143     block that was not dominated by the block containing the set(s) of
144     this variable.  This variable is assumed to need PHI nodes.  */
145  NEED_PHI_STATE_MAYBE
146};
147
148
149/* The "no alias" attribute allows alias analysis to make more
150   aggressive assumptions when assigning alias sets, computing
151   points-to information and memory partitions.  These attributes
152   are the result of user annotations or flags (e.g.,
153   -fargument-noalias).  */
154enum noalias_state {
155    /* Default state.  No special assumptions can be made about this
156       symbol.  */
157    MAY_ALIAS = 0,
158
159    /* The symbol does not alias with other symbols that have a
160       NO_ALIAS* attribute.  */
161    NO_ALIAS,
162
163    /* The symbol does not alias with other symbols that have a
164       NO_ALIAS*, and it may not alias with global symbols.  */
165    NO_ALIAS_GLOBAL,
166
167    /* The symbol does not alias with any other symbols.  */
168    NO_ALIAS_ANYTHING
169};
170
171
172struct GTY(()) var_ann_d {
173  /* Used when building base variable structures in a var_map.  */
174  unsigned base_var_processed : 1;
175
176  /* Nonzero if this variable was used after SSA optimizations were
177     applied.  We set this when translating out of SSA form.  */
178  unsigned used : 1;
179
180  /* This field indicates whether or not the variable may need PHI nodes.
181     See the enum's definition for more detailed information about the
182     states.  */
183  ENUM_BITFIELD (need_phi_state) need_phi_state : 2;
184
185  /* True for HEAP artificial variables.  These variables represent
186     the memory area allocated by a call to malloc.  */
187  unsigned is_heapvar : 1;
188
189  /* This field describes several "no alias" attributes that some
190     symbols are known to have.  See the enum's definition for more
191     information on each attribute.  */
192  ENUM_BITFIELD (noalias_state) noalias_state : 2;
193
194  /* Used by var_map for the base index of ssa base variables.  */
195  unsigned base_index;
196
197  /* During into-ssa and the dominator optimizer, this field holds the
198     current version of this variable (an SSA_NAME).  */
199  tree current_def;
200};
201
202
203/* Immediate use lists are used to directly access all uses for an SSA
204   name and get pointers to the statement for each use.
205
206   The structure ssa_use_operand_d consists of PREV and NEXT pointers
207   to maintain the list.  A USE pointer, which points to address where
208   the use is located and a LOC pointer which can point to the
209   statement where the use is located, or, in the case of the root
210   node, it points to the SSA name itself.
211
212   The list is anchored by an occurrence of ssa_operand_d *in* the
213   ssa_name node itself (named 'imm_uses').  This node is uniquely
214   identified by having a NULL USE pointer. and the LOC pointer
215   pointing back to the ssa_name node itself.  This node forms the
216   base for a circular list, and initially this is the only node in
217   the list.
218
219   Fast iteration allows each use to be examined, but does not allow
220   any modifications to the uses or stmts.
221
222   Normal iteration allows insertion, deletion, and modification. the
223   iterator manages this by inserting a marker node into the list
224   immediately before the node currently being examined in the list.
225   this marker node is uniquely identified by having null stmt *and* a
226   null use pointer.
227
228   When iterating to the next use, the iteration routines check to see
229   if the node after the marker has changed. if it has, then the node
230   following the marker is now the next one to be visited. if not, the
231   marker node is moved past that node in the list (visualize it as
232   bumping the marker node through the list).  this continues until
233   the marker node is moved to the original anchor position. the
234   marker node is then removed from the list.
235
236   If iteration is halted early, the marker node must be removed from
237   the list before continuing.  */
238typedef struct immediate_use_iterator_d
239{
240  /* This is the current use the iterator is processing.  */
241  ssa_use_operand_t *imm_use;
242  /* This marks the last use in the list (use node from SSA_NAME)  */
243  ssa_use_operand_t *end_p;
244  /* This node is inserted and used to mark the end of the uses for a stmt.  */
245  ssa_use_operand_t iter_node;
246  /* This is the next ssa_name to visit.  IMM_USE may get removed before
247     the next one is traversed to, so it must be cached early.  */
248  ssa_use_operand_t *next_imm_name;
249} imm_use_iterator;
250
251
252/* Use this iterator when simply looking at stmts.  Adding, deleting or
253   modifying stmts will cause this iterator to malfunction.  */
254
255#define FOR_EACH_IMM_USE_FAST(DEST, ITER, SSAVAR)			\
256  for ((DEST) = first_readonly_imm_use (&(ITER), (SSAVAR));	\
257       !end_readonly_imm_use_p (&(ITER));			\
258       (DEST) = next_readonly_imm_use (&(ITER)))
259
260/* Use this iterator to visit each stmt which has a use of SSAVAR.  */
261
262#define FOR_EACH_IMM_USE_STMT(STMT, ITER, SSAVAR)		\
263  for ((STMT) = first_imm_use_stmt (&(ITER), (SSAVAR));		\
264       !end_imm_use_stmt_p (&(ITER));				\
265       (STMT) = next_imm_use_stmt (&(ITER)))
266
267/* Use this to terminate the FOR_EACH_IMM_USE_STMT loop early.  Failure to
268   do so will result in leaving a iterator marker node in the immediate
269   use list, and nothing good will come from that.   */
270#define BREAK_FROM_IMM_USE_STMT(ITER)				\
271   {								\
272     end_imm_use_stmt_traverse (&(ITER));			\
273     break;							\
274   }
275
276
277/* Use this iterator in combination with FOR_EACH_IMM_USE_STMT to
278   get access to each occurrence of ssavar on the stmt returned by
279   that iterator..  for instance:
280
281     FOR_EACH_IMM_USE_STMT (stmt, iter, var)
282       {
283         FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
284	   {
285	     SET_USE (use_p, blah);
286	   }
287	 update_stmt (stmt);
288       }							 */
289
290#define FOR_EACH_IMM_USE_ON_STMT(DEST, ITER)			\
291  for ((DEST) = first_imm_use_on_stmt (&(ITER));		\
292       !end_imm_use_on_stmt_p (&(ITER));			\
293       (DEST) = next_imm_use_on_stmt (&(ITER)))
294
295
296
297typedef struct var_ann_d *var_ann_t;
298
299static inline var_ann_t var_ann (const_tree);
300static inline var_ann_t get_var_ann (tree);
301static inline void update_stmt (gimple);
302static inline int get_lineno (const_gimple);
303
304/*---------------------------------------------------------------------------
305                  Structure representing predictions in tree level.
306---------------------------------------------------------------------------*/
307struct GTY((chain_next ("%h.ep_next"))) edge_prediction {
308  struct edge_prediction *ep_next;
309  edge ep_edge;
310  enum br_predictor ep_predictor;
311  int ep_probability;
312};
313
314/* Accessors for basic block annotations.  */
315static inline gimple_seq phi_nodes (const_basic_block);
316static inline void set_phi_nodes (basic_block, gimple_seq);
317
318/*---------------------------------------------------------------------------
319			      Global declarations
320---------------------------------------------------------------------------*/
321struct GTY(()) int_tree_map {
322
323  unsigned int uid;
324  tree to;
325};
326
327extern unsigned int int_tree_map_hash (const void *);
328extern int int_tree_map_eq (const void *, const void *);
329
330extern unsigned int uid_decl_map_hash (const void *);
331extern int uid_decl_map_eq (const void *, const void *);
332
333typedef struct
334{
335  htab_iterator hti;
336} referenced_var_iterator;
337
338/* This macro loops over all the referenced vars, one at a time, putting the
339   current var in VAR.  Note:  You are not allowed to add referenced variables
340   to the hashtable while using this macro.  Doing so may cause it to behave
341   erratically.  */
342
343#define FOR_EACH_REFERENCED_VAR(VAR, ITER) \
344  for ((VAR) = first_referenced_var (&(ITER)); \
345       !end_referenced_vars_p (&(ITER)); \
346       (VAR) = next_referenced_var (&(ITER)))
347
348extern tree referenced_var_lookup (unsigned int);
349extern bool referenced_var_check_and_insert (tree);
350#define num_referenced_vars htab_elements (gimple_referenced_vars (cfun))
351#define referenced_var(i) referenced_var_lookup (i)
352
353#define num_ssa_names (VEC_length (tree, cfun->gimple_df->ssa_names))
354#define ssa_name(i) (VEC_index (tree, cfun->gimple_df->ssa_names, (i)))
355
356/* Macros for showing usage statistics.  */
357#define SCALE(x) ((unsigned long) ((x) < 1024*10	\
358		  ? (x)					\
359		  : ((x) < 1024*1024*10			\
360		     ? (x) / 1024			\
361		     : (x) / (1024*1024))))
362
363#define LABEL(x) ((x) < 1024*10 ? 'b' : ((x) < 1024*1024*10 ? 'k' : 'M'))
364
365#define PERCENT(x,y) ((float)(x) * 100.0 / (float)(y))
366
367/*---------------------------------------------------------------------------
368			      OpenMP Region Tree
369---------------------------------------------------------------------------*/
370
371/* Parallel region information.  Every parallel and workshare
372   directive is enclosed between two markers, the OMP_* directive
373   and a corresponding OMP_RETURN statement.  */
374
375struct omp_region
376{
377  /* The enclosing region.  */
378  struct omp_region *outer;
379
380  /* First child region.  */
381  struct omp_region *inner;
382
383  /* Next peer region.  */
384  struct omp_region *next;
385
386  /* Block containing the omp directive as its last stmt.  */
387  basic_block entry;
388
389  /* Block containing the OMP_RETURN as its last stmt.  */
390  basic_block exit;
391
392  /* Block containing the OMP_CONTINUE as its last stmt.  */
393  basic_block cont;
394
395  /* If this is a combined parallel+workshare region, this is a list
396     of additional arguments needed by the combined parallel+workshare
397     library call.  */
398  tree ws_args;
399
400  /* The code for the omp directive of this region.  */
401  enum gimple_code type;
402
403  /* Schedule kind, only used for OMP_FOR type regions.  */
404  enum omp_clause_schedule_kind sched_kind;
405
406  /* True if this is a combined parallel+workshare region.  */
407  bool is_combined_parallel;
408};
409
410extern struct omp_region *root_omp_region;
411extern struct omp_region *new_omp_region (basic_block, enum gimple_code,
412					  struct omp_region *);
413extern void free_omp_regions (void);
414void omp_expand_local (basic_block);
415extern tree find_omp_clause (tree, enum omp_clause_code);
416tree copy_var_decl (tree, tree, tree);
417
418/*---------------------------------------------------------------------------
419			      Function prototypes
420---------------------------------------------------------------------------*/
421/* In tree-cfg.c  */
422
423/* Location to track pending stmt for edge insertion.  */
424#define PENDING_STMT(e)	((e)->insns.g)
425
426extern void delete_tree_cfg_annotations (void);
427extern bool stmt_ends_bb_p (gimple);
428extern bool is_ctrl_stmt (gimple);
429extern bool is_ctrl_altering_stmt (gimple);
430extern bool simple_goto_p (gimple);
431extern bool stmt_can_make_abnormal_goto (gimple);
432extern basic_block single_noncomplex_succ (basic_block bb);
433extern void gimple_dump_bb (basic_block, FILE *, int, int);
434extern void gimple_debug_bb (basic_block);
435extern basic_block gimple_debug_bb_n (int);
436extern void gimple_dump_cfg (FILE *, int);
437extern void gimple_debug_cfg (int);
438extern void dump_cfg_stats (FILE *);
439extern void dot_cfg (void);
440extern void debug_cfg_stats (void);
441extern void debug_loops (int);
442extern void debug_loop (struct loop *, int);
443extern void debug_loop_num (unsigned, int);
444extern void print_loops (FILE *, int);
445extern void print_loops_bb (FILE *, basic_block, int, int);
446extern void cleanup_dead_labels (void);
447extern void group_case_labels (void);
448extern gimple first_stmt (basic_block);
449extern gimple last_stmt (basic_block);
450extern gimple last_and_only_stmt (basic_block);
451extern edge find_taken_edge (basic_block, tree);
452extern basic_block label_to_block_fn (struct function *, tree);
453#define label_to_block(t) (label_to_block_fn (cfun, t))
454extern void notice_special_calls (gimple);
455extern void clear_special_calls (void);
456extern void verify_stmts (void);
457extern void verify_gimple (void);
458extern void verify_types_in_gimple_seq (gimple_seq);
459extern tree gimple_block_label (basic_block);
460extern void extract_true_false_edges_from_block (basic_block, edge *, edge *);
461extern bool gimple_duplicate_sese_region (edge, edge, basic_block *, unsigned,
462					basic_block *);
463extern bool gimple_duplicate_sese_tail (edge, edge, basic_block *, unsigned,
464				      basic_block *);
465extern void gather_blocks_in_sese_region (basic_block entry, basic_block exit,
466					  VEC(basic_block,heap) **bbs_p);
467extern void add_phi_args_after_copy_bb (basic_block);
468extern void add_phi_args_after_copy (basic_block *, unsigned, edge);
469extern bool gimple_purge_dead_abnormal_call_edges (basic_block);
470extern bool gimple_purge_dead_eh_edges (basic_block);
471extern bool gimple_purge_all_dead_eh_edges (const_bitmap);
472extern tree gimplify_build1 (gimple_stmt_iterator *, enum tree_code,
473			     tree, tree);
474extern tree gimplify_build2 (gimple_stmt_iterator *, enum tree_code,
475			     tree, tree, tree);
476extern tree gimplify_build3 (gimple_stmt_iterator *, enum tree_code,
477			     tree, tree, tree, tree);
478extern void init_empty_tree_cfg (void);
479extern void init_empty_tree_cfg_for_function (struct function *);
480extern void fold_cond_expr_cond (void);
481extern void make_abnormal_goto_edges (basic_block, bool);
482extern void replace_uses_by (tree, tree);
483extern void start_recording_case_labels (void);
484extern void end_recording_case_labels (void);
485extern basic_block move_sese_region_to_fn (struct function *, basic_block,
486				           basic_block, tree);
487void remove_edge_and_dominated_blocks (edge);
488bool tree_node_can_be_shared (tree);
489
490/* In tree-cfgcleanup.c  */
491extern bitmap cfgcleanup_altered_bbs;
492extern bool cleanup_tree_cfg (void);
493
494/* In tree-pretty-print.c.  */
495extern void dump_generic_bb (FILE *, basic_block, int, int);
496extern int op_code_prio (enum tree_code);
497extern int op_prio (const_tree);
498extern const char *op_symbol_code (enum tree_code);
499
500/* In tree-dfa.c  */
501extern var_ann_t create_var_ann (tree);
502extern void renumber_gimple_stmt_uids (void);
503extern void renumber_gimple_stmt_uids_in_blocks (basic_block *, int);
504extern void dump_dfa_stats (FILE *);
505extern void debug_dfa_stats (void);
506extern void debug_referenced_vars (void);
507extern void dump_referenced_vars (FILE *);
508extern void dump_variable (FILE *, tree);
509extern void debug_variable (tree);
510extern tree get_virtual_var (tree);
511extern bool add_referenced_var (tree);
512extern void remove_referenced_var (tree);
513extern void mark_symbols_for_renaming (gimple);
514extern void find_new_referenced_vars (gimple);
515extern tree make_rename_temp (tree, const char *);
516extern void set_default_def (tree, tree);
517extern tree gimple_default_def (struct function *, tree);
518extern bool stmt_references_abnormal_ssa_name (gimple);
519extern tree get_ref_base_and_extent (tree, HOST_WIDE_INT *,
520				     HOST_WIDE_INT *, HOST_WIDE_INT *);
521extern void find_referenced_vars_in (gimple);
522
523/* In tree-phinodes.c  */
524extern void reserve_phi_args_for_new_edge (basic_block);
525extern void add_phi_node_to_bb (gimple phi, basic_block bb);
526extern gimple make_phi_node (tree var, int len);
527extern gimple create_phi_node (tree, basic_block);
528extern void add_phi_arg (gimple, tree, edge, source_location);
529extern void remove_phi_args (edge);
530extern void remove_phi_node (gimple_stmt_iterator *, bool);
531extern void remove_phi_nodes (basic_block);
532extern void init_phinodes (void);
533extern void fini_phinodes (void);
534extern void release_phi_node (gimple);
535#ifdef GATHER_STATISTICS
536extern void phinodes_print_statistics (void);
537#endif
538
539/* In gimple-low.c  */
540extern void record_vars_into (tree, tree);
541extern void record_vars (tree);
542extern bool block_may_fallthru (const_tree);
543extern bool gimple_seq_may_fallthru (gimple_seq);
544extern bool gimple_stmt_may_fallthru (gimple);
545extern bool gimple_check_call_args (gimple);
546
547
548/* In tree-ssa.c  */
549
550/* Mapping for redirected edges.  */
551struct GTY(()) _edge_var_map {
552  tree result;			/* PHI result.  */
553  tree def;			/* PHI arg definition.  */
554  source_location locus;        /* PHI arg location.  */
555};
556typedef struct _edge_var_map edge_var_map;
557
558DEF_VEC_O(edge_var_map);
559DEF_VEC_ALLOC_O(edge_var_map, heap);
560
561/* A vector of var maps.  */
562typedef VEC(edge_var_map, heap) *edge_var_map_vector;
563
564extern void init_tree_ssa (struct function *);
565extern void redirect_edge_var_map_add (edge, tree, tree, source_location);
566extern void redirect_edge_var_map_clear (edge);
567extern void redirect_edge_var_map_dup (edge, edge);
568extern edge_var_map_vector redirect_edge_var_map_vector (edge);
569extern void redirect_edge_var_map_destroy (void);
570
571extern edge ssa_redirect_edge (edge, basic_block);
572extern void flush_pending_stmts (edge);
573extern void verify_ssa (bool);
574extern void delete_tree_ssa (void);
575extern bool ssa_undefined_value_p (tree);
576extern void execute_update_addresses_taken (bool);
577
578/* Call-back function for walk_use_def_chains().  At each reaching
579   definition, a function with this prototype is called.  */
580typedef bool (*walk_use_def_chains_fn) (tree, gimple, void *);
581
582extern void walk_use_def_chains (tree, walk_use_def_chains_fn, void *, bool);
583
584void insert_debug_temps_for_defs (gimple_stmt_iterator *);
585void insert_debug_temp_for_var_def (gimple_stmt_iterator *, tree);
586void release_defs_bitset (bitmap toremove);
587
588/* In tree-into-ssa.c  */
589void update_ssa (unsigned);
590void delete_update_ssa (void);
591void register_new_name_mapping (tree, tree);
592tree create_new_def_for (tree, gimple, def_operand_p);
593bool need_ssa_update_p (struct function *);
594bool name_mappings_registered_p (void);
595bool name_registered_for_update_p (tree);
596bitmap ssa_names_to_replace (void);
597void release_ssa_name_after_update_ssa (tree);
598void compute_global_livein (bitmap, bitmap);
599void mark_sym_for_renaming (tree);
600void mark_set_for_renaming (bitmap);
601tree get_current_def (tree);
602void set_current_def (tree, tree);
603
604/* In tree-ssanames.c  */
605extern void init_ssanames (struct function *, int);
606extern void fini_ssanames (void);
607extern tree make_ssa_name_fn (struct function *, tree, gimple);
608extern tree duplicate_ssa_name (tree, gimple);
609extern void duplicate_ssa_name_ptr_info (tree, struct ptr_info_def *);
610extern void release_ssa_name (tree);
611extern void release_defs (gimple);
612extern void replace_ssa_name_symbol (tree, tree);
613
614#ifdef GATHER_STATISTICS
615extern void ssanames_print_statistics (void);
616#endif
617
618/* In tree-ssa-ccp.c  */
619bool fold_stmt (gimple_stmt_iterator *);
620bool fold_stmt_inplace (gimple);
621tree get_symbol_constant_value (tree);
622tree fold_const_aggregate_ref (tree);
623bool may_propagate_address_into_dereference (tree, tree);
624
625
626/* In tree-ssa-dom.c  */
627extern void dump_dominator_optimization_stats (FILE *);
628extern void debug_dominator_optimization_stats (void);
629int loop_depth_of_name (tree);
630tree degenerate_phi_result (gimple);
631
632/* In tree-ssa-copy.c  */
633extern void propagate_value (use_operand_p, tree);
634extern void propagate_tree_value (tree *, tree);
635extern void propagate_tree_value_into_stmt (gimple_stmt_iterator *, tree);
636extern void replace_exp (use_operand_p, tree);
637extern bool may_propagate_copy (tree, tree);
638extern bool may_propagate_copy_into_stmt (gimple, tree);
639extern bool may_propagate_copy_into_asm (tree);
640
641/* Affine iv.  */
642
643typedef struct
644{
645  /* Iv = BASE + STEP * i.  */
646  tree base, step;
647
648  /* True if this iv does not overflow.  */
649  bool no_overflow;
650} affine_iv;
651
652/* Description of number of iterations of a loop.  All the expressions inside
653   the structure can be evaluated at the end of the loop's preheader
654   (and due to ssa form, also anywhere inside the body of the loop).  */
655
656struct tree_niter_desc
657{
658  tree assumptions;	/* The boolean expression.  If this expression evaluates
659			   to false, then the other fields in this structure
660			   should not be used; there is no guarantee that they
661			   will be correct.  */
662  tree may_be_zero;	/* The boolean expression.  If it evaluates to true,
663			   the loop will exit in the first iteration (i.e.
664			   its latch will not be executed), even if the niter
665			   field says otherwise.  */
666  tree niter;		/* The expression giving the number of iterations of
667			   a loop (provided that assumptions == true and
668			   may_be_zero == false), more precisely the number
669			   of executions of the latch of the loop.  */
670  double_int max;	/* The upper bound on the number of iterations of
671			   the loop.  */
672
673  /* The simplified shape of the exit condition.  The loop exits if
674     CONTROL CMP BOUND is false, where CMP is one of NE_EXPR,
675     LT_EXPR, or GT_EXPR, and step of CONTROL is positive if CMP is
676     LE_EXPR and negative if CMP is GE_EXPR.  This information is used
677     by loop unrolling.  */
678  affine_iv control;
679  tree bound;
680  enum tree_code cmp;
681};
682
683/* In tree-ssa-phiopt.c */
684bool empty_block_p (basic_block);
685basic_block *blocks_in_phiopt_order (void);
686
687/* In tree-ssa-loop*.c  */
688
689void tree_ssa_lim (void);
690unsigned int tree_ssa_unswitch_loops (void);
691unsigned int canonicalize_induction_variables (void);
692unsigned int tree_unroll_loops_completely (bool, bool);
693unsigned int tree_ssa_prefetch_arrays (void);
694void tree_ssa_iv_optimize (void);
695unsigned tree_predictive_commoning (void);
696tree canonicalize_loop_ivs (struct loop *, tree *, bool);
697bool parallelize_loops (void);
698
699bool loop_only_exit_p (const struct loop *, const_edge);
700bool number_of_iterations_exit (struct loop *, edge,
701				struct tree_niter_desc *niter, bool);
702tree find_loop_niter (struct loop *, edge *);
703tree loop_niter_by_eval (struct loop *, edge);
704tree find_loop_niter_by_eval (struct loop *, edge *);
705void estimate_numbers_of_iterations (void);
706bool array_at_struct_end_p (tree);
707bool scev_probably_wraps_p (tree, tree, gimple, struct loop *, bool);
708bool convert_affine_scev (struct loop *, tree, tree *, tree *, gimple, bool);
709
710bool nowrap_type_p (tree);
711enum ev_direction {EV_DIR_GROWS, EV_DIR_DECREASES, EV_DIR_UNKNOWN};
712enum ev_direction scev_direction (const_tree);
713
714void free_numbers_of_iterations_estimates (void);
715void free_numbers_of_iterations_estimates_loop (struct loop *);
716void rewrite_into_loop_closed_ssa (bitmap, unsigned);
717void verify_loop_closed_ssa (void);
718bool for_each_index (tree *, bool (*) (tree, tree *, void *), void *);
719void create_iv (tree, tree, tree, struct loop *, gimple_stmt_iterator *, bool,
720		tree *, tree *);
721basic_block split_loop_exit_edge (edge);
722void standard_iv_increment_position (struct loop *, gimple_stmt_iterator *,
723				     bool *);
724basic_block ip_end_pos (struct loop *);
725basic_block ip_normal_pos (struct loop *);
726bool gimple_duplicate_loop_to_header_edge (struct loop *, edge,
727					 unsigned int, sbitmap,
728					 edge, VEC (edge, heap) **,
729					 int);
730struct loop *slpeel_tree_duplicate_loop_to_edge_cfg (struct loop *, edge);
731void rename_variables_in_loop (struct loop *);
732void rename_variables_in_bb (basic_block bb);
733struct loop *tree_ssa_loop_version (struct loop *, tree,
734				    basic_block *);
735tree expand_simple_operations (tree);
736void substitute_in_loop_info (struct loop *, tree, tree);
737edge single_dom_exit (struct loop *);
738bool can_unroll_loop_p (struct loop *loop, unsigned factor,
739			struct tree_niter_desc *niter);
740void tree_unroll_loop (struct loop *, unsigned,
741		       edge, struct tree_niter_desc *);
742typedef void (*transform_callback)(struct loop *, void *);
743void tree_transform_and_unroll_loop (struct loop *, unsigned,
744				     edge, struct tree_niter_desc *,
745				     transform_callback, void *);
746bool contains_abnormal_ssa_name_p (tree);
747bool stmt_dominates_stmt_p (gimple, gimple);
748void mark_virtual_ops_for_renaming (gimple);
749
750/* In tree-ssa-dce.c */
751void mark_virtual_phi_result_for_renaming (gimple);
752
753/* In tree-ssa-threadedge.c */
754extern void threadedge_initialize_values (void);
755extern void threadedge_finalize_values (void);
756extern VEC(tree,heap) *ssa_name_values;
757#define SSA_NAME_VALUE(x) \
758    (SSA_NAME_VERSION(x) < VEC_length(tree, ssa_name_values) \
759     ? VEC_index(tree, ssa_name_values, SSA_NAME_VERSION(x)) \
760     : NULL_TREE)
761extern void set_ssa_name_value (tree, tree);
762extern bool potentially_threadable_block (basic_block);
763extern void thread_across_edge (gimple, edge, bool,
764				VEC(tree, heap) **, tree (*) (gimple, gimple));
765
766/* In tree-ssa-loop-im.c  */
767/* The possibilities of statement movement.  */
768
769enum move_pos
770  {
771    MOVE_IMPOSSIBLE,		/* No movement -- side effect expression.  */
772    MOVE_PRESERVE_EXECUTION,	/* Must not cause the non-executed statement
773				   become executed -- memory accesses, ... */
774    MOVE_POSSIBLE		/* Unlimited movement.  */
775  };
776extern enum move_pos movement_possibility (gimple);
777char *get_lsm_tmp_name (tree, unsigned);
778
779/* In tree-flow-inline.h  */
780static inline bool is_call_clobbered (const_tree);
781static inline void set_is_used (tree);
782static inline bool unmodifiable_var_p (const_tree);
783static inline bool ref_contains_array_ref (const_tree);
784static inline bool array_ref_contains_indirect_ref (const_tree);
785
786/* In tree-eh.c  */
787extern void make_eh_edges (gimple);
788extern bool make_eh_dispatch_edges (gimple);
789extern edge redirect_eh_edge (edge, basic_block);
790extern void redirect_eh_dispatch_edge (gimple, edge, basic_block);
791extern bool tree_could_trap_p (tree);
792extern bool operation_could_trap_helper_p (enum tree_code, bool, bool, bool,
793					   bool, tree, bool *);
794extern bool operation_could_trap_p (enum tree_code, bool, bool, tree);
795extern bool stmt_could_throw_p (gimple);
796extern bool tree_could_throw_p (tree);
797extern bool stmt_can_throw_internal (gimple);
798extern bool stmt_can_throw_external (gimple);
799extern void add_stmt_to_eh_lp_fn (struct function *, gimple, int);
800extern void add_stmt_to_eh_lp (gimple, int);
801extern bool remove_stmt_from_eh_lp (gimple);
802extern bool remove_stmt_from_eh_lp_fn (struct function *, gimple);
803extern int lookup_stmt_eh_lp_fn (struct function *, gimple);
804extern int lookup_stmt_eh_lp (gimple);
805extern bool maybe_clean_eh_stmt_fn (struct function *, gimple);
806extern bool maybe_clean_eh_stmt (gimple);
807extern bool maybe_clean_or_replace_eh_stmt (gimple, gimple);
808extern bool maybe_duplicate_eh_stmt_fn (struct function *, gimple,
809					struct function *, gimple,
810					struct pointer_map_t *, int);
811extern bool maybe_duplicate_eh_stmt (gimple, gimple);
812extern bool verify_eh_edges (gimple);
813extern bool verify_eh_dispatch_edge (gimple);
814
815/* In tree-ssa-pre.c  */
816struct pre_expr_d;
817void add_to_value (unsigned int, struct pre_expr_d *);
818void debug_value_expressions (unsigned int);
819void print_value_expressions (FILE *, unsigned int);
820
821/* In tree-ssa-sink.c  */
822bool is_hidden_global_store (gimple);
823
824/* In tree-loop-linear.c  */
825extern void linear_transform_loops (void);
826extern unsigned perfect_loop_nest_depth (struct loop *);
827
828/* In graphite.c  */
829extern void graphite_transform_loops (void);
830
831/* In tree-data-ref.c  */
832extern void tree_check_data_deps (void);
833
834/* In tree-ssa-loop-ivopts.c  */
835bool expr_invariant_in_loop_p (struct loop *, tree);
836bool stmt_invariant_in_loop_p (struct loop *, gimple);
837bool multiplier_allowed_in_address_p (HOST_WIDE_INT, enum machine_mode,
838				      addr_space_t);
839unsigned multiply_by_cost (HOST_WIDE_INT, enum machine_mode, bool);
840bool may_be_nonaddressable_p (tree expr);
841
842/* In tree-ssa-threadupdate.c.  */
843extern bool thread_through_all_blocks (bool);
844extern void register_jump_thread (edge, edge);
845
846/* In gimplify.c  */
847tree force_gimple_operand (tree, gimple_seq *, bool, tree);
848tree force_gimple_operand_gsi (gimple_stmt_iterator *, tree, bool, tree,
849			       bool, enum gsi_iterator_update);
850tree gimple_fold_indirect_ref (tree);
851
852/* In tree-ssa-live.c */
853extern void remove_unused_locals (void);
854extern void dump_scope_blocks (FILE *, int);
855extern void debug_scope_blocks (int);
856extern void debug_scope_block (tree, int);
857
858/* In tree-ssa-address.c  */
859
860/* Description of a memory address.  */
861
862struct mem_address
863{
864  tree symbol, base, index, step, offset;
865};
866
867struct affine_tree_combination;
868tree create_mem_ref (gimple_stmt_iterator *, tree,
869		     struct affine_tree_combination *, tree, bool);
870rtx addr_for_mem_ref (struct mem_address *, addr_space_t, bool);
871void get_address_description (tree, struct mem_address *);
872tree maybe_fold_tmr (tree);
873
874unsigned int execute_free_datastructures (void);
875unsigned int execute_fixup_cfg (void);
876
877#include "tree-flow-inline.h"
878
879void swap_tree_operands (gimple, tree *, tree *);
880
881int least_common_multiple (int, int);
882
883#endif /* _TREE_FLOW_H  */
884