gcc/tree-flow.h

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