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, 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22 #ifndef _TREE_FLOW_H
  23 #define _TREE_FLOW_H 1
  24
  25 #include "bitmap.h"
  26 #include "hard-reg-set.h"
  27 #include "basic-block.h"
  28 #include "hashtab.h"
  29 #include "tree-gimple.h"
  30 #include "tree-ssa-operands.h"
  31 #include "cgraph.h"
  32
  33 /* Forward declare structures for the garbage collector GTY markers.  */
  34 #ifndef GCC_BASIC_BLOCK_H
  35 struct edge_def;
  36 typedef struct edge_def *edge;
  37 struct basic_block_def;
  38 typedef struct basic_block_def *basic_block;
  39 #endif
  40
  41 /* True if the code is in ssa form.  */
  42 extern bool in_ssa_p;
  43
  44 /*---------------------------------------------------------------------------
  45                       Attributes for SSA_NAMEs.
  46
  47   NOTE: These structures are stored in struct tree_ssa_name
  48   but are only used by the tree optimizers, so it makes better sense
  49   to declare them here to avoid recompiling unrelated files when
  50   making changes.
  51 ---------------------------------------------------------------------------*/
  52
  53 /* Aliasing information for SSA_NAMEs representing pointer variables.  */
  54 struct ptr_info_def GTY(())
  55 {
  56   /* Nonzero if points-to analysis couldn't determine where this pointer
  57      is pointing to.  */
  58   unsigned int pt_anything : 1;
  59
  60   /* Nonzero if this pointer is the result of a call to malloc.  */
  61   unsigned int pt_malloc : 1;
  62
  63   /* Nonzero if the value of this pointer escapes the current function.  */
  64   unsigned int value_escapes_p : 1;
  65
  66   /* Nonzero if this pointer is dereferenced.  */
  67   unsigned int is_dereferenced : 1;
  68
  69   /* Nonzero if this pointer points to a global variable.  */
  70   unsigned int pt_global_mem : 1;
  71
  72   /* Nonzero if this pointer points to NULL.  */
  73   unsigned int pt_null : 1;
  74
  75   /* Set of variables that this pointer may point to.  */
  76   bitmap pt_vars;
  77
  78   /* If this pointer has been dereferenced, and points-to information is
  79      more precise than type-based aliasing, indirect references to this
  80      pointer will be represented by this memory tag, instead of the type
  81      tag computed by TBAA.  */
  82   tree name_mem_tag;
  83 };
  84
  85
  86 /* Types of value ranges.  */
  87 enum value_range_type { VR_UNDEFINED, VR_RANGE, VR_ANTI_RANGE, VR_VARYING };
  88
  89
  90 /* Ranges of values that can be associated with an SSA_NAME after VRP
  91    has executed.  */
  92 struct value_range_def GTY(())
  93 {
  94   /* Lattice value represented by this range.  */
  95   enum value_range_type type;
  96
  97   /* Minimum and maximum values represented by this range.  These
  98      values are _CST nodes that should be interpreted as follows:
  99
 100         - If TYPE == VR_UNDEFINED then MIN and MAX must be NULL.
 101
 102         - If TYPE == VR_RANGE then MIN holds the minimum value and
 103           MAX holds the maximum value of the range [MIN, MAX].
 104
 105         - If TYPE == ANTI_RANGE the variable is known to NOT
 106           take any values in the range [MIN, MAX].  */
 107   tree min;
 108   tree max;
 109 };
 110
 111 typedef struct value_range_def value_range;
 112
 113
 114 /*---------------------------------------------------------------------------
 115                    Tree annotations stored in tree_common.ann
 116 ---------------------------------------------------------------------------*/
 117 enum tree_ann_type { TREE_ANN_COMMON, VAR_ANN, STMT_ANN };
 118
 119 struct tree_ann_common_d GTY(())
 120 {
 121   /* Annotation type.  */
 122   enum tree_ann_type type;
 123
 124   /* The value handle for this expression.  Used by GVN-PRE.  */
 125   tree GTY((skip)) value_handle;
 126 };
 127
 128 /* It is advantageous to avoid things like life analysis for variables which
 129    do not need PHI nodes.  This enum describes whether or not a particular
 130    variable may need a PHI node.  */
 131
 132 enum need_phi_state {
 133   /* This is the default.  If we are still in this state after finding
 134      all the definition and use sites, then we will assume the variable
 135      needs PHI nodes.  This is probably an overly conservative assumption.  */
 136   NEED_PHI_STATE_UNKNOWN,
 137
 138   /* This state indicates that we have seen one or more sets of the
 139      variable in a single basic block and that the sets dominate all
 140      uses seen so far.  If after finding all definition and use sites
 141      we are still in this state, then the variable does not need any
 142      PHI nodes.  */
 143   NEED_PHI_STATE_NO,
 144
 145   /* This state indicates that we have either seen multiple definitions of
 146      the variable in multiple blocks, or that we encountered a use in a
 147      block that was not dominated by the block containing the set(s) of
 148      this variable.  This variable is assumed to need PHI nodes.  */
 149   NEED_PHI_STATE_MAYBE
 150 };
 151
 152
 153 /* When computing aliasing information, we represent the memory pointed-to
 154    by pointers with artificial variables called "memory tags" (MT).  There
 155    are two kinds of tags: type and name.  Type tags (TMT) are used in
 156    type-based alias analysis, they represent all the pointed-to locations
 157    and variables of the same alias set class.  Name tags (NMT) are used in
 158    flow-sensitive points-to alias analysis, they represent the variables
 159    and memory locations pointed-to by a specific SSA_NAME pointer.  */
 160 enum mem_tag_kind {
 161   /* This variable is not a memory tag.  */
 162   NOT_A_TAG,
 163
 164   /* This variable is a type memory tag (TMT).  */
 165   TYPE_TAG,
 166
 167   /* This variable is a name memory tag (NMT).  */
 168   NAME_TAG,
 169
 170   /* This variable represents a structure field.  */
 171   STRUCT_FIELD
 172 };
 173 struct subvar;
 174 typedef struct subvar *subvar_t;
 175
 176 /* This structure represents a fake sub-variable for a structure field.  */
 177
 178 struct subvar GTY(())
 179 {
 180   /* Fake variable name */
 181   tree var;
 182   /* Offset inside structure.  */
 183   HOST_WIDE_INT offset;
 184   /* Size of field.  */
 185   HOST_WIDE_INT size;
 186   /* Next subvar for this structure.  */
 187   subvar_t next;
 188 };
 189
 190 struct var_ann_d GTY(())
 191 {
 192   struct tree_ann_common_d common;
 193
 194   /* Used by the out of SSA pass to determine whether this variable has
 195      been seen yet or not.  */
 196   unsigned out_of_ssa_tag : 1;
 197
 198   /* Used when building root_var structures in tree_ssa_live.[ch].  */
 199   unsigned root_var_processed : 1;
 200
 201   /* If nonzero, this variable is a memory tag.  */
 202   ENUM_BITFIELD (mem_tag_kind) mem_tag_kind : 2;
 203
 204   /* Nonzero if this variable is an alias tag that represents references to
 205      other variables (i.e., this variable appears in the MAY_ALIASES array
 206      of other variables).  */
 207   unsigned is_alias_tag : 1;
 208
 209   /* Nonzero if this variable was used after SSA optimizations were
 210      applied.  We set this when translating out of SSA form.  */
 211   unsigned used : 1;
 212
 213   /* This field indicates whether or not the variable may need PHI nodes.
 214      See the enum's definition for more detailed information about the
 215      states.  */
 216   ENUM_BITFIELD (need_phi_state) need_phi_state : 2;
 217
 218   /* Used during operand processing to determine if this variable is already
 219      in the vuse list.  */
 220   unsigned in_vuse_list : 1;
 221
 222   /* Used during operand processing to determine if this variable is already
 223      in the v_may_def list.  */
 224   unsigned in_v_may_def_list : 1;
 225
 226   /* An artificial variable representing the memory location pointed-to by
 227      all the pointers that TBAA (type-based alias analysis) considers
 228      to be aliased.  If the variable is not a pointer or if it is never
 229      dereferenced, this must be NULL.  */
 230   tree type_mem_tag;
 231
 232   /* Variables that may alias this variable.  */
 233   varray_type may_aliases;
 234
 235   /* Unique ID of this variable.  */
 236   size_t uid;
 237
 238   /* Used when going out of SSA form to indicate which partition this
 239      variable represents storage for.  */
 240   unsigned partition;
 241
 242   /* Used by the root-var object in tree-ssa-live.[ch].  */
 243   unsigned root_index;
 244
 245   /* Default definition for this symbol.  If this field is not NULL, it
 246      means that the first reference to this variable in the function is a
 247      USE or a VUSE.  In those cases, the SSA renamer creates an SSA name
 248      for this variable with an empty defining statement.  */
 249   tree default_def;
 250
 251   /* During into-ssa and the dominator optimizer, this field holds the
 252      current version of this variable (an SSA_NAME).  */
 253   tree current_def;
 254
 255   /* If this variable is a structure, this fields holds a list of
 256      symbols representing each of the fields of the structure.  */
 257   subvar_t subvars;
 258 };
 259
 260
 261 typedef struct immediate_use_iterator_d
 262 {
 263   ssa_use_operand_t *imm_use;
 264   ssa_use_operand_t *end_p;
 265   ssa_use_operand_t iter_node;
 266 } imm_use_iterator;
 267
 268
 269 /* Use this iterator when simply looking at stmts.  Adding, deleting or
 270    modifying stmts will cause this iterator to malfunction.  */
 271
 272 #define FOR_EACH_IMM_USE_FAST(DEST, ITER, SSAVAR)                       \
 273   for ((DEST) = first_readonly_imm_use (&(ITER), (SSAVAR));     \
 274        !end_readonly_imm_use_p (&(ITER));                       \
 275        (DEST) = next_readonly_imm_use (&(ITER)))
 276
 277
 278 #define FOR_EACH_IMM_USE_SAFE(DEST, ITER, SSAVAR)               \
 279   for ((DEST) = first_safe_imm_use (&(ITER), (SSAVAR));         \
 280        !end_safe_imm_use_p (&(ITER));                           \
 281        (DEST) = next_safe_imm_use (&(ITER)))
 282
 283 #define BREAK_FROM_SAFE_IMM_USE(ITER)                           \
 284    {                                                            \
 285      end_safe_imm_use_traverse (&(ITER));                       \
 286      break;                                                     \
 287    }
 288
 289 struct stmt_ann_d GTY(())
 290 {
 291   struct tree_ann_common_d common;
 292
 293   /* Nonzero if the statement has been modified (meaning that the operands
 294      need to be scanned again).  */
 295   unsigned modified : 1;
 296
 297   /* Nonzero if the statement makes aliased loads.  */
 298   unsigned makes_aliased_loads : 1;
 299
 300   /* Nonzero if the statement makes aliased stores.  */
 301   unsigned makes_aliased_stores : 1;
 302
 303   /* Nonzero if the statement makes references to volatile storage.  */
 304   unsigned has_volatile_ops : 1;
 305
 306   /* Nonzero if the statement makes a function call that may clobber global
 307      and local addressable variables.  */
 308   unsigned makes_clobbering_call : 1;
 309
 310   /* Basic block that contains this statement.  */
 311   basic_block GTY ((skip (""))) bb;
 312
 313   /* Operand cache for stmt.  */
 314   struct stmt_operands_d GTY ((skip (""))) operands;
 315
 316   /* Set of variables that have had their address taken in the statement.  */
 317   bitmap addresses_taken;
 318
 319   /* Unique identifier for this statement.  These ID's are to be created
 320      by each pass on an as-needed basis in any order convenient for the
 321      pass which needs statement UIDs.  */
 322   unsigned int uid;
 323
 324  /* Auxiliary info specific to a pass.  At all times, this
 325     should either point to valid data or be NULL.  */
 326   PTR GTY ((skip (""))) aux;
 327
 328   /* Linked list of histograms for value-based profiling.  This is really a
 329      struct histogram_value*.  We use void* to avoid having to export that
 330      everywhere, and to avoid having to put it in GC memory.  */
 331
 332   void * GTY ((skip (""))) histograms;
 333 };
 334
 335 union tree_ann_d GTY((desc ("ann_type ((tree_ann_t)&%h)")))
 336 {
 337   struct tree_ann_common_d GTY((tag ("TREE_ANN_COMMON"))) common;
 338   struct var_ann_d GTY((tag ("VAR_ANN"))) decl;
 339   struct stmt_ann_d GTY((tag ("STMT_ANN"))) stmt;
 340 };
 341
 342 extern GTY(()) VEC(tree,gc) *modified_noreturn_calls;
 343
 344 typedef union tree_ann_d *tree_ann_t;
 345 typedef struct var_ann_d *var_ann_t;
 346 typedef struct stmt_ann_d *stmt_ann_t;
 347
 348 static inline tree_ann_t tree_ann (tree);
 349 static inline tree_ann_t get_tree_ann (tree);
 350 static inline var_ann_t var_ann (tree);
 351 static inline var_ann_t get_var_ann (tree);
 352 static inline stmt_ann_t stmt_ann (tree);
 353 static inline stmt_ann_t get_stmt_ann (tree);
 354 static inline enum tree_ann_type ann_type (tree_ann_t);
 355 static inline basic_block bb_for_stmt (tree);
 356 extern void set_bb_for_stmt (tree, basic_block);
 357 static inline bool noreturn_call_p (tree);
 358 static inline void update_stmt (tree);
 359 static inline bool stmt_modified_p (tree);
 360 static inline varray_type may_aliases (tree);
 361 static inline int get_lineno (tree);
 362 static inline const char *get_filename (tree);
 363 static inline bool is_exec_stmt (tree);
 364 static inline bool is_label_stmt (tree);
 365 static inline bitmap addresses_taken (tree);
 366 static inline void set_default_def (tree, tree);
 367 static inline tree default_def (tree);
 368
 369 /*---------------------------------------------------------------------------
 370                   Structure representing predictions in tree level.
 371 ---------------------------------------------------------------------------*/
 372 struct edge_prediction GTY((chain_next ("%h.next")))
 373 {
 374   struct edge_prediction *next;
 375   edge edge;
 376   enum br_predictor predictor;
 377   int probability;
 378 };
 379
 380 /*---------------------------------------------------------------------------
 381                   Block annotations stored in basic_block.tree_annotations
 382 ---------------------------------------------------------------------------*/
 383 struct bb_ann_d GTY(())
 384 {
 385   /* Chain of PHI nodes for this block.  */
 386   tree phi_nodes;
 387
 388   /* Nonzero if this block contains an escape point (see is_escape_site).  */
 389   unsigned has_escape_site : 1;
 390
 391   /* Nonzero if one or more incoming edges to this block should be threaded
 392      to an outgoing edge of this block.  */
 393   unsigned incoming_edge_threaded : 1;
 394
 395   struct edge_prediction *predictions;
 396 };
 397
 398 typedef struct bb_ann_d *bb_ann_t;
 399
 400 /* Accessors for basic block annotations.  */
 401 static inline bb_ann_t bb_ann (basic_block);
 402 static inline tree phi_nodes (basic_block);
 403 static inline void set_phi_nodes (basic_block, tree);
 404
 405 /*---------------------------------------------------------------------------
 406                               Global declarations
 407 ---------------------------------------------------------------------------*/
 408 /* Array of all variables referenced in the function.  */
 409 extern GTY(()) VEC(tree,gc) *referenced_vars;
 410
 411 #define num_referenced_vars VEC_length (tree, referenced_vars)
 412 #define referenced_var(i) VEC_index (tree, referenced_vars, i)
 413
 414 /* Array of all SSA_NAMEs used in the function.  */
 415 extern GTY(()) VEC(tree,gc) *ssa_names;
 416
 417 #define num_ssa_names (VEC_length (tree, ssa_names))
 418 #define ssa_name(i) (VEC_index (tree, ssa_names, (i)))
 419
 420 /* Artificial variable used to model the effects of function calls.  */
 421 extern GTY(()) tree global_var;
 422
 423 /* Call clobbered variables in the function.  If bit I is set, then
 424    REFERENCED_VARS (I) is call-clobbered.  */
 425 extern bitmap call_clobbered_vars;
 426
 427 /* Addressable variables in the function.  If bit I is set, then
 428    REFERENCED_VARS (I) has had its address taken.  */
 429 extern bitmap addressable_vars;
 430
 431 /* 'true' after aliases have been computed (see compute_may_aliases).  */
 432 extern bool aliases_computed_p;
 433
 434 /* Macros for showing usage statistics.  */
 435 #define SCALE(x) ((unsigned long) ((x) < 1024*10        \
 436                   ? (x)                                 \
 437                   : ((x) < 1024*1024*10                 \
 438                      ? (x) / 1024                       \
 439                      : (x) / (1024*1024))))
 440
 441 #define LABEL(x) ((x) < 1024*10 ? 'b' : ((x) < 1024*1024*10 ? 'k' : 'M'))
 442
 443 #define PERCENT(x,y) ((float)(x) * 100.0 / (float)(y))
 444
 445 /*---------------------------------------------------------------------------
 446                               Block iterators
 447 ---------------------------------------------------------------------------*/
 448
 449 typedef struct {
 450   tree_stmt_iterator tsi;
 451   basic_block bb;
 452 } block_stmt_iterator;
 453
 454 static inline block_stmt_iterator bsi_start (basic_block);
 455 static inline block_stmt_iterator bsi_last (basic_block);
 456 static inline block_stmt_iterator bsi_after_labels (basic_block);
 457 block_stmt_iterator bsi_for_stmt (tree);
 458 static inline bool bsi_end_p (block_stmt_iterator);
 459 static inline void bsi_next (block_stmt_iterator *);
 460 static inline void bsi_prev (block_stmt_iterator *);
 461 static inline tree bsi_stmt (block_stmt_iterator);
 462 static inline tree * bsi_stmt_ptr (block_stmt_iterator);
 463
 464 extern void bsi_remove (block_stmt_iterator *);
 465 extern void bsi_move_before (block_stmt_iterator *, block_stmt_iterator *);
 466 extern void bsi_move_after (block_stmt_iterator *, block_stmt_iterator *);
 467 extern void bsi_move_to_bb_end (block_stmt_iterator *, basic_block);
 468
 469 enum bsi_iterator_update
 470 {
 471   /* Note that these are intentionally in the same order as TSI_FOO.  They
 472      mean exactly the same as their TSI_* counterparts.  */
 473   BSI_NEW_STMT,
 474   BSI_SAME_STMT,
 475   BSI_CHAIN_START,
 476   BSI_CHAIN_END,
 477   BSI_CONTINUE_LINKING
 478 };
 479
 480 extern void bsi_insert_before (block_stmt_iterator *, tree,
 481                                enum bsi_iterator_update);
 482 extern void bsi_insert_after (block_stmt_iterator *, tree,
 483                               enum bsi_iterator_update);
 484
 485 extern void bsi_replace (const block_stmt_iterator *, tree, bool);
 486
 487 /*---------------------------------------------------------------------------
 488                               Function prototypes
 489 ---------------------------------------------------------------------------*/
 490 /* In tree-cfg.c  */
 491
 492 /* Location to track pending stmt for edge insertion.  */
 493 #define PENDING_STMT(e) ((e)->insns.t)
 494
 495 extern void delete_tree_cfg_annotations (void);
 496 extern void disband_implicit_edges (void);
 497 extern bool stmt_ends_bb_p (tree);
 498 extern bool is_ctrl_stmt (tree);
 499 extern bool is_ctrl_altering_stmt (tree);
 500 extern bool computed_goto_p (tree);
 501 extern bool simple_goto_p (tree);
 502 extern void tree_dump_bb (basic_block, FILE *, int);
 503 extern void debug_tree_bb (basic_block);
 504 extern basic_block debug_tree_bb_n (int);
 505 extern void dump_tree_cfg (FILE *, int);
 506 extern void debug_tree_cfg (int);
 507 extern void dump_cfg_stats (FILE *);
 508 extern void debug_cfg_stats (void);
 509 extern void debug_loop_ir (void);
 510 extern void print_loop_ir (FILE *);
 511 extern void cleanup_dead_labels (void);
 512 extern void group_case_labels (void);
 513 extern bool cleanup_tree_cfg (void);
 514 extern void cleanup_tree_cfg_loop (void);
 515 extern tree first_stmt (basic_block);
 516 extern tree last_stmt (basic_block);
 517 extern tree *last_stmt_ptr (basic_block);
 518 extern tree last_and_only_stmt (basic_block);
 519 extern edge find_taken_edge (basic_block, tree);
 520 extern basic_block label_to_block_fn (struct function *, tree);
 521 #define label_to_block(t) (label_to_block_fn (cfun, t))
 522 extern void bsi_insert_on_edge (edge, tree);
 523 extern basic_block bsi_insert_on_edge_immediate (edge, tree);
 524 extern void bsi_commit_one_edge_insert (edge, basic_block *);
 525 extern void bsi_commit_edge_inserts (void);
 526 extern void notice_special_calls (tree);
 527 extern void clear_special_calls (void);
 528 extern void verify_stmts (void);
 529 extern tree tree_block_label (basic_block);
 530 extern void extract_true_false_edges_from_block (basic_block, edge *, edge *);
 531 extern bool tree_duplicate_sese_region (edge, edge, basic_block *, unsigned,
 532                                         basic_block *);
 533 extern void add_phi_args_after_copy_bb (basic_block);
 534 extern void add_phi_args_after_copy (basic_block *, unsigned);
 535 extern bool tree_purge_dead_eh_edges (basic_block);
 536 extern bool tree_purge_all_dead_eh_edges (bitmap);
 537 extern tree gimplify_val (block_stmt_iterator *, tree, tree);
 538 extern tree gimplify_build1 (block_stmt_iterator *, enum tree_code,
 539                              tree, tree);
 540 extern tree gimplify_build2 (block_stmt_iterator *, enum tree_code,
 541                              tree, tree, tree);
 542 extern tree gimplify_build3 (block_stmt_iterator *, enum tree_code,
 543                              tree, tree, tree, tree);
 544 extern void init_empty_tree_cfg (void);
 545 extern void fold_cond_expr_cond (void);
 546 extern void replace_uses_by (tree, tree);
 547
 548 /* In tree-pretty-print.c.  */
 549 extern void dump_generic_bb (FILE *, basic_block, int, int);
 550
 551 /* In tree-dfa.c  */
 552 extern var_ann_t create_var_ann (tree);
 553 extern stmt_ann_t create_stmt_ann (tree);
 554 extern tree_ann_t create_tree_ann (tree);
 555 extern void reserve_phi_args_for_new_edge (basic_block);
 556 extern tree create_phi_node (tree, basic_block);
 557 extern void add_phi_arg (tree, tree, edge);
 558 extern void remove_phi_args (edge);
 559 extern void remove_phi_node (tree, tree);
 560 extern tree phi_reverse (tree);
 561 extern void dump_dfa_stats (FILE *);
 562 extern void debug_dfa_stats (void);
 563 extern void debug_referenced_vars (void);
 564 extern void dump_referenced_vars (FILE *);
 565 extern void dump_variable (FILE *, tree);
 566 extern void debug_variable (tree);
 567 extern tree get_virtual_var (tree);
 568 extern void add_referenced_tmp_var (tree);
 569 extern void mark_new_vars_to_rename (tree);
 570 extern void find_new_referenced_vars (tree *);
 571
 572 extern tree make_rename_temp (tree, const char *);
 573
 574 /* In gimple-low.c  */
 575 extern void record_vars (tree);
 576 extern bool block_may_fallthru (tree block);
 577
 578 /* In tree-ssa-alias.c  */
 579 extern void dump_may_aliases_for (FILE *, tree);
 580 extern void debug_may_aliases_for (tree);
 581 extern void dump_alias_info (FILE *);
 582 extern void debug_alias_info (void);
 583 extern void dump_points_to_info (FILE *);
 584 extern void debug_points_to_info (void);
 585 extern void dump_points_to_info_for (FILE *, tree);
 586 extern void debug_points_to_info_for (tree);
 587 extern bool may_be_aliased (tree);
 588 extern struct ptr_info_def *get_ptr_info (tree);
 589 extern void add_type_alias (tree, tree);
 590 extern void count_uses_and_derefs (tree, tree, unsigned *, unsigned *, bool *);
 591 static inline subvar_t get_subvars_for_var (tree);
 592 static inline bool ref_contains_array_ref (tree);
 593 extern tree okay_component_ref_for_subvars (tree, HOST_WIDE_INT *,
 594                                             HOST_WIDE_INT *);
 595 static inline bool var_can_have_subvars (tree);
 596 static inline bool overlap_subvar (HOST_WIDE_INT, HOST_WIDE_INT,
 597                                    subvar_t, bool *);
 598
 599 /* Call-back function for walk_use_def_chains().  At each reaching
 600    definition, a function with this prototype is called.  */
 601 typedef bool (*walk_use_def_chains_fn) (tree, tree, void *);
 602
 603
 604 /* In tree-ssa.c  */
 605 extern void init_tree_ssa (void);
 606 extern edge ssa_redirect_edge (edge, basic_block);
 607 extern void flush_pending_stmts (edge);
 608 extern bool tree_ssa_useless_type_conversion (tree);
 609 extern bool tree_ssa_useless_type_conversion_1 (tree, tree);
 610 extern void verify_ssa (bool);
 611 extern void delete_tree_ssa (void);
 612 extern void register_new_def (tree, VEC(tree,heap) **);
 613 extern void walk_use_def_chains (tree, walk_use_def_chains_fn, void *, bool);
 614 extern bool stmt_references_memory_p (tree);
 615
 616 /* In tree-into-ssa.c  */
 617 void update_ssa (unsigned);
 618 void delete_update_ssa (void);
 619 void register_new_name_mapping (tree, tree);
 620 tree create_new_def_for (tree, tree, def_operand_p);
 621 bool need_ssa_update_p (void);
 622 bool name_registered_for_update_p (tree);
 623 bitmap ssa_names_to_replace (void);
 624 void release_ssa_name_after_update_ssa (tree name);
 625 void compute_global_livein (bitmap, bitmap);
 626 tree duplicate_ssa_name (tree, tree);
 627 void mark_sym_for_renaming (tree);
 628 void mark_set_for_renaming (bitmap);
 629 tree get_current_def (tree);
 630 void set_current_def (tree, tree);
 631
 632 /* In tree-ssa-ccp.c  */
 633 bool fold_stmt (tree *);
 634 bool fold_stmt_inplace (tree);
 635 tree widen_bitfield (tree, tree, tree);
 636
 637 /* In tree-vrp.c  */
 638 value_range *get_value_range (tree);
 639 void dump_value_range (FILE *, value_range *);
 640 void debug_value_range (value_range *);
 641 void dump_all_value_ranges (FILE *);
 642 void debug_all_value_ranges (void);
 643 bool expr_computes_nonzero (tree);
 644
 645 /* In tree-ssa-dom.c  */
 646 extern void dump_dominator_optimization_stats (FILE *);
 647 extern void debug_dominator_optimization_stats (void);
 648 int loop_depth_of_name (tree);
 649
 650 /* In tree-ssa-copy.c  */
 651 extern void propagate_value (use_operand_p, tree);
 652 extern void propagate_tree_value (tree *, tree);
 653 extern void replace_exp (use_operand_p, tree);
 654 extern bool may_propagate_copy (tree, tree);
 655 extern bool may_propagate_copy_into_asm (tree);
 656
 657 /* Description of number of iterations of a loop.  All the expressions inside
 658    the structure can be evaluated at the end of the loop's preheader
 659    (and due to ssa form, also anywhere inside the body of the loop).  */
 660
 661 struct tree_niter_desc
 662 {
 663   tree assumptions;     /* The boolean expression.  If this expression evaluates
 664                            to false, then the other fields in this structure
 665                            should not be used; there is no guarantee that they
 666                            will be correct.  */
 667   tree may_be_zero;     /* The boolean expression.  If it evaluates to true,
 668                            the loop will exit in the first iteration (i.e.
 669                            its latch will not be executed), even if the niter
 670                            field says otherwise.  */
 671   tree niter;           /* The expression giving the number of iterations of
 672                            a loop (provided that assumptions == true and
 673                            may_be_zero == false), more precisely the number
 674                            of executions of the latch of the loop.  */
 675   tree additional_info; /* The boolean expression.  Sometimes we use additional
 676                            knowledge to simplify the other expressions
 677                            contained in this structure (for example the
 678                            knowledge about value ranges of operands on entry to
 679                            the loop).  If this is a case, conjunction of such
 680                            condition is stored in this field, so that we do not
 681                            lose the information: for example if may_be_zero
 682                            is (n <= 0) and niter is (unsigned) n, we know
 683                            that the number of iterations is at most
 684                            MAX_SIGNED_INT.  However if the (n <= 0) assumption
 685                            is eliminated (by looking at the guard on entry of
 686                            the loop), then the information would be lost.  */
 687 };
 688
 689 /* In tree-vectorizer.c */
 690 void vectorize_loops (struct loops *);
 691
 692 /* In tree-ssa-phiopt.c */
 693 bool empty_block_p (basic_block);
 694
 695 /* In tree-ssa-loop*.c  */
 696
 697 void tree_ssa_lim (struct loops *);
 698 void tree_ssa_unswitch_loops (struct loops *);
 699 void canonicalize_induction_variables (struct loops *);
 700 void tree_unroll_loops_completely (struct loops *, bool);
 701 void tree_ssa_iv_optimize (struct loops *);
 702
 703 bool number_of_iterations_exit (struct loop *, edge,
 704                                 struct tree_niter_desc *niter);
 705 tree find_loop_niter (struct loop *, edge *);
 706 tree loop_niter_by_eval (struct loop *, edge);
 707 tree find_loop_niter_by_eval (struct loop *, edge *);
 708 void estimate_numbers_of_iterations (struct loops *);
 709 tree can_count_iv_in_wider_type (struct loop *, tree, tree, tree, tree);
 710 void free_numbers_of_iterations_estimates (struct loops *);
 711 void rewrite_into_loop_closed_ssa (bitmap, unsigned);
 712 void verify_loop_closed_ssa (void);
 713 void loop_commit_inserts (void);
 714 bool for_each_index (tree *, bool (*) (tree, tree *, void *), void *);
 715 void create_iv (tree, tree, tree, struct loop *, block_stmt_iterator *, bool,
 716                 tree *, tree *);
 717 void split_loop_exit_edge (edge);
 718 basic_block bsi_insert_on_edge_immediate_loop (edge, tree);
 719 void standard_iv_increment_position (struct loop *, block_stmt_iterator *,
 720                                      bool *);
 721 basic_block ip_end_pos (struct loop *);
 722 basic_block ip_normal_pos (struct loop *);
 723 bool tree_duplicate_loop_to_header_edge (struct loop *, edge, struct loops *,
 724                                          unsigned int, sbitmap,
 725                                          edge, edge *,
 726                                          unsigned int *, int);
 727 struct loop *tree_ssa_loop_version (struct loops *, struct loop *, tree,
 728                                     basic_block *);
 729 tree expand_simple_operations (tree);
 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
 782 /* In tree-loop-linear.c  */
 783 extern void linear_transform_loops (struct loops *);
 784
 785 /* In tree-ssa-loop-ivopts.c  */
 786 extern bool expr_invariant_in_loop_p (struct loop *, tree);
 787
 788 /* In gimplify.c  */
 789 tree force_gimple_operand (tree, tree *, bool, tree);
 790 tree force_gimple_operand_bsi (block_stmt_iterator *, tree, bool, tree);
 791
 792 #include "tree-flow-inline.h"
 793
 794 #endif /* _TREE_FLOW_H  */