gomp-20050608-branch/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   /* Mask of reasons this pointer's value escapes the function  */
  97   unsigned int escape_mask;
  98 };
  99
 100
 101 /*---------------------------------------------------------------------------
 102                    Tree annotations stored in tree_common.ann
 103 ---------------------------------------------------------------------------*/
 104 enum tree_ann_type { TREE_ANN_COMMON, VAR_ANN, FUNCTION_ANN, STMT_ANN };
 105
 106 struct tree_ann_common_d GTY(())
 107 {
 108   /* Annotation type.  */
 109   enum tree_ann_type type;
 110
 111  /* Auxiliary info specific to a pass.  At all times, this
 112     should either point to valid data or be NULL.  */
 113   PTR GTY ((skip (""))) aux;
 114
 115   /* The value handle for this expression.  Used by GVN-PRE.  */
 116   tree GTY((skip)) value_handle;
 117 };
 118
 119 /* It is advantageous to avoid things like life analysis for variables which
 120    do not need PHI nodes.  This enum describes whether or not a particular
 121    variable may need a PHI node.  */
 122
 123 enum need_phi_state {
 124   /* This is the default.  If we are still in this state after finding
 125      all the definition and use sites, then we will assume the variable
 126      needs PHI nodes.  This is probably an overly conservative assumption.  */
 127   NEED_PHI_STATE_UNKNOWN,
 128
 129   /* This state indicates that we have seen one or more sets of the
 130      variable in a single basic block and that the sets dominate all
 131      uses seen so far.  If after finding all definition and use sites
 132      we are still in this state, then the variable does not need any
 133      PHI nodes.  */
 134   NEED_PHI_STATE_NO,
 135
 136   /* This state indicates that we have either seen multiple definitions of
 137      the variable in multiple blocks, or that we encountered a use in a
 138      block that was not dominated by the block containing the set(s) of
 139      this variable.  This variable is assumed to need PHI nodes.  */
 140   NEED_PHI_STATE_MAYBE
 141 };
 142
 143 struct subvar;
 144 typedef struct subvar *subvar_t;
 145
 146 /* This structure represents a fake sub-variable for a structure field.  */
 147 struct subvar GTY(())
 148 {
 149   /* Fake variable.  */
 150   tree var;
 151
 152   /* Next subvar for this structure.  */
 153   subvar_t next;
 154 };
 155
 156 struct var_ann_d GTY(())
 157 {
 158   struct tree_ann_common_d common;
 159
 160   /* Used by the out of SSA pass to determine whether this variable has
 161      been seen yet or not.  */
 162   unsigned out_of_ssa_tag : 1;
 163
 164   /* Used when building root_var structures in tree_ssa_live.[ch].  */
 165   unsigned root_var_processed : 1;
 166
 167   /* Nonzero if this variable is an alias tag that represents references to
 168      other variables (i.e., this variable appears in the MAY_ALIASES array
 169      of other variables).  */
 170   unsigned is_alias_tag : 1;
 171
 172   /* Nonzero if this variable was used after SSA optimizations were
 173      applied.  We set this when translating out of SSA form.  */
 174   unsigned used : 1;
 175
 176   /* This field indicates whether or not the variable may need PHI nodes.
 177      See the enum's definition for more detailed information about the
 178      states.  */
 179   ENUM_BITFIELD (need_phi_state) need_phi_state : 2;
 180
 181   /* Used during operand processing to determine if this variable is already
 182      in the vuse list.  */
 183   unsigned in_vuse_list : 1;
 184
 185   /* Used during operand processing to determine if this variable is already
 186      in the v_may_def list.  */
 187   unsigned in_v_may_def_list : 1;
 188
 189   /* An artificial variable representing the memory location pointed-to by
 190      all the pointers that TBAA (type-based alias analysis) considers
 191      to be aliased.  If the variable is not a pointer or if it is never
 192      dereferenced, this must be NULL.  */
 193   tree type_mem_tag;
 194
 195   /* Variables that may alias this variable.  */
 196   VEC(tree, gc) *may_aliases;
 197
 198   /* Used when going out of SSA form to indicate which partition this
 199      variable represents storage for.  */
 200   unsigned partition;
 201
 202   /* Used by the root-var object in tree-ssa-live.[ch].  */
 203   unsigned root_index;
 204
 205   /* During into-ssa and the dominator optimizer, this field holds the
 206      current version of this variable (an SSA_NAME).  */
 207   tree current_def;
 208
 209
 210   /* If this variable is a structure, this fields holds a list of
 211      symbols representing each of the fields of the structure.  */
 212   subvar_t subvars;
 213
 214   /* Mask of values saying the reasons why this variable has escaped
 215      the function.  */
 216   unsigned int escape_mask;
 217 };
 218
 219 struct function_ann_d GTY(())
 220 {
 221   struct tree_ann_common_d common;
 222
 223   /* Pointer to the structure that contains the sets of global
 224      variables modified by function calls.  This field is only used
 225      for FUNCTION_DECLs.  */
 226   ipa_reference_vars_info_t GTY ((skip)) reference_vars_info;
 227 };
 228
 229 typedef struct immediate_use_iterator_d
 230 {
 231   ssa_use_operand_t *imm_use;
 232   ssa_use_operand_t *end_p;
 233   ssa_use_operand_t iter_node;
 234 } imm_use_iterator;
 235
 236
 237 /* Use this iterator when simply looking at stmts.  Adding, deleting or
 238    modifying stmts will cause this iterator to malfunction.  */
 239
 240 #define FOR_EACH_IMM_USE_FAST(DEST, ITER, SSAVAR)                       \
 241   for ((DEST) = first_readonly_imm_use (&(ITER), (SSAVAR));     \
 242        !end_readonly_imm_use_p (&(ITER));                       \
 243        (DEST) = next_readonly_imm_use (&(ITER)))
 244
 245
 246 #define FOR_EACH_IMM_USE_SAFE(DEST, ITER, SSAVAR)               \
 247   for ((DEST) = first_safe_imm_use (&(ITER), (SSAVAR));         \
 248        !end_safe_imm_use_p (&(ITER));                           \
 249        (DEST) = next_safe_imm_use (&(ITER)))
 250
 251 #define BREAK_FROM_SAFE_IMM_USE(ITER)                           \
 252    {                                                            \
 253      end_safe_imm_use_traverse (&(ITER));                       \
 254      break;                                                     \
 255    }
 256
 257 struct stmt_ann_d GTY(())
 258 {
 259   struct tree_ann_common_d common;
 260
 261   /* Nonzero if the statement has been modified (meaning that the operands
 262      need to be scanned again).  */
 263   unsigned modified : 1;
 264
 265   /* Nonzero if the statement makes references to volatile storage.  */
 266   unsigned has_volatile_ops : 1;
 267
 268   /* Nonzero if the statement makes a function call that may clobber global
 269      and local addressable variables.  */
 270   unsigned makes_clobbering_call : 1;
 271
 272   /* Basic block that contains this statement.  */
 273   basic_block bb;
 274
 275   /* Operand cache for stmt.  */
 276   struct stmt_operands_d GTY ((skip (""))) operands;
 277
 278   /* Set of variables that have had their address taken in the statement.  */
 279   bitmap addresses_taken;
 280
 281   /* Unique identifier for this statement.  These ID's are to be created
 282      by each pass on an as-needed basis in any order convenient for the
 283      pass which needs statement UIDs.  */
 284   unsigned int uid;
 285
 286   /* Linked list of histograms for value-based profiling.  This is really a
 287      struct histogram_value*.  We use void* to avoid having to export that
 288      everywhere, and to avoid having to put it in GC memory.  */
 289
 290   void * GTY ((skip (""))) histograms;
 291 };
 292
 293 union tree_ann_d GTY((desc ("ann_type ((tree_ann_t)&%h)")))
 294 {
 295   struct tree_ann_common_d GTY((tag ("TREE_ANN_COMMON"))) common;
 296   struct var_ann_d GTY((tag ("VAR_ANN"))) vdecl;
 297   struct function_ann_d GTY((tag ("FUNCTION_ANN"))) fdecl;
 298   struct stmt_ann_d GTY((tag ("STMT_ANN"))) stmt;
 299 };
 300
 301 extern GTY(()) VEC(tree,gc) *modified_noreturn_calls;
 302
 303 typedef union tree_ann_d *tree_ann_t;
 304 typedef struct var_ann_d *var_ann_t;
 305 typedef struct function_ann_d *function_ann_t;
 306 typedef struct stmt_ann_d *stmt_ann_t;
 307
 308 static inline tree_ann_t tree_ann (tree);
 309 static inline tree_ann_t get_tree_ann (tree);
 310 static inline var_ann_t var_ann (tree);
 311 static inline var_ann_t get_var_ann (tree);
 312 static inline function_ann_t function_ann (tree);
 313 static inline function_ann_t get_function_ann (tree);
 314 static inline stmt_ann_t stmt_ann (tree);
 315 static inline stmt_ann_t get_stmt_ann (tree);
 316 static inline enum tree_ann_type ann_type (tree_ann_t);
 317 static inline basic_block bb_for_stmt (tree);
 318 extern void set_bb_for_stmt (tree, basic_block);
 319 static inline bool noreturn_call_p (tree);
 320 static inline void update_stmt (tree);
 321 static inline bool stmt_modified_p (tree);
 322 static inline VEC(tree, gc) *may_aliases (tree);
 323 static inline int get_lineno (tree);
 324 static inline const char *get_filename (tree);
 325 static inline bool is_exec_stmt (tree);
 326 static inline bool is_label_stmt (tree);
 327 static inline bitmap addresses_taken (tree);
 328
 329 /*---------------------------------------------------------------------------
 330                   Structure representing predictions in tree level.
 331 ---------------------------------------------------------------------------*/
 332 struct edge_prediction GTY((chain_next ("%h.ep_next")))
 333 {
 334   struct edge_prediction *ep_next;
 335   edge ep_edge;
 336   enum br_predictor ep_predictor;
 337   int ep_probability;
 338 };
 339
 340 /* Accessors for basic block annotations.  */
 341 static inline tree phi_nodes (basic_block);
 342 static inline void set_phi_nodes (basic_block, tree);
 343
 344 /*---------------------------------------------------------------------------
 345                               Global declarations
 346 ---------------------------------------------------------------------------*/
 347 struct int_tree_map GTY(())
 348 {
 349
 350   unsigned int uid;
 351   tree to;
 352 };
 353
 354 extern unsigned int int_tree_map_hash (const void *);
 355 extern int int_tree_map_eq (const void *, const void *);
 356
 357 typedef struct
 358 {
 359   htab_iterator hti;
 360 } referenced_var_iterator;
 361
 362
 363 /* This macro loops over all the referenced vars, one at a time, putting the
 364    current var in VAR.  Note:  You are not allowed to add referenced variables
 365    to the hashtable while using this macro.  Doing so may cause it to behave
 366    erratically.  */
 367
 368 #define FOR_EACH_REFERENCED_VAR(VAR, ITER) \
 369   for ((VAR) = first_referenced_var (&(ITER)); \
 370        !end_referenced_vars_p (&(ITER)); \
 371        (VAR) = next_referenced_var (&(ITER)))
 372
 373
 374 typedef struct
 375 {
 376   int i;
 377 } safe_referenced_var_iterator;
 378
 379 /* This macro loops over all the referenced vars, one at a time, putting the
 380    current var in VAR.  You are allowed to add referenced variables during the
 381    execution of this macro, however, the macro will not iterate over them.  It
 382    requires a temporary vector of trees, VEC, whose lifetime is controlled by
 383    the caller.  The purpose of the vector is to temporarily store the
 384    referenced_variables hashtable so that adding referenced variables does not
 385    affect the hashtable.  */
 386
 387 #define FOR_EACH_REFERENCED_VAR_SAFE(VAR, VEC, ITER) \
 388   for ((ITER).i = 0, fill_referenced_var_vec (&(VEC)); \
 389        VEC_iterate (tree, (VEC), (ITER).i, (VAR)); \
 390        (ITER).i++)
 391
 392 /* Array of all variables referenced in the function.  */
 393 extern GTY((param_is (struct int_tree_map))) htab_t referenced_vars;
 394
 395 /* Default defs for undefined symbols. */
 396 extern GTY((param_is (struct int_tree_map))) htab_t default_defs;
 397
 398 extern tree referenced_var_lookup (unsigned int);
 399 extern tree referenced_var_lookup_if_exists (unsigned int);
 400 #define num_referenced_vars htab_elements (referenced_vars)
 401 #define referenced_var(i) referenced_var_lookup (i)
 402
 403 /* Array of all SSA_NAMEs used in the function.  */
 404 extern GTY(()) VEC(tree,gc) *ssa_names;
 405
 406 #define num_ssa_names (VEC_length (tree, ssa_names))
 407 #define ssa_name(i) (VEC_index (tree, ssa_names, (i)))
 408
 409 /* Artificial variable used to model the effects of function calls.  */
 410 extern GTY(()) tree global_var;
 411
 412 /* Call clobbered variables in the function.  If bit I is set, then
 413    REFERENCED_VARS (I) is call-clobbered.  */
 414 extern bitmap call_clobbered_vars;
 415
 416 /* Addressable variables in the function.  If bit I is set, then
 417    REFERENCED_VARS (I) has had its address taken.  */
 418 extern bitmap addressable_vars;
 419
 420 /* 'true' after aliases have been computed (see compute_may_aliases).  */
 421 extern bool aliases_computed_p;
 422
 423 /* Macros for showing usage statistics.  */
 424 #define SCALE(x) ((unsigned long) ((x) < 1024*10        \
 425                   ? (x)                                 \
 426                   : ((x) < 1024*1024*10                 \
 427                      ? (x) / 1024                       \
 428                      : (x) / (1024*1024))))
 429
 430 #define LABEL(x) ((x) < 1024*10 ? 'b' : ((x) < 1024*1024*10 ? 'k' : 'M'))
 431
 432 #define PERCENT(x,y) ((float)(x) * 100.0 / (float)(y))
 433
 434 /*---------------------------------------------------------------------------
 435                               Block iterators
 436 ---------------------------------------------------------------------------*/
 437
 438 typedef struct {
 439   tree_stmt_iterator tsi;
 440   basic_block bb;
 441 } block_stmt_iterator;
 442
 443 static inline block_stmt_iterator bsi_start (basic_block);
 444 static inline block_stmt_iterator bsi_last (basic_block);
 445 static inline block_stmt_iterator bsi_after_labels (basic_block);
 446 block_stmt_iterator bsi_for_stmt (tree);
 447 static inline bool bsi_end_p (block_stmt_iterator);
 448 static inline void bsi_next (block_stmt_iterator *);
 449 static inline void bsi_prev (block_stmt_iterator *);
 450 static inline tree bsi_stmt (block_stmt_iterator);
 451 static inline tree * bsi_stmt_ptr (block_stmt_iterator);
 452
 453 extern void bsi_remove (block_stmt_iterator *, bool);
 454 extern void bsi_move_before (block_stmt_iterator *, block_stmt_iterator *);
 455 extern void bsi_move_after (block_stmt_iterator *, block_stmt_iterator *);
 456 extern void bsi_move_to_bb_end (block_stmt_iterator *, basic_block);
 457
 458 enum bsi_iterator_update
 459 {
 460   /* Note that these are intentionally in the same order as TSI_FOO.  They
 461      mean exactly the same as their TSI_* counterparts.  */
 462   BSI_NEW_STMT,
 463   BSI_SAME_STMT,
 464   BSI_CHAIN_START,
 465   BSI_CHAIN_END,
 466   BSI_CONTINUE_LINKING
 467 };
 468
 469 extern void bsi_insert_before (block_stmt_iterator *, tree,
 470                                enum bsi_iterator_update);
 471 extern void bsi_insert_after (block_stmt_iterator *, tree,
 472                               enum bsi_iterator_update);
 473
 474 extern void bsi_replace (const block_stmt_iterator *, tree, bool);
 475
 476 /*---------------------------------------------------------------------------
 477                               Function prototypes
 478 ---------------------------------------------------------------------------*/
 479 /* In tree-cfg.c  */
 480
 481 /* Location to track pending stmt for edge insertion.  */
 482 #define PENDING_STMT(e) ((e)->insns.t)
 483
 484 extern void delete_tree_cfg_annotations (void);
 485 extern void disband_implicit_edges (void);
 486 extern bool stmt_ends_bb_p (tree);
 487 extern bool is_ctrl_stmt (tree);
 488 extern bool is_ctrl_altering_stmt (tree);
 489 extern bool computed_goto_p (tree);
 490 extern bool simple_goto_p (tree);
 491 extern basic_block single_noncomplex_succ (basic_block bb);
 492 extern void tree_dump_bb (basic_block, FILE *, int);
 493 extern void debug_tree_bb (basic_block);
 494 extern basic_block debug_tree_bb_n (int);
 495 extern void dump_tree_cfg (FILE *, int);
 496 extern void debug_tree_cfg (int);
 497 extern void dump_cfg_stats (FILE *);
 498 extern void debug_cfg_stats (void);
 499 extern void debug_loop_ir (void);
 500 extern void print_loop_ir (FILE *);
 501 extern void cleanup_dead_labels (void);
 502 extern void group_case_labels (void);
 503 extern tree first_stmt (basic_block);
 504 extern tree last_stmt (basic_block);
 505 extern tree *last_stmt_ptr (basic_block);
 506 extern tree last_and_only_stmt (basic_block);
 507 extern edge find_taken_edge (basic_block, tree);
 508 extern basic_block label_to_block_fn (struct function *, tree);
 509 #define label_to_block(t) (label_to_block_fn (cfun, t))
 510 extern void bsi_insert_on_edge (edge, tree);
 511 extern basic_block bsi_insert_on_edge_immediate (edge, tree);
 512 extern void bsi_commit_one_edge_insert (edge, basic_block *);
 513 extern void bsi_commit_edge_inserts (void);
 514 extern void notice_special_calls (tree);
 515 extern void clear_special_calls (void);
 516 extern void verify_stmts (void);
 517 extern tree tree_block_label (basic_block);
 518 extern void extract_true_false_edges_from_block (basic_block, edge *, edge *);
 519 extern bool tree_duplicate_sese_region (edge, edge, basic_block *, unsigned,
 520                                         basic_block *);
 521 extern void add_phi_args_after_copy_bb (basic_block);
 522 extern void add_phi_args_after_copy (basic_block *, unsigned);
 523 extern bool tree_purge_dead_eh_edges (basic_block);
 524 extern bool tree_purge_all_dead_eh_edges (bitmap);
 525 extern tree gimplify_val (block_stmt_iterator *, tree, tree);
 526 extern tree gimplify_build1 (block_stmt_iterator *, enum tree_code,
 527                              tree, tree);
 528 extern tree gimplify_build2 (block_stmt_iterator *, enum tree_code,
 529                              tree, tree, tree);
 530 extern tree gimplify_build3 (block_stmt_iterator *, enum tree_code,
 531                              tree, tree, tree, tree);
 532 extern void init_empty_tree_cfg (void);
 533 extern void fold_cond_expr_cond (void);
 534 extern void replace_uses_by (tree, tree);
 535 extern void start_recording_case_labels (void);
 536 extern void end_recording_case_labels (void);
 537 extern basic_block move_sese_region_to_fn (struct function *, basic_block,
 538                                            basic_block);
 539
 540 /* In tree-cfgcleanup.c  */
 541 extern bool cleanup_tree_cfg (void);
 542 extern void cleanup_tree_cfg_loop (void);
 543
 544 /* In tree-pretty-print.c.  */
 545 extern void dump_generic_bb (FILE *, basic_block, int, int);
 546
 547 /* In tree-dfa.c  */
 548 extern var_ann_t create_var_ann (tree);
 549 extern function_ann_t create_function_ann (tree);
 550 extern stmt_ann_t create_stmt_ann (tree);
 551 extern tree_ann_t create_tree_ann (tree);
 552 extern void dump_dfa_stats (FILE *);
 553 extern void debug_dfa_stats (void);
 554 extern void debug_referenced_vars (void);
 555 extern void dump_referenced_vars (FILE *);
 556 extern void dump_variable (FILE *, tree);
 557 extern void debug_variable (tree);
 558 extern void dump_subvars_for (FILE *, tree);
 559 extern void debug_subvars_for (tree);
 560 extern tree get_virtual_var (tree);
 561 extern void add_referenced_tmp_var (tree);
 562 extern void mark_new_vars_to_rename (tree);
 563 extern void find_new_referenced_vars (tree *);
 564
 565 extern tree make_rename_temp (tree, const char *);
 566 extern void set_default_def (tree, tree);
 567 extern tree default_def (tree);
 568 extern tree default_def_fn (struct function *, tree);
 569
 570 /* In tree-phinodes.c  */
 571 extern void reserve_phi_args_for_new_edge (basic_block);
 572 extern tree create_phi_node (tree, basic_block);
 573 extern void add_phi_arg (tree, tree, edge);
 574 extern void remove_phi_args (edge);
 575 extern void remove_phi_node (tree, tree);
 576 extern tree phi_reverse (tree);
 577
 578 /* In gimple-low.c  */
 579 extern void record_vars_into (tree, tree);
 580 extern void record_vars (tree);
 581 extern bool block_may_fallthru (tree);
 582
 583 /* In tree-ssa-alias.c  */
 584 extern void dump_may_aliases_for (FILE *, tree);
 585 extern void debug_may_aliases_for (tree);
 586 extern void dump_alias_info (FILE *);
 587 extern void debug_alias_info (void);
 588 extern void dump_points_to_info (FILE *);
 589 extern void debug_points_to_info (void);
 590 extern void dump_points_to_info_for (FILE *, tree);
 591 extern void debug_points_to_info_for (tree);
 592 extern bool may_be_aliased (tree);
 593 extern bool is_aliased_with (tree, tree);
 594 extern struct ptr_info_def *get_ptr_info (tree);
 595 extern void add_type_alias (tree, tree);
 596 extern void new_type_alias (tree, tree);
 597 extern void count_uses_and_derefs (tree, tree, unsigned *, unsigned *, bool *);
 598 static inline subvar_t get_subvars_for_var (tree);
 599 static inline tree get_subvar_at (tree, unsigned HOST_WIDE_INT);
 600 static inline bool ref_contains_array_ref (tree);
 601 static inline bool array_ref_contains_indirect_ref (tree);
 602 extern tree get_ref_base_and_extent (tree, HOST_WIDE_INT *,
 603                                      HOST_WIDE_INT *, HOST_WIDE_INT *);
 604 static inline bool var_can_have_subvars (tree);
 605 static inline bool overlap_subvar (unsigned HOST_WIDE_INT,
 606                                    unsigned HOST_WIDE_INT,
 607                                    tree, bool *);
 608
 609 /* Call-back function for walk_use_def_chains().  At each reaching
 610    definition, a function with this prototype is called.  */
 611 typedef bool (*walk_use_def_chains_fn) (tree, tree, void *);
 612
 613
 614 /* In tree-ssa.c  */
 615 extern void init_tree_ssa (void);
 616 extern edge ssa_redirect_edge (edge, basic_block);
 617 extern void flush_pending_stmts (edge);
 618 extern bool tree_ssa_useless_type_conversion (tree);
 619 extern bool tree_ssa_useless_type_conversion_1 (tree, tree);
 620 extern void verify_ssa (bool);
 621 extern void delete_tree_ssa (void);
 622 extern void register_new_def (tree, VEC(tree,heap) **);
 623 extern void walk_use_def_chains (tree, walk_use_def_chains_fn, void *, bool);
 624 extern bool stmt_references_memory_p (tree);
 625
 626 /* In tree-into-ssa.c  */
 627 void update_ssa (unsigned);
 628 void delete_update_ssa (void);
 629 void register_new_name_mapping (tree, tree);
 630 tree create_new_def_for (tree, tree, def_operand_p);
 631 bool need_ssa_update_p (void);
 632 bool name_registered_for_update_p (tree);
 633 bitmap ssa_names_to_replace (void);
 634 void release_ssa_name_after_update_ssa (tree name);
 635 void compute_global_livein (bitmap, bitmap);
 636 tree duplicate_ssa_name (tree, tree);
 637 void mark_sym_for_renaming (tree);
 638 void mark_set_for_renaming (bitmap);
 639 tree get_current_def (tree);
 640 void set_current_def (tree, tree);
 641
 642 /* In tree-ssa-ccp.c  */
 643 bool fold_stmt (tree *);
 644 bool fold_stmt_inplace (tree);
 645 tree widen_bitfield (tree, tree, tree);
 646
 647 /* In tree-vrp.c  */
 648 tree vrp_evaluate_conditional (tree, bool);
 649 void simplify_stmt_using_ranges (tree);
 650
 651 /* In tree-ssa-dom.c  */
 652 extern void dump_dominator_optimization_stats (FILE *);
 653 extern void debug_dominator_optimization_stats (void);
 654 int loop_depth_of_name (tree);
 655
 656 /* In tree-ssa-copy.c  */
 657 extern void merge_alias_info (tree, tree);
 658 extern void propagate_value (use_operand_p, tree);
 659 extern void propagate_tree_value (tree *, tree);
 660 extern void replace_exp (use_operand_p, tree);
 661 extern bool may_propagate_copy (tree, tree);
 662 extern bool may_propagate_copy_into_asm (tree);
 663
 664 /* Affine iv.  */
 665
 666 typedef struct
 667 {
 668   /* Iv = BASE + STEP * i.  */
 669   tree base, step;
 670
 671   /* True if this iv does not overflow.  */
 672   bool no_overflow;
 673 } affine_iv;
 674
 675 /* Description of number of iterations of a loop.  All the expressions inside
 676    the structure can be evaluated at the end of the loop's preheader
 677    (and due to ssa form, also anywhere inside the body of the loop).  */
 678
 679 struct tree_niter_desc
 680 {
 681   tree assumptions;     /* The boolean expression.  If this expression evaluates
 682                            to false, then the other fields in this structure
 683                            should not be used; there is no guarantee that they
 684                            will be correct.  */
 685   tree may_be_zero;     /* The boolean expression.  If it evaluates to true,
 686                            the loop will exit in the first iteration (i.e.
 687                            its latch will not be executed), even if the niter
 688                            field says otherwise.  */
 689   tree niter;           /* The expression giving the number of iterations of
 690                            a loop (provided that assumptions == true and
 691                            may_be_zero == false), more precisely the number
 692                            of executions of the latch of the loop.  */
 693   tree additional_info; /* The boolean expression.  Sometimes we use additional
 694                            knowledge to simplify the other expressions
 695                            contained in this structure (for example the
 696                            knowledge about value ranges of operands on entry to
 697                            the loop).  If this is a case, conjunction of such
 698                            condition is stored in this field, so that we do not
 699                            lose the information: for example if may_be_zero
 700                            is (n <= 0) and niter is (unsigned) n, we know
 701                            that the number of iterations is at most
 702                            MAX_SIGNED_INT.  However if the (n <= 0) assumption
 703                            is eliminated (by looking at the guard on entry of
 704                            the loop), then the information would be lost.  */
 705
 706   /* The simplified shape of the exit condition.  The loop exits if
 707      CONTROL CMP BOUND is false, where CMP is one of NE_EXPR,
 708      LT_EXPR, or GT_EXPR, and step of CONTROL is positive if CMP is
 709      LE_EXPR and negative if CMP is GE_EXPR.  This information is used
 710      by loop unrolling.  */
 711   affine_iv control;
 712   tree bound;
 713   enum tree_code cmp;
 714 };
 715
 716 /* In tree-vectorizer.c */
 717 void vectorize_loops (struct loops *);
 718
 719 /* In tree-ssa-phiopt.c */
 720 bool empty_block_p (basic_block);
 721
 722 /* In tree-ssa-loop*.c  */
 723
 724 void tree_ssa_lim (struct loops *);
 725 void tree_ssa_unswitch_loops (struct loops *);
 726 void canonicalize_induction_variables (struct loops *);
 727 void tree_unroll_loops_completely (struct loops *, bool);
 728 void tree_ssa_prefetch_arrays (struct loops *);
 729 void remove_empty_loops (struct loops *);
 730 void tree_ssa_iv_optimize (struct loops *);
 731
 732 bool number_of_iterations_exit (struct loop *, edge,
 733                                 struct tree_niter_desc *niter, bool);
 734 tree find_loop_niter (struct loop *, edge *);
 735 tree loop_niter_by_eval (struct loop *, edge);
 736 tree find_loop_niter_by_eval (struct loop *, edge *);
 737 void estimate_numbers_of_iterations (struct loops *);
 738 bool scev_probably_wraps_p (tree, tree, tree, tree, struct loop *, bool *,
 739                             bool *);
 740 tree convert_step (struct loop *, tree, tree, tree, tree);
 741 void free_numbers_of_iterations_estimates (struct loops *);
 742 void free_numbers_of_iterations_estimates_loop (struct loop *);
 743 void rewrite_into_loop_closed_ssa (bitmap, unsigned);
 744 void verify_loop_closed_ssa (void);
 745 void loop_commit_inserts (void);
 746 bool for_each_index (tree *, bool (*) (tree, tree *, void *), void *);
 747 void create_iv (tree, tree, tree, struct loop *, block_stmt_iterator *, bool,
 748                 tree *, tree *);
 749 void split_loop_exit_edge (edge);
 750 void compute_phi_arg_on_exit (edge, tree, tree);
 751 unsigned force_expr_to_var_cost (tree);
 752 basic_block bsi_insert_on_edge_immediate_loop (edge, tree);
 753 void standard_iv_increment_position (struct loop *, block_stmt_iterator *,
 754                                      bool *);
 755 basic_block ip_end_pos (struct loop *);
 756 basic_block ip_normal_pos (struct loop *);
 757 bool tree_duplicate_loop_to_header_edge (struct loop *, edge, struct loops *,
 758                                          unsigned int, sbitmap,
 759                                          edge, edge *,
 760                                          unsigned int *, int);
 761 struct loop *tree_ssa_loop_version (struct loops *, struct loop *, tree,
 762                                     basic_block *);
 763 tree expand_simple_operations (tree);
 764 void substitute_in_loop_info (struct loop *, tree, tree);
 765 edge single_dom_exit (struct loop *);
 766 bool can_unroll_loop_p (struct loop *loop, unsigned factor,
 767                         struct tree_niter_desc *niter);
 768 void tree_unroll_loop (struct loops *, struct loop *, unsigned,
 769                        edge, struct tree_niter_desc *);
 770
 771 /* In tree-ssa-threadedge.c */
 772 extern bool potentially_threadable_block (basic_block);
 773 extern void thread_across_edge (tree, edge, bool,
 774                                 VEC(tree, heap) **, tree (*) (tree));
 775
 776 /* In tree-ssa-loop-im.c  */
 777 /* The possibilities of statement movement.  */
 778
 779 enum move_pos
 780   {
 781     MOVE_IMPOSSIBLE,            /* No movement -- side effect expression.  */
 782     MOVE_PRESERVE_EXECUTION,    /* Must not cause the non-executed statement
 783                                    become executed -- memory accesses, ... */
 784     MOVE_POSSIBLE               /* Unlimited movement.  */
 785   };
 786 extern enum move_pos movement_possibility (tree);
 787
 788 /* The reasons a variable may escape a function.  */
 789 enum escape_type
 790   {
 791     NO_ESCAPE = 0, /* Doesn't escape.  */
 792     ESCAPE_STORED_IN_GLOBAL = 1 << 1,
 793     ESCAPE_TO_ASM = 1 << 2,  /* Passed by address to an assembly
 794                                 statement.  */
 795     ESCAPE_TO_CALL = 1 << 3,  /* Escapes to a function call.  */
 796     ESCAPE_BAD_CAST = 1 << 4, /* Cast from pointer to integer */
 797     ESCAPE_TO_RETURN = 1 << 5, /* Returned from function.  */
 798     ESCAPE_TO_PURE_CONST = 1 << 6, /* Escapes to a pure or constant
 799                                       function call.  */
 800     ESCAPE_IS_GLOBAL = 1 << 7,  /* Is a global variable.  */
 801     ESCAPE_IS_PARM = 1 << 8, /* Is an incoming function parameter.  */
 802     ESCAPE_UNKNOWN = 1 << 9 /* We believe it escapes for some reason
 803                                not enumerated above.  */
 804   };
 805
 806 /* In tree-flow-inline.h  */
 807 static inline bool is_call_clobbered (tree);
 808 static inline void mark_call_clobbered (tree, unsigned int);
 809 static inline void set_is_used (tree);
 810 static inline bool unmodifiable_var_p (tree);
 811
 812 /* In tree-eh.c  */
 813 extern void make_eh_edges (tree);
 814 extern bool tree_could_trap_p (tree);
 815 extern bool tree_could_throw_p (tree);
 816 extern bool tree_can_throw_internal (tree);
 817 extern bool tree_can_throw_external (tree);
 818 extern int lookup_stmt_eh_region (tree);
 819 extern void add_stmt_to_eh_region (tree, int);
 820 extern bool remove_stmt_from_eh_region (tree);
 821 extern bool maybe_clean_or_replace_eh_stmt (tree, tree);
 822
 823 /* In tree-ssa-pre.c  */
 824 void add_to_value (tree, tree);
 825 void debug_value_expressions (tree);
 826 void print_value_expressions (FILE *, tree);
 827
 828
 829 /* In tree-vn.c  */
 830 bool expressions_equal_p (tree, tree);
 831 tree get_value_handle (tree);
 832 hashval_t vn_compute (tree, hashval_t);
 833 void sort_vuses (VEC (tree, gc) *);
 834 tree vn_lookup_or_add (tree, tree);
 835 tree vn_lookup_or_add_with_vuses (tree, VEC (tree, gc) *);
 836 void vn_add (tree, tree);
 837 void vn_add_with_vuses (tree, tree, VEC (tree, gc) *);
 838 tree vn_lookup (tree, tree);
 839 tree vn_lookup_with_vuses (tree, VEC (tree, gc) *);
 840 void vn_init (void);
 841 void vn_delete (void);
 842
 843 /* In tree-ssa-sink.c  */
 844 bool is_hidden_global_store (tree);
 845
 846 /* In tree-sra.c  */
 847 void insert_edge_copies (tree, basic_block);
 848 void sra_insert_before (block_stmt_iterator *, tree);
 849 void sra_insert_after (block_stmt_iterator *, tree);
 850 void sra_init_cache (void);
 851 bool sra_type_can_be_decomposed_p (tree);
 852
 853 /* In tree-loop-linear.c  */
 854 extern void linear_transform_loops (struct loops *);
 855
 856 /* In tree-ssa-loop-ivopts.c  */
 857 bool expr_invariant_in_loop_p (struct loop *, tree);
 858 bool multiplier_allowed_in_address_p (HOST_WIDE_INT);
 859 unsigned multiply_by_cost (HOST_WIDE_INT, enum machine_mode);
 860
 861 /* In tree-ssa-threadupdate.c.  */
 862 extern bool thread_through_all_blocks (void);
 863 extern void register_jump_thread (edge, edge);
 864
 865 /* In gimplify.c  */
 866 tree force_gimple_operand (tree, tree *, bool, tree);
 867 tree force_gimple_operand_bsi (block_stmt_iterator *, tree, bool, tree);
 868
 869 /* In tree-ssa-structalias.c */
 870 bool find_what_p_points_to (tree);
 871
 872 /* In tree-ssa-live.c */
 873 extern void remove_unused_locals (void);
 874
 875 /* In tree-ssa-address.c  */
 876
 877 /* Affine combination of trees.  We keep track of at most MAX_AFF_ELTS elements
 878    to make things simpler; this is sufficient in most cases.  */
 879
 880 #define MAX_AFF_ELTS 8
 881
 882 struct affine_tree_combination
 883 {
 884   /* Type of the result of the combination.  */
 885   tree type;
 886
 887   /* Mask modulo that the operations are performed.  */
 888   unsigned HOST_WIDE_INT mask;
 889
 890   /* Constant offset.  */
 891   unsigned HOST_WIDE_INT offset;
 892
 893   /* Number of elements of the combination.  */
 894   unsigned n;
 895
 896   /* Elements and their coefficients.  */
 897   tree elts[MAX_AFF_ELTS];
 898   unsigned HOST_WIDE_INT coefs[MAX_AFF_ELTS];
 899
 900   /* Remainder of the expression.  */
 901   tree rest;
 902 };
 903
 904 /* Description of a memory address.  */
 905
 906 struct mem_address
 907 {
 908   tree symbol, base, index, step, offset;
 909 };
 910
 911 tree create_mem_ref (block_stmt_iterator *, tree,
 912                      struct affine_tree_combination *);
 913 rtx addr_for_mem_ref (struct mem_address *, bool);
 914 void get_address_description (tree, struct mem_address *);
 915 tree maybe_fold_tmr (tree);
 916
 917 /* This structure is simply used during pushing fields onto the fieldstack
 918    to track the offset of the field, since bitpos_of_field gives it relative
 919    to its immediate containing type, and we want it relative to the ultimate
 920    containing object.  */
 921
 922 struct fieldoff
 923 {
 924   tree type;
 925   tree size;
 926   tree decl;
 927   HOST_WIDE_INT offset;
 928 };
 929 typedef struct fieldoff fieldoff_s;
 930
 931 DEF_VEC_O(fieldoff_s);
 932 DEF_VEC_ALLOC_O(fieldoff_s,heap);
 933 int push_fields_onto_fieldstack (tree, VEC(fieldoff_s,heap) **,
 934                                  HOST_WIDE_INT, bool *);
 935 void sort_fieldstack (VEC(fieldoff_s,heap) *);
 936
 937 void init_alias_heapvars (void);
 938 void delete_alias_heapvars (void);
 939
 940 #include "tree-flow-inline.h"
 941
 942 void swap_tree_operands (tree, tree *, tree *);
 943
 944 #endif /* _TREE_FLOW_H  */