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 in the alias set of another variable.  */
 168   unsigned is_aliased : 1;
 169
 170   /* Nonzero if this variable was used after SSA optimizations were
 171      applied.  We set this when translating out of SSA form.  */
 172   unsigned used : 1;
 173
 174   /* This field indicates whether or not the variable may need PHI nodes.
 175      See the enum's definition for more detailed information about the
 176      states.  */
 177   ENUM_BITFIELD (need_phi_state) need_phi_state : 2;
 178
 179   /* Used during operand processing to determine if this variable is already
 180      in the vuse list.  */
 181   unsigned in_vuse_list : 1;
 182
 183   /* Used during operand processing to determine if this variable is already
 184      in the v_may_def list.  */
 185   unsigned in_v_may_def_list : 1;
 186
 187   /* True for HEAP and PARM_NOALIAS artificial variables.  */
 188   unsigned is_heapvar : 1;
 189
 190   /* An artificial variable representing the memory location pointed-to by
 191      all the pointer symbols that flow-insensitive alias analysis
 192      (mostly type-based) considers to be aliased.  If the variable is
 193      not a pointer or if it is never dereferenced, this must be NULL.  */
 194   tree symbol_mem_tag;
 195
 196   /* Variables that may alias this variable.  */
 197   VEC(tree, gc) *may_aliases;
 198
 199   /* Used when going out of SSA form to indicate which partition this
 200      variable represents storage for.  */
 201   unsigned partition;
 202
 203   /* Used by the root-var object in tree-ssa-live.[ch].  */
 204   unsigned root_index;
 205
 206   /* During into-ssa and the dominator optimizer, this field holds the
 207      current version of this variable (an SSA_NAME).  */
 208   tree current_def;
 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   /* This is the current use the iterator is processing.  */
 232   ssa_use_operand_t *imm_use;
 233   /* This marks the last use in the list (use node from SSA_NAME)  */
 234   ssa_use_operand_t *end_p;
 235   /* This node is inserted and used to mark the end of the uses for a stmt.  */
 236   ssa_use_operand_t iter_node;
 237   /* This is the next ssa_name to visit.  IMM_USE may get removed before
 238      the next one is traversed to, so it must be cached early.  */
 239   ssa_use_operand_t *next_imm_name;
 240 } imm_use_iterator;
 241
 242
 243 /* Use this iterator when simply looking at stmts.  Adding, deleting or
 244    modifying stmts will cause this iterator to malfunction.  */
 245
 246 #define FOR_EACH_IMM_USE_FAST(DEST, ITER, SSAVAR)                       \
 247   for ((DEST) = first_readonly_imm_use (&(ITER), (SSAVAR));     \
 248        !end_readonly_imm_use_p (&(ITER));                       \
 249        (DEST) = next_readonly_imm_use (&(ITER)))
 250
 251 /* Use this iterator to visit each stmt which has a use of SSAVAR.  */
 252
 253 #define FOR_EACH_IMM_USE_STMT(STMT, ITER, SSAVAR)               \
 254   for ((STMT) = first_imm_use_stmt (&(ITER), (SSAVAR));         \
 255        !end_imm_use_stmt_p (&(ITER));                           \
 256        (STMT) = next_imm_use_stmt (&(ITER)))
 257
 258 /* Use this to terminate the FOR_EACH_IMM_USE_STMT loop early.  Failure to
 259    do so will result in leaving a iterator marker node in the immediate
 260    use list, and nothing good will come from that.   */
 261 #define BREAK_FROM_IMM_USE_STMT(ITER)                           \
 262    {                                                            \
 263      end_imm_use_stmt_traverse (&(ITER));                       \
 264      break;                                                     \
 265    }
 266
 267
 268 /* Use this iterator in combination with FOR_EACH_IMM_USE_STMT to
 269    get access to each occurrence of ssavar on the stmt returned by
 270    that iterator..  for instance:
 271
 272      FOR_EACH_IMM_USE_STMT (stmt, iter, var)
 273        {
 274          FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
 275            {
 276              SET_USE (use_p) = blah;
 277            }
 278          update_stmt (stmt);
 279        }                                                         */
 280
 281 #define FOR_EACH_IMM_USE_ON_STMT(DEST, ITER)                    \
 282   for ((DEST) = first_imm_use_on_stmt (&(ITER));                \
 283        !end_imm_use_on_stmt_p (&(ITER));                        \
 284        (DEST) = next_imm_use_on_stmt (&(ITER)))
 285
 286
 287
 288 struct stmt_ann_d GTY(())
 289 {
 290   struct tree_ann_common_d common;
 291
 292   /* Nonzero if the statement has been modified (meaning that the operands
 293      need to be scanned again).  */
 294   unsigned modified : 1;
 295
 296   /* Nonzero if the statement makes references to volatile storage.  */
 297   unsigned has_volatile_ops : 1;
 298
 299   /* Nonzero if the statement makes a function call that may clobber global
 300      and local addressable variables.  */
 301   unsigned makes_clobbering_call : 1;
 302
 303   /* Basic block that contains this statement.  */
 304   basic_block bb;
 305
 306   /* Operand cache for stmt.  */
 307   struct stmt_operands_d GTY ((skip (""))) operands;
 308
 309   /* Set of variables that have had their address taken in the statement.  */
 310   bitmap addresses_taken;
 311
 312   /* Unique identifier for this statement.  These ID's are to be created
 313      by each pass on an as-needed basis in any order convenient for the
 314      pass which needs statement UIDs.  */
 315   unsigned int uid;
 316
 317   /* Linked list of histograms for value-based profiling.  This is really a
 318      struct histogram_value*.  We use void* to avoid having to export that
 319      everywhere, and to avoid having to put it in GC memory.  */
 320
 321   void * GTY ((skip (""))) histograms;
 322 };
 323
 324 union tree_ann_d GTY((desc ("ann_type ((tree_ann_t)&%h)")))
 325 {
 326   struct tree_ann_common_d GTY((tag ("TREE_ANN_COMMON"))) common;
 327   struct var_ann_d GTY((tag ("VAR_ANN"))) vdecl;
 328   struct function_ann_d GTY((tag ("FUNCTION_ANN"))) fdecl;
 329   struct stmt_ann_d GTY((tag ("STMT_ANN"))) stmt;
 330 };
 331
 332 extern GTY(()) VEC(tree,gc) *modified_noreturn_calls;
 333
 334 typedef union tree_ann_d *tree_ann_t;
 335 typedef struct var_ann_d *var_ann_t;
 336 typedef struct function_ann_d *function_ann_t;
 337 typedef struct stmt_ann_d *stmt_ann_t;
 338 typedef struct tree_ann_common_d *tree_ann_common_t;
 339
 340 static inline tree_ann_common_t tree_common_ann (tree);
 341 static inline tree_ann_common_t get_tree_common_ann (tree);
 342 static inline var_ann_t var_ann (tree);
 343 static inline var_ann_t get_var_ann (tree);
 344 static inline function_ann_t function_ann (tree);
 345 static inline function_ann_t get_function_ann (tree);
 346 static inline stmt_ann_t stmt_ann (tree);
 347 static inline bool has_stmt_ann (tree);
 348 static inline stmt_ann_t get_stmt_ann (tree);
 349 static inline enum tree_ann_type ann_type (tree_ann_t);
 350 static inline basic_block bb_for_stmt (tree);
 351 extern void set_bb_for_stmt (tree, basic_block);
 352 static inline bool noreturn_call_p (tree);
 353 static inline void update_stmt (tree);
 354 static inline bool stmt_modified_p (tree);
 355 static inline VEC(tree, gc) *may_aliases (tree);
 356 static inline int get_lineno (tree);
 357 static inline const char *get_filename (tree);
 358 static inline bool is_exec_stmt (tree);
 359 static inline bool is_label_stmt (tree);
 360 static inline bitmap addresses_taken (tree);
 361
 362 /*---------------------------------------------------------------------------
 363                   Structure representing predictions in tree level.
 364 ---------------------------------------------------------------------------*/
 365 struct edge_prediction GTY((chain_next ("%h.ep_next")))
 366 {
 367   struct edge_prediction *ep_next;
 368   edge ep_edge;
 369   enum br_predictor ep_predictor;
 370   int ep_probability;
 371 };
 372
 373 /* Accessors for basic block annotations.  */
 374 static inline tree phi_nodes (basic_block);
 375 static inline void set_phi_nodes (basic_block, tree);
 376
 377 /*---------------------------------------------------------------------------
 378                               Global declarations
 379 ---------------------------------------------------------------------------*/
 380 struct int_tree_map GTY(())
 381 {
 382
 383   unsigned int uid;
 384   tree to;
 385 };
 386
 387 extern unsigned int int_tree_map_hash (const void *);
 388 extern int int_tree_map_eq (const void *, const void *);
 389
 390 typedef struct
 391 {
 392   htab_iterator hti;
 393 } referenced_var_iterator;
 394
 395
 396 /* This macro loops over all the referenced vars, one at a time, putting the
 397    current var in VAR.  Note:  You are not allowed to add referenced variables
 398    to the hashtable while using this macro.  Doing so may cause it to behave
 399    erratically.  */
 400
 401 #define FOR_EACH_REFERENCED_VAR(VAR, ITER) \
 402   for ((VAR) = first_referenced_var (&(ITER)); \
 403        !end_referenced_vars_p (&(ITER)); \
 404        (VAR) = next_referenced_var (&(ITER)))
 405
 406
 407 typedef struct
 408 {
 409   int i;
 410 } safe_referenced_var_iterator;
 411
 412 /* This macro loops over all the referenced vars, one at a time, putting the
 413    current var in VAR.  You are allowed to add referenced variables during the
 414    execution of this macro, however, the macro will not iterate over them.  It
 415    requires a temporary vector of trees, VEC, whose lifetime is controlled by
 416    the caller.  The purpose of the vector is to temporarily store the
 417    referenced_variables hashtable so that adding referenced variables does not
 418    affect the hashtable.  */
 419
 420 #define FOR_EACH_REFERENCED_VAR_SAFE(VAR, VEC, ITER) \
 421   for ((ITER).i = 0, fill_referenced_var_vec (&(VEC)); \
 422        VEC_iterate (tree, (VEC), (ITER).i, (VAR)); \
 423        (ITER).i++)
 424
 425 /* Array of all variables referenced in the function.  */
 426 extern GTY((param_is (struct int_tree_map))) htab_t referenced_vars;
 427
 428 /* Default defs for undefined symbols. */
 429 extern GTY((param_is (struct int_tree_map))) htab_t default_defs;
 430
 431 extern tree referenced_var_lookup (unsigned int);
 432 extern bool referenced_var_check_and_insert (tree);
 433 #define num_referenced_vars htab_elements (referenced_vars)
 434 #define referenced_var(i) referenced_var_lookup (i)
 435
 436 /* Array of all SSA_NAMEs used in the function.  */
 437 extern GTY(()) VEC(tree,gc) *ssa_names;
 438
 439 #define num_ssa_names (VEC_length (tree, ssa_names))
 440 #define ssa_name(i) (VEC_index (tree, ssa_names, (i)))
 441
 442 /* Artificial variable used to model the effects of function calls.  */
 443 extern GTY(()) tree global_var;
 444
 445 /* Artificial variable used to model the effects of nonlocal
 446    variables.  */
 447 extern GTY(()) tree nonlocal_all;
 448
 449 /* Call clobbered variables in the function.  If bit I is set, then
 450    REFERENCED_VARS (I) is call-clobbered.  */
 451 extern bitmap call_clobbered_vars;
 452
 453 /* Addressable variables in the function.  If bit I is set, then
 454    REFERENCED_VARS (I) has had its address taken.  */
 455 extern bitmap addressable_vars;
 456
 457 /* 'true' after aliases have been computed (see compute_may_aliases).  */
 458 extern bool aliases_computed_p;
 459
 460 /* Macros for showing usage statistics.  */
 461 #define SCALE(x) ((unsigned long) ((x) < 1024*10        \
 462                   ? (x)                                 \
 463                   : ((x) < 1024*1024*10                 \
 464                      ? (x) / 1024                       \
 465                      : (x) / (1024*1024))))
 466
 467 #define LABEL(x) ((x) < 1024*10 ? 'b' : ((x) < 1024*1024*10 ? 'k' : 'M'))
 468
 469 #define PERCENT(x,y) ((float)(x) * 100.0 / (float)(y))
 470
 471 /*---------------------------------------------------------------------------
 472                               Block iterators
 473 ---------------------------------------------------------------------------*/
 474
 475 typedef struct {
 476   tree_stmt_iterator tsi;
 477   basic_block bb;
 478 } block_stmt_iterator;
 479
 480 static inline block_stmt_iterator bsi_start (basic_block);
 481 static inline block_stmt_iterator bsi_last (basic_block);
 482 static inline block_stmt_iterator bsi_after_labels (basic_block);
 483 block_stmt_iterator bsi_for_stmt (tree);
 484 static inline bool bsi_end_p (block_stmt_iterator);
 485 static inline void bsi_next (block_stmt_iterator *);
 486 static inline void bsi_prev (block_stmt_iterator *);
 487 static inline tree bsi_stmt (block_stmt_iterator);
 488 static inline tree * bsi_stmt_ptr (block_stmt_iterator);
 489
 490 extern void bsi_remove (block_stmt_iterator *, bool);
 491 extern void bsi_move_before (block_stmt_iterator *, block_stmt_iterator *);
 492 extern void bsi_move_after (block_stmt_iterator *, block_stmt_iterator *);
 493 extern void bsi_move_to_bb_end (block_stmt_iterator *, basic_block);
 494
 495 enum bsi_iterator_update
 496 {
 497   /* Note that these are intentionally in the same order as TSI_FOO.  They
 498      mean exactly the same as their TSI_* counterparts.  */
 499   BSI_NEW_STMT,
 500   BSI_SAME_STMT,
 501   BSI_CHAIN_START,
 502   BSI_CHAIN_END,
 503   BSI_CONTINUE_LINKING
 504 };
 505
 506 extern void bsi_insert_before (block_stmt_iterator *, tree,
 507                                enum bsi_iterator_update);
 508 extern void bsi_insert_after (block_stmt_iterator *, tree,
 509                               enum bsi_iterator_update);
 510
 511 extern void bsi_replace (const block_stmt_iterator *, tree, bool);
 512
 513 /*---------------------------------------------------------------------------
 514                               OpenMP Region Tree
 515 ---------------------------------------------------------------------------*/
 516
 517 /* Parallel region information.  Every parallel and workshare
 518    directive is enclosed between two markers, the OMP_* directive
 519    and a corresponding OMP_RETURN statement.  */
 520
 521 struct omp_region
 522 {
 523   /* The enclosing region.  */
 524   struct omp_region *outer;
 525
 526   /* First child region.  */
 527   struct omp_region *inner;
 528
 529   /* Next peer region.  */
 530   struct omp_region *next;
 531
 532   /* Block containing the omp directive as its last stmt.  */
 533   basic_block entry;
 534
 535   /* Block containing the OMP_RETURN as its last stmt.  */
 536   basic_block exit;
 537
 538   /* Block containing the OMP_CONTINUE as its last stmt.  */
 539   basic_block cont;
 540
 541   /* If this is a combined parallel+workshare region, this is a list
 542      of additional arguments needed by the combined parallel+workshare
 543      library call.  */
 544   tree ws_args;
 545
 546   /* The code for the omp directive of this region.  */
 547   enum tree_code type;
 548
 549   /* Schedule kind, only used for OMP_FOR type regions.  */
 550   enum omp_clause_schedule_kind sched_kind;
 551
 552   /* True if this is a combined parallel+workshare region.  */
 553   bool is_combined_parallel;
 554 };
 555
 556 extern struct omp_region *root_omp_region;
 557 extern struct omp_region *new_omp_region (basic_block, enum tree_code,
 558                                           struct omp_region *);
 559 extern void free_omp_regions (void);
 560
 561 /*---------------------------------------------------------------------------
 562                               Function prototypes
 563 ---------------------------------------------------------------------------*/
 564 /* In tree-cfg.c  */
 565
 566 /* Location to track pending stmt for edge insertion.  */
 567 #define PENDING_STMT(e) ((e)->insns.t)
 568
 569 extern void delete_tree_cfg_annotations (void);
 570 extern void disband_implicit_edges (void);
 571 extern bool stmt_ends_bb_p (tree);
 572 extern bool is_ctrl_stmt (tree);
 573 extern bool is_ctrl_altering_stmt (tree);
 574 extern bool computed_goto_p (tree);
 575 extern bool simple_goto_p (tree);
 576 extern bool tree_can_make_abnormal_goto (tree);
 577 extern basic_block single_noncomplex_succ (basic_block bb);
 578 extern void tree_dump_bb (basic_block, FILE *, int);
 579 extern void debug_tree_bb (basic_block);
 580 extern basic_block debug_tree_bb_n (int);
 581 extern void dump_tree_cfg (FILE *, int);
 582 extern void debug_tree_cfg (int);
 583 extern void dump_cfg_stats (FILE *);
 584 extern void debug_cfg_stats (void);
 585 extern void debug_loop_ir (void);
 586 extern void print_loop_ir (FILE *);
 587 extern void cleanup_dead_labels (void);
 588 extern void group_case_labels (void);
 589 extern tree first_stmt (basic_block);
 590 extern tree last_stmt (basic_block);
 591 extern tree *last_stmt_ptr (basic_block);
 592 extern tree last_and_only_stmt (basic_block);
 593 extern edge find_taken_edge (basic_block, tree);
 594 extern basic_block label_to_block_fn (struct function *, tree);
 595 #define label_to_block(t) (label_to_block_fn (cfun, t))
 596 extern void bsi_insert_on_edge (edge, tree);
 597 extern basic_block bsi_insert_on_edge_immediate (edge, tree);
 598 extern void bsi_commit_one_edge_insert (edge, basic_block *);
 599 extern void bsi_commit_edge_inserts (void);
 600 extern void notice_special_calls (tree);
 601 extern void clear_special_calls (void);
 602 extern void verify_stmts (void);
 603 extern tree tree_block_label (basic_block);
 604 extern void extract_true_false_edges_from_block (basic_block, edge *, edge *);
 605 extern bool tree_duplicate_sese_region (edge, edge, basic_block *, unsigned,
 606                                         basic_block *);
 607 extern void add_phi_args_after_copy_bb (basic_block);
 608 extern void add_phi_args_after_copy (basic_block *, unsigned);
 609 extern bool tree_purge_dead_abnormal_call_edges (basic_block);
 610 extern bool tree_purge_dead_eh_edges (basic_block);
 611 extern bool tree_purge_all_dead_eh_edges (bitmap);
 612 extern tree gimplify_val (block_stmt_iterator *, tree, tree);
 613 extern tree gimplify_build1 (block_stmt_iterator *, enum tree_code,
 614                              tree, tree);
 615 extern tree gimplify_build2 (block_stmt_iterator *, enum tree_code,
 616                              tree, tree, tree);
 617 extern tree gimplify_build3 (block_stmt_iterator *, enum tree_code,
 618                              tree, tree, tree, tree);
 619 extern void init_empty_tree_cfg (void);
 620 extern void fold_cond_expr_cond (void);
 621 extern void make_abnormal_goto_edges (basic_block, bool);
 622 extern void replace_uses_by (tree, tree);
 623 extern void start_recording_case_labels (void);
 624 extern void end_recording_case_labels (void);
 625 extern basic_block move_sese_region_to_fn (struct function *, basic_block,
 626                                            basic_block);
 627
 628 /* In tree-cfgcleanup.c  */
 629 extern bool cleanup_tree_cfg (void);
 630 extern void cleanup_tree_cfg_loop (void);
 631
 632 /* In tree-pretty-print.c.  */
 633 extern void dump_generic_bb (FILE *, basic_block, int, int);
 634
 635 /* In tree-dfa.c  */
 636 extern var_ann_t create_var_ann (tree);
 637 extern function_ann_t create_function_ann (tree);
 638 extern stmt_ann_t create_stmt_ann (tree);
 639 extern tree_ann_common_t create_tree_common_ann (tree);
 640 extern void dump_dfa_stats (FILE *);
 641 extern void debug_dfa_stats (void);
 642 extern void debug_referenced_vars (void);
 643 extern void dump_referenced_vars (FILE *);
 644 extern void dump_variable (FILE *, tree);
 645 extern void debug_variable (tree);
 646 extern void dump_subvars_for (FILE *, tree);
 647 extern void debug_subvars_for (tree);
 648 extern tree get_virtual_var (tree);
 649 extern void add_referenced_var (tree);
 650 extern void mark_new_vars_to_rename (tree);
 651 extern void find_new_referenced_vars (tree *);
 652
 653 extern tree make_rename_temp (tree, const char *);
 654 extern void set_default_def (tree, tree);
 655 extern tree default_def (tree);
 656 extern tree default_def_fn (struct function *, tree);
 657
 658 /* In tree-phinodes.c  */
 659 extern void reserve_phi_args_for_new_edge (basic_block);
 660 extern tree create_phi_node (tree, basic_block);
 661 extern void add_phi_arg (tree, tree, edge);
 662 extern void remove_phi_args (edge);
 663 extern void remove_phi_node (tree, tree);
 664 extern tree phi_reverse (tree);
 665
 666 /* In gimple-low.c  */
 667 extern void record_vars_into (tree, tree);
 668 extern void record_vars (tree);
 669 extern bool block_may_fallthru (tree);
 670
 671 /* In tree-ssa-alias.c  */
 672 extern void dump_may_aliases_for (FILE *, tree);
 673 extern void debug_may_aliases_for (tree);
 674 extern void dump_alias_info (FILE *);
 675 extern void debug_alias_info (void);
 676 extern void dump_points_to_info (FILE *);
 677 extern void debug_points_to_info (void);
 678 extern void dump_points_to_info_for (FILE *, tree);
 679 extern void debug_points_to_info_for (tree);
 680 extern bool may_be_aliased (tree);
 681 extern bool is_aliased_with (tree, tree);
 682 extern struct ptr_info_def *get_ptr_info (tree);
 683 extern void new_type_alias (tree, tree, tree);
 684 extern void count_uses_and_derefs (tree, tree, unsigned *, unsigned *, bool *);
 685 static inline subvar_t get_subvars_for_var (tree);
 686 static inline tree get_subvar_at (tree, unsigned HOST_WIDE_INT);
 687 static inline bool ref_contains_array_ref (tree);
 688 static inline bool array_ref_contains_indirect_ref (tree);
 689 extern tree get_ref_base_and_extent (tree, HOST_WIDE_INT *,
 690                                      HOST_WIDE_INT *, HOST_WIDE_INT *);
 691 static inline bool var_can_have_subvars (tree);
 692 static inline bool overlap_subvar (unsigned HOST_WIDE_INT,
 693                                    unsigned HOST_WIDE_INT,
 694                                    tree, bool *);
 695
 696 /* Call-back function for walk_use_def_chains().  At each reaching
 697    definition, a function with this prototype is called.  */
 698 typedef bool (*walk_use_def_chains_fn) (tree, tree, void *);
 699
 700
 701 /* In tree-ssa.c  */
 702 extern void init_tree_ssa (void);
 703 extern edge ssa_redirect_edge (edge, basic_block);
 704 extern void flush_pending_stmts (edge);
 705 extern bool tree_ssa_useless_type_conversion (tree);
 706 extern bool tree_ssa_useless_type_conversion_1 (tree, tree);
 707 extern void verify_ssa (bool);
 708 extern void delete_tree_ssa (void);
 709 extern void register_new_def (tree, VEC(tree,heap) **);
 710 extern void walk_use_def_chains (tree, walk_use_def_chains_fn, void *, bool);
 711 extern bool stmt_references_memory_p (tree);
 712
 713 /* In tree-into-ssa.c  */
 714 void update_ssa (unsigned);
 715 void delete_update_ssa (void);
 716 void register_new_name_mapping (tree, tree);
 717 tree create_new_def_for (tree, tree, def_operand_p);
 718 bool need_ssa_update_p (void);
 719 bool name_mappings_registered_p (void);
 720 bool name_registered_for_update_p (tree);
 721 bitmap ssa_names_to_replace (void);
 722 void release_ssa_name_after_update_ssa (tree name);
 723 void compute_global_livein (bitmap, bitmap);
 724 tree duplicate_ssa_name (tree, tree);
 725 void mark_sym_for_renaming (tree);
 726 void mark_set_for_renaming (bitmap);
 727 tree get_current_def (tree);
 728 void set_current_def (tree, tree);
 729
 730 /* In tree-ssa-ccp.c  */
 731 bool fold_stmt (tree *);
 732 bool fold_stmt_inplace (tree);
 733 tree widen_bitfield (tree, tree, tree);
 734
 735 /* In tree-vrp.c  */
 736 tree vrp_evaluate_conditional (tree, bool);
 737 void simplify_stmt_using_ranges (tree);
 738
 739 /* In tree-ssa-dom.c  */
 740 extern void dump_dominator_optimization_stats (FILE *);
 741 extern void debug_dominator_optimization_stats (void);
 742 int loop_depth_of_name (tree);
 743
 744 /* In tree-ssa-copy.c  */
 745 extern void merge_alias_info (tree, tree);
 746 extern void propagate_value (use_operand_p, tree);
 747 extern void propagate_tree_value (tree *, tree);
 748 extern void replace_exp (use_operand_p, tree);
 749 extern bool may_propagate_copy (tree, tree);
 750 extern bool may_propagate_copy_into_asm (tree);
 751
 752 /* Affine iv.  */
 753
 754 typedef struct
 755 {
 756   /* Iv = BASE + STEP * i.  */
 757   tree base, step;
 758
 759   /* True if this iv does not overflow.  */
 760   bool no_overflow;
 761 } affine_iv;
 762
 763 /* Description of number of iterations of a loop.  All the expressions inside
 764    the structure can be evaluated at the end of the loop's preheader
 765    (and due to ssa form, also anywhere inside the body of the loop).  */
 766
 767 struct tree_niter_desc
 768 {
 769   tree assumptions;     /* The boolean expression.  If this expression evaluates
 770                            to false, then the other fields in this structure
 771                            should not be used; there is no guarantee that they
 772                            will be correct.  */
 773   tree may_be_zero;     /* The boolean expression.  If it evaluates to true,
 774                            the loop will exit in the first iteration (i.e.
 775                            its latch will not be executed), even if the niter
 776                            field says otherwise.  */
 777   tree niter;           /* The expression giving the number of iterations of
 778                            a loop (provided that assumptions == true and
 779                            may_be_zero == false), more precisely the number
 780                            of executions of the latch of the loop.  */
 781   tree additional_info; /* The boolean expression.  Sometimes we use additional
 782                            knowledge to simplify the other expressions
 783                            contained in this structure (for example the
 784                            knowledge about value ranges of operands on entry to
 785                            the loop).  If this is a case, conjunction of such
 786                            condition is stored in this field, so that we do not
 787                            lose the information: for example if may_be_zero
 788                            is (n <= 0) and niter is (unsigned) n, we know
 789                            that the number of iterations is at most
 790                            MAX_SIGNED_INT.  However if the (n <= 0) assumption
 791                            is eliminated (by looking at the guard on entry of
 792                            the loop), then the information would be lost.  */
 793
 794   /* The simplified shape of the exit condition.  The loop exits if
 795      CONTROL CMP BOUND is false, where CMP is one of NE_EXPR,
 796      LT_EXPR, or GT_EXPR, and step of CONTROL is positive if CMP is
 797      LE_EXPR and negative if CMP is GE_EXPR.  This information is used
 798      by loop unrolling.  */
 799   affine_iv control;
 800   tree bound;
 801   enum tree_code cmp;
 802 };
 803
 804 /* In tree-vectorizer.c */
 805 unsigned vectorize_loops (struct loops *);
 806 extern bool vect_can_force_dr_alignment_p (tree, unsigned int);
 807 extern tree get_vectype_for_scalar_type (tree);
 808
 809 /* In tree-ssa-phiopt.c */
 810 bool empty_block_p (basic_block);
 811
 812 /* In tree-ssa-loop*.c  */
 813
 814 void tree_ssa_lim (struct loops *);
 815 unsigned int tree_ssa_unswitch_loops (struct loops *);
 816 unsigned int canonicalize_induction_variables (struct loops *);
 817 unsigned int tree_unroll_loops_completely (struct loops *, bool);
 818 unsigned int tree_ssa_prefetch_arrays (struct loops *);
 819 unsigned int remove_empty_loops (struct loops *);
 820 void tree_ssa_iv_optimize (struct loops *);
 821
 822 bool number_of_iterations_exit (struct loop *, edge,
 823                                 struct tree_niter_desc *niter, bool);
 824 tree find_loop_niter (struct loop *, edge *);
 825 tree loop_niter_by_eval (struct loop *, edge);
 826 tree find_loop_niter_by_eval (struct loop *, edge *);
 827 void estimate_numbers_of_iterations (struct loops *);
 828 bool scev_probably_wraps_p (tree, tree, tree, struct loop *, bool);
 829 bool convert_affine_scev (struct loop *, tree, tree *, tree *, tree, bool);
 830
 831 bool nowrap_type_p (tree);
 832 enum ev_direction {EV_DIR_GROWS, EV_DIR_DECREASES, EV_DIR_UNKNOWN};
 833 enum ev_direction scev_direction (tree);
 834
 835 void free_numbers_of_iterations_estimates (struct loops *);
 836 void free_numbers_of_iterations_estimates_loop (struct loop *);
 837 void rewrite_into_loop_closed_ssa (bitmap, unsigned);
 838 void verify_loop_closed_ssa (void);
 839 bool for_each_index (tree *, bool (*) (tree, tree *, void *), void *);
 840 void create_iv (tree, tree, tree, struct loop *, block_stmt_iterator *, bool,
 841                 tree *, tree *);
 842 void split_loop_exit_edge (edge);
 843 unsigned force_expr_to_var_cost (tree);
 844 void standard_iv_increment_position (struct loop *, block_stmt_iterator *,
 845                                      bool *);
 846 basic_block ip_end_pos (struct loop *);
 847 basic_block ip_normal_pos (struct loop *);
 848 bool tree_duplicate_loop_to_header_edge (struct loop *, edge, struct loops *,
 849                                          unsigned int, sbitmap,
 850                                          edge, edge *,
 851                                          unsigned int *, int);
 852 struct loop *tree_ssa_loop_version (struct loops *, struct loop *, tree,
 853                                     basic_block *);
 854 tree expand_simple_operations (tree);
 855 void substitute_in_loop_info (struct loop *, tree, tree);
 856 edge single_dom_exit (struct loop *);
 857 bool can_unroll_loop_p (struct loop *loop, unsigned factor,
 858                         struct tree_niter_desc *niter);
 859 void tree_unroll_loop (struct loops *, struct loop *, unsigned,
 860                        edge, struct tree_niter_desc *);
 861 bool contains_abnormal_ssa_name_p (tree);
 862
 863 /* In tree-ssa-threadedge.c */
 864 extern bool potentially_threadable_block (basic_block);
 865 extern void thread_across_edge (tree, edge, bool,
 866                                 VEC(tree, heap) **, tree (*) (tree));
 867
 868 /* In tree-ssa-loop-im.c  */
 869 /* The possibilities of statement movement.  */
 870
 871 enum move_pos
 872   {
 873     MOVE_IMPOSSIBLE,            /* No movement -- side effect expression.  */
 874     MOVE_PRESERVE_EXECUTION,    /* Must not cause the non-executed statement
 875                                    become executed -- memory accesses, ... */
 876     MOVE_POSSIBLE               /* Unlimited movement.  */
 877   };
 878 extern enum move_pos movement_possibility (tree);
 879
 880 /* The reasons a variable may escape a function.  */
 881 enum escape_type
 882   {
 883     NO_ESCAPE = 0, /* Doesn't escape.  */
 884     ESCAPE_STORED_IN_GLOBAL = 1 << 1,
 885     ESCAPE_TO_ASM = 1 << 2,  /* Passed by address to an assembly
 886                                 statement.  */
 887     ESCAPE_TO_CALL = 1 << 3,  /* Escapes to a function call.  */
 888     ESCAPE_BAD_CAST = 1 << 4, /* Cast from pointer to integer */
 889     ESCAPE_TO_RETURN = 1 << 5, /* Returned from function.  */
 890     ESCAPE_TO_PURE_CONST = 1 << 6, /* Escapes to a pure or constant
 891                                       function call.  */
 892     ESCAPE_IS_GLOBAL = 1 << 7,  /* Is a global variable.  */
 893     ESCAPE_IS_PARM = 1 << 8, /* Is an incoming function parameter.  */
 894     ESCAPE_UNKNOWN = 1 << 9 /* We believe it escapes for some reason
 895                                not enumerated above.  */
 896   };
 897
 898 /* In tree-flow-inline.h  */
 899 static inline bool is_call_clobbered (tree);
 900 static inline void mark_call_clobbered (tree, unsigned int);
 901 static inline void set_is_used (tree);
 902 static inline bool unmodifiable_var_p (tree);
 903
 904 /* In tree-eh.c  */
 905 extern void make_eh_edges (tree);
 906 extern bool tree_could_trap_p (tree);
 907 extern bool tree_could_throw_p (tree);
 908 extern bool tree_can_throw_internal (tree);
 909 extern bool tree_can_throw_external (tree);
 910 extern int lookup_stmt_eh_region (tree);
 911 extern void add_stmt_to_eh_region (tree, int);
 912 extern bool remove_stmt_from_eh_region (tree);
 913 extern bool maybe_clean_or_replace_eh_stmt (tree, tree);
 914
 915 /* In tree-ssa-pre.c  */
 916 void add_to_value (tree, tree);
 917 void debug_value_expressions (tree);
 918 void print_value_expressions (FILE *, tree);
 919
 920
 921 /* In tree-vn.c  */
 922 bool expressions_equal_p (tree, tree);
 923 static inline tree get_value_handle (tree);
 924 hashval_t vn_compute (tree, hashval_t);
 925 void sort_vuses (VEC (tree, gc) *);
 926 tree vn_lookup_or_add (tree, tree);
 927 tree vn_lookup_or_add_with_vuses (tree, VEC (tree, gc) *);
 928 void vn_add (tree, tree);
 929 void vn_add_with_vuses (tree, tree, VEC (tree, gc) *);
 930 tree vn_lookup (tree, tree);
 931 tree vn_lookup_with_vuses (tree, VEC (tree, gc) *);
 932 void vn_init (void);
 933 void vn_delete (void);
 934
 935 /* In tree-ssa-sink.c  */
 936 bool is_hidden_global_store (tree);
 937
 938 /* In tree-sra.c  */
 939 void insert_edge_copies (tree, basic_block);
 940 void sra_insert_before (block_stmt_iterator *, tree);
 941 void sra_insert_after (block_stmt_iterator *, tree);
 942 void sra_init_cache (void);
 943 bool sra_type_can_be_decomposed_p (tree);
 944
 945 /* In tree-loop-linear.c  */
 946 extern void linear_transform_loops (struct loops *);
 947
 948 /* In tree-ssa-loop-ivopts.c  */
 949 bool expr_invariant_in_loop_p (struct loop *, tree);
 950 bool multiplier_allowed_in_address_p (HOST_WIDE_INT, enum machine_mode);
 951 unsigned multiply_by_cost (HOST_WIDE_INT, enum machine_mode);
 952
 953 /* In tree-ssa-threadupdate.c.  */
 954 extern bool thread_through_all_blocks (void);
 955 extern void register_jump_thread (edge, edge);
 956
 957 /* In gimplify.c  */
 958 tree force_gimple_operand (tree, tree *, bool, tree);
 959 tree force_gimple_operand_bsi (block_stmt_iterator *, tree, bool, tree);
 960
 961 /* In tree-ssa-structalias.c */
 962 bool find_what_p_points_to (tree);
 963
 964 /* In tree-ssa-live.c */
 965 extern void remove_unused_locals (void);
 966
 967 /* In tree-ssa-address.c  */
 968
 969 /* Affine combination of trees.  We keep track of at most MAX_AFF_ELTS elements
 970    to make things simpler; this is sufficient in most cases.  */
 971
 972 #define MAX_AFF_ELTS 8
 973
 974 struct affine_tree_combination
 975 {
 976   /* Type of the result of the combination.  */
 977   tree type;
 978
 979   /* Mask modulo that the operations are performed.  */
 980   unsigned HOST_WIDE_INT mask;
 981
 982   /* Constant offset.  */
 983   unsigned HOST_WIDE_INT offset;
 984
 985   /* Number of elements of the combination.  */
 986   unsigned n;
 987
 988   /* Elements and their coefficients.  */
 989   tree elts[MAX_AFF_ELTS];
 990   unsigned HOST_WIDE_INT coefs[MAX_AFF_ELTS];
 991
 992   /* Remainder of the expression.  */
 993   tree rest;
 994 };
 995
 996 /* Description of a memory address.  */
 997
 998 struct mem_address
 999 {
1000   tree symbol, base, index, step, offset;
1001 };
1002
1003 tree create_mem_ref (block_stmt_iterator *, tree,
1004                      struct affine_tree_combination *);
1005 rtx addr_for_mem_ref (struct mem_address *, bool);
1006 void get_address_description (tree, struct mem_address *);
1007 tree maybe_fold_tmr (tree);
1008
1009 /* This structure is simply used during pushing fields onto the fieldstack
1010    to track the offset of the field, since bitpos_of_field gives it relative
1011    to its immediate containing type, and we want it relative to the ultimate
1012    containing object.  */
1013
1014 struct fieldoff
1015 {
1016   tree type;
1017   tree size;
1018   tree decl;
1019   HOST_WIDE_INT offset;
1020 };
1021 typedef struct fieldoff fieldoff_s;
1022
1023 DEF_VEC_O(fieldoff_s);
1024 DEF_VEC_ALLOC_O(fieldoff_s,heap);
1025 int push_fields_onto_fieldstack (tree, VEC(fieldoff_s,heap) **,
1026                                  HOST_WIDE_INT, bool *);
1027 void sort_fieldstack (VEC(fieldoff_s,heap) *);
1028
1029 void init_alias_heapvars (void);
1030 void delete_alias_heapvars (void);
1031
1032 #include "tree-flow-inline.h"
1033
1034 void swap_tree_operands (tree, tree *, tree *);
1035
1036 extern void recalculate_used_alone (void);
1037 extern bool updating_used_alone;
1038
1039 int least_common_multiple (int, int);
1040
1041 #endif /* _TREE_FLOW_H  */