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 stmt_ann_t get_stmt_ann (tree);
 348 static inline enum tree_ann_type ann_type (tree_ann_t);
 349 static inline basic_block bb_for_stmt (tree);
 350 extern void set_bb_for_stmt (tree, basic_block);
 351 static inline bool noreturn_call_p (tree);
 352 static inline void update_stmt (tree);
 353 static inline bool stmt_modified_p (tree);
 354 static inline VEC(tree, gc) *may_aliases (tree);
 355 static inline int get_lineno (tree);
 356 static inline const char *get_filename (tree);
 357 static inline bool is_exec_stmt (tree);
 358 static inline bool is_label_stmt (tree);
 359 static inline bitmap addresses_taken (tree);
 360
 361 /*---------------------------------------------------------------------------
 362                   Structure representing predictions in tree level.
 363 ---------------------------------------------------------------------------*/
 364 struct edge_prediction GTY((chain_next ("%h.ep_next")))
 365 {
 366   struct edge_prediction *ep_next;
 367   edge ep_edge;
 368   enum br_predictor ep_predictor;
 369   int ep_probability;
 370 };
 371
 372 /* Accessors for basic block annotations.  */
 373 static inline tree phi_nodes (basic_block);
 374 static inline void set_phi_nodes (basic_block, tree);
 375
 376 /*---------------------------------------------------------------------------
 377                               Global declarations
 378 ---------------------------------------------------------------------------*/
 379 struct int_tree_map GTY(())
 380 {
 381
 382   unsigned int uid;
 383   tree to;
 384 };
 385
 386 extern unsigned int int_tree_map_hash (const void *);
 387 extern int int_tree_map_eq (const void *, const void *);
 388
 389 typedef struct
 390 {
 391   htab_iterator hti;
 392 } referenced_var_iterator;
 393
 394
 395 /* This macro loops over all the referenced vars, one at a time, putting the
 396    current var in VAR.  Note:  You are not allowed to add referenced variables
 397    to the hashtable while using this macro.  Doing so may cause it to behave
 398    erratically.  */
 399
 400 #define FOR_EACH_REFERENCED_VAR(VAR, ITER) \
 401   for ((VAR) = first_referenced_var (&(ITER)); \
 402        !end_referenced_vars_p (&(ITER)); \
 403        (VAR) = next_referenced_var (&(ITER)))
 404
 405
 406 typedef struct
 407 {
 408   int i;
 409 } safe_referenced_var_iterator;
 410
 411 /* This macro loops over all the referenced vars, one at a time, putting the
 412    current var in VAR.  You are allowed to add referenced variables during the
 413    execution of this macro, however, the macro will not iterate over them.  It
 414    requires a temporary vector of trees, VEC, whose lifetime is controlled by
 415    the caller.  The purpose of the vector is to temporarily store the
 416    referenced_variables hashtable so that adding referenced variables does not
 417    affect the hashtable.  */
 418
 419 #define FOR_EACH_REFERENCED_VAR_SAFE(VAR, VEC, ITER) \
 420   for ((ITER).i = 0, fill_referenced_var_vec (&(VEC)); \
 421        VEC_iterate (tree, (VEC), (ITER).i, (VAR)); \
 422        (ITER).i++)
 423
 424 /* Array of all variables referenced in the function.  */
 425 extern GTY((param_is (struct int_tree_map))) htab_t referenced_vars;
 426
 427 /* Default defs for undefined symbols. */
 428 extern GTY((param_is (struct int_tree_map))) htab_t default_defs;
 429
 430 extern tree referenced_var_lookup (unsigned int);
 431 extern bool referenced_var_check_and_insert (tree);
 432 #define num_referenced_vars htab_elements (referenced_vars)
 433 #define referenced_var(i) referenced_var_lookup (i)
 434
 435 /* Array of all SSA_NAMEs used in the function.  */
 436 extern GTY(()) VEC(tree,gc) *ssa_names;
 437
 438 #define num_ssa_names (VEC_length (tree, ssa_names))
 439 #define ssa_name(i) (VEC_index (tree, ssa_names, (i)))
 440
 441 /* Artificial variable used to model the effects of function calls.  */
 442 extern GTY(()) tree global_var;
 443
 444 /* Artificial variable used to model the effects of nonlocal
 445    variables.  */
 446 extern GTY(()) tree nonlocal_all;
 447
 448 /* Call clobbered variables in the function.  If bit I is set, then
 449    REFERENCED_VARS (I) is call-clobbered.  */
 450 extern bitmap call_clobbered_vars;
 451
 452 /* Addressable variables in the function.  If bit I is set, then
 453    REFERENCED_VARS (I) has had its address taken.  */
 454 extern bitmap addressable_vars;
 455
 456 /* 'true' after aliases have been computed (see compute_may_aliases).  */
 457 extern bool aliases_computed_p;
 458
 459 /* Macros for showing usage statistics.  */
 460 #define SCALE(x) ((unsigned long) ((x) < 1024*10        \
 461                   ? (x)                                 \
 462                   : ((x) < 1024*1024*10                 \
 463                      ? (x) / 1024                       \
 464                      : (x) / (1024*1024))))
 465
 466 #define LABEL(x) ((x) < 1024*10 ? 'b' : ((x) < 1024*1024*10 ? 'k' : 'M'))
 467
 468 #define PERCENT(x,y) ((float)(x) * 100.0 / (float)(y))
 469
 470 /*---------------------------------------------------------------------------
 471                               Block iterators
 472 ---------------------------------------------------------------------------*/
 473
 474 typedef struct {
 475   tree_stmt_iterator tsi;
 476   basic_block bb;
 477 } block_stmt_iterator;
 478
 479 static inline block_stmt_iterator bsi_start (basic_block);
 480 static inline block_stmt_iterator bsi_last (basic_block);
 481 static inline block_stmt_iterator bsi_after_labels (basic_block);
 482 block_stmt_iterator bsi_for_stmt (tree);
 483 static inline bool bsi_end_p (block_stmt_iterator);
 484 static inline void bsi_next (block_stmt_iterator *);
 485 static inline void bsi_prev (block_stmt_iterator *);
 486 static inline tree bsi_stmt (block_stmt_iterator);
 487 static inline tree * bsi_stmt_ptr (block_stmt_iterator);
 488
 489 extern void bsi_remove (block_stmt_iterator *, bool);
 490 extern void bsi_move_before (block_stmt_iterator *, block_stmt_iterator *);
 491 extern void bsi_move_after (block_stmt_iterator *, block_stmt_iterator *);
 492 extern void bsi_move_to_bb_end (block_stmt_iterator *, basic_block);
 493
 494 enum bsi_iterator_update
 495 {
 496   /* Note that these are intentionally in the same order as TSI_FOO.  They
 497      mean exactly the same as their TSI_* counterparts.  */
 498   BSI_NEW_STMT,
 499   BSI_SAME_STMT,
 500   BSI_CHAIN_START,
 501   BSI_CHAIN_END,
 502   BSI_CONTINUE_LINKING
 503 };
 504
 505 extern void bsi_insert_before (block_stmt_iterator *, tree,
 506                                enum bsi_iterator_update);
 507 extern void bsi_insert_after (block_stmt_iterator *, tree,
 508                               enum bsi_iterator_update);
 509
 510 extern void bsi_replace (const block_stmt_iterator *, tree, bool);
 511
 512 /*---------------------------------------------------------------------------
 513                               OpenMP Region Tree
 514 ---------------------------------------------------------------------------*/
 515
 516 /* Parallel region information.  Every parallel and workshare
 517    directive is enclosed between two markers, the OMP_* directive
 518    and a corresponding OMP_RETURN statement.  */
 519
 520 struct omp_region
 521 {
 522   /* The enclosing region.  */
 523   struct omp_region *outer;
 524
 525   /* First child region.  */
 526   struct omp_region *inner;
 527
 528   /* Next peer region.  */
 529   struct omp_region *next;
 530
 531   /* Block containing the omp directive as its last stmt.  */
 532   basic_block entry;
 533
 534   /* Block containing the OMP_RETURN as its last stmt.  */
 535   basic_block exit;
 536
 537   /* Block containing the OMP_CONTINUE as its last stmt.  */
 538   basic_block cont;
 539
 540   /* If this is a combined parallel+workshare region, this is a list
 541      of additional arguments needed by the combined parallel+workshare
 542      library call.  */
 543   tree ws_args;
 544
 545   /* The code for the omp directive of this region.  */
 546   enum tree_code type;
 547
 548   /* Schedule kind, only used for OMP_FOR type regions.  */
 549   enum omp_clause_schedule_kind sched_kind;
 550
 551   /* True if this is a combined parallel+workshare region.  */
 552   bool is_combined_parallel;
 553 };
 554
 555 extern struct omp_region *root_omp_region;
 556 extern struct omp_region *new_omp_region (basic_block, enum tree_code,
 557                                           struct omp_region *);
 558 extern void free_omp_regions (void);
 559
 560 /*---------------------------------------------------------------------------
 561                               Function prototypes
 562 ---------------------------------------------------------------------------*/
 563 /* In tree-cfg.c  */
 564
 565 /* Location to track pending stmt for edge insertion.  */
 566 #define PENDING_STMT(e) ((e)->insns.t)
 567
 568 extern void delete_tree_cfg_annotations (void);
 569 extern void disband_implicit_edges (void);
 570 extern bool stmt_ends_bb_p (tree);
 571 extern bool is_ctrl_stmt (tree);
 572 extern bool is_ctrl_altering_stmt (tree);
 573 extern bool computed_goto_p (tree);
 574 extern bool simple_goto_p (tree);
 575 extern bool tree_can_make_abnormal_goto (tree);
 576 extern basic_block single_noncomplex_succ (basic_block bb);
 577 extern void tree_dump_bb (basic_block, FILE *, int);
 578 extern void debug_tree_bb (basic_block);
 579 extern basic_block debug_tree_bb_n (int);
 580 extern void dump_tree_cfg (FILE *, int);
 581 extern void debug_tree_cfg (int);
 582 extern void dump_cfg_stats (FILE *);
 583 extern void debug_cfg_stats (void);
 584 extern void debug_loop_ir (void);
 585 extern void print_loop_ir (FILE *);
 586 extern void cleanup_dead_labels (void);
 587 extern void group_case_labels (void);
 588 extern tree first_stmt (basic_block);
 589 extern tree last_stmt (basic_block);
 590 extern tree *last_stmt_ptr (basic_block);
 591 extern tree last_and_only_stmt (basic_block);
 592 extern edge find_taken_edge (basic_block, tree);
 593 extern basic_block label_to_block_fn (struct function *, tree);
 594 #define label_to_block(t) (label_to_block_fn (cfun, t))
 595 extern void bsi_insert_on_edge (edge, tree);
 596 extern basic_block bsi_insert_on_edge_immediate (edge, tree);
 597 extern void bsi_commit_one_edge_insert (edge, basic_block *);
 598 extern void bsi_commit_edge_inserts (void);
 599 extern void notice_special_calls (tree);
 600 extern void clear_special_calls (void);
 601 extern void verify_stmts (void);
 602 extern tree tree_block_label (basic_block);
 603 extern void extract_true_false_edges_from_block (basic_block, edge *, edge *);
 604 extern bool tree_duplicate_sese_region (edge, edge, basic_block *, unsigned,
 605                                         basic_block *);
 606 extern void add_phi_args_after_copy_bb (basic_block);
 607 extern void add_phi_args_after_copy (basic_block *, unsigned);
 608 extern bool tree_purge_dead_abnormal_call_edges (basic_block);
 609 extern bool tree_purge_dead_eh_edges (basic_block);
 610 extern bool tree_purge_all_dead_eh_edges (bitmap);
 611 extern tree gimplify_val (block_stmt_iterator *, tree, tree);
 612 extern tree gimplify_build1 (block_stmt_iterator *, enum tree_code,
 613                              tree, tree);
 614 extern tree gimplify_build2 (block_stmt_iterator *, enum tree_code,
 615                              tree, tree, tree);
 616 extern tree gimplify_build3 (block_stmt_iterator *, enum tree_code,
 617                              tree, tree, tree, tree);
 618 extern void init_empty_tree_cfg (void);
 619 extern void fold_cond_expr_cond (void);
 620 extern void make_abnormal_goto_edges (basic_block, bool);
 621 extern void replace_uses_by (tree, tree);
 622 extern void start_recording_case_labels (void);
 623 extern void end_recording_case_labels (void);
 624 extern basic_block move_sese_region_to_fn (struct function *, basic_block,
 625                                            basic_block);
 626
 627 /* In tree-cfgcleanup.c  */
 628 extern bool cleanup_tree_cfg (void);
 629 extern void cleanup_tree_cfg_loop (void);
 630
 631 /* In tree-pretty-print.c.  */
 632 extern void dump_generic_bb (FILE *, basic_block, int, int);
 633
 634 /* In tree-dfa.c  */
 635 extern var_ann_t create_var_ann (tree);
 636 extern function_ann_t create_function_ann (tree);
 637 extern stmt_ann_t create_stmt_ann (tree);
 638 extern tree_ann_common_t create_tree_common_ann (tree);
 639 extern void dump_dfa_stats (FILE *);
 640 extern void debug_dfa_stats (void);
 641 extern void debug_referenced_vars (void);
 642 extern void dump_referenced_vars (FILE *);
 643 extern void dump_variable (FILE *, tree);
 644 extern void debug_variable (tree);
 645 extern void dump_subvars_for (FILE *, tree);
 646 extern void debug_subvars_for (tree);
 647 extern tree get_virtual_var (tree);
 648 extern void add_referenced_var (tree);
 649 extern void mark_new_vars_to_rename (tree);
 650 extern void find_new_referenced_vars (tree *);
 651
 652 extern tree make_rename_temp (tree, const char *);
 653 extern void set_default_def (tree, tree);
 654 extern tree default_def (tree);
 655 extern tree default_def_fn (struct function *, tree);
 656
 657 /* In tree-phinodes.c  */
 658 extern void reserve_phi_args_for_new_edge (basic_block);
 659 extern tree create_phi_node (tree, basic_block);
 660 extern void add_phi_arg (tree, tree, edge);
 661 extern void remove_phi_args (edge);
 662 extern void remove_phi_node (tree, tree);
 663 extern tree phi_reverse (tree);
 664
 665 /* In gimple-low.c  */
 666 extern void record_vars_into (tree, tree);
 667 extern void record_vars (tree);
 668 extern bool block_may_fallthru (tree);
 669
 670 /* In tree-ssa-alias.c  */
 671 extern void dump_may_aliases_for (FILE *, tree);
 672 extern void debug_may_aliases_for (tree);
 673 extern void dump_alias_info (FILE *);
 674 extern void debug_alias_info (void);
 675 extern void dump_points_to_info (FILE *);
 676 extern void debug_points_to_info (void);
 677 extern void dump_points_to_info_for (FILE *, tree);
 678 extern void debug_points_to_info_for (tree);
 679 extern bool may_be_aliased (tree);
 680 extern bool is_aliased_with (tree, tree);
 681 extern struct ptr_info_def *get_ptr_info (tree);
 682 extern void new_type_alias (tree, tree, tree);
 683 extern void count_uses_and_derefs (tree, tree, unsigned *, unsigned *, bool *);
 684 static inline subvar_t get_subvars_for_var (tree);
 685 static inline tree get_subvar_at (tree, unsigned HOST_WIDE_INT);
 686 static inline bool ref_contains_array_ref (tree);
 687 static inline bool array_ref_contains_indirect_ref (tree);
 688 extern tree get_ref_base_and_extent (tree, HOST_WIDE_INT *,
 689                                      HOST_WIDE_INT *, HOST_WIDE_INT *);
 690 static inline bool var_can_have_subvars (tree);
 691 static inline bool overlap_subvar (unsigned HOST_WIDE_INT,
 692                                    unsigned HOST_WIDE_INT,
 693                                    tree, bool *);
 694
 695 /* Call-back function for walk_use_def_chains().  At each reaching
 696    definition, a function with this prototype is called.  */
 697 typedef bool (*walk_use_def_chains_fn) (tree, tree, void *);
 698
 699
 700 /* In tree-ssa.c  */
 701 extern void init_tree_ssa (void);
 702 extern edge ssa_redirect_edge (edge, basic_block);
 703 extern void flush_pending_stmts (edge);
 704 extern bool tree_ssa_useless_type_conversion (tree);
 705 extern bool tree_ssa_useless_type_conversion_1 (tree, tree);
 706 extern void verify_ssa (bool);
 707 extern void delete_tree_ssa (void);
 708 extern void register_new_def (tree, VEC(tree,heap) **);
 709 extern void walk_use_def_chains (tree, walk_use_def_chains_fn, void *, bool);
 710 extern bool stmt_references_memory_p (tree);
 711
 712 /* In tree-into-ssa.c  */
 713 void update_ssa (unsigned);
 714 void delete_update_ssa (void);
 715 void register_new_name_mapping (tree, tree);
 716 tree create_new_def_for (tree, tree, def_operand_p);
 717 bool need_ssa_update_p (void);
 718 bool name_registered_for_update_p (tree);
 719 bitmap ssa_names_to_replace (void);
 720 void release_ssa_name_after_update_ssa (tree name);
 721 void compute_global_livein (bitmap, bitmap);
 722 tree duplicate_ssa_name (tree, tree);
 723 void mark_sym_for_renaming (tree);
 724 void mark_set_for_renaming (bitmap);
 725 tree get_current_def (tree);
 726 void set_current_def (tree, tree);
 727
 728 /* In tree-ssa-ccp.c  */
 729 bool fold_stmt (tree *);
 730 bool fold_stmt_inplace (tree);
 731 tree widen_bitfield (tree, tree, tree);
 732
 733 /* In tree-vrp.c  */
 734 tree vrp_evaluate_conditional (tree, bool);
 735 void simplify_stmt_using_ranges (tree);
 736
 737 /* In tree-ssa-dom.c  */
 738 extern void dump_dominator_optimization_stats (FILE *);
 739 extern void debug_dominator_optimization_stats (void);
 740 int loop_depth_of_name (tree);
 741
 742 /* In tree-ssa-copy.c  */
 743 extern void merge_alias_info (tree, tree);
 744 extern void propagate_value (use_operand_p, tree);
 745 extern void propagate_tree_value (tree *, tree);
 746 extern void replace_exp (use_operand_p, tree);
 747 extern bool may_propagate_copy (tree, tree);
 748 extern bool may_propagate_copy_into_asm (tree);
 749
 750 /* Affine iv.  */
 751
 752 typedef struct
 753 {
 754   /* Iv = BASE + STEP * i.  */
 755   tree base, step;
 756
 757   /* True if this iv does not overflow.  */
 758   bool no_overflow;
 759 } affine_iv;
 760
 761 /* Description of number of iterations of a loop.  All the expressions inside
 762    the structure can be evaluated at the end of the loop's preheader
 763    (and due to ssa form, also anywhere inside the body of the loop).  */
 764
 765 struct tree_niter_desc
 766 {
 767   tree assumptions;     /* The boolean expression.  If this expression evaluates
 768                            to false, then the other fields in this structure
 769                            should not be used; there is no guarantee that they
 770                            will be correct.  */
 771   tree may_be_zero;     /* The boolean expression.  If it evaluates to true,
 772                            the loop will exit in the first iteration (i.e.
 773                            its latch will not be executed), even if the niter
 774                            field says otherwise.  */
 775   tree niter;           /* The expression giving the number of iterations of
 776                            a loop (provided that assumptions == true and
 777                            may_be_zero == false), more precisely the number
 778                            of executions of the latch of the loop.  */
 779   tree additional_info; /* The boolean expression.  Sometimes we use additional
 780                            knowledge to simplify the other expressions
 781                            contained in this structure (for example the
 782                            knowledge about value ranges of operands on entry to
 783                            the loop).  If this is a case, conjunction of such
 784                            condition is stored in this field, so that we do not
 785                            lose the information: for example if may_be_zero
 786                            is (n <= 0) and niter is (unsigned) n, we know
 787                            that the number of iterations is at most
 788                            MAX_SIGNED_INT.  However if the (n <= 0) assumption
 789                            is eliminated (by looking at the guard on entry of
 790                            the loop), then the information would be lost.  */
 791
 792   /* The simplified shape of the exit condition.  The loop exits if
 793      CONTROL CMP BOUND is false, where CMP is one of NE_EXPR,
 794      LT_EXPR, or GT_EXPR, and step of CONTROL is positive if CMP is
 795      LE_EXPR and negative if CMP is GE_EXPR.  This information is used
 796      by loop unrolling.  */
 797   affine_iv control;
 798   tree bound;
 799   enum tree_code cmp;
 800 };
 801
 802 /* In tree-vectorizer.c */
 803 void vectorize_loops (struct loops *);
 804 extern bool vect_can_force_dr_alignment_p (tree, unsigned int);
 805 extern tree get_vectype_for_scalar_type (tree);
 806
 807 /* In tree-ssa-phiopt.c */
 808 bool empty_block_p (basic_block);
 809
 810 /* In tree-ssa-loop*.c  */
 811
 812 void tree_ssa_lim (struct loops *);
 813 unsigned int tree_ssa_unswitch_loops (struct loops *);
 814 unsigned int canonicalize_induction_variables (struct loops *);
 815 unsigned int tree_unroll_loops_completely (struct loops *, bool);
 816 unsigned int tree_ssa_prefetch_arrays (struct loops *);
 817 unsigned int remove_empty_loops (struct loops *);
 818 void tree_ssa_iv_optimize (struct loops *);
 819
 820 bool number_of_iterations_exit (struct loop *, edge,
 821                                 struct tree_niter_desc *niter, bool);
 822 tree find_loop_niter (struct loop *, edge *);
 823 tree loop_niter_by_eval (struct loop *, edge);
 824 tree find_loop_niter_by_eval (struct loop *, edge *);
 825 void estimate_numbers_of_iterations (struct loops *);
 826 bool scev_probably_wraps_p (tree, tree, tree, struct loop *, bool);
 827 bool convert_affine_scev (struct loop *, tree, tree *, tree *, tree, bool);
 828
 829 bool nowrap_type_p (tree);
 830 enum ev_direction {EV_DIR_GROWS, EV_DIR_DECREASES, EV_DIR_UNKNOWN};
 831 enum ev_direction scev_direction (tree);
 832
 833 void free_numbers_of_iterations_estimates (struct loops *);
 834 void free_numbers_of_iterations_estimates_loop (struct loop *);
 835 void rewrite_into_loop_closed_ssa (bitmap, unsigned);
 836 void verify_loop_closed_ssa (void);
 837 void loop_commit_inserts (void);
 838 bool for_each_index (tree *, bool (*) (tree, tree *, void *), void *);
 839 void create_iv (tree, tree, tree, struct loop *, block_stmt_iterator *, bool,
 840                 tree *, tree *);
 841 void split_loop_exit_edge (edge);
 842 unsigned force_expr_to_var_cost (tree);
 843 basic_block bsi_insert_on_edge_immediate_loop (edge, 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 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);
 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 #endif /* _TREE_FLOW_H  */