gcc/tree-flow.h

   1 /* Data and Control Flow Analysis for Trees.
   2    Copyright (C) 2001, 2003, 2004, 2005, 2007
   3    Free Software Foundation, Inc.
   4    Contributed by Diego Novillo <dnovillo@redhat.com>
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 3, or (at your option)
  11 any later version.
  12
  13 GCC is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  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   /* An artificial variable representing the memory location pointed-to by
 188      all the pointer symbols that flow-insensitive alias analysis
 189      (mostly type-based) considers to be aliased.  If the variable is
 190      not a pointer or if it is never dereferenced, this must be NULL.  */
 191   tree symbol_mem_tag;
 192
 193   /* Variables that may alias this variable.  */
 194   VEC(tree, gc) *may_aliases;
 195
 196   /* Used when going out of SSA form to indicate which partition this
 197      variable represents storage for.  */
 198   unsigned partition;
 199
 200   /* Used by the root-var object in tree-ssa-live.[ch].  */
 201   unsigned root_index;
 202
 203   /* During into-ssa and the dominator optimizer, this field holds the
 204      current version of this variable (an SSA_NAME).  */
 205   tree current_def;
 206
 207   /* If this variable is a structure, this fields holds a list of
 208      symbols representing each of the fields of the structure.  */
 209   subvar_t subvars;
 210
 211   /* Mask of values saying the reasons why this variable has escaped
 212      the function.  */
 213   unsigned int escape_mask;
 214 };
 215
 216 struct function_ann_d GTY(())
 217 {
 218   struct tree_ann_common_d common;
 219
 220   /* Pointer to the structure that contains the sets of global
 221      variables modified by function calls.  This field is only used
 222      for FUNCTION_DECLs.  */
 223   ipa_reference_vars_info_t GTY ((skip)) reference_vars_info;
 224 };
 225
 226 typedef struct immediate_use_iterator_d
 227 {
 228   /* This is the current use the iterator is processing.  */
 229   ssa_use_operand_t *imm_use;
 230   /* This marks the last use in the list (use node from SSA_NAME)  */
 231   ssa_use_operand_t *end_p;
 232   /* This node is inserted and used to mark the end of the uses for a stmt.  */
 233   ssa_use_operand_t iter_node;
 234   /* This is the next ssa_name to visit.  IMM_USE may get removed before
 235      the next one is traversed to, so it must be cached early.  */
 236   ssa_use_operand_t *next_imm_name;
 237 } imm_use_iterator;
 238
 239
 240 /* Use this iterator when simply looking at stmts.  Adding, deleting or
 241    modifying stmts will cause this iterator to malfunction.  */
 242
 243 #define FOR_EACH_IMM_USE_FAST(DEST, ITER, SSAVAR)                       \
 244   for ((DEST) = first_readonly_imm_use (&(ITER), (SSAVAR));     \
 245        !end_readonly_imm_use_p (&(ITER));                       \
 246        (DEST) = next_readonly_imm_use (&(ITER)))
 247
 248 /* Use this iterator to visit each stmt which has a use of SSAVAR.  */
 249
 250 #define FOR_EACH_IMM_USE_STMT(STMT, ITER, SSAVAR)               \
 251   for ((STMT) = first_imm_use_stmt (&(ITER), (SSAVAR));         \
 252        !end_imm_use_stmt_p (&(ITER));                           \
 253        (STMT) = next_imm_use_stmt (&(ITER)))
 254
 255 /* Use this to terminate the FOR_EACH_IMM_USE_STMT loop early.  Failure to
 256    do so will result in leaving a iterator marker node in the immediate
 257    use list, and nothing good will come from that.   */
 258 #define BREAK_FROM_IMM_USE_STMT(ITER)                           \
 259    {                                                            \
 260      end_imm_use_stmt_traverse (&(ITER));                       \
 261      break;                                                     \
 262    }
 263
 264
 265 /* Use this iterator in combination with FOR_EACH_IMM_USE_STMT to
 266    get access to each occurrence of ssavar on the stmt returned by
 267    that iterator..  for instance:
 268
 269      FOR_EACH_IMM_USE_STMT (stmt, iter, var)
 270        {
 271          FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
 272            {
 273              SET_USE (use_p) = blah;
 274            }
 275          update_stmt (stmt);
 276        }                                                         */
 277
 278 #define FOR_EACH_IMM_USE_ON_STMT(DEST, ITER)                    \
 279   for ((DEST) = first_imm_use_on_stmt (&(ITER));                \
 280        !end_imm_use_on_stmt_p (&(ITER));                        \
 281        (DEST) = next_imm_use_on_stmt (&(ITER)))
 282
 283
 284
 285 struct stmt_ann_d GTY(())
 286 {
 287   struct tree_ann_common_d common;
 288
 289   /* Nonzero if the statement has been modified (meaning that the operands
 290      need to be scanned again).  */
 291   unsigned modified : 1;
 292
 293   /* Nonzero if the statement makes references to volatile storage.  */
 294   unsigned has_volatile_ops : 1;
 295
 296   /* Nonzero if the statement makes a function call that may clobber global
 297      and local addressable variables.  */
 298   unsigned makes_clobbering_call : 1;
 299
 300   /* Basic block that contains this statement.  */
 301   basic_block bb;
 302
 303   /* Operand cache for stmt.  */
 304   struct stmt_operands_d GTY ((skip (""))) operands;
 305
 306   /* Set of variables that have had their address taken in the statement.  */
 307   bitmap addresses_taken;
 308
 309   /* Unique identifier for this statement.  These ID's are to be created
 310      by each pass on an as-needed basis in any order convenient for the
 311      pass which needs statement UIDs.  */
 312   unsigned int uid;
 313
 314   /* Linked list of histograms for value-based profiling.  This is really a
 315      struct histogram_value*.  We use void* to avoid having to export that
 316      everywhere, and to avoid having to put it in GC memory.  */
 317
 318   void * GTY ((skip (""))) histograms;
 319 };
 320
 321 union tree_ann_d GTY((desc ("ann_type ((tree_ann_t)&%h)")))
 322 {
 323   struct tree_ann_common_d GTY((tag ("TREE_ANN_COMMON"))) common;
 324   struct var_ann_d GTY((tag ("VAR_ANN"))) vdecl;
 325   struct function_ann_d GTY((tag ("FUNCTION_ANN"))) fdecl;
 326   struct stmt_ann_d GTY((tag ("STMT_ANN"))) stmt;
 327 };
 328
 329 extern GTY(()) VEC(tree,gc) *modified_noreturn_calls;
 330
 331 typedef union tree_ann_d *tree_ann_t;
 332 typedef struct var_ann_d *var_ann_t;
 333 typedef struct function_ann_d *function_ann_t;
 334 typedef struct stmt_ann_d *stmt_ann_t;
 335 typedef struct tree_ann_common_d *tree_ann_common_t;
 336
 337 static inline tree_ann_common_t tree_common_ann (tree);
 338 static inline tree_ann_common_t get_tree_common_ann (tree);
 339 static inline var_ann_t var_ann (tree);
 340 static inline var_ann_t get_var_ann (tree);
 341 static inline function_ann_t function_ann (tree);
 342 static inline function_ann_t get_function_ann (tree);
 343 static inline stmt_ann_t stmt_ann (tree);
 344 static inline stmt_ann_t get_stmt_ann (tree);
 345 static inline enum tree_ann_type ann_type (tree_ann_t);
 346 static inline basic_block bb_for_stmt (tree);
 347 extern void set_bb_for_stmt (tree, basic_block);
 348 static inline bool noreturn_call_p (tree);
 349 static inline void update_stmt (tree);
 350 static inline bool stmt_modified_p (tree);
 351 static inline VEC(tree, gc) *may_aliases (tree);
 352 static inline int get_lineno (tree);
 353 static inline const char *get_filename (tree);
 354 static inline bool is_exec_stmt (tree);
 355 static inline bool is_label_stmt (tree);
 356 static inline bitmap addresses_taken (tree);
 357
 358 /*---------------------------------------------------------------------------
 359                   Structure representing predictions in tree level.
 360 ---------------------------------------------------------------------------*/
 361 struct edge_prediction GTY((chain_next ("%h.ep_next")))
 362 {
 363   struct edge_prediction *ep_next;
 364   edge ep_edge;
 365   enum br_predictor ep_predictor;
 366   int ep_probability;
 367 };
 368
 369 /* Accessors for basic block annotations.  */
 370 static inline tree phi_nodes (basic_block);
 371 static inline void set_phi_nodes (basic_block, tree);
 372
 373 /*---------------------------------------------------------------------------
 374                               Global declarations
 375 ---------------------------------------------------------------------------*/
 376 struct int_tree_map GTY(())
 377 {
 378
 379   unsigned int uid;
 380   tree to;
 381 };
 382
 383 extern unsigned int int_tree_map_hash (const void *);
 384 extern int int_tree_map_eq (const void *, const void *);
 385
 386 typedef struct
 387 {
 388   htab_iterator hti;
 389 } referenced_var_iterator;
 390
 391
 392 /* This macro loops over all the referenced vars, one at a time, putting the
 393    current var in VAR.  Note:  You are not allowed to add referenced variables
 394    to the hashtable while using this macro.  Doing so may cause it to behave
 395    erratically.  */
 396
 397 #define FOR_EACH_REFERENCED_VAR(VAR, ITER) \
 398   for ((VAR) = first_referenced_var (&(ITER)); \
 399        !end_referenced_vars_p (&(ITER)); \
 400        (VAR) = next_referenced_var (&(ITER)))
 401
 402
 403 typedef struct
 404 {
 405   int i;
 406 } safe_referenced_var_iterator;
 407
 408 /* This macro loops over all the referenced vars, one at a time, putting the
 409    current var in VAR.  You are allowed to add referenced variables during the
 410    execution of this macro, however, the macro will not iterate over them.  It
 411    requires a temporary vector of trees, VEC, whose lifetime is controlled by
 412    the caller.  The purpose of the vector is to temporarily store the
 413    referenced_variables hashtable so that adding referenced variables does not
 414    affect the hashtable.  */
 415
 416 #define FOR_EACH_REFERENCED_VAR_SAFE(VAR, VEC, ITER) \
 417   for ((ITER).i = 0, fill_referenced_var_vec (&(VEC)); \
 418        VEC_iterate (tree, (VEC), (ITER).i, (VAR)); \
 419        (ITER).i++)
 420
 421 /* Array of all variables referenced in the function.  */
 422 extern GTY((param_is (struct int_tree_map))) htab_t referenced_vars;
 423
 424 /* Default defs for undefined symbols. */
 425 extern GTY((param_is (struct int_tree_map))) htab_t default_defs;
 426
 427 extern tree referenced_var_lookup (unsigned int);
 428 extern bool referenced_var_check_and_insert (tree);
 429 #define num_referenced_vars htab_elements (referenced_vars)
 430 #define referenced_var(i) referenced_var_lookup (i)
 431
 432 /* Array of all SSA_NAMEs used in the function.  */
 433 extern GTY(()) VEC(tree,gc) *ssa_names;
 434
 435 #define num_ssa_names (VEC_length (tree, ssa_names))
 436 #define ssa_name(i) (VEC_index (tree, ssa_names, (i)))
 437
 438 /* Artificial variable used to model the effects of function calls.  */
 439 extern GTY(()) tree global_var;
 440
 441 /* Artificial variable used to model the effects of nonlocal
 442    variables.  */
 443 extern GTY(()) tree nonlocal_all;
 444
 445 /* Call clobbered variables in the function.  If bit I is set, then
 446    REFERENCED_VARS (I) is call-clobbered.  */
 447 extern bitmap call_clobbered_vars;
 448
 449 /* Addressable variables in the function.  If bit I is set, then
 450    REFERENCED_VARS (I) has had its address taken.  */
 451 extern bitmap addressable_vars;
 452
 453 /* 'true' after aliases have been computed (see compute_may_aliases).  */
 454 extern bool aliases_computed_p;
 455
 456 /* Macros for showing usage statistics.  */
 457 #define SCALE(x) ((unsigned long) ((x) < 1024*10        \
 458                   ? (x)                                 \
 459                   : ((x) < 1024*1024*10                 \
 460                      ? (x) / 1024                       \
 461                      : (x) / (1024*1024))))
 462
 463 #define LABEL(x) ((x) < 1024*10 ? 'b' : ((x) < 1024*1024*10 ? 'k' : 'M'))
 464
 465 #define PERCENT(x,y) ((float)(x) * 100.0 / (float)(y))
 466
 467 /*---------------------------------------------------------------------------
 468                               Block iterators
 469 ---------------------------------------------------------------------------*/
 470
 471 typedef struct {
 472   tree_stmt_iterator tsi;
 473   basic_block bb;
 474 } block_stmt_iterator;
 475
 476 static inline block_stmt_iterator bsi_start (basic_block);
 477 static inline block_stmt_iterator bsi_last (basic_block);
 478 static inline block_stmt_iterator bsi_after_labels (basic_block);
 479 block_stmt_iterator bsi_for_stmt (tree);
 480 static inline bool bsi_end_p (block_stmt_iterator);
 481 static inline void bsi_next (block_stmt_iterator *);
 482 static inline void bsi_prev (block_stmt_iterator *);
 483 static inline tree bsi_stmt (block_stmt_iterator);
 484 static inline tree * bsi_stmt_ptr (block_stmt_iterator);
 485
 486 extern void bsi_remove (block_stmt_iterator *, bool);
 487 extern void bsi_move_before (block_stmt_iterator *, block_stmt_iterator *);
 488 extern void bsi_move_after (block_stmt_iterator *, block_stmt_iterator *);
 489 extern void bsi_move_to_bb_end (block_stmt_iterator *, basic_block);
 490
 491 enum bsi_iterator_update
 492 {
 493   /* Note that these are intentionally in the same order as TSI_FOO.  They
 494      mean exactly the same as their TSI_* counterparts.  */
 495   BSI_NEW_STMT,
 496   BSI_SAME_STMT,
 497   BSI_CHAIN_START,
 498   BSI_CHAIN_END,
 499   BSI_CONTINUE_LINKING
 500 };
 501
 502 extern void bsi_insert_before (block_stmt_iterator *, tree,
 503                                enum bsi_iterator_update);
 504 extern void bsi_insert_after (block_stmt_iterator *, tree,
 505                               enum bsi_iterator_update);
 506
 507 extern void bsi_replace (const block_stmt_iterator *, tree, bool);
 508
 509 /*---------------------------------------------------------------------------
 510                               OpenMP Region Tree
 511 ---------------------------------------------------------------------------*/
 512
 513 /* Parallel region information.  Every parallel and workshare
 514    directive is enclosed between two markers, the OMP_* directive
 515    and a corresponding OMP_RETURN statement.  */
 516
 517 struct omp_region
 518 {
 519   /* The enclosing region.  */
 520   struct omp_region *outer;
 521
 522   /* First child region.  */
 523   struct omp_region *inner;
 524
 525   /* Next peer region.  */
 526   struct omp_region *next;
 527
 528   /* Block containing the omp directive as its last stmt.  */
 529   basic_block entry;
 530
 531   /* Block containing the OMP_RETURN as its last stmt.  */
 532   basic_block exit;
 533
 534   /* Block containing the OMP_CONTINUE as its last stmt.  */
 535   basic_block cont;
 536
 537   /* If this is a combined parallel+workshare region, this is a list
 538      of additional arguments needed by the combined parallel+workshare
 539      library call.  */
 540   tree ws_args;
 541
 542   /* The code for the omp directive of this region.  */
 543   enum tree_code type;
 544
 545   /* Schedule kind, only used for OMP_FOR type regions.  */
 546   enum omp_clause_schedule_kind sched_kind;
 547
 548   /* True if this is a combined parallel+workshare region.  */
 549   bool is_combined_parallel;
 550 };
 551
 552 extern struct omp_region *root_omp_region;
 553 extern struct omp_region *new_omp_region (basic_block, enum tree_code,
 554                                           struct omp_region *);
 555 extern void free_omp_regions (void);
 556
 557 /*---------------------------------------------------------------------------
 558                               Function prototypes
 559 ---------------------------------------------------------------------------*/
 560 /* In tree-cfg.c  */
 561
 562 /* Location to track pending stmt for edge insertion.  */
 563 #define PENDING_STMT(e) ((e)->insns.t)
 564
 565 extern void delete_tree_cfg_annotations (void);
 566 extern void disband_implicit_edges (void);
 567 extern bool stmt_ends_bb_p (tree);
 568 extern bool is_ctrl_stmt (tree);
 569 extern bool is_ctrl_altering_stmt (tree);
 570 extern bool computed_goto_p (tree);
 571 extern bool simple_goto_p (tree);
 572 extern bool tree_can_make_abnormal_goto (tree);
 573 extern basic_block single_noncomplex_succ (basic_block bb);
 574 extern void tree_dump_bb (basic_block, FILE *, int);
 575 extern void debug_tree_bb (basic_block);
 576 extern basic_block debug_tree_bb_n (int);
 577 extern void dump_tree_cfg (FILE *, int);
 578 extern void debug_tree_cfg (int);
 579 extern void dump_cfg_stats (FILE *);
 580 extern void debug_cfg_stats (void);
 581 extern void debug_loop_ir (void);
 582 extern void print_loop_ir (FILE *);
 583 extern void cleanup_dead_labels (void);
 584 extern void group_case_labels (void);
 585 extern tree first_stmt (basic_block);
 586 extern tree last_stmt (basic_block);
 587 extern tree *last_stmt_ptr (basic_block);
 588 extern tree last_and_only_stmt (basic_block);
 589 extern edge find_taken_edge (basic_block, tree);
 590 extern basic_block label_to_block_fn (struct function *, tree);
 591 #define label_to_block(t) (label_to_block_fn (cfun, t))
 592 extern void bsi_insert_on_edge (edge, tree);
 593 extern basic_block bsi_insert_on_edge_immediate (edge, tree);
 594 extern void bsi_commit_one_edge_insert (edge, basic_block *);
 595 extern void bsi_commit_edge_inserts (void);
 596 extern void notice_special_calls (tree);
 597 extern void clear_special_calls (void);
 598 extern void verify_stmts (void);
 599 extern tree tree_block_label (basic_block);
 600 extern void extract_true_false_edges_from_block (basic_block, edge *, edge *);
 601 extern bool tree_duplicate_sese_region (edge, edge, basic_block *, unsigned,
 602                                         basic_block *);
 603 extern void add_phi_args_after_copy_bb (basic_block);
 604 extern void add_phi_args_after_copy (basic_block *, unsigned);
 605 extern bool tree_purge_dead_abnormal_call_edges (basic_block);
 606 extern bool tree_purge_dead_eh_edges (basic_block);
 607 extern bool tree_purge_all_dead_eh_edges (bitmap);
 608 extern tree gimplify_val (block_stmt_iterator *, tree, tree);
 609 extern tree gimplify_build1 (block_stmt_iterator *, enum tree_code,
 610                              tree, tree);
 611 extern tree gimplify_build2 (block_stmt_iterator *, enum tree_code,
 612                              tree, tree, tree);
 613 extern tree gimplify_build3 (block_stmt_iterator *, enum tree_code,
 614                              tree, tree, tree, tree);
 615 extern void init_empty_tree_cfg (void);
 616 extern void fold_cond_expr_cond (void);
 617 extern void make_abnormal_goto_edges (basic_block, bool);
 618 extern void replace_uses_by (tree, tree);
 619 extern void start_recording_case_labels (void);
 620 extern void end_recording_case_labels (void);
 621 extern basic_block move_sese_region_to_fn (struct function *, basic_block,
 622                                            basic_block);
 623
 624 /* In tree-cfgcleanup.c  */
 625 extern bool cleanup_tree_cfg (void);
 626 extern void cleanup_tree_cfg_loop (void);
 627
 628 /* In tree-pretty-print.c.  */
 629 extern void dump_generic_bb (FILE *, basic_block, int, int);
 630
 631 /* In tree-dfa.c  */
 632 extern var_ann_t create_var_ann (tree);
 633 extern function_ann_t create_function_ann (tree);
 634 extern stmt_ann_t create_stmt_ann (tree);
 635 extern tree_ann_common_t create_tree_common_ann (tree);
 636 extern void dump_dfa_stats (FILE *);
 637 extern void debug_dfa_stats (void);
 638 extern void debug_referenced_vars (void);
 639 extern void dump_referenced_vars (FILE *);
 640 extern void dump_variable (FILE *, tree);
 641 extern void debug_variable (tree);
 642 extern void dump_subvars_for (FILE *, tree);
 643 extern void debug_subvars_for (tree);
 644 extern tree get_virtual_var (tree);
 645 extern void add_referenced_var (tree);
 646 extern void mark_new_vars_to_rename (tree);
 647 extern void find_new_referenced_vars (tree *);
 648
 649 extern tree make_rename_temp (tree, const char *);
 650 extern void set_default_def (tree, tree);
 651 extern tree default_def (tree);
 652 extern tree default_def_fn (struct function *, tree);
 653
 654 /* In tree-phinodes.c  */
 655 extern void reserve_phi_args_for_new_edge (basic_block);
 656 extern tree create_phi_node (tree, basic_block);
 657 extern void add_phi_arg (tree, tree, edge);
 658 extern void remove_phi_args (edge);
 659 extern void remove_phi_node (tree, tree);
 660 extern tree phi_reverse (tree);
 661
 662 /* In gimple-low.c  */
 663 extern void record_vars_into (tree, tree);
 664 extern void record_vars (tree);
 665 extern bool block_may_fallthru (tree);
 666
 667 /* In tree-ssa-alias.c  */
 668 extern void dump_may_aliases_for (FILE *, tree);
 669 extern void debug_may_aliases_for (tree);
 670 extern void dump_alias_info (FILE *);
 671 extern void debug_alias_info (void);
 672 extern void dump_points_to_info (FILE *);
 673 extern void debug_points_to_info (void);
 674 extern void dump_points_to_info_for (FILE *, tree);
 675 extern void debug_points_to_info_for (tree);
 676 extern bool may_be_aliased (tree);
 677 extern bool is_aliased_with (tree, tree);
 678 extern bool may_aliases_intersect (tree, tree);
 679 extern struct ptr_info_def *get_ptr_info (tree);
 680 extern void new_type_alias (tree, tree, tree);
 681 extern void count_uses_and_derefs (tree, tree, unsigned *, unsigned *, bool *);
 682 static inline subvar_t get_subvars_for_var (tree);
 683 static inline tree get_subvar_at (tree, unsigned HOST_WIDE_INT);
 684 static inline bool ref_contains_array_ref (tree);
 685 static inline bool array_ref_contains_indirect_ref (tree);
 686 extern tree get_ref_base_and_extent (tree, HOST_WIDE_INT *,
 687                                      HOST_WIDE_INT *, HOST_WIDE_INT *);
 688 static inline bool var_can_have_subvars (tree);
 689 static inline bool overlap_subvar (unsigned HOST_WIDE_INT,
 690                                    unsigned HOST_WIDE_INT,
 691                                    tree, bool *);
 692
 693 /* Call-back function for walk_use_def_chains().  At each reaching
 694    definition, a function with this prototype is called.  */
 695 typedef bool (*walk_use_def_chains_fn) (tree, tree, void *);
 696
 697
 698 /* In tree-ssa.c  */
 699 extern void init_tree_ssa (void);
 700 extern edge ssa_redirect_edge (edge, basic_block);
 701 extern void flush_pending_stmts (edge);
 702 extern bool tree_ssa_useless_type_conversion (tree);
 703 extern bool tree_ssa_useless_type_conversion_1 (tree, tree);
 704 extern void verify_ssa (bool);
 705 extern void delete_tree_ssa (void);
 706 extern void register_new_def (tree, VEC(tree,heap) **);
 707 extern void walk_use_def_chains (tree, walk_use_def_chains_fn, void *, bool);
 708 extern bool stmt_references_memory_p (tree);
 709
 710 /* In tree-into-ssa.c  */
 711 void update_ssa (unsigned);
 712 void delete_update_ssa (void);
 713 void register_new_name_mapping (tree, tree);
 714 tree create_new_def_for (tree, tree, def_operand_p);
 715 bool need_ssa_update_p (void);
 716 bool name_registered_for_update_p (tree);
 717 bitmap ssa_names_to_replace (void);
 718 void release_ssa_name_after_update_ssa (tree name);
 719 void compute_global_livein (bitmap, bitmap);
 720 tree duplicate_ssa_name (tree, tree);
 721 void mark_sym_for_renaming (tree);
 722 void mark_set_for_renaming (bitmap);
 723 tree get_current_def (tree);
 724 void set_current_def (tree, tree);
 725
 726 /* In tree-ssa-ccp.c  */
 727 bool fold_stmt (tree *);
 728 bool fold_stmt_inplace (tree);
 729 tree widen_bitfield (tree, tree, tree);
 730
 731 /* In tree-vrp.c  */
 732 tree vrp_evaluate_conditional (tree, tree);
 733 void simplify_stmt_using_ranges (tree);
 734
 735 /* In tree-ssa-dom.c  */
 736 extern void dump_dominator_optimization_stats (FILE *);
 737 extern void debug_dominator_optimization_stats (void);
 738 int loop_depth_of_name (tree);
 739
 740 /* In tree-ssa-copy.c  */
 741 extern void merge_alias_info (tree, tree);
 742 extern void propagate_value (use_operand_p, tree);
 743 extern void propagate_tree_value (tree *, tree);
 744 extern void replace_exp (use_operand_p, tree);
 745 extern bool may_propagate_copy (tree, tree);
 746 extern bool may_propagate_copy_into_asm (tree);
 747
 748 /* Affine iv.  */
 749
 750 typedef struct
 751 {
 752   /* Iv = BASE + STEP * i.  */
 753   tree base, step;
 754
 755   /* True if this iv does not overflow.  */
 756   bool no_overflow;
 757 } affine_iv;
 758
 759 /* Description of number of iterations of a loop.  All the expressions inside
 760    the structure can be evaluated at the end of the loop's preheader
 761    (and due to ssa form, also anywhere inside the body of the loop).  */
 762
 763 struct tree_niter_desc
 764 {
 765   tree assumptions;     /* The boolean expression.  If this expression evaluates
 766                            to false, then the other fields in this structure
 767                            should not be used; there is no guarantee that they
 768                            will be correct.  */
 769   tree may_be_zero;     /* The boolean expression.  If it evaluates to true,
 770                            the loop will exit in the first iteration (i.e.
 771                            its latch will not be executed), even if the niter
 772                            field says otherwise.  */
 773   tree niter;           /* The expression giving the number of iterations of
 774                            a loop (provided that assumptions == true and
 775                            may_be_zero == false), more precisely the number
 776                            of executions of the latch of the loop.  */
 777   tree additional_info; /* The boolean expression.  Sometimes we use additional
 778                            knowledge to simplify the other expressions
 779                            contained in this structure (for example the
 780                            knowledge about value ranges of operands on entry to
 781                            the loop).  If this is a case, conjunction of such
 782                            condition is stored in this field, so that we do not
 783                            lose the information: for example if may_be_zero
 784                            is (n <= 0) and niter is (unsigned) n, we know
 785                            that the number of iterations is at most
 786                            MAX_SIGNED_INT.  However if the (n <= 0) assumption
 787                            is eliminated (by looking at the guard on entry of
 788                            the loop), then the information would be lost.  */
 789
 790   /* The simplified shape of the exit condition.  The loop exits if
 791      CONTROL CMP BOUND is false, where CMP is one of NE_EXPR,
 792      LT_EXPR, or GT_EXPR, and step of CONTROL is positive if CMP is
 793      LE_EXPR and negative if CMP is GE_EXPR.  This information is used
 794      by loop unrolling.  */
 795   affine_iv control;
 796   tree bound;
 797   enum tree_code cmp;
 798 };
 799
 800 /* In tree-vectorizer.c */
 801 void vectorize_loops (struct loops *);
 802 extern bool vect_can_force_dr_alignment_p (tree, unsigned int);
 803 extern tree get_vectype_for_scalar_type (tree);
 804
 805 /* In tree-ssa-phiopt.c */
 806 bool empty_block_p (basic_block);
 807
 808 /* In tree-ssa-loop*.c  */
 809
 810 void tree_ssa_lim (struct loops *);
 811 unsigned int tree_ssa_unswitch_loops (struct loops *);
 812 unsigned int canonicalize_induction_variables (struct loops *);
 813 unsigned int tree_unroll_loops_completely (struct loops *, bool);
 814 unsigned int tree_ssa_prefetch_arrays (struct loops *);
 815 unsigned int remove_empty_loops (struct loops *);
 816 void tree_ssa_iv_optimize (struct loops *);
 817
 818 bool number_of_iterations_exit (struct loop *, edge,
 819                                 struct tree_niter_desc *niter, bool);
 820 tree find_loop_niter (struct loop *, edge *);
 821 tree loop_niter_by_eval (struct loop *, edge);
 822 tree find_loop_niter_by_eval (struct loop *, edge *);
 823 void estimate_numbers_of_iterations (struct loops *);
 824 bool scev_probably_wraps_p (tree, tree, tree, struct loop *, bool);
 825 bool convert_affine_scev (struct loop *, tree, tree *, tree *, tree, bool);
 826
 827 bool nowrap_type_p (tree);
 828 enum ev_direction {EV_DIR_GROWS, EV_DIR_DECREASES, EV_DIR_UNKNOWN};
 829 enum ev_direction scev_direction (tree);
 830
 831 void free_numbers_of_iterations_estimates (struct loops *);
 832 void free_numbers_of_iterations_estimates_loop (struct loop *);
 833 void rewrite_into_loop_closed_ssa (bitmap, unsigned);
 834 void verify_loop_closed_ssa (void);
 835 void loop_commit_inserts (void);
 836 bool for_each_index (tree *, bool (*) (tree, tree *, void *), void *);
 837 void create_iv (tree, tree, tree, struct loop *, block_stmt_iterator *, bool,
 838                 tree *, tree *);
 839 void split_loop_exit_edge (edge);
 840 unsigned force_expr_to_var_cost (tree);
 841 basic_block bsi_insert_on_edge_immediate_loop (edge, tree);
 842 void standard_iv_increment_position (struct loop *, block_stmt_iterator *,
 843                                      bool *);
 844 basic_block ip_end_pos (struct loop *);
 845 basic_block ip_normal_pos (struct loop *);
 846 bool tree_duplicate_loop_to_header_edge (struct loop *, edge, struct loops *,
 847                                          unsigned int, sbitmap,
 848                                          edge, edge *,
 849                                          unsigned int *, int);
 850 struct loop *tree_ssa_loop_version (struct loops *, struct loop *, tree,
 851                                     basic_block *);
 852 tree expand_simple_operations (tree);
 853 void substitute_in_loop_info (struct loop *, tree, tree);
 854 edge single_dom_exit (struct loop *);
 855 bool can_unroll_loop_p (struct loop *loop, unsigned factor,
 856                         struct tree_niter_desc *niter);
 857 void tree_unroll_loop (struct loops *, struct loop *, unsigned,
 858                        edge, struct tree_niter_desc *);
 859 bool contains_abnormal_ssa_name_p (tree);
 860
 861 /* In tree-ssa-threadedge.c */
 862 extern bool potentially_threadable_block (basic_block);
 863 extern void thread_across_edge (tree, edge, bool,
 864                                 VEC(tree, heap) **, tree (*) (tree, tree));
 865
 866 /* In tree-ssa-loop-im.c  */
 867 /* The possibilities of statement movement.  */
 868
 869 enum move_pos
 870   {
 871     MOVE_IMPOSSIBLE,            /* No movement -- side effect expression.  */
 872     MOVE_PRESERVE_EXECUTION,    /* Must not cause the non-executed statement
 873                                    become executed -- memory accesses, ... */
 874     MOVE_POSSIBLE               /* Unlimited movement.  */
 875   };
 876 extern enum move_pos movement_possibility (tree);
 877
 878 /* The reasons a variable may escape a function.  */
 879 enum escape_type
 880   {
 881     NO_ESCAPE = 0, /* Doesn't escape.  */
 882     ESCAPE_STORED_IN_GLOBAL = 1 << 1,
 883     ESCAPE_TO_ASM = 1 << 2,  /* Passed by address to an assembly
 884                                 statement.  */
 885     ESCAPE_TO_CALL = 1 << 3,  /* Escapes to a function call.  */
 886     ESCAPE_BAD_CAST = 1 << 4, /* Cast from pointer to integer */
 887     ESCAPE_TO_RETURN = 1 << 5, /* Returned from function.  */
 888     ESCAPE_TO_PURE_CONST = 1 << 6, /* Escapes to a pure or constant
 889                                       function call.  */
 890     ESCAPE_IS_GLOBAL = 1 << 7,  /* Is a global variable.  */
 891     ESCAPE_IS_PARM = 1 << 8, /* Is an incoming function parameter.  */
 892     ESCAPE_UNKNOWN = 1 << 9 /* We believe it escapes for some reason
 893                                not enumerated above.  */
 894   };
 895
 896 /* In tree-flow-inline.h  */
 897 static inline bool is_call_clobbered (tree);
 898 static inline void mark_call_clobbered (tree, unsigned int);
 899 static inline void set_is_used (tree);
 900 static inline bool unmodifiable_var_p (tree);
 901
 902 /* In tree-eh.c  */
 903 extern void make_eh_edges (tree);
 904 extern bool tree_could_trap_p (tree);
 905 extern bool tree_could_throw_p (tree);
 906 extern bool tree_can_throw_internal (tree);
 907 extern bool tree_can_throw_external (tree);
 908 extern int lookup_stmt_eh_region (tree);
 909 extern void add_stmt_to_eh_region (tree, int);
 910 extern bool remove_stmt_from_eh_region (tree);
 911 extern bool maybe_clean_or_replace_eh_stmt (tree, tree);
 912
 913 /* In tree-ssa-pre.c  */
 914 void add_to_value (tree, tree);
 915 void debug_value_expressions (tree);
 916 void print_value_expressions (FILE *, tree);
 917
 918
 919 /* In tree-vn.c  */
 920 bool expressions_equal_p (tree, tree);
 921 tree get_value_handle (tree);
 922 hashval_t vn_compute (tree, hashval_t);
 923 void sort_vuses (VEC (tree, gc) *);
 924 tree vn_lookup_or_add (tree, tree);
 925 tree vn_lookup_or_add_with_vuses (tree, VEC (tree, gc) *);
 926 void vn_add (tree, tree);
 927 void vn_add_with_vuses (tree, tree, VEC (tree, gc) *);
 928 tree vn_lookup (tree, tree);
 929 tree vn_lookup_with_vuses (tree, VEC (tree, gc) *);
 930 void vn_init (void);
 931 void vn_delete (void);
 932
 933 /* In tree-ssa-sink.c  */
 934 bool is_hidden_global_store (tree);
 935
 936 /* In tree-sra.c  */
 937 void insert_edge_copies (tree, basic_block);
 938 void sra_insert_before (block_stmt_iterator *, tree);
 939 void sra_insert_after (block_stmt_iterator *, tree);
 940 void sra_init_cache (void);
 941 bool sra_type_can_be_decomposed_p (tree);
 942
 943 /* In tree-loop-linear.c  */
 944 extern void linear_transform_loops (struct loops *);
 945
 946 /* In tree-ssa-loop-ivopts.c  */
 947 bool expr_invariant_in_loop_p (struct loop *, tree);
 948 bool multiplier_allowed_in_address_p (HOST_WIDE_INT);
 949 unsigned multiply_by_cost (HOST_WIDE_INT, enum machine_mode);
 950
 951 /* In tree-ssa-threadupdate.c.  */
 952 extern bool thread_through_all_blocks (void);
 953 extern void register_jump_thread (edge, edge);
 954
 955 /* In gimplify.c  */
 956 tree force_gimple_operand (tree, tree *, bool, tree);
 957 tree force_gimple_operand_bsi (block_stmt_iterator *, tree, bool, tree);
 958
 959 /* In tree-ssa-structalias.c */
 960 bool find_what_p_points_to (tree);
 961
 962 /* In tree-ssa-live.c */
 963 extern void remove_unused_locals (void);
 964
 965 /* In tree-ssa-address.c  */
 966
 967 /* Affine combination of trees.  We keep track of at most MAX_AFF_ELTS elements
 968    to make things simpler; this is sufficient in most cases.  */
 969
 970 #define MAX_AFF_ELTS 8
 971
 972 struct affine_tree_combination
 973 {
 974   /* Type of the result of the combination.  */
 975   tree type;
 976
 977   /* Mask modulo that the operations are performed.  */
 978   unsigned HOST_WIDE_INT mask;
 979
 980   /* Constant offset.  */
 981   unsigned HOST_WIDE_INT offset;
 982
 983   /* Number of elements of the combination.  */
 984   unsigned n;
 985
 986   /* Elements and their coefficients.  */
 987   tree elts[MAX_AFF_ELTS];
 988   unsigned HOST_WIDE_INT coefs[MAX_AFF_ELTS];
 989
 990   /* Remainder of the expression.  */
 991   tree rest;
 992 };
 993
 994 /* Description of a memory address.  */
 995
 996 struct mem_address
 997 {
 998   tree symbol, base, index, step, offset;
 999 };
1000
1001 tree create_mem_ref (block_stmt_iterator *, tree,
1002                      struct affine_tree_combination *);
1003 rtx addr_for_mem_ref (struct mem_address *, bool);
1004 void get_address_description (tree, struct mem_address *);
1005 tree maybe_fold_tmr (tree);
1006
1007 /* This structure is simply used during pushing fields onto the fieldstack
1008    to track the offset of the field, since bitpos_of_field gives it relative
1009    to its immediate containing type, and we want it relative to the ultimate
1010    containing object.  */
1011
1012 struct fieldoff
1013 {
1014   tree type;
1015   tree size;
1016   tree decl;
1017   HOST_WIDE_INT offset;
1018 };
1019 typedef struct fieldoff fieldoff_s;
1020
1021 DEF_VEC_O(fieldoff_s);
1022 DEF_VEC_ALLOC_O(fieldoff_s,heap);
1023 int push_fields_onto_fieldstack (tree, VEC(fieldoff_s,heap) **,
1024                                  HOST_WIDE_INT, bool *);
1025 void sort_fieldstack (VEC(fieldoff_s,heap) *);
1026
1027 void init_alias_heapvars (void);
1028 void delete_alias_heapvars (void);
1029
1030 #include "tree-flow-inline.h"
1031
1032 void swap_tree_operands (tree, tree *, tree *);
1033
1034 extern void recalculate_used_alone (void);
1035 extern bool updating_used_alone;
1036 #endif /* _TREE_FLOW_H  */