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