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