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
 141 /* When computing aliasing information, we represent the memory pointed-to
 142    by pointers with artificial variables called "memory tags" (MT).  There
 143    are two kinds of tags: type and name.  Type tags (TMT) are used in
 144    type-based alias analysis, they represent all the pointed-to locations
 145    and variables of the same alias set class.  Name tags (NMT) are used in
 146    flow-sensitive points-to alias analysis, they represent the variables
 147    and memory locations pointed-to by a specific SSA_NAME pointer.  */
 148 enum mem_tag_kind {
 149   /* This variable is not a memory tag.  */
 150   NOT_A_TAG,
 151
 152   /* This variable is a type memory tag (TMT).  */
 153   TYPE_TAG,
 154
 155   /* This variable is a name memory tag (NMT).  */
 156   NAME_TAG,
 157
 158   /* This variable represents a structure field.  */
 159   STRUCT_FIELD
 160 };
 161
 162 struct subvar;
 163 typedef struct subvar *subvar_t;
 164
 165 /* This structure represents a fake sub-variable for a structure field.  */
 166 struct subvar GTY(())
 167 {
 168   /* Fake variable.  */
 169   tree var;
 170
 171   /* Offset inside structure.  */
 172   unsigned HOST_WIDE_INT offset;
 173
 174   /* Size of the field.  */
 175   unsigned HOST_WIDE_INT size;
 176
 177   /* Next subvar for this structure.  */
 178   subvar_t next;
 179 };
 180
 181 struct var_ann_d GTY(())
 182 {
 183   struct tree_ann_common_d common;
 184
 185   /* Used by the out of SSA pass to determine whether this variable has
 186      been seen yet or not.  */
 187   unsigned out_of_ssa_tag : 1;
 188
 189   /* Used when building root_var structures in tree_ssa_live.[ch].  */
 190   unsigned root_var_processed : 1;
 191
 192   /* If nonzero, this variable is a memory tag.  */
 193   ENUM_BITFIELD (mem_tag_kind) mem_tag_kind : 2;
 194
 195   /* Nonzero if this variable is an alias tag that represents references to
 196      other variables (i.e., this variable appears in the MAY_ALIASES array
 197      of other variables).  */
 198   unsigned is_alias_tag : 1;
 199
 200   /* Nonzero if this variable was used after SSA optimizations were
 201      applied.  We set this when translating out of SSA form.  */
 202   unsigned used : 1;
 203
 204   /* This field indicates whether or not the variable may need PHI nodes.
 205      See the enum's definition for more detailed information about the
 206      states.  */
 207   ENUM_BITFIELD (need_phi_state) need_phi_state : 2;
 208
 209   /* Used during operand processing to determine if this variable is already
 210      in the vuse list.  */
 211   unsigned in_vuse_list : 1;
 212
 213   /* Used during operand processing to determine if this variable is already
 214      in the v_may_def list.  */
 215   unsigned in_v_may_def_list : 1;
 216
 217   /* An artificial variable representing the memory location pointed-to by
 218      all the pointers that TBAA (type-based alias analysis) considers
 219      to be aliased.  If the variable is not a pointer or if it is never
 220      dereferenced, this must be NULL.  */
 221   tree type_mem_tag;
 222
 223   /* Variables that may alias this variable.  */
 224   varray_type may_aliases;
 225
 226   /* Used when going out of SSA form to indicate which partition this
 227      variable represents storage for.  */
 228   unsigned partition;
 229
 230   /* Used by the root-var object in tree-ssa-live.[ch].  */
 231   unsigned root_index;
 232
 233   /* Default definition for this symbol.  If this field is not NULL, it
 234      means that the first reference to this variable in the function is a
 235      USE or a VUSE.  In those cases, the SSA renamer creates an SSA name
 236      for this variable with an empty defining statement.  */
 237   tree default_def;
 238
 239   /* During into-ssa and the dominator optimizer, this field holds the
 240      current version of this variable (an SSA_NAME).  */
 241   tree current_def;
 242
 243   /* Pointer to the structure that contains the sets of global
 244      variables modified by function calls.  This field is only used
 245      for FUNCTION_DECLs.  */
 246   ipa_reference_vars_info_t GTY ((skip)) reference_vars_info;
 247
 248   /* If this variable is a structure, this fields holds a list of
 249      symbols representing each of the fields of the structure.  */
 250   subvar_t subvars;
 251 };
 252
 253
 254 typedef struct immediate_use_iterator_d
 255 {
 256   ssa_use_operand_t *imm_use;
 257   ssa_use_operand_t *end_p;
 258   ssa_use_operand_t iter_node;
 259 } imm_use_iterator;
 260
 261
 262 /* Use this iterator when simply looking at stmts.  Adding, deleting or
 263    modifying stmts will cause this iterator to malfunction.  */
 264
 265 #define FOR_EACH_IMM_USE_FAST(DEST, ITER, SSAVAR)                       \
 266   for ((DEST) = first_readonly_imm_use (&(ITER), (SSAVAR));     \
 267        !end_readonly_imm_use_p (&(ITER));                       \
 268        (DEST) = next_readonly_imm_use (&(ITER)))
 269
 270
 271 #define FOR_EACH_IMM_USE_SAFE(DEST, ITER, SSAVAR)               \
 272   for ((DEST) = first_safe_imm_use (&(ITER), (SSAVAR));         \
 273        !end_safe_imm_use_p (&(ITER));                           \
 274        (DEST) = next_safe_imm_use (&(ITER)))
 275
 276 #define BREAK_FROM_SAFE_IMM_USE(ITER)                           \
 277    {                                                            \
 278      end_safe_imm_use_traverse (&(ITER));                       \
 279      break;                                                     \
 280    }
 281
 282 struct stmt_ann_d GTY(())
 283 {
 284   struct tree_ann_common_d common;
 285
 286   /* Nonzero if the statement has been modified (meaning that the operands
 287      need to be scanned again).  */
 288   unsigned modified : 1;
 289
 290   /* Nonzero if the statement makes aliased loads.  */
 291   unsigned makes_aliased_loads : 1;
 292
 293   /* Nonzero if the statement makes aliased stores.  */
 294   unsigned makes_aliased_stores : 1;
 295
 296   /* Nonzero if the statement makes references to volatile storage.  */
 297   unsigned has_volatile_ops : 1;
 298
 299   /* Nonzero if the statement makes a function call that may clobber global
 300      and local addressable variables.  */
 301   unsigned makes_clobbering_call : 1;
 302
 303   /* Basic block that contains this statement.  */
 304   basic_block bb;
 305
 306   /* Operand cache for stmt.  */
 307   struct stmt_operands_d GTY ((skip (""))) operands;
 308
 309   /* Set of variables that have had their address taken in the statement.  */
 310   bitmap addresses_taken;
 311
 312   /* Unique identifier for this statement.  These ID's are to be created
 313      by each pass on an as-needed basis in any order convenient for the
 314      pass which needs statement UIDs.  */
 315   unsigned int uid;
 316
 317   /* Linked list of histograms for value-based profiling.  This is really a
 318      struct histogram_value*.  We use void* to avoid having to export that
 319      everywhere, and to avoid having to put it in GC memory.  */
 320
 321   void * GTY ((skip (""))) histograms;
 322 };
 323
 324 union tree_ann_d GTY((desc ("ann_type ((tree_ann_t)&%h)")))
 325 {
 326   struct tree_ann_common_d GTY((tag ("TREE_ANN_COMMON"))) common;
 327   struct var_ann_d GTY((tag ("VAR_ANN"))) decl;
 328   struct stmt_ann_d GTY((tag ("STMT_ANN"))) stmt;
 329 };
 330
 331 extern GTY(()) VEC(tree,gc) *modified_noreturn_calls;
 332
 333 typedef union tree_ann_d *tree_ann_t;
 334 typedef struct var_ann_d *var_ann_t;
 335 typedef struct stmt_ann_d *stmt_ann_t;
 336
 337 static inline tree_ann_t tree_ann (tree);
 338 static inline tree_ann_t get_tree_ann (tree);
 339 static inline var_ann_t var_ann (tree);
 340 static inline var_ann_t get_var_ann (tree);
 341 static inline stmt_ann_t stmt_ann (tree);
 342 static inline stmt_ann_t get_stmt_ann (tree);
 343 static inline enum tree_ann_type ann_type (tree_ann_t);
 344 static inline basic_block bb_for_stmt (tree);
 345 extern void set_bb_for_stmt (tree, basic_block);
 346 static inline bool noreturn_call_p (tree);
 347 static inline void update_stmt (tree);
 348 static inline bool stmt_modified_p (tree);
 349 static inline varray_type may_aliases (tree);
 350 static inline int get_lineno (tree);
 351 static inline const char *get_filename (tree);
 352 static inline bool is_exec_stmt (tree);
 353 static inline bool is_label_stmt (tree);
 354 static inline bitmap addresses_taken (tree);
 355 static inline void set_default_def (tree, tree);
 356 static inline tree default_def (tree);
 357
 358 /*---------------------------------------------------------------------------
 359                   Structure representing predictions in tree level.
 360 ---------------------------------------------------------------------------*/
 361 struct edge_prediction GTY((chain_next ("%h.next")))
 362 {
 363   struct edge_prediction *next;
 364   edge edge;
 365   enum br_predictor predictor;
 366   int 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 extern tree referenced_var_lookup (unsigned int);
 425 extern tree referenced_var_lookup_if_exists (unsigned int);
 426 #define num_referenced_vars htab_elements (referenced_vars)
 427 #define referenced_var(i) referenced_var_lookup (i)
 428
 429 /* Array of all SSA_NAMEs used in the function.  */
 430 extern GTY(()) VEC(tree,gc) *ssa_names;
 431
 432 #define num_ssa_names (VEC_length (tree, ssa_names))
 433 #define ssa_name(i) (VEC_index (tree, ssa_names, (i)))
 434
 435 /* Artificial variable used to model the effects of function calls.  */
 436 extern GTY(()) tree global_var;
 437
 438 /* Call clobbered variables in the function.  If bit I is set, then
 439    REFERENCED_VARS (I) is call-clobbered.  */
 440 extern bitmap call_clobbered_vars;
 441
 442 /* Addressable variables in the function.  If bit I is set, then
 443    REFERENCED_VARS (I) has had its address taken.  */
 444 extern bitmap addressable_vars;
 445
 446 /* 'true' after aliases have been computed (see compute_may_aliases).  */
 447 extern bool aliases_computed_p;
 448
 449 /* Macros for showing usage statistics.  */
 450 #define SCALE(x) ((unsigned long) ((x) < 1024*10        \
 451                   ? (x)                                 \
 452                   : ((x) < 1024*1024*10                 \
 453                      ? (x) / 1024                       \
 454                      : (x) / (1024*1024))))
 455
 456 #define LABEL(x) ((x) < 1024*10 ? 'b' : ((x) < 1024*1024*10 ? 'k' : 'M'))
 457
 458 #define PERCENT(x,y) ((float)(x) * 100.0 / (float)(y))
 459
 460 /*---------------------------------------------------------------------------
 461                               Block iterators
 462 ---------------------------------------------------------------------------*/
 463
 464 typedef struct {
 465   tree_stmt_iterator tsi;
 466   basic_block bb;
 467 } block_stmt_iterator;
 468
 469 static inline block_stmt_iterator bsi_start (basic_block);
 470 static inline block_stmt_iterator bsi_last (basic_block);
 471 static inline block_stmt_iterator bsi_after_labels (basic_block);
 472 block_stmt_iterator bsi_for_stmt (tree);
 473 static inline bool bsi_end_p (block_stmt_iterator);
 474 static inline void bsi_next (block_stmt_iterator *);
 475 static inline void bsi_prev (block_stmt_iterator *);
 476 static inline tree bsi_stmt (block_stmt_iterator);
 477 static inline tree * bsi_stmt_ptr (block_stmt_iterator);
 478
 479 extern void bsi_remove (block_stmt_iterator *);
 480 extern void bsi_move_before (block_stmt_iterator *, block_stmt_iterator *);
 481 extern void bsi_move_after (block_stmt_iterator *, block_stmt_iterator *);
 482 extern void bsi_move_to_bb_end (block_stmt_iterator *, basic_block);
 483
 484 enum bsi_iterator_update
 485 {
 486   /* Note that these are intentionally in the same order as TSI_FOO.  They
 487      mean exactly the same as their TSI_* counterparts.  */
 488   BSI_NEW_STMT,
 489   BSI_SAME_STMT,
 490   BSI_CHAIN_START,
 491   BSI_CHAIN_END,
 492   BSI_CONTINUE_LINKING
 493 };
 494
 495 extern void bsi_insert_before (block_stmt_iterator *, tree,
 496                                enum bsi_iterator_update);
 497 extern void bsi_insert_after (block_stmt_iterator *, tree,
 498                               enum bsi_iterator_update);
 499
 500 extern void bsi_replace (const block_stmt_iterator *, tree, bool);
 501
 502 /*---------------------------------------------------------------------------
 503                               Function prototypes
 504 ---------------------------------------------------------------------------*/
 505 /* In tree-cfg.c  */
 506
 507 /* Location to track pending stmt for edge insertion.  */
 508 #define PENDING_STMT(e) ((e)->insns.t)
 509
 510 extern void delete_tree_cfg_annotations (void);
 511 extern void disband_implicit_edges (void);
 512 extern bool stmt_ends_bb_p (tree);
 513 extern bool is_ctrl_stmt (tree);
 514 extern bool is_ctrl_altering_stmt (tree);
 515 extern bool computed_goto_p (tree);
 516 extern bool simple_goto_p (tree);
 517 extern void tree_dump_bb (basic_block, FILE *, int);
 518 extern void debug_tree_bb (basic_block);
 519 extern basic_block debug_tree_bb_n (int);
 520 extern void dump_tree_cfg (FILE *, int);
 521 extern void debug_tree_cfg (int);
 522 extern void dump_cfg_stats (FILE *);
 523 extern void debug_cfg_stats (void);
 524 extern void debug_loop_ir (void);
 525 extern void print_loop_ir (FILE *);
 526 extern void cleanup_dead_labels (void);
 527 extern void group_case_labels (void);
 528 extern tree first_stmt (basic_block);
 529 extern tree last_stmt (basic_block);
 530 extern tree *last_stmt_ptr (basic_block);
 531 extern tree last_and_only_stmt (basic_block);
 532 extern edge find_taken_edge (basic_block, tree);
 533 extern basic_block label_to_block_fn (struct function *, tree);
 534 #define label_to_block(t) (label_to_block_fn (cfun, t))
 535 extern void bsi_insert_on_edge (edge, tree);
 536 extern basic_block bsi_insert_on_edge_immediate (edge, tree);
 537 extern void bsi_commit_one_edge_insert (edge, basic_block *);
 538 extern void bsi_commit_edge_inserts (void);
 539 extern void notice_special_calls (tree);
 540 extern void clear_special_calls (void);
 541 extern void verify_stmts (void);
 542 extern tree tree_block_label (basic_block);
 543 extern void extract_true_false_edges_from_block (basic_block, edge *, edge *);
 544 extern bool tree_duplicate_sese_region (edge, edge, basic_block *, unsigned,
 545                                         basic_block *);
 546 extern void add_phi_args_after_copy_bb (basic_block);
 547 extern void add_phi_args_after_copy (basic_block *, unsigned);
 548 extern bool tree_purge_dead_eh_edges (basic_block);
 549 extern bool tree_purge_all_dead_eh_edges (bitmap);
 550 extern tree gimplify_val (block_stmt_iterator *, tree, tree);
 551 extern tree gimplify_build1 (block_stmt_iterator *, enum tree_code,
 552                              tree, tree);
 553 extern tree gimplify_build2 (block_stmt_iterator *, enum tree_code,
 554                              tree, tree, tree);
 555 extern tree gimplify_build3 (block_stmt_iterator *, enum tree_code,
 556                              tree, tree, tree, tree);
 557 extern void init_empty_tree_cfg (void);
 558 extern void fold_cond_expr_cond (void);
 559 extern void replace_uses_by (tree, tree);
 560 extern void start_recording_case_labels (void);
 561 extern void end_recording_case_labels (void);
 562
 563 /* In tree-cfgcleanup.c  */
 564 extern bool cleanup_tree_cfg (void);
 565 extern void cleanup_tree_cfg_loop (void);
 566
 567 /* In tree-pretty-print.c.  */
 568 extern void dump_generic_bb (FILE *, basic_block, int, int);
 569
 570 /* In tree-dfa.c  */
 571 extern var_ann_t create_var_ann (tree);
 572 extern stmt_ann_t create_stmt_ann (tree);
 573 extern tree_ann_t create_tree_ann (tree);
 574 extern void dump_dfa_stats (FILE *);
 575 extern void debug_dfa_stats (void);
 576 extern void debug_referenced_vars (void);
 577 extern void dump_referenced_vars (FILE *);
 578 extern void dump_variable (FILE *, tree);
 579 extern void debug_variable (tree);
 580 extern void dump_subvars_for (FILE *, tree);
 581 extern void debug_subvars_for (tree);
 582 extern tree get_virtual_var (tree);
 583 extern void add_referenced_tmp_var (tree);
 584 extern void mark_new_vars_to_rename (tree);
 585 extern void find_new_referenced_vars (tree *);
 586
 587 extern tree make_rename_temp (tree, const char *);
 588
 589 /* In tree-phinodes.c  */
 590 extern void reserve_phi_args_for_new_edge (basic_block);
 591 extern tree create_phi_node (tree, basic_block);
 592 extern void add_phi_arg (tree, tree, edge);
 593 extern void remove_phi_args (edge);
 594 extern void remove_phi_node (tree, tree);
 595 extern tree phi_reverse (tree);
 596
 597 /* In gimple-low.c  */
 598 extern void record_vars (tree);
 599 extern bool block_may_fallthru (tree block);
 600
 601 /* In tree-ssa-alias.c  */
 602 extern void dump_may_aliases_for (FILE *, tree);
 603 extern void debug_may_aliases_for (tree);
 604 extern void dump_alias_info (FILE *);
 605 extern void debug_alias_info (void);
 606 extern void dump_points_to_info (FILE *);
 607 extern void debug_points_to_info (void);
 608 extern void dump_points_to_info_for (FILE *, tree);
 609 extern void debug_points_to_info_for (tree);
 610 extern bool may_be_aliased (tree);
 611 extern bool is_aliased_with (tree, tree);
 612 extern struct ptr_info_def *get_ptr_info (tree);
 613 extern void add_type_alias (tree, tree);
 614 extern void new_type_alias (tree, tree);
 615 extern void count_uses_and_derefs (tree, tree, unsigned *, unsigned *, bool *);
 616 static inline subvar_t get_subvars_for_var (tree);
 617 static inline tree get_subvar_at (tree, unsigned HOST_WIDE_INT);
 618 static inline bool ref_contains_array_ref (tree);
 619 static inline bool array_ref_contains_indirect_ref (tree);
 620 extern tree okay_component_ref_for_subvars (tree, unsigned HOST_WIDE_INT *,
 621                                             unsigned HOST_WIDE_INT *);
 622 static inline bool var_can_have_subvars (tree);
 623 static inline bool overlap_subvar (unsigned HOST_WIDE_INT,
 624                                    unsigned HOST_WIDE_INT,
 625                                    subvar_t, bool *);
 626
 627 /* Call-back function for walk_use_def_chains().  At each reaching
 628    definition, a function with this prototype is called.  */
 629 typedef bool (*walk_use_def_chains_fn) (tree, tree, void *);
 630
 631
 632 /* In tree-ssa.c  */
 633 extern void init_tree_ssa (void);
 634 extern edge ssa_redirect_edge (edge, basic_block);
 635 extern void flush_pending_stmts (edge);
 636 extern bool tree_ssa_useless_type_conversion (tree);
 637 extern bool tree_ssa_useless_type_conversion_1 (tree, tree);
 638 extern void verify_ssa (bool);
 639 extern void delete_tree_ssa (void);
 640 extern void register_new_def (tree, VEC(tree,heap) **);
 641 extern void walk_use_def_chains (tree, walk_use_def_chains_fn, void *, bool);
 642 extern bool stmt_references_memory_p (tree);
 643
 644 /* In tree-into-ssa.c  */
 645 void update_ssa (unsigned);
 646 void delete_update_ssa (void);
 647 void register_new_name_mapping (tree, tree);
 648 tree create_new_def_for (tree, tree, def_operand_p);
 649 bool need_ssa_update_p (void);
 650 bool name_registered_for_update_p (tree);
 651 bitmap ssa_names_to_replace (void);
 652 void release_ssa_name_after_update_ssa (tree name);
 653 void compute_global_livein (bitmap, bitmap);
 654 tree duplicate_ssa_name (tree, tree);
 655 void mark_sym_for_renaming (tree);
 656 void mark_set_for_renaming (bitmap);
 657 tree get_current_def (tree);
 658 void set_current_def (tree, tree);
 659
 660 /* In tree-ssa-ccp.c  */
 661 bool fold_stmt (tree *);
 662 bool fold_stmt_inplace (tree);
 663 tree widen_bitfield (tree, tree, tree);
 664
 665 /* In tree-vrp.c  */
 666 tree vrp_evaluate_conditional (tree, bool);
 667 void simplify_stmt_using_ranges (tree);
 668
 669 /* In tree-ssa-dom.c  */
 670 extern void dump_dominator_optimization_stats (FILE *);
 671 extern void debug_dominator_optimization_stats (void);
 672 int loop_depth_of_name (tree);
 673
 674 /* In tree-ssa-copy.c  */
 675 extern void merge_alias_info (tree, tree);
 676 extern void propagate_value (use_operand_p, tree);
 677 extern void propagate_tree_value (tree *, tree);
 678 extern void replace_exp (use_operand_p, tree);
 679 extern bool may_propagate_copy (tree, tree);
 680 extern bool may_propagate_copy_into_asm (tree);
 681
 682 /* Description of number of iterations of a loop.  All the expressions inside
 683    the structure can be evaluated at the end of the loop's preheader
 684    (and due to ssa form, also anywhere inside the body of the loop).  */
 685
 686 struct tree_niter_desc
 687 {
 688   tree assumptions;     /* The boolean expression.  If this expression evaluates
 689                            to false, then the other fields in this structure
 690                            should not be used; there is no guarantee that they
 691                            will be correct.  */
 692   tree may_be_zero;     /* The boolean expression.  If it evaluates to true,
 693                            the loop will exit in the first iteration (i.e.
 694                            its latch will not be executed), even if the niter
 695                            field says otherwise.  */
 696   tree niter;           /* The expression giving the number of iterations of
 697                            a loop (provided that assumptions == true and
 698                            may_be_zero == false), more precisely the number
 699                            of executions of the latch of the loop.  */
 700   tree additional_info; /* The boolean expression.  Sometimes we use additional
 701                            knowledge to simplify the other expressions
 702                            contained in this structure (for example the
 703                            knowledge about value ranges of operands on entry to
 704                            the loop).  If this is a case, conjunction of such
 705                            condition is stored in this field, so that we do not
 706                            lose the information: for example if may_be_zero
 707                            is (n <= 0) and niter is (unsigned) n, we know
 708                            that the number of iterations is at most
 709                            MAX_SIGNED_INT.  However if the (n <= 0) assumption
 710                            is eliminated (by looking at the guard on entry of
 711                            the loop), then the information would be lost.  */
 712 };
 713
 714 /* In tree-vectorizer.c */
 715 void vectorize_loops (struct loops *);
 716
 717 /* In tree-ssa-phiopt.c */
 718 bool empty_block_p (basic_block);
 719
 720 /* In tree-ssa-loop*.c  */
 721
 722 void tree_ssa_lim (struct loops *);
 723 void tree_ssa_unswitch_loops (struct loops *);
 724 void canonicalize_induction_variables (struct loops *);
 725 void tree_unroll_loops_completely (struct loops *, bool);
 726 void remove_empty_loops (struct loops *);
 727 void tree_ssa_iv_optimize (struct loops *);
 728
 729 bool number_of_iterations_exit (struct loop *, edge,
 730                                 struct tree_niter_desc *niter, bool);
 731 tree find_loop_niter (struct loop *, edge *);
 732 tree loop_niter_by_eval (struct loop *, edge);
 733 tree find_loop_niter_by_eval (struct loop *, edge *);
 734 void estimate_numbers_of_iterations (struct loops *);
 735 bool scev_probably_wraps_p (tree, tree, tree, tree, struct loop *, bool *,
 736                             bool *);
 737 tree convert_step (struct loop *, tree, tree, tree, tree);
 738 void free_numbers_of_iterations_estimates (struct loops *);
 739 void free_numbers_of_iterations_estimates_loop (struct loop *);
 740 void rewrite_into_loop_closed_ssa (bitmap, unsigned);
 741 void verify_loop_closed_ssa (void);
 742 void loop_commit_inserts (void);
 743 bool for_each_index (tree *, bool (*) (tree, tree *, void *), void *);
 744 void create_iv (tree, tree, tree, struct loop *, block_stmt_iterator *, bool,
 745                 tree *, tree *);
 746 void split_loop_exit_edge (edge);
 747 void compute_phi_arg_on_exit (edge, tree, tree);
 748 unsigned force_expr_to_var_cost (tree);
 749 basic_block bsi_insert_on_edge_immediate_loop (edge, tree);
 750 void standard_iv_increment_position (struct loop *, block_stmt_iterator *,
 751                                      bool *);
 752 basic_block ip_end_pos (struct loop *);
 753 basic_block ip_normal_pos (struct loop *);
 754 bool tree_duplicate_loop_to_header_edge (struct loop *, edge, struct loops *,
 755                                          unsigned int, sbitmap,
 756                                          edge, edge *,
 757                                          unsigned int *, int);
 758 struct loop *tree_ssa_loop_version (struct loops *, struct loop *, tree,
 759                                     basic_block *);
 760 tree expand_simple_operations (tree);
 761 void substitute_in_loop_info (struct loop *, tree, tree);
 762 edge single_dom_exit (struct loop *);
 763
 764 /* In tree-ssa-loop-im.c  */
 765 /* The possibilities of statement movement.  */
 766
 767 enum move_pos
 768   {
 769     MOVE_IMPOSSIBLE,            /* No movement -- side effect expression.  */
 770     MOVE_PRESERVE_EXECUTION,    /* Must not cause the non-executed statement
 771                                    become executed -- memory accesses, ... */
 772     MOVE_POSSIBLE               /* Unlimited movement.  */
 773   };
 774 extern enum move_pos movement_possibility (tree);
 775
 776 /* In tree-flow-inline.h  */
 777 static inline bool is_call_clobbered (tree);
 778 static inline void mark_call_clobbered (tree);
 779 static inline void set_is_used (tree);
 780 static inline bool unmodifiable_var_p (tree);
 781
 782 /* In tree-eh.c  */
 783 extern void make_eh_edges (tree);
 784 extern bool tree_could_trap_p (tree);
 785 extern bool tree_could_throw_p (tree);
 786 extern bool tree_can_throw_internal (tree);
 787 extern bool tree_can_throw_external (tree);
 788 extern int lookup_stmt_eh_region (tree);
 789 extern void add_stmt_to_eh_region (tree, int);
 790 extern bool remove_stmt_from_eh_region (tree);
 791 extern bool maybe_clean_or_replace_eh_stmt (tree, tree);
 792
 793 /* In tree-ssa-pre.c  */
 794 void add_to_value (tree, tree);
 795 void debug_value_expressions (tree);
 796 void print_value_expressions (FILE *, tree);
 797
 798
 799 /* In tree-vn.c  */
 800 bool expressions_equal_p (tree, tree);
 801 tree get_value_handle (tree);
 802 hashval_t vn_compute (tree, hashval_t, tree);
 803 tree vn_lookup_or_add (tree, tree);
 804 void vn_add (tree, tree, tree);
 805 tree vn_lookup (tree, tree);
 806 void vn_init (void);
 807 void vn_delete (void);
 808
 809 /* In tree-ssa-sink.c  */
 810 bool is_hidden_global_store (tree);
 811
 812 /* In tree-sra.c  */
 813 void insert_edge_copies (tree, basic_block);
 814 void sra_insert_before (block_stmt_iterator *, tree);
 815 void sra_insert_after (block_stmt_iterator *, tree);
 816 void sra_init_cache (void);
 817 bool sra_type_can_be_decomposed_p (tree);
 818
 819 /* In tree-loop-linear.c  */
 820 extern void linear_transform_loops (struct loops *);
 821
 822 /* In tree-ssa-loop-ivopts.c  */
 823 bool expr_invariant_in_loop_p (struct loop *, tree);
 824 bool multiplier_allowed_in_address_p (HOST_WIDE_INT);
 825 unsigned multiply_by_cost (HOST_WIDE_INT, enum machine_mode);
 826
 827 /* In tree-ssa-threadupdate.c.  */
 828 extern bool thread_through_all_blocks (bitmap);
 829
 830 /* In gimplify.c  */
 831 tree force_gimple_operand (tree, tree *, bool, tree);
 832 tree force_gimple_operand_bsi (block_stmt_iterator *, tree, bool, tree);
 833
 834 /* In tree-ssa-structalias.c */
 835 bool find_what_p_points_to (tree);
 836
 837 /* In tree-ssa-address.c  */
 838
 839 /* Affine combination of trees.  We keep track of at most MAX_AFF_ELTS elements
 840    to make things simpler; this is sufficient in most cases.  */
 841
 842 #define MAX_AFF_ELTS 8
 843
 844 struct affine_tree_combination
 845 {
 846   /* Type of the result of the combination.  */
 847   tree type;
 848
 849   /* Mask modulo that the operations are performed.  */
 850   unsigned HOST_WIDE_INT mask;
 851
 852   /* Constant offset.  */
 853   unsigned HOST_WIDE_INT offset;
 854
 855   /* Number of elements of the combination.  */
 856   unsigned n;
 857
 858   /* Elements and their coefficients.  */
 859   tree elts[MAX_AFF_ELTS];
 860   unsigned HOST_WIDE_INT coefs[MAX_AFF_ELTS];
 861
 862   /* Remainder of the expression.  */
 863   tree rest;
 864 };
 865
 866 /* Description of a memory address.  */
 867
 868 struct mem_address
 869 {
 870   tree symbol, base, index, step, offset;
 871 };
 872
 873 tree create_mem_ref (block_stmt_iterator *, tree,
 874                      struct affine_tree_combination *);
 875 rtx addr_for_mem_ref (struct mem_address *, bool);
 876 void get_address_description (tree, struct mem_address *);
 877 tree maybe_fold_tmr (tree);
 878 /* This structure is simply used during pushing fields onto the fieldstack
 879    to track the offset of the field, since bitpos_of_field gives it relative
 880    to its immediate containing type, and we want it relative to the ultimate
 881    containing object.  */
 882
 883 struct fieldoff
 884 {
 885   tree field;
 886   HOST_WIDE_INT offset;
 887 };
 888 typedef struct fieldoff fieldoff_s;
 889
 890 DEF_VEC_O(fieldoff_s);
 891 DEF_VEC_ALLOC_O(fieldoff_s,heap);
 892 int push_fields_onto_fieldstack (tree, VEC(fieldoff_s,heap) **,
 893                                  HOST_WIDE_INT, bool *);
 894 void sort_fieldstack (VEC(fieldoff_s,heap) *);
 895
 896 void init_alias_heapvars (void);
 897 void delete_alias_heapvars (void);
 898
 899 #include "tree-flow-inline.h"
 900
 901 #endif /* _TREE_FLOW_H  */