gcc/tree-flow.h

   1 /* Data and Control Flow Analysis for Trees.
   2    Copyright (C) 2001, 2003, 2004 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, 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, 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
  32 /* Forward declare structures for the garbage collector GTY markers.  */
  33 #ifndef GCC_BASIC_BLOCK_H
  34 struct edge_def;
  35 typedef struct edge_def *edge;
  36 struct basic_block_def;
  37 typedef struct basic_block_def *basic_block;
  38 #endif
  39
  40 /*---------------------------------------------------------------------------
  41                       Attributes for SSA_NAMEs.
  42
  43   NOTE: These structures are stored in struct tree_ssa_name
  44   but are only used by the tree optimizers, so it makes better sense
  45   to declare them here to avoid recompiling unrelated files when
  46   making changes.
  47 ---------------------------------------------------------------------------*/
  48
  49 /* Aliasing information for SSA_NAMEs representing pointer variables.  */
  50 struct ptr_info_def GTY(())
  51 {
  52   /* Nonzero if points-to analysis couldn't determine where this pointer
  53      is pointing to.  */
  54   unsigned int pt_anything : 1;
  55
  56   /* Nonzero if this pointer is the result of a call to malloc.  */
  57   unsigned int pt_malloc : 1;
  58
  59   /* Nonzero if the value of this pointer escapes the current function.  */
  60   unsigned int value_escapes_p : 1;
  61
  62   /* Nonzero if this pointer is dereferenced.  */
  63   unsigned int is_dereferenced : 1;
  64
  65   /* Nonzero if this pointer points to a global variable.  */
  66   unsigned int pt_global_mem : 1;
  67
  68   /* Set of variables that this pointer may point to.  */
  69   bitmap pt_vars;
  70
  71   /* If this pointer has been dereferenced, and points-to information is
  72      more precise than type-based aliasing, indirect references to this
  73      pointer will be represented by this memory tag, instead of the type
  74      tag computed by TBAA.  */
  75   tree name_mem_tag;
  76 };
  77
  78
  79 /*---------------------------------------------------------------------------
  80                    Tree annotations stored in tree_common.ann
  81 ---------------------------------------------------------------------------*/
  82 enum tree_ann_type { TREE_ANN_COMMON, VAR_ANN, STMT_ANN };
  83
  84 struct tree_ann_common_d GTY(())
  85 {
  86   /* Annotation type.  */
  87   enum tree_ann_type type;
  88
  89  /* Auxiliary info specific to a pass.  At all times, this
  90     should either point to valid data or be NULL.  */
  91   PTR GTY ((skip (""))) aux;
  92
  93   /* The value handle for this expression.  Used by GVN-PRE.  */
  94   tree GTY((skip)) value_handle;
  95 };
  96
  97 /* It is advantageous to avoid things like life analysis for variables which
  98    do not need PHI nodes.  This enum describes whether or not a particular
  99    variable may need a PHI node.  */
 100
 101 enum need_phi_state {
 102   /* This is the default.  If we are still in this state after finding
 103      all the definition and use sites, then we will assume the variable
 104      needs PHI nodes.  This is probably an overly conservative assumption.  */
 105   NEED_PHI_STATE_UNKNOWN,
 106
 107   /* This state indicates that we have seen one or more sets of the
 108      variable in a single basic block and that the sets dominate all
 109      uses seen so far.  If after finding all definition and use sites
 110      we are still in this state, then the variable does not need any
 111      PHI nodes.  */
 112   NEED_PHI_STATE_NO,
 113
 114   /* This state indicates that we have either seen multiple definitions of
 115      the variable in multiple blocks, or that we encountered a use in a
 116      block that was not dominated by the block containing the set(s) of
 117      this variable.  This variable is assumed to need PHI nodes.  */
 118   NEED_PHI_STATE_MAYBE
 119 };
 120
 121
 122 /* When computing aliasing information, we represent the memory pointed-to
 123    by pointers with artificial variables called "memory tags" (MT).  There
 124    are two kinds of tags: type and name.  Type tags (TMT) are used in
 125    type-based alias analysis, they represent all the pointed-to locations
 126    and variables of the same alias set class.  Name tags (NMT) are used in
 127    flow-sensitive points-to alias analysis, they represent the variables
 128    and memory locations pointed-to by a specific SSA_NAME pointer.  */
 129 enum mem_tag_kind {
 130   /* This variable is not a memory tag.  */
 131   NOT_A_TAG,
 132
 133   /* This variable is a type memory tag (TMT).  */
 134   TYPE_TAG,
 135
 136   /* This variable is a name memory tag (NMT).  */
 137   NAME_TAG
 138 };
 139
 140 struct var_ann_d GTY(())
 141 {
 142   struct tree_ann_common_d common;
 143
 144   /* Used by the out of SSA pass to determine whether this variable has
 145      been seen yet or not.  */
 146   unsigned out_of_ssa_tag : 1;
 147
 148   /* Used when building root_var structures in tree_ssa_live.[ch].  */
 149   unsigned root_var_processed : 1;
 150
 151   /* If nonzero, this variable is a memory tag.  */
 152   ENUM_BITFIELD (mem_tag_kind) mem_tag_kind : 2;
 153
 154   /* Nonzero if this variable is an alias tag that represents references to
 155      other variables (i.e., this variable appears in the MAY_ALIASES array
 156      of other variables).  */
 157   unsigned is_alias_tag : 1;
 158
 159   /* Nonzero if this variable was used after SSA optimizations were
 160      applied.  We set this when translating out of SSA form.  */
 161   unsigned used : 1;
 162
 163   /* This field indicates whether or not the variable may need PHI nodes.
 164      See the enum's definition for more detailed information about the
 165      states.  */
 166   ENUM_BITFIELD (need_phi_state) need_phi_state : 2;
 167
 168   /* An artificial variable representing the memory location pointed-to by
 169      all the pointers that TBAA (type-based alias analysis) considers
 170      to be aliased.  If the variable is not a pointer or if it is never
 171      dereferenced, this must be NULL.  */
 172   tree type_mem_tag;
 173
 174   /* Variables that may alias this variable.  */
 175   varray_type may_aliases;
 176
 177   /* Unique ID of this variable.  */
 178   size_t uid;
 179
 180   /* Used when going out of SSA form to indicate which partition this
 181      variable represents storage for.  */
 182   unsigned partition;
 183
 184   /* Used by the root-var object in tree-ssa-live.[ch].  */
 185   unsigned root_index;
 186
 187   /* Default definition for this symbol.  If this field is not NULL, it
 188      means that the first reference to this variable in the function is a
 189      USE or a VUSE.  In those cases, the SSA renamer creates an SSA name
 190      for this variable with an empty defining statement.  */
 191   tree default_def;
 192
 193   /* During into-ssa and the dominator optimizer, this field holds the
 194      current version of this variable (an SSA_NAME).
 195
 196      This was previously two varrays (one in into-ssa the other in the
 197      dominator optimizer).  That is wasteful, particularly since the
 198      dominator optimizer calls into-ssa resulting in having two varrays
 199      live at the same time and this can happen for each call to the
 200      dominator optimizer.  */
 201   tree current_def;
 202 };
 203
 204
 205 struct dataflow_d GTY(())
 206 {
 207   /* Immediate uses.  This is a list of all the statements and PHI nodes
 208      that are immediately reached by the definitions made in this
 209      statement.  */
 210   varray_type immediate_uses;
 211
 212   /* Use this array for very small numbers of uses instead of the varray.  */
 213   tree uses[2];
 214
 215   /* Reached uses.  This is a list of all the possible program statements
 216      that may be reached directly or indirectly by definitions made in this
 217      statement.  Notice that this is a superset of IMMEDIATE_USES.
 218      For instance, given the following piece of code:
 219
 220             1   a1 = 10;
 221             2   if (a1 > 3)
 222             3     a2 = a1 + 5;
 223             4   a3 = PHI (a1, a2)
 224             5   b1 = a3 - 2;
 225
 226      IMMEDIATE_USES for statement #1 are all those statements that use a1
 227      directly (i.e., #2, #3 and #4).  REACHED_USES for statement #1 also
 228      includes statement #5 because 'a1' could reach 'a3' via the PHI node
 229      at statement #4.  The set of REACHED_USES is then the transitive
 230      closure over all the PHI nodes in the IMMEDIATE_USES set.  */
 231
 232   /* Reaching definitions.  Similarly to REACHED_USES, the set
 233      REACHING_DEFS is the set of all the statements that make definitions
 234      that may reach this statement.  Notice that we don't need to have a
 235      similar entry for immediate definitions, as these are represented by
 236      the SSA_NAME nodes themselves (each SSA_NAME node contains a pointer
 237      to the statement that makes that definition).  */
 238 };
 239
 240 typedef struct dataflow_d *dataflow_t;
 241
 242
 243 struct stmt_ann_d GTY(())
 244 {
 245   struct tree_ann_common_d common;
 246
 247   /* Nonzero if the statement has been modified (meaning that the operands
 248      need to be scanned again).  */
 249   unsigned modified : 1;
 250
 251   /* Nonzero if the statement is in the CCP worklist and has not been
 252      "cancelled".  If we ever need to use this bit outside CCP, then
 253      it should be renamed.  */
 254   unsigned in_ccp_worklist: 1;
 255
 256   /* Nonzero if the statement makes aliased loads.  */
 257   unsigned makes_aliased_loads : 1;
 258
 259   /* Nonzero if the statement makes aliased stores.  */
 260   unsigned makes_aliased_stores : 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 GTY ((skip (""))) bb;
 271
 272   struct stmt_operands_d operands;
 273
 274   /* Dataflow information.  */
 275   dataflow_t df;
 276
 277   /* Set of variables that have had their address taken in the statement.  */
 278   bitmap addresses_taken;
 279
 280   /* Unique identifier for this statement.  These ID's are to be created
 281      by each pass on an as-needed basis in any order convenient for the
 282      pass which needs statement UIDs.  */
 283   unsigned int uid;
 284 };
 285
 286 union tree_ann_d GTY((desc ("ann_type ((tree_ann_t)&%h)")))
 287 {
 288   struct tree_ann_common_d GTY((tag ("TREE_ANN_COMMON"))) common;
 289   struct var_ann_d GTY((tag ("VAR_ANN"))) decl;
 290   struct stmt_ann_d GTY((tag ("STMT_ANN"))) stmt;
 291 };
 292
 293 typedef union tree_ann_d *tree_ann_t;
 294 typedef struct var_ann_d *var_ann_t;
 295 typedef struct stmt_ann_d *stmt_ann_t;
 296
 297 static inline tree_ann_t tree_ann (tree);
 298 static inline tree_ann_t get_tree_ann (tree);
 299 static inline var_ann_t var_ann (tree);
 300 static inline var_ann_t get_var_ann (tree);
 301 static inline stmt_ann_t stmt_ann (tree);
 302 static inline stmt_ann_t get_stmt_ann (tree);
 303 static inline enum tree_ann_type ann_type (tree_ann_t);
 304 static inline basic_block bb_for_stmt (tree);
 305 extern void set_bb_for_stmt (tree, basic_block);
 306 static inline void modify_stmt (tree);
 307 static inline void unmodify_stmt (tree);
 308 static inline bool stmt_modified_p (tree);
 309 static inline varray_type may_aliases (tree);
 310 static inline int get_lineno (tree);
 311 static inline const char *get_filename (tree);
 312 static inline bool is_exec_stmt (tree);
 313 static inline bool is_label_stmt (tree);
 314 static inline v_may_def_optype get_v_may_def_ops (stmt_ann_t);
 315 static inline vuse_optype get_vuse_ops (stmt_ann_t);
 316 static inline use_optype get_use_ops (stmt_ann_t);
 317 static inline def_optype get_def_ops (stmt_ann_t);
 318 static inline bitmap addresses_taken (tree);
 319 static inline int num_immediate_uses (dataflow_t);
 320 static inline tree immediate_use (dataflow_t, int);
 321 static inline dataflow_t get_immediate_uses (tree);
 322 static inline void set_default_def (tree, tree);
 323 static inline tree default_def (tree);
 324
 325 /*---------------------------------------------------------------------------
 326                   Structure representing predictions in tree level.
 327 ---------------------------------------------------------------------------*/
 328 struct edge_prediction GTY((chain_next ("%h.next")))
 329 {
 330   struct edge_prediction *next;
 331   edge edge;
 332   enum br_predictor predictor;
 333   int probability;
 334 };
 335
 336 /*---------------------------------------------------------------------------
 337                   Block annotations stored in basic_block.tree_annotations
 338 ---------------------------------------------------------------------------*/
 339 struct bb_ann_d GTY(())
 340 {
 341   /* Chain of PHI nodes for this block.  */
 342   tree phi_nodes;
 343
 344   /* Number of predecessors for this block.  This is only valid during
 345      SSA rewriting.  It is not maintained after conversion into SSA form.  */
 346   int num_preds;
 347
 348   /* Nonzero if this block is forwardable during cfg cleanups.  This is also
 349      used to detect loops during cfg cleanups.  */
 350   unsigned forwardable: 1;
 351
 352   /* Nonzero if this block contains an escape point (see is_escape_site).  */
 353   unsigned has_escape_site : 1;
 354
 355   /* Nonzero if one or more incoming edges to this block should be threaded
 356      to an outgoing edge of this block.  */
 357   unsigned incoming_edge_threaded : 1;
 358
 359   struct edge_prediction *predictions;
 360 };
 361
 362 typedef struct bb_ann_d *bb_ann_t;
 363
 364 /* Accessors for basic block annotations.  */
 365 static inline bb_ann_t bb_ann (basic_block);
 366 static inline tree phi_nodes (basic_block);
 367 static inline void set_phi_nodes (basic_block, tree);
 368
 369 /*---------------------------------------------------------------------------
 370                               Global declarations
 371 ---------------------------------------------------------------------------*/
 372 /* Array of all variables referenced in the function.  */
 373 extern GTY(()) varray_type referenced_vars;
 374
 375 #define num_referenced_vars VARRAY_ACTIVE_SIZE (referenced_vars)
 376 #define referenced_var(i) VARRAY_TREE (referenced_vars, i)
 377
 378 /* Array of all SSA_NAMEs used in the function.  */
 379 extern GTY(()) varray_type ssa_names;
 380
 381 #define num_ssa_names VARRAY_ACTIVE_SIZE (ssa_names)
 382 #define ssa_name(i) VARRAY_TREE (ssa_names, i)
 383
 384 /* Artificial variable used to model the effects of function calls.  */
 385 extern GTY(()) tree global_var;
 386
 387 /* Call clobbered variables in the function.  If bit I is set, then
 388    REFERENCED_VARS (I) is call-clobbered.  */
 389 extern bitmap call_clobbered_vars;
 390
 391 /* Addressable variables in the function.  If bit I is set, then
 392    REFERENCED_VARS (I) has had its address taken.  */
 393 extern bitmap addressable_vars;
 394
 395 /* 'true' after aliases have been computed (see compute_may_aliases).  */
 396 extern bool aliases_computed_p;
 397
 398 /* Macros for showing usage statistics.  */
 399 #define SCALE(x) ((unsigned long) ((x) < 1024*10        \
 400                   ? (x)                                 \
 401                   : ((x) < 1024*1024*10                 \
 402                      ? (x) / 1024                       \
 403                      : (x) / (1024*1024))))
 404
 405 #define LABEL(x) ((x) < 1024*10 ? 'b' : ((x) < 1024*1024*10 ? 'k' : 'M'))
 406
 407 #define PERCENT(x,y) ((float)(x) * 100.0 / (float)(y))
 408
 409
 410 /*---------------------------------------------------------------------------
 411                               Block iterators
 412 ---------------------------------------------------------------------------*/
 413
 414 typedef struct {
 415   tree_stmt_iterator tsi;
 416   basic_block bb;
 417 } block_stmt_iterator;
 418
 419 static inline block_stmt_iterator bsi_start (basic_block);
 420 static inline block_stmt_iterator bsi_last (basic_block);
 421 static inline block_stmt_iterator bsi_after_labels (basic_block);
 422 static inline bool bsi_end_p (block_stmt_iterator);
 423 static inline void bsi_next (block_stmt_iterator *);
 424 static inline void bsi_prev (block_stmt_iterator *);
 425 static inline tree bsi_stmt (block_stmt_iterator);
 426 static inline tree * bsi_stmt_ptr (block_stmt_iterator);
 427
 428 extern void bsi_remove (block_stmt_iterator *);
 429 extern void bsi_move_before (block_stmt_iterator *, block_stmt_iterator *);
 430 extern void bsi_move_after (block_stmt_iterator *, block_stmt_iterator *);
 431 extern void bsi_move_to_bb_end (block_stmt_iterator *, basic_block);
 432
 433 enum bsi_iterator_update
 434 {
 435   /* Note that these are intentionally in the same order as TSI_FOO.  They
 436      mean exactly the same as their TSI_* counterparts.  */
 437   BSI_NEW_STMT,
 438   BSI_SAME_STMT,
 439   BSI_CHAIN_START,
 440   BSI_CHAIN_END,
 441   BSI_CONTINUE_LINKING
 442 };
 443
 444 extern void bsi_insert_before (block_stmt_iterator *, tree,
 445                                enum bsi_iterator_update);
 446 extern void bsi_insert_after (block_stmt_iterator *, tree,
 447                               enum bsi_iterator_update);
 448
 449 extern void bsi_replace (const block_stmt_iterator *, tree, bool);
 450
 451 /*---------------------------------------------------------------------------
 452                               Function prototypes
 453 ---------------------------------------------------------------------------*/
 454 /* In tree-cfg.c  */
 455
 456 /* Location to track pending stmt for edge insertion.  */
 457 #define PENDING_STMT(e) ((e)->insns.t)
 458
 459 extern void delete_tree_cfg_annotations (void);
 460 extern void disband_implicit_edges (void);
 461 extern bool stmt_ends_bb_p (tree);
 462 extern bool is_ctrl_stmt (tree);
 463 extern bool is_ctrl_altering_stmt (tree);
 464 extern bool computed_goto_p (tree);
 465 extern bool simple_goto_p (tree);
 466 extern void tree_dump_bb (basic_block, FILE *, int);
 467 extern void debug_tree_bb (basic_block);
 468 extern basic_block debug_tree_bb_n (int);
 469 extern void dump_tree_cfg (FILE *, int);
 470 extern void debug_tree_cfg (int);
 471 extern void dump_cfg_stats (FILE *);
 472 extern void debug_cfg_stats (void);
 473 extern void debug_loop_ir (void);
 474 extern void print_loop_ir (FILE *);
 475 extern void cleanup_dead_labels (void);
 476 extern void group_case_labels (void);
 477 extern bool cleanup_tree_cfg (void);
 478 extern tree first_stmt (basic_block);
 479 extern tree last_stmt (basic_block);
 480 extern tree *last_stmt_ptr (basic_block);
 481 extern tree last_and_only_stmt (basic_block);
 482 extern edge find_taken_edge (basic_block, tree);
 483 extern void cfg_remove_useless_stmts (void);
 484 extern edge thread_edge (edge, basic_block);
 485 extern basic_block label_to_block (tree);
 486 extern void tree_optimize_tail_calls (bool, enum tree_dump_index);
 487 extern edge tree_block_forwards_to (basic_block bb);
 488 extern void bsi_insert_on_edge (edge, tree);
 489 extern void bsi_commit_edge_inserts (int *);
 490 extern void notice_special_calls (tree);
 491 extern void clear_special_calls (void);
 492 extern void verify_stmts (void);
 493 extern tree tree_block_label (basic_block bb);
 494 extern void extract_true_false_edges_from_block (basic_block, edge *, edge *);
 495 extern bool tree_purge_dead_eh_edges (basic_block);
 496 extern bool tree_purge_all_dead_eh_edges (bitmap);
 497 extern tree gimplify_val (block_stmt_iterator *, tree, tree);
 498 extern tree gimplify_build1 (block_stmt_iterator *, enum tree_code,
 499                              tree, tree);
 500 extern tree gimplify_build2 (block_stmt_iterator *, enum tree_code,
 501                              tree, tree, tree);
 502 extern tree gimplify_build3 (block_stmt_iterator *, enum tree_code,
 503                              tree, tree, tree, tree);
 504
 505 /* In tree-pretty-print.c.  */
 506 extern void dump_generic_bb (FILE *, basic_block, int, int);
 507
 508 /* In tree-dfa.c  */
 509 extern var_ann_t create_var_ann (tree);
 510 extern stmt_ann_t create_stmt_ann (tree);
 511 extern tree_ann_t create_tree_ann (tree);
 512 extern tree create_phi_node (tree, basic_block);
 513 extern void add_phi_arg (tree *, tree, edge);
 514 extern void remove_phi_arg (tree, basic_block);
 515 extern void remove_phi_arg_num (tree, int);
 516 extern void remove_phi_node (tree, tree, basic_block);
 517 extern void remove_all_phi_nodes_for (bitmap);
 518 extern void dump_dfa_stats (FILE *);
 519 extern void debug_dfa_stats (void);
 520 extern void debug_referenced_vars (void);
 521 extern void dump_referenced_vars (FILE *);
 522 extern void dump_variable (FILE *, tree);
 523 extern void debug_variable (tree);
 524 extern void dump_immediate_uses (FILE *);
 525 extern void debug_immediate_uses (void);
 526 extern void dump_immediate_uses_for (FILE *, tree);
 527 extern void debug_immediate_uses_for (tree);
 528 extern void compute_immediate_uses (int, bool (*)(tree));
 529 extern void free_df (void);
 530 extern tree get_virtual_var (tree);
 531 extern void add_referenced_tmp_var (tree var);
 532 extern void mark_new_vars_to_rename (tree, bitmap);
 533 extern void redirect_immediate_uses (tree, tree);
 534 extern tree make_rename_temp (tree, const char *);
 535
 536 /* Flags used when computing reaching definitions and reached uses.  */
 537 #define TDFA_USE_OPS            1 << 0
 538 #define TDFA_USE_VOPS           1 << 1
 539
 540 /* In gimple-low.c  */
 541 struct lower_data;
 542 extern void lower_stmt_body (tree, struct lower_data *);
 543 extern void record_vars (tree);
 544 extern bool block_may_fallthru (tree block);
 545
 546 /* In tree-ssa-alias.c  */
 547 extern void dump_may_aliases_for (FILE *, tree);
 548 extern void debug_may_aliases_for (tree);
 549 extern void dump_alias_info (FILE *);
 550 extern void debug_alias_info (void);
 551 extern void dump_points_to_info (FILE *);
 552 extern void debug_points_to_info (void);
 553 extern void dump_points_to_info_for (FILE *, tree);
 554 extern void debug_points_to_info_for (tree);
 555 extern bool may_be_aliased (tree);
 556
 557 /* Call-back function for walk_use_def_chains().  At each reaching
 558    definition, a function with this prototype is called.  */
 559 typedef bool (*walk_use_def_chains_fn) (tree, tree, void *);
 560
 561 /* In tree-ssa.c  */
 562 extern void init_tree_ssa (void);
 563 extern void dump_reaching_defs (FILE *);
 564 extern void debug_reaching_defs (void);
 565 extern void dump_tree_ssa (FILE *);
 566 extern void debug_tree_ssa (void);
 567 extern void debug_def_blocks (void);
 568 extern void dump_tree_ssa_stats (FILE *);
 569 extern void debug_tree_ssa_stats (void);
 570 extern void ssa_remove_edge (edge);
 571 extern edge ssa_redirect_edge (edge, basic_block);
 572 extern bool tree_ssa_useless_type_conversion (tree);
 573 extern bool tree_ssa_useless_type_conversion_1 (tree, tree);
 574 extern void verify_ssa (void);
 575 extern void delete_tree_ssa (void);
 576 extern void register_new_def (tree, varray_type *);
 577 extern void walk_use_def_chains (tree, walk_use_def_chains_fn, void *, bool);
 578 extern void kill_redundant_phi_nodes (void);
 579
 580 /* In tree-into-ssa.c  */
 581 extern void rewrite_into_ssa (bool);
 582 extern void rewrite_ssa_into_ssa (void);
 583
 584 void compute_global_livein (bitmap, bitmap);
 585 tree duplicate_ssa_name (tree, tree);
 586
 587 /* In tree-ssa-ccp.c  */
 588 bool fold_stmt (tree *);
 589 tree widen_bitfield (tree, tree, tree);
 590
 591 /* In tree-ssa-dom.c  */
 592 extern void dump_dominator_optimization_stats (FILE *);
 593 extern void debug_dominator_optimization_stats (void);
 594
 595 /* In tree-ssa-copy.c  */
 596 extern void propagate_value (use_operand_p, tree);
 597 extern void propagate_tree_value (tree *, tree);
 598 extern void replace_exp (use_operand_p, tree);
 599 extern bool may_propagate_copy (tree, tree);
 600
 601 /* Description of number of iterations of a loop.  All the expressions inside
 602    the structure can be evaluated at the end of the loop's preheader
 603    (and due to ssa form, also anywhere inside the body of the loop).  */
 604
 605 struct tree_niter_desc
 606 {
 607   tree assumptions;     /* The boolean expression.  If this expression evalutes
 608                            to false, then the other fields in this structure
 609                            should not be used; there is no guarantee that they
 610                            will be correct.  */
 611   tree may_be_zero;     /* The booleand expression.  If it evaluates to true,
 612                            the loop will exit in the first iteration (i.e.
 613                            its latch will not be executed), even if the niter
 614                            field says otherwise.  */
 615   tree niter;           /* The expression giving the number of iterations of
 616                            a loop (provided that assumptions == true and
 617                            may_be_zero == false), more precisely the number
 618                            of executions of the latch of the loop.  */
 619   tree additional_info; /* The boolean expression.  Sometimes we use additional
 620                            knowledge to simplify the other expressions
 621                            contained in this structure (for example the
 622                            knowledge about value ranges of operands on entry to
 623                            the loop).  If this is a case, conjunction of such
 624                            condition is stored in this field, so that we do not
 625                            lose the information: for example if may_be_zero
 626                            is (n <= 0) and niter is (unsigned) n, we know
 627                            that the number of iterations is at most
 628                            MAX_SIGNED_INT.  However if the (n <= 0) assumption
 629                            is eliminated (by looking at the guard on entry of
 630                            the loop), then the information would be lost.  */
 631 };
 632
 633 /* In tree-vectorizer.c */
 634 void vectorize_loops (struct loops *);
 635
 636 /* In tree-ssa-phiopt.c */
 637 bool empty_block_p (basic_block);
 638
 639 /* In tree-ssa-loop*.c  */
 640
 641 void tree_ssa_lim (struct loops *);
 642
 643 void number_of_iterations_cond (tree, tree, tree, enum tree_code, tree, tree,
 644                                 struct tree_niter_desc *);
 645 bool number_of_iterations_exit (struct loop *, edge,
 646                                 struct tree_niter_desc *niter);
 647 tree loop_niter_by_eval (struct loop *, edge);
 648 tree find_loop_niter_by_eval (struct loop *, edge *);
 649 void estimate_numbers_of_iterations (struct loops *);
 650 tree can_count_iv_in_wider_type (struct loop *, tree, tree, tree, tree);
 651 void free_numbers_of_iterations_estimates (struct loops *);
 652 void rewrite_into_loop_closed_ssa (void);
 653 void verify_loop_closed_ssa (void);
 654 void loop_commit_inserts (void);
 655 bool for_each_index (tree *, bool (*) (tree, tree *, void *), void *);
 656
 657 /* In tree-flow-inline.h  */
 658 static inline int phi_arg_from_edge (tree, edge);
 659 static inline bool is_call_clobbered (tree);
 660 static inline void mark_call_clobbered (tree);
 661 static inline void set_is_used (tree);
 662
 663 /* In tree-eh.c  */
 664 extern void make_eh_edges (tree);
 665 extern bool tree_could_trap_p (tree);
 666 extern bool tree_could_throw_p (tree);
 667 extern bool tree_can_throw_internal (tree);
 668 extern bool tree_can_throw_external (tree);
 669 extern int lookup_stmt_eh_region (tree);
 670 extern void add_stmt_to_eh_region (tree, int);
 671 extern bool remove_stmt_from_eh_region (tree);
 672 extern bool maybe_clean_eh_stmt (tree);
 673
 674 /* In tree-ssa-pre.c  */
 675 void add_to_value (tree, tree);
 676 void debug_value_expressions (tree);
 677 void print_value_expressions (FILE *, tree);
 678
 679
 680 /* In tree-vn.c  */
 681 bool expressions_equal_p (tree, tree);
 682 tree get_value_handle (tree);
 683 hashval_t vn_compute (tree, hashval_t, vuse_optype);
 684 tree vn_lookup_or_add (tree, vuse_optype);
 685 void vn_add (tree, tree, vuse_optype);
 686 tree vn_lookup (tree, vuse_optype);
 687 void vn_init (void);
 688 void vn_delete (void);
 689
 690
 691 /* In tree-sra.c  */
 692 void insert_edge_copies (tree stmt, basic_block bb);
 693
 694 /* In tree-ssa-operands.c  */
 695 extern void build_ssa_operands (tree, stmt_ann_t, stmt_operands_p,
 696                                 stmt_operands_p);
 697
 698 #include "tree-flow-inline.h"
 699
 700 #endif /* _TREE_FLOW_H  */