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, 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 #include "cgraph.h"
  32
  33 /* Forward declare structures for the garbage collector GTY markers.  */
  34 #ifndef GCC_BASIC_BLOCK_H
  35 struct edge_def;
  36 typedef struct edge_def *edge;
  37 struct basic_block_def;
  38 typedef struct basic_block_def *basic_block;
  39 #endif
  40
  41 /* True if the code is in ssa form.  */
  42 extern bool in_ssa_p;
  43
  44 /*---------------------------------------------------------------------------
  45                       Attributes for SSA_NAMEs.
  46
  47   NOTE: These structures are stored in struct tree_ssa_name
  48   but are only used by the tree optimizers, so it makes better sense
  49   to declare them here to avoid recompiling unrelated files when
  50   making changes.
  51 ---------------------------------------------------------------------------*/
  52
  53 /* Aliasing information for SSA_NAMEs representing pointer variables.  */
  54 struct ptr_info_def GTY(())
  55 {
  56   /* Nonzero if points-to analysis couldn't determine where this pointer
  57      is pointing to.  */
  58   unsigned int pt_anything : 1;
  59
  60   /* Nonzero if this pointer is the result of a call to malloc.  */
  61   unsigned int pt_malloc : 1;
  62
  63   /* Nonzero if the value of this pointer escapes the current function.  */
  64   unsigned int value_escapes_p : 1;
  65
  66   /* Nonzero if this pointer is dereferenced.  */
  67   unsigned int is_dereferenced : 1;
  68
  69   /* Nonzero if this pointer points to a global variable.  */
  70   unsigned int pt_global_mem : 1;
  71
  72   /* Nonzero if this pointer points to NULL.  */
  73   unsigned int pt_null : 1;
  74
  75   /* Set of variables that this pointer may point to.  */
  76   bitmap pt_vars;
  77
  78   /* If this pointer has been dereferenced, and points-to information is
  79      more precise than type-based aliasing, indirect references to this
  80      pointer will be represented by this memory tag, instead of the type
  81      tag computed by TBAA.  */
  82   tree name_mem_tag;
  83 };
  84
  85
  86 /*---------------------------------------------------------------------------
  87                    Tree annotations stored in tree_common.ann
  88 ---------------------------------------------------------------------------*/
  89 enum tree_ann_type { TREE_ANN_COMMON, VAR_ANN, STMT_ANN };
  90
  91 struct tree_ann_common_d GTY(())
  92 {
  93   /* Annotation type.  */
  94   enum tree_ann_type type;
  95
  96  /* Auxiliary info specific to a pass.  At all times, this
  97     should either point to valid data or be NULL.  */
  98   PTR GTY ((skip (""))) aux;
  99
 100   /* The value handle for this expression.  Used by GVN-PRE.  */
 101   tree GTY((skip)) value_handle;
 102 };
 103
 104 /* It is advantageous to avoid things like life analysis for variables which
 105    do not need PHI nodes.  This enum describes whether or not a particular
 106    variable may need a PHI node.  */
 107
 108 enum need_phi_state {
 109   /* This is the default.  If we are still in this state after finding
 110      all the definition and use sites, then we will assume the variable
 111      needs PHI nodes.  This is probably an overly conservative assumption.  */
 112   NEED_PHI_STATE_UNKNOWN,
 113
 114   /* This state indicates that we have seen one or more sets of the
 115      variable in a single basic block and that the sets dominate all
 116      uses seen so far.  If after finding all definition and use sites
 117      we are still in this state, then the variable does not need any
 118      PHI nodes.  */
 119   NEED_PHI_STATE_NO,
 120
 121   /* This state indicates that we have either seen multiple definitions of
 122      the variable in multiple blocks, or that we encountered a use in a
 123      block that was not dominated by the block containing the set(s) of
 124      this variable.  This variable is assumed to need PHI nodes.  */
 125   NEED_PHI_STATE_MAYBE
 126 };
 127
 128
 129 /* When computing aliasing information, we represent the memory pointed-to
 130    by pointers with artificial variables called "memory tags" (MT).  There
 131    are two kinds of tags: type and name.  Type tags (TMT) are used in
 132    type-based alias analysis, they represent all the pointed-to locations
 133    and variables of the same alias set class.  Name tags (NMT) are used in
 134    flow-sensitive points-to alias analysis, they represent the variables
 135    and memory locations pointed-to by a specific SSA_NAME pointer.  */
 136 enum mem_tag_kind {
 137   /* This variable is not a memory tag.  */
 138   NOT_A_TAG,
 139
 140   /* This variable is a type memory tag (TMT).  */
 141   TYPE_TAG,
 142
 143   /* This variable is a name memory tag (NMT).  */
 144   NAME_TAG,
 145
 146   /* This variable represents a structure field.  */
 147   STRUCT_FIELD
 148 };
 149 struct subvar;
 150 typedef struct subvar *subvar_t;
 151
 152 /* This structure represents a fake sub-variable for a structure field.  */
 153
 154 struct subvar GTY(())
 155 {
 156   /* Fake variable name */
 157   tree var;
 158   /* Offset inside structure.  */
 159   HOST_WIDE_INT offset;
 160   /* Size of field.  */
 161   HOST_WIDE_INT size;
 162   /* Next subvar for this structure.  */
 163   subvar_t next;
 164 };
 165
 166 struct var_ann_d GTY(())
 167 {
 168   struct tree_ann_common_d common;
 169
 170   /* Used by the out of SSA pass to determine whether this variable has
 171      been seen yet or not.  */
 172   unsigned out_of_ssa_tag : 1;
 173
 174   /* Used when building root_var structures in tree_ssa_live.[ch].  */
 175   unsigned root_var_processed : 1;
 176
 177   /* If nonzero, this variable is a memory tag.  */
 178   ENUM_BITFIELD (mem_tag_kind) mem_tag_kind : 2;
 179
 180   /* Nonzero if this variable is an alias tag that represents references to
 181      other variables (i.e., this variable appears in the MAY_ALIASES array
 182      of other variables).  */
 183   unsigned is_alias_tag : 1;
 184
 185   /* Nonzero if this variable was used after SSA optimizations were
 186      applied.  We set this when translating out of SSA form.  */
 187   unsigned used : 1;
 188
 189   /* This field indicates whether or not the variable may need PHI nodes.
 190      See the enum's definition for more detailed information about the
 191      states.  */
 192   ENUM_BITFIELD (need_phi_state) need_phi_state : 2;
 193
 194   /* Used during operand processing to determine if this variable is already
 195      in the vuse list.  */
 196   unsigned in_vuse_list : 1;
 197
 198   /* Used during operand processing to determine if this variable is already
 199      in the v_may_def list.  */
 200   unsigned in_v_may_def_list : 1;
 201
 202   /* An artificial variable representing the memory location pointed-to by
 203      all the pointers that TBAA (type-based alias analysis) considers
 204      to be aliased.  If the variable is not a pointer or if it is never
 205      dereferenced, this must be NULL.  */
 206   tree type_mem_tag;
 207
 208   /* Variables that may alias this variable.  */
 209   varray_type may_aliases;
 210
 211   /* Unique ID of this variable.  */
 212   size_t uid;
 213
 214   /* Used when going out of SSA form to indicate which partition this
 215      variable represents storage for.  */
 216   unsigned partition;
 217
 218   /* Used by the root-var object in tree-ssa-live.[ch].  */
 219   unsigned root_index;
 220
 221   /* Default definition for this symbol.  If this field is not NULL, it
 222      means that the first reference to this variable in the function is a
 223      USE or a VUSE.  In those cases, the SSA renamer creates an SSA name
 224      for this variable with an empty defining statement.  */
 225   tree default_def;
 226
 227   /* During into-ssa and the dominator optimizer, this field holds the
 228      current version of this variable (an SSA_NAME).  */
 229   tree current_def;
 230
 231   /* If this variable is a structure, this fields holds a list of
 232      symbols representing each of the fields of the structure.  */
 233   subvar_t subvars;
 234 };
 235
 236
 237 typedef struct immediate_use_iterator_d
 238 {
 239   ssa_use_operand_t *imm_use;
 240   ssa_use_operand_t *end_p;
 241   ssa_use_operand_t iter_node;
 242 } imm_use_iterator;
 243
 244
 245 /* Use this iterator when simply looking at stmts.  Adding, deleting or
 246    modifying stmts will cause this iterator to malfunction.  */
 247
 248 #define FOR_EACH_IMM_USE_FAST(DEST, ITER, SSAVAR)                       \
 249   for ((DEST) = first_readonly_imm_use (&(ITER), (SSAVAR));     \
 250        !end_readonly_imm_use_p (&(ITER));                       \
 251        (DEST) = next_readonly_imm_use (&(ITER)))
 252
 253
 254 #define FOR_EACH_IMM_USE_SAFE(DEST, ITER, SSAVAR)               \
 255   for ((DEST) = first_safe_imm_use (&(ITER), (SSAVAR));         \
 256        !end_safe_imm_use_p (&(ITER));                           \
 257        (DEST) = next_safe_imm_use (&(ITER)))
 258
 259 #define BREAK_FROM_SAFE_IMM_USE(ITER)                           \
 260    {                                                            \
 261      end_safe_imm_use_traverse (&(ITER));                       \
 262      break;                                                     \
 263    }
 264
 265 struct stmt_ann_d GTY(())
 266 {
 267   struct tree_ann_common_d common;
 268
 269   /* Nonzero if the statement has been modified (meaning that the operands
 270      need to be scanned again).  */
 271   unsigned modified : 1;
 272
 273   /* Nonzero if the statement makes aliased loads.  */
 274   unsigned makes_aliased_loads : 1;
 275
 276   /* Nonzero if the statement makes aliased stores.  */
 277   unsigned makes_aliased_stores : 1;
 278
 279   /* Nonzero if the statement makes references to volatile storage.  */
 280   unsigned has_volatile_ops : 1;
 281
 282   /* Nonzero if the statement makes a function call that may clobber global
 283      and local addressable variables.  */
 284   unsigned makes_clobbering_call : 1;
 285
 286   /* Basic block that contains this statement.  */
 287   basic_block bb;
 288
 289   /* Operand cache for stmt.  */
 290   struct stmt_operands_d GTY ((skip (""))) operands;
 291
 292   /* Set of variables that have had their address taken in the statement.  */
 293   bitmap addresses_taken;
 294
 295   /* Unique identifier for this statement.  These ID's are to be created
 296      by each pass on an as-needed basis in any order convenient for the
 297      pass which needs statement UIDs.  */
 298   unsigned int uid;
 299
 300   /* Linked list of histograms for value-based profiling.  This is really a
 301      struct histogram_value*.  We use void* to avoid having to export that
 302      everywhere, and to avoid having to put it in GC memory.  */
 303
 304   void * GTY ((skip (""))) histograms;
 305 };
 306
 307 union tree_ann_d GTY((desc ("ann_type ((tree_ann_t)&%h)")))
 308 {
 309   struct tree_ann_common_d GTY((tag ("TREE_ANN_COMMON"))) common;
 310   struct var_ann_d GTY((tag ("VAR_ANN"))) decl;
 311   struct stmt_ann_d GTY((tag ("STMT_ANN"))) stmt;
 312 };
 313
 314 extern GTY(()) VEC(tree,gc) *modified_noreturn_calls;
 315
 316 typedef union tree_ann_d *tree_ann_t;
 317 typedef struct var_ann_d *var_ann_t;
 318 typedef struct stmt_ann_d *stmt_ann_t;
 319
 320 static inline tree_ann_t tree_ann (tree);
 321 static inline tree_ann_t get_tree_ann (tree);
 322 static inline var_ann_t var_ann (tree);
 323 static inline var_ann_t get_var_ann (tree);
 324 static inline stmt_ann_t stmt_ann (tree);
 325 static inline stmt_ann_t get_stmt_ann (tree);
 326 static inline enum tree_ann_type ann_type (tree_ann_t);
 327 static inline basic_block bb_for_stmt (tree);
 328 extern void set_bb_for_stmt (tree, basic_block);
 329 static inline bool noreturn_call_p (tree);
 330 static inline void update_stmt (tree);
 331 static inline bool stmt_modified_p (tree);
 332 static inline varray_type may_aliases (tree);
 333 static inline int get_lineno (tree);
 334 static inline const char *get_filename (tree);
 335 static inline bool is_exec_stmt (tree);
 336 static inline bool is_label_stmt (tree);
 337 static inline bitmap addresses_taken (tree);
 338 static inline void set_default_def (tree, tree);
 339 static inline tree default_def (tree);
 340
 341 /*---------------------------------------------------------------------------
 342                   Structure representing predictions in tree level.
 343 ---------------------------------------------------------------------------*/
 344 struct edge_prediction GTY((chain_next ("%h.next")))
 345 {
 346   struct edge_prediction *next;
 347   edge edge;
 348   enum br_predictor predictor;
 349   int probability;
 350 };
 351
 352 /* Accessors for basic block annotations.  */
 353 static inline tree phi_nodes (basic_block);
 354 static inline void set_phi_nodes (basic_block, tree);
 355
 356 /*---------------------------------------------------------------------------
 357                               Global declarations
 358 ---------------------------------------------------------------------------*/
 359 /* Array of all variables referenced in the function.  */
 360 extern GTY(()) VEC(tree,gc) *referenced_vars;
 361
 362 #define num_referenced_vars VEC_length (tree, referenced_vars)
 363 #define referenced_var(i) VEC_index (tree, referenced_vars, i)
 364
 365 /* Array of all SSA_NAMEs used in the function.  */
 366 extern GTY(()) VEC(tree,gc) *ssa_names;
 367
 368 #define num_ssa_names (VEC_length (tree, ssa_names))
 369 #define ssa_name(i) (VEC_index (tree, ssa_names, (i)))
 370
 371 /* Artificial variable used to model the effects of function calls.  */
 372 extern GTY(()) tree global_var;
 373
 374 /* Call clobbered variables in the function.  If bit I is set, then
 375    REFERENCED_VARS (I) is call-clobbered.  */
 376 extern bitmap call_clobbered_vars;
 377
 378 /* Addressable variables in the function.  If bit I is set, then
 379    REFERENCED_VARS (I) has had its address taken.  */
 380 extern bitmap addressable_vars;
 381
 382 /* 'true' after aliases have been computed (see compute_may_aliases).  */
 383 extern bool aliases_computed_p;
 384
 385 /* Macros for showing usage statistics.  */
 386 #define SCALE(x) ((unsigned long) ((x) < 1024*10        \
 387                   ? (x)                                 \
 388                   : ((x) < 1024*1024*10                 \
 389                      ? (x) / 1024                       \
 390                      : (x) / (1024*1024))))
 391
 392 #define LABEL(x) ((x) < 1024*10 ? 'b' : ((x) < 1024*1024*10 ? 'k' : 'M'))
 393
 394 #define PERCENT(x,y) ((float)(x) * 100.0 / (float)(y))
 395
 396 /*---------------------------------------------------------------------------
 397                               Block iterators
 398 ---------------------------------------------------------------------------*/
 399
 400 typedef struct {
 401   tree_stmt_iterator tsi;
 402   basic_block bb;
 403 } block_stmt_iterator;
 404
 405 static inline block_stmt_iterator bsi_start (basic_block);
 406 static inline block_stmt_iterator bsi_last (basic_block);
 407 static inline block_stmt_iterator bsi_after_labels (basic_block);
 408 block_stmt_iterator bsi_for_stmt (tree);
 409 static inline bool bsi_end_p (block_stmt_iterator);
 410 static inline void bsi_next (block_stmt_iterator *);
 411 static inline void bsi_prev (block_stmt_iterator *);
 412 static inline tree bsi_stmt (block_stmt_iterator);
 413 static inline tree * bsi_stmt_ptr (block_stmt_iterator);
 414
 415 extern void bsi_remove (block_stmt_iterator *);
 416 extern void bsi_move_before (block_stmt_iterator *, block_stmt_iterator *);
 417 extern void bsi_move_after (block_stmt_iterator *, block_stmt_iterator *);
 418 extern void bsi_move_to_bb_end (block_stmt_iterator *, basic_block);
 419
 420 enum bsi_iterator_update
 421 {
 422   /* Note that these are intentionally in the same order as TSI_FOO.  They
 423      mean exactly the same as their TSI_* counterparts.  */
 424   BSI_NEW_STMT,
 425   BSI_SAME_STMT,
 426   BSI_CHAIN_START,
 427   BSI_CHAIN_END,
 428   BSI_CONTINUE_LINKING
 429 };
 430
 431 extern void bsi_insert_before (block_stmt_iterator *, tree,
 432                                enum bsi_iterator_update);
 433 extern void bsi_insert_after (block_stmt_iterator *, tree,
 434                               enum bsi_iterator_update);
 435
 436 extern void bsi_replace (const block_stmt_iterator *, tree, bool);
 437
 438 /*---------------------------------------------------------------------------
 439                               Function prototypes
 440 ---------------------------------------------------------------------------*/
 441 /* In tree-cfg.c  */
 442
 443 /* Location to track pending stmt for edge insertion.  */
 444 #define PENDING_STMT(e) ((e)->insns.t)
 445
 446 extern void delete_tree_cfg_annotations (void);
 447 extern void disband_implicit_edges (void);
 448 extern bool stmt_ends_bb_p (tree);
 449 extern bool is_ctrl_stmt (tree);
 450 extern bool is_ctrl_altering_stmt (tree);
 451 extern bool computed_goto_p (tree);
 452 extern bool simple_goto_p (tree);
 453 extern void tree_dump_bb (basic_block, FILE *, int);
 454 extern void debug_tree_bb (basic_block);
 455 extern basic_block debug_tree_bb_n (int);
 456 extern void dump_tree_cfg (FILE *, int);
 457 extern void debug_tree_cfg (int);
 458 extern void dump_cfg_stats (FILE *);
 459 extern void debug_cfg_stats (void);
 460 extern void debug_loop_ir (void);
 461 extern void print_loop_ir (FILE *);
 462 extern void cleanup_dead_labels (void);
 463 extern void group_case_labels (void);
 464 extern tree first_stmt (basic_block);
 465 extern tree last_stmt (basic_block);
 466 extern tree *last_stmt_ptr (basic_block);
 467 extern tree last_and_only_stmt (basic_block);
 468 extern edge find_taken_edge (basic_block, tree);
 469 extern basic_block label_to_block_fn (struct function *, tree);
 470 #define label_to_block(t) (label_to_block_fn (cfun, t))
 471 extern void bsi_insert_on_edge (edge, tree);
 472 extern basic_block bsi_insert_on_edge_immediate (edge, tree);
 473 extern void bsi_commit_one_edge_insert (edge, basic_block *);
 474 extern void bsi_commit_edge_inserts (void);
 475 extern void notice_special_calls (tree);
 476 extern void clear_special_calls (void);
 477 extern void verify_stmts (void);
 478 extern tree tree_block_label (basic_block);
 479 extern void extract_true_false_edges_from_block (basic_block, edge *, edge *);
 480 extern bool tree_duplicate_sese_region (edge, edge, basic_block *, unsigned,
 481                                         basic_block *);
 482 extern void add_phi_args_after_copy_bb (basic_block);
 483 extern void add_phi_args_after_copy (basic_block *, unsigned);
 484 extern bool tree_purge_dead_eh_edges (basic_block);
 485 extern bool tree_purge_all_dead_eh_edges (bitmap);
 486 extern tree gimplify_val (block_stmt_iterator *, tree, tree);
 487 extern tree gimplify_build1 (block_stmt_iterator *, enum tree_code,
 488                              tree, tree);
 489 extern tree gimplify_build2 (block_stmt_iterator *, enum tree_code,
 490                              tree, tree, tree);
 491 extern tree gimplify_build3 (block_stmt_iterator *, enum tree_code,
 492                              tree, tree, tree, tree);
 493 extern void init_empty_tree_cfg (void);
 494 extern void fold_cond_expr_cond (void);
 495 extern void replace_uses_by (tree, tree);
 496 extern void start_recording_case_labels (void);
 497 extern void end_recording_case_labels (void);
 498
 499 /* In tree-cfgcleanup.c  */
 500 extern bool cleanup_tree_cfg (void);
 501 extern void cleanup_tree_cfg_loop (void);
 502
 503 /* In tree-pretty-print.c.  */
 504 extern void dump_generic_bb (FILE *, basic_block, int, int);
 505
 506 /* In tree-dfa.c  */
 507 extern var_ann_t create_var_ann (tree);
 508 extern stmt_ann_t create_stmt_ann (tree);
 509 extern tree_ann_t create_tree_ann (tree);
 510 extern void reserve_phi_args_for_new_edge (basic_block);
 511 extern tree create_phi_node (tree, basic_block);
 512 extern void add_phi_arg (tree, tree, edge);
 513 extern void remove_phi_args (edge);
 514 extern void remove_phi_node (tree, tree);
 515 extern tree phi_reverse (tree);
 516 extern void dump_dfa_stats (FILE *);
 517 extern void debug_dfa_stats (void);
 518 extern void debug_referenced_vars (void);
 519 extern void dump_referenced_vars (FILE *);
 520 extern void dump_variable (FILE *, tree);
 521 extern void debug_variable (tree);
 522 extern tree get_virtual_var (tree);
 523 extern void add_referenced_tmp_var (tree);
 524 extern void mark_new_vars_to_rename (tree);
 525 extern void find_new_referenced_vars (tree *);
 526
 527 extern tree make_rename_temp (tree, const char *);
 528
 529 /* In gimple-low.c  */
 530 extern void record_vars (tree);
 531 extern bool block_may_fallthru (tree block);
 532
 533 /* In tree-ssa-alias.c  */
 534 extern void dump_may_aliases_for (FILE *, tree);
 535 extern void debug_may_aliases_for (tree);
 536 extern void dump_alias_info (FILE *);
 537 extern void debug_alias_info (void);
 538 extern void dump_points_to_info (FILE *);
 539 extern void debug_points_to_info (void);
 540 extern void dump_points_to_info_for (FILE *, tree);
 541 extern void debug_points_to_info_for (tree);
 542 extern bool may_be_aliased (tree);
 543 extern struct ptr_info_def *get_ptr_info (tree);
 544 extern void add_type_alias (tree, tree);
 545 extern void new_type_alias (tree, tree);
 546 extern void count_uses_and_derefs (tree, tree, unsigned *, unsigned *, bool *);
 547 static inline subvar_t get_subvars_for_var (tree);
 548 static inline bool ref_contains_array_ref (tree);
 549 extern tree okay_component_ref_for_subvars (tree, HOST_WIDE_INT *,
 550                                             HOST_WIDE_INT *);
 551 static inline bool var_can_have_subvars (tree);
 552 static inline bool overlap_subvar (HOST_WIDE_INT, HOST_WIDE_INT,
 553                                    subvar_t, bool *);
 554
 555 /* Call-back function for walk_use_def_chains().  At each reaching
 556    definition, a function with this prototype is called.  */
 557 typedef bool (*walk_use_def_chains_fn) (tree, tree, void *);
 558
 559
 560 /* In tree-ssa.c  */
 561 extern void init_tree_ssa (void);
 562 extern edge ssa_redirect_edge (edge, basic_block);
 563 extern void flush_pending_stmts (edge);
 564 extern bool tree_ssa_useless_type_conversion (tree);
 565 extern bool tree_ssa_useless_type_conversion_1 (tree, tree);
 566 extern void verify_ssa (bool);
 567 extern void delete_tree_ssa (void);
 568 extern void register_new_def (tree, VEC(tree,heap) **);
 569 extern void walk_use_def_chains (tree, walk_use_def_chains_fn, void *, bool);
 570 extern bool stmt_references_memory_p (tree);
 571
 572 /* In tree-into-ssa.c  */
 573 void update_ssa (unsigned);
 574 void delete_update_ssa (void);
 575 void register_new_name_mapping (tree, tree);
 576 tree create_new_def_for (tree, tree, def_operand_p);
 577 bool need_ssa_update_p (void);
 578 bool name_registered_for_update_p (tree);
 579 bitmap ssa_names_to_replace (void);
 580 void release_ssa_name_after_update_ssa (tree name);
 581 void compute_global_livein (bitmap, bitmap);
 582 tree duplicate_ssa_name (tree, tree);
 583 void mark_sym_for_renaming (tree);
 584 void mark_set_for_renaming (bitmap);
 585 tree get_current_def (tree);
 586 void set_current_def (tree, tree);
 587
 588 /* In tree-ssa-ccp.c  */
 589 bool fold_stmt (tree *);
 590 bool fold_stmt_inplace (tree);
 591 tree widen_bitfield (tree, tree, tree);
 592
 593 /* In tree-vrp.c  */
 594 bool expr_computes_nonzero (tree);
 595 tree vrp_evaluate_conditional (tree, bool);
 596
 597 /* In tree-ssa-dom.c  */
 598 extern void dump_dominator_optimization_stats (FILE *);
 599 extern void debug_dominator_optimization_stats (void);
 600 int loop_depth_of_name (tree);
 601
 602 /* In tree-ssa-copy.c  */
 603 extern void propagate_value (use_operand_p, tree);
 604 extern void propagate_tree_value (tree *, tree);
 605 extern void replace_exp (use_operand_p, tree);
 606 extern bool may_propagate_copy (tree, tree);
 607 extern bool may_propagate_copy_into_asm (tree);
 608
 609 /* Description of number of iterations of a loop.  All the expressions inside
 610    the structure can be evaluated at the end of the loop's preheader
 611    (and due to ssa form, also anywhere inside the body of the loop).  */
 612
 613 struct tree_niter_desc
 614 {
 615   tree assumptions;     /* The boolean expression.  If this expression evaluates
 616                            to false, then the other fields in this structure
 617                            should not be used; there is no guarantee that they
 618                            will be correct.  */
 619   tree may_be_zero;     /* The boolean expression.  If it evaluates to true,
 620                            the loop will exit in the first iteration (i.e.
 621                            its latch will not be executed), even if the niter
 622                            field says otherwise.  */
 623   tree niter;           /* The expression giving the number of iterations of
 624                            a loop (provided that assumptions == true and
 625                            may_be_zero == false), more precisely the number
 626                            of executions of the latch of the loop.  */
 627   tree additional_info; /* The boolean expression.  Sometimes we use additional
 628                            knowledge to simplify the other expressions
 629                            contained in this structure (for example the
 630                            knowledge about value ranges of operands on entry to
 631                            the loop).  If this is a case, conjunction of such
 632                            condition is stored in this field, so that we do not
 633                            lose the information: for example if may_be_zero
 634                            is (n <= 0) and niter is (unsigned) n, we know
 635                            that the number of iterations is at most
 636                            MAX_SIGNED_INT.  However if the (n <= 0) assumption
 637                            is eliminated (by looking at the guard on entry of
 638                            the loop), then the information would be lost.  */
 639 };
 640
 641 /* In tree-vectorizer.c */
 642 void vectorize_loops (struct loops *);
 643
 644 /* In tree-ssa-phiopt.c */
 645 bool empty_block_p (basic_block);
 646
 647 /* In tree-ssa-loop*.c  */
 648
 649 void tree_ssa_lim (struct loops *);
 650 void tree_ssa_unswitch_loops (struct loops *);
 651 void canonicalize_induction_variables (struct loops *);
 652 void tree_unroll_loops_completely (struct loops *, bool);
 653 void tree_ssa_iv_optimize (struct loops *);
 654
 655 bool number_of_iterations_exit (struct loop *, edge,
 656                                 struct tree_niter_desc *niter);
 657 tree find_loop_niter (struct loop *, edge *);
 658 tree loop_niter_by_eval (struct loop *, edge);
 659 tree find_loop_niter_by_eval (struct loop *, edge *);
 660 void estimate_numbers_of_iterations (struct loops *);
 661 tree can_count_iv_in_wider_type (struct loop *, tree, tree, tree, tree);
 662 void free_numbers_of_iterations_estimates (struct loops *);
 663 void rewrite_into_loop_closed_ssa (bitmap, unsigned);
 664 void verify_loop_closed_ssa (void);
 665 void loop_commit_inserts (void);
 666 bool for_each_index (tree *, bool (*) (tree, tree *, void *), void *);
 667 void create_iv (tree, tree, tree, struct loop *, block_stmt_iterator *, bool,
 668                 tree *, tree *);
 669 void split_loop_exit_edge (edge);
 670 basic_block bsi_insert_on_edge_immediate_loop (edge, tree);
 671 void standard_iv_increment_position (struct loop *, block_stmt_iterator *,
 672                                      bool *);
 673 basic_block ip_end_pos (struct loop *);
 674 basic_block ip_normal_pos (struct loop *);
 675 bool tree_duplicate_loop_to_header_edge (struct loop *, edge, struct loops *,
 676                                          unsigned int, sbitmap,
 677                                          edge, edge *,
 678                                          unsigned int *, int);
 679 struct loop *tree_ssa_loop_version (struct loops *, struct loop *, tree,
 680                                     basic_block *);
 681 tree expand_simple_operations (tree);
 682 void substitute_in_loop_info (struct loop *, tree, tree);
 683
 684 /* In tree-ssa-loop-im.c  */
 685 /* The possibilities of statement movement.  */
 686
 687 enum move_pos
 688   {
 689     MOVE_IMPOSSIBLE,            /* No movement -- side effect expression.  */
 690     MOVE_PRESERVE_EXECUTION,    /* Must not cause the non-executed statement
 691                                    become executed -- memory accesses, ... */
 692     MOVE_POSSIBLE               /* Unlimited movement.  */
 693   };
 694 extern enum move_pos movement_possibility (tree);
 695
 696 /* In tree-flow-inline.h  */
 697 static inline bool is_call_clobbered (tree);
 698 static inline void mark_call_clobbered (tree);
 699 static inline void set_is_used (tree);
 700 static inline bool unmodifiable_var_p (tree);
 701
 702 /* In tree-eh.c  */
 703 extern void make_eh_edges (tree);
 704 extern bool tree_could_trap_p (tree);
 705 extern bool tree_could_throw_p (tree);
 706 extern bool tree_can_throw_internal (tree);
 707 extern bool tree_can_throw_external (tree);
 708 extern int lookup_stmt_eh_region (tree);
 709 extern void add_stmt_to_eh_region (tree, int);
 710 extern bool remove_stmt_from_eh_region (tree);
 711 extern bool maybe_clean_or_replace_eh_stmt (tree, tree);
 712
 713 /* In tree-ssa-pre.c  */
 714 void add_to_value (tree, tree);
 715 void debug_value_expressions (tree);
 716 void print_value_expressions (FILE *, tree);
 717
 718
 719 /* In tree-vn.c  */
 720 bool expressions_equal_p (tree, tree);
 721 tree get_value_handle (tree);
 722 hashval_t vn_compute (tree, hashval_t, tree);
 723 tree vn_lookup_or_add (tree, tree);
 724 void vn_add (tree, tree, tree);
 725 tree vn_lookup (tree, tree);
 726 void vn_init (void);
 727 void vn_delete (void);
 728
 729 /* In tree-ssa-sink.c  */
 730 bool is_hidden_global_store (tree);
 731
 732 /* In tree-sra.c  */
 733 void insert_edge_copies (tree, basic_block);
 734
 735 /* In tree-loop-linear.c  */
 736 extern void linear_transform_loops (struct loops *);
 737
 738 /* In tree-ssa-loop-ivopts.c  */
 739 bool expr_invariant_in_loop_p (struct loop *, tree);
 740 bool multiplier_allowed_in_address_p (HOST_WIDE_INT);
 741 unsigned multiply_by_cost (HOST_WIDE_INT, enum machine_mode);
 742
 743 /* In tree-ssa-threadupdate.c.  */
 744 extern bool thread_through_all_blocks (bitmap);
 745
 746 /* In gimplify.c  */
 747 tree force_gimple_operand (tree, tree *, bool, tree);
 748 tree force_gimple_operand_bsi (block_stmt_iterator *, tree, bool, tree);
 749
 750 /* In tree-ssa-address.c  */
 751
 752 /* Affine combination of trees.  We keep track of at most MAX_AFF_ELTS elements
 753    to make things simpler; this is sufficient in most cases.  */
 754
 755 #define MAX_AFF_ELTS 8
 756
 757 struct affine_tree_combination
 758 {
 759   /* Type of the result of the combination.  */
 760   tree type;
 761
 762   /* Mask modulo that the operations are performed.  */
 763   unsigned HOST_WIDE_INT mask;
 764
 765   /* Constant offset.  */
 766   unsigned HOST_WIDE_INT offset;
 767
 768   /* Number of elements of the combination.  */
 769   unsigned n;
 770
 771   /* Elements and their coefficients.  */
 772   tree elts[MAX_AFF_ELTS];
 773   unsigned HOST_WIDE_INT coefs[MAX_AFF_ELTS];
 774
 775   /* Remainder of the expression.  */
 776   tree rest;
 777 };
 778
 779 /* Description of a memory address.  */
 780
 781 struct mem_address
 782 {
 783   tree symbol, base, index, step, offset;
 784 };
 785
 786 tree create_mem_ref (block_stmt_iterator *, tree,
 787                      struct affine_tree_combination *);
 788 rtx addr_for_mem_ref (struct mem_address *, bool);
 789 void get_address_description (tree, struct mem_address *);
 790 tree maybe_fold_tmr (tree);
 791
 792 #include "tree-flow-inline.h"
 793
 794 #endif /* _TREE_FLOW_H  */