gcc/tree-flow.h

   1 /* Data and Control Flow Analysis for Trees.
   2    Copyright (C) 2001, 2003, 2004, 2005 Free Software Foundation, Inc.
   3    Contributed by Diego Novillo <dnovillo@redhat.com>
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 GCC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING.  If not, write to
  19 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
  20 Boston, MA 02110-1301, USA.  */
  21
  22 #ifndef _TREE_FLOW_H
  23 #define _TREE_FLOW_H 1
  24
  25 #include "bitmap.h"
  26 #include "hard-reg-set.h"
  27 #include "basic-block.h"
  28 #include "hashtab.h"
  29 #include "tree-gimple.h"
  30 #include "tree-ssa-operands.h"
  31 #include "cgraph.h"
  32 #include "ipa-reference.h"
  33
  34 /* Forward declare structures for the garbage collector GTY markers.  */
  35 #ifndef GCC_BASIC_BLOCK_H
  36 struct edge_def;
  37 typedef struct edge_def *edge;
  38 struct basic_block_def;
  39 typedef struct basic_block_def *basic_block;
  40 #endif
  41
  42 /* True if the code is in ssa form.  */
  43 extern bool in_ssa_p;
  44
  45 typedef struct
  46 {
  47   htab_t htab;
  48   PTR *slot;
  49   PTR *limit;
  50 } htab_iterator;
  51
  52 /* Iterate through the elements of hashtable HTAB, using htab_iterator ITER,
  53    storing each element in RESULT, which is of type TYPE.  */
  54 #define FOR_EACH_HTAB_ELEMENT(HTAB, RESULT, TYPE, ITER) \
  55   for (RESULT = (TYPE) first_htab_element (&(ITER), (HTAB)); \
  56         !end_htab_p (&(ITER)); \
  57         RESULT = (TYPE) next_htab_element (&(ITER)))
  58
  59 /*---------------------------------------------------------------------------
  60                       Attributes for SSA_NAMEs.
  61
  62   NOTE: These structures are stored in struct tree_ssa_name
  63   but are only used by the tree optimizers, so it makes better sense
  64   to declare them here to avoid recompiling unrelated files when
  65   making changes.
  66 ---------------------------------------------------------------------------*/
  67
  68 /* Aliasing information for SSA_NAMEs representing pointer variables.  */
  69 struct ptr_info_def GTY(())
  70 {
  71   /* Nonzero if points-to analysis couldn't determine where this pointer
  72      is pointing to.  */
  73   unsigned int pt_anything : 1;
  74
  75   /* Nonzero if the value of this pointer escapes the current function.  */
  76   unsigned int value_escapes_p : 1;
  77
  78   /* Nonzero if this pointer is dereferenced.  */
  79   unsigned int is_dereferenced : 1;
  80
  81   /* Nonzero if this pointer points to a global variable.  */
  82   unsigned int pt_global_mem : 1;
  83
  84   /* Nonzero if this pointer points to NULL.  */
  85   unsigned int pt_null : 1;
  86
  87   /* Set of variables that this pointer may point to.  */
  88   bitmap pt_vars;
  89
  90   /* If this pointer has been dereferenced, and points-to information is
  91      more precise than type-based aliasing, indirect references to this
  92      pointer will be represented by this memory tag, instead of the type
  93      tag computed by TBAA.  */
  94   tree name_mem_tag;
  95
  96   /* Mask of reasons this pointer's value escapes the function  */
  97   unsigned int escape_mask;
  98 };
  99
 100
 101 /*---------------------------------------------------------------------------
 102                    Tree annotations stored in tree_common.ann
 103 ---------------------------------------------------------------------------*/
 104 enum tree_ann_type { TREE_ANN_COMMON, VAR_ANN, FUNCTION_ANN, STMT_ANN };
 105
 106 struct tree_ann_common_d GTY(())
 107 {
 108   /* Annotation type.  */
 109   enum tree_ann_type type;
 110
 111  /* Auxiliary info specific to a pass.  At all times, this
 112     should either point to valid data or be NULL.  */
 113   PTR GTY ((skip (""))) aux;
 114
 115   /* The value handle for this expression.  Used by GVN-PRE.  */
 116   tree GTY((skip)) value_handle;
 117 };
 118
 119 /* It is advantageous to avoid things like life analysis for variables which
 120    do not need PHI nodes.  This enum describes whether or not a particular
 121    variable may need a PHI node.  */
 122
 123 enum need_phi_state {
 124   /* This is the default.  If we are still in this state after finding
 125      all the definition and use sites, then we will assume the variable
 126      needs PHI nodes.  This is probably an overly conservative assumption.  */
 127   NEED_PHI_STATE_UNKNOWN,
 128
 129   /* This state indicates that we have seen one or more sets of the
 130      variable in a single basic block and that the sets dominate all
 131      uses seen so far.  If after finding all definition and use sites
 132      we are still in this state, then the variable does not need any
 133      PHI nodes.  */
 134   NEED_PHI_STATE_NO,
 135
 136   /* This state indicates that we have either seen multiple definitions of
 137      the variable in multiple blocks, or that we encountered a use in a
 138      block that was not dominated by the block containing the set(s) of
 139      this variable.  This variable is assumed to need PHI nodes.  */
 140   NEED_PHI_STATE_MAYBE
 141 };
 142
 143 struct subvar;
 144 typedef struct subvar *subvar_t;
 145
 146 /* This structure represents a fake sub-variable for a structure field.  */
 147 struct subvar GTY(())
 148 {
 149   /* Fake variable.  */
 150   tree var;
 151
 152   /* Next subvar for this structure.  */
 153   subvar_t next;
 154 };
 155
 156 struct var_ann_d GTY(())
 157 {
 158   struct tree_ann_common_d common;
 159
 160   /* Used by the out of SSA pass to determine whether this variable has
 161      been seen yet or not.  */
 162   unsigned out_of_ssa_tag : 1;
 163
 164   /* Used when building root_var structures in tree_ssa_live.[ch].  */
 165   unsigned root_var_processed : 1;
 166
 167   /* Nonzero if this variable is in the alias set of another variable.  */
 168   unsigned is_aliased : 1;
 169
 170   /* Nonzero if this variable was used after SSA optimizations were
 171      applied.  We set this when translating out of SSA form.  */
 172   unsigned used : 1;
 173
 174   /* This field indicates whether or not the variable may need PHI nodes.
 175      See the enum's definition for more detailed information about the
 176      states.  */
 177   ENUM_BITFIELD (need_phi_state) need_phi_state : 2;
 178
 179   /* Used during operand processing to determine if this variable is already
 180      in the vuse list.  */
 181   unsigned in_vuse_list : 1;
 182
 183   /* Used during operand processing to determine if this variable is already
 184      in the v_may_def list.  */
 185   unsigned in_v_may_def_list : 1;
 186
 187   /* An artificial variable representing the memory location pointed-to by
 188      all the pointer symbols that flow-insensitive alias analysis
 189      (mostly type-based) considers to be aliased.  If the variable is
 190      not a pointer or if it is never dereferenced, this must be NULL.  */
 191   tree symbol_mem_tag;
 192
 193   /* Variables that may alias this variable.  */
 194   VEC(tree, gc) *may_aliases;
 195
 196   /* Used when going out of SSA form to indicate which partition this
 197      variable represents storage for.  */
 198   unsigned partition;
 199
 200   /* Used by the root-var object in tree-ssa-live.[ch].  */
 201   unsigned root_index;
 202
 203   /* During into-ssa and the dominator optimizer, this field holds the
 204      current version of this variable (an SSA_NAME).  */
 205   tree current_def;
 206
 207   /* If this variable is a structure, this fields holds a list of
 208      symbols representing each of the fields of the structure.  */
 209   subvar_t subvars;
 210
 211   /* Mask of values saying the reasons why this variable has escaped
 212      the function.  */
 213   unsigned int escape_mask;
 214 };
 215
 216 struct function_ann_d GTY(())
 217 {
 218   struct tree_ann_common_d common;
 219
 220   /* Pointer to the structure that contains the sets of global
 221      variables modified by function calls.  This field is only used
 222      for FUNCTION_DECLs.  */
 223   ipa_reference_vars_info_t GTY ((skip)) reference_vars_info;
 224 };
 225
 226 typedef struct immediate_use_iterator_d
 227 {
 228   /* This is the current use the iterator is processing.  */
 229   ssa_use_operand_t *imm_use;
 230   /* This marks the last use in the list (use node from SSA_NAME)  */
 231   ssa_use_operand_t *end_p;
 232   /* This node is inserted and used to mark the end of the uses for a stmt.  */
 233   ssa_use_operand_t iter_node;
 234   /* This is the next ssa_name to visit.  IMM_USE may get removed before
 235      the next one is traversed to, so it must be cached early.  */
 236   ssa_use_operand_t *next_imm_name;
 237 } imm_use_iterator;
 238
 239
 240 /* Use this iterator when simply looking at stmts.  Adding, deleting or
 241    modifying stmts will cause this iterator to malfunction.  */
 242
 243 #define FOR_EACH_IMM_USE_FAST(DEST, ITER, SSAVAR)                       \
 244   for ((DEST) = first_readonly_imm_use (&(ITER), (SSAVAR));     \
 245        !end_readonly_imm_use_p (&(ITER));                       \
 246        (DEST) = next_readonly_imm_use (&(ITER)))
 247
 248 /* Use this iterator to visit each stmt which has a use of SSAVAR.  */
 249
 250 #define FOR_EACH_IMM_USE_STMT(STMT, ITER, SSAVAR)               \
 251   for ((STMT) = first_imm_use_stmt (&(ITER), (SSAVAR));         \
 252        !end_imm_use_stmt_p (&(ITER));                           \
 253        (STMT) = next_imm_use_stmt (&(ITER)))
 254
 255 /* Use this to terminate the FOR_EACH_IMM_USE_STMT loop early.  Failure to
 256    do so will result in leaving a iterator marker node in the immediate
 257    use list, and nothing good will come from that.   */
 258 #define BREAK_FROM_IMM_USE_STMT(ITER)                           \
 259    {                                                            \
 260      end_imm_use_stmt_traverse (&(ITER));                       \
 261      break;                                                     \
 262    }
 263
 264
 265 /* Use this iterator in combination with FOR_EACH_IMM_USE_STMT to
 266    get access to each occurrence of ssavar on the stmt returned by
 267    that iterator..  for instance:
 268
 269      FOR_EACH_IMM_USE_STMT (stmt, iter, var)
 270        {
 271          FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
 272            {
 273              SET_USE (use_p) = blah;
 274            }
 275          update_stmt (stmt);
 276        }                                                         */
 277
 278 #define FOR_EACH_IMM_USE_ON_STMT(DEST, ITER)                    \
 279   for ((DEST) = first_imm_use_on_stmt (&(ITER));                \
 280        !end_imm_use_on_stmt_p (&(ITER));                        \
 281        (DEST) = next_imm_use_on_stmt (&(ITER)))
 282
 283
 284
 285 struct stmt_ann_d GTY(())
 286 {
 287   struct tree_ann_common_d common;
 288
 289   /* Nonzero if the statement has been modified (meaning that the operands
 290      need to be scanned again).  */
 291   unsigned modified : 1;
 292
 293   /* Nonzero if the statement makes references to volatile storage.  */
 294   unsigned has_volatile_ops : 1;
 295
 296   /* Nonzero if the statement makes a function call that may clobber global
 297      and local addressable variables.  */
 298   unsigned makes_clobbering_call : 1;
 299
 300   /* Basic block that contains this statement.  */
 301   basic_block bb;
 302
 303   /* Operand cache for stmt.  */
 304   struct stmt_operands_d GTY ((skip (""))) operands;
 305
 306   /* Set of variables that have had their address taken in the statement.  */
 307   bitmap addresses_taken;
 308
 309   /* Unique identifier for this statement.  These ID's are to be created
 310      by each pass on an as-needed basis in any order convenient for the
 311      pass which needs statement UIDs.  */
 312   unsigned int uid;
 313
 314   /* Linked list of histograms for value-based profiling.  This is really a
 315      struct histogram_value*.  We use void* to avoid having to export that
 316      everywhere, and to avoid having to put it in GC memory.  */
 317
 318   void * GTY ((skip (""))) histograms;
 319 };
 320
 321 union tree_ann_d GTY((desc ("ann_type ((tree_ann_t)&%h)")))
 322 {
 323   struct tree_ann_common_d GTY((tag ("TREE_ANN_COMMON"))) common;
 324   struct var_ann_d GTY((tag ("VAR_ANN"))) vdecl;
 325   struct function_ann_d GTY((tag ("FUNCTION_ANN"))) fdecl;
 326   struct stmt_ann_d GTY((tag ("STMT_ANN"))) stmt;
 327 };
 328
 329 extern GTY(()) VEC(tree,gc) *modified_noreturn_calls;
 330
 331 typedef union tree_ann_d *tree_ann_t;
 332 typedef struct var_ann_d *var_ann_t;
 333 typedef struct function_ann_d *function_ann_t;
 334 typedef struct stmt_ann_d *stmt_ann_t;
 335 typedef struct tree_ann_common_d *tree_ann_common_t;
 336
 337 static inline tree_ann_common_t tree_common_ann (tree);
 338 static inline tree_ann_common_t get_tree_common_ann (tree);
 339 static inline var_ann_t var_ann (tree);
 340 static inline var_ann_t get_var_ann (tree);
 341 static inline function_ann_t function_ann (tree);
 342 static inline function_ann_t get_function_ann (tree);
 343 static inline stmt_ann_t stmt_ann (tree);
 344 static inline stmt_ann_t get_stmt_ann (tree);
 345 static inline enum tree_ann_type ann_type (tree_ann_t);
 346 static inline basic_block bb_for_stmt (tree);
 347 extern void set_bb_for_stmt (tree, basic_block);
 348 static inline bool noreturn_call_p (tree);
 349 static inline void update_stmt (tree);
 350 static inline bool stmt_modified_p (tree);
 351 static inline VEC(tree, gc) *may_aliases (tree);
 352 static inline int get_lineno (tree);
 353 static inline const char *get_filename (tree);
 354 static inline bool is_exec_stmt (tree);
 355 static inline bool is_label_stmt (tree);
 356 static inline bitmap addresses_taken (tree);
 357
 358 /*---------------------------------------------------------------------------
 359                   Structure representing predictions in tree level.
 360 ---------------------------------------------------------------------------*/
 361 struct edge_prediction GTY((chain_next ("%h.ep_next")))
 362 {
 363   struct edge_prediction *ep_next;
 364   edge ep_edge;
 365   enum br_predictor ep_predictor;
 366   int ep_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 /* Default defs for undefined symbols. */
 425 extern GTY((param_is (struct int_tree_map))) htab_t default_defs;
 426
 427 extern tree referenced_var_lookup (unsigned int);
 428 #define num_referenced_vars htab_elements (referenced_vars)
 429 #define referenced_var(i) referenced_var_lookup (i)
 430
 431 /* Array of all SSA_NAMEs used in the function.  */
 432 extern GTY(()) VEC(tree,gc) *ssa_names;
 433
 434 #define num_ssa_names (VEC_length (tree, ssa_names))
 435 #define ssa_name(i) (VEC_index (tree, ssa_names, (i)))
 436
 437 /* Artificial variable used to model the effects of function calls.  */
 438 extern GTY(()) tree global_var;
 439
 440 /* Call clobbered variables in the function.  If bit I is set, then
 441    REFERENCED_VARS (I) is call-clobbered.  */
 442 extern bitmap call_clobbered_vars;
 443
 444 /* Addressable variables in the function.  If bit I is set, then
 445    REFERENCED_VARS (I) has had its address taken.  */
 446 extern bitmap addressable_vars;
 447
 448 /* 'true' after aliases have been computed (see compute_may_aliases).  */
 449 extern bool aliases_computed_p;
 450
 451 /* Macros for showing usage statistics.  */
 452 #define SCALE(x) ((unsigned long) ((x) < 1024*10        \
 453                   ? (x)                                 \
 454                   : ((x) < 1024*1024*10                 \
 455                      ? (x) / 1024                       \
 456                      : (x) / (1024*1024))))
 457
 458 #define LABEL(x) ((x) < 1024*10 ? 'b' : ((x) < 1024*1024*10 ? 'k' : 'M'))
 459
 460 #define PERCENT(x,y) ((float)(x) * 100.0 / (float)(y))
 461
 462 /*---------------------------------------------------------------------------
 463                               Block iterators
 464 ---------------------------------------------------------------------------*/
 465
 466 typedef struct {
 467   tree_stmt_iterator tsi;
 468   basic_block bb;
 469 } block_stmt_iterator;
 470
 471 static inline block_stmt_iterator bsi_start (basic_block);
 472 static inline block_stmt_iterator bsi_last (basic_block);
 473 static inline block_stmt_iterator bsi_after_labels (basic_block);
 474 block_stmt_iterator bsi_for_stmt (tree);
 475 static inline bool bsi_end_p (block_stmt_iterator);
 476 static inline void bsi_next (block_stmt_iterator *);
 477 static inline void bsi_prev (block_stmt_iterator *);
 478 static inline tree bsi_stmt (block_stmt_iterator);
 479 static inline tree * bsi_stmt_ptr (block_stmt_iterator);
 480
 481 extern void bsi_remove (block_stmt_iterator *, bool);
 482 extern void bsi_move_before (block_stmt_iterator *, block_stmt_iterator *);
 483 extern void bsi_move_after (block_stmt_iterator *, block_stmt_iterator *);
 484 extern void bsi_move_to_bb_end (block_stmt_iterator *, basic_block);
 485
 486 enum bsi_iterator_update
 487 {
 488   /* Note that these are intentionally in the same order as TSI_FOO.  They
 489      mean exactly the same as their TSI_* counterparts.  */
 490   BSI_NEW_STMT,
 491   BSI_SAME_STMT,
 492   BSI_CHAIN_START,
 493   BSI_CHAIN_END,
 494   BSI_CONTINUE_LINKING
 495 };
 496
 497 extern void bsi_insert_before (block_stmt_iterator *, tree,
 498                                enum bsi_iterator_update);
 499 extern void bsi_insert_after (block_stmt_iterator *, tree,
 500                               enum bsi_iterator_update);
 501
 502 extern void bsi_replace (const block_stmt_iterator *, tree, bool);
 503
 504 /*---------------------------------------------------------------------------
 505                               OpenMP Region Tree
 506 ---------------------------------------------------------------------------*/
 507
 508 /* Parallel region information.  Every parallel and workshare
 509    directive is enclosed between two markers, the OMP_* directive
 510    and a corresponding OMP_RETURN statement.  */
 511
 512 struct omp_region
 513 {
 514   /* The enclosing region.  */
 515   struct omp_region *outer;
 516
 517   /* First child region.  */
 518   struct omp_region *inner;
 519
 520   /* Next peer region.  */
 521   struct omp_region *next;
 522
 523   /* Block containing the omp directive as its last stmt.  */
 524   basic_block entry;
 525
 526   /* Block containing the OMP_RETURN as its last stmt.  */
 527   basic_block exit;
 528
 529   /* Block containing the OMP_CONTINUE as its last stmt.  */
 530   basic_block cont;
 531
 532   /* If this is a combined parallel+workshare region, this is a list
 533      of additional arguments needed by the combined parallel+workshare
 534      library call.  */
 535   tree ws_args;
 536
 537   /* The code for the omp directive of this region.  */
 538   enum tree_code type;
 539
 540   /* Schedule kind, only used for OMP_FOR type regions.  */
 541   enum omp_clause_schedule_kind sched_kind;
 542
 543   /* True if this is a combined parallel+workshare region.  */
 544   bool is_combined_parallel;
 545 };
 546
 547 extern struct omp_region *root_omp_region;
 548 extern struct omp_region *new_omp_region (basic_block, enum tree_code,
 549                                           struct omp_region *);
 550 extern void free_omp_regions (void);
 551
 552 /*---------------------------------------------------------------------------
 553                               Function prototypes
 554 ---------------------------------------------------------------------------*/
 555 /* In tree-cfg.c  */
 556
 557 /* Location to track pending stmt for edge insertion.  */
 558 #define PENDING_STMT(e) ((e)->insns.t)
 559
 560 extern void delete_tree_cfg_annotations (void);
 561 extern void disband_implicit_edges (void);
 562 extern bool stmt_ends_bb_p (tree);
 563 extern bool is_ctrl_stmt (tree);
 564 extern bool is_ctrl_altering_stmt (tree);
 565 extern bool computed_goto_p (tree);
 566 extern bool simple_goto_p (tree);
 567 extern bool tree_can_make_abnormal_goto (tree);
 568 extern basic_block single_noncomplex_succ (basic_block bb);
 569 extern void tree_dump_bb (basic_block, FILE *, int);
 570 extern void debug_tree_bb (basic_block);
 571 extern basic_block debug_tree_bb_n (int);
 572 extern void dump_tree_cfg (FILE *, int);
 573 extern void debug_tree_cfg (int);
 574 extern void dump_cfg_stats (FILE *);
 575 extern void debug_cfg_stats (void);
 576 extern void debug_loop_ir (void);
 577 extern void print_loop_ir (FILE *);
 578 extern void cleanup_dead_labels (void);
 579 extern void group_case_labels (void);
 580 extern tree first_stmt (basic_block);
 581 extern tree last_stmt (basic_block);
 582 extern tree *last_stmt_ptr (basic_block);
 583 extern tree last_and_only_stmt (basic_block);
 584 extern edge find_taken_edge (basic_block, tree);
 585 extern basic_block label_to_block_fn (struct function *, tree);
 586 #define label_to_block(t) (label_to_block_fn (cfun, t))
 587 extern void bsi_insert_on_edge (edge, tree);
 588 extern basic_block bsi_insert_on_edge_immediate (edge, tree);
 589 extern void bsi_commit_one_edge_insert (edge, basic_block *);
 590 extern void bsi_commit_edge_inserts (void);
 591 extern void notice_special_calls (tree);
 592 extern void clear_special_calls (void);
 593 extern void verify_stmts (void);
 594 extern tree tree_block_label (basic_block);
 595 extern void extract_true_false_edges_from_block (basic_block, edge *, edge *);
 596 extern bool tree_duplicate_sese_region (edge, edge, basic_block *, unsigned,
 597                                         basic_block *);
 598 extern void add_phi_args_after_copy_bb (basic_block);
 599 extern void add_phi_args_after_copy (basic_block *, unsigned);
 600 extern bool tree_purge_dead_abnormal_call_edges (basic_block);
 601 extern bool tree_purge_dead_eh_edges (basic_block);
 602 extern bool tree_purge_all_dead_eh_edges (bitmap);
 603 extern tree gimplify_val (block_stmt_iterator *, tree, tree);
 604 extern tree gimplify_build1 (block_stmt_iterator *, enum tree_code,
 605                              tree, tree);
 606 extern tree gimplify_build2 (block_stmt_iterator *, enum tree_code,
 607                              tree, tree, tree);
 608 extern tree gimplify_build3 (block_stmt_iterator *, enum tree_code,
 609                              tree, tree, tree, tree);
 610 extern void init_empty_tree_cfg (void);
 611 extern void fold_cond_expr_cond (void);
 612 extern void make_abnormal_goto_edges (basic_block, bool);
 613 extern void replace_uses_by (tree, tree);
 614 extern void start_recording_case_labels (void);
 615 extern void end_recording_case_labels (void);
 616 extern basic_block move_sese_region_to_fn (struct function *, basic_block,
 617                                            basic_block);
 618
 619 /* In tree-cfgcleanup.c  */
 620 extern bool cleanup_tree_cfg (void);
 621 extern void cleanup_tree_cfg_loop (void);
 622
 623 /* In tree-pretty-print.c.  */
 624 extern void dump_generic_bb (FILE *, basic_block, int, int);
 625
 626 /* In tree-dfa.c  */
 627 extern var_ann_t create_var_ann (tree);
 628 extern function_ann_t create_function_ann (tree);
 629 extern stmt_ann_t create_stmt_ann (tree);
 630 extern tree_ann_common_t create_tree_common_ann (tree);
 631 extern void dump_dfa_stats (FILE *);
 632 extern void debug_dfa_stats (void);
 633 extern void debug_referenced_vars (void);
 634 extern void dump_referenced_vars (FILE *);
 635 extern void dump_variable (FILE *, tree);
 636 extern void debug_variable (tree);
 637 extern void dump_subvars_for (FILE *, tree);
 638 extern void debug_subvars_for (tree);
 639 extern tree get_virtual_var (tree);
 640 extern void add_referenced_var (tree);
 641 extern void mark_new_vars_to_rename (tree);
 642 extern void find_new_referenced_vars (tree *);
 643
 644 extern tree make_rename_temp (tree, const char *);
 645 extern void set_default_def (tree, tree);
 646 extern tree default_def (tree);
 647 extern tree default_def_fn (struct function *, tree);
 648
 649 /* In tree-phinodes.c  */
 650 extern void reserve_phi_args_for_new_edge (basic_block);
 651 extern tree create_phi_node (tree, basic_block);
 652 extern void add_phi_arg (tree, tree, edge);
 653 extern void remove_phi_args (edge);
 654 extern void remove_phi_node (tree, tree);
 655 extern tree phi_reverse (tree);
 656
 657 /* In gimple-low.c  */
 658 extern void record_vars_into (tree, tree);
 659 extern void record_vars (tree);
 660 extern bool block_may_fallthru (tree);
 661
 662 /* In tree-ssa-alias.c  */
 663 extern void dump_may_aliases_for (FILE *, tree);
 664 extern void debug_may_aliases_for (tree);
 665 extern void dump_alias_info (FILE *);
 666 extern void debug_alias_info (void);
 667 extern void dump_points_to_info (FILE *);
 668 extern void debug_points_to_info (void);
 669 extern void dump_points_to_info_for (FILE *, tree);
 670 extern void debug_points_to_info_for (tree);
 671 extern bool may_be_aliased (tree);
 672 extern bool is_aliased_with (tree, tree);
 673 extern struct ptr_info_def *get_ptr_info (tree);
 674 extern void new_type_alias (tree, tree, tree);
 675 extern void count_uses_and_derefs (tree, tree, unsigned *, unsigned *, bool *);
 676 static inline subvar_t get_subvars_for_var (tree);
 677 static inline tree get_subvar_at (tree, unsigned HOST_WIDE_INT);
 678 static inline bool ref_contains_array_ref (tree);
 679 static inline bool array_ref_contains_indirect_ref (tree);
 680 extern tree get_ref_base_and_extent (tree, HOST_WIDE_INT *,
 681                                      HOST_WIDE_INT *, HOST_WIDE_INT *);
 682 static inline bool var_can_have_subvars (tree);
 683 static inline bool overlap_subvar (unsigned HOST_WIDE_INT,
 684                                    unsigned HOST_WIDE_INT,
 685                                    tree, bool *);
 686
 687 /* Call-back function for walk_use_def_chains().  At each reaching
 688    definition, a function with this prototype is called.  */
 689 typedef bool (*walk_use_def_chains_fn) (tree, tree, void *);
 690
 691
 692 /* In tree-ssa.c  */
 693 extern void init_tree_ssa (void);
 694 extern edge ssa_redirect_edge (edge, basic_block);
 695 extern void flush_pending_stmts (edge);
 696 extern bool tree_ssa_useless_type_conversion (tree);
 697 extern bool tree_ssa_useless_type_conversion_1 (tree, tree);
 698 extern void verify_ssa (bool);
 699 extern void delete_tree_ssa (void);
 700 extern void register_new_def (tree, VEC(tree,heap) **);
 701 extern void walk_use_def_chains (tree, walk_use_def_chains_fn, void *, bool);
 702 extern bool stmt_references_memory_p (tree);
 703
 704 /* In tree-into-ssa.c  */
 705 void update_ssa (unsigned);
 706 void delete_update_ssa (void);
 707 void register_new_name_mapping (tree, tree);
 708 tree create_new_def_for (tree, tree, def_operand_p);
 709 bool need_ssa_update_p (void);
 710 bool name_registered_for_update_p (tree);
 711 bitmap ssa_names_to_replace (void);
 712 void release_ssa_name_after_update_ssa (tree name);
 713 void compute_global_livein (bitmap, bitmap);
 714 tree duplicate_ssa_name (tree, tree);
 715 void mark_sym_for_renaming (tree);
 716 void mark_set_for_renaming (bitmap);
 717 tree get_current_def (tree);
 718 void set_current_def (tree, tree);
 719
 720 /* In tree-ssa-ccp.c  */
 721 bool fold_stmt (tree *);
 722 bool fold_stmt_inplace (tree);
 723 tree widen_bitfield (tree, tree, tree);
 724
 725 /* In tree-vrp.c  */
 726 tree vrp_evaluate_conditional (tree, bool);
 727 void simplify_stmt_using_ranges (tree);
 728
 729 /* In tree-ssa-dom.c  */
 730 extern void dump_dominator_optimization_stats (FILE *);
 731 extern void debug_dominator_optimization_stats (void);
 732 int loop_depth_of_name (tree);
 733
 734 /* In tree-ssa-copy.c  */
 735 extern void merge_alias_info (tree, tree);
 736 extern void propagate_value (use_operand_p, tree);
 737 extern void propagate_tree_value (tree *, tree);
 738 extern void replace_exp (use_operand_p, tree);
 739 extern bool may_propagate_copy (tree, tree);
 740 extern bool may_propagate_copy_into_asm (tree);
 741
 742 /* Affine iv.  */
 743
 744 typedef struct
 745 {
 746   /* Iv = BASE + STEP * i.  */
 747   tree base, step;
 748
 749   /* True if this iv does not overflow.  */
 750   bool no_overflow;
 751 } affine_iv;
 752
 753 /* Description of number of iterations of a loop.  All the expressions inside
 754    the structure can be evaluated at the end of the loop's preheader
 755    (and due to ssa form, also anywhere inside the body of the loop).  */
 756
 757 struct tree_niter_desc
 758 {
 759   tree assumptions;     /* The boolean expression.  If this expression evaluates
 760                            to false, then the other fields in this structure
 761                            should not be used; there is no guarantee that they
 762                            will be correct.  */
 763   tree may_be_zero;     /* The boolean expression.  If it evaluates to true,
 764                            the loop will exit in the first iteration (i.e.
 765                            its latch will not be executed), even if the niter
 766                            field says otherwise.  */
 767   tree niter;           /* The expression giving the number of iterations of
 768                            a loop (provided that assumptions == true and
 769                            may_be_zero == false), more precisely the number
 770                            of executions of the latch of the loop.  */
 771   tree additional_info; /* The boolean expression.  Sometimes we use additional
 772                            knowledge to simplify the other expressions
 773                            contained in this structure (for example the
 774                            knowledge about value ranges of operands on entry to
 775                            the loop).  If this is a case, conjunction of such
 776                            condition is stored in this field, so that we do not
 777                            lose the information: for example if may_be_zero
 778                            is (n <= 0) and niter is (unsigned) n, we know
 779                            that the number of iterations is at most
 780                            MAX_SIGNED_INT.  However if the (n <= 0) assumption
 781                            is eliminated (by looking at the guard on entry of
 782                            the loop), then the information would be lost.  */
 783
 784   /* The simplified shape of the exit condition.  The loop exits if
 785      CONTROL CMP BOUND is false, where CMP is one of NE_EXPR,
 786      LT_EXPR, or GT_EXPR, and step of CONTROL is positive if CMP is
 787      LE_EXPR and negative if CMP is GE_EXPR.  This information is used
 788      by loop unrolling.  */
 789   affine_iv control;
 790   tree bound;
 791   enum tree_code cmp;
 792 };
 793
 794 /* In tree-vectorizer.c */
 795 void vectorize_loops (struct loops *);
 796 extern bool vect_can_force_dr_alignment_p (tree, unsigned int);
 797 extern tree get_vectype_for_scalar_type (tree);
 798
 799 /* In tree-ssa-phiopt.c */
 800 bool empty_block_p (basic_block);
 801
 802 /* In tree-ssa-loop*.c  */
 803
 804 void tree_ssa_lim (struct loops *);
 805 unsigned int tree_ssa_unswitch_loops (struct loops *);
 806 unsigned int canonicalize_induction_variables (struct loops *);
 807 unsigned int tree_unroll_loops_completely (struct loops *, bool);
 808 unsigned int tree_ssa_prefetch_arrays (struct loops *);
 809 unsigned int remove_empty_loops (struct loops *);
 810 void tree_ssa_iv_optimize (struct loops *);
 811
 812 bool number_of_iterations_exit (struct loop *, edge,
 813                                 struct tree_niter_desc *niter, bool);
 814 tree find_loop_niter (struct loop *, edge *);
 815 tree loop_niter_by_eval (struct loop *, edge);
 816 tree find_loop_niter_by_eval (struct loop *, edge *);
 817 void estimate_numbers_of_iterations (struct loops *);
 818 bool scev_probably_wraps_p (tree, tree, tree, struct loop *, bool);
 819 bool convert_affine_scev (struct loop *, tree, tree *, tree *, tree, bool);
 820
 821 bool nowrap_type_p (tree);
 822 enum ev_direction {EV_DIR_GROWS, EV_DIR_DECREASES, EV_DIR_UNKNOWN};
 823 enum ev_direction scev_direction (tree);
 824
 825 void free_numbers_of_iterations_estimates (struct loops *);
 826 void free_numbers_of_iterations_estimates_loop (struct loop *);
 827 void rewrite_into_loop_closed_ssa (bitmap, unsigned);
 828 void verify_loop_closed_ssa (void);
 829 void loop_commit_inserts (void);
 830 bool for_each_index (tree *, bool (*) (tree, tree *, void *), void *);
 831 void create_iv (tree, tree, tree, struct loop *, block_stmt_iterator *, bool,
 832                 tree *, tree *);
 833 void split_loop_exit_edge (edge);
 834 unsigned force_expr_to_var_cost (tree);
 835 basic_block bsi_insert_on_edge_immediate_loop (edge, tree);
 836 void standard_iv_increment_position (struct loop *, block_stmt_iterator *,
 837                                      bool *);
 838 basic_block ip_end_pos (struct loop *);
 839 basic_block ip_normal_pos (struct loop *);
 840 bool tree_duplicate_loop_to_header_edge (struct loop *, edge, struct loops *,
 841                                          unsigned int, sbitmap,
 842                                          edge, edge *,
 843                                          unsigned int *, int);
 844 struct loop *tree_ssa_loop_version (struct loops *, struct loop *, tree,
 845                                     basic_block *);
 846 tree expand_simple_operations (tree);
 847 void substitute_in_loop_info (struct loop *, tree, tree);
 848 edge single_dom_exit (struct loop *);
 849 bool can_unroll_loop_p (struct loop *loop, unsigned factor,
 850                         struct tree_niter_desc *niter);
 851 void tree_unroll_loop (struct loops *, struct loop *, unsigned,
 852                        edge, struct tree_niter_desc *);
 853 bool contains_abnormal_ssa_name_p (tree);
 854
 855 /* In tree-ssa-threadedge.c */
 856 extern bool potentially_threadable_block (basic_block);
 857 extern void thread_across_edge (tree, edge, bool,
 858                                 VEC(tree, heap) **, tree (*) (tree));
 859
 860 /* In tree-ssa-loop-im.c  */
 861 /* The possibilities of statement movement.  */
 862
 863 enum move_pos
 864   {
 865     MOVE_IMPOSSIBLE,            /* No movement -- side effect expression.  */
 866     MOVE_PRESERVE_EXECUTION,    /* Must not cause the non-executed statement
 867                                    become executed -- memory accesses, ... */
 868     MOVE_POSSIBLE               /* Unlimited movement.  */
 869   };
 870 extern enum move_pos movement_possibility (tree);
 871
 872 /* The reasons a variable may escape a function.  */
 873 enum escape_type
 874   {
 875     NO_ESCAPE = 0, /* Doesn't escape.  */
 876     ESCAPE_STORED_IN_GLOBAL = 1 << 1,
 877     ESCAPE_TO_ASM = 1 << 2,  /* Passed by address to an assembly
 878                                 statement.  */
 879     ESCAPE_TO_CALL = 1 << 3,  /* Escapes to a function call.  */
 880     ESCAPE_BAD_CAST = 1 << 4, /* Cast from pointer to integer */
 881     ESCAPE_TO_RETURN = 1 << 5, /* Returned from function.  */
 882     ESCAPE_TO_PURE_CONST = 1 << 6, /* Escapes to a pure or constant
 883                                       function call.  */
 884     ESCAPE_IS_GLOBAL = 1 << 7,  /* Is a global variable.  */
 885     ESCAPE_IS_PARM = 1 << 8, /* Is an incoming function parameter.  */
 886     ESCAPE_UNKNOWN = 1 << 9 /* We believe it escapes for some reason
 887                                not enumerated above.  */
 888   };
 889
 890 /* In tree-flow-inline.h  */
 891 static inline bool is_call_clobbered (tree);
 892 static inline void mark_call_clobbered (tree, unsigned int);
 893 static inline void set_is_used (tree);
 894 static inline bool unmodifiable_var_p (tree);
 895
 896 /* In tree-eh.c  */
 897 extern void make_eh_edges (tree);
 898 extern bool tree_could_trap_p (tree);
 899 extern bool tree_could_throw_p (tree);
 900 extern bool tree_can_throw_internal (tree);
 901 extern bool tree_can_throw_external (tree);
 902 extern int lookup_stmt_eh_region (tree);
 903 extern void add_stmt_to_eh_region (tree, int);
 904 extern bool remove_stmt_from_eh_region (tree);
 905 extern bool maybe_clean_or_replace_eh_stmt (tree, tree);
 906
 907 /* In tree-ssa-pre.c  */
 908 void add_to_value (tree, tree);
 909 void debug_value_expressions (tree);
 910 void print_value_expressions (FILE *, tree);
 911
 912
 913 /* In tree-vn.c  */
 914 bool expressions_equal_p (tree, tree);
 915 tree get_value_handle (tree);
 916 hashval_t vn_compute (tree, hashval_t);
 917 void sort_vuses (VEC (tree, gc) *);
 918 tree vn_lookup_or_add (tree, tree);
 919 tree vn_lookup_or_add_with_vuses (tree, VEC (tree, gc) *);
 920 void vn_add (tree, tree);
 921 void vn_add_with_vuses (tree, tree, VEC (tree, gc) *);
 922 tree vn_lookup (tree, tree);
 923 tree vn_lookup_with_vuses (tree, VEC (tree, gc) *);
 924 void vn_init (void);
 925 void vn_delete (void);
 926
 927 /* In tree-ssa-sink.c  */
 928 bool is_hidden_global_store (tree);
 929
 930 /* In tree-sra.c  */
 931 void insert_edge_copies (tree, basic_block);
 932 void sra_insert_before (block_stmt_iterator *, tree);
 933 void sra_insert_after (block_stmt_iterator *, tree);
 934 void sra_init_cache (void);
 935 bool sra_type_can_be_decomposed_p (tree);
 936
 937 /* In tree-loop-linear.c  */
 938 extern void linear_transform_loops (struct loops *);
 939
 940 /* In tree-ssa-loop-ivopts.c  */
 941 bool expr_invariant_in_loop_p (struct loop *, tree);
 942 bool multiplier_allowed_in_address_p (HOST_WIDE_INT);
 943 unsigned multiply_by_cost (HOST_WIDE_INT, enum machine_mode);
 944
 945 /* In tree-ssa-threadupdate.c.  */
 946 extern bool thread_through_all_blocks (void);
 947 extern void register_jump_thread (edge, edge);
 948
 949 /* In gimplify.c  */
 950 tree force_gimple_operand (tree, tree *, bool, tree);
 951 tree force_gimple_operand_bsi (block_stmt_iterator *, tree, bool, tree);
 952
 953 /* In tree-ssa-structalias.c */
 954 bool find_what_p_points_to (tree);
 955
 956 /* In tree-ssa-live.c */
 957 extern void remove_unused_locals (void);
 958
 959 /* In tree-ssa-address.c  */
 960
 961 /* Affine combination of trees.  We keep track of at most MAX_AFF_ELTS elements
 962    to make things simpler; this is sufficient in most cases.  */
 963
 964 #define MAX_AFF_ELTS 8
 965
 966 struct affine_tree_combination
 967 {
 968   /* Type of the result of the combination.  */
 969   tree type;
 970
 971   /* Mask modulo that the operations are performed.  */
 972   unsigned HOST_WIDE_INT mask;
 973
 974   /* Constant offset.  */
 975   unsigned HOST_WIDE_INT offset;
 976
 977   /* Number of elements of the combination.  */
 978   unsigned n;
 979
 980   /* Elements and their coefficients.  */
 981   tree elts[MAX_AFF_ELTS];
 982   unsigned HOST_WIDE_INT coefs[MAX_AFF_ELTS];
 983
 984   /* Remainder of the expression.  */
 985   tree rest;
 986 };
 987
 988 /* Description of a memory address.  */
 989
 990 struct mem_address
 991 {
 992   tree symbol, base, index, step, offset;
 993 };
 994
 995 tree create_mem_ref (block_stmt_iterator *, tree,
 996                      struct affine_tree_combination *);
 997 rtx addr_for_mem_ref (struct mem_address *, bool);
 998 void get_address_description (tree, struct mem_address *);
 999 tree maybe_fold_tmr (tree);
1000
1001 /* This structure is simply used during pushing fields onto the fieldstack
1002    to track the offset of the field, since bitpos_of_field gives it relative
1003    to its immediate containing type, and we want it relative to the ultimate
1004    containing object.  */
1005
1006 struct fieldoff
1007 {
1008   tree type;
1009   tree size;
1010   tree decl;
1011   HOST_WIDE_INT offset;
1012 };
1013 typedef struct fieldoff fieldoff_s;
1014
1015 DEF_VEC_O(fieldoff_s);
1016 DEF_VEC_ALLOC_O(fieldoff_s,heap);
1017 int push_fields_onto_fieldstack (tree, VEC(fieldoff_s,heap) **,
1018                                  HOST_WIDE_INT, bool *);
1019 void sort_fieldstack (VEC(fieldoff_s,heap) *);
1020
1021 void init_alias_heapvars (void);
1022 void delete_alias_heapvars (void);
1023
1024 #include "tree-flow-inline.h"
1025
1026 void swap_tree_operands (tree, tree *, tree *);
1027
1028 extern void recalculate_used_alone (void);
1029 extern bool updating_used_alone;
1030 #endif /* _TREE_FLOW_H  */