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 /*---------------------------------------------------------------------------
  42                       Attributes for SSA_NAMEs.
  43
  44   NOTE: These structures are stored in struct tree_ssa_name
  45   but are only used by the tree optimizers, so it makes better sense
  46   to declare them here to avoid recompiling unrelated files when
  47   making changes.
  48 ---------------------------------------------------------------------------*/
  49
  50 /* Aliasing information for SSA_NAMEs representing pointer variables.  */
  51 struct ptr_info_def GTY(())
  52 {
  53   /* Nonzero if points-to analysis couldn't determine where this pointer
  54      is pointing to.  */
  55   unsigned int pt_anything : 1;
  56
  57   /* Nonzero if this pointer is the result of a call to malloc.  */
  58   unsigned int pt_malloc : 1;
  59
  60   /* Nonzero if the value of this pointer escapes the current function.  */
  61   unsigned int value_escapes_p : 1;
  62
  63   /* Nonzero if this pointer is dereferenced.  */
  64   unsigned int is_dereferenced : 1;
  65
  66   /* Nonzero if this pointer points to a global variable.  */
  67   unsigned int pt_global_mem : 1;
  68
  69   /* Nonzero if this pointer points to NULL.  */
  70   unsigned int pt_null : 1;
  71
  72   /* Set of variables that this pointer may point to.  */
  73   bitmap pt_vars;
  74
  75   /* If this pointer has been dereferenced, and points-to information is
  76      more precise than type-based aliasing, indirect references to this
  77      pointer will be represented by this memory tag, instead of the type
  78      tag computed by TBAA.  */
  79   tree name_mem_tag;
  80 };
  81
  82
  83 /*---------------------------------------------------------------------------
  84                    Tree annotations stored in tree_common.ann
  85 ---------------------------------------------------------------------------*/
  86 enum tree_ann_type { TREE_ANN_COMMON, VAR_ANN, STMT_ANN };
  87
  88 struct tree_ann_common_d GTY(())
  89 {
  90   /* Annotation type.  */
  91   enum tree_ann_type type;
  92
  93  /* Auxiliary info specific to a pass.  At all times, this
  94     should either point to valid data or be NULL.  */
  95   PTR GTY ((skip (""))) aux;
  96
  97   /* The value handle for this expression.  Used by GVN-PRE.  */
  98   tree GTY((skip)) value_handle;
  99 };
 100
 101 /* It is advantageous to avoid things like life analysis for variables which
 102    do not need PHI nodes.  This enum describes whether or not a particular
 103    variable may need a PHI node.  */
 104
 105 enum need_phi_state {
 106   /* This is the default.  If we are still in this state after finding
 107      all the definition and use sites, then we will assume the variable
 108      needs PHI nodes.  This is probably an overly conservative assumption.  */
 109   NEED_PHI_STATE_UNKNOWN,
 110
 111   /* This state indicates that we have seen one or more sets of the
 112      variable in a single basic block and that the sets dominate all
 113      uses seen so far.  If after finding all definition and use sites
 114      we are still in this state, then the variable does not need any
 115      PHI nodes.  */
 116   NEED_PHI_STATE_NO,
 117
 118   /* This state indicates that we have either seen multiple definitions of
 119      the variable in multiple blocks, or that we encountered a use in a
 120      block that was not dominated by the block containing the set(s) of
 121      this variable.  This variable is assumed to need PHI nodes.  */
 122   NEED_PHI_STATE_MAYBE
 123 };
 124
 125
 126 /* When computing aliasing information, we represent the memory pointed-to
 127    by pointers with artificial variables called "memory tags" (MT).  There
 128    are two kinds of tags: type and name.  Type tags (TMT) are used in
 129    type-based alias analysis, they represent all the pointed-to locations
 130    and variables of the same alias set class.  Name tags (NMT) are used in
 131    flow-sensitive points-to alias analysis, they represent the variables
 132    and memory locations pointed-to by a specific SSA_NAME pointer.  */
 133 enum mem_tag_kind {
 134   /* This variable is not a memory tag.  */
 135   NOT_A_TAG,
 136
 137   /* This variable is a type memory tag (TMT).  */
 138   TYPE_TAG,
 139
 140   /* This variable is a name memory tag (NMT).  */
 141   NAME_TAG,
 142
 143   /* This variable represents a structure field.  */
 144   STRUCT_FIELD
 145 };
 146 struct subvar;
 147 typedef struct subvar *subvar_t;
 148
 149 /* This structure represents a fake sub-variable for a structure field.  */
 150
 151 struct subvar GTY(())
 152 {
 153   /* Fake variable name */
 154   tree var;
 155   /* Offset inside structure.  */
 156   HOST_WIDE_INT offset;
 157   /* Size of field.  */
 158   HOST_WIDE_INT size;
 159   /* Next subvar for this structure.  */
 160   subvar_t next;
 161 };
 162
 163 struct var_ann_d GTY(())
 164 {
 165   struct tree_ann_common_d common;
 166
 167   /* Used by the out of SSA pass to determine whether this variable has
 168      been seen yet or not.  */
 169   unsigned out_of_ssa_tag : 1;
 170
 171   /* Used when building root_var structures in tree_ssa_live.[ch].  */
 172   unsigned root_var_processed : 1;
 173
 174   /* If nonzero, this variable is a memory tag.  */
 175   ENUM_BITFIELD (mem_tag_kind) mem_tag_kind : 2;
 176
 177   /* Nonzero if this variable is an alias tag that represents references to
 178      other variables (i.e., this variable appears in the MAY_ALIASES array
 179      of other variables).  */
 180   unsigned is_alias_tag : 1;
 181
 182   /* Nonzero if this variable was used after SSA optimizations were
 183      applied.  We set this when translating out of SSA form.  */
 184   unsigned used : 1;
 185
 186   /* This field indicates whether or not the variable may need PHI nodes.
 187      See the enum's definition for more detailed information about the
 188      states.  */
 189   ENUM_BITFIELD (need_phi_state) need_phi_state : 2;
 190
 191   /* Used during operand processing to determine if this variable is already
 192      in the vuse list.  */
 193   unsigned in_vuse_list : 1;
 194
 195   /* Used during operand processing to determine if this variable is already
 196      in the v_may_def list.  */
 197   unsigned in_v_may_def_list : 1;
 198
 199   /* An artificial variable representing the memory location pointed-to by
 200      all the pointers that TBAA (type-based alias analysis) considers
 201      to be aliased.  If the variable is not a pointer or if it is never
 202      dereferenced, this must be NULL.  */
 203   tree type_mem_tag;
 204
 205   /* Variables that may alias this variable.  */
 206   varray_type may_aliases;
 207
 208   /* Unique ID of this variable.  */
 209   size_t uid;
 210
 211   /* Used when going out of SSA form to indicate which partition this
 212      variable represents storage for.  */
 213   unsigned partition;
 214
 215   /* Used by the root-var object in tree-ssa-live.[ch].  */
 216   unsigned root_index;
 217
 218   /* Default definition for this symbol.  If this field is not NULL, it
 219      means that the first reference to this variable in the function is a
 220      USE or a VUSE.  In those cases, the SSA renamer creates an SSA name
 221      for this variable with an empty defining statement.  */
 222   tree default_def;
 223
 224   /* During into-ssa and the dominator optimizer, this field holds the
 225      current version of this variable (an SSA_NAME).
 226
 227      This was previously two varrays (one in into-ssa the other in the
 228      dominator optimizer).  That is wasteful, particularly since the
 229      dominator optimizer calls into-ssa resulting in having two varrays
 230      live at the same time and this can happen for each call to the
 231      dominator optimizer.  */
 232   tree current_def;
 233
 234   subvar_t subvars;
 235 };
 236
 237
 238 struct dataflow_d GTY(())
 239 {
 240   /* Immediate uses.  This is a list of all the statements and PHI nodes
 241      that are immediately reached by the definitions made in this
 242      statement.  */
 243   varray_type immediate_uses;
 244
 245   /* Use this array for very small numbers of uses instead of the varray.  */
 246   tree uses[2];
 247
 248   /* Reached uses.  This is a list of all the possible program statements
 249      that may be reached directly or indirectly by definitions made in this
 250      statement.  Notice that this is a superset of IMMEDIATE_USES.
 251      For instance, given the following piece of code:
 252
 253             1   a1 = 10;
 254             2   if (a1 > 3)
 255             3     a2 = a1 + 5;
 256             4   a3 = PHI (a1, a2)
 257             5   b1 = a3 - 2;
 258
 259      IMMEDIATE_USES for statement #1 are all those statements that use a1
 260      directly (i.e., #2, #3 and #4).  REACHED_USES for statement #1 also
 261      includes statement #5 because 'a1' could reach 'a3' via the PHI node
 262      at statement #4.  The set of REACHED_USES is then the transitive
 263      closure over all the PHI nodes in the IMMEDIATE_USES set.  */
 264
 265   /* Reaching definitions.  Similarly to REACHED_USES, the set
 266      REACHING_DEFS is the set of all the statements that make definitions
 267      that may reach this statement.  Notice that we don't need to have a
 268      similar entry for immediate definitions, as these are represented by
 269      the SSA_NAME nodes themselves (each SSA_NAME node contains a pointer
 270      to the statement that makes that definition).  */
 271 };
 272
 273 typedef struct dataflow_d *dataflow_t;
 274
 275
 276 struct stmt_ann_d GTY(())
 277 {
 278   struct tree_ann_common_d common;
 279
 280   /* Nonzero if the statement has been modified (meaning that the operands
 281      need to be scanned again).  */
 282   unsigned modified : 1;
 283
 284   /* Nonzero if the statement makes aliased loads.  */
 285   unsigned makes_aliased_loads : 1;
 286
 287   /* Nonzero if the statement makes aliased stores.  */
 288   unsigned makes_aliased_stores : 1;
 289
 290   /* Nonzero if the statement makes references to volatile storage.  */
 291   unsigned has_volatile_ops : 1;
 292
 293   /* Nonzero if the statement makes a function call that may clobber global
 294      and local addressable variables.  */
 295   unsigned makes_clobbering_call : 1;
 296
 297   /* Basic block that contains this statement.  */
 298   basic_block GTY ((skip (""))) bb;
 299
 300   struct stmt_operands_d operands;
 301
 302   /* Dataflow information.  */
 303   dataflow_t df;
 304
 305   /* Set of variables that have had their address taken in the statement.  */
 306   bitmap addresses_taken;
 307
 308   /* Unique identifier for this statement.  These ID's are to be created
 309      by each pass on an as-needed basis in any order convenient for the
 310      pass which needs statement UIDs.  */
 311   unsigned int uid;
 312
 313   /* Linked list of histograms for value-based profiling.  This is really a
 314      struct histogram_value*.  We use void* to avoid having to export that
 315      everywhere, and to avoid having to put it in GC memory.  */
 316
 317   void * GTY ((skip (""))) histograms;
 318 };
 319
 320 union tree_ann_d GTY((desc ("ann_type ((tree_ann_t)&%h)")))
 321 {
 322   struct tree_ann_common_d GTY((tag ("TREE_ANN_COMMON"))) common;
 323   struct var_ann_d GTY((tag ("VAR_ANN"))) decl;
 324   struct stmt_ann_d GTY((tag ("STMT_ANN"))) stmt;
 325 };
 326
 327 extern GTY(()) VEC(tree) *modified_noreturn_calls;
 328
 329 typedef union tree_ann_d *tree_ann_t;
 330 typedef struct var_ann_d *var_ann_t;
 331 typedef struct stmt_ann_d *stmt_ann_t;
 332
 333 static inline tree_ann_t tree_ann (tree);
 334 static inline tree_ann_t get_tree_ann (tree);
 335 static inline var_ann_t var_ann (tree);
 336 static inline var_ann_t get_var_ann (tree);
 337 static inline stmt_ann_t stmt_ann (tree);
 338 static inline stmt_ann_t get_stmt_ann (tree);
 339 static inline enum tree_ann_type ann_type (tree_ann_t);
 340 static inline basic_block bb_for_stmt (tree);
 341 extern void set_bb_for_stmt (tree, basic_block);
 342 static inline bool noreturn_call_p (tree);
 343 static inline void modify_stmt (tree);
 344 static inline void unmodify_stmt (tree);
 345 static inline bool stmt_modified_p (tree);
 346 static inline varray_type may_aliases (tree);
 347 static inline int get_lineno (tree);
 348 static inline const char *get_filename (tree);
 349 static inline bool is_exec_stmt (tree);
 350 static inline bool is_label_stmt (tree);
 351 static inline v_may_def_optype get_v_may_def_ops (stmt_ann_t);
 352 static inline vuse_optype get_vuse_ops (stmt_ann_t);
 353 static inline use_optype get_use_ops (stmt_ann_t);
 354 static inline def_optype get_def_ops (stmt_ann_t);
 355 static inline bitmap addresses_taken (tree);
 356 static inline int num_immediate_uses (dataflow_t);
 357 static inline tree immediate_use (dataflow_t, int);
 358 static inline dataflow_t get_immediate_uses (tree);
 359 static inline void set_default_def (tree, tree);
 360 static inline tree default_def (tree);
 361
 362 /*---------------------------------------------------------------------------
 363                   Structure representing predictions in tree level.
 364 ---------------------------------------------------------------------------*/
 365 struct edge_prediction GTY((chain_next ("%h.next")))
 366 {
 367   struct edge_prediction *next;
 368   edge edge;
 369   enum br_predictor predictor;
 370   int probability;
 371 };
 372
 373 /*---------------------------------------------------------------------------
 374                   Block annotations stored in basic_block.tree_annotations
 375 ---------------------------------------------------------------------------*/
 376 struct bb_ann_d GTY(())
 377 {
 378   /* Chain of PHI nodes for this block.  */
 379   tree phi_nodes;
 380
 381   /* Nonzero if this block contains an escape point (see is_escape_site).  */
 382   unsigned has_escape_site : 1;
 383
 384   /* Nonzero if one or more incoming edges to this block should be threaded
 385      to an outgoing edge of this block.  */
 386   unsigned incoming_edge_threaded : 1;
 387
 388   struct edge_prediction *predictions;
 389 };
 390
 391 typedef struct bb_ann_d *bb_ann_t;
 392
 393 /* Accessors for basic block annotations.  */
 394 static inline bb_ann_t bb_ann (basic_block);
 395 static inline tree phi_nodes (basic_block);
 396 static inline void set_phi_nodes (basic_block, tree);
 397
 398 /*---------------------------------------------------------------------------
 399                               Global declarations
 400 ---------------------------------------------------------------------------*/
 401 /* Array of all variables referenced in the function.  */
 402 extern GTY(()) varray_type referenced_vars;
 403
 404 #define num_referenced_vars VARRAY_ACTIVE_SIZE (referenced_vars)
 405 #define referenced_var(i) VARRAY_TREE (referenced_vars, i)
 406
 407 /* Array of all SSA_NAMEs used in the function.  */
 408 extern GTY(()) varray_type ssa_names;
 409
 410 #define num_ssa_names VARRAY_ACTIVE_SIZE (ssa_names)
 411 #define ssa_name(i) VARRAY_TREE (ssa_names, i)
 412
 413 /* Artificial variable used to model the effects of function calls.  */
 414 extern GTY(()) tree global_var;
 415
 416 /* Call clobbered variables in the function.  If bit I is set, then
 417    REFERENCED_VARS (I) is call-clobbered.  */
 418 extern bitmap call_clobbered_vars;
 419
 420 /* Addressable variables in the function.  If bit I is set, then
 421    REFERENCED_VARS (I) has had its address taken.  */
 422 extern bitmap addressable_vars;
 423
 424 /* 'true' after aliases have been computed (see compute_may_aliases).  */
 425 extern bool aliases_computed_p;
 426
 427 /* Macros for showing usage statistics.  */
 428 #define SCALE(x) ((unsigned long) ((x) < 1024*10        \
 429                   ? (x)                                 \
 430                   : ((x) < 1024*1024*10                 \
 431                      ? (x) / 1024                       \
 432                      : (x) / (1024*1024))))
 433
 434 #define LABEL(x) ((x) < 1024*10 ? 'b' : ((x) < 1024*1024*10 ? 'k' : 'M'))
 435
 436 #define PERCENT(x,y) ((float)(x) * 100.0 / (float)(y))
 437
 438
 439 /*---------------------------------------------------------------------------
 440                               Block iterators
 441 ---------------------------------------------------------------------------*/
 442
 443 typedef struct {
 444   tree_stmt_iterator tsi;
 445   basic_block bb;
 446 } block_stmt_iterator;
 447
 448 static inline block_stmt_iterator bsi_start (basic_block);
 449 static inline block_stmt_iterator bsi_last (basic_block);
 450 static inline block_stmt_iterator bsi_after_labels (basic_block);
 451 block_stmt_iterator bsi_for_stmt (tree);
 452 static inline bool bsi_end_p (block_stmt_iterator);
 453 static inline void bsi_next (block_stmt_iterator *);
 454 static inline void bsi_prev (block_stmt_iterator *);
 455 static inline tree bsi_stmt (block_stmt_iterator);
 456 static inline tree * bsi_stmt_ptr (block_stmt_iterator);
 457
 458 extern void bsi_remove (block_stmt_iterator *);
 459 extern void bsi_move_before (block_stmt_iterator *, block_stmt_iterator *);
 460 extern void bsi_move_after (block_stmt_iterator *, block_stmt_iterator *);
 461 extern void bsi_move_to_bb_end (block_stmt_iterator *, basic_block);
 462
 463 enum bsi_iterator_update
 464 {
 465   /* Note that these are intentionally in the same order as TSI_FOO.  They
 466      mean exactly the same as their TSI_* counterparts.  */
 467   BSI_NEW_STMT,
 468   BSI_SAME_STMT,
 469   BSI_CHAIN_START,
 470   BSI_CHAIN_END,
 471   BSI_CONTINUE_LINKING
 472 };
 473
 474 extern void bsi_insert_before (block_stmt_iterator *, tree,
 475                                enum bsi_iterator_update);
 476 extern void bsi_insert_after (block_stmt_iterator *, tree,
 477                               enum bsi_iterator_update);
 478
 479 extern void bsi_replace (const block_stmt_iterator *, tree, bool);
 480
 481 /*---------------------------------------------------------------------------
 482                               Function prototypes
 483 ---------------------------------------------------------------------------*/
 484 /* In tree-cfg.c  */
 485
 486 /* Location to track pending stmt for edge insertion.  */
 487 #define PENDING_STMT(e) ((e)->insns.t)
 488
 489 extern void delete_tree_cfg_annotations (void);
 490 extern void disband_implicit_edges (void);
 491 extern bool stmt_ends_bb_p (tree);
 492 extern bool is_ctrl_stmt (tree);
 493 extern bool is_ctrl_altering_stmt (tree);
 494 extern bool computed_goto_p (tree);
 495 extern bool simple_goto_p (tree);
 496 extern void tree_dump_bb (basic_block, FILE *, int);
 497 extern void debug_tree_bb (basic_block);
 498 extern basic_block debug_tree_bb_n (int);
 499 extern void dump_tree_cfg (FILE *, int);
 500 extern void debug_tree_cfg (int);
 501 extern void dump_cfg_stats (FILE *);
 502 extern void debug_cfg_stats (void);
 503 extern void debug_loop_ir (void);
 504 extern void print_loop_ir (FILE *);
 505 extern void cleanup_dead_labels (void);
 506 extern void group_case_labels (void);
 507 extern bool cleanup_tree_cfg (void);
 508 extern void cleanup_tree_cfg_loop (void);
 509 extern tree first_stmt (basic_block);
 510 extern tree last_stmt (basic_block);
 511 extern tree *last_stmt_ptr (basic_block);
 512 extern tree last_and_only_stmt (basic_block);
 513 extern edge find_taken_edge (basic_block, tree);
 514 extern void cfg_remove_useless_stmts (void);
 515 extern basic_block label_to_block (tree);
 516 extern void bsi_insert_on_edge (edge, tree);
 517 extern basic_block bsi_insert_on_edge_immediate (edge, tree);
 518 extern void bsi_commit_one_edge_insert (edge, basic_block *);
 519 extern void bsi_commit_edge_inserts (void);
 520 extern void notice_special_calls (tree);
 521 extern void clear_special_calls (void);
 522 extern void verify_stmts (void);
 523 extern tree tree_block_label (basic_block);
 524 extern void extract_true_false_edges_from_block (basic_block, edge *, edge *);
 525 extern bool tree_duplicate_sese_region (edge, edge, basic_block *, unsigned,
 526                                         basic_block *);
 527 extern void add_phi_args_after_copy_bb (basic_block);
 528 extern void add_phi_args_after_copy (basic_block *, unsigned);
 529 extern void rewrite_to_new_ssa_names_bb (basic_block, struct htab *);
 530 extern void rewrite_to_new_ssa_names (basic_block *, unsigned, htab_t);
 531 extern void allocate_ssa_names (bitmap, struct htab **);
 532 extern bool tree_purge_dead_eh_edges (basic_block);
 533 extern bool tree_purge_all_dead_eh_edges (bitmap);
 534 extern tree gimplify_val (block_stmt_iterator *, tree, tree);
 535 extern tree gimplify_build1 (block_stmt_iterator *, enum tree_code,
 536                              tree, tree);
 537 extern tree gimplify_build2 (block_stmt_iterator *, enum tree_code,
 538                              tree, tree, tree);
 539 extern tree gimplify_build3 (block_stmt_iterator *, enum tree_code,
 540                              tree, tree, tree, tree);
 541
 542 /* In tree-pretty-print.c.  */
 543 extern void dump_generic_bb (FILE *, basic_block, int, int);
 544
 545 /* In tree-dfa.c  */
 546 extern var_ann_t create_var_ann (tree);
 547 extern stmt_ann_t create_stmt_ann (tree);
 548 extern tree_ann_t create_tree_ann (tree);
 549 extern void reserve_phi_args_for_new_edge (basic_block);
 550 extern tree create_phi_node (tree, basic_block);
 551 extern void add_phi_arg (tree, tree, edge);
 552 extern void remove_phi_args (edge);
 553 extern void remove_phi_node (tree, tree);
 554 extern void remove_all_phi_nodes_for (bitmap);
 555 extern tree phi_reverse (tree);
 556 extern void dump_dfa_stats (FILE *);
 557 extern void debug_dfa_stats (void);
 558 extern void debug_referenced_vars (void);
 559 extern void dump_referenced_vars (FILE *);
 560 extern void dump_variable (FILE *, tree);
 561 extern void debug_variable (tree);
 562 extern void dump_immediate_uses (FILE *);
 563 extern void debug_immediate_uses (void);
 564 extern void dump_immediate_uses_for (FILE *, tree);
 565 extern void debug_immediate_uses_for (tree);
 566 extern void compute_immediate_uses (int, bool (*)(tree));
 567 extern void free_df (void);
 568 extern void free_df_for_stmt (tree);
 569 extern tree get_virtual_var (tree);
 570 extern void add_referenced_tmp_var (tree);
 571 extern void mark_new_vars_to_rename (tree, bitmap);
 572 extern void find_new_referenced_vars (tree *);
 573 void mark_call_clobbered_vars_to_rename (void);
 574
 575 extern void redirect_immediate_uses (tree, tree);
 576 extern tree make_rename_temp (tree, const char *);
 577
 578 /* Flags used when computing reaching definitions and reached uses.  */
 579 #define TDFA_USE_OPS            (1 << 0)
 580 #define TDFA_USE_VOPS           (1 << 1)
 581
 582 /* In gimple-low.c  */
 583 extern void record_vars (tree);
 584 extern bool block_may_fallthru (tree block);
 585
 586 typedef tree tree_on_heap;
 587 DEF_VEC_MALLOC_P (tree_on_heap);
 588
 589 /* In tree-ssa-alias.c  */
 590 extern void dump_may_aliases_for (FILE *, tree);
 591 extern void debug_may_aliases_for (tree);
 592 extern void dump_alias_info (FILE *);
 593 extern void debug_alias_info (void);
 594 extern void dump_points_to_info (FILE *);
 595 extern void debug_points_to_info (void);
 596 extern void dump_points_to_info_for (FILE *, tree);
 597 extern void debug_points_to_info_for (tree);
 598 extern bool may_be_aliased (tree);
 599 extern struct ptr_info_def *get_ptr_info (tree);
 600 static inline subvar_t get_subvars_for_var (tree);
 601 static inline bool ref_contains_array_ref (tree);
 602 extern tree okay_component_ref_for_subvars (tree, HOST_WIDE_INT *,
 603                                             HOST_WIDE_INT *);
 604 static inline bool var_can_have_subvars (tree);
 605 static inline bool overlap_subvar (HOST_WIDE_INT, HOST_WIDE_INT,
 606                                    subvar_t, bool *);
 607
 608 /* Call-back function for walk_use_def_chains().  At each reaching
 609    definition, a function with this prototype is called.  */
 610 typedef bool (*walk_use_def_chains_fn) (tree, tree, void *);
 611
 612
 613 /* In tree-ssa.c  */
 614 extern void init_tree_ssa (void);
 615 extern void dump_tree_ssa (FILE *);
 616 extern void debug_tree_ssa (void);
 617 extern void debug_def_blocks (void);
 618 extern void dump_tree_ssa_stats (FILE *);
 619 extern void debug_tree_ssa_stats (void);
 620 extern edge ssa_redirect_edge (edge, basic_block);
 621 extern void flush_pending_stmts (edge);
 622 extern bool tree_ssa_useless_type_conversion (tree);
 623 extern bool tree_ssa_useless_type_conversion_1 (tree, tree);
 624 extern void verify_ssa (void);
 625 extern void delete_tree_ssa (void);
 626 extern void register_new_def (tree, VEC (tree_on_heap) **);
 627 extern void walk_use_def_chains (tree, walk_use_def_chains_fn, void *, bool);
 628 extern void kill_redundant_phi_nodes (void);
 629 extern bool stmt_references_memory_p (tree);
 630
 631 /* In tree-into-ssa.c  */
 632 extern void rewrite_into_ssa (bool);
 633 extern void rewrite_ssa_into_ssa (void);
 634 extern void rewrite_def_def_chains (void);
 635
 636 void compute_global_livein (bitmap, bitmap);
 637 tree duplicate_ssa_name (tree, tree);
 638
 639 /* In tree-ssa-ccp.c  */
 640 bool fold_stmt (tree *);
 641 tree widen_bitfield (tree, tree, tree);
 642
 643 /* In tree-ssa-dom.c  */
 644 extern void dump_dominator_optimization_stats (FILE *);
 645 extern void debug_dominator_optimization_stats (void);
 646
 647 /* In tree-ssa-copy.c  */
 648 extern void propagate_value (use_operand_p, tree);
 649 extern void propagate_tree_value (tree *, tree);
 650 extern void replace_exp (use_operand_p, tree);
 651 extern bool may_propagate_copy (tree, tree);
 652 extern bool may_propagate_copy_into_asm (tree);
 653
 654 /* Description of number of iterations of a loop.  All the expressions inside
 655    the structure can be evaluated at the end of the loop's preheader
 656    (and due to ssa form, also anywhere inside the body of the loop).  */
 657
 658 struct tree_niter_desc
 659 {
 660   tree assumptions;     /* The boolean expression.  If this expression evaluates
 661                            to false, then the other fields in this structure
 662                            should not be used; there is no guarantee that they
 663                            will be correct.  */
 664   tree may_be_zero;     /* The boolean expression.  If it evaluates to true,
 665                            the loop will exit in the first iteration (i.e.
 666                            its latch will not be executed), even if the niter
 667                            field says otherwise.  */
 668   tree niter;           /* The expression giving the number of iterations of
 669                            a loop (provided that assumptions == true and
 670                            may_be_zero == false), more precisely the number
 671                            of executions of the latch of the loop.  */
 672   tree additional_info; /* The boolean expression.  Sometimes we use additional
 673                            knowledge to simplify the other expressions
 674                            contained in this structure (for example the
 675                            knowledge about value ranges of operands on entry to
 676                            the loop).  If this is a case, conjunction of such
 677                            condition is stored in this field, so that we do not
 678                            lose the information: for example if may_be_zero
 679                            is (n <= 0) and niter is (unsigned) n, we know
 680                            that the number of iterations is at most
 681                            MAX_SIGNED_INT.  However if the (n <= 0) assumption
 682                            is eliminated (by looking at the guard on entry of
 683                            the loop), then the information would be lost.  */
 684 };
 685
 686 /* In tree-vectorizer.c */
 687 void vectorize_loops (struct loops *);
 688
 689 /* In tree-ssa-phiopt.c */
 690 bool empty_block_p (basic_block);
 691
 692 /* In tree-ssa-loop*.c  */
 693
 694 void tree_ssa_lim (struct loops *);
 695 void tree_ssa_unswitch_loops (struct loops *);
 696 void canonicalize_induction_variables (struct loops *);
 697 void tree_unroll_loops_completely (struct loops *);
 698 void tree_ssa_iv_optimize (struct loops *);
 699
 700 void number_of_iterations_cond (tree, tree, tree, enum tree_code, tree, tree,
 701                                 struct tree_niter_desc *);
 702 bool number_of_iterations_exit (struct loop *, edge,
 703                                 struct tree_niter_desc *niter);
 704 tree find_loop_niter (struct loop *, edge *);
 705 tree loop_niter_by_eval (struct loop *, edge);
 706 tree find_loop_niter_by_eval (struct loop *, edge *);
 707 void estimate_numbers_of_iterations (struct loops *);
 708 tree can_count_iv_in_wider_type (struct loop *, tree, tree, tree, tree);
 709 void free_numbers_of_iterations_estimates (struct loops *);
 710 void rewrite_into_loop_closed_ssa (bitmap);
 711 void verify_loop_closed_ssa (void);
 712 void loop_commit_inserts (void);
 713 bool for_each_index (tree *, bool (*) (tree, tree *, void *), void *);
 714 void create_iv (tree, tree, tree, struct loop *, block_stmt_iterator *, bool,
 715                 tree *, tree *);
 716 void split_loop_exit_edge (edge);
 717 basic_block bsi_insert_on_edge_immediate_loop (edge, tree);
 718 void standard_iv_increment_position (struct loop *, block_stmt_iterator *,
 719                                      bool *);
 720 basic_block ip_end_pos (struct loop *);
 721 basic_block ip_normal_pos (struct loop *);
 722 bool tree_duplicate_loop_to_header_edge (struct loop *, edge, struct loops *,
 723                                          unsigned int, sbitmap,
 724                                          edge, edge *,
 725                                          unsigned int *, int);
 726 struct loop *tree_ssa_loop_version (struct loops *, struct loop *, tree,
 727                                     basic_block *);
 728
 729 /* In tree-ssa-loop-im.c  */
 730 /* The possibilities of statement movement.  */
 731
 732 enum move_pos
 733   {
 734     MOVE_IMPOSSIBLE,            /* No movement -- side effect expression.  */
 735     MOVE_PRESERVE_EXECUTION,    /* Must not cause the non-executed statement
 736                                    become executed -- memory accesses, ... */
 737     MOVE_POSSIBLE               /* Unlimited movement.  */
 738   };
 739 extern enum move_pos movement_possibility (tree);
 740
 741 /* In tree-flow-inline.h  */
 742 static inline bool is_call_clobbered (tree);
 743 static inline void mark_call_clobbered (tree);
 744 static inline void set_is_used (tree);
 745
 746 /* In tree-eh.c  */
 747 extern void make_eh_edges (tree);
 748 extern bool tree_could_trap_p (tree);
 749 extern bool tree_could_throw_p (tree);
 750 extern bool tree_can_throw_internal (tree);
 751 extern bool tree_can_throw_external (tree);
 752 extern int lookup_stmt_eh_region (tree);
 753 extern void add_stmt_to_eh_region (tree, int);
 754 extern bool remove_stmt_from_eh_region (tree);
 755 extern bool maybe_clean_eh_stmt (tree);
 756
 757 /* In tree-ssa-pre.c  */
 758 void add_to_value (tree, tree);
 759 void debug_value_expressions (tree);
 760 void print_value_expressions (FILE *, tree);
 761
 762
 763 /* In tree-vn.c  */
 764 bool expressions_equal_p (tree, tree);
 765 tree get_value_handle (tree);
 766 hashval_t vn_compute (tree, hashval_t, vuse_optype);
 767 tree vn_lookup_or_add (tree, vuse_optype);
 768 void vn_add (tree, tree, vuse_optype);
 769 tree vn_lookup (tree, vuse_optype);
 770 void vn_init (void);
 771 void vn_delete (void);
 772
 773 /* In tree-ssa-sink.c  */
 774 bool is_hidden_global_store (tree);
 775
 776 /* In tree-sra.c  */
 777 void insert_edge_copies (tree, basic_block);
 778
 779 /* In tree-loop-linear.c  */
 780 extern void linear_transform_loops (struct loops *);
 781
 782 /* In tree-ssa-loop-ivopts.c  */
 783 extern bool expr_invariant_in_loop_p (struct loop *, tree);
 784 /* In gimplify.c  */
 785
 786 tree force_gimple_operand (tree, tree *, bool, tree);
 787
 788 #include "tree-flow-inline.h"
 789
 790 #endif /* _TREE_FLOW_H  */