gcc/tree-flow.h

   1 /* Data and Control Flow Analysis for Trees.
   2    Copyright (C) 2001, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
   3    Free Software Foundation, Inc.
   4    Contributed by Diego Novillo <dnovillo@redhat.com>
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 3, or (at your option)
  11 any later version.
  12
  13 GCC is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22 #ifndef _TREE_FLOW_H
  23 #define _TREE_FLOW_H 1
  24
  25 #include "bitmap.h"
  26 #include "sbitmap.h"
  27 #include "basic-block.h"
  28 #include "hashtab.h"
  29 #include "gimple.h"
  30 #include "tree-ssa-operands.h"
  31 #include "cgraph.h"
  32 #include "ipa-reference.h"
  33 #include "tree-ssa-alias.h"
  34
  35
  36 /* Gimple dataflow datastructure. All publicly available fields shall have
  37    gimple_ accessor defined in tree-flow-inline.h, all publicly modifiable
  38    fields should have gimple_set accessor.  */
  39 struct GTY(()) gimple_df {
  40   /* Array of all variables referenced in the function.  */
  41   htab_t GTY((param_is (union tree_node))) referenced_vars;
  42
  43   /* A vector of all the noreturn calls passed to modify_stmt.
  44      cleanup_control_flow uses it to detect cases where a mid-block
  45      indirect call has been turned into a noreturn call.  When this
  46      happens, all the instructions after the call are no longer
  47      reachable and must be deleted as dead.  */
  48   VEC(gimple,gc) *modified_noreturn_calls;
  49
  50   /* Array of all SSA_NAMEs used in the function.  */
  51   VEC(tree,gc) *ssa_names;
  52
  53   /* Artificial variable used for the virtual operand FUD chain.  */
  54   tree vop;
  55
  56   /* The PTA solution for the ESCAPED artificial variable.  */
  57   struct pt_solution escaped;
  58
  59   /* A map of decls to artificial ssa-names that point to the partition
  60      of the decl.  */
  61   struct pointer_map_t * GTY((skip(""))) decls_to_pointers;
  62
  63   /* Free list of SSA_NAMEs.  */
  64   tree free_ssanames;
  65
  66   /* Hashtable holding definition for symbol.  If this field is not NULL, it
  67      means that the first reference to this variable in the function is a
  68      USE or a VUSE.  In those cases, the SSA renamer creates an SSA name
  69      for this variable with an empty defining statement.  */
  70   htab_t GTY((param_is (union tree_node))) default_defs;
  71
  72   /* Symbols whose SSA form needs to be updated or created for the first
  73      time.  */
  74   bitmap syms_to_rename;
  75
  76   /* True if the code is in ssa form.  */
  77   unsigned int in_ssa_p : 1;
  78
  79   /* True if IPA points-to information was computed for this function.  */
  80   unsigned int ipa_pta : 1;
  81
  82   struct ssa_operands ssa_operands;
  83 };
  84
  85 /* Accessors for internal use only.  Generic code should use abstraction
  86    provided by tree-flow-inline.h or specific modules.  */
  87 #define FREE_SSANAMES(fun) (fun)->gimple_df->free_ssanames
  88 #define SSANAMES(fun) (fun)->gimple_df->ssa_names
  89 #define MODIFIED_NORETURN_CALLS(fun) (fun)->gimple_df->modified_noreturn_calls
  90 #define DEFAULT_DEFS(fun) (fun)->gimple_df->default_defs
  91 #define SYMS_TO_RENAME(fun) (fun)->gimple_df->syms_to_rename
  92
  93 typedef struct
  94 {
  95   htab_t htab;
  96   PTR *slot;
  97   PTR *limit;
  98 } htab_iterator;
  99
 100 /* Iterate through the elements of hashtable HTAB, using htab_iterator ITER,
 101    storing each element in RESULT, which is of type TYPE.  */
 102 #define FOR_EACH_HTAB_ELEMENT(HTAB, RESULT, TYPE, ITER) \
 103   for (RESULT = (TYPE) first_htab_element (&(ITER), (HTAB)); \
 104         !end_htab_p (&(ITER)); \
 105         RESULT = (TYPE) next_htab_element (&(ITER)))
 106
 107 /*---------------------------------------------------------------------------
 108                       Attributes for SSA_NAMEs.
 109
 110   NOTE: These structures are stored in struct tree_ssa_name
 111   but are only used by the tree optimizers, so it makes better sense
 112   to declare them here to avoid recompiling unrelated files when
 113   making changes.
 114 ---------------------------------------------------------------------------*/
 115
 116 /* Aliasing information for SSA_NAMEs representing pointer variables.  */
 117
 118 struct GTY(()) ptr_info_def
 119 {
 120   /* The points-to solution.  */
 121   struct pt_solution pt;
 122 };
 123
 124
 125 /* It is advantageous to avoid things like life analysis for variables which
 126    do not need PHI nodes.  This enum describes whether or not a particular
 127    variable may need a PHI node.  */
 128
 129 enum need_phi_state {
 130   /* This is the default.  If we are still in this state after finding
 131      all the definition and use sites, then we will assume the variable
 132      needs PHI nodes.  This is probably an overly conservative assumption.  */
 133   NEED_PHI_STATE_UNKNOWN,
 134
 135   /* This state indicates that we have seen one or more sets of the
 136      variable in a single basic block and that the sets dominate all
 137      uses seen so far.  If after finding all definition and use sites
 138      we are still in this state, then the variable does not need any
 139      PHI nodes.  */
 140   NEED_PHI_STATE_NO,
 141
 142   /* This state indicates that we have either seen multiple definitions of
 143      the variable in multiple blocks, or that we encountered a use in a
 144      block that was not dominated by the block containing the set(s) of
 145      this variable.  This variable is assumed to need PHI nodes.  */
 146   NEED_PHI_STATE_MAYBE
 147 };
 148
 149
 150 struct GTY(()) var_ann_d {
 151   /* Used when building base variable structures in a var_map.  */
 152   unsigned base_var_processed : 1;
 153
 154   /* Nonzero if this variable was used after SSA optimizations were
 155      applied.  We set this when translating out of SSA form.  */
 156   unsigned used : 1;
 157
 158   /* This field indicates whether or not the variable may need PHI nodes.
 159      See the enum's definition for more detailed information about the
 160      states.  */
 161   ENUM_BITFIELD (need_phi_state) need_phi_state : 2;
 162
 163   /* True for HEAP artificial variables.  These variables represent
 164      the memory area allocated by a call to malloc.  */
 165   unsigned is_heapvar : 1;
 166
 167   /* Used by var_map for the base index of ssa base variables.  */
 168   unsigned base_index;
 169
 170   /* During into-ssa and the dominator optimizer, this field holds the
 171      current version of this variable (an SSA_NAME).  */
 172   tree current_def;
 173 };
 174
 175
 176 /* Immediate use lists are used to directly access all uses for an SSA
 177    name and get pointers to the statement for each use.
 178
 179    The structure ssa_use_operand_d consists of PREV and NEXT pointers
 180    to maintain the list.  A USE pointer, which points to address where
 181    the use is located and a LOC pointer which can point to the
 182    statement where the use is located, or, in the case of the root
 183    node, it points to the SSA name itself.
 184
 185    The list is anchored by an occurrence of ssa_operand_d *in* the
 186    ssa_name node itself (named 'imm_uses').  This node is uniquely
 187    identified by having a NULL USE pointer. and the LOC pointer
 188    pointing back to the ssa_name node itself.  This node forms the
 189    base for a circular list, and initially this is the only node in
 190    the list.
 191
 192    Fast iteration allows each use to be examined, but does not allow
 193    any modifications to the uses or stmts.
 194
 195    Normal iteration allows insertion, deletion, and modification. the
 196    iterator manages this by inserting a marker node into the list
 197    immediately before the node currently being examined in the list.
 198    this marker node is uniquely identified by having null stmt *and* a
 199    null use pointer.
 200
 201    When iterating to the next use, the iteration routines check to see
 202    if the node after the marker has changed. if it has, then the node
 203    following the marker is now the next one to be visited. if not, the
 204    marker node is moved past that node in the list (visualize it as
 205    bumping the marker node through the list).  this continues until
 206    the marker node is moved to the original anchor position. the
 207    marker node is then removed from the list.
 208
 209    If iteration is halted early, the marker node must be removed from
 210    the list before continuing.  */
 211 typedef struct immediate_use_iterator_d
 212 {
 213   /* This is the current use the iterator is processing.  */
 214   ssa_use_operand_t *imm_use;
 215   /* This marks the last use in the list (use node from SSA_NAME)  */
 216   ssa_use_operand_t *end_p;
 217   /* This node is inserted and used to mark the end of the uses for a stmt.  */
 218   ssa_use_operand_t iter_node;
 219   /* This is the next ssa_name to visit.  IMM_USE may get removed before
 220      the next one is traversed to, so it must be cached early.  */
 221   ssa_use_operand_t *next_imm_name;
 222 } imm_use_iterator;
 223
 224
 225 /* Use this iterator when simply looking at stmts.  Adding, deleting or
 226    modifying stmts will cause this iterator to malfunction.  */
 227
 228 #define FOR_EACH_IMM_USE_FAST(DEST, ITER, SSAVAR)               \
 229   for ((DEST) = first_readonly_imm_use (&(ITER), (SSAVAR));     \
 230        !end_readonly_imm_use_p (&(ITER));                       \
 231        (void) ((DEST) = next_readonly_imm_use (&(ITER))))
 232
 233 /* Use this iterator to visit each stmt which has a use of SSAVAR.  */
 234
 235 #define FOR_EACH_IMM_USE_STMT(STMT, ITER, SSAVAR)               \
 236   for ((STMT) = first_imm_use_stmt (&(ITER), (SSAVAR));         \
 237        !end_imm_use_stmt_p (&(ITER));                           \
 238        (void) ((STMT) = next_imm_use_stmt (&(ITER))))
 239
 240 /* Use this to terminate the FOR_EACH_IMM_USE_STMT loop early.  Failure to
 241    do so will result in leaving a iterator marker node in the immediate
 242    use list, and nothing good will come from that.   */
 243 #define BREAK_FROM_IMM_USE_STMT(ITER)                           \
 244    {                                                            \
 245      end_imm_use_stmt_traverse (&(ITER));                       \
 246      break;                                                     \
 247    }
 248
 249
 250 /* Use this iterator in combination with FOR_EACH_IMM_USE_STMT to
 251    get access to each occurrence of ssavar on the stmt returned by
 252    that iterator..  for instance:
 253
 254      FOR_EACH_IMM_USE_STMT (stmt, iter, var)
 255        {
 256          FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
 257            {
 258              SET_USE (use_p, blah);
 259            }
 260          update_stmt (stmt);
 261        }                                                         */
 262
 263 #define FOR_EACH_IMM_USE_ON_STMT(DEST, ITER)                    \
 264   for ((DEST) = first_imm_use_on_stmt (&(ITER));                \
 265        !end_imm_use_on_stmt_p (&(ITER));                        \
 266        (void) ((DEST) = next_imm_use_on_stmt (&(ITER))))
 267
 268
 269
 270 typedef struct var_ann_d *var_ann_t;
 271
 272 static inline var_ann_t var_ann (const_tree);
 273 static inline var_ann_t get_var_ann (tree);
 274 static inline void update_stmt (gimple);
 275 static inline int get_lineno (const_gimple);
 276
 277 /*---------------------------------------------------------------------------
 278                   Structure representing predictions in tree level.
 279 ---------------------------------------------------------------------------*/
 280 struct GTY((chain_next ("%h.ep_next"))) edge_prediction {
 281   struct edge_prediction *ep_next;
 282   edge ep_edge;
 283   enum br_predictor ep_predictor;
 284   int ep_probability;
 285 };
 286
 287 /* Accessors for basic block annotations.  */
 288 static inline gimple_seq phi_nodes (const_basic_block);
 289 static inline void set_phi_nodes (basic_block, gimple_seq);
 290
 291 /*---------------------------------------------------------------------------
 292                               Global declarations
 293 ---------------------------------------------------------------------------*/
 294 struct GTY(()) int_tree_map {
 295
 296   unsigned int uid;
 297   tree to;
 298 };
 299
 300 extern unsigned int int_tree_map_hash (const void *);
 301 extern int int_tree_map_eq (const void *, const void *);
 302
 303 extern unsigned int uid_decl_map_hash (const void *);
 304 extern int uid_decl_map_eq (const void *, const void *);
 305
 306 typedef struct
 307 {
 308   htab_iterator hti;
 309 } referenced_var_iterator;
 310
 311 /* This macro loops over all the referenced vars, one at a time, putting the
 312    current var in VAR.  Note:  You are not allowed to add referenced variables
 313    to the hashtable while using this macro.  Doing so may cause it to behave
 314    erratically.  */
 315
 316 #define FOR_EACH_REFERENCED_VAR(VAR, ITER) \
 317   for ((VAR) = first_referenced_var (&(ITER)); \
 318        !end_referenced_vars_p (&(ITER)); \
 319        (VAR) = next_referenced_var (&(ITER)))
 320
 321 extern tree referenced_var_lookup (unsigned int);
 322 extern bool referenced_var_check_and_insert (tree);
 323 #define num_referenced_vars htab_elements (gimple_referenced_vars (cfun))
 324 #define referenced_var(i) referenced_var_lookup (i)
 325
 326 #define num_ssa_names (VEC_length (tree, cfun->gimple_df->ssa_names))
 327 #define ssa_name(i) (VEC_index (tree, cfun->gimple_df->ssa_names, (i)))
 328
 329 /* Macros for showing usage statistics.  */
 330 #define SCALE(x) ((unsigned long) ((x) < 1024*10        \
 331                   ? (x)                                 \
 332                   : ((x) < 1024*1024*10                 \
 333                      ? (x) / 1024                       \
 334                      : (x) / (1024*1024))))
 335
 336 #define LABEL(x) ((x) < 1024*10 ? 'b' : ((x) < 1024*1024*10 ? 'k' : 'M'))
 337
 338 #define PERCENT(x,y) ((float)(x) * 100.0 / (float)(y))
 339
 340 /*---------------------------------------------------------------------------
 341                               OpenMP Region Tree
 342 ---------------------------------------------------------------------------*/
 343
 344 /* Parallel region information.  Every parallel and workshare
 345    directive is enclosed between two markers, the OMP_* directive
 346    and a corresponding OMP_RETURN statement.  */
 347
 348 struct omp_region
 349 {
 350   /* The enclosing region.  */
 351   struct omp_region *outer;
 352
 353   /* First child region.  */
 354   struct omp_region *inner;
 355
 356   /* Next peer region.  */
 357   struct omp_region *next;
 358
 359   /* Block containing the omp directive as its last stmt.  */
 360   basic_block entry;
 361
 362   /* Block containing the OMP_RETURN as its last stmt.  */
 363   basic_block exit;
 364
 365   /* Block containing the OMP_CONTINUE as its last stmt.  */
 366   basic_block cont;
 367
 368   /* If this is a combined parallel+workshare region, this is a list
 369      of additional arguments needed by the combined parallel+workshare
 370      library call.  */
 371   tree ws_args;
 372
 373   /* The code for the omp directive of this region.  */
 374   enum gimple_code type;
 375
 376   /* Schedule kind, only used for OMP_FOR type regions.  */
 377   enum omp_clause_schedule_kind sched_kind;
 378
 379   /* True if this is a combined parallel+workshare region.  */
 380   bool is_combined_parallel;
 381 };
 382
 383 extern struct omp_region *root_omp_region;
 384 extern struct omp_region *new_omp_region (basic_block, enum gimple_code,
 385                                           struct omp_region *);
 386 extern void free_omp_regions (void);
 387 void omp_expand_local (basic_block);
 388 extern tree find_omp_clause (tree, enum omp_clause_code);
 389 tree copy_var_decl (tree, tree, tree);
 390
 391 /*---------------------------------------------------------------------------
 392                               Function prototypes
 393 ---------------------------------------------------------------------------*/
 394 /* In tree-cfg.c  */
 395
 396 /* Location to track pending stmt for edge insertion.  */
 397 #define PENDING_STMT(e) ((e)->insns.g)
 398
 399 extern void delete_tree_cfg_annotations (void);
 400 extern bool stmt_ends_bb_p (gimple);
 401 extern bool is_ctrl_stmt (gimple);
 402 extern bool is_ctrl_altering_stmt (gimple);
 403 extern bool simple_goto_p (gimple);
 404 extern bool stmt_can_make_abnormal_goto (gimple);
 405 extern basic_block single_noncomplex_succ (basic_block bb);
 406 extern void gimple_dump_bb (basic_block, FILE *, int, int);
 407 extern void gimple_debug_bb (basic_block);
 408 extern basic_block gimple_debug_bb_n (int);
 409 extern void gimple_dump_cfg (FILE *, int);
 410 extern void gimple_debug_cfg (int);
 411 extern void dump_cfg_stats (FILE *);
 412 extern void dot_cfg (void);
 413 extern void debug_cfg_stats (void);
 414 extern void debug_loops (int);
 415 extern void debug_loop (struct loop *, int);
 416 extern void debug_loop_num (unsigned, int);
 417 extern void print_loops (FILE *, int);
 418 extern void print_loops_bb (FILE *, basic_block, int, int);
 419 extern void cleanup_dead_labels (void);
 420 extern void group_case_labels (void);
 421 extern gimple first_stmt (basic_block);
 422 extern gimple last_stmt (basic_block);
 423 extern gimple last_and_only_stmt (basic_block);
 424 extern edge find_taken_edge (basic_block, tree);
 425 extern basic_block label_to_block_fn (struct function *, tree);
 426 #define label_to_block(t) (label_to_block_fn (cfun, t))
 427 extern void notice_special_calls (gimple);
 428 extern void clear_special_calls (void);
 429 extern void verify_stmts (void);
 430 extern void verify_gimple (void);
 431 extern void verify_types_in_gimple_seq (gimple_seq);
 432 extern tree gimple_block_label (basic_block);
 433 extern void extract_true_false_edges_from_block (basic_block, edge *, edge *);
 434 extern bool gimple_duplicate_sese_region (edge, edge, basic_block *, unsigned,
 435                                         basic_block *);
 436 extern bool gimple_duplicate_sese_tail (edge, edge, basic_block *, unsigned,
 437                                       basic_block *);
 438 extern void gather_blocks_in_sese_region (basic_block entry, basic_block exit,
 439                                           VEC(basic_block,heap) **bbs_p);
 440 extern void add_phi_args_after_copy_bb (basic_block);
 441 extern void add_phi_args_after_copy (basic_block *, unsigned, edge);
 442 extern bool gimple_purge_dead_abnormal_call_edges (basic_block);
 443 extern bool gimple_purge_dead_eh_edges (basic_block);
 444 extern bool gimple_purge_all_dead_eh_edges (const_bitmap);
 445 extern tree gimplify_build1 (gimple_stmt_iterator *, enum tree_code,
 446                              tree, tree);
 447 extern tree gimplify_build2 (gimple_stmt_iterator *, enum tree_code,
 448                              tree, tree, tree);
 449 extern tree gimplify_build3 (gimple_stmt_iterator *, enum tree_code,
 450                              tree, tree, tree, tree);
 451 extern void init_empty_tree_cfg (void);
 452 extern void init_empty_tree_cfg_for_function (struct function *);
 453 extern void fold_cond_expr_cond (void);
 454 extern void make_abnormal_goto_edges (basic_block, bool);
 455 extern void replace_uses_by (tree, tree);
 456 extern void start_recording_case_labels (void);
 457 extern void end_recording_case_labels (void);
 458 extern basic_block move_sese_region_to_fn (struct function *, basic_block,
 459                                            basic_block, tree);
 460 void remove_edge_and_dominated_blocks (edge);
 461 bool tree_node_can_be_shared (tree);
 462
 463 /* In tree-cfgcleanup.c  */
 464 extern bitmap cfgcleanup_altered_bbs;
 465 extern bool cleanup_tree_cfg (void);
 466
 467 /* In tree-pretty-print.c.  */
 468 extern void dump_generic_bb (FILE *, basic_block, int, int);
 469 extern int op_code_prio (enum tree_code);
 470 extern int op_prio (const_tree);
 471 extern const char *op_symbol_code (enum tree_code);
 472
 473 /* In tree-dfa.c  */
 474 extern var_ann_t create_var_ann (tree);
 475 extern void renumber_gimple_stmt_uids (void);
 476 extern void renumber_gimple_stmt_uids_in_blocks (basic_block *, int);
 477 extern void dump_dfa_stats (FILE *);
 478 extern void debug_dfa_stats (void);
 479 extern void debug_referenced_vars (void);
 480 extern void dump_referenced_vars (FILE *);
 481 extern void dump_variable (FILE *, tree);
 482 extern void debug_variable (tree);
 483 extern tree get_virtual_var (tree);
 484 extern bool add_referenced_var (tree);
 485 extern void remove_referenced_var (tree);
 486 extern void mark_symbols_for_renaming (gimple);
 487 extern void find_new_referenced_vars (gimple);
 488 extern tree make_rename_temp (tree, const char *);
 489 extern void set_default_def (tree, tree);
 490 extern tree gimple_default_def (struct function *, tree);
 491 extern bool stmt_references_abnormal_ssa_name (gimple);
 492 extern tree get_ref_base_and_extent (tree, HOST_WIDE_INT *,
 493                                      HOST_WIDE_INT *, HOST_WIDE_INT *);
 494 extern tree get_addr_base_and_unit_offset (tree, HOST_WIDE_INT *);
 495 extern void find_referenced_vars_in (gimple);
 496
 497 /* In tree-phinodes.c  */
 498 extern void reserve_phi_args_for_new_edge (basic_block);
 499 extern void add_phi_node_to_bb (gimple phi, basic_block bb);
 500 extern gimple make_phi_node (tree var, int len);
 501 extern gimple create_phi_node (tree, basic_block);
 502 extern void add_phi_arg (gimple, tree, edge, source_location);
 503 extern void remove_phi_args (edge);
 504 extern void remove_phi_node (gimple_stmt_iterator *, bool);
 505 extern void remove_phi_nodes (basic_block);
 506 extern void init_phinodes (void);
 507 extern void fini_phinodes (void);
 508 extern void release_phi_node (gimple);
 509 #ifdef GATHER_STATISTICS
 510 extern void phinodes_print_statistics (void);
 511 #endif
 512
 513 /* In gimple-low.c  */
 514 extern void record_vars_into (tree, tree);
 515 extern void record_vars (tree);
 516 extern bool gimple_seq_may_fallthru (gimple_seq);
 517 extern bool gimple_stmt_may_fallthru (gimple);
 518 extern bool gimple_check_call_args (gimple);
 519
 520
 521 /* In tree-ssa.c  */
 522
 523 /* Mapping for redirected edges.  */
 524 struct GTY(()) _edge_var_map {
 525   tree result;                  /* PHI result.  */
 526   tree def;                     /* PHI arg definition.  */
 527   source_location locus;        /* PHI arg location.  */
 528 };
 529 typedef struct _edge_var_map edge_var_map;
 530
 531 DEF_VEC_O(edge_var_map);
 532 DEF_VEC_ALLOC_O(edge_var_map, heap);
 533
 534 /* A vector of var maps.  */
 535 typedef VEC(edge_var_map, heap) *edge_var_map_vector;
 536
 537 extern void init_tree_ssa (struct function *);
 538 extern void redirect_edge_var_map_add (edge, tree, tree, source_location);
 539 extern void redirect_edge_var_map_clear (edge);
 540 extern void redirect_edge_var_map_dup (edge, edge);
 541 extern edge_var_map_vector redirect_edge_var_map_vector (edge);
 542 extern void redirect_edge_var_map_destroy (void);
 543
 544 extern edge ssa_redirect_edge (edge, basic_block);
 545 extern void flush_pending_stmts (edge);
 546 extern void verify_ssa (bool);
 547 extern void delete_tree_ssa (void);
 548 extern bool ssa_undefined_value_p (tree);
 549 extern void warn_uninit (tree, const char *, void *);
 550 extern unsigned int warn_uninitialized_vars (bool);
 551 extern void execute_update_addresses_taken (bool);
 552
 553 /* Call-back function for walk_use_def_chains().  At each reaching
 554    definition, a function with this prototype is called.  */
 555 typedef bool (*walk_use_def_chains_fn) (tree, gimple, void *);
 556
 557 extern void walk_use_def_chains (tree, walk_use_def_chains_fn, void *, bool);
 558
 559 void insert_debug_temps_for_defs (gimple_stmt_iterator *);
 560 void insert_debug_temp_for_var_def (gimple_stmt_iterator *, tree);
 561 void release_defs_bitset (bitmap toremove);
 562
 563 /* In tree-into-ssa.c  */
 564 void update_ssa (unsigned);
 565 void delete_update_ssa (void);
 566 void register_new_name_mapping (tree, tree);
 567 tree create_new_def_for (tree, gimple, def_operand_p);
 568 bool need_ssa_update_p (struct function *);
 569 bool name_mappings_registered_p (void);
 570 bool name_registered_for_update_p (tree);
 571 bitmap ssa_names_to_replace (void);
 572 void release_ssa_name_after_update_ssa (tree);
 573 void compute_global_livein (bitmap, bitmap);
 574 void mark_sym_for_renaming (tree);
 575 void mark_set_for_renaming (bitmap);
 576 bool symbol_marked_for_renaming (tree);
 577 tree get_current_def (tree);
 578 void set_current_def (tree, tree);
 579
 580 /* In tree-ssanames.c  */
 581 extern void init_ssanames (struct function *, int);
 582 extern void fini_ssanames (void);
 583 extern tree make_ssa_name_fn (struct function *, tree, gimple);
 584 extern tree duplicate_ssa_name (tree, gimple);
 585 extern void duplicate_ssa_name_ptr_info (tree, struct ptr_info_def *);
 586 extern void release_ssa_name (tree);
 587 extern void release_defs (gimple);
 588 extern void replace_ssa_name_symbol (tree, tree);
 589
 590 #ifdef GATHER_STATISTICS
 591 extern void ssanames_print_statistics (void);
 592 #endif
 593
 594 /* In tree-ssa-ccp.c  */
 595 tree fold_const_aggregate_ref (tree);
 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 tree degenerate_phi_result (gimple);
 602
 603 /* In tree-ssa-copy.c  */
 604 extern void propagate_value (use_operand_p, tree);
 605 extern void propagate_tree_value (tree *, tree);
 606 extern void propagate_tree_value_into_stmt (gimple_stmt_iterator *, tree);
 607 extern void replace_exp (use_operand_p, tree);
 608 extern bool may_propagate_copy (tree, tree);
 609 extern bool may_propagate_copy_into_stmt (gimple, tree);
 610 extern bool may_propagate_copy_into_asm (tree);
 611
 612 /* Affine iv.  */
 613
 614 typedef struct
 615 {
 616   /* Iv = BASE + STEP * i.  */
 617   tree base, step;
 618
 619   /* True if this iv does not overflow.  */
 620   bool no_overflow;
 621 } affine_iv;
 622
 623 /* Description of number of iterations of a loop.  All the expressions inside
 624    the structure can be evaluated at the end of the loop's preheader
 625    (and due to ssa form, also anywhere inside the body of the loop).  */
 626
 627 struct tree_niter_desc
 628 {
 629   tree assumptions;     /* The boolean expression.  If this expression evaluates
 630                            to false, then the other fields in this structure
 631                            should not be used; there is no guarantee that they
 632                            will be correct.  */
 633   tree may_be_zero;     /* The boolean expression.  If it evaluates to true,
 634                            the loop will exit in the first iteration (i.e.
 635                            its latch will not be executed), even if the niter
 636                            field says otherwise.  */
 637   tree niter;           /* The expression giving the number of iterations of
 638                            a loop (provided that assumptions == true and
 639                            may_be_zero == false), more precisely the number
 640                            of executions of the latch of the loop.  */
 641   double_int max;       /* The upper bound on the number of iterations of
 642                            the loop.  */
 643
 644   /* The simplified shape of the exit condition.  The loop exits if
 645      CONTROL CMP BOUND is false, where CMP is one of NE_EXPR,
 646      LT_EXPR, or GT_EXPR, and step of CONTROL is positive if CMP is
 647      LE_EXPR and negative if CMP is GE_EXPR.  This information is used
 648      by loop unrolling.  */
 649   affine_iv control;
 650   tree bound;
 651   enum tree_code cmp;
 652 };
 653
 654 /* In tree-ssa-phiopt.c */
 655 bool empty_block_p (basic_block);
 656 basic_block *blocks_in_phiopt_order (void);
 657
 658 /* In tree-ssa-loop*.c  */
 659
 660 unsigned int tree_ssa_lim (void);
 661 unsigned int tree_ssa_unswitch_loops (void);
 662 unsigned int canonicalize_induction_variables (void);
 663 unsigned int tree_unroll_loops_completely (bool, bool);
 664 unsigned int tree_ssa_prefetch_arrays (void);
 665 void tree_ssa_iv_optimize (void);
 666 unsigned tree_predictive_commoning (void);
 667 tree canonicalize_loop_ivs (struct loop *, tree *, bool);
 668 bool parallelize_loops (void);
 669
 670 bool loop_only_exit_p (const struct loop *, const_edge);
 671 bool number_of_iterations_exit (struct loop *, edge,
 672                                 struct tree_niter_desc *niter, bool);
 673 tree find_loop_niter (struct loop *, edge *);
 674 tree loop_niter_by_eval (struct loop *, edge);
 675 tree find_loop_niter_by_eval (struct loop *, edge *);
 676 void estimate_numbers_of_iterations (void);
 677 bool array_at_struct_end_p (tree);
 678 bool scev_probably_wraps_p (tree, tree, gimple, struct loop *, bool);
 679 bool convert_affine_scev (struct loop *, tree, tree *, tree *, gimple, bool);
 680
 681 bool nowrap_type_p (tree);
 682 enum ev_direction {EV_DIR_GROWS, EV_DIR_DECREASES, EV_DIR_UNKNOWN};
 683 enum ev_direction scev_direction (const_tree);
 684
 685 void free_numbers_of_iterations_estimates (void);
 686 void free_numbers_of_iterations_estimates_loop (struct loop *);
 687 void rewrite_into_loop_closed_ssa (bitmap, unsigned);
 688 void verify_loop_closed_ssa (bool);
 689 bool for_each_index (tree *, bool (*) (tree, tree *, void *), void *);
 690 void create_iv (tree, tree, tree, struct loop *, gimple_stmt_iterator *, bool,
 691                 tree *, tree *);
 692 basic_block split_loop_exit_edge (edge);
 693 void standard_iv_increment_position (struct loop *, gimple_stmt_iterator *,
 694                                      bool *);
 695 basic_block ip_end_pos (struct loop *);
 696 basic_block ip_normal_pos (struct loop *);
 697 bool gimple_duplicate_loop_to_header_edge (struct loop *, edge,
 698                                          unsigned int, sbitmap,
 699                                          edge, VEC (edge, heap) **,
 700                                          int);
 701 struct loop *slpeel_tree_duplicate_loop_to_edge_cfg (struct loop *, edge);
 702 void rename_variables_in_loop (struct loop *);
 703 void rename_variables_in_bb (basic_block bb);
 704 struct loop *tree_ssa_loop_version (struct loop *, tree,
 705                                     basic_block *);
 706 tree expand_simple_operations (tree);
 707 void substitute_in_loop_info (struct loop *, tree, tree);
 708 edge single_dom_exit (struct loop *);
 709 bool can_unroll_loop_p (struct loop *loop, unsigned factor,
 710                         struct tree_niter_desc *niter);
 711 void tree_unroll_loop (struct loop *, unsigned,
 712                        edge, struct tree_niter_desc *);
 713 typedef void (*transform_callback)(struct loop *, void *);
 714 void tree_transform_and_unroll_loop (struct loop *, unsigned,
 715                                      edge, struct tree_niter_desc *,
 716                                      transform_callback, void *);
 717 bool contains_abnormal_ssa_name_p (tree);
 718 bool stmt_dominates_stmt_p (gimple, gimple);
 719 void mark_virtual_ops_for_renaming (gimple);
 720
 721 /* In tree-ssa-dce.c */
 722 void mark_virtual_phi_result_for_renaming (gimple);
 723
 724 /* In tree-ssa-threadedge.c */
 725 extern void threadedge_initialize_values (void);
 726 extern void threadedge_finalize_values (void);
 727 extern VEC(tree,heap) *ssa_name_values;
 728 #define SSA_NAME_VALUE(x) \
 729     (SSA_NAME_VERSION(x) < VEC_length(tree, ssa_name_values) \
 730      ? VEC_index(tree, ssa_name_values, SSA_NAME_VERSION(x)) \
 731      : NULL_TREE)
 732 extern void set_ssa_name_value (tree, tree);
 733 extern bool potentially_threadable_block (basic_block);
 734 extern void thread_across_edge (gimple, edge, bool,
 735                                 VEC(tree, heap) **, tree (*) (gimple, gimple));
 736
 737 /* In tree-ssa-loop-im.c  */
 738 /* The possibilities of statement movement.  */
 739
 740 enum move_pos
 741   {
 742     MOVE_IMPOSSIBLE,            /* No movement -- side effect expression.  */
 743     MOVE_PRESERVE_EXECUTION,    /* Must not cause the non-executed statement
 744                                    become executed -- memory accesses, ... */
 745     MOVE_POSSIBLE               /* Unlimited movement.  */
 746   };
 747 extern enum move_pos movement_possibility (gimple);
 748 char *get_lsm_tmp_name (tree, unsigned);
 749
 750 /* In tree-flow-inline.h  */
 751 static inline void set_is_used (tree);
 752 static inline bool unmodifiable_var_p (const_tree);
 753 static inline bool ref_contains_array_ref (const_tree);
 754
 755 /* In tree-eh.c  */
 756 extern void make_eh_edges (gimple);
 757 extern bool make_eh_dispatch_edges (gimple);
 758 extern edge redirect_eh_edge (edge, basic_block);
 759 extern void redirect_eh_dispatch_edge (gimple, edge, basic_block);
 760 extern bool tree_could_trap_p (tree);
 761 extern bool operation_could_trap_helper_p (enum tree_code, bool, bool, bool,
 762                                            bool, tree, bool *);
 763 extern bool operation_could_trap_p (enum tree_code, bool, bool, tree);
 764 extern bool stmt_could_throw_p (gimple);
 765 extern bool tree_could_throw_p (tree);
 766 extern bool stmt_can_throw_internal (gimple);
 767 extern bool stmt_can_throw_external (gimple);
 768 extern void add_stmt_to_eh_lp_fn (struct function *, gimple, int);
 769 extern void add_stmt_to_eh_lp (gimple, int);
 770 extern bool remove_stmt_from_eh_lp (gimple);
 771 extern bool remove_stmt_from_eh_lp_fn (struct function *, gimple);
 772 extern int lookup_stmt_eh_lp_fn (struct function *, gimple);
 773 extern int lookup_stmt_eh_lp (gimple);
 774 extern bool maybe_clean_eh_stmt_fn (struct function *, gimple);
 775 extern bool maybe_clean_eh_stmt (gimple);
 776 extern bool maybe_clean_or_replace_eh_stmt (gimple, gimple);
 777 extern bool maybe_duplicate_eh_stmt_fn (struct function *, gimple,
 778                                         struct function *, gimple,
 779                                         struct pointer_map_t *, int);
 780 extern bool maybe_duplicate_eh_stmt (gimple, gimple);
 781 extern bool verify_eh_edges (gimple);
 782 extern bool verify_eh_dispatch_edge (gimple);
 783
 784 /* In tree-ssa-pre.c  */
 785 struct pre_expr_d;
 786 void add_to_value (unsigned int, struct pre_expr_d *);
 787 void debug_value_expressions (unsigned int);
 788 void print_value_expressions (FILE *, unsigned int);
 789
 790 /* In tree-ssa-sink.c  */
 791 bool is_hidden_global_store (gimple);
 792
 793 /* In tree-loop-linear.c  */
 794 extern void linear_transform_loops (void);
 795 extern unsigned perfect_loop_nest_depth (struct loop *);
 796
 797 /* In graphite.c  */
 798 extern void graphite_transform_loops (void);
 799
 800 /* In tree-data-ref.c  */
 801 extern void tree_check_data_deps (void);
 802
 803 /* In tree-ssa-loop-ivopts.c  */
 804 bool expr_invariant_in_loop_p (struct loop *, tree);
 805 bool stmt_invariant_in_loop_p (struct loop *, gimple);
 806 bool multiplier_allowed_in_address_p (HOST_WIDE_INT, enum machine_mode,
 807                                       addr_space_t);
 808 unsigned multiply_by_cost (HOST_WIDE_INT, enum machine_mode, bool);
 809
 810 /* In tree-ssa-threadupdate.c.  */
 811 extern bool thread_through_all_blocks (bool);
 812 extern void register_jump_thread (edge, edge);
 813
 814 /* In gimplify.c  */
 815 tree force_gimple_operand (tree, gimple_seq *, bool, tree);
 816 tree force_gimple_operand_gsi (gimple_stmt_iterator *, tree, bool, tree,
 817                                bool, enum gsi_iterator_update);
 818 tree gimple_fold_indirect_ref (tree);
 819
 820 /* In tree-ssa-live.c */
 821 extern void remove_unused_locals (void);
 822 extern void dump_scope_blocks (FILE *, int);
 823 extern void debug_scope_blocks (int);
 824 extern void debug_scope_block (tree, int);
 825
 826 /* In tree-ssa-address.c  */
 827
 828 /* Description of a memory address.  */
 829
 830 struct mem_address
 831 {
 832   tree symbol, base, index, step, offset;
 833 };
 834
 835 struct affine_tree_combination;
 836 tree create_mem_ref (gimple_stmt_iterator *, tree,
 837                      struct affine_tree_combination *, tree, bool);
 838 rtx addr_for_mem_ref (struct mem_address *, addr_space_t, bool);
 839 void get_address_description (tree, struct mem_address *);
 840 tree maybe_fold_tmr (tree);
 841
 842 unsigned int execute_free_datastructures (void);
 843 unsigned int execute_fixup_cfg (void);
 844 bool fixup_noreturn_call (gimple stmt);
 845
 846 /* In ipa-pure-const.c  */
 847 void warn_function_noreturn (tree);
 848
 849 #include "tree-flow-inline.h"
 850
 851 void swap_tree_operands (gimple, tree *, tree *);
 852
 853 int least_common_multiple (int, int);
 854
 855 #endif /* _TREE_FLOW_H  */