gcc/tree-flow.h

   1 /* Data and Control Flow Analysis for Trees.
   2    Copyright (C) 2001, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
   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   VEC(tree,gc) *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   /* Alignment and misalignment of the pointer in bytes.  Together
 124      align and misalign specify low known bits of the pointer.
 125      ptr & (align - 1) == misalign.  */
 126
 127   /* The power-of-two byte alignment of the object this pointer
 128      points into.  This is usually DECL_ALIGN_UNIT for decls and
 129      MALLOC_ABI_ALIGNMENT for allocated storage.  */
 130   unsigned int align;
 131
 132   /* The byte offset this pointer differs from the above alignment.  */
 133   unsigned int misalign;
 134 };
 135
 136
 137 /* It is advantageous to avoid things like life analysis for variables which
 138    do not need PHI nodes.  This enum describes whether or not a particular
 139    variable may need a PHI node.  */
 140
 141 enum need_phi_state {
 142   /* This is the default.  If we are still in this state after finding
 143      all the definition and use sites, then we will assume the variable
 144      needs PHI nodes.  This is probably an overly conservative assumption.  */
 145   NEED_PHI_STATE_UNKNOWN,
 146
 147   /* This state indicates that we have seen one or more sets of the
 148      variable in a single basic block and that the sets dominate all
 149      uses seen so far.  If after finding all definition and use sites
 150      we are still in this state, then the variable does not need any
 151      PHI nodes.  */
 152   NEED_PHI_STATE_NO,
 153
 154   /* This state indicates that we have either seen multiple definitions of
 155      the variable in multiple blocks, or that we encountered a use in a
 156      block that was not dominated by the block containing the set(s) of
 157      this variable.  This variable is assumed to need PHI nodes.  */
 158   NEED_PHI_STATE_MAYBE
 159 };
 160
 161
 162 struct GTY(()) var_ann_d {
 163   /* Used when building base variable structures in a var_map.  */
 164   unsigned base_var_processed : 1;
 165
 166   /* Nonzero if this variable was used after SSA optimizations were
 167      applied.  We set this when translating out of SSA form.  */
 168   unsigned used : 1;
 169
 170   /* This field indicates whether or not the variable may need PHI nodes.
 171      See the enum's definition for more detailed information about the
 172      states.  */
 173   ENUM_BITFIELD (need_phi_state) need_phi_state : 2;
 174
 175   /* Used by var_map for the base index of ssa base variables.  */
 176   unsigned base_index;
 177
 178   /* During into-ssa and the dominator optimizer, this field holds the
 179      current version of this variable (an SSA_NAME).  */
 180   tree current_def;
 181 };
 182
 183
 184 /* Immediate use lists are used to directly access all uses for an SSA
 185    name and get pointers to the statement for each use.
 186
 187    The structure ssa_use_operand_d consists of PREV and NEXT pointers
 188    to maintain the list.  A USE pointer, which points to address where
 189    the use is located and a LOC pointer which can point to the
 190    statement where the use is located, or, in the case of the root
 191    node, it points to the SSA name itself.
 192
 193    The list is anchored by an occurrence of ssa_operand_d *in* the
 194    ssa_name node itself (named 'imm_uses').  This node is uniquely
 195    identified by having a NULL USE pointer. and the LOC pointer
 196    pointing back to the ssa_name node itself.  This node forms the
 197    base for a circular list, and initially this is the only node in
 198    the list.
 199
 200    Fast iteration allows each use to be examined, but does not allow
 201    any modifications to the uses or stmts.
 202
 203    Normal iteration allows insertion, deletion, and modification. the
 204    iterator manages this by inserting a marker node into the list
 205    immediately before the node currently being examined in the list.
 206    this marker node is uniquely identified by having null stmt *and* a
 207    null use pointer.
 208
 209    When iterating to the next use, the iteration routines check to see
 210    if the node after the marker has changed. if it has, then the node
 211    following the marker is now the next one to be visited. if not, the
 212    marker node is moved past that node in the list (visualize it as
 213    bumping the marker node through the list).  this continues until
 214    the marker node is moved to the original anchor position. the
 215    marker node is then removed from the list.
 216
 217    If iteration is halted early, the marker node must be removed from
 218    the list before continuing.  */
 219 typedef struct immediate_use_iterator_d
 220 {
 221   /* This is the current use the iterator is processing.  */
 222   ssa_use_operand_t *imm_use;
 223   /* This marks the last use in the list (use node from SSA_NAME)  */
 224   ssa_use_operand_t *end_p;
 225   /* This node is inserted and used to mark the end of the uses for a stmt.  */
 226   ssa_use_operand_t iter_node;
 227   /* This is the next ssa_name to visit.  IMM_USE may get removed before
 228      the next one is traversed to, so it must be cached early.  */
 229   ssa_use_operand_t *next_imm_name;
 230 } imm_use_iterator;
 231
 232
 233 /* Use this iterator when simply looking at stmts.  Adding, deleting or
 234    modifying stmts will cause this iterator to malfunction.  */
 235
 236 #define FOR_EACH_IMM_USE_FAST(DEST, ITER, SSAVAR)               \
 237   for ((DEST) = first_readonly_imm_use (&(ITER), (SSAVAR));     \
 238        !end_readonly_imm_use_p (&(ITER));                       \
 239        (void) ((DEST) = next_readonly_imm_use (&(ITER))))
 240
 241 /* Use this iterator to visit each stmt which has a use of SSAVAR.  */
 242
 243 #define FOR_EACH_IMM_USE_STMT(STMT, ITER, SSAVAR)               \
 244   for ((STMT) = first_imm_use_stmt (&(ITER), (SSAVAR));         \
 245        !end_imm_use_stmt_p (&(ITER));                           \
 246        (void) ((STMT) = next_imm_use_stmt (&(ITER))))
 247
 248 /* Use this to terminate the FOR_EACH_IMM_USE_STMT loop early.  Failure to
 249    do so will result in leaving a iterator marker node in the immediate
 250    use list, and nothing good will come from that.   */
 251 #define BREAK_FROM_IMM_USE_STMT(ITER)                           \
 252    {                                                            \
 253      end_imm_use_stmt_traverse (&(ITER));                       \
 254      break;                                                     \
 255    }
 256
 257
 258 /* Use this iterator in combination with FOR_EACH_IMM_USE_STMT to
 259    get access to each occurrence of ssavar on the stmt returned by
 260    that iterator..  for instance:
 261
 262      FOR_EACH_IMM_USE_STMT (stmt, iter, var)
 263        {
 264          FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
 265            {
 266              SET_USE (use_p, blah);
 267            }
 268          update_stmt (stmt);
 269        }                                                         */
 270
 271 #define FOR_EACH_IMM_USE_ON_STMT(DEST, ITER)                    \
 272   for ((DEST) = first_imm_use_on_stmt (&(ITER));                \
 273        !end_imm_use_on_stmt_p (&(ITER));                        \
 274        (void) ((DEST) = next_imm_use_on_stmt (&(ITER))))
 275
 276
 277
 278 typedef struct var_ann_d *var_ann_t;
 279
 280 static inline var_ann_t var_ann (const_tree);
 281 static inline void update_stmt (gimple);
 282 static inline int get_lineno (const_gimple);
 283
 284 /* Accessors for basic block annotations.  */
 285 static inline gimple_seq phi_nodes (const_basic_block);
 286 static inline void set_phi_nodes (basic_block, gimple_seq);
 287
 288 /*---------------------------------------------------------------------------
 289                               Global declarations
 290 ---------------------------------------------------------------------------*/
 291 struct int_tree_map {
 292   unsigned int uid;
 293   tree to;
 294 };
 295
 296 extern unsigned int int_tree_map_hash (const void *);
 297 extern int int_tree_map_eq (const void *, const void *);
 298
 299 extern unsigned int uid_decl_map_hash (const void *);
 300 extern int uid_decl_map_eq (const void *, const void *);
 301
 302 typedef struct
 303 {
 304   htab_iterator hti;
 305 } referenced_var_iterator;
 306
 307 /* This macro loops over all the referenced vars, one at a time, putting the
 308    current var in VAR.  Note:  You are not allowed to add referenced variables
 309    to the hashtable while using this macro.  Doing so may cause it to behave
 310    erratically.  */
 311
 312 #define FOR_EACH_REFERENCED_VAR(FN, VAR, ITER)          \
 313   for ((VAR) = first_referenced_var ((FN), &(ITER));    \
 314        !end_referenced_vars_p (&(ITER));                \
 315        (VAR) = next_referenced_var (&(ITER)))
 316
 317 extern tree referenced_var_lookup (struct function *, unsigned int);
 318 extern bool referenced_var_check_and_insert (tree);
 319 #define num_referenced_vars htab_elements (gimple_referenced_vars (cfun))
 320
 321 #define num_ssa_names (VEC_length (tree, cfun->gimple_df->ssa_names))
 322 #define ssa_name(i) (VEC_index (tree, cfun->gimple_df->ssa_names, (i)))
 323
 324 /* Macros for showing usage statistics.  */
 325 #define SCALE(x) ((unsigned long) ((x) < 1024*10        \
 326                   ? (x)                                 \
 327                   : ((x) < 1024*1024*10                 \
 328                      ? (x) / 1024                       \
 329                      : (x) / (1024*1024))))
 330
 331 #define LABEL(x) ((x) < 1024*10 ? 'b' : ((x) < 1024*1024*10 ? 'k' : 'M'))
 332
 333 #define PERCENT(x,y) ((float)(x) * 100.0 / (float)(y))
 334
 335 /*---------------------------------------------------------------------------
 336                               OpenMP Region Tree
 337 ---------------------------------------------------------------------------*/
 338
 339 /* Parallel region information.  Every parallel and workshare
 340    directive is enclosed between two markers, the OMP_* directive
 341    and a corresponding OMP_RETURN statement.  */
 342
 343 struct omp_region
 344 {
 345   /* The enclosing region.  */
 346   struct omp_region *outer;
 347
 348   /* First child region.  */
 349   struct omp_region *inner;
 350
 351   /* Next peer region.  */
 352   struct omp_region *next;
 353
 354   /* Block containing the omp directive as its last stmt.  */
 355   basic_block entry;
 356
 357   /* Block containing the OMP_RETURN as its last stmt.  */
 358   basic_block exit;
 359
 360   /* Block containing the OMP_CONTINUE as its last stmt.  */
 361   basic_block cont;
 362
 363   /* If this is a combined parallel+workshare region, this is a list
 364      of additional arguments needed by the combined parallel+workshare
 365      library call.  */
 366   VEC(tree,gc) *ws_args;
 367
 368   /* The code for the omp directive of this region.  */
 369   enum gimple_code type;
 370
 371   /* Schedule kind, only used for OMP_FOR type regions.  */
 372   enum omp_clause_schedule_kind sched_kind;
 373
 374   /* True if this is a combined parallel+workshare region.  */
 375   bool is_combined_parallel;
 376 };
 377
 378 extern struct omp_region *root_omp_region;
 379 extern struct omp_region *new_omp_region (basic_block, enum gimple_code,
 380                                           struct omp_region *);
 381 extern void free_omp_regions (void);
 382 void omp_expand_local (basic_block);
 383 extern tree find_omp_clause (tree, enum omp_clause_code);
 384 tree copy_var_decl (tree, tree, tree);
 385
 386 /*---------------------------------------------------------------------------
 387                               Function prototypes
 388 ---------------------------------------------------------------------------*/
 389 /* In tree-cfg.c  */
 390
 391 /* Location to track pending stmt for edge insertion.  */
 392 #define PENDING_STMT(e) ((e)->insns.g)
 393
 394 extern void delete_tree_cfg_annotations (void);
 395 extern bool stmt_ends_bb_p (gimple);
 396 extern bool is_ctrl_stmt (gimple);
 397 extern bool is_ctrl_altering_stmt (gimple);
 398 extern bool simple_goto_p (gimple);
 399 extern bool stmt_can_make_abnormal_goto (gimple);
 400 extern basic_block single_noncomplex_succ (basic_block bb);
 401 extern void gimple_dump_bb (basic_block, FILE *, int, int);
 402 extern void gimple_debug_bb (basic_block);
 403 extern basic_block gimple_debug_bb_n (int);
 404 extern void gimple_dump_cfg (FILE *, int);
 405 extern void gimple_debug_cfg (int);
 406 extern void dump_cfg_stats (FILE *);
 407 extern void dot_cfg (void);
 408 extern void debug_cfg_stats (void);
 409 extern void debug_loops (int);
 410 extern void debug_loop (struct loop *, int);
 411 extern void debug_loop_num (unsigned, int);
 412 extern void print_loops (FILE *, int);
 413 extern void print_loops_bb (FILE *, basic_block, int, int);
 414 extern void cleanup_dead_labels (void);
 415 extern void group_case_labels (void);
 416 extern gimple first_stmt (basic_block);
 417 extern gimple last_stmt (basic_block);
 418 extern gimple last_and_only_stmt (basic_block);
 419 extern edge find_taken_edge (basic_block, tree);
 420 extern basic_block label_to_block_fn (struct function *, tree);
 421 #define label_to_block(t) (label_to_block_fn (cfun, t))
 422 extern void notice_special_calls (gimple);
 423 extern void clear_special_calls (void);
 424 extern void verify_gimple_in_seq (gimple_seq);
 425 extern void verify_gimple_in_cfg (struct function *);
 426 extern tree gimple_block_label (basic_block);
 427 extern void extract_true_false_edges_from_block (basic_block, edge *, edge *);
 428 extern bool gimple_duplicate_sese_region (edge, edge, basic_block *, unsigned,
 429                                         basic_block *);
 430 extern bool gimple_duplicate_sese_tail (edge, edge, basic_block *, unsigned,
 431                                       basic_block *);
 432 extern void gather_blocks_in_sese_region (basic_block entry, basic_block exit,
 433                                           VEC(basic_block,heap) **bbs_p);
 434 extern void add_phi_args_after_copy_bb (basic_block);
 435 extern void add_phi_args_after_copy (basic_block *, unsigned, edge);
 436 extern bool gimple_purge_dead_eh_edges (basic_block);
 437 extern bool gimple_purge_all_dead_eh_edges (const_bitmap);
 438 extern bool gimple_purge_dead_abnormal_call_edges (basic_block);
 439 extern bool gimple_purge_all_dead_abnormal_call_edges (const_bitmap);
 440 extern tree gimplify_build1 (gimple_stmt_iterator *, enum tree_code,
 441                              tree, tree);
 442 extern tree gimplify_build2 (gimple_stmt_iterator *, enum tree_code,
 443                              tree, tree, tree);
 444 extern tree gimplify_build3 (gimple_stmt_iterator *, enum tree_code,
 445                              tree, tree, tree, tree);
 446 extern void init_empty_tree_cfg (void);
 447 extern void init_empty_tree_cfg_for_function (struct function *);
 448 extern void fold_cond_expr_cond (void);
 449 extern void make_abnormal_goto_edges (basic_block, bool);
 450 extern void replace_uses_by (tree, tree);
 451 extern void start_recording_case_labels (void);
 452 extern void end_recording_case_labels (void);
 453 extern basic_block move_sese_region_to_fn (struct function *, basic_block,
 454                                            basic_block, tree);
 455 void remove_edge_and_dominated_blocks (edge);
 456 bool tree_node_can_be_shared (tree);
 457
 458 /* In tree-cfgcleanup.c  */
 459 extern bitmap cfgcleanup_altered_bbs;
 460 extern bool cleanup_tree_cfg (void);
 461
 462 /* In tree-pretty-print.c.  */
 463 extern void dump_generic_bb (FILE *, basic_block, int, int);
 464 extern int op_code_prio (enum tree_code);
 465 extern int op_prio (const_tree);
 466 extern const char *op_symbol_code (enum tree_code);
 467
 468 /* In tree-dfa.c  */
 469 extern var_ann_t create_var_ann (tree);
 470 extern void renumber_gimple_stmt_uids (void);
 471 extern void renumber_gimple_stmt_uids_in_blocks (basic_block *, int);
 472 extern void dump_dfa_stats (FILE *);
 473 extern void debug_dfa_stats (void);
 474 extern void debug_referenced_vars (void);
 475 extern void dump_referenced_vars (FILE *);
 476 extern void dump_variable (FILE *, tree);
 477 extern void debug_variable (tree);
 478 extern tree get_virtual_var (tree);
 479 extern bool add_referenced_var (tree);
 480 extern void remove_referenced_var (tree);
 481 extern void mark_symbols_for_renaming (gimple);
 482 extern void find_new_referenced_vars (gimple);
 483 extern tree make_rename_temp (tree, const char *);
 484 extern void set_default_def (tree, tree);
 485 extern tree gimple_default_def (struct function *, tree);
 486 extern bool stmt_references_abnormal_ssa_name (gimple);
 487 extern tree get_ref_base_and_extent (tree, HOST_WIDE_INT *,
 488                                      HOST_WIDE_INT *, HOST_WIDE_INT *);
 489 extern tree get_addr_base_and_unit_offset (tree, HOST_WIDE_INT *);
 490 extern void find_referenced_vars_in (gimple);
 491
 492 /* In tree-phinodes.c  */
 493 extern void reserve_phi_args_for_new_edge (basic_block);
 494 extern void add_phi_node_to_bb (gimple phi, basic_block bb);
 495 extern gimple make_phi_node (tree var, int len);
 496 extern gimple create_phi_node (tree, basic_block);
 497 extern void add_phi_arg (gimple, tree, edge, source_location);
 498 extern void remove_phi_args (edge);
 499 extern void remove_phi_node (gimple_stmt_iterator *, bool);
 500 extern void remove_phi_nodes (basic_block);
 501 extern void init_phinodes (void);
 502 extern void fini_phinodes (void);
 503 extern void release_phi_node (gimple);
 504 #ifdef GATHER_STATISTICS
 505 extern void phinodes_print_statistics (void);
 506 #endif
 507
 508 /* In gimple-low.c  */
 509 extern void record_vars_into (tree, tree);
 510 extern void record_vars (tree);
 511 extern bool gimple_seq_may_fallthru (gimple_seq);
 512 extern bool gimple_stmt_may_fallthru (gimple);
 513 extern bool gimple_check_call_matching_types (gimple, tree);
 514
 515
 516 /* In tree-ssa.c  */
 517
 518 /* Mapping for redirected edges.  */
 519 struct _edge_var_map {
 520   tree result;                  /* PHI result.  */
 521   tree def;                     /* PHI arg definition.  */
 522   source_location locus;        /* PHI arg location.  */
 523 };
 524 typedef struct _edge_var_map edge_var_map;
 525
 526 DEF_VEC_O(edge_var_map);
 527 DEF_VEC_ALLOC_O(edge_var_map, heap);
 528
 529 /* A vector of var maps.  */
 530 typedef VEC(edge_var_map, heap) *edge_var_map_vector;
 531
 532 extern void init_tree_ssa (struct function *);
 533 extern void redirect_edge_var_map_add (edge, tree, tree, source_location);
 534 extern void redirect_edge_var_map_clear (edge);
 535 extern void redirect_edge_var_map_dup (edge, edge);
 536 extern edge_var_map_vector redirect_edge_var_map_vector (edge);
 537 extern void redirect_edge_var_map_destroy (void);
 538
 539 extern edge ssa_redirect_edge (edge, basic_block);
 540 extern void flush_pending_stmts (edge);
 541 extern void verify_ssa (bool);
 542 extern void delete_tree_ssa (void);
 543 extern bool ssa_undefined_value_p (tree);
 544 extern void warn_uninit (enum opt_code, tree, tree, tree, const char *, void *);
 545 extern unsigned int warn_uninitialized_vars (bool);
 546 extern void execute_update_addresses_taken (void);
 547
 548 /* Call-back function for walk_use_def_chains().  At each reaching
 549    definition, a function with this prototype is called.  */
 550 typedef bool (*walk_use_def_chains_fn) (tree, gimple, void *);
 551
 552 extern void walk_use_def_chains (tree, walk_use_def_chains_fn, void *, bool);
 553
 554 void insert_debug_temps_for_defs (gimple_stmt_iterator *);
 555 void insert_debug_temp_for_var_def (gimple_stmt_iterator *, tree);
 556 void reset_debug_uses (gimple);
 557 void release_defs_bitset (bitmap toremove);
 558
 559 /* In tree-into-ssa.c  */
 560 void update_ssa (unsigned);
 561 void delete_update_ssa (void);
 562 void register_new_name_mapping (tree, tree);
 563 tree create_new_def_for (tree, gimple, def_operand_p);
 564 bool need_ssa_update_p (struct function *);
 565 bool name_mappings_registered_p (void);
 566 bool name_registered_for_update_p (tree);
 567 bitmap ssa_names_to_replace (void);
 568 void release_ssa_name_after_update_ssa (tree);
 569 void compute_global_livein (bitmap, bitmap);
 570 void mark_sym_for_renaming (tree);
 571 void mark_set_for_renaming (bitmap);
 572 bool symbol_marked_for_renaming (tree);
 573 tree get_current_def (tree);
 574 void set_current_def (tree, tree);
 575
 576 /* In tree-ssanames.c  */
 577 extern void init_ssanames (struct function *, int);
 578 extern void fini_ssanames (void);
 579 extern tree make_ssa_name_fn (struct function *, tree, gimple);
 580 extern tree duplicate_ssa_name (tree, gimple);
 581 extern void duplicate_ssa_name_ptr_info (tree, struct ptr_info_def *);
 582 extern void release_ssa_name (tree);
 583 extern void release_defs (gimple);
 584 extern void replace_ssa_name_symbol (tree, tree);
 585
 586 #ifdef GATHER_STATISTICS
 587 extern void ssanames_print_statistics (void);
 588 #endif
 589
 590 /* In tree-ssa-ccp.c  */
 591 tree fold_const_aggregate_ref (tree);
 592 tree gimple_fold_stmt_to_constant (gimple, tree (*)(tree));
 593
 594 /* In tree-ssa-dom.c  */
 595 extern void dump_dominator_optimization_stats (FILE *);
 596 extern void debug_dominator_optimization_stats (void);
 597 int loop_depth_of_name (tree);
 598 tree degenerate_phi_result (gimple);
 599 bool simple_iv_increment_p (gimple);
 600
 601 /* In tree-ssa-copy.c  */
 602 extern void propagate_value (use_operand_p, tree);
 603 extern void propagate_tree_value (tree *, tree);
 604 extern void propagate_tree_value_into_stmt (gimple_stmt_iterator *, tree);
 605 extern void replace_exp (use_operand_p, tree);
 606 extern bool may_propagate_copy (tree, tree);
 607 extern bool may_propagate_copy_into_stmt (gimple, tree);
 608 extern bool may_propagate_copy_into_asm (tree);
 609
 610 /* Affine iv.  */
 611
 612 typedef struct
 613 {
 614   /* Iv = BASE + STEP * i.  */
 615   tree base, step;
 616
 617   /* True if this iv does not overflow.  */
 618   bool no_overflow;
 619 } affine_iv;
 620
 621 /* Description of number of iterations of a loop.  All the expressions inside
 622    the structure can be evaluated at the end of the loop's preheader
 623    (and due to ssa form, also anywhere inside the body of the loop).  */
 624
 625 struct tree_niter_desc
 626 {
 627   tree assumptions;     /* The boolean expression.  If this expression evaluates
 628                            to false, then the other fields in this structure
 629                            should not be used; there is no guarantee that they
 630                            will be correct.  */
 631   tree may_be_zero;     /* The boolean expression.  If it evaluates to true,
 632                            the loop will exit in the first iteration (i.e.
 633                            its latch will not be executed), even if the niter
 634                            field says otherwise.  */
 635   tree niter;           /* The expression giving the number of iterations of
 636                            a loop (provided that assumptions == true and
 637                            may_be_zero == false), more precisely the number
 638                            of executions of the latch of the loop.  */
 639   double_int max;       /* The upper bound on the number of iterations of
 640                            the loop.  */
 641
 642   /* The simplified shape of the exit condition.  The loop exits if
 643      CONTROL CMP BOUND is false, where CMP is one of NE_EXPR,
 644      LT_EXPR, or GT_EXPR, and step of CONTROL is positive if CMP is
 645      LE_EXPR and negative if CMP is GE_EXPR.  This information is used
 646      by loop unrolling.  */
 647   affine_iv control;
 648   tree bound;
 649   enum tree_code cmp;
 650 };
 651
 652 /* In tree-ssa-phiopt.c */
 653 bool empty_block_p (basic_block);
 654 basic_block *blocks_in_phiopt_order (void);
 655
 656 /* In tree-ssa-loop*.c  */
 657
 658 unsigned int tree_ssa_lim (void);
 659 unsigned int tree_ssa_unswitch_loops (void);
 660 unsigned int canonicalize_induction_variables (void);
 661 unsigned int tree_unroll_loops_completely (bool, bool);
 662 unsigned int tree_ssa_prefetch_arrays (void);
 663 void tree_ssa_iv_optimize (void);
 664 unsigned tree_predictive_commoning (void);
 665 tree canonicalize_loop_ivs (struct loop *, tree *, bool);
 666 bool parallelize_loops (void);
 667
 668 bool loop_only_exit_p (const struct loop *, const_edge);
 669 bool number_of_iterations_exit (struct loop *, edge,
 670                                 struct tree_niter_desc *niter, bool);
 671 tree find_loop_niter (struct loop *, edge *);
 672 tree loop_niter_by_eval (struct loop *, edge);
 673 tree find_loop_niter_by_eval (struct loop *, edge *);
 674 void estimate_numbers_of_iterations (bool);
 675 bool array_at_struct_end_p (tree);
 676 bool scev_probably_wraps_p (tree, tree, gimple, struct loop *, bool);
 677 bool convert_affine_scev (struct loop *, tree, tree *, tree *, gimple, bool);
 678
 679 bool nowrap_type_p (tree);
 680 enum ev_direction {EV_DIR_GROWS, EV_DIR_DECREASES, EV_DIR_UNKNOWN};
 681 enum ev_direction scev_direction (const_tree);
 682
 683 void free_numbers_of_iterations_estimates (void);
 684 void free_numbers_of_iterations_estimates_loop (struct loop *);
 685 void rewrite_into_loop_closed_ssa (bitmap, unsigned);
 686 void verify_loop_closed_ssa (bool);
 687 bool for_each_index (tree *, bool (*) (tree, tree *, void *), void *);
 688 void create_iv (tree, tree, tree, struct loop *, gimple_stmt_iterator *, bool,
 689                 tree *, tree *);
 690 basic_block split_loop_exit_edge (edge);
 691 void standard_iv_increment_position (struct loop *, gimple_stmt_iterator *,
 692                                      bool *);
 693 basic_block ip_end_pos (struct loop *);
 694 basic_block ip_normal_pos (struct loop *);
 695 bool gimple_duplicate_loop_to_header_edge (struct loop *, edge,
 696                                          unsigned int, sbitmap,
 697                                          edge, VEC (edge, heap) **,
 698                                          int);
 699 struct loop *slpeel_tree_duplicate_loop_to_edge_cfg (struct loop *, edge);
 700 void rename_variables_in_loop (struct loop *);
 701 void rename_variables_in_bb (basic_block bb);
 702 tree expand_simple_operations (tree);
 703 void substitute_in_loop_info (struct loop *, tree, tree);
 704 edge single_dom_exit (struct loop *);
 705 bool can_unroll_loop_p (struct loop *loop, unsigned factor,
 706                         struct tree_niter_desc *niter);
 707 void tree_unroll_loop (struct loop *, unsigned,
 708                        edge, struct tree_niter_desc *);
 709 typedef void (*transform_callback)(struct loop *, void *);
 710 void tree_transform_and_unroll_loop (struct loop *, unsigned,
 711                                      edge, struct tree_niter_desc *,
 712                                      transform_callback, void *);
 713 bool contains_abnormal_ssa_name_p (tree);
 714 bool stmt_dominates_stmt_p (gimple, gimple);
 715 void mark_virtual_ops_for_renaming (gimple);
 716
 717 /* In tree-ssa-dce.c */
 718 void mark_virtual_operand_for_renaming (tree);
 719 void mark_virtual_phi_result_for_renaming (gimple);
 720
 721 /* In tree-ssa-threadedge.c */
 722 extern void threadedge_initialize_values (void);
 723 extern void threadedge_finalize_values (void);
 724 extern VEC(tree,heap) *ssa_name_values;
 725 #define SSA_NAME_VALUE(x) \
 726     (SSA_NAME_VERSION(x) < VEC_length(tree, ssa_name_values) \
 727      ? VEC_index(tree, ssa_name_values, SSA_NAME_VERSION(x)) \
 728      : NULL_TREE)
 729 extern void set_ssa_name_value (tree, tree);
 730 extern bool potentially_threadable_block (basic_block);
 731 extern void thread_across_edge (gimple, edge, bool,
 732                                 VEC(tree, heap) **, tree (*) (gimple, gimple));
 733
 734 /* In tree-ssa-loop-im.c  */
 735 /* The possibilities of statement movement.  */
 736
 737 enum move_pos
 738   {
 739     MOVE_IMPOSSIBLE,            /* No movement -- side effect expression.  */
 740     MOVE_PRESERVE_EXECUTION,    /* Must not cause the non-executed statement
 741                                    become executed -- memory accesses, ... */
 742     MOVE_POSSIBLE               /* Unlimited movement.  */
 743   };
 744 extern enum move_pos movement_possibility (gimple);
 745 char *get_lsm_tmp_name (tree, unsigned);
 746
 747 /* In tree-flow-inline.h  */
 748 static inline void set_is_used (tree);
 749 static inline bool unmodifiable_var_p (const_tree);
 750 static inline bool ref_contains_array_ref (const_tree);
 751
 752 /* In tree-eh.c  */
 753 extern void make_eh_edges (gimple);
 754 extern bool make_eh_dispatch_edges (gimple);
 755 extern edge redirect_eh_edge (edge, basic_block);
 756 extern void redirect_eh_dispatch_edge (gimple, edge, basic_block);
 757 extern bool tree_could_trap_p (tree);
 758 extern bool operation_could_trap_helper_p (enum tree_code, bool, bool, bool,
 759                                            bool, tree, bool *);
 760 extern bool operation_could_trap_p (enum tree_code, bool, bool, tree);
 761 extern bool stmt_could_throw_p (gimple);
 762 extern bool tree_could_throw_p (tree);
 763 extern bool stmt_can_throw_internal (gimple);
 764 extern bool stmt_can_throw_external (gimple);
 765 extern void add_stmt_to_eh_lp_fn (struct function *, gimple, int);
 766 extern void add_stmt_to_eh_lp (gimple, int);
 767 extern bool remove_stmt_from_eh_lp (gimple);
 768 extern bool remove_stmt_from_eh_lp_fn (struct function *, gimple);
 769 extern int lookup_stmt_eh_lp_fn (struct function *, gimple);
 770 extern int lookup_stmt_eh_lp (gimple);
 771 extern bool maybe_clean_eh_stmt_fn (struct function *, gimple);
 772 extern bool maybe_clean_eh_stmt (gimple);
 773 extern bool maybe_clean_or_replace_eh_stmt (gimple, gimple);
 774 extern bool maybe_duplicate_eh_stmt_fn (struct function *, gimple,
 775                                         struct function *, gimple,
 776                                         struct pointer_map_t *, int);
 777 extern bool maybe_duplicate_eh_stmt (gimple, gimple);
 778 extern bool verify_eh_edges (gimple);
 779 extern bool verify_eh_dispatch_edge (gimple);
 780
 781 /* In tree-ssa-pre.c  */
 782 struct pre_expr_d;
 783 void add_to_value (unsigned int, struct pre_expr_d *);
 784 void debug_value_expressions (unsigned int);
 785 void print_value_expressions (FILE *, unsigned int);
 786
 787 /* In tree-ssa-sink.c  */
 788 bool is_hidden_global_store (gimple);
 789
 790 /* In tree-loop-linear.c  */
 791 extern void linear_transform_loops (void);
 792 extern unsigned perfect_loop_nest_depth (struct loop *);
 793
 794 /* In graphite.c  */
 795 extern void graphite_transform_loops (void);
 796
 797 /* In tree-data-ref.c  */
 798 extern void tree_check_data_deps (void);
 799
 800 /* In tree-ssa-loop-ivopts.c  */
 801 bool expr_invariant_in_loop_p (struct loop *, tree);
 802 bool stmt_invariant_in_loop_p (struct loop *, gimple);
 803 bool multiplier_allowed_in_address_p (HOST_WIDE_INT, enum machine_mode,
 804                                       addr_space_t);
 805 unsigned multiply_by_cost (HOST_WIDE_INT, enum machine_mode, bool);
 806 bool may_be_nonaddressable_p (tree expr);
 807
 808 /* In tree-ssa-threadupdate.c.  */
 809 extern bool thread_through_all_blocks (bool);
 810 extern void register_jump_thread (edge, edge, edge);
 811
 812 /* In gimplify.c  */
 813 tree force_gimple_operand_1 (tree, gimple_seq *, gimple_predicate, tree);
 814 tree force_gimple_operand (tree, gimple_seq *, bool, tree);
 815 tree force_gimple_operand_gsi_1 (gimple_stmt_iterator *, tree,
 816                                  gimple_predicate, tree,
 817                                  bool, enum gsi_iterator_update);
 818 tree force_gimple_operand_gsi (gimple_stmt_iterator *, tree, bool, tree,
 819                                bool, enum gsi_iterator_update);
 820 tree gimple_fold_indirect_ref (tree);
 821
 822 /* In tree-ssa-live.c */
 823 extern void remove_unused_locals (void);
 824 extern void dump_scope_blocks (FILE *, int);
 825 extern void debug_scope_blocks (int);
 826 extern void debug_scope_block (tree, int);
 827
 828 /* In tree-ssa-address.c  */
 829
 830 /* Description of a memory address.  */
 831
 832 struct mem_address
 833 {
 834   tree symbol, base, index, step, offset;
 835 };
 836
 837 struct affine_tree_combination;
 838 tree create_mem_ref (gimple_stmt_iterator *, tree,
 839                      struct affine_tree_combination *, tree, tree, tree, bool);
 840 rtx addr_for_mem_ref (struct mem_address *, addr_space_t, bool);
 841 void get_address_description (tree, struct mem_address *);
 842 tree maybe_fold_tmr (tree);
 843
 844 unsigned int execute_free_datastructures (void);
 845 unsigned int execute_fixup_cfg (void);
 846 bool fixup_noreturn_call (gimple stmt);
 847
 848 /* In ipa-pure-const.c  */
 849 void warn_function_noreturn (tree);
 850
 851 /* In tree-ssa-ter.c  */
 852 bool stmt_is_replaceable_p (gimple);
 853
 854 #include "tree-flow-inline.h"
 855
 856 void swap_tree_operands (gimple, tree *, tree *);
 857
 858 #endif /* _TREE_FLOW_H  */