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 /* This structure is used to map a gimple statement to a label,
  37    or list of labels to represent transaction restart.  */
  38
  39 struct GTY(()) tm_restart_node {
  40   gimple stmt;
  41   tree label_or_list;
  42 };
  43
  44 /* Gimple dataflow datastructure. All publicly available fields shall have
  45    gimple_ accessor defined in tree-flow-inline.h, all publicly modifiable
  46    fields should have gimple_set accessor.  */
  47 struct GTY(()) gimple_df {
  48   /* Array of all variables referenced in the function.  */
  49   htab_t GTY((param_is (union tree_node))) referenced_vars;
  50
  51   /* A vector of all the noreturn calls passed to modify_stmt.
  52      cleanup_control_flow uses it to detect cases where a mid-block
  53      indirect call has been turned into a noreturn call.  When this
  54      happens, all the instructions after the call are no longer
  55      reachable and must be deleted as dead.  */
  56   VEC(gimple,gc) *modified_noreturn_calls;
  57
  58   /* Array of all SSA_NAMEs used in the function.  */
  59   VEC(tree,gc) *ssa_names;
  60
  61   /* Artificial variable used for the virtual operand FUD chain.  */
  62   tree vop;
  63
  64   /* The PTA solution for the ESCAPED artificial variable.  */
  65   struct pt_solution escaped;
  66
  67   /* A map of decls to artificial ssa-names that point to the partition
  68      of the decl.  */
  69   struct pointer_map_t * GTY((skip(""))) decls_to_pointers;
  70
  71   /* Free list of SSA_NAMEs.  */
  72   VEC(tree,gc) *free_ssanames;
  73
  74   /* Hashtable holding definition for symbol.  If this field is not NULL, it
  75      means that the first reference to this variable in the function is a
  76      USE or a VUSE.  In those cases, the SSA renamer creates an SSA name
  77      for this variable with an empty defining statement.  */
  78   htab_t GTY((param_is (union tree_node))) default_defs;
  79
  80   /* Symbols whose SSA form needs to be updated or created for the first
  81      time.  */
  82   bitmap syms_to_rename;
  83
  84   /* True if the code is in ssa form.  */
  85   unsigned int in_ssa_p : 1;
  86
  87   /* True if IPA points-to information was computed for this function.  */
  88   unsigned int ipa_pta : 1;
  89
  90   struct ssa_operands ssa_operands;
  91
  92   /* Map gimple stmt to tree label (or list of labels) for transaction
  93      restart and abort.  */
  94   htab_t GTY ((param_is (struct tm_restart_node))) tm_restart;
  95 };
  96
  97 /* Accessors for internal use only.  Generic code should use abstraction
  98    provided by tree-flow-inline.h or specific modules.  */
  99 #define FREE_SSANAMES(fun) (fun)->gimple_df->free_ssanames
 100 #define SSANAMES(fun) (fun)->gimple_df->ssa_names
 101 #define MODIFIED_NORETURN_CALLS(fun) (fun)->gimple_df->modified_noreturn_calls
 102 #define DEFAULT_DEFS(fun) (fun)->gimple_df->default_defs
 103 #define SYMS_TO_RENAME(fun) (fun)->gimple_df->syms_to_rename
 104
 105 typedef struct
 106 {
 107   htab_t htab;
 108   PTR *slot;
 109   PTR *limit;
 110 } htab_iterator;
 111
 112 /* Iterate through the elements of hashtable HTAB, using htab_iterator ITER,
 113    storing each element in RESULT, which is of type TYPE.  */
 114 #define FOR_EACH_HTAB_ELEMENT(HTAB, RESULT, TYPE, ITER) \
 115   for (RESULT = (TYPE) first_htab_element (&(ITER), (HTAB)); \
 116         !end_htab_p (&(ITER)); \
 117         RESULT = (TYPE) next_htab_element (&(ITER)))
 118
 119 /*---------------------------------------------------------------------------
 120                       Attributes for SSA_NAMEs.
 121
 122   NOTE: These structures are stored in struct tree_ssa_name
 123   but are only used by the tree optimizers, so it makes better sense
 124   to declare them here to avoid recompiling unrelated files when
 125   making changes.
 126 ---------------------------------------------------------------------------*/
 127
 128 /* Aliasing information for SSA_NAMEs representing pointer variables.  */
 129
 130 struct GTY(()) ptr_info_def
 131 {
 132   /* The points-to solution.  */
 133   struct pt_solution pt;
 134
 135   /* Alignment and misalignment of the pointer in bytes.  Together
 136      align and misalign specify low known bits of the pointer.
 137      ptr & (align - 1) == misalign.  */
 138
 139   /* The power-of-two byte alignment of the object this pointer
 140      points into.  This is usually DECL_ALIGN_UNIT for decls and
 141      MALLOC_ABI_ALIGNMENT for allocated storage.  */
 142   unsigned int align;
 143
 144   /* The byte offset this pointer differs from the above alignment.  */
 145   unsigned int misalign;
 146 };
 147
 148
 149 /* It is advantageous to avoid things like life analysis for variables which
 150    do not need PHI nodes.  This enum describes whether or not a particular
 151    variable may need a PHI node.  */
 152
 153 enum need_phi_state {
 154   /* This is the default.  If we are still in this state after finding
 155      all the definition and use sites, then we will assume the variable
 156      needs PHI nodes.  This is probably an overly conservative assumption.  */
 157   NEED_PHI_STATE_UNKNOWN,
 158
 159   /* This state indicates that we have seen one or more sets of the
 160      variable in a single basic block and that the sets dominate all
 161      uses seen so far.  If after finding all definition and use sites
 162      we are still in this state, then the variable does not need any
 163      PHI nodes.  */
 164   NEED_PHI_STATE_NO,
 165
 166   /* This state indicates that we have either seen multiple definitions of
 167      the variable in multiple blocks, or that we encountered a use in a
 168      block that was not dominated by the block containing the set(s) of
 169      this variable.  This variable is assumed to need PHI nodes.  */
 170   NEED_PHI_STATE_MAYBE
 171 };
 172
 173
 174 struct GTY(()) var_ann_d {
 175   /* Used when building base variable structures in a var_map.  */
 176   unsigned base_var_processed : 1;
 177
 178   /* Nonzero if this variable was used after SSA optimizations were
 179      applied.  We set this when translating out of SSA form.  */
 180   unsigned used : 1;
 181
 182   /* This field indicates whether or not the variable may need PHI nodes.
 183      See the enum's definition for more detailed information about the
 184      states.  */
 185   ENUM_BITFIELD (need_phi_state) need_phi_state : 2;
 186
 187   /* Used by var_map for the base index of ssa base variables.  */
 188   unsigned base_index;
 189
 190   /* During into-ssa and the dominator optimizer, this field holds the
 191      current version of this variable (an SSA_NAME).  */
 192   tree current_def;
 193 };
 194
 195
 196 /* Immediate use lists are used to directly access all uses for an SSA
 197    name and get pointers to the statement for each use.
 198
 199    The structure ssa_use_operand_d consists of PREV and NEXT pointers
 200    to maintain the list.  A USE pointer, which points to address where
 201    the use is located and a LOC pointer which can point to the
 202    statement where the use is located, or, in the case of the root
 203    node, it points to the SSA name itself.
 204
 205    The list is anchored by an occurrence of ssa_operand_d *in* the
 206    ssa_name node itself (named 'imm_uses').  This node is uniquely
 207    identified by having a NULL USE pointer. and the LOC pointer
 208    pointing back to the ssa_name node itself.  This node forms the
 209    base for a circular list, and initially this is the only node in
 210    the list.
 211
 212    Fast iteration allows each use to be examined, but does not allow
 213    any modifications to the uses or stmts.
 214
 215    Normal iteration allows insertion, deletion, and modification. the
 216    iterator manages this by inserting a marker node into the list
 217    immediately before the node currently being examined in the list.
 218    this marker node is uniquely identified by having null stmt *and* a
 219    null use pointer.
 220
 221    When iterating to the next use, the iteration routines check to see
 222    if the node after the marker has changed. if it has, then the node
 223    following the marker is now the next one to be visited. if not, the
 224    marker node is moved past that node in the list (visualize it as
 225    bumping the marker node through the list).  this continues until
 226    the marker node is moved to the original anchor position. the
 227    marker node is then removed from the list.
 228
 229    If iteration is halted early, the marker node must be removed from
 230    the list before continuing.  */
 231 typedef struct immediate_use_iterator_d
 232 {
 233   /* This is the current use the iterator is processing.  */
 234   ssa_use_operand_t *imm_use;
 235   /* This marks the last use in the list (use node from SSA_NAME)  */
 236   ssa_use_operand_t *end_p;
 237   /* This node is inserted and used to mark the end of the uses for a stmt.  */
 238   ssa_use_operand_t iter_node;
 239   /* This is the next ssa_name to visit.  IMM_USE may get removed before
 240      the next one is traversed to, so it must be cached early.  */
 241   ssa_use_operand_t *next_imm_name;
 242 } imm_use_iterator;
 243
 244
 245 /* Use this iterator when simply looking at stmts.  Adding, deleting or
 246    modifying stmts will cause this iterator to malfunction.  */
 247
 248 #define FOR_EACH_IMM_USE_FAST(DEST, ITER, SSAVAR)               \
 249   for ((DEST) = first_readonly_imm_use (&(ITER), (SSAVAR));     \
 250        !end_readonly_imm_use_p (&(ITER));                       \
 251        (void) ((DEST) = next_readonly_imm_use (&(ITER))))
 252
 253 /* Use this iterator to visit each stmt which has a use of SSAVAR.  */
 254
 255 #define FOR_EACH_IMM_USE_STMT(STMT, ITER, SSAVAR)               \
 256   for ((STMT) = first_imm_use_stmt (&(ITER), (SSAVAR));         \
 257        !end_imm_use_stmt_p (&(ITER));                           \
 258        (void) ((STMT) = next_imm_use_stmt (&(ITER))))
 259
 260 /* Use this to terminate the FOR_EACH_IMM_USE_STMT loop early.  Failure to
 261    do so will result in leaving a iterator marker node in the immediate
 262    use list, and nothing good will come from that.   */
 263 #define BREAK_FROM_IMM_USE_STMT(ITER)                           \
 264    {                                                            \
 265      end_imm_use_stmt_traverse (&(ITER));                       \
 266      break;                                                     \
 267    }
 268
 269
 270 /* Use this iterator in combination with FOR_EACH_IMM_USE_STMT to
 271    get access to each occurrence of ssavar on the stmt returned by
 272    that iterator..  for instance:
 273
 274      FOR_EACH_IMM_USE_STMT (stmt, iter, var)
 275        {
 276          FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
 277            {
 278              SET_USE (use_p, blah);
 279            }
 280          update_stmt (stmt);
 281        }                                                         */
 282
 283 #define FOR_EACH_IMM_USE_ON_STMT(DEST, ITER)                    \
 284   for ((DEST) = first_imm_use_on_stmt (&(ITER));                \
 285        !end_imm_use_on_stmt_p (&(ITER));                        \
 286        (void) ((DEST) = next_imm_use_on_stmt (&(ITER))))
 287
 288
 289
 290 typedef struct var_ann_d *var_ann_t;
 291
 292 static inline var_ann_t var_ann (const_tree);
 293 static inline void update_stmt (gimple);
 294 static inline int get_lineno (const_gimple);
 295
 296 /* Accessors for basic block annotations.  */
 297 static inline gimple_seq phi_nodes (const_basic_block);
 298 static inline void set_phi_nodes (basic_block, gimple_seq);
 299
 300 /*---------------------------------------------------------------------------
 301                               Global declarations
 302 ---------------------------------------------------------------------------*/
 303 struct int_tree_map {
 304   unsigned int uid;
 305   tree to;
 306 };
 307
 308 extern unsigned int int_tree_map_hash (const void *);
 309 extern int int_tree_map_eq (const void *, const void *);
 310
 311 extern unsigned int uid_decl_map_hash (const void *);
 312 extern int uid_decl_map_eq (const void *, const void *);
 313
 314 typedef struct
 315 {
 316   htab_iterator hti;
 317 } referenced_var_iterator;
 318
 319 /* This macro loops over all the referenced vars, one at a time, putting the
 320    current var in VAR.  Note:  You are not allowed to add referenced variables
 321    to the hashtable while using this macro.  Doing so may cause it to behave
 322    erratically.  */
 323
 324 #define FOR_EACH_REFERENCED_VAR(FN, VAR, ITER)          \
 325   for ((VAR) = first_referenced_var ((FN), &(ITER));    \
 326        !end_referenced_vars_p (&(ITER));                \
 327        (VAR) = next_referenced_var (&(ITER)))
 328
 329 extern tree referenced_var_lookup (struct function *, unsigned int);
 330 extern bool referenced_var_check_and_insert (tree);
 331 #define num_referenced_vars htab_elements (gimple_referenced_vars (cfun))
 332
 333 #define num_ssa_names (VEC_length (tree, cfun->gimple_df->ssa_names))
 334 #define ssa_name(i) (VEC_index (tree, cfun->gimple_df->ssa_names, (i)))
 335
 336 /* Macros for showing usage statistics.  */
 337 #define SCALE(x) ((unsigned long) ((x) < 1024*10        \
 338                   ? (x)                                 \
 339                   : ((x) < 1024*1024*10                 \
 340                      ? (x) / 1024                       \
 341                      : (x) / (1024*1024))))
 342
 343 #define LABEL(x) ((x) < 1024*10 ? 'b' : ((x) < 1024*1024*10 ? 'k' : 'M'))
 344
 345 #define PERCENT(x,y) ((float)(x) * 100.0 / (float)(y))
 346
 347 /*---------------------------------------------------------------------------
 348                               OpenMP Region Tree
 349 ---------------------------------------------------------------------------*/
 350
 351 /* Parallel region information.  Every parallel and workshare
 352    directive is enclosed between two markers, the OMP_* directive
 353    and a corresponding OMP_RETURN statement.  */
 354
 355 struct omp_region
 356 {
 357   /* The enclosing region.  */
 358   struct omp_region *outer;
 359
 360   /* First child region.  */
 361   struct omp_region *inner;
 362
 363   /* Next peer region.  */
 364   struct omp_region *next;
 365
 366   /* Block containing the omp directive as its last stmt.  */
 367   basic_block entry;
 368
 369   /* Block containing the OMP_RETURN as its last stmt.  */
 370   basic_block exit;
 371
 372   /* Block containing the OMP_CONTINUE as its last stmt.  */
 373   basic_block cont;
 374
 375   /* If this is a combined parallel+workshare region, this is a list
 376      of additional arguments needed by the combined parallel+workshare
 377      library call.  */
 378   VEC(tree,gc) *ws_args;
 379
 380   /* The code for the omp directive of this region.  */
 381   enum gimple_code type;
 382
 383   /* Schedule kind, only used for OMP_FOR type regions.  */
 384   enum omp_clause_schedule_kind sched_kind;
 385
 386   /* True if this is a combined parallel+workshare region.  */
 387   bool is_combined_parallel;
 388 };
 389
 390 extern struct omp_region *root_omp_region;
 391 extern struct omp_region *new_omp_region (basic_block, enum gimple_code,
 392                                           struct omp_region *);
 393 extern void free_omp_regions (void);
 394 void omp_expand_local (basic_block);
 395 extern tree find_omp_clause (tree, enum omp_clause_code);
 396 tree copy_var_decl (tree, tree, tree);
 397
 398 /*---------------------------------------------------------------------------
 399                               Function prototypes
 400 ---------------------------------------------------------------------------*/
 401 /* In tree-cfg.c  */
 402
 403 /* Location to track pending stmt for edge insertion.  */
 404 #define PENDING_STMT(e) ((e)->insns.g)
 405
 406 extern void delete_tree_cfg_annotations (void);
 407 extern bool stmt_ends_bb_p (gimple);
 408 extern bool is_ctrl_stmt (gimple);
 409 extern bool is_ctrl_altering_stmt (gimple);
 410 extern bool simple_goto_p (gimple);
 411 extern bool stmt_can_make_abnormal_goto (gimple);
 412 extern basic_block single_noncomplex_succ (basic_block bb);
 413 extern void gimple_dump_bb (basic_block, FILE *, int, int);
 414 extern void gimple_debug_bb (basic_block);
 415 extern basic_block gimple_debug_bb_n (int);
 416 extern void gimple_dump_cfg (FILE *, int);
 417 extern void gimple_debug_cfg (int);
 418 extern void dump_cfg_stats (FILE *);
 419 extern void dot_cfg (void);
 420 extern void debug_cfg_stats (void);
 421 extern void debug_loops (int);
 422 extern void debug_loop (struct loop *, int);
 423 extern void debug_loop_num (unsigned, int);
 424 extern void print_loops (FILE *, int);
 425 extern void print_loops_bb (FILE *, basic_block, int, int);
 426 extern void cleanup_dead_labels (void);
 427 extern void group_case_labels (void);
 428 extern gimple first_stmt (basic_block);
 429 extern gimple last_stmt (basic_block);
 430 extern gimple last_and_only_stmt (basic_block);
 431 extern edge find_taken_edge (basic_block, tree);
 432 extern basic_block label_to_block_fn (struct function *, tree);
 433 #define label_to_block(t) (label_to_block_fn (cfun, t))
 434 extern void notice_special_calls (gimple);
 435 extern void clear_special_calls (void);
 436 extern void verify_gimple_in_seq (gimple_seq);
 437 extern void verify_gimple_in_cfg (struct function *);
 438 extern tree gimple_block_label (basic_block);
 439 extern void extract_true_false_edges_from_block (basic_block, edge *, edge *);
 440 extern bool gimple_duplicate_sese_region (edge, edge, basic_block *, unsigned,
 441                                         basic_block *);
 442 extern bool gimple_duplicate_sese_tail (edge, edge, basic_block *, unsigned,
 443                                       basic_block *);
 444 extern void gather_blocks_in_sese_region (basic_block entry, basic_block exit,
 445                                           VEC(basic_block,heap) **bbs_p);
 446 extern void add_phi_args_after_copy_bb (basic_block);
 447 extern void add_phi_args_after_copy (basic_block *, unsigned, edge);
 448 extern bool gimple_purge_dead_eh_edges (basic_block);
 449 extern bool gimple_purge_all_dead_eh_edges (const_bitmap);
 450 extern bool gimple_purge_dead_abnormal_call_edges (basic_block);
 451 extern bool gimple_purge_all_dead_abnormal_call_edges (const_bitmap);
 452 extern tree gimplify_build1 (gimple_stmt_iterator *, enum tree_code,
 453                              tree, tree);
 454 extern tree gimplify_build2 (gimple_stmt_iterator *, enum tree_code,
 455                              tree, tree, tree);
 456 extern tree gimplify_build3 (gimple_stmt_iterator *, enum tree_code,
 457                              tree, tree, tree, tree);
 458 extern void init_empty_tree_cfg (void);
 459 extern void init_empty_tree_cfg_for_function (struct function *);
 460 extern void fold_cond_expr_cond (void);
 461 extern void make_abnormal_goto_edges (basic_block, bool);
 462 extern void replace_uses_by (tree, tree);
 463 extern void start_recording_case_labels (void);
 464 extern void end_recording_case_labels (void);
 465 extern basic_block move_sese_region_to_fn (struct function *, basic_block,
 466                                            basic_block, tree);
 467 void remove_edge_and_dominated_blocks (edge);
 468 bool tree_node_can_be_shared (tree);
 469
 470 /* In tree-cfgcleanup.c  */
 471 extern bitmap cfgcleanup_altered_bbs;
 472 extern bool cleanup_tree_cfg (void);
 473
 474 /* In tree-pretty-print.c.  */
 475 extern void dump_generic_bb (FILE *, basic_block, int, int);
 476 extern int op_code_prio (enum tree_code);
 477 extern int op_prio (const_tree);
 478 extern const char *op_symbol_code (enum tree_code);
 479
 480 /* In tree-dfa.c  */
 481 extern var_ann_t create_var_ann (tree);
 482 extern void renumber_gimple_stmt_uids (void);
 483 extern void renumber_gimple_stmt_uids_in_blocks (basic_block *, int);
 484 extern void dump_dfa_stats (FILE *);
 485 extern void debug_dfa_stats (void);
 486 extern void debug_referenced_vars (void);
 487 extern void dump_referenced_vars (FILE *);
 488 extern void dump_variable (FILE *, tree);
 489 extern void debug_variable (tree);
 490 extern tree get_virtual_var (tree);
 491 extern bool add_referenced_var (tree);
 492 extern void remove_referenced_var (tree);
 493 extern void mark_symbols_for_renaming (gimple);
 494 extern void find_new_referenced_vars (gimple);
 495 extern tree make_rename_temp (tree, const char *);
 496 extern void set_default_def (tree, tree);
 497 extern tree gimple_default_def (struct function *, tree);
 498 extern bool stmt_references_abnormal_ssa_name (gimple);
 499 extern tree get_ref_base_and_extent (tree, HOST_WIDE_INT *,
 500                                      HOST_WIDE_INT *, HOST_WIDE_INT *);
 501 extern tree get_addr_base_and_unit_offset (tree, HOST_WIDE_INT *);
 502 extern void find_referenced_vars_in (gimple);
 503
 504 /* In tree-phinodes.c  */
 505 extern void reserve_phi_args_for_new_edge (basic_block);
 506 extern void add_phi_node_to_bb (gimple phi, basic_block bb);
 507 extern gimple create_phi_node (tree, basic_block);
 508 extern void add_phi_arg (gimple, tree, edge, source_location);
 509 extern void remove_phi_args (edge);
 510 extern void remove_phi_node (gimple_stmt_iterator *, bool);
 511 extern void remove_phi_nodes (basic_block);
 512 extern void init_phinodes (void);
 513 extern void fini_phinodes (void);
 514 extern void release_phi_node (gimple);
 515 #ifdef GATHER_STATISTICS
 516 extern void phinodes_print_statistics (void);
 517 #endif
 518
 519 /* In gimple-low.c  */
 520 extern void record_vars_into (tree, tree);
 521 extern void record_vars (tree);
 522 extern bool gimple_seq_may_fallthru (gimple_seq);
 523 extern bool gimple_stmt_may_fallthru (gimple);
 524 extern bool gimple_check_call_matching_types (gimple, tree);
 525
 526
 527 /* In tree-ssa.c  */
 528
 529 /* Mapping for redirected edges.  */
 530 struct _edge_var_map {
 531   tree result;                  /* PHI result.  */
 532   tree def;                     /* PHI arg definition.  */
 533   source_location locus;        /* PHI arg location.  */
 534 };
 535 typedef struct _edge_var_map edge_var_map;
 536
 537 DEF_VEC_O(edge_var_map);
 538 DEF_VEC_ALLOC_O(edge_var_map, heap);
 539
 540 /* A vector of var maps.  */
 541 typedef VEC(edge_var_map, heap) *edge_var_map_vector;
 542
 543 extern void init_tree_ssa (struct function *);
 544 extern void redirect_edge_var_map_add (edge, tree, tree, source_location);
 545 extern void redirect_edge_var_map_clear (edge);
 546 extern void redirect_edge_var_map_dup (edge, edge);
 547 extern edge_var_map_vector redirect_edge_var_map_vector (edge);
 548 extern void redirect_edge_var_map_destroy (void);
 549
 550 extern edge ssa_redirect_edge (edge, basic_block);
 551 extern void flush_pending_stmts (edge);
 552 extern void verify_ssa (bool);
 553 extern void delete_tree_ssa (void);
 554 extern bool ssa_undefined_value_p (tree);
 555 extern void warn_uninit (enum opt_code, tree, tree, tree, const char *, void *);
 556 extern unsigned int warn_uninitialized_vars (bool);
 557 extern void execute_update_addresses_taken (void);
 558
 559 /* Call-back function for walk_use_def_chains().  At each reaching
 560    definition, a function with this prototype is called.  */
 561 typedef bool (*walk_use_def_chains_fn) (tree, gimple, void *);
 562
 563 extern void walk_use_def_chains (tree, walk_use_def_chains_fn, void *, bool);
 564
 565 void insert_debug_temps_for_defs (gimple_stmt_iterator *);
 566 void insert_debug_temp_for_var_def (gimple_stmt_iterator *, tree);
 567 void reset_debug_uses (gimple);
 568 void release_defs_bitset (bitmap toremove);
 569
 570 /* In tree-into-ssa.c  */
 571 void update_ssa (unsigned);
 572 void delete_update_ssa (void);
 573 void register_new_name_mapping (tree, tree);
 574 tree create_new_def_for (tree, gimple, def_operand_p);
 575 bool need_ssa_update_p (struct function *);
 576 bool name_mappings_registered_p (void);
 577 bool name_registered_for_update_p (tree);
 578 bitmap ssa_names_to_replace (void);
 579 void release_ssa_name_after_update_ssa (tree);
 580 void compute_global_livein (bitmap, bitmap);
 581 void mark_sym_for_renaming (tree);
 582 void mark_set_for_renaming (bitmap);
 583 bool symbol_marked_for_renaming (tree);
 584 tree get_current_def (tree);
 585 void set_current_def (tree, tree);
 586
 587 /* In tree-ssanames.c  */
 588 extern void init_ssanames (struct function *, int);
 589 extern void fini_ssanames (void);
 590 extern tree make_ssa_name_fn (struct function *, tree, gimple);
 591 extern tree duplicate_ssa_name (tree, gimple);
 592 extern void duplicate_ssa_name_ptr_info (tree, struct ptr_info_def *);
 593 extern void release_ssa_name (tree);
 594 extern void release_defs (gimple);
 595 extern void replace_ssa_name_symbol (tree, tree);
 596
 597 #ifdef GATHER_STATISTICS
 598 extern void ssanames_print_statistics (void);
 599 #endif
 600
 601 /* In tree-ssa-ccp.c  */
 602 tree fold_const_aggregate_ref (tree);
 603 tree gimple_fold_stmt_to_constant (gimple, tree (*)(tree));
 604
 605 /* In tree-ssa-dom.c  */
 606 extern void dump_dominator_optimization_stats (FILE *);
 607 extern void debug_dominator_optimization_stats (void);
 608 int loop_depth_of_name (tree);
 609 tree degenerate_phi_result (gimple);
 610 bool simple_iv_increment_p (gimple);
 611
 612 /* In tree-ssa-copy.c  */
 613 extern void propagate_value (use_operand_p, tree);
 614 extern void propagate_tree_value (tree *, tree);
 615 extern void propagate_tree_value_into_stmt (gimple_stmt_iterator *, tree);
 616 extern void replace_exp (use_operand_p, tree);
 617 extern bool may_propagate_copy (tree, tree);
 618 extern bool may_propagate_copy_into_stmt (gimple, tree);
 619 extern bool may_propagate_copy_into_asm (tree);
 620
 621 /* In tree-ssa-loop-ch.c  */
 622 bool do_while_loop_p (struct loop *);
 623
 624 /* Affine iv.  */
 625
 626 typedef struct
 627 {
 628   /* Iv = BASE + STEP * i.  */
 629   tree base, step;
 630
 631   /* True if this iv does not overflow.  */
 632   bool no_overflow;
 633 } affine_iv;
 634
 635 /* Description of number of iterations of a loop.  All the expressions inside
 636    the structure can be evaluated at the end of the loop's preheader
 637    (and due to ssa form, also anywhere inside the body of the loop).  */
 638
 639 struct tree_niter_desc
 640 {
 641   tree assumptions;     /* The boolean expression.  If this expression evaluates
 642                            to false, then the other fields in this structure
 643                            should not be used; there is no guarantee that they
 644                            will be correct.  */
 645   tree may_be_zero;     /* The boolean expression.  If it evaluates to true,
 646                            the loop will exit in the first iteration (i.e.
 647                            its latch will not be executed), even if the niter
 648                            field says otherwise.  */
 649   tree niter;           /* The expression giving the number of iterations of
 650                            a loop (provided that assumptions == true and
 651                            may_be_zero == false), more precisely the number
 652                            of executions of the latch of the loop.  */
 653   double_int max;       /* The upper bound on the number of iterations of
 654                            the loop.  */
 655
 656   /* The simplified shape of the exit condition.  The loop exits if
 657      CONTROL CMP BOUND is false, where CMP is one of NE_EXPR,
 658      LT_EXPR, or GT_EXPR, and step of CONTROL is positive if CMP is
 659      LE_EXPR and negative if CMP is GE_EXPR.  This information is used
 660      by loop unrolling.  */
 661   affine_iv control;
 662   tree bound;
 663   enum tree_code cmp;
 664 };
 665
 666 /* In tree-ssa-phiopt.c */
 667 bool empty_block_p (basic_block);
 668 basic_block *blocks_in_phiopt_order (void);
 669
 670 /* In tree-ssa-loop*.c  */
 671
 672 unsigned int tree_ssa_lim (void);
 673 unsigned int tree_ssa_unswitch_loops (void);
 674 unsigned int canonicalize_induction_variables (void);
 675 unsigned int tree_unroll_loops_completely (bool, bool);
 676 unsigned int tree_ssa_prefetch_arrays (void);
 677 void tree_ssa_iv_optimize (void);
 678 unsigned tree_predictive_commoning (void);
 679 tree canonicalize_loop_ivs (struct loop *, tree *, bool);
 680 bool parallelize_loops (void);
 681
 682 bool loop_only_exit_p (const struct loop *, const_edge);
 683 bool number_of_iterations_exit (struct loop *, edge,
 684                                 struct tree_niter_desc *niter, bool);
 685 tree find_loop_niter (struct loop *, edge *);
 686 tree loop_niter_by_eval (struct loop *, edge);
 687 tree find_loop_niter_by_eval (struct loop *, edge *);
 688 void estimate_numbers_of_iterations (void);
 689 bool scev_probably_wraps_p (tree, tree, gimple, struct loop *, bool);
 690 bool convert_affine_scev (struct loop *, tree, tree *, tree *, gimple, bool);
 691
 692 bool nowrap_type_p (tree);
 693 enum ev_direction {EV_DIR_GROWS, EV_DIR_DECREASES, EV_DIR_UNKNOWN};
 694 enum ev_direction scev_direction (const_tree);
 695
 696 void free_numbers_of_iterations_estimates (void);
 697 void free_numbers_of_iterations_estimates_loop (struct loop *);
 698 void rewrite_into_loop_closed_ssa (bitmap, unsigned);
 699 void verify_loop_closed_ssa (bool);
 700 bool for_each_index (tree *, bool (*) (tree, tree *, void *), void *);
 701 void create_iv (tree, tree, tree, struct loop *, gimple_stmt_iterator *, bool,
 702                 tree *, tree *);
 703 basic_block split_loop_exit_edge (edge);
 704 void standard_iv_increment_position (struct loop *, gimple_stmt_iterator *,
 705                                      bool *);
 706 basic_block ip_end_pos (struct loop *);
 707 basic_block ip_normal_pos (struct loop *);
 708 bool gimple_duplicate_loop_to_header_edge (struct loop *, edge,
 709                                          unsigned int, sbitmap,
 710                                          edge, VEC (edge, heap) **,
 711                                          int);
 712 struct loop *slpeel_tree_duplicate_loop_to_edge_cfg (struct loop *, edge);
 713 void rename_variables_in_loop (struct loop *);
 714 void rename_variables_in_bb (basic_block bb);
 715 tree expand_simple_operations (tree);
 716 void substitute_in_loop_info (struct loop *, tree, tree);
 717 edge single_dom_exit (struct loop *);
 718 bool can_unroll_loop_p (struct loop *loop, unsigned factor,
 719                         struct tree_niter_desc *niter);
 720 void tree_unroll_loop (struct loop *, unsigned,
 721                        edge, struct tree_niter_desc *);
 722 typedef void (*transform_callback)(struct loop *, void *);
 723 void tree_transform_and_unroll_loop (struct loop *, unsigned,
 724                                      edge, struct tree_niter_desc *,
 725                                      transform_callback, void *);
 726 bool contains_abnormal_ssa_name_p (tree);
 727 bool stmt_dominates_stmt_p (gimple, gimple);
 728 void mark_virtual_ops_for_renaming (gimple);
 729
 730 /* In tree-ssa-dce.c */
 731 void mark_virtual_operand_for_renaming (tree);
 732 void mark_virtual_phi_result_for_renaming (gimple);
 733
 734 /* In tree-ssa-threadedge.c */
 735 extern void threadedge_initialize_values (void);
 736 extern void threadedge_finalize_values (void);
 737 extern VEC(tree,heap) *ssa_name_values;
 738 #define SSA_NAME_VALUE(x) \
 739     (SSA_NAME_VERSION(x) < VEC_length(tree, ssa_name_values) \
 740      ? VEC_index(tree, ssa_name_values, SSA_NAME_VERSION(x)) \
 741      : NULL_TREE)
 742 extern void set_ssa_name_value (tree, tree);
 743 extern bool potentially_threadable_block (basic_block);
 744 extern void thread_across_edge (gimple, edge, bool,
 745                                 VEC(tree, heap) **, tree (*) (gimple, gimple));
 746
 747 /* In tree-ssa-loop-im.c  */
 748 /* The possibilities of statement movement.  */
 749
 750 enum move_pos
 751   {
 752     MOVE_IMPOSSIBLE,            /* No movement -- side effect expression.  */
 753     MOVE_PRESERVE_EXECUTION,    /* Must not cause the non-executed statement
 754                                    become executed -- memory accesses, ... */
 755     MOVE_POSSIBLE               /* Unlimited movement.  */
 756   };
 757 extern enum move_pos movement_possibility (gimple);
 758 char *get_lsm_tmp_name (tree, unsigned);
 759
 760 /* In tree-flow-inline.h  */
 761 static inline void set_is_used (tree);
 762 static inline bool unmodifiable_var_p (const_tree);
 763 static inline bool ref_contains_array_ref (const_tree);
 764
 765 /* In tree-eh.c  */
 766 extern void make_eh_edges (gimple);
 767 extern bool make_eh_dispatch_edges (gimple);
 768 extern edge redirect_eh_edge (edge, basic_block);
 769 extern void redirect_eh_dispatch_edge (gimple, edge, basic_block);
 770 extern bool tree_could_trap_p (tree);
 771 extern bool operation_could_trap_helper_p (enum tree_code, bool, bool, bool,
 772                                            bool, tree, bool *);
 773 extern bool operation_could_trap_p (enum tree_code, bool, bool, tree);
 774 extern bool stmt_could_throw_p (gimple);
 775 extern bool tree_could_throw_p (tree);
 776 extern bool stmt_can_throw_internal (gimple);
 777 extern bool stmt_can_throw_external (gimple);
 778 extern void add_stmt_to_eh_lp_fn (struct function *, gimple, int);
 779 extern void add_stmt_to_eh_lp (gimple, int);
 780 extern bool remove_stmt_from_eh_lp (gimple);
 781 extern bool remove_stmt_from_eh_lp_fn (struct function *, gimple);
 782 extern int lookup_stmt_eh_lp_fn (struct function *, gimple);
 783 extern int lookup_stmt_eh_lp (gimple);
 784 extern bool maybe_clean_eh_stmt_fn (struct function *, gimple);
 785 extern bool maybe_clean_eh_stmt (gimple);
 786 extern bool maybe_clean_or_replace_eh_stmt (gimple, gimple);
 787 extern bool maybe_duplicate_eh_stmt_fn (struct function *, gimple,
 788                                         struct function *, gimple,
 789                                         struct pointer_map_t *, int);
 790 extern bool maybe_duplicate_eh_stmt (gimple, gimple);
 791 extern bool verify_eh_edges (gimple);
 792 extern bool verify_eh_dispatch_edge (gimple);
 793 extern void maybe_remove_unreachable_handlers (void);
 794
 795 /* In tree-ssa-pre.c  */
 796 void debug_value_expressions (unsigned int);
 797
 798 /* In tree-loop-linear.c  */
 799 extern void linear_transform_loops (void);
 800 extern unsigned perfect_loop_nest_depth (struct loop *);
 801
 802 /* In graphite.c  */
 803 extern void graphite_transform_loops (void);
 804
 805 /* In tree-data-ref.c  */
 806 extern void tree_check_data_deps (void);
 807
 808 /* In tree-ssa-loop-ivopts.c  */
 809 bool expr_invariant_in_loop_p (struct loop *, tree);
 810 bool stmt_invariant_in_loop_p (struct loop *, gimple);
 811 bool multiplier_allowed_in_address_p (HOST_WIDE_INT, enum machine_mode,
 812                                       addr_space_t);
 813 unsigned multiply_by_cost (HOST_WIDE_INT, enum machine_mode, bool);
 814 bool may_be_nonaddressable_p (tree expr);
 815
 816 /* In tree-ssa-threadupdate.c.  */
 817 extern bool thread_through_all_blocks (bool);
 818 extern void register_jump_thread (edge, edge, edge);
 819
 820 /* In gimplify.c  */
 821 tree force_gimple_operand_1 (tree, gimple_seq *, gimple_predicate, tree);
 822 tree force_gimple_operand (tree, gimple_seq *, bool, tree);
 823 tree force_gimple_operand_gsi_1 (gimple_stmt_iterator *, tree,
 824                                  gimple_predicate, tree,
 825                                  bool, enum gsi_iterator_update);
 826 tree force_gimple_operand_gsi (gimple_stmt_iterator *, tree, bool, tree,
 827                                bool, enum gsi_iterator_update);
 828 tree gimple_fold_indirect_ref (tree);
 829
 830 /* In tree-ssa-live.c */
 831 extern void remove_unused_locals (void);
 832 extern void dump_scope_blocks (FILE *, int);
 833 extern void debug_scope_blocks (int);
 834 extern void debug_scope_block (tree, int);
 835
 836 /* In tree-ssa-address.c  */
 837
 838 /* Description of a memory address.  */
 839
 840 struct mem_address
 841 {
 842   tree symbol, base, index, step, offset;
 843 };
 844
 845 struct affine_tree_combination;
 846 tree create_mem_ref (gimple_stmt_iterator *, tree,
 847                      struct affine_tree_combination *, tree, tree, tree, bool);
 848 rtx addr_for_mem_ref (struct mem_address *, addr_space_t, bool);
 849 void get_address_description (tree, struct mem_address *);
 850 tree maybe_fold_tmr (tree);
 851
 852 unsigned int execute_fixup_cfg (void);
 853 bool fixup_noreturn_call (gimple stmt);
 854
 855 /* In ipa-pure-const.c  */
 856 void warn_function_noreturn (tree);
 857
 858 /* In tree-ssa-ter.c  */
 859 bool stmt_is_replaceable_p (gimple);
 860
 861 #include "tree-flow-inline.h"
 862
 863 void swap_tree_operands (gimple, tree *, tree *);
 864
 865 #endif /* _TREE_FLOW_H  */