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   /* When known, this is the power-of-two byte alignment of the object this
 140      pointer points into.  This is usually DECL_ALIGN_UNIT for decls and
 141      MALLOC_ABI_ALIGNMENT for allocated storage.  When the alignment is not
 142      known, it is zero.  Do not access directly but use functions
 143      get_ptr_info_alignment, set_ptr_info_alignment,
 144      mark_ptr_info_alignment_unknown and similar.  */
 145   unsigned int align;
 146
 147   /* When alignment is known, the byte offset this pointer differs from the
 148      above alignment.  Access only through the same helper functions as align
 149      above.  */
 150   unsigned int misalign;
 151 };
 152
 153
 154 /* It is advantageous to avoid things like life analysis for variables which
 155    do not need PHI nodes.  This enum describes whether or not a particular
 156    variable may need a PHI node.  */
 157
 158 enum need_phi_state {
 159   /* This is the default.  If we are still in this state after finding
 160      all the definition and use sites, then we will assume the variable
 161      needs PHI nodes.  This is probably an overly conservative assumption.  */
 162   NEED_PHI_STATE_UNKNOWN,
 163
 164   /* This state indicates that we have seen one or more sets of the
 165      variable in a single basic block and that the sets dominate all
 166      uses seen so far.  If after finding all definition and use sites
 167      we are still in this state, then the variable does not need any
 168      PHI nodes.  */
 169   NEED_PHI_STATE_NO,
 170
 171   /* This state indicates that we have either seen multiple definitions of
 172      the variable in multiple blocks, or that we encountered a use in a
 173      block that was not dominated by the block containing the set(s) of
 174      this variable.  This variable is assumed to need PHI nodes.  */
 175   NEED_PHI_STATE_MAYBE
 176 };
 177
 178
 179 struct GTY(()) var_ann_d {
 180   /* Used when building base variable structures in a var_map.  */
 181   unsigned base_var_processed : 1;
 182
 183   /* Nonzero if this variable was used after SSA optimizations were
 184      applied.  We set this when translating out of SSA form.  */
 185   unsigned used : 1;
 186
 187   /* Used by var_map for the base index of ssa base variables.  */
 188   unsigned base_index;
 189 };
 190
 191
 192 /* Immediate use lists are used to directly access all uses for an SSA
 193    name and get pointers to the statement for each use.
 194
 195    The structure ssa_use_operand_d consists of PREV and NEXT pointers
 196    to maintain the list.  A USE pointer, which points to address where
 197    the use is located and a LOC pointer which can point to the
 198    statement where the use is located, or, in the case of the root
 199    node, it points to the SSA name itself.
 200
 201    The list is anchored by an occurrence of ssa_operand_d *in* the
 202    ssa_name node itself (named 'imm_uses').  This node is uniquely
 203    identified by having a NULL USE pointer. and the LOC pointer
 204    pointing back to the ssa_name node itself.  This node forms the
 205    base for a circular list, and initially this is the only node in
 206    the list.
 207
 208    Fast iteration allows each use to be examined, but does not allow
 209    any modifications to the uses or stmts.
 210
 211    Normal iteration allows insertion, deletion, and modification. the
 212    iterator manages this by inserting a marker node into the list
 213    immediately before the node currently being examined in the list.
 214    this marker node is uniquely identified by having null stmt *and* a
 215    null use pointer.
 216
 217    When iterating to the next use, the iteration routines check to see
 218    if the node after the marker has changed. if it has, then the node
 219    following the marker is now the next one to be visited. if not, the
 220    marker node is moved past that node in the list (visualize it as
 221    bumping the marker node through the list).  this continues until
 222    the marker node is moved to the original anchor position. the
 223    marker node is then removed from the list.
 224
 225    If iteration is halted early, the marker node must be removed from
 226    the list before continuing.  */
 227 typedef struct immediate_use_iterator_d
 228 {
 229   /* This is the current use the iterator is processing.  */
 230   ssa_use_operand_t *imm_use;
 231   /* This marks the last use in the list (use node from SSA_NAME)  */
 232   ssa_use_operand_t *end_p;
 233   /* This node is inserted and used to mark the end of the uses for a stmt.  */
 234   ssa_use_operand_t iter_node;
 235   /* This is the next ssa_name to visit.  IMM_USE may get removed before
 236      the next one is traversed to, so it must be cached early.  */
 237   ssa_use_operand_t *next_imm_name;
 238 } imm_use_iterator;
 239
 240
 241 /* Use this iterator when simply looking at stmts.  Adding, deleting or
 242    modifying stmts will cause this iterator to malfunction.  */
 243
 244 #define FOR_EACH_IMM_USE_FAST(DEST, ITER, SSAVAR)               \
 245   for ((DEST) = first_readonly_imm_use (&(ITER), (SSAVAR));     \
 246        !end_readonly_imm_use_p (&(ITER));                       \
 247        (void) ((DEST) = next_readonly_imm_use (&(ITER))))
 248
 249 /* Use this iterator to visit each stmt which has a use of SSAVAR.  */
 250
 251 #define FOR_EACH_IMM_USE_STMT(STMT, ITER, SSAVAR)               \
 252   for ((STMT) = first_imm_use_stmt (&(ITER), (SSAVAR));         \
 253        !end_imm_use_stmt_p (&(ITER));                           \
 254        (void) ((STMT) = next_imm_use_stmt (&(ITER))))
 255
 256 /* Use this to terminate the FOR_EACH_IMM_USE_STMT loop early.  Failure to
 257    do so will result in leaving a iterator marker node in the immediate
 258    use list, and nothing good will come from that.   */
 259 #define BREAK_FROM_IMM_USE_STMT(ITER)                           \
 260    {                                                            \
 261      end_imm_use_stmt_traverse (&(ITER));                       \
 262      break;                                                     \
 263    }
 264
 265
 266 /* Use this iterator in combination with FOR_EACH_IMM_USE_STMT to
 267    get access to each occurrence of ssavar on the stmt returned by
 268    that iterator..  for instance:
 269
 270      FOR_EACH_IMM_USE_STMT (stmt, iter, var)
 271        {
 272          FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
 273            {
 274              SET_USE (use_p, blah);
 275            }
 276          update_stmt (stmt);
 277        }                                                         */
 278
 279 #define FOR_EACH_IMM_USE_ON_STMT(DEST, ITER)                    \
 280   for ((DEST) = first_imm_use_on_stmt (&(ITER));                \
 281        !end_imm_use_on_stmt_p (&(ITER));                        \
 282        (void) ((DEST) = next_imm_use_on_stmt (&(ITER))))
 283
 284
 285
 286 typedef struct var_ann_d *var_ann_t;
 287
 288 static inline var_ann_t var_ann (const_tree);
 289 static inline void update_stmt (gimple);
 290 static inline int get_lineno (const_gimple);
 291
 292 /* Accessors for basic block annotations.  */
 293 static inline gimple_seq phi_nodes (const_basic_block);
 294 static inline void set_phi_nodes (basic_block, gimple_seq);
 295
 296 /*---------------------------------------------------------------------------
 297                               Global declarations
 298 ---------------------------------------------------------------------------*/
 299 struct int_tree_map {
 300   unsigned int uid;
 301   tree to;
 302 };
 303
 304 extern unsigned int int_tree_map_hash (const void *);
 305 extern int int_tree_map_eq (const void *, const void *);
 306
 307 extern unsigned int uid_decl_map_hash (const void *);
 308 extern int uid_decl_map_eq (const void *, const void *);
 309
 310 typedef struct
 311 {
 312   htab_iterator hti;
 313 } referenced_var_iterator;
 314
 315 /* This macro loops over all the referenced vars, one at a time, putting the
 316    current var in VAR.  Note:  You are not allowed to add referenced variables
 317    to the hashtable while using this macro.  Doing so may cause it to behave
 318    erratically.  */
 319
 320 #define FOR_EACH_REFERENCED_VAR(FN, VAR, ITER)          \
 321   for ((VAR) = first_referenced_var ((FN), &(ITER));    \
 322        !end_referenced_vars_p (&(ITER));                \
 323        (VAR) = next_referenced_var (&(ITER)))
 324
 325 extern tree referenced_var_lookup (struct function *, unsigned int);
 326 #define num_referenced_vars htab_elements (gimple_referenced_vars (cfun))
 327
 328 #define num_ssa_names (VEC_length (tree, cfun->gimple_df->ssa_names))
 329 #define ssa_name(i) (VEC_index (tree, cfun->gimple_df->ssa_names, (i)))
 330
 331 /* Macros for showing usage statistics.  */
 332 #define SCALE(x) ((unsigned long) ((x) < 1024*10        \
 333                   ? (x)                                 \
 334                   : ((x) < 1024*1024*10                 \
 335                      ? (x) / 1024                       \
 336                      : (x) / (1024*1024))))
 337
 338 #define LABEL(x) ((x) < 1024*10 ? 'b' : ((x) < 1024*1024*10 ? 'k' : 'M'))
 339
 340 #define PERCENT(x,y) ((float)(x) * 100.0 / (float)(y))
 341
 342 /*---------------------------------------------------------------------------
 343                               OpenMP Region Tree
 344 ---------------------------------------------------------------------------*/
 345
 346 /* Parallel region information.  Every parallel and workshare
 347    directive is enclosed between two markers, the OMP_* directive
 348    and a corresponding OMP_RETURN statement.  */
 349
 350 struct omp_region
 351 {
 352   /* The enclosing region.  */
 353   struct omp_region *outer;
 354
 355   /* First child region.  */
 356   struct omp_region *inner;
 357
 358   /* Next peer region.  */
 359   struct omp_region *next;
 360
 361   /* Block containing the omp directive as its last stmt.  */
 362   basic_block entry;
 363
 364   /* Block containing the OMP_RETURN as its last stmt.  */
 365   basic_block exit;
 366
 367   /* Block containing the OMP_CONTINUE as its last stmt.  */
 368   basic_block cont;
 369
 370   /* If this is a combined parallel+workshare region, this is a list
 371      of additional arguments needed by the combined parallel+workshare
 372      library call.  */
 373   VEC(tree,gc) *ws_args;
 374
 375   /* The code for the omp directive of this region.  */
 376   enum gimple_code type;
 377
 378   /* Schedule kind, only used for OMP_FOR type regions.  */
 379   enum omp_clause_schedule_kind sched_kind;
 380
 381   /* True if this is a combined parallel+workshare region.  */
 382   bool is_combined_parallel;
 383 };
 384
 385 extern struct omp_region *root_omp_region;
 386 extern struct omp_region *new_omp_region (basic_block, enum gimple_code,
 387                                           struct omp_region *);
 388 extern void free_omp_regions (void);
 389 void omp_expand_local (basic_block);
 390 extern tree find_omp_clause (tree, enum omp_clause_code);
 391 tree copy_var_decl (tree, tree, tree);
 392
 393 /*---------------------------------------------------------------------------
 394                               Function prototypes
 395 ---------------------------------------------------------------------------*/
 396 /* In tree-cfg.c  */
 397
 398 /* Location to track pending stmt for edge insertion.  */
 399 #define PENDING_STMT(e) ((e)->insns.g)
 400
 401 extern void delete_tree_cfg_annotations (void);
 402 extern bool stmt_ends_bb_p (gimple);
 403 extern bool is_ctrl_stmt (gimple);
 404 extern bool is_ctrl_altering_stmt (gimple);
 405 extern bool simple_goto_p (gimple);
 406 extern bool stmt_can_make_abnormal_goto (gimple);
 407 extern basic_block single_noncomplex_succ (basic_block bb);
 408 extern void gimple_dump_bb (FILE *, basic_block, int, int);
 409 extern void gimple_debug_bb (basic_block);
 410 extern basic_block gimple_debug_bb_n (int);
 411 extern void gimple_dump_cfg (FILE *, int);
 412 extern void gimple_debug_cfg (int);
 413 extern void dump_cfg_stats (FILE *);
 414 extern void dot_cfg (void);
 415 extern void debug_cfg_stats (void);
 416 extern void debug_loops (int);
 417 extern void debug_loop (struct loop *, int);
 418 extern void debug_loop_num (unsigned, int);
 419 extern void print_loops (FILE *, int);
 420 extern void print_loops_bb (FILE *, basic_block, int, int);
 421 extern void cleanup_dead_labels (void);
 422 extern void group_case_labels_stmt (gimple);
 423 extern void group_case_labels (void);
 424 extern gimple first_stmt (basic_block);
 425 extern gimple last_stmt (basic_block);
 426 extern gimple last_and_only_stmt (basic_block);
 427 extern edge find_taken_edge (basic_block, tree);
 428 extern basic_block label_to_block_fn (struct function *, tree);
 429 #define label_to_block(t) (label_to_block_fn (cfun, t))
 430 extern void notice_special_calls (gimple);
 431 extern void clear_special_calls (void);
 432 extern void verify_gimple_in_seq (gimple_seq);
 433 extern void verify_gimple_in_cfg (struct function *);
 434 extern tree gimple_block_label (basic_block);
 435 extern void extract_true_false_edges_from_block (basic_block, edge *, edge *);
 436 extern bool gimple_duplicate_sese_region (edge, edge, basic_block *, unsigned,
 437                                         basic_block *);
 438 extern bool gimple_duplicate_sese_tail (edge, edge, basic_block *, unsigned,
 439                                       basic_block *);
 440 extern void gather_blocks_in_sese_region (basic_block entry, basic_block exit,
 441                                           VEC(basic_block,heap) **bbs_p);
 442 extern void add_phi_args_after_copy_bb (basic_block);
 443 extern void add_phi_args_after_copy (basic_block *, unsigned, edge);
 444 extern bool gimple_purge_dead_eh_edges (basic_block);
 445 extern bool gimple_purge_all_dead_eh_edges (const_bitmap);
 446 extern bool gimple_purge_dead_abnormal_call_edges (basic_block);
 447 extern bool gimple_purge_all_dead_abnormal_call_edges (const_bitmap);
 448 extern tree gimplify_build1 (gimple_stmt_iterator *, enum tree_code,
 449                              tree, tree);
 450 extern tree gimplify_build2 (gimple_stmt_iterator *, enum tree_code,
 451                              tree, tree, tree);
 452 extern tree gimplify_build3 (gimple_stmt_iterator *, enum tree_code,
 453                              tree, tree, tree, tree);
 454 extern void init_empty_tree_cfg (void);
 455 extern void init_empty_tree_cfg_for_function (struct function *);
 456 extern void fold_cond_expr_cond (void);
 457 extern void make_abnormal_goto_edges (basic_block, bool);
 458 extern void replace_uses_by (tree, tree);
 459 extern void start_recording_case_labels (void);
 460 extern void end_recording_case_labels (void);
 461 extern basic_block move_sese_region_to_fn (struct function *, basic_block,
 462                                            basic_block, tree);
 463 void remove_edge_and_dominated_blocks (edge);
 464 bool tree_node_can_be_shared (tree);
 465
 466 /* In tree-cfgcleanup.c  */
 467 extern bitmap cfgcleanup_altered_bbs;
 468 extern bool cleanup_tree_cfg (void);
 469
 470 /* In tree-pretty-print.c.  */
 471 extern void dump_generic_bb (FILE *, basic_block, int, int);
 472 extern int op_code_prio (enum tree_code);
 473 extern int op_prio (const_tree);
 474 extern const char *op_symbol_code (enum tree_code);
 475
 476 /* In tree-dfa.c  */
 477 extern void renumber_gimple_stmt_uids (void);
 478 extern void renumber_gimple_stmt_uids_in_blocks (basic_block *, int);
 479 extern void dump_dfa_stats (FILE *);
 480 extern void debug_dfa_stats (void);
 481 extern void debug_referenced_vars (void);
 482 extern void dump_referenced_vars (FILE *);
 483 extern void dump_variable (FILE *, tree);
 484 extern void debug_variable (tree);
 485 extern bool add_referenced_var_1 (tree, struct function *);
 486 #define add_referenced_var(v) add_referenced_var_1 ((v), cfun)
 487 extern void remove_referenced_var (tree);
 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_addr_base_and_unit_offset (tree, HOST_WIDE_INT *);
 493 extern void find_referenced_vars_in (gimple);
 494 extern void dump_enumerated_decls (FILE *, int);
 495
 496 /* In tree-phinodes.c  */
 497 extern void reserve_phi_args_for_new_edge (basic_block);
 498 extern void add_phi_node_to_bb (gimple phi, basic_block bb);
 499 extern gimple create_phi_node (tree, basic_block);
 500 extern void add_phi_arg (gimple, tree, edge, source_location);
 501 extern void remove_phi_args (edge);
 502 extern void remove_phi_node (gimple_stmt_iterator *, bool);
 503 extern void remove_phi_nodes (basic_block);
 504 extern void release_phi_node (gimple);
 505 extern void phinodes_print_statistics (void);
 506
 507 /* In gimple-low.c  */
 508 extern void record_vars_into (tree, tree);
 509 extern void record_vars (tree);
 510 extern bool gimple_seq_may_fallthru (gimple_seq);
 511 extern bool gimple_stmt_may_fallthru (gimple);
 512 extern bool gimple_check_call_matching_types (gimple, tree);
 513
 514
 515 /* In tree-ssa.c  */
 516
 517 /* Mapping for redirected edges.  */
 518 struct _edge_var_map {
 519   tree result;                  /* PHI result.  */
 520   tree def;                     /* PHI arg definition.  */
 521   source_location locus;        /* PHI arg location.  */
 522 };
 523 typedef struct _edge_var_map edge_var_map;
 524
 525 DEF_VEC_O(edge_var_map);
 526 DEF_VEC_ALLOC_O(edge_var_map, heap);
 527
 528 /* A vector of var maps.  */
 529 typedef VEC(edge_var_map, heap) *edge_var_map_vector;
 530
 531 extern void init_tree_ssa (struct function *);
 532 extern void redirect_edge_var_map_add (edge, tree, tree, source_location);
 533 extern void redirect_edge_var_map_clear (edge);
 534 extern void redirect_edge_var_map_dup (edge, edge);
 535 extern edge_var_map_vector redirect_edge_var_map_vector (edge);
 536 extern void redirect_edge_var_map_destroy (void);
 537
 538 extern edge ssa_redirect_edge (edge, basic_block);
 539 extern void flush_pending_stmts (edge);
 540 extern void verify_ssa (bool);
 541 extern void delete_tree_ssa (void);
 542 extern bool ssa_undefined_value_p (tree);
 543 extern void warn_uninit (enum opt_code, tree, tree, tree, const char *, void *);
 544 extern unsigned int warn_uninitialized_vars (bool);
 545 extern void execute_update_addresses_taken (void);
 546
 547 /* Call-back function for walk_use_def_chains().  At each reaching
 548    definition, a function with this prototype is called.  */
 549 typedef bool (*walk_use_def_chains_fn) (tree, gimple, void *);
 550
 551 extern void walk_use_def_chains (tree, walk_use_def_chains_fn, void *, bool);
 552
 553 void insert_debug_temps_for_defs (gimple_stmt_iterator *);
 554 void insert_debug_temp_for_var_def (gimple_stmt_iterator *, tree);
 555 void reset_debug_uses (gimple);
 556 void release_defs_bitset (bitmap toremove);
 557
 558 /* In tree-into-ssa.c  */
 559 void update_ssa (unsigned);
 560 void delete_update_ssa (void);
 561 void register_new_name_mapping (tree, tree);
 562 tree create_new_def_for (tree, gimple, def_operand_p);
 563 bool need_ssa_update_p (struct function *);
 564 bool name_registered_for_update_p (tree);
 565 void release_ssa_name_after_update_ssa (tree);
 566 void compute_global_livein (bitmap, bitmap);
 567 void mark_sym_for_renaming (tree);
 568 bool symbol_marked_for_renaming (tree);
 569 tree get_current_def (tree);
 570 void set_current_def (tree, tree);
 571
 572 /* In tree-ssanames.c  */
 573 extern void init_ssanames (struct function *, int);
 574 extern void fini_ssanames (void);
 575 extern tree make_ssa_name_fn (struct function *, tree, gimple);
 576 extern tree duplicate_ssa_name (tree, gimple);
 577 extern void duplicate_ssa_name_ptr_info (tree, struct ptr_info_def *);
 578 extern void release_ssa_name (tree);
 579 extern void release_defs (gimple);
 580 extern void replace_ssa_name_symbol (tree, tree);
 581 extern bool get_ptr_info_alignment (struct ptr_info_def *, unsigned int *,
 582                                     unsigned int *);
 583 extern void mark_ptr_info_alignment_unknown (struct ptr_info_def *);
 584 extern void set_ptr_info_alignment (struct ptr_info_def *, unsigned int,
 585                                     unsigned int);
 586 extern void adjust_ptr_info_misalignment (struct ptr_info_def *,
 587                                           unsigned int);
 588
 589 extern void ssanames_print_statistics (void);
 590
 591 /* In tree-ssa-ccp.c  */
 592 tree fold_const_aggregate_ref (tree);
 593 tree gimple_fold_stmt_to_constant (gimple, tree (*)(tree));
 594
 595 /* In tree-ssa-dom.c  */
 596 extern void dump_dominator_optimization_stats (FILE *);
 597 extern void debug_dominator_optimization_stats (void);
 598 int loop_depth_of_name (tree);
 599 tree degenerate_phi_result (gimple);
 600 bool simple_iv_increment_p (gimple);
 601
 602 /* In tree-ssa-copy.c  */
 603 extern void propagate_value (use_operand_p, tree);
 604 extern void propagate_tree_value (tree *, tree);
 605 extern void propagate_tree_value_into_stmt (gimple_stmt_iterator *, tree);
 606 extern void replace_exp (use_operand_p, tree);
 607 extern bool may_propagate_copy (tree, tree);
 608 extern bool may_propagate_copy_into_stmt (gimple, tree);
 609 extern bool may_propagate_copy_into_asm (tree);
 610
 611 /* In tree-ssa-loop-ch.c  */
 612 bool do_while_loop_p (struct loop *);
 613
 614 /* Affine iv.  */
 615
 616 typedef struct
 617 {
 618   /* Iv = BASE + STEP * i.  */
 619   tree base, step;
 620
 621   /* True if this iv does not overflow.  */
 622   bool no_overflow;
 623 } affine_iv;
 624
 625 /* Description of number of iterations of a loop.  All the expressions inside
 626    the structure can be evaluated at the end of the loop's preheader
 627    (and due to ssa form, also anywhere inside the body of the loop).  */
 628
 629 struct tree_niter_desc
 630 {
 631   tree assumptions;     /* The boolean expression.  If this expression evaluates
 632                            to false, then the other fields in this structure
 633                            should not be used; there is no guarantee that they
 634                            will be correct.  */
 635   tree may_be_zero;     /* The boolean expression.  If it evaluates to true,
 636                            the loop will exit in the first iteration (i.e.
 637                            its latch will not be executed), even if the niter
 638                            field says otherwise.  */
 639   tree niter;           /* The expression giving the number of iterations of
 640                            a loop (provided that assumptions == true and
 641                            may_be_zero == false), more precisely the number
 642                            of executions of the latch of the loop.  */
 643   double_int max;       /* The upper bound on the number of iterations of
 644                            the loop.  */
 645
 646   /* The simplified shape of the exit condition.  The loop exits if
 647      CONTROL CMP BOUND is false, where CMP is one of NE_EXPR,
 648      LT_EXPR, or GT_EXPR, and step of CONTROL is positive if CMP is
 649      LE_EXPR and negative if CMP is GE_EXPR.  This information is used
 650      by loop unrolling.  */
 651   affine_iv control;
 652   tree bound;
 653   enum tree_code cmp;
 654 };
 655
 656 /* In tree-ssa-phiopt.c */
 657 bool empty_block_p (basic_block);
 658 basic_block *blocks_in_phiopt_order (void);
 659
 660 /* In tree-ssa-loop*.c  */
 661
 662 unsigned int tree_ssa_lim (void);
 663 unsigned int tree_ssa_unswitch_loops (void);
 664 unsigned int canonicalize_induction_variables (void);
 665 unsigned int tree_unroll_loops_completely (bool, bool);
 666 unsigned int tree_ssa_prefetch_arrays (void);
 667 void tree_ssa_iv_optimize (void);
 668 unsigned tree_predictive_commoning (void);
 669 tree canonicalize_loop_ivs (struct loop *, tree *, bool);
 670 bool parallelize_loops (void);
 671
 672 bool loop_only_exit_p (const struct loop *, const_edge);
 673 bool number_of_iterations_exit (struct loop *, edge,
 674                                 struct tree_niter_desc *niter, bool);
 675 tree find_loop_niter (struct loop *, edge *);
 676 tree loop_niter_by_eval (struct loop *, edge);
 677 tree find_loop_niter_by_eval (struct loop *, edge *);
 678 void estimate_numbers_of_iterations (void);
 679 bool scev_probably_wraps_p (tree, tree, gimple, struct loop *, bool);
 680 bool convert_affine_scev (struct loop *, tree, tree *, tree *, gimple, bool);
 681
 682 bool nowrap_type_p (tree);
 683 enum ev_direction {EV_DIR_GROWS, EV_DIR_DECREASES, EV_DIR_UNKNOWN};
 684 enum ev_direction scev_direction (const_tree);
 685
 686 void free_numbers_of_iterations_estimates (void);
 687 void free_numbers_of_iterations_estimates_loop (struct loop *);
 688 void rewrite_into_loop_closed_ssa (bitmap, unsigned);
 689 void verify_loop_closed_ssa (bool);
 690 bool for_each_index (tree *, bool (*) (tree, tree *, void *), void *);
 691 void create_iv (tree, tree, tree, struct loop *, gimple_stmt_iterator *, bool,
 692                 tree *, tree *);
 693 basic_block split_loop_exit_edge (edge);
 694 void standard_iv_increment_position (struct loop *, gimple_stmt_iterator *,
 695                                      bool *);
 696 basic_block ip_end_pos (struct loop *);
 697 basic_block ip_normal_pos (struct loop *);
 698 bool gimple_duplicate_loop_to_header_edge (struct loop *, edge,
 699                                          unsigned int, sbitmap,
 700                                          edge, VEC (edge, heap) **,
 701                                          int);
 702 struct loop *slpeel_tree_duplicate_loop_to_edge_cfg (struct loop *, edge);
 703 void rename_variables_in_loop (struct loop *);
 704 void rename_variables_in_bb (basic_block bb);
 705 tree expand_simple_operations (tree);
 706 void substitute_in_loop_info (struct loop *, tree, tree);
 707 edge single_dom_exit (struct loop *);
 708 bool can_unroll_loop_p (struct loop *loop, unsigned factor,
 709                         struct tree_niter_desc *niter);
 710 void tree_unroll_loop (struct loop *, unsigned,
 711                        edge, struct tree_niter_desc *);
 712 typedef void (*transform_callback)(struct loop *, void *);
 713 void tree_transform_and_unroll_loop (struct loop *, unsigned,
 714                                      edge, struct tree_niter_desc *,
 715                                      transform_callback, void *);
 716 bool contains_abnormal_ssa_name_p (tree);
 717 bool stmt_dominates_stmt_p (gimple, gimple);
 718 void mark_virtual_ops_for_renaming (gimple);
 719
 720 /* In tree-ssa-dce.c */
 721 void mark_virtual_operand_for_renaming (tree);
 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 stmt_could_throw_p (gimple);
 761 extern bool stmt_can_throw_internal (gimple);
 762 extern bool stmt_can_throw_external (gimple);
 763 extern void add_stmt_to_eh_lp_fn (struct function *, gimple, int);
 764 extern void add_stmt_to_eh_lp (gimple, int);
 765 extern bool remove_stmt_from_eh_lp (gimple);
 766 extern bool remove_stmt_from_eh_lp_fn (struct function *, gimple);
 767 extern int lookup_stmt_eh_lp_fn (struct function *, gimple);
 768 extern int lookup_stmt_eh_lp (gimple);
 769 extern bool maybe_clean_eh_stmt_fn (struct function *, gimple);
 770 extern bool maybe_clean_eh_stmt (gimple);
 771 extern bool maybe_clean_or_replace_eh_stmt (gimple, gimple);
 772 extern bool maybe_duplicate_eh_stmt_fn (struct function *, gimple,
 773                                         struct function *, gimple,
 774                                         struct pointer_map_t *, int);
 775 extern bool maybe_duplicate_eh_stmt (gimple, gimple);
 776 extern bool verify_eh_edges (gimple);
 777 extern bool verify_eh_dispatch_edge (gimple);
 778 extern void maybe_remove_unreachable_handlers (void);
 779
 780 /* In tree-ssa-pre.c  */
 781 void debug_value_expressions (unsigned int);
 782
 783 /* In tree-loop-linear.c  */
 784 extern void linear_transform_loops (void);
 785 extern unsigned perfect_loop_nest_depth (struct loop *);
 786
 787 /* In graphite.c  */
 788 extern void graphite_transform_loops (void);
 789
 790 /* In tree-data-ref.c  */
 791 extern void tree_check_data_deps (void);
 792
 793 /* In tree-ssa-loop-ivopts.c  */
 794 bool expr_invariant_in_loop_p (struct loop *, tree);
 795 bool stmt_invariant_in_loop_p (struct loop *, gimple);
 796 bool multiplier_allowed_in_address_p (HOST_WIDE_INT, enum machine_mode,
 797                                       addr_space_t);
 798 bool may_be_nonaddressable_p (tree expr);
 799
 800 /* In tree-ssa-threadupdate.c.  */
 801 extern bool thread_through_all_blocks (bool);
 802 extern void register_jump_thread (edge, edge, edge);
 803
 804 /* In gimplify.c  */
 805 tree force_gimple_operand_1 (tree, gimple_seq *, gimple_predicate, tree);
 806 tree force_gimple_operand (tree, gimple_seq *, bool, tree);
 807 tree force_gimple_operand_gsi_1 (gimple_stmt_iterator *, tree,
 808                                  gimple_predicate, tree,
 809                                  bool, enum gsi_iterator_update);
 810 tree force_gimple_operand_gsi (gimple_stmt_iterator *, tree, bool, tree,
 811                                bool, enum gsi_iterator_update);
 812 tree gimple_fold_indirect_ref (tree);
 813
 814 /* In tree-ssa-live.c */
 815 extern void remove_unused_locals (void);
 816 extern void dump_scope_blocks (FILE *, int);
 817 extern void debug_scope_blocks (int);
 818 extern void debug_scope_block (tree, int);
 819
 820 /* In tree-ssa-address.c  */
 821
 822 /* Description of a memory address.  */
 823
 824 struct mem_address
 825 {
 826   tree symbol, base, index, step, offset;
 827 };
 828
 829 struct affine_tree_combination;
 830 tree create_mem_ref (gimple_stmt_iterator *, tree,
 831                      struct affine_tree_combination *, tree, tree, tree, bool);
 832 rtx addr_for_mem_ref (struct mem_address *, addr_space_t, bool);
 833 void get_address_description (tree, struct mem_address *);
 834 tree maybe_fold_tmr (tree);
 835
 836 unsigned int execute_fixup_cfg (void);
 837 bool fixup_noreturn_call (gimple stmt);
 838
 839 /* In ipa-pure-const.c  */
 840 void warn_function_noreturn (tree);
 841
 842 /* In tree-ssa-ter.c  */
 843 bool stmt_is_replaceable_p (gimple);
 844
 845 /* In tree-parloops.c  */
 846 bool parallelized_function_p (tree);
 847
 848 #include "tree-flow-inline.h"
 849
 850 void swap_tree_operands (gimple, tree *, tree *);
 851
 852 #endif /* _TREE_FLOW_H  */