gcc/tree-flow.h

   1 /* Data and Control Flow Analysis for Trees.
   2    Copyright (C) 2001, 2003, 2004, 2005, 2006, 2007
   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 "hard-reg-set.h"
  27 #include "basic-block.h"
  28 #include "hashtab.h"
  29 #include "tree-gimple.h"
  30 #include "tree-ssa-operands.h"
  31 #include "cgraph.h"
  32 #include "ipa-reference.h"
  33
  34 /* Forward declare structures for the garbage collector GTY markers.  */
  35 #ifndef GCC_BASIC_BLOCK_H
  36 struct edge_def;
  37 typedef struct edge_def *edge;
  38 struct basic_block_def;
  39 typedef struct basic_block_def *basic_block;
  40 #endif
  41 struct static_var_ann_d;
  42
  43 /* The reasons a variable may escape a function.  */
  44 enum escape_type
  45 {
  46   NO_ESCAPE = 0,                        /* Doesn't escape.  */
  47   ESCAPE_STORED_IN_GLOBAL = 1 << 0,
  48   ESCAPE_TO_ASM = 1 << 1,               /* Passed by address to an assembly
  49                                            statement.  */
  50   ESCAPE_TO_CALL = 1 << 2,              /* Escapes to a function call.  */
  51   ESCAPE_BAD_CAST = 1 << 3,             /* Cast from pointer to integer */
  52   ESCAPE_TO_RETURN = 1 << 4,            /* Returned from function.  */
  53   ESCAPE_TO_PURE_CONST = 1 << 5,        /* Escapes to a pure or constant
  54                                            function call.  */
  55   ESCAPE_IS_GLOBAL = 1 << 6,            /* Is a global variable.  */
  56   ESCAPE_IS_PARM = 1 << 7,              /* Is an incoming function argument.  */
  57   ESCAPE_UNKNOWN = 1 << 8               /* We believe it escapes for
  58                                            some reason not enumerated
  59                                            above.  */
  60 };
  61
  62 /* Memory reference statistics for individual memory symbols,
  63    collected during alias analysis.  */
  64 struct mem_sym_stats_d GTY(())
  65 {
  66   /* Memory symbol.  */
  67   tree var;
  68
  69   /* Nonzero if this entry has been assigned a partition.  */
  70   unsigned int partitioned_p : 1;
  71
  72   /* Nonzero if VAR is a memory partition tag that already contains
  73      call-clobbered variables in its partition set.  */
  74   unsigned int has_call_clobbered_vars : 1;
  75
  76   /* Number of direct reference sites.  A direct reference to VAR is any
  77      reference of the form 'VAR = ' or ' = VAR'.  For GIMPLE reg
  78      pointers, this is the number of sites where the pointer is
  79      dereferenced.  */
  80   long num_direct_writes;
  81   long num_direct_reads;
  82
  83   /* Number of indirect reference sites.  An indirect reference to VAR
  84      is any reference via a pointer that contains VAR in its points-to
  85      set or, in the case of call-clobbered symbols, a function call.  */
  86   long num_indirect_writes;
  87   long num_indirect_reads;
  88
  89   /* Execution frequency.  This is the sum of the execution
  90      frequencies of all the statements that reference this object
  91      weighted by the number of references in each statement.  This is
  92      the main key used to sort the list of symbols to partition.
  93      Symbols with high execution frequencies are put at the bottom of
  94      the work list (ie, they are partitioned last).
  95      Execution frequencies are taken directly from each basic block,
  96      so compiling with PGO enabled will increase the precision of this
  97      estimate.  */
  98   long frequency_reads;
  99   long frequency_writes;
 100
 101   /* Set of memory tags that contain VAR in their alias set.  */
 102   bitmap parent_tags;
 103 };
 104
 105 typedef struct mem_sym_stats_d *mem_sym_stats_t;
 106 DEF_VEC_P(mem_sym_stats_t);
 107 DEF_VEC_ALLOC_P(mem_sym_stats_t, heap);
 108
 109 /* Memory reference statistics collected during alias analysis.  */
 110 struct mem_ref_stats_d GTY(())
 111 {
 112   /* Number of statements that make memory references.  */
 113   long num_mem_stmts;
 114
 115   /* Number of statements that make function calls.  */
 116   long num_call_sites;
 117
 118   /* Number of statements that make calls to pure/const functions.  */
 119   long num_pure_const_call_sites;
 120
 121   /* Number of ASM statements.  */
 122   long num_asm_sites;
 123
 124   /* Estimated number of virtual operands needed as computed by
 125    compute_memory_partitions.  */
 126   long num_vuses;
 127   long num_vdefs;
 128
 129   /* This maps every symbol used to make "memory" references
 130      (pointers, arrays, structures, etc) to an instance of struct
 131      mem_sym_stats_d describing reference statistics for the symbol.  */
 132   struct pointer_map_t * GTY((skip)) mem_sym_stats;
 133 };
 134
 135
 136 /* Gimple dataflow datastructure. All publicly available fields shall have
 137    gimple_ accessor defined in tree-flow-inline.h, all publicly modifiable
 138    fields should have gimple_set accessor.  */
 139 struct gimple_df GTY(())
 140 {
 141   /* Array of all variables referenced in the function.  */
 142   htab_t GTY((param_is (union tree_node))) referenced_vars;
 143
 144   /* A vector of all the noreturn calls passed to modify_stmt.
 145      cleanup_control_flow uses it to detect cases where a mid-block
 146      indirect call has been turned into a noreturn call.  When this
 147      happens, all the instructions after the call are no longer
 148      reachable and must be deleted as dead.  */
 149   VEC(gimple,gc) *modified_noreturn_calls;
 150
 151   /* Array of all SSA_NAMEs used in the function.  */
 152   VEC(tree,gc) *ssa_names;
 153
 154   /* Artificial variable used to model the effects of function calls.  */
 155   tree global_var;
 156
 157   /* Artificial variable used to model the effects of nonlocal
 158      variables.  */
 159   tree nonlocal_all;
 160
 161   /* Call clobbered variables in the function.  If bit I is set, then
 162      REFERENCED_VARS (I) is call-clobbered.  */
 163   bitmap call_clobbered_vars;
 164
 165   /* Addressable variables in the function.  If bit I is set, then
 166      REFERENCED_VARS (I) has had its address taken.  Note that
 167      CALL_CLOBBERED_VARS and ADDRESSABLE_VARS are not related.  An
 168      addressable variable is not necessarily call-clobbered (e.g., a
 169      local addressable whose address does not escape) and not all
 170      call-clobbered variables are addressable (e.g., a local static
 171      variable).  */
 172   bitmap addressable_vars;
 173
 174   /* Free list of SSA_NAMEs.  */
 175   tree free_ssanames;
 176
 177   /* Hashtable holding definition for symbol.  If this field is not NULL, it
 178      means that the first reference to this variable in the function is a
 179      USE or a VUSE.  In those cases, the SSA renamer creates an SSA name
 180      for this variable with an empty defining statement.  */
 181   htab_t GTY((param_is (union tree_node))) default_defs;
 182
 183   /* 'true' after aliases have been computed (see compute_may_aliases).  */
 184   unsigned int aliases_computed_p : 1;
 185
 186   /* True if the code is in ssa form.  */
 187   unsigned int in_ssa_p : 1;
 188
 189   struct ssa_operands ssa_operands;
 190
 191   /* Hashtable of variables annotations.  Used for static variables only;
 192      local variables have direct pointer in the tree node.  */
 193   htab_t GTY((param_is (struct static_var_ann_d))) var_anns;
 194
 195   /* Memory reference statistics collected during alias analysis.
 196      This information is used to drive the memory partitioning
 197      heuristics in compute_memory_partitions.  */
 198   struct mem_ref_stats_d mem_ref_stats;
 199 };
 200
 201 /* Accessors for internal use only.  Generic code should use abstraction
 202    provided by tree-flow-inline.h or specific modules.  */
 203 #define FREE_SSANAMES(fun) (fun)->gimple_df->free_ssanames
 204 #define SSANAMES(fun) (fun)->gimple_df->ssa_names
 205 #define MODIFIED_NORETURN_CALLS(fun) (fun)->gimple_df->modified_noreturn_calls
 206 #define DEFAULT_DEFS(fun) (fun)->gimple_df->default_defs
 207
 208 typedef struct
 209 {
 210   htab_t htab;
 211   PTR *slot;
 212   PTR *limit;
 213 } htab_iterator;
 214
 215 /* Iterate through the elements of hashtable HTAB, using htab_iterator ITER,
 216    storing each element in RESULT, which is of type TYPE.  */
 217 #define FOR_EACH_HTAB_ELEMENT(HTAB, RESULT, TYPE, ITER) \
 218   for (RESULT = (TYPE) first_htab_element (&(ITER), (HTAB)); \
 219         !end_htab_p (&(ITER)); \
 220         RESULT = (TYPE) next_htab_element (&(ITER)))
 221
 222 /*---------------------------------------------------------------------------
 223                       Attributes for SSA_NAMEs.
 224
 225   NOTE: These structures are stored in struct tree_ssa_name
 226   but are only used by the tree optimizers, so it makes better sense
 227   to declare them here to avoid recompiling unrelated files when
 228   making changes.
 229 ---------------------------------------------------------------------------*/
 230
 231 /* Aliasing information for SSA_NAMEs representing pointer variables.  */
 232 struct ptr_info_def GTY(())
 233 {
 234   /* Nonzero if points-to analysis couldn't determine where this pointer
 235      is pointing to.  */
 236   unsigned int pt_anything : 1;
 237
 238   /* Nonzero if the value of this pointer escapes the current function.  */
 239   unsigned int value_escapes_p : 1;
 240
 241   /* Nonzero if this pointer is dereferenced.  */
 242   unsigned int is_dereferenced : 1;
 243
 244   /* Nonzero if this pointer points to a global variable.  */
 245   unsigned int pt_global_mem : 1;
 246
 247   /* Nonzero if this pointer points to NULL.  */
 248   unsigned int pt_null : 1;
 249
 250   /* Mask of reasons this pointer's value escapes the function  */
 251   ENUM_BITFIELD (escape_type) escape_mask : 9;
 252
 253   /* Set of variables that this pointer may point to.  */
 254   bitmap pt_vars;
 255
 256   /* If this pointer has been dereferenced, and points-to information is
 257      more precise than type-based aliasing, indirect references to this
 258      pointer will be represented by this memory tag, instead of the type
 259      tag computed by TBAA.  */
 260   tree name_mem_tag;
 261 };
 262
 263
 264 /*---------------------------------------------------------------------------
 265                    Tree annotations stored in tree_base.ann
 266 ---------------------------------------------------------------------------*/
 267 enum tree_ann_type { TREE_ANN_COMMON, VAR_ANN, FUNCTION_ANN };
 268
 269 struct tree_ann_common_d GTY(())
 270 {
 271   /* Annotation type.  */
 272   enum tree_ann_type type;
 273
 274  /* Auxiliary info specific to a pass.  At all times, this
 275     should either point to valid data or be NULL.  */
 276   PTR GTY ((skip (""))) aux;
 277
 278   /* The value handle for this expression.  Used by GVN-PRE.  */
 279   tree GTY((skip)) value_handle;
 280
 281   /* FIXME tuples.  Hack to record EH region number into a statement
 282      tree created during RTL expansion (see gimple_to_tree).  */
 283   int rn;
 284
 285   /* FIXME tuples: Pointer to original GIMPLE statement.  */
 286   gimple stmt;
 287 };
 288
 289 /* It is advantageous to avoid things like life analysis for variables which
 290    do not need PHI nodes.  This enum describes whether or not a particular
 291    variable may need a PHI node.  */
 292
 293 enum need_phi_state {
 294   /* This is the default.  If we are still in this state after finding
 295      all the definition and use sites, then we will assume the variable
 296      needs PHI nodes.  This is probably an overly conservative assumption.  */
 297   NEED_PHI_STATE_UNKNOWN,
 298
 299   /* This state indicates that we have seen one or more sets of the
 300      variable in a single basic block and that the sets dominate all
 301      uses seen so far.  If after finding all definition and use sites
 302      we are still in this state, then the variable does not need any
 303      PHI nodes.  */
 304   NEED_PHI_STATE_NO,
 305
 306   /* This state indicates that we have either seen multiple definitions of
 307      the variable in multiple blocks, or that we encountered a use in a
 308      block that was not dominated by the block containing the set(s) of
 309      this variable.  This variable is assumed to need PHI nodes.  */
 310   NEED_PHI_STATE_MAYBE
 311 };
 312
 313
 314 /* The "no alias" attribute allows alias analysis to make more
 315    aggressive assumptions when assigning alias sets, computing
 316    points-to information and memory partitions.  These attributes
 317    are the result of user annotations or flags (e.g.,
 318    -fargument-noalias).  */
 319 enum noalias_state {
 320     /* Default state.  No special assumptions can be made about this
 321        symbol.  */
 322     MAY_ALIAS = 0,
 323
 324     /* The symbol does not alias with other symbols that have a
 325        NO_ALIAS* attribute.  */
 326     NO_ALIAS,
 327
 328     /* The symbol does not alias with other symbols that have a
 329        NO_ALIAS*, and it may not alias with global symbols.  */
 330     NO_ALIAS_GLOBAL,
 331
 332     /* The symbol does not alias with any other symbols.  */
 333     NO_ALIAS_ANYTHING
 334 };
 335
 336
 337 typedef VEC(tree,gc) *subvar_t;
 338
 339 struct var_ann_d GTY(())
 340 {
 341   struct tree_ann_common_d common;
 342
 343   /* Used by the out of SSA pass to determine whether this variable has
 344      been seen yet or not.  */
 345   unsigned out_of_ssa_tag : 1;
 346
 347   /* Used when building base variable structures in a var_map.  */
 348   unsigned base_var_processed : 1;
 349
 350   /* Nonzero if this variable was used after SSA optimizations were
 351      applied.  We set this when translating out of SSA form.  */
 352   unsigned used : 1;
 353
 354   /* This field indicates whether or not the variable may need PHI nodes.
 355      See the enum's definition for more detailed information about the
 356      states.  */
 357   ENUM_BITFIELD (need_phi_state) need_phi_state : 2;
 358
 359   /* Used during operand processing to determine if this variable is already
 360      in the VUSE list.  */
 361   unsigned in_vuse_list : 1;
 362
 363   /* Used during operand processing to determine if this variable is already
 364      in the VDEF list.  */
 365   unsigned in_vdef_list : 1;
 366
 367   /* True for HEAP artificial variables.  These variables represent
 368      the memory area allocated by a call to malloc.  */
 369   unsigned is_heapvar : 1;
 370
 371   /* True if the variable is call clobbered.  */
 372   unsigned call_clobbered : 1;
 373
 374   /* This field describes several "no alias" attributes that some
 375      symbols are known to have.  See the enum's definition for more
 376      information on each attribute.  */
 377   ENUM_BITFIELD (noalias_state) noalias_state : 2;
 378
 379   /* Mask of values saying the reasons why this variable has escaped
 380      the function.  */
 381   ENUM_BITFIELD (escape_type) escape_mask : 9;
 382
 383   /* Memory partition tag assigned to this symbol.  */
 384   tree mpt;
 385
 386   /* If this variable is a pointer P that has been dereferenced, this
 387      field is an artificial variable that represents the memory
 388      location *P.  Every other pointer Q that is type-compatible with
 389      P will also have the same memory tag.  If the variable is not a
 390      pointer or if it is never dereferenced, this must be NULL.
 391      FIXME, do we really need this here?  How much slower would it be
 392      to convert to hash table?  */
 393   tree symbol_mem_tag;
 394
 395   /* Used when going out of SSA form to indicate which partition this
 396      variable represents storage for.  */
 397   unsigned partition;
 398
 399   /* Used by var_map for the base index of ssa base variables.  */
 400   unsigned base_index;
 401
 402   /* During into-ssa and the dominator optimizer, this field holds the
 403      current version of this variable (an SSA_NAME).  */
 404   tree current_def;
 405
 406   /* If this variable is a structure, this fields holds an array
 407      of symbols representing each of the fields of the structure.  */
 408   VEC(tree,gc) *subvars;
 409 };
 410
 411 /* Container for variable annotation used by hashtable for annotations for
 412    static variables.  */
 413 struct static_var_ann_d GTY(())
 414 {
 415   struct var_ann_d ann;
 416   unsigned int uid;
 417 };
 418
 419 struct function_ann_d GTY(())
 420 {
 421   struct tree_ann_common_d common;
 422
 423   /* FIXME tuples.  */
 424 #if 0
 425   /* Pointer to the structure that contains the sets of global
 426      variables modified by function calls.  This field is only used
 427      for FUNCTION_DECLs.  */
 428   /*ipa_reference_vars_info_t GTY ((skip)) reference_vars_info;*/
 429 #endif
 430 };
 431
 432
 433 /* Immediate use lists are used to directly access all uses for an SSA
 434    name and get pointers to the statement for each use.
 435
 436    The structure ssa_use_operand_d consists of PREV and NEXT pointers
 437    to maintain the list.  A USE pointer, which points to address where
 438    the use is located and a LOC pointer which can point to the
 439    statement where the use is located, or, in the case of the root
 440    node, it points to the SSA name itself.
 441
 442    The list is anchored by an occurrence of ssa_operand_d *in* the
 443    ssa_name node itself (named 'imm_uses').  This node is uniquely
 444    identified by having a NULL USE pointer. and the LOC pointer
 445    pointing back to the ssa_name node itself.  This node forms the
 446    base for a circular list, and initially this is the only node in
 447    the list.
 448
 449    Fast iteration allows each use to be examined, but does not allow
 450    any modifications to the uses or stmts.
 451
 452    Normal iteration allows insertion, deletion, and modification. the
 453    iterator manages this by inserting a marker node into the list
 454    immediately before the node currently being examined in the list.
 455    this marker node is uniquely identified by having null stmt *and* a
 456    null use pointer.
 457
 458    When iterating to the next use, the iteration routines check to see
 459    if the node after the marker has changed. if it has, then the node
 460    following the marker is now the next one to be visited. if not, the
 461    marker node is moved past that node in the list (visualize it as
 462    bumping the marker node through the list).  this continues until
 463    the marker node is moved to the original anchor position. the
 464    marker node is then removed from the list.
 465
 466    If iteration is halted early, the marker node must be removed from
 467    the list before continuing.  */
 468 typedef struct immediate_use_iterator_d
 469 {
 470   /* This is the current use the iterator is processing.  */
 471   ssa_use_operand_t *imm_use;
 472   /* This marks the last use in the list (use node from SSA_NAME)  */
 473   ssa_use_operand_t *end_p;
 474   /* This node is inserted and used to mark the end of the uses for a stmt.  */
 475   ssa_use_operand_t iter_node;
 476   /* This is the next ssa_name to visit.  IMM_USE may get removed before
 477      the next one is traversed to, so it must be cached early.  */
 478   ssa_use_operand_t *next_imm_name;
 479 } imm_use_iterator;
 480
 481
 482 /* Use this iterator when simply looking at stmts.  Adding, deleting or
 483    modifying stmts will cause this iterator to malfunction.  */
 484
 485 #define FOR_EACH_IMM_USE_FAST(DEST, ITER, SSAVAR)                       \
 486   for ((DEST) = first_readonly_imm_use (&(ITER), (SSAVAR));     \
 487        !end_readonly_imm_use_p (&(ITER));                       \
 488        (DEST) = next_readonly_imm_use (&(ITER)))
 489
 490 /* Use this iterator to visit each stmt which has a use of SSAVAR.  */
 491
 492 #define FOR_EACH_IMM_USE_STMT(STMT, ITER, SSAVAR)               \
 493   for ((STMT) = first_imm_use_stmt (&(ITER), (SSAVAR));         \
 494        !end_imm_use_stmt_p (&(ITER));                           \
 495        (STMT) = next_imm_use_stmt (&(ITER)))
 496
 497 /* Use this to terminate the FOR_EACH_IMM_USE_STMT loop early.  Failure to
 498    do so will result in leaving a iterator marker node in the immediate
 499    use list, and nothing good will come from that.   */
 500 #define BREAK_FROM_IMM_USE_STMT(ITER)                           \
 501    {                                                            \
 502      end_imm_use_stmt_traverse (&(ITER));                       \
 503      break;                                                     \
 504    }
 505
 506
 507 /* Use this iterator in combination with FOR_EACH_IMM_USE_STMT to
 508    get access to each occurrence of ssavar on the stmt returned by
 509    that iterator..  for instance:
 510
 511      FOR_EACH_IMM_USE_STMT (stmt, iter, var)
 512        {
 513          FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
 514            {
 515              SET_USE (use_p) = blah;
 516            }
 517          update_stmt (stmt);
 518        }                                                         */
 519
 520 #define FOR_EACH_IMM_USE_ON_STMT(DEST, ITER)                    \
 521   for ((DEST) = first_imm_use_on_stmt (&(ITER));                \
 522        !end_imm_use_on_stmt_p (&(ITER));                        \
 523        (DEST) = next_imm_use_on_stmt (&(ITER)))
 524
 525
 526
 527 union tree_ann_d GTY((desc ("ann_type ((tree_ann_t)&%h)")))
 528 {
 529   struct tree_ann_common_d GTY((tag ("TREE_ANN_COMMON"))) common;
 530   struct var_ann_d GTY((tag ("VAR_ANN"))) vdecl;
 531   struct function_ann_d GTY((tag ("FUNCTION_ANN"))) fdecl;
 532 };
 533
 534 typedef union tree_ann_d *tree_ann_t;
 535 typedef struct var_ann_d *var_ann_t;
 536 typedef struct function_ann_d *function_ann_t;
 537 typedef struct tree_ann_common_d *tree_ann_common_t;
 538
 539 static inline tree_ann_common_t tree_common_ann (const_tree);
 540 static inline tree_ann_common_t get_tree_common_ann (tree);
 541 static inline var_ann_t var_ann (const_tree);
 542 static inline var_ann_t get_var_ann (tree);
 543 static inline function_ann_t function_ann (const_tree);
 544 static inline function_ann_t get_function_ann (tree);
 545 static inline enum tree_ann_type ann_type (tree_ann_t);
 546 static inline void update_stmt (gimple);
 547 static inline bitmap may_aliases (const_tree);
 548 static inline int get_lineno (const_gimple);
 549
 550 /*---------------------------------------------------------------------------
 551                   Structure representing predictions in tree level.
 552 ---------------------------------------------------------------------------*/
 553 struct edge_prediction GTY((chain_next ("%h.ep_next")))
 554 {
 555   struct edge_prediction *ep_next;
 556   edge ep_edge;
 557   enum br_predictor ep_predictor;
 558   int ep_probability;
 559 };
 560
 561 /* Accessors for basic block annotations.  */
 562 static inline gimple_seq phi_nodes (const_basic_block);
 563 static inline void set_phi_nodes (basic_block, gimple_seq);
 564
 565 /*---------------------------------------------------------------------------
 566                               Global declarations
 567 ---------------------------------------------------------------------------*/
 568 struct int_tree_map GTY(())
 569 {
 570
 571   unsigned int uid;
 572   tree to;
 573 };
 574
 575 extern unsigned int int_tree_map_hash (const void *);
 576 extern int int_tree_map_eq (const void *, const void *);
 577
 578 extern unsigned int uid_decl_map_hash (const void *);
 579 extern int uid_decl_map_eq (const void *, const void *);
 580
 581 typedef struct
 582 {
 583   htab_iterator hti;
 584 } referenced_var_iterator;
 585
 586
 587 /* This macro loops over all the referenced vars, one at a time, putting the
 588    current var in VAR.  Note:  You are not allowed to add referenced variables
 589    to the hashtable while using this macro.  Doing so may cause it to behave
 590    erratically.  */
 591
 592 #define FOR_EACH_REFERENCED_VAR(VAR, ITER) \
 593   for ((VAR) = first_referenced_var (&(ITER)); \
 594        !end_referenced_vars_p (&(ITER)); \
 595        (VAR) = next_referenced_var (&(ITER)))
 596
 597
 598 typedef struct
 599 {
 600   int i;
 601 } safe_referenced_var_iterator;
 602
 603 /* This macro loops over all the referenced vars, one at a time, putting the
 604    current var in VAR.  You are allowed to add referenced variables during the
 605    execution of this macro, however, the macro will not iterate over them.  It
 606    requires a temporary vector of trees, VEC, whose lifetime is controlled by
 607    the caller.  The purpose of the vector is to temporarily store the
 608    referenced_variables hashtable so that adding referenced variables does not
 609    affect the hashtable.  */
 610
 611 #define FOR_EACH_REFERENCED_VAR_SAFE(VAR, VEC, ITER) \
 612   for ((ITER).i = 0, fill_referenced_var_vec (&(VEC)); \
 613        VEC_iterate (tree, (VEC), (ITER).i, (VAR)); \
 614        (ITER).i++)
 615
 616 extern tree referenced_var_lookup (unsigned int);
 617 extern bool referenced_var_check_and_insert (tree);
 618 #define num_referenced_vars htab_elements (gimple_referenced_vars (cfun))
 619 #define referenced_var(i) referenced_var_lookup (i)
 620
 621 #define num_ssa_names (VEC_length (tree, cfun->gimple_df->ssa_names))
 622 #define ssa_name(i) (VEC_index (tree, cfun->gimple_df->ssa_names, (i)))
 623
 624 /* Macros for showing usage statistics.  */
 625 #define SCALE(x) ((unsigned long) ((x) < 1024*10        \
 626                   ? (x)                                 \
 627                   : ((x) < 1024*1024*10                 \
 628                      ? (x) / 1024                       \
 629                      : (x) / (1024*1024))))
 630
 631 #define LABEL(x) ((x) < 1024*10 ? 'b' : ((x) < 1024*1024*10 ? 'k' : 'M'))
 632
 633 #define PERCENT(x,y) ((float)(x) * 100.0 / (float)(y))
 634
 635 /*---------------------------------------------------------------------------
 636                               OpenMP Region Tree
 637 ---------------------------------------------------------------------------*/
 638
 639 /* Parallel region information.  Every parallel and workshare
 640    directive is enclosed between two markers, the OMP_* directive
 641    and a corresponding OMP_RETURN statement.  */
 642
 643 struct omp_region
 644 {
 645   /* The enclosing region.  */
 646   struct omp_region *outer;
 647
 648   /* First child region.  */
 649   struct omp_region *inner;
 650
 651   /* Next peer region.  */
 652   struct omp_region *next;
 653
 654   /* Block containing the omp directive as its last stmt.  */
 655   basic_block entry;
 656
 657   /* Block containing the OMP_RETURN as its last stmt.  */
 658   basic_block exit;
 659
 660   /* Block containing the OMP_CONTINUE as its last stmt.  */
 661   basic_block cont;
 662
 663   /* If this is a combined parallel+workshare region, this is a list
 664      of additional arguments needed by the combined parallel+workshare
 665      library call.  */
 666   tree ws_args;
 667
 668   /* The code for the omp directive of this region.  */
 669   enum gimple_code type;
 670
 671   /* Schedule kind, only used for OMP_FOR type regions.  */
 672   enum omp_clause_schedule_kind sched_kind;
 673
 674   /* True if this is a combined parallel+workshare region.  */
 675   bool is_combined_parallel;
 676 };
 677
 678 extern struct omp_region *root_omp_region;
 679 extern struct omp_region *new_omp_region (basic_block, enum gimple_code,
 680                                           struct omp_region *);
 681 extern void free_omp_regions (void);
 682 void omp_expand_local (basic_block);
 683 extern tree find_omp_clause (tree, enum tree_code);
 684 tree copy_var_decl (tree, tree, tree);
 685
 686 /*---------------------------------------------------------------------------
 687                               Function prototypes
 688 ---------------------------------------------------------------------------*/
 689 /* In tree-cfg.c  */
 690
 691 /* Location to track pending stmt for edge insertion.  */
 692 #define PENDING_STMT(e) ((e)->insns.g)
 693
 694 extern void delete_tree_cfg_annotations (void);
 695 extern bool stmt_ends_bb_p (gimple);
 696 extern bool is_ctrl_stmt (gimple);
 697 extern bool is_ctrl_altering_stmt (gimple);
 698 extern bool computed_goto_p (gimple);
 699 extern bool simple_goto_p (gimple);
 700 extern bool stmt_can_make_abnormal_goto (gimple);
 701 extern basic_block single_noncomplex_succ (basic_block bb);
 702 extern void gimple_dump_bb (basic_block, FILE *, int, int);
 703 extern void gimple_debug_bb (basic_block);
 704 extern basic_block gimple_debug_bb_n (int);
 705 extern void gimple_dump_cfg (FILE *, int);
 706 extern void gimple_debug_cfg (int);
 707 extern void dump_cfg_stats (FILE *);
 708 extern void dot_cfg (void);
 709 extern void debug_cfg_stats (void);
 710 extern void debug_loops (int);
 711 extern void debug_loop (struct loop *, int);
 712 extern void debug_loop_num (unsigned, int);
 713 extern void print_loops (FILE *, int);
 714 extern void print_loops_bb (FILE *, basic_block, int, int);
 715 extern void cleanup_dead_labels (void);
 716 extern void group_case_labels (void);
 717 extern gimple first_stmt (basic_block);
 718 extern gimple last_stmt (basic_block);
 719 extern gimple last_and_only_stmt (basic_block);
 720 extern edge find_taken_edge (basic_block, tree);
 721 extern basic_block label_to_block_fn (struct function *, tree);
 722 #define label_to_block(t) (label_to_block_fn (cfun, t))
 723 extern void notice_special_calls (gimple);
 724 extern void clear_special_calls (void);
 725 extern void verify_stmts (void);
 726 extern void verify_gimple (void);
 727 extern void verify_types_in_gimple_seq (gimple_seq);
 728 extern tree gimple_block_label (basic_block);
 729 extern void extract_true_false_edges_from_block (basic_block, edge *, edge *);
 730 extern bool gimple_duplicate_sese_region (edge, edge, basic_block *, unsigned,
 731                                         basic_block *);
 732 extern bool gimple_duplicate_sese_tail (edge, edge, basic_block *, unsigned,
 733                                       basic_block *);
 734 extern void add_phi_args_after_copy_bb (basic_block);
 735 extern void add_phi_args_after_copy (basic_block *, unsigned, edge);
 736 extern bool gimple_purge_dead_abnormal_call_edges (basic_block);
 737 extern bool gimple_purge_dead_eh_edges (basic_block);
 738 extern bool gimple_purge_all_dead_eh_edges (const_bitmap);
 739 extern tree gimplify_val (gimple_stmt_iterator *, tree, tree);
 740 extern tree gimplify_build1 (gimple_stmt_iterator *, enum tree_code,
 741                              tree, tree);
 742 extern tree gimplify_build2 (gimple_stmt_iterator *, enum tree_code,
 743                              tree, tree, tree);
 744 extern tree gimplify_build3 (gimple_stmt_iterator *, enum tree_code,
 745                              tree, tree, tree, tree);
 746 extern void init_empty_tree_cfg (void);
 747 extern void fold_cond_expr_cond (void);
 748 extern void make_abnormal_goto_edges (basic_block, bool);
 749 extern void replace_uses_by (tree, tree);
 750 extern void start_recording_case_labels (void);
 751 extern void end_recording_case_labels (void);
 752 extern basic_block move_sese_region_to_fn (struct function *, basic_block,
 753                                            basic_block);
 754 void remove_edge_and_dominated_blocks (edge);
 755 void mark_virtual_ops_in_bb (basic_block);
 756
 757 /* In tree-cfgcleanup.c  */
 758 extern bitmap cfgcleanup_altered_bbs;
 759 extern bool cleanup_tree_cfg (void);
 760
 761 /* In tree-pretty-print.c.  */
 762 extern void dump_generic_bb (FILE *, basic_block, int, int);
 763 extern const char *op_symbol_code (enum tree_code);
 764
 765 /* In tree-dfa.c  */
 766 extern var_ann_t create_var_ann (tree);
 767 extern function_ann_t create_function_ann (tree);
 768 extern tree_ann_common_t create_tree_common_ann (tree);
 769 extern void dump_dfa_stats (FILE *);
 770 extern void debug_dfa_stats (void);
 771 extern void debug_referenced_vars (void);
 772 extern void dump_referenced_vars (FILE *);
 773 extern void dump_variable (FILE *, tree);
 774 extern void debug_variable (tree);
 775 extern void dump_subvars_for (FILE *, tree);
 776 extern void debug_subvars_for (tree);
 777 extern tree get_virtual_var (tree);
 778 extern void add_referenced_var (tree);
 779 extern void remove_referenced_var (tree);
 780 extern void mark_symbols_for_renaming (gimple);
 781 extern void find_new_referenced_vars (gimple_stmt_iterator *);
 782 extern tree make_rename_temp (tree, const char *);
 783 extern void set_default_def (tree, tree);
 784 extern tree gimple_default_def (struct function *, tree);
 785 extern bool stmt_references_abnormal_ssa_name (gimple);
 786 extern bool refs_may_alias_p (tree, tree);
 787 extern tree get_single_def_stmt (tree);
 788 extern tree get_single_def_stmt_from_phi (tree, tree);
 789 extern tree get_single_def_stmt_with_phi (tree, tree);
 790
 791 /* In tree-phinodes.c  */
 792 extern void reserve_phi_args_for_new_edge (basic_block);
 793 extern gimple create_phi_node (tree, basic_block);
 794 extern void add_phi_arg (gimple, tree, edge);
 795 extern void remove_phi_args (edge);
 796 extern void remove_phi_node (gimple_stmt_iterator *, bool);
 797
 798 /* In gimple-low.c  */
 799 extern void record_vars_into (tree, tree);
 800 extern void record_vars (tree);
 801 extern bool block_may_fallthru (const_tree);
 802 extern bool gimple_seq_may_fallthru (gimple_seq);
 803 extern bool gimple_stmt_may_fallthru (gimple);
 804
 805 /* In tree-ssa-alias.c  */
 806 extern unsigned int compute_may_aliases (void);
 807 extern void dump_may_aliases_for (FILE *, tree);
 808 extern void debug_may_aliases_for (tree);
 809 extern void dump_alias_info (FILE *);
 810 extern void debug_alias_info (void);
 811 extern void dump_points_to_info (FILE *);
 812 extern void debug_points_to_info (void);
 813 extern void dump_points_to_info_for (FILE *, tree);
 814 extern void debug_points_to_info_for (tree);
 815 extern bool may_be_aliased (tree);
 816 extern struct ptr_info_def *get_ptr_info (tree);
 817 extern void new_type_alias (tree, tree, tree);
 818 extern void count_uses_and_derefs (tree, gimple, unsigned *, unsigned *,
 819                                    unsigned *);
 820 static inline subvar_t get_subvars_for_var (tree);
 821 static inline tree get_subvar_at (tree, unsigned HOST_WIDE_INT);
 822 static inline bool ref_contains_array_ref (const_tree);
 823 static inline bool array_ref_contains_indirect_ref (const_tree);
 824 extern tree get_ref_base_and_extent (tree, HOST_WIDE_INT *,
 825                                      HOST_WIDE_INT *, HOST_WIDE_INT *);
 826 static inline bool var_can_have_subvars (const_tree);
 827 static inline bool overlap_subvar (unsigned HOST_WIDE_INT,
 828                                    unsigned HOST_WIDE_INT,
 829                                    const_tree, bool *);
 830 extern tree create_tag_raw (enum tree_code, tree, const char *);
 831 extern void delete_mem_ref_stats (struct function *);
 832 extern void dump_mem_ref_stats (FILE *);
 833 extern void debug_mem_ref_stats (void);
 834 extern void debug_memory_partitions (void);
 835 extern void debug_mem_sym_stats (tree var);
 836 extern void dump_mem_sym_stats_for_var (FILE *, tree);
 837 extern void debug_all_mem_sym_stats (void);
 838
 839 /* Call-back function for walk_use_def_chains().  At each reaching
 840    definition, a function with this prototype is called.  */
 841 typedef bool (*walk_use_def_chains_fn) (tree, gimple, void *);
 842
 843 /* In tree-ssa-alias-warnings.c  */
 844 extern void strict_aliasing_warning_backend (void);
 845
 846
 847 /* In tree-ssa.c  */
 848
 849 /* Mapping for redirected edges.  */
 850 struct _edge_var_map GTY(())
 851 {
 852   tree result;                  /* PHI result.  */
 853   tree def;                     /* PHI arg definition.  */
 854 };
 855 typedef struct _edge_var_map edge_var_map;
 856
 857 DEF_VEC_O(edge_var_map);
 858 DEF_VEC_ALLOC_O(edge_var_map, heap);
 859
 860 /* A vector of var maps.  */
 861 typedef VEC(edge_var_map, heap) *edge_var_map_vector;
 862
 863 extern void redirect_edge_var_map_add (edge, tree, tree);
 864 extern void redirect_edge_var_map_clear (edge);
 865 extern void redirect_edge_var_map_dup (edge, edge);
 866 extern edge_var_map_vector redirect_edge_var_map_vector (edge);
 867 extern void redirect_edge_var_map_destroy (void);
 868
 869
 870 extern void init_tree_ssa (void);
 871 extern edge ssa_redirect_edge (edge, basic_block);
 872 extern void flush_pending_stmts (edge);
 873 extern bool tree_ssa_useless_type_conversion (tree);
 874 extern bool useless_type_conversion_p (tree, tree);
 875 extern bool types_compatible_p (tree, tree);
 876 extern void verify_ssa (bool);
 877 extern void delete_tree_ssa (void);
 878 extern void walk_use_def_chains (tree, walk_use_def_chains_fn, void *, bool);
 879 extern bool stmt_references_memory_p (gimple);
 880 extern bool ssa_undefined_value_p (tree);
 881
 882
 883 /* In tree-into-ssa.c  */
 884 void update_ssa (unsigned);
 885 void delete_update_ssa (void);
 886 void register_new_name_mapping (tree, tree);
 887 tree create_new_def_for (tree, gimple, def_operand_p);
 888 bool need_ssa_update_p (void);
 889 bool name_mappings_registered_p (void);
 890 bool name_registered_for_update_p (tree);
 891 bitmap ssa_names_to_replace (void);
 892 void release_ssa_name_after_update_ssa (tree);
 893 void compute_global_livein (bitmap, bitmap);
 894 void mark_sym_for_renaming (tree);
 895 void mark_set_for_renaming (bitmap);
 896 tree get_current_def (tree);
 897 void set_current_def (tree, tree);
 898
 899 /* In tree-ssa-ccp.c  */
 900 bool fold_stmt (gimple_stmt_iterator *);
 901 bool fold_stmt_inplace (gimple);
 902 tree get_symbol_constant_value (tree);
 903 tree fold_const_aggregate_ref (tree);
 904 tree widen_bitfield (tree, tree, tree);
 905
 906 /* In tree-vrp.c  */
 907 tree vrp_evaluate_conditional (tree, tree);
 908 void simplify_stmt_using_ranges (tree);
 909
 910 /* In tree-ssa-dom.c  */
 911 extern void dump_dominator_optimization_stats (FILE *);
 912 extern void debug_dominator_optimization_stats (void);
 913 int loop_depth_of_name (tree);
 914
 915 /* In tree-ssa-copy.c  */
 916 extern void merge_alias_info (tree, tree);
 917 extern void propagate_value (use_operand_p, tree);
 918 extern void propagate_tree_value (tree *, tree);
 919 extern void replace_exp (use_operand_p, tree);
 920 extern bool may_propagate_copy (tree, tree);
 921 extern bool may_propagate_copy_into_asm (tree);
 922
 923 /* Affine iv.  */
 924
 925 typedef struct
 926 {
 927   /* Iv = BASE + STEP * i.  */
 928   tree base, step;
 929
 930   /* True if this iv does not overflow.  */
 931   bool no_overflow;
 932 } affine_iv;
 933
 934 /* Description of number of iterations of a loop.  All the expressions inside
 935    the structure can be evaluated at the end of the loop's preheader
 936    (and due to ssa form, also anywhere inside the body of the loop).  */
 937
 938 struct tree_niter_desc
 939 {
 940   tree assumptions;     /* The boolean expression.  If this expression evaluates
 941                            to false, then the other fields in this structure
 942                            should not be used; there is no guarantee that they
 943                            will be correct.  */
 944   tree may_be_zero;     /* The boolean expression.  If it evaluates to true,
 945                            the loop will exit in the first iteration (i.e.
 946                            its latch will not be executed), even if the niter
 947                            field says otherwise.  */
 948   tree niter;           /* The expression giving the number of iterations of
 949                            a loop (provided that assumptions == true and
 950                            may_be_zero == false), more precisely the number
 951                            of executions of the latch of the loop.  */
 952   double_int max;       /* The upper bound on the number of iterations of
 953                            the loop.  */
 954
 955   /* The simplified shape of the exit condition.  The loop exits if
 956      CONTROL CMP BOUND is false, where CMP is one of NE_EXPR,
 957      LT_EXPR, or GT_EXPR, and step of CONTROL is positive if CMP is
 958      LE_EXPR and negative if CMP is GE_EXPR.  This information is used
 959      by loop unrolling.  */
 960   affine_iv control;
 961   tree bound;
 962   enum tree_code cmp;
 963 };
 964
 965 /* In tree-vectorizer.c */
 966 unsigned vectorize_loops (void);
 967 extern bool vect_can_force_dr_alignment_p (const_tree, unsigned int);
 968 extern tree get_vectype_for_scalar_type (tree);
 969
 970 /* In tree-ssa-phiopt.c */
 971 bool empty_block_p (basic_block);
 972 basic_block *blocks_in_phiopt_order (void);
 973
 974 /* In tree-ssa-loop*.c  */
 975
 976 void tree_ssa_lim (void);
 977 unsigned int tree_ssa_unswitch_loops (void);
 978 unsigned int canonicalize_induction_variables (void);
 979 unsigned int tree_unroll_loops_completely (bool);
 980 unsigned int tree_ssa_prefetch_arrays (void);
 981 unsigned int remove_empty_loops (void);
 982 void tree_ssa_iv_optimize (void);
 983 unsigned tree_predictive_commoning (void);
 984 bool parallelize_loops (void);
 985
 986 bool number_of_iterations_exit (struct loop *, edge,
 987                                 struct tree_niter_desc *niter, bool);
 988 tree find_loop_niter (struct loop *, edge *);
 989 tree loop_niter_by_eval (struct loop *, edge);
 990 tree find_loop_niter_by_eval (struct loop *, edge *);
 991 void estimate_numbers_of_iterations (void);
 992 bool scev_probably_wraps_p (tree, tree, gimple, struct loop *, bool);
 993 bool convert_affine_scev (struct loop *, tree, tree *, tree *, gimple, bool);
 994
 995 bool nowrap_type_p (tree);
 996 enum ev_direction {EV_DIR_GROWS, EV_DIR_DECREASES, EV_DIR_UNKNOWN};
 997 enum ev_direction scev_direction (const_tree);
 998
 999 void free_numbers_of_iterations_estimates (void);
1000 void free_numbers_of_iterations_estimates_loop (struct loop *);
1001 void rewrite_into_loop_closed_ssa (bitmap, unsigned);
1002 void verify_loop_closed_ssa (void);
1003 bool for_each_index (tree *, bool (*) (tree, tree *, void *), void *);
1004 void create_iv (tree, tree, tree, struct loop *, gimple_stmt_iterator *, bool,
1005                 tree *, tree *);
1006 basic_block split_loop_exit_edge (edge);
1007 void standard_iv_increment_position (struct loop *, gimple_stmt_iterator *,
1008                                      bool *);
1009 basic_block ip_end_pos (struct loop *);
1010 basic_block ip_normal_pos (struct loop *);
1011 bool gimple_duplicate_loop_to_header_edge (struct loop *, edge,
1012                                          unsigned int, sbitmap,
1013                                          edge, VEC (edge, heap) **,
1014                                          int);
1015 struct loop *slpeel_tree_duplicate_loop_to_edge_cfg (struct loop *, edge);
1016 void rename_variables_in_loop (struct loop *);
1017 struct loop *tree_ssa_loop_version (struct loop *, tree,
1018                                     basic_block *);
1019 tree expand_simple_operations (tree);
1020 void substitute_in_loop_info (struct loop *, tree, tree);
1021 edge single_dom_exit (struct loop *);
1022 bool can_unroll_loop_p (struct loop *loop, unsigned factor,
1023                         struct tree_niter_desc *niter);
1024 void tree_unroll_loop (struct loop *, unsigned,
1025                        edge, struct tree_niter_desc *);
1026 typedef void (*transform_callback)(struct loop *, void *);
1027 void tree_transform_and_unroll_loop (struct loop *, unsigned,
1028                                      edge, struct tree_niter_desc *,
1029                                      transform_callback, void *);
1030 bool contains_abnormal_ssa_name_p (tree);
1031 bool stmt_dominates_stmt_p (gimple, gimple);
1032 void mark_virtual_ops_for_renaming (gimple);
1033
1034 /* In tree-ssa-threadedge.c */
1035 extern bool potentially_threadable_block (basic_block);
1036 extern void thread_across_edge (tree, edge, bool,
1037                                 VEC(tree, heap) **, tree (*) (tree, tree));
1038
1039 /* In tree-ssa-loop-im.c  */
1040 /* The possibilities of statement movement.  */
1041
1042 enum move_pos
1043   {
1044     MOVE_IMPOSSIBLE,            /* No movement -- side effect expression.  */
1045     MOVE_PRESERVE_EXECUTION,    /* Must not cause the non-executed statement
1046                                    become executed -- memory accesses, ... */
1047     MOVE_POSSIBLE               /* Unlimited movement.  */
1048   };
1049 extern enum move_pos movement_possibility (gimple);
1050 char *get_lsm_tmp_name (tree, unsigned);
1051
1052 /* In tree-flow-inline.h  */
1053 static inline bool is_call_clobbered (const_tree);
1054 static inline void mark_call_clobbered (tree, unsigned int);
1055 static inline void set_is_used (tree);
1056 static inline bool unmodifiable_var_p (const_tree);
1057
1058 /* In tree-eh.c  */
1059 extern void make_eh_edges (gimple);
1060 extern bool tree_could_trap_p (tree);
1061 extern bool operation_could_trap_p (enum tree_code, bool, bool, tree);
1062 extern bool stmt_could_throw_p (gimple);
1063 extern bool tree_could_throw_p (tree);
1064 extern bool stmt_can_throw_internal (gimple);
1065 extern void add_stmt_to_eh_region (gimple, int);
1066 extern bool remove_stmt_from_eh_region (gimple);
1067 extern bool maybe_clean_or_replace_eh_stmt (gimple, gimple);
1068 extern void add_stmt_to_eh_region_fn (struct function *, gimple, int);
1069 extern bool remove_stmt_from_eh_region_fn (struct function *, gimple);
1070 extern int lookup_stmt_eh_region_fn (struct function *, gimple);
1071 extern int lookup_expr_eh_region (tree);
1072 extern int lookup_stmt_eh_region (gimple);
1073 extern bool verify_eh_edges (gimple);
1074
1075
1076 /* In tree-ssa-pre.c  */
1077 void add_to_value (tree, tree);
1078 void debug_value_expressions (tree);
1079 void print_value_expressions (FILE *, tree);
1080
1081
1082 /* In tree-vn.c  */
1083 tree make_value_handle (tree);
1084 void set_value_handle (tree, tree);
1085 bool expressions_equal_p (tree, tree);
1086 static inline tree get_value_handle (tree);
1087 void sort_vuses (VEC (tree, gc) *);
1088 void sort_vuses_heap (VEC (tree, heap) *);
1089 tree vn_lookup_or_add (tree);
1090 tree vn_lookup_or_add_with_stmt (tree, tree);
1091 tree vn_lookup_or_add_with_vuses (tree, VEC (tree, gc) *);
1092 void vn_add (tree, tree);
1093 void vn_add_with_vuses (tree, tree, VEC (tree, gc) *);
1094 tree vn_lookup_with_stmt (tree, tree);
1095 tree vn_lookup (tree);
1096 tree vn_lookup_with_vuses (tree, VEC (tree, gc) *);
1097
1098 /* In tree-ssa-sink.c  */
1099 bool is_hidden_global_store (gimple);
1100
1101 /* In tree-sra.c  */
1102 void insert_edge_copies (tree, basic_block);
1103 void sra_insert_before (gimple_stmt_iterator *, tree);
1104 void sra_insert_after (gimple_stmt_iterator *, tree);
1105 void sra_init_cache (void);
1106 bool sra_type_can_be_decomposed_p (tree);
1107
1108 /* In tree-loop-linear.c  */
1109 extern void linear_transform_loops (void);
1110
1111 /* In tree-data-ref.c  */
1112 extern void tree_check_data_deps (void);
1113
1114 /* In tree-ssa-loop-ivopts.c  */
1115 bool expr_invariant_in_loop_p (struct loop *, tree);
1116 bool multiplier_allowed_in_address_p (HOST_WIDE_INT, enum machine_mode);
1117 unsigned multiply_by_cost (HOST_WIDE_INT, enum machine_mode);
1118
1119 /* In tree-ssa-threadupdate.c.  */
1120 extern bool thread_through_all_blocks (bool);
1121 extern void register_jump_thread (edge, edge);
1122
1123 /* In gimplify.c  */
1124 tree force_gimple_operand (tree, gimple_seq *, bool, tree);
1125 tree force_gimple_operand_gsi (gimple_stmt_iterator *, tree, bool, tree,
1126                                bool, enum gsi_iterator_update);
1127 tree gimple_fold_indirect_ref (tree);
1128
1129 /* In tree-ssa-structalias.c */
1130 bool find_what_p_points_to (tree);
1131
1132 /* In tree-ssa-live.c */
1133 extern void remove_unused_locals (void);
1134
1135 /* In tree-ssa-address.c  */
1136
1137 /* Description of a memory address.  */
1138
1139 struct mem_address
1140 {
1141   tree symbol, base, index, step, offset;
1142 };
1143
1144 struct affine_tree_combination;
1145 tree create_mem_ref (gimple_stmt_iterator *, tree,
1146                      struct affine_tree_combination *);
1147 rtx addr_for_mem_ref (struct mem_address *, bool);
1148 void get_address_description (tree, struct mem_address *);
1149 tree maybe_fold_tmr (tree);
1150
1151 /* This structure is used during pushing fields onto the fieldstack
1152    to track the offset of the field, since bitpos_of_field gives it
1153    relative to its immediate containing type, and we want it relative
1154    to the ultimate containing object.  */
1155
1156 struct fieldoff
1157 {
1158   /* Type of the field.  */
1159   tree type;
1160
1161   /* Size, in bits, of the field.  */
1162   tree size;
1163
1164   /* Field.  */
1165   tree decl;
1166
1167   /* Offset from the base of the base containing object to this field.  */
1168   HOST_WIDE_INT offset;
1169
1170   /* Alias set for the field.  */
1171   alias_set_type alias_set;
1172
1173   /* True, if this offset can be a base for further component accesses.  */
1174   unsigned base_for_components : 1;
1175 };
1176 typedef struct fieldoff fieldoff_s;
1177
1178 DEF_VEC_O(fieldoff_s);
1179 DEF_VEC_ALLOC_O(fieldoff_s,heap);
1180 int push_fields_onto_fieldstack (tree, VEC(fieldoff_s,heap) **,
1181                                  HOST_WIDE_INT, bool *, tree);
1182 void sort_fieldstack (VEC(fieldoff_s,heap) *);
1183
1184 void init_alias_heapvars (void);
1185 void delete_alias_heapvars (void);
1186 unsigned int execute_fixup_cfg (void);
1187
1188 #include "tree-flow-inline.h"
1189
1190 void swap_tree_operands (gimple, tree *, tree *);
1191
1192 int least_common_multiple (int, int);
1193
1194 #endif /* _TREE_FLOW_H  */