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 2, 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 COPYING.  If not, write to
  20 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
  21 Boston, MA 02110-1301, USA.  */
  22
  23 #ifndef _TREE_FLOW_H
  24 #define _TREE_FLOW_H 1
  25
  26 #include "bitmap.h"
  27 #include "hard-reg-set.h"
  28 #include "basic-block.h"
  29 #include "hashtab.h"
  30 #include "tree-gimple.h"
  31 #include "tree-ssa-operands.h"
  32 #include "cgraph.h"
  33 #include "ipa-reference.h"
  34
  35 /* Forward declare structures for the garbage collector GTY markers.  */
  36 #ifndef GCC_BASIC_BLOCK_H
  37 struct edge_def;
  38 typedef struct edge_def *edge;
  39 struct basic_block_def;
  40 typedef struct basic_block_def *basic_block;
  41 #endif
  42 struct static_var_ann_d;
  43
  44 /* Memory reference statistics for individual memory symbols,
  45    collected during alias analysis.  */
  46 struct mem_sym_stats_d GTY(())
  47 {
  48   /* Memory symbol.  */
  49   tree var;
  50
  51   /* Nonzero if this entry has been assigned a partition.  */
  52   unsigned int partitioned_p : 1;
  53
  54   /* Nonzero if VAR is a memory partition tag that already contains
  55      call-clobbered variables in its partition set.  */
  56   unsigned int has_call_clobbered_vars : 1;
  57
  58   /* Number of direct reference sites.  A direct reference to VAR is any
  59      reference of the form 'VAR = ' or ' = VAR'.  For GIMPLE reg
  60      pointers, this is the number of sites where the pointer is
  61      dereferenced.  */
  62   long num_direct_writes;
  63   long num_direct_reads;
  64
  65   /* Number of indirect reference sites.  An indirect reference to VAR
  66      is any reference via a pointer that contains VAR in its points-to
  67      set or, in the case of call-clobbered symbols, a function call.  */
  68   long num_indirect_writes;
  69   long num_indirect_reads;
  70
  71   /* Execution frequency.  This is the sum of the execution
  72      frequencies of all the statements that reference this object
  73      weighted by the number of references in each statement.  This is
  74      the main key used to sort the list of symbols to partition.
  75      Symbols with high execution frequencies are put at the bottom of
  76      the work list (ie, they are partitioned last).
  77      Execution frequencies are taken directly from each basic block,
  78      so compiling with PGO enabled will increase the precision of this
  79      estimate.  */
  80   long frequency_reads;
  81   long frequency_writes;
  82
  83   /* Set of memory tags that contain VAR in their alias set.  */
  84   bitmap parent_tags;
  85 };
  86
  87 typedef struct mem_sym_stats_d *mem_sym_stats_t;
  88 DEF_VEC_P(mem_sym_stats_t);
  89 DEF_VEC_ALLOC_P(mem_sym_stats_t, heap);
  90
  91 /* Memory reference statistics collected during alias analysis.  */
  92 struct mem_ref_stats_d GTY(())
  93 {
  94   /* Number of statements that make memory references.  */
  95   long num_mem_stmts;
  96
  97   /* Number of statements that make function calls.  */
  98   long num_call_sites;
  99
 100   /* Number of statements that make calls to pure/const functions.  */
 101   long num_pure_const_call_sites;
 102
 103   /* Number of ASM statements.  */
 104   long num_asm_sites;
 105
 106   /* Estimated number of virtual operands needed as computed by
 107    compute_memory_partitions.  */
 108   long num_vuses;
 109   long num_vdefs;
 110
 111   /* This maps every symbol used to make "memory" references
 112      (pointers, arrays, structures, etc) to an instance of struct
 113      mem_sym_stats_d describing reference statistics for the symbol.  */
 114   struct pointer_map_t * GTY((skip)) mem_sym_stats;
 115 };
 116
 117
 118 /* Gimple dataflow datastructure. All publicly available fields shall have
 119    gimple_ accessor defined in tree-flow-inline.h, all publicly modifiable
 120    fields should have gimple_set accessor.  */
 121 struct gimple_df GTY(())
 122 {
 123   /* Array of all variables referenced in the function.  */
 124   htab_t GTY((param_is (struct int_tree_map))) referenced_vars;
 125
 126   /* A list of all the noreturn calls passed to modify_stmt.
 127      cleanup_control_flow uses it to detect cases where a mid-block
 128      indirect call has been turned into a noreturn call.  When this
 129      happens, all the instructions after the call are no longer
 130      reachable and must be deleted as dead.  */
 131   VEC(tree,gc) *modified_noreturn_calls;
 132
 133   /* Array of all SSA_NAMEs used in the function.  */
 134   VEC(tree,gc) *ssa_names;
 135
 136   /* Artificial variable used to model the effects of function calls.  */
 137   tree global_var;
 138
 139   /* Artificial variable used to model the effects of nonlocal
 140      variables.  */
 141   tree nonlocal_all;
 142
 143   /* Call clobbered variables in the function.  If bit I is set, then
 144      REFERENCED_VARS (I) is call-clobbered.  */
 145   bitmap call_clobbered_vars;
 146
 147   /* Addressable variables in the function.  If bit I is set, then
 148      REFERENCED_VARS (I) has had its address taken.  Note that
 149      CALL_CLOBBERED_VARS and ADDRESSABLE_VARS are not related.  An
 150      addressable variable is not necessarily call-clobbered (e.g., a
 151      local addressable whose address does not escape) and not all
 152      call-clobbered variables are addressable (e.g., a local static
 153      variable).  */
 154   bitmap addressable_vars;
 155
 156   /* Free list of SSA_NAMEs.  */
 157   tree free_ssanames;
 158
 159   /* Hashtable holding definition for symbol.  If this field is not NULL, it
 160      means that the first reference to this variable in the function is a
 161      USE or a VUSE.  In those cases, the SSA renamer creates an SSA name
 162      for this variable with an empty defining statement.  */
 163   htab_t GTY((param_is (struct int_tree_map))) default_defs;
 164
 165   /* 'true' after aliases have been computed (see compute_may_aliases).  */
 166   unsigned int aliases_computed_p : 1;
 167
 168   /* True if the code is in ssa form.  */
 169   unsigned int in_ssa_p : 1;
 170
 171   struct ssa_operands ssa_operands;
 172
 173   /* Hashtable of variables annotations.  Used for static variables only;
 174      local variables have direct pointer in the tree node.  */
 175   htab_t GTY((param_is (struct static_var_ann_d))) var_anns;
 176
 177   /* Memory reference statistics collected during alias analysis.
 178      This information is used to drive the memory partitioning
 179      heuristics in compute_memory_partitions.  */
 180   struct mem_ref_stats_d mem_ref_stats;
 181 };
 182
 183 /* Accessors for internal use only.  Generic code should use abstraction
 184    provided by tree-flow-inline.h or specific modules.  */
 185 #define FREE_SSANAMES(fun) (fun)->gimple_df->free_ssanames
 186 #define SSANAMES(fun) (fun)->gimple_df->ssa_names
 187 #define MODIFIED_NORETURN_CALLS(fun) (fun)->gimple_df->modified_noreturn_calls
 188 #define DEFAULT_DEFS(fun) (fun)->gimple_df->default_defs
 189
 190 typedef struct
 191 {
 192   htab_t htab;
 193   PTR *slot;
 194   PTR *limit;
 195 } htab_iterator;
 196
 197 /* Iterate through the elements of hashtable HTAB, using htab_iterator ITER,
 198    storing each element in RESULT, which is of type TYPE.  */
 199 #define FOR_EACH_HTAB_ELEMENT(HTAB, RESULT, TYPE, ITER) \
 200   for (RESULT = (TYPE) first_htab_element (&(ITER), (HTAB)); \
 201         !end_htab_p (&(ITER)); \
 202         RESULT = (TYPE) next_htab_element (&(ITER)))
 203
 204 /*---------------------------------------------------------------------------
 205                       Attributes for SSA_NAMEs.
 206
 207   NOTE: These structures are stored in struct tree_ssa_name
 208   but are only used by the tree optimizers, so it makes better sense
 209   to declare them here to avoid recompiling unrelated files when
 210   making changes.
 211 ---------------------------------------------------------------------------*/
 212
 213 /* Aliasing information for SSA_NAMEs representing pointer variables.  */
 214 struct ptr_info_def GTY(())
 215 {
 216   /* Nonzero if points-to analysis couldn't determine where this pointer
 217      is pointing to.  */
 218   unsigned int pt_anything : 1;
 219
 220   /* Nonzero if the value of this pointer escapes the current function.  */
 221   unsigned int value_escapes_p : 1;
 222
 223   /* Nonzero if this pointer is dereferenced.  */
 224   unsigned int is_dereferenced : 1;
 225
 226   /* Nonzero if this pointer points to a global variable.  */
 227   unsigned int pt_global_mem : 1;
 228
 229   /* Nonzero if this pointer points to NULL.  */
 230   unsigned int pt_null : 1;
 231
 232   /* Set of variables that this pointer may point to.  */
 233   bitmap pt_vars;
 234
 235   /* If this pointer has been dereferenced, and points-to information is
 236      more precise than type-based aliasing, indirect references to this
 237      pointer will be represented by this memory tag, instead of the type
 238      tag computed by TBAA.  */
 239   tree name_mem_tag;
 240
 241   /* Mask of reasons this pointer's value escapes the function  */
 242   unsigned int escape_mask;
 243 };
 244
 245
 246 /*---------------------------------------------------------------------------
 247                    Tree annotations stored in tree_base.ann
 248 ---------------------------------------------------------------------------*/
 249 enum tree_ann_type { TREE_ANN_COMMON, VAR_ANN, FUNCTION_ANN, STMT_ANN };
 250
 251 struct tree_ann_common_d GTY(())
 252 {
 253   /* Annotation type.  */
 254   enum tree_ann_type type;
 255
 256  /* Auxiliary info specific to a pass.  At all times, this
 257     should either point to valid data or be NULL.  */
 258   PTR GTY ((skip (""))) aux;
 259
 260   /* The value handle for this expression.  Used by GVN-PRE.  */
 261   tree GTY((skip)) value_handle;
 262 };
 263
 264 /* It is advantageous to avoid things like life analysis for variables which
 265    do not need PHI nodes.  This enum describes whether or not a particular
 266    variable may need a PHI node.  */
 267
 268 enum need_phi_state {
 269   /* This is the default.  If we are still in this state after finding
 270      all the definition and use sites, then we will assume the variable
 271      needs PHI nodes.  This is probably an overly conservative assumption.  */
 272   NEED_PHI_STATE_UNKNOWN,
 273
 274   /* This state indicates that we have seen one or more sets of the
 275      variable in a single basic block and that the sets dominate all
 276      uses seen so far.  If after finding all definition and use sites
 277      we are still in this state, then the variable does not need any
 278      PHI nodes.  */
 279   NEED_PHI_STATE_NO,
 280
 281   /* This state indicates that we have either seen multiple definitions of
 282      the variable in multiple blocks, or that we encountered a use in a
 283      block that was not dominated by the block containing the set(s) of
 284      this variable.  This variable is assumed to need PHI nodes.  */
 285   NEED_PHI_STATE_MAYBE
 286 };
 287
 288
 289 /* The "no alias" attribute allows alias analysis to make more
 290    aggressive assumptions when assigning alias sets, computing
 291    points-to information and memory partitions.  These attributes
 292    are the result of user annotations or flags (e.g.,
 293    -fargument-noalias).  */
 294 enum noalias_state {
 295     /* Default state.  No special assumptions can be made about this
 296        symbol.  */
 297     MAY_ALIAS = 0,
 298
 299     /* The symbol does not alias with other symbols that have a
 300        NO_ALIAS* attribute.  */
 301     NO_ALIAS,
 302
 303     /* The symbol does not alias with other symbols that have a
 304        NO_ALIAS*, and it may not alias with global symbols.  */
 305     NO_ALIAS_GLOBAL,
 306
 307     /* The symbol does not alias with any other symbols.  */
 308     NO_ALIAS_ANYTHING
 309 };
 310
 311
 312 struct subvar;
 313 typedef struct subvar *subvar_t;
 314
 315 /* This structure represents a fake sub-variable for a structure field.  */
 316 struct subvar GTY(())
 317 {
 318   /* Fake variable.  */
 319   tree var;
 320
 321   /* Next subvar for this structure.  */
 322   subvar_t next;
 323 };
 324
 325 struct var_ann_d GTY(())
 326 {
 327   struct tree_ann_common_d common;
 328
 329   /* Used by the out of SSA pass to determine whether this variable has
 330      been seen yet or not.  */
 331   unsigned out_of_ssa_tag : 1;
 332
 333   /* Used when building base variable structures in a var_map.  */
 334   unsigned base_var_processed : 1;
 335
 336   /* Nonzero if this variable was used after SSA optimizations were
 337      applied.  We set this when translating out of SSA form.  */
 338   unsigned used : 1;
 339
 340   /* This field indicates whether or not the variable may need PHI nodes.
 341      See the enum's definition for more detailed information about the
 342      states.  */
 343   ENUM_BITFIELD (need_phi_state) need_phi_state : 2;
 344
 345   /* Used during operand processing to determine if this variable is already
 346      in the VUSE list.  */
 347   unsigned in_vuse_list : 1;
 348
 349   /* Used during operand processing to determine if this variable is already
 350      in the VDEF list.  */
 351   unsigned in_vdef_list : 1;
 352
 353   /* True for HEAP artificial variables.  These variables represent
 354      the memory area allocated by a call to malloc.  */
 355   unsigned is_heapvar : 1;
 356
 357   /* True if the variable is call clobbered.  */
 358   unsigned int call_clobbered : 1;
 359
 360   /* This field describes several "no alias" attributes that some
 361      symbols are known to have.  See the enum's definition for more
 362      information on each attribute.  */
 363   ENUM_BITFIELD (noalias_state) noalias_state : 2;
 364
 365   /* Memory partition tag assigned to this symbol.  */
 366   tree mpt;
 367
 368   /* If this variable is a pointer P that has been dereferenced, this
 369      field is an artificial variable that represents the memory
 370      location *P.  Every other pointer Q that is type-compatible with
 371      P will also have the same memory tag.  If the variable is not a
 372      pointer or if it is never dereferenced, this must be NULL.
 373      FIXME, do we really need this here?  How much slower would it be
 374      to convert to hash table?  */
 375   tree symbol_mem_tag;
 376
 377   /* Used when going out of SSA form to indicate which partition this
 378      variable represents storage for.  */
 379   unsigned partition;
 380
 381   /* Used by var_map for the base index of ssa base variables.  */
 382   unsigned base_index;
 383
 384   /* During into-ssa and the dominator optimizer, this field holds the
 385      current version of this variable (an SSA_NAME).  */
 386   tree current_def;
 387
 388   /* If this variable is a structure, this fields holds a list of
 389      symbols representing each of the fields of the structure.  */
 390   subvar_t subvars;
 391
 392   /* Mask of values saying the reasons why this variable has escaped
 393      the function.  */
 394   unsigned int escape_mask;
 395 };
 396
 397 /* Container for variable annotation used by hashtable for annotations for
 398    static variables.  */
 399 struct static_var_ann_d GTY(())
 400 {
 401   struct var_ann_d ann;
 402   unsigned int uid;
 403 };
 404
 405 struct function_ann_d GTY(())
 406 {
 407   struct tree_ann_common_d common;
 408
 409   /* Pointer to the structure that contains the sets of global
 410      variables modified by function calls.  This field is only used
 411      for FUNCTION_DECLs.  */
 412   ipa_reference_vars_info_t GTY ((skip)) reference_vars_info;
 413 };
 414
 415 typedef struct immediate_use_iterator_d
 416 {
 417   /* This is the current use the iterator is processing.  */
 418   ssa_use_operand_t *imm_use;
 419   /* This marks the last use in the list (use node from SSA_NAME)  */
 420   ssa_use_operand_t *end_p;
 421   /* This node is inserted and used to mark the end of the uses for a stmt.  */
 422   ssa_use_operand_t iter_node;
 423   /* This is the next ssa_name to visit.  IMM_USE may get removed before
 424      the next one is traversed to, so it must be cached early.  */
 425   ssa_use_operand_t *next_imm_name;
 426 } imm_use_iterator;
 427
 428
 429 /* Use this iterator when simply looking at stmts.  Adding, deleting or
 430    modifying stmts will cause this iterator to malfunction.  */
 431
 432 #define FOR_EACH_IMM_USE_FAST(DEST, ITER, SSAVAR)                       \
 433   for ((DEST) = first_readonly_imm_use (&(ITER), (SSAVAR));     \
 434        !end_readonly_imm_use_p (&(ITER));                       \
 435        (DEST) = next_readonly_imm_use (&(ITER)))
 436
 437 /* Use this iterator to visit each stmt which has a use of SSAVAR.  */
 438
 439 #define FOR_EACH_IMM_USE_STMT(STMT, ITER, SSAVAR)               \
 440   for ((STMT) = first_imm_use_stmt (&(ITER), (SSAVAR));         \
 441        !end_imm_use_stmt_p (&(ITER));                           \
 442        (STMT) = next_imm_use_stmt (&(ITER)))
 443
 444 /* Use this to terminate the FOR_EACH_IMM_USE_STMT loop early.  Failure to
 445    do so will result in leaving a iterator marker node in the immediate
 446    use list, and nothing good will come from that.   */
 447 #define BREAK_FROM_IMM_USE_STMT(ITER)                           \
 448    {                                                            \
 449      end_imm_use_stmt_traverse (&(ITER));                       \
 450      break;                                                     \
 451    }
 452
 453
 454 /* Use this iterator in combination with FOR_EACH_IMM_USE_STMT to
 455    get access to each occurrence of ssavar on the stmt returned by
 456    that iterator..  for instance:
 457
 458      FOR_EACH_IMM_USE_STMT (stmt, iter, var)
 459        {
 460          FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
 461            {
 462              SET_USE (use_p) = blah;
 463            }
 464          update_stmt (stmt);
 465        }                                                         */
 466
 467 #define FOR_EACH_IMM_USE_ON_STMT(DEST, ITER)                    \
 468   for ((DEST) = first_imm_use_on_stmt (&(ITER));                \
 469        !end_imm_use_on_stmt_p (&(ITER));                        \
 470        (DEST) = next_imm_use_on_stmt (&(ITER)))
 471
 472
 473
 474 struct stmt_ann_d GTY(())
 475 {
 476   struct tree_ann_common_d common;
 477
 478   /* Basic block that contains this statement.  */
 479   basic_block bb;
 480
 481   /* Operand cache for stmt.  */
 482   struct stmt_operands_d GTY ((skip (""))) operands;
 483
 484   /* Set of variables that have had their address taken in the statement.  */
 485   bitmap addresses_taken;
 486
 487   /* Unique identifier for this statement.  These ID's are to be created
 488      by each pass on an as-needed basis in any order convenient for the
 489      pass which needs statement UIDs.  */
 490   unsigned int uid;
 491
 492   /* Nonzero if the statement references memory (at least one of its
 493      expressions contains a non-register operand).  */
 494   unsigned references_memory : 1;
 495
 496   /* Nonzero if the statement has been modified (meaning that the operands
 497      need to be scanned again).  */
 498   unsigned modified : 1;
 499
 500   /* Nonzero if the statement makes references to volatile storage.  */
 501   unsigned has_volatile_ops : 1;
 502
 503   /* Nonzero if the statement makes a function call that may clobber global
 504      and local addressable variables.  */
 505   unsigned makes_clobbering_call : 1;
 506 };
 507
 508 union tree_ann_d GTY((desc ("ann_type ((tree_ann_t)&%h)")))
 509 {
 510   struct tree_ann_common_d GTY((tag ("TREE_ANN_COMMON"))) common;
 511   struct var_ann_d GTY((tag ("VAR_ANN"))) vdecl;
 512   struct function_ann_d GTY((tag ("FUNCTION_ANN"))) fdecl;
 513   struct stmt_ann_d GTY((tag ("STMT_ANN"))) stmt;
 514 };
 515
 516 typedef union tree_ann_d *tree_ann_t;
 517 typedef struct var_ann_d *var_ann_t;
 518 typedef struct function_ann_d *function_ann_t;
 519 typedef struct stmt_ann_d *stmt_ann_t;
 520 typedef struct tree_ann_common_d *tree_ann_common_t;
 521
 522 static inline tree_ann_common_t tree_common_ann (tree);
 523 static inline tree_ann_common_t get_tree_common_ann (tree);
 524 static inline var_ann_t var_ann (tree);
 525 static inline var_ann_t get_var_ann (tree);
 526 static inline function_ann_t function_ann (tree);
 527 static inline function_ann_t get_function_ann (tree);
 528 static inline stmt_ann_t stmt_ann (tree);
 529 static inline bool has_stmt_ann (tree);
 530 static inline stmt_ann_t get_stmt_ann (tree);
 531 static inline enum tree_ann_type ann_type (tree_ann_t);
 532 static inline basic_block bb_for_stmt (tree);
 533 extern void set_bb_for_stmt (tree, basic_block);
 534 static inline bool noreturn_call_p (tree);
 535 static inline void update_stmt (tree);
 536 static inline bool stmt_modified_p (tree);
 537 static inline bitmap may_aliases (tree);
 538 static inline int get_lineno (tree);
 539 static inline const char *get_filename (tree);
 540 static inline bool is_exec_stmt (tree);
 541 static inline bool is_label_stmt (tree);
 542 static inline bitmap addresses_taken (tree);
 543
 544 /*---------------------------------------------------------------------------
 545                   Structure representing predictions in tree level.
 546 ---------------------------------------------------------------------------*/
 547 struct edge_prediction GTY((chain_next ("%h.ep_next")))
 548 {
 549   struct edge_prediction *ep_next;
 550   edge ep_edge;
 551   enum br_predictor ep_predictor;
 552   int ep_probability;
 553 };
 554
 555 /* Accessors for basic block annotations.  */
 556 static inline tree phi_nodes (basic_block);
 557 static inline void set_phi_nodes (basic_block, tree);
 558
 559 /*---------------------------------------------------------------------------
 560                               Global declarations
 561 ---------------------------------------------------------------------------*/
 562 struct int_tree_map GTY(())
 563 {
 564
 565   unsigned int uid;
 566   tree to;
 567 };
 568
 569 extern unsigned int int_tree_map_hash (const void *);
 570 extern int int_tree_map_eq (const void *, const void *);
 571
 572 typedef struct
 573 {
 574   htab_iterator hti;
 575 } referenced_var_iterator;
 576
 577
 578 /* This macro loops over all the referenced vars, one at a time, putting the
 579    current var in VAR.  Note:  You are not allowed to add referenced variables
 580    to the hashtable while using this macro.  Doing so may cause it to behave
 581    erratically.  */
 582
 583 #define FOR_EACH_REFERENCED_VAR(VAR, ITER) \
 584   for ((VAR) = first_referenced_var (&(ITER)); \
 585        !end_referenced_vars_p (&(ITER)); \
 586        (VAR) = next_referenced_var (&(ITER)))
 587
 588
 589 typedef struct
 590 {
 591   int i;
 592 } safe_referenced_var_iterator;
 593
 594 /* This macro loops over all the referenced vars, one at a time, putting the
 595    current var in VAR.  You are allowed to add referenced variables during the
 596    execution of this macro, however, the macro will not iterate over them.  It
 597    requires a temporary vector of trees, VEC, whose lifetime is controlled by
 598    the caller.  The purpose of the vector is to temporarily store the
 599    referenced_variables hashtable so that adding referenced variables does not
 600    affect the hashtable.  */
 601
 602 #define FOR_EACH_REFERENCED_VAR_SAFE(VAR, VEC, ITER) \
 603   for ((ITER).i = 0, fill_referenced_var_vec (&(VEC)); \
 604        VEC_iterate (tree, (VEC), (ITER).i, (VAR)); \
 605        (ITER).i++)
 606
 607 extern tree referenced_var_lookup (unsigned int);
 608 extern bool referenced_var_check_and_insert (tree);
 609 #define num_referenced_vars htab_elements (gimple_referenced_vars (cfun))
 610 #define referenced_var(i) referenced_var_lookup (i)
 611
 612 #define num_ssa_names (VEC_length (tree, cfun->gimple_df->ssa_names))
 613 #define ssa_name(i) (VEC_index (tree, cfun->gimple_df->ssa_names, (i)))
 614
 615 /* Macros for showing usage statistics.  */
 616 #define SCALE(x) ((unsigned long) ((x) < 1024*10        \
 617                   ? (x)                                 \
 618                   : ((x) < 1024*1024*10                 \
 619                      ? (x) / 1024                       \
 620                      : (x) / (1024*1024))))
 621
 622 #define LABEL(x) ((x) < 1024*10 ? 'b' : ((x) < 1024*1024*10 ? 'k' : 'M'))
 623
 624 #define PERCENT(x,y) ((float)(x) * 100.0 / (float)(y))
 625
 626 /*---------------------------------------------------------------------------
 627                               Block iterators
 628 ---------------------------------------------------------------------------*/
 629
 630 typedef struct {
 631   tree_stmt_iterator tsi;
 632   basic_block bb;
 633 } block_stmt_iterator;
 634
 635 static inline block_stmt_iterator bsi_start (basic_block);
 636 static inline block_stmt_iterator bsi_last (basic_block);
 637 static inline block_stmt_iterator bsi_after_labels (basic_block);
 638 block_stmt_iterator bsi_for_stmt (tree);
 639 static inline bool bsi_end_p (block_stmt_iterator);
 640 static inline void bsi_next (block_stmt_iterator *);
 641 static inline void bsi_prev (block_stmt_iterator *);
 642 static inline tree bsi_stmt (block_stmt_iterator);
 643 static inline tree * bsi_stmt_ptr (block_stmt_iterator);
 644
 645 extern void bsi_remove (block_stmt_iterator *, bool);
 646 extern void bsi_move_before (block_stmt_iterator *, block_stmt_iterator *);
 647 extern void bsi_move_after (block_stmt_iterator *, block_stmt_iterator *);
 648 extern void bsi_move_to_bb_end (block_stmt_iterator *, basic_block);
 649
 650 enum bsi_iterator_update
 651 {
 652   /* Note that these are intentionally in the same order as TSI_FOO.  They
 653      mean exactly the same as their TSI_* counterparts.  */
 654   BSI_NEW_STMT,
 655   BSI_SAME_STMT,
 656   BSI_CHAIN_START,
 657   BSI_CHAIN_END,
 658   BSI_CONTINUE_LINKING
 659 };
 660
 661 extern void bsi_insert_before (block_stmt_iterator *, tree,
 662                                enum bsi_iterator_update);
 663 extern void bsi_insert_after (block_stmt_iterator *, tree,
 664                               enum bsi_iterator_update);
 665
 666 extern void bsi_replace (const block_stmt_iterator *, tree, bool);
 667
 668 /*---------------------------------------------------------------------------
 669                               OpenMP Region Tree
 670 ---------------------------------------------------------------------------*/
 671
 672 /* Parallel region information.  Every parallel and workshare
 673    directive is enclosed between two markers, the OMP_* directive
 674    and a corresponding OMP_RETURN statement.  */
 675
 676 struct omp_region
 677 {
 678   /* The enclosing region.  */
 679   struct omp_region *outer;
 680
 681   /* First child region.  */
 682   struct omp_region *inner;
 683
 684   /* Next peer region.  */
 685   struct omp_region *next;
 686
 687   /* Block containing the omp directive as its last stmt.  */
 688   basic_block entry;
 689
 690   /* Block containing the OMP_RETURN as its last stmt.  */
 691   basic_block exit;
 692
 693   /* Block containing the OMP_CONTINUE as its last stmt.  */
 694   basic_block cont;
 695
 696   /* If this is a combined parallel+workshare region, this is a list
 697      of additional arguments needed by the combined parallel+workshare
 698      library call.  */
 699   tree ws_args;
 700
 701   /* The code for the omp directive of this region.  */
 702   enum tree_code type;
 703
 704   /* Schedule kind, only used for OMP_FOR type regions.  */
 705   enum omp_clause_schedule_kind sched_kind;
 706
 707   /* True if this is a combined parallel+workshare region.  */
 708   bool is_combined_parallel;
 709 };
 710
 711 extern struct omp_region *root_omp_region;
 712 extern struct omp_region *new_omp_region (basic_block, enum tree_code,
 713                                           struct omp_region *);
 714 extern void free_omp_regions (void);
 715
 716 /*---------------------------------------------------------------------------
 717                               Function prototypes
 718 ---------------------------------------------------------------------------*/
 719 /* In tree-cfg.c  */
 720
 721 /* Location to track pending stmt for edge insertion.  */
 722 #define PENDING_STMT(e) ((e)->insns.t)
 723
 724 extern void delete_tree_cfg_annotations (void);
 725 extern bool stmt_ends_bb_p (tree);
 726 extern bool is_ctrl_stmt (tree);
 727 extern bool is_ctrl_altering_stmt (tree);
 728 extern bool computed_goto_p (tree);
 729 extern bool simple_goto_p (tree);
 730 extern bool tree_can_make_abnormal_goto (tree);
 731 extern basic_block single_noncomplex_succ (basic_block bb);
 732 extern void tree_dump_bb (basic_block, FILE *, int);
 733 extern void debug_tree_bb (basic_block);
 734 extern basic_block debug_tree_bb_n (int);
 735 extern void dump_tree_cfg (FILE *, int);
 736 extern void debug_tree_cfg (int);
 737 extern void dump_cfg_stats (FILE *);
 738 extern void debug_cfg_stats (void);
 739 extern void debug_loop_ir (void);
 740 extern void print_loop_ir (FILE *);
 741 extern void cleanup_dead_labels (void);
 742 extern void group_case_labels (void);
 743 extern tree first_stmt (basic_block);
 744 extern tree last_stmt (basic_block);
 745 extern tree last_and_only_stmt (basic_block);
 746 extern edge find_taken_edge (basic_block, tree);
 747 extern basic_block label_to_block_fn (struct function *, tree);
 748 #define label_to_block(t) (label_to_block_fn (cfun, t))
 749 extern void bsi_insert_on_edge (edge, tree);
 750 extern basic_block bsi_insert_on_edge_immediate (edge, tree);
 751 extern void bsi_commit_one_edge_insert (edge, basic_block *);
 752 extern void bsi_commit_edge_inserts (void);
 753 extern void notice_special_calls (tree);
 754 extern void clear_special_calls (void);
 755 extern void verify_stmts (void);
 756 extern tree tree_block_label (basic_block);
 757 extern void extract_true_false_edges_from_block (basic_block, edge *, edge *);
 758 extern bool tree_duplicate_sese_region (edge, edge, basic_block *, unsigned,
 759                                         basic_block *);
 760 extern void add_phi_args_after_copy_bb (basic_block);
 761 extern void add_phi_args_after_copy (basic_block *, unsigned);
 762 extern bool tree_purge_dead_abnormal_call_edges (basic_block);
 763 extern bool tree_purge_dead_eh_edges (basic_block);
 764 extern bool tree_purge_all_dead_eh_edges (bitmap);
 765 extern tree gimplify_val (block_stmt_iterator *, tree, tree);
 766 extern tree gimplify_build1 (block_stmt_iterator *, enum tree_code,
 767                              tree, tree);
 768 extern tree gimplify_build2 (block_stmt_iterator *, enum tree_code,
 769                              tree, tree, tree);
 770 extern tree gimplify_build3 (block_stmt_iterator *, enum tree_code,
 771                              tree, tree, tree, tree);
 772 extern void init_empty_tree_cfg (void);
 773 extern void fold_cond_expr_cond (void);
 774 extern void make_abnormal_goto_edges (basic_block, bool);
 775 extern void replace_uses_by (tree, tree);
 776 extern void start_recording_case_labels (void);
 777 extern void end_recording_case_labels (void);
 778 extern basic_block move_sese_region_to_fn (struct function *, basic_block,
 779                                            basic_block);
 780 void remove_edge_and_dominated_blocks (edge);
 781
 782 /* In tree-cfgcleanup.c  */
 783 extern bitmap cfgcleanup_altered_bbs;
 784 extern bool cleanup_tree_cfg (void);
 785 extern bool cleanup_tree_cfg_loop (void);
 786
 787 /* In tree-pretty-print.c.  */
 788 extern void dump_generic_bb (FILE *, basic_block, int, int);
 789 extern const char *op_symbol_code (enum tree_code);
 790
 791 /* In tree-dfa.c  */
 792 extern var_ann_t create_var_ann (tree);
 793 extern function_ann_t create_function_ann (tree);
 794 extern stmt_ann_t create_stmt_ann (tree);
 795 extern tree_ann_common_t create_tree_common_ann (tree);
 796 extern void dump_dfa_stats (FILE *);
 797 extern void debug_dfa_stats (void);
 798 extern void debug_referenced_vars (void);
 799 extern void dump_referenced_vars (FILE *);
 800 extern void dump_variable (FILE *, tree);
 801 extern void debug_variable (tree);
 802 extern void dump_subvars_for (FILE *, tree);
 803 extern void debug_subvars_for (tree);
 804 extern tree get_virtual_var (tree);
 805 extern void add_referenced_var (tree);
 806 extern void remove_referenced_var (tree);
 807 extern void mark_symbols_for_renaming (tree);
 808 extern void find_new_referenced_vars (tree *);
 809 extern tree make_rename_temp (tree, const char *);
 810 extern void set_default_def (tree, tree);
 811 extern tree gimple_default_def (struct function *, tree);
 812 extern struct mem_sym_stats_d *mem_sym_stats (struct function *, tree);
 813
 814 /* In tree-phinodes.c  */
 815 extern void reserve_phi_args_for_new_edge (basic_block);
 816 extern tree create_phi_node (tree, basic_block);
 817 extern void add_phi_arg (tree, tree, edge);
 818 extern void remove_phi_args (edge);
 819 extern void remove_phi_node (tree, tree, bool);
 820 extern tree phi_reverse (tree);
 821
 822 /* In gimple-low.c  */
 823 extern void record_vars_into (tree, tree);
 824 extern void record_vars (tree);
 825 extern bool block_may_fallthru (tree);
 826
 827 /* In tree-ssa-alias.c  */
 828 extern void dump_may_aliases_for (FILE *, tree);
 829 extern void debug_may_aliases_for (tree);
 830 extern void dump_alias_info (FILE *);
 831 extern void debug_alias_info (void);
 832 extern void dump_points_to_info (FILE *);
 833 extern void debug_points_to_info (void);
 834 extern void dump_points_to_info_for (FILE *, tree);
 835 extern void debug_points_to_info_for (tree);
 836 extern bool may_be_aliased (tree);
 837 extern struct ptr_info_def *get_ptr_info (tree);
 838 extern void new_type_alias (tree, tree, tree);
 839 extern void count_uses_and_derefs (tree, tree, unsigned *, unsigned *,
 840                                    unsigned *);
 841 static inline subvar_t get_subvars_for_var (tree);
 842 static inline tree get_subvar_at (tree, unsigned HOST_WIDE_INT);
 843 static inline bool ref_contains_array_ref (tree);
 844 static inline bool array_ref_contains_indirect_ref (tree);
 845 extern tree get_ref_base_and_extent (tree, HOST_WIDE_INT *,
 846                                      HOST_WIDE_INT *, HOST_WIDE_INT *);
 847 static inline bool var_can_have_subvars (tree);
 848 static inline bool overlap_subvar (unsigned HOST_WIDE_INT,
 849                                    unsigned HOST_WIDE_INT,
 850                                    tree, bool *);
 851 extern tree create_tag_raw (enum tree_code, tree, const char *);
 852 extern void delete_mem_ref_stats (struct function *);
 853 extern void dump_mem_ref_stats (FILE *);
 854 extern void debug_mem_ref_stats (void);
 855 extern void debug_memory_partitions (void);
 856 extern void debug_mem_sym_stats (tree var);
 857 extern void debug_all_mem_sym_stats (void);
 858
 859 /* Call-back function for walk_use_def_chains().  At each reaching
 860    definition, a function with this prototype is called.  */
 861 typedef bool (*walk_use_def_chains_fn) (tree, tree, void *);
 862
 863 /* In tree-ssa-alias-warnings.c  */
 864 extern void strict_aliasing_warning_backend (void);
 865
 866 /* In tree-ssa.c  */
 867 extern void init_tree_ssa (void);
 868 extern edge ssa_redirect_edge (edge, basic_block);
 869 extern void flush_pending_stmts (edge);
 870 extern bool tree_ssa_useless_type_conversion (tree);
 871 extern bool tree_ssa_useless_type_conversion_1 (tree, tree);
 872 extern void verify_ssa (bool);
 873 extern void delete_tree_ssa (void);
 874 extern void walk_use_def_chains (tree, walk_use_def_chains_fn, void *, bool);
 875 extern bool stmt_references_memory_p (tree);
 876
 877 /* In tree-into-ssa.c  */
 878 void update_ssa (unsigned);
 879 void delete_update_ssa (void);
 880 void register_new_name_mapping (tree, tree);
 881 tree create_new_def_for (tree, tree, def_operand_p);
 882 bool need_ssa_update_p (void);
 883 bool name_mappings_registered_p (void);
 884 bool name_registered_for_update_p (tree);
 885 bitmap ssa_names_to_replace (void);
 886 void release_ssa_name_after_update_ssa (tree);
 887 void compute_global_livein (bitmap, bitmap);
 888 tree duplicate_ssa_name (tree, tree);
 889 void mark_sym_for_renaming (tree);
 890 void mark_set_for_renaming (bitmap);
 891 tree get_current_def (tree);
 892 void set_current_def (tree, tree);
 893
 894 /* In tree-ssa-ccp.c  */
 895 bool fold_stmt (tree *);
 896 bool fold_stmt_inplace (tree);
 897 tree widen_bitfield (tree, tree, tree);
 898
 899 /* In tree-vrp.c  */
 900 tree vrp_evaluate_conditional (tree, tree);
 901 void simplify_stmt_using_ranges (tree);
 902
 903 /* In tree-ssa-dom.c  */
 904 extern void dump_dominator_optimization_stats (FILE *);
 905 extern void debug_dominator_optimization_stats (void);
 906 int loop_depth_of_name (tree);
 907
 908 /* In tree-ssa-copy.c  */
 909 extern void merge_alias_info (tree, tree);
 910 extern void propagate_value (use_operand_p, tree);
 911 extern void propagate_tree_value (tree *, tree);
 912 extern void replace_exp (use_operand_p, tree);
 913 extern bool may_propagate_copy (tree, tree);
 914 extern bool may_propagate_copy_into_asm (tree);
 915
 916 /* Affine iv.  */
 917
 918 typedef struct
 919 {
 920   /* Iv = BASE + STEP * i.  */
 921   tree base, step;
 922
 923   /* True if this iv does not overflow.  */
 924   bool no_overflow;
 925 } affine_iv;
 926
 927 /* Description of number of iterations of a loop.  All the expressions inside
 928    the structure can be evaluated at the end of the loop's preheader
 929    (and due to ssa form, also anywhere inside the body of the loop).  */
 930
 931 struct tree_niter_desc
 932 {
 933   tree assumptions;     /* The boolean expression.  If this expression evaluates
 934                            to false, then the other fields in this structure
 935                            should not be used; there is no guarantee that they
 936                            will be correct.  */
 937   tree may_be_zero;     /* The boolean expression.  If it evaluates to true,
 938                            the loop will exit in the first iteration (i.e.
 939                            its latch will not be executed), even if the niter
 940                            field says otherwise.  */
 941   tree niter;           /* The expression giving the number of iterations of
 942                            a loop (provided that assumptions == true and
 943                            may_be_zero == false), more precisely the number
 944                            of executions of the latch of the loop.  */
 945   double_int max;       /* The upper bound on the number of iterations of
 946                            the loop.  */
 947
 948   /* The simplified shape of the exit condition.  The loop exits if
 949      CONTROL CMP BOUND is false, where CMP is one of NE_EXPR,
 950      LT_EXPR, or GT_EXPR, and step of CONTROL is positive if CMP is
 951      LE_EXPR and negative if CMP is GE_EXPR.  This information is used
 952      by loop unrolling.  */
 953   affine_iv control;
 954   tree bound;
 955   enum tree_code cmp;
 956 };
 957
 958 /* In tree-vectorizer.c */
 959 unsigned vectorize_loops (void);
 960 extern bool vect_can_force_dr_alignment_p (tree, unsigned int);
 961 extern tree get_vectype_for_scalar_type (tree);
 962
 963 /* In tree-ssa-phiopt.c */
 964 bool empty_block_p (basic_block);
 965
 966 /* In tree-ssa-loop*.c  */
 967
 968 void tree_ssa_lim (void);
 969 unsigned int tree_ssa_unswitch_loops (void);
 970 unsigned int canonicalize_induction_variables (void);
 971 unsigned int tree_unroll_loops_completely (bool);
 972 unsigned int tree_ssa_prefetch_arrays (void);
 973 unsigned int remove_empty_loops (void);
 974 void tree_ssa_iv_optimize (void);
 975 void tree_predictive_commoning (void);
 976
 977 bool number_of_iterations_exit (struct loop *, edge,
 978                                 struct tree_niter_desc *niter, bool);
 979 tree find_loop_niter (struct loop *, edge *);
 980 tree loop_niter_by_eval (struct loop *, edge);
 981 tree find_loop_niter_by_eval (struct loop *, edge *);
 982 void estimate_numbers_of_iterations (void);
 983 bool scev_probably_wraps_p (tree, tree, tree, struct loop *, bool);
 984 bool convert_affine_scev (struct loop *, tree, tree *, tree *, tree, bool);
 985
 986 bool nowrap_type_p (tree);
 987 enum ev_direction {EV_DIR_GROWS, EV_DIR_DECREASES, EV_DIR_UNKNOWN};
 988 enum ev_direction scev_direction (tree);
 989
 990 void free_numbers_of_iterations_estimates (void);
 991 void free_numbers_of_iterations_estimates_loop (struct loop *);
 992 void rewrite_into_loop_closed_ssa (bitmap, unsigned);
 993 void verify_loop_closed_ssa (void);
 994 bool for_each_index (tree *, bool (*) (tree, tree *, void *), void *);
 995 void create_iv (tree, tree, tree, struct loop *, block_stmt_iterator *, bool,
 996                 tree *, tree *);
 997 void split_loop_exit_edge (edge);
 998 unsigned force_expr_to_var_cost (tree);
 999 void standard_iv_increment_position (struct loop *, block_stmt_iterator *,
1000                                      bool *);
1001 basic_block ip_end_pos (struct loop *);
1002 basic_block ip_normal_pos (struct loop *);
1003 bool tree_duplicate_loop_to_header_edge (struct loop *, edge,
1004                                          unsigned int, sbitmap,
1005                                          edge, VEC (edge, heap) **,
1006                                          int);
1007 struct loop *tree_ssa_loop_version (struct loop *, tree,
1008                                     basic_block *);
1009 tree expand_simple_operations (tree);
1010 void substitute_in_loop_info (struct loop *, tree, tree);
1011 edge single_dom_exit (struct loop *);
1012 bool can_unroll_loop_p (struct loop *loop, unsigned factor,
1013                         struct tree_niter_desc *niter);
1014 void tree_unroll_loop (struct loop *, unsigned,
1015                        edge, struct tree_niter_desc *);
1016 typedef void (*transform_callback)(struct loop *, void *);
1017 void tree_transform_and_unroll_loop (struct loop *, unsigned,
1018                                      edge, struct tree_niter_desc *,
1019                                      transform_callback, void *);
1020 bool contains_abnormal_ssa_name_p (tree);
1021 bool stmt_dominates_stmt_p (tree, tree);
1022
1023 /* In tree-ssa-threadedge.c */
1024 extern bool potentially_threadable_block (basic_block);
1025 extern void thread_across_edge (tree, edge, bool,
1026                                 VEC(tree, heap) **, tree (*) (tree, tree));
1027
1028 /* In tree-ssa-loop-im.c  */
1029 /* The possibilities of statement movement.  */
1030
1031 enum move_pos
1032   {
1033     MOVE_IMPOSSIBLE,            /* No movement -- side effect expression.  */
1034     MOVE_PRESERVE_EXECUTION,    /* Must not cause the non-executed statement
1035                                    become executed -- memory accesses, ... */
1036     MOVE_POSSIBLE               /* Unlimited movement.  */
1037   };
1038 extern enum move_pos movement_possibility (tree);
1039 char *get_lsm_tmp_name (tree, unsigned);
1040
1041 /* The reasons a variable may escape a function.  */
1042 enum escape_type
1043 {
1044   NO_ESCAPE = 0,                        /* Doesn't escape.  */
1045   ESCAPE_STORED_IN_GLOBAL = 1 << 1,
1046   ESCAPE_TO_ASM = 1 << 2,               /* Passed by address to an assembly
1047                                            statement.  */
1048   ESCAPE_TO_CALL = 1 << 3,              /* Escapes to a function call.  */
1049   ESCAPE_BAD_CAST = 1 << 4,             /* Cast from pointer to integer */
1050   ESCAPE_TO_RETURN = 1 << 5,            /* Returned from function.  */
1051   ESCAPE_TO_PURE_CONST = 1 << 6,        /* Escapes to a pure or constant
1052                                            function call.  */
1053   ESCAPE_IS_GLOBAL = 1 << 7,            /* Is a global variable.  */
1054   ESCAPE_IS_PARM = 1 << 8,              /* Is an incoming function argument.  */
1055   ESCAPE_UNKNOWN = 1 << 9               /* We believe it escapes for
1056                                            some reason not enumerated
1057                                            above.  */
1058 };
1059
1060 /* In tree-flow-inline.h  */
1061 static inline bool is_call_clobbered (tree);
1062 static inline void mark_call_clobbered (tree, unsigned int);
1063 static inline void set_is_used (tree);
1064 static inline bool unmodifiable_var_p (tree);
1065
1066 /* In tree-eh.c  */
1067 extern void make_eh_edges (tree);
1068 extern bool tree_could_trap_p (tree);
1069 extern bool tree_could_throw_p (tree);
1070 extern bool tree_can_throw_internal (tree);
1071 extern bool tree_can_throw_external (tree);
1072 extern int lookup_stmt_eh_region (tree);
1073 extern void add_stmt_to_eh_region (tree, int);
1074 extern bool remove_stmt_from_eh_region (tree);
1075 extern bool maybe_clean_or_replace_eh_stmt (tree, tree);
1076
1077 /* In tree-ssa-pre.c  */
1078 void add_to_value (tree, tree);
1079 void debug_value_expressions (tree);
1080 void print_value_expressions (FILE *, tree);
1081
1082
1083 /* In tree-vn.c  */
1084 bool expressions_equal_p (tree, tree);
1085 static inline tree get_value_handle (tree);
1086 hashval_t vn_compute (tree, hashval_t);
1087 void sort_vuses (VEC (tree, gc) *);
1088 tree vn_lookup_or_add (tree, tree);
1089 tree vn_lookup_or_add_with_vuses (tree, VEC (tree, gc) *);
1090 void vn_add (tree, tree);
1091 void vn_add_with_vuses (tree, tree, VEC (tree, gc) *);
1092 tree vn_lookup (tree, tree);
1093 tree vn_lookup_with_vuses (tree, VEC (tree, gc) *);
1094 void vn_init (void);
1095 void vn_delete (void);
1096
1097 /* In tree-ssa-sink.c  */
1098 bool is_hidden_global_store (tree);
1099
1100 /* In tree-sra.c  */
1101 void insert_edge_copies (tree, basic_block);
1102 void sra_insert_before (block_stmt_iterator *, tree);
1103 void sra_insert_after (block_stmt_iterator *, tree);
1104 void sra_init_cache (void);
1105 bool sra_type_can_be_decomposed_p (tree);
1106
1107 /* In tree-loop-linear.c  */
1108 extern void linear_transform_loops (void);
1109
1110 /* In tree-data-ref.c  */
1111 extern void tree_check_data_deps (void);
1112
1113 /* In tree-ssa-loop-ivopts.c  */
1114 bool expr_invariant_in_loop_p (struct loop *, tree);
1115 bool multiplier_allowed_in_address_p (HOST_WIDE_INT, enum machine_mode);
1116 unsigned multiply_by_cost (HOST_WIDE_INT, enum machine_mode);
1117
1118 /* In tree-ssa-threadupdate.c.  */
1119 extern bool thread_through_all_blocks (bool);
1120 extern void register_jump_thread (edge, edge);
1121
1122 /* In gimplify.c  */
1123 tree force_gimple_operand (tree, tree *, bool, tree);
1124 tree force_gimple_operand_bsi (block_stmt_iterator *, tree, bool, tree);
1125
1126 /* In tree-ssa-structalias.c */
1127 bool find_what_p_points_to (tree);
1128
1129 /* In tree-ssa-live.c */
1130 extern void remove_unused_locals (void);
1131
1132 /* In tree-ssa-address.c  */
1133
1134 /* Description of a memory address.  */
1135
1136 struct mem_address
1137 {
1138   tree symbol, base, index, step, offset;
1139 };
1140
1141 struct affine_tree_combination;
1142 tree create_mem_ref (block_stmt_iterator *, tree,
1143                      struct affine_tree_combination *);
1144 rtx addr_for_mem_ref (struct mem_address *, bool);
1145 void get_address_description (tree, struct mem_address *);
1146 tree maybe_fold_tmr (tree);
1147
1148 /* This structure is simply used during pushing fields onto the fieldstack
1149    to track the offset of the field, since bitpos_of_field gives it relative
1150    to its immediate containing type, and we want it relative to the ultimate
1151    containing object.  */
1152
1153 struct fieldoff
1154 {
1155   tree type;
1156   tree size;
1157   tree decl;
1158   HOST_WIDE_INT offset;
1159 };
1160 typedef struct fieldoff fieldoff_s;
1161
1162 DEF_VEC_O(fieldoff_s);
1163 DEF_VEC_ALLOC_O(fieldoff_s,heap);
1164 int push_fields_onto_fieldstack (tree, VEC(fieldoff_s,heap) **,
1165                                  HOST_WIDE_INT, bool *);
1166 void sort_fieldstack (VEC(fieldoff_s,heap) *);
1167
1168 void init_alias_heapvars (void);
1169 void delete_alias_heapvars (void);
1170 unsigned int execute_fixup_cfg (void);
1171
1172 #include "tree-flow-inline.h"
1173
1174 void swap_tree_operands (tree, tree *, tree *);
1175
1176 int least_common_multiple (int, int);
1177
1178 #endif /* _TREE_FLOW_H  */