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      1 /* Data and Control Flow Analysis for Trees.
      2    Copyright (C) 2001, 2003, 2004, 2005, 2006, 2007, 2008, 2009
      3    Free Software Foundation, Inc.
      4    Contributed by Diego Novillo <dnovillo (at) 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 "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   /* Call-used variables in the function.  If bit I is set, then
    166      REFERENCED_VARS (I) is call-used at pure function call-sites.  */
    167   bitmap call_used_vars;
    168 
    169   /* Addressable variables in the function.  If bit I is set, then
    170      REFERENCED_VARS (I) has had its address taken.  Note that
    171      CALL_CLOBBERED_VARS and ADDRESSABLE_VARS are not related.  An
    172      addressable variable is not necessarily call-clobbered (e.g., a
    173      local addressable whose address does not escape) and not all
    174      call-clobbered variables are addressable (e.g., a local static
    175      variable).  */
    176   bitmap addressable_vars;
    177 
    178   /* Free list of SSA_NAMEs.  */
    179   tree free_ssanames;
    180 
    181   /* Hashtable holding definition for symbol.  If this field is not NULL, it
    182      means that the first reference to this variable in the function is a
    183      USE or a VUSE.  In those cases, the SSA renamer creates an SSA name
    184      for this variable with an empty defining statement.  */
    185   htab_t GTY((param_is (union tree_node))) default_defs;
    186 
    187   /* 'true' after aliases have been computed (see compute_may_aliases).  */
    188   unsigned int aliases_computed_p : 1;
    189 
    190   /* True if the code is in ssa form.  */
    191   unsigned int in_ssa_p : 1;
    192 
    193   struct ssa_operands ssa_operands;
    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   /* Mask of reasons this pointer's value escapes the function.  */
    235   ENUM_BITFIELD (escape_type) escape_mask : 9;
    236 
    237   /* Nonzero if points-to analysis couldn't determine where this pointer
    238      is pointing to.  */
    239   unsigned int pt_anything : 1;
    240 
    241   /* Nonzero if the value of this pointer escapes the current function.  */
    242   unsigned int value_escapes_p : 1;
    243 
    244   /* Nonzero if a memory tag is needed for this pointer.  This is
    245      true if this pointer is eventually dereferenced.  */
    246   unsigned int memory_tag_needed : 1;
    247 
    248   /* Nonzero if this pointer is really dereferenced.  */
    249   unsigned int is_dereferenced : 1;
    250 
    251   /* Nonzero if this pointer points to a global variable.  */
    252   unsigned int pt_global_mem : 1;
    253 
    254   /* Nonzero if this pointer points to NULL.  */
    255   unsigned int pt_null : 1;
    256 
    257   /* Set of variables that this pointer may point to.  */
    258   bitmap pt_vars;
    259 
    260   /* If this pointer has been dereferenced, and points-to information is
    261      more precise than type-based aliasing, indirect references to this
    262      pointer will be represented by this memory tag, instead of the type
    263      tag computed by TBAA.  */
    264   tree name_mem_tag;
    265 };
    266 
    267 
    268 /*---------------------------------------------------------------------------
    269 		   Tree annotations stored in tree_base.ann
    270 ---------------------------------------------------------------------------*/
    271 enum tree_ann_type { TREE_ANN_COMMON, VAR_ANN, FUNCTION_ANN };
    272 
    273 struct tree_ann_common_d GTY(())
    274 {
    275   /* Annotation type.  */
    276   enum tree_ann_type type;
    277 
    278   /* Record EH region number into a statement tree created during RTL
    279      expansion (see gimple_to_tree).  */
    280   int rn;
    281 
    282   /* Auxiliary info specific to a pass.  At all times, this
    283      should either point to valid data or be NULL.  */
    284   PTR GTY ((skip (""))) aux;
    285 
    286   /* The value handle for this expression.  Used by GVN-PRE.  */
    287   tree GTY((skip)) value_handle;
    288 
    289   /* Pointer to original GIMPLE statement.  Used during RTL expansion
    290      (see gimple_to_tree).  */
    291   gimple stmt;
    292 };
    293 
    294 /* It is advantageous to avoid things like life analysis for variables which
    295    do not need PHI nodes.  This enum describes whether or not a particular
    296    variable may need a PHI node.  */
    297 
    298 enum need_phi_state {
    299   /* This is the default.  If we are still in this state after finding
    300      all the definition and use sites, then we will assume the variable
    301      needs PHI nodes.  This is probably an overly conservative assumption.  */
    302   NEED_PHI_STATE_UNKNOWN,
    303 
    304   /* This state indicates that we have seen one or more sets of the
    305      variable in a single basic block and that the sets dominate all
    306      uses seen so far.  If after finding all definition and use sites
    307      we are still in this state, then the variable does not need any
    308      PHI nodes.  */
    309   NEED_PHI_STATE_NO,
    310 
    311   /* This state indicates that we have either seen multiple definitions of
    312      the variable in multiple blocks, or that we encountered a use in a
    313      block that was not dominated by the block containing the set(s) of
    314      this variable.  This variable is assumed to need PHI nodes.  */
    315   NEED_PHI_STATE_MAYBE
    316 };
    317 
    318 
    319 /* The "no alias" attribute allows alias analysis to make more
    320    aggressive assumptions when assigning alias sets, computing
    321    points-to information and memory partitions.  These attributes
    322    are the result of user annotations or flags (e.g.,
    323    -fargument-noalias).  */
    324 enum noalias_state {
    325     /* Default state.  No special assumptions can be made about this
    326        symbol.  */
    327     MAY_ALIAS = 0,
    328 
    329     /* The symbol does not alias with other symbols that have a
    330        NO_ALIAS* attribute.  */
    331     NO_ALIAS,
    332 
    333     /* The symbol does not alias with other symbols that have a
    334        NO_ALIAS*, and it may not alias with global symbols.  */
    335     NO_ALIAS_GLOBAL,
    336 
    337     /* The symbol does not alias with any other symbols.  */
    338     NO_ALIAS_ANYTHING
    339 };
    340 
    341 
    342 struct var_ann_d GTY(())
    343 {
    344   struct tree_ann_common_d common;
    345 
    346   /* Used by the out of SSA pass to determine whether this variable has
    347      been seen yet or not.  */
    348   unsigned out_of_ssa_tag : 1;
    349 
    350   /* Used when building base variable structures in a var_map.  */
    351   unsigned base_var_processed : 1;
    352 
    353   /* Nonzero if this variable was used after SSA optimizations were
    354      applied.  We set this when translating out of SSA form.  */
    355   unsigned used : 1;
    356 
    357   /* This field indicates whether or not the variable may need PHI nodes.
    358      See the enum's definition for more detailed information about the
    359      states.  */
    360   ENUM_BITFIELD (need_phi_state) need_phi_state : 2;
    361 
    362   /* Used during operand processing to determine if this variable is already
    363      in the VUSE list.  */
    364   unsigned in_vuse_list : 1;
    365 
    366   /* Used during operand processing to determine if this variable is already
    367      in the VDEF list.  */
    368   unsigned in_vdef_list : 1;
    369 
    370   /* True for HEAP artificial variables.  These variables represent
    371      the memory area allocated by a call to malloc.  */
    372   unsigned is_heapvar : 1;
    373 
    374   /* True if the variable is call clobbered.  */
    375   unsigned call_clobbered : 1;
    376 
    377   /* This field describes several "no alias" attributes that some
    378      symbols are known to have.  See the enum's definition for more
    379      information on each attribute.  */
    380   ENUM_BITFIELD (noalias_state) noalias_state : 2;
    381 
    382   /* Mask of values saying the reasons why this variable has escaped
    383      the function.  */
    384   ENUM_BITFIELD (escape_type) escape_mask : 9;
    385 
    386   /* Memory partition tag assigned to this symbol.  */
    387   tree mpt;
    388 
    389   /* If this variable is a pointer P that has been dereferenced, this
    390      field is an artificial variable that represents the memory
    391      location *P.  Every other pointer Q that is type-compatible with
    392      P will also have the same memory tag.  If the variable is not a
    393      pointer or if it is never dereferenced, this must be NULL.
    394      FIXME, do we really need this here?  How much slower would it be
    395      to convert to hash table?  */
    396   tree symbol_mem_tag;
    397 
    398   /* Used when going out of SSA form to indicate which partition this
    399      variable represents storage for.  */
    400   unsigned partition;
    401 
    402   /* Used by var_map for the base index of ssa base variables.  */
    403   unsigned base_index;
    404 
    405   /* During into-ssa and the dominator optimizer, this field holds the
    406      current version of this variable (an SSA_NAME).  */
    407   tree current_def;
    408 };
    409 
    410 /* Container for variable annotation used by hashtable for annotations for
    411    static variables.  */
    412 struct static_var_ann_d GTY(())
    413 {
    414   struct var_ann_d ann;
    415   unsigned int uid;
    416 };
    417 
    418 struct function_ann_d GTY(())
    419 {
    420   struct tree_ann_common_d common;
    421 };
    422 
    423 
    424 /* Immediate use lists are used to directly access all uses for an SSA
    425    name and get pointers to the statement for each use.
    426 
    427    The structure ssa_use_operand_d consists of PREV and NEXT pointers
    428    to maintain the list.  A USE pointer, which points to address where
    429    the use is located and a LOC pointer which can point to the
    430    statement where the use is located, or, in the case of the root
    431    node, it points to the SSA name itself.
    432 
    433    The list is anchored by an occurrence of ssa_operand_d *in* the
    434    ssa_name node itself (named 'imm_uses').  This node is uniquely
    435    identified by having a NULL USE pointer. and the LOC pointer
    436    pointing back to the ssa_name node itself.  This node forms the
    437    base for a circular list, and initially this is the only node in
    438    the list.
    439 
    440    Fast iteration allows each use to be examined, but does not allow
    441    any modifications to the uses or stmts.
    442 
    443    Normal iteration allows insertion, deletion, and modification. the
    444    iterator manages this by inserting a marker node into the list
    445    immediately before the node currently being examined in the list.
    446    this marker node is uniquely identified by having null stmt *and* a
    447    null use pointer.
    448 
    449    When iterating to the next use, the iteration routines check to see
    450    if the node after the marker has changed. if it has, then the node
    451    following the marker is now the next one to be visited. if not, the
    452    marker node is moved past that node in the list (visualize it as
    453    bumping the marker node through the list).  this continues until
    454    the marker node is moved to the original anchor position. the
    455    marker node is then removed from the list.
    456 
    457    If iteration is halted early, the marker node must be removed from
    458    the list before continuing.  */
    459 typedef struct immediate_use_iterator_d
    460 {
    461   /* This is the current use the iterator is processing.  */
    462   ssa_use_operand_t *imm_use;
    463   /* This marks the last use in the list (use node from SSA_NAME)  */
    464   ssa_use_operand_t *end_p;
    465   /* This node is inserted and used to mark the end of the uses for a stmt.  */
    466   ssa_use_operand_t iter_node;
    467   /* This is the next ssa_name to visit.  IMM_USE may get removed before
    468      the next one is traversed to, so it must be cached early.  */
    469   ssa_use_operand_t *next_imm_name;
    470 } imm_use_iterator;
    471 
    472 
    473 /* Use this iterator when simply looking at stmts.  Adding, deleting or
    474    modifying stmts will cause this iterator to malfunction.  */
    475 
    476 #define FOR_EACH_IMM_USE_FAST(DEST, ITER, SSAVAR)			\
    477   for ((DEST) = first_readonly_imm_use (&(ITER), (SSAVAR));	\
    478        !end_readonly_imm_use_p (&(ITER));			\
    479        (DEST) = next_readonly_imm_use (&(ITER)))
    480 
    481 /* Use this iterator to visit each stmt which has a use of SSAVAR.  */
    482 
    483 #define FOR_EACH_IMM_USE_STMT(STMT, ITER, SSAVAR)		\
    484   for ((STMT) = first_imm_use_stmt (&(ITER), (SSAVAR));		\
    485        !end_imm_use_stmt_p (&(ITER));				\
    486        (STMT) = next_imm_use_stmt (&(ITER)))
    487 
    488 /* Use this to terminate the FOR_EACH_IMM_USE_STMT loop early.  Failure to
    489    do so will result in leaving a iterator marker node in the immediate
    490    use list, and nothing good will come from that.   */
    491 #define BREAK_FROM_IMM_USE_STMT(ITER)				\
    492    {								\
    493      end_imm_use_stmt_traverse (&(ITER));			\
    494      break;							\
    495    }
    496 
    497 
    498 /* Use this iterator in combination with FOR_EACH_IMM_USE_STMT to
    499    get access to each occurrence of ssavar on the stmt returned by
    500    that iterator..  for instance:
    501 
    502      FOR_EACH_IMM_USE_STMT (stmt, iter, var)
    503        {
    504          FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
    505 	   {
    506 	     SET_USE (use_p, blah);
    507 	   }
    508 	 update_stmt (stmt);
    509        }							 */
    510 
    511 #define FOR_EACH_IMM_USE_ON_STMT(DEST, ITER)			\
    512   for ((DEST) = first_imm_use_on_stmt (&(ITER));		\
    513        !end_imm_use_on_stmt_p (&(ITER));			\
    514        (DEST) = next_imm_use_on_stmt (&(ITER)))
    515 
    516 
    517 
    518 union tree_ann_d GTY((desc ("ann_type ((tree_ann_t)&%h)")))
    519 {
    520   struct tree_ann_common_d GTY((tag ("TREE_ANN_COMMON"))) common;
    521   struct var_ann_d GTY((tag ("VAR_ANN"))) vdecl;
    522   struct function_ann_d GTY((tag ("FUNCTION_ANN"))) fdecl;
    523 };
    524 
    525 typedef union tree_ann_d *tree_ann_t;
    526 typedef struct var_ann_d *var_ann_t;
    527 typedef struct function_ann_d *function_ann_t;
    528 typedef struct tree_ann_common_d *tree_ann_common_t;
    529 
    530 static inline tree_ann_common_t tree_common_ann (const_tree);
    531 static inline tree_ann_common_t get_tree_common_ann (tree);
    532 static inline var_ann_t var_ann (const_tree);
    533 static inline var_ann_t get_var_ann (tree);
    534 static inline function_ann_t function_ann (const_tree);
    535 static inline function_ann_t get_function_ann (tree);
    536 static inline enum tree_ann_type ann_type (tree_ann_t);
    537 static inline void update_stmt (gimple);
    538 static inline bitmap may_aliases (const_tree);
    539 static inline int get_lineno (const_gimple);
    540 
    541 /*---------------------------------------------------------------------------
    542                   Structure representing predictions in tree level.
    543 ---------------------------------------------------------------------------*/
    544 struct edge_prediction GTY((chain_next ("%h.ep_next")))
    545 {
    546   struct edge_prediction *ep_next;
    547   edge ep_edge;
    548   enum br_predictor ep_predictor;
    549   int ep_probability;
    550 };
    551 
    552 /* Accessors for basic block annotations.  */
    553 static inline gimple_seq phi_nodes (const_basic_block);
    554 static inline void set_phi_nodes (basic_block, gimple_seq);
    555 
    556 /*---------------------------------------------------------------------------
    557 			      Global declarations
    558 ---------------------------------------------------------------------------*/
    559 struct int_tree_map GTY(())
    560 {
    561 
    562   unsigned int uid;
    563   tree to;
    564 };
    565 
    566 extern unsigned int int_tree_map_hash (const void *);
    567 extern int int_tree_map_eq (const void *, const void *);
    568 
    569 extern unsigned int uid_decl_map_hash (const void *);
    570 extern int uid_decl_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 			      OpenMP Region Tree
    628 ---------------------------------------------------------------------------*/
    629 
    630 /* Parallel region information.  Every parallel and workshare
    631    directive is enclosed between two markers, the OMP_* directive
    632    and a corresponding OMP_RETURN statement.  */
    633 
    634 struct omp_region
    635 {
    636   /* The enclosing region.  */
    637   struct omp_region *outer;
    638 
    639   /* First child region.  */
    640   struct omp_region *inner;
    641 
    642   /* Next peer region.  */
    643   struct omp_region *next;
    644 
    645   /* Block containing the omp directive as its last stmt.  */
    646   basic_block entry;
    647 
    648   /* Block containing the OMP_RETURN as its last stmt.  */
    649   basic_block exit;
    650 
    651   /* Block containing the OMP_CONTINUE as its last stmt.  */
    652   basic_block cont;
    653 
    654   /* If this is a combined parallel+workshare region, this is a list
    655      of additional arguments needed by the combined parallel+workshare
    656      library call.  */
    657   tree ws_args;
    658 
    659   /* The code for the omp directive of this region.  */
    660   enum gimple_code type;
    661 
    662   /* Schedule kind, only used for OMP_FOR type regions.  */
    663   enum omp_clause_schedule_kind sched_kind;
    664 
    665   /* True if this is a combined parallel+workshare region.  */
    666   bool is_combined_parallel;
    667 };
    668 
    669 extern struct omp_region *root_omp_region;
    670 extern struct omp_region *new_omp_region (basic_block, enum gimple_code,
    671 					  struct omp_region *);
    672 extern void free_omp_regions (void);
    673 void omp_expand_local (basic_block);
    674 extern tree find_omp_clause (tree, enum omp_clause_code);
    675 tree copy_var_decl (tree, tree, tree);
    676 
    677 /*---------------------------------------------------------------------------
    678 			      Function prototypes
    679 ---------------------------------------------------------------------------*/
    680 /* In tree-cfg.c  */
    681 
    682 /* Location to track pending stmt for edge insertion.  */
    683 #define PENDING_STMT(e)	((e)->insns.g)
    684 
    685 extern void delete_tree_cfg_annotations (void);
    686 extern bool stmt_ends_bb_p (gimple);
    687 extern bool is_ctrl_stmt (gimple);
    688 extern bool is_ctrl_altering_stmt (gimple);
    689 extern bool simple_goto_p (gimple);
    690 extern bool stmt_can_make_abnormal_goto (gimple);
    691 extern basic_block single_noncomplex_succ (basic_block bb);
    692 extern void gimple_dump_bb (basic_block, FILE *, int, int);
    693 extern void gimple_debug_bb (basic_block);
    694 extern basic_block gimple_debug_bb_n (int);
    695 extern void gimple_dump_cfg (FILE *, int);
    696 extern void gimple_debug_cfg (int);
    697 extern void dump_cfg_stats (FILE *);
    698 extern void dot_cfg (void);
    699 extern void debug_cfg_stats (void);
    700 extern void debug_loops (int);
    701 extern void debug_loop (struct loop *, int);
    702 extern void debug_loop_num (unsigned, int);
    703 extern void print_loops (FILE *, int);
    704 extern void print_loops_bb (FILE *, basic_block, int, int);
    705 extern void cleanup_dead_labels (void);
    706 extern void group_case_labels (void);
    707 extern gimple first_stmt (basic_block);
    708 extern gimple last_stmt (basic_block);
    709 extern gimple last_and_only_stmt (basic_block);
    710 extern edge find_taken_edge (basic_block, tree);
    711 extern basic_block label_to_block_fn (struct function *, tree);
    712 #define label_to_block(t) (label_to_block_fn (cfun, t))
    713 extern void notice_special_calls (gimple);
    714 extern void clear_special_calls (void);
    715 extern void verify_stmts (void);
    716 extern void verify_gimple (void);
    717 extern void verify_types_in_gimple_seq (gimple_seq);
    718 extern tree gimple_block_label (basic_block);
    719 extern void extract_true_false_edges_from_block (basic_block, edge *, edge *);
    720 extern bool gimple_duplicate_sese_region (edge, edge, basic_block *, unsigned,
    721 					basic_block *);
    722 extern bool gimple_duplicate_sese_tail (edge, edge, basic_block *, unsigned,
    723 				      basic_block *);
    724 extern void gather_blocks_in_sese_region (basic_block entry, basic_block exit,
    725 					  VEC(basic_block,heap) **bbs_p);
    726 extern void add_phi_args_after_copy_bb (basic_block);
    727 extern void add_phi_args_after_copy (basic_block *, unsigned, edge);
    728 extern bool gimple_purge_dead_abnormal_call_edges (basic_block);
    729 extern bool gimple_purge_dead_eh_edges (basic_block);
    730 extern bool gimple_purge_all_dead_eh_edges (const_bitmap);
    731 extern tree gimplify_build1 (gimple_stmt_iterator *, enum tree_code,
    732 			     tree, tree);
    733 extern tree gimplify_build2 (gimple_stmt_iterator *, enum tree_code,
    734 			     tree, tree, tree);
    735 extern tree gimplify_build3 (gimple_stmt_iterator *, enum tree_code,
    736 			     tree, tree, tree, tree);
    737 extern void init_empty_tree_cfg (void);
    738 extern void init_empty_tree_cfg_for_function (struct function *);
    739 extern void fold_cond_expr_cond (void);
    740 extern void make_abnormal_goto_edges (basic_block, bool);
    741 extern void replace_uses_by (tree, tree);
    742 extern void start_recording_case_labels (void);
    743 extern void end_recording_case_labels (void);
    744 extern basic_block move_sese_region_to_fn (struct function *, basic_block,
    745 				           basic_block, tree);
    746 void remove_edge_and_dominated_blocks (edge);
    747 void mark_virtual_ops_in_bb (basic_block);
    748 
    749 /* In tree-cfgcleanup.c  */
    750 extern bitmap cfgcleanup_altered_bbs;
    751 extern bool cleanup_tree_cfg (void);
    752 
    753 /* In tree-pretty-print.c.  */
    754 extern void dump_generic_bb (FILE *, basic_block, int, int);
    755 extern int op_code_prio (enum tree_code);
    756 extern int op_prio (const_tree);
    757 extern const char *op_symbol_code (enum tree_code);
    758 
    759 /* In tree-dfa.c  */
    760 extern var_ann_t create_var_ann (tree);
    761 extern function_ann_t create_function_ann (tree);
    762 extern void renumber_gimple_stmt_uids (void);
    763 extern tree_ann_common_t create_tree_common_ann (tree);
    764 extern void dump_dfa_stats (FILE *);
    765 extern void debug_dfa_stats (void);
    766 extern void debug_referenced_vars (void);
    767 extern void dump_referenced_vars (FILE *);
    768 extern void dump_variable (FILE *, tree);
    769 extern void debug_variable (tree);
    770 extern tree get_virtual_var (tree);
    771 extern bool add_referenced_var (tree);
    772 extern void remove_referenced_var (tree);
    773 extern void mark_symbols_for_renaming (gimple);
    774 extern void find_new_referenced_vars (gimple);
    775 extern tree make_rename_temp (tree, const char *);
    776 extern void set_default_def (tree, tree);
    777 extern tree gimple_default_def (struct function *, tree);
    778 extern bool stmt_references_abnormal_ssa_name (gimple);
    779 extern bool refs_may_alias_p (tree, tree);
    780 extern gimple get_single_def_stmt (gimple);
    781 extern gimple get_single_def_stmt_from_phi (tree, gimple);
    782 extern gimple get_single_def_stmt_with_phi (tree, gimple);
    783 
    784 /* In tree-phinodes.c  */
    785 extern void reserve_phi_args_for_new_edge (basic_block);
    786 extern void add_phi_node_to_bb (gimple phi, basic_block bb);
    787 extern gimple make_phi_node (tree var, int len);
    788 extern gimple create_phi_node (tree, basic_block);
    789 extern void add_phi_arg (gimple, tree, edge, source_location);
    790 extern void remove_phi_args (edge);
    791 extern void remove_phi_node (gimple_stmt_iterator *, bool);
    792 extern void remove_phi_nodes (basic_block);
    793 extern void init_phinodes (void);
    794 extern void fini_phinodes (void);
    795 extern void release_phi_node (gimple);
    796 #ifdef GATHER_STATISTICS
    797 extern void phinodes_print_statistics (void);
    798 #endif
    799 
    800 /* In gimple-low.c  */
    801 extern void record_vars_into (tree, tree);
    802 extern void record_vars (tree);
    803 extern bool block_may_fallthru (const_tree);
    804 extern bool gimple_seq_may_fallthru (gimple_seq);
    805 extern bool gimple_stmt_may_fallthru (gimple);
    806 extern void check_call_args (gimple);
    807 
    808 /* In tree-ssa-alias.c  */
    809 extern unsigned int compute_may_aliases (void);
    810 extern void dump_may_aliases_for (FILE *, tree);
    811 extern void debug_may_aliases_for (tree);
    812 extern void dump_alias_info (FILE *);
    813 extern void debug_alias_info (void);
    814 extern void dump_points_to_info (FILE *);
    815 extern void debug_points_to_info (void);
    816 extern void dump_points_to_info_for (FILE *, tree);
    817 extern void debug_points_to_info_for (tree);
    818 extern bool may_be_aliased (tree);
    819 extern bool may_alias_p (tree, alias_set_type, tree, alias_set_type, bool);
    820 extern struct ptr_info_def *get_ptr_info (tree);
    821 extern bool may_point_to_global_var (tree);
    822 extern void new_type_alias (tree, tree, tree);
    823 extern void count_uses_and_derefs (tree, gimple, unsigned *, unsigned *,
    824 				   unsigned *);
    825 static inline bool ref_contains_array_ref (const_tree);
    826 static inline bool array_ref_contains_indirect_ref (const_tree);
    827 extern tree get_ref_base_and_extent (tree, HOST_WIDE_INT *,
    828 				     HOST_WIDE_INT *, HOST_WIDE_INT *);
    829 extern tree create_tag_raw (enum tree_code, tree, const char *);
    830 extern void delete_mem_ref_stats (struct function *);
    831 extern void dump_mem_ref_stats (FILE *);
    832 extern void debug_mem_ref_stats (void);
    833 extern void debug_memory_partitions (void);
    834 extern void debug_mem_sym_stats (tree var);
    835 extern void dump_mem_sym_stats_for_var (FILE *, tree);
    836 extern void debug_all_mem_sym_stats (void);
    837 extern bool is_vptr_access (tree);
    838 extern bool is_vptr_init (gimple);
    839 extern bool is_vtbl_access (tree);
    840 extern bool is_global_delete (tree);
    841 extern bool is_global_delete_call (gimple);
    842 
    843 
    844 /* Call-back function for walk_use_def_chains().  At each reaching
    845    definition, a function with this prototype is called.  */
    846 typedef bool (*walk_use_def_chains_fn) (tree, gimple, void *);
    847 
    848 /* In tree-ssa-alias-warnings.c  */
    849 extern void strict_aliasing_warning_backend (void);
    850 
    851 
    852 /* In tree-ssa.c  */
    853 
    854 /* Mapping for redirected edges.  */
    855 struct _edge_var_map GTY(())
    856 {
    857   tree result;			/* PHI result.  */
    858   tree def;			/* PHI arg definition.  */
    859   source_location locus;        /* PHI arg location.  */
    860 };
    861 typedef struct _edge_var_map edge_var_map;
    862 
    863 DEF_VEC_O(edge_var_map);
    864 DEF_VEC_ALLOC_O(edge_var_map, heap);
    865 
    866 /* A vector of var maps.  */
    867 typedef VEC(edge_var_map, heap) *edge_var_map_vector;
    868 
    869 extern void init_tree_ssa (struct function *);
    870 extern void redirect_edge_var_map_add (edge, tree, tree, source_location);
    871 extern void redirect_edge_var_map_clear (edge);
    872 extern void redirect_edge_var_map_dup (edge, edge);
    873 extern edge_var_map_vector redirect_edge_var_map_vector (edge);
    874 extern void redirect_edge_var_map_destroy (void);
    875 
    876 extern edge ssa_redirect_edge (edge, basic_block);
    877 extern void flush_pending_stmts (edge);
    878 extern void verify_ssa (bool);
    879 extern void delete_tree_ssa (void);
    880 extern void walk_use_def_chains (tree, walk_use_def_chains_fn, void *, bool);
    881 extern bool ssa_undefined_value_p (tree);
    882 extern void warn_uninit (tree, const char *, void *);
    883 extern unsigned int warn_uninitialized_vars (bool);
    884 
    885 
    886 /* In tree-into-ssa.c  */
    887 void update_ssa (unsigned);
    888 void delete_update_ssa (void);
    889 void register_new_name_mapping (tree, tree);
    890 tree create_new_def_for (tree, gimple, def_operand_p);
    891 bool need_ssa_update_p (void);
    892 bool name_mappings_registered_p (void);
    893 bool name_registered_for_update_p (tree);
    894 bitmap ssa_names_to_replace (void);
    895 void release_ssa_name_after_update_ssa (tree);
    896 void compute_global_livein (bitmap, bitmap);
    897 void mark_sym_for_renaming (tree);
    898 void mark_set_for_renaming (bitmap);
    899 tree get_current_def (tree);
    900 void set_current_def (tree, tree);
    901 
    902 /* In tree-ssanames.c  */
    903 extern void init_ssanames (struct function *, int);
    904 extern void fini_ssanames (void);
    905 extern tree make_ssa_name_fn (struct function *, tree, gimple);
    906 extern tree duplicate_ssa_name (tree, gimple);
    907 extern void duplicate_ssa_name_ptr_info (tree, struct ptr_info_def *);
    908 extern void release_ssa_name (tree);
    909 extern void release_defs (gimple);
    910 extern void replace_ssa_name_symbol (tree, tree);
    911 
    912 #ifdef GATHER_STATISTICS
    913 extern void ssanames_print_statistics (void);
    914 #endif
    915 
    916 /* In tree-ssa-ccp.c  */
    917 bool fold_stmt (gimple_stmt_iterator *);
    918 bool fold_stmt_inplace (gimple);
    919 tree get_symbol_constant_value (tree);
    920 tree fold_const_aggregate_ref (tree);
    921 bool may_propagate_address_into_dereference (tree, tree);
    922 
    923 
    924 /* In tree-vrp.c  */
    925 tree vrp_evaluate_conditional (enum tree_code, tree, tree, gimple);
    926 bool simplify_stmt_using_ranges (gimple_stmt_iterator *);
    927 
    928 /* In tree-ssa-dom.c  */
    929 extern void dump_dominator_optimization_stats (FILE *);
    930 extern void debug_dominator_optimization_stats (void);
    931 int loop_depth_of_name (tree);
    932 
    933 /* In tree-ssa-copy.c  */
    934 extern void merge_alias_info (tree, tree);
    935 extern void propagate_value (use_operand_p, tree);
    936 extern void propagate_tree_value (tree *, tree);
    937 extern void propagate_tree_value_into_stmt (gimple_stmt_iterator *, tree);
    938 extern void replace_exp (use_operand_p, tree);
    939 extern bool may_propagate_copy (tree, tree);
    940 extern bool may_propagate_copy_into_stmt (gimple, tree);
    941 extern bool may_propagate_copy_into_asm (tree);
    942 
    943 /* Affine iv.  */
    944 
    945 typedef struct
    946 {
    947   /* Iv = BASE + STEP * i.  */
    948   tree base, step;
    949 
    950   /* True if this iv does not overflow.  */
    951   bool no_overflow;
    952 } affine_iv;
    953 
    954 /* Description of number of iterations of a loop.  All the expressions inside
    955    the structure can be evaluated at the end of the loop's preheader
    956    (and due to ssa form, also anywhere inside the body of the loop).  */
    957 
    958 struct tree_niter_desc
    959 {
    960   tree assumptions;	/* The boolean expression.  If this expression evaluates
    961 			   to false, then the other fields in this structure
    962 			   should not be used; there is no guarantee that they
    963 			   will be correct.  */
    964   tree may_be_zero;	/* The boolean expression.  If it evaluates to true,
    965 			   the loop will exit in the first iteration (i.e.
    966 			   its latch will not be executed), even if the niter
    967 			   field says otherwise.  */
    968   tree niter;		/* The expression giving the number of iterations of
    969 			   a loop (provided that assumptions == true and
    970 			   may_be_zero == false), more precisely the number
    971 			   of executions of the latch of the loop.  */
    972   double_int max;	/* The upper bound on the number of iterations of
    973 			   the loop.  */
    974 
    975   /* The simplified shape of the exit condition.  The loop exits if
    976      CONTROL CMP BOUND is false, where CMP is one of NE_EXPR,
    977      LT_EXPR, or GT_EXPR, and step of CONTROL is positive if CMP is
    978      LE_EXPR and negative if CMP is GE_EXPR.  This information is used
    979      by loop unrolling.  */
    980   affine_iv control;
    981   tree bound;
    982   enum tree_code cmp;
    983 };
    984 
    985 /* In tree-vectorizer.c */
    986 unsigned vectorize_loops (void);
    987 extern bool vect_can_force_dr_alignment_p (const_tree, unsigned int);
    988 extern tree get_vectype_for_scalar_type (tree);
    989 
    990 /* In tree-ssa-phiopt.c */
    991 bool empty_block_p (basic_block);
    992 basic_block *blocks_in_phiopt_order (void);
    993 
    994 /* In tree-ssa-loop*.c  */
    995 
    996 void tree_ssa_lim (void);
    997 unsigned int tree_ssa_unswitch_loops (void);
    998 unsigned int canonicalize_induction_variables (void);
    999 unsigned int tree_unroll_loops_completely (bool, bool);
   1000 unsigned int tree_ssa_prefetch_arrays (void);
   1001 unsigned int remove_empty_loops (void);
   1002 void tree_ssa_iv_optimize (void);
   1003 unsigned tree_predictive_commoning (void);
   1004 tree canonicalize_loop_ivs (struct loop *, htab_t, tree *);
   1005 bool parallelize_loops (void);
   1006 
   1007 bool loop_only_exit_p (const struct loop *, const_edge);
   1008 bool number_of_iterations_exit (struct loop *, edge,
   1009 				struct tree_niter_desc *niter, bool);
   1010 tree find_loop_niter (struct loop *, edge *);
   1011 tree loop_niter_by_eval (struct loop *, edge);
   1012 tree find_loop_niter_by_eval (struct loop *, edge *);
   1013 void estimate_numbers_of_iterations (void);
   1014 bool scev_probably_wraps_p (tree, tree, gimple, struct loop *, bool);
   1015 bool convert_affine_scev (struct loop *, tree, tree *, tree *, gimple, bool);
   1016 
   1017 bool nowrap_type_p (tree);
   1018 enum ev_direction {EV_DIR_GROWS, EV_DIR_DECREASES, EV_DIR_UNKNOWN};
   1019 enum ev_direction scev_direction (const_tree);
   1020 
   1021 void free_numbers_of_iterations_estimates (void);
   1022 void free_numbers_of_iterations_estimates_loop (struct loop *);
   1023 void rewrite_into_loop_closed_ssa (bitmap, unsigned);
   1024 void verify_loop_closed_ssa (void);
   1025 bool for_each_index (tree *, bool (*) (tree, tree *, void *), void *);
   1026 void create_iv (tree, tree, tree, struct loop *, gimple_stmt_iterator *, bool,
   1027 		tree *, tree *);
   1028 basic_block split_loop_exit_edge (edge);
   1029 void standard_iv_increment_position (struct loop *, gimple_stmt_iterator *,
   1030 				     bool *);
   1031 basic_block ip_end_pos (struct loop *);
   1032 basic_block ip_normal_pos (struct loop *);
   1033 bool gimple_duplicate_loop_to_header_edge (struct loop *, edge,
   1034 					 unsigned int, sbitmap,
   1035 					 edge, VEC (edge, heap) **,
   1036 					 int);
   1037 struct loop *slpeel_tree_duplicate_loop_to_edge_cfg (struct loop *, edge);
   1038 void rename_variables_in_loop (struct loop *);
   1039 void rename_variables_in_bb (basic_block bb);
   1040 struct loop *tree_ssa_loop_version (struct loop *, tree,
   1041 				    basic_block *);
   1042 tree expand_simple_operations (tree);
   1043 void substitute_in_loop_info (struct loop *, tree, tree);
   1044 edge single_dom_exit (struct loop *);
   1045 bool can_unroll_loop_p (struct loop *loop, unsigned factor,
   1046 			struct tree_niter_desc *niter);
   1047 void tree_unroll_loop (struct loop *, unsigned,
   1048 		       edge, struct tree_niter_desc *);
   1049 typedef void (*transform_callback)(struct loop *, void *);
   1050 void tree_transform_and_unroll_loop (struct loop *, unsigned,
   1051 				     edge, struct tree_niter_desc *,
   1052 				     transform_callback, void *);
   1053 bool contains_abnormal_ssa_name_p (tree);
   1054 bool stmt_dominates_stmt_p (gimple, gimple);
   1055 void mark_virtual_ops_for_renaming (gimple);
   1056 
   1057 /* In tree-ssa-threadedge.c */
   1058 extern bool potentially_threadable_block (basic_block);
   1059 extern void thread_across_edge (gimple, edge, bool,
   1060 				VEC(tree, heap) **, tree (*) (gimple, gimple));
   1061 
   1062 /* In tree-ssa-loop-im.c  */
   1063 /* The possibilities of statement movement.  */
   1064 
   1065 enum move_pos
   1066   {
   1067     MOVE_IMPOSSIBLE,		/* No movement -- side effect expression.  */
   1068     MOVE_PRESERVE_EXECUTION,	/* Must not cause the non-executed statement
   1069 				   become executed -- memory accesses, ... */
   1070     MOVE_POSSIBLE		/* Unlimited movement.  */
   1071   };
   1072 extern enum move_pos movement_possibility (gimple);
   1073 char *get_lsm_tmp_name (tree, unsigned);
   1074 
   1075 /* In tree-flow-inline.h  */
   1076 static inline bool is_call_clobbered (const_tree);
   1077 static inline void mark_call_clobbered (tree, unsigned int);
   1078 static inline void set_is_used (tree);
   1079 static inline bool unmodifiable_var_p (const_tree);
   1080 
   1081 /* In tree-eh.c  */
   1082 extern void make_eh_edges (gimple);
   1083 extern bool tree_could_trap_p (tree);
   1084 extern bool operation_could_trap_helper_p (enum tree_code, bool, bool, bool,
   1085 					   bool, tree, bool *);
   1086 extern bool operation_could_trap_p (enum tree_code, bool, bool, tree);
   1087 extern bool stmt_could_throw_p (gimple);
   1088 extern bool tree_could_throw_p (tree);
   1089 extern bool stmt_can_throw_internal (gimple);
   1090 extern void add_stmt_to_eh_region (gimple, int);
   1091 extern bool remove_stmt_from_eh_region (gimple);
   1092 extern bool maybe_clean_or_replace_eh_stmt (gimple, gimple);
   1093 extern void add_stmt_to_eh_region_fn (struct function *, gimple, int);
   1094 extern bool remove_stmt_from_eh_region_fn (struct function *, gimple);
   1095 extern int lookup_stmt_eh_region_fn (struct function *, gimple);
   1096 extern int lookup_expr_eh_region (tree);
   1097 extern int lookup_stmt_eh_region (gimple);
   1098 extern bool verify_eh_edges (gimple);
   1099 
   1100 
   1101 /* In tree-ssa-pre.c  */
   1102 struct pre_expr_d;
   1103 void add_to_value (unsigned int, struct pre_expr_d *);
   1104 void debug_value_expressions (unsigned int);
   1105 void print_value_expressions (FILE *, unsigned int);
   1106 
   1107 
   1108 /* In tree-vn.c  */
   1109 tree make_value_handle (tree);
   1110 void set_value_handle (tree, tree);
   1111 bool expressions_equal_p (tree, tree);
   1112 void sort_vuses (VEC (tree, gc) *);
   1113 void sort_vuses_heap (VEC (tree, heap) *);
   1114 tree vn_lookup_or_add (tree);
   1115 tree vn_lookup_or_add_with_stmt (tree, gimple);
   1116 tree vn_lookup_or_add_with_vuses (tree, VEC (tree, gc) *);
   1117 void vn_add (tree, tree);
   1118 void vn_add_with_vuses (tree, tree, VEC (tree, gc) *);
   1119 tree vn_lookup_with_stmt (tree, gimple);
   1120 tree vn_lookup (tree);
   1121 tree vn_lookup_with_vuses (tree, VEC (tree, gc) *);
   1122 
   1123 /* In tree-ssa-sink.c  */
   1124 bool is_hidden_global_store (gimple);
   1125 
   1126 /* In tree-sra.c  */
   1127 void insert_edge_copies_seq (gimple_seq, basic_block);
   1128 void sra_insert_before (gimple_stmt_iterator *, gimple_seq);
   1129 void sra_insert_after (gimple_stmt_iterator *, gimple_seq);
   1130 void sra_init_cache (void);
   1131 bool sra_type_can_be_decomposed_p (tree);
   1132 
   1133 /* In tree-loop-linear.c  */
   1134 extern void linear_transform_loops (void);
   1135 extern unsigned perfect_loop_nest_depth (struct loop *);
   1136 
   1137 /* In graphite.c  */
   1138 extern void graphite_transform_loops (void);
   1139 
   1140 /* In tree-data-ref.c  */
   1141 extern void tree_check_data_deps (void);
   1142 
   1143 /* In tree-ssa-loop-ivopts.c  */
   1144 bool expr_invariant_in_loop_p (struct loop *, tree);
   1145 bool stmt_invariant_in_loop_p (struct loop *, gimple);
   1146 bool multiplier_allowed_in_address_p (HOST_WIDE_INT, enum machine_mode);
   1147 unsigned multiply_by_cost (HOST_WIDE_INT, enum machine_mode, bool);
   1148 
   1149 /* In tree-ssa-threadupdate.c.  */
   1150 extern bool thread_through_all_blocks (bool);
   1151 extern void register_jump_thread (edge, edge);
   1152 
   1153 /* In gimplify.c  */
   1154 tree force_gimple_operand (tree, gimple_seq *, bool, tree);
   1155 tree force_gimple_operand_gsi (gimple_stmt_iterator *, tree, bool, tree,
   1156 			       bool, enum gsi_iterator_update);
   1157 tree gimple_fold_indirect_ref (tree);
   1158 
   1159 /* In tree-ssa-structalias.c */
   1160 bool find_what_p_points_to (tree);
   1161 bool clobber_what_escaped (void);
   1162 void compute_call_used_vars (void);
   1163 
   1164 /* In tree-ssa-live.c */
   1165 extern void remove_unused_locals (void);
   1166 extern void dump_scope_blocks (FILE *, int);
   1167 
   1168 /* In tree-ssa-address.c  */
   1169 
   1170 /* Description of a memory address.  */
   1171 
   1172 struct mem_address
   1173 {
   1174   tree symbol, base, index, step, offset;
   1175 };
   1176 
   1177 struct affine_tree_combination;
   1178 tree create_mem_ref (gimple_stmt_iterator *, tree,
   1179 		     struct affine_tree_combination *,
   1180 		     tree, bool, bool);
   1181 rtx addr_for_mem_ref (struct mem_address *, bool);
   1182 void get_address_description (tree, struct mem_address *);
   1183 tree maybe_fold_tmr (tree);
   1184 
   1185 void init_alias_heapvars (void);
   1186 void delete_alias_heapvars (void);
   1187 unsigned int execute_fixup_cfg (void);
   1188 
   1189 #include "tree-flow-inline.h"
   1190 
   1191 void swap_tree_operands (gimple, tree *, tree *);
   1192 
   1193 int least_common_multiple (int, int);
   1194 
   1195 #endif /* _TREE_FLOW_H  */
   1196