text: /* Callgraph handling code.
     Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008
     Free Software Foundation, Inc.
     Contributed by Jan Hubicka
  
  This file is part of GCC.
  
  GCC is free software; you can redistribute it and/or modify it under
  the terms of the GNU General Public License as published by the Free
  Software Foundation; either version 3, or (at your option) any later
  version.
  
  GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  WARRANTY; without even the implied warranty of MERCHANTABILITY or
  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  for more details.
  
  You should have received a copy of the GNU General Public License
  along with GCC; see the file COPYING3.  If not see
  <http://www.gnu.org/licenses/>.  */
  
  /*  This file contains basic routines manipulating call graph
  
  The callgraph:
  
      The call-graph is data structure designed for intra-procedural optimization
      but it is also used in non-unit-at-a-time compilation to allow easier code
      sharing.
  
      The call-graph consist of nodes and edges represented via linked lists.
      Each function (external or not) corresponds to the unique node.
  
      The mapping from declarations to call-graph nodes is done using hash table
      based on DECL_UID.  The call-graph nodes are created lazily using
      cgraph_node function when called for unknown declaration.
  
      The callgraph at the moment does not represent indirect calls or calls
      from other compilation unit.  Flag NEEDED is set for each node that may
      be accessed in such an invisible way and it shall be considered an
      entry point to the callgraph.
  
      Interprocedural information:
  
        Callgraph is place to store data needed for interprocedural optimization.
        All data structures are divided into three components: local_info that
        is produced while analyzing the function, global_info that is result
        of global walking of the callgraph on the end of compilation and
        rtl_info used by RTL backend to propagate data from already compiled
        functions to their callers.
  
      Inlining plans:
  
        The function inlining information is decided in advance and maintained
        in the callgraph as so called inline plan.
        For each inlined call, the callee's node is cloned to represent the
        new function copy produced by inliner.
        Each inlined call gets a unique corresponding clone node of the callee
        and the data structure is updated while inlining is performed, so
        the clones are eliminated and their callee edges redirected to the
        caller.
  
        Each edge has "inline_failed" field.  When the field is set to NULL,
        the call will be inlined.  When it is non-NULL it contains a reason
        why inlining wasn't performed.  */
  
  #include "config.h"
  #include "system.h"
  #include "coretypes.h"
  #include "tm.h"
  #include "tree.h"
  #include "tree-inline.h"
  #include "langhooks.h"
  #include "hashtab.h"
  #include "toplev.h"
  #include "flags.h"
  #include "ggc.h"
  #include "debug.h"
  #include "target.h"
  #include "basic-block.h"
  #include "cgraph.h"
  #include "varray.h"
  #include "output.h"
  #include "intl.h"
  #include "tree-gimple.h"
  #include "tree-dump.h"
  #include "tree-flow.h"
  
  static void cgraph_node_remove_callers (struct cgraph_node *node);
  static inline void cgraph_edge_remove_caller (struct cgraph_edge *e);
  static inline void cgraph_edge_remove_callee (struct cgraph_edge *e);
  
  /* Hash table used to convert declarations into nodes.  */
  static GTY((param_is (struct cgraph_node))) htab_t cgraph_hash;
  
  /* The linked list of cgraph nodes.  */
  struct cgraph_node *cgraph_nodes;
  
  /* Queue of cgraph nodes scheduled to be lowered.  */
  struct cgraph_node *cgraph_nodes_queue;
  
  /* Queue of cgraph nodes scheduled to be added into cgraph.  This is a
     secondary queue used during optimization to accommodate passes that
     may generate new functions that need to be optimized and expanded.  */
  struct cgraph_node *cgraph_new_nodes;
  
  /* Number of nodes in existence.  */
  int cgraph_n_nodes;
  
  /* Maximal uid used in cgraph nodes.  */
  int cgraph_max_uid;
  
  /* Maximal pid used for profiling */
  int cgraph_max_pid;
  
  /* Set when whole unit has been analyzed so we can access global info.  */
  bool cgraph_global_info_ready = false;
  
  /* What state callgraph is in right now.  */
  enum cgraph_state cgraph_state = CGRAPH_STATE_CONSTRUCTION;
  
  /* Set when the cgraph is fully build and the basic flags are computed.  */
  bool cgraph_function_flags_ready = false;
  
  /* Linked list of cgraph asm nodes.  */
  struct cgraph_asm_node *cgraph_asm_nodes;
  
  /* Last node in cgraph_asm_nodes.  */
  static GTY(()) struct cgraph_asm_node *cgraph_asm_last_node;
  
  /* The order index of the next cgraph node to be created.  This is
     used so that we can sort the cgraph nodes in order by when we saw
     them, to support -fno-toplevel-reorder.  */
  int cgraph_order;
  
  static hashval_t hash_node (const void *);
  static int eq_node (const void *, const void *);
  
  /* Returns a hash code for P.  */
  
  static hashval_t
  hash_node (const void *p)
  {
    const struct cgraph_node *n = (const struct cgraph_node *) p;
    return (hashval_t) DECL_UID (n->decl);
  }
  
  /* Returns nonzero if P1 and P2 are equal.  */
  
  static int
  eq_node (const void *p1, const void *p2)
  {
    const struct cgraph_node *n1 = (const struct cgraph_node *) p1;
    const struct cgraph_node *n2 = (const struct cgraph_node *) p2;
    return DECL_UID (n1->decl) == DECL_UID (n2->decl);
  }
  
  /* Allocate new callgraph node and insert it into basic data structures.  */
  
  static struct cgraph_node *
  cgraph_create_node (void)
  {
    struct cgraph_node *node;
  
    node = GGC_CNEW (struct cgraph_node);
    node->next = cgraph_nodes;
    node->uid = cgraph_max_uid++;
    node->pid = -1;
    node->order = cgraph_order++;
    if (cgraph_nodes)
      cgraph_nodes->previous = node;
    node->previous = NULL;
    node->global.estimated_growth = INT_MIN;
    cgraph_nodes = node;
    cgraph_n_nodes++;
    return node;
  }
  
  /* Return cgraph node assigned to DECL.  Create new one when needed.  */
  
  struct cgraph_node *
  cgraph_node (tree decl)
  {
    struct cgraph_node key, *node, **slot;
  
    gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
  
    if (!cgraph_hash)
      cgraph_hash = htab_create_ggc (10, hash_node, eq_node, NULL);
  
    key.decl = decl;
  
    slot = (struct cgraph_node **) htab_find_slot (cgraph_hash, &key, INSERT);
  
    if (*slot)
      {
        node = *slot;
        if (!node->master_clone)
  	node->master_clone = node;
        return node;
      }
  
    node = cgraph_create_node ();
    node->decl = decl;
    *slot = node;
    if (DECL_CONTEXT (decl) && TREE_CODE (DECL_CONTEXT (decl)) == FUNCTION_DECL)
      {
        node->origin = cgraph_node (DECL_CONTEXT (decl));
        node->next_nested = node->origin->nested;
        node->origin->nested = node;
        node->master_clone = node;
      }
    return node;
  }
  
  /* Insert already constructed node into hashtable.  */
  
  void
  cgraph_insert_node_to_hashtable (struct cgraph_node *node)
  {
    struct cgraph_node **slot;
  
    slot = (struct cgraph_node **) htab_find_slot (cgraph_hash, node, INSERT);
  
    gcc_assert (!*slot);
    *slot = node;
  }
  
  
  /* Return the cgraph node that has ASMNAME for its DECL_ASSEMBLER_NAME.
     Return NULL if there's no such node.  */
  
  struct cgraph_node *
  cgraph_node_for_asm (tree asmname)
  {
    struct cgraph_node *node;
  
    for (node = cgraph_nodes; node ; node = node->next)
      if (decl_assembler_name_equal (node->decl, asmname))
        return node;
  
    return NULL;
  }
  
  /* Returns a hash value for X (which really is a die_struct).  */
  
  static hashval_t
  edge_hash (const void *x)
  {
    return htab_hash_pointer (((const struct cgraph_edge *) x)->call_stmt);
  }
  
  /* Return nonzero if decl_id of die_struct X is the same as UID of decl *Y.  */
  
  static int
  edge_eq (const void *x, const void *y)
  {
    return ((const struct cgraph_edge *) x)->call_stmt == y;
  }
  
  /* Return callgraph edge representing CALL_EXPR statement.  */
  struct cgraph_edge *
  cgraph_edge (struct cgraph_node *node, tree call_stmt)
  {
    struct cgraph_edge *e, *e2;
    int n = 0;
  
    if (node->call_site_hash)
      return htab_find_with_hash (node->call_site_hash, call_stmt,
        				htab_hash_pointer (call_stmt));
  
    /* This loop may turn out to be performance problem.  In such case adding
       hashtables into call nodes with very many edges is probably best
       solution.  It is not good idea to add pointer into CALL_EXPR itself
       because we want to make possible having multiple cgraph nodes representing
       different clones of the same body before the body is actually cloned.  */
    for (e = node->callees; e; e= e->next_callee)
      {
        if (e->call_stmt == call_stmt)
  	break;
        n++;
      }
    if (n > 100)
      {
        node->call_site_hash = htab_create_ggc (120, edge_hash, edge_eq, NULL);
        for (e2 = node->callees; e2; e2 = e2->next_callee)
  	{
            void **slot;
  	  slot = htab_find_slot_with_hash (node->call_site_hash,
  					   e2->call_stmt,
  					   htab_hash_pointer (e2->call_stmt),
  					   INSERT);
  	  gcc_assert (!*slot);
  	  *slot = e2;
  	}
      }
    return e;
  }
  
  /* Change call_smtt of edge E to NEW_STMT.  */
  
  void
  cgraph_set_call_stmt (struct cgraph_edge *e, tree new_stmt)
  {
    if (e->caller->call_site_hash)
      {
        htab_remove_elt_with_hash (e->caller->call_site_hash,
  				 e->call_stmt,
  				 htab_hash_pointer (e->call_stmt));
      }
    e->call_stmt = new_stmt;
    if (e->caller->call_site_hash)
      {
        void **slot;
        slot = htab_find_slot_with_hash (e->caller->call_site_hash,
  				       e->call_stmt,
  				       htab_hash_pointer
  				       (e->call_stmt), INSERT);
        gcc_assert (!*slot);
        *slot = e;
      }
  }
  
  /* Create edge from CALLER to CALLEE in the cgraph.  */
  
  struct cgraph_edge *
  cgraph_create_edge (struct cgraph_node *caller, struct cgraph_node *callee,
  		    tree call_stmt, gcov_type count, int freq, int nest)
  {
    struct cgraph_edge *edge = GGC_NEW (struct cgraph_edge);
  #ifdef ENABLE_CHECKING
    struct cgraph_edge *e;
  
    for (e = caller->callees; e; e = e->next_callee)
      gcc_assert (e->call_stmt != call_stmt);
  #endif
  
    gcc_assert (get_call_expr_in (call_stmt));
  
    if (!DECL_SAVED_TREE (callee->decl))
      edge->inline_failed = N_("function body not available");
    else if (callee->local.redefined_extern_inline)
      edge->inline_failed = N_("redefined extern inline functions are not "
  			     "considered for inlining");
    else if (callee->local.inlinable)
      edge->inline_failed = N_("function not considered for inlining");
    else
      edge->inline_failed = N_("function not inlinable");
  
    edge->aux = NULL;
  
    edge->caller = caller;
    edge->callee = callee;
    edge->call_stmt = call_stmt;
    edge->prev_caller = NULL;
    edge->next_caller = callee->callers;
    if (callee->callers)
      callee->callers->prev_caller = edge;
    edge->prev_callee = NULL;
    edge->next_callee = caller->callees;
    if (caller->callees)
      caller->callees->prev_callee = edge;
    caller->callees = edge;
    callee->callers = edge;
    edge->count = count;
    gcc_assert (count >= 0);
    edge->frequency = freq;
    gcc_assert (freq >= 0);
    gcc_assert (freq <= CGRAPH_FREQ_MAX);
    edge->loop_nest = nest;
    if (caller->call_site_hash)
      {
        void **slot;
        slot = htab_find_slot_with_hash (caller->call_site_hash,
  				       edge->call_stmt,
  				       htab_hash_pointer
  					 (edge->call_stmt),
  				       INSERT);
        gcc_assert (!*slot);
        *slot = edge;
      }
    return edge;
  }
  
  /* Remove the edge E from the list of the callers of the callee.  */
  
  static inline void
  cgraph_edge_remove_callee (struct cgraph_edge *e)
  {
    if (e->prev_caller)
      e->prev_caller->next_caller = e->next_caller;
    if (e->next_caller)
      e->next_caller->prev_caller = e->prev_caller;
    if (!e->prev_caller)
      e->callee->callers = e->next_caller;
  }
  
  /* Remove the edge E from the list of the callees of the caller.  */
  
  static inline void
  cgraph_edge_remove_caller (struct cgraph_edge *e)
  {
    if (e->prev_callee)
      e->prev_callee->next_callee = e->next_callee;
    if (e->next_callee)
      e->next_callee->prev_callee = e->prev_callee;
    if (!e->prev_callee)
      e->caller->callees = e->next_callee;
    if (e->caller->call_site_hash)
      htab_remove_elt_with_hash (e->caller->call_site_hash,
  			       e->call_stmt,
  	  		       htab_hash_pointer (e->call_stmt));
  }
  
  /* Remove the edge E in the cgraph.  */
  
  void
  cgraph_remove_edge (struct cgraph_edge *e)
  {
    /* Remove from callers list of the callee.  */
    cgraph_edge_remove_callee (e);
  
    /* Remove from callees list of the callers.  */
    cgraph_edge_remove_caller (e);
  }
  
  /* Redirect callee of E to N.  The function does not update underlying
     call expression.  */
  
  void
  cgraph_redirect_edge_callee (struct cgraph_edge *e, struct cgraph_node *n)
  {
    /* Remove from callers list of the current callee.  */
    cgraph_edge_remove_callee (e);
  
    /* Insert to callers list of the new callee.  */
    e->prev_caller = NULL;
    if (n->callers)
      n->callers->prev_caller = e;
    e->next_caller = n->callers;
    n->callers = e;
    e->callee = n;
  }
  
  /* Update or remove corresponding cgraph edge if a call OLD_CALL
     in OLD_STMT changed into NEW_STMT.  */
  
  void
  cgraph_update_edges_for_call_stmt (tree old_stmt, tree old_call,
  				   tree new_stmt)
  {
    tree new_call = get_call_expr_in (new_stmt);
    struct cgraph_node *node = cgraph_node (cfun->decl);
  
    if (old_call != new_call)
      {
        struct cgraph_edge *e = cgraph_edge (node, old_stmt);
        struct cgraph_edge *ne = NULL;
        tree new_decl;
  
        if (e)
  	{
  	  gcov_type count = e->count;
  	  int frequency = e->frequency;
  	  int loop_nest = e->loop_nest;
  
  	  cgraph_remove_edge (e);
  	  if (new_call)
  	    {
  	      new_decl = get_callee_fndecl (new_call);
  	      if (new_decl)
  		{
  		  ne = cgraph_create_edge (node, cgraph_node (new_decl),
  					   new_stmt, count, frequency,
  					   loop_nest);
  		  gcc_assert (ne->inline_failed);
  		}
  	    }
  	}
      }
    else if (old_stmt != new_stmt)
      {
        struct cgraph_edge *e = cgraph_edge (node, old_stmt);
  
        if (e)
  	cgraph_set_call_stmt (e, new_stmt);
      }
  }
  
  /* Remove all callees from the node.  */
  
  void
  cgraph_node_remove_callees (struct cgraph_node *node)
  {
    struct cgraph_edge *e;
  
    /* It is sufficient to remove the edges from the lists of callers of
       the callees.  The callee list of the node can be zapped with one
       assignment.  */
    for (e = node->callees; e; e = e->next_callee)
      cgraph_edge_remove_callee (e);
    node->callees = NULL;
    if (node->call_site_hash)
      {
        htab_delete (node->call_site_hash);
        node->call_site_hash = NULL;
      }
  }
  
  /* Remove all callers from the node.  */
  
  static void
  cgraph_node_remove_callers (struct cgraph_node *node)
  {
    struct cgraph_edge *e;
  
    /* It is sufficient to remove the edges from the lists of callees of
       the callers.  The caller list of the node can be zapped with one
       assignment.  */
    for (e = node->callers; e; e = e->next_caller)
      cgraph_edge_remove_caller (e);
    node->callers = NULL;
  }
  
  /* Release memory used to represent body of function NODE.  */
  
  void
  cgraph_release_function_body (struct cgraph_node *node)
  {
    if (DECL_STRUCT_FUNCTION (node->decl)
        && DECL_STRUCT_FUNCTION (node->decl)->gimple_df)
      {
        tree old_decl = current_function_decl;
        push_cfun (DECL_STRUCT_FUNCTION (node->decl));
        current_function_decl = node->decl;
        delete_tree_ssa ();
        delete_tree_cfg_annotations ();
        cfun->eh = NULL;
        current_function_decl = old_decl;
        pop_cfun();
      }
    DECL_SAVED_TREE (node->decl) = NULL;
    DECL_STRUCT_FUNCTION (node->decl) = NULL;
    /* If the node is abstract and needed, then do not clear DECL_INITIAL
       of its associated function function declaration because it's
       needed to emit debug info later.  */
    if (!node->abstract_and_needed)
      DECL_INITIAL (node->decl) = error_mark_node;
  }
  
  /* Remove the node from cgraph.  */
  
  void
  cgraph_remove_node (struct cgraph_node *node)
  {
    void **slot;
    bool kill_body = false;
  
    cgraph_node_remove_callers (node);
    cgraph_node_remove_callees (node);
    /* Incremental inlining access removed nodes stored in the postorder list.
       */
    node->needed = node->reachable = false;
    while (node->nested)
      cgraph_remove_node (node->nested);
    if (node->origin)
      {
        struct cgraph_node **node2 = &node->origin->nested;
  
        while (*node2 != node)
  	node2 = &(*node2)->next_nested;
        *node2 = node->next_nested;
      }
    if (node->previous)
      node->previous->next = node->next;
    else
      cgraph_nodes = node->next;
    if (node->next)
      node->next->previous = node->previous;
    node->next = NULL;
    node->previous = NULL;
    slot = htab_find_slot (cgraph_hash, node, NO_INSERT);
    if (*slot == node)
      {
        if (node->next_clone)
        {
  	struct cgraph_node *new_node = node->next_clone;
  	struct cgraph_node *n;
  
  	/* Make the next clone be the master clone */
  	for (n = new_node; n; n = n->next_clone)
  	  n->master_clone = new_node;
  
  	*slot = new_node;
  	node->next_clone->prev_clone = NULL;
        }
        else
  	{
  	  htab_clear_slot (cgraph_hash, slot);
  	  kill_body = true;
  	}
      }
    else
      {
        node->prev_clone->next_clone = node->next_clone;
        if (node->next_clone)
  	node->next_clone->prev_clone = node->prev_clone;
      }
  
    /* While all the clones are removed after being proceeded, the function
       itself is kept in the cgraph even after it is compiled.  Check whether
       we are done with this body and reclaim it proactively if this is the case.
       */
    if (!kill_body && *slot)
      {
        struct cgraph_node *n = (struct cgraph_node *) *slot;
        if (!n->next_clone && !n->global.inlined_to
  	  && (cgraph_global_info_ready
  	      && (TREE_ASM_WRITTEN (n->decl) || DECL_EXTERNAL (n->decl))))
  	kill_body = true;
      }
  
    if (kill_body && flag_unit_at_a_time)
      cgraph_release_function_body (node);
    node->decl = NULL;
    if (node->call_site_hash)
      {
        htab_delete (node->call_site_hash);
        node->call_site_hash = NULL;
      }
    cgraph_n_nodes--;
    /* Do not free the structure itself so the walk over chain can continue.  */
  }
  
  /* Notify finalize_compilation_unit that given node is reachable.  */
  
  void
  cgraph_mark_reachable_node (struct cgraph_node *node)
  {
    if (!node->reachable && node->local.finalized)
      {
        notice_global_symbol (node->decl);
        node->reachable = 1;
        gcc_assert (!cgraph_global_info_ready);
  
        node->next_needed = cgraph_nodes_queue;
        cgraph_nodes_queue = node;
      }
  }
  
  /* Likewise indicate that a node is needed, i.e. reachable via some
     external means.  */
  
  void
  cgraph_mark_needed_node (struct cgraph_node *node)
  {
    node->needed = 1;
    cgraph_mark_reachable_node (node);
  }
  
  /* Return local info for the compiled function.  */
  
  struct cgraph_local_info *
  cgraph_local_info (tree decl)
  {
    struct cgraph_node *node;
  
    gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
    node = cgraph_node (decl);
    return &node->local;
  }
  
  /* Return local info for the compiled function.  */
  
  struct cgraph_global_info *
  cgraph_global_info (tree decl)
  {
    struct cgraph_node *node;
  
    gcc_assert (TREE_CODE (decl) == FUNCTION_DECL && cgraph_global_info_ready);
    node = cgraph_node (decl);
    return &node->global;
  }
  
  /* Return local info for the compiled function.  */
  
  struct cgraph_rtl_info *
  cgraph_rtl_info (tree decl)
  {
    struct cgraph_node *node;
  
    gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
    node = cgraph_node (decl);
    if (decl != current_function_decl
        && !TREE_ASM_WRITTEN (node->decl))
      return NULL;
    return &node->rtl;
  }
  
  /* Return name of the node used in debug output.  */
  const char *
  cgraph_node_name (struct cgraph_node *node)
  {
    return lang_hooks.decl_printable_name (node->decl, 2);
  }
  
  /* Names used to print out the availability enum.  */
  const char * const cgraph_availability_names[] =
    {"unset", "not_available", "overwrittable", "available", "local"};
  
  
  /* Dump call graph node NODE to file F.  */
  
  void
  dump_cgraph_node (FILE *f, struct cgraph_node *node)
  {
    struct cgraph_edge *edge;
    fprintf (f, "%s/%i(%i):", cgraph_node_name (node), node->uid, node->pid);
    if (node->global.inlined_to)
      fprintf (f, " (inline copy in %s/%i)",
  	     cgraph_node_name (node->global.inlined_to),
  	     node->global.inlined_to->uid);
    if (cgraph_function_flags_ready)
      fprintf (f, " availability:%s",
  	     cgraph_availability_names [cgraph_function_body_availability (node)]);
    if (node->master_clone && node->master_clone->uid != node->uid)
      fprintf (f, "(%i)", node->master_clone->uid);
    if (node->count)
      fprintf (f, " executed "HOST_WIDEST_INT_PRINT_DEC"x",
  	     (HOST_WIDEST_INT)node->count);
    if (node->local.self_insns)
      fprintf (f, " %i insns", node->local.self_insns);
    if (node->global.insns && node->global.insns != node->local.self_insns)
      fprintf (f, " (%i after inlining)", node->global.insns);
    if (node->local.estimated_self_stack_size)
      fprintf (f, " %i bytes stack usage", (int)node->local.estimated_self_stack_size);
    if (node->global.estimated_stack_size != node->local.estimated_self_stack_size)
      fprintf (f, " %i bytes after inlining", (int)node->global.estimated_stack_size);
    if (node->origin)
      fprintf (f, " nested in: %s", cgraph_node_name (node->origin));
    if (node->needed)
      fprintf (f, " needed");
    else if (node->reachable)
      fprintf (f, " reachable");
    if (DECL_SAVED_TREE (node->decl))
      fprintf (f, " tree");
    if (node->output)
      fprintf (f, " output");
    if (node->local.local)
      fprintf (f, " local");
    if (node->local.externally_visible)
      fprintf (f, " externally_visible");
    if (node->local.finalized)
      fprintf (f, " finalized");
    if (node->local.disregard_inline_limits)
      fprintf (f, " always_inline");
    else if (node->local.inlinable)
      fprintf (f, " inlinable");
    if (node->local.redefined_extern_inline)
      fprintf (f, " redefined_extern_inline");
    if (TREE_ASM_WRITTEN (node->decl))
      fprintf (f, " asm_written");
  
    fprintf (f, "\n  called by: ");
    for (edge = node->callers; edge; edge = edge->next_caller)
      {
        fprintf (f, "%s/%i ", cgraph_node_name (edge->caller),
  	       edge->caller->uid);
        if (edge->count)
  	fprintf (f, "("HOST_WIDEST_INT_PRINT_DEC"x) ",
  		 (HOST_WIDEST_INT)edge->count);
        if (edge->frequency)
  	fprintf (f, "(%.2f per call) ",
  		 edge->frequency / (double)CGRAPH_FREQ_BASE);
        if (!edge->inline_failed)
  	fprintf(f, "(inlined) ");
      }
  
    fprintf (f, "\n  calls: ");
    for (edge = node->callees; edge; edge = edge->next_callee)
      {
        fprintf (f, "%s/%i ", cgraph_node_name (edge->callee),
  	       edge->callee->uid);
        if (!edge->inline_failed)
  	fprintf(f, "(inlined) ");
        if (edge->count)
  	fprintf (f, "("HOST_WIDEST_INT_PRINT_DEC"x) ",
  		 (HOST_WIDEST_INT)edge->count);
        if (edge->frequency)
  	fprintf (f, "(%.2f per call) ",
  		 edge->frequency / (double)CGRAPH_FREQ_BASE);
        if (edge->loop_nest)
  	fprintf (f, "(nested in %i loops) ", edge->loop_nest);
      }
    fprintf (f, "\n");
  }
  
  
  /* Dump call graph node NODE to stderr.  */
  
  void
  debug_cgraph_node (struct cgraph_node *node)
  {
    dump_cgraph_node (stderr, node);
  }
  
  
  /* Dump the callgraph to file F.  */
  
  void
  dump_cgraph (FILE *f)
  {
    struct cgraph_node *node;
  
    fprintf (f, "callgraph:\n\n");
    for (node = cgraph_nodes; node; node = node->next)
      dump_cgraph_node (f, node);
  }
  
  
  /* Dump the call graph to stderr.  */
  
  void
  debug_cgraph (void)
  {
    dump_cgraph (stderr);
  }
  
  
  /* Set the DECL_ASSEMBLER_NAME and update cgraph hashtables.  */
  
  void
  change_decl_assembler_name (tree decl, tree name)
  {
    if (!DECL_ASSEMBLER_NAME_SET_P (decl))
      {
        SET_DECL_ASSEMBLER_NAME (decl, name);
        return;
      }
    if (name == DECL_ASSEMBLER_NAME (decl))
      return;
  
    if (TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl))
        && DECL_RTL_SET_P (decl))
      warning (0, "%D renamed after being referenced in assembly", decl);
  
    SET_DECL_ASSEMBLER_NAME (decl, name);
  }
  
  /* Add a top-level asm statement to the list.  */
  
  struct cgraph_asm_node *
  cgraph_add_asm_node (tree asm_str)
  {
    struct cgraph_asm_node *node;
  
    node = GGC_CNEW (struct cgraph_asm_node);
    node->asm_str = asm_str;
    node->order = cgraph_order++;
    node->next = NULL;
    if (cgraph_asm_nodes == NULL)
      cgraph_asm_nodes = node;
    else
      cgraph_asm_last_node->next = node;
    cgraph_asm_last_node = node;
    return node;
  }
  
  /* Return true when the DECL can possibly be inlined.  */
  bool
  cgraph_function_possibly_inlined_p (tree decl)
  {
    if (!cgraph_global_info_ready)
      return (DECL_INLINE (decl) && !flag_really_no_inline);
    return DECL_POSSIBLY_INLINED (decl);
  }
  
  /* Create clone of E in the node N represented by CALL_EXPR the callgraph.  */
  struct cgraph_edge *
  cgraph_clone_edge (struct cgraph_edge *e, struct cgraph_node *n,
  		   tree call_stmt, gcov_type count_scale, int freq_scale,
  		   int loop_nest, bool update_original)
  {
    struct cgraph_edge *new;
    gcov_type count = e->count * count_scale / REG_BR_PROB_BASE;
    gcov_type freq = e->frequency * (gcov_type) freq_scale / CGRAPH_FREQ_BASE;
  
    if (freq > CGRAPH_FREQ_MAX)
      freq = CGRAPH_FREQ_MAX;
    new = cgraph_create_edge (n, e->callee, call_stmt, count, freq,
  			    e->loop_nest + loop_nest);
  
    new->inline_failed = e->inline_failed;
    if (update_original)
      {
        e->count -= new->count;
        if (e->count < 0)
  	e->count = 0;
      }
    return new;
  }
  
  /* Create node representing clone of N executed COUNT times.  Decrease
     the execution counts from original node too.
  
     When UPDATE_ORIGINAL is true, the counts are subtracted from the original
     function's profile to reflect the fact that part of execution is handled
     by node.  */
  struct cgraph_node *
  cgraph_clone_node (struct cgraph_node *n, gcov_type count, int freq, int loop_nest,
  		   bool update_original)
  {
    struct cgraph_node *new = cgraph_create_node ();
    struct cgraph_edge *e;
    gcov_type count_scale;
  
    new->decl = n->decl;
    new->origin = n->origin;
    if (new->origin)
      {
        new->next_nested = new->origin->nested;
        new->origin->nested = new;
      }
    new->analyzed = n->analyzed;
    new->local = n->local;
    new->global = n->global;
    new->rtl = n->rtl;
    new->master_clone = n->master_clone;
    new->count = count;
    if (n->count)
      count_scale = new->count * REG_BR_PROB_BASE / n->count;
    else
      count_scale = 0;
    if (update_original)
      {
        n->count -= count;
        if (n->count < 0)
  	n->count = 0;
      }
  
    for (e = n->callees;e; e=e->next_callee)
      cgraph_clone_edge (e, new, e->call_stmt, count_scale, freq, loop_nest,
  		       update_original);
  
    new->next_clone = n->next_clone;
    new->prev_clone = n;
    n->next_clone = new;
    if (new->next_clone)
      new->next_clone->prev_clone = new;
  
    return new;
  }
  
  /* Return true if N is an master_clone, (see cgraph_master_clone).  */
  
  bool
  cgraph_is_master_clone (struct cgraph_node *n)
  {
    return (n == cgraph_master_clone (n));
  }
  
  struct cgraph_node *
  cgraph_master_clone (struct cgraph_node *n)
  {
    enum availability avail = cgraph_function_body_availability (n);
  
    if (avail == AVAIL_NOT_AVAILABLE || avail == AVAIL_OVERWRITABLE)
      return NULL;
  
    if (!n->master_clone)
      n->master_clone = cgraph_node (n->decl);
  
    return n->master_clone;
  }
  
  /* NODE is no longer nested function; update cgraph accordingly.  */
  void
  cgraph_unnest_node (struct cgraph_node *node)
  {
    struct cgraph_node **node2 = &node->origin->nested;
    gcc_assert (node->origin);
  
    while (*node2 != node)
      node2 = &(*node2)->next_nested;
    *node2 = node->next_nested;
    node->origin = NULL;
  }
  
  /* Return function availability.  See cgraph.h for description of individual
     return values.  */
  enum availability
  cgraph_function_body_availability (struct cgraph_node *node)
  {
    enum availability avail;
    gcc_assert (cgraph_function_flags_ready);
    if (!node->analyzed)
      avail = AVAIL_NOT_AVAILABLE;
    else if (node->local.local)
      avail = AVAIL_LOCAL;
    else if (node->local.externally_visible)
      avail = AVAIL_AVAILABLE;
  
    /* If the function can be overwritten, return OVERWRITABLE.  Take
       care at least of two notable extensions - the COMDAT functions
       used to share template instantiations in C++ (this is symmetric
       to code cp_cannot_inline_tree_fn and probably shall be shared and
       the inlinability hooks completely eliminated).
  
       ??? Does the C++ one definition rule allow us to always return
       AVAIL_AVAILABLE here?  That would be good reason to preserve this
       hook Similarly deal with extern inline functions - this is again
       necessary to get C++ shared functions having keyed templates
       right and in the C extension documentation we probably should
       document the requirement of both versions of function (extern
       inline and offline) having same side effect characteristics as
       good optimization is what this optimization is about.  */
  
    else if (!(*targetm.binds_local_p) (node->decl)
  	   && !DECL_COMDAT (node->decl) && !DECL_EXTERNAL (node->decl))
      avail = AVAIL_OVERWRITABLE;
    else avail = AVAIL_AVAILABLE;
  
    return avail;
  }
  
  /* Add the function FNDECL to the call graph.
     Unlike cgraph_finalize_function, this function is intended to be used
     by middle end and allows insertion of new function at arbitrary point
     of compilation.  The function can be either in high, low or SSA form
     GIMPLE.
  
     The function is assumed to be reachable and have address taken (so no
     API breaking optimizations are performed on it).  
  
     Main work done by this function is to enqueue the function for later
     processing to avoid need the passes to be re-entrant.  */
  
  void
  cgraph_add_new_function (tree fndecl, bool lowered)
  {
    struct cgraph_node *node;
    switch (cgraph_state)
      {
        case CGRAPH_STATE_CONSTRUCTION:
  	/* Just enqueue function to be processed at nearest occurence.  */
  	node = cgraph_node (fndecl);
  	node->next_needed = cgraph_new_nodes;
  	if (lowered)
  	  node->lowered = true;
  	cgraph_new_nodes = node;
          break;
  
        case CGRAPH_STATE_IPA:
        case CGRAPH_STATE_IPA_SSA:
        case CGRAPH_STATE_EXPANSION:
  	/* Bring the function into finalized state and enqueue for later
  	   analyzing and compilation.  */
  	node = cgraph_node (fndecl);
  	node->local.local = false;
  	node->local.finalized = true;
  	node->reachable = node->needed = true;
  	if (lowered)
  	  node->lowered = true;
  	node->next_needed = cgraph_new_nodes;
  	cgraph_new_nodes = node;
          break;
  
        case CGRAPH_STATE_FINISHED:
  	/* At the very end of compilation we have to do all the work up
  	   to expansion.  */
  	push_cfun (DECL_STRUCT_FUNCTION (fndecl));
  	current_function_decl = fndecl;
  	tree_register_cfg_hooks ();
  	if (!lowered)
            tree_lowering_passes (fndecl);
  	bitmap_obstack_initialize (NULL);
  	if (!gimple_in_ssa_p (DECL_STRUCT_FUNCTION (fndecl)) && optimize)
  	  execute_pass_list (pass_early_local_passes.sub);
  	bitmap_obstack_release (NULL);
  	tree_rest_of_compilation (fndecl);
  	pop_cfun ();
  	current_function_decl = NULL;
  	break;
      }
  }
  
  #include "gt-cgraph.h"
  