tree-flow-inline.h

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/* Inline functions for tree-flow.h
   Copyright (C) 2001-2013 Free Software Foundation, Inc.
   Contributed by Diego Novillo <dnovillo@redhat.com>

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/>.  */

#ifndef _TREE_FLOW_INLINE_H
#define _TREE_FLOW_INLINE_H 1

/* Inline functions for manipulating various data structures defined in
   tree-flow.h.  See tree-flow.h for documentation.  */

/* Return true when gimple SSA form was built.
   gimple_in_ssa_p is queried by gimplifier in various early stages before SSA
   infrastructure is initialized.  Check for presence of the datastructures
   at first place.  */
static inline bool
gimple_in_ssa_p (const struct function *fun)
{
  return fun && fun->gimple_df && fun->gimple_df->in_ssa_p;
}

/* Artificial variable used for the virtual operand FUD chain.  */
static inline tree
gimple_vop (const struct function *fun)
{
  gcc_checking_assert (fun && fun->gimple_df);
  return fun->gimple_df->vop;
}

/* Initialize the hashtable iterator HTI to point to hashtable TABLE */

static inline void *
first_htab_element (htab_iterator *hti, htab_t table)
{
  hti->htab = table;
  hti->slot = table->entries;
  hti->limit = hti->slot + htab_size (table);
  do
    {
      PTR x = *(hti->slot);
      if (x != HTAB_EMPTY_ENTRY && x != HTAB_DELETED_ENTRY)
        break;
    } while (++(hti->slot) < hti->limit);

  if (hti->slot < hti->limit)
    return *(hti->slot);
  return NULL;
}

/* Return current non-empty/deleted slot of the hashtable pointed to by HTI,
   or NULL if we have  reached the end.  */

static inline bool
end_htab_p (const htab_iterator *hti)
{
  if (hti->slot >= hti->limit)
    return true;
  return false;
}

/* Advance the hashtable iterator pointed to by HTI to the next element of the
   hashtable.  */

static inline void *
next_htab_element (htab_iterator *hti)
{
  while (++(hti->slot) < hti->limit)
    {
      PTR x = *(hti->slot);
      if (x != HTAB_EMPTY_ENTRY && x != HTAB_DELETED_ENTRY)
        return x;
    };
  return NULL;
}

/* Get the number of the next statement uid to be allocated.  */
static inline unsigned int
gimple_stmt_max_uid (struct function *fn)
{
  return fn->last_stmt_uid;
}

/* Set the number of the next statement uid to be allocated.  */
static inline void
set_gimple_stmt_max_uid (struct function *fn, unsigned int maxid)
{
  fn->last_stmt_uid = maxid;
}

/* Set the number of the next statement uid to be allocated.  */
static inline unsigned int
inc_gimple_stmt_max_uid (struct function *fn)
{
  return fn->last_stmt_uid++;
}

/* Return the line number for EXPR, or return -1 if we have no line
   number information for it.  */
static inline int
get_lineno (const_gimple stmt)
{
  location_t loc;

  if (!stmt)
    return -1;

  loc = gimple_location (stmt);
  if (loc == UNKNOWN_LOCATION)
    return -1;

  return LOCATION_LINE (loc);
}

/* Delink an immediate_uses node from its chain.  */
static inline void
delink_imm_use (ssa_use_operand_t *linknode)
{
  /* Return if this node is not in a list.  */
  if (linknode->prev == NULL)
    return;

  linknode->prev->next = linknode->next;
  linknode->next->prev = linknode->prev;
  linknode->prev = NULL;
  linknode->next = NULL;
}

/* Link ssa_imm_use node LINKNODE into the chain for LIST.  */
static inline void
link_imm_use_to_list (ssa_use_operand_t *linknode, ssa_use_operand_t *list)
{
  /* Link the new node at the head of the list.  If we are in the process of
     traversing the list, we won't visit any new nodes added to it.  */
  linknode->prev = list;
  linknode->next = list->next;
  list->next->prev = linknode;
  list->next = linknode;
}

/* Link ssa_imm_use node LINKNODE into the chain for DEF.  */
static inline void
link_imm_use (ssa_use_operand_t *linknode, tree def)
{
  ssa_use_operand_t *root;

  if (!def || TREE_CODE (def) != SSA_NAME)
    linknode->prev = NULL;
  else
    {
      root = &(SSA_NAME_IMM_USE_NODE (def));
      if (linknode->use)
        gcc_checking_assert (*(linknode->use) == def);
      link_imm_use_to_list (linknode, root);
    }
}

/* Set the value of a use pointed to by USE to VAL.  */
static inline void
set_ssa_use_from_ptr (use_operand_p use, tree val)
{
  delink_imm_use (use);
  *(use->use) = val;
  link_imm_use (use, val);
}

/* Link ssa_imm_use node LINKNODE into the chain for DEF, with use occurring
   in STMT.  */
static inline void
link_imm_use_stmt (ssa_use_operand_t *linknode, tree def, gimple stmt)
{
  if (stmt)
    link_imm_use (linknode, def);
  else
    link_imm_use (linknode, NULL);
  linknode->loc.stmt = stmt;
}

/* Relink a new node in place of an old node in the list.  */
static inline void
relink_imm_use (ssa_use_operand_t *node, ssa_use_operand_t *old)
{
  /* The node one had better be in the same list.  */
  gcc_checking_assert (*(old->use) == *(node->use));
  node->prev = old->prev;
  node->next = old->next;
  if (old->prev)
    {
      old->prev->next = node;
      old->next->prev = node;
      /* Remove the old node from the list.  */
      old->prev = NULL;
    }
}

/* Relink ssa_imm_use node LINKNODE into the chain for OLD, with use occurring
   in STMT.  */
static inline void
relink_imm_use_stmt (ssa_use_operand_t *linknode, ssa_use_operand_t *old,
                     gimple stmt)
{
  if (stmt)
    relink_imm_use (linknode, old);
  else
    link_imm_use (linknode, NULL);
  linknode->loc.stmt = stmt;
}


/* Return true is IMM has reached the end of the immediate use list.  */
static inline bool
end_readonly_imm_use_p (const imm_use_iterator *imm)
{
  return (imm->imm_use == imm->end_p);
}

/* Initialize iterator IMM to process the list for VAR.  */
static inline use_operand_p
first_readonly_imm_use (imm_use_iterator *imm, tree var)
{
  imm->end_p = &(SSA_NAME_IMM_USE_NODE (var));
  imm->imm_use = imm->end_p->next;
#ifdef ENABLE_CHECKING
  imm->iter_node.next = imm->imm_use->next;
#endif
  if (end_readonly_imm_use_p (imm))
    return NULL_USE_OPERAND_P;
  return imm->imm_use;
}

/* Bump IMM to the next use in the list.  */
static inline use_operand_p
next_readonly_imm_use (imm_use_iterator *imm)
{
  use_operand_p old = imm->imm_use;

#ifdef ENABLE_CHECKING
  /* If this assertion fails, it indicates the 'next' pointer has changed
     since the last bump.  This indicates that the list is being modified
     via stmt changes, or SET_USE, or somesuch thing, and you need to be
     using the SAFE version of the iterator.  */
  gcc_assert (imm->iter_node.next == old->next);
  imm->iter_node.next = old->next->next;
#endif

  imm->imm_use = old->next;
  if (end_readonly_imm_use_p (imm))
    return NULL_USE_OPERAND_P;
  return imm->imm_use;
}

/* tree-cfg.c */
extern bool has_zero_uses_1 (const ssa_use_operand_t *head);
extern bool single_imm_use_1 (const ssa_use_operand_t *head,
                              use_operand_p *use_p, gimple *stmt);

/* Return true if VAR has no nondebug uses.  */
static inline bool
has_zero_uses (const_tree var)
{
  const ssa_use_operand_t *const ptr = &(SSA_NAME_IMM_USE_NODE (var));

  /* A single use_operand means there is no items in the list.  */
  if (ptr == ptr->next)
    return true;

  /* If there are debug stmts, we have to look at each use and see
     whether there are any nondebug uses.  */
  if (!MAY_HAVE_DEBUG_STMTS)
    return false;

  return has_zero_uses_1 (ptr);
}

/* Return true if VAR has a single nondebug use.  */
static inline bool
has_single_use (const_tree var)
{
  const ssa_use_operand_t *const ptr = &(SSA_NAME_IMM_USE_NODE (var));

  /* If there aren't any uses whatsoever, we're done.  */
  if (ptr == ptr->next)
    return false;

  /* If there's a single use, check that it's not a debug stmt.  */
  if (ptr == ptr->next->next)
    return !is_gimple_debug (USE_STMT (ptr->next));

  /* If there are debug stmts, we have to look at each of them.  */
  if (!MAY_HAVE_DEBUG_STMTS)
    return false;

  return single_imm_use_1 (ptr, NULL, NULL);
}


/* If VAR has only a single immediate nondebug use, return true, and
   set USE_P and STMT to the use pointer and stmt of occurrence.  */
static inline bool
single_imm_use (const_tree var, use_operand_p *use_p, gimple *stmt)
{
  const ssa_use_operand_t *const ptr = &(SSA_NAME_IMM_USE_NODE (var));

  /* If there aren't any uses whatsoever, we're done.  */
  if (ptr == ptr->next)
    {
    return_false:
      *use_p = NULL_USE_OPERAND_P;
      *stmt = NULL;
      return false;
    }

  /* If there's a single use, check that it's not a debug stmt.  */
  if (ptr == ptr->next->next)
    {
      if (!is_gimple_debug (USE_STMT (ptr->next)))
        {
          *use_p = ptr->next;
          *stmt = ptr->next->loc.stmt;
          return true;
        }
      else
        goto return_false;
    }

  /* If there are debug stmts, we have to look at each of them.  */
  if (!MAY_HAVE_DEBUG_STMTS)
    goto return_false;

  return single_imm_use_1 (ptr, use_p, stmt);
}

/* Return the number of nondebug immediate uses of VAR.  */
static inline unsigned int
num_imm_uses (const_tree var)
{
  const ssa_use_operand_t *const start = &(SSA_NAME_IMM_USE_NODE (var));
  const ssa_use_operand_t *ptr;
  unsigned int num = 0;

  if (!MAY_HAVE_DEBUG_STMTS)
    for (ptr = start->next; ptr != start; ptr = ptr->next)
      num++;
  else
    for (ptr = start->next; ptr != start; ptr = ptr->next)
      if (!is_gimple_debug (USE_STMT (ptr)))
        num++;

  return num;
}

/* Return the tree pointed-to by USE.  */
static inline tree
get_use_from_ptr (use_operand_p use)
{
  return *(use->use);
}

/* Return the tree pointed-to by DEF.  */
static inline tree
get_def_from_ptr (def_operand_p def)
{
  return *def;
}

/* Return a use_operand_p pointer for argument I of PHI node GS.  */

static inline use_operand_p
gimple_phi_arg_imm_use_ptr (gimple gs, int i)
{
  return &gimple_phi_arg (gs, i)->imm_use;
}

/* Return the tree operand for argument I of PHI node GS.  */

static inline tree
gimple_phi_arg_def (gimple gs, size_t index)
{
  struct phi_arg_d *pd = gimple_phi_arg (gs, index);
  return get_use_from_ptr (&pd->imm_use);
}

/* Return a pointer to the tree operand for argument I of PHI node GS.  */

static inline tree *
gimple_phi_arg_def_ptr (gimple gs, size_t index)
{
  return &gimple_phi_arg (gs, index)->def;
}

/* Return the edge associated with argument I of phi node GS.  */

static inline edge
gimple_phi_arg_edge (gimple gs, size_t i)
{
  return EDGE_PRED (gimple_bb (gs), i);
}

/* Return the source location of gimple argument I of phi node GS.  */

static inline source_location
gimple_phi_arg_location (gimple gs, size_t i)
{
  return gimple_phi_arg (gs, i)->locus;
}

/* Return the source location of the argument on edge E of phi node GS.  */

static inline source_location
gimple_phi_arg_location_from_edge (gimple gs, edge e)
{
  return gimple_phi_arg (gs, e->dest_idx)->locus;
}

/* Set the source location of gimple argument I of phi node GS to LOC.  */

static inline void
gimple_phi_arg_set_location (gimple gs, size_t i, source_location loc)
{
  gimple_phi_arg (gs, i)->locus = loc;
}

/* Return TRUE if argument I of phi node GS has a location record.  */

static inline bool
gimple_phi_arg_has_location (gimple gs, size_t i)
{
  return gimple_phi_arg_location (gs, i) != UNKNOWN_LOCATION;
}


/* Return the PHI nodes for basic block BB, or NULL if there are no
   PHI nodes.  */
static inline gimple_seq
phi_nodes (const_basic_block bb)
{
  gcc_checking_assert (!(bb->flags & BB_RTL));
  return bb->il.gimple.phi_nodes;
}

static inline gimple_seq *
phi_nodes_ptr (basic_block bb)
{
  gcc_checking_assert (!(bb->flags & BB_RTL));
  return &bb->il.gimple.phi_nodes;
}

/* Set PHI nodes of a basic block BB to SEQ.  */

static inline void
set_phi_nodes (basic_block bb, gimple_seq seq)
{
  gimple_stmt_iterator i;

  gcc_checking_assert (!(bb->flags & BB_RTL));
  bb->il.gimple.phi_nodes = seq;
  if (seq)
    for (i = gsi_start (seq); !gsi_end_p (i); gsi_next (&i))
      gimple_set_bb (gsi_stmt (i), bb);
}

/* Return the phi argument which contains the specified use.  */

static inline int
phi_arg_index_from_use (use_operand_p use)
{
  struct phi_arg_d *element, *root;
  size_t index;
  gimple phi;

  /* Since the use is the first thing in a PHI argument element, we can
     calculate its index based on casting it to an argument, and performing
     pointer arithmetic.  */

  phi = USE_STMT (use);

  element = (struct phi_arg_d *)use;
  root = gimple_phi_arg (phi, 0);
  index = element - root;

  /* Make sure the calculation doesn't have any leftover bytes.  If it does,
     then imm_use is likely not the first element in phi_arg_d.  */
  gcc_checking_assert ((((char *)element - (char *)root)
                        % sizeof (struct phi_arg_d)) == 0
                       && index < gimple_phi_capacity (phi));

 return index;
}

/* Return true if T (assumed to be a DECL) is a global variable.
   A variable is considered global if its storage is not automatic.  */

static inline bool
is_global_var (const_tree t)
{
  return (TREE_STATIC (t) || DECL_EXTERNAL (t));
}


/* Return true if VAR may be aliased.  A variable is considered as
   maybe aliased if it has its address taken by the local TU
   or possibly by another TU and might be modified through a pointer.  */

static inline bool
may_be_aliased (const_tree var)
{
  return (TREE_CODE (var) != CONST_DECL
          && !((TREE_STATIC (var) || TREE_PUBLIC (var) || DECL_EXTERNAL (var))
               && TREE_READONLY (var)
               && !TYPE_NEEDS_CONSTRUCTING (TREE_TYPE (var)))
          && (TREE_PUBLIC (var)
              || DECL_EXTERNAL (var)
              || TREE_ADDRESSABLE (var)));
}


/* PHI nodes should contain only ssa_names and invariants.  A test
   for ssa_name is definitely simpler; don't let invalid contents
   slip in in the meantime.  */

static inline bool
phi_ssa_name_p (const_tree t)
{
  if (TREE_CODE (t) == SSA_NAME)
    return true;
  gcc_checking_assert (is_gimple_min_invariant (t));
  return false;
}


/* Returns the loop of the statement STMT.  */

static inline struct loop *
loop_containing_stmt (gimple stmt)
{
  basic_block bb = gimple_bb (stmt);
  if (!bb)
    return NULL;

  return bb->loop_father;
}


/*  -----------------------------------------------------------------------  */

/* The following set of routines are used to iterator over various type of
   SSA operands.  */

/* Return true if PTR is finished iterating.  */
static inline bool
op_iter_done (const ssa_op_iter *ptr)
{
  return ptr->done;
}

/* Get the next iterator use value for PTR.  */
static inline use_operand_p
op_iter_next_use (ssa_op_iter *ptr)
{
  use_operand_p use_p;
  gcc_checking_assert (ptr->iter_type == ssa_op_iter_use);
  if (ptr->uses)
    {
      use_p = USE_OP_PTR (ptr->uses);
      ptr->uses = ptr->uses->next;
      return use_p;
    }
  if (ptr->i < ptr->numops)
    {
      return PHI_ARG_DEF_PTR (ptr->stmt, (ptr->i)++);
    }
  ptr->done = true;
  return NULL_USE_OPERAND_P;
}

/* Get the next iterator def value for PTR.  */
static inline def_operand_p
op_iter_next_def (ssa_op_iter *ptr)
{
  gcc_checking_assert (ptr->iter_type == ssa_op_iter_def);
  if (ptr->flags & SSA_OP_VDEF)
    {
      tree *p;
      ptr->flags &= ~SSA_OP_VDEF;
      p = gimple_vdef_ptr (ptr->stmt);
      if (p && *p)
        return p;
    }
  if (ptr->flags & SSA_OP_DEF)
    {
      while (ptr->i < ptr->numops)
        {
          tree *val = gimple_op_ptr (ptr->stmt, ptr->i);
          ptr->i++;
          if (*val)
            {
              if (TREE_CODE (*val) == TREE_LIST)
                val = &TREE_VALUE (*val);
              if (TREE_CODE (*val) == SSA_NAME
                  || is_gimple_reg (*val))
                return val;
            }
        }
      ptr->flags &= ~SSA_OP_DEF;
    }

  ptr->done = true;
  return NULL_DEF_OPERAND_P;
}

/* Get the next iterator tree value for PTR.  */
static inline tree
op_iter_next_tree (ssa_op_iter *ptr)
{
  tree val;
  gcc_checking_assert (ptr->iter_type == ssa_op_iter_tree);
  if (ptr->uses)
    {
      val = USE_OP (ptr->uses);
      ptr->uses = ptr->uses->next;
      return val;
    }
  if (ptr->flags & SSA_OP_VDEF)
    {
      ptr->flags &= ~SSA_OP_VDEF;
      if ((val = gimple_vdef (ptr->stmt)))
        return val;
    }
  if (ptr->flags & SSA_OP_DEF)
    {
      while (ptr->i < ptr->numops)
        {
          val = gimple_op (ptr->stmt, ptr->i);
          ptr->i++;
          if (val)
            {
              if (TREE_CODE (val) == TREE_LIST)
                val = TREE_VALUE (val);
              if (TREE_CODE (val) == SSA_NAME
                  || is_gimple_reg (val))
                return val;
            }
        }
      ptr->flags &= ~SSA_OP_DEF;
    }

  ptr->done = true;
  return NULL_TREE;
}


/* This functions clears the iterator PTR, and marks it done.  This is normally
   used to prevent warnings in the compile about might be uninitialized
   components.  */

static inline void
clear_and_done_ssa_iter (ssa_op_iter *ptr)
{
  ptr->i = 0;
  ptr->numops = 0;
  ptr->uses = NULL;
  ptr->iter_type = ssa_op_iter_none;
  ptr->stmt = NULL;
  ptr->done = true;
  ptr->flags = 0;
}

/* Initialize the iterator PTR to the virtual defs in STMT.  */
static inline void
op_iter_init (ssa_op_iter *ptr, gimple stmt, int flags)
{
  /* PHI nodes require a different iterator initialization path.  We
     do not support iterating over virtual defs or uses without
     iterating over defs or uses at the same time.  */
  gcc_checking_assert (gimple_code (stmt) != GIMPLE_PHI
                       && (!(flags & SSA_OP_VDEF) || (flags & SSA_OP_DEF))
                       && (!(flags & SSA_OP_VUSE) || (flags & SSA_OP_USE)));
  ptr->numops = 0;
  if (flags & (SSA_OP_DEF | SSA_OP_VDEF))
    {
      switch (gimple_code (stmt))
        {
          case GIMPLE_ASSIGN:
          case GIMPLE_CALL:
            ptr->numops = 1;
            break;
          case GIMPLE_ASM:
            ptr->numops = gimple_asm_noutputs (stmt);
            break;
          default:
            ptr->numops = 0;
            flags &= ~(SSA_OP_DEF | SSA_OP_VDEF);
            break;
        }
    }
  ptr->uses = (flags & (SSA_OP_USE|SSA_OP_VUSE)) ? gimple_use_ops (stmt) : NULL;
  if (!(flags & SSA_OP_VUSE)
      && ptr->uses
      && gimple_vuse (stmt) != NULL_TREE)
    ptr->uses = ptr->uses->next;
  ptr->done = false;
  ptr->i = 0;

  ptr->stmt = stmt;
  ptr->flags = flags;
}

/* Initialize iterator PTR to the use operands in STMT based on FLAGS. Return
   the first use.  */
static inline use_operand_p
op_iter_init_use (ssa_op_iter *ptr, gimple stmt, int flags)
{
  gcc_checking_assert ((flags & SSA_OP_ALL_DEFS) == 0
                       && (flags & SSA_OP_USE));
  op_iter_init (ptr, stmt, flags);
  ptr->iter_type = ssa_op_iter_use;
  return op_iter_next_use (ptr);
}

/* Initialize iterator PTR to the def operands in STMT based on FLAGS. Return
   the first def.  */
static inline def_operand_p
op_iter_init_def (ssa_op_iter *ptr, gimple stmt, int flags)
{
  gcc_checking_assert ((flags & SSA_OP_ALL_USES) == 0
                       && (flags & SSA_OP_DEF));
  op_iter_init (ptr, stmt, flags);
  ptr->iter_type = ssa_op_iter_def;
  return op_iter_next_def (ptr);
}

/* Initialize iterator PTR to the operands in STMT based on FLAGS. Return
   the first operand as a tree.  */
static inline tree
op_iter_init_tree (ssa_op_iter *ptr, gimple stmt, int flags)
{
  op_iter_init (ptr, stmt, flags);
  ptr->iter_type = ssa_op_iter_tree;
  return op_iter_next_tree (ptr);
}


/* If there is a single operand in STMT matching FLAGS, return it.  Otherwise
   return NULL.  */
static inline tree
single_ssa_tree_operand (gimple stmt, int flags)
{
  tree var;
  ssa_op_iter iter;

  var = op_iter_init_tree (&iter, stmt, flags);
  if (op_iter_done (&iter))
    return NULL_TREE;
  op_iter_next_tree (&iter);
  if (op_iter_done (&iter))
    return var;
  return NULL_TREE;
}


/* If there is a single operand in STMT matching FLAGS, return it.  Otherwise
   return NULL.  */
static inline use_operand_p
single_ssa_use_operand (gimple stmt, int flags)
{
  use_operand_p var;
  ssa_op_iter iter;

  var = op_iter_init_use (&iter, stmt, flags);
  if (op_iter_done (&iter))
    return NULL_USE_OPERAND_P;
  op_iter_next_use (&iter);
  if (op_iter_done (&iter))
    return var;
  return NULL_USE_OPERAND_P;
}



/* If there is a single operand in STMT matching FLAGS, return it.  Otherwise
   return NULL.  */
static inline def_operand_p
single_ssa_def_operand (gimple stmt, int flags)
{
  def_operand_p var;
  ssa_op_iter iter;

  var = op_iter_init_def (&iter, stmt, flags);
  if (op_iter_done (&iter))
    return NULL_DEF_OPERAND_P;
  op_iter_next_def (&iter);
  if (op_iter_done (&iter))
    return var;
  return NULL_DEF_OPERAND_P;
}


/* Return true if there are zero operands in STMT matching the type
   given in FLAGS.  */
static inline bool
zero_ssa_operands (gimple stmt, int flags)
{
  ssa_op_iter iter;

  op_iter_init_tree (&iter, stmt, flags);
  return op_iter_done (&iter);
}


/* Return the number of operands matching FLAGS in STMT.  */
static inline int
num_ssa_operands (gimple stmt, int flags)
{
  ssa_op_iter iter;
  tree t;
  int num = 0;

  gcc_checking_assert (gimple_code (stmt) != GIMPLE_PHI);
  FOR_EACH_SSA_TREE_OPERAND (t, stmt, iter, flags)
    num++;
  return num;
}

static inline use_operand_p
op_iter_init_phiuse (ssa_op_iter *ptr, gimple phi, int flags);

/* Delink all immediate_use information for STMT.  */
static inline void
delink_stmt_imm_use (gimple stmt)
{
   ssa_op_iter iter;
   use_operand_p use_p;

   if (ssa_operands_active (cfun))
     FOR_EACH_PHI_OR_STMT_USE (use_p, stmt, iter, SSA_OP_ALL_USES)
       delink_imm_use (use_p);
}


/* If there is a single DEF in the PHI node which matches FLAG, return it.
   Otherwise return NULL_DEF_OPERAND_P.  */
static inline tree
single_phi_def (gimple stmt, int flags)
{
  tree def = PHI_RESULT (stmt);
  if ((flags & SSA_OP_DEF) && is_gimple_reg (def))
    return def;
  if ((flags & SSA_OP_VIRTUAL_DEFS) && !is_gimple_reg (def))
    return def;
  return NULL_TREE;
}

/* Initialize the iterator PTR for uses matching FLAGS in PHI.  FLAGS should
   be either SSA_OP_USES or SSA_OP_VIRTUAL_USES.  */
static inline use_operand_p
op_iter_init_phiuse (ssa_op_iter *ptr, gimple phi, int flags)
{
  tree phi_def = gimple_phi_result (phi);
  int comp;

  clear_and_done_ssa_iter (ptr);
  ptr->done = false;

  gcc_checking_assert ((flags & (SSA_OP_USE | SSA_OP_VIRTUAL_USES)) != 0);

  comp = (is_gimple_reg (phi_def) ? SSA_OP_USE : SSA_OP_VIRTUAL_USES);

  /* If the PHI node doesn't the operand type we care about, we're done.  */
  if ((flags & comp) == 0)
    {
      ptr->done = true;
      return NULL_USE_OPERAND_P;
    }

  ptr->stmt = phi;
  ptr->numops = gimple_phi_num_args (phi);
  ptr->iter_type = ssa_op_iter_use;
  ptr->flags = flags;
  return op_iter_next_use (ptr);
}


/* Start an iterator for a PHI definition.  */

static inline def_operand_p
op_iter_init_phidef (ssa_op_iter *ptr, gimple phi, int flags)
{
  tree phi_def = PHI_RESULT (phi);
  int comp;

  clear_and_done_ssa_iter (ptr);
  ptr->done = false;

  gcc_checking_assert ((flags & (SSA_OP_DEF | SSA_OP_VIRTUAL_DEFS)) != 0);

  comp = (is_gimple_reg (phi_def) ? SSA_OP_DEF : SSA_OP_VIRTUAL_DEFS);

  /* If the PHI node doesn't have the operand type we care about,
     we're done.  */
  if ((flags & comp) == 0)
    {
      ptr->done = true;
      return NULL_DEF_OPERAND_P;
    }

  ptr->iter_type = ssa_op_iter_def;
  /* The first call to op_iter_next_def will terminate the iterator since
     all the fields are NULL.  Simply return the result here as the first and
     therefore only result.  */
  return PHI_RESULT_PTR (phi);
}

/* Return true is IMM has reached the end of the immediate use stmt list.  */

static inline bool
end_imm_use_stmt_p (const imm_use_iterator *imm)
{
  return (imm->imm_use == imm->end_p);
}

/* Finished the traverse of an immediate use stmt list IMM by removing the
   placeholder node from the list.  */

static inline void
end_imm_use_stmt_traverse (imm_use_iterator *imm)
{
  delink_imm_use (&(imm->iter_node));
}

/* Immediate use traversal of uses within a stmt require that all the
   uses on a stmt be sequentially listed.  This routine is used to build up
   this sequential list by adding USE_P to the end of the current list
   currently delimited by HEAD and LAST_P.  The new LAST_P value is
   returned.  */

static inline use_operand_p
move_use_after_head (use_operand_p use_p, use_operand_p head,
                      use_operand_p last_p)
{
  gcc_checking_assert (USE_FROM_PTR (use_p) == USE_FROM_PTR (head));
  /* Skip head when we find it.  */
  if (use_p != head)
    {
      /* If use_p is already linked in after last_p, continue.  */
      if (last_p->next == use_p)
        last_p = use_p;
      else
        {
          /* Delink from current location, and link in at last_p.  */
          delink_imm_use (use_p);
          link_imm_use_to_list (use_p, last_p);
          last_p = use_p;
        }
    }
  return last_p;
}


/* This routine will relink all uses with the same stmt as HEAD into the list
   immediately following HEAD for iterator IMM.  */

static inline void
link_use_stmts_after (use_operand_p head, imm_use_iterator *imm)
{
  use_operand_p use_p;
  use_operand_p last_p = head;
  gimple head_stmt = USE_STMT (head);
  tree use = USE_FROM_PTR (head);
  ssa_op_iter op_iter;
  int flag;

  /* Only look at virtual or real uses, depending on the type of HEAD.  */
  flag = (is_gimple_reg (use) ? SSA_OP_USE : SSA_OP_VIRTUAL_USES);

  if (gimple_code (head_stmt) == GIMPLE_PHI)
    {
      FOR_EACH_PHI_ARG (use_p, head_stmt, op_iter, flag)
        if (USE_FROM_PTR (use_p) == use)
          last_p = move_use_after_head (use_p, head, last_p);
    }
  else
    {
      if (flag == SSA_OP_USE)
        {
          FOR_EACH_SSA_USE_OPERAND (use_p, head_stmt, op_iter, flag)
            if (USE_FROM_PTR (use_p) == use)
              last_p = move_use_after_head (use_p, head, last_p);
        }
      else if ((use_p = gimple_vuse_op (head_stmt)) != NULL_USE_OPERAND_P)
        {
          if (USE_FROM_PTR (use_p) == use)
            last_p = move_use_after_head (use_p, head, last_p);
        }
    }
  /* Link iter node in after last_p.  */
  if (imm->iter_node.prev != NULL)
    delink_imm_use (&imm->iter_node);
  link_imm_use_to_list (&(imm->iter_node), last_p);
}

/* Initialize IMM to traverse over uses of VAR.  Return the first statement.  */
static inline gimple
first_imm_use_stmt (imm_use_iterator *imm, tree var)
{
  imm->end_p = &(SSA_NAME_IMM_USE_NODE (var));
  imm->imm_use = imm->end_p->next;
  imm->next_imm_name = NULL_USE_OPERAND_P;

  /* iter_node is used as a marker within the immediate use list to indicate
     where the end of the current stmt's uses are.  Initialize it to NULL
     stmt and use, which indicates a marker node.  */
  imm->iter_node.prev = NULL_USE_OPERAND_P;
  imm->iter_node.next = NULL_USE_OPERAND_P;
  imm->iter_node.loc.stmt = NULL;
  imm->iter_node.use = NULL;

  if (end_imm_use_stmt_p (imm))
    return NULL;

  link_use_stmts_after (imm->imm_use, imm);

  return USE_STMT (imm->imm_use);
}

/* Bump IMM to the next stmt which has a use of var.  */

static inline gimple
next_imm_use_stmt (imm_use_iterator *imm)
{
  imm->imm_use = imm->iter_node.next;
  if (end_imm_use_stmt_p (imm))
    {
      if (imm->iter_node.prev != NULL)
        delink_imm_use (&imm->iter_node);
      return NULL;
    }

  link_use_stmts_after (imm->imm_use, imm);
  return USE_STMT (imm->imm_use);
}

/* This routine will return the first use on the stmt IMM currently refers
   to.  */

static inline use_operand_p
first_imm_use_on_stmt (imm_use_iterator *imm)
{
  imm->next_imm_name = imm->imm_use->next;
  return imm->imm_use;
}

/*  Return TRUE if the last use on the stmt IMM refers to has been visited.  */

static inline bool
end_imm_use_on_stmt_p (const imm_use_iterator *imm)
{
  return (imm->imm_use == &(imm->iter_node));
}

/* Bump to the next use on the stmt IMM refers to, return NULL if done.  */

static inline use_operand_p
next_imm_use_on_stmt (imm_use_iterator *imm)
{
  imm->imm_use = imm->next_imm_name;
  if (end_imm_use_on_stmt_p (imm))
    return NULL_USE_OPERAND_P;
  else
    {
      imm->next_imm_name = imm->imm_use->next;
      return imm->imm_use;
    }
}

/* Return true if VAR cannot be modified by the program.  */

static inline bool
unmodifiable_var_p (const_tree var)
{
  if (TREE_CODE (var) == SSA_NAME)
    var = SSA_NAME_VAR (var);

  return TREE_READONLY (var) && (TREE_STATIC (var) || DECL_EXTERNAL (var));
}

/* Return true if REF, a handled component reference, has an ARRAY_REF
   somewhere in it.  */

static inline bool
ref_contains_array_ref (const_tree ref)
{
  gcc_checking_assert (handled_component_p (ref));

  do {
    if (TREE_CODE (ref) == ARRAY_REF)
      return true;
    ref = TREE_OPERAND (ref, 0);
  } while (handled_component_p (ref));

  return false;
}

/* Return true if REF has an VIEW_CONVERT_EXPR somewhere in it.  */

static inline bool
contains_view_convert_expr_p (const_tree ref)
{
  while (handled_component_p (ref))
    {
      if (TREE_CODE (ref) == VIEW_CONVERT_EXPR)
        return true;
      ref = TREE_OPERAND (ref, 0);
    }

  return false;
}

/* Return true, if the two ranges [POS1, SIZE1] and [POS2, SIZE2]
   overlap.  SIZE1 and/or SIZE2 can be (unsigned)-1 in which case the
   range is open-ended.  Otherwise return false.  */

static inline bool
ranges_overlap_p (unsigned HOST_WIDE_INT pos1,
                  unsigned HOST_WIDE_INT size1,
                  unsigned HOST_WIDE_INT pos2,
                  unsigned HOST_WIDE_INT size2)
{
  if (pos1 >= pos2
      && (size2 == (unsigned HOST_WIDE_INT)-1
          || pos1 < (pos2 + size2)))
    return true;
  if (pos2 >= pos1
      && (size1 == (unsigned HOST_WIDE_INT)-1
          || pos2 < (pos1 + size1)))
    return true;

  return false;
}

/* Accessor to tree-ssa-operands.c caches.  */
static inline struct ssa_operands *
gimple_ssa_operands (const struct function *fun)
{
  return &fun->gimple_df->ssa_operands;
}

/* Given an edge_var_map V, return the PHI arg definition.  */

static inline tree
redirect_edge_var_map_def (edge_var_map *v)
{
  return v->def;
}

/* Given an edge_var_map V, return the PHI result.  */

static inline tree
redirect_edge_var_map_result (edge_var_map *v)
{
  return v->result;
}

/* Given an edge_var_map V, return the PHI arg location.  */

static inline source_location
redirect_edge_var_map_location (edge_var_map *v)
{
  return v->locus;
}


/* Return an SSA_NAME node for variable VAR defined in statement STMT
   in function cfun.  */

static inline tree
make_ssa_name (tree var, gimple stmt)
{
  return make_ssa_name_fn (cfun, var, stmt);
}

/* Return an SSA_NAME node using the template SSA name NAME defined in
   statement STMT in function cfun.  */

static inline tree
copy_ssa_name (tree var, gimple stmt)
{
  return copy_ssa_name_fn (cfun, var, stmt);
}

/*  Creates a duplicate of a SSA name NAME tobe defined by statement STMT
    in function cfun.  */

static inline tree
duplicate_ssa_name (tree var, gimple stmt)
{
  return duplicate_ssa_name_fn (cfun, var, stmt);
}

/* Return an anonymous SSA_NAME node for type TYPE defined in statement STMT
   in function cfun.  Arrange so that it uses NAME in dumps.  */

static inline tree
make_temp_ssa_name (tree type, gimple stmt, const char *name)
{
  tree ssa_name;
  gcc_checking_assert (TYPE_P (type));
  ssa_name = make_ssa_name_fn (cfun, type, stmt);
  SET_SSA_NAME_VAR_OR_IDENTIFIER (ssa_name, get_identifier (name));
  return ssa_name;
}

/* Returns the base object and a constant BITS_PER_UNIT offset in *POFFSET that
   denotes the starting address of the memory access EXP.
   Returns NULL_TREE if the offset is not constant or any component
   is not BITS_PER_UNIT-aligned.
   VALUEIZE if non-NULL is used to valueize SSA names.  It should return
   its argument or a constant if the argument is known to be constant.  */
/* ??? This is a static inline here to avoid the overhead of the indirect calls
   to VALUEIZE.  But is this overhead really that significant?  And should we
   perhaps just rely on WHOPR to specialize the function?  */

static inline tree
get_addr_base_and_unit_offset_1 (tree exp, HOST_WIDE_INT *poffset,
                                 tree (*valueize) (tree))
{
  HOST_WIDE_INT byte_offset = 0;

  /* Compute cumulative byte-offset for nested component-refs and array-refs,
     and find the ultimate containing object.  */
  while (1)
    {
      switch (TREE_CODE (exp))
        {
        case BIT_FIELD_REF:
          {
            HOST_WIDE_INT this_off = TREE_INT_CST_LOW (TREE_OPERAND (exp, 2));
            if (this_off % BITS_PER_UNIT)
              return NULL_TREE;
            byte_offset += this_off / BITS_PER_UNIT;
          }
          break;

        case COMPONENT_REF:
          {
            tree field = TREE_OPERAND (exp, 1);
            tree this_offset = component_ref_field_offset (exp);
            HOST_WIDE_INT hthis_offset;

            if (!this_offset
                || TREE_CODE (this_offset) != INTEGER_CST
                || (TREE_INT_CST_LOW (DECL_FIELD_BIT_OFFSET (field))
                    % BITS_PER_UNIT))
              return NULL_TREE;

            hthis_offset = TREE_INT_CST_LOW (this_offset);
            hthis_offset += (TREE_INT_CST_LOW (DECL_FIELD_BIT_OFFSET (field))
                             / BITS_PER_UNIT);
            byte_offset += hthis_offset;
          }
          break;

        case ARRAY_REF:
        case ARRAY_RANGE_REF:
          {
            tree index = TREE_OPERAND (exp, 1);
            tree low_bound, unit_size;

            if (valueize
                && TREE_CODE (index) == SSA_NAME)
              index = (*valueize) (index);

            /* If the resulting bit-offset is constant, track it.  */
            if (TREE_CODE (index) == INTEGER_CST
                && (low_bound = array_ref_low_bound (exp),
                    TREE_CODE (low_bound) == INTEGER_CST)
                && (unit_size = array_ref_element_size (exp),
                    TREE_CODE (unit_size) == INTEGER_CST))
              {
                HOST_WIDE_INT hindex = TREE_INT_CST_LOW (index);

                hindex -= TREE_INT_CST_LOW (low_bound);
                hindex *= TREE_INT_CST_LOW (unit_size);
                byte_offset += hindex;
              }
            else
              return NULL_TREE;
          }
          break;

        case REALPART_EXPR:
          break;

        case IMAGPART_EXPR:
          byte_offset += TREE_INT_CST_LOW (TYPE_SIZE_UNIT (TREE_TYPE (exp)));
          break;

        case VIEW_CONVERT_EXPR:
          break;

        case MEM_REF:
          {
            tree base = TREE_OPERAND (exp, 0);
            if (valueize
                && TREE_CODE (base) == SSA_NAME)
              base = (*valueize) (base);

            /* Hand back the decl for MEM[&decl, off].  */
            if (TREE_CODE (base) == ADDR_EXPR)
              {
                if (!integer_zerop (TREE_OPERAND (exp, 1)))
                  {
                    double_int off = mem_ref_offset (exp);
                    gcc_assert (off.high == -1 || off.high == 0);
                    byte_offset += off.to_shwi ();
                  }
                exp = TREE_OPERAND (base, 0);
              }
            goto done;
          }

        case TARGET_MEM_REF:
          {
            tree base = TREE_OPERAND (exp, 0);
            if (valueize
                && TREE_CODE (base) == SSA_NAME)
              base = (*valueize) (base);

            /* Hand back the decl for MEM[&decl, off].  */
            if (TREE_CODE (base) == ADDR_EXPR)
              {
                if (TMR_INDEX (exp) || TMR_INDEX2 (exp))
                  return NULL_TREE;
                if (!integer_zerop (TMR_OFFSET (exp)))
                  {
                    double_int off = mem_ref_offset (exp);
                    gcc_assert (off.high == -1 || off.high == 0);
                    byte_offset += off.to_shwi ();
                  }
                exp = TREE_OPERAND (base, 0);
              }
            goto done;
          }

        default:
          goto done;
        }

      exp = TREE_OPERAND (exp, 0);
    }
done:

  *poffset = byte_offset;
  return exp;
}

#endif /* _TREE_FLOW_INLINE_H  */