gcc/gcc/tree-flow-inline.h

/* Inline functions for tree-flow.h
   Copyright (C) 2001, 2003 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 2, 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 COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

#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 the variable annotation for T, which must be a _DECL node.
   Return NULL if the variable annotation doesn't already exist.  */
static inline var_ann_t
var_ann (tree t)
{
#if defined ENABLE_CHECKING
  if (t == NULL_TREE
      || !DECL_P (t)
      || (t->common.ann
	  && t->common.ann->common.type != VAR_ANN))
    abort ();
#endif

  return (var_ann_t) t->common.ann;
}

/* Return the variable annotation for T, which must be a _DECL node.
   Create the variable annotation if it doesn't exist.  */
static inline var_ann_t
get_var_ann (tree var)
{
  var_ann_t ann = var_ann (var);
  return (ann) ? ann : create_var_ann (var);
}

/* Return the statement annotation for T, which must be a statement
   node.  Return NULL if the statement annotation doesn't exist.  */
static inline stmt_ann_t
stmt_ann (tree t)
{
#if defined ENABLE_CHECKING
  if (!is_gimple_stmt (t))
    abort ();
#endif

  return (stmt_ann_t) t->common.ann;
}

/* Return the statement annotation for T, which must be a statement
   node.  Create the statement annotation if it doesn't exist.  */
static inline stmt_ann_t
get_stmt_ann (tree stmt)
{
  stmt_ann_t ann = stmt_ann (stmt);
  return (ann) ? ann : create_stmt_ann (stmt);
}


/* Return the annotation type for annotation ANN.  */
static inline enum tree_ann_type
ann_type (tree_ann_t ann)
{
  return ann->common.type;
}

/* Return the basic block for statement T.  */
static inline basic_block
bb_for_stmt (tree t)
{
  stmt_ann_t ann = stmt_ann (t);
  return ann ? ann->bb : NULL;
}

/* Return the may_aliases varray for variable VAR, or NULL if it has
   no may aliases.  */
static inline varray_type
may_aliases (tree var)
{
  var_ann_t ann = var_ann (var);
  return ann ? ann->may_aliases : NULL;
}

/* Return true if VAR has a hidden use, false if it does not.  */
static inline bool
has_hidden_use (tree var)
{
  var_ann_t ann = var_ann (var);
  return ann ? ann->has_hidden_use : false;
}

/* Set the hidden use flag on VAR.  */ 
static inline void
set_has_hidden_use (tree var)
{
  var_ann_t ann = var_ann (var);
  if (ann == NULL)
    ann = create_var_ann (var);
  ann->has_hidden_use = 1;
}

/* Return the line number for EXPR, or return -1 if we have no line
   number information for it.  */
static inline int
get_lineno (tree expr)
{
  if (expr == NULL_TREE)
    return -1;

  if (TREE_CODE (expr) == COMPOUND_EXPR)
    expr = TREE_OPERAND (expr, 0);

  if (! EXPR_HAS_LOCATION (expr))
    return -1;

  return EXPR_LINENO (expr);
}

/* Return the file name for EXPR, or return "???" if we have no
   filename information.  */
static inline const char *
get_filename (tree expr)
{
  const char *filename;
  if (expr == NULL_TREE)
    return "???";

  if (TREE_CODE (expr) == COMPOUND_EXPR)
    expr = TREE_OPERAND (expr, 0);

  if (EXPR_HAS_LOCATION (expr) && (filename = EXPR_FILENAME (expr)))
    return filename;
  else
    return "???";
}

/* Mark statement T as modified.  */
static inline void
modify_stmt (tree t)
{
  stmt_ann_t ann = stmt_ann (t);
  if (ann == NULL)
    ann = create_stmt_ann (t);
  ann->modified = 1;
}

/* Mark statement T as unmodified.  */
static inline void
unmodify_stmt (tree t)
{
  stmt_ann_t ann = stmt_ann (t);
  if (ann == NULL)
    ann = create_stmt_ann (t);
  ann->modified = 0;
}

/* Return true if T is marked as modified, false otherwise.  */
static inline bool
stmt_modified_p (tree t)
{
  stmt_ann_t ann = stmt_ann (t);

  /* Note that if the statement doesn't yet have an annotation, we consider it
     modified.  This will force the next call to get_stmt_operands to scan the
     statement.  */
  return ann ? ann->modified : true;
}

/* Return the definitions present in ANN, a statement annotation.
   Return NULL if this annotation contains no definitions.  */
static inline def_optype
get_def_ops (stmt_ann_t ann)
{
  return ann ? ann->def_ops : NULL;
}

/* Return the uses present in ANN, a statement annotation.
   Return NULL if this annotation contains no uses.  */
static inline use_optype
get_use_ops (stmt_ann_t ann)
{
  return ann ? ann->use_ops : NULL;
}

/* Return the virtual may-defs present in ANN, a statement
   annotation.
   Return NULL if this annotation contains no virtual may-defs.  */
static inline v_may_def_optype
get_v_may_def_ops (stmt_ann_t ann)
{
  return ann ? ann->v_may_def_ops : NULL;
}

/* Return the virtual uses present in ANN, a statement annotation.
   Return NULL if this annotation contains no virtual uses.  */
static inline vuse_optype
get_vuse_ops (stmt_ann_t ann)
{
  return ann ? ann->vuse_ops : NULL;
}

/* Return the virtual must-defs present in ANN, a statement
   annotation.  Return NULL if this annotation contains no must-defs.*/
static inline v_must_def_optype
get_v_must_def_ops (stmt_ann_t ann)
{
  return ann ? ann->v_must_def_ops : NULL;
}

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

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

/* Return a pointer to the tree that is at INDEX in the USES array.  */
static inline use_operand_p
get_use_op_ptr (use_optype uses, unsigned int index)
{
#ifdef ENABLE_CHECKING
  if (index >= uses->num_uses)
    abort();
#endif
  return uses->uses[index];
}

/* Return a def_operand_p pointer for element INDEX of DEFS.  */
static inline def_operand_p
get_def_op_ptr (def_optype defs, unsigned int index)
{
#ifdef ENABLE_CHECKING
  if (index >= defs->num_defs)
    abort();
#endif
  return defs->defs[index];
}


/* Return the def_operand_p that is the V_MAY_DEF_RESULT for the V_MAY_DEF
   at INDEX in the V_MAY_DEFS array.  */
static inline def_operand_p
get_v_may_def_result_ptr(v_may_def_optype v_may_defs, unsigned int index)
{
  def_operand_p op;
#ifdef ENABLE_CHECKING
  if (index >= v_may_defs->num_v_may_defs)
    abort();
#endif
  op.def = &(v_may_defs->v_may_defs[index * 2]);
  return op;
}

/* Return a use_operand_p that is the V_MAY_DEF_OP for the V_MAY_DEF at
   INDEX in the V_MAY_DEFS array.  */
static inline use_operand_p
get_v_may_def_op_ptr(v_may_def_optype v_may_defs, unsigned int index)
{
  use_operand_p op;
#ifdef ENABLE_CHECKING
  if (index >= v_may_defs->num_v_may_defs)
    abort();
#endif
  op.use = &(v_may_defs->v_may_defs[index * 2 + 1]);
  return op;
}

/* Return a use_operand_p that is at INDEX in the VUSES array.  */
static inline use_operand_p
get_vuse_op_ptr(vuse_optype vuses, unsigned int index)
{
  use_operand_p op;
#ifdef ENABLE_CHECKING
  if (index >= vuses->num_vuses)
    abort();
#endif
  op.use = &(vuses->vuses[index]);
  return op;
}

/* Return a def_operand_p that is the V_MUST_DEF_OP for the
   V_MUST_DEF at INDEX in the V_MUST_DEFS array.  */
static inline def_operand_p
get_v_must_def_op_ptr (v_must_def_optype v_must_defs, unsigned int index)
{
  def_operand_p op;
#ifdef ENABLE_CHECKING
  if (index >= v_must_defs->num_v_must_defs)
    abort();
#endif
  op.def = &(v_must_defs->v_must_defs[index]);
  return op;
}

/* Return a def_operand_p pointer for the result of PHI.  */
static inline def_operand_p
get_phi_result_ptr (tree phi)
{
  def_operand_p op;
  op.def = &(PHI_RESULT_TREE (phi));
  return op;
}

/* Return a use_operand_p pointer for argument I of phinode PHI.  */
static inline use_operand_p
get_phi_arg_def_ptr (tree phi, int i)
{
  use_operand_p op;
  op.use = &(PHI_ARG_DEF_TREE (phi, i));
  return op;
}
 
/* Mark the beginning of changes to the SSA operands for STMT.  */
static inline void
start_ssa_stmt_operands (tree stmt ATTRIBUTE_UNUSED)
{
#ifdef ENABLE_CHECKING
  verify_start_operands (stmt);
#endif
}

/* Return the bitmap of addresses taken by STMT, or NULL if it takes
   no addresses.  */
static inline bitmap
addresses_taken (tree stmt)
{
  stmt_ann_t ann = stmt_ann (stmt);
  return ann ? ann->addresses_taken : NULL;
}

/* Return the immediate uses of STMT, or NULL if this information is
   not computed.  */
static dataflow_t
get_immediate_uses (tree stmt)
{
  stmt_ann_t ann = stmt_ann (stmt);
  return ann ? ann->df : NULL;
}

/* Return the number of immediate uses present in the dataflow
   information at DF.  */
static inline int
num_immediate_uses (dataflow_t df)
{
  varray_type imm;

  if (!df)
    return 0;

  imm = df->immediate_uses;
  if (!imm)
    return df->uses[1] ? 2 : 1;

  return VARRAY_ACTIVE_SIZE (imm) + 2;
}

/* Return the tree that is at NUM in the immediate use DF array.  */
static inline tree
immediate_use (dataflow_t df, int num)
{
  if (!df)
    return NULL_TREE;

#ifdef ENABLE_CHECKING
  if (num >= num_immediate_uses (df))
    abort ();
#endif
  if (num < 2)
    return df->uses[num];
  return VARRAY_TREE (df->immediate_uses, num - 2);
}

/* Return the basic_block annotation for BB.  */
static inline bb_ann_t
bb_ann (basic_block bb)
{
  return (bb_ann_t)bb->tree_annotations;
}

/* Return the PHI nodes for basic block BB, or NULL if there are no
   PHI nodes.  */
static inline tree
phi_nodes (basic_block bb)
{
  if (bb->index < 0)
    return NULL;
  return bb_ann (bb)->phi_nodes;
}

/* Set list of phi nodes of a basic block BB to L.  */

static inline void
set_phi_nodes (basic_block bb, tree l)
{
  tree phi;

  bb_ann (bb)->phi_nodes = l;
  for (phi = l; phi; phi = PHI_CHAIN (phi))
    set_bb_for_stmt (phi, bb);
}

/* Return the phi index number for an edge.  */
static inline int
phi_arg_from_edge (tree phi, edge e)
{
  int i;
#if defined ENABLE_CHECKING
  if (!phi || TREE_CODE (phi) != PHI_NODE)
    abort();
#endif

  for (i = 0; i < PHI_NUM_ARGS (phi); i++)
    if (PHI_ARG_EDGE (phi, i) == e)
      return i;

  return -1;
}

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

/* Return true if T is an executable statement.  */
static inline bool
is_exec_stmt (tree t)
{
  return (t && !IS_EMPTY_STMT (t) && t != error_mark_node);
}


/* Return true if this stmt can be the target of a control transfer stmt such
   as a goto.  */
static inline bool
is_label_stmt (tree t)
{
  if (t)
    switch (TREE_CODE (t))
      {
	case LABEL_DECL:
	case LABEL_EXPR:
	case CASE_LABEL_EXPR:
	  return true;
	default:
	  return false;
      }
  return false;
}

/* Return true if we may propagate ORIG into DEST, false otherwise.  */
static inline bool
may_propagate_copy (tree dest, tree orig)
{
  /* FIXME.  GIMPLE is allowing pointer assignments and comparisons of
     pointers that have different alias sets.  This means that these
     pointers will have different memory tags associated to them.
     
     If we allow copy propagation in these cases, statements de-referencing
     the new pointer will now have a reference to a different memory tag
     with potentially incorrect SSA information.

     This was showing up in libjava/java/util/zip/ZipFile.java with code
     like:

     	struct java.io.BufferedInputStream *T.660;
	struct java.io.BufferedInputStream *T.647;
	struct java.io.InputStream *is;
	struct java.io.InputStream *is.662;
	[ ... ]
	T.660 = T.647;
	is = T.660;	<-- This ought to be type-casted
	is.662 = is;

     Also, f/name.c exposed a similar problem with a COND_EXPR predicate
     that was causing DOM to generate and equivalence with two pointers of
     alias-incompatible types:

     	struct _ffename_space *n;
	struct _ffename *ns;
	[ ... ]
	if (n == ns)
	  goto lab;
	...
	lab:
	return n;

     I think that GIMPLE should emit the appropriate type-casts.  For the
     time being, blocking copy-propagation in these cases is the safe thing
     to do.  */
  if (TREE_CODE (dest) == SSA_NAME
      && TREE_CODE (orig) == SSA_NAME
      && POINTER_TYPE_P (TREE_TYPE (dest))
      && POINTER_TYPE_P (TREE_TYPE (orig)))
    {
      tree mt_dest = var_ann (SSA_NAME_VAR (dest))->type_mem_tag;
      tree mt_orig = var_ann (SSA_NAME_VAR (orig))->type_mem_tag;
      if (mt_dest && mt_orig && mt_dest != mt_orig)
	return false;
    }

  /* If the destination is a SSA_NAME for a virtual operand, then we have
     some special cases to handle.  */
  if (TREE_CODE (dest) == SSA_NAME && !is_gimple_reg (dest))
    {
      /* If both operands are SSA_NAMEs referring to virtual operands, then
	 we can always propagate.  */
      if (TREE_CODE (orig) == SSA_NAME)
	{
	  if (!is_gimple_reg (orig))
	    return true;

#ifdef ENABLE_CHECKING
	  /* If we have one real and one virtual operand, then something has
	     gone terribly wrong.  */
	  if (is_gimple_reg (orig))
	    abort ();
#endif
	}

      /* We have a "copy" from something like a constant into a virtual
	 operand.  Reject these.  */
      return false;
    }

  /* If ORIG flows in from an abnormal edge, it cannot be propagated.  */
  if (TREE_CODE (orig) == SSA_NAME
      && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (orig))
    return false;

  /* If DEST is an SSA_NAME that flows from an abnormal edge or if it
     represents a hard register, then it cannot be replaced.  */
  if (TREE_CODE (dest) == SSA_NAME
      && (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (dest)
	  || DECL_HARD_REGISTER (SSA_NAME_VAR (dest))))
    return false;

  /* Anything else is OK.  */
  return true;
}

/* Set the default definition for VAR to DEF.  */
static inline void
set_default_def (tree var, tree def)
{
  var_ann_t ann = var_ann (var);
  if (ann == NULL)
    ann = create_var_ann (var);
  ann->default_def = def;
}

/* Return the default definition for variable VAR, or NULL if none
   exists.  */
static inline tree
default_def (tree var)
{
  var_ann_t ann = var_ann (var);
  return ann ? ann->default_def : NULL_TREE;
}

/* 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 (tree t)
{
  if (TREE_CODE (t) == SSA_NAME)
    return true;
#ifdef ENABLE_CHECKING
  if (!is_gimple_min_invariant (t))
    abort ();
#endif
  return false;
}

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

/* Return a block_stmt_iterator that points to beginning of basic
   block BB.  */
static inline block_stmt_iterator
bsi_start (basic_block bb)
{
  block_stmt_iterator bsi;
  if (bb->stmt_list)
    bsi.tsi = tsi_start (bb->stmt_list);
  else
    {
#ifdef ENABLE_CHECKING
      if (bb->index >= 0)
	abort ();
#endif
      bsi.tsi.ptr = NULL;
      bsi.tsi.container = NULL;
    }
  bsi.bb = bb;
  return bsi;
}

/* Return a block statement iterator that points to the last label in
   block BB.  */

static inline block_stmt_iterator
bsi_after_labels (basic_block bb)
{
  block_stmt_iterator bsi;
  tree_stmt_iterator next;

  bsi.bb = bb;

  if (!bb->stmt_list)
    {
#ifdef ENABLE_CHECKING
      if (bb->index >= 0)
	abort ();
#endif
      bsi.tsi.ptr = NULL;
      bsi.tsi.container = NULL;
      return bsi;
    }

  bsi.tsi = tsi_start (bb->stmt_list);
  if (tsi_end_p (bsi.tsi))
    return bsi;

  /* Ensure that there are some labels.  The rationale is that we want
     to insert after the bsi that is returned, and these insertions should
     be placed at the start of the basic block.  This would not work if the
     first statement was not label; rather fail here than enable the user
     proceed in wrong way.  */
  if (TREE_CODE (tsi_stmt (bsi.tsi)) != LABEL_EXPR)
    abort ();

  next = bsi.tsi;
  tsi_next (&next);

  while (!tsi_end_p (next)
	 && TREE_CODE (tsi_stmt (next)) == LABEL_EXPR)
    {
      bsi.tsi = next;
      tsi_next (&next);
    }

  return bsi;
}

/* Return a block statement iterator that points to the end of basic
   block BB.  */
static inline block_stmt_iterator
bsi_last (basic_block bb)
{
  block_stmt_iterator bsi;
  if (bb->stmt_list)
    bsi.tsi = tsi_last (bb->stmt_list);
  else
    {
#ifdef ENABLE_CHECKING
      if (bb->index >= 0)
	abort ();
#endif
      bsi.tsi.ptr = NULL;
      bsi.tsi.container = NULL;
    }
  bsi.bb = bb;
  return bsi;
}

/* Return true if block statement iterator I has reached the end of
   the basic block.  */
static inline bool
bsi_end_p (block_stmt_iterator i)
{
  return tsi_end_p (i.tsi);
}

/* Modify block statement iterator I so that it is at the next
   statement in the basic block.  */
static inline void
bsi_next (block_stmt_iterator *i)
{
  tsi_next (&i->tsi);
}

/* Modify block statement iterator I so that it is at the previous
   statement in the basic block.  */
static inline void
bsi_prev (block_stmt_iterator *i)
{
  tsi_prev (&i->tsi);
}

/* Return the statement that block statement iterator I is currently
   at.  */
static inline tree
bsi_stmt (block_stmt_iterator i)
{
  return tsi_stmt (i.tsi);
}

/* Return a pointer to the statement that block statement iterator I
   is currently at.  */
static inline tree *
bsi_stmt_ptr (block_stmt_iterator i)
{
  return tsi_stmt_ptr (i.tsi);
}

/* Return true if VAR may be aliased.  */
static inline bool
may_be_aliased (tree var)
{
  return (TREE_ADDRESSABLE (var)
          || decl_function_context (var) != current_function_decl);
}

/* Return true if VAR is a clobbered by function calls.  */
static inline bool
is_call_clobbered (tree var)
{
  return needs_to_live_in_memory (var)
	 || bitmap_bit_p (call_clobbered_vars, var_ann (var)->uid);
}

/* Mark variable VAR as being clobbered by function calls.  */
static inline void
mark_call_clobbered (tree var)
{
  var_ann_t ann = var_ann (var);
  /* Call-clobbered variables need to live in memory.  */
  DECL_NEEDS_TO_LIVE_IN_MEMORY_INTERNAL (var) = 1;
  bitmap_set_bit (call_clobbered_vars, ann->uid);
}

/* Mark variable VAR as being non-addressable.  */
static inline void
mark_non_addressable (tree var)
{
  bitmap_clear_bit (call_clobbered_vars, var_ann (var)->uid);
  DECL_NEEDS_TO_LIVE_IN_MEMORY_INTERNAL (var) = 0;
  TREE_ADDRESSABLE (var) = 0;
}

/* Return the common annotation for T.  Return NULL if the annotation
   doesn't already exist.  */
static inline tree_ann_t
tree_ann (tree t)
{
  return t->common.ann;
}

/* Return a common annotation for T.  Create the constant annotation if it
   doesn't exist.  */
static inline tree_ann_t
get_tree_ann (tree t)
{
  tree_ann_t ann = tree_ann (t);
  return (ann) ? ann : create_tree_ann (t);
}

#endif /* _TREE_FLOW_INLINE_H  */