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1 files changed, 2126 insertions, 0 deletions

diff --git a/gcc/ipa-type-escape.c b/gcc/ipa-type-escape.c
new file mode 100644
index 000000000..1ecf68ef2
--- /dev/null
+++ b/gcc/ipa-type-escape.c
@@ -0,0 +1,2126 @@
+/* Escape analysis for types.
+   Copyright (C) 2004, 2005, 2006, 2007, 2008, 2010
+   Free Software Foundation, Inc.
+   Contributed by Kenneth Zadeck <zadeck@naturalbridge.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/>.  */
+
+/* This pass determines which types in the program contain only
+   instances that are completely encapsulated by the compilation unit.
+   Those types that are encapsulated must also pass the further
+   requirement that there be no bad operations on any instances of
+   those types.
+
+   A great deal of freedom in compilation is allowed for the instances
+   of those types that pass these conditions.
+*/
+
+/* The code in this module is called by the ipa pass manager. It
+   should be one of the later passes since its information is used by
+   the rest of the compilation. */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "tree.h"
+#include "tree-flow.h"
+#include "tree-inline.h"
+#include "tree-pass.h"
+#include "langhooks.h"
+#include "pointer-set.h"
+#include "splay-tree.h"
+#include "ggc.h"
+#include "ipa-utils.h"
+#include "ipa-type-escape.h"
+#include "gimple.h"
+#include "cgraph.h"
+#include "output.h"
+#include "flags.h"
+#include "timevar.h"
+#include "diagnostic.h"
+#include "tree-pretty-print.h"
+#include "langhooks.h"
+
+/* Some of the aliasing is called very early, before this phase is
+   called.  To assure that this is not a problem, we keep track of if
+   this phase has been run.  */
+static bool initialized = false;
+
+/* Scratch bitmap for avoiding work. */
+static bitmap been_there_done_that;
+static bitmap bitmap_tmp;
+
+/* There are two levels of escape that types can undergo.
+
+   EXPOSED_PARAMETER - some instance of the variable is
+   passed by value into an externally visible function or some
+   instance of the variable is passed out of an externally visible
+   function as a return value.  In this case any of the fields of the
+   variable that are pointer types end up having their types marked as
+   FULL_ESCAPE.
+
+   FULL_ESCAPE - when bad things happen to good types. One of the
+   following things happens to the type: (a) either an instance of the
+   variable has its address passed to an externally visible function,
+   (b) the address is taken and some bad cast happens to the address
+   or (c) explicit arithmetic is done to the address.
+*/
+
+enum escape_t
+{
+  EXPOSED_PARAMETER,
+  FULL_ESCAPE
+};
+
+/* The following two bit vectors global_types_* correspond to
+   previous cases above.  During the analysis phase, a bit is set in
+   one of these vectors if an operation of the offending class is
+   discovered to happen on the associated type.  */
+
+static bitmap global_types_exposed_parameter;
+static bitmap global_types_full_escape;
+
+/* All of the types seen in this compilation unit. */
+static bitmap global_types_seen;
+/* Reverse map to take a canon uid and map it to a canon type.  Uid's
+   are never manipulated unless they are associated with a canon
+   type.  */
+static splay_tree uid_to_canon_type;
+
+/* Internal structure of type mapping code.  This maps a canon type
+   name to its canon type.  */
+static splay_tree all_canon_types;
+
+/* Map from type clones to the single canon type.  */
+static splay_tree type_to_canon_type;
+
+/* A splay tree of bitmaps.  An element X in the splay tree has a bit
+   set in its bitmap at TYPE_UID (TYPE_MAIN_VARIANT (Y)) if there was
+   an operation in the program of the form "&X.Y".  */
+static splay_tree uid_to_addressof_down_map;
+
+/* A splay tree of bitmaps.  An element Y in the splay tree has a bit
+   set in its bitmap at TYPE_UID (TYPE_MAIN_VARIANT (X)) if there was
+   an operation in the program of the form "&X.Y".  */
+static splay_tree uid_to_addressof_up_map;
+
+/* Tree to hold the subtype maps used to mark subtypes of escaped
+   types.  */
+static splay_tree uid_to_subtype_map;
+
+/* Records tree nodes seen in cgraph_create_edges.  Simply using
+   walk_tree_without_duplicates doesn't guarantee each node is visited
+   once because it gets a new htab upon each recursive call from
+   scan_for_refs.  */
+static struct pointer_set_t *visited_nodes;
+
+/* Visited stmts by walk_use_def_chains function because it's called
+   recursively.  */
+static struct pointer_set_t *visited_stmts;
+
+static bitmap_obstack ipa_obstack;
+
+/* Static functions from this file that are used
+   before being defined.  */
+static unsigned int look_for_casts (tree);
+static bool is_cast_from_non_pointer (tree, gimple, void *);
+
+/* Get the name of TYPE or return the string "<UNNAMED>".  */
+static const char*
+get_name_of_type (tree type)
+{
+  tree name = TYPE_NAME (type);
+
+  if (!name)
+    /* Unnamed type, do what you like here.  */
+    return "<UNNAMED>";
+
+  /* It will be a TYPE_DECL in the case of a typedef, otherwise, an
+     identifier_node */
+  if (TREE_CODE (name) == TYPE_DECL)
+    {
+      /*  Each DECL has a DECL_NAME field which contains an
+	  IDENTIFIER_NODE.  (Some decls, most often labels, may have
+	  zero as the DECL_NAME).  */
+      if (DECL_NAME (name))
+	return IDENTIFIER_POINTER (DECL_NAME (name));
+      else
+	/* Unnamed type, do what you like here.  */
+	return "<UNNAMED>";
+    }
+  else if (TREE_CODE (name) == IDENTIFIER_NODE)
+    return IDENTIFIER_POINTER (name);
+  else
+    return "<UNNAMED>";
+}
+
+struct type_brand_s
+{
+  const char* name;
+  int seq;
+};
+
+/* Splay tree comparison function on type_brand_s structures.  */
+
+static int
+compare_type_brand (splay_tree_key sk1, splay_tree_key sk2)
+{
+  struct type_brand_s * k1 = (struct type_brand_s *) sk1;
+  struct type_brand_s * k2 = (struct type_brand_s *) sk2;
+
+  int value = strcmp(k1->name, k2->name);
+  if (value == 0)
+    return k2->seq - k1->seq;
+  else
+    return value;
+}
+
+/* All of the "unique_type" code is a hack to get around the sleazy
+   implementation used to compile more than file.  Currently gcc does
+   not get rid of multiple instances of the same type that have been
+   collected from different compilation units.  */
+/* This is a trivial algorithm for removing duplicate types.  This
+   would not work for any language that used structural equivalence as
+   the basis of its type system.  */
+/* Return TYPE if no type compatible with TYPE has been seen so far,
+   otherwise return a type compatible with TYPE that has already been
+   processed.  */
+
+static tree
+discover_unique_type (tree type)
+{
+  struct type_brand_s * brand = XNEW (struct type_brand_s);
+  int i = 0;
+  splay_tree_node result;
+
+  brand->name = get_name_of_type (type);
+
+  while (1)
+    {
+      brand->seq = i++;
+      result = splay_tree_lookup (all_canon_types, (splay_tree_key) brand);
+
+      if (result)
+	{
+	  /* Create an alias since this is just the same as
+	     other_type.  */
+	  tree other_type = (tree) result->value;
+	  if (types_compatible_p (type, other_type))
+	    {
+	      free (brand);
+	      /* Insert this new type as an alias for other_type.  */
+	      splay_tree_insert (type_to_canon_type,
+				 (splay_tree_key) type,
+				 (splay_tree_value) other_type);
+	      return other_type;
+	    }
+	  /* Not compatible, look for next instance with same name.  */
+	}
+      else
+	{
+	  /* No more instances, create new one since this is the first
+	     time we saw this type.  */
+	  brand->seq = i++;
+	  /* Insert the new brand.  */
+	  splay_tree_insert (all_canon_types,
+			     (splay_tree_key) brand,
+			     (splay_tree_value) type);
+
+	  /* Insert this new type as an alias for itself.  */
+	  splay_tree_insert (type_to_canon_type,
+			     (splay_tree_key) type,
+			     (splay_tree_value) type);
+
+	  /* Insert the uid for reverse lookup; */
+	  splay_tree_insert (uid_to_canon_type,
+			     (splay_tree_key) TYPE_UID (type),
+			     (splay_tree_value) type);
+
+	  bitmap_set_bit (global_types_seen, TYPE_UID (type));
+	  return type;
+	}
+    }
+}
+
+/* Return true if TYPE is one of the type classes that we are willing
+   to analyze.  This skips the goofy types like arrays of pointers to
+   methods. */
+static bool
+type_to_consider (tree type)
+{
+  /* Strip the *'s off.  */
+  type = TYPE_MAIN_VARIANT (type);
+  while (POINTER_TYPE_P (type) || TREE_CODE (type) == ARRAY_TYPE)
+    type = TYPE_MAIN_VARIANT (TREE_TYPE (type));
+
+  switch (TREE_CODE (type))
+    {
+    case BOOLEAN_TYPE:
+    case COMPLEX_TYPE:
+    case ENUMERAL_TYPE:
+    case INTEGER_TYPE:
+    case QUAL_UNION_TYPE:
+    case REAL_TYPE:
+    case FIXED_POINT_TYPE:
+    case RECORD_TYPE:
+    case UNION_TYPE:
+    case VECTOR_TYPE:
+    case VOID_TYPE:
+      return true;
+
+    default:
+      return false;
+    }
+}
+
+/* Get the canon type of TYPE.  If SEE_THRU_PTRS is true, remove all
+   the POINTER_TOs and if SEE_THRU_ARRAYS is true, remove all of the
+   ARRAY_OFs and POINTER_TOs.  */
+
+static tree
+get_canon_type (tree type, bool see_thru_ptrs, bool see_thru_arrays)
+{
+  splay_tree_node result;
+  /* Strip the *'s off.  */
+  if (!type || !type_to_consider (type))
+    return NULL;
+
+  type = TYPE_MAIN_VARIANT (type);
+  if (see_thru_arrays)
+    while (POINTER_TYPE_P (type) || TREE_CODE (type) == ARRAY_TYPE)
+      type = TYPE_MAIN_VARIANT (TREE_TYPE (type));
+
+  else if (see_thru_ptrs)
+    while (POINTER_TYPE_P (type))
+	type = TYPE_MAIN_VARIANT (TREE_TYPE (type));
+
+  result = splay_tree_lookup (type_to_canon_type, (splay_tree_key) type);
+
+  if (result == NULL)
+    return discover_unique_type (type);
+  else return (tree) result->value;
+}
+
+/* Same as GET_CANON_TYPE, except return the TYPE_ID rather than the
+   TYPE.  */
+
+static int
+get_canon_type_uid (tree type, bool see_thru_ptrs, bool see_thru_arrays)
+{
+  type = get_canon_type (type, see_thru_ptrs, see_thru_arrays);
+  if (type)
+    return TYPE_UID(type);
+  else return 0;
+}
+
+/* Return 0 if TYPE is a record or union type.  Return a positive
+   number if TYPE is a pointer to a record or union.  The number is
+   the number of pointer types stripped to get to the record or union
+   type.  Return -1 if TYPE is none of the above.  */
+
+int
+ipa_type_escape_star_count_of_interesting_type (tree type)
+{
+  int count = 0;
+  /* Strip the *'s off.  */
+  if (!type)
+    return -1;
+  type = TYPE_MAIN_VARIANT (type);
+  while (POINTER_TYPE_P (type))
+    {
+      type = TYPE_MAIN_VARIANT (TREE_TYPE (type));
+      count++;
+    }
+
+  /* We are interested in records, and unions only.  */
+  if (TREE_CODE (type) == RECORD_TYPE
+      || TREE_CODE (type) == QUAL_UNION_TYPE
+      || TREE_CODE (type) == UNION_TYPE)
+    return count;
+  else
+    return -1;
+}
+
+
+/* Return 0 if TYPE is a record or union type.  Return a positive
+   number if TYPE is a pointer to a record or union.  The number is
+   the number of pointer types stripped to get to the record or union
+   type.  Return -1 if TYPE is none of the above.  */
+
+int
+ipa_type_escape_star_count_of_interesting_or_array_type (tree type)
+{
+  int count = 0;
+  /* Strip the *'s off.  */
+  if (!type)
+    return -1;
+  type = TYPE_MAIN_VARIANT (type);
+  while (POINTER_TYPE_P (type) || TREE_CODE (type) == ARRAY_TYPE)
+    {
+      type = TYPE_MAIN_VARIANT (TREE_TYPE (type));
+      count++;
+    }
+
+  /* We are interested in records, and unions only.  */
+  if (TREE_CODE (type) == RECORD_TYPE
+      || TREE_CODE (type) == QUAL_UNION_TYPE
+      || TREE_CODE (type) == UNION_TYPE)
+    return count;
+  else
+    return -1;
+}
+
+
+/* Return true if the record, or union TYPE passed in escapes this
+   compilation unit. Note that all of the pointer-to's are removed
+   before testing since these may not be correct.  */
+
+bool
+ipa_type_escape_type_contained_p (tree type)
+{
+  if (!initialized)
+    return false;
+  return !bitmap_bit_p (global_types_full_escape,
+			get_canon_type_uid (type, true, false));
+}
+
+/* Return true if a modification to a field of type FIELD_TYPE cannot
+   clobber a record of RECORD_TYPE.  */
+
+bool
+ipa_type_escape_field_does_not_clobber_p (tree record_type, tree field_type)
+{
+  splay_tree_node result;
+  int uid;
+
+  if (!initialized)
+    return false;
+
+  /* Strip off all of the pointer tos on the record type.  Strip the
+     same number of pointer tos from the field type.  If the field
+     type has fewer, it could not have been aliased. */
+  record_type = TYPE_MAIN_VARIANT (record_type);
+  field_type = TYPE_MAIN_VARIANT (field_type);
+  while (POINTER_TYPE_P (record_type))
+    {
+      record_type = TYPE_MAIN_VARIANT (TREE_TYPE (record_type));
+      if (POINTER_TYPE_P (field_type))
+	field_type = TYPE_MAIN_VARIANT (TREE_TYPE (field_type));
+      else
+	/* However, if field_type is a union, this quick test is not
+	   correct since one of the variants of the union may be a
+	   pointer to type and we cannot see across that here.  So we
+	   just strip the remaining pointer tos off the record type
+	   and fall thru to the more precise code.  */
+	if (TREE_CODE (field_type) == QUAL_UNION_TYPE
+	    || TREE_CODE (field_type) == UNION_TYPE)
+	  {
+	    while (POINTER_TYPE_P (record_type))
+	      record_type = TYPE_MAIN_VARIANT (TREE_TYPE (record_type));
+	    break;
+	  }
+	else
+	  return true;
+    }
+
+  record_type = get_canon_type (record_type, true, true);
+  /* The record type must be contained.  The field type may
+     escape.  */
+  if (!ipa_type_escape_type_contained_p (record_type))
+    return false;
+
+  uid = TYPE_UID (record_type);
+  result = splay_tree_lookup (uid_to_addressof_down_map, (splay_tree_key) uid);
+
+  if (result)
+    {
+      bitmap field_type_map = (bitmap) result->value;
+      uid = get_canon_type_uid (field_type, true, true);
+      /* If the bit is there, the address was taken. If not, it
+	 wasn't.  */
+      return !bitmap_bit_p (field_type_map, uid);
+    }
+  else
+    /* No bitmap means no addresses were taken.  */
+    return true;
+}
+
+
+/* Add TYPE to the suspect type set. Return true if the bit needed to
+   be marked.  */
+
+static tree
+mark_type (tree type, enum escape_t escape_status)
+{
+  bitmap map = NULL;
+  int uid;
+
+  type = get_canon_type (type, true, true);
+  if (!type)
+    return NULL;
+
+  switch (escape_status)
+    {
+    case EXPOSED_PARAMETER:
+      map = global_types_exposed_parameter;
+      break;
+    case FULL_ESCAPE:
+      map = global_types_full_escape;
+      break;
+    }
+
+  uid = TYPE_UID (type);
+  if (!bitmap_set_bit (map, uid))
+    return type;
+  else if (escape_status == FULL_ESCAPE)
+    /* Efficiency hack. When things are bad, do not mess around
+       with this type anymore.  */
+    bitmap_set_bit (global_types_exposed_parameter, uid);
+
+  return type;
+}
+
+/* Add interesting TYPE to the suspect type set. If the set is
+   EXPOSED_PARAMETER and the TYPE is a pointer type, the set is
+   changed to FULL_ESCAPE.  */
+
+static void
+mark_interesting_type (tree type, enum escape_t escape_status)
+{
+  if (!type) return;
+  if (ipa_type_escape_star_count_of_interesting_type (type) >= 0)
+    {
+      if ((escape_status == EXPOSED_PARAMETER)
+	  && POINTER_TYPE_P (type))
+	/* EXPOSED_PARAMETERs are only structs or unions are passed by
+	   value.  Anything passed by reference to an external
+	   function fully exposes the type.  */
+	mark_type (type, FULL_ESCAPE);
+      else
+	mark_type (type, escape_status);
+    }
+}
+
+/* Return true if PARENT is supertype of CHILD.  Both types must be
+   known to be structures or unions. */
+
+static bool
+parent_type_p (tree parent, tree child)
+{
+  int i;
+  tree binfo, base_binfo;
+  if (TYPE_BINFO (parent))
+    for (binfo = TYPE_BINFO (parent), i = 0;
+	 BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
+      {
+	tree binfotype = BINFO_TYPE (base_binfo);
+	if (binfotype == child)
+	  return true;
+	else if (parent_type_p (binfotype, child))
+	  return true;
+      }
+  if (TREE_CODE (parent) == UNION_TYPE
+      || TREE_CODE (parent) == QUAL_UNION_TYPE)
+    {
+      tree field;
+      /* Search all of the variants in the union to see if one of them
+	 is the child.  */
+      for (field = TYPE_FIELDS (parent);
+	   field;
+	   field = TREE_CHAIN (field))
+	{
+	  tree field_type;
+	  if (TREE_CODE (field) != FIELD_DECL)
+	    continue;
+
+	  field_type = TREE_TYPE (field);
+	  if (field_type == child)
+	    return true;
+	}
+
+      /* If we did not find it, recursively ask the variants if one of
+	 their children is the child type.  */
+      for (field = TYPE_FIELDS (parent);
+	   field;
+	   field = TREE_CHAIN (field))
+	{
+	  tree field_type;
+	  if (TREE_CODE (field) != FIELD_DECL)
+	    continue;
+
+	  field_type = TREE_TYPE (field);
+	  if (TREE_CODE (field_type) == RECORD_TYPE
+	      || TREE_CODE (field_type) == QUAL_UNION_TYPE
+	      || TREE_CODE (field_type) == UNION_TYPE)
+	    if (parent_type_p (field_type, child))
+	      return true;
+	}
+    }
+
+  if (TREE_CODE (parent) == RECORD_TYPE)
+    {
+      tree field;
+      for (field = TYPE_FIELDS (parent);
+	   field;
+	   field = TREE_CHAIN (field))
+	{
+	  tree field_type;
+	  if (TREE_CODE (field) != FIELD_DECL)
+	    continue;
+
+	  field_type = TREE_TYPE (field);
+	  if (field_type == child)
+	    return true;
+	  /* You can only cast to the first field so if it does not
+	     match, quit.  */
+	  if (TREE_CODE (field_type) == RECORD_TYPE
+	      || TREE_CODE (field_type) == QUAL_UNION_TYPE
+	      || TREE_CODE (field_type) == UNION_TYPE)
+	    {
+	      if (parent_type_p (field_type, child))
+		return true;
+	      else
+		break;
+	    }
+	}
+    }
+  return false;
+}
+
+/* Return the number of pointer tos for TYPE and return TYPE with all
+   of these stripped off.  */
+
+static int
+count_stars (tree* type_ptr)
+{
+  tree type = *type_ptr;
+  int i = 0;
+  type = TYPE_MAIN_VARIANT (type);
+  while (POINTER_TYPE_P (type))
+    {
+      type = TYPE_MAIN_VARIANT (TREE_TYPE (type));
+      i++;
+    }
+
+  *type_ptr = type;
+  return i;
+}
+
+enum cast_type {
+  CT_UP = 0x1,
+  CT_DOWN = 0x2,
+  CT_SIDEWAYS = 0x4,
+  CT_USELESS = 0x8,
+  CT_FROM_P_BAD = 0x10,
+  CT_FROM_NON_P = 0x20,
+  CT_TO_NON_INTER = 0x40,
+  CT_FROM_MALLOC = 0x80,
+  CT_NO_CAST = 0x100
+};
+
+/* Check the cast FROM_TYPE to TO_TYPE.  This function requires that
+   the two types have already passed the
+   ipa_type_escape_star_count_of_interesting_type test.  */
+
+static enum cast_type
+check_cast_type (tree to_type, tree from_type)
+{
+  int to_stars = count_stars (&to_type);
+  int from_stars = count_stars (&from_type);
+  if (to_stars != from_stars)
+    return CT_SIDEWAYS;
+
+  if (to_type == from_type)
+    return CT_USELESS;
+
+  if (parent_type_p (to_type, from_type)) return CT_UP;
+  if (parent_type_p (from_type, to_type)) return CT_DOWN;
+  return CT_SIDEWAYS;
+}
+
+/* This function returns nonzero if VAR is result of call
+   to malloc function.  */
+
+static bool
+is_malloc_result (tree var)
+{
+  gimple def_stmt;
+
+  if (!var)
+    return false;
+
+  if (SSA_NAME_IS_DEFAULT_DEF (var))
+    return false;
+
+  def_stmt = SSA_NAME_DEF_STMT (var);
+
+  if (!is_gimple_call (def_stmt))
+    return false;
+
+  if (var != gimple_call_lhs (def_stmt))
+    return false;
+
+  return ((gimple_call_flags (def_stmt) & ECF_MALLOC) != 0);
+
+}
+
+/* Check a cast FROM this variable, TO_TYPE.  Mark the escaping types
+   if appropriate. Returns cast_type as detected.  */
+
+static enum cast_type
+check_cast (tree to_type, tree from)
+{
+  tree from_type = get_canon_type (TREE_TYPE (from), false, false);
+  bool to_interesting_type, from_interesting_type;
+  enum cast_type cast = CT_NO_CAST;
+
+  to_type = get_canon_type (to_type, false, false);
+  if (!from_type || !to_type || from_type == to_type)
+    return cast;
+
+  to_interesting_type =
+    ipa_type_escape_star_count_of_interesting_type (to_type) >= 0;
+  from_interesting_type =
+    ipa_type_escape_star_count_of_interesting_type (from_type) >= 0;
+
+  if (to_interesting_type)
+    if (from_interesting_type)
+      {
+	/* Both types are interesting. This can be one of four types
+	   of cast: useless, up, down, or sideways.  We do not care
+	   about up or useless.  Sideways casts are always bad and
+	   both sides get marked as escaping.  Downcasts are not
+	   interesting here because if type is marked as escaping, all
+	   of its subtypes escape.  */
+	cast = check_cast_type (to_type, from_type);
+	switch (cast)
+	  {
+	  case CT_UP:
+	  case CT_USELESS:
+	  case CT_DOWN:
+	    break;
+
+	  case CT_SIDEWAYS:
+	    mark_type (to_type, FULL_ESCAPE);
+	    mark_type (from_type, FULL_ESCAPE);
+	    break;
+
+	  default:
+	    break;
+	  }
+      }
+    else
+      {
+	/* This code excludes two cases from marking as escaped:
+
+	1. if this is a cast of index of array of structures/unions
+	that happens before accessing array element, we should not
+	mark it as escaped.
+	2. if this is a cast from the local that is a result from a
+	call to malloc, do not mark the cast as bad.
+
+	*/
+
+	if (POINTER_TYPE_P (to_type) && !POINTER_TYPE_P (from_type))
+	  cast = CT_FROM_NON_P;
+	else if (TREE_CODE (from) == SSA_NAME
+		 && is_malloc_result (from))
+	  cast = CT_FROM_MALLOC;
+	else
+	  {
+	    cast = CT_FROM_P_BAD;
+	    mark_type (to_type, FULL_ESCAPE);
+	  }
+      }
+  else if (from_interesting_type)
+    {
+      mark_type (from_type, FULL_ESCAPE);
+      cast = CT_TO_NON_INTER;
+    }
+
+  return cast;
+}
+
+
+/* Scan assignment statement S to see if there are any casts within it.  */
+
+static unsigned int
+look_for_casts_stmt (gimple s)
+{
+  unsigned int cast = 0;
+
+  gcc_assert (is_gimple_assign (s));
+
+  if (gimple_assign_cast_p (s))
+    {
+      tree castfromvar = gimple_assign_rhs1 (s);
+      cast |= check_cast (TREE_TYPE (gimple_assign_lhs (s)), castfromvar);
+    }
+  else
+    {
+      size_t i;
+      for (i = 0; i < gimple_num_ops (s); i++)
+	cast |= look_for_casts (gimple_op (s, i));
+    }
+
+  if (!cast)
+    cast = CT_NO_CAST;
+
+  return cast;
+}
+
+
+typedef struct cast
+{
+  int type;
+  gimple stmt;
+} cast_t;
+
+/* This function is a callback for walk_use_def_chains function called
+   from is_array_access_through_pointer_and_index.  */
+
+static bool
+is_cast_from_non_pointer (tree var, gimple def_stmt, void *data)
+{
+  if (!def_stmt || !var)
+    return false;
+
+  if (gimple_code (def_stmt) == GIMPLE_PHI)
+    return false;
+
+  if (SSA_NAME_IS_DEFAULT_DEF (var))
+      return false;
+
+  if (is_gimple_assign (def_stmt))
+    {
+      use_operand_p use_p;
+      ssa_op_iter iter;
+      unsigned int cast = look_for_casts_stmt (def_stmt);
+
+      /* Check that only one cast happened, and it's of non-pointer
+	 type.  */
+      if ((cast & CT_FROM_NON_P) == (CT_FROM_NON_P)
+	  && (cast & ~(CT_FROM_NON_P)) == 0)
+	{
+	  ((cast_t *)data)->stmt = def_stmt;
+	  ((cast_t *)data)->type++;
+
+	  FOR_EACH_SSA_USE_OPERAND (use_p, def_stmt, iter, SSA_OP_ALL_USES)
+	    {
+	      walk_use_def_chains (USE_FROM_PTR (use_p),
+				   is_cast_from_non_pointer, data, false);
+	      if (((cast_t*)data)->type == -1)
+		break;
+	    }
+	}
+      /* Check that there is no cast, or cast is not harmful. */
+      else if ((cast & CT_NO_CAST) == (CT_NO_CAST)
+	  || (cast & CT_DOWN) == (CT_DOWN)
+	  || (cast & CT_UP) == (CT_UP)
+	  || (cast & CT_USELESS) == (CT_USELESS)
+	  || (cast & CT_FROM_MALLOC) == (CT_FROM_MALLOC))
+	{
+	  FOR_EACH_SSA_USE_OPERAND (use_p, def_stmt, iter, SSA_OP_ALL_USES)
+	    {
+	      walk_use_def_chains (USE_FROM_PTR (use_p),
+				   is_cast_from_non_pointer, data, false);
+	      if (((cast_t*)data)->type == -1)
+		break;
+	    }
+	}
+	/* The cast is harmful.  */
+	else
+	  ((cast_t *)data)->type = -1;
+    }
+
+  if (((cast_t*)data)->type == -1)
+    return true;
+
+  return false;
+}
+
+/* When array element a_p[i] is accessed through the pointer a_p
+   and index i, it's translated into the following sequence
+   in gimple:
+
+  i.1_5 = (unsigned int) i_1;
+  D.1605_6 = i.1_5 * 16;
+  D.1606_7 = (struct str_t *) D.1605_6;
+  a_p.2_8 = a_p;
+  D.1608_9 = D.1606_7 + a_p.2_8;
+
+  OP0 and OP1 are of the same pointer types and stand for
+  D.1606_7 and a_p.2_8 or vise versa.
+
+  This function checks that:
+
+  1. one of OP0 and OP1 (D.1606_7) has passed only one cast from
+  non-pointer type (D.1606_7 = (struct str_t *) D.1605_6;).
+
+  2. one of OP0 and OP1 which has passed the cast from
+  non-pointer type (D.1606_7), is actually generated by multiplication of
+  index by size of type to which both OP0 and OP1 point to
+  (in this case D.1605_6 = i.1_5 * 16; ).
+
+  3. an address of def of the var to which was made cast (D.1605_6)
+  was not taken.(How can it happen?)
+
+  The following items are checked implicitly by the end of algorithm:
+
+  4. one of OP0 and OP1 (a_p.2_8) have never been cast
+  (because if it was cast to pointer type, its type, that is also
+  the type of OP0 and OP1, will be marked as escaped during
+  analysis of casting stmt (when check_cast() is called
+  from scan_for_refs for this stmt)).
+
+  5. defs of OP0 and OP1 are not passed into externally visible function
+  (because if they are passed then their type, that is also the type of OP0
+  and OP1, will be marked and escaped during check_call function called from
+  scan_for_refs with call stmt).
+
+  In total, 1-5 guaranty that it's an access to array by pointer and index.
+
+*/
+
+bool
+is_array_access_through_pointer_and_index (enum tree_code code, tree op0,
+					   tree op1, tree *base, tree *offset,
+					   gimple *offset_cast_stmt)
+{
+  tree before_cast;
+  gimple before_cast_def_stmt;
+  cast_t op0_cast, op1_cast;
+
+  *base = NULL;
+  *offset = NULL;
+  *offset_cast_stmt = NULL;
+
+  /* Check 1.  */
+  if (code == POINTER_PLUS_EXPR)
+    {
+      tree op0type = TYPE_MAIN_VARIANT (TREE_TYPE (op0));
+      tree op1type = TYPE_MAIN_VARIANT (TREE_TYPE (op1));
+
+      /* One of op0 and op1 is of pointer type and the other is numerical.  */
+      if (POINTER_TYPE_P (op0type) && NUMERICAL_TYPE_CHECK (op1type))
+	{
+	  *base = op0;
+	  *offset = op1;
+	}
+      else if (POINTER_TYPE_P (op1type) && NUMERICAL_TYPE_CHECK (op0type))
+	{
+	  *base = op1;
+	  *offset = op0;
+	}
+      else
+	return false;
+    }
+  else
+    {
+      /* Init data for walk_use_def_chains function.  */
+      op0_cast.type = op1_cast.type = 0;
+      op0_cast.stmt = op1_cast.stmt = NULL;
+
+      visited_stmts = pointer_set_create ();
+      walk_use_def_chains (op0, is_cast_from_non_pointer,(void *)(&op0_cast),
+			   false);
+      pointer_set_destroy (visited_stmts);
+
+      visited_stmts = pointer_set_create ();
+      walk_use_def_chains (op1, is_cast_from_non_pointer,(void *)(&op1_cast),
+			   false);
+      pointer_set_destroy (visited_stmts);
+
+      if (op0_cast.type == 1 && op1_cast.type == 0)
+	{
+	  *base = op1;
+	  *offset = op0;
+	  *offset_cast_stmt = op0_cast.stmt;
+	}
+      else if (op0_cast.type == 0 && op1_cast.type == 1)
+	{
+	  *base = op0;
+	  *offset = op1;
+	  *offset_cast_stmt = op1_cast.stmt;
+	}
+      else
+	return false;
+    }
+
+  /* Check 2.
+     offset_cast_stmt is of the form:
+     D.1606_7 = (struct str_t *) D.1605_6;  */
+
+  if (*offset_cast_stmt)
+    {
+      before_cast = SINGLE_SSA_TREE_OPERAND (*offset_cast_stmt, SSA_OP_USE);
+      if (!before_cast)
+	return false;
+
+      if (SSA_NAME_IS_DEFAULT_DEF (before_cast))
+	return false;
+
+      before_cast_def_stmt = SSA_NAME_DEF_STMT (before_cast);
+      if (!before_cast_def_stmt)
+	return false;
+    }
+  else
+    before_cast_def_stmt = SSA_NAME_DEF_STMT (*offset);
+
+  /* before_cast_def_stmt should be of the form:
+     D.1605_6 = i.1_5 * 16; */
+
+  if (is_gimple_assign (before_cast_def_stmt))
+    {
+      /* We expect temporary here.  */
+      if (!is_gimple_reg (gimple_assign_lhs (before_cast_def_stmt)))
+	return false;
+
+      if (gimple_assign_rhs_code (before_cast_def_stmt) == MULT_EXPR)
+	{
+	  tree arg0 = gimple_assign_rhs1 (before_cast_def_stmt);
+	  tree arg1 = gimple_assign_rhs2 (before_cast_def_stmt);
+	  tree unit_size =
+	    TYPE_SIZE_UNIT (TREE_TYPE (TYPE_MAIN_VARIANT (TREE_TYPE (op0))));
+
+	  if (!(CONSTANT_CLASS_P (arg0)
+	      && simple_cst_equal (arg0, unit_size))
+	      && !(CONSTANT_CLASS_P (arg1)
+	      && simple_cst_equal (arg1, unit_size)))
+	    return false;
+	}
+      else
+	return false;
+    }
+  else
+    return false;
+
+  /* Check 3.
+     check that address of D.1605_6 was not taken.
+     FIXME: if D.1605_6 is gimple reg than it cannot be addressable.  */
+
+  return true;
+}
+
+/* Register the parameter and return types of function FN.  The type
+   ESCAPES if the function is visible outside of the compilation
+   unit.  */
+static void
+check_function_parameter_and_return_types (tree fn, bool escapes)
+{
+  tree arg;
+
+  if (prototype_p (TREE_TYPE (fn)))
+    {
+      for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
+	   arg && TREE_VALUE (arg) != void_type_node;
+	   arg = TREE_CHAIN (arg))
+	{
+	  tree type = get_canon_type (TREE_VALUE (arg), false, false);
+	  if (escapes)
+	    mark_interesting_type (type, EXPOSED_PARAMETER);
+	}
+    }
+  else
+    {
+      /* FIXME - According to Geoff Keating, we should never have to
+	 do this; the front ends should always process the arg list
+	 from the TYPE_ARG_LIST. However, Geoff is wrong, this code
+	 does seem to be live.  */
+
+      for (arg = DECL_ARGUMENTS (fn); arg; arg = DECL_CHAIN (arg))
+	{
+	  tree type = get_canon_type (TREE_TYPE (arg), false, false);
+	  if (escapes)
+	    mark_interesting_type (type, EXPOSED_PARAMETER);
+	}
+    }
+  if (escapes)
+    {
+      tree type = get_canon_type (TREE_TYPE (TREE_TYPE (fn)), false, false);
+      mark_interesting_type (type, EXPOSED_PARAMETER);
+    }
+}
+
+/* Return true if the variable T is the right kind of static variable to
+   perform compilation unit scope escape analysis.  */
+
+static inline void
+has_proper_scope_for_analysis (tree t)
+{
+  /* If the variable has the "used" attribute, treat it as if it had a
+     been touched by the devil.  */
+  tree type = get_canon_type (TREE_TYPE (t), false, false);
+  if (!type) return;
+
+  if (DECL_PRESERVE_P (t))
+    {
+      mark_interesting_type (type, FULL_ESCAPE);
+      return;
+    }
+
+  /* Do not want to do anything with volatile except mark any
+     function that uses one to be not const or pure.  */
+  if (TREE_THIS_VOLATILE (t))
+    return;
+
+  /* Do not care about a local automatic that is not static.  */
+  if (!TREE_STATIC (t) && !DECL_EXTERNAL (t))
+    return;
+
+  if (DECL_EXTERNAL (t) || TREE_PUBLIC (t))
+    {
+      /* If the front end set the variable to be READONLY and
+	 constant, we can allow this variable in pure or const
+	 functions but the scope is too large for our analysis to set
+	 these bits ourselves.  */
+
+      if (TREE_READONLY (t)
+	  && DECL_INITIAL (t)
+	  && is_gimple_min_invariant (DECL_INITIAL (t)))
+	; /* Read of a constant, do not change the function state.  */
+      else
+	{
+	  /* The type escapes for all public and externs. */
+	  mark_interesting_type (type, FULL_ESCAPE);
+	}
+    }
+}
+
+/* If T is a VAR_DECL for a static that we are interested in, add the
+   uid to the bitmap.  */
+
+static void
+check_operand (tree t)
+{
+  if (!t) return;
+
+  /* This is an assignment from a function, register the types as
+     escaping.  */
+  if (TREE_CODE (t) == FUNCTION_DECL)
+    check_function_parameter_and_return_types (t, true);
+
+  else if (TREE_CODE (t) == VAR_DECL)
+    has_proper_scope_for_analysis (t);
+}
+
+/* Examine tree T for references.   */
+
+static void
+check_tree (tree t)
+{
+  /* We want to catch here also REALPART_EXPR and IMAGEPART_EXPR,
+     but they already included in handled_component_p.  */
+  while (handled_component_p (t))
+    {
+      if (TREE_CODE (t) == ARRAY_REF)
+	check_operand (TREE_OPERAND (t, 1));
+      t = TREE_OPERAND (t, 0);
+    }
+
+  if (INDIRECT_REF_P (t))
+/*  || TREE_CODE (t) == MEM_REF) */
+    check_tree (TREE_OPERAND (t, 0));
+
+  if (SSA_VAR_P (t) || (TREE_CODE (t) == FUNCTION_DECL))
+    {
+      check_operand (t);
+      if (DECL_P (t) && DECL_INITIAL (t))
+	check_tree (DECL_INITIAL (t));
+    }
+}
+
+/* Create an address_of edge FROM_TYPE.TO_TYPE.  */
+static void
+mark_interesting_addressof (tree to_type, tree from_type)
+{
+  int from_uid;
+  int to_uid;
+  bitmap type_map;
+  splay_tree_node result;
+
+  from_type = get_canon_type (from_type, false, false);
+  to_type = get_canon_type (to_type, false, false);
+
+  if (!from_type || !to_type)
+    return;
+
+  from_uid = TYPE_UID (from_type);
+  to_uid = TYPE_UID (to_type);
+
+  gcc_assert (ipa_type_escape_star_count_of_interesting_type (from_type) == 0);
+
+  /* Process the Y into X map pointer.  */
+  result = splay_tree_lookup (uid_to_addressof_down_map,
+			      (splay_tree_key) from_uid);
+
+  if (result)
+    type_map = (bitmap) result->value;
+  else
+    {
+      type_map = BITMAP_ALLOC (&ipa_obstack);
+      splay_tree_insert (uid_to_addressof_down_map,
+			 from_uid,
+			 (splay_tree_value)type_map);
+    }
+  bitmap_set_bit (type_map, TYPE_UID (to_type));
+
+  /* Process the X into Y reverse map pointer.  */
+  result =
+    splay_tree_lookup (uid_to_addressof_up_map, (splay_tree_key) to_uid);
+
+  if (result)
+    type_map = (bitmap) result->value;
+  else
+    {
+      type_map = BITMAP_ALLOC (&ipa_obstack);
+      splay_tree_insert (uid_to_addressof_up_map,
+			 to_uid,
+			 (splay_tree_value)type_map);
+    }
+  bitmap_set_bit (type_map, TYPE_UID (from_type));
+}
+
+/* Scan tree T to see if there are any addresses taken in within T.  */
+
+static void
+look_for_address_of (tree t)
+{
+  if (TREE_CODE (t) == ADDR_EXPR)
+    {
+      tree x = get_base_var (t);
+      tree cref = TREE_OPERAND (t, 0);
+
+      /* If we have an expression of the form "&a.b.c.d", mark a.b,
+	 b.c and c.d. as having its address taken.  */
+      tree fielddecl = NULL_TREE;
+      while (cref!= x)
+	{
+	  if (TREE_CODE (cref) == COMPONENT_REF)
+	    {
+	      fielddecl =  TREE_OPERAND (cref, 1);
+	      mark_interesting_addressof (TREE_TYPE (fielddecl),
+					  DECL_FIELD_CONTEXT (fielddecl));
+	    }
+	  else if (TREE_CODE (cref) == ARRAY_REF)
+	    get_canon_type (TREE_TYPE (cref), false, false);
+
+	  cref = TREE_OPERAND (cref, 0);
+	}
+
+      if (TREE_CODE (x) == VAR_DECL)
+	has_proper_scope_for_analysis (x);
+    }
+}
+
+
+/* Scan tree T to see if there are any casts within it.  */
+
+static unsigned int
+look_for_casts (tree t)
+{
+  unsigned int cast = 0;
+
+  if (CONVERT_EXPR_P (t) || TREE_CODE (t) == VIEW_CONVERT_EXPR)
+    {
+      tree castfromvar = TREE_OPERAND (t, 0);
+      cast = cast | check_cast (TREE_TYPE (t), castfromvar);
+    }
+  else
+    while (handled_component_p (t))
+      {
+	t = TREE_OPERAND (t, 0);
+	if (TREE_CODE (t) == VIEW_CONVERT_EXPR)
+	  {
+	    /* This may be some part of a component ref.
+	       IE it may be a.b.VIEW_CONVERT_EXPR<weird_type>(c).d, AFAIK.
+	       castfromref will give you a.b.c, not a. */
+	    tree castfromref = TREE_OPERAND (t, 0);
+	    cast = cast | check_cast (TREE_TYPE (t), castfromref);
+	  }
+	else if (TREE_CODE (t) == COMPONENT_REF)
+	  get_canon_type (TREE_TYPE (TREE_OPERAND (t, 1)), false, false);
+      }
+
+  if (!cast)
+    cast = CT_NO_CAST;
+  return cast;
+}
+
+/* Check to see if T is a read or address of operation on a static var
+   we are interested in analyzing.  */
+
+static void
+check_rhs_var (tree t)
+{
+  look_for_address_of (t);
+  check_tree (t);
+}
+
+/* Check to see if T is an assignment to a static var we are
+   interested in analyzing.  */
+
+static void
+check_lhs_var (tree t)
+{
+  check_tree (t);
+}
+
+/* This is a scaled down version of get_asm_expr_operands from
+   tree_ssa_operands.c.  The version there runs much later and assumes
+   that aliasing information is already available. Here we are just
+   trying to find if the set of inputs and outputs contain references
+   or address of operations to local.  FN is the function being
+   analyzed and STMT is the actual asm statement.  */
+
+static void
+check_asm (gimple stmt)
+{
+  size_t i;
+
+  for (i = 0; i < gimple_asm_noutputs (stmt); i++)
+    check_lhs_var (gimple_asm_output_op (stmt, i));
+
+  for (i = 0; i < gimple_asm_ninputs (stmt); i++)
+    check_rhs_var (gimple_asm_input_op (stmt, i));
+
+  /* There is no code here to check for asm memory clobbers.  The
+     casual maintainer might think that such code would be necessary,
+     but that appears to be wrong.  In other parts of the compiler,
+     the asm memory clobbers are assumed to only clobber variables
+     that are addressable.  All types with addressable instances are
+     assumed to already escape.  So, we are protected here.  */
+}
+
+
+/* Check the parameters of function call to CALL to mark the
+   types that pass across the function boundary.  Also check to see if
+   this is either an indirect call, a call outside the compilation
+   unit.  */
+
+static void
+check_call (gimple call)
+{
+  tree callee_t = gimple_call_fndecl (call);
+  struct cgraph_node* callee;
+  enum availability avail = AVAIL_NOT_AVAILABLE;
+  size_t i;
+
+  for (i = 0; i < gimple_call_num_args (call); i++)
+    check_rhs_var (gimple_call_arg (call, i));
+
+  if (callee_t)
+    {
+      tree arg_type;
+      tree last_arg_type = NULL;
+      callee = cgraph_node(callee_t);
+      avail = cgraph_function_body_availability (callee);
+
+      /* Check that there are no implicit casts in the passing of
+	 parameters.  */
+      if (prototype_p (TREE_TYPE (callee_t)))
+	{
+	  for (arg_type = TYPE_ARG_TYPES (TREE_TYPE (callee_t)), i = 0;
+	       arg_type && TREE_VALUE (arg_type) != void_type_node
+	       && i < gimple_call_num_args (call);
+	       arg_type = TREE_CHAIN (arg_type), i++)
+	    {
+	      tree operand = gimple_call_arg (call, i);
+	      if (operand)
+		{
+		  last_arg_type = TREE_VALUE(arg_type);
+		  check_cast (last_arg_type, operand);
+		}
+	      else
+		/* The code reaches here for some unfortunate
+		   builtin functions that do not have a list of
+		   argument types.  */
+		break;
+	    }
+	}
+      else
+	{
+	  /* FIXME - According to Geoff Keating, we should never
+	     have to do this; the front ends should always process
+	     the arg list from the TYPE_ARG_LIST. */
+	  for (arg_type = DECL_ARGUMENTS (callee_t), i = 0;
+	       arg_type && i < gimple_call_num_args (call);
+	       arg_type = TREE_CHAIN (arg_type), i++)
+	    {
+	      tree operand = gimple_call_arg (call, i);
+	      if (operand)
+		{
+		  last_arg_type = TREE_TYPE (arg_type);
+		  check_cast (last_arg_type, operand);
+		}
+	      else
+		/* The code reaches here for some unfortunate
+		   builtin functions that do not have a list of
+		   argument types.  */
+		break;
+	    }
+	}
+
+      /* In the case where we have a var_args function, we need to
+	 check the remaining parameters against the last argument.  */
+      arg_type = last_arg_type;
+      for ( ; i < gimple_call_num_args (call); i++)
+	{
+	  tree operand = gimple_call_arg (call, i);
+	  if (arg_type)
+	    check_cast (arg_type, operand);
+	  else
+	    {
+	      /* The code reaches here for some unfortunate
+		 builtin functions that do not have a list of
+		 argument types.  Most of these functions have
+		 been marked as having their parameters not
+		 escape, but for the rest, the type is doomed.  */
+	      tree type = get_canon_type (TREE_TYPE (operand), false, false);
+	      mark_interesting_type (type, FULL_ESCAPE);
+	    }
+	}
+    }
+
+  /* The callee is either unknown (indirect call) or there is just no
+     scannable code for it (external call) .  We look to see if there
+     are any bits available for the callee (such as by declaration or
+     because it is builtin) and process solely on the basis of those
+     bits. */
+  if (avail == AVAIL_NOT_AVAILABLE || avail == AVAIL_OVERWRITABLE)
+    {
+      /* If this is a direct call to an external function, mark all of
+	 the parameter and return types.  */
+      for (i = 0; i < gimple_call_num_args (call); i++)
+	{
+	  tree operand = gimple_call_arg (call, i);
+	  tree type = get_canon_type (TREE_TYPE (operand), false, false);
+	  mark_interesting_type (type, EXPOSED_PARAMETER);
+	}
+
+      if (callee_t)
+	{
+	  tree type =
+	    get_canon_type (TREE_TYPE (TREE_TYPE (callee_t)), false, false);
+	  mark_interesting_type (type, EXPOSED_PARAMETER);
+	}
+    }
+}
+
+/* CODE is the operation on OP0 and OP1.  OP0 is the operand that we
+   *know* is a pointer type.  OP1 may be a pointer type.  */
+static bool
+okay_pointer_operation (enum tree_code code, tree op0, tree op1)
+{
+  tree op0type = TYPE_MAIN_VARIANT (TREE_TYPE (op0));
+
+  switch (code)
+    {
+    case MULT_EXPR:
+      /* Multiplication does not change alignment.  */
+      return true;
+      break;
+    case MINUS_EXPR:
+    case PLUS_EXPR:
+    case POINTER_PLUS_EXPR:
+      {
+	tree base, offset;
+	gimple offset_cast_stmt;
+
+	if (POINTER_TYPE_P (op0type)
+	    && TREE_CODE (op0) == SSA_NAME
+	    && TREE_CODE (op1) == SSA_NAME
+	    && is_array_access_through_pointer_and_index (code, op0, op1,
+							  &base,
+							  &offset,
+							  &offset_cast_stmt))
+	  return true;
+	else
+	  {
+	    tree size_of_op0_points_to = TYPE_SIZE_UNIT (TREE_TYPE (op0type));
+
+	    if (CONSTANT_CLASS_P (op1)
+		&& size_of_op0_points_to
+		&& multiple_of_p (TREE_TYPE (size_of_op0_points_to),
+				  op1, size_of_op0_points_to))
+	      return true;
+
+	    if (CONSTANT_CLASS_P (op0)
+		&& size_of_op0_points_to
+		&& multiple_of_p (TREE_TYPE (size_of_op0_points_to),
+				  op0, size_of_op0_points_to))
+	      return true;
+	  }
+      }
+      break;
+    default:
+      return false;
+    }
+  return false;
+}
+
+
+
+/* Helper for scan_for_refs.  Check the operands of an assignment to
+   mark types that may escape.  */
+
+static void
+check_assign (gimple t)
+{
+  /* First look on the lhs and see what variable is stored to */
+  check_lhs_var (gimple_assign_lhs (t));
+
+  /* For the purposes of figuring out what the cast affects */
+
+  /* Next check the operands on the rhs to see if they are ok. */
+  switch (TREE_CODE_CLASS (gimple_assign_rhs_code (t)))
+    {
+    case tcc_binary:
+      {
+	tree op0 = gimple_assign_rhs1 (t);
+	tree type0 = get_canon_type (TREE_TYPE (op0), false, false);
+	tree op1 = gimple_assign_rhs2 (t);
+	tree type1 = get_canon_type (TREE_TYPE (op1), false, false);
+
+	/* If this is pointer arithmetic of any bad sort, then
+	    we need to mark the types as bad.  For binary
+	    operations, no binary operator we currently support
+	    is always "safe" in regard to what it would do to
+	    pointers for purposes of determining which types
+	    escape, except operations of the size of the type.
+	    It is possible that min and max under the right set
+	    of circumstances and if the moon is in the correct
+	    place could be safe, but it is hard to see how this
+	    is worth the effort.  */
+	if (type0 && POINTER_TYPE_P (type0)
+	    && !okay_pointer_operation (gimple_assign_rhs_code (t), op0, op1))
+	  mark_interesting_type (type0, FULL_ESCAPE);
+
+	if (type1 && POINTER_TYPE_P (type1)
+	    && !okay_pointer_operation (gimple_assign_rhs_code (t), op1, op0))
+	  mark_interesting_type (type1, FULL_ESCAPE);
+
+	look_for_casts (op0);
+	look_for_casts (op1);
+	check_rhs_var (op0);
+	check_rhs_var (op1);
+      }
+      break;
+
+    case tcc_unary:
+      {
+	tree op0 = gimple_assign_rhs1 (t);
+	tree type0 = get_canon_type (TREE_TYPE (op0), false, false);
+
+	/* For unary operations, if the operation is NEGATE or ABS on
+	   a pointer, this is also considered pointer arithmetic and
+	   thus, bad for business.  */
+	if (type0
+	    && POINTER_TYPE_P (type0)
+	    && (TREE_CODE (op0) == NEGATE_EXPR
+	      || TREE_CODE (op0) == ABS_EXPR))
+	  mark_interesting_type (type0, FULL_ESCAPE);
+
+	check_rhs_var (op0);
+	look_for_casts (op0);
+      }
+      break;
+
+    case tcc_reference:
+      look_for_casts (gimple_assign_rhs1 (t));
+      check_rhs_var (gimple_assign_rhs1 (t));
+      break;
+
+    case tcc_declaration:
+      check_rhs_var (gimple_assign_rhs1 (t));
+      break;
+
+    case tcc_expression:
+      if (gimple_assign_rhs_code (t) == ADDR_EXPR)
+	{
+	  tree rhs = gimple_assign_rhs1 (t);
+	  look_for_casts (TREE_OPERAND (rhs, 0));
+	  check_rhs_var (rhs);
+	}
+      break;
+
+    default:
+      break;
+    }
+}
+
+
+/* Scan statement T for references to types and mark anything
+   interesting.  */
+
+static void
+scan_for_refs (gimple t)
+{
+  switch (gimple_code (t))
+    {
+    case GIMPLE_ASSIGN:
+      check_assign (t);
+      break;
+
+    case GIMPLE_CALL:
+      /* If this is a call to malloc, squirrel away the result so we
+	 do mark the resulting cast as being bad.  */
+      check_call (t);
+      break;
+
+    case GIMPLE_ASM:
+      check_asm (t);
+      break;
+
+    default:
+      break;
+    }
+
+  return;
+}
+
+
+/* The init routine for analyzing global static variable usage.  See
+   comments at top for description.  */
+static void
+ipa_init (void)
+{
+  bitmap_obstack_initialize (&ipa_obstack);
+  global_types_exposed_parameter = BITMAP_ALLOC (&ipa_obstack);
+  global_types_full_escape = BITMAP_ALLOC (&ipa_obstack);
+  global_types_seen = BITMAP_ALLOC (&ipa_obstack);
+
+  uid_to_canon_type = splay_tree_new (splay_tree_compare_ints, 0, 0);
+  all_canon_types = splay_tree_new (compare_type_brand, 0, 0);
+  type_to_canon_type = splay_tree_new (splay_tree_compare_pointers, 0, 0);
+  uid_to_subtype_map = splay_tree_new (splay_tree_compare_ints, 0, 0);
+  uid_to_addressof_down_map = splay_tree_new (splay_tree_compare_ints, 0, 0);
+  uid_to_addressof_up_map = splay_tree_new (splay_tree_compare_ints, 0, 0);
+
+  /* There are some shared nodes, in particular the initializers on
+     static declarations.  We do not need to scan them more than once
+     since all we would be interested in are the addressof
+     operations.  */
+  visited_nodes = pointer_set_create ();
+  initialized = true;
+}
+
+/* Check out the rhs of a static or global initialization VNODE to see
+   if any of them contain addressof operations.  Note that some of
+   these variables may not even be referenced in the code in this
+   compilation unit but their right hand sides may contain references
+   to variables defined within this unit.  */
+
+static void
+analyze_variable (struct varpool_node *vnode)
+{
+  tree global = vnode->decl;
+  tree type = get_canon_type (TREE_TYPE (global), false, false);
+
+  /* If this variable has exposure beyond the compilation unit, add
+     its type to the global types.  */
+
+  if (vnode->externally_visible)
+    mark_interesting_type (type, FULL_ESCAPE);
+
+  gcc_assert (TREE_CODE (global) == VAR_DECL);
+
+  if (DECL_INITIAL (global))
+    check_tree (DECL_INITIAL (global));
+}
+
+/* This is the main routine for finding the reference patterns for
+   global variables within a function FN.  */
+
+static void
+analyze_function (struct cgraph_node *fn)
+{
+  tree decl = fn->decl;
+  check_function_parameter_and_return_types (decl,
+					     fn->local.externally_visible);
+  if (dump_file)
+    fprintf (dump_file, "\n local analysis of %s", cgraph_node_name (fn));
+
+  {
+    struct function *this_cfun = DECL_STRUCT_FUNCTION (decl);
+    basic_block this_block;
+
+    FOR_EACH_BB_FN (this_block, this_cfun)
+      {
+	gimple_stmt_iterator gsi;
+	for (gsi = gsi_start_bb (this_block); !gsi_end_p (gsi); gsi_next (&gsi))
+	  scan_for_refs (gsi_stmt (gsi));
+      }
+  }
+
+  /* There may be const decls with interesting right hand sides.  */
+  if (DECL_STRUCT_FUNCTION (decl))
+    {
+      tree var;
+      unsigned ix;
+
+      FOR_EACH_LOCAL_DECL (DECL_STRUCT_FUNCTION (decl), ix, var)
+	{
+	  if (TREE_CODE (var) == VAR_DECL
+	      && DECL_INITIAL (var)
+	      && !TREE_STATIC (var))
+	    check_tree (DECL_INITIAL (var));
+	  get_canon_type (TREE_TYPE (var), false, false);
+	}
+    }
+}
+
+
+
+/* Convert a type_UID into a type.  */
+static tree
+type_for_uid (int uid)
+{
+  splay_tree_node result =
+    splay_tree_lookup (uid_to_canon_type, (splay_tree_key) uid);
+
+  if (result)
+    return (tree) result->value;
+  else return NULL;
+}
+
+/* Return a bitmap with the subtypes of the type for UID.  If it
+   does not exist, return either NULL or a new bitmap depending on the
+   value of CREATE.  */
+
+static bitmap
+subtype_map_for_uid (int uid, bool create)
+{
+  splay_tree_node result = splay_tree_lookup (uid_to_subtype_map,
+			      (splay_tree_key) uid);
+
+  if (result)
+    return (bitmap) result->value;
+  else if (create)
+    {
+      bitmap subtype_map = BITMAP_ALLOC (&ipa_obstack);
+      splay_tree_insert (uid_to_subtype_map,
+			 uid,
+			 (splay_tree_value)subtype_map);
+      return subtype_map;
+    }
+  else return NULL;
+}
+
+/* Mark all of the supertypes and field types of TYPE as being seen.
+   Also accumulate the subtypes for each type so that
+   close_types_full_escape can mark a subtype as escaping if the
+   supertype escapes.  */
+
+static void
+close_type_seen (tree type)
+{
+  tree field;
+  int i, uid;
+  tree binfo, base_binfo;
+
+  /* See thru all pointer tos and array ofs. */
+  type = get_canon_type (type, true, true);
+  if (!type)
+    return;
+
+  uid = TYPE_UID (type);
+
+  if (!bitmap_set_bit (been_there_done_that, uid))
+    return;
+
+  /* If we are doing a language with a type hierarchy, mark all of
+     the superclasses.  */
+  if (TYPE_BINFO (type))
+    for (binfo = TYPE_BINFO (type), i = 0;
+	 BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
+      {
+	tree binfo_type = BINFO_TYPE (base_binfo);
+	bitmap subtype_map = subtype_map_for_uid
+	  (TYPE_UID (TYPE_MAIN_VARIANT (binfo_type)), true);
+	bitmap_set_bit (subtype_map, uid);
+	close_type_seen (get_canon_type (binfo_type, true, true));
+      }
+
+  /* If the field is a struct or union type, mark all of the
+     subfields.  */
+  for (field = TYPE_FIELDS (type);
+       field;
+       field = DECL_CHAIN (field))
+    {
+      tree field_type;
+      if (TREE_CODE (field) != FIELD_DECL)
+	continue;
+
+      field_type = TREE_TYPE (field);
+      if (ipa_type_escape_star_count_of_interesting_or_array_type (field_type) >= 0)
+	close_type_seen (get_canon_type (field_type, true, true));
+    }
+}
+
+/* Take a TYPE that has been passed by value to an external function
+   and mark all of the fields that have pointer types as escaping. For
+   any of the non pointer types that are structures or unions,
+   recurse.  TYPE is never a pointer type.  */
+
+static void
+close_type_exposed_parameter (tree type)
+{
+  tree field;
+  int uid;
+
+  type = get_canon_type (type, false, false);
+  if (!type)
+    return;
+  uid = TYPE_UID (type);
+  gcc_assert (!POINTER_TYPE_P (type));
+
+  if (!bitmap_set_bit (been_there_done_that, uid))
+    return;
+
+  /* If the field is a struct or union type, mark all of the
+     subfields.  */
+  for (field = TYPE_FIELDS (type);
+       field;
+       field = TREE_CHAIN (field))
+    {
+      tree field_type;
+
+      if (TREE_CODE (field) != FIELD_DECL)
+	continue;
+
+      field_type = get_canon_type (TREE_TYPE (field), false, false);
+      mark_interesting_type (field_type, EXPOSED_PARAMETER);
+
+      /* Only recurse for non pointer types of structures and unions.  */
+      if (ipa_type_escape_star_count_of_interesting_type (field_type) == 0)
+	close_type_exposed_parameter (field_type);
+    }
+}
+
+/* The next function handles the case where a type fully escapes.
+   This means that not only does the type itself escape,
+
+   a) the type of every field recursively escapes
+   b) the type of every subtype escapes as well as the super as well
+   as all of the pointer to types for each field.
+
+   Note that pointer to types are not marked as escaping.  If the
+   pointed to type escapes, the pointer to type also escapes.
+
+   Take a TYPE that has had the address taken for an instance of it
+   and mark all of the types for its fields as having their addresses
+   taken. */
+
+static void
+close_type_full_escape (tree type)
+{
+  tree field;
+  unsigned int i;
+  int uid;
+  tree binfo, base_binfo;
+  bitmap_iterator bi;
+  bitmap subtype_map;
+  splay_tree_node address_result;
+
+  /* Strip off any pointer or array types.  */
+  type = get_canon_type (type, true, true);
+  if (!type)
+    return;
+  uid = TYPE_UID (type);
+
+  if (!bitmap_set_bit (been_there_done_that, uid))
+    return;
+
+  subtype_map = subtype_map_for_uid (uid, false);
+
+  /* If we are doing a language with a type hierarchy, mark all of
+     the superclasses.  */
+  if (TYPE_BINFO (type))
+    for (binfo = TYPE_BINFO (type), i = 0;
+	 BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
+      {
+	tree binfotype = BINFO_TYPE (base_binfo);
+	binfotype = mark_type (binfotype, FULL_ESCAPE);
+	close_type_full_escape (binfotype);
+      }
+
+  /* Mark as escaped any types that have been down casted to
+     this type. */
+  if (subtype_map)
+    EXECUTE_IF_SET_IN_BITMAP (subtype_map, 0, i, bi)
+      {
+	tree subtype = type_for_uid (i);
+	subtype = mark_type (subtype, FULL_ESCAPE);
+	close_type_full_escape (subtype);
+      }
+
+  /* If the field is a struct or union type, mark all of the
+     subfields.  */
+  for (field = TYPE_FIELDS (type);
+       field;
+       field = TREE_CHAIN (field))
+    {
+      tree field_type;
+      if (TREE_CODE (field) != FIELD_DECL)
+	continue;
+
+      field_type = TREE_TYPE (field);
+      if (ipa_type_escape_star_count_of_interesting_or_array_type (field_type) >= 0)
+	{
+	  field_type = mark_type (field_type, FULL_ESCAPE);
+	  close_type_full_escape (field_type);
+	}
+    }
+
+  /* For all of the types A that contain this type B and were part of
+     an expression like "&...A.B...", mark the A's as escaping.  */
+  address_result = splay_tree_lookup (uid_to_addressof_up_map,
+				      (splay_tree_key) uid);
+  if (address_result)
+    {
+      bitmap containing_classes = (bitmap) address_result->value;
+      EXECUTE_IF_SET_IN_BITMAP (containing_classes, 0, i, bi)
+	{
+	  close_type_full_escape (type_for_uid (i));
+	}
+    }
+}
+
+/* Transitively close the addressof bitmap for the type with UID.
+   This means that if we had a.b and b.c, a would have both b and c in
+   its maps.  */
+
+static bitmap
+close_addressof_down (int uid)
+{
+  bitmap_iterator bi;
+  splay_tree_node result =
+    splay_tree_lookup (uid_to_addressof_down_map, (splay_tree_key) uid);
+  bitmap map = NULL;
+  bitmap new_map;
+  unsigned int i;
+
+  if (result)
+    map = (bitmap) result->value;
+  else
+    return NULL;
+
+  if (!bitmap_set_bit (been_there_done_that, uid))
+    return map;
+
+  /* If the type escapes, get rid of the addressof map, it will not be
+     needed.  */
+  if (bitmap_bit_p (global_types_full_escape, uid))
+    {
+      BITMAP_FREE (map);
+      splay_tree_remove (uid_to_addressof_down_map, (splay_tree_key) uid);
+      return NULL;
+    }
+
+  /* The new_map will have all of the bits for the enclosed fields and
+     will have the unique id version of the old map.  */
+  new_map = BITMAP_ALLOC (&ipa_obstack);
+
+  EXECUTE_IF_SET_IN_BITMAP (map, 0, i, bi)
+    {
+      bitmap submap = close_addressof_down (i);
+      bitmap_set_bit (new_map, i);
+      if (submap)
+	bitmap_ior_into (new_map, submap);
+    }
+  result->value = (splay_tree_value) new_map;
+
+  BITMAP_FREE (map);
+  return new_map;
+}
+
+
+/* The main entry point for type escape analysis.  */
+
+static unsigned int
+type_escape_execute (void)
+{
+  struct cgraph_node *node;
+  struct varpool_node *vnode;
+  unsigned int i;
+  bitmap_iterator bi;
+  splay_tree_node result;
+
+  ipa_init ();
+
+  /* Process all of the variables first.  */
+  FOR_EACH_STATIC_VARIABLE (vnode)
+    analyze_variable (vnode);
+
+  /* Process all of the functions next.
+
+     We do not want to process any of the clones so we check that this
+     is a master clone.  However, we do need to process any
+     AVAIL_OVERWRITABLE functions (these are never clones) because
+     they may cause a type variable to escape.
+  */
+  for (node = cgraph_nodes; node; node = node->next)
+    if (node->analyzed && !node->clone_of)
+      analyze_function (node);
+
+
+  pointer_set_destroy (visited_nodes);
+  visited_nodes = NULL;
+
+  /* Do all of the closures to discover which types escape the
+     compilation unit.  */
+
+  been_there_done_that = BITMAP_ALLOC (&ipa_obstack);
+  bitmap_tmp = BITMAP_ALLOC (&ipa_obstack);
+
+  /* Examine the types that we have directly seen in scanning the code
+     and add to that any contained types or superclasses.  */
+
+  bitmap_copy (bitmap_tmp, global_types_seen);
+  EXECUTE_IF_SET_IN_BITMAP (bitmap_tmp, 0, i, bi)
+    {
+      tree type = type_for_uid (i);
+      /* Only look at records and unions and pointer tos.  */
+      if (ipa_type_escape_star_count_of_interesting_or_array_type (type) >= 0)
+	close_type_seen (type);
+    }
+  bitmap_clear (been_there_done_that);
+
+  /* Examine all of the types passed by value and mark any enclosed
+     pointer types as escaping.  */
+  bitmap_copy (bitmap_tmp, global_types_exposed_parameter);
+  EXECUTE_IF_SET_IN_BITMAP (bitmap_tmp, 0, i, bi)
+    {
+      close_type_exposed_parameter (type_for_uid (i));
+    }
+  bitmap_clear (been_there_done_that);
+
+  /* Close the types for escape.  If something escapes, then any
+     enclosed types escape as well as any subtypes.  */
+  bitmap_copy (bitmap_tmp, global_types_full_escape);
+  EXECUTE_IF_SET_IN_BITMAP (bitmap_tmp, 0, i, bi)
+    {
+      close_type_full_escape (type_for_uid (i));
+    }
+  bitmap_clear (been_there_done_that);
+
+  /* Before this pass, the uid_to_addressof_down_map for type X
+     contained an entry for Y if there had been an operation of the
+     form &X.Y.  This step adds all of the fields contained within Y
+     (recursively) to X's map.  */
+
+  result = splay_tree_min (uid_to_addressof_down_map);
+  while (result)
+    {
+      int uid = result->key;
+      /* Close the addressof map, i.e. copy all of the transitive
+	 substructures up to this level.  */
+      close_addressof_down (uid);
+      result = splay_tree_successor (uid_to_addressof_down_map, uid);
+    }
+
+  /* Do not need the array types and pointer types in the persistent
+     data structures.  */
+  result = splay_tree_min (all_canon_types);
+  while (result)
+    {
+      tree type = (tree) result->value;
+      tree key = (tree) result->key;
+      if (POINTER_TYPE_P (type)
+	  || TREE_CODE (type) == ARRAY_TYPE)
+	{
+	  splay_tree_remove (all_canon_types, (splay_tree_key) result->key);
+	  splay_tree_remove (type_to_canon_type, (splay_tree_key) type);
+	  splay_tree_remove (uid_to_canon_type, (splay_tree_key) TYPE_UID (type));
+	  bitmap_clear_bit (global_types_seen, TYPE_UID (type));
+	}
+      result = splay_tree_successor (all_canon_types, (splay_tree_key) key);
+    }
+
+  if (dump_file)
+    {
+      EXECUTE_IF_SET_IN_BITMAP (global_types_seen, 0, i, bi)
+	{
+	  /* The pointer types are in the global_types_full_escape
+	     bitmap but not in the backwards map.  They also contain
+	     no useful information since they are not marked.  */
+	  tree type = type_for_uid (i);
+	  fprintf(dump_file, "type %d ", i);
+	  print_generic_expr (dump_file, type, 0);
+	  if (bitmap_bit_p (global_types_full_escape, i))
+	    fprintf(dump_file, " escaped\n");
+	  else
+	    fprintf(dump_file, " contained\n");
+	}
+    }
+
+  /* Get rid of uid_to_addressof_up_map and its bitmaps.  */
+  result = splay_tree_min (uid_to_addressof_up_map);
+  while (result)
+    {
+      int uid = (int)result->key;
+      bitmap bm = (bitmap)result->value;
+
+      BITMAP_FREE (bm);
+      splay_tree_remove (uid_to_addressof_up_map, (splay_tree_key) uid);
+      result = splay_tree_successor (uid_to_addressof_up_map, uid);
+    }
+
+  /* Get rid of the subtype map.  */
+  result = splay_tree_min (uid_to_subtype_map);
+  while (result)
+    {
+      bitmap b = (bitmap)result->value;
+      BITMAP_FREE(b);
+      splay_tree_remove (uid_to_subtype_map, result->key);
+      result = splay_tree_min (uid_to_subtype_map);
+    }
+  splay_tree_delete (uid_to_subtype_map);
+  uid_to_subtype_map = NULL;
+
+  BITMAP_FREE (global_types_exposed_parameter);
+  BITMAP_FREE (been_there_done_that);
+  BITMAP_FREE (bitmap_tmp);
+  return 0;
+}
+
+static bool
+gate_type_escape_vars (void)
+{
+  return flag_ipa_struct_reorg && flag_whole_program && (optimize > 0);
+}
+
+struct simple_ipa_opt_pass pass_ipa_type_escape =
+{
+ {
+  SIMPLE_IPA_PASS,
+  "type-escape-var",			/* name */
+  gate_type_escape_vars,		/* gate */
+  type_escape_execute,			/* execute */
+  NULL,					/* sub */
+  NULL,					/* next */
+  0,					/* static_pass_number */
+  TV_IPA_TYPE_ESCAPE,	        	/* tv_id */
+  0,	                                /* properties_required */
+  0,					/* properties_provided */
+  0,					/* properties_destroyed */
+  0,					/* todo_flags_start */
+  0                                     /* todo_flags_finish */
+ }
+};