--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/tree-eh.c	Fri Jul 17 14:47:48 2009 +0900
@@ -0,0 +1,2593 @@
+/* Exception handling semantics and decomposition for trees.
+   Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009
+   Free Software Foundation, Inc.
+
+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/>.  */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "tree.h"
+#include "rtl.h"
+#include "tm_p.h"
+#include "flags.h"
+#include "function.h"
+#include "except.h"
+#include "tree-flow.h"
+#include "tree-dump.h"
+#include "tree-inline.h"
+#include "tree-iterator.h"
+#include "tree-pass.h"
+#include "timevar.h"
+#include "langhooks.h"
+#include "ggc.h"
+#include "toplev.h"
+#include "gimple.h"
+
+/* In some instances a tree and a gimple need to be stored in a same table,
+   i.e. in hash tables. This is a structure to do this. */
+typedef union {tree *tp; tree t; gimple g;} treemple;
+
+/* Nonzero if we are using EH to handle cleanups.  */
+static int using_eh_for_cleanups_p = 0;
+
+void
+using_eh_for_cleanups (void)
+{
+  using_eh_for_cleanups_p = 1;
+}
+
+/* Misc functions used in this file.  */
+
+/* Compare and hash for any structure which begins with a canonical
+   pointer.  Assumes all pointers are interchangeable, which is sort
+   of already assumed by gcc elsewhere IIRC.  */
+
+static int
+struct_ptr_eq (const void *a, const void *b)
+{
+  const void * const * x = (const void * const *) a;
+  const void * const * y = (const void * const *) b;
+  return *x == *y;
+}
+
+static hashval_t
+struct_ptr_hash (const void *a)
+{
+  const void * const * x = (const void * const *) a;
+  return (size_t)*x >> 4;
+}
+
+
+/* Remember and lookup EH region data for arbitrary statements.
+   Really this means any statement that could_throw_p.  We could
+   stuff this information into the stmt_ann data structure, but:
+
+   (1) We absolutely rely on this information being kept until
+   we get to rtl.  Once we're done with lowering here, if we lose
+   the information there's no way to recover it!
+
+   (2) There are many more statements that *cannot* throw as
+   compared to those that can.  We should be saving some amount
+   of space by only allocating memory for those that can throw.  */
+
+static void
+record_stmt_eh_region (struct eh_region *region, gimple t)
+{
+  if (!region)
+    return;
+
+  add_stmt_to_eh_region (t, get_eh_region_number (region));
+}
+
+
+/* Add statement T in function IFUN to EH region NUM.  */
+
+void
+add_stmt_to_eh_region_fn (struct function *ifun, gimple t, int num)
+{
+  struct throw_stmt_node *n;
+  void **slot;
+
+  gcc_assert (num >= 0);
+  gcc_assert (gimple_code (t) != GIMPLE_RESX);
+
+  n = GGC_NEW (struct throw_stmt_node);
+  n->stmt = t;
+  n->region_nr = num;
+
+  if (!get_eh_throw_stmt_table (ifun))
+    set_eh_throw_stmt_table (ifun, htab_create_ggc (31, struct_ptr_hash,
+						    struct_ptr_eq,
+						    ggc_free));
+
+  slot = htab_find_slot (get_eh_throw_stmt_table (ifun), n, INSERT);
+  gcc_assert (!*slot);
+  *slot = n;
+}
+
+
+/* Add statement T in the current function (cfun) to EH region number
+   NUM.  */
+
+void
+add_stmt_to_eh_region (gimple t, int num)
+{
+  add_stmt_to_eh_region_fn (cfun, t, num);
+}
+
+
+/* Remove statement T in function IFUN from the EH region holding it.  */
+
+bool
+remove_stmt_from_eh_region_fn (struct function *ifun, gimple t)
+{
+  struct throw_stmt_node dummy;
+  void **slot;
+
+  if (!get_eh_throw_stmt_table (ifun))
+    return false;
+
+  dummy.stmt = t;
+  slot = htab_find_slot (get_eh_throw_stmt_table (ifun), &dummy,
+                        NO_INSERT);
+  if (slot)
+    {
+      htab_clear_slot (get_eh_throw_stmt_table (ifun), slot);
+      return true;
+    }
+  else
+    return false;
+}
+
+
+/* Remove statement T in the current function (cfun) from the EH
+   region holding it.  */
+
+bool
+remove_stmt_from_eh_region (gimple t)
+{
+  return remove_stmt_from_eh_region_fn (cfun, t);
+}
+
+/* Determine if statement T is inside an EH region in function IFUN.
+   Return the EH region number if found, return -2 if IFUN does not
+   have an EH table and -1 if T could not be found in IFUN's EH region
+   table.  */
+
+int
+lookup_stmt_eh_region_fn (struct function *ifun, gimple t)
+{
+  struct throw_stmt_node *p, n;
+
+  if (!get_eh_throw_stmt_table (ifun))
+    return -2;
+
+  n.stmt = t;
+  p = (struct throw_stmt_node *) htab_find (get_eh_throw_stmt_table (ifun), &n);
+  return (p ? p->region_nr : -1);
+}
+
+
+/* Determine if statement T is inside an EH region in the current
+   function (cfun).  Return the EH region number if found, return -2
+   if cfun does not have an EH table and -1 if T could not be found in
+   cfun's EH region table.  */
+
+int
+lookup_stmt_eh_region (gimple t)
+{
+  /* We can get called from initialized data when -fnon-call-exceptions
+     is on; prevent crash.  */
+  if (!cfun)
+    return -1;
+
+  return lookup_stmt_eh_region_fn (cfun, t);
+}
+
+
+/* Determine if expression T is inside an EH region in the current
+   function (cfun).  Return the EH region number if found, return -2
+   if IFUN does not have an EH table and -1 if T could not be found in
+   IFUN's EH region table.  */
+
+int
+lookup_expr_eh_region (tree t)
+{
+  /* We can get called from initialized data when -fnon-call-exceptions
+     is on; prevent crash.  */
+  if (!cfun)
+    return -1;
+
+  if (!get_eh_throw_stmt_table (cfun))
+    return -2;
+
+  if (t && EXPR_P (t))
+    {
+      tree_ann_common_t ann = tree_common_ann (t);
+      if (ann)
+	return (int) ann->rn;
+    }
+
+  return -1;
+}
+
+
+/* First pass of EH node decomposition.  Build up a tree of GIMPLE_TRY_FINALLY
+   nodes and LABEL_DECL nodes.  We will use this during the second phase to
+   determine if a goto leaves the body of a TRY_FINALLY_EXPR node.  */
+
+struct finally_tree_node
+{
+  /* When storing a GIMPLE_TRY, we have to record a gimple.  However
+     when deciding whether a GOTO to a certain LABEL_DECL (which is a
+     tree) leaves the TRY block, its necessary to record a tree in
+     this field.  Thus a treemple is used. */
+  treemple child; 
+  gimple parent;
+};
+
+/* Note that this table is *not* marked GTY.  It is short-lived.  */
+static htab_t finally_tree;
+
+static void
+record_in_finally_tree (treemple child, gimple parent)
+{
+  struct finally_tree_node *n;
+  void **slot;
+
+  n = XNEW (struct finally_tree_node);
+  n->child = child;
+  n->parent = parent;
+
+  slot = htab_find_slot (finally_tree, n, INSERT);
+  gcc_assert (!*slot);
+  *slot = n;
+}
+
+static void
+collect_finally_tree (gimple stmt, gimple region);
+
+/* Go through the gimple sequence.  Works with collect_finally_tree to 
+   record all GIMPLE_LABEL and GIMPLE_TRY statements. */
+
+static void
+collect_finally_tree_1 (gimple_seq seq, gimple region)
+{
+  gimple_stmt_iterator gsi;
+
+  for (gsi = gsi_start (seq); !gsi_end_p (gsi); gsi_next (&gsi))
+    collect_finally_tree (gsi_stmt (gsi), region);
+}
+
+static void
+collect_finally_tree (gimple stmt, gimple region)
+{
+  treemple temp;
+
+  switch (gimple_code (stmt))
+    {
+    case GIMPLE_LABEL:
+      temp.t = gimple_label_label (stmt);
+      record_in_finally_tree (temp, region);
+      break;
+
+    case GIMPLE_TRY:
+      if (gimple_try_kind (stmt) == GIMPLE_TRY_FINALLY)
+        {
+          temp.g = stmt;
+          record_in_finally_tree (temp, region);
+          collect_finally_tree_1 (gimple_try_eval (stmt), stmt);
+	  collect_finally_tree_1 (gimple_try_cleanup (stmt), region);
+        }
+      else if (gimple_try_kind (stmt) == GIMPLE_TRY_CATCH)
+        {
+          collect_finally_tree_1 (gimple_try_eval (stmt), region);
+          collect_finally_tree_1 (gimple_try_cleanup (stmt), region);
+        }
+      break;
+
+    case GIMPLE_CATCH:
+      collect_finally_tree_1 (gimple_catch_handler (stmt), region);
+      break;
+
+    case GIMPLE_EH_FILTER:
+      collect_finally_tree_1 (gimple_eh_filter_failure (stmt), region);
+      break;
+
+    default:
+      /* A type, a decl, or some kind of statement that we're not
+	 interested in.  Don't walk them.  */
+      break;
+    }
+}
+
+
+/* Use the finally tree to determine if a jump from START to TARGET
+   would leave the try_finally node that START lives in.  */
+
+static bool
+outside_finally_tree (treemple start, gimple target)
+{
+  struct finally_tree_node n, *p;
+
+  do
+    {
+      n.child = start;
+      p = (struct finally_tree_node *) htab_find (finally_tree, &n);
+      if (!p)
+	return true;
+      start.g = p->parent;
+    }
+  while (start.g != target);
+
+  return false;
+}
+
+/* Second pass of EH node decomposition.  Actually transform the GIMPLE_TRY
+   nodes into a set of gotos, magic labels, and eh regions.
+   The eh region creation is straight-forward, but frobbing all the gotos
+   and such into shape isn't.  */
+
+/* State of the world while lowering.  */
+
+struct leh_state
+{
+  /* What's "current" while constructing the eh region tree.  These
+     correspond to variables of the same name in cfun->eh, which we
+     don't have easy access to.  */
+  struct eh_region *cur_region;
+  struct eh_region *prev_try;
+
+  /* Processing of TRY_FINALLY requires a bit more state.  This is
+     split out into a separate structure so that we don't have to
+     copy so much when processing other nodes.  */
+  struct leh_tf_state *tf;
+};
+
+struct leh_tf_state
+{
+  /* Pointer to the GIMPLE_TRY_FINALLY node under discussion.  The
+     try_finally_expr is the original GIMPLE_TRY_FINALLY.  We need to retain
+     this so that outside_finally_tree can reliably reference the tree used
+     in the collect_finally_tree data structures.  */
+  gimple try_finally_expr;
+  gimple top_p;
+  /* While lowering a top_p usually it is expanded into multiple statements,
+     thus we need the following field to store them. */
+  gimple_seq top_p_seq;
+
+  /* The state outside this try_finally node.  */
+  struct leh_state *outer;
+
+  /* The exception region created for it.  */
+  struct eh_region *region;
+
+  /* The GOTO_QUEUE is is an array of GIMPLE_GOTO and GIMPLE_RETURN statements
+     that are seen to escape this GIMPLE_TRY_FINALLY node.
+     The idea is to record a gimple statement for everything except for 
+     the conditionals, which get their labels recorded. Since labels are of
+     type 'tree', we need this node to store both gimple and tree objects.
+     REPL_STMT is the sequence used to replace the goto/return statement.
+     CONT_STMT is used to store the statement that allows the return/goto to
+     jump to the original destination. */
+  struct goto_queue_node {
+    treemple stmt;
+    gimple_seq repl_stmt;
+    gimple cont_stmt;
+    int index;
+    /* this is used when index >= 0 to indicate that stmt is a label(as
+       opposed to a goto stmt) */
+    int is_label;
+  } *goto_queue;
+  size_t goto_queue_size;
+  size_t goto_queue_active;
+
+  /* Pointer map to help in searching goto_queue when it is large.  */
+  struct pointer_map_t *goto_queue_map;
+
+  /* The set of unique labels seen as entries in the goto queue.  */
+  VEC(tree,heap) *dest_array;
+
+  /* A label to be added at the end of the completed transformed
+     sequence.  It will be set if may_fallthru was true *at one time*,
+     though subsequent transformations may have cleared that flag.  */
+  tree fallthru_label;
+
+  /* A label that has been registered with except.c to be the
+     landing pad for this try block.  */
+  tree eh_label;
+
+  /* True if it is possible to fall out the bottom of the try block.
+     Cleared if the fallthru is converted to a goto.  */
+  bool may_fallthru;
+
+  /* True if any entry in goto_queue is a GIMPLE_RETURN.  */
+  bool may_return;
+
+  /* True if the finally block can receive an exception edge.
+     Cleared if the exception case is handled by code duplication.  */
+  bool may_throw;
+};
+
+static gimple_seq lower_eh_filter (struct leh_state *, gimple);
+
+/* Search for STMT in the goto queue.  Return the replacement,
+   or null if the statement isn't in the queue.  */
+
+#define LARGE_GOTO_QUEUE 20
+
+static void lower_eh_constructs_1 (struct leh_state *state, gimple_seq seq);
+
+static gimple_seq
+find_goto_replacement (struct leh_tf_state *tf, treemple stmt)
+{
+  unsigned int i;
+  void **slot;
+
+  if (tf->goto_queue_active < LARGE_GOTO_QUEUE)
+    {
+      for (i = 0; i < tf->goto_queue_active; i++)
+	if ( tf->goto_queue[i].stmt.g == stmt.g)
+	  return tf->goto_queue[i].repl_stmt;
+      return NULL;
+    }
+
+  /* If we have a large number of entries in the goto_queue, create a
+     pointer map and use that for searching.  */
+
+  if (!tf->goto_queue_map)
+    {
+      tf->goto_queue_map = pointer_map_create ();
+      for (i = 0; i < tf->goto_queue_active; i++)
+	{
+	  slot = pointer_map_insert (tf->goto_queue_map,
+                                     tf->goto_queue[i].stmt.g);
+          gcc_assert (*slot == NULL);
+	  *slot = &tf->goto_queue[i];
+	}
+    }
+
+  slot = pointer_map_contains (tf->goto_queue_map, stmt.g);
+  if (slot != NULL)
+    return (((struct goto_queue_node *) *slot)->repl_stmt);
+
+  return NULL;
+}
+
+/* A subroutine of replace_goto_queue_1.  Handles the sub-clauses of a
+   lowered GIMPLE_COND.  If, by chance, the replacement is a simple goto,
+   then we can just splat it in, otherwise we add the new stmts immediately
+   after the GIMPLE_COND and redirect.  */
+
+static void
+replace_goto_queue_cond_clause (tree *tp, struct leh_tf_state *tf,
+				gimple_stmt_iterator *gsi)
+{
+  tree label;
+  gimple_seq new_seq;
+  treemple temp;
+
+  temp.tp = tp;
+  new_seq = find_goto_replacement (tf, temp);
+  if (!new_seq)
+    return;
+
+  if (gimple_seq_singleton_p (new_seq)
+      && gimple_code (gimple_seq_first_stmt (new_seq)) == GIMPLE_GOTO)
+    {
+      *tp = gimple_goto_dest (gimple_seq_first_stmt (new_seq));
+      return;
+    }
+
+  label = create_artificial_label ();
+  /* Set the new label for the GIMPLE_COND */
+  *tp = label;
+
+  gsi_insert_after (gsi, gimple_build_label (label), GSI_CONTINUE_LINKING);
+  gsi_insert_seq_after (gsi, gimple_seq_copy (new_seq), GSI_CONTINUE_LINKING);
+}
+
+/* The real work of replace_goto_queue.  Returns with TSI updated to
+   point to the next statement.  */
+
+static void replace_goto_queue_stmt_list (gimple_seq, struct leh_tf_state *);
+
+static void
+replace_goto_queue_1 (gimple stmt, struct leh_tf_state *tf,
+		      gimple_stmt_iterator *gsi)
+{
+  gimple_seq seq;
+  treemple temp;
+  temp.g = NULL;
+
+  switch (gimple_code (stmt))
+    {
+    case GIMPLE_GOTO:
+    case GIMPLE_RETURN:
+      temp.g = stmt;
+      seq = find_goto_replacement (tf, temp);
+      if (seq)
+	{
+	  gsi_insert_seq_before (gsi, gimple_seq_copy (seq), GSI_SAME_STMT);
+	  gsi_remove (gsi, false);
+	  return;
+	}
+      break;
+
+    case GIMPLE_COND:
+      replace_goto_queue_cond_clause (gimple_op_ptr (stmt, 2), tf, gsi);
+      replace_goto_queue_cond_clause (gimple_op_ptr (stmt, 3), tf, gsi);
+      break;
+
+    case GIMPLE_TRY:
+      replace_goto_queue_stmt_list (gimple_try_eval (stmt), tf);
+      replace_goto_queue_stmt_list (gimple_try_cleanup (stmt), tf);
+      break;
+    case GIMPLE_CATCH:
+      replace_goto_queue_stmt_list (gimple_catch_handler (stmt), tf);
+      break;
+    case GIMPLE_EH_FILTER:
+      replace_goto_queue_stmt_list (gimple_eh_filter_failure (stmt), tf);
+      break;
+
+    default:
+      /* These won't have gotos in them.  */
+      break;
+    }
+
+  gsi_next (gsi);
+}
+
+/* A subroutine of replace_goto_queue.  Handles GIMPLE_SEQ.  */
+
+static void
+replace_goto_queue_stmt_list (gimple_seq seq, struct leh_tf_state *tf)
+{
+  gimple_stmt_iterator gsi = gsi_start (seq);
+
+  while (!gsi_end_p (gsi))
+    replace_goto_queue_1 (gsi_stmt (gsi), tf, &gsi);
+}
+
+/* Replace all goto queue members.  */
+
+static void
+replace_goto_queue (struct leh_tf_state *tf)
+{
+  if (tf->goto_queue_active == 0)
+    return;
+  replace_goto_queue_stmt_list (tf->top_p_seq, tf);
+}
+
+/* Add a new record to the goto queue contained in TF. NEW_STMT is the
+   data to be added, IS_LABEL indicates whether NEW_STMT is a label or
+   a gimple return. */
+
+static void
+record_in_goto_queue (struct leh_tf_state *tf,
+                      treemple new_stmt,
+                      int index,
+                      bool is_label)
+{
+  size_t active, size;
+  struct goto_queue_node *q;
+
+  gcc_assert (!tf->goto_queue_map);
+
+  active = tf->goto_queue_active;
+  size = tf->goto_queue_size;
+  if (active >= size)
+    {
+      size = (size ? size * 2 : 32);
+      tf->goto_queue_size = size;
+      tf->goto_queue
+         = XRESIZEVEC (struct goto_queue_node, tf->goto_queue, size);
+    }
+
+  q = &tf->goto_queue[active];
+  tf->goto_queue_active = active + 1;
+
+  memset (q, 0, sizeof (*q));
+  q->stmt = new_stmt;
+  q->index = index;
+  q->is_label = is_label;
+}
+
+/* Record the LABEL label in the goto queue contained in TF.
+   TF is not null.  */
+
+static void
+record_in_goto_queue_label (struct leh_tf_state *tf, treemple stmt, tree label)
+{
+  int index;
+  treemple temp, new_stmt;
+
+  if (!label)
+    return;
+
+  /* Computed and non-local gotos do not get processed.  Given
+     their nature we can neither tell whether we've escaped the
+     finally block nor redirect them if we knew.  */
+  if (TREE_CODE (label) != LABEL_DECL)
+    return;
+
+  /* No need to record gotos that don't leave the try block.  */
+  temp.t = label;
+  if (!outside_finally_tree (temp, tf->try_finally_expr))
+    return;
+
+  if (! tf->dest_array)
+    {
+      tf->dest_array = VEC_alloc (tree, heap, 10);
+      VEC_quick_push (tree, tf->dest_array, label);
+      index = 0;
+    }
+  else
+    {
+      int n = VEC_length (tree, tf->dest_array);
+      for (index = 0; index < n; ++index)
+        if (VEC_index (tree, tf->dest_array, index) == label)
+          break;
+      if (index == n)
+        VEC_safe_push (tree, heap, tf->dest_array, label);
+    }
+
+  /* In the case of a GOTO we want to record the destination label,
+     since with a GIMPLE_COND we have an easy access to the then/else
+     labels. */
+  new_stmt = stmt;
+  record_in_goto_queue (tf, new_stmt, index, true);
+
+}
+
+/* For any GIMPLE_GOTO or GIMPLE_RETURN, decide whether it leaves a try_finally
+   node, and if so record that fact in the goto queue associated with that
+   try_finally node.  */
+
+static void
+maybe_record_in_goto_queue (struct leh_state *state, gimple stmt)
+{
+  struct leh_tf_state *tf = state->tf;
+  treemple new_stmt;
+
+  if (!tf)
+    return;
+
+  switch (gimple_code (stmt))
+    {
+    case GIMPLE_COND:
+      new_stmt.tp = gimple_op_ptr (stmt, 2);
+      record_in_goto_queue_label (tf, new_stmt, gimple_cond_true_label (stmt));
+      new_stmt.tp = gimple_op_ptr (stmt, 3);
+      record_in_goto_queue_label (tf, new_stmt, gimple_cond_false_label (stmt));
+      break;
+    case GIMPLE_GOTO:
+      new_stmt.g = stmt;
+      record_in_goto_queue_label (tf, new_stmt, gimple_goto_dest (stmt));
+      break;
+
+    case GIMPLE_RETURN:
+      tf->may_return = true;
+      new_stmt.g = stmt;
+      record_in_goto_queue (tf, new_stmt, -1, false);
+      break;
+
+    default:
+      gcc_unreachable ();
+    }
+}
+
+
+#ifdef ENABLE_CHECKING
+/* We do not process GIMPLE_SWITCHes for now.  As long as the original source
+   was in fact structured, and we've not yet done jump threading, then none
+   of the labels will leave outer GIMPLE_TRY_FINALLY nodes. Verify this.  */
+
+static void
+verify_norecord_switch_expr (struct leh_state *state, gimple switch_expr)
+{
+  struct leh_tf_state *tf = state->tf;
+  size_t i, n;
+
+  if (!tf)
+    return;
+
+  n = gimple_switch_num_labels (switch_expr);
+
+  for (i = 0; i < n; ++i)
+    {
+      treemple temp;
+      tree lab = CASE_LABEL (gimple_switch_label (switch_expr, i));
+      temp.t = lab;
+      gcc_assert (!outside_finally_tree (temp, tf->try_finally_expr));
+    }
+}
+#else
+#define verify_norecord_switch_expr(state, switch_expr)
+#endif
+
+/* Redirect a RETURN_EXPR pointed to by STMT_P to FINLAB.  Place in CONT_P
+   whatever is needed to finish the return.  If MOD is non-null, insert it
+   before the new branch.  RETURN_VALUE_P is a cache containing a temporary
+   variable to be used in manipulating the value returned from the function.  */
+
+static void
+do_return_redirection (struct goto_queue_node *q, tree finlab, gimple_seq mod,
+		       tree *return_value_p)
+{
+  tree ret_expr;
+  gimple x;
+
+  /* In the case of a return, the queue node must be a gimple statement. */
+  gcc_assert (!q->is_label);
+
+  ret_expr = gimple_return_retval (q->stmt.g);
+
+  if (ret_expr)
+    {
+      if (!*return_value_p)
+        *return_value_p = ret_expr;
+      else
+        gcc_assert (*return_value_p == ret_expr);
+      q->cont_stmt = q->stmt.g;
+      /* The nasty part about redirecting the return value is that the
+	 return value itself is to be computed before the FINALLY block
+	 is executed.  e.g.
+
+		int x;
+		int foo (void)
+		{
+		  x = 0;
+		  try {
+		    return x;
+		  } finally {
+		    x++;
+		  }
+		}
+
+	  should return 0, not 1.  Arrange for this to happen by copying
+	  computed the return value into a local temporary.  This also
+	  allows us to redirect multiple return statements through the
+	  same destination block; whether this is a net win or not really
+	  depends, I guess, but it does make generation of the switch in
+	  lower_try_finally_switch easier.  */
+
+      if (TREE_CODE (ret_expr) == RESULT_DECL)
+	{
+	  if (!*return_value_p)
+	    *return_value_p = ret_expr;
+	  else
+	    gcc_assert (*return_value_p == ret_expr);
+	  q->cont_stmt = q->stmt.g;
+	}
+      else
+	  gcc_unreachable ();
+    }
+  else
+      /* If we don't return a value, all return statements are the same.  */
+      q->cont_stmt = q->stmt.g;
+
+  if (!q->repl_stmt)
+    q->repl_stmt = gimple_seq_alloc ();
+
+  if (mod)
+    gimple_seq_add_seq (&q->repl_stmt, mod);
+
+  x = gimple_build_goto (finlab);
+  gimple_seq_add_stmt (&q->repl_stmt, x);
+}
+
+/* Similar, but easier, for GIMPLE_GOTO.  */
+
+static void
+do_goto_redirection (struct goto_queue_node *q, tree finlab, gimple_seq mod,
+		     struct leh_tf_state *tf)
+{
+  gimple x;
+
+  gcc_assert (q->is_label);
+  if (!q->repl_stmt)
+    q->repl_stmt = gimple_seq_alloc ();
+
+  q->cont_stmt = gimple_build_goto (VEC_index (tree, tf->dest_array,q->index));
+
+  if (mod)
+    gimple_seq_add_seq (&q->repl_stmt, mod);
+
+  x = gimple_build_goto (finlab);
+  gimple_seq_add_stmt (&q->repl_stmt, x);
+}
+
+/* We want to transform
+	try { body; } catch { stuff; }
+   to
+	body; goto over; lab: stuff; over:
+
+   TP is a GIMPLE_TRY node.  LAB is the label that
+   should be placed before the second operand, or NULL.  OVER is
+   an existing label that should be put at the exit, or NULL.  */
+
+static gimple_seq
+frob_into_branch_around (gimple tp, tree lab, tree over)
+{
+  gimple x;
+  gimple_seq cleanup, result;
+
+  cleanup = gimple_try_cleanup (tp);
+  result = gimple_try_eval (tp);
+
+  if (gimple_seq_may_fallthru (result))
+    {
+      if (!over)
+	over = create_artificial_label ();
+      x = gimple_build_goto (over);
+      gimple_seq_add_stmt (&result, x);
+    }
+
+  if (lab)
+    {
+      x = gimple_build_label (lab);
+      gimple_seq_add_stmt (&result, x);
+    }
+
+  gimple_seq_add_seq (&result, cleanup);
+
+  if (over)
+    {
+      x = gimple_build_label (over);
+      gimple_seq_add_stmt (&result, x);
+    }
+  return result;
+}
+
+/* A subroutine of lower_try_finally.  Duplicate the tree rooted at T.
+   Make sure to record all new labels found.  */
+
+static gimple_seq
+lower_try_finally_dup_block (gimple_seq seq, struct leh_state *outer_state)
+{
+  gimple region = NULL;
+  gimple_seq new_seq;
+
+  new_seq = copy_gimple_seq_and_replace_locals (seq);
+
+  if (outer_state->tf)
+    region = outer_state->tf->try_finally_expr;
+  collect_finally_tree_1 (new_seq, region);
+
+  return new_seq;
+}
+
+/* A subroutine of lower_try_finally.  Create a fallthru label for
+   the given try_finally state.  The only tricky bit here is that
+   we have to make sure to record the label in our outer context.  */
+
+static tree
+lower_try_finally_fallthru_label (struct leh_tf_state *tf)
+{
+  tree label = tf->fallthru_label;
+  treemple temp;
+
+  if (!label)
+    {
+      label = create_artificial_label ();
+      tf->fallthru_label = label;
+      if (tf->outer->tf)
+        {
+          temp.t = label;
+          record_in_finally_tree (temp, tf->outer->tf->try_finally_expr);
+        }
+    }
+  return label;
+}
+
+/* A subroutine of lower_try_finally.  If lang_protect_cleanup_actions
+   returns non-null, then the language requires that the exception path out
+   of a try_finally be treated specially.  To wit: the code within the
+   finally block may not itself throw an exception.  We have two choices here.
+   First we can duplicate the finally block and wrap it in a must_not_throw
+   region.  Second, we can generate code like
+
+	try {
+	  finally_block;
+	} catch {
+	  if (fintmp == eh_edge)
+	    protect_cleanup_actions;
+	}
+
+   where "fintmp" is the temporary used in the switch statement generation
+   alternative considered below.  For the nonce, we always choose the first
+   option.
+
+   THIS_STATE may be null if this is a try-cleanup, not a try-finally.  */
+
+static void
+honor_protect_cleanup_actions (struct leh_state *outer_state,
+			       struct leh_state *this_state,
+			       struct leh_tf_state *tf)
+{
+  gimple protect_cleanup_actions;
+  gimple_stmt_iterator gsi;
+  bool finally_may_fallthru;
+  gimple_seq finally;
+  gimple x;
+
+  /* First check for nothing to do.  */
+  if (lang_protect_cleanup_actions)
+    protect_cleanup_actions = lang_protect_cleanup_actions ();
+  else
+    protect_cleanup_actions = NULL;
+
+  finally = gimple_try_cleanup (tf->top_p);
+
+  /* If the EH case of the finally block can fall through, this may be a
+     structure of the form
+	try {
+	  try {
+	    throw ...;
+	  } cleanup {
+	    try {
+	      throw ...;
+	    } catch (...) {
+	    }
+	  }
+	} catch (...) {
+	  yyy;
+	}
+    E.g. with an inline destructor with an embedded try block.  In this
+    case we must save the runtime EH data around the nested exception.
+
+    This complication means that any time the previous runtime data might
+    be used (via fallthru from the finally) we handle the eh case here,
+    whether or not protect_cleanup_actions is active.  */
+
+  finally_may_fallthru = gimple_seq_may_fallthru (finally);
+  if (!finally_may_fallthru && !protect_cleanup_actions)
+    return;
+
+  /* Duplicate the FINALLY block.  Only need to do this for try-finally,
+     and not for cleanups.  */
+  if (this_state)
+    finally = lower_try_finally_dup_block (finally, outer_state);
+
+  /* If this cleanup consists of a TRY_CATCH_EXPR with TRY_CATCH_IS_CLEANUP
+     set, the handler of the TRY_CATCH_EXPR is another cleanup which ought
+     to be in an enclosing scope, but needs to be implemented at this level
+     to avoid a nesting violation (see wrap_temporary_cleanups in
+     cp/decl.c).  Since it's logically at an outer level, we should call
+     terminate before we get to it, so strip it away before adding the
+     MUST_NOT_THROW filter.  */
+  gsi = gsi_start (finally);
+  x = gsi_stmt (gsi);
+  if (protect_cleanup_actions
+      && gimple_code (x) == GIMPLE_TRY
+      && gimple_try_kind (x) == GIMPLE_TRY_CATCH
+      && gimple_try_catch_is_cleanup (x))
+    {
+      gsi_insert_seq_before (&gsi, gimple_try_eval (x), GSI_SAME_STMT);
+      gsi_remove (&gsi, false);
+    }
+
+  /* Resume execution after the exception.  Adding this now lets
+     lower_eh_filter not add unnecessary gotos, as it is clear that
+     we never fallthru from this copy of the finally block.  */
+  if (finally_may_fallthru)
+    {
+      tree save_eptr, save_filt;
+      tree tmp;
+
+      save_eptr = create_tmp_var (ptr_type_node, "save_eptr");
+      save_filt = create_tmp_var (integer_type_node, "save_filt");
+
+      gsi = gsi_start (finally);
+      tmp = build0 (EXC_PTR_EXPR, ptr_type_node);
+      x = gimple_build_assign (save_eptr, tmp);
+      gsi_insert_before (&gsi, x, GSI_CONTINUE_LINKING);
+
+      tmp = build0 (FILTER_EXPR, integer_type_node);
+      x = gimple_build_assign (save_filt, tmp);
+      gsi_insert_before (&gsi, x, GSI_CONTINUE_LINKING);
+
+      gsi = gsi_last (finally);
+      tmp = build0 (EXC_PTR_EXPR, ptr_type_node);
+      x = gimple_build_assign (tmp, save_eptr);
+      gsi_insert_after (&gsi, x, GSI_CONTINUE_LINKING);
+
+      tmp = build0 (FILTER_EXPR, integer_type_node);
+      x = gimple_build_assign (tmp, save_filt);
+      gsi_insert_after (&gsi, x, GSI_CONTINUE_LINKING);
+
+      x = gimple_build_resx (get_eh_region_number (tf->region));
+      gsi_insert_after (&gsi, x, GSI_CONTINUE_LINKING);
+    }
+
+  /* Wrap the block with protect_cleanup_actions as the action.  */
+  if (protect_cleanup_actions)
+    {
+      gimple_seq seq = NULL, failure = NULL;
+
+      gimple_seq_add_stmt (&failure, protect_cleanup_actions);
+      x = gimple_build_eh_filter (NULL, failure);
+      gimple_eh_filter_set_must_not_throw (x, 1);
+
+      gimple_seq_add_stmt (&seq, x);
+      x = gimple_build_try (finally, seq, GIMPLE_TRY_CATCH);
+      finally = lower_eh_filter (outer_state, x);
+    }
+  else
+    lower_eh_constructs_1 (outer_state, finally);
+
+  /* Hook this up to the end of the existing try block.  If we
+     previously fell through the end, we'll have to branch around.
+     This means adding a new goto, and adding it to the queue.  */
+
+  gsi = gsi_last (gimple_try_eval (tf->top_p));
+
+  if (tf->may_fallthru)
+    {
+      tree tmp;
+      tmp = lower_try_finally_fallthru_label (tf);
+      x = gimple_build_goto (tmp);
+      gsi_insert_after (&gsi, x, GSI_CONTINUE_LINKING);
+
+      if (this_state)
+        maybe_record_in_goto_queue (this_state, x);
+
+      tf->may_fallthru = false;
+    }
+
+  x = gimple_build_label (tf->eh_label);
+  gsi_insert_after (&gsi, x, GSI_CONTINUE_LINKING);
+  gsi_insert_seq_after (&gsi, finally, GSI_CONTINUE_LINKING);
+
+  /* Having now been handled, EH isn't to be considered with
+     the rest of the outgoing edges.  */
+  tf->may_throw = false;
+}
+
+/* A subroutine of lower_try_finally.  We have determined that there is
+   no fallthru edge out of the finally block.  This means that there is
+   no outgoing edge corresponding to any incoming edge.  Restructure the
+   try_finally node for this special case.  */
+
+static void
+lower_try_finally_nofallthru (struct leh_state *state,
+			      struct leh_tf_state *tf)
+{
+  tree lab, return_val;
+  gimple x;
+  gimple_seq finally;
+  struct goto_queue_node *q, *qe;
+
+  if (tf->may_throw)
+    lab = tf->eh_label;
+  else
+    lab = create_artificial_label ();
+
+  /* We expect that tf->top_p is a GIMPLE_TRY. */
+  finally = gimple_try_cleanup (tf->top_p);
+  tf->top_p_seq = gimple_try_eval (tf->top_p);
+
+  x = gimple_build_label (lab);
+  gimple_seq_add_stmt (&tf->top_p_seq, x);
+
+  return_val = NULL;
+  q = tf->goto_queue;
+  qe = q + tf->goto_queue_active;
+  for (; q < qe; ++q)
+    if (q->index < 0)
+      do_return_redirection (q, lab, NULL, &return_val);
+    else
+      do_goto_redirection (q, lab, NULL, tf);
+
+  replace_goto_queue (tf);
+
+  lower_eh_constructs_1 (state, finally);
+  gimple_seq_add_seq (&tf->top_p_seq, finally);
+}
+
+/* A subroutine of lower_try_finally.  We have determined that there is
+   exactly one destination of the finally block.  Restructure the
+   try_finally node for this special case.  */
+
+static void
+lower_try_finally_onedest (struct leh_state *state, struct leh_tf_state *tf)
+{
+  struct goto_queue_node *q, *qe;
+  gimple x;
+  gimple_seq finally;
+  tree finally_label;
+
+  finally = gimple_try_cleanup (tf->top_p);
+  tf->top_p_seq = gimple_try_eval (tf->top_p);
+
+  lower_eh_constructs_1 (state, finally);
+
+  if (tf->may_throw)
+    {
+      /* Only reachable via the exception edge.  Add the given label to
+         the head of the FINALLY block.  Append a RESX at the end.  */
+
+      x = gimple_build_label (tf->eh_label);
+      gimple_seq_add_stmt (&tf->top_p_seq, x);
+
+      gimple_seq_add_seq (&tf->top_p_seq, finally);
+
+      x = gimple_build_resx (get_eh_region_number (tf->region));
+
+      gimple_seq_add_stmt (&tf->top_p_seq, x);
+
+      return;
+    }
+
+  if (tf->may_fallthru)
+    {
+      /* Only reachable via the fallthru edge.  Do nothing but let
+	 the two blocks run together; we'll fall out the bottom.  */
+      gimple_seq_add_seq (&tf->top_p_seq, finally);
+      return;
+    }
+
+  finally_label = create_artificial_label ();
+  x = gimple_build_label (finally_label);
+  gimple_seq_add_stmt (&tf->top_p_seq, x);
+
+  gimple_seq_add_seq (&tf->top_p_seq, finally);
+
+  q = tf->goto_queue;
+  qe = q + tf->goto_queue_active;
+
+  if (tf->may_return)
+    {
+      /* Reachable by return expressions only.  Redirect them.  */
+      tree return_val = NULL;
+      for (; q < qe; ++q)
+	do_return_redirection (q, finally_label, NULL, &return_val);
+      replace_goto_queue (tf);
+    }
+  else
+    {
+      /* Reachable by goto expressions only.  Redirect them.  */
+      for (; q < qe; ++q)
+	do_goto_redirection (q, finally_label, NULL, tf);
+      replace_goto_queue (tf);
+
+      if (VEC_index (tree, tf->dest_array, 0) == tf->fallthru_label)
+	{
+	  /* Reachable by goto to fallthru label only.  Redirect it
+	     to the new label (already created, sadly), and do not
+	     emit the final branch out, or the fallthru label.  */
+	  tf->fallthru_label = NULL;
+	  return;
+	}
+    }
+
+  /* Place the original return/goto to the original destination
+     immediately after the finally block. */
+  x = tf->goto_queue[0].cont_stmt;
+  gimple_seq_add_stmt (&tf->top_p_seq, x);
+  maybe_record_in_goto_queue (state, x);
+}
+
+/* A subroutine of lower_try_finally.  There are multiple edges incoming
+   and outgoing from the finally block.  Implement this by duplicating the
+   finally block for every destination.  */
+
+static void
+lower_try_finally_copy (struct leh_state *state, struct leh_tf_state *tf)
+{
+  gimple_seq finally;
+  gimple_seq new_stmt;
+  gimple_seq seq;
+  gimple x;
+  tree tmp;
+
+  finally = gimple_try_cleanup (tf->top_p);
+  tf->top_p_seq = gimple_try_eval (tf->top_p);
+  new_stmt = NULL;
+
+  if (tf->may_fallthru)
+    {
+      seq = lower_try_finally_dup_block (finally, state);
+      lower_eh_constructs_1 (state, seq);
+      gimple_seq_add_seq (&new_stmt, seq);
+
+      tmp = lower_try_finally_fallthru_label (tf);
+      x = gimple_build_goto (tmp);
+      gimple_seq_add_stmt (&new_stmt, x);
+    }
+
+  if (tf->may_throw)
+    {
+      x = gimple_build_label (tf->eh_label);
+      gimple_seq_add_stmt (&new_stmt, x);
+
+      seq = lower_try_finally_dup_block (finally, state);
+      lower_eh_constructs_1 (state, seq);
+      gimple_seq_add_seq (&new_stmt, seq);
+
+      x = gimple_build_resx (get_eh_region_number (tf->region));
+      gimple_seq_add_stmt (&new_stmt, x);
+    }
+
+  if (tf->goto_queue)
+    {
+      struct goto_queue_node *q, *qe;
+      tree return_val = NULL;
+      int return_index, index;
+      struct labels_s
+      {
+	struct goto_queue_node *q;
+	tree label;
+      } *labels;
+
+      return_index = VEC_length (tree, tf->dest_array);
+      labels = XCNEWVEC (struct labels_s, return_index + 1);
+
+      q = tf->goto_queue;
+      qe = q + tf->goto_queue_active;
+      for (; q < qe; q++)
+	{
+	  index = q->index < 0 ? return_index : q->index;
+
+	  if (!labels[index].q)
+	    labels[index].q = q;
+	}
+
+      for (index = 0; index < return_index + 1; index++)
+	{
+	  tree lab;
+
+	  q = labels[index].q;
+	  if (! q)
+	    continue;
+
+	  lab = labels[index].label = create_artificial_label ();
+
+	  if (index == return_index)
+	    do_return_redirection (q, lab, NULL, &return_val);
+	  else
+	    do_goto_redirection (q, lab, NULL, tf);
+
+	  x = gimple_build_label (lab);
+          gimple_seq_add_stmt (&new_stmt, x);
+
+	  seq = lower_try_finally_dup_block (finally, state);
+	  lower_eh_constructs_1 (state, seq);
+          gimple_seq_add_seq (&new_stmt, seq);
+
+          gimple_seq_add_stmt (&new_stmt, q->cont_stmt);
+	  maybe_record_in_goto_queue (state, q->cont_stmt);
+	}
+
+      for (q = tf->goto_queue; q < qe; q++)
+	{
+	  tree lab;
+
+	  index = q->index < 0 ? return_index : q->index;
+
+	  if (labels[index].q == q)
+	    continue;
+
+	  lab = labels[index].label;
+
+	  if (index == return_index)
+	    do_return_redirection (q, lab, NULL, &return_val);
+	  else
+	    do_goto_redirection (q, lab, NULL, tf);
+	}
+	
+      replace_goto_queue (tf);
+      free (labels);
+    }
+
+  /* Need to link new stmts after running replace_goto_queue due
+     to not wanting to process the same goto stmts twice.  */
+  gimple_seq_add_seq (&tf->top_p_seq, new_stmt);
+}
+
+/* A subroutine of lower_try_finally.  There are multiple edges incoming
+   and outgoing from the finally block.  Implement this by instrumenting
+   each incoming edge and creating a switch statement at the end of the
+   finally block that branches to the appropriate destination.  */
+
+static void
+lower_try_finally_switch (struct leh_state *state, struct leh_tf_state *tf)
+{
+  struct goto_queue_node *q, *qe;
+  tree return_val = NULL;
+  tree finally_tmp, finally_label;
+  int return_index, eh_index, fallthru_index;
+  int nlabels, ndests, j, last_case_index;
+  tree last_case;
+  VEC (tree,heap) *case_label_vec;
+  gimple_seq switch_body;
+  gimple x;
+  tree tmp;
+  gimple switch_stmt;
+  gimple_seq finally;
+  struct pointer_map_t *cont_map = NULL;
+
+  switch_body = gimple_seq_alloc ();
+
+  /* Mash the TRY block to the head of the chain.  */
+  finally = gimple_try_cleanup (tf->top_p);
+  tf->top_p_seq = gimple_try_eval (tf->top_p);
+
+  /* Lower the finally block itself.  */
+  lower_eh_constructs_1 (state, finally);
+
+  /* Prepare for switch statement generation.  */
+  nlabels = VEC_length (tree, tf->dest_array);
+  return_index = nlabels;
+  eh_index = return_index + tf->may_return;
+  fallthru_index = eh_index + tf->may_throw;
+  ndests = fallthru_index + tf->may_fallthru;
+
+  finally_tmp = create_tmp_var (integer_type_node, "finally_tmp");
+  finally_label = create_artificial_label ();
+
+  /* We use VEC_quick_push on case_label_vec throughout this function,
+     since we know the size in advance and allocate precisely as muce
+     space as needed.  */
+  case_label_vec = VEC_alloc (tree, heap, ndests);
+  last_case = NULL;
+  last_case_index = 0;
+
+  /* Begin inserting code for getting to the finally block.  Things
+     are done in this order to correspond to the sequence the code is
+     layed out.  */
+
+  if (tf->may_fallthru)
+    {
+      x = gimple_build_assign (finally_tmp, build_int_cst (integer_type_node,
+					                   fallthru_index));
+      gimple_seq_add_stmt (&tf->top_p_seq, x);
+
+      if (tf->may_throw)
+	{
+	  x = gimple_build_goto (finally_label);
+          gimple_seq_add_stmt (&tf->top_p_seq, x);
+	}
+
+
+      last_case = build3 (CASE_LABEL_EXPR, void_type_node,
+			  build_int_cst (NULL_TREE, fallthru_index), NULL,
+			  create_artificial_label ());
+      VEC_quick_push (tree, case_label_vec, last_case);
+      last_case_index++;
+
+      x = gimple_build_label (CASE_LABEL (last_case));
+      gimple_seq_add_stmt (&switch_body, x);
+
+      tmp = lower_try_finally_fallthru_label (tf);
+      x = gimple_build_goto (tmp);
+      gimple_seq_add_stmt (&switch_body, x);
+    }
+
+  if (tf->may_throw)
+    {
+      x = gimple_build_label (tf->eh_label);
+      gimple_seq_add_stmt (&tf->top_p_seq, x);
+
+      x = gimple_build_assign (finally_tmp, build_int_cst (integer_type_node,
+                                                           eh_index));
+      gimple_seq_add_stmt (&tf->top_p_seq, x);
+
+      last_case = build3 (CASE_LABEL_EXPR, void_type_node,
+			  build_int_cst (NULL_TREE, eh_index), NULL,
+			  create_artificial_label ());
+      VEC_quick_push (tree, case_label_vec, last_case);
+      last_case_index++;
+
+      x = gimple_build_label (CASE_LABEL (last_case));
+      gimple_seq_add_stmt (&switch_body, x);
+      x = gimple_build_resx (get_eh_region_number (tf->region));
+      gimple_seq_add_stmt (&switch_body, x);
+    }
+
+  x = gimple_build_label (finally_label);
+  gimple_seq_add_stmt (&tf->top_p_seq, x);
+
+  gimple_seq_add_seq (&tf->top_p_seq, finally);
+
+  /* Redirect each incoming goto edge.  */
+  q = tf->goto_queue;
+  qe = q + tf->goto_queue_active;
+  j = last_case_index + tf->may_return;
+  /* Prepare the assignments to finally_tmp that are executed upon the
+     entrance through a particular edge. */
+  for (; q < qe; ++q)
+    {
+      gimple_seq mod;
+      int switch_id;
+      unsigned int case_index;
+
+      mod = gimple_seq_alloc ();
+
+      if (q->index < 0)
+	{
+	  x = gimple_build_assign (finally_tmp,
+				   build_int_cst (integer_type_node,
+						  return_index));
+	  gimple_seq_add_stmt (&mod, x);
+	  do_return_redirection (q, finally_label, mod, &return_val);
+	  switch_id = return_index;
+	}
+      else
+	{
+	  x = gimple_build_assign (finally_tmp,
+				   build_int_cst (integer_type_node, q->index));
+	  gimple_seq_add_stmt (&mod, x);
+	  do_goto_redirection (q, finally_label, mod, tf);
+	  switch_id = q->index;
+	}
+
+      case_index = j + q->index;
+      if (VEC_length (tree, case_label_vec) <= case_index
+          || !VEC_index (tree, case_label_vec, case_index))
+        {
+          tree case_lab;
+          void **slot;
+          case_lab = build3 (CASE_LABEL_EXPR, void_type_node,
+                             build_int_cst (NULL_TREE, switch_id), NULL,
+                             NULL);
+          /* We store the cont_stmt in the pointer map, so that we can recover
+             it in the loop below.  We don't create the new label while
+             walking the goto_queue because pointers don't offer a stable 
+             order.  */
+          if (!cont_map)
+            cont_map = pointer_map_create ();
+          slot = pointer_map_insert (cont_map, case_lab);
+          *slot = q->cont_stmt;
+          VEC_quick_push (tree, case_label_vec, case_lab);
+        }
+    }
+  for (j = last_case_index; j < last_case_index + nlabels; j++)
+    {
+      tree label;
+      gimple cont_stmt;
+      void **slot;
+
+      last_case = VEC_index (tree, case_label_vec, j);
+
+      gcc_assert (last_case);
+      gcc_assert (cont_map);
+
+      slot = pointer_map_contains (cont_map, last_case);
+      /* As the comment above suggests, CASE_LABEL (last_case) was just a
+         placeholder, it does not store an actual label, yet. */
+      gcc_assert (slot);
+      cont_stmt = *(gimple *) slot;
+
+      label = create_artificial_label ();
+      CASE_LABEL (last_case) = label;
+
+      x = gimple_build_label (label);
+      gimple_seq_add_stmt (&switch_body, x);
+      gimple_seq_add_stmt (&switch_body, cont_stmt);
+      maybe_record_in_goto_queue (state, cont_stmt);
+    }
+  if (cont_map)
+    pointer_map_destroy (cont_map);
+
+  replace_goto_queue (tf);
+
+  /* Make sure that the last case is the default label, as one is required.
+     Then sort the labels, which is also required in GIMPLE.  */
+  CASE_LOW (last_case) = NULL;
+  sort_case_labels (case_label_vec);
+
+  /* Build the switch statement, setting last_case to be the default
+     label.  */
+  switch_stmt = gimple_build_switch_vec (finally_tmp, last_case,
+                                         case_label_vec);
+
+  /* Need to link SWITCH_STMT after running replace_goto_queue
+     due to not wanting to process the same goto stmts twice.  */
+  gimple_seq_add_stmt (&tf->top_p_seq, switch_stmt);
+  gimple_seq_add_seq (&tf->top_p_seq, switch_body);
+}
+
+/* Decide whether or not we are going to duplicate the finally block.
+   There are several considerations.
+
+   First, if this is Java, then the finally block contains code
+   written by the user.  It has line numbers associated with it,
+   so duplicating the block means it's difficult to set a breakpoint.
+   Since controlling code generation via -g is verboten, we simply
+   never duplicate code without optimization.
+
+   Second, we'd like to prevent egregious code growth.  One way to
+   do this is to estimate the size of the finally block, multiply
+   that by the number of copies we'd need to make, and compare against
+   the estimate of the size of the switch machinery we'd have to add.  */
+
+static bool
+decide_copy_try_finally (int ndests, gimple_seq finally)
+{
+  int f_estimate, sw_estimate;
+
+  if (!optimize)
+    return false;
+
+  /* Finally estimate N times, plus N gotos.  */
+  f_estimate = count_insns_seq (finally, &eni_size_weights);
+  f_estimate = (f_estimate + 1) * ndests;
+
+  /* Switch statement (cost 10), N variable assignments, N gotos.  */
+  sw_estimate = 10 + 2 * ndests;
+
+  /* Optimize for size clearly wants our best guess.  */
+  if (optimize_function_for_size_p (cfun))
+    return f_estimate < sw_estimate;
+
+  /* ??? These numbers are completely made up so far.  */
+  if (optimize > 1)
+    return f_estimate < 100 || f_estimate < sw_estimate * 2;
+  else
+    return f_estimate < 40 || f_estimate * 2 < sw_estimate * 3;
+}
+
+
+/* A subroutine of lower_eh_constructs_1.  Lower a GIMPLE_TRY_FINALLY nodes
+   to a sequence of labels and blocks, plus the exception region trees
+   that record all the magic.  This is complicated by the need to
+   arrange for the FINALLY block to be executed on all exits.  */
+
+static gimple_seq
+lower_try_finally (struct leh_state *state, gimple tp)
+{
+  struct leh_tf_state this_tf;
+  struct leh_state this_state;
+  int ndests;
+
+  /* Process the try block.  */
+
+  memset (&this_tf, 0, sizeof (this_tf));
+  this_tf.try_finally_expr = tp;
+  this_tf.top_p = tp;
+  this_tf.outer = state;
+  if (using_eh_for_cleanups_p)
+    this_tf.region
+      = gen_eh_region_cleanup (state->cur_region, state->prev_try);
+  else
+    this_tf.region = NULL;
+
+  this_state.cur_region = this_tf.region;
+  this_state.prev_try = state->prev_try;
+  this_state.tf = &this_tf;
+
+  lower_eh_constructs_1 (&this_state, gimple_try_eval(tp));
+
+  /* Determine if the try block is escaped through the bottom.  */
+  this_tf.may_fallthru = gimple_seq_may_fallthru (gimple_try_eval (tp));
+
+  /* Determine if any exceptions are possible within the try block.  */
+  if (using_eh_for_cleanups_p)
+    this_tf.may_throw = get_eh_region_may_contain_throw (this_tf.region);
+  if (this_tf.may_throw)
+    {
+      this_tf.eh_label = create_artificial_label ();
+      set_eh_region_tree_label (this_tf.region, this_tf.eh_label);
+      honor_protect_cleanup_actions (state, &this_state, &this_tf);
+    }
+
+  /* Determine how many edges (still) reach the finally block.  Or rather,
+     how many destinations are reached by the finally block.  Use this to
+     determine how we process the finally block itself.  */
+
+  ndests = VEC_length (tree, this_tf.dest_array);
+  ndests += this_tf.may_fallthru;
+  ndests += this_tf.may_return;
+  ndests += this_tf.may_throw;
+
+  /* If the FINALLY block is not reachable, dike it out.  */
+  if (ndests == 0)
+    {
+      gimple_seq_add_seq (&this_tf.top_p_seq, gimple_try_eval (tp));
+      gimple_try_set_cleanup (tp, NULL);
+    }
+  /* If the finally block doesn't fall through, then any destination
+     we might try to impose there isn't reached either.  There may be
+     some minor amount of cleanup and redirection still needed.  */
+  else if (!gimple_seq_may_fallthru (gimple_try_cleanup (tp)))
+    lower_try_finally_nofallthru (state, &this_tf);
+
+  /* We can easily special-case redirection to a single destination.  */
+  else if (ndests == 1)
+    lower_try_finally_onedest (state, &this_tf);
+  else if (decide_copy_try_finally (ndests, gimple_try_cleanup (tp)))
+    lower_try_finally_copy (state, &this_tf);
+  else
+    lower_try_finally_switch (state, &this_tf);
+
+  /* If someone requested we add a label at the end of the transformed
+     block, do so.  */
+  if (this_tf.fallthru_label)
+    {
+      /* This must be reached only if ndests == 0. */
+      gimple x = gimple_build_label (this_tf.fallthru_label);
+      gimple_seq_add_stmt (&this_tf.top_p_seq, x);
+    }
+
+  VEC_free (tree, heap, this_tf.dest_array);
+  if (this_tf.goto_queue)
+    free (this_tf.goto_queue);
+  if (this_tf.goto_queue_map)
+    pointer_map_destroy (this_tf.goto_queue_map);
+
+  return this_tf.top_p_seq;
+}
+
+/* A subroutine of lower_eh_constructs_1.  Lower a GIMPLE_TRY_CATCH with a
+   list of GIMPLE_CATCH to a sequence of labels and blocks, plus the
+   exception region trees that records all the magic.  */
+
+static gimple_seq
+lower_catch (struct leh_state *state, gimple tp)
+{
+  struct eh_region *try_region;
+  struct leh_state this_state;
+  gimple_stmt_iterator gsi;
+  tree out_label;
+
+  try_region = gen_eh_region_try (state->cur_region);
+  this_state.cur_region = try_region;
+  this_state.prev_try = try_region;
+  this_state.tf = state->tf;
+
+  lower_eh_constructs_1 (&this_state, gimple_try_eval (tp));
+
+  if (!get_eh_region_may_contain_throw (try_region))
+    {
+      return gimple_try_eval (tp);
+    }
+
+  out_label = NULL;
+  for (gsi = gsi_start (gimple_try_cleanup (tp)); !gsi_end_p (gsi); )
+    {
+      struct eh_region *catch_region;
+      tree eh_label;
+      gimple x, gcatch;
+
+      gcatch = gsi_stmt (gsi);
+      catch_region = gen_eh_region_catch (try_region,
+                                          gimple_catch_types (gcatch));
+
+      this_state.cur_region = catch_region;
+      this_state.prev_try = state->prev_try;
+      lower_eh_constructs_1 (&this_state, gimple_catch_handler (gcatch));
+
+      eh_label = create_artificial_label ();
+      set_eh_region_tree_label (catch_region, eh_label);
+
+      x = gimple_build_label (eh_label);
+      gsi_insert_before (&gsi, x, GSI_SAME_STMT);
+
+      if (gimple_seq_may_fallthru (gimple_catch_handler (gcatch)))
+	{
+	  if (!out_label)
+	    out_label = create_artificial_label ();
+
+	  x = gimple_build_goto (out_label);
+	  gimple_seq_add_stmt (gimple_catch_handler_ptr (gcatch), x);
+	}
+
+      gsi_insert_seq_before (&gsi, gimple_catch_handler (gcatch),
+			     GSI_SAME_STMT);
+      gsi_remove (&gsi, false);
+    }
+
+  return frob_into_branch_around (tp, NULL, out_label);
+}
+
+/* A subroutine of lower_eh_constructs_1.  Lower a GIMPLE_TRY with a
+   GIMPLE_EH_FILTER to a sequence of labels and blocks, plus the exception
+   region trees that record all the magic.  */
+
+static gimple_seq
+lower_eh_filter (struct leh_state *state, gimple tp)
+{
+  struct leh_state this_state;
+  struct eh_region *this_region;
+  gimple inner;
+  tree eh_label;
+
+  inner = gimple_seq_first_stmt (gimple_try_cleanup (tp));
+
+  if (gimple_eh_filter_must_not_throw (inner))
+    this_region = gen_eh_region_must_not_throw (state->cur_region);
+  else
+    this_region = gen_eh_region_allowed (state->cur_region,
+					 gimple_eh_filter_types (inner));
+  this_state = *state;
+  this_state.cur_region = this_region;
+  /* For must not throw regions any cleanup regions inside it
+     can't reach outer catch regions.  */
+  if (gimple_eh_filter_must_not_throw (inner))
+    this_state.prev_try = NULL;
+
+  lower_eh_constructs_1 (&this_state, gimple_try_eval (tp));
+
+  if (!get_eh_region_may_contain_throw (this_region))
+    {
+      return gimple_try_eval (tp);
+    }
+
+  lower_eh_constructs_1 (state, gimple_eh_filter_failure (inner));
+  gimple_try_set_cleanup (tp, gimple_eh_filter_failure (inner));
+
+  eh_label = create_artificial_label ();
+  set_eh_region_tree_label (this_region, eh_label);
+
+  return frob_into_branch_around (tp, eh_label, NULL);
+}
+
+/* Implement a cleanup expression.  This is similar to try-finally,
+   except that we only execute the cleanup block for exception edges.  */
+
+static gimple_seq
+lower_cleanup (struct leh_state *state, gimple tp)
+{
+  struct leh_state this_state;
+  struct eh_region *this_region;
+  struct leh_tf_state fake_tf;
+  gimple_seq result;
+
+  /* If not using eh, then exception-only cleanups are no-ops.  */
+  if (!flag_exceptions)
+    {
+      result = gimple_try_eval (tp);
+      lower_eh_constructs_1 (state, result);
+      return result;
+    }
+
+  this_region = gen_eh_region_cleanup (state->cur_region, state->prev_try);
+  this_state = *state;
+  this_state.cur_region = this_region;
+
+  lower_eh_constructs_1 (&this_state, gimple_try_eval (tp));
+
+  if (!get_eh_region_may_contain_throw (this_region))
+    {
+      return gimple_try_eval (tp);
+    }
+
+  /* Build enough of a try-finally state so that we can reuse
+     honor_protect_cleanup_actions.  */
+  memset (&fake_tf, 0, sizeof (fake_tf));
+  fake_tf.top_p = tp;
+  fake_tf.outer = state;
+  fake_tf.region = this_region;
+  fake_tf.may_fallthru = gimple_seq_may_fallthru (gimple_try_eval (tp));
+  fake_tf.may_throw = true;
+
+  fake_tf.eh_label = create_artificial_label ();
+  set_eh_region_tree_label (this_region, fake_tf.eh_label);
+
+  honor_protect_cleanup_actions (state, NULL, &fake_tf);
+
+  if (fake_tf.may_throw)
+    {
+      /* In this case honor_protect_cleanup_actions had nothing to do,
+	 and we should process this normally.  */
+      lower_eh_constructs_1 (state, gimple_try_cleanup (tp));
+      result = frob_into_branch_around (tp, fake_tf.eh_label,
+                                       fake_tf.fallthru_label);
+    }
+  else
+    {
+      /* In this case honor_protect_cleanup_actions did nearly all of
+	 the work.  All we have left is to append the fallthru_label.  */
+
+      result = gimple_try_eval (tp);
+      if (fake_tf.fallthru_label)
+	{
+	  gimple x = gimple_build_label (fake_tf.fallthru_label);
+	  gimple_seq_add_stmt (&result, x);
+	}
+    }
+  return result;
+}
+
+
+
+/* Main loop for lowering eh constructs. Also moves gsi to the next 
+   statement. */
+
+static void
+lower_eh_constructs_2 (struct leh_state *state, gimple_stmt_iterator *gsi)
+{
+  gimple_seq replace;
+  gimple x;
+  gimple stmt = gsi_stmt (*gsi);
+
+  switch (gimple_code (stmt))
+    {
+    case GIMPLE_CALL:
+    case GIMPLE_ASSIGN:
+      /* Look for things that can throw exceptions, and record them.  */
+      if (state->cur_region && stmt_could_throw_p (stmt))
+	{
+	  record_stmt_eh_region (state->cur_region, stmt);
+	  note_eh_region_may_contain_throw (state->cur_region);
+	}
+      break;
+
+    case GIMPLE_COND:
+    case GIMPLE_GOTO:
+    case GIMPLE_RETURN:
+      maybe_record_in_goto_queue (state, stmt);
+      break;
+
+    case GIMPLE_SWITCH:
+      verify_norecord_switch_expr (state, stmt);
+      break;
+
+    case GIMPLE_TRY:
+      if (gimple_try_kind (stmt) == GIMPLE_TRY_FINALLY)
+	replace = lower_try_finally (state, stmt);
+      else
+	{
+	  x = gimple_seq_first_stmt (gimple_try_cleanup (stmt));
+	  switch (gimple_code (x))
+	    {
+	    case GIMPLE_CATCH:
+	      replace = lower_catch (state, stmt);
+	      break;
+	    case GIMPLE_EH_FILTER:
+	      replace = lower_eh_filter (state, stmt);
+	      break;
+	    default:
+	      replace = lower_cleanup (state, stmt);
+	      break;
+	    }
+	}
+
+      /* Remove the old stmt and insert the transformed sequence
+	 instead. */
+      gsi_insert_seq_before (gsi, replace, GSI_SAME_STMT);
+      gsi_remove (gsi, true);
+
+      /* Return since we don't want gsi_next () */
+      return;
+
+    default:
+      /* A type, a decl, or some kind of statement that we're not
+	 interested in.  Don't walk them.  */
+      break;
+    }
+
+  gsi_next (gsi);
+}
+
+/* A helper to unwrap a gimple_seq and feed stmts to lower_eh_constructs_2. */
+
+static void
+lower_eh_constructs_1 (struct leh_state *state, gimple_seq seq)
+{
+  gimple_stmt_iterator gsi;
+  for (gsi = gsi_start (seq); !gsi_end_p (gsi);)
+    lower_eh_constructs_2 (state, &gsi);
+}
+
+static unsigned int
+lower_eh_constructs (void)
+{
+  struct leh_state null_state;
+
+  gimple_seq bodyp = gimple_body (current_function_decl);
+
+  finally_tree = htab_create (31, struct_ptr_hash, struct_ptr_eq, free);
+
+  collect_finally_tree_1 (bodyp, NULL);
+
+  memset (&null_state, 0, sizeof (null_state));
+  lower_eh_constructs_1 (&null_state, bodyp);
+
+  htab_delete (finally_tree);
+
+  collect_eh_region_array ();
+  return 0;
+}
+
+struct gimple_opt_pass pass_lower_eh =
+{
+ {
+  GIMPLE_PASS,
+  "eh",					/* name */
+  NULL,					/* gate */
+  lower_eh_constructs,			/* execute */
+  NULL,					/* sub */
+  NULL,					/* next */
+  0,					/* static_pass_number */
+  TV_TREE_EH,				/* tv_id */
+  PROP_gimple_lcf,			/* properties_required */
+  PROP_gimple_leh,			/* properties_provided */
+  0,					/* properties_destroyed */
+  0,					/* todo_flags_start */
+  TODO_dump_func			/* todo_flags_finish */
+ }
+};
+
+
+/* Construct EH edges for STMT.  */
+
+static void
+make_eh_edge (struct eh_region *region, void *data)
+{
+  gimple stmt;
+  tree lab;
+  basic_block src, dst;
+
+  stmt = (gimple) data;
+  lab = get_eh_region_tree_label (region);
+
+  src = gimple_bb (stmt);
+  dst = label_to_block (lab);
+
+  make_edge (src, dst, EDGE_ABNORMAL | EDGE_EH);
+}
+
+void
+make_eh_edges (gimple stmt)
+{
+  int region_nr;
+  bool is_resx;
+
+  if (gimple_code (stmt) == GIMPLE_RESX)
+    {
+      region_nr = gimple_resx_region (stmt);
+      is_resx = true;
+    }
+  else
+    {
+      region_nr = lookup_stmt_eh_region (stmt);
+      if (region_nr < 0)
+	return;
+      is_resx = false;
+    }
+
+  foreach_reachable_handler (region_nr, is_resx, make_eh_edge, stmt);
+}
+
+static bool mark_eh_edge_found_error;
+
+/* Mark edge make_eh_edge would create for given region by setting it aux
+   field, output error if something goes wrong.  */
+
+static void
+mark_eh_edge (struct eh_region *region, void *data)
+{
+  gimple stmt;
+  tree lab;
+  basic_block src, dst;
+  edge e;
+
+  stmt = (gimple) data;
+  lab = get_eh_region_tree_label (region);
+
+  src = gimple_bb (stmt);
+  dst = label_to_block (lab);
+
+  e = find_edge (src, dst);
+  if (!e)
+    {
+      error ("EH edge %i->%i is missing", src->index, dst->index);
+      mark_eh_edge_found_error = true;
+    }
+  else if (!(e->flags & EDGE_EH))
+    {
+      error ("EH edge %i->%i miss EH flag", src->index, dst->index);
+      mark_eh_edge_found_error = true;
+    }
+  else if (e->aux)
+    {
+      /* ??? might not be mistake.  */
+      error ("EH edge %i->%i has duplicated regions", src->index, dst->index);
+      mark_eh_edge_found_error = true;
+    }
+  else
+    e->aux = (void *)1;
+}
+
+/* Verify that BB containing STMT as the last statement, has precisely the
+   edges that make_eh_edges would create.  */
+
+bool
+verify_eh_edges (gimple stmt)
+{
+  int region_nr;
+  bool is_resx;
+  basic_block bb = gimple_bb (stmt);
+  edge_iterator ei;
+  edge e;
+
+  FOR_EACH_EDGE (e, ei, bb->succs)
+    gcc_assert (!e->aux);
+  mark_eh_edge_found_error = false;
+  if (gimple_code (stmt) == GIMPLE_RESX)
+    {
+      region_nr = gimple_resx_region (stmt);
+      is_resx = true;
+    }
+  else
+    {
+      region_nr = lookup_stmt_eh_region (stmt);
+      if (region_nr < 0)
+	{
+	  FOR_EACH_EDGE (e, ei, bb->succs)
+	    if (e->flags & EDGE_EH)
+	      {
+		error ("BB %i can not throw but has EH edges", bb->index);
+		return true;
+	      }
+	   return false;
+	}
+      if (!stmt_could_throw_p (stmt))
+	{
+	  error ("BB %i last statement has incorrectly set region", bb->index);
+	  return true;
+	}
+      is_resx = false;
+    }
+
+  foreach_reachable_handler (region_nr, is_resx, mark_eh_edge, stmt);
+  FOR_EACH_EDGE (e, ei, bb->succs)
+    {
+      if ((e->flags & EDGE_EH) && !e->aux)
+	{
+	  error ("unnecessary EH edge %i->%i", bb->index, e->dest->index);
+	  mark_eh_edge_found_error = true;
+	  return true;
+	}
+      e->aux = NULL;
+    }
+
+  return mark_eh_edge_found_error;
+}
+
+
+/* Helper function for operation_could_trap_p and stmt_could_throw_p.  */
+
+bool
+operation_could_trap_helper_p (enum tree_code op,
+			       bool fp_operation,
+			       bool honor_trapv,
+			       bool honor_nans,
+			       bool honor_snans,
+			       tree divisor,
+			       bool *handled)
+{
+  *handled = true;
+  switch (op)
+    {
+    case TRUNC_DIV_EXPR:
+    case CEIL_DIV_EXPR:
+    case FLOOR_DIV_EXPR:
+    case ROUND_DIV_EXPR:
+    case EXACT_DIV_EXPR:
+    case CEIL_MOD_EXPR:
+    case FLOOR_MOD_EXPR:
+    case ROUND_MOD_EXPR:
+    case TRUNC_MOD_EXPR:
+    case RDIV_EXPR:
+      if (honor_snans || honor_trapv)
+	return true;
+      if (fp_operation)
+	return flag_trapping_math;
+      if (!TREE_CONSTANT (divisor) || integer_zerop (divisor))
+        return true;
+      return false;
+
+    case LT_EXPR:
+    case LE_EXPR:
+    case GT_EXPR:
+    case GE_EXPR:
+    case LTGT_EXPR:
+      /* Some floating point comparisons may trap.  */
+      return honor_nans;
+
+    case EQ_EXPR:
+    case NE_EXPR:
+    case UNORDERED_EXPR:
+    case ORDERED_EXPR:
+    case UNLT_EXPR:
+    case UNLE_EXPR:
+    case UNGT_EXPR:
+    case UNGE_EXPR:
+    case UNEQ_EXPR:
+      return honor_snans;
+
+    case CONVERT_EXPR:
+    case FIX_TRUNC_EXPR:
+      /* Conversion of floating point might trap.  */
+      return honor_nans;
+
+    case NEGATE_EXPR:
+    case ABS_EXPR:
+    case CONJ_EXPR:
+      /* These operations don't trap with floating point.  */
+      if (honor_trapv)
+	return true;
+      return false;
+
+    case PLUS_EXPR:
+    case MINUS_EXPR:
+    case MULT_EXPR:
+      /* Any floating arithmetic may trap.  */
+      if (fp_operation && flag_trapping_math)
+	return true;
+      if (honor_trapv)
+	return true;
+      return false;
+
+    default:
+      /* Any floating arithmetic may trap.  */
+      if (fp_operation && flag_trapping_math)
+	return true;
+
+      *handled = false;
+      return false;
+    }
+}
+
+/* Return true if operation OP may trap.  FP_OPERATION is true if OP is applied
+   on floating-point values.  HONOR_TRAPV is true if OP is applied on integer
+   type operands that may trap.  If OP is a division operator, DIVISOR contains
+   the value of the divisor.  */
+
+bool
+operation_could_trap_p (enum tree_code op, bool fp_operation, bool honor_trapv,
+			tree divisor)
+{
+  bool honor_nans = (fp_operation && flag_trapping_math
+		     && !flag_finite_math_only);
+  bool honor_snans = fp_operation && flag_signaling_nans != 0;
+  bool handled;
+
+  if (TREE_CODE_CLASS (op) != tcc_comparison
+      && TREE_CODE_CLASS (op) != tcc_unary
+      && TREE_CODE_CLASS (op) != tcc_binary)
+    return false;
+
+  return operation_could_trap_helper_p (op, fp_operation, honor_trapv,
+					honor_nans, honor_snans, divisor,
+					&handled);
+}
+
+/* Return true if EXPR can trap, as in dereferencing an invalid pointer
+   location or floating point arithmetic.  C.f. the rtl version, may_trap_p.
+   This routine expects only GIMPLE lhs or rhs input.  */
+
+bool
+tree_could_trap_p (tree expr)
+{
+  enum tree_code code;
+  bool fp_operation = false;
+  bool honor_trapv = false;
+  tree t, base, div = NULL_TREE;
+
+  if (!expr)
+    return false;
+ 
+  code = TREE_CODE (expr);
+  t = TREE_TYPE (expr);
+
+  if (t)
+    {
+      if (COMPARISON_CLASS_P (expr))
+	fp_operation = FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (expr, 0)));
+      else
+	fp_operation = FLOAT_TYPE_P (t);
+      honor_trapv = INTEGRAL_TYPE_P (t) && TYPE_OVERFLOW_TRAPS (t);
+    }
+
+  if (TREE_CODE_CLASS (code) == tcc_binary)
+    div = TREE_OPERAND (expr, 1);
+  if (operation_could_trap_p (code, fp_operation, honor_trapv, div))
+    return true;
+
+ restart:
+  switch (code)
+    {
+    case TARGET_MEM_REF:
+      /* For TARGET_MEM_REFs use the information based on the original
+	 reference.  */
+      expr = TMR_ORIGINAL (expr);
+      code = TREE_CODE (expr);
+      goto restart;
+
+    case COMPONENT_REF:
+    case REALPART_EXPR:
+    case IMAGPART_EXPR:
+    case BIT_FIELD_REF:
+    case VIEW_CONVERT_EXPR:
+    case WITH_SIZE_EXPR:
+      expr = TREE_OPERAND (expr, 0);
+      code = TREE_CODE (expr);
+      goto restart;
+
+    case ARRAY_RANGE_REF:
+      base = TREE_OPERAND (expr, 0);
+      if (tree_could_trap_p (base))
+	return true;
+
+      if (TREE_THIS_NOTRAP (expr))
+	return false;
+
+      return !range_in_array_bounds_p (expr);
+
+    case ARRAY_REF:
+      base = TREE_OPERAND (expr, 0);
+      if (tree_could_trap_p (base))
+	return true;
+
+      if (TREE_THIS_NOTRAP (expr))
+	return false;
+
+      return !in_array_bounds_p (expr);
+
+    case INDIRECT_REF:
+    case ALIGN_INDIRECT_REF:
+    case MISALIGNED_INDIRECT_REF:
+      return !TREE_THIS_NOTRAP (expr);
+
+    case ASM_EXPR:
+      return TREE_THIS_VOLATILE (expr);
+
+
+    case CALL_EXPR:
+      t = get_callee_fndecl (expr);
+      /* Assume that calls to weak functions may trap.  */
+      if (!t || !DECL_P (t) || DECL_WEAK (t))
+	return true;
+      return false;
+
+    default:
+      return false;
+    }
+}
+
+
+/* Helper for stmt_could_throw_p.  Return true if STMT (assumed to be a
+   an assignment or a conditional) may throw.  */
+
+static bool
+stmt_could_throw_1_p (gimple stmt)
+{
+  enum tree_code code = gimple_expr_code (stmt);
+  bool honor_nans = false;
+  bool honor_snans = false;
+  bool fp_operation = false;
+  bool honor_trapv = false;
+  tree t;
+  size_t i;
+  bool handled, ret;
+
+  if (TREE_CODE_CLASS (code) == tcc_comparison
+      || TREE_CODE_CLASS (code) == tcc_unary
+      || TREE_CODE_CLASS (code) == tcc_binary)
+    {
+      t = gimple_expr_type (stmt);
+      fp_operation = FLOAT_TYPE_P (t);
+      if (fp_operation)
+	{
+	  honor_nans = flag_trapping_math && !flag_finite_math_only;
+	  honor_snans = flag_signaling_nans != 0;
+	}
+      else if (INTEGRAL_TYPE_P (t) && TYPE_OVERFLOW_TRAPS (t))
+	honor_trapv = true;
+    }
+
+  /* Check if the main expression may trap.  */
+  t = is_gimple_assign (stmt) ? gimple_assign_rhs2 (stmt) : NULL;
+  ret = operation_could_trap_helper_p (code, fp_operation, honor_trapv,
+				       honor_nans, honor_snans, t,
+				       &handled);
+  if (handled)
+    return ret;
+
+  /* If the expression does not trap, see if any of the individual operands may
+     trap.  */
+  for (i = 0; i < gimple_num_ops (stmt); i++)
+    if (tree_could_trap_p (gimple_op (stmt, i)))
+      return true;
+
+  return false;
+}
+
+
+/* Return true if statement STMT could throw an exception.  */
+
+bool
+stmt_could_throw_p (gimple stmt)
+{
+  enum gimple_code code;
+
+  if (!flag_exceptions)
+    return false;
+
+  /* The only statements that can throw an exception are assignments,
+     conditionals, calls and asms.  */
+  code = gimple_code (stmt);
+  if (code != GIMPLE_ASSIGN
+      && code != GIMPLE_COND
+      && code != GIMPLE_CALL
+      && code != GIMPLE_ASM)
+    return false;
+
+  /* If exceptions can only be thrown by function calls and STMT is not a
+     GIMPLE_CALL, the statement cannot throw.  */
+  if (!flag_non_call_exceptions && code != GIMPLE_CALL)
+    return false;
+
+  if (code == GIMPLE_ASSIGN || code == GIMPLE_COND)
+    return stmt_could_throw_1_p (stmt);
+  else if (is_gimple_call (stmt))
+    {
+      tree t = gimple_call_fndecl (stmt);
+
+      /* Assume that calls to weak functions may trap.  */
+      if (!t || !DECL_P (t) || DECL_WEAK (t))
+	return true;
+
+      return (gimple_call_flags (stmt) & ECF_NOTHROW) == 0;
+    }
+  else if (gimple_code (stmt) == GIMPLE_ASM)
+    return (gimple_asm_volatile_p (stmt));
+  else
+    gcc_unreachable ();
+
+  return false;
+}
+
+
+/* Return true if expression T could throw an exception.  */
+
+bool
+tree_could_throw_p (tree t)
+{
+  if (!flag_exceptions)
+    return false;
+  if (TREE_CODE (t) == MODIFY_EXPR)
+    {
+      if (flag_non_call_exceptions
+	  && tree_could_trap_p (TREE_OPERAND (t, 0)))
+	return true;
+      t = TREE_OPERAND (t, 1);
+    }
+
+  if (TREE_CODE (t) == WITH_SIZE_EXPR)
+    t = TREE_OPERAND (t, 0);
+  if (TREE_CODE (t) == CALL_EXPR)
+    return (call_expr_flags (t) & ECF_NOTHROW) == 0;
+  if (flag_non_call_exceptions)
+    return tree_could_trap_p (t);
+  return false;
+}
+
+
+/* Return true if STMT can throw an exception that is caught within
+   the current function (CFUN).  */
+
+bool
+stmt_can_throw_internal (gimple stmt)
+{
+  int region_nr;
+  bool is_resx = false;
+
+  if (gimple_code (stmt) == GIMPLE_RESX)
+    {
+      region_nr = gimple_resx_region (stmt);
+      is_resx = true;
+    }
+  else
+    region_nr = lookup_stmt_eh_region (stmt);
+
+  if (region_nr < 0)
+    return false;
+
+  return can_throw_internal_1 (region_nr, is_resx);
+}
+
+
+/* Given a statement OLD_STMT and a new statement NEW_STMT that has replaced
+   OLD_STMT in the function, remove OLD_STMT from the EH table and put NEW_STMT
+   in the table if it should be in there.  Return TRUE if a replacement was
+   done that my require an EH edge purge.  */
+
+bool 
+maybe_clean_or_replace_eh_stmt (gimple old_stmt, gimple new_stmt) 
+{
+  int region_nr = lookup_stmt_eh_region (old_stmt);
+
+  if (region_nr >= 0)
+    {
+      bool new_stmt_could_throw = stmt_could_throw_p (new_stmt);
+
+      if (new_stmt == old_stmt && new_stmt_could_throw)
+	return false;
+
+      remove_stmt_from_eh_region (old_stmt);
+      if (new_stmt_could_throw)
+	{
+	  add_stmt_to_eh_region (new_stmt, region_nr);
+	  return false;
+	}
+      else
+	return true;
+    }
+
+  return false;
+}
+
+/* Returns TRUE if oneh and twoh are exception handlers (gimple_try_cleanup of
+   GIMPLE_TRY) that are similar enough to be considered the same.  Currently
+   this only handles handlers consisting of a single call, as that's the
+   important case for C++: a destructor call for a particular object showing
+   up in multiple handlers.  */
+
+static bool
+same_handler_p (gimple_seq oneh, gimple_seq twoh)
+{
+  gimple_stmt_iterator gsi;
+  gimple ones, twos;
+  unsigned int ai;
+
+  gsi = gsi_start (oneh);
+  if (!gsi_one_before_end_p (gsi))
+    return false;
+  ones = gsi_stmt (gsi);
+
+  gsi = gsi_start (twoh);
+  if (!gsi_one_before_end_p (gsi))
+    return false;
+  twos = gsi_stmt (gsi);
+
+  if (!is_gimple_call (ones)
+      || !is_gimple_call (twos)
+      || gimple_call_lhs (ones)
+      || gimple_call_lhs (twos)
+      || gimple_call_chain (ones)
+      || gimple_call_chain (twos)
+      || !operand_equal_p (gimple_call_fn (ones), gimple_call_fn (twos), 0)
+      || gimple_call_num_args (ones) != gimple_call_num_args (twos))
+    return false;
+
+  for (ai = 0; ai < gimple_call_num_args (ones); ++ai)
+    if (!operand_equal_p (gimple_call_arg (ones, ai),
+			  gimple_call_arg (twos, ai), 0))
+      return false;
+
+  return true;
+}
+
+/* Optimize
+    try { A() } finally { try { ~B() } catch { ~A() } }
+    try { ... } finally { ~A() }
+   into
+    try { A() } catch { ~B() }
+    try { ~B() ... } finally { ~A() }
+
+   This occurs frequently in C++, where A is a local variable and B is a
+   temporary used in the initializer for A.  */
+
+static void
+optimize_double_finally (gimple one, gimple two)
+{
+  gimple oneh;
+  gimple_stmt_iterator gsi;
+
+  gsi = gsi_start (gimple_try_cleanup (one));
+  if (!gsi_one_before_end_p (gsi))
+    return;
+
+  oneh = gsi_stmt (gsi);
+  if (gimple_code (oneh) != GIMPLE_TRY
+      || gimple_try_kind (oneh) != GIMPLE_TRY_CATCH)
+    return;
+
+  if (same_handler_p (gimple_try_cleanup (oneh), gimple_try_cleanup (two)))
+    {
+      gimple_seq seq = gimple_try_eval (oneh);
+
+      gimple_try_set_cleanup (one, seq);
+      gimple_try_set_kind (one, GIMPLE_TRY_CATCH);
+      seq = copy_gimple_seq_and_replace_locals (seq);
+      gimple_seq_add_seq (&seq, gimple_try_eval (two));
+      gimple_try_set_eval (two, seq);
+    }
+}
+
+/* Perform EH refactoring optimizations that are simpler to do when code
+   flow has been lowered but EH structures haven't.  */
+
+static void
+refactor_eh_r (gimple_seq seq)
+{
+  gimple_stmt_iterator gsi;
+  gimple one, two;
+
+  one = NULL;
+  two = NULL;
+  gsi = gsi_start (seq);
+  while (1)
+    {
+      one = two;
+      if (gsi_end_p (gsi))
+	two = NULL;
+      else
+	two = gsi_stmt (gsi);
+      if (one
+	  && two
+	  && gimple_code (one) == GIMPLE_TRY
+	  && gimple_code (two) == GIMPLE_TRY
+	  && gimple_try_kind (one) == GIMPLE_TRY_FINALLY
+	  && gimple_try_kind (two) == GIMPLE_TRY_FINALLY)
+	optimize_double_finally (one, two);
+      if (one)
+	switch (gimple_code (one))
+	  {
+	  case GIMPLE_TRY:
+	    refactor_eh_r (gimple_try_eval (one));
+	    refactor_eh_r (gimple_try_cleanup (one));
+	    break;
+	  case GIMPLE_CATCH:
+	    refactor_eh_r (gimple_catch_handler (one));
+	    break;
+	  case GIMPLE_EH_FILTER:
+	    refactor_eh_r (gimple_eh_filter_failure (one));
+	    break;
+	  default:
+	    break;
+	  }
+      if (two)
+	gsi_next (&gsi);
+      else
+	break;
+    }
+}
+
+static unsigned
+refactor_eh (void)
+{
+  refactor_eh_r (gimple_body (current_function_decl));
+  return 0;
+}
+
+struct gimple_opt_pass pass_refactor_eh =
+{
+ {
+  GIMPLE_PASS,
+  "ehopt",				/* name */
+  NULL,					/* gate */
+  refactor_eh,				/* execute */
+  NULL,					/* sub */
+  NULL,					/* next */
+  0,					/* static_pass_number */
+  TV_TREE_EH,				/* tv_id */
+  PROP_gimple_lcf,			/* properties_required */
+  0,					/* properties_provided */
+  0,					/* properties_destroyed */
+  0,					/* todo_flags_start */
+  TODO_dump_func			/* todo_flags_finish */
+ }
+};