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imported gcc-4.6.4 source tree from verified upstream tarball.

downloading a git-generated archive based on the 'upstream' tag
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1 files changed, 4179 insertions, 0 deletions

diff --git a/gcc/tree-eh.c b/gcc/tree-eh.c
new file mode 100644
index 000000000..fab4a3a48
--- /dev/null
+++ b/gcc/tree-eh.c
@@ -0,0 +1,4179 @@
+/* Exception handling semantics and decomposition for trees.
+   Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
+   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 "flags.h"
+#include "function.h"
+#include "except.h"
+#include "pointer-set.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 "diagnostic-core.h"
+#include "gimple.h"
+#include "target.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 landing pad 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.  */
+
+/* Add statement T in function IFUN to landing pad NUM.  */
+
+void
+add_stmt_to_eh_lp_fn (struct function *ifun, gimple t, int num)
+{
+  struct throw_stmt_node *n;
+  void **slot;
+
+  gcc_assert (num != 0);
+
+  n = ggc_alloc_throw_stmt_node ();
+  n->stmt = t;
+  n->lp_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 landing pad NUM.  */
+
+void
+add_stmt_to_eh_lp (gimple t, int num)
+{
+  add_stmt_to_eh_lp_fn (cfun, t, num);
+}
+
+/* Add statement T to the single EH landing pad in REGION.  */
+
+static void
+record_stmt_eh_region (eh_region region, gimple t)
+{
+  if (region == NULL)
+    return;
+  if (region->type == ERT_MUST_NOT_THROW)
+    add_stmt_to_eh_lp_fn (cfun, t, -region->index);
+  else
+    {
+      eh_landing_pad lp = region->landing_pads;
+      if (lp == NULL)
+	lp = gen_eh_landing_pad (region);
+      else
+	gcc_assert (lp->next_lp == NULL);
+      add_stmt_to_eh_lp_fn (cfun, t, lp->index);
+    }
+}
+
+
+/* Remove statement T in function IFUN from its EH landing pad.  */
+
+bool
+remove_stmt_from_eh_lp_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 its
+   EH landing pad.  */
+
+bool
+remove_stmt_from_eh_lp (gimple t)
+{
+  return remove_stmt_from_eh_lp_fn (cfun, t);
+}
+
+/* Determine if statement T is inside an EH region in function IFUN.
+   Positive numbers indicate a landing pad index; negative numbers
+   indicate a MUST_NOT_THROW region index; zero indicates that the
+   statement is not recorded in the region table.  */
+
+int
+lookup_stmt_eh_lp_fn (struct function *ifun, gimple t)
+{
+  struct throw_stmt_node *p, n;
+
+  if (ifun->eh->throw_stmt_table == NULL)
+    return 0;
+
+  n.stmt = t;
+  p = (struct throw_stmt_node *) htab_find (ifun->eh->throw_stmt_table, &n);
+  return p ? p->lp_nr : 0;
+}
+
+/* Likewise, but always use the current function.  */
+
+int
+lookup_stmt_eh_lp (gimple t)
+{
+  /* We can get called from initialized data when -fnon-call-exceptions
+     is on; prevent crash.  */
+  if (!cfun)
+    return 0;
+  return lookup_stmt_eh_lp_fn (cfun, t);
+}
+
+/* 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.  */
+
+/* The sequence into which we record all EH stuff.  This will be
+   placed at the end of the function when we're all done.  */
+static gimple_seq eh_seq;
+
+/* Record whether an EH region contains something that can throw,
+   indexed by EH region number.  */
+static bitmap eh_region_may_contain_throw_map;
+
+/* 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;
+};
+
+/* 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.  */
+  eh_region cur_region;
+
+  /* What's "current" for the purposes of __builtin_eh_pointer.  For
+     a CATCH, this is the associated TRY.  For an EH_FILTER, this is
+     the associated ALLOWED_EXCEPTIONS, etc.  */
+  eh_region ehp_region;
+
+  /* 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.  */
+  eh_region region;
+
+  /* The goto queue.  */
+  struct goto_queue_node *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;
+
+  /* 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_must_not_throw (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;
+  location_t loc = gimple_location (gsi_stmt (*gsi));
+
+  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 (loc);
+  /* 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);
+  replace_goto_queue_stmt_list (eh_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);
+}
+
+/* Emit a standard landing pad sequence into SEQ for REGION.  */
+
+static void
+emit_post_landing_pad (gimple_seq *seq, eh_region region)
+{
+  eh_landing_pad lp = region->landing_pads;
+  gimple x;
+
+  if (lp == NULL)
+    lp = gen_eh_landing_pad (region);
+
+  lp->post_landing_pad = create_artificial_label (UNKNOWN_LOCATION);
+  EH_LANDING_PAD_NR (lp->post_landing_pad) = lp->index;
+
+  x = gimple_build_label (lp->post_landing_pad);
+  gimple_seq_add_stmt (seq, x);
+}
+
+/* Emit a RESX statement into SEQ for REGION.  */
+
+static void
+emit_resx (gimple_seq *seq, eh_region region)
+{
+  gimple x = gimple_build_resx (region->index);
+  gimple_seq_add_stmt (seq, x);
+  if (region->outer)
+    record_stmt_eh_region (region->outer, x);
+}
+
+/* Emit an EH_DISPATCH statement into SEQ for REGION.  */
+
+static void
+emit_eh_dispatch (gimple_seq *seq, eh_region region)
+{
+  gimple x = gimple_build_eh_dispatch (region->index);
+  gimple_seq_add_stmt (seq, x);
+}
+
+/* Note that the current EH region may contain a throw, or a
+   call to a function which itself may contain a throw.  */
+
+static void
+note_eh_region_may_contain_throw (eh_region region)
+{
+  while (bitmap_set_bit (eh_region_may_contain_throw_map, region->index))
+    {
+      if (region->type == ERT_MUST_NOT_THROW)
+	break;
+      region = region->outer;
+      if (region == NULL)
+	break;
+    }
+}
+
+/* Check if REGION has been marked as containing a throw.  If REGION is
+   NULL, this predicate is false.  */
+
+static inline bool
+eh_region_may_contain_throw (eh_region r)
+{
+  return r && bitmap_bit_p (eh_region_may_contain_throw_map, r->index);
+}
+
+/* We want to transform
+	try { body; } catch { stuff; }
+   to
+	normal_seqence:
+	  body;
+	  over:
+	eh_seqence:
+	  landing_pad:
+	  stuff;
+	  goto over;
+
+   TP is a GIMPLE_TRY node.  REGION is the region whose post_landing_pad
+   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, eh_region region, tree over)
+{
+  gimple x;
+  gimple_seq cleanup, result;
+  location_t loc = gimple_location (tp);
+
+  cleanup = gimple_try_cleanup (tp);
+  result = gimple_try_eval (tp);
+
+  if (region)
+    emit_post_landing_pad (&eh_seq, region);
+
+  if (gimple_seq_may_fallthru (cleanup))
+    {
+      if (!over)
+	over = create_artificial_label (loc);
+      x = gimple_build_goto (over);
+      gimple_seq_add_stmt (&cleanup, x);
+    }
+  gimple_seq_add_seq (&eh_seq, 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 (gimple_location (tf->try_finally_expr));
+      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 the eh_protect_cleanup_actions
+   langhook 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)
+{
+  tree protect_cleanup_actions;
+  gimple_stmt_iterator gsi;
+  bool finally_may_fallthru;
+  gimple_seq finally;
+  gimple x;
+
+  /* First check for nothing to do.  */
+  if (lang_hooks.eh_protect_cleanup_actions == NULL)
+    return;
+  protect_cleanup_actions = lang_hooks.eh_protect_cleanup_actions ();
+  if (protect_cleanup_actions == NULL)
+    return;
+
+  finally = gimple_try_cleanup (tf->top_p);
+  finally_may_fallthru = gimple_seq_may_fallthru (finally);
+
+  /* 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 (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);
+    }
+
+  /* Wrap the block with protect_cleanup_actions as the action.  */
+  x = gimple_build_eh_must_not_throw (protect_cleanup_actions);
+  x = gimple_build_try (finally, gimple_seq_alloc_with_stmt (x),
+			GIMPLE_TRY_CATCH);
+  finally = lower_eh_must_not_throw (outer_state, x);
+
+  /* Drop all of this into the exception sequence.  */
+  emit_post_landing_pad (&eh_seq, tf->region);
+  gimple_seq_add_seq (&eh_seq, finally);
+  if (finally_may_fallthru)
+    emit_resx (&eh_seq, tf->region);
+
+  /* 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;
+
+  lab = create_artificial_label (gimple_location (tf->try_finally_expr));
+
+  /* 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);
+
+  if (tf->may_throw)
+    {
+      emit_post_landing_pad (&eh_seq, tf->region);
+
+      x = gimple_build_goto (lab);
+      gimple_seq_add_stmt (&eh_seq, x);
+    }
+}
+
+/* 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;
+  location_t loc = gimple_location (tf->try_finally_expr);
+
+  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.  */
+      emit_post_landing_pad (&eh_seq, tf->region);
+      gimple_seq_add_seq (&eh_seq, finally);
+      emit_resx (&eh_seq, tf->region);
+      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 (loc);
+  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;
+  location_t tf_loc = gimple_location (tf->try_finally_expr);
+
+  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)
+    {
+      seq = lower_try_finally_dup_block (finally, state);
+      lower_eh_constructs_1 (state, seq);
+
+      emit_post_landing_pad (&eh_seq, tf->region);
+      gimple_seq_add_seq (&eh_seq, seq);
+      emit_resx (&eh_seq, tf->region);
+    }
+
+  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 (tf_loc);
+
+	  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;
+  /* The location of the TRY_FINALLY stmt.  */
+  location_t tf_loc = gimple_location (tf->try_finally_expr);
+  /* The location of the finally block.  */
+  location_t finally_loc;
+
+  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);
+
+  /* The location of the finally is either the last stmt in the finally
+     block or the location of the TRY_FINALLY itself.  */
+  finally_loc = gimple_seq_last_stmt (tf->top_p_seq) != NULL ?
+    gimple_location (gimple_seq_last_stmt (tf->top_p_seq))
+    : tf_loc;
+
+  /* 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 (finally_loc);
+
+  /* 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 (NULL, fallthru_index));
+      gimple_seq_add_stmt (&tf->top_p_seq, x);
+
+      last_case = build3 (CASE_LABEL_EXPR, void_type_node,
+			  build_int_cst (NULL, fallthru_index),
+			  NULL, create_artificial_label (tf_loc));
+      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)
+    {
+      emit_post_landing_pad (&eh_seq, tf->region);
+
+      x = gimple_build_assign (finally_tmp,
+			       build_int_cst (NULL, eh_index));
+      gimple_seq_add_stmt (&eh_seq, x);
+
+      x = gimple_build_goto (finally_label);
+      gimple_seq_add_stmt (&eh_seq, x);
+
+      last_case = build3 (CASE_LABEL_EXPR, void_type_node,
+			  build_int_cst (NULL, eh_index),
+			  NULL, create_artificial_label (tf_loc));
+      VEC_quick_push (tree, case_label_vec, last_case);
+      last_case_index++;
+
+      x = gimple_build_label (CASE_LABEL (last_case));
+      gimple_seq_add_stmt (&eh_seq, x);
+      emit_resx (&eh_seq, tf->region);
+    }
+
+  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 (NULL, 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 (NULL, 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, 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 (tf_loc);
+      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);
+  gimple_set_location (switch_stmt, finally_loc);
+
+  /* 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;
+}
+
+/* REG is the enclosing region for a possible cleanup region, or the region
+   itself.  Returns TRUE if such a region would be unreachable.
+
+   Cleanup regions within a must-not-throw region aren't actually reachable
+   even if there are throwing stmts within them, because the personality
+   routine will call terminate before unwinding.  */
+
+static bool
+cleanup_is_dead_in (eh_region reg)
+{
+  while (reg && reg->type == ERT_CLEANUP)
+    reg = reg->outer;
+  return (reg && reg->type == ERT_MUST_NOT_THROW);
+}
+
+/* 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;
+  gimple_seq old_eh_seq;
+
+  /* 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 && !cleanup_is_dead_in (state->cur_region))
+    {
+      this_tf.region = gen_eh_region_cleanup (state->cur_region);
+      this_state.cur_region = this_tf.region;
+    }
+  else
+    {
+      this_tf.region = NULL;
+      this_state.cur_region = state->cur_region;
+    }
+
+  this_state.ehp_region = state->ehp_region;
+  this_state.tf = &this_tf;
+
+  old_eh_seq = eh_seq;
+  eh_seq = NULL;
+
+  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 (this_tf.region)
+    this_tf.may_throw = eh_region_may_contain_throw (this_tf.region);
+  if (this_tf.may_throw)
+    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);
+
+  /* If there was an old (aka outer) eh_seq, append the current eh_seq.
+     If there was no old eh_seq, then the append is trivially already done.  */
+  if (old_eh_seq)
+    {
+      if (eh_seq == NULL)
+	eh_seq = old_eh_seq;
+      else
+	{
+	  gimple_seq new_eh_seq = eh_seq;
+	  eh_seq = old_eh_seq;
+	  gimple_seq_add_seq(&eh_seq, new_eh_seq);
+	}
+    }
+
+  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)
+{
+  eh_region try_region = NULL;
+  struct leh_state this_state = *state;
+  gimple_stmt_iterator gsi;
+  tree out_label;
+  gimple_seq new_seq;
+  gimple x;
+  location_t try_catch_loc = gimple_location (tp);
+
+  if (flag_exceptions)
+    {
+      try_region = gen_eh_region_try (state->cur_region);
+      this_state.cur_region = try_region;
+    }
+
+  lower_eh_constructs_1 (&this_state, gimple_try_eval (tp));
+
+  if (!eh_region_may_contain_throw (try_region))
+    return gimple_try_eval (tp);
+
+  new_seq = NULL;
+  emit_eh_dispatch (&new_seq, try_region);
+  emit_resx (&new_seq, try_region);
+
+  this_state.cur_region = state->cur_region;
+  this_state.ehp_region = try_region;
+
+  out_label = NULL;
+  for (gsi = gsi_start (gimple_try_cleanup (tp));
+       !gsi_end_p (gsi);
+       gsi_next (&gsi))
+    {
+      eh_catch c;
+      gimple gcatch;
+      gimple_seq handler;
+
+      gcatch = gsi_stmt (gsi);
+      c = gen_eh_region_catch (try_region, gimple_catch_types (gcatch));
+
+      handler = gimple_catch_handler (gcatch);
+      lower_eh_constructs_1 (&this_state, handler);
+
+      c->label = create_artificial_label (UNKNOWN_LOCATION);
+      x = gimple_build_label (c->label);
+      gimple_seq_add_stmt (&new_seq, x);
+
+      gimple_seq_add_seq (&new_seq, handler);
+
+      if (gimple_seq_may_fallthru (new_seq))
+	{
+	  if (!out_label)
+	    out_label = create_artificial_label (try_catch_loc);
+
+	  x = gimple_build_goto (out_label);
+	  gimple_seq_add_stmt (&new_seq, x);
+	}
+      if (!c->type_list)
+	break;
+    }
+
+  gimple_try_set_cleanup (tp, new_seq);
+
+  return frob_into_branch_around (tp, try_region, 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 = *state;
+  eh_region this_region = NULL;
+  gimple inner, x;
+  gimple_seq new_seq;
+
+  inner = gimple_seq_first_stmt (gimple_try_cleanup (tp));
+
+  if (flag_exceptions)
+    {
+      this_region = gen_eh_region_allowed (state->cur_region,
+				           gimple_eh_filter_types (inner));
+      this_state.cur_region = this_region;
+    }
+
+  lower_eh_constructs_1 (&this_state, gimple_try_eval (tp));
+
+  if (!eh_region_may_contain_throw (this_region))
+    return gimple_try_eval (tp);
+
+  new_seq = NULL;
+  this_state.cur_region = state->cur_region;
+  this_state.ehp_region = this_region;
+
+  emit_eh_dispatch (&new_seq, this_region);
+  emit_resx (&new_seq, this_region);
+
+  this_region->u.allowed.label = create_artificial_label (UNKNOWN_LOCATION);
+  x = gimple_build_label (this_region->u.allowed.label);
+  gimple_seq_add_stmt (&new_seq, x);
+
+  lower_eh_constructs_1 (&this_state, gimple_eh_filter_failure (inner));
+  gimple_seq_add_seq (&new_seq, gimple_eh_filter_failure (inner));
+
+  gimple_try_set_cleanup (tp, new_seq);
+
+  return frob_into_branch_around (tp, this_region, NULL);
+}
+
+/* A subroutine of lower_eh_constructs_1.  Lower a GIMPLE_TRY with
+   an GIMPLE_EH_MUST_NOT_THROW to a sequence of labels and blocks,
+   plus the exception region trees that record all the magic.  */
+
+static gimple_seq
+lower_eh_must_not_throw (struct leh_state *state, gimple tp)
+{
+  struct leh_state this_state = *state;
+
+  if (flag_exceptions)
+    {
+      gimple inner = gimple_seq_first_stmt (gimple_try_cleanup (tp));
+      eh_region this_region;
+
+      this_region = gen_eh_region_must_not_throw (state->cur_region);
+      this_region->u.must_not_throw.failure_decl
+	= gimple_eh_must_not_throw_fndecl (inner);
+      this_region->u.must_not_throw.failure_loc = gimple_location (tp);
+
+      /* In order to get mangling applied to this decl, we must mark it
+	 used now.  Otherwise, pass_ipa_free_lang_data won't think it
+	 needs to happen.  */
+      TREE_USED (this_region->u.must_not_throw.failure_decl) = 1;
+
+      this_state.cur_region = this_region;
+    }
+
+  lower_eh_constructs_1 (&this_state, gimple_try_eval (tp));
+
+  return gimple_try_eval (tp);
+}
+
+/* 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 = *state;
+  eh_region this_region = NULL;
+  struct leh_tf_state fake_tf;
+  gimple_seq result;
+  bool cleanup_dead = cleanup_is_dead_in (state->cur_region);
+
+  if (flag_exceptions && !cleanup_dead)
+    {
+      this_region = gen_eh_region_cleanup (state->cur_region);
+      this_state.cur_region = this_region;
+    }
+
+  lower_eh_constructs_1 (&this_state, gimple_try_eval (tp));
+
+  if (cleanup_dead || !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 = fake_tf.try_finally_expr = 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;
+
+  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, this_region,
+                                        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:
+      {
+	tree fndecl = gimple_call_fndecl (stmt);
+	tree rhs, lhs;
+
+	if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
+	  switch (DECL_FUNCTION_CODE (fndecl))
+	    {
+	    case BUILT_IN_EH_POINTER:
+	      /* The front end may have generated a call to
+		 __builtin_eh_pointer (0) within a catch region.  Replace
+		 this zero argument with the current catch region number.  */
+	      if (state->ehp_region)
+		{
+		  tree nr = build_int_cst (NULL, state->ehp_region->index);
+		  gimple_call_set_arg (stmt, 0, nr);
+		}
+	      else
+		{
+		  /* The user has dome something silly.  Remove it.  */
+		  rhs = null_pointer_node;
+		  goto do_replace;
+		}
+	      break;
+
+	    case BUILT_IN_EH_FILTER:
+	      /* ??? This should never appear, but since it's a builtin it
+		 is accessible to abuse by users.  Just remove it and
+		 replace the use with the arbitrary value zero.  */
+	      rhs = build_int_cst (TREE_TYPE (TREE_TYPE (fndecl)), 0);
+	    do_replace:
+	      lhs = gimple_call_lhs (stmt);
+	      x = gimple_build_assign (lhs, rhs);
+	      gsi_insert_before (gsi, x, GSI_SAME_STMT);
+	      /* FALLTHRU */
+
+	    case BUILT_IN_EH_COPY_VALUES:
+	      /* Likewise this should not appear.  Remove it.  */
+	      gsi_remove (gsi, true);
+	      return;
+
+	    default:
+	      break;
+	    }
+      }
+      /* FALLTHRU */
+
+    case GIMPLE_ASSIGN:
+      /* If the stmt can throw use a new temporary for the assignment
+         to a LHS.  This makes sure the old value of the LHS is
+	 available on the EH edge.  Only do so for statements that
+	 potentially fall thru (no noreturn calls e.g.), otherwise
+	 this new assignment might create fake fallthru regions.  */
+      if (stmt_could_throw_p (stmt)
+	  && gimple_has_lhs (stmt)
+	  && gimple_stmt_may_fallthru (stmt)
+	  && !tree_could_throw_p (gimple_get_lhs (stmt))
+	  && is_gimple_reg_type (TREE_TYPE (gimple_get_lhs (stmt))))
+	{
+	  tree lhs = gimple_get_lhs (stmt);
+	  tree tmp = create_tmp_var (TREE_TYPE (lhs), NULL);
+	  gimple s = gimple_build_assign (lhs, tmp);
+	  gimple_set_location (s, gimple_location (stmt));
+	  gimple_set_block (s, gimple_block (stmt));
+	  gimple_set_lhs (stmt, tmp);
+	  if (TREE_CODE (TREE_TYPE (tmp)) == COMPLEX_TYPE
+	      || TREE_CODE (TREE_TYPE (tmp)) == VECTOR_TYPE)
+	    DECL_GIMPLE_REG_P (tmp) = 1;
+	  gsi_insert_after (gsi, s, GSI_SAME_STMT);
+	}
+      /* 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));
+	  if (!x)
+	    {
+	      replace = gimple_try_eval (stmt);
+	      lower_eh_constructs_1 (state, replace);
+	    }
+	  else
+	    switch (gimple_code (x))
+	      {
+		case GIMPLE_CATCH:
+		    replace = lower_catch (state, stmt);
+		    break;
+		case GIMPLE_EH_FILTER:
+		    replace = lower_eh_filter (state, stmt);
+		    break;
+		case GIMPLE_EH_MUST_NOT_THROW:
+		    replace = lower_eh_must_not_throw (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;
+
+  bodyp = gimple_body (current_function_decl);
+  if (bodyp == NULL)
+    return 0;
+
+  finally_tree = htab_create (31, struct_ptr_hash, struct_ptr_eq, free);
+  eh_region_may_contain_throw_map = BITMAP_ALLOC (NULL);
+  memset (&null_state, 0, sizeof (null_state));
+
+  collect_finally_tree_1 (bodyp, NULL);
+  lower_eh_constructs_1 (&null_state, bodyp);
+
+  /* We assume there's a return statement, or something, at the end of
+     the function, and thus ploping the EH sequence afterward won't
+     change anything.  */
+  gcc_assert (!gimple_seq_may_fallthru (bodyp));
+  gimple_seq_add_seq (&bodyp, eh_seq);
+
+  /* We assume that since BODYP already existed, adding EH_SEQ to it
+     didn't change its value, and we don't have to re-set the function.  */
+  gcc_assert (bodyp == gimple_body (current_function_decl));
+
+  htab_delete (finally_tree);
+  BITMAP_FREE (eh_region_may_contain_throw_map);
+  eh_seq = NULL;
+
+  /* If this function needs a language specific EH personality routine
+     and the frontend didn't already set one do so now.  */
+  if (function_needs_eh_personality (cfun) == eh_personality_lang
+      && !DECL_FUNCTION_PERSONALITY (current_function_decl))
+    DECL_FUNCTION_PERSONALITY (current_function_decl)
+      = lang_hooks.eh_personality ();
+
+  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 */
+ }
+};
+
+/* Create the multiple edges from an EH_DISPATCH statement to all of
+   the possible handlers for its EH region.  Return true if there's
+   no fallthru edge; false if there is.  */
+
+bool
+make_eh_dispatch_edges (gimple stmt)
+{
+  eh_region r;
+  eh_catch c;
+  basic_block src, dst;
+
+  r = get_eh_region_from_number (gimple_eh_dispatch_region (stmt));
+  src = gimple_bb (stmt);
+
+  switch (r->type)
+    {
+    case ERT_TRY:
+      for (c = r->u.eh_try.first_catch; c ; c = c->next_catch)
+	{
+	  dst = label_to_block (c->label);
+	  make_edge (src, dst, 0);
+
+	  /* A catch-all handler doesn't have a fallthru.  */
+	  if (c->type_list == NULL)
+	    return false;
+	}
+      break;
+
+    case ERT_ALLOWED_EXCEPTIONS:
+      dst = label_to_block (r->u.allowed.label);
+      make_edge (src, dst, 0);
+      break;
+
+    default:
+      gcc_unreachable ();
+    }
+
+  return true;
+}
+
+/* Create the single EH edge from STMT to its nearest landing pad,
+   if there is such a landing pad within the current function.  */
+
+void
+make_eh_edges (gimple stmt)
+{
+  basic_block src, dst;
+  eh_landing_pad lp;
+  int lp_nr;
+
+  lp_nr = lookup_stmt_eh_lp (stmt);
+  if (lp_nr <= 0)
+    return;
+
+  lp = get_eh_landing_pad_from_number (lp_nr);
+  gcc_assert (lp != NULL);
+
+  src = gimple_bb (stmt);
+  dst = label_to_block (lp->post_landing_pad);
+  make_edge (src, dst, EDGE_EH);
+}
+
+/* Do the work in redirecting EDGE_IN to NEW_BB within the EH region tree;
+   do not actually perform the final edge redirection.
+
+   CHANGE_REGION is true when we're being called from cleanup_empty_eh and
+   we intend to change the destination EH region as well; this means
+   EH_LANDING_PAD_NR must already be set on the destination block label.
+   If false, we're being called from generic cfg manipulation code and we
+   should preserve our place within the region tree.  */
+
+static void
+redirect_eh_edge_1 (edge edge_in, basic_block new_bb, bool change_region)
+{
+  eh_landing_pad old_lp, new_lp;
+  basic_block old_bb;
+  gimple throw_stmt;
+  int old_lp_nr, new_lp_nr;
+  tree old_label, new_label;
+  edge_iterator ei;
+  edge e;
+
+  old_bb = edge_in->dest;
+  old_label = gimple_block_label (old_bb);
+  old_lp_nr = EH_LANDING_PAD_NR (old_label);
+  gcc_assert (old_lp_nr > 0);
+  old_lp = get_eh_landing_pad_from_number (old_lp_nr);
+
+  throw_stmt = last_stmt (edge_in->src);
+  gcc_assert (lookup_stmt_eh_lp (throw_stmt) == old_lp_nr);
+
+  new_label = gimple_block_label (new_bb);
+
+  /* Look for an existing region that might be using NEW_BB already.  */
+  new_lp_nr = EH_LANDING_PAD_NR (new_label);
+  if (new_lp_nr)
+    {
+      new_lp = get_eh_landing_pad_from_number (new_lp_nr);
+      gcc_assert (new_lp);
+
+      /* Unless CHANGE_REGION is true, the new and old landing pad
+	 had better be associated with the same EH region.  */
+      gcc_assert (change_region || new_lp->region == old_lp->region);
+    }
+  else
+    {
+      new_lp = NULL;
+      gcc_assert (!change_region);
+    }
+
+  /* Notice when we redirect the last EH edge away from OLD_BB.  */
+  FOR_EACH_EDGE (e, ei, old_bb->preds)
+    if (e != edge_in && (e->flags & EDGE_EH))
+      break;
+
+  if (new_lp)
+    {
+      /* NEW_LP already exists.  If there are still edges into OLD_LP,
+	 there's nothing to do with the EH tree.  If there are no more
+	 edges into OLD_LP, then we want to remove OLD_LP as it is unused.
+	 If CHANGE_REGION is true, then our caller is expecting to remove
+	 the landing pad.  */
+      if (e == NULL && !change_region)
+	remove_eh_landing_pad (old_lp);
+    }
+  else
+    {
+      /* No correct landing pad exists.  If there are no more edges
+	 into OLD_LP, then we can simply re-use the existing landing pad.
+	 Otherwise, we have to create a new landing pad.  */
+      if (e == NULL)
+	{
+	  EH_LANDING_PAD_NR (old_lp->post_landing_pad) = 0;
+	  new_lp = old_lp;
+	}
+      else
+	new_lp = gen_eh_landing_pad (old_lp->region);
+      new_lp->post_landing_pad = new_label;
+      EH_LANDING_PAD_NR (new_label) = new_lp->index;
+    }
+
+  /* Maybe move the throwing statement to the new region.  */
+  if (old_lp != new_lp)
+    {
+      remove_stmt_from_eh_lp (throw_stmt);
+      add_stmt_to_eh_lp (throw_stmt, new_lp->index);
+    }
+}
+
+/* Redirect EH edge E to NEW_BB.  */
+
+edge
+redirect_eh_edge (edge edge_in, basic_block new_bb)
+{
+  redirect_eh_edge_1 (edge_in, new_bb, false);
+  return ssa_redirect_edge (edge_in, new_bb);
+}
+
+/* This is a subroutine of gimple_redirect_edge_and_branch.  Update the
+   labels for redirecting a non-fallthru EH_DISPATCH edge E to NEW_BB.
+   The actual edge update will happen in the caller.  */
+
+void
+redirect_eh_dispatch_edge (gimple stmt, edge e, basic_block new_bb)
+{
+  tree new_lab = gimple_block_label (new_bb);
+  bool any_changed = false;
+  basic_block old_bb;
+  eh_region r;
+  eh_catch c;
+
+  r = get_eh_region_from_number (gimple_eh_dispatch_region (stmt));
+  switch (r->type)
+    {
+    case ERT_TRY:
+      for (c = r->u.eh_try.first_catch; c ; c = c->next_catch)
+	{
+	  old_bb = label_to_block (c->label);
+	  if (old_bb == e->dest)
+	    {
+	      c->label = new_lab;
+	      any_changed = true;
+	    }
+	}
+      break;
+
+    case ERT_ALLOWED_EXCEPTIONS:
+      old_bb = label_to_block (r->u.allowed.label);
+      gcc_assert (old_bb == e->dest);
+      r->u.allowed.label = new_lab;
+      any_changed = true;
+      break;
+
+    default:
+      gcc_unreachable ();
+    }
+
+  gcc_assert (any_changed);
+}
+
+/* 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;
+
+    case COMPLEX_EXPR:
+    case CONSTRUCTOR:
+      /* Constructing an object cannot trap.  */
+      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:
+      if (TREE_CODE (TMR_BASE (expr)) == ADDR_EXPR
+	  && !TMR_INDEX (expr) && !TMR_INDEX2 (expr))
+	return false;
+      return !TREE_THIS_NOTRAP (expr);
+
+    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 MEM_REF:
+      if (TREE_CODE (TREE_OPERAND (expr, 0)) == ADDR_EXPR)
+	return false;
+      /* Fallthru.  */
+    case 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;
+
+    case VAR_DECL:
+    case FUNCTION_DECL:
+      /* Assume that accesses to weak vars or functions may trap.  */
+      if (DECL_WEAK (expr))
+        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)
+{
+  if (!flag_exceptions)
+    return false;
+
+  /* The only statements that can throw an exception are assignments,
+     conditionals, calls, resx, and asms.  */
+  switch (gimple_code (stmt))
+    {
+    case GIMPLE_RESX:
+      return true;
+
+    case GIMPLE_CALL:
+      return !gimple_call_nothrow_p (stmt);
+
+    case GIMPLE_ASSIGN:
+    case GIMPLE_COND:
+      if (!cfun->can_throw_non_call_exceptions)
+        return false;
+      return stmt_could_throw_1_p (stmt);
+
+    case GIMPLE_ASM:
+      if (!cfun->can_throw_non_call_exceptions)
+        return false;
+      return gimple_asm_volatile_p (stmt);
+
+    default:
+      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 (cfun->can_throw_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 (cfun->can_throw_non_call_exceptions)
+    return tree_could_trap_p (t);
+  return false;
+}
+
+/* Return true if STMT can throw an exception that is not caught within
+   the current function (CFUN).  */
+
+bool
+stmt_can_throw_external (gimple stmt)
+{
+  int lp_nr;
+
+  if (!stmt_could_throw_p (stmt))
+    return false;
+
+  lp_nr = lookup_stmt_eh_lp (stmt);
+  return lp_nr == 0;
+}
+
+/* Return true if STMT can throw an exception that is caught within
+   the current function (CFUN).  */
+
+bool
+stmt_can_throw_internal (gimple stmt)
+{
+  int lp_nr;
+
+  if (!stmt_could_throw_p (stmt))
+    return false;
+
+  lp_nr = lookup_stmt_eh_lp (stmt);
+  return lp_nr > 0;
+}
+
+/* Given a statement STMT in IFUN, if STMT can no longer throw, then
+   remove any entry it might have from the EH table.  Return true if
+   any change was made.  */
+
+bool
+maybe_clean_eh_stmt_fn (struct function *ifun, gimple stmt)
+{
+  if (stmt_could_throw_p (stmt))
+    return false;
+  return remove_stmt_from_eh_lp_fn (ifun, stmt);
+}
+
+/* Likewise, but always use the current function.  */
+
+bool
+maybe_clean_eh_stmt (gimple stmt)
+{
+  return maybe_clean_eh_stmt_fn (cfun, stmt);
+}
+
+/* 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 lp_nr = lookup_stmt_eh_lp (old_stmt);
+
+  if (lp_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_lp (old_stmt);
+      if (new_stmt_could_throw)
+	{
+	  add_stmt_to_eh_lp (new_stmt, lp_nr);
+	  return false;
+	}
+      else
+	return true;
+    }
+
+  return false;
+}
+
+/* Given a statement OLD_STMT in OLD_FUN and a duplicate statment NEW_STMT
+   in NEW_FUN, copy the EH table data from OLD_STMT to NEW_STMT.  The MAP
+   operand is the return value of duplicate_eh_regions.  */
+
+bool
+maybe_duplicate_eh_stmt_fn (struct function *new_fun, gimple new_stmt,
+			    struct function *old_fun, gimple old_stmt,
+			    struct pointer_map_t *map, int default_lp_nr)
+{
+  int old_lp_nr, new_lp_nr;
+  void **slot;
+
+  if (!stmt_could_throw_p (new_stmt))
+    return false;
+
+  old_lp_nr = lookup_stmt_eh_lp_fn (old_fun, old_stmt);
+  if (old_lp_nr == 0)
+    {
+      if (default_lp_nr == 0)
+	return false;
+      new_lp_nr = default_lp_nr;
+    }
+  else if (old_lp_nr > 0)
+    {
+      eh_landing_pad old_lp, new_lp;
+
+      old_lp = VEC_index (eh_landing_pad, old_fun->eh->lp_array, old_lp_nr);
+      slot = pointer_map_contains (map, old_lp);
+      new_lp = (eh_landing_pad) *slot;
+      new_lp_nr = new_lp->index;
+    }
+  else
+    {
+      eh_region old_r, new_r;
+
+      old_r = VEC_index (eh_region, old_fun->eh->region_array, -old_lp_nr);
+      slot = pointer_map_contains (map, old_r);
+      new_r = (eh_region) *slot;
+      new_lp_nr = -new_r->index;
+    }
+
+  add_stmt_to_eh_lp_fn (new_fun, new_stmt, new_lp_nr);
+  return true;
+}
+
+/* Similar, but both OLD_STMT and NEW_STMT are within the current function,
+   and thus no remapping is required.  */
+
+bool
+maybe_duplicate_eh_stmt (gimple new_stmt, gimple old_stmt)
+{
+  int lp_nr;
+
+  if (!stmt_could_throw_p (new_stmt))
+    return false;
+
+  lp_nr = lookup_stmt_eh_lp (old_stmt);
+  if (lp_nr == 0)
+    return false;
+
+  add_stmt_to_eh_lp (new_stmt, lp_nr);
+  return true;
+}
+
+/* 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;
+}
+
+static bool
+gate_refactor_eh (void)
+{
+  return flag_exceptions != 0;
+}
+
+struct gimple_opt_pass pass_refactor_eh =
+{
+ {
+  GIMPLE_PASS,
+  "ehopt",				/* name */
+  gate_refactor_eh,			/* 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 */
+ }
+};
+
+/* At the end of gimple optimization, we can lower RESX.  */
+
+static bool
+lower_resx (basic_block bb, gimple stmt, struct pointer_map_t *mnt_map)
+{
+  int lp_nr;
+  eh_region src_r, dst_r;
+  gimple_stmt_iterator gsi;
+  gimple x;
+  tree fn, src_nr;
+  bool ret = false;
+
+  lp_nr = lookup_stmt_eh_lp (stmt);
+  if (lp_nr != 0)
+    dst_r = get_eh_region_from_lp_number (lp_nr);
+  else
+    dst_r = NULL;
+
+  src_r = get_eh_region_from_number (gimple_resx_region (stmt));
+  gsi = gsi_last_bb (bb);
+
+  if (src_r == NULL)
+    {
+      /* We can wind up with no source region when pass_cleanup_eh shows
+	 that there are no entries into an eh region and deletes it, but
+	 then the block that contains the resx isn't removed.  This can
+	 happen without optimization when the switch statement created by
+	 lower_try_finally_switch isn't simplified to remove the eh case.
+
+	 Resolve this by expanding the resx node to an abort.  */
+
+      fn = implicit_built_in_decls[BUILT_IN_TRAP];
+      x = gimple_build_call (fn, 0);
+      gsi_insert_before (&gsi, x, GSI_SAME_STMT);
+
+      while (EDGE_COUNT (bb->succs) > 0)
+	remove_edge (EDGE_SUCC (bb, 0));
+    }
+  else if (dst_r)
+    {
+      /* When we have a destination region, we resolve this by copying
+	 the excptr and filter values into place, and changing the edge
+	 to immediately after the landing pad.  */
+      edge e;
+
+      if (lp_nr < 0)
+	{
+	  basic_block new_bb;
+	  void **slot;
+	  tree lab;
+
+	  /* We are resuming into a MUST_NOT_CALL region.  Expand a call to
+	     the failure decl into a new block, if needed.  */
+	  gcc_assert (dst_r->type == ERT_MUST_NOT_THROW);
+
+	  slot = pointer_map_contains (mnt_map, dst_r);
+	  if (slot == NULL)
+	    {
+	      gimple_stmt_iterator gsi2;
+
+	      new_bb = create_empty_bb (bb);
+	      lab = gimple_block_label (new_bb);
+	      gsi2 = gsi_start_bb (new_bb);
+
+	      fn = dst_r->u.must_not_throw.failure_decl;
+	      x = gimple_build_call (fn, 0);
+	      gimple_set_location (x, dst_r->u.must_not_throw.failure_loc);
+	      gsi_insert_after (&gsi2, x, GSI_CONTINUE_LINKING);
+
+	      slot = pointer_map_insert (mnt_map, dst_r);
+	      *slot = lab;
+	    }
+	  else
+	    {
+	      lab = (tree) *slot;
+	      new_bb = label_to_block (lab);
+	    }
+
+	  gcc_assert (EDGE_COUNT (bb->succs) == 0);
+	  e = make_edge (bb, new_bb, EDGE_FALLTHRU);
+	  e->count = bb->count;
+	  e->probability = REG_BR_PROB_BASE;
+	}
+      else
+	{
+	  edge_iterator ei;
+	  tree dst_nr = build_int_cst (NULL, dst_r->index);
+
+	  fn = implicit_built_in_decls[BUILT_IN_EH_COPY_VALUES];
+	  src_nr = build_int_cst (NULL, src_r->index);
+	  x = gimple_build_call (fn, 2, dst_nr, src_nr);
+	  gsi_insert_before (&gsi, x, GSI_SAME_STMT);
+
+	  /* Update the flags for the outgoing edge.  */
+	  e = single_succ_edge (bb);
+	  gcc_assert (e->flags & EDGE_EH);
+	  e->flags = (e->flags & ~EDGE_EH) | EDGE_FALLTHRU;
+
+	  /* If there are no more EH users of the landing pad, delete it.  */
+	  FOR_EACH_EDGE (e, ei, e->dest->preds)
+	    if (e->flags & EDGE_EH)
+	      break;
+	  if (e == NULL)
+	    {
+	      eh_landing_pad lp = get_eh_landing_pad_from_number (lp_nr);
+	      remove_eh_landing_pad (lp);
+	    }
+	}
+
+      ret = true;
+    }
+  else
+    {
+      tree var;
+
+      /* When we don't have a destination region, this exception escapes
+	 up the call chain.  We resolve this by generating a call to the
+	 _Unwind_Resume library function.  */
+
+      /* The ARM EABI redefines _Unwind_Resume as __cxa_end_cleanup
+	 with no arguments for C++ and Java.  Check for that.  */
+      if (src_r->use_cxa_end_cleanup)
+	{
+	  fn = implicit_built_in_decls[BUILT_IN_CXA_END_CLEANUP];
+	  x = gimple_build_call (fn, 0);
+	  gsi_insert_before (&gsi, x, GSI_SAME_STMT);
+	}
+      else
+	{
+	  fn = implicit_built_in_decls[BUILT_IN_EH_POINTER];
+	  src_nr = build_int_cst (NULL, src_r->index);
+	  x = gimple_build_call (fn, 1, src_nr);
+	  var = create_tmp_var (ptr_type_node, NULL);
+	  var = make_ssa_name (var, x);
+	  gimple_call_set_lhs (x, var);
+	  gsi_insert_before (&gsi, x, GSI_SAME_STMT);
+
+	  fn = implicit_built_in_decls[BUILT_IN_UNWIND_RESUME];
+	  x = gimple_build_call (fn, 1, var);
+	  gsi_insert_before (&gsi, x, GSI_SAME_STMT);
+	}
+
+      gcc_assert (EDGE_COUNT (bb->succs) == 0);
+    }
+
+  gsi_remove (&gsi, true);
+
+  return ret;
+}
+
+static unsigned
+execute_lower_resx (void)
+{
+  basic_block bb;
+  struct pointer_map_t *mnt_map;
+  bool dominance_invalidated = false;
+  bool any_rewritten = false;
+
+  mnt_map = pointer_map_create ();
+
+  FOR_EACH_BB (bb)
+    {
+      gimple last = last_stmt (bb);
+      if (last && is_gimple_resx (last))
+	{
+	  dominance_invalidated |= lower_resx (bb, last, mnt_map);
+	  any_rewritten = true;
+	}
+    }
+
+  pointer_map_destroy (mnt_map);
+
+  if (dominance_invalidated)
+    {
+      free_dominance_info (CDI_DOMINATORS);
+      free_dominance_info (CDI_POST_DOMINATORS);
+    }
+
+  return any_rewritten ? TODO_update_ssa_only_virtuals : 0;
+}
+
+static bool
+gate_lower_resx (void)
+{
+  return flag_exceptions != 0;
+}
+
+struct gimple_opt_pass pass_lower_resx =
+{
+ {
+  GIMPLE_PASS,
+  "resx",				/* name */
+  gate_lower_resx,			/* gate */
+  execute_lower_resx,			/* 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_verify_flow	/* todo_flags_finish */
+ }
+};
+
+
+/* At the end of inlining, we can lower EH_DISPATCH.  Return true when 
+   we have found some duplicate labels and removed some edges.  */
+
+static bool
+lower_eh_dispatch (basic_block src, gimple stmt)
+{
+  gimple_stmt_iterator gsi;
+  int region_nr;
+  eh_region r;
+  tree filter, fn;
+  gimple x;
+  bool redirected = false;
+
+  region_nr = gimple_eh_dispatch_region (stmt);
+  r = get_eh_region_from_number (region_nr);
+
+  gsi = gsi_last_bb (src);
+
+  switch (r->type)
+    {
+    case ERT_TRY:
+      {
+	VEC (tree, heap) *labels = NULL;
+	tree default_label = NULL;
+	eh_catch c;
+	edge_iterator ei;
+	edge e;
+	struct pointer_set_t *seen_values = pointer_set_create ();
+
+	/* Collect the labels for a switch.  Zero the post_landing_pad
+	   field becase we'll no longer have anything keeping these labels
+	   in existance and the optimizer will be free to merge these
+	   blocks at will.  */
+	for (c = r->u.eh_try.first_catch; c ; c = c->next_catch)
+	  {
+	    tree tp_node, flt_node, lab = c->label;
+	    bool have_label = false;
+
+	    c->label = NULL;
+	    tp_node = c->type_list;
+	    flt_node = c->filter_list;
+
+	    if (tp_node == NULL)
+	      {
+	        default_label = lab;
+		break;
+	      }
+	    do
+	      {
+		/* Filter out duplicate labels that arise when this handler 
+		   is shadowed by an earlier one.  When no labels are 
+		   attached to the handler anymore, we remove 
+		   the corresponding edge and then we delete unreachable 
+		   blocks at the end of this pass.  */
+		if (! pointer_set_contains (seen_values, TREE_VALUE (flt_node)))
+		  {
+		    tree t = build3 (CASE_LABEL_EXPR, void_type_node,
+				     TREE_VALUE (flt_node), NULL, lab);
+		    VEC_safe_push (tree, heap, labels, t);
+		    pointer_set_insert (seen_values, TREE_VALUE (flt_node));
+		    have_label = true;
+		  }
+
+		tp_node = TREE_CHAIN (tp_node);
+		flt_node = TREE_CHAIN (flt_node);
+	      }
+	    while (tp_node);
+	    if (! have_label)
+	      {
+	        remove_edge (find_edge (src, label_to_block (lab)));
+	        redirected = true;
+	      }
+	  }
+
+	/* Clean up the edge flags.  */
+	FOR_EACH_EDGE (e, ei, src->succs)
+	  {
+	    if (e->flags & EDGE_FALLTHRU)
+	      {
+		/* If there was no catch-all, use the fallthru edge.  */
+		if (default_label == NULL)
+		  default_label = gimple_block_label (e->dest);
+		e->flags &= ~EDGE_FALLTHRU;
+	      }
+	  }
+	gcc_assert (default_label != NULL);
+
+	/* Don't generate a switch if there's only a default case.
+	   This is common in the form of try { A; } catch (...) { B; }.  */
+	if (labels == NULL)
+	  {
+	    e = single_succ_edge (src);
+	    e->flags |= EDGE_FALLTHRU;
+	  }
+	else
+	  {
+	    fn = implicit_built_in_decls[BUILT_IN_EH_FILTER];
+	    x = gimple_build_call (fn, 1, build_int_cst (NULL, region_nr));
+	    filter = create_tmp_var (TREE_TYPE (TREE_TYPE (fn)), NULL);
+	    filter = make_ssa_name (filter, x);
+	    gimple_call_set_lhs (x, filter);
+	    gsi_insert_before (&gsi, x, GSI_SAME_STMT);
+
+	    /* Turn the default label into a default case.  */
+	    default_label = build3 (CASE_LABEL_EXPR, void_type_node,
+				    NULL, NULL, default_label);
+	    sort_case_labels (labels);
+
+	    x = gimple_build_switch_vec (filter, default_label, labels);
+	    gsi_insert_before (&gsi, x, GSI_SAME_STMT);
+
+	    VEC_free (tree, heap, labels);
+	  }
+	pointer_set_destroy (seen_values);
+      }
+      break;
+
+    case ERT_ALLOWED_EXCEPTIONS:
+      {
+	edge b_e = BRANCH_EDGE (src);
+	edge f_e = FALLTHRU_EDGE (src);
+
+	fn = implicit_built_in_decls[BUILT_IN_EH_FILTER];
+	x = gimple_build_call (fn, 1, build_int_cst (NULL, region_nr));
+	filter = create_tmp_var (TREE_TYPE (TREE_TYPE (fn)), NULL);
+	filter = make_ssa_name (filter, x);
+	gimple_call_set_lhs (x, filter);
+	gsi_insert_before (&gsi, x, GSI_SAME_STMT);
+
+	r->u.allowed.label = NULL;
+	x = gimple_build_cond (EQ_EXPR, filter,
+			       build_int_cst (TREE_TYPE (filter),
+					      r->u.allowed.filter),
+			       NULL_TREE, NULL_TREE);
+	gsi_insert_before (&gsi, x, GSI_SAME_STMT);
+
+	b_e->flags = b_e->flags | EDGE_TRUE_VALUE;
+        f_e->flags = (f_e->flags & ~EDGE_FALLTHRU) | EDGE_FALSE_VALUE;
+      }
+      break;
+
+    default:
+      gcc_unreachable ();
+    }
+
+  /* Replace the EH_DISPATCH with the SWITCH or COND generated above.  */
+  gsi_remove (&gsi, true);
+  return redirected;
+}
+
+static unsigned
+execute_lower_eh_dispatch (void)
+{
+  basic_block bb;
+  bool any_rewritten = false;
+  bool redirected = false;
+
+  assign_filter_values ();
+
+  FOR_EACH_BB (bb)
+    {
+      gimple last = last_stmt (bb);
+      if (last && gimple_code (last) == GIMPLE_EH_DISPATCH)
+	{
+	  redirected |= lower_eh_dispatch (bb, last);
+	  any_rewritten = true;
+	}
+    }
+
+  if (redirected)
+    delete_unreachable_blocks ();
+  return any_rewritten ? TODO_update_ssa_only_virtuals : 0;
+}
+
+static bool
+gate_lower_eh_dispatch (void)
+{
+  return cfun->eh->region_tree != NULL;
+}
+
+struct gimple_opt_pass pass_lower_eh_dispatch =
+{
+ {
+  GIMPLE_PASS,
+  "ehdisp",				/* name */
+  gate_lower_eh_dispatch,		/* gate */
+  execute_lower_eh_dispatch,		/* 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_verify_flow	/* todo_flags_finish */
+ }
+};
+
+/* Walk statements, see what regions are really referenced and remove
+   those that are unused.  */
+
+static void
+remove_unreachable_handlers (void)
+{
+  sbitmap r_reachable, lp_reachable;
+  eh_region region;
+  eh_landing_pad lp;
+  basic_block bb;
+  int lp_nr, r_nr;
+
+  r_reachable = sbitmap_alloc (VEC_length (eh_region, cfun->eh->region_array));
+  lp_reachable
+    = sbitmap_alloc (VEC_length (eh_landing_pad, cfun->eh->lp_array));
+  sbitmap_zero (r_reachable);
+  sbitmap_zero (lp_reachable);
+
+  FOR_EACH_BB (bb)
+    {
+      gimple_stmt_iterator gsi = gsi_start_bb (bb);
+
+      for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+	{
+	  gimple stmt = gsi_stmt (gsi);
+	  lp_nr = lookup_stmt_eh_lp (stmt);
+
+	  /* Negative LP numbers are MUST_NOT_THROW regions which
+	     are not considered BB enders.  */
+	  if (lp_nr < 0)
+	    SET_BIT (r_reachable, -lp_nr);
+
+	  /* Positive LP numbers are real landing pads, are are BB enders.  */
+	  else if (lp_nr > 0)
+	    {
+	      gcc_assert (gsi_one_before_end_p (gsi));
+	      region = get_eh_region_from_lp_number (lp_nr);
+	      SET_BIT (r_reachable, region->index);
+	      SET_BIT (lp_reachable, lp_nr);
+	    }
+
+	  /* Avoid removing regions referenced from RESX/EH_DISPATCH.  */
+	  switch (gimple_code (stmt))
+	    {
+	    case GIMPLE_RESX:
+	      SET_BIT (r_reachable, gimple_resx_region (stmt));
+	      break;
+	    case GIMPLE_EH_DISPATCH:
+	      SET_BIT (r_reachable, gimple_eh_dispatch_region (stmt));
+	      break;
+	    default:
+	      break;
+	    }
+	}
+    }
+
+  if (dump_file)
+    {
+      fprintf (dump_file, "Before removal of unreachable regions:\n");
+      dump_eh_tree (dump_file, cfun);
+      fprintf (dump_file, "Reachable regions: ");
+      dump_sbitmap_file (dump_file, r_reachable);
+      fprintf (dump_file, "Reachable landing pads: ");
+      dump_sbitmap_file (dump_file, lp_reachable);
+    }
+
+  for (r_nr = 1;
+       VEC_iterate (eh_region, cfun->eh->region_array, r_nr, region); ++r_nr)
+    if (region && !TEST_BIT (r_reachable, r_nr))
+      {
+	if (dump_file)
+	  fprintf (dump_file, "Removing unreachable region %d\n", r_nr);
+	remove_eh_handler (region);
+      }
+
+  for (lp_nr = 1;
+       VEC_iterate (eh_landing_pad, cfun->eh->lp_array, lp_nr, lp); ++lp_nr)
+    if (lp && !TEST_BIT (lp_reachable, lp_nr))
+      {
+	if (dump_file)
+	  fprintf (dump_file, "Removing unreachable landing pad %d\n", lp_nr);
+	remove_eh_landing_pad (lp);
+      }
+
+  if (dump_file)
+    {
+      fprintf (dump_file, "\n\nAfter removal of unreachable regions:\n");
+      dump_eh_tree (dump_file, cfun);
+      fprintf (dump_file, "\n\n");
+    }
+
+  sbitmap_free (r_reachable);
+  sbitmap_free (lp_reachable);
+
+#ifdef ENABLE_CHECKING
+  verify_eh_tree (cfun);
+#endif
+}
+
+/* Remove regions that do not have landing pads.  This assumes
+   that remove_unreachable_handlers has already been run, and
+   that we've just manipulated the landing pads since then.  */
+
+static void
+remove_unreachable_handlers_no_lp (void)
+{
+  eh_region r;
+  int i;
+
+  for (i = 1; VEC_iterate (eh_region, cfun->eh->region_array, i, r); ++i)
+    if (r && r->landing_pads == NULL && r->type != ERT_MUST_NOT_THROW)
+      {
+	if (dump_file)
+	  fprintf (dump_file, "Removing unreachable region %d\n", i);
+	remove_eh_handler (r);
+      }
+}
+
+/* Undo critical edge splitting on an EH landing pad.  Earlier, we
+   optimisticaly split all sorts of edges, including EH edges.  The
+   optimization passes in between may not have needed them; if not,
+   we should undo the split.
+
+   Recognize this case by having one EH edge incoming to the BB and
+   one normal edge outgoing; BB should be empty apart from the
+   post_landing_pad label.
+
+   Note that this is slightly different from the empty handler case
+   handled by cleanup_empty_eh, in that the actual handler may yet
+   have actual code but the landing pad has been separated from the
+   handler.  As such, cleanup_empty_eh relies on this transformation
+   having been done first.  */
+
+static bool
+unsplit_eh (eh_landing_pad lp)
+{
+  basic_block bb = label_to_block (lp->post_landing_pad);
+  gimple_stmt_iterator gsi;
+  edge e_in, e_out;
+
+  /* Quickly check the edge counts on BB for singularity.  */
+  if (EDGE_COUNT (bb->preds) != 1 || EDGE_COUNT (bb->succs) != 1)
+    return false;
+  e_in = EDGE_PRED (bb, 0);
+  e_out = EDGE_SUCC (bb, 0);
+
+  /* Input edge must be EH and output edge must be normal.  */
+  if ((e_in->flags & EDGE_EH) == 0 || (e_out->flags & EDGE_EH) != 0)
+    return false;
+
+  /* The block must be empty except for the labels and debug insns.  */
+  gsi = gsi_after_labels (bb);
+  if (!gsi_end_p (gsi) && is_gimple_debug (gsi_stmt (gsi)))
+    gsi_next_nondebug (&gsi);
+  if (!gsi_end_p (gsi))
+    return false;
+
+  /* The destination block must not already have a landing pad
+     for a different region.  */
+  for (gsi = gsi_start_bb (e_out->dest); !gsi_end_p (gsi); gsi_next (&gsi))
+    {
+      gimple stmt = gsi_stmt (gsi);
+      tree lab;
+      int lp_nr;
+
+      if (gimple_code (stmt) != GIMPLE_LABEL)
+	break;
+      lab = gimple_label_label (stmt);
+      lp_nr = EH_LANDING_PAD_NR (lab);
+      if (lp_nr && get_eh_region_from_lp_number (lp_nr) != lp->region)
+	return false;
+    }
+
+  /* The new destination block must not already be a destination of
+     the source block, lest we merge fallthru and eh edges and get
+     all sorts of confused.  */
+  if (find_edge (e_in->src, e_out->dest))
+    return false;
+
+  /* ??? We can get degenerate phis due to cfg cleanups.  I would have
+     thought this should have been cleaned up by a phicprop pass, but
+     that doesn't appear to handle virtuals.  Propagate by hand.  */
+  if (!gimple_seq_empty_p (phi_nodes (bb)))
+    {
+      for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); )
+	{
+	  gimple use_stmt, phi = gsi_stmt (gsi);
+	  tree lhs = gimple_phi_result (phi);
+	  tree rhs = gimple_phi_arg_def (phi, 0);
+	  use_operand_p use_p;
+	  imm_use_iterator iter;
+
+	  FOR_EACH_IMM_USE_STMT (use_stmt, iter, lhs)
+	    {
+	      FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
+		SET_USE (use_p, rhs);
+	    }
+
+	  if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs))
+	    SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs) = 1;
+
+	  remove_phi_node (&gsi, true);
+	}
+    }
+
+  if (dump_file && (dump_flags & TDF_DETAILS))
+    fprintf (dump_file, "Unsplit EH landing pad %d to block %i.\n",
+	     lp->index, e_out->dest->index);
+
+  /* Redirect the edge.  Since redirect_eh_edge_1 expects to be moving
+     a successor edge, humor it.  But do the real CFG change with the
+     predecessor of E_OUT in order to preserve the ordering of arguments
+     to the PHI nodes in E_OUT->DEST.  */
+  redirect_eh_edge_1 (e_in, e_out->dest, false);
+  redirect_edge_pred (e_out, e_in->src);
+  e_out->flags = e_in->flags;
+  e_out->probability = e_in->probability;
+  e_out->count = e_in->count;
+  remove_edge (e_in);
+
+  return true;
+}
+
+/* Examine each landing pad block and see if it matches unsplit_eh.  */
+
+static bool
+unsplit_all_eh (void)
+{
+  bool changed = false;
+  eh_landing_pad lp;
+  int i;
+
+  for (i = 1; VEC_iterate (eh_landing_pad, cfun->eh->lp_array, i, lp); ++i)
+    if (lp)
+      changed |= unsplit_eh (lp);
+
+  return changed;
+}
+
+/* A subroutine of cleanup_empty_eh.  Redirect all EH edges incoming
+   to OLD_BB to NEW_BB; return true on success, false on failure.
+
+   OLD_BB_OUT is the edge into NEW_BB from OLD_BB, so if we miss any
+   PHI variables from OLD_BB we can pick them up from OLD_BB_OUT.
+   Virtual PHIs may be deleted and marked for renaming.  */
+
+static bool
+cleanup_empty_eh_merge_phis (basic_block new_bb, basic_block old_bb,
+			     edge old_bb_out, bool change_region)
+{
+  gimple_stmt_iterator ngsi, ogsi;
+  edge_iterator ei;
+  edge e;
+  bitmap rename_virts;
+  bitmap ophi_handled;
+
+  FOR_EACH_EDGE (e, ei, old_bb->preds)
+    redirect_edge_var_map_clear (e);
+
+  ophi_handled = BITMAP_ALLOC (NULL);
+  rename_virts = BITMAP_ALLOC (NULL);
+
+  /* First, iterate through the PHIs on NEW_BB and set up the edge_var_map
+     for the edges we're going to move.  */
+  for (ngsi = gsi_start_phis (new_bb); !gsi_end_p (ngsi); gsi_next (&ngsi))
+    {
+      gimple ophi, nphi = gsi_stmt (ngsi);
+      tree nresult, nop;
+
+      nresult = gimple_phi_result (nphi);
+      nop = gimple_phi_arg_def (nphi, old_bb_out->dest_idx);
+
+      /* Find the corresponding PHI in OLD_BB so we can forward-propagate
+	 the source ssa_name.  */
+      ophi = NULL;
+      for (ogsi = gsi_start_phis (old_bb); !gsi_end_p (ogsi); gsi_next (&ogsi))
+	{
+	  ophi = gsi_stmt (ogsi);
+	  if (gimple_phi_result (ophi) == nop)
+	    break;
+	  ophi = NULL;
+	}
+
+      /* If we did find the corresponding PHI, copy those inputs.  */
+      if (ophi)
+	{
+	  /* If NOP is used somewhere else beyond phis in new_bb, give up.  */
+	  if (!has_single_use (nop))
+	    {
+	      imm_use_iterator imm_iter;
+	      use_operand_p use_p;
+
+	      FOR_EACH_IMM_USE_FAST (use_p, imm_iter, nop)
+		{
+		  if (!gimple_debug_bind_p (USE_STMT (use_p))
+		      && (gimple_code (USE_STMT (use_p)) != GIMPLE_PHI
+			  || gimple_bb (USE_STMT (use_p)) != new_bb))
+		    goto fail;
+		}
+	    }
+	  bitmap_set_bit (ophi_handled, SSA_NAME_VERSION (nop));
+	  FOR_EACH_EDGE (e, ei, old_bb->preds)
+	    {
+	      location_t oloc;
+	      tree oop;
+
+	      if ((e->flags & EDGE_EH) == 0)
+		continue;
+	      oop = gimple_phi_arg_def (ophi, e->dest_idx);
+	      oloc = gimple_phi_arg_location (ophi, e->dest_idx);
+	      redirect_edge_var_map_add (e, nresult, oop, oloc);
+	    }
+	}
+      /* If we didn't find the PHI, but it's a VOP, remember to rename
+	 it later, assuming all other tests succeed.  */
+      else if (!is_gimple_reg (nresult))
+	bitmap_set_bit (rename_virts, SSA_NAME_VERSION (nresult));
+      /* If we didn't find the PHI, and it's a real variable, we know
+	 from the fact that OLD_BB is tree_empty_eh_handler_p that the
+	 variable is unchanged from input to the block and we can simply
+	 re-use the input to NEW_BB from the OLD_BB_OUT edge.  */
+      else
+	{
+	  location_t nloc
+	    = gimple_phi_arg_location (nphi, old_bb_out->dest_idx);
+	  FOR_EACH_EDGE (e, ei, old_bb->preds)
+	    redirect_edge_var_map_add (e, nresult, nop, nloc);
+	}
+    }
+
+  /* Second, verify that all PHIs from OLD_BB have been handled.  If not,
+     we don't know what values from the other edges into NEW_BB to use.  */
+  for (ogsi = gsi_start_phis (old_bb); !gsi_end_p (ogsi); gsi_next (&ogsi))
+    {
+      gimple ophi = gsi_stmt (ogsi);
+      tree oresult = gimple_phi_result (ophi);
+      if (!bitmap_bit_p (ophi_handled, SSA_NAME_VERSION (oresult)))
+	goto fail;
+    }
+
+  /* At this point we know that the merge will succeed.  Remove the PHI
+     nodes for the virtuals that we want to rename.  */
+  if (!bitmap_empty_p (rename_virts))
+    {
+      for (ngsi = gsi_start_phis (new_bb); !gsi_end_p (ngsi); )
+	{
+	  gimple nphi = gsi_stmt (ngsi);
+	  tree nresult = gimple_phi_result (nphi);
+	  if (bitmap_bit_p (rename_virts, SSA_NAME_VERSION (nresult)))
+	    {
+	      mark_virtual_phi_result_for_renaming (nphi);
+	      remove_phi_node (&ngsi, true);
+	    }
+	  else
+	    gsi_next (&ngsi);
+	}
+    }
+
+  /* Finally, move the edges and update the PHIs.  */
+  for (ei = ei_start (old_bb->preds); (e = ei_safe_edge (ei)); )
+    if (e->flags & EDGE_EH)
+      {
+	redirect_eh_edge_1 (e, new_bb, change_region);
+	redirect_edge_succ (e, new_bb);
+	flush_pending_stmts (e);
+      }
+    else
+      ei_next (&ei);
+
+  BITMAP_FREE (ophi_handled);
+  BITMAP_FREE (rename_virts);
+  return true;
+
+ fail:
+  FOR_EACH_EDGE (e, ei, old_bb->preds)
+    redirect_edge_var_map_clear (e);
+  BITMAP_FREE (ophi_handled);
+  BITMAP_FREE (rename_virts);
+  return false;
+}
+
+/* A subroutine of cleanup_empty_eh.  Move a landing pad LP from its
+   old region to NEW_REGION at BB.  */
+
+static void
+cleanup_empty_eh_move_lp (basic_block bb, edge e_out,
+			  eh_landing_pad lp, eh_region new_region)
+{
+  gimple_stmt_iterator gsi;
+  eh_landing_pad *pp;
+
+  for (pp = &lp->region->landing_pads; *pp != lp; pp = &(*pp)->next_lp)
+    continue;
+  *pp = lp->next_lp;
+
+  lp->region = new_region;
+  lp->next_lp = new_region->landing_pads;
+  new_region->landing_pads = lp;
+
+  /* Delete the RESX that was matched within the empty handler block.  */
+  gsi = gsi_last_bb (bb);
+  mark_virtual_ops_for_renaming (gsi_stmt (gsi));
+  gsi_remove (&gsi, true);
+
+  /* Clean up E_OUT for the fallthru.  */
+  e_out->flags = (e_out->flags & ~EDGE_EH) | EDGE_FALLTHRU;
+  e_out->probability = REG_BR_PROB_BASE;
+}
+
+/* A subroutine of cleanup_empty_eh.  Handle more complex cases of
+   unsplitting than unsplit_eh was prepared to handle, e.g. when
+   multiple incoming edges and phis are involved.  */
+
+static bool
+cleanup_empty_eh_unsplit (basic_block bb, edge e_out, eh_landing_pad lp)
+{
+  gimple_stmt_iterator gsi;
+  tree lab;
+  edge_iterator ei;
+  edge e;
+
+  /* We really ought not have totally lost everything following
+     a landing pad label.  Given that BB is empty, there had better
+     be a successor.  */
+  gcc_assert (e_out != NULL);
+
+  /* The destination block must not already have a landing pad
+     for a different region.  */
+  lab = NULL;
+  for (gsi = gsi_start_bb (e_out->dest); !gsi_end_p (gsi); gsi_next (&gsi))
+    {
+      gimple stmt = gsi_stmt (gsi);
+      int lp_nr;
+
+      if (gimple_code (stmt) != GIMPLE_LABEL)
+	break;
+      lab = gimple_label_label (stmt);
+      lp_nr = EH_LANDING_PAD_NR (lab);
+      if (lp_nr && get_eh_region_from_lp_number (lp_nr) != lp->region)
+	return false;
+    }
+
+  /* The destination block must not be a regular successor for any
+     of the preds of the landing pad.  Thus, avoid turning
+        <..>
+	 |  \ EH
+	 |  <..>
+	 |  /
+	<..>
+     into
+        <..>
+	|  | EH
+	<..>
+     which CFG verification would choke on.  See PR45172.  */
+  FOR_EACH_EDGE (e, ei, bb->preds)
+    if (find_edge (e->src, e_out->dest))
+      return false;
+
+  /* Attempt to move the PHIs into the successor block.  */
+  if (cleanup_empty_eh_merge_phis (e_out->dest, bb, e_out, false))
+    {
+      if (dump_file && (dump_flags & TDF_DETAILS))
+	fprintf (dump_file,
+		 "Unsplit EH landing pad %d to block %i "
+		 "(via cleanup_empty_eh).\n",
+		 lp->index, e_out->dest->index);
+      return true;
+    }
+
+  return false;
+}
+
+/* Return true if edge E_FIRST is part of an empty infinite loop
+   or leads to such a loop through a series of single successor
+   empty bbs.  */
+
+static bool
+infinite_empty_loop_p (edge e_first)
+{
+  bool inf_loop = false;
+  edge e;
+
+  if (e_first->dest == e_first->src)
+    return true;
+
+  e_first->src->aux = (void *) 1;
+  for (e = e_first; single_succ_p (e->dest); e = single_succ_edge (e->dest))
+    {
+      gimple_stmt_iterator gsi;
+      if (e->dest->aux)
+	{
+	  inf_loop = true;
+	  break;
+	}
+      e->dest->aux = (void *) 1;
+      gsi = gsi_after_labels (e->dest);
+      if (!gsi_end_p (gsi) && is_gimple_debug (gsi_stmt (gsi)))
+	gsi_next_nondebug (&gsi);
+      if (!gsi_end_p (gsi))
+	break;
+    }
+  e_first->src->aux = NULL;
+  for (e = e_first; e->dest->aux; e = single_succ_edge (e->dest))
+    e->dest->aux = NULL;
+
+  return inf_loop;
+}
+
+/* Examine the block associated with LP to determine if it's an empty
+   handler for its EH region.  If so, attempt to redirect EH edges to
+   an outer region.  Return true the CFG was updated in any way.  This
+   is similar to jump forwarding, just across EH edges.  */
+
+static bool
+cleanup_empty_eh (eh_landing_pad lp)
+{
+  basic_block bb = label_to_block (lp->post_landing_pad);
+  gimple_stmt_iterator gsi;
+  gimple resx;
+  eh_region new_region;
+  edge_iterator ei;
+  edge e, e_out;
+  bool has_non_eh_pred;
+  int new_lp_nr;
+
+  /* There can be zero or one edges out of BB.  This is the quickest test.  */
+  switch (EDGE_COUNT (bb->succs))
+    {
+    case 0:
+      e_out = NULL;
+      break;
+    case 1:
+      e_out = EDGE_SUCC (bb, 0);
+      break;
+    default:
+      return false;
+    }
+  gsi = gsi_after_labels (bb);
+
+  /* Make sure to skip debug statements.  */
+  if (!gsi_end_p (gsi) && is_gimple_debug (gsi_stmt (gsi)))
+    gsi_next_nondebug (&gsi);
+
+  /* If the block is totally empty, look for more unsplitting cases.  */
+  if (gsi_end_p (gsi))
+    {
+      /* For the degenerate case of an infinite loop bail out.  */
+      if (infinite_empty_loop_p (e_out))
+	return false;
+
+      return cleanup_empty_eh_unsplit (bb, e_out, lp);
+    }
+
+  /* The block should consist only of a single RESX statement.  */
+  resx = gsi_stmt (gsi);
+  if (!is_gimple_resx (resx))
+    return false;
+  gcc_assert (gsi_one_before_end_p (gsi));
+
+  /* Determine if there are non-EH edges, or resx edges into the handler.  */
+  has_non_eh_pred = false;
+  FOR_EACH_EDGE (e, ei, bb->preds)
+    if (!(e->flags & EDGE_EH))
+      has_non_eh_pred = true;
+
+  /* Find the handler that's outer of the empty handler by looking at
+     where the RESX instruction was vectored.  */
+  new_lp_nr = lookup_stmt_eh_lp (resx);
+  new_region = get_eh_region_from_lp_number (new_lp_nr);
+
+  /* If there's no destination region within the current function,
+     redirection is trivial via removing the throwing statements from
+     the EH region, removing the EH edges, and allowing the block
+     to go unreachable.  */
+  if (new_region == NULL)
+    {
+      gcc_assert (e_out == NULL);
+      for (ei = ei_start (bb->preds); (e = ei_safe_edge (ei)); )
+	if (e->flags & EDGE_EH)
+	  {
+	    gimple stmt = last_stmt (e->src);
+	    remove_stmt_from_eh_lp (stmt);
+	    remove_edge (e);
+	  }
+	else
+	  ei_next (&ei);
+      goto succeed;
+    }
+
+  /* If the destination region is a MUST_NOT_THROW, allow the runtime
+     to handle the abort and allow the blocks to go unreachable.  */
+  if (new_region->type == ERT_MUST_NOT_THROW)
+    {
+      for (ei = ei_start (bb->preds); (e = ei_safe_edge (ei)); )
+	if (e->flags & EDGE_EH)
+	  {
+	    gimple stmt = last_stmt (e->src);
+	    remove_stmt_from_eh_lp (stmt);
+	    add_stmt_to_eh_lp (stmt, new_lp_nr);
+	    remove_edge (e);
+	  }
+	else
+	  ei_next (&ei);
+      goto succeed;
+    }
+
+  /* Try to redirect the EH edges and merge the PHIs into the destination
+     landing pad block.  If the merge succeeds, we'll already have redirected
+     all the EH edges.  The handler itself will go unreachable if there were
+     no normal edges.  */
+  if (cleanup_empty_eh_merge_phis (e_out->dest, bb, e_out, true))
+    goto succeed;
+
+  /* Finally, if all input edges are EH edges, then we can (potentially)
+     reduce the number of transfers from the runtime by moving the landing
+     pad from the original region to the new region.  This is a win when
+     we remove the last CLEANUP region along a particular exception
+     propagation path.  Since nothing changes except for the region with
+     which the landing pad is associated, the PHI nodes do not need to be
+     adjusted at all.  */
+  if (!has_non_eh_pred)
+    {
+      cleanup_empty_eh_move_lp (bb, e_out, lp, new_region);
+      if (dump_file && (dump_flags & TDF_DETAILS))
+	fprintf (dump_file, "Empty EH handler %i moved to EH region %i.\n",
+		 lp->index, new_region->index);
+
+      /* ??? The CFG didn't change, but we may have rendered the
+	 old EH region unreachable.  Trigger a cleanup there.  */
+      return true;
+    }
+
+  return false;
+
+ succeed:
+  if (dump_file && (dump_flags & TDF_DETAILS))
+    fprintf (dump_file, "Empty EH handler %i removed.\n", lp->index);
+  remove_eh_landing_pad (lp);
+  return true;
+}
+
+/* Do a post-order traversal of the EH region tree.  Examine each
+   post_landing_pad block and see if we can eliminate it as empty.  */
+
+static bool
+cleanup_all_empty_eh (void)
+{
+  bool changed = false;
+  eh_landing_pad lp;
+  int i;
+
+  for (i = 1; VEC_iterate (eh_landing_pad, cfun->eh->lp_array, i, lp); ++i)
+    if (lp)
+      changed |= cleanup_empty_eh (lp);
+
+  return changed;
+}
+
+/* Perform cleanups and lowering of exception handling
+    1) cleanups regions with handlers doing nothing are optimized out
+    2) MUST_NOT_THROW regions that became dead because of 1) are optimized out
+    3) Info about regions that are containing instructions, and regions
+       reachable via local EH edges is collected
+    4) Eh tree is pruned for regions no longer neccesary.
+
+   TODO: Push MUST_NOT_THROW regions to the root of the EH tree.
+	 Unify those that have the same failure decl and locus.
+*/
+
+static unsigned int
+execute_cleanup_eh_1 (void)
+{
+  /* Do this first: unsplit_all_eh and cleanup_all_empty_eh can die
+     looking up unreachable landing pads.  */
+  remove_unreachable_handlers ();
+
+  /* Watch out for the region tree vanishing due to all unreachable.  */
+  if (cfun->eh->region_tree && optimize)
+    {
+      bool changed = false;
+
+      changed |= unsplit_all_eh ();
+      changed |= cleanup_all_empty_eh ();
+
+      if (changed)
+	{
+	  free_dominance_info (CDI_DOMINATORS);
+	  free_dominance_info (CDI_POST_DOMINATORS);
+
+          /* We delayed all basic block deletion, as we may have performed
+	     cleanups on EH edges while non-EH edges were still present.  */
+	  delete_unreachable_blocks ();
+
+	  /* We manipulated the landing pads.  Remove any region that no
+	     longer has a landing pad.  */
+	  remove_unreachable_handlers_no_lp ();
+
+	  return TODO_cleanup_cfg | TODO_update_ssa_only_virtuals;
+	}
+    }
+
+  return 0;
+}
+
+static unsigned int
+execute_cleanup_eh (void)
+{
+  int ret = execute_cleanup_eh_1 ();
+
+  /* If the function no longer needs an EH personality routine
+     clear it.  This exposes cross-language inlining opportunities
+     and avoids references to a never defined personality routine.  */
+  if (DECL_FUNCTION_PERSONALITY (current_function_decl)
+      && function_needs_eh_personality (cfun) != eh_personality_lang)
+    DECL_FUNCTION_PERSONALITY (current_function_decl) = NULL_TREE;
+
+  return ret;
+}
+
+static bool
+gate_cleanup_eh (void)
+{
+  return cfun->eh != NULL && cfun->eh->region_tree != NULL;
+}
+
+struct gimple_opt_pass pass_cleanup_eh = {
+  {
+   GIMPLE_PASS,
+   "ehcleanup",			/* name */
+   gate_cleanup_eh,		/* gate */
+   execute_cleanup_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 */
+   }
+};
+
+/* Verify that BB containing STMT as the last statement, has precisely the
+   edge that make_eh_edges would create.  */
+
+DEBUG_FUNCTION bool
+verify_eh_edges (gimple stmt)
+{
+  basic_block bb = gimple_bb (stmt);
+  eh_landing_pad lp = NULL;
+  int lp_nr;
+  edge_iterator ei;
+  edge e, eh_edge;
+
+  lp_nr = lookup_stmt_eh_lp (stmt);
+  if (lp_nr > 0)
+    lp = get_eh_landing_pad_from_number (lp_nr);
+
+  eh_edge = NULL;
+  FOR_EACH_EDGE (e, ei, bb->succs)
+    {
+      if (e->flags & EDGE_EH)
+	{
+	  if (eh_edge)
+	    {
+	      error ("BB %i has multiple EH edges", bb->index);
+	      return true;
+	    }
+	  else
+	    eh_edge = e;
+	}
+    }
+
+  if (lp == NULL)
+    {
+      if (eh_edge)
+	{
+	  error ("BB %i can not throw but has an EH edge", bb->index);
+	  return true;
+	}
+      return false;
+    }
+
+  if (!stmt_could_throw_p (stmt))
+    {
+      error ("BB %i last statement has incorrectly set lp", bb->index);
+      return true;
+    }
+
+  if (eh_edge == NULL)
+    {
+      error ("BB %i is missing an EH edge", bb->index);
+      return true;
+    }
+
+  if (eh_edge->dest != label_to_block (lp->post_landing_pad))
+    {
+      error ("Incorrect EH edge %i->%i", bb->index, eh_edge->dest->index);
+      return true;
+    }
+
+  return false;
+}
+
+/* Similarly, but handle GIMPLE_EH_DISPATCH specifically.  */
+
+DEBUG_FUNCTION bool
+verify_eh_dispatch_edge (gimple stmt)
+{
+  eh_region r;
+  eh_catch c;
+  basic_block src, dst;
+  bool want_fallthru = true;
+  edge_iterator ei;
+  edge e, fall_edge;
+
+  r = get_eh_region_from_number (gimple_eh_dispatch_region (stmt));
+  src = gimple_bb (stmt);
+
+  FOR_EACH_EDGE (e, ei, src->succs)
+    gcc_assert (e->aux == NULL);
+
+  switch (r->type)
+    {
+    case ERT_TRY:
+      for (c = r->u.eh_try.first_catch; c ; c = c->next_catch)
+	{
+	  dst = label_to_block (c->label);
+	  e = find_edge (src, dst);
+	  if (e == NULL)
+	    {
+	      error ("BB %i is missing an edge", src->index);
+	      return true;
+	    }
+	  e->aux = (void *)e;
+
+	  /* A catch-all handler doesn't have a fallthru.  */
+	  if (c->type_list == NULL)
+	    {
+	      want_fallthru = false;
+	      break;
+	    }
+	}
+      break;
+
+    case ERT_ALLOWED_EXCEPTIONS:
+      dst = label_to_block (r->u.allowed.label);
+      e = find_edge (src, dst);
+      if (e == NULL)
+	{
+	  error ("BB %i is missing an edge", src->index);
+	  return true;
+	}
+      e->aux = (void *)e;
+      break;
+
+    default:
+      gcc_unreachable ();
+    }
+
+  fall_edge = NULL;
+  FOR_EACH_EDGE (e, ei, src->succs)
+    {
+      if (e->flags & EDGE_FALLTHRU)
+	{
+	  if (fall_edge != NULL)
+	    {
+	      error ("BB %i too many fallthru edges", src->index);
+	      return true;
+	    }
+	  fall_edge = e;
+	}
+      else if (e->aux)
+	e->aux = NULL;
+      else
+	{
+	  error ("BB %i has incorrect edge", src->index);
+	  return true;
+	}
+    }
+  if ((fall_edge != NULL) ^ want_fallthru)
+    {
+      error ("BB %i has incorrect fallthru edge", src->index);
+      return true;
+    }
+
+  return false;
+}