GCC 4.2.0 release.

1 files changed, 4622 insertions, 0 deletions

diff --git a/contrib/gcc/omp-low.c b/contrib/gcc/omp-low.c
new file mode 100644
index 0000000..6931b41
--- /dev/null
+++ b/contrib/gcc/omp-low.c
@@ -0,0 +1,4622 @@
+/* Lowering pass for OpenMP directives.  Converts OpenMP directives
+   into explicit calls to the runtime library (libgomp) and data
+   marshalling to implement data sharing and copying clauses.
+   Contributed by Diego Novillo <dnovillo@redhat.com>
+
+   Copyright (C) 2005, 2006 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 2, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING.  If not, write to the Free
+Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301, USA.  */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "tree.h"
+#include "rtl.h"
+#include "tree-gimple.h"
+#include "tree-inline.h"
+#include "langhooks.h"
+#include "diagnostic.h"
+#include "tree-flow.h"
+#include "timevar.h"
+#include "flags.h"
+#include "function.h"
+#include "expr.h"
+#include "toplev.h"
+#include "tree-pass.h"
+#include "ggc.h"
+#include "except.h"
+
+
+/* Lowering of OpenMP parallel and workshare constructs proceeds in two 
+   phases.  The first phase scans the function looking for OMP statements
+   and then for variables that must be replaced to satisfy data sharing
+   clauses.  The second phase expands code for the constructs, as well as
+   re-gimplifying things when variables have been replaced with complex
+   expressions.
+
+   Final code generation is done by pass_expand_omp.  The flowgraph is
+   scanned for parallel regions which are then moved to a new
+   function, to be invoked by the thread library.  */
+
+/* Context structure.  Used to store information about each parallel
+   directive in the code.  */
+
+typedef struct omp_context
+{
+  /* This field must be at the beginning, as we do "inheritance": Some
+     callback functions for tree-inline.c (e.g., omp_copy_decl)
+     receive a copy_body_data pointer that is up-casted to an
+     omp_context pointer.  */
+  copy_body_data cb;
+
+  /* The tree of contexts corresponding to the encountered constructs.  */
+  struct omp_context *outer;
+  tree stmt;
+
+  /* Map variables to fields in a structure that allows communication 
+     between sending and receiving threads.  */
+  splay_tree field_map;
+  tree record_type;
+  tree sender_decl;
+  tree receiver_decl;
+
+  /* A chain of variables to add to the top-level block surrounding the
+     construct.  In the case of a parallel, this is in the child function.  */
+  tree block_vars;
+
+  /* What to do with variables with implicitly determined sharing
+     attributes.  */
+  enum omp_clause_default_kind default_kind;
+
+  /* Nesting depth of this context.  Used to beautify error messages re
+     invalid gotos.  The outermost ctx is depth 1, with depth 0 being
+     reserved for the main body of the function.  */
+  int depth;
+
+  /* True if this parallel directive is nested within another.  */
+  bool is_nested;
+} omp_context;
+
+
+/* A structure describing the main elements of a parallel loop.  */
+
+struct omp_for_data
+{
+  tree v, n1, n2, step, chunk_size, for_stmt;
+  enum tree_code cond_code;
+  tree pre;
+  bool have_nowait, have_ordered;
+  enum omp_clause_schedule_kind sched_kind;
+};
+
+
+static splay_tree all_contexts;
+static int parallel_nesting_level;
+struct omp_region *root_omp_region;
+
+static void scan_omp (tree *, omp_context *);
+static void lower_omp (tree *, omp_context *);
+static tree lookup_decl_in_outer_ctx (tree, omp_context *);
+static tree maybe_lookup_decl_in_outer_ctx (tree, omp_context *);
+
+/* Find an OpenMP clause of type KIND within CLAUSES.  */
+
+static tree
+find_omp_clause (tree clauses, enum tree_code kind)
+{
+  for (; clauses ; clauses = OMP_CLAUSE_CHAIN (clauses))
+    if (OMP_CLAUSE_CODE (clauses) == kind)
+      return clauses;
+
+  return NULL_TREE;
+}
+
+/* Return true if CTX is for an omp parallel.  */
+
+static inline bool
+is_parallel_ctx (omp_context *ctx)
+{
+  return TREE_CODE (ctx->stmt) == OMP_PARALLEL;
+}
+
+
+/* Return true if REGION is a combined parallel+workshare region.  */
+
+static inline bool
+is_combined_parallel (struct omp_region *region)
+{
+  return region->is_combined_parallel;
+}
+
+
+/* Extract the header elements of parallel loop FOR_STMT and store
+   them into *FD.  */
+
+static void
+extract_omp_for_data (tree for_stmt, struct omp_for_data *fd)
+{
+  tree t;
+
+  fd->for_stmt = for_stmt;
+  fd->pre = NULL;
+
+  t = OMP_FOR_INIT (for_stmt);
+  gcc_assert (TREE_CODE (t) == MODIFY_EXPR);
+  fd->v = TREE_OPERAND (t, 0);
+  gcc_assert (DECL_P (fd->v));
+  gcc_assert (TREE_CODE (TREE_TYPE (fd->v)) == INTEGER_TYPE);
+  fd->n1 = TREE_OPERAND (t, 1);
+
+  t = OMP_FOR_COND (for_stmt);
+  fd->cond_code = TREE_CODE (t);
+  gcc_assert (TREE_OPERAND (t, 0) == fd->v);
+  fd->n2 = TREE_OPERAND (t, 1);
+  switch (fd->cond_code)
+    {
+    case LT_EXPR:
+    case GT_EXPR:
+      break;
+    case LE_EXPR:
+      fd->n2 = fold_build2 (PLUS_EXPR, TREE_TYPE (fd->n2), fd->n2,
+			   build_int_cst (TREE_TYPE (fd->n2), 1));
+      fd->cond_code = LT_EXPR;
+      break;
+    case GE_EXPR:
+      fd->n2 = fold_build2 (MINUS_EXPR, TREE_TYPE (fd->n2), fd->n2,
+			   build_int_cst (TREE_TYPE (fd->n2), 1));
+      fd->cond_code = GT_EXPR;
+      break;
+    default:
+      gcc_unreachable ();
+    }
+
+  t = OMP_FOR_INCR (fd->for_stmt);
+  gcc_assert (TREE_CODE (t) == MODIFY_EXPR);
+  gcc_assert (TREE_OPERAND (t, 0) == fd->v);
+  t = TREE_OPERAND (t, 1);
+  gcc_assert (TREE_OPERAND (t, 0) == fd->v);
+  switch (TREE_CODE (t))
+    {
+    case PLUS_EXPR:
+      fd->step = TREE_OPERAND (t, 1);
+      break;
+    case MINUS_EXPR:
+      fd->step = TREE_OPERAND (t, 1);
+      fd->step = fold_build1 (NEGATE_EXPR, TREE_TYPE (fd->step), fd->step);
+      break;
+    default:
+      gcc_unreachable ();
+    }
+
+  fd->have_nowait = fd->have_ordered = false;
+  fd->sched_kind = OMP_CLAUSE_SCHEDULE_STATIC;
+  fd->chunk_size = NULL_TREE;
+
+  for (t = OMP_FOR_CLAUSES (for_stmt); t ; t = OMP_CLAUSE_CHAIN (t))
+    switch (OMP_CLAUSE_CODE (t))
+      {
+      case OMP_CLAUSE_NOWAIT:
+	fd->have_nowait = true;
+	break;
+      case OMP_CLAUSE_ORDERED:
+	fd->have_ordered = true;
+	break;
+      case OMP_CLAUSE_SCHEDULE:
+	fd->sched_kind = OMP_CLAUSE_SCHEDULE_KIND (t);
+	fd->chunk_size = OMP_CLAUSE_SCHEDULE_CHUNK_EXPR (t);
+	break;
+      default:
+	break;
+      }
+
+  if (fd->sched_kind == OMP_CLAUSE_SCHEDULE_RUNTIME)
+    gcc_assert (fd->chunk_size == NULL);
+  else if (fd->chunk_size == NULL)
+    {
+      /* We only need to compute a default chunk size for ordered
+	 static loops and dynamic loops.  */
+      if (fd->sched_kind != OMP_CLAUSE_SCHEDULE_STATIC || fd->have_ordered)
+	fd->chunk_size = (fd->sched_kind == OMP_CLAUSE_SCHEDULE_STATIC)
+			 ? integer_zero_node : integer_one_node;
+    }
+}
+
+
+/* Given two blocks PAR_ENTRY_BB and WS_ENTRY_BB such that WS_ENTRY_BB
+   is the immediate dominator of PAR_ENTRY_BB, return true if there
+   are no data dependencies that would prevent expanding the parallel
+   directive at PAR_ENTRY_BB as a combined parallel+workshare region.
+
+   When expanding a combined parallel+workshare region, the call to
+   the child function may need additional arguments in the case of
+   OMP_FOR regions.  In some cases, these arguments are computed out
+   of variables passed in from the parent to the child via 'struct
+   .omp_data_s'.  For instance:
+
+	#pragma omp parallel for schedule (guided, i * 4)
+	for (j ...)
+
+   Is lowered into:
+
+   	# BLOCK 2 (PAR_ENTRY_BB)
+	.omp_data_o.i = i;
+	#pragma omp parallel [child fn: bar.omp_fn.0 ( ..., D.1598)
+	
+	# BLOCK 3 (WS_ENTRY_BB)
+	.omp_data_i = &.omp_data_o;
+	D.1667 = .omp_data_i->i;
+	D.1598 = D.1667 * 4;
+	#pragma omp for schedule (guided, D.1598)
+
+   When we outline the parallel region, the call to the child function
+   'bar.omp_fn.0' will need the value D.1598 in its argument list, but
+   that value is computed *after* the call site.  So, in principle we
+   cannot do the transformation.
+
+   To see whether the code in WS_ENTRY_BB blocks the combined
+   parallel+workshare call, we collect all the variables used in the
+   OMP_FOR header check whether they appear on the LHS of any
+   statement in WS_ENTRY_BB.  If so, then we cannot emit the combined
+   call.
+
+   FIXME.  If we had the SSA form built at this point, we could merely
+   hoist the code in block 3 into block 2 and be done with it.  But at
+   this point we don't have dataflow information and though we could
+   hack something up here, it is really not worth the aggravation.  */
+
+static bool
+workshare_safe_to_combine_p (basic_block par_entry_bb, basic_block ws_entry_bb)
+{
+  struct omp_for_data fd;
+  tree par_stmt, ws_stmt;
+
+  par_stmt = last_stmt (par_entry_bb);
+  ws_stmt = last_stmt (ws_entry_bb);
+
+  if (TREE_CODE (ws_stmt) == OMP_SECTIONS)
+    return true;
+
+  gcc_assert (TREE_CODE (ws_stmt) == OMP_FOR);
+
+  extract_omp_for_data (ws_stmt, &fd);
+
+  /* FIXME.  We give up too easily here.  If any of these arguments
+     are not constants, they will likely involve variables that have
+     been mapped into fields of .omp_data_s for sharing with the child
+     function.  With appropriate data flow, it would be possible to
+     see through this.  */
+  if (!is_gimple_min_invariant (fd.n1)
+      || !is_gimple_min_invariant (fd.n2)
+      || !is_gimple_min_invariant (fd.step)
+      || (fd.chunk_size && !is_gimple_min_invariant (fd.chunk_size)))
+    return false;
+
+  return true;
+}
+
+
+/* Collect additional arguments needed to emit a combined
+   parallel+workshare call.  WS_STMT is the workshare directive being
+   expanded.  */
+
+static tree
+get_ws_args_for (tree ws_stmt)
+{
+  tree t;
+
+  if (TREE_CODE (ws_stmt) == OMP_FOR)
+    {
+      struct omp_for_data fd;
+      tree ws_args;
+
+      extract_omp_for_data (ws_stmt, &fd);
+
+      ws_args = NULL_TREE;
+      if (fd.chunk_size)
+	{
+	  t = fold_convert (long_integer_type_node, fd.chunk_size);
+	  ws_args = tree_cons (NULL, t, ws_args);
+	}
+
+      t = fold_convert (long_integer_type_node, fd.step);
+      ws_args = tree_cons (NULL, t, ws_args);
+
+      t = fold_convert (long_integer_type_node, fd.n2);
+      ws_args = tree_cons (NULL, t, ws_args);
+
+      t = fold_convert (long_integer_type_node, fd.n1);
+      ws_args = tree_cons (NULL, t, ws_args);
+
+      return ws_args;
+    }
+  else if (TREE_CODE (ws_stmt) == OMP_SECTIONS)
+    {
+      basic_block bb = bb_for_stmt (ws_stmt);
+      t = build_int_cst (unsigned_type_node, EDGE_COUNT (bb->succs));
+      t = tree_cons (NULL, t, NULL);
+      return t;
+    }
+
+  gcc_unreachable ();
+}
+
+
+/* Discover whether REGION is a combined parallel+workshare region.  */
+
+static void
+determine_parallel_type (struct omp_region *region)
+{
+  basic_block par_entry_bb, par_exit_bb;
+  basic_block ws_entry_bb, ws_exit_bb;
+
+  if (region == NULL || region->inner == NULL
+      || region->exit == NULL || region->inner->exit == NULL)
+    return;
+
+  /* We only support parallel+for and parallel+sections.  */
+  if (region->type != OMP_PARALLEL
+      || (region->inner->type != OMP_FOR
+	  && region->inner->type != OMP_SECTIONS))
+    return;
+
+  /* Check for perfect nesting PAR_ENTRY_BB -> WS_ENTRY_BB and
+     WS_EXIT_BB -> PAR_EXIT_BB.  */
+  par_entry_bb = region->entry;
+  par_exit_bb = region->exit;
+  ws_entry_bb = region->inner->entry;
+  ws_exit_bb = region->inner->exit;
+
+  if (single_succ (par_entry_bb) == ws_entry_bb
+      && single_succ (ws_exit_bb) == par_exit_bb
+      && workshare_safe_to_combine_p (par_entry_bb, ws_entry_bb))
+    {
+      tree ws_stmt = last_stmt (region->inner->entry);
+
+      if (region->inner->type == OMP_FOR)
+	{
+	  /* If this is a combined parallel loop, we need to determine
+	     whether or not to use the combined library calls.  There
+	     are two cases where we do not apply the transformation:
+	     static loops and any kind of ordered loop.  In the first
+	     case, we already open code the loop so there is no need
+	     to do anything else.  In the latter case, the combined
+	     parallel loop call would still need extra synchronization
+	     to implement ordered semantics, so there would not be any
+	     gain in using the combined call.  */
+	  tree clauses = OMP_FOR_CLAUSES (ws_stmt);
+	  tree c = find_omp_clause (clauses, OMP_CLAUSE_SCHEDULE);
+	  if (c == NULL
+	      || OMP_CLAUSE_SCHEDULE_KIND (c) == OMP_CLAUSE_SCHEDULE_STATIC
+	      || find_omp_clause (clauses, OMP_CLAUSE_ORDERED))
+	    {
+	      region->is_combined_parallel = false;
+	      region->inner->is_combined_parallel = false;
+	      return;
+	    }
+	}
+
+      region->is_combined_parallel = true;
+      region->inner->is_combined_parallel = true;
+      region->ws_args = get_ws_args_for (ws_stmt);
+    }
+}
+
+
+/* Return true if EXPR is variable sized.  */
+
+static inline bool
+is_variable_sized (tree expr)
+{
+  return !TREE_CONSTANT (TYPE_SIZE_UNIT (TREE_TYPE (expr)));
+}
+
+/* Return true if DECL is a reference type.  */
+
+static inline bool
+is_reference (tree decl)
+{
+  return lang_hooks.decls.omp_privatize_by_reference (decl);
+}
+
+/* Lookup variables in the decl or field splay trees.  The "maybe" form
+   allows for the variable form to not have been entered, otherwise we
+   assert that the variable must have been entered.  */
+
+static inline tree
+lookup_decl (tree var, omp_context *ctx)
+{
+  splay_tree_node n;
+  n = splay_tree_lookup (ctx->cb.decl_map, (splay_tree_key) var);
+  return (tree) n->value;
+}
+
+static inline tree
+maybe_lookup_decl (tree var, omp_context *ctx)
+{
+  splay_tree_node n;
+  n = splay_tree_lookup (ctx->cb.decl_map, (splay_tree_key) var);
+  return n ? (tree) n->value : NULL_TREE;
+}
+
+static inline tree
+lookup_field (tree var, omp_context *ctx)
+{
+  splay_tree_node n;
+  n = splay_tree_lookup (ctx->field_map, (splay_tree_key) var);
+  return (tree) n->value;
+}
+
+static inline tree
+maybe_lookup_field (tree var, omp_context *ctx)
+{
+  splay_tree_node n;
+  n = splay_tree_lookup (ctx->field_map, (splay_tree_key) var);
+  return n ? (tree) n->value : NULL_TREE;
+}
+
+/* Return true if DECL should be copied by pointer.  SHARED_P is true
+   if DECL is to be shared.  */
+
+static bool
+use_pointer_for_field (tree decl, bool shared_p)
+{
+  if (AGGREGATE_TYPE_P (TREE_TYPE (decl)))
+    return true;
+
+  /* We can only use copy-in/copy-out semantics for shared variables
+     when we know the value is not accessible from an outer scope.  */
+  if (shared_p)
+    {
+      /* ??? Trivially accessible from anywhere.  But why would we even
+	 be passing an address in this case?  Should we simply assert
+	 this to be false, or should we have a cleanup pass that removes
+	 these from the list of mappings?  */
+      if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
+	return true;
+
+      /* For variables with DECL_HAS_VALUE_EXPR_P set, we cannot tell
+	 without analyzing the expression whether or not its location
+	 is accessible to anyone else.  In the case of nested parallel
+	 regions it certainly may be.  */
+      if (TREE_CODE (decl) != RESULT_DECL && DECL_HAS_VALUE_EXPR_P (decl))
+	return true;
+
+      /* Do not use copy-in/copy-out for variables that have their
+	 address taken.  */
+      if (TREE_ADDRESSABLE (decl))
+	return true;
+    }
+
+  return false;
+}
+
+/* Construct a new automatic decl similar to VAR.  */
+
+static tree
+omp_copy_decl_2 (tree var, tree name, tree type, omp_context *ctx)
+{
+  tree copy = build_decl (VAR_DECL, name, type);
+
+  TREE_ADDRESSABLE (copy) = TREE_ADDRESSABLE (var);
+  DECL_COMPLEX_GIMPLE_REG_P (copy) = DECL_COMPLEX_GIMPLE_REG_P (var);
+  DECL_ARTIFICIAL (copy) = DECL_ARTIFICIAL (var);
+  DECL_IGNORED_P (copy) = DECL_IGNORED_P (var);
+  TREE_USED (copy) = 1;
+  DECL_CONTEXT (copy) = current_function_decl;
+  DECL_SEEN_IN_BIND_EXPR_P (copy) = 1;
+
+  TREE_CHAIN (copy) = ctx->block_vars;
+  ctx->block_vars = copy;
+
+  return copy;
+}
+
+static tree
+omp_copy_decl_1 (tree var, omp_context *ctx)
+{
+  return omp_copy_decl_2 (var, DECL_NAME (var), TREE_TYPE (var), ctx);
+}
+
+/* Build tree nodes to access the field for VAR on the receiver side.  */
+
+static tree
+build_receiver_ref (tree var, bool by_ref, omp_context *ctx)
+{
+  tree x, field = lookup_field (var, ctx);
+
+  /* If the receiver record type was remapped in the child function,
+     remap the field into the new record type.  */
+  x = maybe_lookup_field (field, ctx);
+  if (x != NULL)
+    field = x;
+
+  x = build_fold_indirect_ref (ctx->receiver_decl);
+  x = build3 (COMPONENT_REF, TREE_TYPE (field), x, field, NULL);
+  if (by_ref)
+    x = build_fold_indirect_ref (x);
+
+  return x;
+}
+
+/* Build tree nodes to access VAR in the scope outer to CTX.  In the case
+   of a parallel, this is a component reference; for workshare constructs
+   this is some variable.  */
+
+static tree
+build_outer_var_ref (tree var, omp_context *ctx)
+{
+  tree x;
+
+  if (is_global_var (maybe_lookup_decl_in_outer_ctx (var, ctx)))
+    x = var;
+  else if (is_variable_sized (var))
+    {
+      x = TREE_OPERAND (DECL_VALUE_EXPR (var), 0);
+      x = build_outer_var_ref (x, ctx);
+      x = build_fold_indirect_ref (x);
+    }
+  else if (is_parallel_ctx (ctx))
+    {
+      bool by_ref = use_pointer_for_field (var, false);
+      x = build_receiver_ref (var, by_ref, ctx);
+    }
+  else if (ctx->outer)
+    x = lookup_decl (var, ctx->outer);
+  else if (is_reference (var))
+    /* This can happen with orphaned constructs.  If var is reference, it is
+       possible it is shared and as such valid.  */
+    x = var;
+  else
+    gcc_unreachable ();
+
+  if (is_reference (var))
+    x = build_fold_indirect_ref (x);
+
+  return x;
+}
+
+/* Build tree nodes to access the field for VAR on the sender side.  */
+
+static tree
+build_sender_ref (tree var, omp_context *ctx)
+{
+  tree field = lookup_field (var, ctx);
+  return build3 (COMPONENT_REF, TREE_TYPE (field),
+		 ctx->sender_decl, field, NULL);
+}
+
+/* Add a new field for VAR inside the structure CTX->SENDER_DECL.  */
+
+static void
+install_var_field (tree var, bool by_ref, omp_context *ctx)
+{
+  tree field, type;
+
+  gcc_assert (!splay_tree_lookup (ctx->field_map, (splay_tree_key) var));
+
+  type = TREE_TYPE (var);
+  if (by_ref)
+    type = build_pointer_type (type);
+
+  field = build_decl (FIELD_DECL, DECL_NAME (var), type);
+
+  /* Remember what variable this field was created for.  This does have a
+     side effect of making dwarf2out ignore this member, so for helpful
+     debugging we clear it later in delete_omp_context.  */
+  DECL_ABSTRACT_ORIGIN (field) = var;
+
+  insert_field_into_struct (ctx->record_type, field);
+
+  splay_tree_insert (ctx->field_map, (splay_tree_key) var,
+		     (splay_tree_value) field);
+}
+
+static tree
+install_var_local (tree var, omp_context *ctx)
+{
+  tree new_var = omp_copy_decl_1 (var, ctx);
+  insert_decl_map (&ctx->cb, var, new_var);
+  return new_var;
+}
+
+/* Adjust the replacement for DECL in CTX for the new context.  This means
+   copying the DECL_VALUE_EXPR, and fixing up the type.  */
+
+static void
+fixup_remapped_decl (tree decl, omp_context *ctx, bool private_debug)
+{
+  tree new_decl, size;
+
+  new_decl = lookup_decl (decl, ctx);
+
+  TREE_TYPE (new_decl) = remap_type (TREE_TYPE (decl), &ctx->cb);
+
+  if ((!TREE_CONSTANT (DECL_SIZE (new_decl)) || private_debug)
+      && DECL_HAS_VALUE_EXPR_P (decl))
+    {
+      tree ve = DECL_VALUE_EXPR (decl);
+      walk_tree (&ve, copy_body_r, &ctx->cb, NULL);
+      SET_DECL_VALUE_EXPR (new_decl, ve);
+      DECL_HAS_VALUE_EXPR_P (new_decl) = 1;
+    }
+
+  if (!TREE_CONSTANT (DECL_SIZE (new_decl)))
+    {
+      size = remap_decl (DECL_SIZE (decl), &ctx->cb);
+      if (size == error_mark_node)
+	size = TYPE_SIZE (TREE_TYPE (new_decl));
+      DECL_SIZE (new_decl) = size;
+
+      size = remap_decl (DECL_SIZE_UNIT (decl), &ctx->cb);
+      if (size == error_mark_node)
+	size = TYPE_SIZE_UNIT (TREE_TYPE (new_decl));
+      DECL_SIZE_UNIT (new_decl) = size;
+    }
+}
+
+/* The callback for remap_decl.  Search all containing contexts for a
+   mapping of the variable; this avoids having to duplicate the splay
+   tree ahead of time.  We know a mapping doesn't already exist in the
+   given context.  Create new mappings to implement default semantics.  */
+
+static tree
+omp_copy_decl (tree var, copy_body_data *cb)
+{
+  omp_context *ctx = (omp_context *) cb;
+  tree new_var;
+
+  if (TREE_CODE (var) == LABEL_DECL)
+    {
+      new_var = create_artificial_label ();
+      DECL_CONTEXT (new_var) = current_function_decl;
+      insert_decl_map (&ctx->cb, var, new_var);
+      return new_var;
+    }
+
+  while (!is_parallel_ctx (ctx))
+    {
+      ctx = ctx->outer;
+      if (ctx == NULL)
+	return var;
+      new_var = maybe_lookup_decl (var, ctx);
+      if (new_var)
+	return new_var;
+    }
+
+  if (is_global_var (var) || decl_function_context (var) != ctx->cb.src_fn)
+    return var;
+
+  return error_mark_node;
+}
+
+
+/* Return the parallel region associated with STMT.  */
+
+/* Debugging dumps for parallel regions.  */
+void dump_omp_region (FILE *, struct omp_region *, int);
+void debug_omp_region (struct omp_region *);
+void debug_all_omp_regions (void);
+
+/* Dump the parallel region tree rooted at REGION.  */
+
+void
+dump_omp_region (FILE *file, struct omp_region *region, int indent)
+{
+  fprintf (file, "%*sbb %d: %s\n", indent, "", region->entry->index,
+	   tree_code_name[region->type]);
+
+  if (region->inner)
+    dump_omp_region (file, region->inner, indent + 4);
+
+  if (region->cont)
+    {
+      fprintf (file, "%*sbb %d: OMP_CONTINUE\n", indent, "",
+	       region->cont->index);
+    }
+    
+  if (region->exit)
+    fprintf (file, "%*sbb %d: OMP_RETURN\n", indent, "",
+	     region->exit->index);
+  else
+    fprintf (file, "%*s[no exit marker]\n", indent, "");
+
+  if (region->next)
+    dump_omp_region (file, region->next, indent);
+}
+
+void
+debug_omp_region (struct omp_region *region)
+{
+  dump_omp_region (stderr, region, 0);
+}
+
+void
+debug_all_omp_regions (void)
+{
+  dump_omp_region (stderr, root_omp_region, 0);
+}
+
+
+/* Create a new parallel region starting at STMT inside region PARENT.  */
+
+struct omp_region *
+new_omp_region (basic_block bb, enum tree_code type, struct omp_region *parent)
+{
+  struct omp_region *region = xcalloc (1, sizeof (*region));
+
+  region->outer = parent;
+  region->entry = bb;
+  region->type = type;
+
+  if (parent)
+    {
+      /* This is a nested region.  Add it to the list of inner
+	 regions in PARENT.  */
+      region->next = parent->inner;
+      parent->inner = region;
+    }
+  else
+    {
+      /* This is a toplevel region.  Add it to the list of toplevel
+	 regions in ROOT_OMP_REGION.  */
+      region->next = root_omp_region;
+      root_omp_region = region;
+    }
+
+  return region;
+}
+
+/* Release the memory associated with the region tree rooted at REGION.  */
+
+static void
+free_omp_region_1 (struct omp_region *region)
+{
+  struct omp_region *i, *n;
+
+  for (i = region->inner; i ; i = n)
+    {
+      n = i->next;
+      free_omp_region_1 (i);
+    }
+
+  free (region);
+}
+
+/* Release the memory for the entire omp region tree.  */
+
+void
+free_omp_regions (void)
+{
+  struct omp_region *r, *n;
+  for (r = root_omp_region; r ; r = n)
+    {
+      n = r->next;
+      free_omp_region_1 (r);
+    }
+  root_omp_region = NULL;
+}
+
+
+/* Create a new context, with OUTER_CTX being the surrounding context.  */
+
+static omp_context *
+new_omp_context (tree stmt, omp_context *outer_ctx)
+{
+  omp_context *ctx = XCNEW (omp_context);
+
+  splay_tree_insert (all_contexts, (splay_tree_key) stmt,
+		     (splay_tree_value) ctx);
+  ctx->stmt = stmt;
+
+  if (outer_ctx)
+    {
+      ctx->outer = outer_ctx;
+      ctx->cb = outer_ctx->cb;
+      ctx->cb.block = NULL;
+      ctx->depth = outer_ctx->depth + 1;
+    }
+  else
+    {
+      ctx->cb.src_fn = current_function_decl;
+      ctx->cb.dst_fn = current_function_decl;
+      ctx->cb.src_node = cgraph_node (current_function_decl);
+      ctx->cb.dst_node = ctx->cb.src_node;
+      ctx->cb.src_cfun = cfun;
+      ctx->cb.copy_decl = omp_copy_decl;
+      ctx->cb.eh_region = -1;
+      ctx->cb.transform_call_graph_edges = CB_CGE_MOVE;
+      ctx->depth = 1;
+    }
+
+  ctx->cb.decl_map = splay_tree_new (splay_tree_compare_pointers, 0, 0);
+
+  return ctx;
+}
+
+/* Destroy a omp_context data structures.  Called through the splay tree
+   value delete callback.  */
+
+static void
+delete_omp_context (splay_tree_value value)
+{
+  omp_context *ctx = (omp_context *) value;
+
+  splay_tree_delete (ctx->cb.decl_map);
+
+  if (ctx->field_map)
+    splay_tree_delete (ctx->field_map);
+
+  /* We hijacked DECL_ABSTRACT_ORIGIN earlier.  We need to clear it before
+     it produces corrupt debug information.  */
+  if (ctx->record_type)
+    {
+      tree t;
+      for (t = TYPE_FIELDS (ctx->record_type); t ; t = TREE_CHAIN (t))
+	DECL_ABSTRACT_ORIGIN (t) = NULL;
+    }
+
+  XDELETE (ctx);
+}
+
+/* Fix up RECEIVER_DECL with a type that has been remapped to the child
+   context.  */
+
+static void
+fixup_child_record_type (omp_context *ctx)
+{
+  tree f, type = ctx->record_type;
+
+  /* ??? It isn't sufficient to just call remap_type here, because
+     variably_modified_type_p doesn't work the way we expect for
+     record types.  Testing each field for whether it needs remapping
+     and creating a new record by hand works, however.  */
+  for (f = TYPE_FIELDS (type); f ; f = TREE_CHAIN (f))
+    if (variably_modified_type_p (TREE_TYPE (f), ctx->cb.src_fn))
+      break;
+  if (f)
+    {
+      tree name, new_fields = NULL;
+
+      type = lang_hooks.types.make_type (RECORD_TYPE);
+      name = DECL_NAME (TYPE_NAME (ctx->record_type));
+      name = build_decl (TYPE_DECL, name, type);
+      TYPE_NAME (type) = name;
+
+      for (f = TYPE_FIELDS (ctx->record_type); f ; f = TREE_CHAIN (f))
+	{
+	  tree new_f = copy_node (f);
+	  DECL_CONTEXT (new_f) = type;
+	  TREE_TYPE (new_f) = remap_type (TREE_TYPE (f), &ctx->cb);
+	  TREE_CHAIN (new_f) = new_fields;
+	  new_fields = new_f;
+
+	  /* Arrange to be able to look up the receiver field
+	     given the sender field.  */
+	  splay_tree_insert (ctx->field_map, (splay_tree_key) f,
+			     (splay_tree_value) new_f);
+	}
+      TYPE_FIELDS (type) = nreverse (new_fields);
+      layout_type (type);
+    }
+
+  TREE_TYPE (ctx->receiver_decl) = build_pointer_type (type);
+}
+
+/* Instantiate decls as necessary in CTX to satisfy the data sharing
+   specified by CLAUSES.  */
+
+static void
+scan_sharing_clauses (tree clauses, omp_context *ctx)
+{
+  tree c, decl;
+  bool scan_array_reductions = false;
+
+  for (c = clauses; c; c = OMP_CLAUSE_CHAIN (c))
+    {
+      bool by_ref;
+
+      switch (OMP_CLAUSE_CODE (c))
+	{
+	case OMP_CLAUSE_PRIVATE:
+	  decl = OMP_CLAUSE_DECL (c);
+	  if (!is_variable_sized (decl))
+	    install_var_local (decl, ctx);
+	  break;
+
+	case OMP_CLAUSE_SHARED:
+	  gcc_assert (is_parallel_ctx (ctx));
+	  decl = OMP_CLAUSE_DECL (c);
+	  gcc_assert (!is_variable_sized (decl));
+	  by_ref = use_pointer_for_field (decl, true);
+	  /* Global variables don't need to be copied,
+	     the receiver side will use them directly.  */
+	  if (is_global_var (maybe_lookup_decl_in_outer_ctx (decl, ctx)))
+	    break;
+	  if (! TREE_READONLY (decl)
+	      || TREE_ADDRESSABLE (decl)
+	      || by_ref
+	      || is_reference (decl))
+	    {
+	      install_var_field (decl, by_ref, ctx);
+	      install_var_local (decl, ctx);
+	      break;
+	    }
+	  /* We don't need to copy const scalar vars back.  */
+	  OMP_CLAUSE_SET_CODE (c, OMP_CLAUSE_FIRSTPRIVATE);
+	  goto do_private;
+
+	case OMP_CLAUSE_LASTPRIVATE:
+	  /* Let the corresponding firstprivate clause create
+	     the variable.  */
+	  if (OMP_CLAUSE_LASTPRIVATE_FIRSTPRIVATE (c))
+	    break;
+	  /* FALLTHRU */
+
+	case OMP_CLAUSE_FIRSTPRIVATE:
+	case OMP_CLAUSE_REDUCTION:
+	  decl = OMP_CLAUSE_DECL (c);
+	do_private:
+	  if (is_variable_sized (decl))
+	    break;
+	  else if (is_parallel_ctx (ctx)
+		   && ! is_global_var (maybe_lookup_decl_in_outer_ctx (decl,
+								       ctx)))
+	    {
+	      by_ref = use_pointer_for_field (decl, false);
+	      install_var_field (decl, by_ref, ctx);
+	    }
+	  install_var_local (decl, ctx);
+	  break;
+
+	case OMP_CLAUSE_COPYPRIVATE:
+	  if (ctx->outer)
+	    scan_omp (&OMP_CLAUSE_DECL (c), ctx->outer);
+	  /* FALLTHRU */
+
+	case OMP_CLAUSE_COPYIN:
+	  decl = OMP_CLAUSE_DECL (c);
+	  by_ref = use_pointer_for_field (decl, false);
+	  install_var_field (decl, by_ref, ctx);
+	  break;
+
+	case OMP_CLAUSE_DEFAULT:
+	  ctx->default_kind = OMP_CLAUSE_DEFAULT_KIND (c);
+	  break;
+
+	case OMP_CLAUSE_IF:
+	case OMP_CLAUSE_NUM_THREADS:
+	case OMP_CLAUSE_SCHEDULE:
+	  if (ctx->outer)
+	    scan_omp (&OMP_CLAUSE_OPERAND (c, 0), ctx->outer);
+	  break;
+
+	case OMP_CLAUSE_NOWAIT:
+	case OMP_CLAUSE_ORDERED:
+	  break;
+
+	default:
+	  gcc_unreachable ();
+	}
+    }
+
+  for (c = clauses; c; c = OMP_CLAUSE_CHAIN (c))
+    {
+      switch (OMP_CLAUSE_CODE (c))
+	{
+	case OMP_CLAUSE_LASTPRIVATE:
+	  /* Let the corresponding firstprivate clause create
+	     the variable.  */
+	  if (OMP_CLAUSE_LASTPRIVATE_FIRSTPRIVATE (c))
+	    break;
+	  /* FALLTHRU */
+
+	case OMP_CLAUSE_PRIVATE:
+	case OMP_CLAUSE_FIRSTPRIVATE:
+	case OMP_CLAUSE_REDUCTION:
+	  decl = OMP_CLAUSE_DECL (c);
+	  if (is_variable_sized (decl))
+	    install_var_local (decl, ctx);
+	  fixup_remapped_decl (decl, ctx,
+			       OMP_CLAUSE_CODE (c) == OMP_CLAUSE_PRIVATE
+			       && OMP_CLAUSE_PRIVATE_DEBUG (c));
+	  if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION
+	      && OMP_CLAUSE_REDUCTION_PLACEHOLDER (c))
+	    scan_array_reductions = true;
+	  break;
+
+	case OMP_CLAUSE_SHARED:
+	  decl = OMP_CLAUSE_DECL (c);
+	  if (! is_global_var (maybe_lookup_decl_in_outer_ctx (decl, ctx)))
+	    fixup_remapped_decl (decl, ctx, false);
+	  break;
+
+	case OMP_CLAUSE_COPYPRIVATE:
+	case OMP_CLAUSE_COPYIN:
+	case OMP_CLAUSE_DEFAULT:
+	case OMP_CLAUSE_IF:
+	case OMP_CLAUSE_NUM_THREADS:
+	case OMP_CLAUSE_SCHEDULE:
+	case OMP_CLAUSE_NOWAIT:
+	case OMP_CLAUSE_ORDERED:
+	  break;
+
+	default:
+	  gcc_unreachable ();
+	}
+    }
+
+  if (scan_array_reductions)
+    for (c = clauses; c; c = OMP_CLAUSE_CHAIN (c))
+      if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION
+	  && OMP_CLAUSE_REDUCTION_PLACEHOLDER (c))
+	{
+	  scan_omp (&OMP_CLAUSE_REDUCTION_INIT (c), ctx);
+	  scan_omp (&OMP_CLAUSE_REDUCTION_MERGE (c), ctx);
+	}
+}
+
+/* Create a new name for omp child function.  Returns an identifier.  */
+
+static GTY(()) unsigned int tmp_ompfn_id_num;
+
+static tree
+create_omp_child_function_name (void)
+{
+  tree name = DECL_ASSEMBLER_NAME (current_function_decl);
+  size_t len = IDENTIFIER_LENGTH (name);
+  char *tmp_name, *prefix;
+
+  prefix = alloca (len + sizeof ("_omp_fn"));
+  memcpy (prefix, IDENTIFIER_POINTER (name), len);
+  strcpy (prefix + len, "_omp_fn");
+#ifndef NO_DOT_IN_LABEL
+  prefix[len] = '.';
+#elif !defined NO_DOLLAR_IN_LABEL
+  prefix[len] = '$';
+#endif
+  ASM_FORMAT_PRIVATE_NAME (tmp_name, prefix, tmp_ompfn_id_num++);
+  return get_identifier (tmp_name);
+}
+
+/* Build a decl for the omp child function.  It'll not contain a body
+   yet, just the bare decl.  */
+
+static void
+create_omp_child_function (omp_context *ctx)
+{
+  tree decl, type, name, t;
+
+  name = create_omp_child_function_name ();
+  type = build_function_type_list (void_type_node, ptr_type_node, NULL_TREE);
+
+  decl = build_decl (FUNCTION_DECL, name, type);
+  decl = lang_hooks.decls.pushdecl (decl);
+
+  ctx->cb.dst_fn = decl;
+
+  TREE_STATIC (decl) = 1;
+  TREE_USED (decl) = 1;
+  DECL_ARTIFICIAL (decl) = 1;
+  DECL_IGNORED_P (decl) = 0;
+  TREE_PUBLIC (decl) = 0;
+  DECL_UNINLINABLE (decl) = 1;
+  DECL_EXTERNAL (decl) = 0;
+  DECL_CONTEXT (decl) = NULL_TREE;
+  DECL_INITIAL (decl) = make_node (BLOCK);
+
+  t = build_decl (RESULT_DECL, NULL_TREE, void_type_node);
+  DECL_ARTIFICIAL (t) = 1;
+  DECL_IGNORED_P (t) = 1;
+  DECL_RESULT (decl) = t;
+
+  t = build_decl (PARM_DECL, get_identifier (".omp_data_i"), ptr_type_node);
+  DECL_ARTIFICIAL (t) = 1;
+  DECL_ARG_TYPE (t) = ptr_type_node;
+  DECL_CONTEXT (t) = current_function_decl;
+  TREE_USED (t) = 1;
+  DECL_ARGUMENTS (decl) = t;
+  ctx->receiver_decl = t;
+
+  /* Allocate memory for the function structure.  The call to 
+     allocate_struct_function clobbers CFUN, so we need to restore
+     it afterward.  */
+  allocate_struct_function (decl);
+  DECL_SOURCE_LOCATION (decl) = EXPR_LOCATION (ctx->stmt);
+  cfun->function_end_locus = EXPR_LOCATION (ctx->stmt);
+  cfun = ctx->cb.src_cfun;
+}
+
+
+/* Scan an OpenMP parallel directive.  */
+
+static void
+scan_omp_parallel (tree *stmt_p, omp_context *outer_ctx)
+{
+  omp_context *ctx;
+  tree name;
+
+  /* Ignore parallel directives with empty bodies, unless there
+     are copyin clauses.  */
+  if (optimize > 0
+      && empty_body_p (OMP_PARALLEL_BODY (*stmt_p))
+      && find_omp_clause (OMP_CLAUSES (*stmt_p), OMP_CLAUSE_COPYIN) == NULL)
+    {
+      *stmt_p = build_empty_stmt ();
+      return;
+    }
+
+  ctx = new_omp_context (*stmt_p, outer_ctx);
+  if (parallel_nesting_level > 1)
+    ctx->is_nested = true;
+  ctx->field_map = splay_tree_new (splay_tree_compare_pointers, 0, 0);
+  ctx->default_kind = OMP_CLAUSE_DEFAULT_SHARED;
+  ctx->record_type = lang_hooks.types.make_type (RECORD_TYPE);
+  name = create_tmp_var_name (".omp_data_s");
+  name = build_decl (TYPE_DECL, name, ctx->record_type);
+  TYPE_NAME (ctx->record_type) = name;
+  create_omp_child_function (ctx);
+  OMP_PARALLEL_FN (*stmt_p) = ctx->cb.dst_fn;
+
+  scan_sharing_clauses (OMP_PARALLEL_CLAUSES (*stmt_p), ctx);
+  scan_omp (&OMP_PARALLEL_BODY (*stmt_p), ctx);
+
+  if (TYPE_FIELDS (ctx->record_type) == NULL)
+    ctx->record_type = ctx->receiver_decl = NULL;
+  else
+    {
+      layout_type (ctx->record_type);
+      fixup_child_record_type (ctx);
+    }
+}
+
+
+/* Scan an OpenMP loop directive.  */
+
+static void
+scan_omp_for (tree *stmt_p, omp_context *outer_ctx)
+{
+  omp_context *ctx;
+  tree stmt;
+
+  stmt = *stmt_p;
+  ctx = new_omp_context (stmt, outer_ctx);
+
+  scan_sharing_clauses (OMP_FOR_CLAUSES (stmt), ctx);
+
+  scan_omp (&OMP_FOR_PRE_BODY (stmt), ctx);
+  scan_omp (&OMP_FOR_INIT (stmt), ctx);
+  scan_omp (&OMP_FOR_COND (stmt), ctx);
+  scan_omp (&OMP_FOR_INCR (stmt), ctx);
+  scan_omp (&OMP_FOR_BODY (stmt), ctx);
+}
+
+/* Scan an OpenMP sections directive.  */
+
+static void
+scan_omp_sections (tree *stmt_p, omp_context *outer_ctx)
+{
+  tree stmt;
+  omp_context *ctx;
+
+  stmt = *stmt_p;
+  ctx = new_omp_context (stmt, outer_ctx);
+  scan_sharing_clauses (OMP_SECTIONS_CLAUSES (stmt), ctx);
+  scan_omp (&OMP_SECTIONS_BODY (stmt), ctx);
+}
+
+/* Scan an OpenMP single directive.  */
+
+static void
+scan_omp_single (tree *stmt_p, omp_context *outer_ctx)
+{
+  tree stmt = *stmt_p;
+  omp_context *ctx;
+  tree name;
+
+  ctx = new_omp_context (stmt, outer_ctx);
+  ctx->field_map = splay_tree_new (splay_tree_compare_pointers, 0, 0);
+  ctx->record_type = lang_hooks.types.make_type (RECORD_TYPE);
+  name = create_tmp_var_name (".omp_copy_s");
+  name = build_decl (TYPE_DECL, name, ctx->record_type);
+  TYPE_NAME (ctx->record_type) = name;
+
+  scan_sharing_clauses (OMP_SINGLE_CLAUSES (stmt), ctx);
+  scan_omp (&OMP_SINGLE_BODY (stmt), ctx);
+
+  if (TYPE_FIELDS (ctx->record_type) == NULL)
+    ctx->record_type = NULL;
+  else
+    layout_type (ctx->record_type);
+}
+
+
+/* Check OpenMP nesting restrictions.  */
+static void
+check_omp_nesting_restrictions (tree t, omp_context *ctx)
+{
+  switch (TREE_CODE (t))
+    {
+    case OMP_FOR:
+    case OMP_SECTIONS:
+    case OMP_SINGLE:
+      for (; ctx != NULL; ctx = ctx->outer)
+	switch (TREE_CODE (ctx->stmt))
+	  {
+	  case OMP_FOR:
+	  case OMP_SECTIONS:
+	  case OMP_SINGLE:
+	  case OMP_ORDERED:
+	  case OMP_MASTER:
+	    warning (0, "work-sharing region may not be closely nested inside "
+			"of work-sharing, critical, ordered or master region");
+	    return;
+	  case OMP_PARALLEL:
+	    return;
+	  default:
+	    break;
+	  }
+      break;
+    case OMP_MASTER:
+      for (; ctx != NULL; ctx = ctx->outer)
+	switch (TREE_CODE (ctx->stmt))
+	  {
+	  case OMP_FOR:
+	  case OMP_SECTIONS:
+	  case OMP_SINGLE:
+	    warning (0, "master region may not be closely nested inside "
+			"of work-sharing region");
+	    return;
+	  case OMP_PARALLEL:
+	    return;
+	  default:
+	    break;
+	  }
+      break;
+    case OMP_ORDERED:
+      for (; ctx != NULL; ctx = ctx->outer)
+	switch (TREE_CODE (ctx->stmt))
+	  {
+	  case OMP_CRITICAL:
+	    warning (0, "ordered region may not be closely nested inside "
+			"of critical region");
+	    return;
+	  case OMP_FOR:
+	    if (find_omp_clause (OMP_CLAUSES (ctx->stmt),
+				 OMP_CLAUSE_ORDERED) == NULL)
+	      warning (0, "ordered region must be closely nested inside "
+			  "a loop region with an ordered clause");
+	    return;
+	  case OMP_PARALLEL:
+	    return;
+	  default:
+	    break;
+	  }
+      break;
+    case OMP_CRITICAL:
+      for (; ctx != NULL; ctx = ctx->outer)
+	if (TREE_CODE (ctx->stmt) == OMP_CRITICAL
+	    && OMP_CRITICAL_NAME (t) == OMP_CRITICAL_NAME (ctx->stmt))
+	  {
+	    warning (0, "critical region may not be nested inside a critical "
+			"region with the same name");
+	    return;
+	  }
+      break;
+    default:
+      break;
+    }
+}
+
+
+/* Callback for walk_stmts used to scan for OpenMP directives at TP.  */
+
+static tree
+scan_omp_1 (tree *tp, int *walk_subtrees, void *data)
+{
+  struct walk_stmt_info *wi = data;
+  omp_context *ctx = wi->info;
+  tree t = *tp;
+
+  if (EXPR_HAS_LOCATION (t))
+    input_location = EXPR_LOCATION (t);
+
+  /* Check the OpenMP nesting restrictions.  */
+  if (OMP_DIRECTIVE_P (t) && ctx != NULL)
+    check_omp_nesting_restrictions (t, ctx);
+
+  *walk_subtrees = 0;
+  switch (TREE_CODE (t))
+    {
+    case OMP_PARALLEL:
+      parallel_nesting_level++;
+      scan_omp_parallel (tp, ctx);
+      parallel_nesting_level--;
+      break;
+
+    case OMP_FOR:
+      scan_omp_for (tp, ctx);
+      break;
+
+    case OMP_SECTIONS:
+      scan_omp_sections (tp, ctx);
+      break;
+
+    case OMP_SINGLE:
+      scan_omp_single (tp, ctx);
+      break;
+
+    case OMP_SECTION:
+    case OMP_MASTER:
+    case OMP_ORDERED:
+    case OMP_CRITICAL:
+      ctx = new_omp_context (*tp, ctx);
+      scan_omp (&OMP_BODY (*tp), ctx);
+      break;
+
+    case BIND_EXPR:
+      {
+	tree var;
+	*walk_subtrees = 1;
+
+	for (var = BIND_EXPR_VARS (t); var ; var = TREE_CHAIN (var))
+	  insert_decl_map (&ctx->cb, var, var);
+      }
+      break;
+
+    case VAR_DECL:
+    case PARM_DECL:
+    case LABEL_DECL:
+    case RESULT_DECL:
+      if (ctx)
+	*tp = remap_decl (t, &ctx->cb);
+      break;
+
+    default:
+      if (ctx && TYPE_P (t))
+	*tp = remap_type (t, &ctx->cb);
+      else if (!DECL_P (t))
+	*walk_subtrees = 1;
+      break;
+    }
+
+  return NULL_TREE;
+}
+
+
+/* Scan all the statements starting at STMT_P.  CTX contains context
+   information about the OpenMP directives and clauses found during
+   the scan.  */
+
+static void
+scan_omp (tree *stmt_p, omp_context *ctx)
+{
+  location_t saved_location;
+  struct walk_stmt_info wi;
+
+  memset (&wi, 0, sizeof (wi));
+  wi.callback = scan_omp_1;
+  wi.info = ctx;
+  wi.want_bind_expr = (ctx != NULL);
+  wi.want_locations = true;
+
+  saved_location = input_location;
+  walk_stmts (&wi, stmt_p);
+  input_location = saved_location;
+}
+
+/* Re-gimplification and code generation routines.  */
+
+/* Build a call to GOMP_barrier.  */
+
+static void
+build_omp_barrier (tree *stmt_list)
+{
+  tree t;
+
+  t = built_in_decls[BUILT_IN_GOMP_BARRIER];
+  t = build_function_call_expr (t, NULL);
+  gimplify_and_add (t, stmt_list);
+}
+
+/* If a context was created for STMT when it was scanned, return it.  */
+
+static omp_context *
+maybe_lookup_ctx (tree stmt)
+{
+  splay_tree_node n;
+  n = splay_tree_lookup (all_contexts, (splay_tree_key) stmt);
+  return n ? (omp_context *) n->value : NULL;
+}
+
+
+/* Find the mapping for DECL in CTX or the immediately enclosing
+   context that has a mapping for DECL.
+
+   If CTX is a nested parallel directive, we may have to use the decl
+   mappings created in CTX's parent context.  Suppose that we have the
+   following parallel nesting (variable UIDs showed for clarity):
+
+	iD.1562 = 0;
+     	#omp parallel shared(iD.1562)		-> outer parallel
+	  iD.1562 = iD.1562 + 1;
+
+	  #omp parallel shared (iD.1562)	-> inner parallel
+	     iD.1562 = iD.1562 - 1;
+
+   Each parallel structure will create a distinct .omp_data_s structure
+   for copying iD.1562 in/out of the directive:
+
+  	outer parallel		.omp_data_s.1.i -> iD.1562
+	inner parallel		.omp_data_s.2.i -> iD.1562
+
+   A shared variable mapping will produce a copy-out operation before
+   the parallel directive and a copy-in operation after it.  So, in
+   this case we would have:
+
+  	iD.1562 = 0;
+	.omp_data_o.1.i = iD.1562;
+	#omp parallel shared(iD.1562)		-> outer parallel
+	  .omp_data_i.1 = &.omp_data_o.1
+	  .omp_data_i.1->i = .omp_data_i.1->i + 1;
+
+	  .omp_data_o.2.i = iD.1562;		-> **
+	  #omp parallel shared(iD.1562)		-> inner parallel
+	    .omp_data_i.2 = &.omp_data_o.2
+	    .omp_data_i.2->i = .omp_data_i.2->i - 1;
+
+
+    ** This is a problem.  The symbol iD.1562 cannot be referenced
+       inside the body of the outer parallel region.  But since we are
+       emitting this copy operation while expanding the inner parallel
+       directive, we need to access the CTX structure of the outer
+       parallel directive to get the correct mapping:
+
+	  .omp_data_o.2.i = .omp_data_i.1->i
+
+    Since there may be other workshare or parallel directives enclosing
+    the parallel directive, it may be necessary to walk up the context
+    parent chain.  This is not a problem in general because nested
+    parallelism happens only rarely.  */
+
+static tree
+lookup_decl_in_outer_ctx (tree decl, omp_context *ctx)
+{
+  tree t;
+  omp_context *up;
+
+  gcc_assert (ctx->is_nested);
+
+  for (up = ctx->outer, t = NULL; up && t == NULL; up = up->outer)
+    t = maybe_lookup_decl (decl, up);
+
+  gcc_assert (t);
+
+  return t;
+}
+
+
+/* Similar to lookup_decl_in_outer_ctx, but return DECL if not found
+   in outer contexts.  */
+
+static tree
+maybe_lookup_decl_in_outer_ctx (tree decl, omp_context *ctx)
+{
+  tree t = NULL;
+  omp_context *up;
+
+  if (ctx->is_nested)
+    for (up = ctx->outer, t = NULL; up && t == NULL; up = up->outer)
+      t = maybe_lookup_decl (decl, up);
+
+  return t ? t : decl;
+}
+
+
+/* Construct the initialization value for reduction CLAUSE.  */
+
+tree
+omp_reduction_init (tree clause, tree type)
+{
+  switch (OMP_CLAUSE_REDUCTION_CODE (clause))
+    {
+    case PLUS_EXPR:
+    case MINUS_EXPR:
+    case BIT_IOR_EXPR:
+    case BIT_XOR_EXPR:
+    case TRUTH_OR_EXPR:
+    case TRUTH_ORIF_EXPR:
+    case TRUTH_XOR_EXPR:
+    case NE_EXPR:
+      return fold_convert (type, integer_zero_node);
+
+    case MULT_EXPR:
+    case TRUTH_AND_EXPR:
+    case TRUTH_ANDIF_EXPR:
+    case EQ_EXPR:
+      return fold_convert (type, integer_one_node);
+
+    case BIT_AND_EXPR:
+      return fold_convert (type, integer_minus_one_node);
+
+    case MAX_EXPR:
+      if (SCALAR_FLOAT_TYPE_P (type))
+	{
+	  REAL_VALUE_TYPE max, min;
+	  if (HONOR_INFINITIES (TYPE_MODE (type)))
+	    {
+	      real_inf (&max);
+	      real_arithmetic (&min, NEGATE_EXPR, &max, NULL);
+	    }
+	  else
+	    real_maxval (&min, 1, TYPE_MODE (type));
+	  return build_real (type, min);
+	}
+      else
+	{
+	  gcc_assert (INTEGRAL_TYPE_P (type));
+	  return TYPE_MIN_VALUE (type);
+	}
+
+    case MIN_EXPR:
+      if (SCALAR_FLOAT_TYPE_P (type))
+	{
+	  REAL_VALUE_TYPE max;
+	  if (HONOR_INFINITIES (TYPE_MODE (type)))
+	    real_inf (&max);
+	  else
+	    real_maxval (&max, 0, TYPE_MODE (type));
+	  return build_real (type, max);
+	}
+      else
+	{
+	  gcc_assert (INTEGRAL_TYPE_P (type));
+	  return TYPE_MAX_VALUE (type);
+	}
+
+    default:
+      gcc_unreachable ();
+    }
+}
+
+/* Generate code to implement the input clauses, FIRSTPRIVATE and COPYIN,
+   from the receiver (aka child) side and initializers for REFERENCE_TYPE
+   private variables.  Initialization statements go in ILIST, while calls
+   to destructors go in DLIST.  */
+
+static void
+lower_rec_input_clauses (tree clauses, tree *ilist, tree *dlist,
+			 omp_context *ctx)
+{
+  tree_stmt_iterator diter;
+  tree c, dtor, copyin_seq, x, args, ptr;
+  bool copyin_by_ref = false;
+  bool lastprivate_firstprivate = false;
+  int pass;
+
+  *dlist = alloc_stmt_list ();
+  diter = tsi_start (*dlist);
+  copyin_seq = NULL;
+
+  /* Do all the fixed sized types in the first pass, and the variable sized
+     types in the second pass.  This makes sure that the scalar arguments to
+     the variable sized types are processed before we use them in the 
+     variable sized operations.  */
+  for (pass = 0; pass < 2; ++pass)
+    {
+      for (c = clauses; c ; c = OMP_CLAUSE_CHAIN (c))
+	{
+	  enum omp_clause_code c_kind = OMP_CLAUSE_CODE (c);
+	  tree var, new_var;
+	  bool by_ref;
+
+	  switch (c_kind)
+	    {
+	    case OMP_CLAUSE_PRIVATE:
+	      if (OMP_CLAUSE_PRIVATE_DEBUG (c))
+		continue;
+	      break;
+	    case OMP_CLAUSE_SHARED:
+	      if (maybe_lookup_decl (OMP_CLAUSE_DECL (c), ctx) == NULL)
+		{
+		  gcc_assert (is_global_var (OMP_CLAUSE_DECL (c)));
+		  continue;
+		}
+	    case OMP_CLAUSE_FIRSTPRIVATE:
+	    case OMP_CLAUSE_COPYIN:
+	    case OMP_CLAUSE_REDUCTION:
+	      break;
+	    case OMP_CLAUSE_LASTPRIVATE:
+	      if (OMP_CLAUSE_LASTPRIVATE_FIRSTPRIVATE (c))
+		{
+		  lastprivate_firstprivate = true;
+		  if (pass != 0)
+		    continue;
+		}
+	      break;
+	    default:
+	      continue;
+	    }
+
+	  new_var = var = OMP_CLAUSE_DECL (c);
+	  if (c_kind != OMP_CLAUSE_COPYIN)
+	    new_var = lookup_decl (var, ctx);
+
+	  if (c_kind == OMP_CLAUSE_SHARED || c_kind == OMP_CLAUSE_COPYIN)
+	    {
+	      if (pass != 0)
+		continue;
+	    }
+	  else if (is_variable_sized (var))
+	    {
+	      /* For variable sized types, we need to allocate the
+		 actual storage here.  Call alloca and store the
+		 result in the pointer decl that we created elsewhere.  */
+	      if (pass == 0)
+		continue;
+
+	      ptr = DECL_VALUE_EXPR (new_var);
+	      gcc_assert (TREE_CODE (ptr) == INDIRECT_REF);
+	      ptr = TREE_OPERAND (ptr, 0);
+	      gcc_assert (DECL_P (ptr));
+
+	      x = TYPE_SIZE_UNIT (TREE_TYPE (new_var));
+	      args = tree_cons (NULL, x, NULL);
+	      x = built_in_decls[BUILT_IN_ALLOCA];
+	      x = build_function_call_expr (x, args);
+	      x = fold_convert (TREE_TYPE (ptr), x);
+	      x = build2 (MODIFY_EXPR, void_type_node, ptr, x);
+	      gimplify_and_add (x, ilist);
+	    }
+	  else if (is_reference (var))
+	    {
+	      /* For references that are being privatized for Fortran,
+		 allocate new backing storage for the new pointer
+		 variable.  This allows us to avoid changing all the
+		 code that expects a pointer to something that expects
+		 a direct variable.  Note that this doesn't apply to
+		 C++, since reference types are disallowed in data
+		 sharing clauses there, except for NRV optimized
+		 return values.  */
+	      if (pass == 0)
+		continue;
+
+	      x = TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (new_var)));
+	      if (TREE_CONSTANT (x))
+		{
+		  const char *name = NULL;
+		  if (DECL_NAME (var))
+		    name = IDENTIFIER_POINTER (DECL_NAME (new_var));
+
+		  x = create_tmp_var_raw (TREE_TYPE (TREE_TYPE (new_var)),
+					  name);
+		  gimple_add_tmp_var (x);
+		  x = build_fold_addr_expr_with_type (x, TREE_TYPE (new_var));
+		}
+	      else
+		{
+		  args = tree_cons (NULL, x, NULL);
+		  x = built_in_decls[BUILT_IN_ALLOCA];
+		  x = build_function_call_expr (x, args);
+		  x = fold_convert (TREE_TYPE (new_var), x);
+		}
+
+	      x = build2 (MODIFY_EXPR, void_type_node, new_var, x);
+	      gimplify_and_add (x, ilist);
+
+	      new_var = build_fold_indirect_ref (new_var);
+	    }
+	  else if (c_kind == OMP_CLAUSE_REDUCTION
+		   && OMP_CLAUSE_REDUCTION_PLACEHOLDER (c))
+	    {
+	      if (pass == 0)
+		continue;
+	    }
+	  else if (pass != 0)
+	    continue;
+
+	  switch (OMP_CLAUSE_CODE (c))
+	    {
+	    case OMP_CLAUSE_SHARED:
+	      /* Shared global vars are just accessed directly.  */
+	      if (is_global_var (new_var))
+		break;
+	      /* Set up the DECL_VALUE_EXPR for shared variables now.  This
+		 needs to be delayed until after fixup_child_record_type so
+		 that we get the correct type during the dereference.  */
+	      by_ref = use_pointer_for_field (var, true);
+	      x = build_receiver_ref (var, by_ref, ctx);
+	      SET_DECL_VALUE_EXPR (new_var, x);
+	      DECL_HAS_VALUE_EXPR_P (new_var) = 1;
+
+	      /* ??? If VAR is not passed by reference, and the variable
+		 hasn't been initialized yet, then we'll get a warning for
+		 the store into the omp_data_s structure.  Ideally, we'd be
+		 able to notice this and not store anything at all, but 
+		 we're generating code too early.  Suppress the warning.  */
+	      if (!by_ref)
+		TREE_NO_WARNING (var) = 1;
+	      break;
+
+	    case OMP_CLAUSE_LASTPRIVATE:
+	      if (OMP_CLAUSE_LASTPRIVATE_FIRSTPRIVATE (c))
+		break;
+	      /* FALLTHRU */
+
+	    case OMP_CLAUSE_PRIVATE:
+	      x = lang_hooks.decls.omp_clause_default_ctor (c, new_var);
+	      if (x)
+		gimplify_and_add (x, ilist);
+	      /* FALLTHRU */
+
+	    do_dtor:
+	      x = lang_hooks.decls.omp_clause_dtor (c, new_var);
+	      if (x)
+		{
+		  dtor = x;
+		  gimplify_stmt (&dtor);
+		  tsi_link_before (&diter, dtor, TSI_SAME_STMT);
+		}
+	      break;
+
+	    case OMP_CLAUSE_FIRSTPRIVATE:
+	      x = build_outer_var_ref (var, ctx);
+	      x = lang_hooks.decls.omp_clause_copy_ctor (c, new_var, x);
+	      gimplify_and_add (x, ilist);
+	      goto do_dtor;
+	      break;
+
+	    case OMP_CLAUSE_COPYIN:
+	      by_ref = use_pointer_for_field (var, false);
+	      x = build_receiver_ref (var, by_ref, ctx);
+	      x = lang_hooks.decls.omp_clause_assign_op (c, new_var, x);
+	      append_to_statement_list (x, &copyin_seq);
+	      copyin_by_ref |= by_ref;
+	      break;
+
+	    case OMP_CLAUSE_REDUCTION:
+	      if (OMP_CLAUSE_REDUCTION_PLACEHOLDER (c))
+		{
+		  gimplify_and_add (OMP_CLAUSE_REDUCTION_INIT (c), ilist);
+		  OMP_CLAUSE_REDUCTION_INIT (c) = NULL;
+		}
+	      else
+		{
+		  x = omp_reduction_init (c, TREE_TYPE (new_var));
+		  gcc_assert (TREE_CODE (TREE_TYPE (new_var)) != ARRAY_TYPE);
+		  x = build2 (MODIFY_EXPR, void_type_node, new_var, x);
+		  gimplify_and_add (x, ilist);
+		}
+	      break;
+
+	    default:
+	      gcc_unreachable ();
+	    }
+	}
+    }
+
+  /* The copyin sequence is not to be executed by the main thread, since
+     that would result in self-copies.  Perhaps not visible to scalars,
+     but it certainly is to C++ operator=.  */
+  if (copyin_seq)
+    {
+      x = built_in_decls[BUILT_IN_OMP_GET_THREAD_NUM];
+      x = build_function_call_expr (x, NULL);
+      x = build2 (NE_EXPR, boolean_type_node, x,
+		  build_int_cst (TREE_TYPE (x), 0));
+      x = build3 (COND_EXPR, void_type_node, x, copyin_seq, NULL);
+      gimplify_and_add (x, ilist);
+    }
+
+  /* If any copyin variable is passed by reference, we must ensure the
+     master thread doesn't modify it before it is copied over in all
+     threads.  Similarly for variables in both firstprivate and
+     lastprivate clauses we need to ensure the lastprivate copying
+     happens after firstprivate copying in all threads.  */
+  if (copyin_by_ref || lastprivate_firstprivate)
+    build_omp_barrier (ilist);
+}
+
+
+/* Generate code to implement the LASTPRIVATE clauses.  This is used for
+   both parallel and workshare constructs.  PREDICATE may be NULL if it's
+   always true.   */
+
+static void
+lower_lastprivate_clauses (tree clauses, tree predicate, tree *stmt_list,
+			    omp_context *ctx)
+{
+  tree sub_list, x, c;
+
+  /* Early exit if there are no lastprivate clauses.  */
+  clauses = find_omp_clause (clauses, OMP_CLAUSE_LASTPRIVATE);
+  if (clauses == NULL)
+    {
+      /* If this was a workshare clause, see if it had been combined
+	 with its parallel.  In that case, look for the clauses on the
+	 parallel statement itself.  */
+      if (is_parallel_ctx (ctx))
+	return;
+
+      ctx = ctx->outer;
+      if (ctx == NULL || !is_parallel_ctx (ctx))
+	return;
+
+      clauses = find_omp_clause (OMP_PARALLEL_CLAUSES (ctx->stmt),
+				 OMP_CLAUSE_LASTPRIVATE);
+      if (clauses == NULL)
+	return;
+    }
+
+  sub_list = alloc_stmt_list ();
+
+  for (c = clauses; c ; c = OMP_CLAUSE_CHAIN (c))
+    {
+      tree var, new_var;
+
+      if (OMP_CLAUSE_CODE (c) != OMP_CLAUSE_LASTPRIVATE)
+	continue;
+
+      var = OMP_CLAUSE_DECL (c);
+      new_var = lookup_decl (var, ctx);
+
+      x = build_outer_var_ref (var, ctx);
+      if (is_reference (var))
+	new_var = build_fold_indirect_ref (new_var);
+      x = lang_hooks.decls.omp_clause_assign_op (c, x, new_var);
+      append_to_statement_list (x, &sub_list);
+    }
+
+  if (predicate)
+    x = build3 (COND_EXPR, void_type_node, predicate, sub_list, NULL);
+  else
+    x = sub_list;
+
+  gimplify_and_add (x, stmt_list);
+}
+
+
+/* Generate code to implement the REDUCTION clauses.  */
+
+static void
+lower_reduction_clauses (tree clauses, tree *stmt_list, omp_context *ctx)
+{
+  tree sub_list = NULL, x, c;
+  int count = 0;
+
+  /* First see if there is exactly one reduction clause.  Use OMP_ATOMIC
+     update in that case, otherwise use a lock.  */
+  for (c = clauses; c && count < 2; c = OMP_CLAUSE_CHAIN (c))
+    if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION)
+      {
+	if (OMP_CLAUSE_REDUCTION_PLACEHOLDER (c))
+	  {
+	    /* Never use OMP_ATOMIC for array reductions.  */
+	    count = -1;
+	    break;
+	  }
+	count++;
+      }
+
+  if (count == 0)
+    return;
+
+  for (c = clauses; c ; c = OMP_CLAUSE_CHAIN (c))
+    {
+      tree var, ref, new_var;
+      enum tree_code code;
+
+      if (OMP_CLAUSE_CODE (c) != OMP_CLAUSE_REDUCTION)
+	continue;
+
+      var = OMP_CLAUSE_DECL (c);
+      new_var = lookup_decl (var, ctx);
+      if (is_reference (var))
+	new_var = build_fold_indirect_ref (new_var);
+      ref = build_outer_var_ref (var, ctx);
+      code = OMP_CLAUSE_REDUCTION_CODE (c);
+
+      /* reduction(-:var) sums up the partial results, so it acts
+	 identically to reduction(+:var).  */
+      if (code == MINUS_EXPR)
+        code = PLUS_EXPR;
+
+      if (count == 1)
+	{
+	  tree addr = build_fold_addr_expr (ref);
+
+	  addr = save_expr (addr);
+	  ref = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (addr)), addr);
+	  x = fold_build2 (code, TREE_TYPE (ref), ref, new_var);
+	  x = build2 (OMP_ATOMIC, void_type_node, addr, x);
+	  gimplify_and_add (x, stmt_list);
+	  return;
+	}
+
+      if (OMP_CLAUSE_REDUCTION_PLACEHOLDER (c))
+	{
+	  tree placeholder = OMP_CLAUSE_REDUCTION_PLACEHOLDER (c);
+
+	  if (is_reference (var))
+	    ref = build_fold_addr_expr (ref);
+	  SET_DECL_VALUE_EXPR (placeholder, ref);
+	  DECL_HAS_VALUE_EXPR_P (placeholder) = 1;
+	  gimplify_and_add (OMP_CLAUSE_REDUCTION_MERGE (c), &sub_list);
+	  OMP_CLAUSE_REDUCTION_MERGE (c) = NULL;
+	  OMP_CLAUSE_REDUCTION_PLACEHOLDER (c) = NULL;
+	}
+      else
+	{
+	  x = build2 (code, TREE_TYPE (ref), ref, new_var);
+	  ref = build_outer_var_ref (var, ctx);
+	  x = build2 (MODIFY_EXPR, void_type_node, ref, x);
+	  append_to_statement_list (x, &sub_list);
+	}
+    }
+
+  x = built_in_decls[BUILT_IN_GOMP_ATOMIC_START];
+  x = build_function_call_expr (x, NULL);
+  gimplify_and_add (x, stmt_list);
+
+  gimplify_and_add (sub_list, stmt_list);
+
+  x = built_in_decls[BUILT_IN_GOMP_ATOMIC_END];
+  x = build_function_call_expr (x, NULL);
+  gimplify_and_add (x, stmt_list);
+}
+
+
+/* Generate code to implement the COPYPRIVATE clauses.  */
+
+static void
+lower_copyprivate_clauses (tree clauses, tree *slist, tree *rlist,
+			    omp_context *ctx)
+{
+  tree c;
+
+  for (c = clauses; c ; c = OMP_CLAUSE_CHAIN (c))
+    {
+      tree var, ref, x;
+      bool by_ref;
+
+      if (OMP_CLAUSE_CODE (c) != OMP_CLAUSE_COPYPRIVATE)
+	continue;
+
+      var = OMP_CLAUSE_DECL (c);
+      by_ref = use_pointer_for_field (var, false);
+
+      ref = build_sender_ref (var, ctx);
+      x = (ctx->is_nested) ? lookup_decl_in_outer_ctx (var, ctx) : var;
+      x = by_ref ? build_fold_addr_expr (x) : x;
+      x = build2 (MODIFY_EXPR, void_type_node, ref, x);
+      gimplify_and_add (x, slist);
+
+      ref = build_receiver_ref (var, by_ref, ctx);
+      if (is_reference (var))
+	{
+	  ref = build_fold_indirect_ref (ref);
+	  var = build_fold_indirect_ref (var);
+	}
+      x = lang_hooks.decls.omp_clause_assign_op (c, var, ref);
+      gimplify_and_add (x, rlist);
+    }
+}
+
+
+/* Generate code to implement the clauses, FIRSTPRIVATE, COPYIN, LASTPRIVATE,
+   and REDUCTION from the sender (aka parent) side.  */
+
+static void
+lower_send_clauses (tree clauses, tree *ilist, tree *olist, omp_context *ctx)
+{
+  tree c;
+
+  for (c = clauses; c ; c = OMP_CLAUSE_CHAIN (c))
+    {
+      tree val, ref, x, var;
+      bool by_ref, do_in = false, do_out = false;
+
+      switch (OMP_CLAUSE_CODE (c))
+	{
+	case OMP_CLAUSE_FIRSTPRIVATE:
+	case OMP_CLAUSE_COPYIN:
+	case OMP_CLAUSE_LASTPRIVATE:
+	case OMP_CLAUSE_REDUCTION:
+	  break;
+	default:
+	  continue;
+	}
+
+      var = val = OMP_CLAUSE_DECL (c);
+      if (ctx->is_nested)
+	var = lookup_decl_in_outer_ctx (val, ctx);
+
+      if (OMP_CLAUSE_CODE (c) != OMP_CLAUSE_COPYIN
+	  && is_global_var (var))
+	continue;
+      if (is_variable_sized (val))
+	continue;
+      by_ref = use_pointer_for_field (val, false);
+
+      switch (OMP_CLAUSE_CODE (c))
+	{
+	case OMP_CLAUSE_FIRSTPRIVATE:
+	case OMP_CLAUSE_COPYIN:
+	  do_in = true;
+	  break;
+
+	case OMP_CLAUSE_LASTPRIVATE:
+	  if (by_ref || is_reference (val))
+	    {
+	      if (OMP_CLAUSE_LASTPRIVATE_FIRSTPRIVATE (c))
+		continue;
+	      do_in = true;
+	    }
+	  else
+	    do_out = true;
+	  break;
+
+	case OMP_CLAUSE_REDUCTION:
+	  do_in = true;
+	  do_out = !(by_ref || is_reference (val));
+	  break;
+
+	default:
+	  gcc_unreachable ();
+	}
+
+      if (do_in)
+	{
+	  ref = build_sender_ref (val, ctx);
+	  x = by_ref ? build_fold_addr_expr (var) : var;
+	  x = build2 (MODIFY_EXPR, void_type_node, ref, x);
+	  gimplify_and_add (x, ilist);
+	}
+
+      if (do_out)
+	{
+	  ref = build_sender_ref (val, ctx);
+	  x = build2 (MODIFY_EXPR, void_type_node, var, ref);
+	  gimplify_and_add (x, olist);
+	}
+    }
+}
+
+/* Generate code to implement SHARED from the sender (aka parent) side.
+   This is trickier, since OMP_PARALLEL_CLAUSES doesn't list things that
+   got automatically shared.  */
+
+static void
+lower_send_shared_vars (tree *ilist, tree *olist, omp_context *ctx)
+{
+  tree var, ovar, nvar, f, x;
+
+  if (ctx->record_type == NULL)
+    return;
+
+  for (f = TYPE_FIELDS (ctx->record_type); f ; f = TREE_CHAIN (f))
+    {
+      ovar = DECL_ABSTRACT_ORIGIN (f);
+      nvar = maybe_lookup_decl (ovar, ctx);
+      if (!nvar || !DECL_HAS_VALUE_EXPR_P (nvar))
+	continue;
+
+      var = ovar;
+
+      /* If CTX is a nested parallel directive.  Find the immediately
+	 enclosing parallel or workshare construct that contains a
+	 mapping for OVAR.  */
+      if (ctx->is_nested)
+	var = lookup_decl_in_outer_ctx (ovar, ctx);
+
+      if (use_pointer_for_field (ovar, true))
+	{
+	  x = build_sender_ref (ovar, ctx);
+	  var = build_fold_addr_expr (var);
+	  x = build2 (MODIFY_EXPR, void_type_node, x, var);
+	  gimplify_and_add (x, ilist);
+	}
+      else
+	{
+	  x = build_sender_ref (ovar, ctx);
+	  x = build2 (MODIFY_EXPR, void_type_node, x, var);
+	  gimplify_and_add (x, ilist);
+
+	  x = build_sender_ref (ovar, ctx);
+	  x = build2 (MODIFY_EXPR, void_type_node, var, x);
+	  gimplify_and_add (x, olist);
+	}
+    }
+}
+
+/* Build the function calls to GOMP_parallel_start etc to actually 
+   generate the parallel operation.  REGION is the parallel region
+   being expanded.  BB is the block where to insert the code.  WS_ARGS
+   will be set if this is a call to a combined parallel+workshare
+   construct, it contains the list of additional arguments needed by
+   the workshare construct.  */
+
+static void
+expand_parallel_call (struct omp_region *region, basic_block bb,
+		      tree entry_stmt, tree ws_args)
+{
+  tree t, args, val, cond, c, list, clauses;
+  block_stmt_iterator si;
+  int start_ix;
+
+  clauses = OMP_PARALLEL_CLAUSES (entry_stmt);
+  push_gimplify_context ();
+
+  /* Determine what flavor of GOMP_parallel_start we will be
+     emitting.  */
+  start_ix = BUILT_IN_GOMP_PARALLEL_START;
+  if (is_combined_parallel (region))
+    {
+      switch (region->inner->type)
+	{
+	case OMP_FOR:
+	  start_ix = BUILT_IN_GOMP_PARALLEL_LOOP_STATIC_START
+		     + region->inner->sched_kind;
+	  break;
+	case OMP_SECTIONS:
+	  start_ix = BUILT_IN_GOMP_PARALLEL_SECTIONS_START;
+	  break;
+	default:
+	  gcc_unreachable ();
+	}
+    }
+
+  /* By default, the value of NUM_THREADS is zero (selected at run time)
+     and there is no conditional.  */
+  cond = NULL_TREE;
+  val = build_int_cst (unsigned_type_node, 0);
+
+  c = find_omp_clause (clauses, OMP_CLAUSE_IF);
+  if (c)
+    cond = OMP_CLAUSE_IF_EXPR (c);
+
+  c = find_omp_clause (clauses, OMP_CLAUSE_NUM_THREADS);
+  if (c)
+    val = OMP_CLAUSE_NUM_THREADS_EXPR (c);
+
+  /* Ensure 'val' is of the correct type.  */
+  val = fold_convert (unsigned_type_node, val);
+
+  /* If we found the clause 'if (cond)', build either
+     (cond != 0) or (cond ? val : 1u).  */
+  if (cond)
+    {
+      block_stmt_iterator si;
+
+      cond = gimple_boolify (cond);
+
+      if (integer_zerop (val))
+	val = build2 (EQ_EXPR, unsigned_type_node, cond,
+		      build_int_cst (TREE_TYPE (cond), 0));
+      else
+	{
+	  basic_block cond_bb, then_bb, else_bb;
+	  edge e;
+	  tree t, then_lab, else_lab, tmp;
+
+	  tmp = create_tmp_var (TREE_TYPE (val), NULL);
+	  e = split_block (bb, NULL);
+	  cond_bb = e->src;
+	  bb = e->dest;
+	  remove_edge (e);
+
+	  then_bb = create_empty_bb (cond_bb);
+	  else_bb = create_empty_bb (then_bb);
+	  then_lab = create_artificial_label ();
+	  else_lab = create_artificial_label ();
+
+	  t = build3 (COND_EXPR, void_type_node,
+		      cond,
+		      build_and_jump (&then_lab),
+		      build_and_jump (&else_lab));
+
+	  si = bsi_start (cond_bb);
+	  bsi_insert_after (&si, t, BSI_CONTINUE_LINKING);
+
+	  si = bsi_start (then_bb);
+	  t = build1 (LABEL_EXPR, void_type_node, then_lab);
+	  bsi_insert_after (&si, t, BSI_CONTINUE_LINKING);
+	  t = build2 (MODIFY_EXPR, void_type_node, tmp, val);
+	  bsi_insert_after (&si, t, BSI_CONTINUE_LINKING);
+
+	  si = bsi_start (else_bb);
+	  t = build1 (LABEL_EXPR, void_type_node, else_lab);
+	  bsi_insert_after (&si, t, BSI_CONTINUE_LINKING);
+	  t = build2 (MODIFY_EXPR, void_type_node, tmp, 
+	              build_int_cst (unsigned_type_node, 1));
+	  bsi_insert_after (&si, t, BSI_CONTINUE_LINKING);
+
+	  make_edge (cond_bb, then_bb, EDGE_TRUE_VALUE);
+	  make_edge (cond_bb, else_bb, EDGE_FALSE_VALUE);
+	  make_edge (then_bb, bb, EDGE_FALLTHRU);
+	  make_edge (else_bb, bb, EDGE_FALLTHRU);
+
+	  val = tmp;
+	}
+
+      list = NULL_TREE;
+      val = get_formal_tmp_var (val, &list);
+      si = bsi_start (bb);
+      bsi_insert_after (&si, list, BSI_CONTINUE_LINKING);
+    }
+
+  list = NULL_TREE;
+  args = tree_cons (NULL, val, NULL);
+  t = OMP_PARALLEL_DATA_ARG (entry_stmt);
+  if (t == NULL)
+    t = null_pointer_node;
+  else
+    t = build_fold_addr_expr (t);
+  args = tree_cons (NULL, t, args);
+  t = build_fold_addr_expr (OMP_PARALLEL_FN (entry_stmt));
+  args = tree_cons (NULL, t, args);
+
+  if (ws_args)
+    args = chainon (args, ws_args);
+
+  t = built_in_decls[start_ix];
+  t = build_function_call_expr (t, args);
+  gimplify_and_add (t, &list);
+
+  t = OMP_PARALLEL_DATA_ARG (entry_stmt);
+  if (t == NULL)
+    t = null_pointer_node;
+  else
+    t = build_fold_addr_expr (t);
+  args = tree_cons (NULL, t, NULL);
+  t = build_function_call_expr (OMP_PARALLEL_FN (entry_stmt), args);
+  gimplify_and_add (t, &list);
+
+  t = built_in_decls[BUILT_IN_GOMP_PARALLEL_END];
+  t = build_function_call_expr (t, NULL);
+  gimplify_and_add (t, &list);
+
+  si = bsi_last (bb);
+  bsi_insert_after (&si, list, BSI_CONTINUE_LINKING);
+
+  pop_gimplify_context (NULL_TREE);
+}
+
+
+/* If exceptions are enabled, wrap *STMT_P in a MUST_NOT_THROW catch
+   handler.  This prevents programs from violating the structured
+   block semantics with throws.  */
+
+static void
+maybe_catch_exception (tree *stmt_p)
+{
+  tree f, t;
+
+  if (!flag_exceptions)
+    return;
+
+  if (lang_protect_cleanup_actions)
+    t = lang_protect_cleanup_actions ();
+  else
+    {
+      t = built_in_decls[BUILT_IN_TRAP];
+      t = build_function_call_expr (t, NULL);
+    }
+  f = build2 (EH_FILTER_EXPR, void_type_node, NULL, NULL);
+  EH_FILTER_MUST_NOT_THROW (f) = 1;
+  gimplify_and_add (t, &EH_FILTER_FAILURE (f));
+  
+  t = build2 (TRY_CATCH_EXPR, void_type_node, *stmt_p, NULL);
+  append_to_statement_list (f, &TREE_OPERAND (t, 1));
+
+  *stmt_p = NULL;
+  append_to_statement_list (t, stmt_p);
+}
+
+/* Chain all the DECLs in LIST by their TREE_CHAIN fields.  */
+
+static tree
+list2chain (tree list)
+{
+  tree t;
+
+  for (t = list; t; t = TREE_CHAIN (t))
+    {
+      tree var = TREE_VALUE (t);
+      if (TREE_CHAIN (t))
+	TREE_CHAIN (var) = TREE_VALUE (TREE_CHAIN (t));
+      else
+	TREE_CHAIN (var) = NULL_TREE;
+    }
+
+  return list ? TREE_VALUE (list) : NULL_TREE;
+}
+
+
+/* Remove barriers in REGION->EXIT's block.  Note that this is only
+   valid for OMP_PARALLEL regions.  Since the end of a parallel region
+   is an implicit barrier, any workshare inside the OMP_PARALLEL that
+   left a barrier at the end of the OMP_PARALLEL region can now be
+   removed.  */
+
+static void
+remove_exit_barrier (struct omp_region *region)
+{
+  block_stmt_iterator si;
+  basic_block exit_bb;
+  edge_iterator ei;
+  edge e;
+  tree t;
+
+  exit_bb = region->exit;
+
+  /* If the parallel region doesn't return, we don't have REGION->EXIT
+     block at all.  */
+  if (! exit_bb)
+    return;
+
+  /* The last insn in the block will be the parallel's OMP_RETURN.  The
+     workshare's OMP_RETURN will be in a preceding block.  The kinds of
+     statements that can appear in between are extremely limited -- no
+     memory operations at all.  Here, we allow nothing at all, so the
+     only thing we allow to precede this OMP_RETURN is a label.  */
+  si = bsi_last (exit_bb);
+  gcc_assert (TREE_CODE (bsi_stmt (si)) == OMP_RETURN);
+  bsi_prev (&si);
+  if (!bsi_end_p (si) && TREE_CODE (bsi_stmt (si)) != LABEL_EXPR)
+    return;
+
+  FOR_EACH_EDGE (e, ei, exit_bb->preds)
+    {
+      si = bsi_last (e->src);
+      if (bsi_end_p (si))
+	continue;
+      t = bsi_stmt (si);
+      if (TREE_CODE (t) == OMP_RETURN)
+	OMP_RETURN_NOWAIT (t) = 1;
+    }
+}
+
+static void
+remove_exit_barriers (struct omp_region *region)
+{
+  if (region->type == OMP_PARALLEL)
+    remove_exit_barrier (region);
+
+  if (region->inner)
+    {
+      region = region->inner;
+      remove_exit_barriers (region);
+      while (region->next)
+	{
+	  region = region->next;
+	  remove_exit_barriers (region);
+	}
+    }
+}
+
+/* Expand the OpenMP parallel directive starting at REGION.  */
+
+static void
+expand_omp_parallel (struct omp_region *region)
+{
+  basic_block entry_bb, exit_bb, new_bb;
+  struct function *child_cfun, *saved_cfun;
+  tree child_fn, block, t, ws_args;
+  block_stmt_iterator si;
+  tree entry_stmt;
+  edge e;
+  bool do_cleanup_cfg = false;
+
+  entry_stmt = last_stmt (region->entry);
+  child_fn = OMP_PARALLEL_FN (entry_stmt);
+  child_cfun = DECL_STRUCT_FUNCTION (child_fn);
+  saved_cfun = cfun;
+
+  entry_bb = region->entry;
+  exit_bb = region->exit;
+
+  if (is_combined_parallel (region))
+    ws_args = region->ws_args;
+  else
+    ws_args = NULL_TREE;
+
+  if (child_cfun->cfg)
+    {
+      /* Due to inlining, it may happen that we have already outlined
+	 the region, in which case all we need to do is make the
+	 sub-graph unreachable and emit the parallel call.  */
+      edge entry_succ_e, exit_succ_e;
+      block_stmt_iterator si;
+
+      entry_succ_e = single_succ_edge (entry_bb);
+
+      si = bsi_last (entry_bb);
+      gcc_assert (TREE_CODE (bsi_stmt (si)) == OMP_PARALLEL);
+      bsi_remove (&si, true);
+
+      new_bb = entry_bb;
+      remove_edge (entry_succ_e);
+      if (exit_bb)
+	{
+	  exit_succ_e = single_succ_edge (exit_bb);
+	  make_edge (new_bb, exit_succ_e->dest, EDGE_FALLTHRU);
+	}
+      do_cleanup_cfg = true;
+    }
+  else
+    {
+      /* If the parallel region needs data sent from the parent
+	 function, then the very first statement (except possible
+	 tree profile counter updates) of the parallel body
+	 is a copy assignment .OMP_DATA_I = &.OMP_DATA_O.  Since
+	 &.OMP_DATA_O is passed as an argument to the child function,
+	 we need to replace it with the argument as seen by the child
+	 function.
+
+	 In most cases, this will end up being the identity assignment
+	 .OMP_DATA_I = .OMP_DATA_I.  However, if the parallel body had
+	 a function call that has been inlined, the original PARM_DECL
+	 .OMP_DATA_I may have been converted into a different local
+	 variable.  In which case, we need to keep the assignment.  */
+      if (OMP_PARALLEL_DATA_ARG (entry_stmt))
+	{
+	  basic_block entry_succ_bb = single_succ (entry_bb);
+	  block_stmt_iterator si;
+
+	  for (si = bsi_start (entry_succ_bb); ; bsi_next (&si))
+	    {
+	      tree stmt, arg;
+
+	      gcc_assert (!bsi_end_p (si));
+	      stmt = bsi_stmt (si);
+	      if (TREE_CODE (stmt) != MODIFY_EXPR)
+		continue;
+
+	      arg = TREE_OPERAND (stmt, 1);
+	      STRIP_NOPS (arg);
+	      if (TREE_CODE (arg) == ADDR_EXPR
+		  && TREE_OPERAND (arg, 0)
+		     == OMP_PARALLEL_DATA_ARG (entry_stmt))
+		{
+		  if (TREE_OPERAND (stmt, 0) == DECL_ARGUMENTS (child_fn))
+		    bsi_remove (&si, true);
+		  else
+		    TREE_OPERAND (stmt, 1) = DECL_ARGUMENTS (child_fn);
+		  break;
+		}
+	    }
+	}
+
+      /* Declare local variables needed in CHILD_CFUN.  */
+      block = DECL_INITIAL (child_fn);
+      BLOCK_VARS (block) = list2chain (child_cfun->unexpanded_var_list);
+      DECL_SAVED_TREE (child_fn) = single_succ (entry_bb)->stmt_list;
+
+      /* Reset DECL_CONTEXT on locals and function arguments.  */
+      for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
+	DECL_CONTEXT (t) = child_fn;
+
+      for (t = DECL_ARGUMENTS (child_fn); t; t = TREE_CHAIN (t))
+	DECL_CONTEXT (t) = child_fn;
+
+      /* Split ENTRY_BB at OMP_PARALLEL so that it can be moved to the
+	 child function.  */
+      si = bsi_last (entry_bb);
+      t = bsi_stmt (si);
+      gcc_assert (t && TREE_CODE (t) == OMP_PARALLEL);
+      bsi_remove (&si, true);
+      e = split_block (entry_bb, t);
+      entry_bb = e->dest;
+      single_succ_edge (entry_bb)->flags = EDGE_FALLTHRU;
+
+      /* Move the parallel region into CHILD_CFUN.  We need to reset
+	 dominance information because the expansion of the inner
+	 regions has invalidated it.  */
+      free_dominance_info (CDI_DOMINATORS);
+      new_bb = move_sese_region_to_fn (child_cfun, entry_bb, exit_bb);
+      if (exit_bb)
+	single_succ_edge (new_bb)->flags = EDGE_FALLTHRU;
+      cgraph_add_new_function (child_fn);
+
+      /* Convert OMP_RETURN into a RETURN_EXPR.  */
+      if (exit_bb)
+	{
+	  si = bsi_last (exit_bb);
+	  gcc_assert (!bsi_end_p (si)
+		      && TREE_CODE (bsi_stmt (si)) == OMP_RETURN);
+	  t = build1 (RETURN_EXPR, void_type_node, NULL);
+	  bsi_insert_after (&si, t, BSI_SAME_STMT);
+	  bsi_remove (&si, true);
+	}
+    }
+
+  /* Emit a library call to launch the children threads.  */
+  expand_parallel_call (region, new_bb, entry_stmt, ws_args);
+
+  if (do_cleanup_cfg)
+    {
+      /* Clean up the unreachable sub-graph we created above.  */
+      free_dominance_info (CDI_DOMINATORS);
+      free_dominance_info (CDI_POST_DOMINATORS);
+      cleanup_tree_cfg ();
+    }
+}
+
+
+/* A subroutine of expand_omp_for.  Generate code for a parallel
+   loop with any schedule.  Given parameters:
+
+	for (V = N1; V cond N2; V += STEP) BODY;
+
+   where COND is "<" or ">", we generate pseudocode
+
+	more = GOMP_loop_foo_start (N1, N2, STEP, CHUNK, &istart0, &iend0);
+	if (more) goto L0; else goto L3;
+    L0:
+	V = istart0;
+	iend = iend0;
+    L1:
+	BODY;
+	V += STEP;
+	if (V cond iend) goto L1; else goto L2;
+    L2:
+	if (GOMP_loop_foo_next (&istart0, &iend0)) goto L0; else goto L3;
+    L3:
+
+    If this is a combined omp parallel loop, instead of the call to
+    GOMP_loop_foo_start, we emit 'goto L3'.  */
+
+static void
+expand_omp_for_generic (struct omp_region *region,
+			struct omp_for_data *fd,
+			enum built_in_function start_fn,
+			enum built_in_function next_fn)
+{
+  tree l0, l1, l2 = NULL, l3 = NULL;
+  tree type, istart0, iend0, iend;
+  tree t, args, list;
+  basic_block entry_bb, cont_bb, exit_bb, l0_bb, l1_bb;
+  basic_block l2_bb = NULL, l3_bb = NULL;
+  block_stmt_iterator si;
+  bool in_combined_parallel = is_combined_parallel (region);
+
+  type = TREE_TYPE (fd->v);
+
+  istart0 = create_tmp_var (long_integer_type_node, ".istart0");
+  iend0 = create_tmp_var (long_integer_type_node, ".iend0");
+  iend = create_tmp_var (type, NULL);
+  TREE_ADDRESSABLE (istart0) = 1;
+  TREE_ADDRESSABLE (iend0) = 1;
+
+  gcc_assert ((region->cont != NULL) ^ (region->exit == NULL));
+
+  entry_bb = region->entry;
+  l0_bb = create_empty_bb (entry_bb);
+  l1_bb = single_succ (entry_bb);
+
+  l0 = tree_block_label (l0_bb);
+  l1 = tree_block_label (l1_bb);
+
+  cont_bb = region->cont;
+  exit_bb = region->exit;
+  if (cont_bb)
+    {
+      l2_bb = create_empty_bb (cont_bb);
+      l3_bb = single_succ (cont_bb);
+
+      l2 = tree_block_label (l2_bb);
+      l3 = tree_block_label (l3_bb);
+    }
+
+  si = bsi_last (entry_bb);
+  gcc_assert (TREE_CODE (bsi_stmt (si)) == OMP_FOR);
+  if (!in_combined_parallel)
+    {
+      /* If this is not a combined parallel loop, emit a call to
+	 GOMP_loop_foo_start in ENTRY_BB.  */
+      list = alloc_stmt_list ();
+      t = build_fold_addr_expr (iend0);
+      args = tree_cons (NULL, t, NULL);
+      t = build_fold_addr_expr (istart0);
+      args = tree_cons (NULL, t, args);
+      if (fd->chunk_size)
+	{
+	  t = fold_convert (long_integer_type_node, fd->chunk_size);
+	  args = tree_cons (NULL, t, args);
+	}
+      t = fold_convert (long_integer_type_node, fd->step);
+      args = tree_cons (NULL, t, args);
+      t = fold_convert (long_integer_type_node, fd->n2);
+      args = tree_cons (NULL, t, args);
+      t = fold_convert (long_integer_type_node, fd->n1);
+      args = tree_cons (NULL, t, args);
+      t = build_function_call_expr (built_in_decls[start_fn], args);
+      t = get_formal_tmp_var (t, &list);
+      if (cont_bb)
+	{
+	  t = build3 (COND_EXPR, void_type_node, t, build_and_jump (&l0),
+		      build_and_jump (&l3));
+	  append_to_statement_list (t, &list);
+	}
+      bsi_insert_after (&si, list, BSI_SAME_STMT);
+    }
+  bsi_remove (&si, true);
+
+  /* Iteration setup for sequential loop goes in L0_BB.  */
+  list = alloc_stmt_list ();
+  t = fold_convert (type, istart0);
+  t = build2 (MODIFY_EXPR, void_type_node, fd->v, t);
+  gimplify_and_add (t, &list);
+
+  t = fold_convert (type, iend0);
+  t = build2 (MODIFY_EXPR, void_type_node, iend, t);
+  gimplify_and_add (t, &list);
+
+  si = bsi_start (l0_bb);
+  bsi_insert_after (&si, list, BSI_CONTINUE_LINKING);
+
+  /* Handle the rare case where BODY doesn't ever return.  */
+  if (cont_bb == NULL)
+    {
+      remove_edge (single_succ_edge (entry_bb));
+      make_edge (entry_bb, l0_bb, EDGE_FALLTHRU);
+      make_edge (l0_bb, l1_bb, EDGE_FALLTHRU);
+      return;
+    }
+
+  /* Code to control the increment and predicate for the sequential
+     loop goes in the first half of EXIT_BB (we split EXIT_BB so
+     that we can inherit all the edges going out of the loop
+     body).  */
+  list = alloc_stmt_list ();
+
+  t = build2 (PLUS_EXPR, type, fd->v, fd->step);
+  t = build2 (MODIFY_EXPR, void_type_node, fd->v, t);
+  gimplify_and_add (t, &list);
+  
+  t = build2 (fd->cond_code, boolean_type_node, fd->v, iend);
+  t = get_formal_tmp_var (t, &list);
+  t = build3 (COND_EXPR, void_type_node, t, build_and_jump (&l1),
+	      build_and_jump (&l2));
+  append_to_statement_list (t, &list);
+
+  si = bsi_last (cont_bb);
+  bsi_insert_after (&si, list, BSI_SAME_STMT);
+  gcc_assert (TREE_CODE (bsi_stmt (si)) == OMP_CONTINUE);
+  bsi_remove (&si, true);
+
+  /* Emit code to get the next parallel iteration in L2_BB.  */
+  list = alloc_stmt_list ();
+
+  t = build_fold_addr_expr (iend0);
+  args = tree_cons (NULL, t, NULL);
+  t = build_fold_addr_expr (istart0);
+  args = tree_cons (NULL, t, args);
+  t = build_function_call_expr (built_in_decls[next_fn], args);
+  t = get_formal_tmp_var (t, &list);
+  t = build3 (COND_EXPR, void_type_node, t, build_and_jump (&l0),
+	      build_and_jump (&l3));
+  append_to_statement_list (t, &list);
+  
+  si = bsi_start (l2_bb);
+  bsi_insert_after (&si, list, BSI_CONTINUE_LINKING);
+
+  /* Add the loop cleanup function.  */
+  si = bsi_last (exit_bb);
+  if (OMP_RETURN_NOWAIT (bsi_stmt (si)))
+    t = built_in_decls[BUILT_IN_GOMP_LOOP_END_NOWAIT];
+  else
+    t = built_in_decls[BUILT_IN_GOMP_LOOP_END];
+  t = build_function_call_expr (t, NULL);
+  bsi_insert_after (&si, t, BSI_SAME_STMT);
+  bsi_remove (&si, true);
+
+  /* Connect the new blocks.  */
+  remove_edge (single_succ_edge (entry_bb));
+  if (in_combined_parallel)
+    make_edge (entry_bb, l2_bb, EDGE_FALLTHRU);
+  else
+    {
+      make_edge (entry_bb, l0_bb, EDGE_TRUE_VALUE);
+      make_edge (entry_bb, l3_bb, EDGE_FALSE_VALUE);
+    }
+
+  make_edge (l0_bb, l1_bb, EDGE_FALLTHRU);
+
+  remove_edge (single_succ_edge (cont_bb));
+  make_edge (cont_bb, l1_bb, EDGE_TRUE_VALUE);
+  make_edge (cont_bb, l2_bb, EDGE_FALSE_VALUE);
+
+  make_edge (l2_bb, l0_bb, EDGE_TRUE_VALUE);
+  make_edge (l2_bb, l3_bb, EDGE_FALSE_VALUE);
+}
+
+
+/* A subroutine of expand_omp_for.  Generate code for a parallel
+   loop with static schedule and no specified chunk size.  Given
+   parameters:
+
+	for (V = N1; V cond N2; V += STEP) BODY;
+
+   where COND is "<" or ">", we generate pseudocode
+
+	if (cond is <)
+	  adj = STEP - 1;
+	else
+	  adj = STEP + 1;
+	n = (adj + N2 - N1) / STEP;
+	q = n / nthreads;
+	q += (q * nthreads != n);
+	s0 = q * threadid;
+	e0 = min(s0 + q, n);
+	if (s0 >= e0) goto L2; else goto L0;
+    L0:
+	V = s0 * STEP + N1;
+	e = e0 * STEP + N1;
+    L1:
+	BODY;
+	V += STEP;
+	if (V cond e) goto L1;
+    L2:
+*/
+
+static void
+expand_omp_for_static_nochunk (struct omp_region *region,
+			       struct omp_for_data *fd)
+{
+  tree l0, l1, l2, n, q, s0, e0, e, t, nthreads, threadid;
+  tree type, list;
+  basic_block entry_bb, exit_bb, seq_start_bb, body_bb, cont_bb;
+  basic_block fin_bb;
+  block_stmt_iterator si;
+
+  type = TREE_TYPE (fd->v);
+
+  entry_bb = region->entry;
+  seq_start_bb = create_empty_bb (entry_bb);
+  body_bb = single_succ (entry_bb);
+  cont_bb = region->cont;
+  fin_bb = single_succ (cont_bb);
+  exit_bb = region->exit;
+
+  l0 = tree_block_label (seq_start_bb);
+  l1 = tree_block_label (body_bb);
+  l2 = tree_block_label (fin_bb);
+
+  /* Iteration space partitioning goes in ENTRY_BB.  */
+  list = alloc_stmt_list ();
+
+  t = built_in_decls[BUILT_IN_OMP_GET_NUM_THREADS];
+  t = build_function_call_expr (t, NULL);
+  t = fold_convert (type, t);
+  nthreads = get_formal_tmp_var (t, &list);
+  
+  t = built_in_decls[BUILT_IN_OMP_GET_THREAD_NUM];
+  t = build_function_call_expr (t, NULL);
+  t = fold_convert (type, t);
+  threadid = get_formal_tmp_var (t, &list);
+
+  fd->n1 = fold_convert (type, fd->n1);
+  if (!is_gimple_val (fd->n1))
+    fd->n1 = get_formal_tmp_var (fd->n1, &list);
+
+  fd->n2 = fold_convert (type, fd->n2);
+  if (!is_gimple_val (fd->n2))
+    fd->n2 = get_formal_tmp_var (fd->n2, &list);
+
+  fd->step = fold_convert (type, fd->step);
+  if (!is_gimple_val (fd->step))
+    fd->step = get_formal_tmp_var (fd->step, &list);
+
+  t = build_int_cst (type, (fd->cond_code == LT_EXPR ? -1 : 1));
+  t = fold_build2 (PLUS_EXPR, type, fd->step, t);
+  t = fold_build2 (PLUS_EXPR, type, t, fd->n2);
+  t = fold_build2 (MINUS_EXPR, type, t, fd->n1);
+  t = fold_build2 (TRUNC_DIV_EXPR, type, t, fd->step);
+  t = fold_convert (type, t);
+  if (is_gimple_val (t))
+    n = t;
+  else
+    n = get_formal_tmp_var (t, &list);
+
+  t = build2 (TRUNC_DIV_EXPR, type, n, nthreads);
+  q = get_formal_tmp_var (t, &list);
+
+  t = build2 (MULT_EXPR, type, q, nthreads);
+  t = build2 (NE_EXPR, type, t, n);
+  t = build2 (PLUS_EXPR, type, q, t);
+  q = get_formal_tmp_var (t, &list);
+
+  t = build2 (MULT_EXPR, type, q, threadid);
+  s0 = get_formal_tmp_var (t, &list);
+
+  t = build2 (PLUS_EXPR, type, s0, q);
+  t = build2 (MIN_EXPR, type, t, n);
+  e0 = get_formal_tmp_var (t, &list);
+
+  t = build2 (GE_EXPR, boolean_type_node, s0, e0);
+  t = build3 (COND_EXPR, void_type_node, t, build_and_jump (&l2),
+	      build_and_jump (&l0));
+  append_to_statement_list (t, &list);
+
+  si = bsi_last (entry_bb);
+  gcc_assert (TREE_CODE (bsi_stmt (si)) == OMP_FOR);
+  bsi_insert_after (&si, list, BSI_SAME_STMT);
+  bsi_remove (&si, true);
+
+  /* Setup code for sequential iteration goes in SEQ_START_BB.  */
+  list = alloc_stmt_list ();
+
+  t = fold_convert (type, s0);
+  t = build2 (MULT_EXPR, type, t, fd->step);
+  t = build2 (PLUS_EXPR, type, t, fd->n1);
+  t = build2 (MODIFY_EXPR, void_type_node, fd->v, t);
+  gimplify_and_add (t, &list);
+
+  t = fold_convert (type, e0);
+  t = build2 (MULT_EXPR, type, t, fd->step);
+  t = build2 (PLUS_EXPR, type, t, fd->n1);
+  e = get_formal_tmp_var (t, &list);
+
+  si = bsi_start (seq_start_bb);
+  bsi_insert_after (&si, list, BSI_CONTINUE_LINKING);
+
+  /* The code controlling the sequential loop replaces the OMP_CONTINUE.  */
+  list = alloc_stmt_list ();
+
+  t = build2 (PLUS_EXPR, type, fd->v, fd->step);
+  t = build2 (MODIFY_EXPR, void_type_node, fd->v, t);
+  gimplify_and_add (t, &list);
+
+  t = build2 (fd->cond_code, boolean_type_node, fd->v, e);
+  t = get_formal_tmp_var (t, &list);
+  t = build3 (COND_EXPR, void_type_node, t, build_and_jump (&l1),
+	      build_and_jump (&l2));
+  append_to_statement_list (t, &list);
+
+  si = bsi_last (cont_bb);
+  gcc_assert (TREE_CODE (bsi_stmt (si)) == OMP_CONTINUE);
+  bsi_insert_after (&si, list, BSI_SAME_STMT);
+  bsi_remove (&si, true);
+
+  /* Replace the OMP_RETURN with a barrier, or nothing.  */
+  si = bsi_last (exit_bb);
+  if (!OMP_RETURN_NOWAIT (bsi_stmt (si)))
+    {
+      list = alloc_stmt_list ();
+      build_omp_barrier (&list);
+      bsi_insert_after (&si, list, BSI_SAME_STMT);
+    }
+  bsi_remove (&si, true);
+
+  /* Connect all the blocks.  */
+  make_edge (seq_start_bb, body_bb, EDGE_FALLTHRU);
+
+  remove_edge (single_succ_edge (entry_bb));
+  make_edge (entry_bb, fin_bb, EDGE_TRUE_VALUE);
+  make_edge (entry_bb, seq_start_bb, EDGE_FALSE_VALUE);
+
+  make_edge (cont_bb, body_bb, EDGE_TRUE_VALUE);
+  find_edge (cont_bb, fin_bb)->flags = EDGE_FALSE_VALUE;
+}
+
+
+/* A subroutine of expand_omp_for.  Generate code for a parallel
+   loop with static schedule and a specified chunk size.  Given
+   parameters:
+
+	for (V = N1; V cond N2; V += STEP) BODY;
+
+   where COND is "<" or ">", we generate pseudocode
+
+	if (cond is <)
+	  adj = STEP - 1;
+	else
+	  adj = STEP + 1;
+	n = (adj + N2 - N1) / STEP;
+	trip = 0;
+    L0:
+	s0 = (trip * nthreads + threadid) * CHUNK;
+	e0 = min(s0 + CHUNK, n);
+	if (s0 < n) goto L1; else goto L4;
+    L1:
+	V = s0 * STEP + N1;
+	e = e0 * STEP + N1;
+    L2:
+	BODY;
+	V += STEP;
+	if (V cond e) goto L2; else goto L3;
+    L3:
+	trip += 1;
+	goto L0;
+    L4:
+*/
+
+static void
+expand_omp_for_static_chunk (struct omp_region *region, struct omp_for_data *fd)
+{
+  tree l0, l1, l2, l3, l4, n, s0, e0, e, t;
+  tree trip, nthreads, threadid;
+  tree type;
+  basic_block entry_bb, exit_bb, body_bb, seq_start_bb, iter_part_bb;
+  basic_block trip_update_bb, cont_bb, fin_bb;
+  tree list;
+  block_stmt_iterator si;
+
+  type = TREE_TYPE (fd->v);
+
+  entry_bb = region->entry;
+  iter_part_bb = create_empty_bb (entry_bb);
+  seq_start_bb = create_empty_bb (iter_part_bb);
+  body_bb = single_succ (entry_bb);
+  cont_bb = region->cont;
+  trip_update_bb = create_empty_bb (cont_bb);
+  fin_bb = single_succ (cont_bb);
+  exit_bb = region->exit;
+
+  l0 = tree_block_label (iter_part_bb);
+  l1 = tree_block_label (seq_start_bb);
+  l2 = tree_block_label (body_bb);
+  l3 = tree_block_label (trip_update_bb);
+  l4 = tree_block_label (fin_bb);
+
+  /* Trip and adjustment setup goes in ENTRY_BB.  */
+  list = alloc_stmt_list ();
+
+  t = built_in_decls[BUILT_IN_OMP_GET_NUM_THREADS];
+  t = build_function_call_expr (t, NULL);
+  t = fold_convert (type, t);
+  nthreads = get_formal_tmp_var (t, &list);
+  
+  t = built_in_decls[BUILT_IN_OMP_GET_THREAD_NUM];
+  t = build_function_call_expr (t, NULL);
+  t = fold_convert (type, t);
+  threadid = get_formal_tmp_var (t, &list);
+
+  fd->n1 = fold_convert (type, fd->n1);
+  if (!is_gimple_val (fd->n1))
+    fd->n1 = get_formal_tmp_var (fd->n1, &list);
+
+  fd->n2 = fold_convert (type, fd->n2);
+  if (!is_gimple_val (fd->n2))
+    fd->n2 = get_formal_tmp_var (fd->n2, &list);
+
+  fd->step = fold_convert (type, fd->step);
+  if (!is_gimple_val (fd->step))
+    fd->step = get_formal_tmp_var (fd->step, &list);
+
+  fd->chunk_size = fold_convert (type, fd->chunk_size);
+  if (!is_gimple_val (fd->chunk_size))
+    fd->chunk_size = get_formal_tmp_var (fd->chunk_size, &list);
+
+  t = build_int_cst (type, (fd->cond_code == LT_EXPR ? -1 : 1));
+  t = fold_build2 (PLUS_EXPR, type, fd->step, t);
+  t = fold_build2 (PLUS_EXPR, type, t, fd->n2);
+  t = fold_build2 (MINUS_EXPR, type, t, fd->n1);
+  t = fold_build2 (TRUNC_DIV_EXPR, type, t, fd->step);
+  t = fold_convert (type, t);
+  if (is_gimple_val (t))
+    n = t;
+  else
+    n = get_formal_tmp_var (t, &list);
+
+  t = build_int_cst (type, 0);
+  trip = get_initialized_tmp_var (t, &list, NULL);
+
+  si = bsi_last (entry_bb);
+  gcc_assert (TREE_CODE (bsi_stmt (si)) == OMP_FOR);
+  bsi_insert_after (&si, list, BSI_SAME_STMT);
+  bsi_remove (&si, true);
+
+  /* Iteration space partitioning goes in ITER_PART_BB.  */
+  list = alloc_stmt_list ();
+
+  t = build2 (MULT_EXPR, type, trip, nthreads);
+  t = build2 (PLUS_EXPR, type, t, threadid);
+  t = build2 (MULT_EXPR, type, t, fd->chunk_size);
+  s0 = get_formal_tmp_var (t, &list);
+
+  t = build2 (PLUS_EXPR, type, s0, fd->chunk_size);
+  t = build2 (MIN_EXPR, type, t, n);
+  e0 = get_formal_tmp_var (t, &list);
+
+  t = build2 (LT_EXPR, boolean_type_node, s0, n);
+  t = build3 (COND_EXPR, void_type_node, t,
+	      build_and_jump (&l1), build_and_jump (&l4));
+  append_to_statement_list (t, &list);
+
+  si = bsi_start (iter_part_bb);
+  bsi_insert_after (&si, list, BSI_CONTINUE_LINKING);
+
+  /* Setup code for sequential iteration goes in SEQ_START_BB.  */
+  list = alloc_stmt_list ();
+
+  t = fold_convert (type, s0);
+  t = build2 (MULT_EXPR, type, t, fd->step);
+  t = build2 (PLUS_EXPR, type, t, fd->n1);
+  t = build2 (MODIFY_EXPR, void_type_node, fd->v, t);
+  gimplify_and_add (t, &list);
+
+  t = fold_convert (type, e0);
+  t = build2 (MULT_EXPR, type, t, fd->step);
+  t = build2 (PLUS_EXPR, type, t, fd->n1);
+  e = get_formal_tmp_var (t, &list);
+
+  si = bsi_start (seq_start_bb);
+  bsi_insert_after (&si, list, BSI_CONTINUE_LINKING);
+
+  /* The code controlling the sequential loop goes in CONT_BB,
+     replacing the OMP_CONTINUE.  */
+  list = alloc_stmt_list ();
+
+  t = build2 (PLUS_EXPR, type, fd->v, fd->step);
+  t = build2 (MODIFY_EXPR, void_type_node, fd->v, t);
+  gimplify_and_add (t, &list);
+
+  t = build2 (fd->cond_code, boolean_type_node, fd->v, e);
+  t = get_formal_tmp_var (t, &list);
+  t = build3 (COND_EXPR, void_type_node, t,
+	      build_and_jump (&l2), build_and_jump (&l3));
+  append_to_statement_list (t, &list);
+  
+  si = bsi_last (cont_bb);
+  gcc_assert (TREE_CODE (bsi_stmt (si)) == OMP_CONTINUE);
+  bsi_insert_after (&si, list, BSI_SAME_STMT);
+  bsi_remove (&si, true);
+
+  /* Trip update code goes into TRIP_UPDATE_BB.  */
+  list = alloc_stmt_list ();
+
+  t = build_int_cst (type, 1);
+  t = build2 (PLUS_EXPR, type, trip, t);
+  t = build2 (MODIFY_EXPR, void_type_node, trip, t);
+  gimplify_and_add (t, &list);
+
+  si = bsi_start (trip_update_bb);
+  bsi_insert_after (&si, list, BSI_CONTINUE_LINKING);
+
+  /* Replace the OMP_RETURN with a barrier, or nothing.  */
+  si = bsi_last (exit_bb);
+  if (!OMP_RETURN_NOWAIT (bsi_stmt (si)))
+    {
+      list = alloc_stmt_list ();
+      build_omp_barrier (&list);
+      bsi_insert_after (&si, list, BSI_SAME_STMT);
+    }
+  bsi_remove (&si, true);
+
+  /* Connect the new blocks.  */
+  remove_edge (single_succ_edge (entry_bb));
+  make_edge (entry_bb, iter_part_bb, EDGE_FALLTHRU);
+
+  make_edge (iter_part_bb, seq_start_bb, EDGE_TRUE_VALUE);
+  make_edge (iter_part_bb, fin_bb, EDGE_FALSE_VALUE);
+
+  make_edge (seq_start_bb, body_bb, EDGE_FALLTHRU);
+
+  remove_edge (single_succ_edge (cont_bb));
+  make_edge (cont_bb, body_bb, EDGE_TRUE_VALUE);
+  make_edge (cont_bb, trip_update_bb, EDGE_FALSE_VALUE);
+
+  make_edge (trip_update_bb, iter_part_bb, EDGE_FALLTHRU);
+}
+
+
+/* Expand the OpenMP loop defined by REGION.  */
+
+static void
+expand_omp_for (struct omp_region *region)
+{
+  struct omp_for_data fd;
+
+  push_gimplify_context ();
+
+  extract_omp_for_data (last_stmt (region->entry), &fd);
+  region->sched_kind = fd.sched_kind;
+
+  if (fd.sched_kind == OMP_CLAUSE_SCHEDULE_STATIC
+      && !fd.have_ordered
+      && region->cont
+      && region->exit)
+    {
+      if (fd.chunk_size == NULL)
+	expand_omp_for_static_nochunk (region, &fd);
+      else
+	expand_omp_for_static_chunk (region, &fd);
+    }
+  else
+    {
+      int fn_index = fd.sched_kind + fd.have_ordered * 4;
+      int start_ix = BUILT_IN_GOMP_LOOP_STATIC_START + fn_index;
+      int next_ix = BUILT_IN_GOMP_LOOP_STATIC_NEXT + fn_index;
+      expand_omp_for_generic (region, &fd, start_ix, next_ix);
+    }
+
+  pop_gimplify_context (NULL);
+}
+
+
+/* Expand code for an OpenMP sections directive.  In pseudo code, we generate
+
+	v = GOMP_sections_start (n);
+    L0:
+	switch (v)
+	  {
+	  case 0:
+	    goto L2;
+	  case 1:
+	    section 1;
+	    goto L1;
+	  case 2:
+	    ...
+	  case n:
+	    ...
+	  default:
+	    abort ();
+	  }
+    L1:
+	v = GOMP_sections_next ();
+	goto L0;
+    L2:
+	reduction;
+
+    If this is a combined parallel sections, replace the call to
+    GOMP_sections_start with 'goto L1'.  */
+
+static void
+expand_omp_sections (struct omp_region *region)
+{
+  tree label_vec, l0, l1, l2, t, u, v, sections_stmt;
+  unsigned i, len;
+  basic_block entry_bb, exit_bb, l0_bb, l1_bb, l2_bb, default_bb;
+  block_stmt_iterator si;
+  struct omp_region *inner;
+  edge e;
+
+  entry_bb = region->entry;
+  l0_bb = create_empty_bb (entry_bb);
+  l0 = tree_block_label (l0_bb);
+
+  gcc_assert ((region->cont != NULL) ^ (region->exit == NULL));
+  l1_bb = region->cont;
+  if (l1_bb)
+    {
+      l2_bb = single_succ (l1_bb);
+      default_bb = create_empty_bb (l1_bb->prev_bb);
+
+      l1 = tree_block_label (l1_bb);
+    }
+  else
+    {
+      l2_bb = create_empty_bb (l0_bb);
+      default_bb = l2_bb;
+
+      l1 = NULL;
+    }
+  l2 = tree_block_label (l2_bb);
+
+  exit_bb = region->exit;
+
+  v = create_tmp_var (unsigned_type_node, ".section");
+
+  /* We will build a switch() with enough cases for all the
+     OMP_SECTION regions, a '0' case to handle the end of more work
+     and a default case to abort if something goes wrong.  */
+  len = EDGE_COUNT (entry_bb->succs);
+  label_vec = make_tree_vec (len + 2);
+
+  /* The call to GOMP_sections_start goes in ENTRY_BB, replacing the
+     OMP_SECTIONS statement.  */
+  si = bsi_last (entry_bb);
+  sections_stmt = bsi_stmt (si);
+  gcc_assert (TREE_CODE (sections_stmt) == OMP_SECTIONS);
+  if (!is_combined_parallel (region))
+    {
+      /* If we are not inside a combined parallel+sections region,
+	 call GOMP_sections_start.  */
+      t = build_int_cst (unsigned_type_node, len);
+      t = tree_cons (NULL, t, NULL);
+      u = built_in_decls[BUILT_IN_GOMP_SECTIONS_START];
+      t = build_function_call_expr (u, t);
+      t = build2 (MODIFY_EXPR, void_type_node, v, t);
+      bsi_insert_after (&si, t, BSI_SAME_STMT);
+    }
+  bsi_remove (&si, true);
+
+  /* The switch() statement replacing OMP_SECTIONS goes in L0_BB.  */
+  si = bsi_start (l0_bb);
+
+  t = build3 (SWITCH_EXPR, void_type_node, v, NULL, label_vec);
+  bsi_insert_after (&si, t, BSI_CONTINUE_LINKING);
+
+  t = build3 (CASE_LABEL_EXPR, void_type_node,
+	      build_int_cst (unsigned_type_node, 0), NULL, l2);
+  TREE_VEC_ELT (label_vec, 0) = t;
+  make_edge (l0_bb, l2_bb, 0);
+
+  /* Convert each OMP_SECTION into a CASE_LABEL_EXPR.  */
+  for (inner = region->inner, i = 1; inner; inner = inner->next, ++i)
+    {
+      basic_block s_entry_bb, s_exit_bb;
+
+      s_entry_bb = inner->entry;
+      s_exit_bb = inner->exit;
+
+      t = tree_block_label (s_entry_bb);
+      u = build_int_cst (unsigned_type_node, i);
+      u = build3 (CASE_LABEL_EXPR, void_type_node, u, NULL, t);
+      TREE_VEC_ELT (label_vec, i) = u;
+
+      si = bsi_last (s_entry_bb);
+      gcc_assert (TREE_CODE (bsi_stmt (si)) == OMP_SECTION);
+      gcc_assert (i < len || OMP_SECTION_LAST (bsi_stmt (si)));
+      bsi_remove (&si, true);
+
+      e = single_pred_edge (s_entry_bb);
+      e->flags = 0;
+      redirect_edge_pred (e, l0_bb);
+
+      single_succ_edge (s_entry_bb)->flags = EDGE_FALLTHRU;
+
+      if (s_exit_bb == NULL)
+	continue;
+
+      si = bsi_last (s_exit_bb);
+      gcc_assert (TREE_CODE (bsi_stmt (si)) == OMP_RETURN);
+      bsi_remove (&si, true);
+
+      single_succ_edge (s_exit_bb)->flags = EDGE_FALLTHRU;
+    }
+
+  /* Error handling code goes in DEFAULT_BB.  */
+  t = tree_block_label (default_bb);
+  u = build3 (CASE_LABEL_EXPR, void_type_node, NULL, NULL, t);
+  TREE_VEC_ELT (label_vec, len + 1) = u;
+  make_edge (l0_bb, default_bb, 0);
+
+  si = bsi_start (default_bb);
+  t = built_in_decls[BUILT_IN_TRAP];
+  t = build_function_call_expr (t, NULL);
+  bsi_insert_after (&si, t, BSI_CONTINUE_LINKING);
+
+  /* Code to get the next section goes in L1_BB.  */
+  if (l1_bb)
+    {
+      si = bsi_last (l1_bb);
+      gcc_assert (TREE_CODE (bsi_stmt (si)) == OMP_CONTINUE);
+
+      t = built_in_decls[BUILT_IN_GOMP_SECTIONS_NEXT];
+      t = build_function_call_expr (t, NULL);
+      t = build2 (MODIFY_EXPR, void_type_node, v, t);
+      bsi_insert_after (&si, t, BSI_SAME_STMT);
+      bsi_remove (&si, true);
+    }
+
+  /* Cleanup function replaces OMP_RETURN in EXIT_BB.  */
+  if (exit_bb)
+    {
+      si = bsi_last (exit_bb);
+      if (OMP_RETURN_NOWAIT (bsi_stmt (si)))
+	t = built_in_decls[BUILT_IN_GOMP_SECTIONS_END_NOWAIT];
+      else
+	t = built_in_decls[BUILT_IN_GOMP_SECTIONS_END];
+      t = build_function_call_expr (t, NULL);
+      bsi_insert_after (&si, t, BSI_SAME_STMT);
+      bsi_remove (&si, true);
+    }
+
+  /* Connect the new blocks.  */
+  if (is_combined_parallel (region))
+    {
+      /* If this was a combined parallel+sections region, we did not
+	 emit a GOMP_sections_start in the entry block, so we just
+	 need to jump to L1_BB to get the next section.  */
+      make_edge (entry_bb, l1_bb, EDGE_FALLTHRU);
+    }
+  else
+    make_edge (entry_bb, l0_bb, EDGE_FALLTHRU);
+
+  if (l1_bb)
+    {
+      e = single_succ_edge (l1_bb);
+      redirect_edge_succ (e, l0_bb);
+      e->flags = EDGE_FALLTHRU;
+    }
+}
+
+
+/* Expand code for an OpenMP single directive.  We've already expanded
+   much of the code, here we simply place the GOMP_barrier call.  */
+
+static void
+expand_omp_single (struct omp_region *region)
+{
+  basic_block entry_bb, exit_bb;
+  block_stmt_iterator si;
+  bool need_barrier = false;
+
+  entry_bb = region->entry;
+  exit_bb = region->exit;
+
+  si = bsi_last (entry_bb);
+  /* The terminal barrier at the end of a GOMP_single_copy sequence cannot
+     be removed.  We need to ensure that the thread that entered the single
+     does not exit before the data is copied out by the other threads.  */
+  if (find_omp_clause (OMP_SINGLE_CLAUSES (bsi_stmt (si)),
+		       OMP_CLAUSE_COPYPRIVATE))
+    need_barrier = true;
+  gcc_assert (TREE_CODE (bsi_stmt (si)) == OMP_SINGLE);
+  bsi_remove (&si, true);
+  single_succ_edge (entry_bb)->flags = EDGE_FALLTHRU;
+
+  si = bsi_last (exit_bb);
+  if (!OMP_RETURN_NOWAIT (bsi_stmt (si)) || need_barrier)
+    {
+      tree t = alloc_stmt_list ();
+      build_omp_barrier (&t);
+      bsi_insert_after (&si, t, BSI_SAME_STMT);
+    }
+  bsi_remove (&si, true);
+  single_succ_edge (exit_bb)->flags = EDGE_FALLTHRU;
+}
+
+
+/* Generic expansion for OpenMP synchronization directives: master,
+   ordered and critical.  All we need to do here is remove the entry
+   and exit markers for REGION.  */
+
+static void
+expand_omp_synch (struct omp_region *region)
+{
+  basic_block entry_bb, exit_bb;
+  block_stmt_iterator si;
+
+  entry_bb = region->entry;
+  exit_bb = region->exit;
+
+  si = bsi_last (entry_bb);
+  gcc_assert (TREE_CODE (bsi_stmt (si)) == OMP_SINGLE
+	      || TREE_CODE (bsi_stmt (si)) == OMP_MASTER
+	      || TREE_CODE (bsi_stmt (si)) == OMP_ORDERED
+	      || TREE_CODE (bsi_stmt (si)) == OMP_CRITICAL);
+  bsi_remove (&si, true);
+  single_succ_edge (entry_bb)->flags = EDGE_FALLTHRU;
+
+  if (exit_bb)
+    {
+      si = bsi_last (exit_bb);
+      gcc_assert (TREE_CODE (bsi_stmt (si)) == OMP_RETURN);
+      bsi_remove (&si, true);
+      single_succ_edge (exit_bb)->flags = EDGE_FALLTHRU;
+    }
+}
+
+
+/* Expand the parallel region tree rooted at REGION.  Expansion
+   proceeds in depth-first order.  Innermost regions are expanded
+   first.  This way, parallel regions that require a new function to
+   be created (e.g., OMP_PARALLEL) can be expanded without having any
+   internal dependencies in their body.  */
+
+static void
+expand_omp (struct omp_region *region)
+{
+  while (region)
+    {
+      if (region->inner)
+	expand_omp (region->inner);
+
+      switch (region->type)
+	{
+	case OMP_PARALLEL:
+	  expand_omp_parallel (region);
+	  break;
+
+	case OMP_FOR:
+	  expand_omp_for (region);
+	  break;
+
+	case OMP_SECTIONS:
+	  expand_omp_sections (region);
+	  break;
+
+	case OMP_SECTION:
+	  /* Individual omp sections are handled together with their
+	     parent OMP_SECTIONS region.  */
+	  break;
+
+	case OMP_SINGLE:
+	  expand_omp_single (region);
+	  break;
+
+	case OMP_MASTER:
+	case OMP_ORDERED:
+	case OMP_CRITICAL:
+	  expand_omp_synch (region);
+	  break;
+
+	default:
+	  gcc_unreachable ();
+	}
+
+      region = region->next;
+    }
+}
+
+
+/* Helper for build_omp_regions.  Scan the dominator tree starting at
+   block BB.  PARENT is the region that contains BB.  */
+
+static void
+build_omp_regions_1 (basic_block bb, struct omp_region *parent)
+{
+  block_stmt_iterator si;
+  tree stmt;
+  basic_block son;
+
+  si = bsi_last (bb);
+  if (!bsi_end_p (si) && OMP_DIRECTIVE_P (bsi_stmt (si)))
+    {
+      struct omp_region *region;
+      enum tree_code code;
+
+      stmt = bsi_stmt (si);
+      code = TREE_CODE (stmt);
+
+      if (code == OMP_RETURN)
+	{
+	  /* STMT is the return point out of region PARENT.  Mark it
+	     as the exit point and make PARENT the immediately
+	     enclosing region.  */
+	  gcc_assert (parent);
+	  region = parent;
+	  region->exit = bb;
+	  parent = parent->outer;
+
+	  /* If REGION is a parallel region, determine whether it is
+	     a combined parallel+workshare region.  */
+	  if (region->type == OMP_PARALLEL)
+	    determine_parallel_type (region);
+	}
+      else if (code == OMP_CONTINUE)
+	{
+	  gcc_assert (parent);
+	  parent->cont = bb;
+	}
+      else
+	{
+	  /* Otherwise, this directive becomes the parent for a new
+	     region.  */
+	  region = new_omp_region (bb, code, parent);
+	  parent = region;
+	}
+    }
+
+  for (son = first_dom_son (CDI_DOMINATORS, bb);
+       son;
+       son = next_dom_son (CDI_DOMINATORS, son))
+    build_omp_regions_1 (son, parent);
+}
+
+
+/* Scan the CFG and build a tree of OMP regions.  Return the root of
+   the OMP region tree.  */
+
+static void
+build_omp_regions (void)
+{
+  gcc_assert (root_omp_region == NULL);
+  calculate_dominance_info (CDI_DOMINATORS);
+  build_omp_regions_1 (ENTRY_BLOCK_PTR, NULL);
+}
+
+
+/* Main entry point for expanding OMP-GIMPLE into runtime calls.  */
+
+static unsigned int
+execute_expand_omp (void)
+{
+  build_omp_regions ();
+
+  if (!root_omp_region)
+    return 0;
+
+  if (dump_file)
+    {
+      fprintf (dump_file, "\nOMP region tree\n\n");
+      dump_omp_region (dump_file, root_omp_region, 0);
+      fprintf (dump_file, "\n");
+    }
+
+  remove_exit_barriers (root_omp_region);
+
+  expand_omp (root_omp_region);
+
+  free_dominance_info (CDI_DOMINATORS);
+  free_dominance_info (CDI_POST_DOMINATORS);
+  cleanup_tree_cfg ();
+
+  free_omp_regions ();
+
+  return 0;
+}
+
+static bool
+gate_expand_omp (void)
+{
+  return flag_openmp != 0 && errorcount == 0;
+}
+
+struct tree_opt_pass pass_expand_omp = 
+{
+  "ompexp",				/* name */
+  gate_expand_omp,			/* gate */
+  execute_expand_omp,			/* execute */
+  NULL,					/* sub */
+  NULL,					/* next */
+  0,					/* static_pass_number */
+  0,					/* tv_id */
+  PROP_gimple_any,			/* properties_required */
+  PROP_gimple_lomp,			/* properties_provided */
+  0,					/* properties_destroyed */
+  0,					/* todo_flags_start */
+  TODO_dump_func,			/* todo_flags_finish */
+  0					/* letter */
+};
+
+/* Routines to lower OpenMP directives into OMP-GIMPLE.  */
+
+/* Lower the OpenMP sections directive in *STMT_P.  */
+
+static void
+lower_omp_sections (tree *stmt_p, omp_context *ctx)
+{
+  tree new_stmt, stmt, body, bind, block, ilist, olist, new_body;
+  tree t, dlist;
+  tree_stmt_iterator tsi;
+  unsigned i, len;
+
+  stmt = *stmt_p;
+
+  push_gimplify_context ();
+
+  dlist = NULL;
+  ilist = NULL;
+  lower_rec_input_clauses (OMP_SECTIONS_CLAUSES (stmt), &ilist, &dlist, ctx);
+
+  tsi = tsi_start (OMP_SECTIONS_BODY (stmt));
+  for (len = 0; !tsi_end_p (tsi); len++, tsi_next (&tsi))
+    continue;
+
+  tsi = tsi_start (OMP_SECTIONS_BODY (stmt));
+  body = alloc_stmt_list ();
+  for (i = 0; i < len; i++, tsi_next (&tsi))
+    {
+      omp_context *sctx;
+      tree sec_start, sec_end;
+
+      sec_start = tsi_stmt (tsi);
+      sctx = maybe_lookup_ctx (sec_start);
+      gcc_assert (sctx);
+
+      append_to_statement_list (sec_start, &body);
+
+      lower_omp (&OMP_SECTION_BODY (sec_start), sctx);
+      append_to_statement_list (OMP_SECTION_BODY (sec_start), &body);
+      OMP_SECTION_BODY (sec_start) = NULL;
+
+      if (i == len - 1)
+	{
+	  tree l = alloc_stmt_list ();
+	  lower_lastprivate_clauses (OMP_SECTIONS_CLAUSES (stmt), NULL,
+				     &l, ctx);
+	  append_to_statement_list (l, &body);
+	  OMP_SECTION_LAST (sec_start) = 1;
+	}
+      
+      sec_end = make_node (OMP_RETURN);
+      append_to_statement_list (sec_end, &body);
+    }
+
+  block = make_node (BLOCK);
+  bind = build3 (BIND_EXPR, void_type_node, NULL, body, block);
+
+  olist = NULL_TREE;
+  lower_reduction_clauses (OMP_SECTIONS_CLAUSES (stmt), &olist, ctx);
+
+  pop_gimplify_context (NULL_TREE);
+  record_vars_into (ctx->block_vars, ctx->cb.dst_fn);
+
+  new_stmt = build3 (BIND_EXPR, void_type_node, NULL, NULL, NULL);
+  TREE_SIDE_EFFECTS (new_stmt) = 1;
+
+  new_body = alloc_stmt_list ();
+  append_to_statement_list (ilist, &new_body);
+  append_to_statement_list (stmt, &new_body);
+  append_to_statement_list (bind, &new_body);
+
+  t = make_node (OMP_CONTINUE);
+  append_to_statement_list (t, &new_body);
+
+  append_to_statement_list (olist, &new_body);
+  append_to_statement_list (dlist, &new_body);
+
+  maybe_catch_exception (&new_body);
+
+  t = make_node (OMP_RETURN);
+  OMP_RETURN_NOWAIT (t) = !!find_omp_clause (OMP_SECTIONS_CLAUSES (stmt),
+					     OMP_CLAUSE_NOWAIT);
+  append_to_statement_list (t, &new_body);
+
+  BIND_EXPR_BODY (new_stmt) = new_body;
+  OMP_SECTIONS_BODY (stmt) = NULL;
+
+  *stmt_p = new_stmt;
+}
+
+
+/* A subroutine of lower_omp_single.  Expand the simple form of
+   an OMP_SINGLE, without a copyprivate clause:
+
+     	if (GOMP_single_start ())
+	  BODY;
+	[ GOMP_barrier (); ]	-> unless 'nowait' is present.
+
+  FIXME.  It may be better to delay expanding the logic of this until
+  pass_expand_omp.  The expanded logic may make the job more difficult
+  to a synchronization analysis pass.  */
+
+static void
+lower_omp_single_simple (tree single_stmt, tree *pre_p)
+{
+  tree t;
+
+  t = built_in_decls[BUILT_IN_GOMP_SINGLE_START];
+  t = build_function_call_expr (t, NULL);
+  t = build3 (COND_EXPR, void_type_node, t,
+	      OMP_SINGLE_BODY (single_stmt), NULL);
+  gimplify_and_add (t, pre_p);
+}
+
+
+/* A subroutine of lower_omp_single.  Expand the simple form of
+   an OMP_SINGLE, with a copyprivate clause:
+
+	#pragma omp single copyprivate (a, b, c)
+
+   Create a new structure to hold copies of 'a', 'b' and 'c' and emit:
+
+      {
+	if ((copyout_p = GOMP_single_copy_start ()) == NULL)
+	  {
+	    BODY;
+	    copyout.a = a;
+	    copyout.b = b;
+	    copyout.c = c;
+	    GOMP_single_copy_end (&copyout);
+	  }
+	else
+	  {
+	    a = copyout_p->a;
+	    b = copyout_p->b;
+	    c = copyout_p->c;
+	  }
+	GOMP_barrier ();
+      }
+
+  FIXME.  It may be better to delay expanding the logic of this until
+  pass_expand_omp.  The expanded logic may make the job more difficult
+  to a synchronization analysis pass.  */
+
+static void
+lower_omp_single_copy (tree single_stmt, tree *pre_p, omp_context *ctx)
+{
+  tree ptr_type, t, args, l0, l1, l2, copyin_seq;
+
+  ctx->sender_decl = create_tmp_var (ctx->record_type, ".omp_copy_o");
+
+  ptr_type = build_pointer_type (ctx->record_type);
+  ctx->receiver_decl = create_tmp_var (ptr_type, ".omp_copy_i");
+
+  l0 = create_artificial_label ();
+  l1 = create_artificial_label ();
+  l2 = create_artificial_label ();
+
+  t = built_in_decls[BUILT_IN_GOMP_SINGLE_COPY_START];
+  t = build_function_call_expr (t, NULL);
+  t = fold_convert (ptr_type, t);
+  t = build2 (MODIFY_EXPR, void_type_node, ctx->receiver_decl, t);
+  gimplify_and_add (t, pre_p);
+
+  t = build2 (EQ_EXPR, boolean_type_node, ctx->receiver_decl,
+	      build_int_cst (ptr_type, 0));
+  t = build3 (COND_EXPR, void_type_node, t,
+	      build_and_jump (&l0), build_and_jump (&l1));
+  gimplify_and_add (t, pre_p);
+
+  t = build1 (LABEL_EXPR, void_type_node, l0);
+  gimplify_and_add (t, pre_p);
+
+  append_to_statement_list (OMP_SINGLE_BODY (single_stmt), pre_p);
+
+  copyin_seq = NULL;
+  lower_copyprivate_clauses (OMP_SINGLE_CLAUSES (single_stmt), pre_p,
+			      &copyin_seq, ctx);
+
+  t = build_fold_addr_expr (ctx->sender_decl);
+  args = tree_cons (NULL, t, NULL);
+  t = built_in_decls[BUILT_IN_GOMP_SINGLE_COPY_END];
+  t = build_function_call_expr (t, args);
+  gimplify_and_add (t, pre_p);
+
+  t = build_and_jump (&l2);
+  gimplify_and_add (t, pre_p);
+
+  t = build1 (LABEL_EXPR, void_type_node, l1);
+  gimplify_and_add (t, pre_p);
+
+  append_to_statement_list (copyin_seq, pre_p);
+
+  t = build1 (LABEL_EXPR, void_type_node, l2);
+  gimplify_and_add (t, pre_p);
+}
+
+
+/* Expand code for an OpenMP single directive.  */
+
+static void
+lower_omp_single (tree *stmt_p, omp_context *ctx)
+{
+  tree t, bind, block, single_stmt = *stmt_p, dlist;
+
+  push_gimplify_context ();
+
+  block = make_node (BLOCK);
+  *stmt_p = bind = build3 (BIND_EXPR, void_type_node, NULL, NULL, block);
+  TREE_SIDE_EFFECTS (bind) = 1;
+
+  lower_rec_input_clauses (OMP_SINGLE_CLAUSES (single_stmt),
+			   &BIND_EXPR_BODY (bind), &dlist, ctx);
+  lower_omp (&OMP_SINGLE_BODY (single_stmt), ctx);
+
+  append_to_statement_list (single_stmt, &BIND_EXPR_BODY (bind));
+
+  if (ctx->record_type)
+    lower_omp_single_copy (single_stmt, &BIND_EXPR_BODY (bind), ctx);
+  else
+    lower_omp_single_simple (single_stmt, &BIND_EXPR_BODY (bind));
+
+  OMP_SINGLE_BODY (single_stmt) = NULL;
+
+  append_to_statement_list (dlist, &BIND_EXPR_BODY (bind));
+
+  maybe_catch_exception (&BIND_EXPR_BODY (bind));
+
+  t = make_node (OMP_RETURN);
+  OMP_RETURN_NOWAIT (t) = !!find_omp_clause (OMP_SINGLE_CLAUSES (single_stmt),
+					     OMP_CLAUSE_NOWAIT);
+  append_to_statement_list (t, &BIND_EXPR_BODY (bind));
+
+  pop_gimplify_context (bind);
+
+  BIND_EXPR_VARS (bind) = chainon (BIND_EXPR_VARS (bind), ctx->block_vars);
+  BLOCK_VARS (block) = BIND_EXPR_VARS (bind);
+}
+
+
+/* Expand code for an OpenMP master directive.  */
+
+static void
+lower_omp_master (tree *stmt_p, omp_context *ctx)
+{
+  tree bind, block, stmt = *stmt_p, lab = NULL, x;
+
+  push_gimplify_context ();
+
+  block = make_node (BLOCK);
+  *stmt_p = bind = build3 (BIND_EXPR, void_type_node, NULL, NULL, block);
+  TREE_SIDE_EFFECTS (bind) = 1;
+
+  append_to_statement_list (stmt, &BIND_EXPR_BODY (bind));
+
+  x = built_in_decls[BUILT_IN_OMP_GET_THREAD_NUM];
+  x = build_function_call_expr (x, NULL);
+  x = build2 (EQ_EXPR, boolean_type_node, x, integer_zero_node);
+  x = build3 (COND_EXPR, void_type_node, x, NULL, build_and_jump (&lab));
+  gimplify_and_add (x, &BIND_EXPR_BODY (bind));
+
+  lower_omp (&OMP_MASTER_BODY (stmt), ctx);
+  maybe_catch_exception (&OMP_MASTER_BODY (stmt));
+  append_to_statement_list (OMP_MASTER_BODY (stmt), &BIND_EXPR_BODY (bind));
+  OMP_MASTER_BODY (stmt) = NULL;
+
+  x = build1 (LABEL_EXPR, void_type_node, lab);
+  gimplify_and_add (x, &BIND_EXPR_BODY (bind));
+
+  x = make_node (OMP_RETURN);
+  OMP_RETURN_NOWAIT (x) = 1;
+  append_to_statement_list (x, &BIND_EXPR_BODY (bind));
+
+  pop_gimplify_context (bind);
+
+  BIND_EXPR_VARS (bind) = chainon (BIND_EXPR_VARS (bind), ctx->block_vars);
+  BLOCK_VARS (block) = BIND_EXPR_VARS (bind);
+}
+
+
+/* Expand code for an OpenMP ordered directive.  */
+
+static void
+lower_omp_ordered (tree *stmt_p, omp_context *ctx)
+{
+  tree bind, block, stmt = *stmt_p, x;
+
+  push_gimplify_context ();
+
+  block = make_node (BLOCK);
+  *stmt_p = bind = build3 (BIND_EXPR, void_type_node, NULL, NULL, block);
+  TREE_SIDE_EFFECTS (bind) = 1;
+
+  append_to_statement_list (stmt, &BIND_EXPR_BODY (bind));
+
+  x = built_in_decls[BUILT_IN_GOMP_ORDERED_START];
+  x = build_function_call_expr (x, NULL);
+  gimplify_and_add (x, &BIND_EXPR_BODY (bind));
+
+  lower_omp (&OMP_ORDERED_BODY (stmt), ctx);
+  maybe_catch_exception (&OMP_ORDERED_BODY (stmt));
+  append_to_statement_list (OMP_ORDERED_BODY (stmt), &BIND_EXPR_BODY (bind));
+  OMP_ORDERED_BODY (stmt) = NULL;
+
+  x = built_in_decls[BUILT_IN_GOMP_ORDERED_END];
+  x = build_function_call_expr (x, NULL);
+  gimplify_and_add (x, &BIND_EXPR_BODY (bind));
+
+  x = make_node (OMP_RETURN);
+  OMP_RETURN_NOWAIT (x) = 1;
+  append_to_statement_list (x, &BIND_EXPR_BODY (bind));
+
+  pop_gimplify_context (bind);
+
+  BIND_EXPR_VARS (bind) = chainon (BIND_EXPR_VARS (bind), ctx->block_vars);
+  BLOCK_VARS (block) = BIND_EXPR_VARS (bind);
+}
+
+
+/* Gimplify an OMP_CRITICAL statement.  This is a relatively simple
+   substitution of a couple of function calls.  But in the NAMED case,
+   requires that languages coordinate a symbol name.  It is therefore
+   best put here in common code.  */
+
+static GTY((param1_is (tree), param2_is (tree)))
+  splay_tree critical_name_mutexes;
+
+static void
+lower_omp_critical (tree *stmt_p, omp_context *ctx)
+{
+  tree bind, block, stmt = *stmt_p;
+  tree t, lock, unlock, name;
+
+  name = OMP_CRITICAL_NAME (stmt);
+  if (name)
+    {
+      tree decl, args;
+      splay_tree_node n;
+
+      if (!critical_name_mutexes)
+	critical_name_mutexes
+	  = splay_tree_new_ggc (splay_tree_compare_pointers);
+
+      n = splay_tree_lookup (critical_name_mutexes, (splay_tree_key) name);
+      if (n == NULL)
+	{
+	  char *new_str;
+
+	  decl = create_tmp_var_raw (ptr_type_node, NULL);
+
+	  new_str = ACONCAT ((".gomp_critical_user_",
+			      IDENTIFIER_POINTER (name), NULL));
+	  DECL_NAME (decl) = get_identifier (new_str);
+	  TREE_PUBLIC (decl) = 1;
+	  TREE_STATIC (decl) = 1;
+	  DECL_COMMON (decl) = 1;
+	  DECL_ARTIFICIAL (decl) = 1;
+	  DECL_IGNORED_P (decl) = 1;
+	  cgraph_varpool_finalize_decl (decl);
+
+	  splay_tree_insert (critical_name_mutexes, (splay_tree_key) name,
+			     (splay_tree_value) decl);
+	}
+      else
+	decl = (tree) n->value;
+
+      args = tree_cons (NULL, build_fold_addr_expr (decl), NULL);
+      lock = built_in_decls[BUILT_IN_GOMP_CRITICAL_NAME_START];
+      lock = build_function_call_expr (lock, args);
+
+      args = tree_cons (NULL, build_fold_addr_expr (decl), NULL);
+      unlock = built_in_decls[BUILT_IN_GOMP_CRITICAL_NAME_END];
+      unlock = build_function_call_expr (unlock, args);
+    }
+  else
+    {
+      lock = built_in_decls[BUILT_IN_GOMP_CRITICAL_START];
+      lock = build_function_call_expr (lock, NULL);
+
+      unlock = built_in_decls[BUILT_IN_GOMP_CRITICAL_END];
+      unlock = build_function_call_expr (unlock, NULL);
+    }
+
+  push_gimplify_context ();
+
+  block = make_node (BLOCK);
+  *stmt_p = bind = build3 (BIND_EXPR, void_type_node, NULL, NULL, block);
+  TREE_SIDE_EFFECTS (bind) = 1;
+
+  append_to_statement_list (stmt, &BIND_EXPR_BODY (bind));
+
+  gimplify_and_add (lock, &BIND_EXPR_BODY (bind));
+
+  lower_omp (&OMP_CRITICAL_BODY (stmt), ctx);
+  maybe_catch_exception (&OMP_CRITICAL_BODY (stmt));
+  append_to_statement_list (OMP_CRITICAL_BODY (stmt), &BIND_EXPR_BODY (bind));
+  OMP_CRITICAL_BODY (stmt) = NULL;
+
+  gimplify_and_add (unlock, &BIND_EXPR_BODY (bind));
+
+  t = make_node (OMP_RETURN);
+  OMP_RETURN_NOWAIT (t) = 1;
+  append_to_statement_list (t, &BIND_EXPR_BODY (bind));
+
+  pop_gimplify_context (bind);
+  BIND_EXPR_VARS (bind) = chainon (BIND_EXPR_VARS (bind), ctx->block_vars);
+  BLOCK_VARS (block) = BIND_EXPR_VARS (bind);
+}
+
+
+/* A subroutine of lower_omp_for.  Generate code to emit the predicate
+   for a lastprivate clause.  Given a loop control predicate of (V
+   cond N2), we gate the clause on (!(V cond N2)).  The lowered form
+   is appended to *DLIST, iterator initialization is appended to
+   *BODY_P.  */
+
+static void
+lower_omp_for_lastprivate (struct omp_for_data *fd, tree *body_p,
+			   tree *dlist, struct omp_context *ctx)
+{
+  tree clauses, cond, stmts, vinit, t;
+  enum tree_code cond_code;
+  
+  cond_code = fd->cond_code;
+  cond_code = cond_code == LT_EXPR ? GE_EXPR : LE_EXPR;
+
+  /* When possible, use a strict equality expression.  This can let VRP
+     type optimizations deduce the value and remove a copy.  */
+  if (host_integerp (fd->step, 0))
+    {
+      HOST_WIDE_INT step = TREE_INT_CST_LOW (fd->step);
+      if (step == 1 || step == -1)
+	cond_code = EQ_EXPR;
+    }
+
+  cond = build2 (cond_code, boolean_type_node, fd->v, fd->n2);
+
+  clauses = OMP_FOR_CLAUSES (fd->for_stmt);
+  stmts = NULL;
+  lower_lastprivate_clauses (clauses, cond, &stmts, ctx);
+  if (stmts != NULL)
+    {
+      append_to_statement_list (stmts, dlist);
+
+      /* Optimize: v = 0; is usually cheaper than v = some_other_constant.  */
+      vinit = fd->n1;
+      if (cond_code == EQ_EXPR
+	  && host_integerp (fd->n2, 0)
+	  && ! integer_zerop (fd->n2))
+	vinit = build_int_cst (TREE_TYPE (fd->v), 0);
+
+      /* Initialize the iterator variable, so that threads that don't execute
+	 any iterations don't execute the lastprivate clauses by accident.  */
+      t = build2 (MODIFY_EXPR, void_type_node, fd->v, vinit);
+      gimplify_and_add (t, body_p);
+    }
+}
+
+
+/* Lower code for an OpenMP loop directive.  */
+
+static void
+lower_omp_for (tree *stmt_p, omp_context *ctx)
+{
+  tree t, stmt, ilist, dlist, new_stmt, *body_p, *rhs_p;
+  struct omp_for_data fd;
+
+  stmt = *stmt_p;
+
+  push_gimplify_context ();
+
+  lower_omp (&OMP_FOR_PRE_BODY (stmt), ctx);
+  lower_omp (&OMP_FOR_BODY (stmt), ctx);
+
+  /* Move declaration of temporaries in the loop body before we make
+     it go away.  */
+  if (TREE_CODE (OMP_FOR_BODY (stmt)) == BIND_EXPR)
+    record_vars_into (BIND_EXPR_VARS (OMP_FOR_BODY (stmt)), ctx->cb.dst_fn);
+
+  new_stmt = build3 (BIND_EXPR, void_type_node, NULL, NULL, NULL);
+  TREE_SIDE_EFFECTS (new_stmt) = 1;
+  body_p = &BIND_EXPR_BODY (new_stmt);
+
+  /* The pre-body and input clauses go before the lowered OMP_FOR.  */
+  ilist = NULL;
+  dlist = NULL;
+  append_to_statement_list (OMP_FOR_PRE_BODY (stmt), body_p);
+  lower_rec_input_clauses (OMP_FOR_CLAUSES (stmt), body_p, &dlist, ctx);
+
+  /* Lower the header expressions.  At this point, we can assume that
+     the header is of the form:
+
+     	#pragma omp for (V = VAL1; V {<|>|<=|>=} VAL2; V = V [+-] VAL3)
+
+     We just need to make sure that VAL1, VAL2 and VAL3 are lowered
+     using the .omp_data_s mapping, if needed.  */
+  rhs_p = &TREE_OPERAND (OMP_FOR_INIT (stmt), 1);
+  if (!is_gimple_min_invariant (*rhs_p))
+    *rhs_p = get_formal_tmp_var (*rhs_p, body_p);
+
+  rhs_p = &TREE_OPERAND (OMP_FOR_COND (stmt), 1);
+  if (!is_gimple_min_invariant (*rhs_p))
+    *rhs_p = get_formal_tmp_var (*rhs_p, body_p);
+
+  rhs_p = &TREE_OPERAND (TREE_OPERAND (OMP_FOR_INCR (stmt), 1), 1);
+  if (!is_gimple_min_invariant (*rhs_p))
+    *rhs_p = get_formal_tmp_var (*rhs_p, body_p);
+
+  /* Once lowered, extract the bounds and clauses.  */
+  extract_omp_for_data (stmt, &fd);
+
+  lower_omp_for_lastprivate (&fd, body_p, &dlist, ctx);
+
+  append_to_statement_list (stmt, body_p);
+
+  append_to_statement_list (OMP_FOR_BODY (stmt), body_p);
+
+  t = make_node (OMP_CONTINUE);
+  append_to_statement_list (t, body_p);
+
+  /* After the loop, add exit clauses.  */
+  lower_reduction_clauses (OMP_FOR_CLAUSES (stmt), body_p, ctx);
+  append_to_statement_list (dlist, body_p);
+
+  maybe_catch_exception (body_p);
+
+  /* Region exit marker goes at the end of the loop body.  */
+  t = make_node (OMP_RETURN);
+  OMP_RETURN_NOWAIT (t) = fd.have_nowait;
+  append_to_statement_list (t, body_p);
+
+  pop_gimplify_context (NULL_TREE);
+  record_vars_into (ctx->block_vars, ctx->cb.dst_fn);
+
+  OMP_FOR_BODY (stmt) = NULL_TREE;
+  OMP_FOR_PRE_BODY (stmt) = NULL_TREE;
+  *stmt_p = new_stmt;
+}
+
+
+/* Lower the OpenMP parallel directive in *STMT_P.  CTX holds context
+   information for the directive.  */
+
+static void
+lower_omp_parallel (tree *stmt_p, omp_context *ctx)
+{
+  tree clauses, par_bind, par_body, new_body, bind;
+  tree olist, ilist, par_olist, par_ilist;
+  tree stmt, child_fn, t;
+
+  stmt = *stmt_p;
+
+  clauses = OMP_PARALLEL_CLAUSES (stmt);
+  par_bind = OMP_PARALLEL_BODY (stmt);
+  par_body = BIND_EXPR_BODY (par_bind);
+  child_fn = ctx->cb.dst_fn;
+
+  push_gimplify_context ();
+
+  par_olist = NULL_TREE;
+  par_ilist = NULL_TREE;
+  lower_rec_input_clauses (clauses, &par_ilist, &par_olist, ctx);
+  lower_omp (&par_body, ctx);
+  lower_reduction_clauses (clauses, &par_olist, ctx);
+
+  /* Declare all the variables created by mapping and the variables
+     declared in the scope of the parallel body.  */
+  record_vars_into (ctx->block_vars, child_fn);
+  record_vars_into (BIND_EXPR_VARS (par_bind), child_fn);
+
+  if (ctx->record_type)
+    {
+      ctx->sender_decl = create_tmp_var (ctx->record_type, ".omp_data_o");
+      OMP_PARALLEL_DATA_ARG (stmt) = ctx->sender_decl;
+    }
+
+  olist = NULL_TREE;
+  ilist = NULL_TREE;
+  lower_send_clauses (clauses, &ilist, &olist, ctx);
+  lower_send_shared_vars (&ilist, &olist, ctx);
+
+  /* Once all the expansions are done, sequence all the different
+     fragments inside OMP_PARALLEL_BODY.  */
+  bind = build3 (BIND_EXPR, void_type_node, NULL, NULL, NULL);
+  append_to_statement_list (ilist, &BIND_EXPR_BODY (bind));
+
+  new_body = alloc_stmt_list ();
+
+  if (ctx->record_type)
+    {
+      t = build_fold_addr_expr (ctx->sender_decl);
+      /* fixup_child_record_type might have changed receiver_decl's type.  */
+      t = fold_convert (TREE_TYPE (ctx->receiver_decl), t);
+      t = build2 (MODIFY_EXPR, void_type_node, ctx->receiver_decl, t);
+      append_to_statement_list (t, &new_body);
+    }
+
+  append_to_statement_list (par_ilist, &new_body);
+  append_to_statement_list (par_body, &new_body);
+  append_to_statement_list (par_olist, &new_body);
+  maybe_catch_exception (&new_body);
+  t = make_node (OMP_RETURN);
+  append_to_statement_list (t, &new_body);
+  OMP_PARALLEL_BODY (stmt) = new_body;
+
+  append_to_statement_list (stmt, &BIND_EXPR_BODY (bind));
+  append_to_statement_list (olist, &BIND_EXPR_BODY (bind));
+
+  *stmt_p = bind;
+
+  pop_gimplify_context (NULL_TREE);
+}
+
+
+/* Pass *TP back through the gimplifier within the context determined by WI.
+   This handles replacement of DECL_VALUE_EXPR, as well as adjusting the 
+   flags on ADDR_EXPR.  */
+
+static void
+lower_regimplify (tree *tp, struct walk_stmt_info *wi)
+{
+  enum gimplify_status gs;
+  tree pre = NULL;
+
+  if (wi->is_lhs)
+    gs = gimplify_expr (tp, &pre, NULL, is_gimple_lvalue, fb_lvalue);
+  else if (wi->val_only)
+    gs = gimplify_expr (tp, &pre, NULL, is_gimple_val, fb_rvalue);
+  else
+    gs = gimplify_expr (tp, &pre, NULL, is_gimple_formal_tmp_var, fb_rvalue);
+  gcc_assert (gs == GS_ALL_DONE);
+
+  if (pre)
+    tsi_link_before (&wi->tsi, pre, TSI_SAME_STMT);
+}
+
+/* Copy EXP into a temporary.  Insert the initialization statement before TSI.  */
+
+static tree
+init_tmp_var (tree exp, tree_stmt_iterator *tsi)
+{
+  tree t, stmt;
+
+  t = create_tmp_var (TREE_TYPE (exp), NULL);
+  if (TREE_CODE (TREE_TYPE (t)) == COMPLEX_TYPE)
+    DECL_COMPLEX_GIMPLE_REG_P (t) = 1;
+  stmt = build2 (MODIFY_EXPR, TREE_TYPE (t), t, exp);
+  SET_EXPR_LOCUS (stmt, EXPR_LOCUS (tsi_stmt (*tsi)));
+  tsi_link_before (tsi, stmt, TSI_SAME_STMT);
+
+  return t;
+}
+
+/* Similarly, but copy from the temporary and insert the statement
+   after the iterator.  */
+
+static tree
+save_tmp_var (tree exp, tree_stmt_iterator *tsi)
+{
+  tree t, stmt;
+
+  t = create_tmp_var (TREE_TYPE (exp), NULL);
+  if (TREE_CODE (TREE_TYPE (t)) == COMPLEX_TYPE)
+    DECL_COMPLEX_GIMPLE_REG_P (t) = 1;
+  stmt = build2 (MODIFY_EXPR, TREE_TYPE (t), exp, t);
+  SET_EXPR_LOCUS (stmt, EXPR_LOCUS (tsi_stmt (*tsi)));
+  tsi_link_after (tsi, stmt, TSI_SAME_STMT);
+
+  return t;
+}
+
+/* Callback for walk_stmts.  Lower the OpenMP directive pointed by TP.  */
+
+static tree
+lower_omp_1 (tree *tp, int *walk_subtrees, void *data)
+{
+  struct walk_stmt_info *wi = data;
+  omp_context *ctx = wi->info;
+  tree t = *tp;
+
+  /* If we have issued syntax errors, avoid doing any heavy lifting.
+     Just replace the OpenMP directives with a NOP to avoid
+     confusing RTL expansion.  */
+  if (errorcount && OMP_DIRECTIVE_P (*tp))
+    {
+      *tp = build_empty_stmt ();
+      return NULL_TREE;
+    }
+
+  *walk_subtrees = 0;
+  switch (TREE_CODE (*tp))
+    {
+    case OMP_PARALLEL:
+      ctx = maybe_lookup_ctx (t);
+      lower_omp_parallel (tp, ctx);
+      break;
+
+    case OMP_FOR:
+      ctx = maybe_lookup_ctx (t);
+      gcc_assert (ctx);
+      lower_omp_for (tp, ctx);
+      break;
+
+    case OMP_SECTIONS:
+      ctx = maybe_lookup_ctx (t);
+      gcc_assert (ctx);
+      lower_omp_sections (tp, ctx);
+      break;
+
+    case OMP_SINGLE:
+      ctx = maybe_lookup_ctx (t);
+      gcc_assert (ctx);
+      lower_omp_single (tp, ctx);
+      break;
+
+    case OMP_MASTER:
+      ctx = maybe_lookup_ctx (t);
+      gcc_assert (ctx);
+      lower_omp_master (tp, ctx);
+      break;
+
+    case OMP_ORDERED:
+      ctx = maybe_lookup_ctx (t);
+      gcc_assert (ctx);
+      lower_omp_ordered (tp, ctx);
+      break;
+
+    case OMP_CRITICAL:
+      ctx = maybe_lookup_ctx (t);
+      gcc_assert (ctx);
+      lower_omp_critical (tp, ctx);
+      break;
+
+    case VAR_DECL:
+      if (ctx && DECL_HAS_VALUE_EXPR_P (t))
+	{
+	  lower_regimplify (&t, wi);
+	  if (wi->val_only)
+	    {
+	      if (wi->is_lhs)
+		t = save_tmp_var (t, &wi->tsi);
+	      else
+		t = init_tmp_var (t, &wi->tsi);
+	    }
+	  *tp = t;
+	}
+      break;
+
+    case ADDR_EXPR:
+      if (ctx)
+	lower_regimplify (tp, wi);
+      break;
+
+    case ARRAY_REF:
+    case ARRAY_RANGE_REF:
+    case REALPART_EXPR:
+    case IMAGPART_EXPR:
+    case COMPONENT_REF:
+    case VIEW_CONVERT_EXPR:
+      if (ctx)
+	lower_regimplify (tp, wi);
+      break;
+
+    case INDIRECT_REF:
+      if (ctx)
+	{
+	  wi->is_lhs = false;
+	  wi->val_only = true;
+	  lower_regimplify (&TREE_OPERAND (t, 0), wi);
+	}
+      break;
+
+    default:
+      if (!TYPE_P (t) && !DECL_P (t))
+	*walk_subtrees = 1;
+      break;
+    }
+
+  return NULL_TREE;
+}
+
+static void
+lower_omp (tree *stmt_p, omp_context *ctx)
+{
+  struct walk_stmt_info wi;
+
+  memset (&wi, 0, sizeof (wi));
+  wi.callback = lower_omp_1;
+  wi.info = ctx;
+  wi.val_only = true;
+  wi.want_locations = true;
+
+  walk_stmts (&wi, stmt_p);
+}
+
+/* Main entry point.  */
+
+static unsigned int
+execute_lower_omp (void)
+{
+  all_contexts = splay_tree_new (splay_tree_compare_pointers, 0,
+				 delete_omp_context);
+
+  scan_omp (&DECL_SAVED_TREE (current_function_decl), NULL);
+  gcc_assert (parallel_nesting_level == 0);
+
+  if (all_contexts->root)
+    lower_omp (&DECL_SAVED_TREE (current_function_decl), NULL);
+
+  if (all_contexts)
+    {
+      splay_tree_delete (all_contexts);
+      all_contexts = NULL;
+    }
+  return 0;
+}
+
+static bool
+gate_lower_omp (void)
+{
+  return flag_openmp != 0;
+}
+
+struct tree_opt_pass pass_lower_omp = 
+{
+  "omplower",				/* name */
+  gate_lower_omp,			/* gate */
+  execute_lower_omp,			/* execute */
+  NULL,					/* sub */
+  NULL,					/* next */
+  0,					/* static_pass_number */
+  0,					/* tv_id */
+  PROP_gimple_any,			/* properties_required */
+  PROP_gimple_lomp,			/* properties_provided */
+  0,					/* properties_destroyed */
+  0,					/* todo_flags_start */
+  TODO_dump_func,			/* todo_flags_finish */
+  0					/* letter */
+};
+
+/* The following is a utility to diagnose OpenMP structured block violations.
+   It is not part of the "omplower" pass, as that's invoked too late.  It
+   should be invoked by the respective front ends after gimplification.  */
+
+static splay_tree all_labels;
+
+/* Check for mismatched contexts and generate an error if needed.  Return
+   true if an error is detected.  */
+
+static bool
+diagnose_sb_0 (tree *stmt_p, tree branch_ctx, tree label_ctx)
+{
+  bool exit_p = true;
+
+  if ((label_ctx ? TREE_VALUE (label_ctx) : NULL) == branch_ctx)
+    return false;
+
+  /* Try to avoid confusing the user by producing and error message
+     with correct "exit" or "enter" verbage.  We prefer "exit"
+     unless we can show that LABEL_CTX is nested within BRANCH_CTX.  */
+  if (branch_ctx == NULL)
+    exit_p = false;
+  else
+    {
+      while (label_ctx)
+	{
+	  if (TREE_VALUE (label_ctx) == branch_ctx)
+	    {
+	      exit_p = false;
+	      break;
+	    }
+	  label_ctx = TREE_CHAIN (label_ctx);
+	}
+    }
+
+  if (exit_p)
+    error ("invalid exit from OpenMP structured block");
+  else
+    error ("invalid entry to OpenMP structured block");
+
+  *stmt_p = build_empty_stmt ();
+  return true;
+}
+
+/* Pass 1: Create a minimal tree of OpenMP structured blocks, and record
+   where in the tree each label is found.  */
+
+static tree
+diagnose_sb_1 (tree *tp, int *walk_subtrees, void *data)
+{
+  struct walk_stmt_info *wi = data;
+  tree context = (tree) wi->info;
+  tree inner_context;
+  tree t = *tp;
+
+  *walk_subtrees = 0;
+  switch (TREE_CODE (t))
+    {
+    case OMP_PARALLEL:
+    case OMP_SECTIONS:
+    case OMP_SINGLE:
+      walk_tree (&OMP_CLAUSES (t), diagnose_sb_1, wi, NULL);
+      /* FALLTHRU */
+    case OMP_SECTION:
+    case OMP_MASTER:
+    case OMP_ORDERED:
+    case OMP_CRITICAL:
+      /* The minimal context here is just a tree of statements.  */
+      inner_context = tree_cons (NULL, t, context);
+      wi->info = inner_context;
+      walk_stmts (wi, &OMP_BODY (t));
+      wi->info = context;
+      break;
+
+    case OMP_FOR:
+      walk_tree (&OMP_FOR_CLAUSES (t), diagnose_sb_1, wi, NULL);
+      inner_context = tree_cons (NULL, t, context);
+      wi->info = inner_context;
+      walk_tree (&OMP_FOR_INIT (t), diagnose_sb_1, wi, NULL);
+      walk_tree (&OMP_FOR_COND (t), diagnose_sb_1, wi, NULL);
+      walk_tree (&OMP_FOR_INCR (t), diagnose_sb_1, wi, NULL);
+      walk_stmts (wi, &OMP_FOR_PRE_BODY (t));
+      walk_stmts (wi, &OMP_FOR_BODY (t));
+      wi->info = context;
+      break;
+
+    case LABEL_EXPR:
+      splay_tree_insert (all_labels, (splay_tree_key) LABEL_EXPR_LABEL (t),
+			 (splay_tree_value) context);
+      break;
+
+    default:
+      break;
+    }
+
+  return NULL_TREE;
+}
+
+/* Pass 2: Check each branch and see if its context differs from that of
+   the destination label's context.  */
+
+static tree
+diagnose_sb_2 (tree *tp, int *walk_subtrees, void *data)
+{
+  struct walk_stmt_info *wi = data;
+  tree context = (tree) wi->info;
+  splay_tree_node n;
+  tree t = *tp;
+
+  *walk_subtrees = 0;
+  switch (TREE_CODE (t))
+    {
+    case OMP_PARALLEL:
+    case OMP_SECTIONS:
+    case OMP_SINGLE:
+      walk_tree (&OMP_CLAUSES (t), diagnose_sb_2, wi, NULL);
+      /* FALLTHRU */
+    case OMP_SECTION:
+    case OMP_MASTER:
+    case OMP_ORDERED:
+    case OMP_CRITICAL:
+      wi->info = t;
+      walk_stmts (wi, &OMP_BODY (t));
+      wi->info = context;
+      break;
+
+    case OMP_FOR:
+      walk_tree (&OMP_FOR_CLAUSES (t), diagnose_sb_2, wi, NULL);
+      wi->info = t;
+      walk_tree (&OMP_FOR_INIT (t), diagnose_sb_2, wi, NULL);
+      walk_tree (&OMP_FOR_COND (t), diagnose_sb_2, wi, NULL);
+      walk_tree (&OMP_FOR_INCR (t), diagnose_sb_2, wi, NULL);
+      walk_stmts (wi, &OMP_FOR_PRE_BODY (t));
+      walk_stmts (wi, &OMP_FOR_BODY (t));
+      wi->info = context;
+      break;
+
+    case GOTO_EXPR:
+      {
+	tree lab = GOTO_DESTINATION (t);
+	if (TREE_CODE (lab) != LABEL_DECL)
+	  break;
+
+	n = splay_tree_lookup (all_labels, (splay_tree_key) lab);
+	diagnose_sb_0 (tp, context, n ? (tree) n->value : NULL_TREE);
+      }
+      break;
+
+    case SWITCH_EXPR:
+      {
+	tree vec = SWITCH_LABELS (t);
+	int i, len = TREE_VEC_LENGTH (vec);
+	for (i = 0; i < len; ++i)
+	  {
+	    tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i));
+	    n = splay_tree_lookup (all_labels, (splay_tree_key) lab);
+	    if (diagnose_sb_0 (tp, context, (tree) n->value))
+	      break;
+	  }
+      }
+      break;
+
+    case RETURN_EXPR:
+      diagnose_sb_0 (tp, context, NULL_TREE);
+      break;
+
+    default:
+      break;
+    }
+
+  return NULL_TREE;
+}
+
+void
+diagnose_omp_structured_block_errors (tree fndecl)
+{
+  tree save_current = current_function_decl;
+  struct walk_stmt_info wi;
+
+  current_function_decl = fndecl;
+
+  all_labels = splay_tree_new (splay_tree_compare_pointers, 0, 0);
+
+  memset (&wi, 0, sizeof (wi));
+  wi.callback = diagnose_sb_1;
+  walk_stmts (&wi, &DECL_SAVED_TREE (fndecl));
+
+  memset (&wi, 0, sizeof (wi));
+  wi.callback = diagnose_sb_2;
+  wi.want_locations = true;
+  wi.want_return_expr = true;
+  walk_stmts (&wi, &DECL_SAVED_TREE (fndecl));
+
+  splay_tree_delete (all_labels);
+  all_labels = NULL;
+
+  current_function_decl = save_current;
+}
+
+#include "gt-omp-low.h"