--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/tree-streamer.h	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,124 @@
+/* Data structures and functions for streaming trees.
+
+   Copyright (C) 2011-2017 Free Software Foundation, Inc.
+   Contributed by Diego Novillo <dnovillo@google.com>
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#ifndef GCC_TREE_STREAMER_H
+#define GCC_TREE_STREAMER_H
+
+#include "streamer-hooks.h"
+#include "data-streamer.h"
+
+/* Cache of pickled nodes.  Used to avoid writing the same node more
+   than once.  The first time a tree node is streamed out, it is
+   entered in this cache.  Subsequent references to the same node are
+   resolved by looking it up in this cache.
+
+   This is used in two ways:
+
+   - On the writing side, the first time T is added to STREAMER_CACHE,
+     a new reference index is created for T and T is emitted on the
+     stream.  If T needs to be emitted again to the stream, instead of
+     pickling it again, the reference index is emitted.
+
+   - On the reading side, the first time T is read from the stream, it
+     is reconstructed in memory and a new reference index created for
+     T.  The reconstructed T is inserted in some array so that when
+     the reference index for T is found in the input stream, it can be
+     used to look up into the array to get the reconstructed T.  */
+
+struct streamer_tree_cache_d
+{
+  /* The mapping between tree nodes and slots into the nodes array.  */
+  hash_map<tree, unsigned> *node_map;
+
+  /* The nodes pickled so far.  */
+  vec<tree> nodes;
+  /* The node hashes (if available).  */
+  vec<hashval_t> hashes;
+
+  /* Next index to assign.  */
+  unsigned next_idx;
+};
+
+/* In tree-streamer-in.c.  */
+tree streamer_read_string_cst (struct data_in *, struct lto_input_block *);
+tree streamer_read_chain (struct lto_input_block *, struct data_in *);
+tree streamer_alloc_tree (struct lto_input_block *, struct data_in *,
+		          enum LTO_tags);
+void streamer_read_tree_body (struct lto_input_block *, struct data_in *, tree);
+tree streamer_get_pickled_tree (struct lto_input_block *, struct data_in *);
+void streamer_read_tree_bitfields (struct lto_input_block *,
+				   struct data_in *, tree);
+
+/* In tree-streamer-out.c.  */
+void streamer_write_string_cst (struct output_block *,
+				struct lto_output_stream *, tree);
+void streamer_write_chain (struct output_block *, tree, bool);
+void streamer_write_tree_header (struct output_block *, tree);
+void streamer_write_tree_bitfields (struct output_block *, tree);
+void streamer_write_tree_body (struct output_block *, tree, bool);
+void streamer_write_integer_cst (struct output_block *, tree, bool);
+
+/* In tree-streamer.c.  */
+extern unsigned char streamer_mode_table[1 << 8];
+void streamer_check_handled_ts_structures (void);
+bool streamer_tree_cache_insert (struct streamer_tree_cache_d *, tree,
+				 hashval_t, unsigned *);
+void streamer_tree_cache_replace_tree (struct streamer_tree_cache_d *, tree,
+				       unsigned);
+void streamer_tree_cache_append (struct streamer_tree_cache_d *, tree,
+				 hashval_t);
+bool streamer_tree_cache_lookup (struct streamer_tree_cache_d *, tree,
+				 unsigned *);
+struct streamer_tree_cache_d *streamer_tree_cache_create (bool, bool, bool);
+void streamer_tree_cache_delete (struct streamer_tree_cache_d *);
+
+/* Return the tree node at slot IX in CACHE.  */
+
+static inline tree
+streamer_tree_cache_get_tree (struct streamer_tree_cache_d *cache, unsigned ix)
+{
+  return cache->nodes[ix];
+}
+
+/* Return the tree hash value at slot IX in CACHE.  */
+
+static inline hashval_t
+streamer_tree_cache_get_hash (struct streamer_tree_cache_d *cache, unsigned ix)
+{
+  return cache->hashes[ix];
+}
+
+static inline void
+bp_pack_machine_mode (struct bitpack_d *bp, machine_mode mode)
+{
+  streamer_mode_table[mode] = 1;
+  bp_pack_enum (bp, machine_mode, 1 << 8, mode);
+}
+
+static inline machine_mode
+bp_unpack_machine_mode (struct bitpack_d *bp)
+{
+  return (machine_mode)
+	   ((struct lto_input_block *)
+	    bp->stream)->mode_table[bp_unpack_enum (bp, machine_mode, 1 << 8)];
+}
+
+#endif  /* GCC_TREE_STREAMER_H  */