1 | /* Data structures and functions for streaming trees. |
2 | |
3 | Copyright (C) 2011-2017 Free Software Foundation, Inc. |
4 | Contributed by Diego Novillo <dnovillo@google.com> |
5 | |
6 | This file is part of GCC. |
7 | |
8 | GCC is free software; you can redistribute it and/or modify it under |
9 | the terms of the GNU General Public License as published by the Free |
10 | Software Foundation; either version 3, or (at your option) any later |
11 | version. |
12 | |
13 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
14 | WARRANTY; without even the implied warranty of MERCHANTABILITY or |
15 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
16 | for more details. |
17 | |
18 | You should have received a copy of the GNU General Public License |
19 | along with GCC; see the file COPYING3. If not see |
20 | <http://www.gnu.org/licenses/>. */ |
21 | |
22 | #ifndef GCC_TREE_STREAMER_H |
23 | #define GCC_TREE_STREAMER_H |
24 | |
25 | #include "streamer-hooks.h" |
26 | #include "data-streamer.h" |
27 | |
28 | /* Cache of pickled nodes. Used to avoid writing the same node more |
29 | than once. The first time a tree node is streamed out, it is |
30 | entered in this cache. Subsequent references to the same node are |
31 | resolved by looking it up in this cache. |
32 | |
33 | This is used in two ways: |
34 | |
35 | - On the writing side, the first time T is added to STREAMER_CACHE, |
36 | a new reference index is created for T and T is emitted on the |
37 | stream. If T needs to be emitted again to the stream, instead of |
38 | pickling it again, the reference index is emitted. |
39 | |
40 | - On the reading side, the first time T is read from the stream, it |
41 | is reconstructed in memory and a new reference index created for |
42 | T. The reconstructed T is inserted in some array so that when |
43 | the reference index for T is found in the input stream, it can be |
44 | used to look up into the array to get the reconstructed T. */ |
45 | |
46 | struct streamer_tree_cache_d |
47 | { |
48 | /* The mapping between tree nodes and slots into the nodes array. */ |
49 | hash_map<tree, unsigned> *node_map; |
50 | |
51 | /* The nodes pickled so far. */ |
52 | vec<tree> nodes; |
53 | /* The node hashes (if available). */ |
54 | vec<hashval_t> hashes; |
55 | |
56 | /* Next index to assign. */ |
57 | unsigned next_idx; |
58 | }; |
59 | |
60 | /* In tree-streamer-in.c. */ |
61 | tree streamer_read_string_cst (struct data_in *, struct lto_input_block *); |
62 | tree streamer_read_chain (struct lto_input_block *, struct data_in *); |
63 | tree streamer_alloc_tree (struct lto_input_block *, struct data_in *, |
64 | enum LTO_tags); |
65 | void streamer_read_tree_body (struct lto_input_block *, struct data_in *, tree); |
66 | tree streamer_get_pickled_tree (struct lto_input_block *, struct data_in *); |
67 | void streamer_read_tree_bitfields (struct lto_input_block *, |
68 | struct data_in *, tree); |
69 | |
70 | /* In tree-streamer-out.c. */ |
71 | void streamer_write_string_cst (struct output_block *, |
72 | struct lto_output_stream *, tree); |
73 | void streamer_write_chain (struct output_block *, tree, bool); |
74 | void (struct output_block *, tree); |
75 | void streamer_write_tree_bitfields (struct output_block *, tree); |
76 | void streamer_write_tree_body (struct output_block *, tree, bool); |
77 | void streamer_write_integer_cst (struct output_block *, tree, bool); |
78 | |
79 | /* In tree-streamer.c. */ |
80 | extern unsigned char streamer_mode_table[1 << 8]; |
81 | void streamer_check_handled_ts_structures (void); |
82 | bool streamer_tree_cache_insert (struct streamer_tree_cache_d *, tree, |
83 | hashval_t, unsigned *); |
84 | void streamer_tree_cache_replace_tree (struct streamer_tree_cache_d *, tree, |
85 | unsigned); |
86 | void streamer_tree_cache_append (struct streamer_tree_cache_d *, tree, |
87 | hashval_t); |
88 | bool streamer_tree_cache_lookup (struct streamer_tree_cache_d *, tree, |
89 | unsigned *); |
90 | struct streamer_tree_cache_d *streamer_tree_cache_create (bool, bool, bool); |
91 | void streamer_tree_cache_delete (struct streamer_tree_cache_d *); |
92 | |
93 | /* Return the tree node at slot IX in CACHE. */ |
94 | |
95 | static inline tree |
96 | streamer_tree_cache_get_tree (struct streamer_tree_cache_d *cache, unsigned ix) |
97 | { |
98 | return cache->nodes[ix]; |
99 | } |
100 | |
101 | /* Return the tree hash value at slot IX in CACHE. */ |
102 | |
103 | static inline hashval_t |
104 | streamer_tree_cache_get_hash (struct streamer_tree_cache_d *cache, unsigned ix) |
105 | { |
106 | return cache->hashes[ix]; |
107 | } |
108 | |
109 | static inline void |
110 | bp_pack_machine_mode (struct bitpack_d *bp, machine_mode mode) |
111 | { |
112 | streamer_mode_table[mode] = 1; |
113 | bp_pack_enum (bp, machine_mode, 1 << 8, mode); |
114 | } |
115 | |
116 | static inline machine_mode |
117 | bp_unpack_machine_mode (struct bitpack_d *bp) |
118 | { |
119 | return (machine_mode) |
120 | ((struct lto_input_block *) |
121 | bp->stream)->mode_table[bp_unpack_enum (bp, machine_mode, 1 << 8)]; |
122 | } |
123 | |
124 | #endif /* GCC_TREE_STREAMER_H */ |
125 | |