gcc/
[official-gcc.git] / gcc / data-streamer.h
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1 /* Generic streaming support for various data types.
3 Copyright (C) 2011-2015 Free Software Foundation, Inc.
4 Contributed by Diego Novillo <dnovillo@google.com>
6 This file is part of GCC.
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.
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.
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/>. */
22 #ifndef GCC_DATA_STREAMER_H
23 #define GCC_DATA_STREAMER_H
25 #include "vec.h"
26 #include "lto-streamer.h"
28 /* Data structures used to pack values and bitflags into a vector of
29 words. Used to stream values of a fixed number of bits in a space
30 efficient way. */
31 static unsigned const BITS_PER_BITPACK_WORD = HOST_BITS_PER_WIDE_INT;
33 typedef unsigned HOST_WIDE_INT bitpack_word_t;
35 struct bitpack_d
37 /* The position of the first unused or unconsumed bit in the word. */
38 unsigned pos;
40 /* The current word we are (un)packing. */
41 bitpack_word_t word;
43 /* The lto_output_stream or the lto_input_block we are streaming to/from. */
44 void *stream;
47 /* In data-streamer.c */
48 void bp_pack_var_len_unsigned (struct bitpack_d *, unsigned HOST_WIDE_INT);
49 void bp_pack_var_len_int (struct bitpack_d *, HOST_WIDE_INT);
50 unsigned HOST_WIDE_INT bp_unpack_var_len_unsigned (struct bitpack_d *);
51 HOST_WIDE_INT bp_unpack_var_len_int (struct bitpack_d *);
53 /* In data-streamer-out.c */
54 void streamer_write_zero (struct output_block *);
55 void streamer_write_uhwi (struct output_block *, unsigned HOST_WIDE_INT);
56 void streamer_write_hwi (struct output_block *, HOST_WIDE_INT);
57 void streamer_write_gcov_count (struct output_block *, gcov_type);
58 void streamer_write_string (struct output_block *, struct lto_output_stream *,
59 const char *, bool);
60 void streamer_write_string_with_length (struct output_block *,
61 struct lto_output_stream *,
62 const char *, unsigned int, bool);
63 void bp_pack_string_with_length (struct output_block *, struct bitpack_d *,
64 const char *, unsigned int, bool);
65 void bp_pack_string (struct output_block *, struct bitpack_d *,
66 const char *, bool);
67 void streamer_write_uhwi_stream (struct lto_output_stream *,
68 unsigned HOST_WIDE_INT);
69 void streamer_write_hwi_stream (struct lto_output_stream *, HOST_WIDE_INT);
70 void streamer_write_gcov_count_stream (struct lto_output_stream *, gcov_type);
71 void streamer_write_data_stream (struct lto_output_stream *, const void *,
72 size_t);
74 /* In data-streamer-in.c */
75 const char *streamer_read_string (struct data_in *, struct lto_input_block *);
76 const char *streamer_read_indexed_string (struct data_in *,
77 struct lto_input_block *,
78 unsigned int *);
79 const char *bp_unpack_indexed_string (struct data_in *, struct bitpack_d *,
80 unsigned int *);
81 const char *bp_unpack_string (struct data_in *, struct bitpack_d *);
82 unsigned HOST_WIDE_INT streamer_read_uhwi (struct lto_input_block *);
83 HOST_WIDE_INT streamer_read_hwi (struct lto_input_block *);
84 gcov_type streamer_read_gcov_count (struct lto_input_block *);
86 /* Returns a new bit-packing context for bit-packing into S. */
87 static inline struct bitpack_d
88 bitpack_create (struct lto_output_stream *s)
90 struct bitpack_d bp;
91 bp.pos = 0;
92 bp.word = 0;
93 bp.stream = (void *)s;
94 return bp;
97 /* Pack the NBITS bit sized value VAL into the bit-packing context BP. */
98 static inline void
99 bp_pack_value (struct bitpack_d *bp, bitpack_word_t val, unsigned nbits)
101 bitpack_word_t word = bp->word;
102 int pos = bp->pos;
104 /* Verify that VAL fits in the NBITS. */
105 gcc_checking_assert (nbits == BITS_PER_BITPACK_WORD
106 || !(val & ~(((bitpack_word_t)1<<nbits)-1)));
108 /* If val does not fit into the current bitpack word switch to the
109 next one. */
110 if (pos + nbits > BITS_PER_BITPACK_WORD)
112 streamer_write_uhwi_stream ((struct lto_output_stream *) bp->stream,
113 word);
114 word = val;
115 pos = nbits;
117 else
119 word |= val << pos;
120 pos += nbits;
122 bp->word = word;
123 bp->pos = pos;
126 /* Finishes bit-packing of BP. */
127 static inline void
128 streamer_write_bitpack (struct bitpack_d *bp)
130 streamer_write_uhwi_stream ((struct lto_output_stream *) bp->stream,
131 bp->word);
132 bp->word = 0;
133 bp->pos = 0;
136 /* Returns a new bit-packing context for bit-unpacking from IB. */
137 static inline struct bitpack_d
138 streamer_read_bitpack (struct lto_input_block *ib)
140 struct bitpack_d bp;
141 bp.word = streamer_read_uhwi (ib);
142 bp.pos = 0;
143 bp.stream = (void *)ib;
144 return bp;
147 /* Unpacks NBITS bits from the bit-packing context BP and returns them. */
148 static inline bitpack_word_t
149 bp_unpack_value (struct bitpack_d *bp, unsigned nbits)
151 bitpack_word_t mask, val;
152 int pos = bp->pos;
154 mask = (nbits == BITS_PER_BITPACK_WORD
155 ? (bitpack_word_t) -1
156 : ((bitpack_word_t) 1 << nbits) - 1);
158 /* If there are not continuous nbits in the current bitpack word
159 switch to the next one. */
160 if (pos + nbits > BITS_PER_BITPACK_WORD)
162 bp->word = val
163 = streamer_read_uhwi ((struct lto_input_block *)bp->stream);
164 bp->pos = nbits;
165 return val & mask;
167 val = bp->word;
168 val >>= pos;
169 bp->pos = pos + nbits;
171 return val & mask;
175 /* Write a character to the output block. */
177 static inline void
178 streamer_write_char_stream (struct lto_output_stream *obs, char c)
180 /* No space left. */
181 if (obs->left_in_block == 0)
182 lto_append_block (obs);
184 /* Write the actual character. */
185 char *current_pointer = obs->current_pointer;
186 *(current_pointer++) = c;
187 obs->current_pointer = current_pointer;
188 obs->total_size++;
189 obs->left_in_block--;
193 /* Read byte from the input block. */
195 static inline unsigned char
196 streamer_read_uchar (struct lto_input_block *ib)
198 if (ib->p >= ib->len)
199 lto_section_overrun (ib);
200 return (ib->data[ib->p++]);
203 /* Output VAL into OBS and verify it is in range MIN...MAX that is supposed
204 to be compile time constant.
205 Be host independent, limit range to 31bits. */
207 static inline void
208 streamer_write_hwi_in_range (struct lto_output_stream *obs,
209 HOST_WIDE_INT min,
210 HOST_WIDE_INT max,
211 HOST_WIDE_INT val)
213 HOST_WIDE_INT range = max - min;
215 gcc_checking_assert (val >= min && val <= max && range > 0
216 && range < 0x7fffffff);
218 val -= min;
219 streamer_write_uhwi_stream (obs, (unsigned HOST_WIDE_INT) val);
222 /* Input VAL into OBS and verify it is in range MIN...MAX that is supposed
223 to be compile time constant. PURPOSE is used for error reporting. */
225 static inline HOST_WIDE_INT
226 streamer_read_hwi_in_range (struct lto_input_block *ib,
227 const char *purpose,
228 HOST_WIDE_INT min,
229 HOST_WIDE_INT max)
231 HOST_WIDE_INT range = max - min;
232 unsigned HOST_WIDE_INT uval = streamer_read_uhwi (ib);
234 gcc_checking_assert (range > 0 && range < 0x7fffffff);
236 HOST_WIDE_INT val = (HOST_WIDE_INT) (uval + (unsigned HOST_WIDE_INT) min);
237 if (val < min || val > max)
238 lto_value_range_error (purpose, val, min, max);
239 return val;
242 /* Output VAL into BP and verify it is in range MIN...MAX that is supposed
243 to be compile time constant.
244 Be host independent, limit range to 31bits. */
246 static inline void
247 bp_pack_int_in_range (struct bitpack_d *bp,
248 HOST_WIDE_INT min,
249 HOST_WIDE_INT max,
250 HOST_WIDE_INT val)
252 HOST_WIDE_INT range = max - min;
253 int nbits = floor_log2 (range) + 1;
255 gcc_checking_assert (val >= min && val <= max && range > 0
256 && range < 0x7fffffff);
258 val -= min;
259 bp_pack_value (bp, val, nbits);
262 /* Input VAL into BP and verify it is in range MIN...MAX that is supposed
263 to be compile time constant. PURPOSE is used for error reporting. */
265 static inline HOST_WIDE_INT
266 bp_unpack_int_in_range (struct bitpack_d *bp,
267 const char *purpose,
268 HOST_WIDE_INT min,
269 HOST_WIDE_INT max)
271 HOST_WIDE_INT range = max - min;
272 int nbits = floor_log2 (range) + 1;
273 HOST_WIDE_INT val = bp_unpack_value (bp, nbits);
275 gcc_checking_assert (range > 0 && range < 0x7fffffff);
277 if (val < min || val > max)
278 lto_value_range_error (purpose, val, min, max);
279 return val;
282 /* Output VAL of type "enum enum_name" into OBS.
283 Assume range 0...ENUM_LAST - 1. */
284 #define streamer_write_enum(obs,enum_name,enum_last,val) \
285 streamer_write_hwi_in_range ((obs), 0, (int)(enum_last) - 1, (int)(val))
287 /* Input enum of type "enum enum_name" from IB.
288 Assume range 0...ENUM_LAST - 1. */
289 #define streamer_read_enum(ib,enum_name,enum_last) \
290 (enum enum_name)streamer_read_hwi_in_range ((ib), #enum_name, 0, \
291 (int)(enum_last) - 1)
293 /* Output VAL of type "enum enum_name" into BP.
294 Assume range 0...ENUM_LAST - 1. */
295 #define bp_pack_enum(bp,enum_name,enum_last,val) \
296 bp_pack_int_in_range ((bp), 0, (int)(enum_last) - 1, (int)(val))
298 /* Input enum of type "enum enum_name" from BP.
299 Assume range 0...ENUM_LAST - 1. */
300 #define bp_unpack_enum(bp,enum_name,enum_last) \
301 (enum enum_name)bp_unpack_int_in_range ((bp), #enum_name, 0, \
302 (int)(enum_last) - 1)
304 /* Output the start of a record with TAG to output block OB. */
306 static inline void
307 streamer_write_record_start (struct output_block *ob, enum LTO_tags tag)
309 streamer_write_enum (ob->main_stream, LTO_tags, LTO_NUM_TAGS, tag);
312 /* Return the next tag in the input block IB. */
314 static inline enum LTO_tags
315 streamer_read_record_start (struct lto_input_block *ib)
317 return streamer_read_enum (ib, LTO_tags, LTO_NUM_TAGS);
320 #endif /* GCC_DATA_STREAMER_H */