1 /* Generic streaming support for various data types.
2
3 Copyright (C) 2011-2018 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_DATA_STREAMER_H
23 #define GCC_DATA_STREAMER_H
24
25 #include "lto-streamer.h"
26
27 /* Data structures used to pack values and bitflags into a vector of
28 words. Used to stream values of a fixed number of bits in a space
29 efficient way. */
30 static unsigned const BITS_PER_BITPACK_WORD = HOST_BITS_PER_WIDE_INT;
31
32 typedef unsigned HOST_WIDE_INT bitpack_word_t;
33
34 struct bitpack_d
35 {
36 /* The position of the first unused or unconsumed bit in the word. */
37 unsigned pos;
38
39 /* The current word we are (un)packing. */
40 bitpack_word_t word;
41
42 /* The lto_output_stream or the lto_input_block we are streaming to/from. */
43 void *stream;
44 };
45
46 /* In data-streamer.c */
47 void bp_pack_var_len_unsigned (struct bitpack_d *, unsigned HOST_WIDE_INT);
48 void bp_pack_var_len_int (struct bitpack_d *, HOST_WIDE_INT);
49 unsigned HOST_WIDE_INT bp_unpack_var_len_unsigned (struct bitpack_d *);
50 HOST_WIDE_INT bp_unpack_var_len_int (struct bitpack_d *);
51
52 /* In data-streamer-out.c */
53 void streamer_write_zero (struct output_block *);
54 void streamer_write_uhwi (struct output_block *, unsigned HOST_WIDE_INT);
55 void streamer_write_hwi (struct output_block *, HOST_WIDE_INT);
56 void streamer_write_gcov_count (struct output_block *, gcov_type);
57 void streamer_write_string (struct output_block *, struct lto_output_stream *,
58 const char *, bool);
59 void streamer_write_string_with_length (struct output_block *,
60 struct lto_output_stream *,
61 const char *, unsigned int, bool);
62 void bp_pack_string_with_length (struct output_block *, struct bitpack_d *,
63 const char *, unsigned int, bool);
64 void bp_pack_string (struct output_block *, struct bitpack_d *,
65 const char *, bool);
66 void streamer_write_uhwi_stream (struct lto_output_stream *,
67 unsigned HOST_WIDE_INT);
68 void streamer_write_hwi_stream (struct lto_output_stream *, HOST_WIDE_INT);
69 void streamer_write_gcov_count_stream (struct lto_output_stream *, gcov_type);
70 void streamer_write_data_stream (struct lto_output_stream *, const void *,
71 size_t);
72 void streamer_write_wide_int (struct output_block *, const wide_int &);
73 void streamer_write_widest_int (struct output_block *, const widest_int &);
74
75 /* In data-streamer-in.c */
76 const char *streamer_read_string (struct data_in *, struct lto_input_block *);
77 const char *streamer_read_indexed_string (struct data_in *,
78 struct lto_input_block *,
79 unsigned int *);
80 const char *bp_unpack_indexed_string (struct data_in *, struct bitpack_d *,
81 unsigned int *);
82 const char *bp_unpack_string (struct data_in *, struct bitpack_d *);
83 unsigned HOST_WIDE_INT streamer_read_uhwi (struct lto_input_block *);
84 HOST_WIDE_INT streamer_read_hwi (struct lto_input_block *);
85 gcov_type streamer_read_gcov_count (struct lto_input_block *);
86 wide_int streamer_read_wide_int (struct lto_input_block *);
87 widest_int streamer_read_widest_int (struct lto_input_block *);
88
89 /* Returns a new bit-packing context for bit-packing into S. */
90 static inline struct bitpack_d
bitpack_create(struct lto_output_stream * s)91 bitpack_create (struct lto_output_stream *s)
92 {
93 struct bitpack_d bp;
94 bp.pos = 0;
95 bp.word = 0;
96 bp.stream = (void *)s;
97 return bp;
98 }
99
100 /* Pack the NBITS bit sized value VAL into the bit-packing context BP. */
101 static inline void
bp_pack_value(struct bitpack_d * bp,bitpack_word_t val,unsigned nbits)102 bp_pack_value (struct bitpack_d *bp, bitpack_word_t val, unsigned nbits)
103 {
104 bitpack_word_t word = bp->word;
105 int pos = bp->pos;
106
107 /* Verify that VAL fits in the NBITS. */
108 gcc_checking_assert (nbits == BITS_PER_BITPACK_WORD
109 || !(val & ~(((bitpack_word_t)1<<nbits)-1)));
110
111 /* If val does not fit into the current bitpack word switch to the
112 next one. */
113 if (pos + nbits > BITS_PER_BITPACK_WORD)
114 {
115 streamer_write_uhwi_stream ((struct lto_output_stream *) bp->stream,
116 word);
117 word = val;
118 pos = nbits;
119 }
120 else
121 {
122 word |= val << pos;
123 pos += nbits;
124 }
125 bp->word = word;
126 bp->pos = pos;
127 }
128
129 /* Pack VAL into the bit-packing context BP, using NBITS for each
130 coefficient. */
131 static inline void
bp_pack_poly_value(struct bitpack_d * bp,const poly_int<NUM_POLY_INT_COEFFS,bitpack_word_t> & val,unsigned nbits)132 bp_pack_poly_value (struct bitpack_d *bp,
133 const poly_int<NUM_POLY_INT_COEFFS, bitpack_word_t> &val,
134 unsigned nbits)
135 {
136 for (int i = 0; i < NUM_POLY_INT_COEFFS; ++i)
137 bp_pack_value (bp, val.coeffs[i], nbits);
138 }
139
140 /* Finishes bit-packing of BP. */
141 static inline void
streamer_write_bitpack(struct bitpack_d * bp)142 streamer_write_bitpack (struct bitpack_d *bp)
143 {
144 streamer_write_uhwi_stream ((struct lto_output_stream *) bp->stream,
145 bp->word);
146 bp->word = 0;
147 bp->pos = 0;
148 }
149
150 /* Returns a new bit-packing context for bit-unpacking from IB. */
151 static inline struct bitpack_d
streamer_read_bitpack(struct lto_input_block * ib)152 streamer_read_bitpack (struct lto_input_block *ib)
153 {
154 struct bitpack_d bp;
155 bp.word = streamer_read_uhwi (ib);
156 bp.pos = 0;
157 bp.stream = (void *)ib;
158 return bp;
159 }
160
161 /* Unpacks NBITS bits from the bit-packing context BP and returns them. */
162 static inline bitpack_word_t
bp_unpack_value(struct bitpack_d * bp,unsigned nbits)163 bp_unpack_value (struct bitpack_d *bp, unsigned nbits)
164 {
165 bitpack_word_t mask, val;
166 int pos = bp->pos;
167
168 mask = (nbits == BITS_PER_BITPACK_WORD
169 ? (bitpack_word_t) -1
170 : ((bitpack_word_t) 1 << nbits) - 1);
171
172 /* If there are not continuous nbits in the current bitpack word
173 switch to the next one. */
174 if (pos + nbits > BITS_PER_BITPACK_WORD)
175 {
176 bp->word = val
177 = streamer_read_uhwi ((struct lto_input_block *)bp->stream);
178 bp->pos = nbits;
179 return val & mask;
180 }
181 val = bp->word;
182 val >>= pos;
183 bp->pos = pos + nbits;
184
185 return val & mask;
186 }
187
188 /* Unpacks a polynomial value from the bit-packing context BP in which each
189 coefficient has NBITS bits. */
190 static inline poly_int<NUM_POLY_INT_COEFFS, bitpack_word_t>
bp_unpack_poly_value(struct bitpack_d * bp,unsigned nbits)191 bp_unpack_poly_value (struct bitpack_d *bp, unsigned nbits)
192 {
193 poly_int_pod<NUM_POLY_INT_COEFFS, bitpack_word_t> x;
194 for (int i = 0; i < NUM_POLY_INT_COEFFS; ++i)
195 x.coeffs[i] = bp_unpack_value (bp, nbits);
196 return x;
197 }
198
199
200 /* Write a character to the output block. */
201
202 static inline void
streamer_write_char_stream(struct lto_output_stream * obs,char c)203 streamer_write_char_stream (struct lto_output_stream *obs, char c)
204 {
205 /* No space left. */
206 if (obs->left_in_block == 0)
207 lto_append_block (obs);
208
209 /* Write the actual character. */
210 char *current_pointer = obs->current_pointer;
211 *(current_pointer++) = c;
212 obs->current_pointer = current_pointer;
213 obs->total_size++;
214 obs->left_in_block--;
215 }
216
217
218 /* Read byte from the input block. */
219
220 static inline unsigned char
streamer_read_uchar(struct lto_input_block * ib)221 streamer_read_uchar (struct lto_input_block *ib)
222 {
223 if (ib->p >= ib->len)
224 lto_section_overrun (ib);
225 return (ib->data[ib->p++]);
226 }
227
228 /* Output VAL into OBS and verify it is in range MIN...MAX that is supposed
229 to be compile time constant.
230 Be host independent, limit range to 31bits. */
231
232 static inline void
streamer_write_hwi_in_range(struct lto_output_stream * obs,HOST_WIDE_INT min,HOST_WIDE_INT max,HOST_WIDE_INT val)233 streamer_write_hwi_in_range (struct lto_output_stream *obs,
234 HOST_WIDE_INT min,
235 HOST_WIDE_INT max,
236 HOST_WIDE_INT val)
237 {
238 HOST_WIDE_INT range = max - min;
239
240 gcc_checking_assert (val >= min && val <= max && range > 0
241 && range < 0x7fffffff);
242
243 val -= min;
244 streamer_write_uhwi_stream (obs, (unsigned HOST_WIDE_INT) val);
245 }
246
247 /* Input VAL into OBS and verify it is in range MIN...MAX that is supposed
248 to be compile time constant. PURPOSE is used for error reporting. */
249
250 static inline HOST_WIDE_INT
streamer_read_hwi_in_range(struct lto_input_block * ib,const char * purpose,HOST_WIDE_INT min,HOST_WIDE_INT max)251 streamer_read_hwi_in_range (struct lto_input_block *ib,
252 const char *purpose,
253 HOST_WIDE_INT min,
254 HOST_WIDE_INT max)
255 {
256 HOST_WIDE_INT range = max - min;
257 unsigned HOST_WIDE_INT uval = streamer_read_uhwi (ib);
258
259 gcc_checking_assert (range > 0 && range < 0x7fffffff);
260
261 HOST_WIDE_INT val = (HOST_WIDE_INT) (uval + (unsigned HOST_WIDE_INT) min);
262 if (val < min || val > max)
263 lto_value_range_error (purpose, val, min, max);
264 return val;
265 }
266
267 /* Output VAL into BP and verify it is in range MIN...MAX that is supposed
268 to be compile time constant.
269 Be host independent, limit range to 31bits. */
270
271 static inline void
bp_pack_int_in_range(struct bitpack_d * bp,HOST_WIDE_INT min,HOST_WIDE_INT max,HOST_WIDE_INT val)272 bp_pack_int_in_range (struct bitpack_d *bp,
273 HOST_WIDE_INT min,
274 HOST_WIDE_INT max,
275 HOST_WIDE_INT val)
276 {
277 HOST_WIDE_INT range = max - min;
278 int nbits = floor_log2 (range) + 1;
279
280 gcc_checking_assert (val >= min && val <= max && range > 0
281 && range < 0x7fffffff);
282
283 val -= min;
284 bp_pack_value (bp, val, nbits);
285 }
286
287 /* Input VAL into BP and verify it is in range MIN...MAX that is supposed
288 to be compile time constant. PURPOSE is used for error reporting. */
289
290 static inline HOST_WIDE_INT
bp_unpack_int_in_range(struct bitpack_d * bp,const char * purpose,HOST_WIDE_INT min,HOST_WIDE_INT max)291 bp_unpack_int_in_range (struct bitpack_d *bp,
292 const char *purpose,
293 HOST_WIDE_INT min,
294 HOST_WIDE_INT max)
295 {
296 HOST_WIDE_INT range = max - min;
297 int nbits = floor_log2 (range) + 1;
298 HOST_WIDE_INT val = bp_unpack_value (bp, nbits);
299
300 gcc_checking_assert (range > 0 && range < 0x7fffffff);
301
302 if (val < min || val > max)
303 lto_value_range_error (purpose, val, min, max);
304 return val;
305 }
306
307 /* Output VAL of type "enum enum_name" into OBS.
308 Assume range 0...ENUM_LAST - 1. */
309 #define streamer_write_enum(obs,enum_name,enum_last,val) \
310 streamer_write_hwi_in_range ((obs), 0, (int)(enum_last) - 1, (int)(val))
311
312 /* Input enum of type "enum enum_name" from IB.
313 Assume range 0...ENUM_LAST - 1. */
314 #define streamer_read_enum(ib,enum_name,enum_last) \
315 (enum enum_name)streamer_read_hwi_in_range ((ib), #enum_name, 0, \
316 (int)(enum_last) - 1)
317
318 /* Output VAL of type "enum enum_name" into BP.
319 Assume range 0...ENUM_LAST - 1. */
320 #define bp_pack_enum(bp,enum_name,enum_last,val) \
321 bp_pack_int_in_range ((bp), 0, (int)(enum_last) - 1, (int)(val))
322
323 /* Input enum of type "enum enum_name" from BP.
324 Assume range 0...ENUM_LAST - 1. */
325 #define bp_unpack_enum(bp,enum_name,enum_last) \
326 (enum enum_name)bp_unpack_int_in_range ((bp), #enum_name, 0, \
327 (int)(enum_last) - 1)
328
329 /* Output the start of a record with TAG to output block OB. */
330
331 static inline void
streamer_write_record_start(struct output_block * ob,enum LTO_tags tag)332 streamer_write_record_start (struct output_block *ob, enum LTO_tags tag)
333 {
334 streamer_write_enum (ob->main_stream, LTO_tags, LTO_NUM_TAGS, tag);
335 }
336
337 /* Return the next tag in the input block IB. */
338
339 static inline enum LTO_tags
streamer_read_record_start(struct lto_input_block * ib)340 streamer_read_record_start (struct lto_input_block *ib)
341 {
342 return streamer_read_enum (ib, LTO_tags, LTO_NUM_TAGS);
343 }
344
345 #endif /* GCC_DATA_STREAMER_H */
346