1 /* Generic streaming support for various data types.
2
3 Copyright (C) 2011-2023 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.cc */
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.cc */
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_poly_uint64 (struct output_block *, poly_uint64);
57 void streamer_write_poly_int64 (struct output_block *, poly_int64);
58 void streamer_write_gcov_count (struct output_block *, gcov_type);
59 void streamer_write_string (struct output_block *, struct lto_output_stream *,
60 const char *, bool);
61 void streamer_write_string_with_length (struct output_block *,
62 struct lto_output_stream *,
63 const char *, unsigned int, bool);
64 void bp_pack_string_with_length (struct output_block *, struct bitpack_d *,
65 const char *, unsigned int, bool);
66 void bp_pack_string (struct output_block *, struct bitpack_d *,
67 const char *, bool);
68 void streamer_write_uhwi_stream (struct lto_output_stream *,
69 unsigned HOST_WIDE_INT);
70 void streamer_write_hwi_stream (struct lto_output_stream *, HOST_WIDE_INT);
71 void streamer_write_gcov_count_stream (struct lto_output_stream *, gcov_type);
72 void streamer_write_data_stream (struct lto_output_stream *, const void *,
73 size_t);
74 void streamer_write_wide_int (struct output_block *, const wide_int &);
75 void streamer_write_widest_int (struct output_block *, const widest_int &);
76
77 /* In data-streamer-in.cc */
78 const char *streamer_read_string (class data_in *, class lto_input_block *);
79 const char *streamer_read_indexed_string (class data_in *,
80 class lto_input_block *,
81 unsigned int *);
82 const char *bp_unpack_indexed_string (class data_in *, struct bitpack_d *,
83 unsigned int *);
84 const char *bp_unpack_string (class data_in *, struct bitpack_d *);
85 unsigned HOST_WIDE_INT streamer_read_uhwi (class lto_input_block *);
86 HOST_WIDE_INT streamer_read_hwi (class lto_input_block *);
87 poly_uint64 streamer_read_poly_uint64 (class lto_input_block *);
88 poly_int64 streamer_read_poly_int64 (class lto_input_block *);
89 gcov_type streamer_read_gcov_count (class lto_input_block *);
90 wide_int streamer_read_wide_int (class lto_input_block *);
91 widest_int streamer_read_widest_int (class lto_input_block *);
92
93 /* Returns a new bit-packing context for bit-packing into S. */
94 inline struct bitpack_d
95 bitpack_create (struct lto_output_stream *s)
96 {
97 struct bitpack_d bp;
98 bp.pos = 0;
99 bp.word = 0;
100 bp.stream = (void *)s;
101 return bp;
102 }
103
104 /* Pack the NBITS bit sized value VAL into the bit-packing context BP. */
105 inline void
106 bp_pack_value (struct bitpack_d *bp, bitpack_word_t val, unsigned nbits)
107 {
108 bitpack_word_t word = bp->word;
109 int pos = bp->pos;
110
111 /* Verify that VAL fits in the NBITS. */
112 gcc_checking_assert (nbits == BITS_PER_BITPACK_WORD
113 || !(val & ~(((bitpack_word_t)1<<nbits)-1)));
114
115 /* If val does not fit into the current bitpack word switch to the
116 next one. */
117 if (pos + nbits > BITS_PER_BITPACK_WORD)
118 {
119 streamer_write_uhwi_stream ((struct lto_output_stream *) bp->stream,
120 word);
121 word = val;
122 pos = nbits;
123 }
124 else
125 {
126 word |= val << pos;
127 pos += nbits;
128 }
129 bp->word = word;
130 bp->pos = pos;
131 }
132
133 /* Pack VAL into the bit-packing context BP, using NBITS for each
134 coefficient. */
135 inline void
136 bp_pack_poly_value (struct bitpack_d *bp,
137 const poly_int<NUM_POLY_INT_COEFFS, bitpack_word_t> &val,
138 unsigned nbits)
139 {
140 for (int i = 0; i < NUM_POLY_INT_COEFFS; ++i)
141 bp_pack_value (bp, val.coeffs[i], nbits);
142 }
143
144 /* Finishes bit-packing of BP. */
145 inline void
146 streamer_write_bitpack (struct bitpack_d *bp)
147 {
148 streamer_write_uhwi_stream ((struct lto_output_stream *) bp->stream,
149 bp->word);
150 bp->word = 0;
151 bp->pos = 0;
152 }
153
154 /* Returns a new bit-packing context for bit-unpacking from IB. */
155 inline struct bitpack_d
156 streamer_read_bitpack (class lto_input_block *ib)
157 {
158 struct bitpack_d bp;
159 bp.word = streamer_read_uhwi (ib);
160 bp.pos = 0;
161 bp.stream = (void *)ib;
162 return bp;
163 }
164
165 /* Unpacks NBITS bits from the bit-packing context BP and returns them. */
166 inline bitpack_word_t
167 bp_unpack_value (struct bitpack_d *bp, unsigned nbits)
168 {
169 bitpack_word_t mask, val;
170 int pos = bp->pos;
171
172 mask = (nbits == BITS_PER_BITPACK_WORD
173 ? (bitpack_word_t) -1
174 : ((bitpack_word_t) 1 << nbits) - 1);
175
176 /* If there are not continuous nbits in the current bitpack word
177 switch to the next one. */
178 if (pos + nbits > BITS_PER_BITPACK_WORD)
179 {
180 bp->word = val
181 = streamer_read_uhwi ((class lto_input_block *)bp->stream);
182 bp->pos = nbits;
183 return val & mask;
184 }
185 val = bp->word;
186 val >>= pos;
187 bp->pos = pos + nbits;
188
189 return val & mask;
190 }
191
192 /* Unpacks a polynomial value from the bit-packing context BP in which each
193 coefficient has NBITS bits. */
194 inline poly_int<NUM_POLY_INT_COEFFS, bitpack_word_t>
195 bp_unpack_poly_value (struct bitpack_d *bp, unsigned nbits)
196 {
197 poly_int_pod<NUM_POLY_INT_COEFFS, bitpack_word_t> x;
198 for (int i = 0; i < NUM_POLY_INT_COEFFS; ++i)
199 x.coeffs[i] = bp_unpack_value (bp, nbits);
200 return x;
201 }
202
203
204 /* Write a character to the output block. */
205
206 inline void
207 streamer_write_char_stream (struct lto_output_stream *obs, char c)
208 {
209 /* No space left. */
210 if (obs->left_in_block == 0)
211 lto_append_block (obs);
212
213 /* Write the actual character. */
214 char *current_pointer = obs->current_pointer;
215 *(current_pointer++) = c;
216 obs->current_pointer = current_pointer;
217 obs->total_size++;
218 obs->left_in_block--;
219 }
220
221
222 /* Read byte from the input block. */
223
224 inline unsigned char
225 streamer_read_uchar (class lto_input_block *ib)
226 {
227 if (ib->p >= ib->len)
228 lto_section_overrun (ib);
229 return (ib->data[ib->p++]);
230 }
231
232 /* Output VAL into OBS and verify it is in range MIN...MAX that is supposed
233 to be compile time constant.
234 Be host independent, limit range to 31bits. */
235
236 inline void
237 streamer_write_hwi_in_range (struct lto_output_stream *obs,
238 HOST_WIDE_INT min,
239 HOST_WIDE_INT max,
240 HOST_WIDE_INT val)
241 {
242 HOST_WIDE_INT range = max - min;
243
244 gcc_checking_assert (val >= min && val <= max && range > 0
245 && range < 0x7fffffff);
246
247 val -= min;
248 streamer_write_uhwi_stream (obs, (unsigned HOST_WIDE_INT) val);
249 }
250
251 /* Input VAL into OBS and verify it is in range MIN...MAX that is supposed
252 to be compile time constant. PURPOSE is used for error reporting. */
253
254 inline HOST_WIDE_INT
255 streamer_read_hwi_in_range (class lto_input_block *ib,
256 const char *purpose,
257 HOST_WIDE_INT min,
258 HOST_WIDE_INT max)
259 {
260 HOST_WIDE_INT range = max - min;
261 unsigned HOST_WIDE_INT uval = streamer_read_uhwi (ib);
262
263 gcc_checking_assert (range > 0 && range < 0x7fffffff);
264
265 HOST_WIDE_INT val = (HOST_WIDE_INT) (uval + (unsigned HOST_WIDE_INT) min);
266 if (val < min || val > max)
267 lto_value_range_error (purpose, val, min, max);
268 return val;
269 }
270
271 /* Output VAL into BP and verify it is in range MIN...MAX that is supposed
272 to be compile time constant.
273 Be host independent, limit range to 31bits. */
274
275 inline void
276 bp_pack_int_in_range (struct bitpack_d *bp,
277 HOST_WIDE_INT min,
278 HOST_WIDE_INT max,
279 HOST_WIDE_INT val)
280 {
281 HOST_WIDE_INT range = max - min;
282 int nbits = floor_log2 (range) + 1;
283
284 gcc_checking_assert (val >= min && val <= max && range > 0
285 && range < 0x7fffffff);
286
287 val -= min;
288 bp_pack_value (bp, val, nbits);
289 }
290
291 /* Input VAL into BP and verify it is in range MIN...MAX that is supposed
292 to be compile time constant. PURPOSE is used for error reporting. */
293
294 inline HOST_WIDE_INT
295 bp_unpack_int_in_range (struct bitpack_d *bp,
296 const char *purpose,
297 HOST_WIDE_INT min,
298 HOST_WIDE_INT max)
299 {
300 HOST_WIDE_INT range = max - min;
301 int nbits = floor_log2 (range) + 1;
302 HOST_WIDE_INT val = bp_unpack_value (bp, nbits);
303
304 gcc_checking_assert (range > 0 && range < 0x7fffffff);
305
306 if (val < min || val > max)
307 lto_value_range_error (purpose, val, min, max);
308 return val;
309 }
310
311 /* Output VAL of type "enum enum_name" into OBS.
312 Assume range 0...ENUM_LAST - 1. */
313 #define streamer_write_enum(obs,enum_name,enum_last,val) \
314 streamer_write_hwi_in_range ((obs), 0, (int)(enum_last) - 1, (int)(val))
315
316 /* Input enum of type "enum enum_name" from IB.
317 Assume range 0...ENUM_LAST - 1. */
318 #define streamer_read_enum(ib,enum_name,enum_last) \
319 (enum enum_name)streamer_read_hwi_in_range ((ib), #enum_name, 0, \
320 (int)(enum_last) - 1)
321
322 /* Output VAL of type "enum enum_name" into BP.
323 Assume range 0...ENUM_LAST - 1. */
324 #define bp_pack_enum(bp,enum_name,enum_last,val) \
325 bp_pack_int_in_range ((bp), 0, (int)(enum_last) - 1, (int)(val))
326
327 /* Input enum of type "enum enum_name" from BP.
328 Assume range 0...ENUM_LAST - 1. */
329 #define bp_unpack_enum(bp,enum_name,enum_last) \
330 (enum enum_name)bp_unpack_int_in_range ((bp), #enum_name, 0, \
331 (int)(enum_last) - 1)
332
333 /* Output the start of a record with TAG to output block OB. */
334
335 inline void
336 streamer_write_record_start (struct output_block *ob, enum LTO_tags tag)
337 {
338 streamer_write_enum (ob->main_stream, LTO_tags, LTO_NUM_TAGS, tag);
339 }
340
341 /* Return the next tag in the input block IB. */
342
343 inline enum LTO_tags
344 streamer_read_record_start (class lto_input_block *ib)
345 {
346 return streamer_read_enum (ib, LTO_tags, LTO_NUM_TAGS);
347 }
348
349 #endif /* GCC_DATA_STREAMER_H */