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
6This file is part of GCC.
7
8GCC is free software; you can redistribute it and/or modify it under
9the terms of the GNU General Public License as published by the Free
10Software Foundation; either version 3, or (at your option) any later
11version.
12
13GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14WARRANTY; without even the implied warranty of MERCHANTABILITY or
15FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16for more details.
17
18You should have received a copy of the GNU General Public License
19along 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. */
30static unsigned const BITS_PER_BITPACK_WORD = HOST_BITS_PER_WIDE_INT;
31
32typedef unsigned HOST_WIDE_INT bitpack_word_t;
33
34struct 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 */
47void bp_pack_var_len_unsigned (struct bitpack_d *, unsigned HOST_WIDE_INT);
48void bp_pack_var_len_int (struct bitpack_d *, HOST_WIDE_INT);
49void bp_pack_real_value (struct bitpack_d *, const REAL_VALUE_TYPE *);
50void bp_unpack_real_value (struct bitpack_d *, REAL_VALUE_TYPE *);
51unsigned HOST_WIDE_INT bp_unpack_var_len_unsigned (struct bitpack_d *);
52HOST_WIDE_INT bp_unpack_var_len_int (struct bitpack_d *);
53
54/* In data-streamer-out.cc */
55void streamer_write_zero (struct output_block *);
56void streamer_write_uhwi (struct output_block *, unsigned HOST_WIDE_INT);
57void streamer_write_hwi (struct output_block *, HOST_WIDE_INT);
58void streamer_write_poly_uint64 (struct output_block *, poly_uint64);
59void streamer_write_poly_int64 (struct output_block *, poly_int64);
60void streamer_write_gcov_count (struct output_block *, gcov_type);
61void streamer_write_string (struct output_block *, struct lto_output_stream *,
62 const char *, bool);
63void streamer_write_string_with_length (struct output_block *,
64 struct lto_output_stream *,
65 const char *, unsigned int, bool);
66void bp_pack_string_with_length (struct output_block *, struct bitpack_d *,
67 const char *, unsigned int, bool);
68void bp_pack_string (struct output_block *, struct bitpack_d *,
69 const char *, bool);
70void streamer_write_uhwi_stream (struct lto_output_stream *,
71 unsigned HOST_WIDE_INT);
72void streamer_write_hwi_stream (struct lto_output_stream *, HOST_WIDE_INT);
73void streamer_write_gcov_count_stream (struct lto_output_stream *, gcov_type);
74void streamer_write_data_stream (struct lto_output_stream *, const void *,
75 size_t);
76void streamer_write_wide_int (struct output_block *, const wide_int &);
77void streamer_write_widest_int (struct output_block *, const widest_int &);
78void streamer_write_vrange (struct output_block *, const class vrange &);
79
80/* In data-streamer-in.cc */
81const char *streamer_read_string (class data_in *, class lto_input_block *);
82const char *streamer_read_indexed_string (class data_in *,
83 class lto_input_block *,
84 unsigned int *);
85const char *bp_unpack_indexed_string (class data_in *, struct bitpack_d *,
86 unsigned int *);
87const char *bp_unpack_string (class data_in *, struct bitpack_d *);
88unsigned HOST_WIDE_INT streamer_read_uhwi (class lto_input_block *);
89HOST_WIDE_INT streamer_read_hwi (class lto_input_block *);
90poly_uint64 streamer_read_poly_uint64 (class lto_input_block *);
91poly_int64 streamer_read_poly_int64 (class lto_input_block *);
92gcov_type streamer_read_gcov_count (class lto_input_block *);
93wide_int streamer_read_wide_int (class lto_input_block *);
94widest_int streamer_read_widest_int (class lto_input_block *);
95void streamer_read_value_range (class lto_input_block *, class data_in *,
96 class Value_Range &);
97
98/* Returns a new bit-packing context for bit-packing into S. */
99inline struct bitpack_d
100bitpack_create (struct lto_output_stream *s)
101{
102 struct bitpack_d bp;
103 bp.pos = 0;
104 bp.word = 0;
105 bp.stream = (void *)s;
106 return bp;
107}
108
109/* Pack the NBITS bit sized value VAL into the bit-packing context BP. */
110inline void
111bp_pack_value (struct bitpack_d *bp, bitpack_word_t val, unsigned nbits)
112{
113 bitpack_word_t word = bp->word;
114 int pos = bp->pos;
115
116 /* Verify that VAL fits in the NBITS. */
117 gcc_checking_assert (nbits == BITS_PER_BITPACK_WORD
118 || !(val & ~(((bitpack_word_t)1<<nbits)-1)));
119
120 /* If val does not fit into the current bitpack word switch to the
121 next one. */
122 if (pos + nbits > BITS_PER_BITPACK_WORD)
123 {
124 streamer_write_uhwi_stream ((struct lto_output_stream *) bp->stream,
125 word);
126 word = val;
127 pos = nbits;
128 }
129 else
130 {
131 word |= val << pos;
132 pos += nbits;
133 }
134 bp->word = word;
135 bp->pos = pos;
136}
137
138/* Pack VAL into the bit-packing context BP, using NBITS for each
139 coefficient. */
140inline void
141bp_pack_poly_value (struct bitpack_d *bp,
142 const poly_int<NUM_POLY_INT_COEFFS, bitpack_word_t> &val,
143 unsigned nbits)
144{
145 for (int i = 0; i < NUM_POLY_INT_COEFFS; ++i)
146 bp_pack_value (bp, val: val.coeffs[i], nbits);
147}
148
149/* Finishes bit-packing of BP. */
150inline void
151streamer_write_bitpack (struct bitpack_d *bp)
152{
153 streamer_write_uhwi_stream ((struct lto_output_stream *) bp->stream,
154 bp->word);
155 bp->word = 0;
156 bp->pos = 0;
157}
158
159/* Returns a new bit-packing context for bit-unpacking from IB. */
160inline struct bitpack_d
161streamer_read_bitpack (class lto_input_block *ib)
162{
163 struct bitpack_d bp;
164 bp.word = streamer_read_uhwi (ib);
165 bp.pos = 0;
166 bp.stream = (void *)ib;
167 return bp;
168}
169
170/* Unpacks NBITS bits from the bit-packing context BP and returns them. */
171inline bitpack_word_t
172bp_unpack_value (struct bitpack_d *bp, unsigned nbits)
173{
174 bitpack_word_t mask, val;
175 int pos = bp->pos;
176
177 mask = (nbits == BITS_PER_BITPACK_WORD
178 ? (bitpack_word_t) -1
179 : ((bitpack_word_t) 1 << nbits) - 1);
180
181 /* If there are not continuous nbits in the current bitpack word
182 switch to the next one. */
183 if (pos + nbits > BITS_PER_BITPACK_WORD)
184 {
185 bp->word = val
186 = streamer_read_uhwi ((class lto_input_block *)bp->stream);
187 bp->pos = nbits;
188 return val & mask;
189 }
190 val = bp->word;
191 val >>= pos;
192 bp->pos = pos + nbits;
193
194 return val & mask;
195}
196
197/* Unpacks a polynomial value from the bit-packing context BP in which each
198 coefficient has NBITS bits. */
199inline poly_int<NUM_POLY_INT_COEFFS, bitpack_word_t>
200bp_unpack_poly_value (struct bitpack_d *bp, unsigned nbits)
201{
202 poly_int<NUM_POLY_INT_COEFFS, bitpack_word_t> x;
203 for (int i = 0; i < NUM_POLY_INT_COEFFS; ++i)
204 x.coeffs[i] = bp_unpack_value (bp, nbits);
205 return x;
206}
207
208
209/* Write a character to the output block. */
210
211inline void
212streamer_write_char_stream (struct lto_output_stream *obs, char c)
213{
214 /* No space left. */
215 if (obs->left_in_block == 0)
216 lto_append_block (obs);
217
218 /* Write the actual character. */
219 char *current_pointer = obs->current_pointer;
220 *(current_pointer++) = c;
221 obs->current_pointer = current_pointer;
222 obs->total_size++;
223 obs->left_in_block--;
224}
225
226
227/* Read byte from the input block. */
228
229inline unsigned char
230streamer_read_uchar (class lto_input_block *ib)
231{
232 if (ib->p >= ib->len)
233 lto_section_overrun (ib);
234 return (ib->data[ib->p++]);
235}
236
237/* Output VAL into OBS and verify it is in range MIN...MAX that is supposed
238 to be compile time constant.
239 Be host independent, limit range to 31bits. */
240
241inline void
242streamer_write_hwi_in_range (struct lto_output_stream *obs,
243 HOST_WIDE_INT min,
244 HOST_WIDE_INT max,
245 HOST_WIDE_INT val)
246{
247 HOST_WIDE_INT range = max - min;
248
249 gcc_checking_assert (val >= min && val <= max && range > 0
250 && range < 0x7fffffff);
251
252 val -= min;
253 streamer_write_uhwi_stream (obs, (unsigned HOST_WIDE_INT) val);
254}
255
256/* Input VAL into OBS and verify it is in range MIN...MAX that is supposed
257 to be compile time constant. PURPOSE is used for error reporting. */
258
259inline HOST_WIDE_INT
260streamer_read_hwi_in_range (class lto_input_block *ib,
261 const char *purpose,
262 HOST_WIDE_INT min,
263 HOST_WIDE_INT max)
264{
265 HOST_WIDE_INT range = max - min;
266 unsigned HOST_WIDE_INT uval = streamer_read_uhwi (ib);
267
268 gcc_checking_assert (range > 0 && range < 0x7fffffff);
269
270 HOST_WIDE_INT val = (HOST_WIDE_INT) (uval + (unsigned HOST_WIDE_INT) min);
271 if (val < min || val > max)
272 lto_value_range_error (purpose, val, min, max);
273 return val;
274}
275
276/* Output VAL into BP and verify it is in range MIN...MAX that is supposed
277 to be compile time constant.
278 Be host independent, limit range to 31bits. */
279
280inline void
281bp_pack_int_in_range (struct bitpack_d *bp,
282 HOST_WIDE_INT min,
283 HOST_WIDE_INT max,
284 HOST_WIDE_INT val)
285{
286 HOST_WIDE_INT range = max - min;
287 int nbits = floor_log2 (x: range) + 1;
288
289 gcc_checking_assert (val >= min && val <= max && range > 0
290 && range < 0x7fffffff);
291
292 val -= min;
293 bp_pack_value (bp, val, nbits);
294}
295
296/* Input VAL into BP and verify it is in range MIN...MAX that is supposed
297 to be compile time constant. PURPOSE is used for error reporting. */
298
299inline HOST_WIDE_INT
300bp_unpack_int_in_range (struct bitpack_d *bp,
301 const char *purpose,
302 HOST_WIDE_INT min,
303 HOST_WIDE_INT max)
304{
305 HOST_WIDE_INT range = max - min;
306 int nbits = floor_log2 (x: range) + 1;
307 HOST_WIDE_INT val = bp_unpack_value (bp, nbits);
308
309 gcc_checking_assert (range > 0 && range < 0x7fffffff);
310
311 if (val < min || val > max)
312 lto_value_range_error (purpose, val, min, max);
313 return val;
314}
315
316/* Output VAL of type "enum enum_name" into OBS.
317 Assume range 0...ENUM_LAST - 1. */
318#define streamer_write_enum(obs,enum_name,enum_last,val) \
319 streamer_write_hwi_in_range ((obs), 0, (int)(enum_last) - 1, (int)(val))
320
321/* Input enum of type "enum enum_name" from IB.
322 Assume range 0...ENUM_LAST - 1. */
323#define streamer_read_enum(ib,enum_name,enum_last) \
324 (enum enum_name)streamer_read_hwi_in_range ((ib), #enum_name, 0, \
325 (int)(enum_last) - 1)
326
327/* Output VAL of type "enum enum_name" into BP.
328 Assume range 0...ENUM_LAST - 1. */
329#define bp_pack_enum(bp,enum_name,enum_last,val) \
330 bp_pack_int_in_range ((bp), 0, (int)(enum_last) - 1, (int)(val))
331
332/* Input enum of type "enum enum_name" from BP.
333 Assume range 0...ENUM_LAST - 1. */
334#define bp_unpack_enum(bp,enum_name,enum_last) \
335 (enum enum_name)bp_unpack_int_in_range ((bp), #enum_name, 0, \
336 (int)(enum_last) - 1)
337
338/* Output the start of a record with TAG to output block OB. */
339
340inline void
341streamer_write_record_start (struct output_block *ob, enum LTO_tags tag)
342{
343 streamer_write_enum (ob->main_stream, LTO_tags, LTO_NUM_TAGS, tag);
344}
345
346/* Return the next tag in the input block IB. */
347
348inline enum LTO_tags
349streamer_read_record_start (class lto_input_block *ib)
350{
351 return streamer_read_enum (ib, LTO_tags, LTO_NUM_TAGS);
352}
353
354#endif /* GCC_DATA_STREAMER_H */
355

source code of gcc/data-streamer.h