1 /* Generic streaming support for various data types.
2
3 Copyright (C) 2011-2020 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_poly_uint64 (struct output_block *, poly_uint64);
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);
73 void streamer_write_wide_int (struct output_block *, const wide_int &);
74 void streamer_write_widest_int (struct output_block *, const widest_int &);
75
76 /* In data-streamer-in.c */
77 const char *streamer_read_string (class data_in *, class lto_input_block *);
78 const char *streamer_read_indexed_string (class data_in *,
79 class lto_input_block *,
80 unsigned int *);
81 const char *bp_unpack_indexed_string (class data_in *, struct bitpack_d *,
82 unsigned int *);
83 const char *bp_unpack_string (class data_in *, struct bitpack_d *);
84 unsigned HOST_WIDE_INT streamer_read_uhwi (class lto_input_block *);
85 HOST_WIDE_INT streamer_read_hwi (class lto_input_block *);
86 poly_uint64 streamer_read_poly_uint64 (class lto_input_block *);
87 gcov_type streamer_read_gcov_count (class lto_input_block *);
88 wide_int streamer_read_wide_int (class lto_input_block *);
89 widest_int streamer_read_widest_int (class lto_input_block *);
90
91 /* Returns a new bit-packing context for bit-packing into S. */
92 static inline struct bitpack_d
bitpack_create(struct lto_output_stream * s)93 bitpack_create (struct lto_output_stream *s)
94 {
95 struct bitpack_d bp;
96 bp.pos = 0;
97 bp.word = 0;
98 bp.stream = (void *)s;
99 return bp;
100 }
101
102 /* Pack the NBITS bit sized value VAL into the bit-packing context BP. */
103 static inline void
bp_pack_value(struct bitpack_d * bp,bitpack_word_t val,unsigned nbits)104 bp_pack_value (struct bitpack_d *bp, bitpack_word_t val, unsigned nbits)
105 {
106 bitpack_word_t word = bp->word;
107 int pos = bp->pos;
108
109 /* Verify that VAL fits in the NBITS. */
110 gcc_checking_assert (nbits == BITS_PER_BITPACK_WORD
111 || !(val & ~(((bitpack_word_t)1<<nbits)-1)));
112
113 /* If val does not fit into the current bitpack word switch to the
114 next one. */
115 if (pos + nbits > BITS_PER_BITPACK_WORD)
116 {
117 streamer_write_uhwi_stream ((struct lto_output_stream *) bp->stream,
118 word);
119 word = val;
120 pos = nbits;
121 }
122 else
123 {
124 word |= val << pos;
125 pos += nbits;
126 }
127 bp->word = word;
128 bp->pos = pos;
129 }
130
131 /* Pack VAL into the bit-packing context BP, using NBITS for each
132 coefficient. */
133 static inline void
bp_pack_poly_value(struct bitpack_d * bp,const poly_int<NUM_POLY_INT_COEFFS,bitpack_word_t> & val,unsigned nbits)134 bp_pack_poly_value (struct bitpack_d *bp,
135 const poly_int<NUM_POLY_INT_COEFFS, bitpack_word_t> &val,
136 unsigned nbits)
137 {
138 for (int i = 0; i < NUM_POLY_INT_COEFFS; ++i)
139 bp_pack_value (bp, val.coeffs[i], nbits);
140 }
141
142 /* Finishes bit-packing of BP. */
143 static inline void
streamer_write_bitpack(struct bitpack_d * bp)144 streamer_write_bitpack (struct bitpack_d *bp)
145 {
146 streamer_write_uhwi_stream ((struct lto_output_stream *) bp->stream,
147 bp->word);
148 bp->word = 0;
149 bp->pos = 0;
150 }
151
152 /* Returns a new bit-packing context for bit-unpacking from IB. */
153 static inline struct bitpack_d
streamer_read_bitpack(class lto_input_block * ib)154 streamer_read_bitpack (class lto_input_block *ib)
155 {
156 struct bitpack_d bp;
157 bp.word = streamer_read_uhwi (ib);
158 bp.pos = 0;
159 bp.stream = (void *)ib;
160 return bp;
161 }
162
163 /* Unpacks NBITS bits from the bit-packing context BP and returns them. */
164 static inline bitpack_word_t
bp_unpack_value(struct bitpack_d * bp,unsigned nbits)165 bp_unpack_value (struct bitpack_d *bp, unsigned nbits)
166 {
167 bitpack_word_t mask, val;
168 int pos = bp->pos;
169
170 mask = (nbits == BITS_PER_BITPACK_WORD
171 ? (bitpack_word_t) -1
172 : ((bitpack_word_t) 1 << nbits) - 1);
173
174 /* If there are not continuous nbits in the current bitpack word
175 switch to the next one. */
176 if (pos + nbits > BITS_PER_BITPACK_WORD)
177 {
178 bp->word = val
179 = streamer_read_uhwi ((class lto_input_block *)bp->stream);
180 bp->pos = nbits;
181 return val & mask;
182 }
183 val = bp->word;
184 val >>= pos;
185 bp->pos = pos + nbits;
186
187 return val & mask;
188 }
189
190 /* Unpacks a polynomial value from the bit-packing context BP in which each
191 coefficient has NBITS bits. */
192 static inline poly_int<NUM_POLY_INT_COEFFS, bitpack_word_t>
bp_unpack_poly_value(struct bitpack_d * bp,unsigned nbits)193 bp_unpack_poly_value (struct bitpack_d *bp, unsigned nbits)
194 {
195 poly_int_pod<NUM_POLY_INT_COEFFS, bitpack_word_t> x;
196 for (int i = 0; i < NUM_POLY_INT_COEFFS; ++i)
197 x.coeffs[i] = bp_unpack_value (bp, nbits);
198 return x;
199 }
200
201
202 /* Write a character to the output block. */
203
204 static inline void
streamer_write_char_stream(struct lto_output_stream * obs,char c)205 streamer_write_char_stream (struct lto_output_stream *obs, char c)
206 {
207 /* No space left. */
208 if (obs->left_in_block == 0)
209 lto_append_block (obs);
210
211 /* Write the actual character. */
212 char *current_pointer = obs->current_pointer;
213 *(current_pointer++) = c;
214 obs->current_pointer = current_pointer;
215 obs->total_size++;
216 obs->left_in_block--;
217 }
218
219
220 /* Read byte from the input block. */
221
222 static inline unsigned char
streamer_read_uchar(class lto_input_block * ib)223 streamer_read_uchar (class lto_input_block *ib)
224 {
225 if (ib->p >= ib->len)
226 lto_section_overrun (ib);
227 return (ib->data[ib->p++]);
228 }
229
230 /* Output VAL into OBS and verify it is in range MIN...MAX that is supposed
231 to be compile time constant.
232 Be host independent, limit range to 31bits. */
233
234 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)235 streamer_write_hwi_in_range (struct lto_output_stream *obs,
236 HOST_WIDE_INT min,
237 HOST_WIDE_INT max,
238 HOST_WIDE_INT val)
239 {
240 HOST_WIDE_INT range = max - min;
241
242 gcc_checking_assert (val >= min && val <= max && range > 0
243 && range < 0x7fffffff);
244
245 val -= min;
246 streamer_write_uhwi_stream (obs, (unsigned HOST_WIDE_INT) val);
247 }
248
249 /* Input VAL into OBS and verify it is in range MIN...MAX that is supposed
250 to be compile time constant. PURPOSE is used for error reporting. */
251
252 static inline HOST_WIDE_INT
streamer_read_hwi_in_range(class lto_input_block * ib,const char * purpose,HOST_WIDE_INT min,HOST_WIDE_INT max)253 streamer_read_hwi_in_range (class lto_input_block *ib,
254 const char *purpose,
255 HOST_WIDE_INT min,
256 HOST_WIDE_INT max)
257 {
258 HOST_WIDE_INT range = max - min;
259 unsigned HOST_WIDE_INT uval = streamer_read_uhwi (ib);
260
261 gcc_checking_assert (range > 0 && range < 0x7fffffff);
262
263 HOST_WIDE_INT val = (HOST_WIDE_INT) (uval + (unsigned HOST_WIDE_INT) min);
264 if (val < min || val > max)
265 lto_value_range_error (purpose, val, min, max);
266 return val;
267 }
268
269 /* Output VAL into BP and verify it is in range MIN...MAX that is supposed
270 to be compile time constant.
271 Be host independent, limit range to 31bits. */
272
273 static inline void
bp_pack_int_in_range(struct bitpack_d * bp,HOST_WIDE_INT min,HOST_WIDE_INT max,HOST_WIDE_INT val)274 bp_pack_int_in_range (struct bitpack_d *bp,
275 HOST_WIDE_INT min,
276 HOST_WIDE_INT max,
277 HOST_WIDE_INT val)
278 {
279 HOST_WIDE_INT range = max - min;
280 int nbits = floor_log2 (range) + 1;
281
282 gcc_checking_assert (val >= min && val <= max && range > 0
283 && range < 0x7fffffff);
284
285 val -= min;
286 bp_pack_value (bp, val, nbits);
287 }
288
289 /* Input VAL into BP and verify it is in range MIN...MAX that is supposed
290 to be compile time constant. PURPOSE is used for error reporting. */
291
292 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)293 bp_unpack_int_in_range (struct bitpack_d *bp,
294 const char *purpose,
295 HOST_WIDE_INT min,
296 HOST_WIDE_INT max)
297 {
298 HOST_WIDE_INT range = max - min;
299 int nbits = floor_log2 (range) + 1;
300 HOST_WIDE_INT val = bp_unpack_value (bp, nbits);
301
302 gcc_checking_assert (range > 0 && range < 0x7fffffff);
303
304 if (val < min || val > max)
305 lto_value_range_error (purpose, val, min, max);
306 return val;
307 }
308
309 /* Output VAL of type "enum enum_name" into OBS.
310 Assume range 0...ENUM_LAST - 1. */
311 #define streamer_write_enum(obs,enum_name,enum_last,val) \
312 streamer_write_hwi_in_range ((obs), 0, (int)(enum_last) - 1, (int)(val))
313
314 /* Input enum of type "enum enum_name" from IB.
315 Assume range 0...ENUM_LAST - 1. */
316 #define streamer_read_enum(ib,enum_name,enum_last) \
317 (enum enum_name)streamer_read_hwi_in_range ((ib), #enum_name, 0, \
318 (int)(enum_last) - 1)
319
320 /* Output VAL of type "enum enum_name" into BP.
321 Assume range 0...ENUM_LAST - 1. */
322 #define bp_pack_enum(bp,enum_name,enum_last,val) \
323 bp_pack_int_in_range ((bp), 0, (int)(enum_last) - 1, (int)(val))
324
325 /* Input enum of type "enum enum_name" from BP.
326 Assume range 0...ENUM_LAST - 1. */
327 #define bp_unpack_enum(bp,enum_name,enum_last) \
328 (enum enum_name)bp_unpack_int_in_range ((bp), #enum_name, 0, \
329 (int)(enum_last) - 1)
330
331 /* Output the start of a record with TAG to output block OB. */
332
333 static inline void
streamer_write_record_start(struct output_block * ob,enum LTO_tags tag)334 streamer_write_record_start (struct output_block *ob, enum LTO_tags tag)
335 {
336 streamer_write_enum (ob->main_stream, LTO_tags, LTO_NUM_TAGS, tag);
337 }
338
339 /* Return the next tag in the input block IB. */
340
341 static inline enum LTO_tags
streamer_read_record_start(class lto_input_block * ib)342 streamer_read_record_start (class lto_input_block *ib)
343 {
344 return streamer_read_enum (ib, LTO_tags, LTO_NUM_TAGS);
345 }
346
347 #endif /* GCC_DATA_STREAMER_H */
348