gcc/data-streamer.h

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