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 void streamer_write_vrange (struct output_block *, const class vrange &);
  79
  80 /* In data-streamer-in.cc  */
  81 const char *streamer_read_string (class data_in *, class lto_input_block *);
  82 const char *streamer_read_indexed_string (class data_in *,
  83                                           class lto_input_block *,
  84                                           unsigned int *);
  85 const char *bp_unpack_indexed_string (class data_in *, struct bitpack_d *,
  86                                       unsigned int *);
  87 const char *bp_unpack_string (class data_in *, struct bitpack_d *);
  88 unsigned HOST_WIDE_INT streamer_read_uhwi (class lto_input_block *);
  89 HOST_WIDE_INT streamer_read_hwi (class lto_input_block *);
  90 poly_uint64 streamer_read_poly_uint64 (class lto_input_block *);
  91 poly_int64 streamer_read_poly_int64 (class lto_input_block *);
  92 gcov_type streamer_read_gcov_count (class lto_input_block *);
  93 wide_int streamer_read_wide_int (class lto_input_block *);
  94 widest_int streamer_read_widest_int (class lto_input_block *);
  95 void 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.  */
  99 inline struct bitpack_d
 100 bitpack_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.  */
 110 inline void
 111 bp_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.  */
 140 inline void
 141 bp_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.coeffs[i], nbits);
 147 }
 148
 149 /* Finishes bit-packing of BP.  */
 150 inline void
 151 streamer_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.  */
 160 inline struct bitpack_d
 161 streamer_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.  */
 171 inline bitpack_word_t
 172 bp_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.  */
 199 inline poly_int<NUM_POLY_INT_COEFFS, bitpack_word_t>
 200 bp_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
 211 inline void
 212 streamer_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
 229 inline unsigned char
 230 streamer_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
 241 inline void
 242 streamer_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
 259 inline HOST_WIDE_INT
 260 streamer_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
 280 inline void
 281 bp_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 (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
 299 inline HOST_WIDE_INT
 300 bp_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 (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
 340 inline void
 341 streamer_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
 348 inline enum LTO_tags
 349 streamer_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  */