gcc/data-streamer.h

   1 /* Generic streaming support for various data types.
   2
   3    Copyright (C) 2011-2021 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_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.c  */
  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 static 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 static 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 static 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 static 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 static 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 static 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 static 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 static 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 static 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 static 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 static 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 static 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 static 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 static 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 static 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  */