gcc/lto-streamer.c

   1 /* Miscellaneous utilities for GIMPLE streaming.  Things that are used
   2    in both input and output are here.
   3
   4    Copyright (C) 2009-2015 Free Software Foundation, Inc.
   5    Contributed by Doug Kwan <dougkwan@google.com>
   6
   7 This file is part of GCC.
   8
   9 GCC is free software; you can redistribute it and/or modify it under
  10 the terms of the GNU General Public License as published by the Free
  11 Software Foundation; either version 3, or (at your option) any later
  12 version.
  13
  14 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  15 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  16 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  17 for more details.
  18
  19 You should have received a copy of the GNU General Public License
  20 along with GCC; see the file COPYING3.  If not see
  21 <http://www.gnu.org/licenses/>.  */
  22
  23 #include "config.h"
  24 #include "system.h"
  25 #include "coretypes.h"
  26 #include "tm.h"
  27 #include "toplev.h"
  28 #include "flags.h"
  29 #include "alias.h"
  30 #include "symtab.h"
  31 #include "tree.h"
  32 #include "fold-const.h"
  33 #include "predict.h"
  34 #include "hard-reg-set.h"
  35 #include "function.h"
  36 #include "basic-block.h"
  37 #include "tree-ssa-alias.h"
  38 #include "internal-fn.h"
  39 #include "gimple-expr.h"
  40 #include "gimple.h"
  41 #include "bitmap.h"
  42 #include "diagnostic-core.h"
  43 #include "plugin-api.h"
  44 #include "ipa-ref.h"
  45 #include "cgraph.h"
  46 #include "tree-streamer.h"
  47 #include "lto-streamer.h"
  48 #include "lto-section-names.h"
  49 #include "streamer-hooks.h"
  50
  51 /* Statistics gathered during LTO, WPA and LTRANS.  */
  52 struct lto_stats_d lto_stats;
  53
  54 /* LTO uses bitmaps with different life-times.  So use a separate
  55    obstack for all LTO bitmaps.  */
  56 static bitmap_obstack lto_obstack;
  57 static bool lto_obstack_initialized;
  58
  59 const char *section_name_prefix = LTO_SECTION_NAME_PREFIX;
  60 /* Set when streaming LTO for offloading compiler.  */
  61 bool lto_stream_offload_p;
  62
  63 /* Return a string representing LTO tag TAG.  */
  64
  65 const char *
  66 lto_tag_name (enum LTO_tags tag)
  67 {
  68   if (lto_tag_is_tree_code_p (tag))
  69     {
  70       /* For tags representing tree nodes, return the name of the
  71          associated tree code.  */
  72       return get_tree_code_name (lto_tag_to_tree_code (tag));
  73     }
  74
  75   if (lto_tag_is_gimple_code_p (tag))
  76     {
  77       /* For tags representing gimple statements, return the name of
  78          the associated gimple code.  */
  79       return gimple_code_name[lto_tag_to_gimple_code (tag)];
  80     }
  81
  82   switch (tag)
  83     {
  84     case LTO_null:
  85       return "LTO_null";
  86     case LTO_bb0:
  87       return "LTO_bb0";
  88     case LTO_bb1:
  89       return "LTO_bb1";
  90     case LTO_eh_region:
  91       return "LTO_eh_region";
  92     case LTO_function:
  93       return "LTO_function";
  94     case LTO_eh_table:
  95       return "LTO_eh_table";
  96     case LTO_ert_cleanup:
  97       return "LTO_ert_cleanup";
  98     case LTO_ert_try:
  99       return "LTO_ert_try";
 100     case LTO_ert_allowed_exceptions:
 101       return "LTO_ert_allowed_exceptions";
 102     case LTO_ert_must_not_throw:
 103       return "LTO_ert_must_not_throw";
 104     case LTO_tree_pickle_reference:
 105       return "LTO_tree_pickle_reference";
 106     case LTO_field_decl_ref:
 107       return "LTO_field_decl_ref";
 108     case LTO_function_decl_ref:
 109       return "LTO_function_decl_ref";
 110     case LTO_label_decl_ref:
 111       return "LTO_label_decl_ref";
 112     case LTO_namespace_decl_ref:
 113       return "LTO_namespace_decl_ref";
 114     case LTO_result_decl_ref:
 115       return "LTO_result_decl_ref";
 116     case LTO_ssa_name_ref:
 117       return "LTO_ssa_name_ref";
 118     case LTO_type_decl_ref:
 119       return "LTO_type_decl_ref";
 120     case LTO_type_ref:
 121       return "LTO_type_ref";
 122     case LTO_global_decl_ref:
 123       return "LTO_global_decl_ref";
 124     default:
 125       return "LTO_UNKNOWN";
 126     }
 127 }
 128
 129
 130 /* Allocate a bitmap from heap.  Initializes the LTO obstack if necessary.  */
 131
 132 bitmap
 133 lto_bitmap_alloc (void)
 134 {
 135   if (!lto_obstack_initialized)
 136     {
 137       bitmap_obstack_initialize (&lto_obstack);
 138       lto_obstack_initialized = true;
 139     }
 140   return BITMAP_ALLOC (&lto_obstack);
 141 }
 142
 143 /* Free bitmap B.  */
 144
 145 void
 146 lto_bitmap_free (bitmap b)
 147 {
 148   BITMAP_FREE (b);
 149 }
 150
 151
 152 /* Get a section name for a particular type or name.  The NAME field
 153    is only used if SECTION_TYPE is LTO_section_function_body. For all
 154    others it is ignored.  The callee of this function is responsible
 155    to free the returned name.  */
 156
 157 char *
 158 lto_get_section_name (int section_type, const char *name, struct lto_file_decl_data *f)
 159 {
 160   const char *add;
 161   char post[32];
 162   const char *sep;
 163
 164   if (section_type == LTO_section_function_body)
 165     {
 166       gcc_assert (name != NULL);
 167       if (name[0] == '*')
 168         name++;
 169       add = name;
 170       sep = "";
 171     }
 172   else if (section_type < LTO_N_SECTION_TYPES)
 173     {
 174       add = lto_section_name[section_type];
 175       sep = ".";
 176     }
 177   else
 178     internal_error ("bytecode stream: unexpected LTO section %s", name);
 179
 180   /* Make the section name unique so that ld -r combining sections
 181      doesn't confuse the reader with merged sections.
 182
 183      For options don't add a ID, the option reader cannot deal with them
 184      and merging should be ok here. */
 185   if (section_type == LTO_section_opts)
 186     strcpy (post, "");
 187   else if (f != NULL)
 188     sprintf (post, "." HOST_WIDE_INT_PRINT_HEX_PURE, f->id);
 189   else
 190     sprintf (post, "." HOST_WIDE_INT_PRINT_HEX_PURE, get_random_seed (false));
 191   return concat (section_name_prefix, sep, add, post, NULL);
 192 }
 193
 194
 195 /* Show various memory usage statistics related to LTO.  */
 196
 197 void
 198 print_lto_report (const char *s)
 199 {
 200   unsigned i;
 201
 202   fprintf (stderr, "[%s] # of input files: "
 203            HOST_WIDE_INT_PRINT_UNSIGNED "\n", s, lto_stats.num_input_files);
 204
 205   fprintf (stderr, "[%s] # of input cgraph nodes: "
 206            HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 207            lto_stats.num_input_cgraph_nodes);
 208
 209   fprintf (stderr, "[%s] # of function bodies: "
 210            HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 211            lto_stats.num_function_bodies);
 212
 213   for (i = 0; i < NUM_TREE_CODES; i++)
 214     if (lto_stats.num_trees[i])
 215       fprintf (stderr, "[%s] # of '%s' objects read: "
 216                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 217                get_tree_code_name ((enum tree_code) i), lto_stats.num_trees[i]);
 218
 219   if (flag_lto)
 220     {
 221       fprintf (stderr, "[%s] Compression: "
 222                HOST_WIDE_INT_PRINT_UNSIGNED " output bytes, "
 223                HOST_WIDE_INT_PRINT_UNSIGNED " compressed bytes", s,
 224                lto_stats.num_output_il_bytes,
 225                lto_stats.num_compressed_il_bytes);
 226       if (lto_stats.num_output_il_bytes > 0)
 227         {
 228           const float dividend = (float) lto_stats.num_compressed_il_bytes;
 229           const float divisor = (float) lto_stats.num_output_il_bytes;
 230           fprintf (stderr, " (ratio: %f)", dividend / divisor);
 231         }
 232       fprintf (stderr, "\n");
 233     }
 234
 235   if (flag_wpa)
 236     {
 237       fprintf (stderr, "[%s] # of output files: "
 238                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 239                lto_stats.num_output_files);
 240
 241       fprintf (stderr, "[%s] # of output symtab nodes: "
 242                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 243                lto_stats.num_output_symtab_nodes);
 244
 245       fprintf (stderr, "[%s] # of output tree pickle references: "
 246                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 247                lto_stats.num_pickle_refs_output);
 248       fprintf (stderr, "[%s] # of output tree bodies: "
 249                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 250                lto_stats.num_tree_bodies_output);
 251
 252       fprintf (stderr, "[%s] # callgraph partitions: "
 253                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 254                lto_stats.num_cgraph_partitions);
 255
 256       fprintf (stderr, "[%s] Compression: "
 257                HOST_WIDE_INT_PRINT_UNSIGNED " input bytes, "
 258                HOST_WIDE_INT_PRINT_UNSIGNED " uncompressed bytes", s,
 259                lto_stats.num_input_il_bytes,
 260                lto_stats.num_uncompressed_il_bytes);
 261       if (lto_stats.num_input_il_bytes > 0)
 262         {
 263           const float dividend = (float) lto_stats.num_uncompressed_il_bytes;
 264           const float divisor = (float) lto_stats.num_input_il_bytes;
 265           fprintf (stderr, " (ratio: %f)", dividend / divisor);
 266         }
 267       fprintf (stderr, "\n");
 268     }
 269
 270   for (i = 0; i < LTO_N_SECTION_TYPES; i++)
 271     fprintf (stderr, "[%s] Size of mmap'd section %s: "
 272              HOST_WIDE_INT_PRINT_UNSIGNED " bytes\n", s,
 273              lto_section_name[i], lto_stats.section_size[i]);
 274 }
 275
 276
 277 #ifdef LTO_STREAMER_DEBUG
 278 struct tree_hash_entry
 279 {
 280   tree key;
 281   intptr_t value;
 282 };
 283
 284 struct tree_entry_hasher : typed_noop_remove <tree_hash_entry>
 285 {
 286   typedef tree_hash_entry value_type;
 287   typedef tree_hash_entry compare_type;
 288   static inline hashval_t hash (const value_type *);
 289   static inline bool equal (const value_type *, const compare_type *);
 290 };
 291
 292 inline hashval_t
 293 tree_entry_hasher::hash (const value_type *e)
 294 {
 295   return htab_hash_pointer (e->key);
 296 }
 297
 298 inline bool
 299 tree_entry_hasher::equal (const value_type *e1, const compare_type *e2)
 300 {
 301   return (e1->key == e2->key);
 302 }
 303
 304 static hash_table<tree_hash_entry> *tree_htab;
 305 #endif
 306
 307 /* Initialization common to the LTO reader and writer.  */
 308
 309 void
 310 lto_streamer_init (void)
 311 {
 312 #ifdef ENABLE_CHECKING
 313   /* Check that all the TS_* handled by the reader and writer routines
 314      match exactly the structures defined in treestruct.def.  When a
 315      new TS_* astructure is added, the streamer should be updated to
 316      handle it.  */
 317   streamer_check_handled_ts_structures ();
 318 #endif
 319
 320 #ifdef LTO_STREAMER_DEBUG
 321   tree_htab = new hash_table<tree_hash_entry> (31);
 322 #endif
 323 }
 324
 325
 326 /* Gate function for all LTO streaming passes.  */
 327
 328 bool
 329 gate_lto_out (void)
 330 {
 331   return ((flag_generate_lto || flag_generate_offload || in_lto_p)
 332           /* Don't bother doing anything if the program has errors.  */
 333           && !seen_error ());
 334 }
 335
 336
 337 #ifdef LTO_STREAMER_DEBUG
 338 /* Add a mapping between T and ORIG_T, which is the numeric value of
 339    the original address of T as it was seen by the LTO writer.  This
 340    mapping is useful when debugging streaming problems.  A debugging
 341    session can be started on both reader and writer using ORIG_T
 342    as a breakpoint value in both sessions.
 343
 344    Note that this mapping is transient and only valid while T is
 345    being reconstructed.  Once T is fully built, the mapping is
 346    removed.  */
 347
 348 void
 349 lto_orig_address_map (tree t, intptr_t orig_t)
 350 {
 351   struct tree_hash_entry ent;
 352   struct tree_hash_entry **slot;
 353
 354   ent.key = t;
 355   ent.value = orig_t;
 356   slot = tree_htab->find_slot (&ent, INSERT);
 357   gcc_assert (!*slot);
 358   *slot = XNEW (struct tree_hash_entry);
 359   **slot = ent;
 360 }
 361
 362
 363 /* Get the original address of T as it was seen by the writer.  This
 364    is only valid while T is being reconstructed.  */
 365
 366 intptr_t
 367 lto_orig_address_get (tree t)
 368 {
 369   struct tree_hash_entry ent;
 370   struct tree_hash_entry **slot;
 371
 372   ent.key = t;
 373   slot = tree_htab->find_slot (&ent, NO_INSERT);
 374   return (slot ? (*slot)->value : 0);
 375 }
 376
 377
 378 /* Clear the mapping of T to its original address.  */
 379
 380 void
 381 lto_orig_address_remove (tree t)
 382 {
 383   struct tree_hash_entry ent;
 384   struct tree_hash_entry **slot;
 385
 386   ent.key = t;
 387   slot = tree_htab->find_slot (&ent, NO_INSERT);
 388   gcc_assert (slot);
 389   free (*slot);
 390   tree_htab->clear_slot (slot);
 391 }
 392 #endif
 393
 394
 395 /* Check that the version MAJOR.MINOR is the correct version number.  */
 396
 397 void
 398 lto_check_version (int major, int minor)
 399 {
 400   if (major != LTO_major_version || minor != LTO_minor_version)
 401     fatal_error (input_location,
 402                  "bytecode stream generated with LTO version %d.%d instead "
 403                  "of the expected %d.%d",
 404                  major, minor,
 405                  LTO_major_version, LTO_minor_version);
 406 }
 407
 408
 409 /* Initialize all the streamer hooks used for streaming GIMPLE.  */
 410
 411 void
 412 lto_streamer_hooks_init (void)
 413 {
 414   streamer_hooks_init ();
 415   streamer_hooks.write_tree = lto_output_tree;
 416   streamer_hooks.read_tree = lto_input_tree;
 417   streamer_hooks.input_location = lto_input_location;
 418   streamer_hooks.output_location = lto_output_location;
 419 }