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