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 "hash-set.h"
  30 #include "vec.h"
  31 #include "input.h"
  32 #include "alias.h"
  33 #include "symtab.h"
  34 #include "inchash.h"
  35 #include "tree.h"
  36 #include "fold-const.h"
  37 #include "predict.h"
  38 #include "hard-reg-set.h"
  39 #include "input.h"
  40 #include "function.h"
  41 #include "basic-block.h"
  42 #include "tree-ssa-alias.h"
  43 #include "internal-fn.h"
  44 #include "gimple-expr.h"
  45 #include "is-a.h"
  46 #include "gimple.h"
  47 #include "bitmap.h"
  48 #include "diagnostic-core.h"
  49 #include "hash-map.h"
  50 #include "plugin-api.h"
  51 #include "ipa-ref.h"
  52 #include "cgraph.h"
  53 #include "tree-streamer.h"
  54 #include "lto-streamer.h"
  55 #include "lto-section-names.h"
  56 #include "streamer-hooks.h"
  57
  58 /* Statistics gathered during LTO, WPA and LTRANS.  */
  59 struct lto_stats_d lto_stats;
  60
  61 /* LTO uses bitmaps with different life-times.  So use a separate
  62    obstack for all LTO bitmaps.  */
  63 static bitmap_obstack lto_obstack;
  64 static bool lto_obstack_initialized;
  65
  66 const char *section_name_prefix = LTO_SECTION_NAME_PREFIX;
  67 /* Set when streaming LTO for offloading compiler.  */
  68 bool lto_stream_offload_p;
  69
  70 /* Return a string representing LTO tag TAG.  */
  71
  72 const char *
  73 lto_tag_name (enum LTO_tags tag)
  74 {
  75   if (lto_tag_is_tree_code_p (tag))
  76     {
  77       /* For tags representing tree nodes, return the name of the
  78          associated tree code.  */
  79       return get_tree_code_name (lto_tag_to_tree_code (tag));
  80     }
  81
  82   if (lto_tag_is_gimple_code_p (tag))
  83     {
  84       /* For tags representing gimple statements, return the name of
  85          the associated gimple code.  */
  86       return gimple_code_name[lto_tag_to_gimple_code (tag)];
  87     }
  88
  89   switch (tag)
  90     {
  91     case LTO_null:
  92       return "LTO_null";
  93     case LTO_bb0:
  94       return "LTO_bb0";
  95     case LTO_bb1:
  96       return "LTO_bb1";
  97     case LTO_eh_region:
  98       return "LTO_eh_region";
  99     case LTO_function:
 100       return "LTO_function";
 101     case LTO_eh_table:
 102       return "LTO_eh_table";
 103     case LTO_ert_cleanup:
 104       return "LTO_ert_cleanup";
 105     case LTO_ert_try:
 106       return "LTO_ert_try";
 107     case LTO_ert_allowed_exceptions:
 108       return "LTO_ert_allowed_exceptions";
 109     case LTO_ert_must_not_throw:
 110       return "LTO_ert_must_not_throw";
 111     case LTO_tree_pickle_reference:
 112       return "LTO_tree_pickle_reference";
 113     case LTO_field_decl_ref:
 114       return "LTO_field_decl_ref";
 115     case LTO_function_decl_ref:
 116       return "LTO_function_decl_ref";
 117     case LTO_label_decl_ref:
 118       return "LTO_label_decl_ref";
 119     case LTO_namespace_decl_ref:
 120       return "LTO_namespace_decl_ref";
 121     case LTO_result_decl_ref:
 122       return "LTO_result_decl_ref";
 123     case LTO_ssa_name_ref:
 124       return "LTO_ssa_name_ref";
 125     case LTO_type_decl_ref:
 126       return "LTO_type_decl_ref";
 127     case LTO_type_ref:
 128       return "LTO_type_ref";
 129     case LTO_global_decl_ref:
 130       return "LTO_global_decl_ref";
 131     default:
 132       return "LTO_UNKNOWN";
 133     }
 134 }
 135
 136
 137 /* Allocate a bitmap from heap.  Initializes the LTO obstack if necessary.  */
 138
 139 bitmap
 140 lto_bitmap_alloc (void)
 141 {
 142   if (!lto_obstack_initialized)
 143     {
 144       bitmap_obstack_initialize (&lto_obstack);
 145       lto_obstack_initialized = true;
 146     }
 147   return BITMAP_ALLOC (&lto_obstack);
 148 }
 149
 150 /* Free bitmap B.  */
 151
 152 void
 153 lto_bitmap_free (bitmap b)
 154 {
 155   BITMAP_FREE (b);
 156 }
 157
 158
 159 /* Get a section name for a particular type or name.  The NAME field
 160    is only used if SECTION_TYPE is LTO_section_function_body. For all
 161    others it is ignored.  The callee of this function is responsible
 162    to free the returned name.  */
 163
 164 char *
 165 lto_get_section_name (int section_type, const char *name, struct lto_file_decl_data *f)
 166 {
 167   const char *add;
 168   char post[32];
 169   const char *sep;
 170
 171   if (section_type == LTO_section_function_body)
 172     {
 173       gcc_assert (name != NULL);
 174       if (name[0] == '*')
 175         name++;
 176       add = name;
 177       sep = "";
 178     }
 179   else if (section_type < LTO_N_SECTION_TYPES)
 180     {
 181       add = lto_section_name[section_type];
 182       sep = ".";
 183     }
 184   else
 185     internal_error ("bytecode stream: unexpected LTO section %s", name);
 186
 187   /* Make the section name unique so that ld -r combining sections
 188      doesn't confuse the reader with merged sections.
 189
 190      For options don't add a ID, the option reader cannot deal with them
 191      and merging should be ok here. */
 192   if (section_type == LTO_section_opts)
 193     strcpy (post, "");
 194   else if (f != NULL)
 195     sprintf (post, "." HOST_WIDE_INT_PRINT_HEX_PURE, f->id);
 196   else
 197     sprintf (post, "." HOST_WIDE_INT_PRINT_HEX_PURE, get_random_seed (false));
 198   return concat (section_name_prefix, sep, add, post, NULL);
 199 }
 200
 201
 202 /* Show various memory usage statistics related to LTO.  */
 203
 204 void
 205 print_lto_report (const char *s)
 206 {
 207   unsigned i;
 208
 209   fprintf (stderr, "[%s] # of input files: "
 210            HOST_WIDE_INT_PRINT_UNSIGNED "\n", s, lto_stats.num_input_files);
 211
 212   fprintf (stderr, "[%s] # of input cgraph nodes: "
 213            HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 214            lto_stats.num_input_cgraph_nodes);
 215
 216   fprintf (stderr, "[%s] # of function bodies: "
 217            HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 218            lto_stats.num_function_bodies);
 219
 220   for (i = 0; i < NUM_TREE_CODES; i++)
 221     if (lto_stats.num_trees[i])
 222       fprintf (stderr, "[%s] # of '%s' objects read: "
 223                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 224                get_tree_code_name ((enum tree_code) i), lto_stats.num_trees[i]);
 225
 226   if (flag_lto)
 227     {
 228       fprintf (stderr, "[%s] Compression: "
 229                HOST_WIDE_INT_PRINT_UNSIGNED " output bytes, "
 230                HOST_WIDE_INT_PRINT_UNSIGNED " compressed bytes", s,
 231                lto_stats.num_output_il_bytes,
 232                lto_stats.num_compressed_il_bytes);
 233       if (lto_stats.num_output_il_bytes > 0)
 234         {
 235           const float dividend = (float) lto_stats.num_compressed_il_bytes;
 236           const float divisor = (float) lto_stats.num_output_il_bytes;
 237           fprintf (stderr, " (ratio: %f)", dividend / divisor);
 238         }
 239       fprintf (stderr, "\n");
 240     }
 241
 242   if (flag_wpa)
 243     {
 244       fprintf (stderr, "[%s] # of output files: "
 245                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 246                lto_stats.num_output_files);
 247
 248       fprintf (stderr, "[%s] # of output symtab nodes: "
 249                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 250                lto_stats.num_output_symtab_nodes);
 251
 252       fprintf (stderr, "[%s] # of output tree pickle references: "
 253                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 254                lto_stats.num_pickle_refs_output);
 255       fprintf (stderr, "[%s] # of output tree bodies: "
 256                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 257                lto_stats.num_tree_bodies_output);
 258
 259       fprintf (stderr, "[%s] # callgraph partitions: "
 260                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 261                lto_stats.num_cgraph_partitions);
 262
 263       fprintf (stderr, "[%s] Compression: "
 264                HOST_WIDE_INT_PRINT_UNSIGNED " input bytes, "
 265                HOST_WIDE_INT_PRINT_UNSIGNED " uncompressed bytes", s,
 266                lto_stats.num_input_il_bytes,
 267                lto_stats.num_uncompressed_il_bytes);
 268       if (lto_stats.num_input_il_bytes > 0)
 269         {
 270           const float dividend = (float) lto_stats.num_uncompressed_il_bytes;
 271           const float divisor = (float) lto_stats.num_input_il_bytes;
 272           fprintf (stderr, " (ratio: %f)", dividend / divisor);
 273         }
 274       fprintf (stderr, "\n");
 275     }
 276
 277   for (i = 0; i < LTO_N_SECTION_TYPES; i++)
 278     fprintf (stderr, "[%s] Size of mmap'd section %s: "
 279              HOST_WIDE_INT_PRINT_UNSIGNED " bytes\n", s,
 280              lto_section_name[i], lto_stats.section_size[i]);
 281 }
 282
 283
 284 #ifdef LTO_STREAMER_DEBUG
 285 struct tree_hash_entry
 286 {
 287   tree key;
 288   intptr_t value;
 289 };
 290
 291 struct tree_entry_hasher : typed_noop_remove <tree_hash_entry>
 292 {
 293   typedef tree_hash_entry value_type;
 294   typedef tree_hash_entry compare_type;
 295   static inline hashval_t hash (const value_type *);
 296   static inline bool equal (const value_type *, const compare_type *);
 297 };
 298
 299 inline hashval_t
 300 tree_entry_hasher::hash (const value_type *e)
 301 {
 302   return htab_hash_pointer (e->key);
 303 }
 304
 305 inline bool
 306 tree_entry_hasher::equal (const value_type *e1, const compare_type *e2)
 307 {
 308   return (e1->key == e2->key);
 309 }
 310
 311 static hash_table<tree_hash_entry> *tree_htab;
 312 #endif
 313
 314 /* Initialization common to the LTO reader and writer.  */
 315
 316 void
 317 lto_streamer_init (void)
 318 {
 319 #ifdef ENABLE_CHECKING
 320   /* Check that all the TS_* handled by the reader and writer routines
 321      match exactly the structures defined in treestruct.def.  When a
 322      new TS_* astructure is added, the streamer should be updated to
 323      handle it.  */
 324   streamer_check_handled_ts_structures ();
 325 #endif
 326
 327 #ifdef LTO_STREAMER_DEBUG
 328   tree_htab = new hash_table<tree_hash_entry> (31);
 329 #endif
 330 }
 331
 332
 333 /* Gate function for all LTO streaming passes.  */
 334
 335 bool
 336 gate_lto_out (void)
 337 {
 338   return ((flag_generate_lto || flag_generate_offload || in_lto_p)
 339           /* Don't bother doing anything if the program has errors.  */
 340           && !seen_error ());
 341 }
 342
 343
 344 #ifdef LTO_STREAMER_DEBUG
 345 /* Add a mapping between T and ORIG_T, which is the numeric value of
 346    the original address of T as it was seen by the LTO writer.  This
 347    mapping is useful when debugging streaming problems.  A debugging
 348    session can be started on both reader and writer using ORIG_T
 349    as a breakpoint value in both sessions.
 350
 351    Note that this mapping is transient and only valid while T is
 352    being reconstructed.  Once T is fully built, the mapping is
 353    removed.  */
 354
 355 void
 356 lto_orig_address_map (tree t, intptr_t orig_t)
 357 {
 358   struct tree_hash_entry ent;
 359   struct tree_hash_entry **slot;
 360
 361   ent.key = t;
 362   ent.value = orig_t;
 363   slot = tree_htab->find_slot (&ent, INSERT);
 364   gcc_assert (!*slot);
 365   *slot = XNEW (struct tree_hash_entry);
 366   **slot = ent;
 367 }
 368
 369
 370 /* Get the original address of T as it was seen by the writer.  This
 371    is only valid while T is being reconstructed.  */
 372
 373 intptr_t
 374 lto_orig_address_get (tree t)
 375 {
 376   struct tree_hash_entry ent;
 377   struct tree_hash_entry **slot;
 378
 379   ent.key = t;
 380   slot = tree_htab->find_slot (&ent, NO_INSERT);
 381   return (slot ? (*slot)->value : 0);
 382 }
 383
 384
 385 /* Clear the mapping of T to its original address.  */
 386
 387 void
 388 lto_orig_address_remove (tree t)
 389 {
 390   struct tree_hash_entry ent;
 391   struct tree_hash_entry **slot;
 392
 393   ent.key = t;
 394   slot = tree_htab->find_slot (&ent, NO_INSERT);
 395   gcc_assert (slot);
 396   free (*slot);
 397   tree_htab->clear_slot (slot);
 398 }
 399 #endif
 400
 401
 402 /* Check that the version MAJOR.MINOR is the correct version number.  */
 403
 404 void
 405 lto_check_version (int major, int minor)
 406 {
 407   if (major != LTO_major_version || minor != LTO_minor_version)
 408     fatal_error (input_location,
 409                  "bytecode stream generated with LTO version %d.%d instead "
 410                  "of the expected %d.%d",
 411                  major, minor,
 412                  LTO_major_version, LTO_minor_version);
 413 }
 414
 415
 416 /* Initialize all the streamer hooks used for streaming GIMPLE.  */
 417
 418 void
 419 lto_streamer_hooks_init (void)
 420 {
 421   streamer_hooks_init ();
 422   streamer_hooks.write_tree = lto_output_tree;
 423   streamer_hooks.read_tree = lto_input_tree;
 424   streamer_hooks.input_location = lto_input_location;
 425   streamer_hooks.output_location = lto_output_location;
 426 }