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) 2009-2014 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 "tree.h"
  30 #include "predict.h"
  31 #include "vec.h"
  32 #include "hashtab.h"
  33 #include "hash-set.h"
  34 #include "machmode.h"
  35 #include "hard-reg-set.h"
  36 #include "input.h"
  37 #include "function.h"
  38 #include "basic-block.h"
  39 #include "tree-ssa-alias.h"
  40 #include "internal-fn.h"
  41 #include "gimple-expr.h"
  42 #include "is-a.h"
  43 #include "gimple.h"
  44 #include "bitmap.h"
  45 #include "diagnostic-core.h"
  46 #include "hash-map.h"
  47 #include "plugin-api.h"
  48 #include "ipa-ref.h"
  49 #include "cgraph.h"
  50 #include "tree-streamer.h"
  51 #include "lto-streamer.h"
  52 #include "lto-section-names.h"
  53 #include "streamer-hooks.h"
  54
  55 /* Statistics gathered during LTO, WPA and LTRANS.  */
  56 struct lto_stats_d lto_stats;
  57
  58 /* LTO uses bitmaps with different life-times.  So use a separate
  59    obstack for all LTO bitmaps.  */
  60 static bitmap_obstack lto_obstack;
  61 static bool lto_obstack_initialized;
  62
  63
  64 /* Return a string representing LTO tag TAG.  */
  65
  66 const char *
  67 lto_tag_name (enum LTO_tags tag)
  68 {
  69   if (lto_tag_is_tree_code_p (tag))
  70     {
  71       /* For tags representing tree nodes, return the name of the
  72          associated tree code.  */
  73       return get_tree_code_name (lto_tag_to_tree_code (tag));
  74     }
  75
  76   if (lto_tag_is_gimple_code_p (tag))
  77     {
  78       /* For tags representing gimple statements, return the name of
  79          the associated gimple code.  */
  80       return gimple_code_name[lto_tag_to_gimple_code (tag)];
  81     }
  82
  83   switch (tag)
  84     {
  85     case LTO_null:
  86       return "LTO_null";
  87     case LTO_bb0:
  88       return "LTO_bb0";
  89     case LTO_bb1:
  90       return "LTO_bb1";
  91     case LTO_eh_region:
  92       return "LTO_eh_region";
  93     case LTO_function:
  94       return "LTO_function";
  95     case LTO_eh_table:
  96       return "LTO_eh_table";
  97     case LTO_ert_cleanup:
  98       return "LTO_ert_cleanup";
  99     case LTO_ert_try:
 100       return "LTO_ert_try";
 101     case LTO_ert_allowed_exceptions:
 102       return "LTO_ert_allowed_exceptions";
 103     case LTO_ert_must_not_throw:
 104       return "LTO_ert_must_not_throw";
 105     case LTO_tree_pickle_reference:
 106       return "LTO_tree_pickle_reference";
 107     case LTO_field_decl_ref:
 108       return "LTO_field_decl_ref";
 109     case LTO_function_decl_ref:
 110       return "LTO_function_decl_ref";
 111     case LTO_label_decl_ref:
 112       return "LTO_label_decl_ref";
 113     case LTO_namespace_decl_ref:
 114       return "LTO_namespace_decl_ref";
 115     case LTO_result_decl_ref:
 116       return "LTO_result_decl_ref";
 117     case LTO_ssa_name_ref:
 118       return "LTO_ssa_name_ref";
 119     case LTO_type_decl_ref:
 120       return "LTO_type_decl_ref";
 121     case LTO_type_ref:
 122       return "LTO_type_ref";
 123     case LTO_global_decl_ref:
 124       return "LTO_global_decl_ref";
 125     default:
 126       return "LTO_UNKNOWN";
 127     }
 128 }
 129
 130
 131 /* Allocate a bitmap from heap.  Initializes the LTO obstack if necessary.  */
 132
 133 bitmap
 134 lto_bitmap_alloc (void)
 135 {
 136   if (!lto_obstack_initialized)
 137     {
 138       bitmap_obstack_initialize (&lto_obstack);
 139       lto_obstack_initialized = true;
 140     }
 141   return BITMAP_ALLOC (&lto_obstack);
 142 }
 143
 144 /* Free bitmap B.  */
 145
 146 void
 147 lto_bitmap_free (bitmap b)
 148 {
 149   BITMAP_FREE (b);
 150 }
 151
 152
 153 /* Get a section name for a particular type or name.  The NAME field
 154    is only used if SECTION_TYPE is LTO_section_function_body. For all
 155    others it is ignored.  The callee of this function is responsible
 156    to free the returned name.  */
 157
 158 char *
 159 lto_get_section_name (int section_type, const char *name, struct lto_file_decl_data *f)
 160 {
 161   const char *add;
 162   char post[32];
 163   const char *sep;
 164
 165   if (section_type == LTO_section_function_body)
 166     {
 167       gcc_assert (name != NULL);
 168       if (name[0] == '*')
 169         name++;
 170       add = name;
 171       sep = "";
 172     }
 173   else if (section_type < LTO_N_SECTION_TYPES)
 174     {
 175       add = lto_section_name[section_type];
 176       sep = ".";
 177     }
 178   else
 179     internal_error ("bytecode stream: unexpected LTO section %s", name);
 180
 181   /* Make the section name unique so that ld -r combining sections
 182      doesn't confuse the reader with merged sections.
 183
 184      For options don't add a ID, the option reader cannot deal with them
 185      and merging should be ok here. */
 186   if (section_type == LTO_section_opts)
 187     strcpy (post, "");
 188   else if (f != NULL)
 189     sprintf (post, "." HOST_WIDE_INT_PRINT_HEX_PURE, f->id);
 190   else
 191     sprintf (post, "." HOST_WIDE_INT_PRINT_HEX_PURE, get_random_seed (false));
 192   return concat (LTO_SECTION_NAME_PREFIX, sep, add, post, NULL);
 193 }
 194
 195
 196 /* Show various memory usage statistics related to LTO.  */
 197
 198 void
 199 print_lto_report (const char *s)
 200 {
 201   unsigned i;
 202
 203   fprintf (stderr, "[%s] # of input files: "
 204            HOST_WIDE_INT_PRINT_UNSIGNED "\n", s, lto_stats.num_input_files);
 205
 206   fprintf (stderr, "[%s] # of input cgraph nodes: "
 207            HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 208            lto_stats.num_input_cgraph_nodes);
 209
 210   fprintf (stderr, "[%s] # of function bodies: "
 211            HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 212            lto_stats.num_function_bodies);
 213
 214   for (i = 0; i < NUM_TREE_CODES; i++)
 215     if (lto_stats.num_trees[i])
 216       fprintf (stderr, "[%s] # of '%s' objects read: "
 217                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 218                get_tree_code_name ((enum tree_code) i), lto_stats.num_trees[i]);
 219
 220   if (flag_lto)
 221     {
 222       fprintf (stderr, "[%s] Compression: "
 223                HOST_WIDE_INT_PRINT_UNSIGNED " output bytes, "
 224                HOST_WIDE_INT_PRINT_UNSIGNED " compressed bytes", s,
 225                lto_stats.num_output_il_bytes,
 226                lto_stats.num_compressed_il_bytes);
 227       if (lto_stats.num_output_il_bytes > 0)
 228         {
 229           const float dividend = (float) lto_stats.num_compressed_il_bytes;
 230           const float divisor = (float) lto_stats.num_output_il_bytes;
 231           fprintf (stderr, " (ratio: %f)", dividend / divisor);
 232         }
 233       fprintf (stderr, "\n");
 234     }
 235
 236   if (flag_wpa)
 237     {
 238       fprintf (stderr, "[%s] # of output files: "
 239                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 240                lto_stats.num_output_files);
 241
 242       fprintf (stderr, "[%s] # of output symtab nodes: "
 243                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 244                lto_stats.num_output_symtab_nodes);
 245
 246       fprintf (stderr, "[%s] # of output tree pickle references: "
 247                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 248                lto_stats.num_pickle_refs_output);
 249       fprintf (stderr, "[%s] # of output tree bodies: "
 250                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 251                lto_stats.num_tree_bodies_output);
 252
 253       fprintf (stderr, "[%s] # callgraph partitions: "
 254                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 255                lto_stats.num_cgraph_partitions);
 256
 257       fprintf (stderr, "[%s] Compression: "
 258                HOST_WIDE_INT_PRINT_UNSIGNED " input bytes, "
 259                HOST_WIDE_INT_PRINT_UNSIGNED " uncompressed bytes", s,
 260                lto_stats.num_input_il_bytes,
 261                lto_stats.num_uncompressed_il_bytes);
 262       if (lto_stats.num_input_il_bytes > 0)
 263         {
 264           const float dividend = (float) lto_stats.num_uncompressed_il_bytes;
 265           const float divisor = (float) lto_stats.num_input_il_bytes;
 266           fprintf (stderr, " (ratio: %f)", dividend / divisor);
 267         }
 268       fprintf (stderr, "\n");
 269     }
 270
 271   for (i = 0; i < LTO_N_SECTION_TYPES; i++)
 272     fprintf (stderr, "[%s] Size of mmap'd section %s: "
 273              HOST_WIDE_INT_PRINT_UNSIGNED " bytes\n", s,
 274              lto_section_name[i], lto_stats.section_size[i]);
 275 }
 276
 277
 278 #ifdef LTO_STREAMER_DEBUG
 279 struct tree_hash_entry
 280 {
 281   tree key;
 282   intptr_t value;
 283 };
 284
 285 struct tree_entry_hasher : typed_noop_remove <tree_hash_entry>
 286 {
 287   typedef tree_hash_entry value_type;
 288   typedef tree_hash_entry compare_type;
 289   static inline hashval_t hash (const value_type *);
 290   static inline bool equal (const value_type *, const compare_type *);
 291 };
 292
 293 inline hashval_t
 294 tree_entry_hasher::hash (const value_type *e)
 295 {
 296   return htab_hash_pointer (e->key);
 297 }
 298
 299 inline bool
 300 tree_entry_hasher::equal (const value_type *e1, const compare_type *e2)
 301 {
 302   return (e1->key == e2->key);
 303 }
 304
 305 static hash_table<tree_hash_entry> *tree_htab;
 306 #endif
 307
 308 /* Initialization common to the LTO reader and writer.  */
 309
 310 void
 311 lto_streamer_init (void)
 312 {
 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
 319 #ifdef LTO_STREAMER_DEBUG
 320   tree_htab = new hash_table<tree_hash_entry> (31);
 321 #endif
 322 }
 323
 324
 325 /* Gate function for all LTO streaming passes.  */
 326
 327 bool
 328 gate_lto_out (void)
 329 {
 330   return ((flag_generate_lto || in_lto_p)
 331           /* Don't bother doing anything if the program has errors.  */
 332           && !seen_error ());
 333 }
 334
 335
 336 #ifdef LTO_STREAMER_DEBUG
 337 /* Add a mapping between T and ORIG_T, which is the numeric value of
 338    the original address of T as it was seen by the LTO writer.  This
 339    mapping is useful when debugging streaming problems.  A debugging
 340    session can be started on both reader and writer using ORIG_T
 341    as a breakpoint value in both sessions.
 342
 343    Note that this mapping is transient and only valid while T is
 344    being reconstructed.  Once T is fully built, the mapping is
 345    removed.  */
 346
 347 void
 348 lto_orig_address_map (tree t, intptr_t orig_t)
 349 {
 350   struct tree_hash_entry ent;
 351   struct tree_hash_entry **slot;
 352
 353   ent.key = t;
 354   ent.value = orig_t;
 355   slot = tree_htab->find_slot (&ent, INSERT);
 356   gcc_assert (!*slot);
 357   *slot = XNEW (struct tree_hash_entry);
 358   **slot = ent;
 359 }
 360
 361
 362 /* Get the original address of T as it was seen by the writer.  This
 363    is only valid while T is being reconstructed.  */
 364
 365 intptr_t
 366 lto_orig_address_get (tree t)
 367 {
 368   struct tree_hash_entry ent;
 369   struct tree_hash_entry **slot;
 370
 371   ent.key = t;
 372   slot = tree_htab->find_slot (&ent, NO_INSERT);
 373   return (slot ? (*slot)->value : 0);
 374 }
 375
 376
 377 /* Clear the mapping of T to its original address.  */
 378
 379 void
 380 lto_orig_address_remove (tree t)
 381 {
 382   struct tree_hash_entry ent;
 383   struct tree_hash_entry **slot;
 384
 385   ent.key = t;
 386   slot = tree_htab->find_slot (&ent, NO_INSERT);
 387   gcc_assert (slot);
 388   free (*slot);
 389   tree_htab->clear_slot (slot);
 390 }
 391 #endif
 392
 393
 394 /* Check that the version MAJOR.MINOR is the correct version number.  */
 395
 396 void
 397 lto_check_version (int major, int minor)
 398 {
 399   if (major != LTO_major_version || minor != LTO_minor_version)
 400     fatal_error ("bytecode stream generated with LTO version %d.%d instead "
 401                  "of the expected %d.%d",
 402                  major, minor,
 403                  LTO_major_version, LTO_minor_version);
 404 }
 405
 406
 407 /* Initialize all the streamer hooks used for streaming GIMPLE.  */
 408
 409 void
 410 lto_streamer_hooks_init (void)
 411 {
 412   streamer_hooks_init ();
 413   streamer_hooks.write_tree = lto_output_tree;
 414   streamer_hooks.read_tree = lto_input_tree;
 415   streamer_hooks.input_location = lto_input_location;
 416   streamer_hooks.output_location = lto_output_location;
 417 }