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 "machmode.h"
  31 #include "vec.h"
  32 #include "double-int.h"
  33 #include "input.h"
  34 #include "alias.h"
  35 #include "symtab.h"
  36 #include "wide-int.h"
  37 #include "inchash.h"
  38 #include "tree.h"
  39 #include "fold-const.h"
  40 #include "predict.h"
  41 #include "hard-reg-set.h"
  42 #include "input.h"
  43 #include "function.h"
  44 #include "basic-block.h"
  45 #include "tree-ssa-alias.h"
  46 #include "internal-fn.h"
  47 #include "gimple-expr.h"
  48 #include "is-a.h"
  49 #include "gimple.h"
  50 #include "bitmap.h"
  51 #include "diagnostic-core.h"
  52 #include "hash-map.h"
  53 #include "plugin-api.h"
  54 #include "ipa-ref.h"
  55 #include "cgraph.h"
  56 #include "tree-streamer.h"
  57 #include "lto-streamer.h"
  58 #include "lto-section-names.h"
  59 #include "streamer-hooks.h"
  60
  61 /* Statistics gathered during LTO, WPA and LTRANS.  */
  62 struct lto_stats_d lto_stats;
  63
  64 /* LTO uses bitmaps with different life-times.  So use a separate
  65    obstack for all LTO bitmaps.  */
  66 static bitmap_obstack lto_obstack;
  67 static bool lto_obstack_initialized;
  68
  69 const char *section_name_prefix = LTO_SECTION_NAME_PREFIX;
  70 /* Set when streaming LTO for offloading compiler.  */
  71 bool lto_stream_offload_p;
  72
  73 /* Return a string representing LTO tag TAG.  */
  74
  75 const char *
  76 lto_tag_name (enum LTO_tags tag)
  77 {
  78   if (lto_tag_is_tree_code_p (tag))
  79     {
  80       /* For tags representing tree nodes, return the name of the
  81          associated tree code.  */
  82       return get_tree_code_name (lto_tag_to_tree_code (tag));
  83     }
  84
  85   if (lto_tag_is_gimple_code_p (tag))
  86     {
  87       /* For tags representing gimple statements, return the name of
  88          the associated gimple code.  */
  89       return gimple_code_name[lto_tag_to_gimple_code (tag)];
  90     }
  91
  92   switch (tag)
  93     {
  94     case LTO_null:
  95       return "LTO_null";
  96     case LTO_bb0:
  97       return "LTO_bb0";
  98     case LTO_bb1:
  99       return "LTO_bb1";
 100     case LTO_eh_region:
 101       return "LTO_eh_region";
 102     case LTO_function:
 103       return "LTO_function";
 104     case LTO_eh_table:
 105       return "LTO_eh_table";
 106     case LTO_ert_cleanup:
 107       return "LTO_ert_cleanup";
 108     case LTO_ert_try:
 109       return "LTO_ert_try";
 110     case LTO_ert_allowed_exceptions:
 111       return "LTO_ert_allowed_exceptions";
 112     case LTO_ert_must_not_throw:
 113       return "LTO_ert_must_not_throw";
 114     case LTO_tree_pickle_reference:
 115       return "LTO_tree_pickle_reference";
 116     case LTO_field_decl_ref:
 117       return "LTO_field_decl_ref";
 118     case LTO_function_decl_ref:
 119       return "LTO_function_decl_ref";
 120     case LTO_label_decl_ref:
 121       return "LTO_label_decl_ref";
 122     case LTO_namespace_decl_ref:
 123       return "LTO_namespace_decl_ref";
 124     case LTO_result_decl_ref:
 125       return "LTO_result_decl_ref";
 126     case LTO_ssa_name_ref:
 127       return "LTO_ssa_name_ref";
 128     case LTO_type_decl_ref:
 129       return "LTO_type_decl_ref";
 130     case LTO_type_ref:
 131       return "LTO_type_ref";
 132     case LTO_global_decl_ref:
 133       return "LTO_global_decl_ref";
 134     default:
 135       return "LTO_UNKNOWN";
 136     }
 137 }
 138
 139
 140 /* Allocate a bitmap from heap.  Initializes the LTO obstack if necessary.  */
 141
 142 bitmap
 143 lto_bitmap_alloc (void)
 144 {
 145   if (!lto_obstack_initialized)
 146     {
 147       bitmap_obstack_initialize (&lto_obstack);
 148       lto_obstack_initialized = true;
 149     }
 150   return BITMAP_ALLOC (&lto_obstack);
 151 }
 152
 153 /* Free bitmap B.  */
 154
 155 void
 156 lto_bitmap_free (bitmap b)
 157 {
 158   BITMAP_FREE (b);
 159 }
 160
 161
 162 /* Get a section name for a particular type or name.  The NAME field
 163    is only used if SECTION_TYPE is LTO_section_function_body. For all
 164    others it is ignored.  The callee of this function is responsible
 165    to free the returned name.  */
 166
 167 char *
 168 lto_get_section_name (int section_type, const char *name, struct lto_file_decl_data *f)
 169 {
 170   const char *add;
 171   char post[32];
 172   const char *sep;
 173
 174   if (section_type == LTO_section_function_body)
 175     {
 176       gcc_assert (name != NULL);
 177       if (name[0] == '*')
 178         name++;
 179       add = name;
 180       sep = "";
 181     }
 182   else if (section_type < LTO_N_SECTION_TYPES)
 183     {
 184       add = lto_section_name[section_type];
 185       sep = ".";
 186     }
 187   else
 188     internal_error ("bytecode stream: unexpected LTO section %s", name);
 189
 190   /* Make the section name unique so that ld -r combining sections
 191      doesn't confuse the reader with merged sections.
 192
 193      For options don't add a ID, the option reader cannot deal with them
 194      and merging should be ok here. */
 195   if (section_type == LTO_section_opts)
 196     strcpy (post, "");
 197   else if (f != NULL)
 198     sprintf (post, "." HOST_WIDE_INT_PRINT_HEX_PURE, f->id);
 199   else
 200     sprintf (post, "." HOST_WIDE_INT_PRINT_HEX_PURE, get_random_seed (false));
 201   return concat (section_name_prefix, sep, add, post, NULL);
 202 }
 203
 204
 205 /* Show various memory usage statistics related to LTO.  */
 206
 207 void
 208 print_lto_report (const char *s)
 209 {
 210   unsigned i;
 211
 212   fprintf (stderr, "[%s] # of input files: "
 213            HOST_WIDE_INT_PRINT_UNSIGNED "\n", s, lto_stats.num_input_files);
 214
 215   fprintf (stderr, "[%s] # of input cgraph nodes: "
 216            HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 217            lto_stats.num_input_cgraph_nodes);
 218
 219   fprintf (stderr, "[%s] # of function bodies: "
 220            HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 221            lto_stats.num_function_bodies);
 222
 223   for (i = 0; i < NUM_TREE_CODES; i++)
 224     if (lto_stats.num_trees[i])
 225       fprintf (stderr, "[%s] # of '%s' objects read: "
 226                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 227                get_tree_code_name ((enum tree_code) i), lto_stats.num_trees[i]);
 228
 229   if (flag_lto)
 230     {
 231       fprintf (stderr, "[%s] Compression: "
 232                HOST_WIDE_INT_PRINT_UNSIGNED " output bytes, "
 233                HOST_WIDE_INT_PRINT_UNSIGNED " compressed bytes", s,
 234                lto_stats.num_output_il_bytes,
 235                lto_stats.num_compressed_il_bytes);
 236       if (lto_stats.num_output_il_bytes > 0)
 237         {
 238           const float dividend = (float) lto_stats.num_compressed_il_bytes;
 239           const float divisor = (float) lto_stats.num_output_il_bytes;
 240           fprintf (stderr, " (ratio: %f)", dividend / divisor);
 241         }
 242       fprintf (stderr, "\n");
 243     }
 244
 245   if (flag_wpa)
 246     {
 247       fprintf (stderr, "[%s] # of output files: "
 248                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 249                lto_stats.num_output_files);
 250
 251       fprintf (stderr, "[%s] # of output symtab nodes: "
 252                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 253                lto_stats.num_output_symtab_nodes);
 254
 255       fprintf (stderr, "[%s] # of output tree pickle references: "
 256                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 257                lto_stats.num_pickle_refs_output);
 258       fprintf (stderr, "[%s] # of output tree bodies: "
 259                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 260                lto_stats.num_tree_bodies_output);
 261
 262       fprintf (stderr, "[%s] # callgraph partitions: "
 263                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 264                lto_stats.num_cgraph_partitions);
 265
 266       fprintf (stderr, "[%s] Compression: "
 267                HOST_WIDE_INT_PRINT_UNSIGNED " input bytes, "
 268                HOST_WIDE_INT_PRINT_UNSIGNED " uncompressed bytes", s,
 269                lto_stats.num_input_il_bytes,
 270                lto_stats.num_uncompressed_il_bytes);
 271       if (lto_stats.num_input_il_bytes > 0)
 272         {
 273           const float dividend = (float) lto_stats.num_uncompressed_il_bytes;
 274           const float divisor = (float) lto_stats.num_input_il_bytes;
 275           fprintf (stderr, " (ratio: %f)", dividend / divisor);
 276         }
 277       fprintf (stderr, "\n");
 278     }
 279
 280   for (i = 0; i < LTO_N_SECTION_TYPES; i++)
 281     fprintf (stderr, "[%s] Size of mmap'd section %s: "
 282              HOST_WIDE_INT_PRINT_UNSIGNED " bytes\n", s,
 283              lto_section_name[i], lto_stats.section_size[i]);
 284 }
 285
 286
 287 #ifdef LTO_STREAMER_DEBUG
 288 struct tree_hash_entry
 289 {
 290   tree key;
 291   intptr_t value;
 292 };
 293
 294 struct tree_entry_hasher : typed_noop_remove <tree_hash_entry>
 295 {
 296   typedef tree_hash_entry value_type;
 297   typedef tree_hash_entry compare_type;
 298   static inline hashval_t hash (const value_type *);
 299   static inline bool equal (const value_type *, const compare_type *);
 300 };
 301
 302 inline hashval_t
 303 tree_entry_hasher::hash (const value_type *e)
 304 {
 305   return htab_hash_pointer (e->key);
 306 }
 307
 308 inline bool
 309 tree_entry_hasher::equal (const value_type *e1, const compare_type *e2)
 310 {
 311   return (e1->key == e2->key);
 312 }
 313
 314 static hash_table<tree_hash_entry> *tree_htab;
 315 #endif
 316
 317 /* Initialization common to the LTO reader and writer.  */
 318
 319 void
 320 lto_streamer_init (void)
 321 {
 322   /* Check that all the TS_* handled by the reader and writer routines
 323      match exactly the structures defined in treestruct.def.  When a
 324      new TS_* astructure is added, the streamer should be updated to
 325      handle it.  */
 326   streamer_check_handled_ts_structures ();
 327
 328 #ifdef LTO_STREAMER_DEBUG
 329   tree_htab = new hash_table<tree_hash_entry> (31);
 330 #endif
 331 }
 332
 333
 334 /* Gate function for all LTO streaming passes.  */
 335
 336 bool
 337 gate_lto_out (void)
 338 {
 339   return ((flag_generate_lto || flag_generate_offload || in_lto_p)
 340           /* Don't bother doing anything if the program has errors.  */
 341           && !seen_error ());
 342 }
 343
 344
 345 #ifdef LTO_STREAMER_DEBUG
 346 /* Add a mapping between T and ORIG_T, which is the numeric value of
 347    the original address of T as it was seen by the LTO writer.  This
 348    mapping is useful when debugging streaming problems.  A debugging
 349    session can be started on both reader and writer using ORIG_T
 350    as a breakpoint value in both sessions.
 351
 352    Note that this mapping is transient and only valid while T is
 353    being reconstructed.  Once T is fully built, the mapping is
 354    removed.  */
 355
 356 void
 357 lto_orig_address_map (tree t, intptr_t orig_t)
 358 {
 359   struct tree_hash_entry ent;
 360   struct tree_hash_entry **slot;
 361
 362   ent.key = t;
 363   ent.value = orig_t;
 364   slot = tree_htab->find_slot (&ent, INSERT);
 365   gcc_assert (!*slot);
 366   *slot = XNEW (struct tree_hash_entry);
 367   **slot = ent;
 368 }
 369
 370
 371 /* Get the original address of T as it was seen by the writer.  This
 372    is only valid while T is being reconstructed.  */
 373
 374 intptr_t
 375 lto_orig_address_get (tree t)
 376 {
 377   struct tree_hash_entry ent;
 378   struct tree_hash_entry **slot;
 379
 380   ent.key = t;
 381   slot = tree_htab->find_slot (&ent, NO_INSERT);
 382   return (slot ? (*slot)->value : 0);
 383 }
 384
 385
 386 /* Clear the mapping of T to its original address.  */
 387
 388 void
 389 lto_orig_address_remove (tree t)
 390 {
 391   struct tree_hash_entry ent;
 392   struct tree_hash_entry **slot;
 393
 394   ent.key = t;
 395   slot = tree_htab->find_slot (&ent, NO_INSERT);
 396   gcc_assert (slot);
 397   free (*slot);
 398   tree_htab->clear_slot (slot);
 399 }
 400 #endif
 401
 402
 403 /* Check that the version MAJOR.MINOR is the correct version number.  */
 404
 405 void
 406 lto_check_version (int major, int minor)
 407 {
 408   if (major != LTO_major_version || minor != LTO_minor_version)
 409     fatal_error (input_location,
 410                  "bytecode stream generated with LTO version %d.%d instead "
 411                  "of the expected %d.%d",
 412                  major, minor,
 413                  LTO_major_version, LTO_minor_version);
 414 }
 415
 416
 417 /* Initialize all the streamer hooks used for streaming GIMPLE.  */
 418
 419 void
 420 lto_streamer_hooks_init (void)
 421 {
 422   streamer_hooks_init ();
 423   streamer_hooks.write_tree = lto_output_tree;
 424   streamer_hooks.read_tree = lto_input_tree;
 425   streamer_hooks.input_location = lto_input_location;
 426   streamer_hooks.output_location = lto_output_location;
 427 }