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