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