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) 2009-2013 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 "gimple.h"
  31 #include "tree-ssa.h"
  32 #include "diagnostic-core.h"
  33 #include "bitmap.h"
  34 #include "vec.h"
  35 #include "tree-streamer.h"
  36 #include "lto-streamer.h"
  37 #include "streamer-hooks.h"
  38
  39 /* Statistics gathered during LTO, WPA and LTRANS.  */
  40 struct lto_stats_d lto_stats;
  41
  42 /* LTO uses bitmaps with different life-times.  So use a separate
  43    obstack for all LTO bitmaps.  */
  44 static bitmap_obstack lto_obstack;
  45 static bool lto_obstack_initialized;
  46
  47
  48 /* Return a string representing LTO tag TAG.  */
  49
  50 const char *
  51 lto_tag_name (enum LTO_tags tag)
  52 {
  53   if (lto_tag_is_tree_code_p (tag))
  54     {
  55       /* For tags representing tree nodes, return the name of the
  56          associated tree code.  */
  57       return tree_code_name[lto_tag_to_tree_code (tag)];
  58     }
  59
  60   if (lto_tag_is_gimple_code_p (tag))
  61     {
  62       /* For tags representing gimple statements, return the name of
  63          the associated gimple code.  */
  64       return gimple_code_name[lto_tag_to_gimple_code (tag)];
  65     }
  66
  67   switch (tag)
  68     {
  69     case LTO_null:
  70       return "LTO_null";
  71     case LTO_bb0:
  72       return "LTO_bb0";
  73     case LTO_bb1:
  74       return "LTO_bb1";
  75     case LTO_eh_region:
  76       return "LTO_eh_region";
  77     case LTO_function:
  78       return "LTO_function";
  79     case LTO_eh_table:
  80       return "LTO_eh_table";
  81     case LTO_ert_cleanup:
  82       return "LTO_ert_cleanup";
  83     case LTO_ert_try:
  84       return "LTO_ert_try";
  85     case LTO_ert_allowed_exceptions:
  86       return "LTO_ert_allowed_exceptions";
  87     case LTO_ert_must_not_throw:
  88       return "LTO_ert_must_not_throw";
  89     case LTO_tree_pickle_reference:
  90       return "LTO_tree_pickle_reference";
  91     case LTO_field_decl_ref:
  92       return "LTO_field_decl_ref";
  93     case LTO_function_decl_ref:
  94       return "LTO_function_decl_ref";
  95     case LTO_label_decl_ref:
  96       return "LTO_label_decl_ref";
  97     case LTO_namespace_decl_ref:
  98       return "LTO_namespace_decl_ref";
  99     case LTO_result_decl_ref:
 100       return "LTO_result_decl_ref";
 101     case LTO_ssa_name_ref:
 102       return "LTO_ssa_name_ref";
 103     case LTO_type_decl_ref:
 104       return "LTO_type_decl_ref";
 105     case LTO_type_ref:
 106       return "LTO_type_ref";
 107     case LTO_global_decl_ref:
 108       return "LTO_global_decl_ref";
 109     default:
 110       return "LTO_UNKNOWN";
 111     }
 112 }
 113
 114
 115 /* Allocate a bitmap from heap.  Initializes the LTO obstack if necessary.  */
 116
 117 bitmap
 118 lto_bitmap_alloc (void)
 119 {
 120   if (!lto_obstack_initialized)
 121     {
 122       bitmap_obstack_initialize (&lto_obstack);
 123       lto_obstack_initialized = true;
 124     }
 125   return BITMAP_ALLOC (&lto_obstack);
 126 }
 127
 128 /* Free bitmap B.  */
 129
 130 void
 131 lto_bitmap_free (bitmap b)
 132 {
 133   BITMAP_FREE (b);
 134 }
 135
 136
 137 /* Get a section name for a particular type or name.  The NAME field
 138    is only used if SECTION_TYPE is LTO_section_function_body. For all
 139    others it is ignored.  The callee of this function is responsible
 140    to free the returned name.  */
 141
 142 char *
 143 lto_get_section_name (int section_type, const char *name, struct lto_file_decl_data *f)
 144 {
 145   const char *add;
 146   char post[32];
 147   const char *sep;
 148
 149   if (section_type == LTO_section_function_body)
 150     {
 151       gcc_assert (name != NULL);
 152       if (name[0] == '*')
 153         name++;
 154       add = name;
 155       sep = "";
 156     }
 157   else if (section_type < LTO_N_SECTION_TYPES)
 158     {
 159       add = lto_section_name[section_type];
 160       sep = ".";
 161     }
 162   else
 163     internal_error ("bytecode stream: unexpected LTO section %s", name);
 164
 165   /* Make the section name unique so that ld -r combining sections
 166      doesn't confuse the reader with merged sections.
 167
 168      For options don't add a ID, the option reader cannot deal with them
 169      and merging should be ok here. */
 170   if (section_type == LTO_section_opts)
 171     strcpy (post, "");
 172   else if (f != NULL)
 173     sprintf (post, "." HOST_WIDE_INT_PRINT_HEX_PURE, f->id);
 174   else
 175     sprintf (post, "." HOST_WIDE_INT_PRINT_HEX_PURE, get_random_seed (false));
 176   return concat (LTO_SECTION_NAME_PREFIX, sep, add, post, NULL);
 177 }
 178
 179
 180 /* Show various memory usage statistics related to LTO.  */
 181
 182 void
 183 print_lto_report (const char *s)
 184 {
 185   unsigned i;
 186
 187   fprintf (stderr, "[%s] # of input files: "
 188            HOST_WIDE_INT_PRINT_UNSIGNED "\n", s, lto_stats.num_input_files);
 189
 190   fprintf (stderr, "[%s] # of input cgraph nodes: "
 191            HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 192            lto_stats.num_input_cgraph_nodes);
 193
 194   fprintf (stderr, "[%s] # of function bodies: "
 195            HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 196            lto_stats.num_function_bodies);
 197
 198   for (i = 0; i < NUM_TREE_CODES; i++)
 199     if (lto_stats.num_trees[i])
 200       fprintf (stderr, "[%s] # of '%s' objects read: "
 201                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 202                tree_code_name[i], lto_stats.num_trees[i]);
 203
 204   if (flag_lto)
 205     {
 206       fprintf (stderr, "[%s] Compression: "
 207                HOST_WIDE_INT_PRINT_UNSIGNED " output bytes, "
 208                HOST_WIDE_INT_PRINT_UNSIGNED " compressed bytes", s,
 209                lto_stats.num_output_il_bytes,
 210                lto_stats.num_compressed_il_bytes);
 211       if (lto_stats.num_output_il_bytes > 0)
 212         {
 213           const float dividend = (float) lto_stats.num_compressed_il_bytes;
 214           const float divisor = (float) lto_stats.num_output_il_bytes;
 215           fprintf (stderr, " (ratio: %f)", dividend / divisor);
 216         }
 217       fprintf (stderr, "\n");
 218     }
 219
 220   if (flag_wpa)
 221     {
 222       fprintf (stderr, "[%s] # of output files: "
 223                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 224                lto_stats.num_output_files);
 225
 226       fprintf (stderr, "[%s] # of output symtab nodes: "
 227                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 228                lto_stats.num_output_symtab_nodes);
 229
 230       fprintf (stderr, "[%s] # of output tree pickle references: "
 231                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 232                lto_stats.num_pickle_refs_output);
 233       fprintf (stderr, "[%s] # of output tree bodies: "
 234                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 235                lto_stats.num_tree_bodies_output);
 236
 237       fprintf (stderr, "[%s] # callgraph partitions: "
 238                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 239                lto_stats.num_cgraph_partitions);
 240
 241       fprintf (stderr, "[%s] Compression: "
 242                HOST_WIDE_INT_PRINT_UNSIGNED " input bytes, "
 243                HOST_WIDE_INT_PRINT_UNSIGNED " uncompressed bytes", s,
 244                lto_stats.num_input_il_bytes,
 245                lto_stats.num_uncompressed_il_bytes);
 246       if (lto_stats.num_input_il_bytes > 0)
 247         {
 248           const float dividend = (float) lto_stats.num_uncompressed_il_bytes;
 249           const float divisor = (float) lto_stats.num_input_il_bytes;
 250           fprintf (stderr, " (ratio: %f)", dividend / divisor);
 251         }
 252       fprintf (stderr, "\n");
 253     }
 254
 255   for (i = 0; i < LTO_N_SECTION_TYPES; i++)
 256     fprintf (stderr, "[%s] Size of mmap'd section %s: "
 257              HOST_WIDE_INT_PRINT_UNSIGNED " bytes\n", s,
 258              lto_section_name[i], lto_stats.section_size[i]);
 259 }
 260
 261
 262 #ifdef LTO_STREAMER_DEBUG
 263 struct tree_hash_entry
 264 {
 265   tree key;
 266   intptr_t value;
 267 };
 268
 269 struct tree_entry_hasher : typed_noop_remove <tree_hash_entry>
 270 {
 271   typedef tree_hash_entry value_type;
 272   typedef tree_hash_entry compare_type;
 273   static inline hashval_t hash (const value_type *);
 274   static inline bool equal (const value_type *, const compare_type *);
 275 };
 276
 277 inline hashval_t
 278 tree_entry_hasher::hash (const value_type *e)
 279 {
 280   return htab_hash_pointer (e->key);
 281 }
 282
 283 inline bool
 284 tree_entry_hasher::equal (const value_type *e1, const compare_type *e2)
 285 {
 286   return (e1->key == e2->key);
 287 }
 288
 289 static hash_table <tree_hash_entry> tree_htab;
 290 #endif
 291
 292 /* Initialization common to the LTO reader and writer.  */
 293
 294 void
 295 lto_streamer_init (void)
 296 {
 297   /* Check that all the TS_* handled by the reader and writer routines
 298      match exactly the structures defined in treestruct.def.  When a
 299      new TS_* astructure is added, the streamer should be updated to
 300      handle it.  */
 301   streamer_check_handled_ts_structures ();
 302
 303 #ifdef LTO_STREAMER_DEBUG
 304   tree_htab.create (31);
 305 #endif
 306 }
 307
 308
 309 /* Gate function for all LTO streaming passes.  */
 310
 311 bool
 312 gate_lto_out (void)
 313 {
 314   return ((flag_generate_lto || in_lto_p)
 315           /* Don't bother doing anything if the program has errors.  */
 316           && !seen_error ());
 317 }
 318
 319
 320 #ifdef LTO_STREAMER_DEBUG
 321 /* Add a mapping between T and ORIG_T, which is the numeric value of
 322    the original address of T as it was seen by the LTO writer.  This
 323    mapping is useful when debugging streaming problems.  A debugging
 324    session can be started on both reader and writer using ORIG_T
 325    as a breakpoint value in both sessions.
 326
 327    Note that this mapping is transient and only valid while T is
 328    being reconstructed.  Once T is fully built, the mapping is
 329    removed.  */
 330
 331 void
 332 lto_orig_address_map (tree t, intptr_t orig_t)
 333 {
 334   struct tree_hash_entry ent;
 335   struct tree_hash_entry **slot;
 336
 337   ent.key = t;
 338   ent.value = orig_t;
 339   slot = tree_htab.find_slot (&ent, INSERT);
 340   gcc_assert (!*slot);
 341   *slot = XNEW (struct tree_hash_entry);
 342   **slot = ent;
 343 }
 344
 345
 346 /* Get the original address of T as it was seen by the writer.  This
 347    is only valid while T is being reconstructed.  */
 348
 349 intptr_t
 350 lto_orig_address_get (tree t)
 351 {
 352   struct tree_hash_entry ent;
 353   struct tree_hash_entry **slot;
 354
 355   ent.key = t;
 356   slot = tree_htab.find_slot (&ent, NO_INSERT);
 357   return (slot ? (*slot)->value : 0);
 358 }
 359
 360
 361 /* Clear the mapping of T to its original address.  */
 362
 363 void
 364 lto_orig_address_remove (tree t)
 365 {
 366   struct tree_hash_entry ent;
 367   struct tree_hash_entry **slot;
 368
 369   ent.key = t;
 370   slot = tree_htab.find_slot (&ent, NO_INSERT);
 371   gcc_assert (slot);
 372   free (*slot);
 373   tree_htab.clear_slot (slot);
 374 }
 375 #endif
 376
 377
 378 /* Check that the version MAJOR.MINOR is the correct version number.  */
 379
 380 void
 381 lto_check_version (int major, int minor)
 382 {
 383   if (major != LTO_major_version || minor != LTO_minor_version)
 384     fatal_error ("bytecode stream generated with LTO version %d.%d instead "
 385                  "of the expected %d.%d",
 386                  major, minor,
 387                  LTO_major_version, LTO_minor_version);
 388 }
 389
 390
 391 /* Initialize all the streamer hooks used for streaming GIMPLE.  */
 392
 393 void
 394 lto_streamer_hooks_init (void)
 395 {
 396   streamer_hooks_init ();
 397   streamer_hooks.write_tree = lto_output_tree;
 398   streamer_hooks.read_tree = lto_input_tree;
 399   streamer_hooks.input_location = lto_input_location;
 400   streamer_hooks.output_location = lto_output_location;
 401 }