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