gcc/tree-streamer.c

   1 /* Miscellaneous utilities for tree streaming.  Things that are used
   2    in both input and output are here.
   3
   4    Copyright (C) 2011-2015 Free Software Foundation, Inc.
   5    Contributed by Diego Novillo <dnovillo@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 "alias.h"
  27 #include "symtab.h"
  28 #include "options.h"
  29 #include "tree.h"
  30 #include "fold-const.h"
  31 #include "predict.h"
  32 #include "tm.h"
  33 #include "hard-reg-set.h"
  34 #include "function.h"
  35 #include "basic-block.h"
  36 #include "tree-ssa-alias.h"
  37 #include "internal-fn.h"
  38 #include "gimple-expr.h"
  39 #include "gimple.h"
  40 #include "streamer-hooks.h"
  41 #include "plugin-api.h"
  42 #include "ipa-ref.h"
  43 #include "cgraph.h"
  44 #include "tree-streamer.h"
  45
  46 /* Table indexed by machine_mode, used for 2 different purposes.
  47    During streaming out we record there non-zero value for all modes
  48    that were streamed out.
  49    During streaming in, we translate the on the disk mode using this
  50    table.  For normal LTO it is set to identity, for ACCEL_COMPILER
  51    depending on the mode_table content.  */
  52 unsigned char streamer_mode_table[1 << 8];
  53
  54 /* Check that all the TS_* structures handled by the streamer_write_* and
  55    streamer_read_* routines are exactly ALL the structures defined in
  56    treestruct.def.  */
  57
  58 void
  59 streamer_check_handled_ts_structures (void)
  60 {
  61   bool handled_p[LAST_TS_ENUM];
  62   unsigned i;
  63
  64   memset (&handled_p, 0, sizeof (handled_p));
  65
  66   /* These are the TS_* structures that are either handled or
  67      explicitly ignored by the streamer routines.  */
  68   handled_p[TS_BASE] = true;
  69   handled_p[TS_TYPED] = true;
  70   handled_p[TS_COMMON] = true;
  71   handled_p[TS_INT_CST] = true;
  72   handled_p[TS_REAL_CST] = true;
  73   handled_p[TS_FIXED_CST] = true;
  74   handled_p[TS_VECTOR] = true;
  75   handled_p[TS_STRING] = true;
  76   handled_p[TS_COMPLEX] = true;
  77   handled_p[TS_IDENTIFIER] = true;
  78   handled_p[TS_DECL_MINIMAL] = true;
  79   handled_p[TS_DECL_COMMON] = true;
  80   handled_p[TS_DECL_WRTL] = true;
  81   handled_p[TS_DECL_NON_COMMON] = true;
  82   handled_p[TS_DECL_WITH_VIS] = true;
  83   handled_p[TS_FIELD_DECL] = true;
  84   handled_p[TS_VAR_DECL] = true;
  85   handled_p[TS_PARM_DECL] = true;
  86   handled_p[TS_LABEL_DECL] = true;
  87   handled_p[TS_RESULT_DECL] = true;
  88   handled_p[TS_CONST_DECL] = true;
  89   handled_p[TS_TYPE_DECL] = true;
  90   handled_p[TS_FUNCTION_DECL] = true;
  91   handled_p[TS_TYPE_COMMON] = true;
  92   handled_p[TS_TYPE_WITH_LANG_SPECIFIC] = true;
  93   handled_p[TS_TYPE_NON_COMMON] = true;
  94   handled_p[TS_LIST] = true;
  95   handled_p[TS_VEC] = true;
  96   handled_p[TS_EXP] = true;
  97   handled_p[TS_SSA_NAME] = true;
  98   handled_p[TS_BLOCK] = true;
  99   handled_p[TS_BINFO] = true;
 100   handled_p[TS_STATEMENT_LIST] = true;
 101   handled_p[TS_CONSTRUCTOR] = true;
 102   handled_p[TS_OMP_CLAUSE] = true;
 103   handled_p[TS_OPTIMIZATION] = true;
 104   handled_p[TS_TARGET_OPTION] = true;
 105   handled_p[TS_TRANSLATION_UNIT_DECL] = true;
 106
 107   /* Anything not marked above will trigger the following assertion.
 108      If this assertion triggers, it means that there is a new TS_*
 109      structure that should be handled by the streamer.  */
 110   for (i = 0; i < LAST_TS_ENUM; i++)
 111     gcc_assert (handled_p[i]);
 112 }
 113
 114
 115 /* Helper for streamer_tree_cache_insert_1.  Add T to CACHE->NODES at
 116    slot IX.  */
 117
 118 static void
 119 streamer_tree_cache_add_to_node_array (struct streamer_tree_cache_d *cache,
 120                                        unsigned ix, tree t, hashval_t hash)
 121 {
 122   /* We're either replacing an old element or appending consecutively.  */
 123   if (cache->nodes.exists ())
 124     {
 125       if (cache->nodes.length () == ix)
 126         cache->nodes.safe_push (t);
 127       else
 128         cache->nodes[ix] = t;
 129     }
 130   if (cache->hashes.exists ())
 131     {
 132       if (cache->hashes.length () == ix)
 133         cache->hashes.safe_push (hash);
 134       else
 135         cache->hashes[ix] = hash;
 136     }
 137 }
 138
 139
 140 /* Helper for streamer_tree_cache_insert and streamer_tree_cache_insert_at.
 141    CACHE, T, and IX_P are as in streamer_tree_cache_insert.
 142
 143    If INSERT_AT_NEXT_SLOT_P is true, T is inserted at the next available
 144    slot in the cache.  Otherwise, T is inserted at the position indicated
 145    in *IX_P.
 146
 147    If T already existed in CACHE, return true.  Otherwise,
 148    return false.  */
 149
 150 static bool
 151 streamer_tree_cache_insert_1 (struct streamer_tree_cache_d *cache,
 152                               tree t, hashval_t hash, unsigned *ix_p,
 153                               bool insert_at_next_slot_p)
 154 {
 155   bool existed_p;
 156
 157   gcc_assert (t);
 158
 159   unsigned int &ix = cache->node_map->get_or_insert (t, &existed_p);
 160   if (!existed_p)
 161     {
 162       /* Determine the next slot to use in the cache.  */
 163       if (insert_at_next_slot_p)
 164         ix = cache->next_idx++;
 165       else
 166         ix = *ix_p;
 167
 168       streamer_tree_cache_add_to_node_array (cache, ix, t, hash);
 169     }
 170   else
 171     {
 172       if (!insert_at_next_slot_p && ix != *ix_p)
 173         {
 174           /* If the caller wants to insert T at a specific slot
 175              location, and ENTRY->TO does not match *IX_P, add T to
 176              the requested location slot.  */
 177           ix = *ix_p;
 178           streamer_tree_cache_add_to_node_array (cache, ix, t, hash);
 179         }
 180     }
 181
 182   if (ix_p)
 183     *ix_p = ix;
 184
 185   return existed_p;
 186 }
 187
 188
 189 /* Insert tree node T in CACHE.  If T already existed in the cache
 190    return true.  Otherwise, return false.
 191
 192    If IX_P is non-null, update it with the index into the cache where
 193    T has been stored.  */
 194
 195 bool
 196 streamer_tree_cache_insert (struct streamer_tree_cache_d *cache, tree t,
 197                             hashval_t hash, unsigned *ix_p)
 198 {
 199   return streamer_tree_cache_insert_1 (cache, t, hash, ix_p, true);
 200 }
 201
 202
 203 /* Replace the tree node with T in CACHE at slot IX.  */
 204
 205 void
 206 streamer_tree_cache_replace_tree (struct streamer_tree_cache_d *cache,
 207                                   tree t, unsigned ix)
 208 {
 209   hashval_t hash = 0;
 210   if (cache->hashes.exists ())
 211     hash = streamer_tree_cache_get_hash (cache, ix);
 212   if (!cache->node_map)
 213     streamer_tree_cache_add_to_node_array (cache, ix, t, hash);
 214   else
 215     streamer_tree_cache_insert_1 (cache, t, hash, &ix, false);
 216 }
 217
 218
 219 /* Appends tree node T to CACHE, even if T already existed in it.  */
 220
 221 void
 222 streamer_tree_cache_append (struct streamer_tree_cache_d *cache,
 223                             tree t, hashval_t hash)
 224 {
 225   unsigned ix = cache->next_idx++;
 226   if (!cache->node_map)
 227     streamer_tree_cache_add_to_node_array (cache, ix, t, hash);
 228   else
 229     streamer_tree_cache_insert_1 (cache, t, hash, &ix, false);
 230 }
 231
 232 /* Return true if tree node T exists in CACHE, otherwise false.  If IX_P is
 233    not NULL, write to *IX_P the index into the cache where T is stored
 234    ((unsigned)-1 if T is not found).  */
 235
 236 bool
 237 streamer_tree_cache_lookup (struct streamer_tree_cache_d *cache, tree t,
 238                             unsigned *ix_p)
 239 {
 240   unsigned *slot;
 241   bool retval;
 242   unsigned ix;
 243
 244   gcc_assert (t);
 245
 246   slot = cache->node_map->get (t);
 247   if (slot == NULL)
 248     {
 249       retval = false;
 250       ix = -1;
 251     }
 252   else
 253     {
 254       retval = true;
 255       ix = *slot;
 256     }
 257
 258   if (ix_p)
 259     *ix_p = ix;
 260
 261   return retval;
 262 }
 263
 264
 265 /* Record NODE in CACHE.  */
 266
 267 static void
 268 record_common_node (struct streamer_tree_cache_d *cache, tree node)
 269 {
 270   /* If we recursively end up at nodes we do not want to preload simply don't.
 271      ???  We'd want to verify that this doesn't happen, or alternatively
 272      do not recurse at all.  */
 273   if (node == char_type_node)
 274     return;
 275
 276   gcc_checking_assert (node != boolean_type_node
 277                        && node != boolean_true_node
 278                        && node != boolean_false_node);
 279
 280   /* We have to make sure to fill exactly the same number of
 281      elements for all frontends.  That can include NULL trees.
 282      As our hash table can't deal with zero entries we'll simply stream
 283      a random other tree.  A NULL tree never will be looked up so it
 284      doesn't matter which tree we replace it with, just to be sure
 285      use error_mark_node.  */
 286   if (!node)
 287     node = error_mark_node;
 288
 289   /* ???  FIXME, devise a better hash value.  But the hash needs to be equal
 290      for all frontend and lto1 invocations.  So just use the position
 291      in the cache as hash value.  */
 292   streamer_tree_cache_append (cache, node, cache->nodes.length ());
 293
 294   if (POINTER_TYPE_P (node)
 295       || TREE_CODE (node) == COMPLEX_TYPE
 296       || TREE_CODE (node) == ARRAY_TYPE)
 297     record_common_node (cache, TREE_TYPE (node));
 298   else if (TREE_CODE (node) == RECORD_TYPE)
 299     {
 300       /* The FIELD_DECLs of structures should be shared, so that every
 301          COMPONENT_REF uses the same tree node when referencing a field.
 302          Pointer equality between FIELD_DECLs is used by the alias
 303          machinery to compute overlapping component references (see
 304          nonoverlapping_component_refs_p and
 305          nonoverlapping_component_refs_of_decl_p).  */
 306       for (tree f = TYPE_FIELDS (node); f; f = TREE_CHAIN (f))
 307         record_common_node (cache, f);
 308     }
 309 }
 310
 311
 312 /* Preload common nodes into CACHE and make sure they are merged
 313    properly according to the gimple type table.  */
 314
 315 static void
 316 preload_common_nodes (struct streamer_tree_cache_d *cache)
 317 {
 318   unsigned i;
 319
 320   for (i = 0; i < itk_none; i++)
 321     /* Skip itk_char.  char_type_node is dependent on -f[un]signed-char.  */
 322     if (i != itk_char)
 323       record_common_node (cache, integer_types[i]);
 324
 325   for (i = 0; i < stk_type_kind_last; i++)
 326     record_common_node (cache, sizetype_tab[i]);
 327
 328   for (i = 0; i < TI_MAX; i++)
 329     /* Skip boolean type and constants, they are frontend dependent.  */
 330     if (i != TI_BOOLEAN_TYPE
 331         && i != TI_BOOLEAN_FALSE
 332         && i != TI_BOOLEAN_TRUE
 333         /* MAIN_IDENTIFIER is not always initialized by Fortran FE.  */
 334         && i != TI_MAIN_IDENTIFIER
 335         /* PID_TYPE is initialized only by C family front-ends.  */
 336         && i != TI_PID_TYPE
 337         /* Skip optimization and target option nodes; they depend on flags.  */
 338         && i != TI_OPTIMIZATION_DEFAULT
 339         && i != TI_OPTIMIZATION_CURRENT
 340         && i != TI_TARGET_OPTION_DEFAULT
 341         && i != TI_TARGET_OPTION_CURRENT
 342         && i != TI_CURRENT_TARGET_PRAGMA
 343         && i != TI_CURRENT_OPTIMIZE_PRAGMA
 344         /* Skip va_list* related nodes if offloading.  For native LTO
 345            we want them to be merged for the stdarg pass, for offloading
 346            they might not be identical between host and offloading target.  */
 347         && (!lto_stream_offload_p
 348             || (i != TI_VA_LIST_TYPE
 349                 && i != TI_VA_LIST_GPR_COUNTER_FIELD
 350                 && i != TI_VA_LIST_FPR_COUNTER_FIELD)))
 351       record_common_node (cache, global_trees[i]);
 352 }
 353
 354
 355 /* Create a cache of pickled nodes.  */
 356
 357 struct streamer_tree_cache_d *
 358 streamer_tree_cache_create (bool with_hashes, bool with_map, bool with_vec)
 359 {
 360   struct streamer_tree_cache_d *cache;
 361
 362   cache = XCNEW (struct streamer_tree_cache_d);
 363
 364   if (with_map)
 365     cache->node_map = new hash_map<tree, unsigned> (251);
 366   cache->next_idx = 0;
 367   if (with_vec)
 368     cache->nodes.create (165);
 369   if (with_hashes)
 370     cache->hashes.create (165);
 371
 372   /* Load all the well-known tree nodes that are always created by
 373      the compiler on startup.  This prevents writing them out
 374      unnecessarily.  */
 375   preload_common_nodes (cache);
 376
 377   return cache;
 378 }
 379
 380
 381 /* Delete the streamer cache C.  */
 382
 383 void
 384 streamer_tree_cache_delete (struct streamer_tree_cache_d *c)
 385 {
 386   if (c == NULL)
 387     return;
 388
 389   delete c->node_map;
 390   c->node_map = NULL;
 391   c->nodes.release ();
 392   c->hashes.release ();
 393   free (c);
 394 }