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