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