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