gcc/lto-cgraph.c

   1 /* Write and read the cgraph to the memory mapped representation of a
   2    .o file.
   3
   4    Copyright 2009 Free Software Foundation, Inc.
   5    Contributed by Kenneth Zadeck <zadeck@naturalbridge.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 "tm.h"
  27 #include "toplev.h"
  28 #include "tree.h"
  29 #include "expr.h"
  30 #include "flags.h"
  31 #include "params.h"
  32 #include "input.h"
  33 #include "varray.h"
  34 #include "hashtab.h"
  35 #include "langhooks.h"
  36 #include "basic-block.h"
  37 #include "tree-flow.h"
  38 #include "cgraph.h"
  39 #include "function.h"
  40 #include "ggc.h"
  41 #include "diagnostic.h"
  42 #include "except.h"
  43 #include "vec.h"
  44 #include "timevar.h"
  45 #include "output.h"
  46 #include "pointer-set.h"
  47 #include "lto-streamer.h"
  48 #include "gcov-io.h"
  49
  50 /* Create a new cgraph encoder.  */
  51
  52 lto_cgraph_encoder_t
  53 lto_cgraph_encoder_new (void)
  54 {
  55   lto_cgraph_encoder_t encoder = XCNEW (struct lto_cgraph_encoder_d);
  56   encoder->map = pointer_map_create ();
  57   encoder->nodes = NULL;
  58   return encoder;
  59 }
  60
  61
  62 /* Delete ENCODER and its components.  */
  63
  64 void
  65 lto_cgraph_encoder_delete (lto_cgraph_encoder_t encoder)
  66 {
  67    VEC_free (cgraph_node_ptr, heap, encoder->nodes);
  68    pointer_map_destroy (encoder->map);
  69    free (encoder);
  70 }
  71
  72
  73 /* Return the existing reference number of NODE in the cgraph encoder in
  74    output block OB.  Assign a new reference if this is the first time
  75    NODE is encoded.  */
  76
  77 int
  78 lto_cgraph_encoder_encode (lto_cgraph_encoder_t encoder,
  79                            struct cgraph_node *node)
  80 {
  81   int ref;
  82   void **slot;
  83
  84   slot = pointer_map_contains (encoder->map, node);
  85   if (!slot)
  86     {
  87       ref = VEC_length (cgraph_node_ptr, encoder->nodes);
  88       slot = pointer_map_insert (encoder->map, node);
  89       *slot = (void *) (intptr_t) ref;
  90       VEC_safe_push (cgraph_node_ptr, heap, encoder->nodes, node);
  91     }
  92   else
  93     ref = (int) (intptr_t) *slot;
  94
  95   return ref;
  96 }
  97
  98
  99 /* Look up NODE in encoder.  Return NODE's reference if it has been encoded
 100    or LCC_NOT_FOUND if it is not there.  */
 101
 102 int
 103 lto_cgraph_encoder_lookup (lto_cgraph_encoder_t encoder,
 104                            struct cgraph_node *node)
 105 {
 106   void **slot = pointer_map_contains (encoder->map, node);
 107   return (slot ? (int) (intptr_t) *slot : LCC_NOT_FOUND);
 108 }
 109
 110
 111 /* Return the cgraph node corresponding to REF using ENCODER.  */
 112
 113 struct cgraph_node *
 114 lto_cgraph_encoder_deref (lto_cgraph_encoder_t encoder, int ref)
 115 {
 116   if (ref == LCC_NOT_FOUND)
 117     return NULL;
 118
 119   return VEC_index (cgraph_node_ptr, encoder->nodes, ref);
 120 }
 121
 122
 123 /* Return number of encoded nodes in ENCODER.  */
 124
 125 static int
 126 lto_cgraph_encoder_size (lto_cgraph_encoder_t encoder)
 127 {
 128   return VEC_length (cgraph_node_ptr, encoder->nodes);
 129 }
 130
 131
 132 /* Output the cgraph EDGE to OB using ENCODER.  */
 133
 134 static void
 135 lto_output_edge (struct lto_simple_output_block *ob, struct cgraph_edge *edge,
 136                  lto_cgraph_encoder_t encoder)
 137 {
 138   unsigned int uid;
 139   intptr_t ref;
 140   struct bitpack_d *bp;
 141
 142   lto_output_uleb128_stream (ob->main_stream, LTO_cgraph_edge);
 143
 144   ref = lto_cgraph_encoder_lookup (encoder, edge->caller);
 145   gcc_assert (ref != LCC_NOT_FOUND);
 146   lto_output_sleb128_stream (ob->main_stream, ref);
 147
 148   ref = lto_cgraph_encoder_lookup (encoder, edge->callee);
 149   gcc_assert (ref != LCC_NOT_FOUND);
 150   lto_output_sleb128_stream (ob->main_stream, ref);
 151
 152   lto_output_sleb128_stream (ob->main_stream, edge->count);
 153
 154   bp = bitpack_create ();
 155   uid = flag_wpa ? edge->lto_stmt_uid : gimple_uid (edge->call_stmt);
 156   bp_pack_value (bp, uid, HOST_BITS_PER_INT);
 157   bp_pack_value (bp, edge->inline_failed, HOST_BITS_PER_INT);
 158   bp_pack_value (bp, edge->frequency, HOST_BITS_PER_INT);
 159   bp_pack_value (bp, edge->loop_nest, 30);
 160   bp_pack_value (bp, edge->indirect_call, 1);
 161   bp_pack_value (bp, edge->call_stmt_cannot_inline_p, 1);
 162   bp_pack_value (bp, edge->can_throw_external, 1);
 163   lto_output_bitpack (ob->main_stream, bp);
 164   bitpack_delete (bp);
 165 }
 166
 167 /* Return true when node is reachable from other partition.  */
 168
 169 static bool
 170 reachable_from_other_partition_p (struct cgraph_node *node, cgraph_node_set set)
 171 {
 172   struct cgraph_edge *e;
 173   if (node->needed)
 174     return true;
 175   if (!node->analyzed)
 176     return false;
 177   if (node->global.inlined_to)
 178     return false;
 179   for (e = node->callers; e; e = e->next_caller)
 180     if (!cgraph_node_in_set_p (e->caller, set))
 181       return true;
 182   return false;
 183 }
 184
 185 /* Output the cgraph NODE to OB.  ENCODER is used to find the
 186    reference number of NODE->inlined_to.  SET is the set of nodes we
 187    are writing to the current file.  If NODE is not in SET, then NODE
 188    is a boundary of a cgraph_node_set and we pretend NODE just has a
 189    decl and no callees.  WRITTEN_DECLS is the set of FUNCTION_DECLs
 190    that have had their callgraph node written so far.  This is used to
 191    determine if NODE is a clone of a previously written node.  */
 192
 193 static void
 194 lto_output_node (struct lto_simple_output_block *ob, struct cgraph_node *node,
 195                  lto_cgraph_encoder_t encoder, cgraph_node_set set,
 196                  bitmap written_decls)
 197 {
 198   unsigned int tag;
 199   struct bitpack_d *bp;
 200   unsigned local, externally_visible, inlinable, analyzed;
 201   bool boundary_p, wrote_decl_p;
 202   intptr_t ref;
 203   bool in_other_partition = false;
 204
 205   boundary_p = !cgraph_node_in_set_p (node, set);
 206   wrote_decl_p = bitmap_bit_p (written_decls, DECL_UID (node->decl));
 207
 208   switch (cgraph_function_body_availability (node))
 209     {
 210     case AVAIL_NOT_AVAILABLE:
 211       tag = LTO_cgraph_unavail_node;
 212       break;
 213
 214     case AVAIL_AVAILABLE:
 215     case AVAIL_LOCAL:
 216       tag = LTO_cgraph_avail_node;
 217       break;
 218
 219     case AVAIL_OVERWRITABLE:
 220       tag = LTO_cgraph_overwritable_node;
 221       break;
 222
 223     default:
 224       gcc_unreachable ();
 225     }
 226
 227   if (boundary_p)
 228     tag = LTO_cgraph_unavail_node;
 229
 230   lto_output_uleb128_stream (ob->main_stream, tag);
 231
 232   local = node->local.local;
 233   externally_visible = node->local.externally_visible;
 234   inlinable = node->local.inlinable;
 235   analyzed = node->analyzed;
 236
 237   /* In WPA mode, we only output part of the call-graph.  Also, we
 238      fake cgraph node attributes.  There are two cases that we care.
 239
 240      Boundary nodes: There are nodes that are not part of SET but are
 241      called from within SET.  We artificially make them look like
 242      externally visible nodes with no function body.
 243
 244      Cherry-picked nodes:  These are nodes we pulled from other
 245      translation units into SET during IPA-inlining.  We make them as
 246      local static nodes to prevent clashes with other local statics.  */
 247   if (boundary_p)
 248     {
 249       /* Inline clones can not be part of boundary.
 250          gcc_assert (!node->global.inlined_to);
 251
 252          FIXME: At the moment they can be, when partition contains an inline
 253          clone that is clone of inline clone from outside partition.  We can
 254          reshape the clone tree and make other tree to be the root, but it
 255          needs a bit extra work and will be promplty done by cgraph_remove_node
 256          after reading back.  */
 257       in_other_partition = 1;
 258       analyzed = 0;
 259     }
 260
 261   lto_output_uleb128_stream (ob->main_stream, wrote_decl_p);
 262
 263   if (!wrote_decl_p)
 264     bitmap_set_bit (written_decls, DECL_UID (node->decl));
 265
 266   lto_output_fn_decl_index (ob->decl_state, ob->main_stream, node->decl);
 267   lto_output_sleb128_stream (ob->main_stream, node->count);
 268
 269   bp = bitpack_create ();
 270   bp_pack_value (bp, local, 1);
 271   bp_pack_value (bp, externally_visible, 1);
 272   bp_pack_value (bp, node->local.finalized, 1);
 273   bp_pack_value (bp, inlinable, 1);
 274   bp_pack_value (bp, node->local.disregard_inline_limits, 1);
 275   bp_pack_value (bp, node->local.redefined_extern_inline, 1);
 276   bp_pack_value (bp, node->local.for_functions_valid, 1);
 277   bp_pack_value (bp, node->local.vtable_method, 1);
 278   bp_pack_value (bp, node->needed, 1);
 279   bp_pack_value (bp, node->address_taken, 1);
 280   bp_pack_value (bp, node->abstract_and_needed, 1);
 281   bp_pack_value (bp, node->reachable, 1);
 282   bp_pack_value (bp, analyzed && reachable_from_other_partition_p (node, set), 1);
 283   bp_pack_value (bp, node->lowered, 1);
 284   bp_pack_value (bp, analyzed, 1);
 285   bp_pack_value (bp, in_other_partition, 1);
 286   bp_pack_value (bp, node->process, 1);
 287   bp_pack_value (bp, node->alias, 1);
 288   bp_pack_value (bp, node->finalized_by_frontend, 1);
 289   lto_output_bitpack (ob->main_stream, bp);
 290   bitpack_delete (bp);
 291
 292   if (tag != LTO_cgraph_unavail_node)
 293     {
 294       lto_output_sleb128_stream (ob->main_stream,
 295                                  node->local.inline_summary.estimated_self_stack_size);
 296       lto_output_sleb128_stream (ob->main_stream,
 297                                  node->local.inline_summary.self_size);
 298       lto_output_sleb128_stream (ob->main_stream,
 299                                  node->local.inline_summary.size_inlining_benefit);
 300       lto_output_sleb128_stream (ob->main_stream,
 301                                  node->local.inline_summary.self_time);
 302       lto_output_sleb128_stream (ob->main_stream,
 303                                  node->local.inline_summary.time_inlining_benefit);
 304     }
 305
 306   /* FIXME lto: Outputting global info is not neccesary until after
 307      inliner was run.  Global structure holds results of propagation
 308      done by inliner.  */
 309   lto_output_sleb128_stream (ob->main_stream,
 310                              node->global.estimated_stack_size);
 311   lto_output_sleb128_stream (ob->main_stream,
 312                              node->global.stack_frame_offset);
 313   if (node->global.inlined_to && !boundary_p)
 314     {
 315       ref = lto_cgraph_encoder_lookup (encoder, node->global.inlined_to);
 316       gcc_assert (ref != LCC_NOT_FOUND);
 317     }
 318   else
 319     ref = LCC_NOT_FOUND;
 320   lto_output_sleb128_stream (ob->main_stream, ref);
 321
 322   lto_output_sleb128_stream (ob->main_stream, node->global.time);
 323   lto_output_sleb128_stream (ob->main_stream, node->global.size);
 324   lto_output_sleb128_stream (ob->main_stream,
 325                              node->global.estimated_growth);
 326   lto_output_uleb128_stream (ob->main_stream, node->global.inlined);
 327   if (node->same_comdat_group && !boundary_p)
 328     {
 329       ref = lto_cgraph_encoder_lookup (encoder, node->same_comdat_group);
 330       gcc_assert (ref != LCC_NOT_FOUND);
 331     }
 332   else
 333     ref = LCC_NOT_FOUND;
 334   lto_output_sleb128_stream (ob->main_stream, ref);
 335
 336   if (node->same_body)
 337     {
 338       struct cgraph_node *alias;
 339       unsigned long alias_count = 1;
 340       for (alias = node->same_body; alias->next; alias = alias->next)
 341         alias_count++;
 342       lto_output_uleb128_stream (ob->main_stream, alias_count);
 343       do
 344         {
 345           lto_output_fn_decl_index (ob->decl_state, ob->main_stream,
 346                                     alias->decl);
 347           if (alias->thunk.thunk_p)
 348             {
 349               lto_output_uleb128_stream
 350                  (ob->main_stream,
 351                   1 + (alias->thunk.this_adjusting != 0) * 2
 352                   + (alias->thunk.virtual_offset_p != 0) * 4);
 353               lto_output_uleb128_stream (ob->main_stream,
 354                                          alias->thunk.fixed_offset);
 355               lto_output_uleb128_stream (ob->main_stream,
 356                                          alias->thunk.virtual_value);
 357               lto_output_fn_decl_index (ob->decl_state, ob->main_stream,
 358                                         alias->thunk.alias);
 359             }
 360           else
 361             {
 362               lto_output_uleb128_stream (ob->main_stream, 0);
 363               lto_output_fn_decl_index (ob->decl_state, ob->main_stream,
 364                                         alias->thunk.alias);
 365             }
 366           alias = alias->previous;
 367         }
 368       while (alias);
 369     }
 370   else
 371     lto_output_uleb128_stream (ob->main_stream, 0);
 372 }
 373
 374 /* Stream out profile_summary to OB.  */
 375
 376 static void
 377 output_profile_summary (struct lto_simple_output_block *ob)
 378 {
 379   if (profile_info)
 380     {
 381       /* We do not output num, it is not terribly useful.  */
 382       gcc_assert (profile_info->runs);
 383       lto_output_uleb128_stream (ob->main_stream, profile_info->runs);
 384       lto_output_sleb128_stream (ob->main_stream, profile_info->sum_all);
 385       lto_output_sleb128_stream (ob->main_stream, profile_info->run_max);
 386       lto_output_sleb128_stream (ob->main_stream, profile_info->sum_max);
 387     }
 388   else
 389     lto_output_uleb128_stream (ob->main_stream, 0);
 390 }
 391
 392 /* Add NODE into encoder as well as nodes it is cloned from.
 393    Do it in a way so clones appear first.  */
 394 static void
 395 add_node_to (lto_cgraph_encoder_t encoder, struct cgraph_node *node)
 396 {
 397   if (node->clone_of)
 398     add_node_to (encoder, node->clone_of);
 399   lto_cgraph_encoder_encode (encoder, node);
 400 }
 401
 402 /* Output the part of the cgraph in SET.  */
 403
 404 void
 405 output_cgraph (cgraph_node_set set)
 406 {
 407   struct cgraph_node *node;
 408   struct lto_simple_output_block *ob;
 409   cgraph_node_set_iterator csi;
 410   struct cgraph_edge *edge;
 411   int i, n_nodes;
 412   bitmap written_decls;
 413   lto_cgraph_encoder_t encoder;
 414   struct cgraph_asm_node *can;
 415
 416   ob = lto_create_simple_output_block (LTO_section_cgraph);
 417
 418   output_profile_summary (ob);
 419
 420   /* An encoder for cgraph nodes should have been created by
 421      ipa_write_summaries_1.  */
 422   gcc_assert (ob->decl_state->cgraph_node_encoder);
 423   encoder = ob->decl_state->cgraph_node_encoder;
 424
 425   /* The FUNCTION_DECLs for which we have written a node.  The first
 426      node found is written as the "original" node, the remaining nodes
 427      are considered its clones.  */
 428   written_decls = lto_bitmap_alloc ();
 429
 430   /* Go over all the nodes in SET and assign references.  */
 431   for (csi = csi_start (set); !csi_end_p (csi); csi_next (&csi))
 432     {
 433       node = csi_node (csi);
 434       add_node_to (encoder, node);
 435     }
 436
 437   /* Go over all the nodes again to include callees that are not in
 438      SET.  */
 439   for (csi = csi_start (set); !csi_end_p (csi); csi_next (&csi))
 440     {
 441       node = csi_node (csi);
 442       for (edge = node->callees; edge; edge = edge->next_callee)
 443         {
 444           struct cgraph_node *callee = edge->callee;
 445           if (!cgraph_node_in_set_p (callee, set))
 446             {
 447               /* We should have moved all the inlines.  */
 448               gcc_assert (!callee->global.inlined_to);
 449               add_node_to (encoder, callee);
 450             }
 451         }
 452     }
 453
 454   /* Write out the nodes.  We must first output a node and then its clones,
 455      otherwise at a time reading back the node there would be nothing to clone
 456      from.  */
 457   n_nodes = lto_cgraph_encoder_size (encoder);
 458   for (i = 0; i < n_nodes; i++)
 459     {
 460       node = lto_cgraph_encoder_deref (encoder, i);
 461       lto_output_node (ob, node, encoder, set, written_decls);
 462     }
 463
 464   lto_bitmap_free (written_decls);
 465
 466   /* Go over the nodes in SET again to write edges.  */
 467   for (csi = csi_start (set); !csi_end_p (csi); csi_next (&csi))
 468     {
 469       node = csi_node (csi);
 470       if (node->callees)
 471         {
 472           /* Output edges in backward direction, so the reconstructed callgraph
 473              match and it is easy to associate call sites in the IPA pass summaries.  */
 474           edge = node->callees;
 475           while (edge->next_callee)
 476             edge = edge->next_callee;
 477           for (; edge; edge = edge->prev_callee)
 478             lto_output_edge (ob, edge, encoder);
 479         }
 480     }
 481
 482   lto_output_uleb128_stream (ob->main_stream, 0);
 483
 484   /* Emit toplevel asms.  */
 485   for (can = cgraph_asm_nodes; can; can = can->next)
 486     {
 487       int len = TREE_STRING_LENGTH (can->asm_str);
 488       lto_output_uleb128_stream (ob->main_stream, len);
 489       for (i = 0; i < len; ++i)
 490         lto_output_1_stream (ob->main_stream,
 491                              TREE_STRING_POINTER (can->asm_str)[i]);
 492     }
 493
 494   lto_output_uleb128_stream (ob->main_stream, 0);
 495
 496   lto_destroy_simple_output_block (ob);
 497 }
 498
 499
 500 /* Overwrite the information in NODE based on FILE_DATA, TAG, FLAGS,
 501    STACK_SIZE, SELF_TIME and SELF_SIZE.  This is called either to initialize
 502    NODE or to replace the values in it, for instance because the first
 503    time we saw it, the function body was not available but now it
 504    is.  BP is a bitpack with all the bitflags for NODE read from the
 505    stream.  */
 506
 507 static void
 508 input_overwrite_node (struct lto_file_decl_data *file_data,
 509                       struct cgraph_node *node,
 510                       enum LTO_cgraph_tags tag,
 511                       struct bitpack_d *bp,
 512                       unsigned int stack_size,
 513                       unsigned int self_time,
 514                       unsigned int time_inlining_benefit,
 515                       unsigned int self_size,
 516                       unsigned int size_inlining_benefit)
 517 {
 518   node->aux = (void *) tag;
 519   node->local.inline_summary.estimated_self_stack_size = stack_size;
 520   node->local.inline_summary.self_time = self_time;
 521   node->local.inline_summary.time_inlining_benefit = time_inlining_benefit;
 522   node->local.inline_summary.self_size = self_size;
 523   node->local.inline_summary.size_inlining_benefit = size_inlining_benefit;
 524   node->global.time = self_time;
 525   node->global.size = self_size;
 526   node->local.lto_file_data = file_data;
 527
 528   node->local.local = bp_unpack_value (bp, 1);
 529   node->local.externally_visible = bp_unpack_value (bp, 1);
 530   node->local.finalized = bp_unpack_value (bp, 1);
 531   node->local.inlinable = bp_unpack_value (bp, 1);
 532   node->local.disregard_inline_limits = bp_unpack_value (bp, 1);
 533   node->local.redefined_extern_inline = bp_unpack_value (bp, 1);
 534   node->local.for_functions_valid = bp_unpack_value (bp, 1);
 535   node->local.vtable_method = bp_unpack_value (bp, 1);
 536   node->needed = bp_unpack_value (bp, 1);
 537   node->address_taken = bp_unpack_value (bp, 1);
 538   node->abstract_and_needed = bp_unpack_value (bp, 1);
 539   node->reachable = bp_unpack_value (bp, 1);
 540   node->reachable_from_other_partition = bp_unpack_value (bp, 1);
 541   node->lowered = bp_unpack_value (bp, 1);
 542   node->analyzed = bp_unpack_value (bp, 1);
 543   node->in_other_partition = bp_unpack_value (bp, 1);
 544   node->process = bp_unpack_value (bp, 1);
 545   node->alias = bp_unpack_value (bp, 1);
 546   node->finalized_by_frontend = bp_unpack_value (bp, 1);
 547 }
 548
 549
 550 /* Read a node from input_block IB.  TAG is the node's tag just read.
 551    Return the node read or overwriten.  */
 552
 553 static struct cgraph_node *
 554 input_node (struct lto_file_decl_data *file_data,
 555             struct lto_input_block *ib,
 556             enum LTO_cgraph_tags tag)
 557 {
 558   tree fn_decl;
 559   struct cgraph_node *node;
 560   struct bitpack_d *bp;
 561   int stack_size = 0;
 562   unsigned decl_index;
 563   bool clone_p;
 564   int estimated_stack_size = 0;
 565   int stack_frame_offset = 0;
 566   int ref = LCC_NOT_FOUND, ref2 = LCC_NOT_FOUND;
 567   int estimated_growth = 0;
 568   int time = 0;
 569   int size = 0;
 570   int self_time = 0;
 571   int self_size = 0;
 572   int time_inlining_benefit = 0;
 573   int size_inlining_benefit = 0;
 574   unsigned long same_body_count = 0;
 575   bool inlined = false;
 576
 577   clone_p = (lto_input_uleb128 (ib) != 0);
 578
 579   decl_index = lto_input_uleb128 (ib);
 580   fn_decl = lto_file_decl_data_get_fn_decl (file_data, decl_index);
 581
 582   if (clone_p)
 583     node = cgraph_clone_node (cgraph_node (fn_decl), 0,
 584                               CGRAPH_FREQ_BASE, 0, false, NULL);
 585
 586   else
 587     node = cgraph_node (fn_decl);
 588
 589   node->count = lto_input_sleb128 (ib);
 590   bp = lto_input_bitpack (ib);
 591
 592   if (tag != LTO_cgraph_unavail_node)
 593     {
 594       stack_size = lto_input_sleb128 (ib);
 595       self_size = lto_input_sleb128 (ib);
 596       size_inlining_benefit = lto_input_sleb128 (ib);
 597       self_time = lto_input_sleb128 (ib);
 598       time_inlining_benefit = lto_input_sleb128 (ib);
 599     }
 600
 601   estimated_stack_size = lto_input_sleb128 (ib);
 602   stack_frame_offset = lto_input_sleb128 (ib);
 603   ref = lto_input_sleb128 (ib);
 604   time = lto_input_sleb128 (ib);
 605   size = lto_input_sleb128 (ib);
 606   estimated_growth = lto_input_sleb128 (ib);
 607   inlined = lto_input_uleb128 (ib);
 608   ref2 = lto_input_sleb128 (ib);
 609   same_body_count = lto_input_uleb128 (ib);
 610
 611   /* Make sure that we have not read this node before.  Nodes that
 612      have already been read will have their tag stored in the 'aux'
 613      field.  Since built-in functions can be referenced in multiple
 614      functions, they are expected to be read more than once.  */
 615   if (node->aux && !DECL_IS_BUILTIN (node->decl))
 616     internal_error ("bytecode stream: found multiple instances of cgraph "
 617                     "node %d", node->uid);
 618
 619   input_overwrite_node (file_data, node, tag, bp, stack_size, self_time,
 620                         time_inlining_benefit, self_size,
 621                         size_inlining_benefit);
 622   bitpack_delete (bp);
 623
 624   node->global.estimated_stack_size = estimated_stack_size;
 625   node->global.stack_frame_offset = stack_frame_offset;
 626   node->global.time = time;
 627   node->global.size = size;
 628
 629   /* Store a reference for now, and fix up later to be a pointer.  */
 630   node->global.inlined_to = (cgraph_node_ptr) (intptr_t) ref;
 631
 632   node->global.estimated_growth = estimated_growth;
 633   node->global.inlined = inlined;
 634
 635   /* Store a reference for now, and fix up later to be a pointer.  */
 636   node->same_comdat_group = (cgraph_node_ptr) (intptr_t) ref2;
 637
 638   while (same_body_count-- > 0)
 639     {
 640       tree alias_decl;
 641       int type;
 642       decl_index = lto_input_uleb128 (ib);
 643       alias_decl = lto_file_decl_data_get_fn_decl (file_data, decl_index);
 644       type = lto_input_uleb128 (ib);
 645       if (!type)
 646         {
 647           tree real_alias;
 648           decl_index = lto_input_uleb128 (ib);
 649           real_alias = lto_file_decl_data_get_fn_decl (file_data, decl_index);
 650           cgraph_same_body_alias (alias_decl, real_alias);
 651         }
 652       else
 653         {
 654           HOST_WIDE_INT fixed_offset = lto_input_uleb128 (ib);
 655           HOST_WIDE_INT virtual_value = lto_input_uleb128 (ib);
 656           tree real_alias;
 657           decl_index = lto_input_uleb128 (ib);
 658           real_alias = lto_file_decl_data_get_fn_decl (file_data, decl_index);
 659           cgraph_add_thunk (alias_decl, fn_decl, type & 2, fixed_offset,
 660                             virtual_value,
 661                             (type & 4) ? size_int (virtual_value) : NULL_TREE,
 662                             real_alias);
 663         }
 664     }
 665   return node;
 666 }
 667
 668
 669 /* Read an edge from IB.  NODES points to a vector of previously read
 670    nodes for decoding caller and callee of the edge to be read.  */
 671
 672 static void
 673 input_edge (struct lto_input_block *ib, VEC(cgraph_node_ptr, heap) *nodes)
 674 {
 675   struct cgraph_node *caller, *callee;
 676   struct cgraph_edge *edge;
 677   unsigned int stmt_id;
 678   gcov_type count;
 679   int freq;
 680   unsigned int nest;
 681   cgraph_inline_failed_t inline_failed;
 682   struct bitpack_d *bp;
 683   enum ld_plugin_symbol_resolution caller_resolution;
 684
 685   caller = VEC_index (cgraph_node_ptr, nodes, lto_input_sleb128 (ib));
 686   if (caller == NULL || caller->decl == NULL_TREE)
 687     internal_error ("bytecode stream: no caller found while reading edge");
 688
 689   callee = VEC_index (cgraph_node_ptr, nodes, lto_input_sleb128 (ib));
 690   if (callee == NULL || callee->decl == NULL_TREE)
 691     internal_error ("bytecode stream: no callee found while reading edge");
 692
 693   count = (gcov_type) lto_input_sleb128 (ib);
 694
 695   bp = lto_input_bitpack (ib);
 696   stmt_id = (unsigned int) bp_unpack_value (bp, HOST_BITS_PER_INT);
 697   inline_failed = (cgraph_inline_failed_t) bp_unpack_value (bp,
 698                                                             HOST_BITS_PER_INT);
 699   freq = (int) bp_unpack_value (bp, HOST_BITS_PER_INT);
 700   nest = (unsigned) bp_unpack_value (bp, 30);
 701
 702   /* If the caller was preempted, don't create the edge.
 703      ???  Should we ever have edges from a preempted caller?  */
 704   caller_resolution = lto_symtab_get_resolution (caller->decl);
 705   if (caller_resolution == LDPR_PREEMPTED_REG
 706       || caller_resolution == LDPR_PREEMPTED_IR)
 707     return;
 708
 709   edge = cgraph_create_edge (caller, callee, NULL, count, freq, nest);
 710   edge->lto_stmt_uid = stmt_id;
 711   edge->inline_failed = inline_failed;
 712   edge->indirect_call = bp_unpack_value (bp, 1);
 713   edge->call_stmt_cannot_inline_p = bp_unpack_value (bp, 1);
 714   edge->can_throw_external = bp_unpack_value (bp, 1);
 715   bitpack_delete (bp);
 716 }
 717
 718
 719 /* Read a cgraph from IB using the info in FILE_DATA.  */
 720
 721 static void
 722 input_cgraph_1 (struct lto_file_decl_data *file_data,
 723                 struct lto_input_block *ib)
 724 {
 725   enum LTO_cgraph_tags tag;
 726   VEC(cgraph_node_ptr, heap) *nodes = NULL;
 727   struct cgraph_node *node;
 728   unsigned i;
 729   unsigned HOST_WIDE_INT len;
 730
 731   tag = (enum LTO_cgraph_tags) lto_input_uleb128 (ib);
 732   while (tag)
 733     {
 734       if (tag == LTO_cgraph_edge)
 735         input_edge (ib, nodes);
 736       else
 737         {
 738           node = input_node (file_data, ib, tag);
 739           if (node == NULL || node->decl == NULL_TREE)
 740             internal_error ("bytecode stream: found empty cgraph node");
 741           VEC_safe_push (cgraph_node_ptr, heap, nodes, node);
 742           lto_cgraph_encoder_encode (file_data->cgraph_node_encoder, node);
 743         }
 744
 745       tag = (enum LTO_cgraph_tags) lto_input_uleb128 (ib);
 746     }
 747
 748   /* Input toplevel asms.  */
 749   len = lto_input_uleb128 (ib);
 750   while (len)
 751     {
 752       char *str = (char *)xmalloc (len + 1);
 753       for (i = 0; i < len; ++i)
 754         str[i] = lto_input_1_unsigned (ib);
 755       cgraph_add_asm_node (build_string (len, str));
 756       free (str);
 757
 758       len = lto_input_uleb128 (ib);
 759     }
 760
 761   for (i = 0; VEC_iterate (cgraph_node_ptr, nodes, i, node); i++)
 762     {
 763       int ref = (int) (intptr_t) node->global.inlined_to;
 764
 765       /* Fixup inlined_to from reference to pointer.  */
 766       if (ref != LCC_NOT_FOUND)
 767         node->global.inlined_to = VEC_index (cgraph_node_ptr, nodes, ref);
 768       else
 769         node->global.inlined_to = NULL;
 770
 771       ref = (int) (intptr_t) node->same_comdat_group;
 772
 773       /* Fixup same_comdat_group from reference to pointer.  */
 774       if (ref != LCC_NOT_FOUND)
 775         node->same_comdat_group = VEC_index (cgraph_node_ptr, nodes, ref);
 776       else
 777         node->same_comdat_group = NULL;
 778     }
 779
 780   VEC_free (cgraph_node_ptr, heap, nodes);
 781 }
 782
 783 static struct gcov_ctr_summary lto_gcov_summary;
 784
 785 /* Input profile_info from IB.  */
 786 static void
 787 input_profile_summary (struct lto_input_block *ib)
 788 {
 789   unsigned int runs = lto_input_uleb128 (ib);
 790   if (runs)
 791     {
 792       if (!profile_info)
 793         {
 794           profile_info = &lto_gcov_summary;
 795           lto_gcov_summary.runs = runs;
 796           lto_gcov_summary.sum_all = lto_input_sleb128 (ib);
 797           lto_gcov_summary.run_max = lto_input_sleb128 (ib);
 798           lto_gcov_summary.sum_max = lto_input_sleb128 (ib);
 799         }
 800       /* We can support this by scaling all counts to nearest common multiple
 801          of all different runs, but it is perhaps not worth the effort.  */
 802       else if (profile_info->runs != runs
 803                || profile_info->sum_all != lto_input_sleb128 (ib)
 804                || profile_info->run_max != lto_input_sleb128 (ib)
 805                || profile_info->sum_max != lto_input_sleb128 (ib))
 806         sorry ("Combining units with different profiles is not supported.");
 807       /* We allow some units to have profile and other to not have one.  This will
 808          just make unprofiled units to be size optimized that is sane.  */
 809     }
 810
 811 }
 812
 813 /* Input and merge the cgraph from each of the .o files passed to
 814    lto1.  */
 815
 816 void
 817 input_cgraph (void)
 818 {
 819   struct lto_file_decl_data **file_data_vec = lto_get_file_decl_data ();
 820   struct lto_file_decl_data *file_data;
 821   unsigned int j = 0;
 822   struct cgraph_node *node;
 823
 824   while ((file_data = file_data_vec[j++]))
 825     {
 826       const char *data;
 827       size_t len;
 828       struct lto_input_block *ib;
 829
 830       ib = lto_create_simple_input_block (file_data, LTO_section_cgraph,
 831                                           &data, &len);
 832       input_profile_summary (ib);
 833       file_data->cgraph_node_encoder = lto_cgraph_encoder_new ();
 834       input_cgraph_1 (file_data, ib);
 835       lto_destroy_simple_input_block (file_data, LTO_section_cgraph,
 836                                       ib, data, len);
 837
 838       /* Assume that every file read needs to be processed by LTRANS.  */
 839       if (flag_wpa)
 840         lto_mark_file_for_ltrans (file_data);
 841     }
 842
 843   /* Clear out the aux field that was used to store enough state to
 844      tell which nodes should be overwritten.  */
 845   for (node = cgraph_nodes; node; node = node->next)
 846     {
 847       /* Some nodes may have been created by cgraph_node.  This
 848          happens when the callgraph contains nested functions.  If the
 849          node for the parent function was never emitted to the gimple
 850          file, cgraph_node will create a node for it when setting the
 851          context of the nested function.  */
 852       if (node->local.lto_file_data)
 853         node->aux = NULL;
 854     }
 855 }