gcc/ipa-utils.c

   1 /* Utilities for ipa analysis.
   2    Copyright (C) 2005-2021 Free Software Foundation, Inc.
   3    Contributed by Kenneth Zadeck <zadeck@naturalbridge.com>
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 3, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #include "config.h"
  22 #include "system.h"
  23 #include "coretypes.h"
  24 #include "backend.h"
  25 #include "tree.h"
  26 #include "gimple.h"
  27 #include "predict.h"
  28 #include "alloc-pool.h"
  29 #include "cgraph.h"
  30 #include "lto-streamer.h"
  31 #include "dumpfile.h"
  32 #include "splay-tree.h"
  33 #include "ipa-utils.h"
  34 #include "symbol-summary.h"
  35 #include "tree-vrp.h"
  36 #include "ipa-prop.h"
  37 #include "ipa-fnsummary.h"
  38
  39 /* Debugging function for postorder and inorder code. NOTE is a string
  40    that is printed before the nodes are printed.  ORDER is an array of
  41    cgraph_nodes that has COUNT useful nodes in it.  */
  42
  43 void
  44 ipa_print_order (FILE* out,
  45                  const char * note,
  46                  struct cgraph_node** order,
  47                  int count)
  48 {
  49   int i;
  50   fprintf (out, "\n\n ordered call graph: %s\n", note);
  51
  52   for (i = count - 1; i >= 0; i--)
  53     order[i]->dump (out);
  54   fprintf (out, "\n");
  55   fflush (out);
  56 }
  57
  58
  59 struct searchc_env {
  60   struct cgraph_node **stack;
  61   struct cgraph_node **result;
  62   int stack_size;
  63   int order_pos;
  64   splay_tree nodes_marked_new;
  65   bool reduce;
  66   int count;
  67 };
  68
  69 /* This is an implementation of Tarjan's strongly connected region
  70    finder as reprinted in Aho Hopcraft and Ullman's The Design and
  71    Analysis of Computer Programs (1975) pages 192-193.  This version
  72    has been customized for cgraph_nodes.  The env parameter is because
  73    it is recursive and there are no nested functions here.  This
  74    function should only be called from itself or
  75    ipa_reduced_postorder.  ENV is a stack env and would be
  76    unnecessary if C had nested functions.  V is the node to start
  77    searching from.  */
  78
  79 static void
  80 searchc (struct searchc_env* env, struct cgraph_node *v,
  81          bool (*ignore_edge) (struct cgraph_edge *))
  82 {
  83   struct cgraph_edge *edge;
  84   struct ipa_dfs_info *v_info = (struct ipa_dfs_info *) v->aux;
  85
  86   /* mark node as old */
  87   v_info->new_node = false;
  88   splay_tree_remove (env->nodes_marked_new, v->get_uid ());
  89
  90   v_info->dfn_number = env->count;
  91   v_info->low_link = env->count;
  92   env->count++;
  93   env->stack[(env->stack_size)++] = v;
  94   v_info->on_stack = true;
  95
  96   for (edge = v->callees; edge; edge = edge->next_callee)
  97     {
  98       struct ipa_dfs_info * w_info;
  99       enum availability avail;
 100       struct cgraph_node *w = edge->callee->ultimate_alias_target (&avail);
 101
 102       if (!w || (ignore_edge && ignore_edge (edge)))
 103         continue;
 104
 105       if (w->aux
 106           && (avail >= AVAIL_INTERPOSABLE))
 107         {
 108           w_info = (struct ipa_dfs_info *) w->aux;
 109           if (w_info->new_node)
 110             {
 111               searchc (env, w, ignore_edge);
 112               v_info->low_link =
 113                 (v_info->low_link < w_info->low_link) ?
 114                 v_info->low_link : w_info->low_link;
 115             }
 116           else
 117             if ((w_info->dfn_number < v_info->dfn_number)
 118                 && (w_info->on_stack))
 119               v_info->low_link =
 120                 (w_info->dfn_number < v_info->low_link) ?
 121                 w_info->dfn_number : v_info->low_link;
 122         }
 123     }
 124
 125
 126   if (v_info->low_link == v_info->dfn_number)
 127     {
 128       struct cgraph_node *last = NULL;
 129       struct cgraph_node *x;
 130       struct ipa_dfs_info *x_info;
 131       do {
 132         x = env->stack[--(env->stack_size)];
 133         x_info = (struct ipa_dfs_info *) x->aux;
 134         x_info->on_stack = false;
 135         x_info->scc_no = v_info->dfn_number;
 136
 137         if (env->reduce)
 138           {
 139             x_info->next_cycle = last;
 140             last = x;
 141           }
 142         else
 143           env->result[env->order_pos++] = x;
 144       }
 145       while (v != x);
 146       if (env->reduce)
 147         env->result[env->order_pos++] = v;
 148     }
 149 }
 150
 151 /* Topsort the call graph by caller relation.  Put the result in ORDER.
 152
 153    The REDUCE flag is true if you want the cycles reduced to single nodes.
 154    You can use ipa_get_nodes_in_cycle to obtain a vector containing all real
 155    call graph nodes in a reduced node.
 156
 157    Set ALLOW_OVERWRITABLE if nodes with such availability should be included.
 158    IGNORE_EDGE, if non-NULL is a hook that may make some edges insignificant
 159    for the topological sort.   */
 160
 161 int
 162 ipa_reduced_postorder (struct cgraph_node **order,
 163                        bool reduce,
 164                        bool (*ignore_edge) (struct cgraph_edge *))
 165 {
 166   struct cgraph_node *node;
 167   struct searchc_env env;
 168   splay_tree_node result;
 169   env.stack = XCNEWVEC (struct cgraph_node *, symtab->cgraph_count);
 170   env.stack_size = 0;
 171   env.result = order;
 172   env.order_pos = 0;
 173   env.nodes_marked_new = splay_tree_new (splay_tree_compare_ints, 0, 0);
 174   env.count = 1;
 175   env.reduce = reduce;
 176
 177   FOR_EACH_DEFINED_FUNCTION (node)
 178     {
 179       enum availability avail = node->get_availability ();
 180
 181       if (avail > AVAIL_INTERPOSABLE
 182           || avail == AVAIL_INTERPOSABLE)
 183         {
 184           /* Reuse the info if it is already there.  */
 185           struct ipa_dfs_info *info = (struct ipa_dfs_info *) node->aux;
 186           if (!info)
 187             info = XCNEW (struct ipa_dfs_info);
 188           info->new_node = true;
 189           info->on_stack = false;
 190           info->next_cycle = NULL;
 191           node->aux = info;
 192
 193           splay_tree_insert (env.nodes_marked_new,
 194                              (splay_tree_key)node->get_uid (),
 195                              (splay_tree_value)node);
 196         }
 197       else
 198         node->aux = NULL;
 199     }
 200   result = splay_tree_min (env.nodes_marked_new);
 201   while (result)
 202     {
 203       node = (struct cgraph_node *)result->value;
 204       searchc (&env, node, ignore_edge);
 205       result = splay_tree_min (env.nodes_marked_new);
 206     }
 207   splay_tree_delete (env.nodes_marked_new);
 208   free (env.stack);
 209
 210   return env.order_pos;
 211 }
 212
 213 /* Deallocate all ipa_dfs_info structures pointed to by the aux pointer of call
 214    graph nodes.  */
 215
 216 void
 217 ipa_free_postorder_info (void)
 218 {
 219   struct cgraph_node *node;
 220   FOR_EACH_DEFINED_FUNCTION (node)
 221     {
 222       /* Get rid of the aux information.  */
 223       if (node->aux)
 224         {
 225           free (node->aux);
 226           node->aux = NULL;
 227         }
 228     }
 229 }
 230
 231 /* Get the set of nodes for the cycle in the reduced call graph starting
 232    from NODE.  */
 233
 234 vec<cgraph_node *>
 235 ipa_get_nodes_in_cycle (struct cgraph_node *node)
 236 {
 237   vec<cgraph_node *> v = vNULL;
 238   struct ipa_dfs_info *node_dfs_info;
 239   while (node)
 240     {
 241       v.safe_push (node);
 242       node_dfs_info = (struct ipa_dfs_info *) node->aux;
 243       node = node_dfs_info->next_cycle;
 244     }
 245   return v;
 246 }
 247
 248 /* Return true iff the CS is an edge within a strongly connected component as
 249    computed by ipa_reduced_postorder.  */
 250
 251 bool
 252 ipa_edge_within_scc (struct cgraph_edge *cs)
 253 {
 254   struct ipa_dfs_info *caller_dfs = (struct ipa_dfs_info *) cs->caller->aux;
 255   struct ipa_dfs_info *callee_dfs;
 256   struct cgraph_node *callee = cs->callee->function_symbol ();
 257
 258   callee_dfs = (struct ipa_dfs_info *) callee->aux;
 259   return (caller_dfs
 260           && callee_dfs
 261           && caller_dfs->scc_no == callee_dfs->scc_no);
 262 }
 263
 264 struct postorder_stack
 265 {
 266   struct cgraph_node *node;
 267   struct cgraph_edge *edge;
 268   int ref;
 269 };
 270
 271 /* Fill array order with all nodes with output flag set in the reverse
 272    topological order.  Return the number of elements in the array.
 273    FIXME: While walking, consider aliases, too.  */
 274
 275 int
 276 ipa_reverse_postorder (struct cgraph_node **order)
 277 {
 278   struct cgraph_node *node, *node2;
 279   int stack_size = 0;
 280   int order_pos = 0;
 281   struct cgraph_edge *edge;
 282   int pass;
 283   struct ipa_ref *ref = NULL;
 284
 285   struct postorder_stack *stack =
 286     XCNEWVEC (struct postorder_stack, symtab->cgraph_count);
 287
 288   /* We have to deal with cycles nicely, so use a depth first traversal
 289      output algorithm.  Ignore the fact that some functions won't need
 290      to be output and put them into order as well, so we get dependencies
 291      right through inline functions.  */
 292   FOR_EACH_FUNCTION (node)
 293     node->aux = NULL;
 294   for (pass = 0; pass < 2; pass++)
 295     FOR_EACH_FUNCTION (node)
 296       if (!node->aux
 297           && (pass
 298               || (!node->address_taken
 299                   && !node->inlined_to
 300                   && !node->alias && !node->thunk
 301                   && !node->only_called_directly_p ())))
 302         {
 303           stack_size = 0;
 304           stack[stack_size].node = node;
 305           stack[stack_size].edge = node->callers;
 306           stack[stack_size].ref = 0;
 307           node->aux = (void *)(size_t)1;
 308           while (stack_size >= 0)
 309             {
 310               while (true)
 311                 {
 312                   node2 = NULL;
 313                   while (stack[stack_size].edge && !node2)
 314                     {
 315                       edge = stack[stack_size].edge;
 316                       node2 = edge->caller;
 317                       stack[stack_size].edge = edge->next_caller;
 318                       /* Break possible cycles involving always-inline
 319                          functions by ignoring edges from always-inline
 320                          functions to non-always-inline functions.  */
 321                       if (DECL_DISREGARD_INLINE_LIMITS (edge->caller->decl)
 322                           && !DECL_DISREGARD_INLINE_LIMITS
 323                             (edge->callee->function_symbol ()->decl))
 324                         node2 = NULL;
 325                     }
 326                   for (; stack[stack_size].node->iterate_referring (
 327                                                        stack[stack_size].ref,
 328                                                        ref) && !node2;
 329                        stack[stack_size].ref++)
 330                     {
 331                       if (ref->use == IPA_REF_ALIAS)
 332                         node2 = dyn_cast <cgraph_node *> (ref->referring);
 333                     }
 334                   if (!node2)
 335                     break;
 336                   if (!node2->aux)
 337                     {
 338                       stack[++stack_size].node = node2;
 339                       stack[stack_size].edge = node2->callers;
 340                       stack[stack_size].ref = 0;
 341                       node2->aux = (void *)(size_t)1;
 342                     }
 343                 }
 344               order[order_pos++] = stack[stack_size--].node;
 345             }
 346         }
 347   free (stack);
 348   FOR_EACH_FUNCTION (node)
 349     node->aux = NULL;
 350   return order_pos;
 351 }
 352
 353
 354
 355 /* Given a memory reference T, will return the variable at the bottom
 356    of the access.  Unlike get_base_address, this will recurse through
 357    INDIRECT_REFS.  */
 358
 359 tree
 360 get_base_var (tree t)
 361 {
 362   while (!SSA_VAR_P (t)
 363          && (!CONSTANT_CLASS_P (t))
 364          && TREE_CODE (t) != LABEL_DECL
 365          && TREE_CODE (t) != FUNCTION_DECL
 366          && TREE_CODE (t) != CONST_DECL
 367          && TREE_CODE (t) != CONSTRUCTOR)
 368     {
 369       t = TREE_OPERAND (t, 0);
 370     }
 371   return t;
 372 }
 373
 374 /* Scale function of calls in NODE by ratio ORIG_COUNT/NODE->count.  */
 375
 376 void
 377 scale_ipa_profile_for_fn (struct cgraph_node *node, profile_count orig_count)
 378 {
 379   profile_count to = node->count;
 380   profile_count::adjust_for_ipa_scaling (&to, &orig_count);
 381   struct cgraph_edge *e;
 382
 383   for (e = node->callees; e; e = e->next_callee)
 384     e->count = e->count.apply_scale (to, orig_count);
 385   for (e = node->indirect_calls; e; e = e->next_callee)
 386     e->count = e->count.apply_scale (to, orig_count);
 387 }
 388
 389 /* SRC and DST are going to be merged.  Take SRC's profile and merge it into
 390    DST so it is not going to be lost.  Possibly destroy SRC's body on the way
 391    unless PRESERVE_BODY is set.  */
 392
 393 void
 394 ipa_merge_profiles (struct cgraph_node *dst,
 395                     struct cgraph_node *src,
 396                     bool preserve_body)
 397 {
 398   tree oldsrcdecl = src->decl;
 399   struct function *srccfun, *dstcfun;
 400   bool match = true;
 401   bool copy_counts = false;
 402
 403   if (!src->definition
 404       || !dst->definition)
 405     return;
 406
 407   if (src->frequency < dst->frequency)
 408     src->frequency = dst->frequency;
 409
 410   /* Time profiles are merged.  */
 411   if (dst->tp_first_run > src->tp_first_run && src->tp_first_run)
 412     dst->tp_first_run = src->tp_first_run;
 413
 414   if (src->profile_id && !dst->profile_id)
 415     dst->profile_id = src->profile_id;
 416
 417   /* Merging zero profile to dst is no-op.  */
 418   if (src->count.ipa () == profile_count::zero ())
 419     return;
 420
 421   /* FIXME when we merge in unknown profile, we ought to set counts as
 422      unsafe.  */
 423   if (!src->count.initialized_p ()
 424       || !(src->count.ipa () == src->count))
 425     return;
 426   profile_count orig_count = dst->count;
 427
 428   /* Either sum the profiles if both are IPA and not global0, or
 429      pick more informative one (that is nonzero IPA if other is
 430      uninitialized, guessed or global0).   */
 431
 432   if ((dst->count.ipa ().nonzero_p ()
 433        || src->count.ipa ().nonzero_p ())
 434       && dst->count.ipa ().initialized_p ()
 435       && src->count.ipa ().initialized_p ())
 436     dst->count = dst->count.ipa () + src->count.ipa ();
 437   else if (dst->count.ipa ().initialized_p ())
 438     ;
 439   else if (src->count.ipa ().initialized_p ())
 440     {
 441       copy_counts = true;
 442       dst->count = src->count.ipa ();
 443     }
 444
 445   /* If no updating needed return early.  */
 446   if (dst->count == orig_count)
 447     return;
 448
 449   if (symtab->dump_file)
 450     {
 451       fprintf (symtab->dump_file, "Merging profiles of %s count:",
 452                src->dump_name ());
 453       src->count.dump (symtab->dump_file);
 454       fprintf (symtab->dump_file, " to %s count:",
 455                dst->dump_name ());
 456       orig_count.dump (symtab->dump_file);
 457       fprintf (symtab->dump_file, " resulting count:");
 458       dst->count.dump (symtab->dump_file);
 459       fprintf (symtab->dump_file, "\n");
 460     }
 461
 462   /* First handle functions with no gimple body.  */
 463   if (dst->thunk || dst->alias
 464       || src->thunk || src->alias)
 465     {
 466       scale_ipa_profile_for_fn (dst, orig_count);
 467       return;
 468     }
 469
 470   /* This is ugly.  We need to get both function bodies into memory.
 471      If declaration is merged, we need to duplicate it to be able
 472      to load body that is being replaced.  This makes symbol table
 473      temporarily inconsistent.  */
 474   if (src->decl == dst->decl)
 475     {
 476       struct lto_in_decl_state temp;
 477       struct lto_in_decl_state *state;
 478
 479       /* We are going to move the decl, we want to remove its file decl data.
 480          and link these with the new decl. */
 481       temp.fn_decl = src->decl;
 482       lto_in_decl_state **slot
 483         = src->lto_file_data->function_decl_states->find_slot (&temp,
 484                                                                NO_INSERT);
 485       state = *slot;
 486       src->lto_file_data->function_decl_states->clear_slot (slot);
 487       gcc_assert (state);
 488
 489       /* Duplicate the decl and be sure it does not link into body of DST.  */
 490       src->decl = copy_node (src->decl);
 491       DECL_STRUCT_FUNCTION (src->decl) = NULL;
 492       DECL_ARGUMENTS (src->decl) = NULL;
 493       DECL_INITIAL (src->decl) = NULL;
 494       DECL_RESULT (src->decl) = NULL;
 495
 496       /* Associate the decl state with new declaration, so LTO streamer
 497          can look it up.  */
 498       state->fn_decl = src->decl;
 499       slot
 500         = src->lto_file_data->function_decl_states->find_slot (state, INSERT);
 501       gcc_assert (!*slot);
 502       *slot = state;
 503     }
 504   src->get_untransformed_body ();
 505   dst->get_untransformed_body ();
 506   srccfun = DECL_STRUCT_FUNCTION (src->decl);
 507   dstcfun = DECL_STRUCT_FUNCTION (dst->decl);
 508   if (n_basic_blocks_for_fn (srccfun)
 509       != n_basic_blocks_for_fn (dstcfun))
 510     {
 511       if (symtab->dump_file)
 512         fprintf (symtab->dump_file,
 513                  "Giving up; number of basic block mismatch.\n");
 514       match = false;
 515     }
 516   else if (last_basic_block_for_fn (srccfun)
 517            != last_basic_block_for_fn (dstcfun))
 518     {
 519       if (symtab->dump_file)
 520         fprintf (symtab->dump_file,
 521                  "Giving up; last block mismatch.\n");
 522       match = false;
 523     }
 524   else
 525     {
 526       basic_block srcbb, dstbb;
 527       struct cgraph_edge *e, *e2;
 528
 529       for (e = dst->callees, e2 = src->callees; e && e2 && match;
 530            e2 = e2->next_callee, e = e->next_callee)
 531         {
 532           if (gimple_bb (e->call_stmt)->index
 533               != gimple_bb (e2->call_stmt)->index)
 534             {
 535               if (symtab->dump_file)
 536                 fprintf (symtab->dump_file,
 537                          "Giving up; call stmt mismatch.\n");
 538               match = false;
 539             }
 540         }
 541       if (e || e2)
 542         {
 543           if (symtab->dump_file)
 544             fprintf (symtab->dump_file,
 545                      "Giving up; number of calls differs.\n");
 546           match = false;
 547         }
 548       for (e = dst->indirect_calls, e2 = src->indirect_calls; e && e2 && match;
 549            e2 = e2->next_callee, e = e->next_callee)
 550         {
 551           if (gimple_bb (e->call_stmt)->index
 552               != gimple_bb (e2->call_stmt)->index)
 553             {
 554               if (symtab->dump_file)
 555                 fprintf (symtab->dump_file,
 556                          "Giving up; indirect call stmt mismatch.\n");
 557               match = false;
 558             }
 559         }
 560       if (e || e2)
 561         {
 562           if (symtab->dump_file)
 563             fprintf (symtab->dump_file,
 564                      "Giving up; number of indirect calls differs.\n");
 565           match=false;
 566         }
 567
 568       if (match)
 569         FOR_ALL_BB_FN (srcbb, srccfun)
 570           {
 571             unsigned int i;
 572
 573             dstbb = BASIC_BLOCK_FOR_FN (dstcfun, srcbb->index);
 574             if (dstbb == NULL)
 575               {
 576                 if (symtab->dump_file)
 577                   fprintf (symtab->dump_file,
 578                            "No matching block for bb %i.\n",
 579                            srcbb->index);
 580                 match = false;
 581                 break;
 582               }
 583             if (EDGE_COUNT (srcbb->succs) != EDGE_COUNT (dstbb->succs))
 584               {
 585                 if (symtab->dump_file)
 586                   fprintf (symtab->dump_file,
 587                            "Edge count mismatch for bb %i.\n",
 588                            srcbb->index);
 589                 match = false;
 590                 break;
 591               }
 592             for (i = 0; i < EDGE_COUNT (srcbb->succs); i++)
 593               {
 594                 edge srce = EDGE_SUCC (srcbb, i);
 595                 edge dste = EDGE_SUCC (dstbb, i);
 596                 if (srce->dest->index != dste->dest->index)
 597                   {
 598                     if (symtab->dump_file)
 599                       fprintf (symtab->dump_file,
 600                                "Succ edge mismatch for bb %i.\n",
 601                                srce->dest->index);
 602                     match = false;
 603                     break;
 604                   }
 605               }
 606           }
 607     }
 608   if (match)
 609     {
 610       struct cgraph_edge *e, *e2;
 611       basic_block srcbb, dstbb;
 612
 613       /* Function and global profile may be out of sync.  First scale it same
 614          way as fixup_cfg would.  */
 615       profile_count srcnum = src->count;
 616       profile_count srcden = ENTRY_BLOCK_PTR_FOR_FN (srccfun)->count;
 617       bool srcscale = srcnum.initialized_p () && !(srcnum == srcden);
 618       profile_count dstnum = orig_count;
 619       profile_count dstden = ENTRY_BLOCK_PTR_FOR_FN (dstcfun)->count;
 620       bool dstscale = !copy_counts
 621                       && dstnum.initialized_p () && !(dstnum == dstden);
 622
 623       /* TODO: merge also statement histograms.  */
 624       FOR_ALL_BB_FN (srcbb, srccfun)
 625         {
 626           unsigned int i;
 627
 628           dstbb = BASIC_BLOCK_FOR_FN (dstcfun, srcbb->index);
 629
 630           profile_count srccount = srcbb->count;
 631           if (srcscale)
 632             srccount = srccount.apply_scale (srcnum, srcden);
 633           if (dstscale)
 634             dstbb->count = dstbb->count.apply_scale (dstnum, dstden);
 635
 636           if (copy_counts)
 637             {
 638               dstbb->count = srccount;
 639               for (i = 0; i < EDGE_COUNT (srcbb->succs); i++)
 640                 {
 641                   edge srce = EDGE_SUCC (srcbb, i);
 642                   edge dste = EDGE_SUCC (dstbb, i);
 643                   if (srce->probability.initialized_p ())
 644                     dste->probability = srce->probability;
 645                 }
 646             }
 647           else
 648             {
 649               for (i = 0; i < EDGE_COUNT (srcbb->succs); i++)
 650                 {
 651                   edge srce = EDGE_SUCC (srcbb, i);
 652                   edge dste = EDGE_SUCC (dstbb, i);
 653                   dste->probability =
 654                     dste->probability * dstbb->count.ipa ().probability_in
 655                                                  (dstbb->count.ipa ()
 656                                                   + srccount.ipa ())
 657                     + srce->probability * srcbb->count.ipa ().probability_in
 658                                                  (dstbb->count.ipa ()
 659                                                   + srccount.ipa ());
 660                 }
 661               dstbb->count = dstbb->count.ipa () + srccount.ipa ();
 662             }
 663         }
 664       push_cfun (dstcfun);
 665       update_max_bb_count ();
 666       compute_function_frequency ();
 667       pop_cfun ();
 668       for (e = dst->callees; e; e = e->next_callee)
 669         {
 670           if (e->speculative)
 671             continue;
 672           e->count = gimple_bb (e->call_stmt)->count;
 673         }
 674       for (e = dst->indirect_calls, e2 = src->indirect_calls; e;
 675            e2 = (e2 ? e2->next_callee : NULL), e = e->next_callee)
 676         {
 677           if (!e->speculative && !e2->speculative)
 678             {
 679               /* FIXME: we need to also merge ipa-profile histograms
 680                  because with LTO merging happens from lto-symtab before
 681                  these are converted to indirect edges.  */
 682               e->count = gimple_bb (e->call_stmt)->count;
 683               continue;
 684             }
 685
 686           /* When copying just remove all speuclations on dst and then copy
 687              one from src.  */
 688           if (copy_counts)
 689             {
 690               while (e->speculative)
 691                 cgraph_edge::resolve_speculation (e, NULL);
 692               e->count = gimple_bb (e->call_stmt)->count;
 693               if (e2->speculative)
 694                 {
 695                   for (cgraph_edge *e3 = e2->first_speculative_call_target ();
 696                        e3;
 697                        e3 = e3->next_speculative_call_target ())
 698                     {
 699                       cgraph_edge *ns;
 700                       ns = e->make_speculative
 701                          (dyn_cast <cgraph_node *>
 702                             (e3->speculative_call_target_ref ()->referred),
 703                              e3->count, e3->speculative_id);
 704                       /* Target may differ from ref (for example it may be
 705                          redirected to local alias.  */
 706                       ns->redirect_callee (e3->callee);
 707                     }
 708                 }
 709               continue;
 710             }
 711
 712           /* Iterate all speculations in SRC, see if corresponding ones exist
 713              int DST and if so, sum the counts.  Otherwise create new
 714              speculation.  */
 715           int max_spec = 0;
 716           for (cgraph_edge *e3 = e->first_speculative_call_target ();
 717                e3;
 718                e3 = e3->next_speculative_call_target ())
 719             if (e3->speculative_id > max_spec)
 720               max_spec = e3->speculative_id;
 721           for (cgraph_edge *e3 = e2->first_speculative_call_target ();
 722                e3;
 723                e3 = e3->next_speculative_call_target ())
 724             {
 725               cgraph_edge *te
 726                  = e->speculative_call_for_target
 727                          (dyn_cast <cgraph_node *>
 728                             (e3->speculative_call_target_ref ()->referred));
 729               if (te)
 730                 te->count = te->count + e3->count;
 731               else
 732                 {
 733                   e->count = e->count + e3->count;
 734                   cgraph_edge *ns;
 735                   ns = e->make_speculative
 736                          (dyn_cast <cgraph_node *>
 737                             (e3->speculative_call_target_ref ()
 738                              ->referred),
 739                           e3->count,
 740                           e3->speculative_id + max_spec + 1);
 741                   /* Target may differ from ref (for example it may be
 742                      redirected to local alias.  */
 743                   ns->redirect_callee (e3->callee);
 744                 }
 745             }
 746         }
 747       if (!preserve_body)
 748         src->release_body ();
 749       /* Update summary.  */
 750       compute_fn_summary (dst, 0);
 751     }
 752   /* We can't update CFG profile, but we can scale IPA profile. CFG
 753      will be scaled according to dst->count after IPA passes.  */
 754   else
 755     scale_ipa_profile_for_fn (dst, orig_count);
 756   src->decl = oldsrcdecl;
 757 }
 758
 759 /* Return true if call to DEST is known to be self-recusive
 760    call withing FUNC.  */
 761
 762 bool
 763 recursive_call_p (tree func, tree dest)
 764 {
 765   struct cgraph_node *dest_node = cgraph_node::get_create (dest);
 766   struct cgraph_node *cnode = cgraph_node::get_create (func);
 767   ipa_ref *alias;
 768   enum availability avail;
 769
 770   gcc_assert (!cnode->alias);
 771   if (cnode != dest_node->ultimate_alias_target (&avail))
 772     return false;
 773   if (avail >= AVAIL_AVAILABLE)
 774     return true;
 775   if (!dest_node->semantically_equivalent_p (cnode))
 776     return false;
 777   /* If there is only one way to call the fuction or we know all of them
 778      are semantically equivalent, we still can consider call recursive.  */
 779   FOR_EACH_ALIAS (cnode, alias)
 780     if (!dest_node->semantically_equivalent_p (alias->referring))
 781       return false;
 782   return true;
 783 }