1/* Callgraph transformations to handle inlining
2   Copyright (C) 2003-2020 Free Software Foundation, Inc.
3   Contributed by Jan Hubicka
4
5This file is part of GCC.
6
7GCC is free software; you can redistribute it and/or modify it under
8the terms of the GNU General Public License as published by the Free
9Software Foundation; either version 3, or (at your option) any later
10version.
11
12GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13WARRANTY; without even the implied warranty of MERCHANTABILITY or
14FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
15for more details.
16
17You should have received a copy of the GNU General Public License
18along with GCC; see the file COPYING3.  If not see
19<http://www.gnu.org/licenses/>.  */
20
21/* The inline decisions are stored in callgraph in "inline plan" and
22   applied later.
23
24   To mark given call inline, use inline_call function.
25   The function marks the edge inlinable and, if necessary, produces
26   virtual clone in the callgraph representing the new copy of callee's
27   function body.
28
29   The inline plan is applied on given function body by inline_transform.  */
30
31#include "config.h"
32#include "system.h"
33#include "coretypes.h"
34#include "tm.h"
35#include "function.h"
36#include "tree.h"
37#include "alloc-pool.h"
38#include "tree-pass.h"
39#include "cgraph.h"
40#include "tree-cfg.h"
41#include "symbol-summary.h"
42#include "tree-vrp.h"
43#include "ipa-prop.h"
44#include "ipa-fnsummary.h"
45#include "ipa-inline.h"
46#include "tree-inline.h"
47#include "function.h"
48#include "cfg.h"
49#include "basic-block.h"
50#include "ipa-utils.h"
51
52int ncalls_inlined;
53int nfunctions_inlined;
54
55/* Scale counts of NODE edges by NUM/DEN.  */
56
57static void
58update_noncloned_counts (struct cgraph_node *node,
59			 profile_count num, profile_count den)
60{
61  struct cgraph_edge *e;
62
63  profile_count::adjust_for_ipa_scaling (&num, &den);
64
65  for (e = node->callees; e; e = e->next_callee)
66    {
67      if (!e->inline_failed)
68        update_noncloned_counts (e->callee, num, den);
69      e->count = e->count.apply_scale (num, den);
70    }
71  for (e = node->indirect_calls; e; e = e->next_callee)
72    e->count = e->count.apply_scale (num, den);
73  node->count = node->count.apply_scale (num, den);
74}
75
76/* We removed or are going to remove the last call to NODE.
77   Return true if we can and want proactively remove the NODE now.
78   This is important to do, since we want inliner to know when offline
79   copy of function was removed.  */
80
81static bool
82can_remove_node_now_p_1 (struct cgraph_node *node, struct cgraph_edge *e)
83{
84  ipa_ref *ref;
85
86  FOR_EACH_ALIAS (node, ref)
87    {
88      cgraph_node *alias = dyn_cast <cgraph_node *> (ref->referring);
89      if ((alias->callers && alias->callers != e)
90          || !can_remove_node_now_p_1 (alias, e))
91	return false;
92    }
93  /* FIXME: When address is taken of DECL_EXTERNAL function we still
94     can remove its offline copy, but we would need to keep unanalyzed node in
95     the callgraph so references can point to it.
96
97     Also for comdat group we can ignore references inside a group as we
98     want to prove the group as a whole to be dead.  */
99  return (!node->address_taken
100	  && node->can_remove_if_no_direct_calls_and_refs_p ()
101	  /* Inlining might enable more devirtualizing, so we want to remove
102	     those only after all devirtualizable virtual calls are processed.
103	     Lacking may edges in callgraph we just preserve them post
104	     inlining.  */
105	  && (!DECL_VIRTUAL_P (node->decl)
106	      || !opt_for_fn (node->decl, flag_devirtualize))
107	  /* During early inlining some unanalyzed cgraph nodes might be in the
108	     callgraph and they might refer the function in question.  */
109	  && !cgraph_new_nodes.exists ());
110}
111
112/* We are going to eliminate last direct call to NODE (or alias of it) via edge E.
113   Verify that the NODE can be removed from unit and if it is contained in comdat
114   group that the whole comdat group is removable.  */
115
116static bool
117can_remove_node_now_p (struct cgraph_node *node, struct cgraph_edge *e)
118{
119  struct cgraph_node *next;
120  if (!can_remove_node_now_p_1 (node, e))
121    return false;
122
123  /* When we see same comdat group, we need to be sure that all
124     items can be removed.  */
125  if (!node->same_comdat_group || !node->externally_visible)
126    return true;
127  for (next = dyn_cast<cgraph_node *> (node->same_comdat_group);
128       next != node; next = dyn_cast<cgraph_node *> (next->same_comdat_group))
129    {
130      if (next->alias)
131	continue;
132      if ((next->callers && next->callers != e)
133	  || !can_remove_node_now_p_1 (next, e))
134        return false;
135    }
136  return true;
137}
138
139/* Return true if NODE is a master clone with non-inline clones.  */
140
141static bool
142master_clone_with_noninline_clones_p (struct cgraph_node *node)
143{
144  if (node->clone_of)
145    return false;
146
147  for (struct cgraph_node *n = node->clones; n; n = n->next_sibling_clone)
148    if (n->decl != node->decl)
149      return true;
150
151  return false;
152}
153
154/* E is expected to be an edge being inlined.  Clone destination node of
155   the edge and redirect it to the new clone.
156   DUPLICATE is used for bookkeeping on whether we are actually creating new
157   clones or re-using node originally representing out-of-line function call.
158   By default the offline copy is removed, when it appears dead after inlining.
159   UPDATE_ORIGINAL prevents this transformation.
160   If OVERALL_SIZE is non-NULL, the size is updated to reflect the
161   transformation.  */
162
163void
164clone_inlined_nodes (struct cgraph_edge *e, bool duplicate,
165		     bool update_original, int *overall_size)
166{
167  struct cgraph_node *inlining_into;
168  struct cgraph_edge *next;
169
170  if (e->caller->inlined_to)
171    inlining_into = e->caller->inlined_to;
172  else
173    inlining_into = e->caller;
174
175  if (duplicate)
176    {
177      /* We may eliminate the need for out-of-line copy to be output.
178	 In that case just go ahead and re-use it.  This is not just an
179	 memory optimization.  Making offline copy of function disappear
180	 from the program will improve future decisions on inlining.  */
181      if (!e->callee->callers->next_caller
182	  /* Recursive inlining never wants the master clone to
183	     be overwritten.  */
184	  && update_original
185	  && can_remove_node_now_p (e->callee, e)
186	  /* We cannot overwrite a master clone with non-inline clones
187	     until after these clones are materialized.  */
188	  && !master_clone_with_noninline_clones_p (e->callee))
189	{
190	  /* TODO: When callee is in a comdat group, we could remove all of it,
191	     including all inline clones inlined into it.  That would however
192	     need small function inlining to register edge removal hook to
193	     maintain the priority queue.
194
195	     For now we keep the other functions in the group in program until
196	     cgraph_remove_unreachable_functions gets rid of them.  */
197	  gcc_assert (!e->callee->inlined_to);
198	  e->callee->remove_from_same_comdat_group ();
199	  if (e->callee->definition
200	      && inline_account_function_p (e->callee))
201	    {
202	      gcc_assert (!e->callee->alias);
203	      if (overall_size)
204		*overall_size -= ipa_size_summaries->get (e->callee)->size;
205	      nfunctions_inlined++;
206	    }
207	  duplicate = false;
208	  e->callee->externally_visible = false;
209          update_noncloned_counts (e->callee, e->count, e->callee->count);
210
211	  dump_callgraph_transformation (e->callee, inlining_into,
212					 "inlining to");
213	}
214      else
215	{
216	  struct cgraph_node *n;
217
218	  n = e->callee->create_clone (e->callee->decl,
219				       e->count,
220				       update_original, vNULL, true,
221				       inlining_into,
222				       NULL);
223	  n->used_as_abstract_origin = e->callee->used_as_abstract_origin;
224	  e->redirect_callee (n);
225	}
226    }
227  else
228    e->callee->remove_from_same_comdat_group ();
229
230  e->callee->inlined_to = inlining_into;
231
232  /* Recursively clone all bodies.  */
233  for (e = e->callee->callees; e; e = next)
234    {
235      next = e->next_callee;
236      if (!e->inline_failed)
237        clone_inlined_nodes (e, duplicate, update_original, overall_size);
238    }
239}
240
241/* Check all speculations in N and if any seem useless, resolve them.  When a
242   first edge is resolved, pop all edges from NEW_EDGES and insert them to
243   EDGE_SET.  Then remove each resolved edge from EDGE_SET, if it is there.  */
244
245static bool
246check_speculations_1 (cgraph_node *n, vec<cgraph_edge *> *new_edges,
247		      hash_set <cgraph_edge *> *edge_set)
248{
249  bool speculation_removed = false;
250  cgraph_edge *next;
251
252  for (cgraph_edge *e = n->callees; e; e = next)
253    {
254      next = e->next_callee;
255      if (e->speculative && !speculation_useful_p (e, true))
256	{
257	  while (new_edges && !new_edges->is_empty ())
258	    edge_set->add (new_edges->pop ());
259	  edge_set->remove (e);
260
261	  cgraph_edge::resolve_speculation (e, NULL);
262	  speculation_removed = true;
263	}
264      else if (!e->inline_failed)
265	speculation_removed |= check_speculations_1 (e->callee, new_edges,
266						     edge_set);
267    }
268  return speculation_removed;
269}
270
271/* Push E to NEW_EDGES.  Called from hash_set traverse method, which
272   unfortunately means this function has to have external linkage, otherwise
273   the code will not compile with gcc 4.8.  */
274
275bool
276push_all_edges_in_set_to_vec (cgraph_edge * const &e,
277			      vec<cgraph_edge *> *new_edges)
278{
279  new_edges->safe_push (e);
280  return true;
281}
282
283/* Check all speculations in N and if any seem useless, resolve them and remove
284   them from NEW_EDGES.  */
285
286static bool
287check_speculations (cgraph_node *n, vec<cgraph_edge *> *new_edges)
288{
289  hash_set <cgraph_edge *> edge_set;
290  bool res = check_speculations_1 (n, new_edges, &edge_set);
291  if (!edge_set.is_empty ())
292    edge_set.traverse <vec<cgraph_edge *> *,
293		       push_all_edges_in_set_to_vec> (new_edges);
294  return res;
295}
296
297/* Mark all call graph edges coming out of NODE and all nodes that have been
298   inlined to it as in_polymorphic_cdtor.  */
299
300static void
301mark_all_inlined_calls_cdtor (cgraph_node *node)
302{
303  for (cgraph_edge *cs = node->callees; cs; cs = cs->next_callee)
304    {
305      cs->in_polymorphic_cdtor = true;
306      if (!cs->inline_failed)
307	mark_all_inlined_calls_cdtor (cs->callee);
308    }
309  for (cgraph_edge *cs = node->indirect_calls; cs; cs = cs->next_callee)
310    cs->in_polymorphic_cdtor = true;
311}
312
313
314/* Mark edge E as inlined and update callgraph accordingly.  UPDATE_ORIGINAL
315   specify whether profile of original function should be updated.  If any new
316   indirect edges are discovered in the process, add them to NEW_EDGES, unless
317   it is NULL. If UPDATE_OVERALL_SUMMARY is false, do not bother to recompute overall
318   size of caller after inlining. Caller is required to eventually do it via
319   ipa_update_overall_fn_summary.
320   If callee_removed is non-NULL, set it to true if we removed callee node.
321
322   Return true iff any new callgraph edges were discovered as a
323   result of inlining.  */
324
325bool
326inline_call (struct cgraph_edge *e, bool update_original,
327	     vec<cgraph_edge *> *new_edges,
328	     int *overall_size, bool update_overall_summary,
329	     bool *callee_removed)
330{
331  int old_size = 0, new_size = 0;
332  struct cgraph_node *to = NULL;
333  struct cgraph_edge *curr = e;
334  bool comdat_local = e->callee->comdat_local_p ();
335  struct cgraph_node *callee = e->callee->ultimate_alias_target ();
336  bool new_edges_found = false;
337
338  int estimated_growth = 0;
339  if (! update_overall_summary)
340    estimated_growth = estimate_edge_growth (e);
341  /* This is used only for assert bellow.  */
342#if 0
343  bool predicated = inline_edge_summary (e)->predicate != NULL;
344#endif
345
346  /* Don't inline inlined edges.  */
347  gcc_assert (e->inline_failed);
348  /* Don't even think of inlining inline clone.  */
349  gcc_assert (!callee->inlined_to);
350
351  to = e->caller;
352  if (to->inlined_to)
353    to = to->inlined_to;
354  if (to->thunk.thunk_p)
355    {
356      struct cgraph_node *target = to->callees->callee;
357      thunk_expansion = true;
358      symtab->call_cgraph_removal_hooks (to);
359      if (in_lto_p)
360	to->get_untransformed_body ();
361      to->expand_thunk (false, true);
362      /* When thunk is instrumented we may have multiple callees.  */
363      for (e = to->callees; e && e->callee != target; e = e->next_callee)
364	;
365      symtab->call_cgraph_insertion_hooks (to);
366      thunk_expansion = false;
367      gcc_assert (e);
368    }
369
370
371  e->inline_failed = CIF_OK;
372  DECL_POSSIBLY_INLINED (callee->decl) = true;
373
374  if (DECL_FUNCTION_PERSONALITY (callee->decl))
375    DECL_FUNCTION_PERSONALITY (to->decl)
376      = DECL_FUNCTION_PERSONALITY (callee->decl);
377
378  bool reload_optimization_node = false;
379  if (!opt_for_fn (callee->decl, flag_strict_aliasing)
380      && opt_for_fn (to->decl, flag_strict_aliasing))
381    {
382      struct gcc_options opts = global_options;
383
384      cl_optimization_restore (&opts, opts_for_fn (to->decl));
385      opts.x_flag_strict_aliasing = false;
386      if (dump_file)
387	fprintf (dump_file, "Dropping flag_strict_aliasing on %s\n",
388		 to->dump_name ());
389      DECL_FUNCTION_SPECIFIC_OPTIMIZATION (to->decl)
390	 = build_optimization_node (&opts);
391      reload_optimization_node = true;
392    }
393
394  ipa_fn_summary *caller_info = ipa_fn_summaries->get (to);
395  ipa_fn_summary *callee_info = ipa_fn_summaries->get (callee);
396  if (!caller_info->fp_expressions && callee_info->fp_expressions)
397    {
398      caller_info->fp_expressions = true;
399      if (opt_for_fn (callee->decl, flag_rounding_math)
400	  != opt_for_fn (to->decl, flag_rounding_math)
401	  || opt_for_fn (callee->decl, flag_trapping_math)
402	     != opt_for_fn (to->decl, flag_trapping_math)
403	  || opt_for_fn (callee->decl, flag_unsafe_math_optimizations)
404	     != opt_for_fn (to->decl, flag_unsafe_math_optimizations)
405	  || opt_for_fn (callee->decl, flag_finite_math_only)
406	     != opt_for_fn (to->decl, flag_finite_math_only)
407	  || opt_for_fn (callee->decl, flag_signaling_nans)
408	     != opt_for_fn (to->decl, flag_signaling_nans)
409	  || opt_for_fn (callee->decl, flag_cx_limited_range)
410	     != opt_for_fn (to->decl, flag_cx_limited_range)
411	  || opt_for_fn (callee->decl, flag_signed_zeros)
412	     != opt_for_fn (to->decl, flag_signed_zeros)
413	  || opt_for_fn (callee->decl, flag_associative_math)
414	     != opt_for_fn (to->decl, flag_associative_math)
415	  || opt_for_fn (callee->decl, flag_reciprocal_math)
416	     != opt_for_fn (to->decl, flag_reciprocal_math)
417	  || opt_for_fn (callee->decl, flag_fp_int_builtin_inexact)
418	     != opt_for_fn (to->decl, flag_fp_int_builtin_inexact)
419	  || opt_for_fn (callee->decl, flag_errno_math)
420	     != opt_for_fn (to->decl, flag_errno_math))
421	{
422	  struct gcc_options opts = global_options;
423
424	  cl_optimization_restore (&opts, opts_for_fn (to->decl));
425	  opts.x_flag_rounding_math
426	    = opt_for_fn (callee->decl, flag_rounding_math);
427	  opts.x_flag_trapping_math
428	    = opt_for_fn (callee->decl, flag_trapping_math);
429	  opts.x_flag_unsafe_math_optimizations
430	    = opt_for_fn (callee->decl, flag_unsafe_math_optimizations);
431	  opts.x_flag_finite_math_only
432	    = opt_for_fn (callee->decl, flag_finite_math_only);
433	  opts.x_flag_signaling_nans
434	    = opt_for_fn (callee->decl, flag_signaling_nans);
435	  opts.x_flag_cx_limited_range
436	    = opt_for_fn (callee->decl, flag_cx_limited_range);
437	  opts.x_flag_signed_zeros
438	    = opt_for_fn (callee->decl, flag_signed_zeros);
439	  opts.x_flag_associative_math
440	    = opt_for_fn (callee->decl, flag_associative_math);
441	  opts.x_flag_reciprocal_math
442	    = opt_for_fn (callee->decl, flag_reciprocal_math);
443	  opts.x_flag_fp_int_builtin_inexact
444	    = opt_for_fn (callee->decl, flag_fp_int_builtin_inexact);
445	  opts.x_flag_errno_math
446	    = opt_for_fn (callee->decl, flag_errno_math);
447	  if (dump_file)
448	    fprintf (dump_file, "Copying FP flags from %s to %s\n",
449		     callee->dump_name (), to->dump_name ());
450	  DECL_FUNCTION_SPECIFIC_OPTIMIZATION (to->decl)
451	     = build_optimization_node (&opts);
452	  reload_optimization_node = true;
453	}
454    }
455
456  /* Reload global optimization flags.  */
457  if (reload_optimization_node && DECL_STRUCT_FUNCTION (to->decl) == cfun)
458    set_cfun (cfun, true);
459
460  /* If aliases are involved, redirect edge to the actual destination and
461     possibly remove the aliases.  */
462  if (e->callee != callee)
463    {
464      struct cgraph_node *alias = e->callee, *next_alias;
465      e->redirect_callee (callee);
466      while (alias && alias != callee)
467	{
468	  if (!alias->callers
469	      && can_remove_node_now_p (alias,
470					!e->next_caller && !e->prev_caller ? e : NULL))
471	    {
472	      next_alias = alias->get_alias_target ();
473	      alias->remove ();
474	      if (callee_removed)
475		*callee_removed = true;
476	      alias = next_alias;
477	    }
478	  else
479	    break;
480	}
481    }
482
483  clone_inlined_nodes (e, true, update_original, overall_size);
484
485  gcc_assert (curr->callee->inlined_to == to);
486
487  old_size = ipa_size_summaries->get (to)->size;
488  ipa_merge_fn_summary_after_inlining (e);
489  if (e->in_polymorphic_cdtor)
490    mark_all_inlined_calls_cdtor (e->callee);
491  if (opt_for_fn (e->caller->decl, optimize))
492    new_edges_found = ipa_propagate_indirect_call_infos (curr, new_edges);
493  bool removed_p = check_speculations (e->callee, new_edges);
494  if (update_overall_summary)
495    ipa_update_overall_fn_summary (to, new_edges_found || removed_p);
496  else
497    /* Update self size by the estimate so overall function growth limits
498       work for further inlining into this function.  Before inlining
499       the function we inlined to again we expect the caller to update
500       the overall summary.  */
501    ipa_size_summaries->get (to)->size += estimated_growth;
502  new_size = ipa_size_summaries->get (to)->size;
503
504  if (callee->calls_comdat_local)
505    to->calls_comdat_local = true;
506  else if (to->calls_comdat_local && comdat_local)
507    to->calls_comdat_local = to->check_calls_comdat_local_p ();
508
509  /* FIXME: This assert suffers from roundoff errors, disable it for GCC 5
510     and revisit it after conversion to sreals in GCC 6.
511     See PR 65654.  */
512#if 0
513  /* Verify that estimated growth match real growth.  Allow off-by-one
514     error due to ipa_fn_summary::size_scale roudoff errors.  */
515  gcc_assert (!update_overall_summary || !overall_size || new_edges_found
516	      || abs (estimated_growth - (new_size - old_size)) <= 1
517	      || speculation_removed
518	      /* FIXME: a hack.  Edges with false predicate are accounted
519		 wrong, we should remove them from callgraph.  */
520	      || predicated);
521#endif
522
523  /* Account the change of overall unit size; external functions will be
524     removed and are thus not accounted.  */
525  if (overall_size && inline_account_function_p (to))
526    *overall_size += new_size - old_size;
527  ncalls_inlined++;
528
529  /* This must happen after ipa_merge_fn_summary_after_inlining that rely on jump
530     functions of callee to not be updated.  */
531  return new_edges_found;
532}
533
534/* For each node that was made the holder of function body by
535   save_inline_function_body, this summary contains pointer to the previous
536   holder of the body.  */
537
538function_summary <tree *> *ipa_saved_clone_sources;
539
540/* Copy function body of NODE and redirect all inline clones to it.
541   This is done before inline plan is applied to NODE when there are
542   still some inline clones if it.
543
544   This is necessary because inline decisions are not really transitive
545   and the other inline clones may have different bodies.  */
546
547static struct cgraph_node *
548save_inline_function_body (struct cgraph_node *node)
549{
550  struct cgraph_node *first_clone, *n;
551
552  if (dump_file)
553    fprintf (dump_file, "\nSaving body of %s for later reuse\n",
554	     node->dump_name ());
555
556  gcc_assert (node == cgraph_node::get (node->decl));
557
558  /* first_clone will be turned into real function.  */
559  first_clone = node->clones;
560
561  /* Arrange first clone to not be thunk as those do not have bodies.  */
562  if (first_clone->thunk.thunk_p)
563    {
564      while (first_clone->thunk.thunk_p)
565        first_clone = first_clone->next_sibling_clone;
566      first_clone->prev_sibling_clone->next_sibling_clone
567	= first_clone->next_sibling_clone;
568      if (first_clone->next_sibling_clone)
569	first_clone->next_sibling_clone->prev_sibling_clone
570	   = first_clone->prev_sibling_clone;
571      first_clone->next_sibling_clone = node->clones;
572      first_clone->prev_sibling_clone = NULL;
573      node->clones->prev_sibling_clone = first_clone;
574      node->clones = first_clone;
575    }
576  first_clone->decl = copy_node (node->decl);
577  first_clone->decl->decl_with_vis.symtab_node = first_clone;
578  gcc_assert (first_clone == cgraph_node::get (first_clone->decl));
579
580  /* Now reshape the clone tree, so all other clones descends from
581     first_clone.  */
582  if (first_clone->next_sibling_clone)
583    {
584      for (n = first_clone->next_sibling_clone; n->next_sibling_clone;
585	   n = n->next_sibling_clone)
586        n->clone_of = first_clone;
587      n->clone_of = first_clone;
588      n->next_sibling_clone = first_clone->clones;
589      if (first_clone->clones)
590        first_clone->clones->prev_sibling_clone = n;
591      first_clone->clones = first_clone->next_sibling_clone;
592      first_clone->next_sibling_clone->prev_sibling_clone = NULL;
593      first_clone->next_sibling_clone = NULL;
594      gcc_assert (!first_clone->prev_sibling_clone);
595    }
596
597  tree prev_body_holder = node->decl;
598  if (!ipa_saved_clone_sources)
599    ipa_saved_clone_sources = new function_summary <tree *> (symtab);
600  else
601    {
602      tree *p = ipa_saved_clone_sources->get (node);
603      if (p)
604	{
605	  prev_body_holder = *p;
606	  gcc_assert (prev_body_holder);
607	}
608    }
609  *ipa_saved_clone_sources->get_create (first_clone) = prev_body_holder;
610  first_clone->former_clone_of
611    = node->former_clone_of ? node->former_clone_of : node->decl;
612  first_clone->clone_of = NULL;
613
614  /* Now node in question has no clones.  */
615  node->clones = NULL;
616
617  /* Inline clones share decl with the function they are cloned
618     from.  Walk the whole clone tree and redirect them all to the
619     new decl.  */
620  if (first_clone->clones)
621    for (n = first_clone->clones; n != first_clone;)
622      {
623        gcc_assert (n->decl == node->decl);
624	n->decl = first_clone->decl;
625	if (n->clones)
626	  n = n->clones;
627	else if (n->next_sibling_clone)
628	  n = n->next_sibling_clone;
629	else
630	  {
631	    while (n != first_clone && !n->next_sibling_clone)
632	      n = n->clone_of;
633	    if (n != first_clone)
634	      n = n->next_sibling_clone;
635	  }
636      }
637
638  /* Copy the OLD_VERSION_NODE function tree to the new version.  */
639  tree_function_versioning (node->decl, first_clone->decl,
640			    NULL, NULL, true, NULL, NULL);
641
642  /* The function will be short lived and removed after we inline all the clones,
643     but make it internal so we won't confuse ourself.  */
644  DECL_EXTERNAL (first_clone->decl) = 0;
645  TREE_PUBLIC (first_clone->decl) = 0;
646  DECL_COMDAT (first_clone->decl) = 0;
647  first_clone->ipa_transforms_to_apply.release ();
648
649  /* When doing recursive inlining, the clone may become unnecessary.
650     This is possible i.e. in the case when the recursive function is proved to be
651     non-throwing and the recursion happens only in the EH landing pad.
652     We cannot remove the clone until we are done with saving the body.
653     Remove it now.  */
654  if (!first_clone->callers)
655    {
656      first_clone->remove_symbol_and_inline_clones ();
657      first_clone = NULL;
658    }
659  else if (flag_checking)
660    first_clone->verify ();
661
662  return first_clone;
663}
664
665/* Return true when function body of DECL still needs to be kept around
666   for later re-use.  */
667static bool
668preserve_function_body_p (struct cgraph_node *node)
669{
670  gcc_assert (symtab->global_info_ready);
671  gcc_assert (!node->alias && !node->thunk.thunk_p);
672
673  /* Look if there is any non-thunk clone around.  */
674  for (node = node->clones; node; node = node->next_sibling_clone)
675    if (!node->thunk.thunk_p)
676      return true;
677  return false;
678}
679
680/* Apply inline plan to function.  */
681
682unsigned int
683inline_transform (struct cgraph_node *node)
684{
685  unsigned int todo = 0;
686  struct cgraph_edge *e, *next;
687  bool has_inline = false;
688
689  /* FIXME: Currently the pass manager is adding inline transform more than
690     once to some clones.  This needs revisiting after WPA cleanups.  */
691  if (cfun->after_inlining)
692    return 0;
693
694  /* We might need the body of this function so that we can expand
695     it inline somewhere else.  */
696  if (preserve_function_body_p (node))
697    save_inline_function_body (node);
698
699  profile_count num = node->count;
700  profile_count den = ENTRY_BLOCK_PTR_FOR_FN (cfun)->count;
701  bool scale = num.initialized_p () && !(num == den);
702  if (scale)
703    {
704      profile_count::adjust_for_ipa_scaling (&num, &den);
705      if (dump_file)
706	{
707	  fprintf (dump_file, "Applying count scale ");
708	  num.dump (dump_file);
709	  fprintf (dump_file, "/");
710	  den.dump (dump_file);
711	  fprintf (dump_file, "\n");
712	}
713
714      basic_block bb;
715      cfun->cfg->count_max = profile_count::uninitialized ();
716      FOR_ALL_BB_FN (bb, cfun)
717	{
718	  bb->count = bb->count.apply_scale (num, den);
719	  cfun->cfg->count_max = cfun->cfg->count_max.max (bb->count);
720	}
721      ENTRY_BLOCK_PTR_FOR_FN (cfun)->count = node->count;
722    }
723
724  for (e = node->callees; e; e = next)
725    {
726      if (!e->inline_failed)
727	has_inline = true;
728      next = e->next_callee;
729      cgraph_edge::redirect_call_stmt_to_callee (e);
730    }
731  node->remove_all_references ();
732
733  timevar_push (TV_INTEGRATION);
734  if (node->callees && (opt_for_fn (node->decl, optimize) || has_inline))
735    {
736      todo = optimize_inline_calls (current_function_decl);
737    }
738  timevar_pop (TV_INTEGRATION);
739
740  cfun->always_inline_functions_inlined = true;
741  cfun->after_inlining = true;
742  todo |= execute_fixup_cfg ();
743
744  if (!(todo & TODO_update_ssa_any))
745    /* Redirecting edges might lead to a need for vops to be recomputed.  */
746    todo |= TODO_update_ssa_only_virtuals;
747
748  return todo;
749}
750