1/* Interprocedural reference lists.
2   Copyright (C) 2010-2015 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#include "config.h"
22#include "system.h"
23#include "coretypes.h"
24#include "hash-set.h"
25#include "machmode.h"
26#include "vec.h"
27#include "double-int.h"
28#include "input.h"
29#include "alias.h"
30#include "symtab.h"
31#include "options.h"
32#include "wide-int.h"
33#include "inchash.h"
34#include "tree.h"
35#include "fold-const.h"
36#include "ggc.h"
37#include "target.h"
38#include "hash-map.h"
39#include "is-a.h"
40#include "plugin-api.h"
41#include "tm.h"
42#include "hard-reg-set.h"
43#include "input.h"
44#include "function.h"
45#include "ipa-ref.h"
46#include "cgraph.h"
47#include "ipa-utils.h"
48
49/* Remove reference.  */
50
51void
52ipa_ref::remove_reference ()
53{
54  struct ipa_ref_list *list = referred_ref_list ();
55  struct ipa_ref_list *list2 = referring_ref_list ();
56  vec<ipa_ref_t, va_gc> *old_references = list2->references;
57  struct ipa_ref *last;
58
59  gcc_assert (list->referring[referred_index] == this);
60
61  last = list->referring.last ();
62  if (this != last)
63    {
64      if (use == IPA_REF_ALIAS)
65        {
66	  /* If deleted item is IPA_REF_ALIAS, we have to move last
67	  item of IPA_REF_LIST type to the deleted position. After that
68	  we replace last node with deletion slot.  */
69	  struct ipa_ref *last_alias = list->last_alias ();
70
71	  if (last_alias && referred_index < last_alias->referred_index
72	      && last_alias != last)
73	  {
74	    unsigned last_alias_index = last_alias->referred_index;
75
76	    list->referring[referred_index] = last_alias;
77	    list->referring[referred_index]->referred_index = referred_index;
78
79	    /* New position for replacement is previous index
80	       of the last_alias.  */
81	    referred_index = last_alias_index;
82	  }
83	}
84
85      list->referring[referred_index] = list->referring.last ();
86      list->referring[referred_index]->referred_index= referred_index;
87    }
88  list->referring.pop ();
89
90  last = &list2->references->last ();
91
92  struct ipa_ref *ref = this;
93
94  if (ref != last)
95    {
96      *ref = *last;
97      ref->referred_ref_list ()->referring[referred_index] = ref;
98    }
99  list2->references->pop ();
100  gcc_assert (list2->references == old_references);
101}
102
103/* Return true when execution of reference can lead to return from
104   function.  */
105
106bool
107ipa_ref::cannot_lead_to_return ()
108{
109  return dyn_cast <cgraph_node *> (referring)->cannot_return_p ();
110}
111
112/* Return reference list this reference is in.  */
113
114struct ipa_ref_list *
115ipa_ref::referring_ref_list (void)
116{
117  return &referring->ref_list;
118}
119
120/* Return reference list this reference is in.  */
121
122struct ipa_ref_list *
123ipa_ref::referred_ref_list (void)
124{
125  return &referred->ref_list;
126}
127