1/* IPA 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#ifndef GCC_IPA_REF_H
22#define GCC_IPA_REF_H
23
24struct cgraph_node;
25class varpool_node;
26class symtab_node;
27
28
29/* How the reference is done.  */
30enum GTY(()) ipa_ref_use
31{
32  IPA_REF_LOAD,
33  IPA_REF_STORE,
34  IPA_REF_ADDR,
35  IPA_REF_ALIAS,
36  IPA_REF_CHKP
37};
38
39/* Record of reference in callgraph or varpool.  */
40struct GTY(()) ipa_ref
41{
42public:
43  /* Remove reference.  */
44  void remove_reference ();
45
46  /* Return true when execution of reference can lead to return from
47     function.  */
48  bool cannot_lead_to_return ();
49
50  /* Return true if refernece may be used in address compare.  */
51  bool address_matters_p ();
52
53  /* Return reference list this reference is in.  */
54  struct ipa_ref_list * referring_ref_list (void);
55
56  /* Return reference list this reference is in.  */
57  struct ipa_ref_list * referred_ref_list (void);
58
59  symtab_node *referring;
60  symtab_node *referred;
61  gimple stmt;
62  unsigned int lto_stmt_uid;
63  unsigned int referred_index;
64  ENUM_BITFIELD (ipa_ref_use) use:3;
65  unsigned int speculative:1;
66};
67
68typedef struct ipa_ref ipa_ref_t;
69typedef struct ipa_ref *ipa_ref_ptr;
70
71
72/* List of references.  This is stored in both callgraph and varpool nodes.  */
73struct GTY(()) ipa_ref_list
74{
75public:
76  /* Return first reference in list or NULL if empty.  */
77  struct ipa_ref *first_reference (void)
78  {
79    if (!vec_safe_length (references))
80      return NULL;
81    return &(*references)[0];
82  }
83
84  /* Return first referring ref in list or NULL if empty.  */
85  struct ipa_ref *first_referring (void)
86  {
87    if (!referring.length ())
88      return NULL;
89    return referring[0];
90  }
91
92  /* Return first referring alias.  */
93  struct ipa_ref *first_alias (void)
94  {
95    struct ipa_ref *r = first_referring ();
96
97    return r && r->use == IPA_REF_ALIAS ? r : NULL;
98  }
99
100  /* Return last referring alias.  */
101  struct ipa_ref *last_alias (void)
102  {
103    unsigned int i = 0;
104
105    for(i = 0; i < referring.length (); i++)
106      if (referring[i]->use != IPA_REF_ALIAS)
107	break;
108
109    return i == 0 ? NULL : referring[i - 1];
110  }
111
112  /* Return true if the symbol has an alias.  */
113  bool inline has_aliases_p (void)
114  {
115    return first_alias ();
116  }
117
118  /* Clear reference list.  */
119  void clear (void)
120  {
121    referring.create (0);
122    references = NULL;
123  }
124
125  /* Return number of references.  */
126  unsigned int nreferences (void)
127  {
128    return vec_safe_length (references);
129  }
130
131  /* Store actual references in references vector.  */
132  vec<ipa_ref_t, va_gc> *references;
133  /* Referring is vector of pointers to references.  It must not live in GGC space
134     or GGC will try to mark middle of references vectors.  */
135  vec<ipa_ref_ptr>  GTY((skip)) referring;
136};
137
138#endif /* GCC_IPA_REF_H */
139