gcc/ipa-ref.c

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