gcc/ipa-ref.c

   1 /* Interprocedural reference lists.
   2    Copyright (C) 2010-2014 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 "tree.h"
  25 #include "ggc.h"
  26 #include "target.h"
  27 #include "cgraph.h"
  28 #include "ipa-utils.h"
  29
  30 /* Remove reference.  */
  31
  32 void
  33 ipa_ref::remove_reference ()
  34 {
  35   struct ipa_ref_list *list = referred_ref_list ();
  36   struct ipa_ref_list *list2 = referring_ref_list ();
  37   vec<ipa_ref_t, va_gc> *old_references = list2->references;
  38   struct ipa_ref *last;
  39
  40   gcc_assert (list->referring[referred_index] == this);
  41
  42   last = list->referring.last ();
  43   if (this != last)
  44     {
  45       if (use == IPA_REF_ALIAS)
  46         {
  47           /* If deleted item is IPA_REF_ALIAS, we have to move last
  48           item of IPA_REF_LIST type to the deleted position. After that
  49           we replace last node with deletion slot.  */
  50           struct ipa_ref *last_alias = list->last_alias ();
  51
  52           if (last_alias && referred_index < last_alias->referred_index
  53               && last_alias != last)
  54           {
  55             unsigned last_alias_index = last_alias->referred_index;
  56
  57             list->referring[referred_index] = last_alias;
  58             list->referring[referred_index]->referred_index = referred_index;
  59
  60             /* New position for replacement is previous index
  61                of the last_alias.  */
  62             referred_index = last_alias_index;
  63           }
  64         }
  65
  66       list->referring[referred_index] = list->referring.last ();
  67       list->referring[referred_index]->referred_index= referred_index;
  68     }
  69   list->referring.pop ();
  70
  71   last = &list2->references->last ();
  72
  73   struct ipa_ref *ref = this;
  74
  75   if (ref != last)
  76     {
  77       *ref = *last;
  78       ref->referred_ref_list ()->referring[referred_index] = ref;
  79     }
  80   list2->references->pop ();
  81   gcc_assert (list2->references == old_references);
  82 }
  83
  84 /* Return true when execution of reference can lead to return from
  85    function.  */
  86
  87 bool
  88 ipa_ref::cannot_lead_to_return ()
  89 {
  90   return dyn_cast <cgraph_node *> (referring)->cannot_return_p ();
  91 }
  92
  93 /* Return reference list this reference is in.  */
  94
  95 struct ipa_ref_list *
  96 ipa_ref::referring_ref_list (void)
  97 {
  98   return &referring->ref_list;
  99 }
 100
 101 /* Return reference list this reference is in.  */
 102
 103 struct ipa_ref_list *
 104 ipa_ref::referred_ref_list (void)
 105 {
 106   return &referred->ref_list;
 107 }