gcc/ipa-ref.c

   1 /* Interprocedural reference lists.
   2    Copyright (C) 2010-2022 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 "target.h"
  25 #include "tree.h"
  26 #include "cgraph.h"
  27
  28 /* Remove reference.  */
  29
  30 void
  31 ipa_ref::remove_reference ()
  32 {
  33   struct ipa_ref_list *list = referred_ref_list ();
  34   struct ipa_ref_list *list2 = referring_ref_list ();
  35   struct ipa_ref *last;
  36
  37   gcc_assert (list->referring[referred_index] == this);
  38
  39   last = list->referring.last ();
  40   if (this != last)
  41     {
  42       if (use == IPA_REF_ALIAS)
  43         {
  44           /* If deleted item is IPA_REF_ALIAS, we have to move last
  45           item of IPA_REF_LIST type to the deleted position. After that
  46           we replace last node with deletion slot.  */
  47           struct ipa_ref *last_alias = list->last_alias ();
  48
  49           if (last_alias && referred_index < last_alias->referred_index
  50               && last_alias != last)
  51           {
  52             unsigned last_alias_index = last_alias->referred_index;
  53
  54             list->referring[referred_index] = last_alias;
  55             list->referring[referred_index]->referred_index = referred_index;
  56
  57             /* New position for replacement is previous index
  58                of the last_alias.  */
  59             referred_index = last_alias_index;
  60           }
  61         }
  62
  63       list->referring[referred_index] = list->referring.last ();
  64       list->referring[referred_index]->referred_index= referred_index;
  65     }
  66   list->referring.pop ();
  67
  68   last = &list2->references.last ();
  69
  70   struct ipa_ref *ref = this;
  71
  72   if (ref != last)
  73     {
  74       *ref = *last;
  75       ref->referred_ref_list ()->referring[referred_index] = ref;
  76     }
  77   list2->references.pop ();
  78 }
  79
  80 /* Return true when execution of reference can lead to return from
  81    function.  */
  82
  83 bool
  84 ipa_ref::cannot_lead_to_return ()
  85 {
  86   return dyn_cast <cgraph_node *> (referring)->cannot_return_p ();
  87 }
  88
  89 /* Return reference list this reference is in.  */
  90
  91 struct ipa_ref_list *
  92 ipa_ref::referring_ref_list (void)
  93 {
  94   return &referring->ref_list;
  95 }
  96
  97 /* Return reference list this reference is in.  */
  98
  99 struct ipa_ref_list *
 100 ipa_ref::referred_ref_list (void)
 101 {
 102   return &referred->ref_list;
 103 }