gcc/ipa-ref.c

   1 /* Interprocedural reference lists.
   2    Copyright (C) 2010-2017 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   vec<ipa_ref_t, va_gc> *old_references = list2->references;
  36   struct ipa_ref *last;
  37
  38   gcc_assert (list->referring[referred_index] == this);
  39
  40   last = list->referring.last ();
  41   if (this != last)
  42     {
  43       if (use == IPA_REF_ALIAS)
  44         {
  45           /* If deleted item is IPA_REF_ALIAS, we have to move last
  46           item of IPA_REF_LIST type to the deleted position. After that
  47           we replace last node with deletion slot.  */
  48           struct ipa_ref *last_alias = list->last_alias ();
  49
  50           if (last_alias && referred_index < last_alias->referred_index
  51               && last_alias != last)
  52           {
  53             unsigned last_alias_index = last_alias->referred_index;
  54
  55             list->referring[referred_index] = last_alias;
  56             list->referring[referred_index]->referred_index = referred_index;
  57
  58             /* New position for replacement is previous index
  59                of the last_alias.  */
  60             referred_index = last_alias_index;
  61           }
  62         }
  63
  64       list->referring[referred_index] = list->referring.last ();
  65       list->referring[referred_index]->referred_index= referred_index;
  66     }
  67   list->referring.pop ();
  68
  69   last = &list2->references->last ();
  70
  71   struct ipa_ref *ref = this;
  72
  73   if (ref != last)
  74     {
  75       *ref = *last;
  76       ref->referred_ref_list ()->referring[referred_index] = ref;
  77     }
  78   list2->references->pop ();
  79   gcc_assert (list2->references == old_references);
  80 }
  81
  82 /* Return true when execution of reference can lead to return from
  83    function.  */
  84
  85 bool
  86 ipa_ref::cannot_lead_to_return ()
  87 {
  88   return dyn_cast <cgraph_node *> (referring)->cannot_return_p ();
  89 }
  90
  91 /* Return reference list this reference is in.  */
  92
  93 struct ipa_ref_list *
  94 ipa_ref::referring_ref_list (void)
  95 {
  96   return &referring->ref_list;
  97 }
  98
  99 /* Return reference list this reference is in.  */
 100
 101 struct ipa_ref_list *
 102 ipa_ref::referred_ref_list (void)
 103 {
 104   return &referred->ref_list;
 105 }