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