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 "hash-map.h"
  28 #include "is-a.h"
  29 #include "plugin-api.h"
  30 #include "vec.h"
  31 #include "hashtab.h"
  32 #include "hash-set.h"
  33 #include "machmode.h"
  34 #include "tm.h"
  35 #include "hard-reg-set.h"
  36 #include "input.h"
  37 #include "function.h"
  38 #include "ipa-ref.h"
  39 #include "cgraph.h"
  40 #include "ipa-utils.h"
  41
  42 /* Remove reference.  */
  43
  44 void
  45 ipa_ref::remove_reference ()
  46 {
  47   struct ipa_ref_list *list = referred_ref_list ();
  48   struct ipa_ref_list *list2 = referring_ref_list ();
  49   vec<ipa_ref_t, va_gc> *old_references = list2->references;
  50   struct ipa_ref *last;
  51
  52   gcc_assert (list->referring[referred_index] == this);
  53
  54   last = list->referring.last ();
  55   if (this != last)
  56     {
  57       if (use == IPA_REF_ALIAS)
  58         {
  59           /* If deleted item is IPA_REF_ALIAS, we have to move last
  60           item of IPA_REF_LIST type to the deleted position. After that
  61           we replace last node with deletion slot.  */
  62           struct ipa_ref *last_alias = list->last_alias ();
  63
  64           if (last_alias && referred_index < last_alias->referred_index
  65               && last_alias != last)
  66           {
  67             unsigned last_alias_index = last_alias->referred_index;
  68
  69             list->referring[referred_index] = last_alias;
  70             list->referring[referred_index]->referred_index = referred_index;
  71
  72             /* New position for replacement is previous index
  73                of the last_alias.  */
  74             referred_index = last_alias_index;
  75           }
  76         }
  77
  78       list->referring[referred_index] = list->referring.last ();
  79       list->referring[referred_index]->referred_index= referred_index;
  80     }
  81   list->referring.pop ();
  82
  83   last = &list2->references->last ();
  84
  85   struct ipa_ref *ref = this;
  86
  87   if (ref != last)
  88     {
  89       *ref = *last;
  90       ref->referred_ref_list ()->referring[referred_index] = ref;
  91     }
  92   list2->references->pop ();
  93   gcc_assert (list2->references == old_references);
  94 }
  95
  96 /* Return true when execution of reference can lead to return from
  97    function.  */
  98
  99 bool
 100 ipa_ref::cannot_lead_to_return ()
 101 {
 102   return dyn_cast <cgraph_node *> (referring)->cannot_return_p ();
 103 }
 104
 105 /* Return reference list this reference is in.  */
 106
 107 struct ipa_ref_list *
 108 ipa_ref::referring_ref_list (void)
 109 {
 110   return &referring->ref_list;
 111 }
 112
 113 /* Return reference list this reference is in.  */
 114
 115 struct ipa_ref_list *
 116 ipa_ref::referred_ref_list (void)
 117 {
 118   return &referred->ref_list;
 119 }