gcc/ipa-ref.c

   1 /* Interprocedural reference lists.
   2    Copyright (C) 2010-2013 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 static const char *ipa_ref_use_name[] = {"read","write","addr","alias"};
  31
  32 /* Return ipa reference from REFERING_NODE or REFERING_VARPOOL_NODE
  33    to REFERED_NODE or REFERED_VARPOOL_NODE. USE_TYPE specify type
  34    of the use and STMT the statement (if it exists).  */
  35
  36 struct ipa_ref *
  37 ipa_record_reference (symtab_node *referring_node,
  38                       symtab_node *referred_node,
  39                       enum ipa_ref_use use_type, gimple stmt)
  40 {
  41   struct ipa_ref *ref, *ref2;
  42   struct ipa_ref_list *list, *list2;
  43   ipa_ref_t *old_references;
  44
  45   gcc_checking_assert (!stmt || is_a <cgraph_node> (referring_node));
  46   gcc_checking_assert (use_type != IPA_REF_ALIAS || !stmt);
  47
  48   list = &referring_node->ref_list;
  49   old_references = vec_safe_address (list->references);
  50   vec_safe_grow (list->references, vec_safe_length (list->references) + 1);
  51   ref = &list->references->last ();
  52
  53   list2 = &referred_node->ref_list;
  54   list2->referring.safe_push (ref);
  55   ref->referred_index = list2->referring.length () - 1;
  56   ref->referring = referring_node;
  57   ref->referred = referred_node;
  58   ref->stmt = stmt;
  59   ref->lto_stmt_uid = 0;
  60   ref->use = use_type;
  61   ref->speculative = 0;
  62
  63   /* If vector was moved in memory, update pointers.  */
  64   if (old_references != list->references->address ())
  65     {
  66       int i;
  67       for (i = 0; ipa_ref_list_reference_iterate (list, i, ref2); i++)
  68         ipa_ref_referred_ref_list (ref2)->referring[ref2->referred_index] = ref2;
  69     }
  70   return ref;
  71 }
  72
  73 /* If VAL is a reference to a function or a variable, add a reference from
  74    REFERRING_NODE to the corresponding symbol table node.  USE_TYPE specify
  75    type of the use and STMT the statement (if it exists).  Return the new
  76    reference or NULL if none was created.  */
  77
  78 struct ipa_ref *
  79 ipa_maybe_record_reference (symtab_node *referring_node, tree val,
  80                             enum ipa_ref_use use_type, gimple stmt)
  81 {
  82   STRIP_NOPS (val);
  83   if (TREE_CODE (val) != ADDR_EXPR)
  84     return NULL;
  85   val = get_base_var (val);
  86   if (val && (TREE_CODE (val) == FUNCTION_DECL
  87                || TREE_CODE (val) == VAR_DECL))
  88     {
  89       symtab_node *referred = symtab_get_node (val);
  90       gcc_checking_assert (referred);
  91       return ipa_record_reference (referring_node, referred,
  92                                    use_type, stmt);
  93     }
  94   return NULL;
  95 }
  96
  97 /* Remove reference REF.  */
  98
  99 void
 100 ipa_remove_reference (struct ipa_ref *ref)
 101 {
 102   struct ipa_ref_list *list = ipa_ref_referred_ref_list (ref);
 103   struct ipa_ref_list *list2 = ipa_ref_referring_ref_list (ref);
 104   vec<ipa_ref_t, va_gc> *old_references = list2->references;
 105   struct ipa_ref *last;
 106
 107   gcc_assert (list->referring[ref->referred_index] == ref);
 108   last = list->referring.last ();
 109   if (ref != last)
 110     {
 111       list->referring[ref->referred_index] = list->referring.last ();
 112       list->referring[ref->referred_index]->referred_index
 113           = ref->referred_index;
 114     }
 115   list->referring.pop ();
 116
 117   last = &list2->references->last ();
 118   if (ref != last)
 119     {
 120       *ref = *last;
 121       ipa_ref_referred_ref_list (ref)->referring[ref->referred_index] = ref;
 122     }
 123   list2->references->pop ();
 124   gcc_assert (list2->references == old_references);
 125 }
 126
 127 /* Remove all references in ref list LIST.  */
 128
 129 void
 130 ipa_remove_all_references (struct ipa_ref_list *list)
 131 {
 132   while (vec_safe_length (list->references))
 133     ipa_remove_reference (&list->references->last ());
 134   vec_free (list->references);
 135 }
 136
 137 /* Remove all references in ref list LIST.  */
 138
 139 void
 140 ipa_remove_all_referring (struct ipa_ref_list *list)
 141 {
 142   while (list->referring.length ())
 143     ipa_remove_reference (list->referring.last ());
 144   list->referring.release ();
 145 }
 146
 147 /* Dump references in LIST to FILE.  */
 148
 149 void
 150 ipa_dump_references (FILE * file, struct ipa_ref_list *list)
 151 {
 152   struct ipa_ref *ref;
 153   int i;
 154   for (i = 0; ipa_ref_list_reference_iterate (list, i, ref); i++)
 155     {
 156       fprintf (file, "%s/%i (%s)",
 157                ref->referred->asm_name (),
 158                ref->referred->order,
 159                ipa_ref_use_name [ref->use]);
 160       if (ref->speculative)
 161         fprintf (file, " (speculative)");
 162     }
 163   fprintf (file, "\n");
 164 }
 165
 166 /* Dump referring in LIST to FILE.  */
 167
 168 void
 169 ipa_dump_referring (FILE * file, struct ipa_ref_list *list)
 170 {
 171   struct ipa_ref *ref;
 172   int i;
 173   for (i = 0; ipa_ref_list_referring_iterate (list, i, ref); i++)
 174     {
 175       fprintf (file, "%s/%i (%s)",
 176                ref->referring->asm_name (),
 177                ref->referring->order,
 178                ipa_ref_use_name [ref->use]);
 179       if (ref->speculative)
 180         fprintf (file, " (speculative)");
 181     }
 182   fprintf (file, "\n");
 183 }
 184
 185 /* Clone reference REF to DEST_NODE and set its stmt to STMT.  */
 186
 187 struct ipa_ref *
 188 ipa_clone_ref (struct ipa_ref *ref,
 189                symtab_node *dest_node,
 190                gimple stmt)
 191 {
 192   bool speculative = ref->speculative;
 193   unsigned int stmt_uid = ref->lto_stmt_uid;
 194   struct ipa_ref *ref2;
 195
 196   ref2 = ipa_record_reference (dest_node,
 197                                ref->referred,
 198                                ref->use, stmt);
 199   ref2->speculative = speculative;
 200   ref2->lto_stmt_uid = stmt_uid;
 201   return ref2;
 202 }
 203
 204 /* Clone all references from SRC to DEST_NODE or DEST_VARPOOL_NODE.  */
 205
 206 void
 207 ipa_clone_references (symtab_node *dest_node,
 208                       struct ipa_ref_list *src)
 209 {
 210   struct ipa_ref *ref, *ref2;
 211   int i;
 212   for (i = 0; ipa_ref_list_reference_iterate (src, i, ref); i++)
 213     {
 214       bool speculative = ref->speculative;
 215       unsigned int stmt_uid = ref->lto_stmt_uid;
 216
 217       ref2 = ipa_record_reference (dest_node,
 218                                    ref->referred,
 219                                    ref->use, ref->stmt);
 220       ref2->speculative = speculative;
 221       ref2->lto_stmt_uid = stmt_uid;
 222     }
 223 }
 224
 225 /* Clone all referring from SRC to DEST_NODE or DEST_VARPOOL_NODE.  */
 226
 227 void
 228 ipa_clone_referring (symtab_node *dest_node,
 229                     struct ipa_ref_list *src)
 230 {
 231   struct ipa_ref *ref, *ref2;
 232   int i;
 233   for (i = 0; ipa_ref_list_referring_iterate (src, i, ref); i++)
 234     {
 235       bool speculative = ref->speculative;
 236       unsigned int stmt_uid = ref->lto_stmt_uid;
 237
 238       ref2 = ipa_record_reference (ref->referring,
 239                                    dest_node,
 240                                    ref->use, ref->stmt);
 241       ref2->speculative = speculative;
 242       ref2->lto_stmt_uid = stmt_uid;
 243     }
 244 }
 245
 246 /* Return true when execution of REF can lead to return from
 247    function. */
 248 bool
 249 ipa_ref_cannot_lead_to_return (struct ipa_ref *ref)
 250 {
 251   return cgraph_node_cannot_return (ipa_ref_referring_node (ref));
 252 }
 253
 254 /* Return true if list contains an alias.  */
 255 bool
 256 ipa_ref_has_aliases_p (struct ipa_ref_list *ref_list)
 257 {
 258   struct ipa_ref *ref;
 259   int i;
 260
 261   for (i = 0; ipa_ref_list_referring_iterate (ref_list, i, ref); i++)
 262     if (ref->use == IPA_REF_ALIAS)
 263       return true;
 264   return false;
 265 }
 266
 267 /* Find the structure describing a reference in REFERRING_NODE to REFERRED_NODE
 268    and associated with statement STMT.  */
 269
 270 struct ipa_ref *
 271 ipa_find_reference (symtab_node *referring_node, symtab_node *referred_node,
 272                     gimple stmt, unsigned int lto_stmt_uid)
 273 {
 274   struct ipa_ref *r = NULL;
 275   int i;
 276
 277   for (i = 0; ipa_ref_list_reference_iterate (&referring_node->ref_list, i, r); i++)
 278     if (r->referred == referred_node
 279         && !r->speculative
 280         && ((stmt && r->stmt == stmt)
 281             || (lto_stmt_uid && r->lto_stmt_uid == lto_stmt_uid)
 282             || (!stmt && !lto_stmt_uid && !r->stmt && !r->lto_stmt_uid)))
 283       return r;
 284   return NULL;
 285 }
 286
 287 /* Remove all references from REFERRING_NODE that are associated with statement
 288    STMT.  */
 289
 290 void
 291 ipa_remove_stmt_references (symtab_node *referring_node, gimple stmt)
 292 {
 293   struct ipa_ref *r = NULL;
 294   int i;
 295
 296   for (i = 0; ipa_ref_list_reference_iterate (&referring_node->ref_list, i, r); i++)
 297     if (r->stmt == stmt)
 298       ipa_remove_reference (r);
 299 }
 300
 301 /* Remove all stmt references in non-speculative references.
 302    Those are not maintained during inlining & clonning.
 303    The exception are speculative references that are updated along
 304    with callgraph edges associated with them.  */
 305
 306 void
 307 ipa_clear_stmts_in_references (symtab_node *referring_node)
 308 {
 309   struct ipa_ref *r = NULL;
 310   int i;
 311
 312   for (i = 0; ipa_ref_list_reference_iterate (&referring_node->ref_list, i, r); i++)
 313     if (!r->speculative)
 314       {
 315         r->stmt = NULL;
 316         r->lto_stmt_uid = 0;
 317       }
 318 }