gcc/multiple_target.c

   1 /* Pass for parsing functions with multiple target attributes.
   2
   3    Contributed by Evgeny Stupachenko <evstupac@gmail.com>
   4
   5    Copyright (C) 2015-2016 Free Software Foundation, Inc.
   6
   7 This file is part of GCC.
   8
   9 GCC is free software; you can redistribute it and/or modify it under
  10 the terms of the GNU General Public License as published by the Free
  11 Software Foundation; either version 3, or (at your option) any later
  12 version.
  13
  14 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  15 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  16 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  17 for more details.
  18
  19 You should have received a copy of the GNU General Public License
  20 along with GCC; see the file COPYING3.  If not see
  21 <http://www.gnu.org/licenses/>.  */
  22
  23 #include "config.h"
  24 #include "system.h"
  25 #include "coretypes.h"
  26 #include "backend.h"
  27 #include "tree.h"
  28 #include "stringpool.h"
  29 #include "gimple.h"
  30 #include "diagnostic-core.h"
  31 #include "gimple-ssa.h"
  32 #include "cgraph.h"
  33 #include "tree-pass.h"
  34 #include "target.h"
  35 #include "attribs.h"
  36 #include "pretty-print.h"
  37
  38 /* If the call in NODE has multiple target attribute with multiple fields,
  39    replace it with dispatcher call and create dispatcher (once).  */
  40
  41 static void
  42 create_dispatcher_calls (struct cgraph_node *node)
  43 {
  44   cgraph_edge *e;
  45   cgraph_edge *e_next;
  46
  47   /* We need to remember NEXT_CALLER as it could be modified in the loop.  */
  48   for (e = node->callers; e ;e = (e == NULL) ? e_next : e->next_caller)
  49     {
  50       tree resolver_decl;
  51       tree idecl;
  52       tree decl;
  53       gimple *call = e->call_stmt;
  54       struct cgraph_node *inode;
  55
  56       /* Checking if call of function is call of versioned function.
  57          Versioned function are not inlined, so there is no need to
  58          check for inline.  */
  59       if (!call
  60           || !(decl = gimple_call_fndecl (call))
  61           || !DECL_FUNCTION_VERSIONED (decl))
  62         continue;
  63
  64       if (!targetm.has_ifunc_p ())
  65         {
  66           error_at (gimple_location (call),
  67                     "the call requires ifunc, which is not"
  68                     " supported by this target");
  69           break;
  70         }
  71       e_next = e->next_caller;
  72       idecl = targetm.get_function_versions_dispatcher (decl);
  73       if (!idecl)
  74         {
  75           error_at (gimple_location (call),
  76                     "default target_clones attribute was not set");
  77           break;
  78         }
  79       inode = cgraph_node::get (idecl);
  80       gcc_assert (inode);
  81       resolver_decl = targetm.generate_version_dispatcher_body (inode);
  82
  83       /* Update aliases.  */
  84       inode->alias = true;
  85       inode->alias_target = resolver_decl;
  86       if (!inode->analyzed)
  87         inode->resolve_alias (cgraph_node::get (resolver_decl));
  88
  89       e->redirect_callee (inode);
  90       /*  Since REDIRECT_CALLEE modifies NEXT_CALLER field we move to
  91           previously set NEXT_CALLER.  */
  92       e = NULL;
  93     }
  94 }
  95
  96 /* Return length of attribute names string,
  97    if arglist chain > 1, -1 otherwise.  */
  98
  99 static int
 100 get_attr_len (tree arglist)
 101 {
 102   tree arg;
 103   int str_len_sum = 0;
 104   int argnum = 1;
 105
 106   for (arg = arglist; arg; arg = TREE_CHAIN (arg))
 107     {
 108       unsigned int i;
 109       const char *str = TREE_STRING_POINTER (TREE_VALUE (arg));
 110       int len = strlen (str);
 111
 112       str_len_sum += len + 1;
 113       if (arg != arglist)
 114         argnum++;
 115       for (i = 0; i < strlen (str); i++)
 116         if (str[i] == ',')
 117           argnum++;
 118     }
 119   if (argnum == 1)
 120     return -1;
 121   return str_len_sum;
 122 }
 123
 124 /* Create string with attributes separated by comma.
 125    Return number of attributes.  */
 126
 127 static int
 128 get_attr_str (tree arglist, char *attr_str)
 129 {
 130   tree arg;
 131   size_t str_len_sum = 0;
 132   int argnum = 0;
 133
 134   for (arg = arglist; arg; arg = TREE_CHAIN (arg))
 135     {
 136       const char *str = TREE_STRING_POINTER (TREE_VALUE (arg));
 137
 138       size_t len = strlen (str);
 139       memcpy (attr_str + str_len_sum, str, len);
 140       attr_str[str_len_sum + len] = TREE_CHAIN (arg) ? ',' : '\0';
 141       str_len_sum += len + 1;
 142       argnum++;
 143     }
 144   return argnum;
 145 }
 146
 147 /* Return number of attributes separated by comma and put them into ARGS.
 148    If there is no DEFAULT attribute return -1.  */
 149
 150 static int
 151 separate_attrs (char *attr_str, char **attrs)
 152 {
 153   int i = 0;
 154   bool has_default = false;
 155   char *attr = strtok (attr_str, ",");
 156
 157   while (attr != NULL)
 158     {
 159       if (strcmp (attr, "default") == 0)
 160         {
 161           has_default = true;
 162           attr = strtok (NULL, ",");
 163           continue;
 164         }
 165       attrs[i] = attr;
 166       attr = strtok (NULL, ",");
 167       i++;
 168     }
 169   if (!has_default)
 170     return -1;
 171   return i;
 172 }
 173
 174 /*  Return true if symbol is valid in assembler name.  */
 175
 176 static bool
 177 is_valid_asm_symbol (char c)
 178 {
 179   if ('a' <= c && c <= 'z')
 180     return true;
 181   if ('A' <= c && c <= 'Z')
 182     return true;
 183   if ('0' <= c && c <= '9')
 184     return true;
 185   if (c == '_')
 186     return true;
 187   return false;
 188 }
 189
 190 /*  Replace all not valid assembler symbols with '_'.  */
 191
 192 static void
 193 create_new_asm_name (char *old_asm_name, char *new_asm_name)
 194 {
 195   int i;
 196   int old_name_len = strlen (old_asm_name);
 197
 198   /* Replace all not valid assembler symbols with '_'.  */
 199   for (i = 0; i < old_name_len; i++)
 200     if (!is_valid_asm_symbol (old_asm_name[i]))
 201       new_asm_name[i] = '_';
 202     else
 203       new_asm_name[i] = old_asm_name[i];
 204   new_asm_name[old_name_len] = '\0';
 205 }
 206
 207 /*  Creates target clone of NODE.  */
 208
 209 static cgraph_node *
 210 create_target_clone (cgraph_node *node, bool definition, char *name)
 211 {
 212   cgraph_node *new_node;
 213
 214   if (definition)
 215     {
 216       new_node = node->create_version_clone_with_body (vNULL, NULL,
 217                                                        NULL, false,
 218                                                        NULL, NULL,
 219                                                        name);
 220       new_node->force_output = true;
 221     }
 222   else
 223     {
 224       tree new_decl = copy_node (node->decl);
 225       new_node = cgraph_node::get_create (new_decl);
 226       /* Generate a new name for the new version.  */
 227       symtab->change_decl_assembler_name (new_node->decl,
 228                                           clone_function_name (node->decl,
 229                                                                name));
 230     }
 231   return new_node;
 232 }
 233
 234 /* If the function in NODE has multiple target attributes
 235    create the appropriate clone for each valid target attribute.  */
 236
 237 static bool
 238 expand_target_clones (struct cgraph_node *node, bool defenition)
 239 {
 240   int i;
 241   /* Parsing target attributes separated by comma.  */
 242   tree attr_target = lookup_attribute ("target_clones",
 243                                        DECL_ATTRIBUTES (node->decl));
 244   /* No targets specified.  */
 245   if (!attr_target)
 246     return false;
 247
 248   tree arglist = TREE_VALUE (attr_target);
 249   int attr_len = get_attr_len (arglist);
 250
 251   /* No need to clone for 1 target attribute.  */
 252   if (attr_len == -1)
 253     {
 254       warning_at (DECL_SOURCE_LOCATION (node->decl),
 255                   0,
 256                   "single target_clones attribute is ignored");
 257       return false;
 258     }
 259
 260   char *attr_str = XNEWVEC (char, attr_len);
 261   int attrnum = get_attr_str (arglist, attr_str);
 262   char **attrs = XNEWVEC (char *, attrnum);
 263
 264   attrnum = separate_attrs (attr_str, attrs);
 265   if (attrnum == -1)
 266     {
 267       error_at (DECL_SOURCE_LOCATION (node->decl),
 268                 "default target was not set");
 269       return false;
 270     }
 271
 272   cgraph_function_version_info *decl1_v = NULL;
 273   cgraph_function_version_info *decl2_v = NULL;
 274   cgraph_function_version_info *before = NULL;
 275   cgraph_function_version_info *after = NULL;
 276   decl1_v = node->function_version ();
 277   if (decl1_v == NULL)
 278     decl1_v = node->insert_new_function_version ();
 279   before = decl1_v;
 280   DECL_FUNCTION_VERSIONED (node->decl) = 1;
 281
 282   for (i = 0; i < attrnum; i++)
 283     {
 284       char *attr = attrs[i];
 285       char *suffix = XNEWVEC (char, strlen (attr) + 1);
 286
 287       create_new_asm_name (attr, suffix);
 288       /* Create new target clone.  */
 289       cgraph_node *new_node = create_target_clone (node, defenition, suffix);
 290       XDELETEVEC (suffix);
 291
 292       /* Set new attribute for the clone.  */
 293       tree attributes = make_attribute ("target", attr,
 294                                         DECL_ATTRIBUTES (new_node->decl));
 295       DECL_ATTRIBUTES (new_node->decl) = attributes;
 296       if (!targetm.target_option.valid_attribute_p (new_node->decl, NULL,
 297                                                     TREE_VALUE (attributes), 0))
 298         {
 299           warning_at (DECL_SOURCE_LOCATION (node->decl), 0,
 300                       "attribute(target_clones(\"%s\")) is not "
 301                       "valid for current target", attr);
 302           continue;
 303         }
 304
 305       decl2_v = new_node->function_version ();
 306       if (decl2_v != NULL)
 307         continue;
 308       decl2_v = new_node->insert_new_function_version ();
 309
 310       /* Chain decl2_v and decl1_v.  All semantically identical versions
 311          will be chained together.  */
 312       after = decl2_v;
 313       while (before->next != NULL)
 314         before = before->next;
 315       while (after->prev != NULL)
 316         after = after->prev;
 317
 318       before->next = after;
 319       after->prev = before;
 320       DECL_FUNCTION_VERSIONED (new_node->decl) = 1;
 321     }
 322
 323   /* Setting new attribute to initial function.  */
 324   tree attributes =  make_attribute ("target", "default",
 325                                      DECL_ATTRIBUTES (node->decl));
 326   DECL_ATTRIBUTES (node->decl) = attributes;
 327   if (!targetm.target_option.valid_attribute_p (node->decl, NULL,
 328                                                 TREE_VALUE (attributes), 0))
 329     {
 330       error_at (DECL_SOURCE_LOCATION (node->decl),
 331                 "attribute(target_clones(\"default\")) is not "
 332                 "valid for current target");
 333       return false;
 334     }
 335
 336   XDELETEVEC (attrs);
 337   XDELETEVEC (attr_str);
 338   return true;
 339 }
 340
 341 static bool target_clone_pass;
 342
 343 static unsigned int
 344 ipa_target_clone (void)
 345 {
 346   struct cgraph_node *node;
 347
 348   target_clone_pass = false;
 349   FOR_EACH_FUNCTION (node)
 350     if (node->definition)
 351       target_clone_pass |= expand_target_clones (node, true);
 352   return 0;
 353 }
 354
 355 namespace {
 356
 357 const pass_data pass_data_target_clone =
 358 {
 359   SIMPLE_IPA_PASS,              /* type */
 360   "targetclone",                /* name */
 361   OPTGROUP_NONE,                /* optinfo_flags */
 362   TV_NONE,                      /* tv_id */
 363   ( PROP_ssa | PROP_cfg ),      /* properties_required */
 364   0,                            /* properties_provided */
 365   0,                            /* properties_destroyed */
 366   0,                            /* todo_flags_start */
 367   0                             /* todo_flags_finish */
 368 };
 369
 370 class pass_target_clone : public simple_ipa_opt_pass
 371 {
 372 public:
 373   pass_target_clone (gcc::context *ctxt)
 374     : simple_ipa_opt_pass (pass_data_target_clone, ctxt)
 375   {}
 376
 377   /* opt_pass methods: */
 378   virtual bool gate (function *);
 379   virtual unsigned int execute (function *) { return ipa_target_clone (); }
 380 };
 381
 382 bool
 383 pass_target_clone::gate (function *)
 384 {
 385   return true;
 386 }
 387
 388 } // anon namespace
 389
 390 simple_ipa_opt_pass *
 391 make_pass_target_clone (gcc::context *ctxt)
 392 {
 393   return new pass_target_clone (ctxt);
 394 }
 395
 396 static unsigned int
 397 ipa_dispatcher_calls (void)
 398 {
 399   struct cgraph_node *node;
 400
 401   FOR_EACH_FUNCTION (node)
 402     if (!node->definition)
 403       target_clone_pass |= expand_target_clones (node, false);
 404   if (target_clone_pass)
 405     FOR_EACH_FUNCTION (node)
 406       create_dispatcher_calls (node);
 407   return 0;
 408 }
 409
 410 namespace {
 411
 412 const pass_data pass_data_dispatcher_calls =
 413 {
 414   SIMPLE_IPA_PASS,              /* type */
 415   "dispachercalls",             /* name */
 416   OPTGROUP_NONE,                /* optinfo_flags */
 417   TV_NONE,                      /* tv_id */
 418   ( PROP_ssa | PROP_cfg ),      /* properties_required */
 419   0,                            /* properties_provided */
 420   0,                            /* properties_destroyed */
 421   0,                            /* todo_flags_start */
 422   0                             /* todo_flags_finish */
 423 };
 424
 425 class pass_dispatcher_calls : public simple_ipa_opt_pass
 426 {
 427 public:
 428   pass_dispatcher_calls (gcc::context *ctxt)
 429     : simple_ipa_opt_pass (pass_data_dispatcher_calls, ctxt)
 430   {}
 431
 432   /* opt_pass methods: */
 433   virtual bool gate (function *);
 434   virtual unsigned int execute (function *) { return ipa_dispatcher_calls (); }
 435 };
 436
 437 bool
 438 pass_dispatcher_calls::gate (function *)
 439 {
 440   return true;
 441 }
 442
 443 } // anon namespace
 444
 445 simple_ipa_opt_pass *
 446 make_pass_dispatcher_calls (gcc::context *ctxt)
 447 {
 448   return new pass_dispatcher_calls (ctxt);
 449 }