nsz Git - libfirm/blob - ir/ana/vrp.c

   1 /*
   2  * Copyright (C) 1995-2010 University of Karlsruhe.  All right reserved.
   3  *
   4  * This file is part of libFirm.
   5  *
   6  * This file may be distributed and/or modified under the terms of the
   7  * GNU General Public License version 2 as published by the Free Software
   8  * Foundation and appearing in the file LICENSE.GPL included in the
   9  * packaging of this file.
  10  *
  11  * Licensees holding valid libFirm Professional Edition licenses may use
  12  * this file in accordance with the libFirm Commercial License.
  13  * Agreement provided with the Software.
  14  *
  15  * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
  16  * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  17  * PURPOSE.
  18  */
  19
  20 /**
  21  * @file
  22  * @brief   analyze graph to provide value range information
  23  * @author  Jonas Fietz
  24  * @version $Id$
  25  */
  26 #include "config.h"
  27
  28 #include "irtypes.h"
  29 #include "vrp.h"
  30 #include "iroptimize.h"
  31 #include "irouts.h"
  32 #include "irgraph_t.h"
  33 #include "irgopt.h"
  34 #include "irpass.h"
  35 #include "irgwalk.h"
  36 #include "iredges.h"
  37 #include "tv.h"
  38 #include "irop.h"
  39 #include "pdeq.h"
  40 #include "irphase_t.h"
  41 #include "bitset.h"
  42 #include "debug.h"
  43
  44 DEBUG_ONLY(static firm_dbg_module_t *dbg;)
  45
  46 typedef struct vrp_env_t {
  47         waitq    *workqueue;
  48         bitset_t *visited;
  49 } vrp_env_t;
  50
  51 static vrp_attr *get_vrp_attr(const ir_node *node)
  52 {
  53         return (vrp_attr*) get_or_set_irn_phase_info(node, PHASE_VRP);
  54 }
  55
  56 static int vrp_update_node(ir_node *node)
  57 {
  58         ir_tarval *new_bits_set = get_tarval_bad();
  59         ir_tarval *new_bits_not_set = get_tarval_bad();
  60         ir_tarval *new_range_bottom = get_tarval_bad();
  61         ir_tarval *new_range_top = get_tarval_bad();
  62         enum range_types new_range_type = VRP_UNDEFINED;
  63         int something_changed = 0;
  64         vrp_attr *vrp;
  65
  66         if (!mode_is_int(get_irn_mode(node))) {
  67                 return 0; /* we don't optimize for non-int-nodes*/
  68         }
  69
  70         vrp = get_vrp_attr(node);
  71
  72         /* TODO: Check if all predecessors have valid VRP information*/
  73
  74         switch (get_irn_opcode(node)) {
  75         case iro_Const: {
  76                 ir_tarval *tv = get_Const_tarval(node);
  77                 new_bits_set = tv;
  78                 new_bits_not_set = tv;
  79                 new_range_bottom = tv;
  80                 new_range_top = tv;
  81                 new_range_type = VRP_RANGE;
  82                 break;
  83         }
  84         case iro_And: {
  85                 const vrp_attr *vrp_left, *vrp_right;
  86                 const ir_node *left, *right;
  87
  88                 left = get_And_left(node);
  89                 right = get_And_right(node);
  90                 vrp_left = get_vrp_attr(left);
  91                 vrp_right = get_vrp_attr(right);
  92                 new_bits_set = tarval_and(vrp_left->bits_set, vrp_right->bits_set);
  93                 new_bits_not_set = tarval_and(vrp_left->bits_not_set, vrp_right->bits_not_set);
  94
  95                 break;
  96         }
  97
  98         case iro_Add: {
  99                 int overflow_top, overflow_bottom;
 100                 ir_tarval *new_top, *new_bottom;
 101                 const vrp_attr *vrp_left, *vrp_right;
 102                 vrp_left = get_vrp_attr(get_Add_left(node));
 103                 vrp_right = get_vrp_attr(get_Add_right(node));
 104
 105                 if (vrp_left->range_type == VRP_UNDEFINED || vrp_right->range_type ==
 106                                 VRP_UNDEFINED || vrp_left->range_type == VRP_VARYING ||
 107                                 vrp_right->range_type == VRP_VARYING) {
 108                         return 0;
 109                 }
 110
 111                 new_top = tarval_add(vrp_left->range_top, vrp_right->range_top);
 112                 overflow_top = tarval_carry();
 113                 new_bottom = tarval_add(vrp_left->range_bottom, vrp_right->range_bottom);
 114                 overflow_bottom = tarval_carry();
 115
 116                 if (!overflow_top && !overflow_bottom && vrp_left->range_type == VRP_RANGE
 117                                 &&vrp_right->range_type == VRP_RANGE) {
 118                         new_range_bottom = new_bottom;
 119                         new_range_top = new_top;
 120                         new_range_type = VRP_RANGE;
 121                 }
 122
 123                 if (overflow_top || overflow_bottom) {
 124                         /* TODO Implement overflow handling*/
 125                         new_range_type = VRP_UNDEFINED;
 126                 }
 127                 break;
 128         }
 129
 130         case iro_Sub: {
 131                 int overflow_top, overflow_bottom;
 132                 ir_tarval *new_top, *new_bottom;
 133                 const vrp_attr *vrp_left, *vrp_right;
 134                 vrp_left = get_vrp_attr(get_Sub_left(node));
 135                 vrp_right = get_vrp_attr(get_Sub_right(node));
 136
 137                 if (vrp_left->range_type == VRP_UNDEFINED || vrp_right->range_type ==
 138                                 VRP_UNDEFINED || vrp_left->range_type == VRP_VARYING ||
 139                                 vrp_right->range_type == VRP_VARYING) {
 140                         return 0;
 141                 }
 142
 143                 new_top = tarval_sub(vrp_left->range_top, vrp_right->range_top, NULL);
 144                 overflow_top = tarval_carry();
 145                 new_bottom = tarval_sub(vrp_left->range_bottom, vrp_right->range_bottom, NULL);
 146                 overflow_bottom = tarval_carry();
 147
 148                 if (!overflow_top && !overflow_bottom && vrp_left->range_type == VRP_RANGE
 149                                 &&vrp_right->range_type == VRP_RANGE) {
 150                         new_range_bottom = new_bottom;
 151                         new_range_top = new_top;
 152                         new_range_type = VRP_RANGE;
 153                 }
 154
 155                 if (overflow_top || overflow_bottom) {
 156                         /* TODO Implement overflow handling*/
 157                 }
 158                 break;
 159         }
 160
 161         case iro_Or: {
 162                 const vrp_attr *vrp_left, *vrp_right;
 163
 164                 vrp_left = get_vrp_attr(get_Or_left(node));
 165                 vrp_right = get_vrp_attr(get_Or_right(node));
 166
 167                 new_bits_set = tarval_or(vrp_left->bits_set, vrp_right->bits_set);
 168                 new_bits_not_set = tarval_or(vrp_left->bits_not_set, vrp_right->bits_not_set);
 169
 170                 break;
 171         }
 172
 173         case iro_Rotl: {
 174                 const vrp_attr *vrp_left;
 175                 const ir_node *right = get_Rotl_right(node);
 176
 177                 vrp_left = get_vrp_attr(get_Rotl_left(node));
 178
 179                 /* We can only compute this if the right value is a constant*/
 180                 if (is_Const(right)) {
 181                         new_bits_set = tarval_rotl(vrp_left->bits_set, get_Const_tarval(right));
 182                         new_bits_not_set = tarval_rotl(vrp_left->bits_not_set, get_Const_tarval(right));
 183                 }
 184                 break;
 185         }
 186
 187         case iro_Shl: {
 188                 const vrp_attr *vrp_left;
 189                 const ir_node *right = get_Shl_right(node);
 190                 vrp_left = get_vrp_attr(get_Shl_left(node));
 191
 192                 /* We can only compute this if the right value is a constant*/
 193                 if (is_Const(right)) {
 194                         new_bits_set = tarval_shl(vrp_left->bits_set, get_Const_tarval(right));
 195                         new_bits_not_set = tarval_shl(vrp_left->bits_not_set, get_Const_tarval(right));
 196                 }
 197                 break;
 198         }
 199
 200         case iro_Shr: {
 201                 const vrp_attr *vrp_left;
 202                 const ir_node *right = get_Shr_right(node);
 203
 204                 vrp_left = get_vrp_attr(get_Shr_left(node));
 205
 206                 /* We can only compute this if the right value is a constant*/
 207                 if (is_Const(right)) {
 208                         new_bits_set = tarval_shr(vrp_left->bits_set, get_Const_tarval(right));
 209                         new_bits_not_set = tarval_shr(vrp_left->bits_not_set, get_Const_tarval(right));
 210                 }
 211                 break;
 212         }
 213
 214         case iro_Shrs: {
 215                 const vrp_attr *vrp_left;
 216                 const ir_node *right = get_Shrs_right(node);
 217
 218                 vrp_left = get_vrp_attr(get_Shrs_left(node));
 219
 220                 /* We can only compute this if the right value is a constant*/
 221                 if (is_Const(right)) {
 222                         new_bits_set = tarval_shrs(vrp_left->bits_set, get_Const_tarval(right));
 223                         new_bits_not_set = tarval_shrs(vrp_left->bits_not_set, get_Const_tarval(right));
 224                 }
 225                 break;
 226         }
 227
 228         case iro_Eor: {
 229                 const vrp_attr *vrp_left, *vrp_right;
 230
 231                 vrp_left = get_vrp_attr(get_Eor_left(node));
 232                 vrp_right = get_vrp_attr(get_Eor_right(node));
 233
 234                 new_bits_set = tarval_or(
 235                                                 tarval_and(vrp_left->bits_set, tarval_not(vrp_right->bits_not_set)),
 236                                                 tarval_and(tarval_not(vrp_left->bits_not_set), vrp_right->bits_set));
 237
 238                 new_bits_not_set = tarval_not(tarval_or(
 239                                 tarval_and(vrp_left->bits_set,vrp_right->bits_set),
 240                                                         tarval_and(tarval_not(vrp_left->bits_not_set),
 241                                                                 tarval_not(vrp_right->bits_not_set))));
 242
 243                 break;
 244         }
 245
 246         case iro_Id: {
 247                 const vrp_attr *vrp_pred = get_vrp_attr(get_Id_pred(node));
 248                 new_bits_set = vrp_pred->bits_set;
 249                 new_bits_not_set = vrp_pred->bits_not_set;
 250                 new_range_top = vrp_pred->range_top;
 251                 new_range_bottom = vrp_pred->range_bottom;
 252                 new_range_type = vrp_pred->range_type;
 253                 break;
 254         }
 255
 256         case iro_Not: {
 257                 const vrp_attr *vrp_pred = get_vrp_attr(get_Not_op(node));
 258                 new_bits_set = tarval_not(vrp_pred->bits_not_set);
 259                 new_bits_not_set = tarval_not(vrp_pred->bits_set);
 260                 break;
 261         }
 262
 263         case iro_Conv: {
 264                 const ir_node *pred = get_Conv_op(node);
 265                 ir_mode *old_mode = get_irn_mode(pred);
 266                 const vrp_attr *vrp_pred = get_vrp_attr(pred);
 267
 268                 ir_mode *new_mode;
 269
 270                 if (!mode_is_int(old_mode))
 271                         return 0;
 272
 273                 new_mode = get_irn_mode(node);
 274
 275                 /* The second and is needed if target type is smaller*/
 276                 new_bits_not_set = tarval_convert_to(get_mode_all_one(old_mode), new_mode);
 277                 new_bits_not_set = tarval_and(new_bits_not_set, tarval_convert_to(vrp_pred->bits_not_set, new_mode));
 278                 new_bits_set = tarval_and(
 279                                 new_bits_not_set, tarval_convert_to(vrp_pred->bits_set, new_mode));
 280
 281                 /* Matze: TODO, BUGGY, tarval_cmp never returns ir_relation_less_equal */
 282                 if (tarval_cmp(vrp_pred->range_top, get_mode_max(new_mode)) == ir_relation_less_equal) {
 283                         vrp->range_top = vrp_pred->range_top;
 284                 }
 285
 286                 /* Matze: TODO, BUGGY, tarval_cmp never returns ir_relation_greater_equal */
 287                 if (tarval_cmp(vrp_pred->range_bottom, get_mode_min(new_mode)) == ir_relation_greater_equal) {
 288                         vrp->range_bottom = vrp_pred->range_bottom;
 289                 }
 290                 break;
 291         }
 292
 293         case iro_Confirm: {
 294                 const ir_relation relation = get_Confirm_relation(node);
 295                 const ir_node    *bound    = get_Confirm_bound(node);
 296
 297
 298                 if (relation == ir_relation_less_greater) {
 299                         /** @todo: Handle non-Const bounds */
 300                         if (is_Const(bound)) {
 301                                 new_range_type = VRP_ANTIRANGE;
 302                                 new_range_top = get_Const_tarval(bound);
 303                                 new_range_bottom = get_Const_tarval(bound);
 304                         }
 305                 } else if (relation == ir_relation_less_equal) {
 306                         if (is_Const(bound)) {
 307                                 new_range_type = VRP_RANGE;
 308                                 new_range_top = get_Const_tarval(bound);
 309                                 new_range_bottom = get_tarval_min(get_irn_mode(node));
 310                         }
 311                 }
 312                 break;
 313         }
 314
 315         case iro_Phi: {
 316                 /* combine all ranges*/
 317
 318                 int num = get_Phi_n_preds(node);
 319                 ir_relation relation;
 320                 int i;
 321
 322                 const ir_node *pred = get_Phi_pred(node,0);
 323                 const vrp_attr *vrp_pred = get_vrp_attr(pred);
 324                 new_range_top = vrp_pred->range_top;
 325                 new_range_bottom = vrp_pred->range_bottom;
 326                 new_range_type = vrp_pred->range_type;
 327                 new_bits_set = vrp_pred->bits_set;
 328                 new_bits_not_set = vrp_pred->bits_not_set;
 329
 330                 assert(num > 0);
 331
 332                 for (i = 1; i < num; i++) {
 333                         pred = get_Phi_pred(node, i);
 334                         vrp_pred = get_vrp_attr(pred);
 335                         if (new_range_type == VRP_RANGE && vrp_pred->range_type ==
 336                                         VRP_RANGE) {
 337                                 relation = tarval_cmp(new_range_top, vrp_pred->range_top);
 338                                 if (relation == ir_relation_less) {
 339                                         new_range_top = vrp_pred->range_top;
 340                                 }
 341                                 relation = tarval_cmp(new_range_bottom, vrp_pred->range_bottom);
 342                                 if (relation == ir_relation_greater) {
 343                                         new_range_bottom = vrp_pred->range_bottom;
 344                                 }
 345                         } else {
 346                                 new_range_type = VRP_VARYING;
 347                         }
 348                         new_bits_set = tarval_and(new_bits_set, vrp_pred->bits_set);
 349                         new_bits_not_set = tarval_or(new_bits_not_set,
 350                                         vrp_pred->bits_not_set);
 351                 }
 352
 353                 break;
 354         }
 355         default:
 356                 /* unhandled, therefore never updated */
 357                 break;
 358         }
 359
 360
 361
 362         /* TODO: Check, if there can be information derived from any of these:
 363         is_Abs(node) is_Alloc(node) is_Anchor(node) is_Borrow(node) is_Bound(node)
 364         is_Break(node) is_Builtin(node) is_Call(node)
 365         is_Carry(node) is_Cast(node) is_Cmp(node) is_Cond(node)
 366         is_CopyB(node) is_Div(node) is_Dummy(node)
 367         is_End(node) is_Free(node)
 368         is_IJmp(node) is_InstOf(node) is_Jmp(node) is_Load(node) is_Minus(node)
 369         is_Mod(node) is_Mul(node) is_Mulh(node) is_Mux(node) is_NoMem(node)
 370         is_Pin(node) is_Proj(node)
 371         is_Raise(node) is_Return(node) is_Sel(node) is_Start(node) is_Store(node)
 372         is_SymConst(node) is_Sync(node) is_Tuple(node)
 373         */
 374
 375         /* @todo: At this place, we check if the mode of the variable changed. A
 376          * better place for this might be in the convopt.c file
 377          */
 378
 379         if (new_bits_set != tarval_bad && get_tarval_mode(new_bits_set) != get_tarval_mode(vrp->bits_set)) {
 380                 vrp->bits_set = tarval_convert_to(vrp->bits_set, get_irn_mode(node));
 381         }
 382         if (new_bits_not_set != tarval_bad && get_tarval_mode(new_bits_not_set) != get_tarval_mode(vrp->bits_not_set)) {
 383                 vrp->bits_not_set = tarval_convert_to(vrp->bits_not_set, get_irn_mode(node));
 384         }
 385
 386         if (vrp->range_type != VRP_UNDEFINED && new_range_type != VRP_UNDEFINED && get_tarval_mode(new_range_top) != get_tarval_mode(vrp->range_top)) {
 387                 /* @todo: We might be able to preserve this range information if it
 388                  * fits in */
 389                 vrp->range_type = VRP_VARYING;
 390         }
 391
 392         /* Merge the newly calculated values with those that might already exist*/
 393         if (new_bits_set != tarval_bad) {
 394                 new_bits_set = tarval_or(new_bits_set, vrp->bits_set);
 395                 if (tarval_cmp(new_bits_set, vrp->bits_set) != ir_relation_equal) {
 396                         something_changed = 1;
 397                         vrp->bits_set = new_bits_set;
 398                 }
 399         }
 400         if (new_bits_not_set != tarval_bad) {
 401                 new_bits_not_set = tarval_and(new_bits_not_set, vrp->bits_not_set);
 402
 403                 if (tarval_cmp(new_bits_not_set, vrp->bits_not_set) != ir_relation_equal) {
 404                         something_changed = 1;
 405                         vrp->bits_not_set = new_bits_not_set;
 406                 }
 407         }
 408
 409         if (vrp->range_type == VRP_UNDEFINED &&
 410                         new_range_type != VRP_UNDEFINED) {
 411                 something_changed = 1;
 412                 vrp->range_type = new_range_type;
 413                 vrp->range_bottom = new_range_bottom;
 414                 vrp->range_top = new_range_top;
 415
 416         } else if (vrp->range_type == VRP_RANGE) {
 417                 if (new_range_type == VRP_RANGE) {
 418                         if (tarval_cmp(vrp->range_bottom, new_range_bottom) == ir_relation_less) {
 419                                 something_changed = 1;
 420                                 vrp->range_bottom = new_range_bottom;
 421                         }
 422                         if (tarval_cmp(vrp->range_top, new_range_top) == ir_relation_greater) {
 423                                 something_changed = 1;
 424                                 vrp->range_top = new_range_top;
 425                         }
 426                 }
 427
 428                 if (new_range_type == VRP_ANTIRANGE) {
 429                         /* if they are overlapping, cut the range.*/
 430                         /* TODO: Maybe we can preserve more information here*/
 431                         if (tarval_cmp(vrp->range_bottom, new_range_top) == ir_relation_greater &&
 432                                         tarval_cmp(vrp->range_bottom, new_range_bottom) == ir_relation_greater) {
 433                                 something_changed = 1;
 434                                 vrp->range_bottom = new_range_top;
 435
 436                         } else if (tarval_cmp(vrp->range_top, new_range_bottom) == ir_relation_greater &&
 437                                         tarval_cmp(vrp->range_top, new_range_top) == ir_relation_less) {
 438                                 something_changed = 1;
 439                                 vrp->range_top = new_range_bottom;
 440                         }
 441
 442                         /* We can not handle the case where the anti range is in the*/
 443                         /* range*/
 444
 445                 }
 446         } else if (vrp->range_type == VRP_ANTIRANGE) {
 447                 if (new_range_type == VRP_ANTIRANGE) {
 448                         if (tarval_cmp(vrp->range_bottom, new_range_bottom) == ir_relation_greater) {
 449                                 something_changed = 1;
 450                                 vrp->range_bottom = new_range_bottom;
 451                         }
 452                         if (tarval_cmp(vrp->range_top, new_range_top) == ir_relation_less) {
 453                                 something_changed = 1;
 454                                 vrp->range_top = new_range_top;
 455                         }
 456                 }
 457
 458                 if (new_range_type == VRP_RANGE) {
 459                         if (tarval_cmp(vrp->range_bottom, new_range_top) == ir_relation_greater) {
 460                                 something_changed = 1;
 461                                 vrp->range_bottom = new_range_top;
 462                         }
 463                         if (tarval_cmp(vrp->range_top, new_range_bottom) == ir_relation_less) {
 464                                 something_changed = 1;
 465                                 vrp->range_top = new_range_bottom;
 466                         }
 467                 }
 468         }
 469
 470         assert(tarval_is_null(
 471                                 tarval_and(vrp->bits_set, tarval_not(vrp->bits_not_set))));
 472         return something_changed;
 473 }
 474
 475 static void vrp_first_pass(ir_node *n, void *e)
 476 {
 477         int i;
 478         vrp_env_t *env = (vrp_env_t*) e;
 479
 480         if (is_Block(n))
 481                 return;
 482
 483         bitset_set(env->visited, get_irn_idx(n));
 484
 485         vrp_update_node(n);
 486
 487         assure_irg_outs(get_current_ir_graph());
 488         for (i = get_irn_n_outs(n) - 1; i >=0; --i) {
 489                 ir_node *succ = get_irn_out(n, i);
 490                 if (bitset_is_set(env->visited, get_irn_idx(succ))) {
 491                         /* we found a loop*/
 492                         waitq_put(env->workqueue, succ);
 493                 }
 494         }
 495 }
 496
 497 static void *vrp_init_node(ir_phase *phase, const ir_node *n)
 498 {
 499         ir_mode *mode;
 500         vrp_attr *vrp;
 501
 502         DBG((dbg, LEVEL_2, "initialized node nr: %d\n", get_irn_node_nr(n)));
 503         vrp = (vrp_attr*) phase_alloc(phase, sizeof(vrp_attr));
 504
 505         memset(vrp, 0, sizeof(vrp_attr));
 506         /* Initialize the vrp information to default */
 507
 508         mode = get_irn_mode(n);
 509
 510         vrp->range_type = VRP_UNDEFINED;
 511
 512         /* TODO: We might be able to optimize space usage if we do not allocate
 513          * vrp space for non-int nodes. (currently caught by vrp_update_node)
 514          */
 515         if (mode_is_int(mode)) {
 516                 /* We are assuming that 0 is always represented as this modes null */
 517                 vrp->valid = 1;
 518                 vrp->bits_set = get_mode_null(mode);
 519                 vrp->bits_not_set = get_mode_all_one(mode);
 520                 vrp->range_bottom = get_tarval_top();
 521                 vrp->range_top = get_tarval_top();
 522         } else {
 523                 vrp->valid = 0;
 524                 vrp->bits_set = get_tarval_bad();
 525                 vrp->bits_not_set = get_tarval_bad();
 526                 vrp->range_bottom = get_tarval_bad();
 527                 vrp->range_top = get_tarval_bad();
 528         }
 529
 530         /* TODO: We might be able to set better vrp info at this time, if this is
 531          * a node which is newly created in an already initialized irg
 532          *
 533          * maybe just call vrp_update_node and if it returns one, iterate over
 534          * successors
 535          */
 536         return vrp;
 537 }
 538
 539 void set_vrp_data(ir_graph *irg)
 540 {
 541         ir_node *succ, *node;
 542         int i;
 543         vrp_env_t *env;
 544         ir_phase *phase;
 545
 546         FIRM_DBG_REGISTER(dbg, "ir.ana.vrp");
 547
 548         assure_irg_outs(irg); /* ensure that out edges are consistent*/
 549         phase = irg_get_phase(irg, PHASE_VRP);
 550         if (phase == NULL) {
 551                 /* this is our first run */
 552                 phase = new_phase(irg, vrp_init_node);
 553                 irg_register_phase(irg, PHASE_VRP, phase);
 554                 env = (vrp_env_t*) phase_alloc(phase, sizeof(*env));
 555                 phase->priv = env;
 556         } else {
 557                 env = (vrp_env_t*) phase->priv;
 558         }
 559
 560         env->workqueue = new_waitq();
 561
 562         env->visited = bitset_malloc(get_irg_last_idx(irg));
 563         irg_walk_graph(irg, NULL, vrp_first_pass, env);
 564         bitset_free(env->visited);
 565
 566         /* while there are entries in the worklist, continue*/
 567         while (!waitq_empty(env->workqueue)) {
 568                 node = (ir_node*) waitq_get(env->workqueue);
 569
 570                 if (vrp_update_node(node)) {
 571                         /* if something changed, add successors to worklist*/
 572                         for (i = get_irn_n_outs(node) - 1; i >= 0; --i) {
 573                                 succ =  get_irn_out(node, i);
 574                                 waitq_put(env->workqueue, succ);
 575                         }
 576                 }
 577         }
 578         del_waitq(env->workqueue);
 579 }
 580
 581 ir_graph_pass_t *set_vrp_pass(const char *name)
 582 {
 583         return def_graph_pass(name ? name : "set_vrp", set_vrp_data);
 584 }
 585
 586 ir_relation vrp_cmp(const ir_node *left, const ir_node *right)
 587 {
 588         vrp_attr *vrp_left, *vrp_right;
 589
 590         vrp_left = vrp_get_info(left);
 591         vrp_right = vrp_get_info(right);
 592
 593         if (!vrp_left || !vrp_right)
 594                 return ir_relation_true;
 595
 596         if (vrp_left->range_type == VRP_RANGE && vrp_right->range_type == VRP_RANGE) {
 597                 if (tarval_cmp(vrp_left->range_top, vrp_right->range_bottom) == ir_relation_less) {
 598                         return ir_relation_less;
 599                 }
 600                 if (tarval_cmp(vrp_left->range_bottom, vrp_right->range_top) == ir_relation_greater) {
 601                         return ir_relation_greater;
 602                 }
 603         }
 604
 605         if (!tarval_is_null(tarval_and(vrp_left->bits_set, tarval_not(vrp_right->bits_not_set))) ||
 606                         !tarval_is_null(tarval_and(tarval_not(vrp_left->bits_not_set), vrp_right->bits_set))) {
 607                 return ir_relation_less_greater;
 608         }
 609
 610         /* TODO: We can get way more information here*/
 611         return ir_relation_true;
 612 }
 613
 614 vrp_attr *vrp_get_info(const ir_node *node)
 615 {
 616         const ir_graph *irg   = get_irn_irg(node);
 617         const ir_phase *phase = irg_get_phase(irg, PHASE_VRP);
 618         vrp_attr       *vrp;
 619
 620         if (phase == NULL) {
 621                 /* phase has not yet been initialized */
 622                 return NULL;
 623         }
 624
 625         vrp = (vrp_attr*) phase_get_irn_data(phase, node);
 626         if (vrp && vrp->valid) {
 627                 return vrp;
 628         }
 629
 630         return NULL;
 631 }