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                         ir_tarval *bits_set, *bits_not_set;
 182                         bits_set = tarval_rotl(vrp_left->bits_set, get_Const_tarval(right));
 183                         bits_not_set = tarval_rotl(vrp_left->bits_not_set, get_Const_tarval(right));
 184                 }
 185                 break;
 186         }
 187
 188         case iro_Shl: {
 189                 const vrp_attr *vrp_left;
 190                 const ir_node *right = get_Shl_right(node);
 191                 vrp_left = get_vrp_attr(get_Shl_left(node));
 192
 193                 /* We can only compute this if the right value is a constant*/
 194                 if (is_Const(right)) {
 195                         new_bits_set = tarval_shl(vrp_left->bits_set, get_Const_tarval(right));
 196                         new_bits_not_set = tarval_shl(vrp_left->bits_not_set, get_Const_tarval(right));
 197                 }
 198                 break;
 199         }
 200
 201         case iro_Shr: {
 202                 const vrp_attr *vrp_left;
 203                 const ir_node *right = get_Shr_right(node);
 204
 205                 vrp_left = get_vrp_attr(get_Shr_left(node));
 206
 207                 /* We can only compute this if the right value is a constant*/
 208                 if (is_Const(right)) {
 209                         new_bits_set = tarval_shr(vrp_left->bits_set, get_Const_tarval(right));
 210                         new_bits_not_set = tarval_shr(vrp_left->bits_not_set, get_Const_tarval(right));
 211                 }
 212                 break;
 213         }
 214
 215         case iro_Shrs: {
 216                 const vrp_attr *vrp_left;
 217                 const ir_node *right = get_Shrs_right(node);
 218
 219                 vrp_left = get_vrp_attr(get_Shrs_left(node));
 220
 221                 /* We can only compute this if the right value is a constant*/
 222                 if (is_Const(right)) {
 223                         new_bits_set = tarval_shrs(vrp_left->bits_set, get_Const_tarval(right));
 224                         new_bits_not_set = tarval_shrs(vrp_left->bits_not_set, get_Const_tarval(right));
 225                 }
 226                 break;
 227         }
 228
 229         case iro_Eor: {
 230                 const vrp_attr *vrp_left, *vrp_right;
 231
 232                 vrp_left = get_vrp_attr(get_Eor_left(node));
 233                 vrp_right = get_vrp_attr(get_Eor_right(node));
 234
 235                 new_bits_set = tarval_or(
 236                                                 tarval_and(vrp_left->bits_set, tarval_not(vrp_right->bits_not_set)),
 237                                                 tarval_and(tarval_not(vrp_left->bits_not_set), vrp_right->bits_set));
 238
 239                 new_bits_not_set = tarval_not(tarval_or(
 240                                 tarval_and(vrp_left->bits_set,vrp_right->bits_set),
 241                                                         tarval_and(tarval_not(vrp_left->bits_not_set),
 242                                                                 tarval_not(vrp_right->bits_not_set))));
 243
 244                 break;
 245         }
 246
 247         case iro_Id: {
 248                 const vrp_attr *vrp_pred = get_vrp_attr(get_Id_pred(node));
 249                 new_bits_set = vrp_pred->bits_set;
 250                 new_bits_not_set = vrp_pred->bits_not_set;
 251                 new_range_top = vrp_pred->range_top;
 252                 new_range_bottom = vrp_pred->range_bottom;
 253                 new_range_type = vrp_pred->range_type;
 254                 break;
 255         }
 256
 257         case iro_Not: {
 258                 const vrp_attr *vrp_pred = get_vrp_attr(get_Not_op(node));
 259                 new_bits_set = tarval_not(vrp_pred->bits_not_set);
 260                 new_bits_not_set = tarval_not(vrp_pred->bits_set);
 261                 break;
 262         }
 263
 264         case iro_Conv: {
 265                 const ir_node *pred = get_Conv_op(node);
 266                 ir_mode *old_mode = get_irn_mode(pred);
 267                 const vrp_attr *vrp_pred = get_vrp_attr(pred);
 268
 269                 ir_mode *new_mode;
 270
 271                 if (!mode_is_int(old_mode))
 272                         return 0;
 273
 274                 new_mode = get_irn_mode(node);
 275
 276                 /* The second and is needed if target type is smaller*/
 277                 new_bits_not_set = tarval_convert_to(get_mode_all_one(old_mode), new_mode);
 278                 new_bits_not_set = tarval_and(new_bits_not_set, tarval_convert_to(vrp_pred->bits_not_set, new_mode));
 279                 new_bits_set = tarval_and(
 280                                 new_bits_not_set, tarval_convert_to(vrp_pred->bits_set, new_mode));
 281
 282                 /* Matze: TODO, BUGGY, tarval_cmp never returns ir_relation_less_equal */
 283                 if (tarval_cmp(vrp_pred->range_top, get_mode_max(new_mode)) == ir_relation_less_equal) {
 284                         vrp->range_top = vrp_pred->range_top;
 285                 }
 286
 287                 /* Matze: TODO, BUGGY, tarval_cmp never returns ir_relation_greater_equal */
 288                 if (tarval_cmp(vrp_pred->range_bottom, get_mode_min(new_mode)) == ir_relation_greater_equal) {
 289                         vrp->range_bottom = vrp_pred->range_bottom;
 290                 }
 291                 break;
 292         }
 293
 294         case iro_Confirm: {
 295                 const ir_relation relation = get_Confirm_relation(node);
 296                 const ir_node    *bound    = get_Confirm_bound(node);
 297
 298
 299                 if (relation == ir_relation_less_greater) {
 300                         /** @todo: Handle non-Const bounds */
 301                         if (is_Const(bound)) {
 302                                 new_range_type = VRP_ANTIRANGE;
 303                                 new_range_top = get_Const_tarval(bound);
 304                                 new_range_bottom = get_Const_tarval(bound);
 305                         }
 306                 } else if (relation == ir_relation_less_equal) {
 307                         if (is_Const(bound)) {
 308                                 new_range_type = VRP_RANGE;
 309                                 new_range_top = get_Const_tarval(bound);
 310                                 new_range_bottom = get_tarval_min(get_irn_mode(node));
 311                         }
 312                 }
 313                 break;
 314         }
 315
 316         case iro_Phi: {
 317                 /* combine all ranges*/
 318
 319                 int num = get_Phi_n_preds(node);
 320                 ir_relation relation;
 321                 int i;
 322
 323                 const ir_node *pred = get_Phi_pred(node,0);
 324                 const vrp_attr *vrp_pred = get_vrp_attr(pred);
 325                 new_range_top = vrp_pred->range_top;
 326                 new_range_bottom = vrp_pred->range_bottom;
 327                 new_range_type = vrp_pred->range_type;
 328                 new_bits_set = vrp_pred->bits_set;
 329                 new_bits_not_set = vrp_pred->bits_not_set;
 330
 331                 assert(num > 0);
 332
 333                 for (i = 1; i < num; i++) {
 334                         pred = get_Phi_pred(node, i);
 335                         vrp_pred = get_vrp_attr(pred);
 336                         if (new_range_type == VRP_RANGE && vrp_pred->range_type ==
 337                                         VRP_RANGE) {
 338                                 relation = tarval_cmp(new_range_top, vrp_pred->range_top);
 339                                 if (relation == ir_relation_less) {
 340                                         new_range_top = vrp_pred->range_top;
 341                                 }
 342                                 relation = tarval_cmp(new_range_bottom, vrp_pred->range_bottom);
 343                                 if (relation == ir_relation_greater) {
 344                                         new_range_bottom = vrp_pred->range_bottom;
 345                                 }
 346                         } else {
 347                                 new_range_type = VRP_VARYING;
 348                         }
 349                         new_bits_set = tarval_and(new_bits_set, vrp_pred->bits_set);
 350                         new_bits_not_set = tarval_or(new_bits_not_set,
 351                                         vrp_pred->bits_not_set);
 352                 }
 353
 354                 break;
 355         }
 356         default:
 357                 /* unhandled, therefore never updated */
 358                 break;
 359         }
 360
 361
 362
 363         /* TODO: Check, if there can be information derived from any of these:
 364         is_Abs(node) is_Alloc(node) is_Anchor(node) is_Borrow(node) is_Bound(node)
 365         is_Break(node) is_Builtin(node) is_Call(node)
 366         is_Carry(node) is_Cast(node) is_Cmp(node) is_Cond(node)
 367         is_CopyB(node) is_Div(node) is_Dummy(node)
 368         is_End(node) is_Free(node)
 369         is_IJmp(node) is_InstOf(node) is_Jmp(node) is_Load(node) is_Minus(node)
 370         is_Mod(node) is_Mul(node) is_Mulh(node) is_Mux(node) is_NoMem(node)
 371         is_Pin(node) is_Proj(node)
 372         is_Raise(node) is_Return(node) is_Sel(node) is_Start(node) is_Store(node)
 373         is_SymConst(node) is_Sync(node) is_Tuple(node)
 374         */
 375
 376         /* @todo: At this place, we check if the mode of the variable changed. A
 377          * better place for this might be in the convopt.c file
 378          */
 379
 380         if (new_bits_set != tarval_bad && get_tarval_mode(new_bits_set) != get_tarval_mode(vrp->bits_set)) {
 381                 vrp->bits_set = tarval_convert_to(vrp->bits_set, get_irn_mode(node));
 382         }
 383         if (new_bits_not_set != tarval_bad && get_tarval_mode(new_bits_not_set) != get_tarval_mode(vrp->bits_not_set)) {
 384                 vrp->bits_not_set = tarval_convert_to(vrp->bits_not_set, get_irn_mode(node));
 385         }
 386
 387         if (vrp->range_type != VRP_UNDEFINED && new_range_type != VRP_UNDEFINED && get_tarval_mode(new_range_top) != get_tarval_mode(vrp->range_top)) {
 388                 /* @todo: We might be able to preserve this range information if it
 389                  * fits in */
 390                 vrp->range_type = VRP_VARYING;
 391         }
 392
 393         /* Merge the newly calculated values with those that might already exist*/
 394         if (new_bits_set != tarval_bad) {
 395                 new_bits_set = tarval_or(new_bits_set, vrp->bits_set);
 396                 if (tarval_cmp(new_bits_set, vrp->bits_set) != ir_relation_equal) {
 397                         something_changed = 1;
 398                         vrp->bits_set = new_bits_set;
 399                 }
 400         }
 401         if (new_bits_not_set != tarval_bad) {
 402                 new_bits_not_set = tarval_and(new_bits_not_set, vrp->bits_not_set);
 403
 404                 if (tarval_cmp(new_bits_not_set, vrp->bits_not_set) != ir_relation_equal) {
 405                         something_changed = 1;
 406                         vrp->bits_not_set = new_bits_not_set;
 407                 }
 408         }
 409
 410         if (vrp->range_type == VRP_UNDEFINED &&
 411                         new_range_type != VRP_UNDEFINED) {
 412                 something_changed = 1;
 413                 vrp->range_type = new_range_type;
 414                 vrp->range_bottom = new_range_bottom;
 415                 vrp->range_top = new_range_top;
 416
 417         } else if (vrp->range_type == VRP_RANGE) {
 418                 if (new_range_type == VRP_RANGE) {
 419                         if (tarval_cmp(vrp->range_bottom, new_range_bottom) == ir_relation_less) {
 420                                 something_changed = 1;
 421                                 vrp->range_bottom = new_range_bottom;
 422                         }
 423                         if (tarval_cmp(vrp->range_top, new_range_top) == ir_relation_greater) {
 424                                 something_changed = 1;
 425                                 vrp->range_top = new_range_top;
 426                         }
 427                 }
 428
 429                 if (new_range_type == VRP_ANTIRANGE) {
 430                         /* if they are overlapping, cut the range.*/
 431                         /* TODO: Maybe we can preserve more information here*/
 432                         if (tarval_cmp(vrp->range_bottom, new_range_top) == ir_relation_greater &&
 433                                         tarval_cmp(vrp->range_bottom, new_range_bottom) == ir_relation_greater) {
 434                                 something_changed = 1;
 435                                 vrp->range_bottom = new_range_top;
 436
 437                         } else if (tarval_cmp(vrp->range_top, new_range_bottom) == ir_relation_greater &&
 438                                         tarval_cmp(vrp->range_top, new_range_top) == ir_relation_less) {
 439                                 something_changed = 1;
 440                                 vrp->range_top = new_range_bottom;
 441                         }
 442
 443                         /* We can not handle the case where the anti range is in the*/
 444                         /* range*/
 445
 446                 }
 447         } else if (vrp->range_type == VRP_ANTIRANGE) {
 448                 if (new_range_type == VRP_ANTIRANGE) {
 449                         if (tarval_cmp(vrp->range_bottom, new_range_bottom) == ir_relation_greater) {
 450                                 something_changed = 1;
 451                                 vrp->range_bottom = new_range_bottom;
 452                         }
 453                         if (tarval_cmp(vrp->range_top, new_range_top) == ir_relation_less) {
 454                                 something_changed = 1;
 455                                 vrp->range_top = new_range_top;
 456                         }
 457                 }
 458
 459                 if (new_range_type == VRP_RANGE) {
 460                         if (tarval_cmp(vrp->range_bottom, new_range_top) == ir_relation_greater) {
 461                                 something_changed = 1;
 462                                 vrp->range_bottom = new_range_top;
 463                         }
 464                         if (tarval_cmp(vrp->range_top, new_range_bottom) == ir_relation_less) {
 465                                 something_changed = 1;
 466                                 vrp->range_top = new_range_bottom;
 467                         }
 468                 }
 469         }
 470
 471         assert(tarval_is_null(
 472                                 tarval_and(vrp->bits_set, tarval_not(vrp->bits_not_set))));
 473         return something_changed;
 474 }
 475
 476 static void vrp_first_pass(ir_node *n, void *e)
 477 {
 478         int i;
 479         vrp_env_t *env = (vrp_env_t*) e;
 480
 481         if (is_Block(n))
 482                 return;
 483
 484         bitset_set(env->visited, get_irn_idx(n));
 485
 486         vrp_update_node(n);
 487
 488         assure_irg_outs(get_current_ir_graph());
 489         for (i = get_irn_n_outs(n) - 1; i >=0; --i) {
 490                 ir_node *succ = get_irn_out(n, i);
 491                 if (bitset_is_set(env->visited, get_irn_idx(succ))) {
 492                         /* we found a loop*/
 493                         waitq_put(env->workqueue, succ);
 494                 }
 495         }
 496 }
 497
 498 static void *vrp_init_node(ir_phase *phase, const ir_node *n)
 499 {
 500         ir_mode *mode;
 501         vrp_attr *vrp;
 502
 503         DBG((dbg, LEVEL_2, "initialized node nr: %d\n", get_irn_node_nr(n)));
 504         vrp = (vrp_attr*) phase_alloc(phase, sizeof(vrp_attr));
 505
 506         memset(vrp, 0, sizeof(vrp_attr));
 507         /* Initialize the vrp information to default */
 508
 509         mode = get_irn_mode(n);
 510
 511         vrp->range_type = VRP_UNDEFINED;
 512
 513         /* TODO: We might be able to optimize space usage if we do not allocate
 514          * vrp space for non-int nodes. (currently caught by vrp_update_node)
 515          */
 516         if (mode_is_int(mode)) {
 517                 /* We are assuming that 0 is always represented as this modes null */
 518                 vrp->valid = 1;
 519                 vrp->bits_set = get_mode_null(mode);
 520                 vrp->bits_not_set = get_mode_all_one(mode);
 521                 vrp->range_bottom = get_tarval_top();
 522                 vrp->range_top = get_tarval_top();
 523         } else {
 524                 vrp->valid = 0;
 525                 vrp->bits_set = get_tarval_bad();
 526                 vrp->bits_not_set = get_tarval_bad();
 527                 vrp->range_bottom = get_tarval_bad();
 528                 vrp->range_top = get_tarval_bad();
 529         }
 530
 531         /* TODO: We might be able to set better vrp info at this time, if this is
 532          * a node which is newly created in an already initialized irg
 533          *
 534          * maybe just call vrp_update_node and if it returns one, iterate over
 535          * successors
 536          */
 537         return vrp;
 538 }
 539
 540 void set_vrp_data(ir_graph *irg)
 541 {
 542         ir_node *succ, *node;
 543         int i;
 544         vrp_env_t *env;
 545         ir_phase *phase;
 546
 547         FIRM_DBG_REGISTER(dbg, "ir.ana.vrp");
 548
 549         assure_irg_outs(irg); /* ensure that out edges are consistent*/
 550         phase = irg_get_phase(irg, PHASE_VRP);
 551         if (phase == NULL) {
 552                 /* this is our first run */
 553                 phase = new_phase(irg, vrp_init_node);
 554                 irg_register_phase(irg, PHASE_VRP, phase);
 555                 env = (vrp_env_t*) phase_alloc(phase, sizeof(*env));
 556                 phase->priv = env;
 557         } else {
 558                 env = (vrp_env_t*) phase->priv;
 559         }
 560
 561         env->workqueue = new_waitq();
 562
 563         env->visited = bitset_malloc(get_irg_last_idx(irg));
 564         irg_walk_graph(irg, NULL, vrp_first_pass, env);
 565         bitset_free(env->visited);
 566
 567         /* while there are entries in the worklist, continue*/
 568         while (!waitq_empty(env->workqueue)) {
 569                 node = (ir_node*) waitq_get(env->workqueue);
 570
 571                 if (vrp_update_node(node)) {
 572                         /* if something changed, add successors to worklist*/
 573                         for (i = get_irn_n_outs(node) - 1; i >= 0; --i) {
 574                                 succ =  get_irn_out(node, i);
 575                                 waitq_put(env->workqueue, node);
 576                         }
 577                 }
 578         }
 579         del_waitq(env->workqueue);
 580 }
 581
 582 ir_graph_pass_t *set_vrp_pass(const char *name)
 583 {
 584         return def_graph_pass(name ? name : "set_vrp", set_vrp_data);
 585 }
 586
 587 ir_relation vrp_cmp(const ir_node *left, const ir_node *right)
 588 {
 589         vrp_attr *vrp_left, *vrp_right;
 590
 591         vrp_left = vrp_get_info(left);
 592         vrp_right = vrp_get_info(right);
 593
 594         if (!vrp_left || !vrp_right)
 595                 return ir_relation_true;
 596
 597         if (vrp_left->range_type == VRP_RANGE && vrp_right->range_type == VRP_RANGE) {
 598                 if (tarval_cmp(vrp_left->range_top, vrp_right->range_bottom) == ir_relation_less) {
 599                         return ir_relation_less;
 600                 }
 601                 if (tarval_cmp(vrp_left->range_bottom, vrp_right->range_top) == ir_relation_greater) {
 602                         return ir_relation_greater;
 603                 }
 604         }
 605
 606         if (!tarval_is_null(tarval_and(vrp_left->bits_set, tarval_not(vrp_right->bits_not_set))) ||
 607                         !tarval_is_null(tarval_and(tarval_not(vrp_left->bits_not_set), vrp_right->bits_set))) {
 608                 return ir_relation_less_greater;
 609         }
 610
 611         /* TODO: We can get way more information here*/
 612         return ir_relation_true;
 613 }
 614
 615 vrp_attr *vrp_get_info(const ir_node *node)
 616 {
 617         const ir_graph *irg   = get_irn_irg(node);
 618         const ir_phase *phase = irg_get_phase(irg, PHASE_VRP);
 619         vrp_attr       *vrp;
 620
 621         if (phase == NULL) {
 622                 /* phase has not yet been initialized */
 623                 return NULL;
 624         }
 625
 626         vrp = (vrp_attr*) phase_get_irn_data(phase, node);
 627         if (vrp && vrp->valid) {
 628                 return vrp;
 629         }
 630
 631         return NULL;
 632 }