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, *vrp_right;
 175                 const ir_node *right = get_Rotl_right(node);
 176
 177                 vrp_left = get_vrp_attr(get_Rotl_left(node));
 178                 vrp_right = get_vrp_attr(get_Rotl_right(node));
 179
 180                 /* We can only compute this if the right value is a constant*/
 181                 if (is_Const(right)) {
 182                         ir_tarval *bits_set, *bits_not_set;
 183                         bits_set = tarval_rotl(vrp_left->bits_set, get_Const_tarval(right));
 184                         bits_not_set = tarval_rotl(vrp_left->bits_not_set, get_Const_tarval(right));
 185                 }
 186                 break;
 187         }
 188
 189         case iro_Shl: {
 190                 const vrp_attr *vrp_left, *vrp_right;
 191                 const ir_node *right = get_Shl_right(node);
 192                 vrp_left = get_vrp_attr(get_Shl_left(node));
 193                 vrp_right = get_vrp_attr(get_Shl_right(node));
 194
 195                 /* We can only compute this if the right value is a constant*/
 196                 if (is_Const(right)) {
 197                         new_bits_set = tarval_shl(vrp_left->bits_set, get_Const_tarval(right));
 198                         new_bits_not_set = tarval_shl(vrp_left->bits_not_set, get_Const_tarval(right));
 199                 }
 200                 break;
 201         }
 202
 203         case iro_Shr: {
 204                 const vrp_attr *vrp_left, *vrp_right;
 205                 const ir_node *right = get_Shr_right(node);
 206
 207                 vrp_left = get_vrp_attr(get_Shr_left(node));
 208                 vrp_right = get_vrp_attr(get_Shr_right(node));
 209
 210                 /* We can only compute this if the right value is a constant*/
 211                 if (is_Const(right)) {
 212                         new_bits_set = tarval_shr(vrp_left->bits_set, get_Const_tarval(right));
 213                         new_bits_not_set = tarval_shr(vrp_left->bits_not_set, get_Const_tarval(right));
 214                 }
 215                 break;
 216         }
 217
 218         case iro_Shrs: {
 219                 const vrp_attr *vrp_left, *vrp_right;
 220                 const ir_node *right = get_Shrs_right(node);
 221
 222                 vrp_left = get_vrp_attr(get_Shrs_left(node));
 223                 vrp_right = get_vrp_attr(get_Shrs_right(node));
 224
 225                 /* We can only compute this if the right value is a constant*/
 226                 if (is_Const(right)) {
 227                         new_bits_set = tarval_shrs(vrp_left->bits_set, get_Const_tarval(right));
 228                         new_bits_not_set = tarval_shrs(vrp_left->bits_not_set, get_Const_tarval(right));
 229                 }
 230                 break;
 231         }
 232
 233         case iro_Eor: {
 234                 const vrp_attr *vrp_left, *vrp_right;
 235
 236                 vrp_left = get_vrp_attr(get_Eor_left(node));
 237                 vrp_right = get_vrp_attr(get_Eor_right(node));
 238
 239                 new_bits_set = tarval_or(
 240                                                 tarval_and(vrp_left->bits_set, tarval_not(vrp_right->bits_not_set)),
 241                                                 tarval_and(tarval_not(vrp_left->bits_not_set), vrp_right->bits_set));
 242
 243                 new_bits_not_set = tarval_not(tarval_or(
 244                                 tarval_and(vrp_left->bits_set,vrp_right->bits_set),
 245                                                         tarval_and(tarval_not(vrp_left->bits_not_set),
 246                                                                 tarval_not(vrp_right->bits_not_set))));
 247
 248                 break;
 249         }
 250
 251         case iro_Id: {
 252                 const vrp_attr *vrp_pred = get_vrp_attr(get_Id_pred(node));
 253                 new_bits_set = vrp_pred->bits_set;
 254                 new_bits_not_set = vrp_pred->bits_not_set;
 255                 new_range_top = vrp_pred->range_top;
 256                 new_range_bottom = vrp_pred->range_bottom;
 257                 new_range_type = vrp_pred->range_type;
 258                 break;
 259         }
 260
 261         case iro_Not: {
 262                 const vrp_attr *vrp_pred = get_vrp_attr(get_Not_op(node));
 263                 new_bits_set = tarval_not(vrp_pred->bits_not_set);
 264                 new_bits_not_set = tarval_not(vrp_pred->bits_set);
 265                 break;
 266         }
 267
 268         case iro_Conv: {
 269                 const ir_node *pred = get_Conv_op(node);
 270                 ir_mode *old_mode = get_irn_mode(pred);
 271                 const vrp_attr *vrp_pred = get_vrp_attr(pred);
 272
 273                 ir_mode *new_mode;
 274
 275                 if (!mode_is_int(old_mode))
 276                         return 0;
 277
 278                 new_mode = get_irn_mode(node);
 279
 280                 /* The second and is needed if target type is smaller*/
 281                 new_bits_not_set = tarval_convert_to(get_mode_all_one(old_mode), new_mode);
 282                 new_bits_not_set = tarval_and(new_bits_not_set, tarval_convert_to(vrp_pred->bits_not_set, new_mode));
 283                 new_bits_set = tarval_and(
 284                                 new_bits_not_set, tarval_convert_to(vrp_pred->bits_set, new_mode));
 285
 286                 /* Matze: TODO, BUGGY, tarval_cmp never returns ir_relation_less_equal */
 287                 if (tarval_cmp(vrp_pred->range_top, get_mode_max(new_mode)) == ir_relation_less_equal) {
 288                         vrp->range_top = vrp_pred->range_top;
 289                 }
 290
 291                 /* Matze: TODO, BUGGY, tarval_cmp never returns ir_relation_greater_equal */
 292                 if (tarval_cmp(vrp_pred->range_bottom, get_mode_min(new_mode)) == ir_relation_greater_equal) {
 293                         vrp->range_bottom = vrp_pred->range_bottom;
 294                 }
 295                 break;
 296         }
 297
 298         case iro_Confirm: {
 299                 const ir_relation relation = get_Confirm_relation(node);
 300                 const ir_node    *bound    = get_Confirm_bound(node);
 301
 302
 303                 if (relation == ir_relation_less_greater) {
 304                         /** @todo: Handle non-Const bounds */
 305                         if (is_Const(bound)) {
 306                                 new_range_type = VRP_ANTIRANGE;
 307                                 new_range_top = get_Const_tarval(bound);
 308                                 new_range_bottom = get_Const_tarval(bound);
 309                         }
 310                 } else if (relation == ir_relation_less_equal) {
 311                         if (is_Const(bound)) {
 312                                 new_range_type = VRP_RANGE;
 313                                 new_range_top = get_Const_tarval(bound);
 314                                 new_range_bottom = get_tarval_min(get_irn_mode(node));
 315                         }
 316                 }
 317                 break;
 318         }
 319
 320         case iro_Phi: {
 321                 /* combine all ranges*/
 322
 323                 int num = get_Phi_n_preds(node);
 324                 ir_relation relation;
 325                 int i;
 326
 327                 const ir_node *pred = get_Phi_pred(node,0);
 328                 const vrp_attr *vrp_pred = get_vrp_attr(pred);
 329                 new_range_top = vrp_pred->range_top;
 330                 new_range_bottom = vrp_pred->range_bottom;
 331                 new_range_type = vrp_pred->range_type;
 332                 new_bits_set = vrp_pred->bits_set;
 333                 new_bits_not_set = vrp_pred->bits_not_set;
 334
 335                 assert(num > 0);
 336
 337                 for (i = 1; i < num; i++) {
 338                         pred = get_Phi_pred(node, i);
 339                         vrp_pred = get_vrp_attr(pred);
 340                         if (new_range_type == VRP_RANGE && vrp_pred->range_type ==
 341                                         VRP_RANGE) {
 342                                 relation = tarval_cmp(new_range_top, vrp_pred->range_top);
 343                                 if (relation == ir_relation_less) {
 344                                         new_range_top = vrp_pred->range_top;
 345                                 }
 346                                 relation = tarval_cmp(new_range_bottom, vrp_pred->range_bottom);
 347                                 if (relation == ir_relation_greater) {
 348                                         new_range_bottom = vrp_pred->range_bottom;
 349                                 }
 350                         } else {
 351                                 new_range_type = VRP_VARYING;
 352                         }
 353                         new_bits_set = tarval_and(new_bits_set, vrp_pred->bits_set);
 354                         new_bits_not_set = tarval_or(new_bits_not_set,
 355                                         vrp_pred->bits_not_set);
 356                 }
 357
 358                 break;
 359         }
 360         default:
 361                 /* unhandled, therefore never updated */
 362                 break;
 363         }
 364
 365
 366
 367         /* TODO: Check, if there can be information derived from any of these:
 368         is_Abs(node) is_Alloc(node) is_Anchor(node) is_Borrow(node) is_Bound(node)
 369         is_Break(node) is_Builtin(node) is_Call(node)
 370         is_Carry(node) is_Cast(node) is_Cmp(node) is_Cond(node)
 371         is_CopyB(node) is_Div(node) is_Dummy(node)
 372         is_End(node) is_Free(node)
 373         is_IJmp(node) is_InstOf(node) is_Jmp(node) is_Load(node) is_Minus(node)
 374         is_Mod(node) is_Mul(node) is_Mulh(node) is_Mux(node) is_NoMem(node)
 375         is_Pin(node) is_Proj(node)
 376         is_Raise(node) is_Return(node) is_Sel(node) is_Start(node) is_Store(node)
 377         is_SymConst(node) is_Sync(node) is_Tuple(node)
 378         */
 379
 380         /* @todo: At this place, we check if the mode of the variable changed. A
 381          * better place for this might be in the convopt.c file
 382          */
 383
 384         if (new_bits_set != tarval_bad && get_tarval_mode(new_bits_set) != get_tarval_mode(vrp->bits_set)) {
 385                 vrp->bits_set = tarval_convert_to(vrp->bits_set, get_irn_mode(node));
 386         }
 387         if (new_bits_not_set != tarval_bad && get_tarval_mode(new_bits_not_set) != get_tarval_mode(vrp->bits_not_set)) {
 388                 vrp->bits_not_set = tarval_convert_to(vrp->bits_not_set, get_irn_mode(node));
 389         }
 390
 391         if (vrp->range_type != VRP_UNDEFINED && new_range_type != VRP_UNDEFINED && get_tarval_mode(new_range_top) != get_tarval_mode(vrp->range_top)) {
 392                 /* @todo: We might be able to preserve this range information if it
 393                  * fits in */
 394                 vrp->range_type = VRP_VARYING;
 395         }
 396
 397         /* Merge the newly calculated values with those that might already exist*/
 398         if (new_bits_set != tarval_bad) {
 399                 new_bits_set = tarval_or(new_bits_set, vrp->bits_set);
 400                 if (tarval_cmp(new_bits_set, vrp->bits_set) != ir_relation_equal) {
 401                         something_changed = 1;
 402                         vrp->bits_set = new_bits_set;
 403                 }
 404         }
 405         if (new_bits_not_set != tarval_bad) {
 406                 new_bits_not_set = tarval_and(new_bits_not_set, vrp->bits_not_set);
 407
 408                 if (tarval_cmp(new_bits_not_set, vrp->bits_not_set) != ir_relation_equal) {
 409                         something_changed = 1;
 410                         vrp->bits_not_set = new_bits_not_set;
 411                 }
 412         }
 413
 414         if (vrp->range_type == VRP_UNDEFINED &&
 415                         new_range_type != VRP_UNDEFINED) {
 416                 something_changed = 1;
 417                 vrp->range_type = new_range_type;
 418                 vrp->range_bottom = new_range_bottom;
 419                 vrp->range_top = new_range_top;
 420
 421         } else if (vrp->range_type == VRP_RANGE) {
 422                 if (new_range_type == VRP_RANGE) {
 423                         if (tarval_cmp(vrp->range_bottom, new_range_bottom) == ir_relation_less) {
 424                                 something_changed = 1;
 425                                 vrp->range_bottom = new_range_bottom;
 426                         }
 427                         if (tarval_cmp(vrp->range_top, new_range_top) == ir_relation_greater) {
 428                                 something_changed = 1;
 429                                 vrp->range_top = new_range_top;
 430                         }
 431                 }
 432
 433                 if (new_range_type == VRP_ANTIRANGE) {
 434                         /* if they are overlapping, cut the range.*/
 435                         /* TODO: Maybe we can preserve more information here*/
 436                         if (tarval_cmp(vrp->range_bottom, new_range_top) == ir_relation_greater &&
 437                                         tarval_cmp(vrp->range_bottom, new_range_bottom) == ir_relation_greater) {
 438                                 something_changed = 1;
 439                                 vrp->range_bottom = new_range_top;
 440
 441                         } else if (tarval_cmp(vrp->range_top, new_range_bottom) == ir_relation_greater &&
 442                                         tarval_cmp(vrp->range_top, new_range_top) == ir_relation_less) {
 443                                 something_changed = 1;
 444                                 vrp->range_top = new_range_bottom;
 445                         }
 446
 447                         /* We can not handle the case where the anti range is in the*/
 448                         /* range*/
 449
 450                 }
 451         } else if (vrp->range_type == VRP_ANTIRANGE) {
 452                 if (new_range_type == VRP_ANTIRANGE) {
 453                         if (tarval_cmp(vrp->range_bottom, new_range_bottom) == ir_relation_greater) {
 454                                 something_changed = 1;
 455                                 vrp->range_bottom = new_range_bottom;
 456                         }
 457                         if (tarval_cmp(vrp->range_top, new_range_top) == ir_relation_less) {
 458                                 something_changed = 1;
 459                                 vrp->range_top = new_range_top;
 460                         }
 461                 }
 462
 463                 if (new_range_type == VRP_RANGE) {
 464                         if (tarval_cmp(vrp->range_bottom, new_range_top) == ir_relation_greater) {
 465                                 something_changed = 1;
 466                                 vrp->range_bottom = new_range_top;
 467                         }
 468                         if (tarval_cmp(vrp->range_top, new_range_bottom) == ir_relation_less) {
 469                                 something_changed = 1;
 470                                 vrp->range_top = new_range_bottom;
 471                         }
 472                 }
 473         }
 474
 475         assert(tarval_is_null(
 476                                 tarval_and(vrp->bits_set, tarval_not(vrp->bits_not_set))));
 477         return something_changed;
 478 }
 479
 480 static void vrp_first_pass(ir_node *n, void *e)
 481 {
 482         int i;
 483         vrp_env_t *env = (vrp_env_t*) e;
 484
 485         if (is_Block(n))
 486                 return;
 487
 488         bitset_set(env->visited, get_irn_idx(n));
 489
 490         vrp_update_node(n);
 491
 492         assure_irg_outs(get_current_ir_graph());
 493         for (i = get_irn_n_outs(n) - 1; i >=0; --i) {
 494                 ir_node *succ = get_irn_out(n, i);
 495                 if (bitset_is_set(env->visited, get_irn_idx(succ))) {
 496                         /* we found a loop*/
 497                         waitq_put(env->workqueue, succ);
 498                 }
 499         }
 500 }
 501
 502 static void *vrp_init_node(ir_phase *phase, const ir_node *n)
 503 {
 504         ir_mode *mode;
 505         vrp_attr *vrp;
 506
 507         DBG((dbg, LEVEL_2, "initialized node nr: %d\n", get_irn_node_nr(n)));
 508         vrp = (vrp_attr*) phase_alloc(phase, sizeof(vrp_attr));
 509
 510         memset(vrp, 0, sizeof(vrp_attr));
 511         /* Initialize the vrp information to default */
 512
 513         mode = get_irn_mode(n);
 514
 515         vrp->range_type = VRP_UNDEFINED;
 516
 517         /* TODO: We might be able to optimize space usage if we do not allocate
 518          * vrp space for non-int nodes. (currently caught by vrp_update_node)
 519          */
 520         if (mode_is_int(mode)) {
 521                 /* We are assuming that 0 is always represented as this modes null */
 522                 vrp->valid = 1;
 523                 vrp->bits_set = get_mode_null(mode);
 524                 vrp->bits_not_set = get_mode_all_one(mode);
 525                 vrp->range_bottom = get_tarval_top();
 526                 vrp->range_top = get_tarval_top();
 527         } else {
 528                 vrp->valid = 0;
 529                 vrp->bits_set = get_tarval_bad();
 530                 vrp->bits_not_set = get_tarval_bad();
 531                 vrp->range_bottom = get_tarval_bad();
 532                 vrp->range_top = get_tarval_bad();
 533         }
 534
 535         /* TODO: We might be able to set better vrp info at this time, if this is
 536          * a node which is newly created in an already initialized irg
 537          *
 538          * maybe just call vrp_update_node and if it returns one, iterate over
 539          * successors
 540          */
 541         return vrp;
 542 }
 543
 544 void set_vrp_data(ir_graph *irg)
 545 {
 546         ir_node *succ, *node;
 547         int i;
 548         vrp_env_t *env;
 549         ir_phase *phase;
 550
 551         FIRM_DBG_REGISTER(dbg, "ir.ana.vrp");
 552
 553         assure_irg_outs(irg); /* ensure that out edges are consistent*/
 554         phase = irg_get_phase(irg, PHASE_VRP);
 555         if (phase == NULL) {
 556                 /* this is our first run */
 557                 phase = new_phase(irg, vrp_init_node);
 558                 irg_register_phase(irg, PHASE_VRP, phase);
 559                 env = (vrp_env_t*) phase_alloc(phase, sizeof(*env));
 560                 phase->priv = env;
 561         } else {
 562                 env = (vrp_env_t*) phase->priv;
 563         }
 564
 565         env->workqueue = new_waitq();
 566
 567         env->visited = bitset_malloc(get_irg_last_idx(irg));
 568         irg_walk_graph(irg, NULL, vrp_first_pass, env);
 569         bitset_free(env->visited);
 570
 571         /* while there are entries in the worklist, continue*/
 572         while (!waitq_empty(env->workqueue)) {
 573                 node = (ir_node*) waitq_get(env->workqueue);
 574
 575                 if (vrp_update_node(node)) {
 576                         /* if something changed, add successors to worklist*/
 577                         for (i = get_irn_n_outs(node) - 1; i >=0; --i) {
 578                                 succ =  get_irn_out(node, i);
 579                                 waitq_put(env->workqueue, node);
 580                         }
 581                 }
 582         }
 583         del_waitq(env->workqueue);
 584 }
 585
 586 ir_graph_pass_t *set_vrp_pass(const char *name)
 587 {
 588         return def_graph_pass(name ? name : "set_vrp", set_vrp_data);
 589 }
 590
 591 ir_relation vrp_cmp(const ir_node *left, const ir_node *right)
 592 {
 593         vrp_attr *vrp_left, *vrp_right;
 594
 595         vrp_left = vrp_get_info(left);
 596         vrp_right = vrp_get_info(right);
 597
 598         if (!vrp_left || !vrp_right)
 599                 return ir_relation_true;
 600
 601         if (vrp_left->range_type == VRP_RANGE && vrp_right->range_type == VRP_RANGE) {
 602                 if (tarval_cmp(vrp_left->range_top, vrp_right->range_bottom) == ir_relation_less) {
 603                         return ir_relation_less;
 604                 }
 605                 if (tarval_cmp(vrp_left->range_bottom, vrp_right->range_top) == ir_relation_greater) {
 606                         return ir_relation_greater;
 607                 }
 608         }
 609
 610         if (!tarval_is_null(tarval_and(vrp_left->bits_set, tarval_not(vrp_right->bits_not_set))) ||
 611                         !tarval_is_null(tarval_and(tarval_not(vrp_left->bits_not_set), vrp_right->bits_set))) {
 612                 return ir_relation_less_greater;
 613         }
 614
 615         /* TODO: We can get way more information here*/
 616         return ir_relation_true;
 617 }
 618
 619 vrp_attr *vrp_get_info(const ir_node *node)
 620 {
 621         const ir_graph *irg   = get_irn_irg(node);
 622         const ir_phase *phase = irg_get_phase(irg, PHASE_VRP);
 623         vrp_attr       *vrp;
 624
 625         if (phase == NULL) {
 626                 /* phase has not yet been initialized */
 627                 return NULL;
 628         }
 629
 630         vrp = (vrp_attr*) phase_get_irn_data(phase, node);
 631         if (vrp && vrp->valid) {
 632                 return vrp;
 633         }
 634
 635         return NULL;
 636 }