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 "irouts.h"
  31 #include "irgraph_t.h"
  32 #include "irgopt.h"
  33 #include "irpass.h"
  34 #include "irgwalk.h"
  35 #include "iredges.h"
  36 #include "tv.h"
  37 #include "irop.h"
  38 #include "pdeq.h"
  39 #include "irphase_t.h"
  40 #include "irprintf.h"
  41
  42 static char v;
  43 static void *VISITED = &v;
  44
  45 struct vrp_env_t {
  46         waitq *workqueue;
  47 };
  48
  49 static vrp_attr *get_vrp_attr(const ir_node *node)
  50 {
  51         return (vrp_attr*) get_or_set_irn_phase_info(node, PHASE_VRP);
  52 }
  53
  54 static int vrp_update_node(ir_node *node)
  55 {
  56         tarval *new_bits_set = get_tarval_bad();
  57         tarval *new_bits_not_set = get_tarval_bad();
  58         tarval *new_range_bottom = get_tarval_bad();
  59         tarval *new_range_top = get_tarval_bad();
  60         enum range_types new_range_type = VRP_UNDEFINED;
  61         int something_changed = 0;
  62         vrp_attr *vrp;
  63
  64         if (!mode_is_int(get_irn_mode(node))) {
  65                 return 0; /* we don't optimize for non-int-nodes*/
  66         }
  67
  68         ir_printf("update_vrp for %d called\n", get_irn_node_nr(node));
  69         vrp = get_vrp_attr(node);
  70
  71         /* TODO: Check if all predecessors have valid VRP information*/
  72
  73         switch (get_irn_opcode(node)) {
  74         case iro_Const: {
  75                 tarval *tv = get_Const_tarval(node);
  76                 new_bits_set = tv;
  77                 new_bits_not_set = tv;
  78                 new_range_bottom = tv;
  79                 new_range_top = tv;
  80                 new_range_type = VRP_RANGE;
  81                 break;
  82         }
  83         case iro_And: {
  84                 vrp_attr *vrp_left, *vrp_right;
  85                 ir_node *left, *right;
  86
  87                 left = get_And_left(node);
  88                 right = get_And_right(node);
  89                 vrp_left = get_vrp_attr(left);
  90                 vrp_right = get_vrp_attr(right);
  91                 new_bits_set = tarval_and(vrp_left->bits_set, vrp_right->bits_set);
  92                 new_bits_not_set = tarval_and(vrp_left->bits_not_set, vrp_right->bits_not_set);
  93
  94                 break;
  95         }
  96
  97         case iro_Add: {
  98                 int overflow_top, overflow_bottom;
  99                 tarval *new_top, *new_bottom;
 100                 vrp_attr *vrp_left, *vrp_right;
 101                 vrp_left = get_vrp_attr(get_Add_left(node));
 102                 vrp_right = get_vrp_attr(get_Add_right(node));
 103
 104                 if (vrp_left->range_type == VRP_UNDEFINED || vrp_right->range_type ==
 105                                 VRP_UNDEFINED || vrp_left->range_type == VRP_VARYING ||
 106                                 vrp_right->range_type == VRP_VARYING) {
 107                         return 0;
 108                 }
 109
 110                 new_top = tarval_add(vrp_left->range_top, vrp_right->range_top);
 111                 overflow_top = tarval_carry();
 112                 new_bottom = tarval_add(vrp_left->range_bottom, vrp_right->range_bottom);
 113                 overflow_bottom = tarval_carry();
 114
 115                 if (!overflow_top && !overflow_bottom && vrp_left->range_type == VRP_RANGE
 116                                 &&vrp_right->range_type == VRP_RANGE) {
 117                         new_range_bottom = new_bottom;
 118                         new_range_top = new_top;
 119                         new_range_type = VRP_RANGE;
 120                 }
 121
 122                 if (overflow_top || overflow_bottom) {
 123                         /* TODO Implement overflow handling*/
 124                         new_range_type = VRP_UNDEFINED;
 125                 }
 126                 break;
 127         }
 128
 129         case iro_Sub: {
 130                 int overflow_top, overflow_bottom;
 131                 tarval *new_top, *new_bottom;
 132                 vrp_attr *vrp_left, *vrp_right;
 133                 vrp_left = get_vrp_attr(get_Sub_left(node));
 134                 vrp_right = get_vrp_attr(get_Sub_right(node));
 135
 136                 if (vrp_left->range_type == VRP_UNDEFINED || vrp_right->range_type ==
 137                                 VRP_UNDEFINED || vrp_left->range_type == VRP_VARYING ||
 138                                 vrp_right->range_type == VRP_VARYING) {
 139                         return 0;
 140                 }
 141
 142                 new_top = tarval_sub(vrp_left->range_top, vrp_right->range_top, NULL);
 143                 overflow_top = tarval_carry();
 144                 new_bottom = tarval_sub(vrp_left->range_bottom, vrp_right->range_bottom, NULL);
 145                 overflow_bottom = tarval_carry();
 146
 147                 if (!overflow_top && !overflow_bottom && vrp_left->range_type == VRP_RANGE
 148                                 &&vrp_right->range_type == VRP_RANGE) {
 149                         new_range_bottom = new_bottom;
 150                         new_range_top = new_top;
 151                         new_range_type = VRP_RANGE;
 152                 }
 153
 154                 if (overflow_top || overflow_bottom) {
 155                         /* TODO Implement overflow handling*/
 156                 }
 157                 break;
 158         }
 159
 160         case iro_Or: {
 161                 vrp_attr *vrp_left, *vrp_right;
 162
 163                 vrp_left = get_vrp_attr(get_Or_left(node));
 164                 vrp_right = get_vrp_attr(get_Or_right(node));
 165
 166                 new_bits_set = tarval_or(vrp_left->bits_set, vrp_right->bits_set);
 167                 new_bits_not_set = tarval_or(vrp_left->bits_not_set, vrp_right->bits_not_set);
 168
 169                 break;
 170         }
 171
 172         case iro_Rotl: {
 173                 vrp_attr *vrp_left, *vrp_right;
 174                 ir_node *right = get_Rotl_right(node);
 175
 176                 vrp_left = get_vrp_attr(get_Rotl_left(node));
 177                 vrp_right = get_vrp_attr(get_Rotl_right(node));
 178
 179                 /* We can only compute this if the right value is a constant*/
 180                 if (is_Const(right)) {
 181                         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                 vrp_attr *vrp_left, *vrp_right;
 190                 ir_node *right = get_Shl_right(node);
 191                 vrp_left = get_vrp_attr(get_Shl_left(node));
 192                 vrp_right = get_vrp_attr(get_Shl_right(node));
 193
 194                 /* We can only compute this if the right value is a constant*/
 195                 if (is_Const(right)) {
 196                         new_bits_set = tarval_shl(vrp_left->bits_set, get_Const_tarval(right));
 197                         new_bits_not_set = tarval_shl(vrp_left->bits_not_set, get_Const_tarval(right));
 198                 }
 199                 break;
 200         }
 201
 202         case iro_Shr: {
 203                 vrp_attr *vrp_left, *vrp_right;
 204                 ir_node *right = get_Shr_right(node);
 205
 206                 vrp_left = get_vrp_attr(get_Shr_left(node));
 207                 vrp_right = get_vrp_attr(get_Shr_right(node));
 208
 209                 /* We can only compute this if the right value is a constant*/
 210                 if (is_Const(right)) {
 211                         new_bits_set = tarval_shr(vrp_left->bits_set, get_Const_tarval(right));
 212                         new_bits_not_set = tarval_shr(vrp_left->bits_not_set, get_Const_tarval(right));
 213                 }
 214                 break;
 215         }
 216
 217         case iro_Shrs: {
 218                 vrp_attr *vrp_left, *vrp_right;
 219                 ir_node *right = get_Shrs_right(node);
 220
 221                 vrp_left = get_vrp_attr(get_Shrs_left(node));
 222                 vrp_right = get_vrp_attr(get_Shrs_right(node));
 223
 224                 /* We can only compute this if the right value is a constant*/
 225                 if (is_Const(right)) {
 226                         new_bits_set = tarval_shrs(vrp_left->bits_set, get_Const_tarval(right));
 227                         new_bits_not_set = tarval_shrs(vrp_left->bits_not_set, get_Const_tarval(right));
 228                 }
 229                 break;
 230         }
 231
 232         case iro_Eor: {
 233                 tarval *bits_set, *bits_not_set;
 234                 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                 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                 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                 ir_node *pred = get_Conv_op(node);
 270                 ir_mode *old_mode = get_irn_mode(pred);
 271                 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                 if (tarval_cmp(vrp_pred->range_top, get_mode_max(new_mode)) == pn_Cmp_Le) {
 287                         vrp->range_top = vrp_pred->range_top;
 288                 }
 289
 290                 if (tarval_cmp(vrp_pred->range_bottom, get_mode_min(new_mode)) == pn_Cmp_Ge) {
 291                         vrp->range_bottom = vrp_pred->range_bottom;
 292                 }
 293                 break;
 294         }
 295
 296         case iro_Confirm: {
 297                 pn_Cmp cmp = get_Confirm_cmp(node);
 298                 ir_node *bound = get_Confirm_bound(node);
 299
 300
 301                 if (cmp == pn_Cmp_Lg) {
 302                         /** @todo: Handle non-Const bounds */
 303                         if (is_Const(bound)) {
 304                                 new_range_type = VRP_ANTIRANGE;
 305                                 new_range_top = get_Const_tarval(bound);
 306                                 new_range_bottom = get_Const_tarval(bound);
 307                         }
 308                 } else if (cmp == pn_Cmp_Le) {
 309                         if (is_Const(bound)) {
 310                                 new_range_type = VRP_RANGE;
 311                                 new_range_top = get_Const_tarval(bound);
 312                                 new_range_bottom = get_tarval_min(get_irn_mode(node));
 313                         }
 314                 }
 315                 break;
 316         }
 317
 318         case iro_Phi: {
 319                 /* combine all ranges*/
 320
 321                 int num = get_Phi_n_preds(node);
 322                 pn_Cmp cmp;
 323                 int i;
 324
 325                 ir_node *pred = get_Phi_pred(node,0);
 326                 vrp_attr *vrp_pred = get_vrp_attr(pred);
 327                 new_range_top = vrp_pred->range_top;
 328                 new_range_bottom = vrp_pred->range_bottom;
 329                 new_range_type = vrp_pred->range_type;
 330                 new_bits_set = vrp_pred->bits_set;
 331                 new_bits_not_set = vrp_pred->bits_not_set;
 332
 333                 assert(num > 0);
 334
 335                 for (i = 1; i < num; i++) {
 336                         pred = get_Phi_pred(node, i);
 337                         vrp_pred = get_vrp_attr(pred);
 338                         if (new_range_type == VRP_RANGE && vrp_pred->range_type ==
 339                                         VRP_RANGE) {
 340                                 cmp = tarval_cmp(new_range_top, vrp_pred->range_top);
 341                                 if (cmp == pn_Cmp_Lt) {
 342                                         new_range_top = vrp_pred->range_top;
 343                                 }
 344                                 cmp = tarval_cmp(new_range_bottom, vrp_pred->range_bottom);
 345                                 if (cmp == pn_Cmp_Gt) {
 346                                         new_range_bottom = vrp_pred->range_bottom;
 347                                 }
 348                         } else {
 349                                 new_range_type = VRP_VARYING;
 350                         }
 351                         new_bits_set = tarval_and(new_bits_set, vrp_pred->bits_set);
 352                         new_bits_not_set = tarval_or(new_bits_not_set,
 353                                         vrp_pred->bits_not_set);
 354                 }
 355
 356                 break;
 357         }
 358         default:
 359                 /* unhandled, therefore never updated */
 360                 break;
 361         }
 362
 363
 364
 365         /* TODO: Check, if there can be information derived from any of these:
 366         is_Abs(node) is_Alloc(node) is_Anchor(node) is_Borrow(node) is_Bound(node)
 367         is_Break(node) is_Builtin(node) is_Call(node) is_CallBegin(node)
 368         is_Carry(node) is_Cast(node) is_Cmp(node) is_Cond(node)
 369         is_CopyB(node) is_Div(node) is_DivMod(node) is_Dummy(node)
 370         is_End(node) is_EndExcept(node) is_EndReg(node) is_Filter(node) is_Free(node)
 371         is_IJmp(node) is_InstOf(node) is_Jmp(node) is_Load(node) is_Minus(node)
 372         is_Mod(node) is_Mul(node) is_Mulh(node) is_Mux(node) is_NoMem(node)
 373         is_Pin(node) is_Proj(node) is_Quot(node)
 374         is_Raise(node) is_Return(node) is_Sel(node) is_Start(node) is_Store(node)
 375         is_SymConst(node) is_Sync(node) is_Tuple(node)
 376         */
 377
 378         /* Merge the newly calculated values with those that might already exist*/
 379         if (new_bits_set != tarval_bad) {
 380                 new_bits_set = tarval_or(new_bits_set, vrp->bits_set);
 381                 if (tarval_cmp(new_bits_set, vrp->bits_set) != pn_Cmp_Eq) {
 382                         something_changed = 1;
 383                         vrp->bits_set = new_bits_set;
 384                 }
 385         }
 386         if (new_bits_not_set != tarval_bad) {
 387                 new_bits_not_set = tarval_and(new_bits_not_set, vrp->bits_not_set);
 388
 389                 if (tarval_cmp(new_bits_not_set, vrp->bits_not_set) != pn_Cmp_Eq) {
 390                         something_changed = 1;
 391                         vrp->bits_not_set = new_bits_not_set;
 392                 }
 393         }
 394
 395         if (vrp->range_type == VRP_UNDEFINED &&
 396                         new_range_type != VRP_UNDEFINED) {
 397                 something_changed = 1;
 398                 vrp->range_type = new_range_type;
 399                 vrp->range_bottom = new_range_bottom;
 400                 vrp->range_top = new_range_top;
 401
 402         } else if (vrp->range_type == VRP_RANGE) {
 403                 if (new_range_type == VRP_RANGE) {
 404                         if (tarval_cmp(vrp->range_bottom, new_range_bottom) == pn_Cmp_Lt) {
 405                                 something_changed = 1;
 406                                 vrp->range_bottom = new_range_bottom;
 407                         }
 408                         if (tarval_cmp(vrp->range_top, new_range_top) == pn_Cmp_Gt) {
 409                                 something_changed = 1;
 410                                 vrp->range_top = new_range_top;
 411                         }
 412                 }
 413
 414                 if (new_range_type == VRP_ANTIRANGE) {
 415                         /* if they are overlapping, cut the range.*/
 416                         /* TODO: Maybe we can preserve more information here*/
 417                         if (tarval_cmp(vrp->range_bottom, new_range_top) == pn_Cmp_Gt &&
 418                                         tarval_cmp(vrp->range_bottom, new_range_bottom) == pn_Cmp_Gt) {
 419                                 something_changed = 1;
 420                                 vrp->range_bottom = new_range_top;
 421
 422                         } else if (tarval_cmp(vrp->range_top, new_range_bottom) == pn_Cmp_Gt &&
 423                                         tarval_cmp(vrp->range_top, new_range_top) == pn_Cmp_Lt) {
 424                                 something_changed = 1;
 425                                 vrp->range_top = new_range_bottom;
 426                         }
 427
 428                         /* We can not handle the case where the anti range is in the*/
 429                         /* range*/
 430
 431                 }
 432         } else if (vrp->range_type == VRP_ANTIRANGE) {
 433                 if (new_range_type == VRP_ANTIRANGE) {
 434                         if (tarval_cmp(vrp->range_bottom, new_range_bottom) == pn_Cmp_Gt) {
 435                                 something_changed = 1;
 436                                 vrp->range_bottom = new_range_bottom;
 437                         }
 438                         if (tarval_cmp(vrp->range_top, new_range_top) == pn_Cmp_Lt) {
 439                                 something_changed = 1;
 440                                 vrp->range_top = new_range_top;
 441                         }
 442                 }
 443
 444                 if (new_range_type == VRP_RANGE) {
 445                         if (tarval_cmp(vrp->range_bottom, new_range_top) == pn_Cmp_Gt) {
 446                                 something_changed = 1;
 447                                 vrp->range_bottom = new_range_top;
 448                         }
 449                         if (tarval_cmp(vrp->range_top, new_range_bottom) == pn_Cmp_Lt) {
 450                                 something_changed = 1;
 451                                 vrp->range_top = new_range_bottom;
 452                         }
 453                 }
 454         }
 455
 456         assert(tarval_is_null(
 457                                 tarval_and(vrp->bits_set, tarval_not(vrp->bits_not_set))));
 458         return something_changed;
 459 }
 460
 461 static void vrp_first_pass(ir_node *n, void *e)
 462 {
 463         ir_node *succ;
 464         int i;
 465         struct vrp_env_t *env = e;
 466
 467         if (is_Block(n))
 468                 return;
 469
 470         set_irn_link(n, VISITED);
 471
 472         vrp_update_node(n);
 473
 474         assure_irg_outs(get_current_ir_graph());
 475         for (i = get_irn_n_outs(n) - 1; i >=0; --i) {
 476                 succ =  get_irn_out(n, i);
 477                 if (get_irn_link(succ) == VISITED) {
 478                         /* we found a loop*/
 479                         waitq_put(env->workqueue, succ);
 480                 }
 481         }
 482 }
 483
 484 static void *vrp_init_node(ir_phase *phase, const ir_node *n, void *old)
 485 {
 486         ir_mode *mode;
 487         vrp_attr *vrp;
 488
 489         ir_printf("initialized node nr: %d\n", get_irn_node_nr(n));
 490         if (old) {
 491                 assert(1==0 && "init called for node already initialized");
 492         }
 493         vrp = phase_alloc(phase, sizeof(vrp_attr));
 494
 495         memset(vrp, 0, sizeof(vrp_attr));
 496         /* Initialize the vrp information to default */
 497
 498         mode = get_irn_mode(n);
 499
 500         vrp->range_type = VRP_UNDEFINED;
 501
 502         /* TODO: We might be able to optimize space usage if we do not allocate
 503          * vrp space for non-int nodes. (currently caught by vrp_update_node)
 504          */
 505         if (mode_is_int(mode)) {
 506                 /* We are assuming that 0 is always represented as this modes null */
 507                 vrp->valid = 1;
 508                 vrp->bits_set = get_mode_null(mode);
 509                 vrp->bits_not_set = get_mode_all_one(mode);
 510                 vrp->range_bottom = get_tarval_top();
 511                 vrp->range_top = get_tarval_top();
 512         } else {
 513                 vrp->valid = 0;
 514                 vrp->bits_set = get_tarval_bad();
 515                 vrp->bits_not_set = get_tarval_bad();
 516                 vrp->range_bottom = get_tarval_bad();
 517                 vrp->range_top = get_tarval_bad();
 518         }
 519
 520         /* TODO: We might be able to set better vrp info at this time, if this is
 521          * a node which is newly created in an already initialized irg
 522          *
 523          * maybe just call vrp_update_node and if it returns one, iterate over
 524          * successors
 525          */
 526         return vrp;
 527 }
 528
 529 void set_vrp_data(ir_graph *irg)
 530 {
 531         ir_node *succ, *node;
 532         int i;
 533         struct vrp_env_t *env;
 534         ir_phase *phase;
 535
 536         assure_irg_outs(irg); /* ensure that out edges are consistent*/
 537         phase = irg_get_phase(irg, PHASE_VRP);
 538         if (phase == NULL) {
 539                 /* this is our first run */
 540                 phase = new_phase(irg, vrp_init_node);
 541                 irg_register_phase(irg, PHASE_VRP, phase);
 542                 env = phase_alloc(phase, sizeof(*env));
 543                 phase->priv = env;
 544         } else {
 545                 env = phase->priv;
 546         }
 547
 548         env->workqueue = new_waitq();
 549
 550         irg_walk_graph(irg, NULL, vrp_first_pass, env);
 551
 552         /* while there are entries in the worklist, continue*/
 553         while (!waitq_empty(env->workqueue)) {
 554                 node = waitq_get(env->workqueue);
 555
 556                 if (vrp_update_node(node)) {
 557                         /* if something changed, add successors to worklist*/
 558                         for (i = get_irn_n_outs(node) - 1; i >=0; --i) {
 559                                 succ =  get_irn_out(node, i);
 560                                 waitq_put(env->workqueue, node);
 561                         }
 562                 }
 563         }
 564         del_waitq(env->workqueue);
 565 }
 566
 567
 568 ir_graph_pass_t *set_vrp_pass(const char *name)
 569 {
 570         return def_graph_pass(name ? name : "set_vrp", set_vrp_data);
 571 }
 572
 573 pn_Cmp vrp_cmp(const ir_node *left, const ir_node *right)
 574 {
 575         vrp_attr *vrp_left, *vrp_right;
 576
 577         vrp_left = vrp_get_info(left);
 578         vrp_right = vrp_get_info(right);
 579
 580         if (!vrp_left || !vrp_right) {
 581                 return pn_Cmp_False;
 582         }
 583
 584         if (vrp_left->range_type == VRP_RANGE && vrp_right->range_type == VRP_RANGE) {
 585                 if (tarval_cmp(vrp_left->range_top, vrp_right->range_bottom) == pn_Cmp_Lt) {
 586                         return pn_Cmp_Lt;
 587                 }
 588                 if (tarval_cmp(vrp_left->range_bottom, vrp_right->range_top) == pn_Cmp_Gt) {
 589                         return pn_Cmp_Gt;
 590                 }
 591         }
 592
 593         if (!tarval_is_null(tarval_and(vrp_left->bits_set, tarval_not(vrp_right->bits_not_set))) ||
 594                         !tarval_is_null(tarval_and(tarval_not(vrp_left->bits_not_set), vrp_right->bits_set))) {
 595                 return pn_Cmp_Lg;
 596         }
 597         /* TODO: We can get way more information here*/
 598
 599         return pn_Cmp_False;
 600 }
 601
 602 vrp_attr *vrp_get_info(const ir_node *node)
 603 {
 604         const ir_graph *irg   = get_irn_irg(node);
 605         const ir_phase *phase = irg_get_phase(irg, PHASE_VRP);
 606
 607         if (phase == NULL) {
 608                 /* phase has not yet been initialized */
 609                 return NULL;
 610         }
 611
 612
 613         vrp_attr *vrp = phase_get_irn_data(phase, node);
 614         if (vrp && vrp->valid) {
 615                 return vrp;
 616         }
 617         return NULL;
 618 }