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

   1 /*
   2  * Copyright (C) 1995-2009 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 "config.h"
  29 #include "irtypes.h"
  30 #include "vrp.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
  42
  43 static char v;
  44 static void *VISITED = &v;
  45
  46 struct vrp_env_t {
  47         waitq *workqueue;
  48 };
  49
  50 static int vrp_update_node(ir_node *node)
  51 {
  52         tarval *new_bits_set = get_tarval_bad();
  53         tarval *new_bits_not_set = get_tarval_bad();
  54         tarval *new_range_bottom = get_tarval_bad();
  55         tarval *new_range_top = get_tarval_bad();
  56         enum range_types new_range_type = VRP_UNDEFINED;
  57         int something_changed = 0;
  58         vrp_attr *vrp;
  59         ir_phase *phase;
  60
  61         if (!mode_is_int(get_irn_mode(node))) {
  62                 return 0; /* we don't optimize for non-int-nodes*/
  63         }
  64
  65         phase = get_irg_phase(get_irn_irg(node), PHASE_VRP);
  66
  67         ir_printf("update_vrp for %d called\n", get_irn_node_nr(node));
  68         vrp = phase_get_or_set_irn_data(phase, node);
  69
  70         /* TODO: Check if all predecessors have valid VRP information*/
  71
  72
  73
  74         switch (get_irn_opcode(node)) {
  75         case iro_Const: {
  76                 tarval *tv = get_Const_tarval(node);
  77                 new_bits_set = tv;
  78                 new_bits_not_set = tarval_not(tv);
  79                 new_range_bottom = tv;
  80                 new_range_top = tv;
  81                 new_range_type = VRP_RANGE;
  82                 break;
  83         }
  84
  85         case iro_And: {
  86                 vrp_attr *vrp_left, *vrp_right;
  87                 ir_node *left, *right;
  88
  89                 left = get_And_left(node);
  90                 right = get_And_right(node);
  91                 vrp_left = phase_get_or_set_irn_data(phase, left);
  92                 vrp_right = phase_get_or_set_irn_data(phase, right);
  93                 new_bits_set = tarval_and(vrp_left->bits_set, vrp_right->bits_set);
  94                 new_bits_not_set = tarval_or(vrp_left->bits_not_set, vrp_right->bits_not_set);
  95
  96                 break;
  97         }
  98
  99         case iro_Add: {
 100                 vrp_attr *vrp_left, *vrp_right;
 101                 vrp_left = phase_get_or_set_irn_data(phase, get_Add_left(node));
 102                 vrp_right = phase_get_or_set_irn_data(phase, get_Add_right(node));
 103                 int overflow_top, overflow_bottom;
 104                 tarval *new_top, *new_bottom;
 105
 106                 if (vrp_left->range_type == VRP_UNDEFINED || vrp_right->range_type ==
 107                                 VRP_UNDEFINED || vrp_left->range_type == VRP_VARYING ||
 108                                 vrp_right->range_type == VRP_VARYING) {
 109                         return 0;
 110                 }
 111
 112                 new_top = tarval_add(vrp_left->range_top, vrp_right->range_top);
 113                 overflow_top = tarval_carry();
 114                 new_bottom = tarval_add(vrp_left->range_bottom, vrp_right->range_bottom);
 115                 overflow_bottom = tarval_carry();
 116
 117                 if (!overflow_top && !overflow_bottom && vrp_left->range_type == VRP_RANGE
 118                                 &&vrp_right->range_type == VRP_RANGE) {
 119                         new_range_bottom = new_bottom;
 120                         new_range_top = new_top;
 121                         new_range_type = VRP_RANGE;
 122                 }
 123
 124                 if (overflow_top || overflow_bottom) {
 125                         /* TODO Implement overflow handling*/
 126                         new_range_type = VRP_UNDEFINED;
 127                 }
 128                 break;
 129         }
 130
 131         case iro_Sub: {
 132                 vrp_attr *vrp_left, *vrp_right;
 133                 vrp_left = phase_get_or_set_irn_data(phase, get_Sub_left(node));
 134                 vrp_right = phase_get_or_set_irn_data(phase, get_Sub_right(node));
 135                 int overflow_top, overflow_bottom;
 136                 tarval *new_top, *new_bottom;
 137
 138                 if (vrp_left->range_type == VRP_UNDEFINED || vrp_right->range_type ==
 139                                 VRP_UNDEFINED) {
 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                 vrp_attr *vrp_left, *vrp_right;
 163                 ir_node *left, *right;
 164
 165                 left = get_Or_left(node);
 166                 right = get_Or_right(node);
 167
 168                 vrp_left = phase_get_or_set_irn_data(phase, get_Or_left(node));
 169                 vrp_right = phase_get_or_set_irn_data(phase, get_Or_right(node));
 170
 171                 new_bits_set = tarval_or(vrp_left->bits_set, vrp_right->bits_set);
 172                 new_bits_not_set = tarval_and(vrp_left->bits_not_set, vrp_right->bits_not_set);
 173
 174                 break;
 175         }
 176
 177         case iro_Rotl: {
 178                 vrp_attr *vrp_left, *vrp_right;
 179                 ir_node *right = get_Rotl_right(node);
 180
 181                 vrp_left = phase_get_or_set_irn_data(phase, get_Rotl_left(node));
 182                 vrp_right = phase_get_or_set_irn_data(phase, get_Rotl_right(node));
 183
 184                 /* We can only compute this if the right value is a constant*/
 185                 if (is_Const(right)) {
 186                         tarval *bits_set, *bits_not_set;
 187                         bits_set = tarval_rotl(vrp_left->bits_set, get_Const_tarval(right));
 188                         bits_not_set = tarval_rotl(vrp_left->bits_not_set, get_Const_tarval(right));
 189
 190                         new_bits_set = tarval_or(bits_set, vrp->bits_set);
 191                         new_bits_not_set = tarval_or(bits_not_set, vrp->bits_not_set);
 192                 }
 193                 break;
 194         }
 195
 196         case iro_Shl: {
 197                 vrp_attr *vrp_left, *vrp_right;
 198                 ir_node *right = get_Shl_right(node);
 199                 vrp_left = phase_get_or_set_irn_data(phase, get_Shl_left(node));
 200                 vrp_right = phase_get_or_set_irn_data(phase, get_Shl_right(node));
 201
 202                 /* We can only compute this if the right value is a constant*/
 203                 if (is_Const(right)) {
 204                         tarval *bits_set, *bits_not_set;
 205                         ir_mode *m = get_tarval_mode(vrp->bits_not_set);
 206                         bits_set = tarval_shl(vrp_left->bits_set, get_Const_tarval(right));
 207                         bits_not_set = tarval_shl(vrp_left->bits_not_set, get_Const_tarval(right));
 208
 209                         new_bits_set = tarval_or(bits_set, vrp->bits_set);
 210                         new_bits_not_set = tarval_or(bits_not_set, vrp->bits_not_set);
 211
 212                         bits_not_set = tarval_not( tarval_shl(
 213                                                                                 get_mode_all_one(m),
 214                                                                                 get_Const_tarval(right)));
 215                         new_bits_not_set = tarval_or(bits_not_set, new_bits_not_set);
 216
 217                 }
 218                 break;
 219         }
 220
 221         case iro_Shr: {
 222                 vrp_attr *vrp_left, *vrp_right;
 223                 ir_node *right = get_Shr_right(node);
 224
 225                 vrp_left = phase_get_or_set_irn_data(phase, get_Shr_left(node));
 226                 vrp_right = phase_get_or_set_irn_data(phase, get_Shr_right(node));
 227
 228                 /* We can only compute this if the right value is a constant*/
 229                 if (is_Const(right)) {
 230                         tarval *bits_set, *bits_not_set;
 231                         ir_mode *m = get_tarval_mode(vrp->bits_not_set);
 232                         bits_set = tarval_shr(vrp_left->bits_set, get_Const_tarval(right));
 233                         bits_not_set = tarval_shr(vrp_left->bits_not_set, get_Const_tarval(right));
 234
 235                         new_bits_set = tarval_or(bits_set, vrp->bits_set);
 236                         new_bits_not_set = tarval_or(bits_not_set, vrp->bits_not_set);
 237
 238                         bits_not_set = tarval_not( tarval_shr(
 239                                                                                 get_mode_all_one(m),
 240                                                                                 get_Const_tarval(right)));
 241                         new_bits_not_set = tarval_or(bits_not_set, new_bits_not_set);
 242                 }
 243                 break;
 244         }
 245
 246         case iro_Shrs: {
 247                 vrp_attr *vrp_left, *vrp_right;
 248                 ir_node *right = get_Shrs_right(node);
 249
 250                 vrp_left = phase_get_or_set_irn_data(phase, get_Shrs_left(node));
 251                 vrp_right = phase_get_or_set_irn_data(phase, get_Shrs_right(node));
 252
 253                 /* We can only compute this if the right value is a constant*/
 254                 if (is_Const(right)) {
 255                         tarval *bits_set, *bits_not_set;
 256                         ir_mode *m = get_tarval_mode(vrp->bits_not_set);
 257                         bits_set = tarval_shrs(vrp_left->bits_set, get_Const_tarval(right));
 258                         bits_not_set = tarval_shrs(vrp_left->bits_not_set, get_Const_tarval(right));
 259
 260                         new_bits_set = tarval_or(bits_set, vrp->bits_set);
 261                         new_bits_not_set = tarval_or(bits_not_set, vrp->bits_not_set);
 262
 263                         bits_not_set = tarval_not( tarval_shrs(
 264                                                                                 get_mode_all_one(m),
 265                                                                                 get_Const_tarval(right)));
 266                         new_bits_not_set = tarval_or(bits_not_set, new_bits_not_set);
 267                 }
 268                 break;
 269         }
 270
 271         case iro_Eor: {
 272                 vrp_attr *vrp_left, *vrp_right;
 273
 274                 vrp_left = phase_get_or_set_irn_data(phase, get_Eor_left(node));
 275                 vrp_right = phase_get_or_set_irn_data(phase, get_Eor_right(node));
 276
 277                 tarval *bits_set, *bits_not_set;
 278                 bits_not_set = tarval_or(
 279                                                         tarval_and(vrp_left->bits_set, vrp_right->bits_set),
 280                                                         tarval_and(vrp_left->bits_not_set,
 281                                                                 vrp_right->bits_not_set));
 282
 283                 bits_set = tarval_or(
 284                                                 tarval_and(vrp_left->bits_set, vrp_right->bits_not_set),
 285                                                 tarval_and(vrp_left->bits_not_set, vrp_right->bits_set));
 286
 287                 new_bits_set = tarval_or(bits_set, vrp->bits_set);
 288                 new_bits_not_set = tarval_or(bits_not_set, vrp->bits_not_set);
 289                 break;
 290         }
 291
 292         case iro_Id: {
 293                 vrp_attr *vrp_pred = phase_get_or_set_irn_data(phase, get_Id_pred(node));
 294                 new_bits_set = vrp_pred->bits_set;
 295                 new_bits_not_set = vrp_pred->bits_not_set;
 296                 new_range_top = vrp_pred->range_top;
 297                 new_range_bottom = vrp_pred->range_bottom;
 298                 new_range_type = vrp_pred->range_type;
 299                 break;
 300         }
 301
 302         case iro_Not: {
 303                 vrp_attr *vrp_pred = phase_get_or_set_irn_data(phase, get_Not_op(node));
 304                 new_bits_set = tarval_or(vrp_pred->bits_not_set, vrp->bits_set);
 305                 new_bits_not_set = tarval_or(vrp_pred->bits_set, vrp->bits_not_set);
 306                 break;
 307         }
 308
 309         case iro_Conv: {
 310                 ir_node *pred = get_Conv_op(node);
 311                 ir_mode *old_mode = get_irn_mode(pred);
 312                 vrp_attr *vrp_pred = phase_get_or_set_irn_data(phase, pred);
 313
 314                 ir_mode *new_mode;
 315                 tarval *bits_not_set;
 316
 317                 if (!mode_is_int(old_mode))
 318                         return 0;
 319
 320                 new_mode = get_irn_mode(node);
 321
 322                 /* The second and is needed if target type is smaller*/
 323                 bits_not_set = tarval_not(
 324                                                         tarval_convert_to(get_mode_all_one(old_mode),
 325                                                                 new_mode
 326                                                                 ));
 327                 bits_not_set = tarval_or(bits_not_set, tarval_convert_to(vrp_pred->bits_not_set, new_mode));
 328                 new_bits_not_set = tarval_or(bits_not_set, vrp->bits_not_set);
 329                 new_bits_set = tarval_and(
 330                                 tarval_not(bits_not_set), tarval_convert_to(vrp_pred->bits_set, new_mode));
 331
 332                 if (tarval_cmp(vrp_pred->range_top, get_mode_max(new_mode)) == pn_Cmp_Le) {
 333                         vrp->range_top = vrp_pred->range_top;
 334                 }
 335
 336                 if (tarval_cmp(vrp_pred->range_bottom, get_mode_min(new_mode)) == pn_Cmp_Ge) {
 337                         vrp->range_bottom = vrp_pred->range_bottom;
 338                 }
 339                 break;
 340         }
 341
 342         case iro_Confirm: {
 343                 pn_Cmp cmp = get_Confirm_cmp(node);
 344                 ir_node *bound = get_Confirm_bound(node);
 345
 346                 /** @todo: Handle non-Const bounds */
 347
 348                 if (cmp == pn_Cmp_Lg) {
 349                         /** @todo: Is there some way to preserve the information? */
 350                         new_range_type = VRP_ANTIRANGE;
 351                         if (is_Const(bound)) {
 352                                 new_range_top = get_Const_tarval(bound);
 353                                 new_range_bottom = get_Const_tarval(bound);
 354                         }
 355                 } else if (cmp == pn_Cmp_Le) {
 356                         if (vrp->range_type == VRP_UNDEFINED) {
 357                                 new_range_type = VRP_RANGE;
 358                                 if (is_Const(bound)) {
 359                                         new_range_top = get_Const_tarval(bound);
 360                                 }
 361                                 new_range_bottom = get_tarval_min(get_irn_mode(node));
 362                         } else if (vrp->range_type == VRP_RANGE) {
 363                                 if (is_Const(bound)) {
 364                                         if (tarval_cmp(vrp->range_top,
 365                                                                 get_Const_tarval(bound)) == pn_Cmp_Le) {
 366                                                 new_range_top = get_Const_tarval(bound);
 367                                         }
 368                                         new_range_bottom = get_tarval_min(get_irn_mode(node));
 369
 370                                 } else if (vrp->range_type == VRP_ANTIRANGE) {
 371                                         /** @todo: How do we manage not to get a never ending loop? */
 372                                 }
 373                         }
 374                 }
 375                 break;
 376         }
 377
 378         case iro_Phi: {
 379                 /* combine all ranges*/
 380
 381                 ir_node *pred = get_Phi_pred(node,0);
 382                 vrp_attr *vrp_pred = phase_get_or_set_irn_data(phase, pred);
 383                 new_range_top = vrp_pred->range_top;
 384                 new_range_bottom = vrp_pred->range_bottom;
 385                 new_range_type = vrp_pred->range_type;
 386                 new_bits_set = vrp_pred->bits_set;
 387                 new_bits_not_set = vrp_pred->bits_not_set;
 388
 389                 int num = get_Phi_n_preds(node);
 390                 pn_Cmp cmp;
 391                 int i;
 392
 393                 assert(num > 0);
 394
 395
 396                 for (i = 1; i < num; i++) {
 397                         pred = get_Phi_pred(node, i);
 398                         vrp_pred = phase_get_or_set_irn_data(phase, pred);
 399                         if (new_range_type == VRP_RANGE && vrp_pred->range_type ==
 400                                         VRP_RANGE) {
 401                                 cmp = tarval_cmp(new_range_top, vrp_pred->range_top);
 402                                 if (cmp == pn_Cmp_Lt) {
 403                                         new_range_top = vrp_pred->range_top;
 404                                 }
 405                                 cmp = tarval_cmp(new_range_bottom, vrp_pred->range_bottom);
 406                                 if (cmp == pn_Cmp_Gt) {
 407                                         new_range_bottom = vrp_pred->range_bottom;
 408                                 }
 409                         } else {
 410                                 new_range_type = VRP_VARYING;
 411                                 break;
 412                         }
 413                 }
 414
 415                 break;
 416         }
 417         default:
 418                 /* unhandled, therefore never updated */
 419                 break;
 420         }
 421
 422
 423
 424         /* TODO: Check, if there can be information derived from any of these:
 425         is_Abs(node) is_Alloc(node) is_Anchor(node) is_Borrow(node) is_Bound(node)
 426         is_Break(node) is_Builtin(node) is_Call(node) is_CallBegin(node)
 427         is_Carry(node) is_Cast(node) is_Cmp(node) is_Cond(node)
 428         is_CopyB(node) is_Div(node) is_DivMod(node) is_Dummy(node)
 429         is_End(node) is_EndExcept(node) is_EndReg(node) is_Filter(node) is_Free(node)
 430         is_IJmp(node) is_InstOf(node) is_Jmp(node) is_Load(node) is_Minus(node)
 431         is_Mod(node) is_Mul(node) is_Mulh(node) is_Mux(node) is_NoMem(node)
 432         is_Pin(node) is_Proj(node) is_Quot(node)
 433         is_Raise(node) is_Return(node) is_Sel(node) is_Start(node) is_Store(node)
 434         is_SymConst(node) is_Sync(node) is_Tuple(node)
 435         */
 436
 437         /* Merge the newly calculated values with those that might already exist*/
 438         if (new_bits_set != tarval_bad) {
 439                 new_bits_set = tarval_or(new_bits_set, vrp->bits_set);
 440                 if (tarval_cmp(new_bits_set, vrp->bits_set) != pn_Cmp_Eq) {
 441                         something_changed = 1;
 442                         vrp->bits_set = new_bits_set;
 443                 }
 444         }
 445
 446         if (new_bits_not_set != tarval_bad) {
 447                 new_bits_not_set = tarval_or(new_bits_not_set, vrp->bits_not_set);
 448
 449                 if (tarval_cmp(new_bits_not_set, vrp->bits_not_set) != pn_Cmp_Eq) {
 450                         something_changed = 1;
 451                         vrp->bits_not_set = new_bits_not_set;
 452                 }
 453         }
 454
 455         if (vrp->range_type == VRP_UNDEFINED &&
 456                         new_range_type != VRP_UNDEFINED) {
 457                 something_changed = 1;
 458                 vrp->range_type = new_range_type;
 459                 vrp->range_bottom = new_range_bottom;
 460                 vrp->range_top = new_range_top;
 461
 462         } else if (vrp->range_type == VRP_RANGE) {
 463                 if (new_range_type == VRP_RANGE) {
 464                         if (tarval_cmp(vrp->range_bottom, new_range_bottom) == pn_Cmp_Lt) {
 465                                 something_changed = 1;
 466                                 vrp->range_bottom = new_range_bottom;
 467                         }
 468                         if (tarval_cmp(vrp->range_top, new_range_top) == pn_Cmp_Gt) {
 469                                 something_changed = 1;
 470                                 vrp->range_top = new_range_top;
 471                         }
 472                 }
 473
 474                 if (new_range_type == VRP_ANTIRANGE) {
 475                         /* if they are overlapping, cut the range.*/
 476                         /* TODO: Maybe we can preserve more information here*/
 477                         if (tarval_cmp(vrp->range_bottom, new_range_top) == pn_Cmp_Gt &&
 478                                         tarval_cmp(vrp->range_bottom, new_range_bottom) == pn_Cmp_Gt) {
 479                                 something_changed = 1;
 480                                 vrp->range_bottom = new_range_top;
 481
 482                         } else if (tarval_cmp(vrp->range_top, new_range_bottom) == pn_Cmp_Gt &&
 483                                         tarval_cmp(vrp->range_top, new_range_top) == pn_Cmp_Lt) {
 484                                 something_changed = 1;
 485                                 vrp->range_top = new_range_bottom;
 486                         }
 487
 488                         /* We can not handle the case where the anti range is in the*/
 489                         /* range*/
 490
 491                 }
 492         } else if (vrp->range_type == VRP_ANTIRANGE) {
 493                 if (new_range_type == VRP_ANTIRANGE) {
 494                         if (tarval_cmp(vrp->range_bottom, new_range_bottom) == pn_Cmp_Gt) {
 495                                 something_changed = 1;
 496                                 vrp->range_bottom = new_range_bottom;
 497                         }
 498                         if (tarval_cmp(vrp->range_top, new_range_top) == pn_Cmp_Lt) {
 499                                 something_changed = 1;
 500                                 vrp->range_top = new_range_top;
 501                         }
 502                 }
 503
 504                 if (new_range_type == VRP_RANGE) {
 505                         if (tarval_cmp(vrp->range_bottom, new_range_top) == pn_Cmp_Gt) {
 506                                 something_changed = 1;
 507                                 vrp->range_bottom = new_range_top;
 508                         }
 509                         if (tarval_cmp(vrp->range_top, new_range_bottom) == pn_Cmp_Lt) {
 510                                 something_changed = 1;
 511                                 vrp->range_top = new_range_bottom;
 512                         }
 513                 }
 514         }
 515
 516         assert(tarval_is_null(
 517                                 tarval_and(vrp->bits_set, vrp->bits_not_set)));
 518         return something_changed;
 519 }
 520
 521 static void vrp_first_pass(ir_node *n, void *e)
 522 {
 523         ir_node *succ;
 524         int i;
 525         struct vrp_env_t *env = e;
 526
 527         if (is_Block(n))
 528                 return;
 529
 530         set_irn_link(n, VISITED);
 531
 532         vrp_update_node(n);
 533
 534         for (i = get_irn_n_outs(n) - 1; i >=0; --i) {
 535                 succ =  get_irn_out(n, i);
 536                 if (get_irn_link(succ) == VISITED) {
 537                         /* we found a loop*/
 538                         waitq_put(env->workqueue, n);
 539                 }
 540         }
 541 }
 542
 543 static void *vrp_init_node(ir_phase *phase, const ir_node *n, void *old)
 544 {
 545         ir_printf("initialized node nr: %d\n", get_irn_node_nr(n));
 546         ir_mode *mode;
 547         if (old) {
 548                 assert(1==0 && "init called for node already initialized");
 549         }
 550         vrp_attr *vrp = phase_alloc(phase, sizeof(vrp_attr));
 551
 552         memset(vrp, 0, sizeof(vrp_attr));
 553         /* Initialize the vrp information to default */
 554
 555         mode = get_irn_mode(n);
 556
 557         vrp->range_type = VRP_UNDEFINED;
 558
 559         /* TODO: We might be able to optimize space usage if we do not allocate
 560          * vrp space for non-int nodes. (currently caught by vrp_update_node)
 561          */
 562         if (mode_is_int(mode)) {
 563                 // We are assuming that 0 is always represented as 0x0000
 564                 vrp->valid = 1;
 565                 vrp->bits_set = new_tarval_from_long(0, mode);
 566                 vrp->bits_not_set = new_tarval_from_long(0, mode);
 567                 vrp->range_bottom = get_tarval_top();
 568                 vrp->range_top = get_tarval_top();
 569         } else {
 570                 vrp->valid = 0;
 571                 vrp->bits_set = get_tarval_bad();
 572                 vrp->bits_not_set = get_tarval_bad();
 573                 vrp->range_bottom = get_tarval_bad();
 574                 vrp->range_top = get_tarval_bad();
 575         }
 576
 577         /* TODO: We might be able to set better vrp info at this time, if this is
 578          * a node which is newly created in an already initalized irg
 579          *
 580          * maybe just call vrp_update_node and if it returns one, iterate over
 581          * successors
 582          */
 583         return vrp;
 584 }
 585
 586 void set_vrp_data(ir_graph *irg)
 587 {
 588
 589         ir_node *succ, *node;
 590         int i;
 591         struct vrp_env_t *env;
 592         ir_phase *phase;
 593
 594         if (!irg) {
 595                 /* no graph, skip */
 596                 return;
 597         }
 598
 599         assure_irg_outs(irg); /* ensure that out edges are consistent*/
 600         if (!(phase = get_irg_phase(irg, PHASE_VRP))) {
 601                                 /* this is our first run */
 602                 phase = init_irg_phase(irg, PHASE_VRP, 0, vrp_init_node);
 603                 env = phase_alloc(phase, sizeof(struct vrp_env_t));
 604                 phase->priv = env;
 605         } else {
 606                 env = phase->priv;
 607         }
 608
 609         env->workqueue = new_waitq();
 610
 611
 612         irg_walk_graph(irg, NULL, vrp_first_pass, env);
 613
 614         /* while there are entries in the worklist, continue*/
 615         while (!waitq_empty(env->workqueue)) {
 616                 node = waitq_get(env->workqueue);
 617
 618                 if (vrp_update_node(node)) {
 619                         /* if something changed, add successors to worklist*/
 620                         for (i = get_irn_n_outs(node) - 1; i >=0; --i) {
 621                                 succ =  get_irn_out(node, i);
 622                                 waitq_put(env->workqueue, node);
 623                         }
 624                 }
 625         }
 626         del_waitq(env->workqueue);
 627 }
 628
 629
 630 ir_graph_pass_t *set_vrp_pass(const char *name)
 631 {
 632         return def_graph_pass(name ? name : "set_vrp", set_vrp_data);
 633 }
 634
 635 pn_Cmp vrp_cmp(const ir_node *left, const ir_node *right)
 636 {
 637         vrp_attr *vrp_left, *vrp_right;
 638
 639         vrp_left = vrp_get_info(left);
 640         vrp_right = vrp_get_info(right);
 641
 642         if (!vrp_left || !vrp_right) {
 643                 return pn_Cmp_False;
 644         }
 645
 646         if (vrp_left->range_type == VRP_RANGE && vrp_right->range_type == VRP_RANGE) {
 647                 if (tarval_cmp(vrp_left->range_top, vrp_right->range_bottom) == pn_Cmp_Lt) {
 648                         return pn_Cmp_Lt;
 649                 }
 650                 if (tarval_cmp(vrp_left->range_bottom, vrp_right->range_top) == pn_Cmp_Gt) {
 651                         return pn_Cmp_Gt;
 652                 }
 653         }
 654
 655         if (!tarval_is_null(tarval_and(vrp_left->bits_set, vrp_right->bits_not_set)) ||
 656                         !tarval_is_null(tarval_and(vrp_left->bits_not_set, vrp_right->bits_set))) {
 657                 return pn_Cmp_Lg;
 658         }
 659         /* TODO: We can get way more information here*/
 660
 661         return pn_Cmp_False;
 662 }
 663
 664 vrp_attr *vrp_get_info(const ir_node *n) {
 665         ir_graph *irg = get_irn_irg(n);
 666         ir_phase *phase = get_irg_phase(irg, PHASE_VRP);
 667
 668
 669         if (!phase) {
 670                 /* phase has not yet been initialized */
 671                 return NULL;
 672         }
 673
 674         return phase_get_irn_data(phase, n);
 675 }