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 "irnodemap.h"
  41 #include "irhooks.h"
  42 #include "bitset.h"
  43 #include "debug.h"
  44
  45 DEBUG_ONLY(static firm_dbg_module_t *dbg;)
  46
  47 typedef struct vrp_env_t {
  48         waitq       *workqueue;
  49         bitset_t    *visited;
  50         ir_vrp_info *info;
  51 } vrp_env_t;
  52
  53 static vrp_attr *vrp_get_or_set_info(ir_vrp_info *info, const ir_node *node)
  54 {
  55         vrp_attr *attr = ir_nodemap_get(&info->infos, node);
  56         if (attr == NULL) {
  57                 ir_mode *mode = get_irn_mode(node);
  58                 assert(mode_is_int(mode));
  59
  60                 attr = obstack_alloc(&info->obst, sizeof(*attr));
  61                 memset(attr, 0, sizeof(*attr));
  62                 attr->range_type   = VRP_UNDEFINED;
  63                 attr->bits_set     = get_mode_null(mode);
  64                 attr->bits_not_set = get_mode_all_one(mode);
  65                 attr->range_bottom = get_tarval_top();
  66                 attr->range_top    = get_tarval_top();
  67
  68                 ir_nodemap_insert(&info->infos, node, attr);
  69         }
  70         return attr;
  71 }
  72
  73 vrp_attr *vrp_get_info(const ir_node *node)
  74 {
  75         ir_graph *irg = get_irn_irg(node);
  76         if (irg->vrp.infos.data == NULL)
  77                 return NULL;
  78         return (vrp_attr*) ir_nodemap_get(&irg->vrp.infos, node);
  79 }
  80
  81 static int vrp_update_node(ir_vrp_info *info, ir_node *node)
  82 {
  83         ir_tarval *new_bits_set = get_tarval_bad();
  84         ir_tarval *new_bits_not_set = get_tarval_bad();
  85         ir_tarval *new_range_bottom = get_tarval_bad();
  86         ir_tarval *new_range_top = get_tarval_bad();
  87         enum range_types new_range_type = VRP_UNDEFINED;
  88         int something_changed = 0;
  89         vrp_attr *vrp;
  90
  91         if (!mode_is_int(get_irn_mode(node))) {
  92                 return 0; /* we don't optimize for non-int-nodes*/
  93         }
  94
  95         vrp = vrp_get_or_set_info(info, node);
  96
  97         /* TODO: Check if all predecessors have valid VRP information*/
  98
  99         switch (get_irn_opcode(node)) {
 100         case iro_Const: {
 101                 ir_tarval *tv = get_Const_tarval(node);
 102                 new_bits_set = tv;
 103                 new_bits_not_set = tv;
 104                 new_range_bottom = tv;
 105                 new_range_top = tv;
 106                 new_range_type = VRP_RANGE;
 107                 break;
 108         }
 109         case iro_And: {
 110                 const vrp_attr *vrp_left, *vrp_right;
 111                 const ir_node *left, *right;
 112
 113                 left = get_And_left(node);
 114                 right = get_And_right(node);
 115                 vrp_left = vrp_get_or_set_info(info, left);
 116                 vrp_right = vrp_get_or_set_info(info, right);
 117                 new_bits_set = tarval_and(vrp_left->bits_set, vrp_right->bits_set);
 118                 new_bits_not_set = tarval_and(vrp_left->bits_not_set, vrp_right->bits_not_set);
 119
 120                 break;
 121         }
 122
 123         case iro_Add: {
 124                 int overflow_top, overflow_bottom;
 125                 ir_tarval *new_top, *new_bottom;
 126                 const vrp_attr *vrp_left, *vrp_right;
 127                 vrp_left = vrp_get_or_set_info(info, get_Add_left(node));
 128                 vrp_right = vrp_get_or_set_info(info, get_Add_right(node));
 129
 130                 if (vrp_left->range_type == VRP_UNDEFINED || vrp_right->range_type ==
 131                                 VRP_UNDEFINED || vrp_left->range_type == VRP_VARYING ||
 132                                 vrp_right->range_type == VRP_VARYING) {
 133                         return 0;
 134                 }
 135
 136                 new_top = tarval_add(vrp_left->range_top, vrp_right->range_top);
 137                 overflow_top = tarval_carry();
 138                 new_bottom = tarval_add(vrp_left->range_bottom, vrp_right->range_bottom);
 139                 overflow_bottom = tarval_carry();
 140
 141                 if (!overflow_top && !overflow_bottom && vrp_left->range_type == VRP_RANGE
 142                                 &&vrp_right->range_type == VRP_RANGE) {
 143                         new_range_bottom = new_bottom;
 144                         new_range_top = new_top;
 145                         new_range_type = VRP_RANGE;
 146                 }
 147
 148                 if (overflow_top || overflow_bottom) {
 149                         /* TODO Implement overflow handling*/
 150                         new_range_type = VRP_UNDEFINED;
 151                 }
 152                 break;
 153         }
 154
 155         case iro_Sub: {
 156                 ir_node *left  = get_Sub_left(node);
 157                 ir_node *right = get_Sub_right(node);
 158                 int overflow_top, overflow_bottom;
 159                 ir_tarval *new_top, *new_bottom;
 160                 const vrp_attr *vrp_left, *vrp_right;
 161
 162                 if (!mode_is_int(get_irn_mode(left)))
 163                         return 0;
 164
 165                 vrp_left  = vrp_get_or_set_info(info, left);
 166                 vrp_right = vrp_get_or_set_info(info, right);
 167
 168                 if (vrp_left->range_type == VRP_UNDEFINED || vrp_right->range_type ==
 169                                 VRP_UNDEFINED || vrp_left->range_type == VRP_VARYING ||
 170                                 vrp_right->range_type == VRP_VARYING) {
 171                         return 0;
 172                 }
 173
 174                 new_top = tarval_sub(vrp_left->range_top, vrp_right->range_top, NULL);
 175                 overflow_top = tarval_carry();
 176                 new_bottom = tarval_sub(vrp_left->range_bottom, vrp_right->range_bottom, NULL);
 177                 overflow_bottom = tarval_carry();
 178
 179                 if (!overflow_top && !overflow_bottom && vrp_left->range_type == VRP_RANGE
 180                                 &&vrp_right->range_type == VRP_RANGE) {
 181                         new_range_bottom = new_bottom;
 182                         new_range_top = new_top;
 183                         new_range_type = VRP_RANGE;
 184                 }
 185
 186                 if (overflow_top || overflow_bottom) {
 187                         /* TODO Implement overflow handling*/
 188                 }
 189                 break;
 190         }
 191
 192         case iro_Or: {
 193                 const vrp_attr *vrp_left, *vrp_right;
 194
 195                 vrp_left = vrp_get_or_set_info(info, get_Or_left(node));
 196                 vrp_right = vrp_get_or_set_info(info, get_Or_right(node));
 197
 198                 new_bits_set = tarval_or(vrp_left->bits_set, vrp_right->bits_set);
 199                 new_bits_not_set = tarval_or(vrp_left->bits_not_set, vrp_right->bits_not_set);
 200
 201                 break;
 202         }
 203
 204         case iro_Rotl: {
 205                 const vrp_attr *vrp_left;
 206                 const ir_node *right = get_Rotl_right(node);
 207
 208                 vrp_left = vrp_get_or_set_info(info, get_Rotl_left(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_rotl(vrp_left->bits_set, get_Const_tarval(right));
 213                         new_bits_not_set = tarval_rotl(vrp_left->bits_not_set, get_Const_tarval(right));
 214                 }
 215                 break;
 216         }
 217
 218         case iro_Shl: {
 219                 const vrp_attr *vrp_left;
 220                 const ir_node *right = get_Shl_right(node);
 221                 vrp_left = vrp_get_or_set_info(info, get_Shl_left(node));
 222
 223                 /* We can only compute this if the right value is a constant*/
 224                 if (is_Const(right)) {
 225                         new_bits_set = tarval_shl(vrp_left->bits_set, get_Const_tarval(right));
 226                         new_bits_not_set = tarval_shl(vrp_left->bits_not_set, get_Const_tarval(right));
 227                 }
 228                 break;
 229         }
 230
 231         case iro_Shr: {
 232                 const vrp_attr *vrp_left;
 233                 const ir_node *right = get_Shr_right(node);
 234
 235                 vrp_left = vrp_get_or_set_info(info, get_Shr_left(node));
 236
 237                 /* We can only compute this if the right value is a constant*/
 238                 if (is_Const(right)) {
 239                         new_bits_set = tarval_shr(vrp_left->bits_set, get_Const_tarval(right));
 240                         new_bits_not_set = tarval_shr(vrp_left->bits_not_set, get_Const_tarval(right));
 241                 }
 242                 break;
 243         }
 244
 245         case iro_Shrs: {
 246                 const vrp_attr *vrp_left;
 247                 const ir_node *right = get_Shrs_right(node);
 248
 249                 vrp_left = vrp_get_or_set_info(info, get_Shrs_left(node));
 250
 251                 /* We can only compute this if the right value is a constant*/
 252                 if (is_Const(right)) {
 253                         new_bits_set = tarval_shrs(vrp_left->bits_set, get_Const_tarval(right));
 254                         new_bits_not_set = tarval_shrs(vrp_left->bits_not_set, get_Const_tarval(right));
 255                 }
 256                 break;
 257         }
 258
 259         case iro_Eor: {
 260                 const vrp_attr *vrp_left, *vrp_right;
 261
 262                 vrp_left = vrp_get_or_set_info(info, get_Eor_left(node));
 263                 vrp_right = vrp_get_or_set_info(info, get_Eor_right(node));
 264
 265                 new_bits_set = tarval_or(
 266                                                 tarval_and(vrp_left->bits_set, tarval_not(vrp_right->bits_not_set)),
 267                                                 tarval_and(tarval_not(vrp_left->bits_not_set), vrp_right->bits_set));
 268
 269                 new_bits_not_set = tarval_not(tarval_or(
 270                                 tarval_and(vrp_left->bits_set,vrp_right->bits_set),
 271                                                         tarval_and(tarval_not(vrp_left->bits_not_set),
 272                                                                 tarval_not(vrp_right->bits_not_set))));
 273
 274                 break;
 275         }
 276
 277         case iro_Id: {
 278                 const vrp_attr *vrp_pred = vrp_get_or_set_info(info, get_Id_pred(node));
 279                 new_bits_set = vrp_pred->bits_set;
 280                 new_bits_not_set = vrp_pred->bits_not_set;
 281                 new_range_top = vrp_pred->range_top;
 282                 new_range_bottom = vrp_pred->range_bottom;
 283                 new_range_type = vrp_pred->range_type;
 284                 break;
 285         }
 286
 287         case iro_Not: {
 288                 const vrp_attr *vrp_pred = vrp_get_or_set_info(info, get_Not_op(node));
 289                 new_bits_set = tarval_not(vrp_pred->bits_not_set);
 290                 new_bits_not_set = tarval_not(vrp_pred->bits_set);
 291                 break;
 292         }
 293
 294         case iro_Conv: {
 295                 const ir_node *pred = get_Conv_op(node);
 296                 ir_mode *old_mode = get_irn_mode(pred);
 297                 const vrp_attr *vrp_pred;
 298
 299                 ir_mode *new_mode;
 300
 301                 if (!mode_is_int(old_mode))
 302                         return 0;
 303
 304                 vrp_pred = vrp_get_or_set_info(info, pred);
 305                 new_mode = get_irn_mode(node);
 306
 307                 /* The second and is needed if target type is smaller*/
 308                 new_bits_not_set = tarval_convert_to(get_mode_all_one(old_mode), new_mode);
 309                 new_bits_not_set = tarval_and(new_bits_not_set, tarval_convert_to(vrp_pred->bits_not_set, new_mode));
 310                 new_bits_set = tarval_and(
 311                                 new_bits_not_set, tarval_convert_to(vrp_pred->bits_set, new_mode));
 312
 313                 /* Matze: TODO, BUGGY, tarval_cmp never returns ir_relation_less_equal */
 314                 if (tarval_cmp(vrp_pred->range_top, get_mode_max(new_mode)) == ir_relation_less_equal) {
 315                         vrp->range_top = vrp_pred->range_top;
 316                 }
 317
 318                 /* Matze: TODO, BUGGY, tarval_cmp never returns ir_relation_greater_equal */
 319                 if (tarval_cmp(vrp_pred->range_bottom, get_mode_min(new_mode)) == ir_relation_greater_equal) {
 320                         vrp->range_bottom = vrp_pred->range_bottom;
 321                 }
 322                 break;
 323         }
 324
 325         case iro_Confirm: {
 326                 const ir_relation relation = get_Confirm_relation(node);
 327                 const ir_node    *bound    = get_Confirm_bound(node);
 328
 329
 330                 if (relation == ir_relation_less_greater) {
 331                         /** @todo: Handle non-Const bounds */
 332                         if (is_Const(bound)) {
 333                                 new_range_type = VRP_ANTIRANGE;
 334                                 new_range_top = get_Const_tarval(bound);
 335                                 new_range_bottom = get_Const_tarval(bound);
 336                         }
 337                 } else if (relation == ir_relation_less_equal) {
 338                         if (is_Const(bound)) {
 339                                 new_range_type = VRP_RANGE;
 340                                 new_range_top = get_Const_tarval(bound);
 341                                 new_range_bottom = get_tarval_min(get_irn_mode(node));
 342                         }
 343                 }
 344                 break;
 345         }
 346
 347         case iro_Phi: {
 348                 /* combine all ranges*/
 349
 350                 int num = get_Phi_n_preds(node);
 351                 ir_relation relation;
 352                 int i;
 353
 354                 const ir_node *pred = get_Phi_pred(node,0);
 355                 const vrp_attr *vrp_pred = vrp_get_or_set_info(info, pred);
 356                 new_range_top = vrp_pred->range_top;
 357                 new_range_bottom = vrp_pred->range_bottom;
 358                 new_range_type = vrp_pred->range_type;
 359                 new_bits_set = vrp_pred->bits_set;
 360                 new_bits_not_set = vrp_pred->bits_not_set;
 361
 362                 assert(num > 0);
 363
 364                 for (i = 1; i < num; i++) {
 365                         pred = get_Phi_pred(node, i);
 366                         vrp_pred = vrp_get_or_set_info(info, pred);
 367                         if (new_range_type == VRP_RANGE && vrp_pred->range_type ==
 368                                         VRP_RANGE) {
 369                                 relation = tarval_cmp(new_range_top, vrp_pred->range_top);
 370                                 if (relation == ir_relation_less) {
 371                                         new_range_top = vrp_pred->range_top;
 372                                 }
 373                                 relation = tarval_cmp(new_range_bottom, vrp_pred->range_bottom);
 374                                 if (relation == ir_relation_greater) {
 375                                         new_range_bottom = vrp_pred->range_bottom;
 376                                 }
 377                         } else {
 378                                 new_range_type = VRP_VARYING;
 379                         }
 380                         new_bits_set = tarval_and(new_bits_set, vrp_pred->bits_set);
 381                         new_bits_not_set = tarval_or(new_bits_not_set,
 382                                         vrp_pred->bits_not_set);
 383                 }
 384
 385                 break;
 386         }
 387         default:
 388                 /* unhandled, therefore never updated */
 389                 break;
 390         }
 391
 392
 393
 394         /* TODO: Check, if there can be information derived from any of these:
 395         is_Abs(node) is_Alloc(node) is_Anchor(node) is_Borrow(node) is_Bound(node)
 396         is_Break(node) is_Builtin(node) is_Call(node)
 397         is_Carry(node) is_Cast(node) is_Cmp(node) is_Cond(node)
 398         is_CopyB(node) is_Div(node) is_Dummy(node)
 399         is_End(node) is_Free(node)
 400         is_IJmp(node) is_InstOf(node) is_Jmp(node) is_Load(node) is_Minus(node)
 401         is_Mod(node) is_Mul(node) is_Mulh(node) is_Mux(node) is_NoMem(node)
 402         is_Pin(node) is_Proj(node)
 403         is_Raise(node) is_Return(node) is_Sel(node) is_Start(node) is_Store(node)
 404         is_SymConst(node) is_Sync(node) is_Tuple(node)
 405         */
 406
 407         /* @todo: At this place, we check if the mode of the variable changed. A
 408          * better place for this might be in the convopt.c file
 409          */
 410
 411         if (new_bits_set != tarval_bad && get_tarval_mode(new_bits_set) != get_tarval_mode(vrp->bits_set)) {
 412                 vrp->bits_set = tarval_convert_to(vrp->bits_set, get_irn_mode(node));
 413         }
 414         if (new_bits_not_set != tarval_bad && get_tarval_mode(new_bits_not_set) != get_tarval_mode(vrp->bits_not_set)) {
 415                 vrp->bits_not_set = tarval_convert_to(vrp->bits_not_set, get_irn_mode(node));
 416         }
 417
 418         if (vrp->range_type != VRP_UNDEFINED && new_range_type != VRP_UNDEFINED && get_tarval_mode(new_range_top) != get_tarval_mode(vrp->range_top)) {
 419                 /* @todo: We might be able to preserve this range information if it
 420                  * fits in */
 421                 vrp->range_type = VRP_VARYING;
 422         }
 423
 424         /* Merge the newly calculated values with those that might already exist*/
 425         if (new_bits_set != tarval_bad) {
 426                 new_bits_set = tarval_or(new_bits_set, vrp->bits_set);
 427                 if (new_bits_set != vrp->bits_set) {
 428                         something_changed = 1;
 429                         vrp->bits_set = new_bits_set;
 430                 }
 431         }
 432         if (new_bits_not_set != tarval_bad) {
 433                 new_bits_not_set = tarval_and(new_bits_not_set, vrp->bits_not_set);
 434
 435                 if (new_bits_not_set != vrp->bits_not_set) {
 436                         something_changed = 1;
 437                         vrp->bits_not_set = new_bits_not_set;
 438                 }
 439         }
 440
 441         if (vrp->range_type == VRP_UNDEFINED &&
 442                         new_range_type != VRP_UNDEFINED) {
 443                 something_changed = 1;
 444                 vrp->range_type = new_range_type;
 445                 vrp->range_bottom = new_range_bottom;
 446                 vrp->range_top = new_range_top;
 447
 448         } else if (vrp->range_type == VRP_RANGE) {
 449                 if (new_range_type == VRP_RANGE) {
 450                         if (tarval_cmp(vrp->range_bottom, new_range_bottom) == ir_relation_less) {
 451                                 something_changed = 1;
 452                                 vrp->range_bottom = new_range_bottom;
 453                         }
 454                         if (tarval_cmp(vrp->range_top, new_range_top) == ir_relation_greater) {
 455                                 something_changed = 1;
 456                                 vrp->range_top = new_range_top;
 457                         }
 458                 }
 459
 460                 if (new_range_type == VRP_ANTIRANGE) {
 461                         /* if they are overlapping, cut the range.*/
 462                         /* TODO: Maybe we can preserve more information here*/
 463                         if (tarval_cmp(vrp->range_bottom, new_range_top) == ir_relation_greater &&
 464                                         tarval_cmp(vrp->range_bottom, new_range_bottom) == ir_relation_greater) {
 465                                 something_changed = 1;
 466                                 vrp->range_bottom = new_range_top;
 467
 468                         } else if (tarval_cmp(vrp->range_top, new_range_bottom) == ir_relation_greater &&
 469                                         tarval_cmp(vrp->range_top, new_range_top) == ir_relation_less) {
 470                                 something_changed = 1;
 471                                 vrp->range_top = new_range_bottom;
 472                         }
 473
 474                         /* We can not handle the case where the anti range is in the*/
 475                         /* range*/
 476
 477                 }
 478         } else if (vrp->range_type == VRP_ANTIRANGE) {
 479                 if (new_range_type == VRP_ANTIRANGE) {
 480                         if (tarval_cmp(vrp->range_bottom, new_range_bottom) == ir_relation_greater) {
 481                                 something_changed = 1;
 482                                 vrp->range_bottom = new_range_bottom;
 483                         }
 484                         if (tarval_cmp(vrp->range_top, new_range_top) == ir_relation_less) {
 485                                 something_changed = 1;
 486                                 vrp->range_top = new_range_top;
 487                         }
 488                 }
 489
 490                 if (new_range_type == VRP_RANGE) {
 491                         if (tarval_cmp(vrp->range_bottom, new_range_top) == ir_relation_greater) {
 492                                 something_changed = 1;
 493                                 vrp->range_bottom = new_range_top;
 494                         }
 495                         if (tarval_cmp(vrp->range_top, new_range_bottom) == ir_relation_less) {
 496                                 something_changed = 1;
 497                                 vrp->range_top = new_range_bottom;
 498                         }
 499                 }
 500         }
 501
 502         assert(tarval_is_null(
 503                                 tarval_and(vrp->bits_set, tarval_not(vrp->bits_not_set))));
 504         return something_changed;
 505 }
 506
 507 static void vrp_first_pass(ir_node *n, void *e)
 508 {
 509         int i;
 510         vrp_env_t *env = (vrp_env_t*) e;
 511
 512         if (is_Block(n))
 513                 return;
 514
 515         bitset_set(env->visited, get_irn_idx(n));
 516
 517         vrp_update_node(env->info, n);
 518
 519         assure_irg_outs(get_current_ir_graph());
 520         for (i = get_irn_n_outs(n) - 1; i >=0; --i) {
 521                 ir_node *succ = get_irn_out(n, i);
 522                 if (bitset_is_set(env->visited, get_irn_idx(succ))) {
 523                         /* we found a loop*/
 524                         waitq_put(env->workqueue, succ);
 525                 }
 526         }
 527 }
 528
 529 static void dump_vrp_info(void *ctx, FILE *F, const ir_node *node)
 530 {
 531         vrp_attr *vrp;
 532
 533         (void) ctx;
 534         if (!mode_is_int(get_irn_mode(node)))
 535                 return;
 536
 537         vrp = vrp_get_info(node);
 538         if (vrp == NULL)
 539                 return;
 540
 541         fprintf(F, "vrp range type: %d\n", (int) vrp->range_type);
 542         if (vrp->range_type == VRP_RANGE || vrp->range_type == VRP_ANTIRANGE) {
 543                 ir_fprintf(F, "vrp range bottom: %T\n",vrp->range_bottom);
 544                 ir_fprintf(F, "vrp range top: %T\n", vrp->range_top);
 545         }
 546         ir_fprintf(F, "vrp bits set: %T\n", vrp->bits_set);
 547         ir_fprintf(F, "vrp bits not set: %T\n", vrp->bits_not_set);
 548 }
 549
 550 static hook_entry_t dump_hook;
 551
 552 void set_vrp_data(ir_graph *irg)
 553 {
 554         ir_node *succ, *node;
 555         int i;
 556         vrp_env_t *env;
 557         ir_vrp_info *info;
 558
 559         if (irg->vrp.infos.data != NULL)
 560                 free_vrp_data(irg);
 561
 562         FIRM_DBG_REGISTER(dbg, "ir.ana.vrp");
 563
 564         assure_irg_outs(irg); /* ensure that out edges are consistent*/
 565         ir_nodemap_init(&irg->vrp.infos, irg);
 566         obstack_init(&irg->vrp.obst);
 567         info = &irg->vrp;
 568
 569         if (dump_hook.hook._hook_node_info == NULL) {
 570                 dump_hook.hook._hook_node_info = dump_vrp_info;
 571                 register_hook(hook_node_info, &dump_hook);
 572         }
 573
 574         env = obstack_alloc(&irg->vrp.obst, sizeof(*env));
 575         env->workqueue = new_waitq();
 576         env->info      = info;
 577
 578         env->visited = bitset_malloc(get_irg_last_idx(irg));
 579         irg_walk_graph(irg, NULL, vrp_first_pass, env);
 580         bitset_free(env->visited);
 581
 582         /* while there are entries in the worklist, continue*/
 583         while (!waitq_empty(env->workqueue)) {
 584                 node = (ir_node*) waitq_get(env->workqueue);
 585
 586                 if (vrp_update_node(info, node)) {
 587                         /* if something changed, add successors to worklist*/
 588                         for (i = get_irn_n_outs(node) - 1; i >= 0; --i) {
 589                                 succ =  get_irn_out(node, i);
 590                                 waitq_put(env->workqueue, succ);
 591                         }
 592                 }
 593         }
 594         del_waitq(env->workqueue);
 595 }
 596
 597 void free_vrp_data(ir_graph *irg)
 598 {
 599         if (irg->vrp.infos.data == NULL)
 600                 return;
 601         obstack_free(&irg->vrp.obst, NULL);
 602         ir_nodemap_destroy(&irg->vrp.infos);
 603 }
 604
 605 ir_graph_pass_t *set_vrp_pass(const char *name)
 606 {
 607         return def_graph_pass(name ? name : "set_vrp", set_vrp_data);
 608 }
 609
 610 ir_relation vrp_cmp(const ir_node *left, const ir_node *right)
 611 {
 612         vrp_attr *vrp_left, *vrp_right;
 613
 614         if (!mode_is_int(get_irn_mode(left)))
 615                 return ir_relation_true;
 616
 617         vrp_left = vrp_get_info(left);
 618         vrp_right = vrp_get_info(right);
 619
 620         if (!vrp_left || !vrp_right)
 621                 return ir_relation_true;
 622
 623         if (vrp_left->range_type == VRP_RANGE && vrp_right->range_type == VRP_RANGE) {
 624                 if (tarval_cmp(vrp_left->range_top, vrp_right->range_bottom) == ir_relation_less) {
 625                         return ir_relation_less;
 626                 }
 627                 if (tarval_cmp(vrp_left->range_bottom, vrp_right->range_top) == ir_relation_greater) {
 628                         return ir_relation_greater;
 629                 }
 630         }
 631
 632         if (!tarval_is_null(tarval_and(vrp_left->bits_set, tarval_not(vrp_right->bits_not_set))) ||
 633                         !tarval_is_null(tarval_and(tarval_not(vrp_left->bits_not_set), vrp_right->bits_set))) {
 634                 return ir_relation_less_greater;
 635         }
 636
 637         /* TODO: We can get way more information here*/
 638         return ir_relation_true;
 639 }