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

   1 /*
   2  * This file is part of libFirm.
   3  * Copyright (C) 2012 University of Karlsruhe.
   4  */
   5
   6 /**
   7  * @file
   8  * @brief   analyze graph to provide value range information
   9  * @author  Jonas Fietz
  10  */
  11 #include "config.h"
  12
  13 #include "irtypes.h"
  14 #include "vrp.h"
  15 #include "iroptimize.h"
  16 #include "irouts.h"
  17 #include "irgraph_t.h"
  18 #include "irgopt.h"
  19 #include "irpass.h"
  20 #include "irgwalk.h"
  21 #include "iredges.h"
  22 #include "tv.h"
  23 #include "irop.h"
  24 #include "pdeq.h"
  25 #include "irnodemap.h"
  26 #include "irhooks.h"
  27 #include "bitset.h"
  28 #include "debug.h"
  29
  30 DEBUG_ONLY(static firm_dbg_module_t *dbg;)
  31
  32 typedef struct vrp_env_t {
  33         waitq       *workqueue;
  34         bitset_t    *visited;
  35         ir_vrp_info *info;
  36 } vrp_env_t;
  37
  38 static vrp_attr *vrp_get_or_set_info(ir_vrp_info *info, const ir_node *node)
  39 {
  40         vrp_attr *attr = ir_nodemap_get(vrp_attr, &info->infos, node);
  41         if (attr == NULL) {
  42                 ir_mode *mode = get_irn_mode(node);
  43                 assert(mode_is_int(mode));
  44
  45                 attr = OALLOCZ(&info->obst, vrp_attr);
  46                 attr->range_type   = VRP_UNDEFINED;
  47                 attr->bits_set     = get_mode_null(mode);
  48                 attr->bits_not_set = get_mode_all_one(mode);
  49                 attr->range_bottom = get_tarval_top();
  50                 attr->range_top    = get_tarval_top();
  51
  52                 ir_nodemap_insert(&info->infos, node, attr);
  53         }
  54         return attr;
  55 }
  56
  57 vrp_attr *vrp_get_info(const ir_node *node)
  58 {
  59         ir_graph *irg = get_irn_irg(node);
  60         if (irg->vrp.infos.data == NULL)
  61                 return NULL;
  62         return ir_nodemap_get(vrp_attr, &irg->vrp.infos, node);
  63 }
  64
  65 static int vrp_update_node(ir_vrp_info *info, ir_node *node)
  66 {
  67         ir_tarval *new_bits_set = get_tarval_bad();
  68         ir_tarval *new_bits_not_set = get_tarval_bad();
  69         ir_tarval *new_range_bottom = get_tarval_bad();
  70         ir_tarval *new_range_top = get_tarval_bad();
  71         enum range_types new_range_type = VRP_UNDEFINED;
  72         int something_changed = 0;
  73         vrp_attr *vrp;
  74
  75         if (!mode_is_int(get_irn_mode(node))) {
  76                 return 0; /* we don't optimize for non-int-nodes*/
  77         }
  78
  79         vrp = vrp_get_or_set_info(info, node);
  80
  81         /* TODO: Check if all predecessors have valid VRP information*/
  82
  83         switch (get_irn_opcode(node)) {
  84         case iro_Const: {
  85                 ir_tarval *tv = get_Const_tarval(node);
  86                 new_bits_set = tv;
  87                 new_bits_not_set = tv;
  88                 new_range_bottom = tv;
  89                 new_range_top = tv;
  90                 new_range_type = VRP_RANGE;
  91                 break;
  92         }
  93         case iro_And: {
  94                 const vrp_attr *vrp_left, *vrp_right;
  95                 const ir_node *left, *right;
  96
  97                 left = get_And_left(node);
  98                 right = get_And_right(node);
  99                 vrp_left = vrp_get_or_set_info(info, left);
 100                 vrp_right = vrp_get_or_set_info(info, right);
 101                 new_bits_set = tarval_and(vrp_left->bits_set, vrp_right->bits_set);
 102                 new_bits_not_set = tarval_and(vrp_left->bits_not_set, vrp_right->bits_not_set);
 103
 104                 break;
 105         }
 106
 107         case iro_Add: {
 108                 const vrp_attr *vrp_left  = vrp_get_or_set_info(info, get_Add_left(node));
 109                 const vrp_attr *vrp_right = vrp_get_or_set_info(info, get_Add_right(node));
 110
 111                 if (vrp_left->range_type == VRP_UNDEFINED
 112                  || vrp_right->range_type == VRP_UNDEFINED
 113                  || vrp_left->range_type == VRP_VARYING
 114                  || vrp_right->range_type == VRP_VARYING) {
 115                         return 0;
 116                 }
 117
 118                 if (vrp_left->range_type == VRP_RANGE
 119                  && vrp_right->range_type == VRP_RANGE) {
 120                         tarval_int_overflow_mode_t rem = tarval_get_integer_overflow_mode();
 121                         tarval_set_integer_overflow_mode(TV_OVERFLOW_BAD);
 122                         ir_tarval *new_top
 123                                 = tarval_add(vrp_left->range_top, vrp_right->range_top);
 124                         ir_tarval *new_bottom
 125                                 = tarval_add(vrp_left->range_bottom, vrp_right->range_bottom);
 126                         tarval_set_integer_overflow_mode(rem);
 127
 128                         if (new_top != tarval_bad && new_bottom != tarval_bad) {
 129                                 new_range_bottom = new_bottom;
 130                                 new_range_top    = new_top;
 131                                 new_range_type   = VRP_RANGE;
 132                         } else {
 133                                 /* TODO Implement overflow handling*/
 134                                 new_range_type = VRP_UNDEFINED;
 135                         }
 136                 }
 137                 break;
 138         }
 139
 140         case iro_Sub: {
 141                 ir_node *left  = get_Sub_left(node);
 142                 ir_node *right = get_Sub_right(node);
 143
 144                 if (!mode_is_int(get_irn_mode(left)))
 145                         return 0;
 146
 147                 const vrp_attr *vrp_left  = vrp_get_or_set_info(info, left);
 148                 const vrp_attr *vrp_right = vrp_get_or_set_info(info, right);
 149
 150                 if (vrp_left->range_type == VRP_UNDEFINED
 151                  || vrp_right->range_type == VRP_UNDEFINED
 152                  || vrp_left->range_type == VRP_VARYING
 153                  || vrp_right->range_type == VRP_VARYING) {
 154                         return 0;
 155                 }
 156
 157                 if (vrp_left->range_type == VRP_RANGE
 158                  && vrp_right->range_type == VRP_RANGE) {
 159                         tarval_int_overflow_mode_t rem = tarval_get_integer_overflow_mode();
 160                         tarval_set_integer_overflow_mode(TV_OVERFLOW_BAD);
 161                         ir_tarval *new_top = tarval_sub(vrp_left->range_top, vrp_right->range_top, NULL);
 162                         ir_tarval *new_bottom = tarval_sub(vrp_left->range_bottom, vrp_right->range_bottom, NULL);
 163                         tarval_set_integer_overflow_mode(rem);
 164
 165                         if (new_top != tarval_bad && new_bottom != tarval_bad) {
 166                                 new_range_bottom = new_bottom;
 167                                 new_range_top = new_top;
 168                                 new_range_type = VRP_RANGE;
 169                         } else {
 170                                 /* TODO Implement overflow handling*/
 171                                 new_range_type = VRP_UNDEFINED;
 172                         }
 173                 }
 174                 break;
 175         }
 176
 177         case iro_Or: {
 178                 const vrp_attr *vrp_left, *vrp_right;
 179
 180                 vrp_left = vrp_get_or_set_info(info, get_Or_left(node));
 181                 vrp_right = vrp_get_or_set_info(info, get_Or_right(node));
 182
 183                 new_bits_set = tarval_or(vrp_left->bits_set, vrp_right->bits_set);
 184                 new_bits_not_set = tarval_or(vrp_left->bits_not_set, vrp_right->bits_not_set);
 185
 186                 break;
 187         }
 188
 189         case iro_Rotl: {
 190                 const vrp_attr *vrp_left;
 191                 const ir_node *right = get_Rotl_right(node);
 192
 193                 vrp_left = vrp_get_or_set_info(info, get_Rotl_left(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_rotl(vrp_left->bits_set, get_Const_tarval(right));
 198                         new_bits_not_set = tarval_rotl(vrp_left->bits_not_set, get_Const_tarval(right));
 199                 }
 200                 break;
 201         }
 202
 203         case iro_Shl: {
 204                 const vrp_attr *vrp_left;
 205                 const ir_node *right = get_Shl_right(node);
 206                 vrp_left = vrp_get_or_set_info(info, get_Shl_left(node));
 207
 208                 /* We can only compute this if the right value is a constant*/
 209                 if (is_Const(right)) {
 210                         new_bits_set = tarval_shl(vrp_left->bits_set, get_Const_tarval(right));
 211                         new_bits_not_set = tarval_shl(vrp_left->bits_not_set, get_Const_tarval(right));
 212                 }
 213                 break;
 214         }
 215
 216         case iro_Shr: {
 217                 const vrp_attr *vrp_left;
 218                 const ir_node *right = get_Shr_right(node);
 219
 220                 vrp_left = vrp_get_or_set_info(info, get_Shr_left(node));
 221
 222                 /* We can only compute this if the right value is a constant*/
 223                 if (is_Const(right)) {
 224                         new_bits_set = tarval_shr(vrp_left->bits_set, get_Const_tarval(right));
 225                         new_bits_not_set = tarval_shr(vrp_left->bits_not_set, get_Const_tarval(right));
 226                 }
 227                 break;
 228         }
 229
 230         case iro_Shrs: {
 231                 const vrp_attr *vrp_left;
 232                 const ir_node *right = get_Shrs_right(node);
 233
 234                 vrp_left = vrp_get_or_set_info(info, get_Shrs_left(node));
 235
 236                 /* We can only compute this if the right value is a constant*/
 237                 if (is_Const(right)) {
 238                         new_bits_set = tarval_shrs(vrp_left->bits_set, get_Const_tarval(right));
 239                         new_bits_not_set = tarval_shrs(vrp_left->bits_not_set, get_Const_tarval(right));
 240                 }
 241                 break;
 242         }
 243
 244         case iro_Eor: {
 245                 const vrp_attr *vrp_left, *vrp_right;
 246
 247                 vrp_left = vrp_get_or_set_info(info, get_Eor_left(node));
 248                 vrp_right = vrp_get_or_set_info(info, get_Eor_right(node));
 249
 250                 new_bits_set = tarval_or(
 251                                                 tarval_and(vrp_left->bits_set, tarval_not(vrp_right->bits_not_set)),
 252                                                 tarval_and(tarval_not(vrp_left->bits_not_set), vrp_right->bits_set));
 253
 254                 new_bits_not_set = tarval_not(tarval_or(
 255                                 tarval_and(vrp_left->bits_set,vrp_right->bits_set),
 256                                                         tarval_and(tarval_not(vrp_left->bits_not_set),
 257                                                                 tarval_not(vrp_right->bits_not_set))));
 258
 259                 break;
 260         }
 261
 262         case iro_Id: {
 263                 const vrp_attr *vrp_pred = vrp_get_or_set_info(info, get_Id_pred(node));
 264                 new_bits_set = vrp_pred->bits_set;
 265                 new_bits_not_set = vrp_pred->bits_not_set;
 266                 new_range_top = vrp_pred->range_top;
 267                 new_range_bottom = vrp_pred->range_bottom;
 268                 new_range_type = vrp_pred->range_type;
 269                 break;
 270         }
 271
 272         case iro_Not: {
 273                 const vrp_attr *vrp_pred = vrp_get_or_set_info(info, get_Not_op(node));
 274                 new_bits_set = tarval_not(vrp_pred->bits_not_set);
 275                 new_bits_not_set = tarval_not(vrp_pred->bits_set);
 276                 break;
 277         }
 278
 279         case iro_Conv: {
 280                 const ir_node *pred = get_Conv_op(node);
 281                 ir_mode *old_mode = get_irn_mode(pred);
 282                 const vrp_attr *vrp_pred;
 283
 284                 ir_mode *new_mode;
 285
 286                 if (!mode_is_int(old_mode))
 287                         return 0;
 288
 289                 vrp_pred = vrp_get_or_set_info(info, pred);
 290                 new_mode = get_irn_mode(node);
 291
 292                 /* The second and is needed if target type is smaller*/
 293                 new_bits_not_set = tarval_convert_to(get_mode_all_one(old_mode), new_mode);
 294                 new_bits_not_set = tarval_and(new_bits_not_set, tarval_convert_to(vrp_pred->bits_not_set, new_mode));
 295                 new_bits_set = tarval_and(
 296                                 new_bits_not_set, tarval_convert_to(vrp_pred->bits_set, new_mode));
 297
 298                 /* Matze: TODO, BUGGY, tarval_cmp never returns ir_relation_less_equal */
 299                 if (tarval_cmp(vrp_pred->range_top, get_mode_max(new_mode)) == ir_relation_less_equal) {
 300                         vrp->range_top = vrp_pred->range_top;
 301                 }
 302
 303                 /* Matze: TODO, BUGGY, tarval_cmp never returns ir_relation_greater_equal */
 304                 if (tarval_cmp(vrp_pred->range_bottom, get_mode_min(new_mode)) == ir_relation_greater_equal) {
 305                         vrp->range_bottom = vrp_pred->range_bottom;
 306                 }
 307                 break;
 308         }
 309
 310         case iro_Confirm: {
 311                 const ir_relation relation = get_Confirm_relation(node);
 312                 const ir_node    *bound    = get_Confirm_bound(node);
 313
 314
 315                 if (relation == ir_relation_less_greater) {
 316                         /** @todo: Handle non-Const bounds */
 317                         if (is_Const(bound)) {
 318                                 new_range_type = VRP_ANTIRANGE;
 319                                 new_range_top = get_Const_tarval(bound);
 320                                 new_range_bottom = get_Const_tarval(bound);
 321                         }
 322                 } else if (relation == ir_relation_less_equal) {
 323                         if (is_Const(bound)) {
 324                                 new_range_type = VRP_RANGE;
 325                                 new_range_top = get_Const_tarval(bound);
 326                                 new_range_bottom = get_tarval_min(get_irn_mode(node));
 327                         }
 328                 }
 329                 break;
 330         }
 331
 332         case iro_Phi: {
 333                 /* combine all ranges*/
 334
 335                 int num = get_Phi_n_preds(node);
 336                 ir_relation relation;
 337                 int i;
 338
 339                 const ir_node *pred = get_Phi_pred(node,0);
 340                 const vrp_attr *vrp_pred = vrp_get_or_set_info(info, pred);
 341                 new_range_top = vrp_pred->range_top;
 342                 new_range_bottom = vrp_pred->range_bottom;
 343                 new_range_type = vrp_pred->range_type;
 344                 new_bits_set = vrp_pred->bits_set;
 345                 new_bits_not_set = vrp_pred->bits_not_set;
 346
 347                 assert(num > 0);
 348
 349                 for (i = 1; i < num; i++) {
 350                         pred = get_Phi_pred(node, i);
 351                         vrp_pred = vrp_get_or_set_info(info, pred);
 352                         if (new_range_type == VRP_RANGE && vrp_pred->range_type ==
 353                                         VRP_RANGE) {
 354                                 relation = tarval_cmp(new_range_top, vrp_pred->range_top);
 355                                 if (relation == ir_relation_less) {
 356                                         new_range_top = vrp_pred->range_top;
 357                                 }
 358                                 relation = tarval_cmp(new_range_bottom, vrp_pred->range_bottom);
 359                                 if (relation == ir_relation_greater) {
 360                                         new_range_bottom = vrp_pred->range_bottom;
 361                                 }
 362                         } else {
 363                                 new_range_type = VRP_VARYING;
 364                         }
 365                         new_bits_set = tarval_and(new_bits_set, vrp_pred->bits_set);
 366                         new_bits_not_set = tarval_or(new_bits_not_set,
 367                                         vrp_pred->bits_not_set);
 368                 }
 369
 370                 break;
 371         }
 372         default:
 373                 /* unhandled, therefore never updated */
 374                 break;
 375         }
 376
 377
 378
 379         /* TODO: Check, if there can be information derived from any of these:
 380         is_Abs(node) is_Alloc(node) is_Anchor(node) is_Borrow(node) is_Bound(node)
 381         is_Break(node) is_Builtin(node) is_Call(node)
 382         is_Carry(node) is_Cmp(node) is_Cond(node)
 383         is_CopyB(node) is_Div(node) is_Dummy(node)
 384         is_End(node) is_Free(node)
 385         is_IJmp(node) is_InstOf(node) is_Jmp(node) is_Load(node) is_Minus(node)
 386         is_Mod(node) is_Mul(node) is_Mulh(node) is_Mux(node) is_NoMem(node)
 387         is_Pin(node) is_Proj(node)
 388         is_Raise(node) is_Return(node) is_Sel(node) is_Start(node) is_Store(node)
 389         is_SymConst(node) is_Sync(node) is_Tuple(node)
 390         */
 391
 392         /* @todo: At this place, we check if the mode of the variable changed. A
 393          * better place for this might be in the convopt.c file
 394          */
 395
 396         if (new_bits_set != tarval_bad && get_tarval_mode(new_bits_set) != get_tarval_mode(vrp->bits_set)) {
 397                 vrp->bits_set = tarval_convert_to(vrp->bits_set, get_irn_mode(node));
 398         }
 399         if (new_bits_not_set != tarval_bad && get_tarval_mode(new_bits_not_set) != get_tarval_mode(vrp->bits_not_set)) {
 400                 vrp->bits_not_set = tarval_convert_to(vrp->bits_not_set, get_irn_mode(node));
 401         }
 402
 403         if (vrp->range_type != VRP_UNDEFINED && new_range_type != VRP_UNDEFINED && get_tarval_mode(new_range_top) != get_tarval_mode(vrp->range_top)) {
 404                 /* @todo: We might be able to preserve this range information if it
 405                  * fits in */
 406                 vrp->range_type = VRP_VARYING;
 407         }
 408
 409         /* Merge the newly calculated values with those that might already exist*/
 410         if (new_bits_set != tarval_bad) {
 411                 new_bits_set = tarval_or(new_bits_set, vrp->bits_set);
 412                 if (new_bits_set != vrp->bits_set) {
 413                         something_changed = 1;
 414                         vrp->bits_set = new_bits_set;
 415                 }
 416         }
 417         if (new_bits_not_set != tarval_bad) {
 418                 new_bits_not_set = tarval_and(new_bits_not_set, vrp->bits_not_set);
 419
 420                 if (new_bits_not_set != vrp->bits_not_set) {
 421                         something_changed = 1;
 422                         vrp->bits_not_set = new_bits_not_set;
 423                 }
 424         }
 425
 426         if (vrp->range_type == VRP_UNDEFINED &&
 427                         new_range_type != VRP_UNDEFINED) {
 428                 something_changed = 1;
 429                 vrp->range_type = new_range_type;
 430                 vrp->range_bottom = new_range_bottom;
 431                 vrp->range_top = new_range_top;
 432
 433         } else if (vrp->range_type == VRP_RANGE) {
 434                 if (new_range_type == VRP_RANGE) {
 435                         if (tarval_cmp(vrp->range_bottom, new_range_bottom) == ir_relation_less) {
 436                                 something_changed = 1;
 437                                 vrp->range_bottom = new_range_bottom;
 438                         }
 439                         if (tarval_cmp(vrp->range_top, new_range_top) == ir_relation_greater) {
 440                                 something_changed = 1;
 441                                 vrp->range_top = new_range_top;
 442                         }
 443                 }
 444
 445                 if (new_range_type == VRP_ANTIRANGE) {
 446                         /* if they are overlapping, cut the range.*/
 447                         /* TODO: Maybe we can preserve more information here*/
 448                         if (tarval_cmp(vrp->range_bottom, new_range_top) == ir_relation_greater &&
 449                                         tarval_cmp(vrp->range_bottom, new_range_bottom) == ir_relation_greater) {
 450                                 something_changed = 1;
 451                                 vrp->range_bottom = new_range_top;
 452
 453                         } else if (tarval_cmp(vrp->range_top, new_range_bottom) == ir_relation_greater &&
 454                                         tarval_cmp(vrp->range_top, new_range_top) == ir_relation_less) {
 455                                 something_changed = 1;
 456                                 vrp->range_top = new_range_bottom;
 457                         }
 458
 459                         /* We can not handle the case where the anti range is in the*/
 460                         /* range*/
 461
 462                 }
 463         } else if (vrp->range_type == VRP_ANTIRANGE) {
 464                 if (new_range_type == VRP_ANTIRANGE) {
 465                         if (tarval_cmp(vrp->range_bottom, new_range_bottom) == ir_relation_greater) {
 466                                 something_changed = 1;
 467                                 vrp->range_bottom = new_range_bottom;
 468                         }
 469                         if (tarval_cmp(vrp->range_top, new_range_top) == ir_relation_less) {
 470                                 something_changed = 1;
 471                                 vrp->range_top = new_range_top;
 472                         }
 473                 }
 474
 475                 if (new_range_type == VRP_RANGE) {
 476                         if (tarval_cmp(vrp->range_bottom, new_range_top) == ir_relation_greater) {
 477                                 something_changed = 1;
 478                                 vrp->range_bottom = new_range_top;
 479                         }
 480                         if (tarval_cmp(vrp->range_top, new_range_bottom) == ir_relation_less) {
 481                                 something_changed = 1;
 482                                 vrp->range_top = new_range_bottom;
 483                         }
 484                 }
 485         }
 486
 487         assert(tarval_is_null(
 488                                 tarval_and(vrp->bits_set, tarval_not(vrp->bits_not_set))));
 489         return something_changed;
 490 }
 491
 492 static void vrp_first_pass(ir_node *n, void *e)
 493 {
 494         int i;
 495         vrp_env_t *env = (vrp_env_t*) e;
 496
 497         if (is_Block(n))
 498                 return;
 499
 500         bitset_set(env->visited, get_irn_idx(n));
 501
 502         vrp_update_node(env->info, n);
 503
 504         for (i = get_irn_n_outs(n) - 1; i >=0; --i) {
 505                 ir_node *succ = get_irn_out(n, i);
 506                 if (bitset_is_set(env->visited, get_irn_idx(succ))) {
 507                         /* we found a loop*/
 508                         waitq_put(env->workqueue, succ);
 509                 }
 510         }
 511 }
 512
 513 static void dump_vrp_info(void *ctx, FILE *F, const ir_node *node)
 514 {
 515         vrp_attr *vrp;
 516
 517         (void) ctx;
 518         if (!mode_is_int(get_irn_mode(node)))
 519                 return;
 520
 521         vrp = vrp_get_info(node);
 522         if (vrp == NULL)
 523                 return;
 524
 525         fprintf(F, "vrp range type: %d\n", (int) vrp->range_type);
 526         if (vrp->range_type == VRP_RANGE || vrp->range_type == VRP_ANTIRANGE) {
 527                 ir_fprintf(F, "vrp range bottom: %T\n",vrp->range_bottom);
 528                 ir_fprintf(F, "vrp range top: %T\n", vrp->range_top);
 529         }
 530         ir_fprintf(F, "vrp bits set: %T\n", vrp->bits_set);
 531         ir_fprintf(F, "vrp bits not set: %T\n", vrp->bits_not_set);
 532 }
 533
 534 static hook_entry_t dump_hook;
 535
 536 void set_vrp_data(ir_graph *irg)
 537 {
 538         ir_node *succ, *node;
 539         int i;
 540         vrp_env_t *env;
 541         ir_vrp_info *info;
 542
 543         if (irg->vrp.infos.data != NULL)
 544                 free_vrp_data(irg);
 545
 546         FIRM_DBG_REGISTER(dbg, "ir.ana.vrp");
 547
 548         assure_irg_outs(irg); /* ensure that out edges are consistent*/
 549         ir_nodemap_init(&irg->vrp.infos, irg);
 550         obstack_init(&irg->vrp.obst);
 551         info = &irg->vrp;
 552
 553         if (dump_hook.hook._hook_node_info == NULL) {
 554                 dump_hook.hook._hook_node_info = dump_vrp_info;
 555                 register_hook(hook_node_info, &dump_hook);
 556         }
 557
 558         env = OALLOCZ(&irg->vrp.obst, vrp_env_t);
 559         env->workqueue = new_waitq();
 560         env->info      = info;
 561
 562         env->visited = bitset_malloc(get_irg_last_idx(irg));
 563         irg_walk_graph(irg, NULL, vrp_first_pass, env);
 564         bitset_free(env->visited);
 565
 566         /* while there are entries in the worklist, continue*/
 567         while (!waitq_empty(env->workqueue)) {
 568                 node = (ir_node*) waitq_get(env->workqueue);
 569
 570                 if (vrp_update_node(info, node)) {
 571                         /* if something changed, add successors to worklist*/
 572                         for (i = get_irn_n_outs(node) - 1; i >= 0; --i) {
 573                                 succ =  get_irn_out(node, i);
 574                                 waitq_put(env->workqueue, succ);
 575                         }
 576                 }
 577         }
 578         del_waitq(env->workqueue);
 579 }
 580
 581 void free_vrp_data(ir_graph *irg)
 582 {
 583         if (irg->vrp.infos.data == NULL)
 584                 return;
 585         obstack_free(&irg->vrp.obst, NULL);
 586         ir_nodemap_destroy(&irg->vrp.infos);
 587 }
 588
 589 ir_graph_pass_t *set_vrp_pass(const char *name)
 590 {
 591         return def_graph_pass(name ? name : "set_vrp", set_vrp_data);
 592 }
 593
 594 ir_relation vrp_cmp(const ir_node *left, const ir_node *right)
 595 {
 596         vrp_attr *vrp_left, *vrp_right;
 597
 598         if (!mode_is_int(get_irn_mode(left)))
 599                 return ir_relation_true;
 600
 601         vrp_left = vrp_get_info(left);
 602         vrp_right = vrp_get_info(right);
 603
 604         if (!vrp_left || !vrp_right)
 605                 return ir_relation_true;
 606
 607         if (vrp_left->range_type == VRP_RANGE && vrp_right->range_type == VRP_RANGE) {
 608                 if (tarval_cmp(vrp_left->range_top, vrp_right->range_bottom) == ir_relation_less) {
 609                         return ir_relation_less;
 610                 }
 611                 if (tarval_cmp(vrp_left->range_bottom, vrp_right->range_top) == ir_relation_greater) {
 612                         return ir_relation_greater;
 613                 }
 614         }
 615
 616         if (!tarval_is_null(tarval_and(vrp_left->bits_set, tarval_not(vrp_right->bits_not_set))) ||
 617                         !tarval_is_null(tarval_and(tarval_not(vrp_left->bits_not_set), vrp_right->bits_set))) {
 618                 return ir_relation_less_greater;
 619         }
 620
 621         /* TODO: We can get way more information here*/
 622         return ir_relation_true;
 623 }