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
  27 #include "irtypes.h"
  28 #include "vrp.h"
  29 #include "irouts.h"
  30 #include "irgraph_t.h"
  31 #include "irpass.h"
  32 #include "list.h"
  33 #include "irgwalk.h"
  34 #include "iredges.h"
  35 #include "tv.h"
  36
  37
  38 static char v;
  39 static void *VISITED = &v;
  40
  41 typedef struct worklist_t worklist_t;
  42 struct worklist_t {
  43          struct list_head nodes;
  44         ir_node *node;
  45 };
  46
  47 struct vrp_env_t {
  48         worklist_t *worklist;
  49 };
  50
  51 int update_vrp_data( ir_node *node) {
  52
  53         tarval *new_bits_set = get_tarval_bad();
  54         tarval *new_bits_not_set = get_tarval_bad();
  55         tarval *new_range_bottom = get_tarval_bad();
  56         tarval *new_range_top = get_tarval_bad();
  57         ir_node *new_bits_node = NULL;
  58         ir_node *new_range_node = NULL;
  59         enum range_types new_range_type = VRP_UNDEFINED;
  60         enum range_ops new_range_op = VRP_NONE;
  61
  62         node->vrp.valid = 1;
  63         // TODO: Check if all predecessors have valid VRP information
  64
  65
  66         if (!mode_is_int(get_irn_mode(node))) {
  67                 return 0; // we don't optimize for non-int-nodes
  68         }
  69
  70         if (is_Const(node)) {
  71                 tarval *tv = get_Const_tarval(node);
  72
  73                 new_bits_set = tv;
  74                 new_bits_not_set = tarval_not(tv);
  75                 new_range_bottom = tv;
  76                 new_range_top = tv;
  77                 new_range_type = VRP_RANGE;
  78         } else if (is_And(node)) {
  79                 ir_node *pred0 = get_And_left(node);
  80                 ir_node *pred1 = get_And_right(node);
  81
  82                 new_bits_set = tarval_and(pred0->vrp.bits_set, pred1->vrp.bits_set);
  83                 new_bits_not_set = tarval_or(pred0->vrp.bits_not_set, pred1->vrp.bits_not_set);
  84
  85                 tarval *tmp;
  86
  87                 tmp = tarval_not(pred0->vrp.bits_set);
  88                 tmp = tarval_eor(pred0->vrp.bits_not_set, tmp);
  89                 //check if one of the predecessors is completely determined
  90                 if (tarval_is_null(tmp)) {
  91                         new_bits_node = pred1;
  92                 }
  93
  94                 tmp = tarval_not(pred1->vrp.bits_set);
  95                 tmp = tarval_eor(pred1->vrp.bits_not_set, tmp);
  96                 if (tarval_is_null(tmp)) {
  97                         new_bits_node = pred0;
  98                 }
  99         } else if (is_Add(node)) {
 100                 ir_node *pred0 = get_Add_left(node);
 101                 ir_node *pred1 = get_Add_right(node);
 102
 103                 int overflow_top, overflow_bottom;
 104                 if (pred0->vrp.range_type == VRP_UNDEFINED || pred1->vrp.range_type ==
 105                                 VRP_UNDEFINED || pred0->vrp.range_type == VRP_VARYING ||
 106                                 pred1->vrp.range_type == VRP_VARYING) {
 107                         return 0;
 108                 }
 109
 110                 tarval *new_top = tarval_add(pred0->vrp.range_top, pred1->vrp.range_top);
 111                 overflow_top = tarval_carry();
 112                 tarval *new_bottom = tarval_add(pred0->vrp.range_bottom, pred1->vrp.range_bottom);
 113                 overflow_bottom = tarval_carry();
 114
 115                 if (!overflow_top && !overflow_bottom && pred0->vrp.range_type == VRP_RANGE
 116                                 &&pred1->vrp.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         } else if (is_Sub(node)) {
 127                 ir_node *pred0 = get_Sub_left(node);
 128                 ir_node *pred1 = get_Sub_right(node);
 129
 130                 if (pred0->vrp.range_type == VRP_UNDEFINED || pred1->vrp.range_type ==
 131                                 VRP_UNDEFINED) {
 132                         return 0;
 133                 }
 134
 135                 int overflow_top, overflow_bottom;
 136                 tarval *new_top = tarval_sub(pred0->vrp.range_top, pred1->vrp.range_top, NULL);
 137                 overflow_top = tarval_carry();
 138                 tarval *new_bottom = tarval_sub(pred0->vrp.range_bottom, pred1->vrp.range_bottom, NULL);
 139                 overflow_bottom = tarval_carry();
 140
 141                 if (!overflow_top && !overflow_bottom && pred0->vrp.range_type == VRP_RANGE
 142                                 &&pred1->vrp.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                 }
 151         } else if (is_Or(node)) {
 152                 ir_node *a = get_Or_left(node);
 153                 ir_node *b = get_Or_right(node);
 154
 155                 new_bits_set = tarval_or(a->vrp.bits_set, b->vrp.bits_set);
 156                 new_bits_not_set = tarval_and(a->vrp.bits_not_set, b->vrp.bits_not_set);
 157
 158                 tarval *tmp;
 159                 tmp = tarval_not(a->vrp.bits_set);
 160                 tmp = tarval_eor(a->vrp.bits_not_set, tmp);
 161                 //check if one of the predecessors is completely determined
 162                 if (tarval_is_null(tmp)) {
 163                         new_bits_node = b;
 164                 }
 165
 166                 tmp = tarval_not(b->vrp.bits_set);
 167                 tmp = tarval_eor(b->vrp.bits_not_set, tmp);
 168                 if (tarval_is_null(tmp)) {
 169                         new_bits_node = a;
 170                 }
 171
 172         } else if (is_Rotl(node)) {
 173                 ir_node *a = get_Rotl_left(node);
 174                 ir_node *b = get_Rotl_right(node);
 175
 176                 // We can only compute this if the right value is a constant
 177                 if (is_Const(b)) {
 178                         tarval *bits_set, *bits_not_set;
 179                         bits_set = tarval_rotl(a->vrp.bits_set, get_Const_tarval(b));
 180                         bits_not_set = tarval_rotl(a->vrp.bits_not_set, get_Const_tarval(b));
 181
 182                         new_bits_set = tarval_or(bits_set, node->vrp.bits_set);
 183                         new_bits_not_set = tarval_or(bits_not_set, node->vrp.bits_not_set);
 184                 }
 185
 186         } else if (is_Shl(node)) {
 187                 ir_node *a = get_Shl_left(node);
 188                 ir_node *b = get_Shl_right(node);
 189
 190                 // We can only compute this if the right value is a constant
 191                 if (is_Const(b)) {
 192                         tarval *bits_set, *bits_not_set;
 193                         bits_set = tarval_shl(a->vrp.bits_set, get_Const_tarval(b));
 194                         bits_not_set = tarval_shl(a->vrp.bits_not_set, get_Const_tarval(b));
 195                         ir_mode *m = get_tarval_mode(node->vrp.bits_not_set);
 196
 197                         new_bits_set = tarval_or(bits_set, node->vrp.bits_set);
 198                         new_bits_not_set = tarval_or(bits_not_set, node->vrp.bits_not_set);
 199
 200                         bits_not_set = tarval_not( tarval_shl(
 201                                                                                 get_tarval_all_one(m),
 202                                                                                 get_Const_tarval(b)));
 203                         new_bits_not_set = tarval_or(bits_not_set, new_bits_not_set);
 204
 205                 }
 206
 207         } else if (is_Shr(node)) {
 208                 ir_node *a = get_Shr_left(node);
 209                 ir_node *b = get_Shr_right(node);
 210
 211                 // We can only compute this if the right value is a constant
 212                 if (is_Const(b)) {
 213                         tarval *bits_set, *bits_not_set;
 214                         bits_set = tarval_shr(a->vrp.bits_set, get_Const_tarval(b));
 215                         bits_not_set = tarval_shr(a->vrp.bits_not_set, get_Const_tarval(b));
 216                         ir_mode *m = get_tarval_mode(node->vrp.bits_not_set);
 217
 218                         new_bits_set = tarval_or(bits_set, node->vrp.bits_set);
 219                         new_bits_not_set = tarval_or(bits_not_set, node->vrp.bits_not_set);
 220
 221                         bits_not_set = tarval_not( tarval_shr(
 222                                                                                 get_tarval_all_one(m),
 223                                                                                 get_Const_tarval(b)));
 224                         new_bits_not_set = tarval_or(bits_not_set, new_bits_not_set);
 225                 }
 226
 227         } else if (is_Shrs(node)) {
 228                 ir_node *a = get_Shrs_left(node);
 229                 ir_node *b = get_Shrs_right(node);
 230
 231                 // We can only compute this if the right value is a constant
 232                 if (is_Const(b)) {
 233                         tarval *bits_set, *bits_not_set;
 234                         bits_set = tarval_shrs(a->vrp.bits_set, get_Const_tarval(b));
 235                         bits_not_set = tarval_shrs(a->vrp.bits_not_set, get_Const_tarval(b));
 236                         ir_mode *m = get_tarval_mode(node->vrp.bits_not_set);
 237
 238                         new_bits_set = tarval_or(bits_set, node->vrp.bits_set);
 239                         new_bits_not_set = tarval_or(bits_not_set, node->vrp.bits_not_set);
 240
 241                         bits_not_set = tarval_not( tarval_shrs(
 242                                                                                 get_tarval_all_one(m),
 243                                                                                 get_Const_tarval(b)));
 244                         new_bits_not_set = tarval_or(bits_not_set, new_bits_not_set);
 245                 }
 246
 247         } else if (is_Eor(node)) {
 248                 ir_node *a = get_Eor_left(node);
 249                 ir_node *b = get_Eor_right(node);
 250
 251                 tarval *bits_set, *bits_not_set;
 252                 bits_not_set = tarval_or(
 253                                                         tarval_and(a->vrp.bits_set, b->vrp.bits_set),
 254                                                         tarval_and(a->vrp.bits_not_set,
 255                                                                 b->vrp.bits_not_set));
 256
 257                 bits_set = tarval_or(
 258                                                 tarval_and(a->vrp.bits_set, b->vrp.bits_not_set),
 259                                                 tarval_and(a->vrp.bits_not_set, b->vrp.bits_set));
 260
 261                 new_bits_set = tarval_or(bits_set, node->vrp.bits_set);
 262                 new_bits_not_set = tarval_or(bits_not_set, node->vrp.bits_not_set);
 263
 264         } else if (is_Id(node)) {
 265                 ir_node *pred = get_Id_pred(node);
 266                 new_bits_set = pred->vrp.bits_set;
 267                 new_bits_not_set = pred->vrp.bits_not_set;
 268                 new_range_top = pred->vrp.range_top;
 269                 new_range_bottom = pred->vrp.range_bottom;
 270                 new_range_type = pred->vrp.range_type;
 271
 272         } else if (is_Not(node)) {
 273                 ir_node *pred = get_Not_op(node);
 274                 new_bits_set = tarval_or(pred->vrp.bits_not_set, node->vrp.bits_set);
 275                 new_bits_not_set = tarval_or(pred->vrp.bits_set, node->vrp.bits_not_set);
 276
 277         } else if (is_Conv(node)) {
 278                 ir_node *pred = get_Conv_op(node);
 279                 if (!mode_is_int(get_irn_mode(pred)))
 280                         return 0;
 281
 282                 ir_mode *old_mode = get_irn_mode(pred);
 283                 ir_mode *new_mode = get_irn_mode(node);
 284
 285                 // The second and is needed if target type is smaller
 286                 tarval *bits_not_set =  tarval_not(
 287                                                                         tarval_convert_to(get_tarval_all_one(old_mode),
 288                                                                                 new_mode
 289                                                                                 ));
 290                 bits_not_set = tarval_or(bits_not_set, tarval_convert_to(pred->vrp.bits_not_set, new_mode));
 291                 new_bits_not_set = tarval_or(bits_not_set, node->vrp.bits_not_set);
 292                 new_bits_set = tarval_and(
 293                                 tarval_not(bits_not_set), tarval_convert_to(pred->vrp.bits_set, new_mode));
 294
 295                 if (tarval_cmp(pred->vrp.range_top, get_tarval_max(new_mode)) == pn_Cmp_Le) {
 296                         node->vrp.range_top = pred->vrp.range_top;
 297                 }
 298
 299                 if (tarval_cmp(pred->vrp.range_bottom, get_tarval_min(new_mode)) == pn_Cmp_Ge) {
 300                         node->vrp.range_bottom = pred->vrp.range_bottom;
 301                 }
 302
 303         } else if (is_Confirm(node)) {
 304                 pn_Cmp cmp = get_Confirm_cmp(node);
 305                 ir_node *bound = get_Confirm_bound(node);
 306
 307                 /** @todo: Handle non-Const bounds */
 308
 309                 if (cmp == pn_Cmp_Lg) {
 310                         /** @todo: Is there some way to preserve the information? */
 311                         new_range_type = VRP_ANTIRANGE;
 312                         if (is_Const(bound)) {
 313                                 new_range_top = get_Const_tarval(bound);
 314                                 new_range_bottom = get_Const_tarval(bound);
 315                         }
 316                 } else if (cmp == pn_Cmp_Le) {
 317                         if (node->vrp.range_type == VRP_UNDEFINED) {
 318                                 new_range_type = VRP_RANGE;
 319                                 if (is_Const(bound)) {
 320                                         new_range_top = get_Const_tarval(bound);
 321                                 }
 322                                 new_range_bottom = get_tarval_min(get_irn_mode(node));
 323                         } else if (node->vrp.range_type == VRP_RANGE) {
 324                                 if (is_Const(bound)) {
 325                                         if (tarval_cmp(node->vrp.range_top,
 326                                                                 get_Const_tarval(bound)) == pn_Cmp_Le) {
 327                                                 new_range_top = get_Const_tarval(bound);
 328                                         }
 329                                         new_range_bottom = get_tarval_min(get_irn_mode(node));
 330
 331                                 } else if (node->vrp.range_type == VRP_ANTIRANGE) {
 332                                         /** @todo: How do we manage not to get a never ending loop? */
 333                                 }
 334                         }
 335                 }
 336
 337         } else if (is_Phi(node)) {
 338                 // combine all ranges
 339                 ir_node *pred;
 340                 int num = get_Phi_n_preds(node);
 341                 pn_Cmp cmp;
 342                 int i;
 343                 tarval *range_top, *range_bottom, *bits_set, *bits_not_set;
 344                 enum range_types range_type;
 345
 346                 assert(num > 0);
 347
 348                 pred = get_Phi_pred(node,0);
 349                 range_top = pred->vrp.range_top;
 350                 range_bottom = pred->vrp.range_bottom;
 351                 range_type = pred->vrp.range_type;
 352                 bits_set = pred->vrp.bits_set;
 353                 bits_not_set = pred->vrp.bits_not_set;
 354
 355                 for(i = 1; i < num; i++) {
 356                         pred = get_Phi_pred(node, i);
 357                         if (range_type == VRP_RANGE && pred->vrp.range_type ==
 358                                         VRP_RANGE) {
 359                                 cmp = tarval_cmp(range_top, pred->vrp.range_top);
 360                                 if (cmp == pn_Cmp_Lt) {
 361                                         range_top = pred->vrp.range_top;
 362                                 }
 363                                 cmp = tarval_cmp(range_bottom, pred->vrp.range_bottom);
 364                                 if (cmp == pn_Cmp_Gt) {
 365                                         range_bottom = pred->vrp.range_bottom;
 366                                 }
 367                         } else {
 368                                 range_type = VRP_VARYING;
 369                                 break;
 370                         }
 371                 }
 372
 373                 new_range_type = range_type;
 374                 new_range_top = range_top;
 375                 new_range_bottom = range_bottom;
 376
 377         } else {
 378                 // unhandled, therefore never updated
 379                 return 0;
 380         }
 381
 382
 383
 384         /* TODO: Check, if there can be information derived from any of these:
 385         is_Abs(node) is_Alloc(node) is_Anchor(node) is_Borrow(node) is_Bound(node)
 386         is_Break(node) is_Builtin(node) is_Call(node) is_CallBegin(node)
 387         is_Carry(node) is_Cast(node) is_Cmp(node) is_Cond(node)
 388         is_CopyB(node) is_Div(node) is_DivMod(node) is_Dummy(node)
 389         is_End(node) is_EndExcept(node) is_EndReg(node) is_Filter(node) is_Free(node)
 390         is_IJmp(node) is_InstOf(node) is_Jmp(node) is_Load(node) is_Minus(node)
 391         is_Mod(node) is_Mul(node) is_Mulh(node) is_Mux(node) is_NoMem(node)
 392         is_Pin(node) is_Proj(node) is_Quot(node)
 393         is_Raise(node) is_Return(node) is_Sel(node) is_Start(node) is_Store(node)
 394         is_SymConst(node) is_Sync(node) is_Tuple(node)
 395         */
 396         int something_changed = 0;
 397
 398         // Merge the newly calculated values with those that might already exist
 399
 400         if (new_bits_set != tarval_bad) {
 401                 new_bits_set = tarval_or(new_bits_set, node->vrp.bits_set);
 402                 if (tarval_cmp(new_bits_set, node->vrp.bits_set) != pn_Cmp_Eq) {
 403                         something_changed = 1;
 404                         node->vrp.bits_set = new_bits_set;
 405                 }
 406         }
 407
 408         if (new_bits_not_set != tarval_bad) {
 409                 new_bits_not_set = tarval_or(new_bits_not_set, node->vrp.bits_not_set);
 410
 411                 if (tarval_cmp(new_bits_not_set, node->vrp.bits_not_set) != pn_Cmp_Eq) {
 412                         something_changed = 1;
 413                         node->vrp.bits_not_set = new_bits_not_set;
 414                 }
 415         }
 416
 417         if (node->vrp.bits_node == NULL && new_bits_node != NULL) {
 418                 something_changed = 1;
 419                 node->vrp.bits_node = new_bits_node;
 420         }
 421
 422         if (node->vrp.range_type == VRP_UNDEFINED &&
 423                         new_range_type != VRP_UNDEFINED) {
 424                 something_changed = 1;
 425                 node->vrp.range_type = new_range_type;
 426                 node->vrp.range_bottom = new_range_bottom;
 427                 node->vrp.range_top = new_range_top;
 428                 node->vrp.range_op = new_range_op;
 429                 node->vrp.range_node = new_range_node;
 430
 431         } else if (node->vrp.range_type == VRP_RANGE) {
 432                 if (new_range_type == VRP_RANGE) {
 433                         if ((new_range_node == NULL && node->vrp.range_node == NULL) ||
 434                                         (new_range_node == node->vrp.range_node &&
 435                                          new_range_op == node->vrp.range_op)) {
 436                                 if (tarval_cmp(node->vrp.range_bottom, new_range_bottom) == pn_Cmp_Lt) {
 437                                         something_changed = 1;
 438                                         node->vrp.range_bottom = new_range_bottom;
 439                                 }
 440                                 if (tarval_cmp(node->vrp.range_top, new_range_top) == pn_Cmp_Gt) {
 441                                         something_changed = 1;
 442                                         node->vrp.range_top = new_range_top;
 443                                 }
 444                         }
 445
 446                         // prefer the absolute value
 447                         if (new_range_node == NULL && node->vrp.range_node != NULL) {
 448                                 something_changed = 1;
 449                                 node->vrp.range_node = NULL;
 450                                 node->vrp.range_top = new_range_top;
 451                                 node->vrp.range_bottom = new_range_bottom;
 452                         }
 453                 }
 454
 455                 if (new_range_type == VRP_ANTIRANGE) {
 456                         // if they are overlapping, cut the range.
 457                         // TODO: Maybe we can preserve more information here
 458                         if (new_range_node == NULL && node->vrp.range_node == NULL) {
 459                                 if (tarval_cmp(node->vrp.range_bottom, new_range_top) == pn_Cmp_Gt &&
 460                                                 tarval_cmp(node->vrp.range_bottom, new_range_bottom) == pn_Cmp_Gt) {
 461                                         something_changed = 1;
 462                                         node->vrp.range_bottom = new_range_top;
 463
 464                                 } else if (tarval_cmp(node->vrp.range_top, new_range_bottom) == pn_Cmp_Gt &&
 465                                                 tarval_cmp(node->vrp.range_top, new_range_top) == pn_Cmp_Lt) {
 466                                         something_changed = 1;
 467                                         node->vrp.range_top = new_range_bottom;
 468                                 }
 469
 470                                 // We can not handle the case where the anti range is in the
 471                                 // range
 472                         }
 473
 474                         // prefer the absolute value
 475                         if (new_range_node == NULL && node->vrp.range_node != NULL) {
 476                                 something_changed = 1;
 477                                 node->vrp.range_node = NULL;
 478                                 node->vrp.range_top = new_range_top;
 479                                 node->vrp.range_bottom = new_range_bottom;
 480                         }
 481                 }
 482         } else if (node->vrp.range_type == VRP_ANTIRANGE) {
 483                 if (new_range_type == VRP_ANTIRANGE) {
 484                         if ((new_range_node == NULL && node->vrp.range_node == NULL) ||
 485                                         (new_range_node == node->vrp.range_node &&
 486                                          new_range_op == node->vrp.range_op)) {
 487                                 if (tarval_cmp(node->vrp.range_bottom, new_range_bottom) == pn_Cmp_Gt) {
 488                                         something_changed = 1;
 489                                         node->vrp.range_bottom = new_range_bottom;
 490                                 }
 491                                 if (tarval_cmp(node->vrp.range_top, new_range_top) == pn_Cmp_Lt) {
 492                                         something_changed = 1;
 493                                         node->vrp.range_top = new_range_top;
 494                                 }
 495                         }
 496
 497                         // prefer the absolute value
 498                         if (new_range_node == NULL && node->vrp.range_node != NULL) {
 499                                 something_changed = 1;
 500                                 node->vrp.range_node = NULL;
 501                                 node->vrp.range_top = new_range_top;
 502                                 node->vrp.range_bottom = new_range_bottom;
 503                         }
 504                 }
 505
 506                 if (new_range_type == VRP_RANGE) {
 507                         if ((new_range_node == NULL && node->vrp.range_node == NULL) ||
 508                                         (new_range_node == node->vrp.range_node &&
 509                                          new_range_op == node->vrp.range_op)) {
 510                                 if (tarval_cmp(node->vrp.range_bottom, new_range_top) == pn_Cmp_Gt) {
 511                                         something_changed = 1;
 512                                         node->vrp.range_bottom = new_range_top;
 513                                 }
 514                                 if (tarval_cmp(node->vrp.range_top, new_range_bottom) == pn_Cmp_Lt) {
 515                                         something_changed = 1;
 516                                         node->vrp.range_top = new_range_bottom;
 517                                 }
 518                         }
 519
 520                         // prefer the absolute value
 521                         if (new_range_node == NULL && node->vrp.range_node != NULL) {
 522                                 something_changed = 1;
 523                                 node->vrp.range_node = NULL;
 524                                 node->vrp.range_top = new_range_top;
 525                                 node->vrp.range_bottom = new_range_bottom;
 526                         }
 527                 }
 528         }
 529
 530         assert(tarval_is_null(
 531                                 tarval_and(node->vrp.bits_set, node->vrp.bits_not_set)));
 532
 533         return something_changed;
 534 }
 535
 536 void vrp_first_pass(ir_node *n, void *e) {
 537         ir_node *succ;
 538         worklist_t *tmp_entry;
 539         int i;
 540         struct vrp_env_t *env;
 541
 542         if (is_Block(n))
 543                 return;
 544
 545         env = (struct vrp_env_t *) e;
 546
 547
 548         set_irn_link(n, VISITED);
 549
 550         update_vrp_data(n);
 551
 552         for (i = get_irn_n_outs(n) - 1; i >=0; --i) {
 553                 succ =  get_irn_out(n, i);
 554                 if (get_irn_link(succ) == VISITED) {
 555                         // we found a loop
 556
 557                         tmp_entry = (struct worklist_t *)malloc(sizeof(struct worklist_t));
 558                         tmp_entry->node = n;
 559                         list_add(&(tmp_entry->nodes), &(env->worklist->nodes));
 560
 561
 562                 }
 563         }
 564 }
 565
 566
 567 void set_vrp_data(ir_graph *irg) {
 568
 569         ir_node *succ;
 570         int i;
 571         worklist_t worklist;
 572         worklist_t *tmp_entry, *tmp_entry2, *q;
 573         struct vrp_env_t *env;
 574
 575         env = malloc(sizeof(struct vrp_env_t));
 576         if (env == NULL) {
 577                 return;
 578         }
 579
 580         if (!irg) {
 581                 /* no graph, skip */
 582                 return;
 583         }
 584
 585         assure_irg_outs(irg); // ensure that out edges are consistent
 586
 587 //      edges_activate(irg);
 588
 589         INIT_LIST_HEAD(&worklist.nodes);
 590
 591         env->worklist = &worklist;
 592         irg_walk_graph(irg, NULL, vrp_first_pass, env);
 593
 594
 595
 596         // while there are entries in the worklist, continue
 597         while( !list_empty(&worklist.nodes) ) {
 598
 599                 struct list_head *pos;
 600                 list_for_each_safe(pos, q, &worklist.nodes) {
 601
 602                         tmp_entry = list_entry(pos, struct worklist_t, nodes);
 603
 604                         if (update_vrp_data(tmp_entry->node)) {
 605                                 // if something changed, add successors to worklist
 606                                 for (i = get_irn_n_outs(tmp_entry->node) - 1; i >=0; --i) {
 607                                         succ =  get_irn_out(tmp_entry->node, i);
 608
 609                                         tmp_entry2 = (struct worklist_t *)malloc(sizeof(struct worklist_t));
 610                                         tmp_entry2->node = succ;
 611                                         list_add(&(tmp_entry2->nodes), &worklist.nodes);
 612                                 }
 613                         }
 614
 615                         list_del(pos);
 616                         free(tmp_entry);
 617                 }
 618         }
 619 }
 620
 621
 622 ir_graph_pass_t *set_vrp_pass(const char *name) {
 623         return def_graph_pass(name ? name : "set_vrp", set_vrp_data);
 624 }
 625
 626 pn_Cmp vrp_cmp(ir_node *left, ir_node *right) {
 627         if (!(left->vrp.range_type == VRP_UNDEFINED ||
 628                         left->vrp.range_type == VRP_VARYING) && !(
 629                         right->vrp.range_type == VRP_UNDEFINED ||
 630                         right->vrp.range_type == VRP_VARYING)) {
 631
 632                 tarval *lefttop = left->vrp.range_top;
 633                 tarval *leftbottom = left->vrp.range_bottom;
 634                 tarval *righttop = right->vrp.range_top;
 635                 tarval *rightbottom = right->vrp.range_bottom;
 636                 if (left->vrp.range_type == VRP_RANGE && right->vrp.range_type ==
 637                                 VRP_RANGE) {
 638                         if (tarval_cmp(lefttop, rightbottom) == pn_Cmp_Lt) {
 639                                 return pn_Cmp_Lt;
 640                         }
 641                         if (tarval_cmp(leftbottom, righttop) == pn_Cmp_Gt) {
 642                                 return pn_Cmp_Gt;
 643                         }
 644
 645                 }
 646         }
 647
 648         if (!tarval_is_null(tarval_and(left->vrp.bits_set, right->vrp.bits_not_set)) ||
 649                         !tarval_is_null(tarval_and(left->vrp.bits_not_set, right->vrp.bits_set))) {
 650                 return pn_Cmp_Lg;
 651         }
 652         // TODO: We can get way more information here
 653
 654         return pn_Cmp_False;
 655 }