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
  54         tarval *new_bits_set = get_tarval_bad();
  55         tarval *new_bits_not_set = get_tarval_bad();
  56         tarval *new_range_bottom = get_tarval_bad();
  57         tarval *new_range_top = get_tarval_bad();
  58         ir_node *new_bits_node = NULL;
  59         ir_node *new_range_node = NULL;
  60         enum range_types new_range_type = VRP_UNDEFINED;
  61         enum range_ops new_range_op = VRP_NONE;
  62         int something_changed = 0;
  63
  64         node->vrp.valid = 1;
  65         // TODO: Check if all predecessors have valid VRP information
  66
  67
  68         if (!mode_is_int(get_irn_mode(node))) {
  69                 return 0; // we don't optimize for non-int-nodes
  70         }
  71
  72         if (is_Const(node)) {
  73                 tarval *tv = get_Const_tarval(node);
  74
  75                 new_bits_set = tv;
  76                 new_bits_not_set = tarval_not(tv);
  77                 new_range_bottom = tv;
  78                 new_range_top = tv;
  79                 new_range_type = VRP_RANGE;
  80         } else if (is_And(node)) {
  81                 ir_node *pred0 = get_And_left(node);
  82                 ir_node *pred1 = get_And_right(node);
  83                 tarval *tmp;
  84
  85                 new_bits_set = tarval_and(pred0->vrp.bits_set, pred1->vrp.bits_set);
  86                 new_bits_not_set = tarval_or(pred0->vrp.bits_not_set, pred1->vrp.bits_not_set);
  87
  88                 tmp = tarval_not(pred0->vrp.bits_set);
  89                 tmp = tarval_eor(pred0->vrp.bits_not_set, tmp);
  90                 //check if one of the predecessors is completely determined
  91                 if (tarval_is_null(tmp)) {
  92                         new_bits_node = pred1;
  93                 }
  94
  95                 tmp = tarval_not(pred1->vrp.bits_set);
  96                 tmp = tarval_eor(pred1->vrp.bits_not_set, tmp);
  97                 if (tarval_is_null(tmp)) {
  98                         new_bits_node = pred0;
  99                 }
 100         } else if (is_Add(node)) {
 101                 ir_node *pred0 = get_Add_left(node);
 102                 ir_node *pred1 = get_Add_right(node);
 103                 int overflow_top, overflow_bottom;
 104                 tarval *new_top, *new_bottom;
 105
 106                 if (pred0->vrp.range_type == VRP_UNDEFINED || pred1->vrp.range_type ==
 107                                 VRP_UNDEFINED || pred0->vrp.range_type == VRP_VARYING ||
 108                                 pred1->vrp.range_type == VRP_VARYING) {
 109                         return 0;
 110                 }
 111
 112                 new_top = tarval_add(pred0->vrp.range_top, pred1->vrp.range_top);
 113                 overflow_top = tarval_carry();
 114                 new_bottom = tarval_add(pred0->vrp.range_bottom, pred1->vrp.range_bottom);
 115                 overflow_bottom = tarval_carry();
 116
 117                 if (!overflow_top && !overflow_bottom && pred0->vrp.range_type == VRP_RANGE
 118                                 &&pred1->vrp.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         } else if (is_Sub(node)) {
 129                 ir_node *pred0 = get_Sub_left(node);
 130                 ir_node *pred1 = get_Sub_right(node);
 131                 int overflow_top, overflow_bottom;
 132                 tarval *new_top, *new_bottom;
 133
 134                 if (pred0->vrp.range_type == VRP_UNDEFINED || pred1->vrp.range_type ==
 135                                 VRP_UNDEFINED) {
 136                         return 0;
 137                 }
 138
 139                 new_top = tarval_sub(pred0->vrp.range_top, pred1->vrp.range_top, NULL);
 140                 overflow_top = tarval_carry();
 141                 new_bottom = tarval_sub(pred0->vrp.range_bottom, pred1->vrp.range_bottom, NULL);
 142                 overflow_bottom = tarval_carry();
 143
 144                 if (!overflow_top && !overflow_bottom && pred0->vrp.range_type == VRP_RANGE
 145                                 &&pred1->vrp.range_type == VRP_RANGE) {
 146                         new_range_bottom = new_bottom;
 147                         new_range_top = new_top;
 148                         new_range_type = VRP_RANGE;
 149                 }
 150
 151                 if (overflow_top || overflow_bottom) {
 152                         // TODO Implement overflow handling
 153                 }
 154         } else if (is_Or(node)) {
 155                 ir_node *a = get_Or_left(node);
 156                 ir_node *b = get_Or_right(node);
 157                 tarval *tmp;
 158
 159                 new_bits_set = tarval_or(a->vrp.bits_set, b->vrp.bits_set);
 160                 new_bits_not_set = tarval_and(a->vrp.bits_not_set, b->vrp.bits_not_set);
 161
 162                 tmp = tarval_not(a->vrp.bits_set);
 163                 tmp = tarval_eor(a->vrp.bits_not_set, tmp);
 164                 //check if one of the predecessors is completely determined
 165                 if (tarval_is_null(tmp)) {
 166                         new_bits_node = b;
 167                 }
 168
 169                 tmp = tarval_not(b->vrp.bits_set);
 170                 tmp = tarval_eor(b->vrp.bits_not_set, tmp);
 171                 if (tarval_is_null(tmp)) {
 172                         new_bits_node = a;
 173                 }
 174
 175         } else if (is_Rotl(node)) {
 176                 ir_node *a = get_Rotl_left(node);
 177                 ir_node *b = get_Rotl_right(node);
 178
 179                 // We can only compute this if the right value is a constant
 180                 if (is_Const(b)) {
 181                         tarval *bits_set, *bits_not_set;
 182                         bits_set = tarval_rotl(a->vrp.bits_set, get_Const_tarval(b));
 183                         bits_not_set = tarval_rotl(a->vrp.bits_not_set, get_Const_tarval(b));
 184
 185                         new_bits_set = tarval_or(bits_set, node->vrp.bits_set);
 186                         new_bits_not_set = tarval_or(bits_not_set, node->vrp.bits_not_set);
 187                 }
 188
 189         } else if (is_Shl(node)) {
 190                 ir_node *a = get_Shl_left(node);
 191                 ir_node *b = get_Shl_right(node);
 192
 193                 // We can only compute this if the right value is a constant
 194                 if (is_Const(b)) {
 195                         tarval *bits_set, *bits_not_set;
 196                         ir_mode *m = get_tarval_mode(node->vrp.bits_not_set);
 197                         bits_set = tarval_shl(a->vrp.bits_set, get_Const_tarval(b));
 198                         bits_not_set = tarval_shl(a->vrp.bits_not_set, get_Const_tarval(b));
 199
 200                         new_bits_set = tarval_or(bits_set, node->vrp.bits_set);
 201                         new_bits_not_set = tarval_or(bits_not_set, node->vrp.bits_not_set);
 202
 203                         bits_not_set = tarval_not( tarval_shl(
 204                                                                                 get_mode_all_one(m),
 205                                                                                 get_Const_tarval(b)));
 206                         new_bits_not_set = tarval_or(bits_not_set, new_bits_not_set);
 207
 208                 }
 209
 210         } else if (is_Shr(node)) {
 211                 ir_node *a = get_Shr_left(node);
 212                 ir_node *b = get_Shr_right(node);
 213
 214                 // We can only compute this if the right value is a constant
 215                 if (is_Const(b)) {
 216                         tarval *bits_set, *bits_not_set;
 217                         ir_mode *m = get_tarval_mode(node->vrp.bits_not_set);
 218                         bits_set = tarval_shr(a->vrp.bits_set, get_Const_tarval(b));
 219                         bits_not_set = tarval_shr(a->vrp.bits_not_set, get_Const_tarval(b));
 220
 221                         new_bits_set = tarval_or(bits_set, node->vrp.bits_set);
 222                         new_bits_not_set = tarval_or(bits_not_set, node->vrp.bits_not_set);
 223
 224                         bits_not_set = tarval_not( tarval_shr(
 225                                                                                 get_mode_all_one(m),
 226                                                                                 get_Const_tarval(b)));
 227                         new_bits_not_set = tarval_or(bits_not_set, new_bits_not_set);
 228                 }
 229
 230         } else if (is_Shrs(node)) {
 231                 ir_node *a = get_Shrs_left(node);
 232                 ir_node *b = get_Shrs_right(node);
 233
 234                 // We can only compute this if the right value is a constant
 235                 if (is_Const(b)) {
 236                         tarval *bits_set, *bits_not_set;
 237                         ir_mode *m = get_tarval_mode(node->vrp.bits_not_set);
 238                         bits_set = tarval_shrs(a->vrp.bits_set, get_Const_tarval(b));
 239                         bits_not_set = tarval_shrs(a->vrp.bits_not_set, get_Const_tarval(b));
 240
 241                         new_bits_set = tarval_or(bits_set, node->vrp.bits_set);
 242                         new_bits_not_set = tarval_or(bits_not_set, node->vrp.bits_not_set);
 243
 244                         bits_not_set = tarval_not( tarval_shrs(
 245                                                                                 get_mode_all_one(m),
 246                                                                                 get_Const_tarval(b)));
 247                         new_bits_not_set = tarval_or(bits_not_set, new_bits_not_set);
 248                 }
 249
 250         } else if (is_Eor(node)) {
 251                 ir_node *a = get_Eor_left(node);
 252                 ir_node *b = get_Eor_right(node);
 253
 254                 tarval *bits_set, *bits_not_set;
 255                 bits_not_set = tarval_or(
 256                                                         tarval_and(a->vrp.bits_set, b->vrp.bits_set),
 257                                                         tarval_and(a->vrp.bits_not_set,
 258                                                                 b->vrp.bits_not_set));
 259
 260                 bits_set = tarval_or(
 261                                                 tarval_and(a->vrp.bits_set, b->vrp.bits_not_set),
 262                                                 tarval_and(a->vrp.bits_not_set, b->vrp.bits_set));
 263
 264                 new_bits_set = tarval_or(bits_set, node->vrp.bits_set);
 265                 new_bits_not_set = tarval_or(bits_not_set, node->vrp.bits_not_set);
 266
 267         } else if (is_Id(node)) {
 268                 ir_node *pred = get_Id_pred(node);
 269                 new_bits_set = pred->vrp.bits_set;
 270                 new_bits_not_set = pred->vrp.bits_not_set;
 271                 new_range_top = pred->vrp.range_top;
 272                 new_range_bottom = pred->vrp.range_bottom;
 273                 new_range_type = pred->vrp.range_type;
 274
 275         } else if (is_Not(node)) {
 276                 ir_node *pred = get_Not_op(node);
 277                 new_bits_set = tarval_or(pred->vrp.bits_not_set, node->vrp.bits_set);
 278                 new_bits_not_set = tarval_or(pred->vrp.bits_set, node->vrp.bits_not_set);
 279
 280         } else if (is_Conv(node)) {
 281                 ir_node *pred = get_Conv_op(node);
 282                 ir_mode *old_mode = get_irn_mode(pred);
 283                 ir_mode *new_mode;
 284                 tarval *bits_not_set;
 285
 286                 if (!mode_is_int(old_mode))
 287                         return 0;
 288
 289                 new_mode = get_irn_mode(node);
 290
 291                 // The second and is needed if target type is smaller
 292                 bits_not_set = tarval_not(
 293                                                         tarval_convert_to(get_mode_all_one(old_mode),
 294                                                                 new_mode
 295                                                                 ));
 296                 bits_not_set = tarval_or(bits_not_set, tarval_convert_to(pred->vrp.bits_not_set, new_mode));
 297                 new_bits_not_set = tarval_or(bits_not_set, node->vrp.bits_not_set);
 298                 new_bits_set = tarval_and(
 299                                 tarval_not(bits_not_set), tarval_convert_to(pred->vrp.bits_set, new_mode));
 300
 301                 if (tarval_cmp(pred->vrp.range_top, get_mode_max(new_mode)) == pn_Cmp_Le) {
 302                         node->vrp.range_top = pred->vrp.range_top;
 303                 }
 304
 305                 if (tarval_cmp(pred->vrp.range_bottom, get_mode_min(new_mode)) == pn_Cmp_Ge) {
 306                         node->vrp.range_bottom = pred->vrp.range_bottom;
 307                 }
 308
 309         } else if (is_Confirm(node)) {
 310                 pn_Cmp cmp = get_Confirm_cmp(node);
 311                 ir_node *bound = get_Confirm_bound(node);
 312
 313                 /** @todo: Handle non-Const bounds */
 314
 315                 if (cmp == pn_Cmp_Lg) {
 316                         /** @todo: Is there some way to preserve the information? */
 317                         new_range_type = VRP_ANTIRANGE;
 318                         if (is_Const(bound)) {
 319                                 new_range_top = get_Const_tarval(bound);
 320                                 new_range_bottom = get_Const_tarval(bound);
 321                         }
 322                 } else if (cmp == pn_Cmp_Le) {
 323                         if (node->vrp.range_type == VRP_UNDEFINED) {
 324                                 new_range_type = VRP_RANGE;
 325                                 if (is_Const(bound)) {
 326                                         new_range_top = get_Const_tarval(bound);
 327                                 }
 328                                 new_range_bottom = get_tarval_min(get_irn_mode(node));
 329                         } else if (node->vrp.range_type == VRP_RANGE) {
 330                                 if (is_Const(bound)) {
 331                                         if (tarval_cmp(node->vrp.range_top,
 332                                                                 get_Const_tarval(bound)) == pn_Cmp_Le) {
 333                                                 new_range_top = get_Const_tarval(bound);
 334                                         }
 335                                         new_range_bottom = get_tarval_min(get_irn_mode(node));
 336
 337                                 } else if (node->vrp.range_type == VRP_ANTIRANGE) {
 338                                         /** @todo: How do we manage not to get a never ending loop? */
 339                                 }
 340                         }
 341                 }
 342
 343         } else if (is_Phi(node)) {
 344                 // combine all ranges
 345                 ir_node *pred;
 346                 int num = get_Phi_n_preds(node);
 347                 pn_Cmp cmp;
 348                 int i;
 349                 tarval *range_top, *range_bottom, *bits_set, *bits_not_set;
 350                 enum range_types range_type;
 351
 352                 assert(num > 0);
 353
 354                 pred = get_Phi_pred(node,0);
 355                 range_top = pred->vrp.range_top;
 356                 range_bottom = pred->vrp.range_bottom;
 357                 range_type = pred->vrp.range_type;
 358                 bits_set = pred->vrp.bits_set;
 359                 bits_not_set = pred->vrp.bits_not_set;
 360
 361                 for (i = 1; i < num; i++) {
 362                         pred = get_Phi_pred(node, i);
 363                         if (range_type == VRP_RANGE && pred->vrp.range_type ==
 364                                         VRP_RANGE) {
 365                                 cmp = tarval_cmp(range_top, pred->vrp.range_top);
 366                                 if (cmp == pn_Cmp_Lt) {
 367                                         range_top = pred->vrp.range_top;
 368                                 }
 369                                 cmp = tarval_cmp(range_bottom, pred->vrp.range_bottom);
 370                                 if (cmp == pn_Cmp_Gt) {
 371                                         range_bottom = pred->vrp.range_bottom;
 372                                 }
 373                         } else {
 374                                 range_type = VRP_VARYING;
 375                                 break;
 376                         }
 377                 }
 378
 379                 new_range_type = range_type;
 380                 new_range_top = range_top;
 381                 new_range_bottom = range_bottom;
 382
 383         } else {
 384                 // unhandled, therefore never updated
 385                 return 0;
 386         }
 387
 388
 389
 390         /* TODO: Check, if there can be information derived from any of these:
 391         is_Abs(node) is_Alloc(node) is_Anchor(node) is_Borrow(node) is_Bound(node)
 392         is_Break(node) is_Builtin(node) is_Call(node) is_CallBegin(node)
 393         is_Carry(node) is_Cast(node) is_Cmp(node) is_Cond(node)
 394         is_CopyB(node) is_Div(node) is_DivMod(node) is_Dummy(node)
 395         is_End(node) is_EndExcept(node) is_EndReg(node) is_Filter(node) is_Free(node)
 396         is_IJmp(node) is_InstOf(node) is_Jmp(node) is_Load(node) is_Minus(node)
 397         is_Mod(node) is_Mul(node) is_Mulh(node) is_Mux(node) is_NoMem(node)
 398         is_Pin(node) is_Proj(node) is_Quot(node)
 399         is_Raise(node) is_Return(node) is_Sel(node) is_Start(node) is_Store(node)
 400         is_SymConst(node) is_Sync(node) is_Tuple(node)
 401         */
 402
 403         // Merge the newly calculated values with those that might already exist
 404
 405         if (new_bits_set != tarval_bad) {
 406                 new_bits_set = tarval_or(new_bits_set, node->vrp.bits_set);
 407                 if (tarval_cmp(new_bits_set, node->vrp.bits_set) != pn_Cmp_Eq) {
 408                         something_changed = 1;
 409                         node->vrp.bits_set = new_bits_set;
 410                 }
 411         }
 412
 413         if (new_bits_not_set != tarval_bad) {
 414                 new_bits_not_set = tarval_or(new_bits_not_set, node->vrp.bits_not_set);
 415
 416                 if (tarval_cmp(new_bits_not_set, node->vrp.bits_not_set) != pn_Cmp_Eq) {
 417                         something_changed = 1;
 418                         node->vrp.bits_not_set = new_bits_not_set;
 419                 }
 420         }
 421
 422         if (node->vrp.bits_node == NULL && new_bits_node != NULL) {
 423                 something_changed = 1;
 424                 node->vrp.bits_node = new_bits_node;
 425         }
 426
 427         if (node->vrp.range_type == VRP_UNDEFINED &&
 428                         new_range_type != VRP_UNDEFINED) {
 429                 something_changed = 1;
 430                 node->vrp.range_type = new_range_type;
 431                 node->vrp.range_bottom = new_range_bottom;
 432                 node->vrp.range_top = new_range_top;
 433                 node->vrp.range_op = new_range_op;
 434                 node->vrp.range_node = new_range_node;
 435
 436         } else if (node->vrp.range_type == VRP_RANGE) {
 437                 if (new_range_type == VRP_RANGE) {
 438                         if ((new_range_node == NULL && node->vrp.range_node == NULL) ||
 439                                         (new_range_node == node->vrp.range_node &&
 440                                          new_range_op == node->vrp.range_op)) {
 441                                 if (tarval_cmp(node->vrp.range_bottom, new_range_bottom) == pn_Cmp_Lt) {
 442                                         something_changed = 1;
 443                                         node->vrp.range_bottom = new_range_bottom;
 444                                 }
 445                                 if (tarval_cmp(node->vrp.range_top, new_range_top) == pn_Cmp_Gt) {
 446                                         something_changed = 1;
 447                                         node->vrp.range_top = new_range_top;
 448                                 }
 449                         }
 450
 451                         // prefer the absolute value
 452                         if (new_range_node == NULL && node->vrp.range_node != NULL) {
 453                                 something_changed = 1;
 454                                 node->vrp.range_node = NULL;
 455                                 node->vrp.range_top = new_range_top;
 456                                 node->vrp.range_bottom = new_range_bottom;
 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 (new_range_node == NULL && node->vrp.range_node == NULL) {
 464                                 if (tarval_cmp(node->vrp.range_bottom, new_range_top) == pn_Cmp_Gt &&
 465                                                 tarval_cmp(node->vrp.range_bottom, new_range_bottom) == pn_Cmp_Gt) {
 466                                         something_changed = 1;
 467                                         node->vrp.range_bottom = new_range_top;
 468
 469                                 } else if (tarval_cmp(node->vrp.range_top, new_range_bottom) == pn_Cmp_Gt &&
 470                                                 tarval_cmp(node->vrp.range_top, new_range_top) == pn_Cmp_Lt) {
 471                                         something_changed = 1;
 472                                         node->vrp.range_top = new_range_bottom;
 473                                 }
 474
 475                                 // We can not handle the case where the anti range is in the
 476                                 // range
 477                         }
 478
 479                         // prefer the absolute value
 480                         if (new_range_node == NULL && node->vrp.range_node != NULL) {
 481                                 something_changed = 1;
 482                                 node->vrp.range_node = NULL;
 483                                 node->vrp.range_top = new_range_top;
 484                                 node->vrp.range_bottom = new_range_bottom;
 485                         }
 486                 }
 487         } else if (node->vrp.range_type == VRP_ANTIRANGE) {
 488                 if (new_range_type == VRP_ANTIRANGE) {
 489                         if ((new_range_node == NULL && node->vrp.range_node == NULL) ||
 490                                         (new_range_node == node->vrp.range_node &&
 491                                          new_range_op == node->vrp.range_op)) {
 492                                 if (tarval_cmp(node->vrp.range_bottom, new_range_bottom) == pn_Cmp_Gt) {
 493                                         something_changed = 1;
 494                                         node->vrp.range_bottom = new_range_bottom;
 495                                 }
 496                                 if (tarval_cmp(node->vrp.range_top, new_range_top) == pn_Cmp_Lt) {
 497                                         something_changed = 1;
 498                                         node->vrp.range_top = new_range_top;
 499                                 }
 500                         }
 501
 502                         // prefer the absolute value
 503                         if (new_range_node == NULL && node->vrp.range_node != NULL) {
 504                                 something_changed = 1;
 505                                 node->vrp.range_node = NULL;
 506                                 node->vrp.range_top = new_range_top;
 507                                 node->vrp.range_bottom = new_range_bottom;
 508                         }
 509                 }
 510
 511                 if (new_range_type == VRP_RANGE) {
 512                         if ((new_range_node == NULL && node->vrp.range_node == NULL) ||
 513                                         (new_range_node == node->vrp.range_node &&
 514                                          new_range_op == node->vrp.range_op)) {
 515                                 if (tarval_cmp(node->vrp.range_bottom, new_range_top) == pn_Cmp_Gt) {
 516                                         something_changed = 1;
 517                                         node->vrp.range_bottom = new_range_top;
 518                                 }
 519                                 if (tarval_cmp(node->vrp.range_top, new_range_bottom) == pn_Cmp_Lt) {
 520                                         something_changed = 1;
 521                                         node->vrp.range_top = new_range_bottom;
 522                                 }
 523                         }
 524
 525                         // prefer the absolute value
 526                         if (new_range_node == NULL && node->vrp.range_node != NULL) {
 527                                 something_changed = 1;
 528                                 node->vrp.range_node = NULL;
 529                                 node->vrp.range_top = new_range_top;
 530                                 node->vrp.range_bottom = new_range_bottom;
 531                         }
 532                 }
 533         }
 534
 535         assert(tarval_is_null(
 536                                 tarval_and(node->vrp.bits_set, node->vrp.bits_not_set)));
 537
 538         return something_changed;
 539 }
 540
 541 void vrp_first_pass(ir_node *n, void *e)
 542 {
 543         ir_node *succ;
 544         worklist_t *tmp_entry;
 545         int i;
 546         struct vrp_env_t *env = e;
 547
 548         if (is_Block(n))
 549                 return;
 550
 551         set_irn_link(n, VISITED);
 552
 553         update_vrp_data(n);
 554
 555         for (i = get_irn_n_outs(n) - 1; i >=0; --i) {
 556                 succ =  get_irn_out(n, i);
 557                 if (get_irn_link(succ) == VISITED) {
 558                         // we found a loop
 559
 560                         tmp_entry = XMALLOC(worklist_t);
 561                         tmp_entry->node = n;
 562                         list_add(&(tmp_entry->nodes), &(env->worklist->nodes));
 563
 564
 565                 }
 566         }
 567 }
 568
 569
 570 void set_vrp_data(ir_graph *irg)
 571 {
 572
 573         ir_node *succ;
 574         int i;
 575         worklist_t worklist;
 576         worklist_t *tmp_entry, *tmp_entry2;
 577         struct vrp_env_t env;
 578
 579         if (!irg) {
 580                 /* no graph, skip */
 581                 return;
 582         }
 583
 584         assure_irg_outs(irg); // ensure that out edges are consistent
 585
 586 //      edges_activate(irg);
 587
 588         INIT_LIST_HEAD(&worklist.nodes);
 589
 590         env.worklist = &worklist;
 591         irg_walk_graph(irg, NULL, vrp_first_pass, &env);
 592
 593
 594
 595         // while there are entries in the worklist, continue
 596         while ( !list_empty(&worklist.nodes) ) {
 597
 598                 list_head *pos, *next;
 599                 list_for_each_safe(pos, next, &worklist.nodes) {
 600
 601                         tmp_entry = list_entry(pos, worklist_t, nodes);
 602
 603                         if (update_vrp_data(tmp_entry->node)) {
 604                                 // if something changed, add successors to worklist
 605                                 for (i = get_irn_n_outs(tmp_entry->node) - 1; i >=0; --i) {
 606                                         succ =  get_irn_out(tmp_entry->node, i);
 607
 608                                         tmp_entry2 = XMALLOC(worklist_t);
 609                                         tmp_entry2->node = succ;
 610                                         list_add(&(tmp_entry2->nodes), &worklist.nodes);
 611                                 }
 612                         }
 613
 614                         list_del(pos);
 615                         xfree(tmp_entry);
 616                 }
 617         }
 618 }
 619
 620
 621 ir_graph_pass_t *set_vrp_pass(const char *name)
 622 {
 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 {
 628         if (!left->vrp.valid || !right->vrp.valid) {
 629                 return pn_Cmp_False;
 630         }
 631
 632         if (left->vrp.range_type == VRP_RANGE && right->vrp.range_type == VRP_RANGE) {
 633                 if (tarval_cmp(left->vrp.range_top, right->vrp.range_bottom) == pn_Cmp_Lt) {
 634                         return pn_Cmp_Lt;
 635                 }
 636                 if (tarval_cmp(left->vrp.range_bottom, right->vrp.range_top) == pn_Cmp_Gt) {
 637                         return pn_Cmp_Gt;
 638                 }
 639         }
 640
 641         if (!tarval_is_null(tarval_and(left->vrp.bits_set, right->vrp.bits_not_set)) ||
 642                         !tarval_is_null(tarval_and(left->vrp.bits_not_set, right->vrp.bits_set))) {
 643                 return pn_Cmp_Lg;
 644         }
 645         // TODO: We can get way more information here
 646
 647         return pn_Cmp_False;
 648 }