SparseBitVector.h revision c6d939818b7c50f6e14d04447657e670aedc3f6f
1//===- llvm/ADT/SparseBitVector.h - Efficient Sparse BitVector -*- C++ -*- ===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file was developed by Daniel Berlin and is distributed under 6// the University of Illinois Open Source License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file defines the SparseBitVector class. See the doxygen comment for 11// SparseBitVector for more details on the algorithm used. 12// 13//===----------------------------------------------------------------------===// 14 15#ifndef LLVM_ADT_SPARSEBITVECTOR_H 16#define LLVM_ADT_SPARSEBITVECTOR_H 17 18#include <cassert> 19#include <cstring> 20#include <algorithm> 21#include "llvm/Support/DataTypes.h" 22#include "llvm/ADT/STLExtras.h" 23#include "llvm/Support/MathExtras.h" 24#include "llvm/ADT/ilist" 25namespace llvm { 26 27/// SparseBitVector is an implementation of a bitvector that is sparse by only 28/// storing the elements that have non-zero bits set. In order to make this 29/// fast for the most common cases, SparseBitVector is implemented as a linked 30/// list of SparseBitVectorElements. We maintain a pointer to the last 31/// SparseBitVectorElement accessed (in the form of a list iterator), in order 32/// to make multiple in-order test/set constant time after the first one is 33/// executed. Note that using vectors to store SparseBitVectorElement's does 34/// not work out very well because it causes insertion in the middle to take 35/// enormous amounts of time with a large amount of bits. Other structures that 36/// have better worst cases for insertion in the middle (various balanced trees, 37/// etc) do not perform as well in practice as a linked list with this iterator 38/// kept up to date. They are also significantly more memory intensive. 39 40 41template <unsigned ElementSize = 128> 42struct SparseBitVectorElement { 43public: 44 typedef unsigned long BitWord; 45 enum { 46 BITWORD_SIZE = sizeof(BitWord) * 8, 47 BITWORDS_PER_ELEMENT = (ElementSize + BITWORD_SIZE - 1) / BITWORD_SIZE, 48 BITS_PER_ELEMENT = ElementSize 49 }; 50 51 SparseBitVectorElement<ElementSize> *getNext() const { 52 return Next; 53 } 54 SparseBitVectorElement<ElementSize> *getPrev() const { 55 return Prev; 56 } 57 58 void setNext(SparseBitVectorElement<ElementSize> *RHS) { 59 Next = RHS; 60 } 61 void setPrev(SparseBitVectorElement<ElementSize> *RHS) { 62 Prev = RHS; 63 } 64 65private: 66 SparseBitVectorElement<ElementSize> *Next; 67 SparseBitVectorElement<ElementSize> *Prev; 68 // Index of Element in terms of where first bit starts. 69 unsigned ElementIndex; 70 BitWord Bits[BITWORDS_PER_ELEMENT]; 71 // Needed for sentinels 72 SparseBitVectorElement() { 73 ElementIndex = ~0UL; 74 memset(&Bits[0], 0, sizeof (BitWord) * BITWORDS_PER_ELEMENT); 75 } 76 77 friend struct ilist_traits<SparseBitVectorElement<ElementSize> >; 78 79public: 80 explicit SparseBitVectorElement(unsigned Idx) { 81 ElementIndex = Idx; 82 memset(&Bits[0], 0, sizeof (BitWord) * BITWORDS_PER_ELEMENT); 83 } 84 85 ~SparseBitVectorElement() { 86 } 87 88 // Copy ctor. 89 SparseBitVectorElement(const SparseBitVectorElement &RHS) { 90 ElementIndex = RHS.ElementIndex; 91 std::copy(&RHS.Bits[0], &RHS.Bits[BITWORDS_PER_ELEMENT], Bits); 92 } 93 94 // Comparison. 95 bool operator==(const SparseBitVectorElement &RHS) const { 96 if (ElementIndex != RHS.ElementIndex) 97 return false; 98 for (unsigned i = 0; i < BITWORDS_PER_ELEMENT; ++i) 99 if (Bits[i] != RHS.Bits[i]) 100 return false; 101 return true; 102 } 103 104 bool operator!=(const SparseBitVectorElement &RHS) const { 105 return !(*this == RHS); 106 } 107 108 // Return the bits that make up word Idx in our element. 109 BitWord word(unsigned Idx) const { 110 assert (Idx < BITWORDS_PER_ELEMENT); 111 return Bits[Idx]; 112 } 113 114 unsigned index() const { 115 return ElementIndex; 116 } 117 118 bool empty() const { 119 for (unsigned i = 0; i < BITWORDS_PER_ELEMENT; ++i) 120 if (Bits[i]) 121 return false; 122 return true; 123 } 124 125 void set(unsigned Idx) { 126 Bits[Idx / BITWORD_SIZE] |= 1L << (Idx % BITWORD_SIZE); 127 } 128 129 bool test_and_set (unsigned Idx) { 130 bool old = test(Idx); 131 if (!old) { 132 set(Idx); 133 return true; 134 } 135 return false; 136 } 137 138 void reset(unsigned Idx) { 139 Bits[Idx / BITWORD_SIZE] &= ~(1L << (Idx % BITWORD_SIZE)); 140 } 141 142 bool test(unsigned Idx) const { 143 return Bits[Idx / BITWORD_SIZE] & (1L << (Idx % BITWORD_SIZE)); 144 } 145 146 unsigned count() const { 147 unsigned NumBits = 0; 148 for (unsigned i = 0; i < BITWORDS_PER_ELEMENT; ++i) 149 if (sizeof(BitWord) == 4) 150 NumBits += CountPopulation_32(Bits[i]); 151 else if (sizeof(BitWord) == 8) 152 NumBits += CountPopulation_64(Bits[i]); 153 else 154 assert(0 && "Unsupported!"); 155 return NumBits; 156 } 157 158 /// find_first - Returns the index of the first set bit. 159 int find_first() const { 160 for (unsigned i = 0; i < BITWORDS_PER_ELEMENT; ++i) 161 if (Bits[i] != 0) { 162 if (sizeof(BitWord) == 4) 163 return i * BITWORD_SIZE + CountTrailingZeros_32(Bits[i]); 164 else if (sizeof(BitWord) == 8) 165 return i * BITWORD_SIZE + CountTrailingZeros_64(Bits[i]); 166 else 167 assert(0 && "Unsupported!"); 168 } 169 assert(0 && "Illegal empty element"); 170 } 171 172 /// find_next - Returns the index of the next set bit following the 173 /// "Prev" bit. Returns -1 if the next set bit is not found. 174 int find_next(unsigned Prev) const { 175 ++Prev; 176 if (Prev >= BITS_PER_ELEMENT) 177 return -1; 178 179 unsigned WordPos = Prev / BITWORD_SIZE; 180 unsigned BitPos = Prev % BITWORD_SIZE; 181 BitWord Copy = Bits[WordPos]; 182 assert (WordPos <= BITWORDS_PER_ELEMENT 183 && "Word Position outside of element"); 184 185 // Mask off previous bits. 186 Copy &= ~0L << BitPos; 187 188 if (Copy != 0) { 189 if (sizeof(BitWord) == 4) 190 return WordPos * BITWORD_SIZE + CountTrailingZeros_32(Copy); 191 else if (sizeof(BitWord) == 8) 192 return WordPos * BITWORD_SIZE + CountTrailingZeros_64(Copy); 193 else 194 assert(0 && "Unsupported!"); 195 } 196 197 // Check subsequent words. 198 for (unsigned i = WordPos+1; i < BITWORDS_PER_ELEMENT; ++i) 199 if (Bits[i] != 0) { 200 if (sizeof(BitWord) == 4) 201 return i * BITWORD_SIZE + CountTrailingZeros_32(Bits[i]); 202 else if (sizeof(BitWord) == 8) 203 return i * BITWORD_SIZE + CountTrailingZeros_64(Bits[i]); 204 else 205 assert(0 && "Unsupported!"); 206 } 207 return -1; 208 } 209 210 // Union this element with RHS and return true if this one changed. 211 bool unionWith(const SparseBitVectorElement &RHS) { 212 bool changed = false; 213 for (unsigned i = 0; i < BITWORDS_PER_ELEMENT; ++i) { 214 BitWord old = changed ? 0 : Bits[i]; 215 216 Bits[i] |= RHS.Bits[i]; 217 if (!changed && old != Bits[i]) 218 changed = true; 219 } 220 return changed; 221 } 222 223 // Return true if we have any bits in common with RHS 224 bool intersects(const SparseBitVectorElement &RHS) const { 225 for (unsigned i = 0; i < BITWORDS_PER_ELEMENT; ++i) { 226 if (RHS.Bits[i] & Bits[i]) 227 return true; 228 } 229 return false; 230 } 231 232 // Intersect this Element with RHS and return true if this one changed. 233 // BecameZero is set to true if this element became all-zero bits. 234 bool intersectWith(const SparseBitVectorElement &RHS, 235 bool &BecameZero) { 236 bool changed = false; 237 bool allzero = true; 238 239 BecameZero = false; 240 for (unsigned i = 0; i < BITWORDS_PER_ELEMENT; ++i) { 241 BitWord old = changed ? 0 : Bits[i]; 242 243 Bits[i] &= RHS.Bits[i]; 244 if (Bits[i] != 0) 245 allzero = false; 246 247 if (!changed && old != Bits[i]) 248 changed = true; 249 } 250 BecameZero = allzero; 251 return changed; 252 } 253 // Intersect this Element with the complement of RHS and return true if this 254 // one changed. BecameZero is set to true if this element became all-zero 255 // bits. 256 bool intersectWithComplement(const SparseBitVectorElement &RHS, 257 bool &BecameZero) { 258 bool changed = false; 259 bool allzero = true; 260 261 BecameZero = false; 262 for (unsigned i = 0; i < BITWORDS_PER_ELEMENT; ++i) { 263 BitWord old = changed ? 0 : Bits[i]; 264 265 Bits[i] &= ~RHS.Bits[i]; 266 if (Bits[i] != 0) 267 allzero = false; 268 269 if (!changed && old != Bits[i]) 270 changed = true; 271 } 272 BecameZero = allzero; 273 return changed; 274 } 275 // Three argument version of intersectWithComplement that intersects 276 // RHS1 & ~RHS2 into this element 277 void intersectWithComplement(const SparseBitVectorElement &RHS1, 278 const SparseBitVectorElement &RHS2, 279 bool &BecameZero) { 280 bool allzero = true; 281 282 BecameZero = false; 283 for (unsigned i = 0; i < BITWORDS_PER_ELEMENT; ++i) { 284 Bits[i] = RHS1.Bits[i] & ~RHS2.Bits[i]; 285 if (Bits[i] != 0) 286 allzero = false; 287 } 288 BecameZero = allzero; 289 } 290}; 291 292template <unsigned ElementSize = 128> 293class SparseBitVector { 294 typedef ilist<SparseBitVectorElement<ElementSize> > ElementList; 295 typedef typename ElementList::iterator ElementListIter; 296 typedef typename ElementList::const_iterator ElementListConstIter; 297 enum { 298 BITWORD_SIZE = SparseBitVectorElement<ElementSize>::BITWORD_SIZE 299 }; 300 301 // Pointer to our current Element. 302 ElementListIter CurrElementIter; 303 ElementList Elements; 304 305 // This is like std::lower_bound, except we do linear searching from the 306 // current position. 307 ElementListIter FindLowerBound(unsigned ElementIndex) { 308 309 if (Elements.empty()) { 310 CurrElementIter = Elements.begin(); 311 return Elements.begin(); 312 } 313 314 // Make sure our current iterator is valid. 315 if (CurrElementIter == Elements.end()) 316 --CurrElementIter; 317 318 // Search from our current iterator, either backwards or forwards, 319 // depending on what element we are looking for. 320 ElementListIter ElementIter = CurrElementIter; 321 if (CurrElementIter->index() == ElementIndex) { 322 return ElementIter; 323 } else if (CurrElementIter->index() > ElementIndex) { 324 while (ElementIter != Elements.begin() 325 && ElementIter->index() > ElementIndex) 326 --ElementIter; 327 } else { 328 while (ElementIter != Elements.end() && 329 ElementIter->index() <= ElementIndex) 330 ++ElementIter; 331 --ElementIter; 332 } 333 CurrElementIter = ElementIter; 334 return ElementIter; 335 } 336 337 // Iterator to walk set bits in the bitmap. This iterator is a lot uglier 338 // than it would be, in order to be efficient. 339 class SparseBitVectorIterator { 340 private: 341 bool AtEnd; 342 343 const SparseBitVector<ElementSize> *BitVector; 344 345 // Current element inside of bitmap. 346 ElementListConstIter Iter; 347 348 // Current bit number inside of our bitmap. 349 unsigned BitNumber; 350 351 // Current word number inside of our element. 352 unsigned WordNumber; 353 354 // Current bits from the element. 355 typename SparseBitVectorElement<ElementSize>::BitWord Bits; 356 357 // Move our iterator to the first non-zero bit in the bitmap. 358 void AdvanceToFirstNonZero() { 359 if (AtEnd) 360 return; 361 if (BitVector->Elements.empty()) { 362 AtEnd = true; 363 return; 364 } 365 Iter = BitVector->Elements.begin(); 366 BitNumber = Iter->index() * ElementSize; 367 unsigned BitPos = Iter->find_first(); 368 BitNumber += BitPos; 369 WordNumber = (BitNumber % ElementSize) / BITWORD_SIZE; 370 Bits = Iter->word(WordNumber); 371 Bits >>= BitPos % BITWORD_SIZE; 372 } 373 374 // Move our iterator to the next non-zero bit. 375 void AdvanceToNextNonZero() { 376 if (AtEnd) 377 return; 378 379 while (Bits && !(Bits & 1)) { 380 Bits >>= 1; 381 BitNumber += 1; 382 } 383 384 // See if we ran out of Bits in this word. 385 if (!Bits) { 386 int NextSetBitNumber = Iter->find_next(BitNumber % ElementSize) ; 387 // If we ran out of set bits in this element, move to next element. 388 if (NextSetBitNumber == -1 || (BitNumber % ElementSize == 0)) { 389 ++Iter; 390 WordNumber = 0; 391 392 // We may run out of elements in the bitmap. 393 if (Iter == BitVector->Elements.end()) { 394 AtEnd = true; 395 return; 396 } 397 // Set up for next non zero word in bitmap. 398 BitNumber = Iter->index() * ElementSize; 399 NextSetBitNumber = Iter->find_first(); 400 BitNumber += NextSetBitNumber; 401 WordNumber = (BitNumber % ElementSize) / BITWORD_SIZE; 402 Bits = Iter->word(WordNumber); 403 Bits >>= NextSetBitNumber % BITWORD_SIZE; 404 } else { 405 WordNumber = (NextSetBitNumber % ElementSize) / BITWORD_SIZE; 406 Bits = Iter->word(WordNumber); 407 Bits >>= NextSetBitNumber % BITWORD_SIZE; 408 } 409 } 410 } 411 public: 412 // Preincrement. 413 inline SparseBitVectorIterator& operator++() { 414 ++BitNumber; 415 Bits >>= 1; 416 AdvanceToNextNonZero(); 417 return *this; 418 } 419 420 // Postincrement. 421 inline SparseBitVectorIterator operator++(int) { 422 SparseBitVectorIterator tmp = *this; 423 ++*this; 424 return tmp; 425 } 426 427 // Return the current set bit number. 428 unsigned operator*() const { 429 return BitNumber; 430 } 431 432 bool operator==(const SparseBitVectorIterator &RHS) const { 433 // If they are both at the end, ignore the rest of the fields. 434 if (AtEnd == RHS.AtEnd) 435 return true; 436 // Otherwise they are the same if they have the same bit number and 437 // bitmap. 438 return AtEnd == RHS.AtEnd && RHS.BitNumber == BitNumber; 439 } 440 bool operator!=(const SparseBitVectorIterator &RHS) const { 441 return !(*this == RHS); 442 } 443 SparseBitVectorIterator(): BitVector(NULL) { 444 } 445 446 447 SparseBitVectorIterator(const SparseBitVector<ElementSize> *RHS, 448 bool end = false):BitVector(RHS) { 449 Iter = BitVector->Elements.begin(); 450 BitNumber = 0; 451 Bits = 0; 452 WordNumber = ~0; 453 AtEnd = end; 454 AdvanceToFirstNonZero(); 455 } 456 }; 457public: 458 typedef SparseBitVectorIterator iterator; 459 460 SparseBitVector () { 461 CurrElementIter = Elements.begin (); 462 } 463 464 ~SparseBitVector() { 465 } 466 467 // SparseBitVector copy ctor. 468 SparseBitVector(const SparseBitVector &RHS) { 469 ElementListConstIter ElementIter = RHS.Elements.begin(); 470 while (ElementIter != RHS.Elements.end()) { 471 Elements.push_back(SparseBitVectorElement<ElementSize>(*ElementIter)); 472 ++ElementIter; 473 } 474 475 CurrElementIter = Elements.begin (); 476 } 477 478 // Test, Reset, and Set a bit in the bitmap. 479 bool test(unsigned Idx) { 480 if (Elements.empty()) 481 return false; 482 483 unsigned ElementIndex = Idx / ElementSize; 484 ElementListIter ElementIter = FindLowerBound(ElementIndex); 485 486 // If we can't find an element that is supposed to contain this bit, there 487 // is nothing more to do. 488 if (ElementIter == Elements.end() || 489 ElementIter->index() != ElementIndex) 490 return false; 491 return ElementIter->test(Idx % ElementSize); 492 } 493 494 void reset(unsigned Idx) { 495 if (Elements.empty()) 496 return; 497 498 unsigned ElementIndex = Idx / ElementSize; 499 ElementListIter ElementIter = FindLowerBound(ElementIndex); 500 501 // If we can't find an element that is supposed to contain this bit, there 502 // is nothing more to do. 503 if (ElementIter == Elements.end() || 504 ElementIter->index() != ElementIndex) 505 return; 506 ElementIter->reset(Idx % ElementSize); 507 508 // When the element is zeroed out, delete it. 509 if (ElementIter->empty()) { 510 ++CurrElementIter; 511 Elements.erase(ElementIter); 512 } 513 } 514 515 void set(unsigned Idx) { 516 unsigned ElementIndex = Idx / ElementSize; 517 SparseBitVectorElement<ElementSize> *Element; 518 ElementListIter ElementIter; 519 if (Elements.empty()) { 520 Element = new SparseBitVectorElement<ElementSize>(ElementIndex); 521 ElementIter = Elements.insert(Elements.end(), Element); 522 523 } else { 524 ElementIter = FindLowerBound(ElementIndex); 525 526 if (ElementIter == Elements.end() || 527 ElementIter->index() != ElementIndex) { 528 Element = new SparseBitVectorElement<ElementSize>(ElementIndex); 529 // Insert does insert before, and lower bound gives the one before. 530 ElementIter = Elements.insert(++ElementIter, Element); 531 } 532 } 533 ElementIter->set(Idx % ElementSize); 534 } 535 536 bool test_and_set (unsigned Idx) { 537 bool old = test(Idx); 538 if (!old) { 539 set(Idx); 540 return true; 541 } 542 return false; 543 } 544 545 bool operator!=(const SparseBitVector &RHS) { 546 return !(*this == RHS); 547 } 548 549 bool operator==(const SparseBitVector &RHS) { 550 ElementListConstIter Iter1 = Elements.begin(); 551 ElementListConstIter Iter2 = RHS.Elements.begin(); 552 553 while (Iter2 != RHS.Elements.end()) { 554 if (Iter1->index() != Iter2->index() 555 || *Iter1 != *Iter2) 556 return false; 557 ++Iter1; 558 ++Iter2; 559 } 560 return Iter1 == Elements.end(); 561 } 562 563 // Union our bitmap with the RHS and return true if we changed. 564 bool operator|=(const SparseBitVector &RHS) { 565 bool changed = false; 566 ElementListIter Iter1 = Elements.begin(); 567 ElementListConstIter Iter2 = RHS.Elements.begin(); 568 569 // Check if both bitmaps are empty 570 if (Elements.empty() && RHS.Elements.empty()) 571 return false; 572 573 while (Iter2 != RHS.Elements.end()) { 574 if (Iter1 == Elements.end() || Iter1->index() > Iter2->index()) { 575 Elements.insert(Iter1, 576 new SparseBitVectorElement<ElementSize>(*Iter2)); 577 ++Iter2; 578 changed = true; 579 } else if (Iter1->index() == Iter2->index()) { 580 changed |= Iter1->unionWith(*Iter2); 581 ++Iter1; 582 ++Iter2; 583 } else { 584 ++Iter1; 585 } 586 } 587 CurrElementIter = Elements.begin(); 588 return changed; 589 } 590 591 // Intersect our bitmap with the RHS and return true if ours changed. 592 bool operator&=(const SparseBitVector &RHS) { 593 bool changed = false; 594 ElementListIter Iter1 = Elements.begin(); 595 ElementListConstIter Iter2 = RHS.Elements.begin(); 596 597 // Check if both bitmaps are empty. 598 if (Elements.empty() && RHS.Elements.empty()) 599 return false; 600 601 // Loop through, intersecting as we go, erasing elements when necessary. 602 while (Iter2 != RHS.Elements.end()) { 603 if (Iter1 == Elements.end()) 604 return changed; 605 606 if (Iter1->index() > Iter2->index()) { 607 ++Iter2; 608 } else if (Iter1->index() == Iter2->index()) { 609 bool BecameZero; 610 changed |= Iter1->intersectWith(*Iter2, BecameZero); 611 if (BecameZero) { 612 ElementListIter IterTmp = Iter1; 613 ++Iter1; 614 Elements.erase(IterTmp); 615 } else { 616 ++Iter1; 617 } 618 ++Iter2; 619 } else { 620 ElementListIter IterTmp = Iter1; 621 ++Iter1; 622 Elements.erase(IterTmp); 623 } 624 } 625 Elements.erase(Iter1, Elements.end()); 626 CurrElementIter = Elements.begin(); 627 return changed; 628 } 629 630 // Intersect our bitmap with the complement of the RHS and return true if ours 631 // changed. 632 bool intersectWithComplement(const SparseBitVector &RHS) { 633 bool changed = false; 634 ElementListIter Iter1 = Elements.begin(); 635 ElementListConstIter Iter2 = RHS.Elements.begin(); 636 637 // Check if they are both empty 638 if (Elements.empty() && RHS.Elements.empty()) 639 return false; 640 641 // Loop through, intersecting as we go, erasing elements when necessary. 642 while (Iter2 != RHS.Elements.end()) { 643 if (Iter1 == Elements.end()) 644 return changed; 645 646 if (Iter1->index() > Iter2->index()) { 647 ++Iter2; 648 } else if (Iter1->index() == Iter2->index()) { 649 bool BecameZero; 650 changed |= Iter1->intersectWithComplement(*Iter2, BecameZero); 651 if (BecameZero) { 652 ElementListIter IterTmp = Iter1; 653 ++Iter1; 654 Elements.erase(IterTmp); 655 } else { 656 ++Iter1; 657 } 658 ++Iter2; 659 } else { 660 ElementListIter IterTmp = Iter1; 661 ++Iter1; 662 Elements.erase(IterTmp); 663 } 664 } 665 CurrElementIter = Elements.begin(); 666 return changed; 667 } 668 669 bool intersectWithComplement(const SparseBitVector<ElementSize> *RHS) const { 670 return intersectWithComplement(*RHS); 671 } 672 673 674 // Three argument version of intersectWithComplement. Result of RHS1 & ~RHS2 675 // is stored into this bitmap. 676 void intersectWithComplement(const SparseBitVector<ElementSize> &RHS1, 677 const SparseBitVector<ElementSize> &RHS2) 678 { 679 Elements.clear(); 680 ElementListConstIter Iter1 = RHS1.Elements.begin(); 681 ElementListConstIter Iter2 = RHS2.Elements.begin(); 682 683 // Check if they are both empty. 684 if (RHS1.empty() && RHS2.empty()) 685 return; 686 687 // Loop through, intersecting as we go, erasing elements when necessary. 688 while (Iter2 != RHS2.Elements.end()) { 689 if (Iter1 == RHS1.Elements.end()) 690 return; 691 692 if (Iter1->index() > Iter2->index()) { 693 ++Iter2; 694 } else if (Iter1->index() == Iter2->index()) { 695 bool BecameZero = false; 696 SparseBitVectorElement<ElementSize> *NewElement = 697 new SparseBitVectorElement<ElementSize>(Iter1->index()); 698 NewElement->intersectWithComplement(*Iter1, *Iter2, BecameZero); 699 if (!BecameZero) { 700 Elements.push_back(NewElement); 701 } 702 else 703 delete NewElement; 704 ++Iter1; 705 ++Iter2; 706 } else { 707 ++Iter1; 708 } 709 } 710 711 // copy the remaining elements 712 while (Iter1 != RHS1.Elements.end()) { 713 SparseBitVectorElement<ElementSize> *NewElement = 714 new SparseBitVectorElement<ElementSize>(*Iter1); 715 Elements.push_back(NewElement); 716 ++Iter1; 717 } 718 719 CurrElementIter = Elements.begin(); 720 return; 721 } 722 723 void intersectWithComplement(const SparseBitVector<ElementSize> *RHS1, 724 const SparseBitVector<ElementSize> *RHS2) { 725 intersectWithComplement(*RHS1, *RHS2); 726 } 727 728 bool intersects(const SparseBitVector<ElementSize> *RHS) const { 729 return intersects(*RHS); 730 } 731 732 // Return true if we share any bits in common with RHS 733 bool intersects(const SparseBitVector<ElementSize> &RHS) const { 734 ElementListConstIter Iter1 = Elements.begin(); 735 ElementListConstIter Iter2 = RHS.Elements.begin(); 736 737 // Check if both bitmaps are empty. 738 if (Elements.empty() && RHS.Elements.empty()) 739 return false; 740 741 // Loop through, intersecting stopping when we hit bits in common. 742 while (Iter2 != RHS.Elements.end()) { 743 if (Iter1 == Elements.end()) 744 return false; 745 746 if (Iter1->index() > Iter2->index()) { 747 ++Iter2; 748 } else if (Iter1->index() == Iter2->index()) { 749 if (Iter1->intersects(*Iter2)) 750 return true; 751 ++Iter1; 752 ++Iter2; 753 } else { 754 ++Iter1; 755 } 756 } 757 return false; 758 } 759 760 // Return the first set bit in the bitmap. Return -1 if no bits are set. 761 int find_first() const { 762 if (Elements.empty()) 763 return -1; 764 const SparseBitVectorElement<ElementSize> &First = *(Elements.begin()); 765 return (First.index() * ElementSize) + First.find_first(); 766 } 767 768 // Return true if the SparseBitVector is empty 769 bool empty() const { 770 return Elements.empty(); 771 } 772 773 unsigned count() const { 774 unsigned BitCount = 0; 775 for (ElementListConstIter Iter = Elements.begin(); 776 Iter != Elements.end(); 777 ++Iter) 778 BitCount += Iter->count(); 779 780 return BitCount; 781 } 782 iterator begin() const { 783 return iterator(this); 784 } 785 786 iterator end() const { 787 return iterator(this, ~0); 788 } 789 790}; 791 792// Convenience functions to allow Or and And without dereferencing in the user 793// code. 794 795template <unsigned ElementSize> 796inline bool operator |=(SparseBitVector<ElementSize> &LHS, 797 const SparseBitVector<ElementSize> *RHS) { 798 return LHS |= *RHS; 799} 800 801template <unsigned ElementSize> 802inline bool operator |=(SparseBitVector<ElementSize> *LHS, 803 const SparseBitVector<ElementSize> &RHS) { 804 return LHS->operator|=(RHS); 805} 806 807template <unsigned ElementSize> 808inline bool operator &=(SparseBitVector<ElementSize> *LHS, 809 const SparseBitVector<ElementSize> &RHS) { 810 return LHS->operator&=(RHS); 811} 812 813template <unsigned ElementSize> 814inline bool operator &=(SparseBitVector<ElementSize> &LHS, 815 const SparseBitVector<ElementSize> *RHS) { 816 return LHS &= (*RHS); 817} 818 819 820// Dump a SparseBitVector to a stream 821template <unsigned ElementSize> 822void dump(const SparseBitVector<ElementSize> &LHS, llvm::OStream &out) { 823 out << "[ "; 824 825 typename SparseBitVector<ElementSize>::iterator bi; 826 for (bi = LHS.begin(); bi != LHS.end(); ++bi) { 827 out << *bi << " "; 828 } 829 out << "\n"; 830} 831 832} 833 834#endif 835