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			350 lines
		
	
	
		
			9.3 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			350 lines
		
	
	
		
			9.3 KiB
		
	
	
	
		
			C++
		
	
	
	
| //===-- sanitizer_bitvector.h -----------------------------------*- C++ -*-===//
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| //
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| // This file is distributed under the University of Illinois Open Source
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| // License. See LICENSE.TXT for details.
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| //
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| //===----------------------------------------------------------------------===//
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| //
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| // Specializer BitVector implementation.
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| //
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| //===----------------------------------------------------------------------===//
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| 
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| #ifndef SANITIZER_BITVECTOR_H
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| #define SANITIZER_BITVECTOR_H
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| 
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| #include "sanitizer_common.h"
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| 
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| namespace __sanitizer {
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| 
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| // Fixed size bit vector based on a single basic integer.
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| template <class basic_int_t = uptr>
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| class BasicBitVector {
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|  public:
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|   enum SizeEnum : uptr { kSize = sizeof(basic_int_t) * 8 };
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| 
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|   uptr size() const { return kSize; }
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|   // No CTOR.
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|   void clear() { bits_ = 0; }
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|   void setAll() { bits_ = ~(basic_int_t)0; }
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|   bool empty() const { return bits_ == 0; }
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| 
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|   // Returns true if the bit has changed from 0 to 1.
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|   bool setBit(uptr idx) {
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|     basic_int_t old = bits_;
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|     bits_ |= mask(idx);
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|     return bits_ != old;
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|   }
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| 
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|   // Returns true if the bit has changed from 1 to 0.
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|   bool clearBit(uptr idx) {
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|     basic_int_t old = bits_;
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|     bits_ &= ~mask(idx);
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|     return bits_ != old;
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|   }
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| 
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|   bool getBit(uptr idx) const { return (bits_ & mask(idx)) != 0; }
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| 
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|   uptr getAndClearFirstOne() {
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|     CHECK(!empty());
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|     uptr idx = LeastSignificantSetBitIndex(bits_);
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|     clearBit(idx);
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|     return idx;
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|   }
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| 
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|   // Do "this |= v" and return whether new bits have been added.
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|   bool setUnion(const BasicBitVector &v) {
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|     basic_int_t old = bits_;
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|     bits_ |= v.bits_;
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|     return bits_ != old;
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|   }
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| 
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|   // Do "this &= v" and return whether any bits have been removed.
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|   bool setIntersection(const BasicBitVector &v) {
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|     basic_int_t old = bits_;
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|     bits_ &= v.bits_;
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|     return bits_ != old;
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|   }
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| 
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|   // Do "this &= ~v" and return whether any bits have been removed.
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|   bool setDifference(const BasicBitVector &v) {
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|     basic_int_t old = bits_;
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|     bits_ &= ~v.bits_;
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|     return bits_ != old;
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|   }
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| 
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|   void copyFrom(const BasicBitVector &v) { bits_ = v.bits_; }
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| 
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|   // Returns true if 'this' intersects with 'v'.
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|   bool intersectsWith(const BasicBitVector &v) const {
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|     return (bits_ & v.bits_) != 0;
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|   }
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| 
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|   // for (BasicBitVector<>::Iterator it(bv); it.hasNext();) {
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|   //   uptr idx = it.next();
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|   //   use(idx);
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|   // }
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|   class Iterator {
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|    public:
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|     Iterator() { }
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|     explicit Iterator(const BasicBitVector &bv) : bv_(bv) {}
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|     bool hasNext() const { return !bv_.empty(); }
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|     uptr next() { return bv_.getAndClearFirstOne(); }
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|     void clear() { bv_.clear(); }
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|    private:
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|     BasicBitVector bv_;
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|   };
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| 
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|  private:
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|   basic_int_t mask(uptr idx) const {
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|     CHECK_LT(idx, size());
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|     return (basic_int_t)1UL << idx;
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|   }
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|   basic_int_t bits_;
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| };
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| 
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| // Fixed size bit vector of (kLevel1Size*BV::kSize**2) bits.
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| // The implementation is optimized for better performance on
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| // sparse bit vectors, i.e. the those with few set bits.
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| template <uptr kLevel1Size = 1, class BV = BasicBitVector<> >
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| class TwoLevelBitVector {
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|   // This is essentially a 2-level bit vector.
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|   // Set bit in the first level BV indicates that there are set bits
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|   // in the corresponding BV of the second level.
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|   // This structure allows O(kLevel1Size) time for clear() and empty(),
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|   // as well fast handling of sparse BVs.
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|  public:
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|   enum SizeEnum : uptr { kSize = BV::kSize * BV::kSize * kLevel1Size };
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|   // No CTOR.
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| 
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|   uptr size() const { return kSize; }
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| 
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|   void clear() {
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|     for (uptr i = 0; i < kLevel1Size; i++)
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|       l1_[i].clear();
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|   }
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| 
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|   void setAll() {
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|     for (uptr i0 = 0; i0 < kLevel1Size; i0++) {
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|       l1_[i0].setAll();
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|       for (uptr i1 = 0; i1 < BV::kSize; i1++)
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|         l2_[i0][i1].setAll();
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|     }
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|   }
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| 
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|   bool empty() const {
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|     for (uptr i = 0; i < kLevel1Size; i++)
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|       if (!l1_[i].empty())
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|         return false;
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|     return true;
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|   }
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| 
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|   // Returns true if the bit has changed from 0 to 1.
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|   bool setBit(uptr idx) {
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|     check(idx);
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|     uptr i0 = idx0(idx);
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|     uptr i1 = idx1(idx);
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|     uptr i2 = idx2(idx);
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|     if (!l1_[i0].getBit(i1)) {
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|       l1_[i0].setBit(i1);
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|       l2_[i0][i1].clear();
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|     }
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|     bool res = l2_[i0][i1].setBit(i2);
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|     // Printf("%s: %zd => %zd %zd %zd; %d\n", __func__,
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|     // idx, i0, i1, i2, res);
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|     return res;
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|   }
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| 
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|   bool clearBit(uptr idx) {
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|     check(idx);
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|     uptr i0 = idx0(idx);
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|     uptr i1 = idx1(idx);
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|     uptr i2 = idx2(idx);
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|     bool res = false;
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|     if (l1_[i0].getBit(i1)) {
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|       res = l2_[i0][i1].clearBit(i2);
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|       if (l2_[i0][i1].empty())
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|         l1_[i0].clearBit(i1);
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|     }
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|     return res;
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|   }
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| 
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|   bool getBit(uptr idx) const {
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|     check(idx);
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|     uptr i0 = idx0(idx);
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|     uptr i1 = idx1(idx);
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|     uptr i2 = idx2(idx);
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|     // Printf("%s: %zd => %zd %zd %zd\n", __func__, idx, i0, i1, i2);
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|     return l1_[i0].getBit(i1) && l2_[i0][i1].getBit(i2);
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|   }
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| 
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|   uptr getAndClearFirstOne() {
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|     for (uptr i0 = 0; i0 < kLevel1Size; i0++) {
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|       if (l1_[i0].empty()) continue;
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|       uptr i1 = l1_[i0].getAndClearFirstOne();
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|       uptr i2 = l2_[i0][i1].getAndClearFirstOne();
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|       if (!l2_[i0][i1].empty())
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|         l1_[i0].setBit(i1);
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|       uptr res = i0 * BV::kSize * BV::kSize + i1 * BV::kSize + i2;
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|       // Printf("getAndClearFirstOne: %zd %zd %zd => %zd\n", i0, i1, i2, res);
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|       return res;
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|     }
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|     CHECK(0);
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|     return 0;
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|   }
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| 
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|   // Do "this |= v" and return whether new bits have been added.
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|   bool setUnion(const TwoLevelBitVector &v) {
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|     bool res = false;
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|     for (uptr i0 = 0; i0 < kLevel1Size; i0++) {
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|       BV t = v.l1_[i0];
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|       while (!t.empty()) {
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|         uptr i1 = t.getAndClearFirstOne();
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|         if (l1_[i0].setBit(i1))
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|           l2_[i0][i1].clear();
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|         if (l2_[i0][i1].setUnion(v.l2_[i0][i1]))
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|           res = true;
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|       }
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|     }
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|     return res;
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|   }
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| 
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|   // Do "this &= v" and return whether any bits have been removed.
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|   bool setIntersection(const TwoLevelBitVector &v) {
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|     bool res = false;
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|     for (uptr i0 = 0; i0 < kLevel1Size; i0++) {
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|       if (l1_[i0].setIntersection(v.l1_[i0]))
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|         res = true;
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|       if (!l1_[i0].empty()) {
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|         BV t = l1_[i0];
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|         while (!t.empty()) {
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|           uptr i1 = t.getAndClearFirstOne();
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|           if (l2_[i0][i1].setIntersection(v.l2_[i0][i1]))
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|             res = true;
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|           if (l2_[i0][i1].empty())
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|             l1_[i0].clearBit(i1);
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|         }
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|       }
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|     }
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|     return res;
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|   }
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| 
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|   // Do "this &= ~v" and return whether any bits have been removed.
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|   bool setDifference(const TwoLevelBitVector &v) {
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|     bool res = false;
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|     for (uptr i0 = 0; i0 < kLevel1Size; i0++) {
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|       BV t = l1_[i0];
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|       t.setIntersection(v.l1_[i0]);
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|       while (!t.empty()) {
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|         uptr i1 = t.getAndClearFirstOne();
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|         if (l2_[i0][i1].setDifference(v.l2_[i0][i1]))
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|           res = true;
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|         if (l2_[i0][i1].empty())
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|           l1_[i0].clearBit(i1);
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|       }
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|     }
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|     return res;
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|   }
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| 
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|   void copyFrom(const TwoLevelBitVector &v) {
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|     clear();
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|     setUnion(v);
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|   }
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| 
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|   // Returns true if 'this' intersects with 'v'.
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|   bool intersectsWith(const TwoLevelBitVector &v) const {
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|     for (uptr i0 = 0; i0 < kLevel1Size; i0++) {
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|       BV t = l1_[i0];
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|       t.setIntersection(v.l1_[i0]);
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|       while (!t.empty()) {
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|         uptr i1 = t.getAndClearFirstOne();
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|         if (!v.l1_[i0].getBit(i1)) continue;
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|         if (l2_[i0][i1].intersectsWith(v.l2_[i0][i1]))
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|           return true;
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|       }
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|     }
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|     return false;
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|   }
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| 
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|   // for (TwoLevelBitVector<>::Iterator it(bv); it.hasNext();) {
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|   //   uptr idx = it.next();
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|   //   use(idx);
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|   // }
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|   class Iterator {
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|    public:
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|     Iterator() { }
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|     explicit Iterator(const TwoLevelBitVector &bv) : bv_(bv), i0_(0), i1_(0) {
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|       it1_.clear();
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|       it2_.clear();
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|     }
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| 
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|     bool hasNext() const {
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|       if (it1_.hasNext()) return true;
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|       for (uptr i = i0_; i < kLevel1Size; i++)
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|         if (!bv_.l1_[i].empty()) return true;
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|       return false;
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|     }
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| 
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|     uptr next() {
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|       // Printf("++++: %zd %zd; %d %d; size %zd\n", i0_, i1_, it1_.hasNext(),
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|       //       it2_.hasNext(), kSize);
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|       if (!it1_.hasNext() && !it2_.hasNext()) {
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|         for (; i0_ < kLevel1Size; i0_++) {
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|           if (bv_.l1_[i0_].empty()) continue;
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|           it1_ = typename BV::Iterator(bv_.l1_[i0_]);
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|           // Printf("+i0: %zd %zd; %d %d; size %zd\n", i0_, i1_, it1_.hasNext(),
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|           //   it2_.hasNext(), kSize);
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|           break;
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|         }
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|       }
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|       if (!it2_.hasNext()) {
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|         CHECK(it1_.hasNext());
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|         i1_ = it1_.next();
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|         it2_ = typename BV::Iterator(bv_.l2_[i0_][i1_]);
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|         // Printf("++i1: %zd %zd; %d %d; size %zd\n", i0_, i1_, it1_.hasNext(),
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|         //       it2_.hasNext(), kSize);
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|       }
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|       CHECK(it2_.hasNext());
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|       uptr i2 = it2_.next();
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|       uptr res = i0_ * BV::kSize * BV::kSize + i1_ * BV::kSize + i2;
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|       // Printf("+ret: %zd %zd; %d %d; size %zd; res: %zd\n", i0_, i1_,
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|       //       it1_.hasNext(), it2_.hasNext(), kSize, res);
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|       if (!it1_.hasNext() && !it2_.hasNext())
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|         i0_++;
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|       return res;
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|     }
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| 
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|    private:
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|     const TwoLevelBitVector &bv_;
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|     uptr i0_, i1_;
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|     typename BV::Iterator it1_, it2_;
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|   };
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| 
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|  private:
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|   void check(uptr idx) const { CHECK_LE(idx, size()); }
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| 
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|   uptr idx0(uptr idx) const {
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|     uptr res = idx / (BV::kSize * BV::kSize);
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|     CHECK_LE(res, kLevel1Size);
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|     return res;
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|   }
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| 
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|   uptr idx1(uptr idx) const {
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|     uptr res = (idx / BV::kSize) % BV::kSize;
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|     CHECK_LE(res, BV::kSize);
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|     return res;
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|   }
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| 
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|   uptr idx2(uptr idx) const {
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|     uptr res = idx % BV::kSize;
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|     CHECK_LE(res, BV::kSize);
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|     return res;
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|   }
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| 
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|   BV l1_[kLevel1Size];
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|   BV l2_[kLevel1Size][BV::kSize];
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| };
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| 
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| } // namespace __sanitizer
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| 
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| #endif // SANITIZER_BITVECTOR_H
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