| //===-- sanitizer_bitvector.h -----------------------------------*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // Specializer BitVector implementation. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef SANITIZER_BITVECTOR_H |
| #define SANITIZER_BITVECTOR_H |
| |
| #include "sanitizer_common.h" |
| |
| namespace __sanitizer { |
| |
| // Fixed size bit vector based on a single basic integer. |
| template <class basic_int_t = uptr> |
| class BasicBitVector { |
| public: |
| enum SizeEnum : uptr { kSize = sizeof(basic_int_t) * 8 }; |
| |
| uptr size() const { return kSize; } |
| // No CTOR. |
| void clear() { bits_ = 0; } |
| void setAll() { bits_ = ~(basic_int_t)0; } |
| bool empty() const { return bits_ == 0; } |
| |
| // Returns true if the bit has changed from 0 to 1. |
| bool setBit(uptr idx) { |
| basic_int_t old = bits_; |
| bits_ |= mask(idx); |
| return bits_ != old; |
| } |
| |
| // Returns true if the bit has changed from 1 to 0. |
| bool clearBit(uptr idx) { |
| basic_int_t old = bits_; |
| bits_ &= ~mask(idx); |
| return bits_ != old; |
| } |
| |
| bool getBit(uptr idx) const { return (bits_ & mask(idx)) != 0; } |
| |
| uptr getAndClearFirstOne() { |
| CHECK(!empty()); |
| uptr idx = LeastSignificantSetBitIndex(bits_); |
| clearBit(idx); |
| return idx; |
| } |
| |
| // Do "this |= v" and return whether new bits have been added. |
| bool setUnion(const BasicBitVector &v) { |
| basic_int_t old = bits_; |
| bits_ |= v.bits_; |
| return bits_ != old; |
| } |
| |
| // Do "this &= v" and return whether any bits have been removed. |
| bool setIntersection(const BasicBitVector &v) { |
| basic_int_t old = bits_; |
| bits_ &= v.bits_; |
| return bits_ != old; |
| } |
| |
| // Do "this &= ~v" and return whether any bits have been removed. |
| bool setDifference(const BasicBitVector &v) { |
| basic_int_t old = bits_; |
| bits_ &= ~v.bits_; |
| return bits_ != old; |
| } |
| |
| void copyFrom(const BasicBitVector &v) { bits_ = v.bits_; } |
| |
| // Returns true if 'this' intersects with 'v'. |
| bool intersectsWith(const BasicBitVector &v) const { |
| return (bits_ & v.bits_) != 0; |
| } |
| |
| // for (BasicBitVector<>::Iterator it(bv); it.hasNext();) { |
| // uptr idx = it.next(); |
| // use(idx); |
| // } |
| class Iterator { |
| public: |
| Iterator() { } |
| explicit Iterator(const BasicBitVector &bv) : bv_(bv) {} |
| bool hasNext() const { return !bv_.empty(); } |
| uptr next() { return bv_.getAndClearFirstOne(); } |
| void clear() { bv_.clear(); } |
| private: |
| BasicBitVector bv_; |
| }; |
| |
| private: |
| basic_int_t mask(uptr idx) const { |
| CHECK_LT(idx, size()); |
| return (basic_int_t)1UL << idx; |
| } |
| basic_int_t bits_; |
| }; |
| |
| // Fixed size bit vector of (kLevel1Size*BV::kSize**2) bits. |
| // The implementation is optimized for better performance on |
| // sparse bit vectors, i.e. the those with few set bits. |
| template <uptr kLevel1Size = 1, class BV = BasicBitVector<> > |
| class TwoLevelBitVector { |
| // This is essentially a 2-level bit vector. |
| // Set bit in the first level BV indicates that there are set bits |
| // in the corresponding BV of the second level. |
| // This structure allows O(kLevel1Size) time for clear() and empty(), |
| // as well fast handling of sparse BVs. |
| public: |
| enum SizeEnum : uptr { kSize = BV::kSize * BV::kSize * kLevel1Size }; |
| // No CTOR. |
| |
| uptr size() const { return kSize; } |
| |
| void clear() { |
| for (uptr i = 0; i < kLevel1Size; i++) |
| l1_[i].clear(); |
| } |
| |
| void setAll() { |
| for (uptr i0 = 0; i0 < kLevel1Size; i0++) { |
| l1_[i0].setAll(); |
| for (uptr i1 = 0; i1 < BV::kSize; i1++) |
| l2_[i0][i1].setAll(); |
| } |
| } |
| |
| bool empty() const { |
| for (uptr i = 0; i < kLevel1Size; i++) |
| if (!l1_[i].empty()) |
| return false; |
| return true; |
| } |
| |
| // Returns true if the bit has changed from 0 to 1. |
| bool setBit(uptr idx) { |
| check(idx); |
| uptr i0 = idx0(idx); |
| uptr i1 = idx1(idx); |
| uptr i2 = idx2(idx); |
| if (!l1_[i0].getBit(i1)) { |
| l1_[i0].setBit(i1); |
| l2_[i0][i1].clear(); |
| } |
| bool res = l2_[i0][i1].setBit(i2); |
| // Printf("%s: %zd => %zd %zd %zd; %d\n", __func__, |
| // idx, i0, i1, i2, res); |
| return res; |
| } |
| |
| bool clearBit(uptr idx) { |
| check(idx); |
| uptr i0 = idx0(idx); |
| uptr i1 = idx1(idx); |
| uptr i2 = idx2(idx); |
| bool res = false; |
| if (l1_[i0].getBit(i1)) { |
| res = l2_[i0][i1].clearBit(i2); |
| if (l2_[i0][i1].empty()) |
| l1_[i0].clearBit(i1); |
| } |
| return res; |
| } |
| |
| bool getBit(uptr idx) const { |
| check(idx); |
| uptr i0 = idx0(idx); |
| uptr i1 = idx1(idx); |
| uptr i2 = idx2(idx); |
| // Printf("%s: %zd => %zd %zd %zd\n", __func__, idx, i0, i1, i2); |
| return l1_[i0].getBit(i1) && l2_[i0][i1].getBit(i2); |
| } |
| |
| uptr getAndClearFirstOne() { |
| for (uptr i0 = 0; i0 < kLevel1Size; i0++) { |
| if (l1_[i0].empty()) continue; |
| uptr i1 = l1_[i0].getAndClearFirstOne(); |
| uptr i2 = l2_[i0][i1].getAndClearFirstOne(); |
| if (!l2_[i0][i1].empty()) |
| l1_[i0].setBit(i1); |
| uptr res = i0 * BV::kSize * BV::kSize + i1 * BV::kSize + i2; |
| // Printf("getAndClearFirstOne: %zd %zd %zd => %zd\n", i0, i1, i2, res); |
| return res; |
| } |
| CHECK(0); |
| return 0; |
| } |
| |
| // Do "this |= v" and return whether new bits have been added. |
| bool setUnion(const TwoLevelBitVector &v) { |
| bool res = false; |
| for (uptr i0 = 0; i0 < kLevel1Size; i0++) { |
| BV t = v.l1_[i0]; |
| while (!t.empty()) { |
| uptr i1 = t.getAndClearFirstOne(); |
| if (l1_[i0].setBit(i1)) |
| l2_[i0][i1].clear(); |
| if (l2_[i0][i1].setUnion(v.l2_[i0][i1])) |
| res = true; |
| } |
| } |
| return res; |
| } |
| |
| // Do "this &= v" and return whether any bits have been removed. |
| bool setIntersection(const TwoLevelBitVector &v) { |
| bool res = false; |
| for (uptr i0 = 0; i0 < kLevel1Size; i0++) { |
| if (l1_[i0].setIntersection(v.l1_[i0])) |
| res = true; |
| if (!l1_[i0].empty()) { |
| BV t = l1_[i0]; |
| while (!t.empty()) { |
| uptr i1 = t.getAndClearFirstOne(); |
| if (l2_[i0][i1].setIntersection(v.l2_[i0][i1])) |
| res = true; |
| if (l2_[i0][i1].empty()) |
| l1_[i0].clearBit(i1); |
| } |
| } |
| } |
| return res; |
| } |
| |
| // Do "this &= ~v" and return whether any bits have been removed. |
| bool setDifference(const TwoLevelBitVector &v) { |
| bool res = false; |
| for (uptr i0 = 0; i0 < kLevel1Size; i0++) { |
| BV t = l1_[i0]; |
| t.setIntersection(v.l1_[i0]); |
| while (!t.empty()) { |
| uptr i1 = t.getAndClearFirstOne(); |
| if (l2_[i0][i1].setDifference(v.l2_[i0][i1])) |
| res = true; |
| if (l2_[i0][i1].empty()) |
| l1_[i0].clearBit(i1); |
| } |
| } |
| return res; |
| } |
| |
| void copyFrom(const TwoLevelBitVector &v) { |
| clear(); |
| setUnion(v); |
| } |
| |
| // Returns true if 'this' intersects with 'v'. |
| bool intersectsWith(const TwoLevelBitVector &v) const { |
| for (uptr i0 = 0; i0 < kLevel1Size; i0++) { |
| BV t = l1_[i0]; |
| t.setIntersection(v.l1_[i0]); |
| while (!t.empty()) { |
| uptr i1 = t.getAndClearFirstOne(); |
| if (!v.l1_[i0].getBit(i1)) continue; |
| if (l2_[i0][i1].intersectsWith(v.l2_[i0][i1])) |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| // for (TwoLevelBitVector<>::Iterator it(bv); it.hasNext();) { |
| // uptr idx = it.next(); |
| // use(idx); |
| // } |
| class Iterator { |
| public: |
| Iterator() { } |
| explicit Iterator(const TwoLevelBitVector &bv) : bv_(bv), i0_(0), i1_(0) { |
| it1_.clear(); |
| it2_.clear(); |
| } |
| |
| bool hasNext() const { |
| if (it1_.hasNext()) return true; |
| for (uptr i = i0_; i < kLevel1Size; i++) |
| if (!bv_.l1_[i].empty()) return true; |
| return false; |
| } |
| |
| uptr next() { |
| // Printf("++++: %zd %zd; %d %d; size %zd\n", i0_, i1_, it1_.hasNext(), |
| // it2_.hasNext(), kSize); |
| if (!it1_.hasNext() && !it2_.hasNext()) { |
| for (; i0_ < kLevel1Size; i0_++) { |
| if (bv_.l1_[i0_].empty()) continue; |
| it1_ = typename BV::Iterator(bv_.l1_[i0_]); |
| // Printf("+i0: %zd %zd; %d %d; size %zd\n", i0_, i1_, it1_.hasNext(), |
| // it2_.hasNext(), kSize); |
| break; |
| } |
| } |
| if (!it2_.hasNext()) { |
| CHECK(it1_.hasNext()); |
| i1_ = it1_.next(); |
| it2_ = typename BV::Iterator(bv_.l2_[i0_][i1_]); |
| // Printf("++i1: %zd %zd; %d %d; size %zd\n", i0_, i1_, it1_.hasNext(), |
| // it2_.hasNext(), kSize); |
| } |
| CHECK(it2_.hasNext()); |
| uptr i2 = it2_.next(); |
| uptr res = i0_ * BV::kSize * BV::kSize + i1_ * BV::kSize + i2; |
| // Printf("+ret: %zd %zd; %d %d; size %zd; res: %zd\n", i0_, i1_, |
| // it1_.hasNext(), it2_.hasNext(), kSize, res); |
| if (!it1_.hasNext() && !it2_.hasNext()) |
| i0_++; |
| return res; |
| } |
| |
| private: |
| const TwoLevelBitVector &bv_; |
| uptr i0_, i1_; |
| typename BV::Iterator it1_, it2_; |
| }; |
| |
| private: |
| void check(uptr idx) const { CHECK_LT(idx, size()); } |
| |
| uptr idx0(uptr idx) const { |
| uptr res = idx / (BV::kSize * BV::kSize); |
| CHECK_LT(res, kLevel1Size); |
| return res; |
| } |
| |
| uptr idx1(uptr idx) const { |
| uptr res = (idx / BV::kSize) % BV::kSize; |
| CHECK_LT(res, BV::kSize); |
| return res; |
| } |
| |
| uptr idx2(uptr idx) const { |
| uptr res = idx % BV::kSize; |
| CHECK_LT(res, BV::kSize); |
| return res; |
| } |
| |
| BV l1_[kLevel1Size]; |
| BV l2_[kLevel1Size][BV::kSize]; |
| }; |
| |
| } // namespace __sanitizer |
| |
| #endif // SANITIZER_BITVECTOR_H |