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+//===-- sanitizer_bitvector.h -----------------------------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// 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 { 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 { 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_LE(idx, size()); }
+
+ uptr idx0(uptr idx) const {
+ uptr res = idx / (BV::kSize * BV::kSize);
+ CHECK_LE(res, kLevel1Size);
+ return res;
+ }
+
+ uptr idx1(uptr idx) const {
+ uptr res = (idx / BV::kSize) % BV::kSize;
+ CHECK_LE(res, BV::kSize);
+ return res;
+ }
+
+ uptr idx2(uptr idx) const {
+ uptr res = idx % BV::kSize;
+ CHECK_LE(res, BV::kSize);
+ return res;
+ }
+
+ BV l1_[kLevel1Size];
+ BV l2_[kLevel1Size][BV::kSize];
+};
+
+} // namespace __sanitizer
+
+#endif // SANITIZER_BITVECTOR_H
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