--- /dev/null
+//===- llvm/ADT/BitVector.h - Bit vectors -----------------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by Evan Cheng and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the BitVector class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ADT_BITVECTOR_H
+#define LLVM_ADT_BITVECTOR_H
+
+#include "llvm/Support/MathExtras.h"
+
+namespace llvm {
+
+class BitVector {
+ typedef unsigned long BitWord;
+
+ enum { BITS_PER_WORD = sizeof(BitWord) * 8 };
+
+ BitWord *Bits; // Actual bits.
+ unsigned Size; // Size of bitvector in bits.
+ unsigned Capacity; // Size of allocated memory in BitWord.
+
+public:
+ // Encapsulation of a single bit.
+ class reference {
+ friend class BitVector;
+
+ BitWord *WordRef;
+ unsigned BitPos;
+
+ reference(); // Undefined
+
+ public:
+ reference(BitVector &b, unsigned Idx) {
+ WordRef = &b.Bits[Idx / BITS_PER_WORD];
+ BitPos = Idx % BITS_PER_WORD;
+ }
+
+ ~reference() {}
+
+ reference& operator=(bool t) {
+ if (t)
+ *WordRef |= 1 << BitPos;
+ else
+ *WordRef &= ~(1 << BitPos);
+ return *this;
+ }
+
+ reference& operator=(const reference& rhs) {
+ if (*rhs.WordRef & (1 << rhs.BitPos))
+ *WordRef |= 1 << BitPos;
+ else
+ *WordRef &= ~(1 << BitPos);
+ return *this;
+ }
+
+ operator bool() const {
+ return (*WordRef) & (1 << BitPos);
+ }
+ };
+
+
+ /// BitVector default ctor - Creates an empty bitvector.
+ BitVector() : Size(0), Capacity(0) {
+ Bits = new BitWord[0];
+ }
+
+ /// BitVector ctor - Creates a bitvector of specified number of bits. All
+ /// bits are initialized to false;
+ BitVector(unsigned s) : Size(s) {
+ Capacity = NumBitWords(s);
+ Bits = new BitWord[Capacity];
+ init_words(Bits, Capacity, false);
+ }
+
+ /// BitVector ctor - Creates a bitvector of specified number of bits. All
+ /// bits are initialized to the specified value.
+ BitVector(unsigned s, bool t) : Size(s) {
+ Capacity = NumBitWords(s);
+ Bits = new BitWord[Capacity];
+ init_words(Bits, Capacity, t);
+ }
+
+ /// BitVector copy ctor.
+ BitVector(const BitVector &RHS) : Size(RHS.size()) {
+ Capacity = NumBitWords(RHS.size());
+ Bits = new BitWord[Capacity];
+ std::copy(RHS.Bits, &RHS.Bits[Capacity], Bits);
+ }
+
+ /// size - Returns the number of bits in this bitvector.
+ unsigned size() const { return Size; }
+
+ /// count - Returns the number of bits which are set.
+ unsigned count() const {
+ unsigned NumBits = 0;
+ for (unsigned i = 0; i < NumBitWords(size()); ++i)
+ NumBits = CountPopulation_32(Bits[i]);
+ return NumBits;
+ }
+
+ /// any - Returns true if any bit is set.
+ bool any() const {
+ for (unsigned i = 0; i < NumBitWords(size()); ++i)
+ if (Bits[i] != 0)
+ return true;
+ return false;
+ }
+
+ /// none - Returns true if none of the bits are set.
+ bool none() const {
+ return !any();
+ }
+
+ /// find_first - Returns the index of the first set bit, -1 if none
+ /// of the bits are set.
+ int find_first() const {
+ for (unsigned i = 0; i < NumBitWords(size()); ++i)
+ if (Bits[i] != 0)
+ return i * BITS_PER_WORD + CountTrailingZeros_32(Bits[i]);
+ return -1;
+ }
+
+ /// find_next - Returns the index of the next set bit following the
+ /// "Prev" bit. Returns -1 if the next set bit is not found.
+ int find_next(unsigned Prev) const {
+ ++Prev;
+ if (Prev >= Size)
+ return -1;
+
+ unsigned WordPos = Prev / BITS_PER_WORD;
+ unsigned BitPos = Prev % BITS_PER_WORD;
+ BitWord Copy = Bits[WordPos];
+ // Mask off previous bits.
+ Copy &= ~0 << BitPos;
+
+ if (Copy != 0)
+ return WordPos * BITS_PER_WORD + CountTrailingZeros_32(Copy);
+
+ // Check subsequent words.
+ for (unsigned i = WordPos+1; i < NumBitWords(size()); ++i)
+ if (Bits[i] != 0)
+ return i * BITS_PER_WORD + CountTrailingZeros_32(Bits[i]);
+ return -1;
+ }
+
+ /// clear - Clear all bits.
+ void clear() {
+ delete[] Bits;
+ Bits = new BitWord[0];
+ Size = Capacity = 0;
+ }
+
+ /// resize - Grow or shrink the bitvector.
+ void resize(unsigned N) {
+ if (N > Capacity * BITS_PER_WORD) {
+ unsigned OldCapacity = Capacity;
+ grow(N);
+ init_words(&Bits[OldCapacity], (Capacity-OldCapacity), false);
+ }
+ Size = N;
+ }
+
+ void resize(unsigned N, bool t) {
+ if (N > Capacity * BITS_PER_WORD) {
+ unsigned OldCapacity = Capacity;
+ grow(N);
+ init_words(&Bits[OldCapacity], (Capacity-OldCapacity), t);
+ }
+ Size = N;
+ }
+
+ void reserve(unsigned N) {
+ if (N > Capacity * BITS_PER_WORD)
+ grow(N);
+ }
+
+ // Set, reset, flip
+ BitVector &set() {
+ init_words(Bits, Capacity, true);
+ clear_unused_bits();
+ return *this;
+ }
+
+ BitVector &set(unsigned Idx) {
+ Bits[Idx / BITS_PER_WORD] |= 1 << (Idx % BITS_PER_WORD);
+ return *this;
+ }
+
+ BitVector &reset() {
+ init_words(Bits, Capacity, false);
+ return *this;
+ }
+
+ BitVector &reset(unsigned Idx) {
+ Bits[Idx / BITS_PER_WORD] &= ~(1 << (Idx % BITS_PER_WORD));
+ return *this;
+ }
+
+ BitVector &flip() {
+ for (unsigned i = 0; i < NumBitWords(size()); ++i)
+ Bits[i] = ~Bits[i];
+ clear_unused_bits();
+ return *this;
+ }
+
+ BitVector &flip(unsigned Idx) {
+ Bits[Idx / BITS_PER_WORD] ^= 1 << (Idx % BITS_PER_WORD);
+ return *this;
+ }
+
+ // No argument flip.
+ BitVector operator~() const {
+ return BitVector(*this).flip();
+ }
+
+ // Indexing.
+ reference operator[](unsigned Idx) {
+ return reference(*this, Idx);
+ }
+
+ bool operator[](unsigned Idx) const {
+ BitWord Mask = 1 << (Idx % BITS_PER_WORD);
+ return (Bits[Idx / BITS_PER_WORD] & Mask) != 0;
+ }
+
+ bool test(unsigned Idx) const {
+ return (*this)[Idx];
+ }
+
+ // Comparison operators.
+ bool operator==(const BitVector &RHS) const {
+ assert(Size == RHS.Size && "Illegal operation!");
+ for (unsigned i = 0; i < NumBitWords(size()); ++i)
+ if (Bits[i] != RHS.Bits[i])
+ return false;
+ return true;
+ }
+
+ bool operator!=(const BitVector &RHS) const {
+ return !(*this == RHS);
+ }
+
+ // Intersection, union, disjoint union.
+ BitVector operator&=(const BitVector &RHS) {
+ assert(Size == RHS.Size && "Illegal operation!");
+ for (unsigned i = 0; i < NumBitWords(size()); ++i)
+ Bits[i] &= RHS.Bits[i];
+ return *this;
+ }
+
+ BitVector operator|=(const BitVector &RHS) {
+ assert(Size == RHS.Size && "Illegal operation!");
+ for (unsigned i = 0; i < NumBitWords(size()); ++i)
+ Bits[i] |= RHS.Bits[i];
+ return *this;
+ }
+
+ BitVector operator^=(const BitVector &RHS) {
+ assert(Size == RHS.Size && "Illegal operation!");
+ for (unsigned i = 0; i < NumBitWords(size()); ++i)
+ Bits[i] ^= RHS.Bits[i];
+ return *this;
+ }
+
+ // Assignment operator.
+ const BitVector &operator=(const BitVector &RHS) {
+ if (this == &RHS) return *this;
+
+ unsigned RHSWords = NumBitWords(RHS.size());
+ unsigned NewSize = RHS.size();
+ if (NewSize <= Capacity * BITS_PER_WORD) {
+ std::copy(RHS.Bits, &RHS.Bits[RHSWords], Bits);
+ Size = NewSize;
+ clear_unused_bits();
+ return *this;
+ }
+
+ // Grow the bitvector to have enough elements.
+ Capacity = NumBitWords(NewSize);
+ BitWord *NewBits = new BitWord[Capacity];
+ std::copy(RHS.Bits, &RHS.Bits[RHSWords], NewBits);
+
+ // Destroy the old bits.
+ delete[] Bits;
+ Bits = NewBits;
+
+ return *this;
+ }
+
+private:
+ unsigned NumBitWords(unsigned S) const {
+ return (S + BITS_PER_WORD-1) / BITS_PER_WORD;
+ }
+
+ // Clear the unused top bits in the high word.
+ void clear_unused_bits() {
+ unsigned ExtraBits = Size % BITS_PER_WORD;
+ Bits[Size / BITS_PER_WORD] &= ~(~0 << ExtraBits);
+ }
+
+ void grow(unsigned NewSize) {
+ unsigned OldCapacity = Capacity;
+ Capacity = NumBitWords(NewSize);
+ BitWord *NewBits = new BitWord[Capacity];
+
+ // Copy the old bits over.
+ if (OldCapacity != 0)
+ std::copy(Bits, &Bits[OldCapacity], NewBits);
+
+ // Destroy the old bits.
+ delete[] Bits;
+ Bits = NewBits;
+ }
+
+ void init_words(BitWord *B, unsigned NumWords, bool t) {
+ memset(B, 0 - (int)t, NumWords*sizeof(BitWord));
+ }
+};
+
+inline BitVector operator&(const BitVector &LHS, const BitVector &RHS) {
+ BitVector Result(LHS);
+ Result &= RHS;
+ return Result;
+}
+
+inline BitVector operator|(const BitVector &LHS, const BitVector &RHS) {
+ BitVector Result(LHS);
+ Result |= RHS;
+ return Result;
+}
+
+inline BitVector operator^(const BitVector &LHS, const BitVector &RHS) {
+ BitVector Result(LHS);
+ Result ^= RHS;
+ return Result;
+}
+
+} // End llvm namespace
+#endif
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