//
// 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 is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
#define LLVM_ADT_BITVECTOR_H
#include "llvm/Support/MathExtras.h"
+#include <algorithm>
+#include <cassert>
+#include <climits>
+#include <cstring>
namespace llvm {
class BitVector {
typedef unsigned long BitWord;
- enum { BITS_PER_WORD = sizeof(BitWord) * 8 };
+ enum { BITWORD_SIZE = (unsigned)sizeof(BitWord) * CHAR_BIT };
- BitWord *Bits; // Actual bits.
+ BitWord *Bits; // Actual bits.
unsigned Size; // Size of bitvector in bits.
unsigned Capacity; // Size of allocated memory in BitWord.
public:
reference(BitVector &b, unsigned Idx) {
- WordRef = &b.Bits[Idx / BITS_PER_WORD];
- BitPos = Idx % BITS_PER_WORD;
+ WordRef = &b.Bits[Idx / BITWORD_SIZE];
+ BitPos = Idx % BITWORD_SIZE;
}
~reference() {}
}
operator bool() const {
- return (*WordRef) & (1L << BitPos);
+ return ((*WordRef) & (1L << BitPos)) ? true : false;
}
};
/// BitVector default ctor - Creates an empty bitvector.
BitVector() : Size(0), Capacity(0) {
- Bits = NULL;
+ Bits = 0;
}
/// BitVector ctor - Creates a bitvector of specified number of bits. All
/// BitVector copy ctor.
BitVector(const BitVector &RHS) : Size(RHS.size()) {
if (Size == 0) {
- Bits = NULL;
+ Bits = 0;
+ Capacity = 0;
return;
}
std::copy(RHS.Bits, &RHS.Bits[Capacity], Bits);
}
+ ~BitVector() {
+ delete[] Bits;
+ }
+
/// size - Returns the number of bits in this bitvector.
unsigned size() const { return Size; }
unsigned NumBits = 0;
for (unsigned i = 0; i < NumBitWords(size()); ++i)
if (sizeof(BitWord) == 4)
- NumBits += CountPopulation_32(Bits[i]);
+ NumBits += CountPopulation_32((uint32_t)Bits[i]);
else if (sizeof(BitWord) == 8)
NumBits += CountPopulation_64(Bits[i]);
else
- assert(0 && "Unsupported!")
+ assert(0 && "Unsupported!");
return NumBits;
}
/// 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]);
+ if (Bits[i] != 0) {
+ if (sizeof(BitWord) == 4)
+ return i * BITWORD_SIZE + CountTrailingZeros_32((uint32_t)Bits[i]);
+ else if (sizeof(BitWord) == 8)
+ return i * BITWORD_SIZE + CountTrailingZeros_64(Bits[i]);
+ else
+ assert(0 && "Unsupported!");
+ }
return -1;
}
if (Prev >= Size)
return -1;
- unsigned WordPos = Prev / BITS_PER_WORD;
- unsigned BitPos = Prev % BITS_PER_WORD;
+ unsigned WordPos = Prev / BITWORD_SIZE;
+ unsigned BitPos = Prev % BITWORD_SIZE;
BitWord Copy = Bits[WordPos];
// Mask off previous bits.
- Copy &= ~0 << BitPos;
+ Copy &= ~0L << BitPos;
- if (Copy != 0)
- return WordPos * BITS_PER_WORD + CountTrailingZeros_32(Copy);
+ if (Copy != 0) {
+ if (sizeof(BitWord) == 4)
+ return WordPos * BITWORD_SIZE + CountTrailingZeros_32((uint32_t)Copy);
+ else if (sizeof(BitWord) == 8)
+ return WordPos * BITWORD_SIZE + CountTrailingZeros_64(Copy);
+ else
+ assert(0 && "Unsupported!");
+ }
// 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]);
+ if (Bits[i] != 0) {
+ if (sizeof(BitWord) == 4)
+ return i * BITWORD_SIZE + CountTrailingZeros_32((uint32_t)Bits[i]);
+ else if (sizeof(BitWord) == 8)
+ return i * BITWORD_SIZE + CountTrailingZeros_64(Bits[i]);
+ else
+ assert(0 && "Unsupported!");
+ }
return -1;
}
/// resize - Grow or shrink the bitvector.
void resize(unsigned N, bool t = false) {
- if (N > Capacity * BITS_PER_WORD) {
+ if (N > Capacity * BITWORD_SIZE) {
unsigned OldCapacity = Capacity;
grow(N);
init_words(&Bits[OldCapacity], (Capacity-OldCapacity), t);
}
+
+ // Set any old unused bits that are now included in the BitVector. This
+ // may set bits that are not included in the new vector, but we will clear
+ // them back out below.
+ if (N > Size)
+ set_unused_bits(t);
+
+ // Update the size, and clear out any bits that are now unused
+ unsigned OldSize = Size;
Size = N;
- if (t)
+ if (t || N < OldSize)
clear_unused_bits();
}
void reserve(unsigned N) {
- if (N > Capacity * BITS_PER_WORD)
+ if (N > Capacity * BITWORD_SIZE)
grow(N);
}
}
BitVector &set(unsigned Idx) {
- Bits[Idx / BITS_PER_WORD] |= 1L << (Idx % BITS_PER_WORD);
+ Bits[Idx / BITWORD_SIZE] |= 1L << (Idx % BITWORD_SIZE);
return *this;
}
}
BitVector &reset(unsigned Idx) {
- Bits[Idx / BITS_PER_WORD] &= ~(1L << (Idx % BITS_PER_WORD));
+ Bits[Idx / BITWORD_SIZE] &= ~(1L << (Idx % BITWORD_SIZE));
return *this;
}
}
BitVector &flip(unsigned Idx) {
- Bits[Idx / BITS_PER_WORD] ^= 1L << (Idx % BITS_PER_WORD);
+ Bits[Idx / BITWORD_SIZE] ^= 1L << (Idx % BITWORD_SIZE);
return *this;
}
// Indexing.
reference operator[](unsigned Idx) {
+ assert (Idx < Size && "Out-of-bounds Bit access.");
return reference(*this, Idx);
}
bool operator[](unsigned Idx) const {
- BitWord Mask = 1L << (Idx % BITS_PER_WORD);
- return (Bits[Idx / BITS_PER_WORD] & Mask) != 0;
+ assert (Idx < Size && "Out-of-bounds Bit access.");
+ BitWord Mask = 1L << (Idx % BITWORD_SIZE);
+ return (Bits[Idx / BITWORD_SIZE] & Mask) != 0;
}
bool test(unsigned Idx) const {
// Comparison operators.
bool operator==(const BitVector &RHS) const {
- if (Size != RHS.Size)
- return false;
-
- for (unsigned i = 0; i < NumBitWords(size()); ++i)
+ unsigned ThisWords = NumBitWords(size());
+ unsigned RHSWords = NumBitWords(RHS.size());
+ unsigned i;
+ for (i = 0; i != std::min(ThisWords, RHSWords); ++i)
if (Bits[i] != RHS.Bits[i])
return false;
+
+ // Verify that any extra words are all zeros.
+ if (i != ThisWords) {
+ for (; i != ThisWords; ++i)
+ if (Bits[i])
+ return false;
+ } else if (i != RHSWords) {
+ for (; i != RHSWords; ++i)
+ if (RHS.Bits[i])
+ return false;
+ }
return true;
}
}
// Intersection, union, disjoint union.
- BitVector operator&=(const BitVector &RHS) {
- assert(Size == RHS.Size && "Illegal operation!");
- for (unsigned i = 0; i < NumBitWords(size()); ++i)
+ BitVector &operator&=(const BitVector &RHS) {
+ unsigned ThisWords = NumBitWords(size());
+ unsigned RHSWords = NumBitWords(RHS.size());
+ unsigned i;
+ for (i = 0; i != std::min(ThisWords, RHSWords); ++i)
Bits[i] &= RHS.Bits[i];
+
+ // Any bits that are just in this bitvector become zero, because they aren't
+ // in the RHS bit vector. Any words only in RHS are ignored because they
+ // are already zero in the LHS.
+ for (; i != ThisWords; ++i)
+ Bits[i] = 0;
+
return *this;
}
- BitVector operator|=(const BitVector &RHS) {
+ 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) {
+ 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;
Size = RHS.size();
unsigned RHSWords = NumBitWords(Size);
- if (Size <= Capacity * BITS_PER_WORD) {
+ if (Size <= Capacity * BITWORD_SIZE) {
std::copy(RHS.Bits, &RHS.Bits[RHSWords], Bits);
clear_unused_bits();
return *this;
}
-
+
// Grow the bitvector to have enough elements.
- Capacity = NumBitWords(Size);
+ Capacity = RHSWords;
BitWord *NewBits = new BitWord[Capacity];
std::copy(RHS.Bits, &RHS.Bits[RHSWords], NewBits);
private:
unsigned NumBitWords(unsigned S) const {
- return (S + BITS_PER_WORD-1) / BITS_PER_WORD;
+ return (S + BITWORD_SIZE-1) / BITWORD_SIZE;
}
- // Clear the unused top bits in the high word.
- void clear_unused_bits() {
- if (Size) {
- unsigned ExtraBits = Size % BITS_PER_WORD;
- Bits[Size / BITS_PER_WORD] &= ~(~0 << ExtraBits);
+ // Set the unused bits in the high words.
+ void set_unused_bits(bool t = true) {
+ // Set high words first.
+ unsigned UsedWords = NumBitWords(Size);
+ if (Capacity > UsedWords)
+ init_words(&Bits[UsedWords], (Capacity-UsedWords), t);
+
+ // Then set any stray high bits of the last used word.
+ unsigned ExtraBits = Size % BITWORD_SIZE;
+ if (ExtraBits) {
+ Bits[UsedWords-1] &= ~(~0L << ExtraBits);
+ Bits[UsedWords-1] |= (0 - (BitWord)t) << ExtraBits;
}
}
+ // Clear the unused bits in the high words.
+ void clear_unused_bits() {
+ set_unused_bits(false);
+ }
+
void grow(unsigned NewSize) {
unsigned OldCapacity = Capacity;
Capacity = NumBitWords(NewSize);
// Destroy the old bits.
delete[] Bits;
Bits = NewBits;
+
+ clear_unused_bits();
}
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) {
Result ^= RHS;
return Result;
}
-
+
} // End llvm namespace
#endif
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