//===- llvm/ADT/BitVector.h - Bit vectors -----------------------*- 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
//
//===----------------------------------------------------------------------===//
///
/// \file
/// This file implements the BitVector class.
///
//===----------------------------------------------------------------------===//
#ifndef LLVM_ADT_BITVECTOR_H
#define LLVM_ADT_BITVECTOR_H
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMapInfo.h"
#include "llvm/ADT/iterator_range.h"
#include "llvm/Support/MathExtras.h"
#include <algorithm>
#include <cassert>
#include <climits>
#include <cstdint>
#include <cstdlib>
#include <cstring>
#include <utility>
namespace llvm {
/// ForwardIterator for the bits that are set.
/// Iterators get invalidated when resize / reserve is called.
template <typename BitVectorT> class const_set_bits_iterator_impl {
const BitVectorT &Parent;
int Current = 0;
void advance() {
assert(Current != -1 && "Trying to advance past end.");
Current = Parent.find_next(Current);
}
public:
const_set_bits_iterator_impl(const BitVectorT &Parent, int Current)
: Parent(Parent), Current(Current) {}
explicit const_set_bits_iterator_impl(const BitVectorT &Parent)
: const_set_bits_iterator_impl(Parent, Parent.find_first()) {}
const_set_bits_iterator_impl(const const_set_bits_iterator_impl &) = default;
const_set_bits_iterator_impl operator++(int) {
auto Prev = *this;
advance();
return Prev;
}
const_set_bits_iterator_impl &operator++() {
advance();
return *this;
}
unsigned operator*() const { return Current; }
bool operator==(const const_set_bits_iterator_impl &Other) const {
assert(&Parent == &Other.Parent &&
"Comparing iterators from different BitVectors");
return Current == Other.Current;
}
bool operator!=(const const_set_bits_iterator_impl &Other) const {
assert(&Parent == &Other.Parent &&
"Comparing iterators from different BitVectors");
return Current != Other.Current;
}
};
class BitVector {
typedef uintptr_t BitWord;
enum { BITWORD_SIZE = (unsigned)sizeof(BitWord) * CHAR_BIT };
static_assert(BITWORD_SIZE == 64 || BITWORD_SIZE == 32,
"Unsupported word size");
using Storage = SmallVector<BitWord>;
Storage Bits; // Actual bits.
unsigned Size = 0; // Size of bitvector in bits.
public:
using size_type = unsigned;
// Encapsulation of a single bit.
class reference {
BitWord *WordRef;
unsigned BitPos;
public:
reference(BitVector &b, unsigned Idx) {
WordRef = &b.Bits[Idx / BITWORD_SIZE];
BitPos = Idx % BITWORD_SIZE;
}
reference() = delete;
reference(const reference&) = default;
reference &operator=(reference t) {
*this = bool(t);
return *this;
}
reference& operator=(bool t) {
if (t)
*WordRef |= BitWord(1) << BitPos;
else
*WordRef &= ~(BitWord(1) << BitPos);
return *this;
}
operator bool() const {
return ((*WordRef) & (BitWord(1) << BitPos)) != 0;
}
};
typedef const_set_bits_iterator_impl<BitVector> const_set_bits_iterator;
typedef const_set_bits_iterator set_iterator;
const_set_bits_iterator set_bits_begin() const {
return const_set_bits_iterator(*this);
}
const_set_bits_iterator set_bits_end() const {
return const_set_bits_iterator(*this, -1);
}
iterator_range<const_set_bits_iterator> set_bits() const {
return make_range(set_bits_begin(), set_bits_end());
}
/// BitVector default ctor - Creates an empty bitvector.
BitVector() = default;
/// BitVector ctor - Creates a bitvector of specified number of bits. All
/// bits are initialized to the specified value.
explicit BitVector(unsigned s, bool t = false)
: Bits(NumBitWords(s), 0 - (BitWord)t), Size(s) {
if (t)
clear_unused_bits();
}
/// empty - Tests whether there are no bits in this bitvector.
bool empty() const { return Size == 0; }
/// size - Returns the number of bits in this bitvector.
size_type size() const { return Size; }
/// count - Returns the number of bits which are set.
size_type count() const {
unsigned NumBits = 0;
for (auto Bit : Bits)
NumBits += llvm::popcount(Bit);
return NumBits;
}
/// any - Returns true if any bit is set.
bool any() const {
return any_of(Bits, [](BitWord Bit) { return Bit != 0; });
}
/// all - Returns true if all bits are set.
bool all() const {
for (unsigned i = 0; i < Size / BITWORD_SIZE; ++i)
if (Bits[i] != ~BitWord(0))
return false;
// If bits remain check that they are ones. The unused bits are always zero.
if (unsigned Remainder = Size % BITWORD_SIZE)
return Bits[Size / BITWORD_SIZE] == (BitWord(1) << Remainder) - 1;
return true;
}
/// none - Returns true if none of the bits are set.
bool none() const {
return !any();
}
/// find_first_in - Returns the index of the first set / unset bit,
/// depending on \p Set, in the range [Begin, End).
/// Returns -1 if all bits in the range are unset / set.
int find_first_in(unsigned Begin, unsigned End, bool Set = true) const {
assert(Begin <= End && End <= Size);
if (Begin == End)
return -1;
unsigned FirstWord = Begin / BITWORD_SIZE;
unsigned LastWord = (End - 1) / BITWORD_SIZE;
// Check subsequent words.
// The code below is based on search for the first _set_ bit. If
// we're searching for the first _unset_, we just take the
// complement of each word before we use it and apply
// the same method.
for (unsigned i = FirstWord; i <= LastWord; ++i) {
BitWord Copy = Bits[i];
if (!Set)
Copy = ~Copy;
if (i == FirstWord) {
unsigned FirstBit = Begin % BITWORD_SIZE;
Copy &= maskTrailingZeros<BitWord>(FirstBit);
}
if (i == LastWord) {
unsigned LastBit = (End - 1) % BITWORD_SIZE;
Copy &= maskTrailingOnes<BitWord>(LastBit + 1);
}
if (Copy != 0)
return i * BITWORD_SIZE + countTrailingZeros(Copy);
}
return -1;
}
/// find_last_in - Returns the index of the last set bit in the range
/// [Begin, End). Returns -1 if all bits in the range are unset.
int find_last_in(unsigned Begin, unsigned End) const {
assert(Begin <= End && End <= Size);
if (Begin == End)
return -1;
unsigned LastWord = (End - 1) / BITWORD_SIZE;
unsigned FirstWord = Begin / BITWORD_SIZE;
for (unsigned i = LastWord + 1; i >= FirstWord + 1; --i) {
unsigned CurrentWord = i - 1;
BitWord Copy = Bits[CurrentWord];
if (CurrentWord == LastWord) {
unsigned LastBit = (End - 1) % BITWORD_SIZE;
Copy &= maskTrailingOnes<BitWord>(LastBit + 1);
}
if (CurrentWord == FirstWord) {
unsigned FirstBit = Begin % BITWORD_SIZE;
Copy &= maskTrailingZeros<BitWord>(FirstBit);
}
if (Copy != 0)
return (CurrentWord + 1) * BITWORD_SIZE - countLeadingZeros(Copy) - 1;
}
return -1;
}
/// find_first_unset_in - Returns the index of the first unset bit in the
/// range [Begin, End). Returns -1 if all bits in the range are set.
int find_first_unset_in(unsigned Begin, unsigned End) const {
return find_first_in(Begin, End, /* Set = */ false);
}
/// find_last_unset_in - Returns the index of the last unset bit in the
/// range [Begin, End). Returns -1 if all bits in the range are set.
int find_last_unset_in(unsigned Begin, unsigned End) const {
assert(Begin <= End && End <= Size);
if (Begin == End)
return -1;
unsigned LastWord = (End - 1) / BITWORD_SIZE;
unsigned FirstWord = Begin / BITWORD_SIZE;
for (unsigned i = LastWord + 1; i >= FirstWord + 1; --i) {
unsigned CurrentWord = i - 1;
BitWord Copy = Bits[CurrentWord];
if (CurrentWord == LastWord) {
unsigned LastBit = (End - 1) % BITWORD_SIZE;
Copy |= maskTrailingZeros<BitWord>(LastBit + 1);
}
if (CurrentWord == FirstWord) {
unsigned FirstBit = Begin % BITWORD_SIZE;
Copy |= maskTrailingOnes<BitWord>(FirstBit);
}
if (Copy != ~BitWord(0)) {
unsigned Result =
(CurrentWord + 1) * BITWORD_SIZE - countLeadingOnes(Copy) - 1;
return Result < Size ? Result : -1;
}
}
return -1;
}
/// find_first - Returns the index of the first set bit, -1 if none
/// of the bits are set.
int find_first() const { return find_first_in(0, Size); }
/// find_last - Returns the index of the last set bit, -1 if none of the bits
/// are set.
int find_last() const { return find_last_in(0, Size); }
/// 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 { return find_first_in(Prev + 1, Size); }
/// find_prev - Returns the index of the first set bit that precedes the
/// the bit at \p PriorTo. Returns -1 if all previous bits are unset.
int find_prev(unsigned PriorTo) const { return find_last_in(0, PriorTo); }
/// find_first_unset - Returns the index of the first unset bit, -1 if all
/// of the bits are set.
int find_first_unset() const { return find_first_unset_in(0, Size); }
/// find_next_unset - Returns the index of the next unset bit following the
/// "Prev" bit. Returns -1 if all remaining bits are set.
int find_next_unset(unsigned Prev) const {
return find_first_unset_in(Prev + 1, Size);
}
/// find_last_unset - Returns the index of the last unset bit, -1 if all of
/// the bits are set.
int find_last_unset() const { return find_last_unset_in(0, Size); }
/// find_prev_unset - Returns the index of the first unset bit that precedes
/// the bit at \p PriorTo. Returns -1 if all previous bits are set.
int find_prev_unset(unsigned PriorTo) {
return find_last_unset_in(0, PriorTo);
}
/// clear - Removes all bits from the bitvector.
void clear() {
Size = 0;
Bits.clear();
}
/// resize - Grow or shrink the bitvector.
void resize(unsigned N, bool t = false) {
set_unused_bits(t);
Size = N;
Bits.resize(NumBitWords(N), 0 - BitWord(t));
clear_unused_bits();
}
void reserve(unsigned N) { Bits.reserve(NumBitWords(N)); }
// Set, reset, flip
BitVector &set() {
init_words(true);
clear_unused_bits();
return *this;
}
BitVector &set(unsigned Idx) {
assert(Idx < Size && "access in bound");
Bits[Idx / BITWORD_SIZE] |= BitWord(1) << (Idx % BITWORD_SIZE);
return *this;
}
/// set - Efficiently set a range of bits in [I, E)
BitVector &set(unsigned I, unsigned E) {
assert(I <= E && "Attempted to set backwards range!");
assert(E <= size() && "Attempted to set out-of-bounds range!");
if (I == E) return *this;
if (I / BITWORD_SIZE == E / BITWORD_SIZE) {
BitWord EMask = BitWord(1) << (E % BITWORD_SIZE);
BitWord IMask = BitWord(1) << (I % BITWORD_SIZE);
BitWord Mask = EMask - IMask;
Bits[I / BITWORD_SIZE] |= Mask;
return *this;
}
BitWord PrefixMask = ~BitWord(0) << (I % BITWORD_SIZE);
Bits[I / BITWORD_SIZE] |= PrefixMask;
I = alignTo(I, BITWORD_SIZE);
for (; I + BITWORD_SIZE <= E; I += BITWORD_SIZE)
Bits[I / BITWORD_SIZE] = ~BitWord(0);
BitWord PostfixMask = (BitWord(1) << (E % BITWORD_SIZE)) - 1;
if (I < E)
Bits[I / BITWORD_SIZE] |= PostfixMask;
return *this;
}
BitVector &reset() {
init_words(false);
return *this;
}
BitVector &reset(unsigned Idx) {
Bits[Idx / BITWORD_SIZE] &= ~(BitWord(1) << (Idx % BITWORD_SIZE));
return *this;
}
/// reset - Efficiently reset a range of bits in [I, E)
BitVector &reset(unsigned I, unsigned E) {
assert(I <= E && "Attempted to reset backwards range!");
assert(E <= size() && "Attempted to reset out-of-bounds range!");
if (I == E) return *this;
if (I / BITWORD_SIZE == E / BITWORD_SIZE) {
BitWord EMask = BitWord(1) << (E % BITWORD_SIZE);
BitWord IMask = BitWord(1) << (I % BITWORD_SIZE);
BitWord Mask = EMask - IMask;
Bits[I / BITWORD_SIZE] &= ~Mask;
return *this;
}
BitWord PrefixMask = ~BitWord(0) << (I % BITWORD_SIZE);
Bits[I / BITWORD_SIZE] &= ~PrefixMask;
I = alignTo(I, BITWORD_SIZE);
for (; I + BITWORD_SIZE <= E; I += BITWORD_SIZE)
Bits[I / BITWORD_SIZE] = BitWord(0);
BitWord PostfixMask = (BitWord(1) << (E % BITWORD_SIZE)) - 1;
if (I < E)
Bits[I / BITWORD_SIZE] &= ~PostfixMask;
return *this;
}
BitVector &flip() {
for (auto &Bit : Bits)
Bit = ~Bit;
clear_unused_bits();
return *this;
}
BitVector &flip(unsigned Idx) {
Bits[Idx / BITWORD_SIZE] ^= BitWord(1) << (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 {
assert (Idx < Size && "Out-of-bounds Bit access.");
BitWord Mask = BitWord(1) << (Idx % BITWORD_SIZE);
return (Bits[Idx / BITWORD_SIZE] & Mask) != 0;
}
/// Return the last element in the vector.
bool back() const {
assert(!empty() && "Getting last element of empty vector.");
return (*this)[size() - 1];
}
bool test(unsigned Idx) const {
return (*this)[Idx];
}
// Push single bit to end of vector.
void push_back(bool Val) {
unsigned OldSize = Size;
unsigned NewSize = Size + 1;
// Resize, which will insert zeros.
// If we already fit then the unused bits will be already zero.
if (NewSize > getBitCapacity())
resize(NewSize, false);
else
Size = NewSize;
// If true, set single bit.
if (Val)
set(OldSize);
}
/// Pop one bit from the end of the vector.
void pop_back() {
assert(!empty() && "Empty vector has no element to pop.");
resize(size() - 1);
}
/// Test if any common bits are set.
bool anyCommon(const BitVector &RHS) const {
unsigned ThisWords = Bits.size();
unsigned RHSWords = RHS.Bits.size();
for (unsigned i = 0, e = std::min(ThisWords, RHSWords); i != e; ++i)
if (Bits[i] & RHS.Bits[i])
return true;
return false;
}
// Comparison operators.
bool operator==(const BitVector &RHS) const {
if (size() != RHS.size())
return false;
unsigned NumWords = Bits.size();
return std::equal(Bits.begin(), Bits.begin() + NumWords, RHS.Bits.begin());
}
bool operator!=(const BitVector &RHS) const { return !(*this == RHS); }
/// Intersection, union, disjoint union.
BitVector &operator&=(const BitVector &RHS) {
unsigned ThisWords = Bits.size();
unsigned RHSWords = RHS.Bits.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;
}
/// reset - Reset bits that are set in RHS. Same as *this &= ~RHS.
BitVector &reset(const BitVector &RHS) {
unsigned ThisWords = Bits.size();
unsigned RHSWords = RHS.Bits.size();
for (unsigned i = 0; i != std::min(ThisWords, RHSWords); ++i)
Bits[i] &= ~RHS.Bits[i];
return *this;
}
/// test - Check if (This - RHS) is zero.
/// This is the same as reset(RHS) and any().
bool test(const BitVector &RHS) const {
unsigned ThisWords = Bits.size();
unsigned RHSWords = RHS.Bits.size();
unsigned i;
for (i = 0; i != std::min(ThisWords, RHSWords); ++i)
if ((Bits[i] & ~RHS.Bits[i]) != 0)
return true;
for (; i != ThisWords ; ++i)
if (Bits[i] != 0)
return true;
return false;
}
template <class F, class... ArgTys>
static BitVector &apply(F &&f, BitVector &Out, BitVector const &Arg,
ArgTys const &...Args) {
assert(llvm::all_of(
std::initializer_list<unsigned>{Args.size()...},
[&Arg](auto const &BV) { return Arg.size() == BV; }) &&
"consistent sizes");
Out.resize(Arg.size());
for (size_type I = 0, E = Arg.Bits.size(); I != E; ++I)
Out.Bits[I] = f(Arg.Bits[I], Args.Bits[I]...);
Out.clear_unused_bits();
return Out;
}
BitVector &operator|=(const BitVector &RHS) {
if (size() < RHS.size())
resize(RHS.size());
for (size_type I = 0, E = RHS.Bits.size(); I != E; ++I)
Bits[I] |= RHS.Bits[I];
return *this;
}
BitVector &operator^=(const BitVector &RHS) {
if (size() < RHS.size())
resize(RHS.size());
for (size_type I = 0, E = RHS.Bits.size(); I != E; ++I)
Bits[I] ^= RHS.Bits[I];
return *this;
}
BitVector &operator>>=(unsigned N) {
assert(N <= Size);
if (LLVM_UNLIKELY(empty() || N == 0))
return *this;
unsigned NumWords = Bits.size();
assert(NumWords >= 1);
wordShr(N / BITWORD_SIZE);
unsigned BitDistance = N % BITWORD_SIZE;
if (BitDistance == 0)
return *this;
// When the shift size is not a multiple of the word size, then we have
// a tricky situation where each word in succession needs to extract some
// of the bits from the next word and or them into this word while
// shifting this word to make room for the new bits. This has to be done
// for every word in the array.
// Since we're shifting each word right, some bits will fall off the end
// of each word to the right, and empty space will be created on the left.
// The final word in the array will lose bits permanently, so starting at
// the beginning, work forwards shifting each word to the right, and
// OR'ing in the bits from the end of the next word to the beginning of
// the current word.
// Example:
// Starting with {0xAABBCCDD, 0xEEFF0011, 0x22334455} and shifting right
// by 4 bits.
// Step 1: Word[0] >>= 4 ; 0x0ABBCCDD
// Step 2: Word[0] |= 0x10000000 ; 0x1ABBCCDD
// Step 3: Word[1] >>= 4 ; 0x0EEFF001
// Step 4: Word[1] |= 0x50000000 ; 0x5EEFF001
// Step 5: Word[2] >>= 4 ; 0x02334455
// Result: { 0x1ABBCCDD, 0x5EEFF001, 0x02334455 }
const BitWord Mask = maskTrailingOnes<BitWord>(BitDistance);
const unsigned LSH = BITWORD_SIZE - BitDistance;
for (unsigned I = 0; I < NumWords - 1; ++I) {
Bits[I] >>= BitDistance;
Bits[I] |= (Bits[I + 1] & Mask) << LSH;
}
Bits[NumWords - 1] >>= BitDistance;
return *this;
}
BitVector &operator<<=(unsigned N) {
assert(N <= Size);
if (LLVM_UNLIKELY(empty() || N == 0))
return *this;
unsigned NumWords = Bits.size();
assert(NumWords >= 1);
wordShl(N / BITWORD_SIZE);
unsigned BitDistance = N % BITWORD_SIZE;
if (BitDistance == 0)
return *this;
// When the shift size is not a multiple of the word size, then we have
// a tricky situation where each word in succession needs to extract some
// of the bits from the previous word and or them into this word while
// shifting this word to make room for the new bits. This has to be done
// for every word in the array. This is similar to the algorithm outlined
// in operator>>=, but backwards.
// Since we're shifting each word left, some bits will fall off the end
// of each word to the left, and empty space will be created on the right.
// The first word in the array will lose bits permanently, so starting at
// the end, work backwards shifting each word to the left, and OR'ing
// in the bits from the end of the next word to the beginning of the
// current word.
// Example:
// Starting with {0xAABBCCDD, 0xEEFF0011, 0x22334455} and shifting left
// by 4 bits.
// Step 1: Word[2] <<= 4 ; 0x23344550
// Step 2: Word[2] |= 0x0000000E ; 0x2334455E
// Step 3: Word[1] <<= 4 ; 0xEFF00110
// Step 4: Word[1] |= 0x0000000A ; 0xEFF0011A
// Step 5: Word[0] <<= 4 ; 0xABBCCDD0
// Result: { 0xABBCCDD0, 0xEFF0011A, 0x2334455E }
const BitWord Mask = maskLeadingOnes<BitWord>(BitDistance);
const unsigned RSH = BITWORD_SIZE - BitDistance;
for (int I = NumWords - 1; I > 0; --I) {
Bits[I] <<= BitDistance;
Bits[I] |= (Bits[I - 1] & Mask) >> RSH;
}
Bits[0] <<= BitDistance;
clear_unused_bits();
return *this;
}
void swap(BitVector &RHS) {
std::swap(Bits, RHS.Bits);
std::swap(Size, RHS.Size);
}
void invalid() {
assert(!Size && Bits.empty());
Size = (unsigned)-1;
}
bool isInvalid() const { return Size == (unsigned)-1; }
ArrayRef<BitWord> getData() const { return {&Bits[0], Bits.size()}; }
//===--------------------------------------------------------------------===//
// Portable bit mask operations.
//===--------------------------------------------------------------------===//
//
// These methods all operate on arrays of uint32_t, each holding 32 bits. The
// fixed word size makes it easier to work with literal bit vector constants
// in portable code.
//
// The LSB in each word is the lowest numbered bit. The size of a portable
// bit mask is always a whole multiple of 32 bits. If no bit mask size is
// given, the bit mask is assumed to cover the entire BitVector.
/// setBitsInMask - Add '1' bits from Mask to this vector. Don't resize.
/// This computes "*this |= Mask".
void setBitsInMask(const uint32_t *Mask, unsigned MaskWords = ~0u) {
applyMask<true, false>(Mask, MaskWords);
}
/// clearBitsInMask - Clear any bits in this vector that are set in Mask.
/// Don't resize. This computes "*this &= ~Mask".
void clearBitsInMask(const uint32_t *Mask, unsigned MaskWords = ~0u) {
applyMask<false, false>(Mask, MaskWords);
}
/// setBitsNotInMask - Add a bit to this vector for every '0' bit in Mask.
/// Don't resize. This computes "*this |= ~Mask".
void setBitsNotInMask(const uint32_t *Mask, unsigned MaskWords = ~0u) {
applyMask<true, true>(Mask, MaskWords);
}
/// clearBitsNotInMask - Clear a bit in this vector for every '0' bit in Mask.
/// Don't resize. This computes "*this &= Mask".
void clearBitsNotInMask(const uint32_t *Mask, unsigned MaskWords = ~0u) {
applyMask<false, true>(Mask, MaskWords);
}
private:
/// Perform a logical left shift of \p Count words by moving everything
/// \p Count words to the right in memory.
///
/// While confusing, words are stored from least significant at Bits[0] to
/// most significant at Bits[NumWords-1]. A logical shift left, however,
/// moves the current least significant bit to a higher logical index, and
/// fills the previous least significant bits with 0. Thus, we actually
/// need to move the bytes of the memory to the right, not to the left.
/// Example:
/// Words = [0xBBBBAAAA, 0xDDDDFFFF, 0x00000000, 0xDDDD0000]
/// represents a BitVector where 0xBBBBAAAA contain the least significant
/// bits. So if we want to shift the BitVector left by 2 words, we need
/// to turn this into 0x00000000 0x00000000 0xBBBBAAAA 0xDDDDFFFF by using a
/// memmove which moves right, not left.
void wordShl(uint32_t Count) {
if (Count == 0)
return;
uint32_t NumWords = Bits.size();
// Since we always move Word-sized chunks of data with src and dest both
// aligned to a word-boundary, we don't need to worry about endianness
// here.
std::copy(Bits.begin(), Bits.begin() + NumWords - Count,
Bits.begin() + Count);
std::fill(Bits.begin(), Bits.begin() + Count, 0);
clear_unused_bits();
}
/// Perform a logical right shift of \p Count words by moving those
/// words to the left in memory. See wordShl for more information.
///
void wordShr(uint32_t Count) {
if (Count == 0)
return;
uint32_t NumWords = Bits.size();
std::copy(Bits.begin() + Count, Bits.begin() + NumWords, Bits.begin());
std::fill(Bits.begin() + NumWords - Count, Bits.begin() + NumWords, 0);
}
int next_unset_in_word(int WordIndex, BitWord Word) const {
unsigned Result = WordIndex * BITWORD_SIZE + countTrailingOnes(Word);
return Result < size() ? Result : -1;
}
unsigned NumBitWords(unsigned S) const {
return (S + BITWORD_SIZE-1) / BITWORD_SIZE;
}
// Set the unused bits in the high words.
void set_unused_bits(bool t = true) {
// Then set any stray high bits of the last used word.
if (unsigned ExtraBits = Size % BITWORD_SIZE) {
BitWord ExtraBitMask = ~BitWord(0) << ExtraBits;
if (t)
Bits.back() |= ExtraBitMask;
else
Bits.back() &= ~ExtraBitMask;
}
}
// Clear the unused bits in the high words.
void clear_unused_bits() {
set_unused_bits(false);
}
void init_words(bool t) {
std::fill(Bits.begin(), Bits.end(), 0 - (BitWord)t);
}
template<bool AddBits, bool InvertMask>
void applyMask(const uint32_t *Mask, unsigned MaskWords) {
static_assert(BITWORD_SIZE % 32 == 0, "Unsupported BitWord size.");
MaskWords = std::min(MaskWords, (size() + 31) / 32);
const unsigned Scale = BITWORD_SIZE / 32;
unsigned i;
for (i = 0; MaskWords >= Scale; ++i, MaskWords -= Scale) {
BitWord BW = Bits[i];
// This inner loop should unroll completely when BITWORD_SIZE > 32.
for (unsigned b = 0; b != BITWORD_SIZE; b += 32) {
uint32_t M = *Mask++;
if (InvertMask) M = ~M;
if (AddBits) BW |= BitWord(M) << b;
else BW &= ~(BitWord(M) << b);
}
Bits[i] = BW;
}
for (unsigned b = 0; MaskWords; b += 32, --MaskWords) {
uint32_t M = *Mask++;
if (InvertMask) M = ~M;
if (AddBits) Bits[i] |= BitWord(M) << b;
else Bits[i] &= ~(BitWord(M) << b);
}
if (AddBits)
clear_unused_bits();
}
public:
/// Return the size (in bytes) of the bit vector.
size_type getMemorySize() const { return Bits.size() * sizeof(BitWord); }
size_type getBitCapacity() const { return Bits.size() * BITWORD_SIZE; }
};
inline BitVector::size_type capacity_in_bytes(const BitVector &X) {
return X.getMemorySize();
}
template <> struct DenseMapInfo<BitVector> {
static inline BitVector getEmptyKey() { return {}; }
static inline BitVector getTombstoneKey() {
BitVector V;
V.invalid();
return V;
}
static unsigned getHashValue(const BitVector &V) {
return DenseMapInfo<std::pair<BitVector::size_type, ArrayRef<uintptr_t>>>::
getHashValue(std::make_pair(V.size(), V.getData()));
}
static bool isEqual(const BitVector &LHS, const BitVector &RHS) {
if (LHS.isInvalid() || RHS.isInvalid())
return LHS.isInvalid() == RHS.isInvalid();
return LHS == RHS;
}
};
} // end namespace llvm
namespace std {
/// Implement std::swap in terms of BitVector swap.
inline void swap(llvm::BitVector &LHS, llvm::BitVector &RHS) { LHS.swap(RHS); }
} // end namespace std
#endif // LLVM_ADT_BITVECTOR_H