LLVM  8.0.0svn
BitVector.h
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1 //===- llvm/ADT/BitVector.h - Bit vectors -----------------------*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements the BitVector class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_ADT_BITVECTOR_H
15 #define LLVM_ADT_BITVECTOR_H
16 
17 #include "llvm/ADT/ArrayRef.h"
20 #include <algorithm>
21 #include <cassert>
22 #include <climits>
23 #include <cstdint>
24 #include <cstdlib>
25 #include <cstring>
26 #include <utility>
27 
28 namespace llvm {
29 
30 /// ForwardIterator for the bits that are set.
31 /// Iterators get invalidated when resize / reserve is called.
32 template <typename BitVectorT> class const_set_bits_iterator_impl {
33  const BitVectorT &Parent;
34  int Current = 0;
35 
36  void advance() {
37  assert(Current != -1 && "Trying to advance past end.");
38  Current = Parent.find_next(Current);
39  }
40 
41 public:
42  const_set_bits_iterator_impl(const BitVectorT &Parent, int Current)
43  : Parent(Parent), Current(Current) {}
44  explicit const_set_bits_iterator_impl(const BitVectorT &Parent)
45  : const_set_bits_iterator_impl(Parent, Parent.find_first()) {}
47 
49  auto Prev = *this;
50  advance();
51  return Prev;
52  }
53 
55  advance();
56  return *this;
57  }
58 
59  unsigned operator*() const { return Current; }
60 
61  bool operator==(const const_set_bits_iterator_impl &Other) const {
62  assert(&Parent == &Other.Parent &&
63  "Comparing iterators from different BitVectors");
64  return Current == Other.Current;
65  }
66 
67  bool operator!=(const const_set_bits_iterator_impl &Other) const {
68  assert(&Parent == &Other.Parent &&
69  "Comparing iterators from different BitVectors");
70  return Current != Other.Current;
71  }
72 };
73 
74 class BitVector {
75  typedef unsigned long BitWord;
76 
77  enum { BITWORD_SIZE = (unsigned)sizeof(BitWord) * CHAR_BIT };
78 
79  static_assert(BITWORD_SIZE == 64 || BITWORD_SIZE == 32,
80  "Unsupported word size");
81 
82  MutableArrayRef<BitWord> Bits; // Actual bits.
83  unsigned Size; // Size of bitvector in bits.
84 
85 public:
86  typedef unsigned size_type;
87  // Encapsulation of a single bit.
88  class reference {
89  friend class BitVector;
90 
91  BitWord *WordRef;
92  unsigned BitPos;
93 
94  public:
95  reference(BitVector &b, unsigned Idx) {
96  WordRef = &b.Bits[Idx / BITWORD_SIZE];
97  BitPos = Idx % BITWORD_SIZE;
98  }
99 
100  reference() = delete;
101  reference(const reference&) = default;
102 
104  *this = bool(t);
105  return *this;
106  }
107 
108  reference& operator=(bool t) {
109  if (t)
110  *WordRef |= BitWord(1) << BitPos;
111  else
112  *WordRef &= ~(BitWord(1) << BitPos);
113  return *this;
114  }
115 
116  operator bool() const {
117  return ((*WordRef) & (BitWord(1) << BitPos)) != 0;
118  }
119  };
120 
122  typedef const_set_bits_iterator set_iterator;
123 
124  const_set_bits_iterator set_bits_begin() const {
125  return const_set_bits_iterator(*this);
126  }
127  const_set_bits_iterator set_bits_end() const {
128  return const_set_bits_iterator(*this, -1);
129  }
131  return make_range(set_bits_begin(), set_bits_end());
132  }
133 
134  /// BitVector default ctor - Creates an empty bitvector.
135  BitVector() : Size(0) {}
136 
137  /// BitVector ctor - Creates a bitvector of specified number of bits. All
138  /// bits are initialized to the specified value.
139  explicit BitVector(unsigned s, bool t = false) : Size(s) {
140  size_t Capacity = NumBitWords(s);
141  Bits = allocate(Capacity);
142  init_words(Bits, t);
143  if (t)
144  clear_unused_bits();
145  }
146 
147  /// BitVector copy ctor.
148  BitVector(const BitVector &RHS) : Size(RHS.size()) {
149  if (Size == 0) {
150  Bits = MutableArrayRef<BitWord>();
151  return;
152  }
153 
154  size_t Capacity = NumBitWords(RHS.size());
155  Bits = allocate(Capacity);
156  std::memcpy(Bits.data(), RHS.Bits.data(), Capacity * sizeof(BitWord));
157  }
158 
159  BitVector(BitVector &&RHS) : Bits(RHS.Bits), Size(RHS.Size) {
160  RHS.Bits = MutableArrayRef<BitWord>();
161  RHS.Size = 0;
162  }
163 
164  ~BitVector() { std::free(Bits.data()); }
165 
166  /// empty - Tests whether there are no bits in this bitvector.
167  bool empty() const { return Size == 0; }
168 
169  /// size - Returns the number of bits in this bitvector.
170  size_type size() const { return Size; }
171 
172  /// count - Returns the number of bits which are set.
173  size_type count() const {
174  unsigned NumBits = 0;
175  for (unsigned i = 0; i < NumBitWords(size()); ++i)
176  NumBits += countPopulation(Bits[i]);
177  return NumBits;
178  }
179 
180  /// any - Returns true if any bit is set.
181  bool any() const {
182  for (unsigned i = 0; i < NumBitWords(size()); ++i)
183  if (Bits[i] != 0)
184  return true;
185  return false;
186  }
187 
188  /// all - Returns true if all bits are set.
189  bool all() const {
190  for (unsigned i = 0; i < Size / BITWORD_SIZE; ++i)
191  if (Bits[i] != ~0UL)
192  return false;
193 
194  // If bits remain check that they are ones. The unused bits are always zero.
195  if (unsigned Remainder = Size % BITWORD_SIZE)
196  return Bits[Size / BITWORD_SIZE] == (1UL << Remainder) - 1;
197 
198  return true;
199  }
200 
201  /// none - Returns true if none of the bits are set.
202  bool none() const {
203  return !any();
204  }
205 
206  /// find_first_in - Returns the index of the first set bit in the range
207  /// [Begin, End). Returns -1 if all bits in the range are unset.
208  int find_first_in(unsigned Begin, unsigned End) const {
209  assert(Begin <= End && End <= Size);
210  if (Begin == End)
211  return -1;
212 
213  unsigned FirstWord = Begin / BITWORD_SIZE;
214  unsigned LastWord = (End - 1) / BITWORD_SIZE;
215 
216  // Check subsequent words.
217  for (unsigned i = FirstWord; i <= LastWord; ++i) {
218  BitWord Copy = Bits[i];
219 
220  if (i == FirstWord) {
221  unsigned FirstBit = Begin % BITWORD_SIZE;
222  Copy &= maskTrailingZeros<BitWord>(FirstBit);
223  }
224 
225  if (i == LastWord) {
226  unsigned LastBit = (End - 1) % BITWORD_SIZE;
227  Copy &= maskTrailingOnes<BitWord>(LastBit + 1);
228  }
229  if (Copy != 0)
230  return i * BITWORD_SIZE + countTrailingZeros(Copy);
231  }
232  return -1;
233  }
234 
235  /// find_last_in - Returns the index of the last set bit in the range
236  /// [Begin, End). Returns -1 if all bits in the range are unset.
237  int find_last_in(unsigned Begin, unsigned End) const {
238  assert(Begin <= End && End <= Size);
239  if (Begin == End)
240  return -1;
241 
242  unsigned LastWord = (End - 1) / BITWORD_SIZE;
243  unsigned FirstWord = Begin / BITWORD_SIZE;
244 
245  for (unsigned i = LastWord + 1; i >= FirstWord + 1; --i) {
246  unsigned CurrentWord = i - 1;
247 
248  BitWord Copy = Bits[CurrentWord];
249  if (CurrentWord == LastWord) {
250  unsigned LastBit = (End - 1) % BITWORD_SIZE;
251  Copy &= maskTrailingOnes<BitWord>(LastBit + 1);
252  }
253 
254  if (CurrentWord == FirstWord) {
255  unsigned FirstBit = Begin % BITWORD_SIZE;
256  Copy &= maskTrailingZeros<BitWord>(FirstBit);
257  }
258 
259  if (Copy != 0)
260  return (CurrentWord + 1) * BITWORD_SIZE - countLeadingZeros(Copy) - 1;
261  }
262 
263  return -1;
264  }
265 
266  /// find_first_unset_in - Returns the index of the first unset bit in the
267  /// range [Begin, End). Returns -1 if all bits in the range are set.
268  int find_first_unset_in(unsigned Begin, unsigned End) const {
269  assert(Begin <= End && End <= Size);
270  if (Begin == End)
271  return -1;
272 
273  unsigned FirstWord = Begin / BITWORD_SIZE;
274  unsigned LastWord = (End - 1) / BITWORD_SIZE;
275 
276  // Check subsequent words.
277  for (unsigned i = FirstWord; i <= LastWord; ++i) {
278  BitWord Copy = Bits[i];
279 
280  if (i == FirstWord) {
281  unsigned FirstBit = Begin % BITWORD_SIZE;
282  Copy |= maskTrailingOnes<BitWord>(FirstBit);
283  }
284 
285  if (i == LastWord) {
286  unsigned LastBit = (End - 1) % BITWORD_SIZE;
287  Copy |= maskTrailingZeros<BitWord>(LastBit + 1);
288  }
289  if (Copy != ~0UL) {
290  unsigned Result = i * BITWORD_SIZE + countTrailingOnes(Copy);
291  return Result < size() ? Result : -1;
292  }
293  }
294  return -1;
295  }
296 
297  /// find_last_unset_in - Returns the index of the last unset bit in the
298  /// range [Begin, End). Returns -1 if all bits in the range are set.
299  int find_last_unset_in(unsigned Begin, unsigned End) const {
300  assert(Begin <= End && End <= Size);
301  if (Begin == End)
302  return -1;
303 
304  unsigned LastWord = (End - 1) / BITWORD_SIZE;
305  unsigned FirstWord = Begin / BITWORD_SIZE;
306 
307  for (unsigned i = LastWord + 1; i >= FirstWord + 1; --i) {
308  unsigned CurrentWord = i - 1;
309 
310  BitWord Copy = Bits[CurrentWord];
311  if (CurrentWord == LastWord) {
312  unsigned LastBit = (End - 1) % BITWORD_SIZE;
313  Copy |= maskTrailingZeros<BitWord>(LastBit + 1);
314  }
315 
316  if (CurrentWord == FirstWord) {
317  unsigned FirstBit = Begin % BITWORD_SIZE;
318  Copy |= maskTrailingOnes<BitWord>(FirstBit);
319  }
320 
321  if (Copy != ~0UL) {
322  unsigned Result =
323  (CurrentWord + 1) * BITWORD_SIZE - countLeadingOnes(Copy) - 1;
324  return Result < Size ? Result : -1;
325  }
326  }
327  return -1;
328  }
329 
330  /// find_first - Returns the index of the first set bit, -1 if none
331  /// of the bits are set.
332  int find_first() const { return find_first_in(0, Size); }
333 
334  /// find_last - Returns the index of the last set bit, -1 if none of the bits
335  /// are set.
336  int find_last() const { return find_last_in(0, Size); }
337 
338  /// find_next - Returns the index of the next set bit following the
339  /// "Prev" bit. Returns -1 if the next set bit is not found.
340  int find_next(unsigned Prev) const { return find_first_in(Prev + 1, Size); }
341 
342  /// find_prev - Returns the index of the first set bit that precedes the
343  /// the bit at \p PriorTo. Returns -1 if all previous bits are unset.
344  int find_prev(unsigned PriorTo) const { return find_last_in(0, PriorTo); }
345 
346  /// find_first_unset - Returns the index of the first unset bit, -1 if all
347  /// of the bits are set.
348  int find_first_unset() const { return find_first_unset_in(0, Size); }
349 
350  /// find_next_unset - Returns the index of the next unset bit following the
351  /// "Prev" bit. Returns -1 if all remaining bits are set.
352  int find_next_unset(unsigned Prev) const {
353  return find_first_unset_in(Prev + 1, Size);
354  }
355 
356  /// find_last_unset - Returns the index of the last unset bit, -1 if all of
357  /// the bits are set.
358  int find_last_unset() const { return find_last_unset_in(0, Size); }
359 
360  /// find_prev_unset - Returns the index of the first unset bit that precedes
361  /// the bit at \p PriorTo. Returns -1 if all previous bits are set.
362  int find_prev_unset(unsigned PriorTo) {
363  return find_last_unset_in(0, PriorTo);
364  }
365 
366  /// clear - Removes all bits from the bitvector. Does not change capacity.
367  void clear() {
368  Size = 0;
369  }
370 
371  /// resize - Grow or shrink the bitvector.
372  void resize(unsigned N, bool t = false) {
373  if (N > getBitCapacity()) {
374  unsigned OldCapacity = Bits.size();
375  grow(N);
376  init_words(Bits.drop_front(OldCapacity), t);
377  }
378 
379  // Set any old unused bits that are now included in the BitVector. This
380  // may set bits that are not included in the new vector, but we will clear
381  // them back out below.
382  if (N > Size)
383  set_unused_bits(t);
384 
385  // Update the size, and clear out any bits that are now unused
386  unsigned OldSize = Size;
387  Size = N;
388  if (t || N < OldSize)
389  clear_unused_bits();
390  }
391 
392  void reserve(unsigned N) {
393  if (N > getBitCapacity())
394  grow(N);
395  }
396 
397  // Set, reset, flip
398  BitVector &set() {
399  init_words(Bits, true);
400  clear_unused_bits();
401  return *this;
402  }
403 
404  BitVector &set(unsigned Idx) {
405  assert(Bits.data() && "Bits never allocated");
406  Bits[Idx / BITWORD_SIZE] |= BitWord(1) << (Idx % BITWORD_SIZE);
407  return *this;
408  }
409 
410  /// set - Efficiently set a range of bits in [I, E)
411  BitVector &set(unsigned I, unsigned E) {
412  assert(I <= E && "Attempted to set backwards range!");
413  assert(E <= size() && "Attempted to set out-of-bounds range!");
414 
415  if (I == E) return *this;
416 
417  if (I / BITWORD_SIZE == E / BITWORD_SIZE) {
418  BitWord EMask = 1UL << (E % BITWORD_SIZE);
419  BitWord IMask = 1UL << (I % BITWORD_SIZE);
420  BitWord Mask = EMask - IMask;
421  Bits[I / BITWORD_SIZE] |= Mask;
422  return *this;
423  }
424 
425  BitWord PrefixMask = ~0UL << (I % BITWORD_SIZE);
426  Bits[I / BITWORD_SIZE] |= PrefixMask;
427  I = alignTo(I, BITWORD_SIZE);
428 
429  for (; I + BITWORD_SIZE <= E; I += BITWORD_SIZE)
430  Bits[I / BITWORD_SIZE] = ~0UL;
431 
432  BitWord PostfixMask = (1UL << (E % BITWORD_SIZE)) - 1;
433  if (I < E)
434  Bits[I / BITWORD_SIZE] |= PostfixMask;
435 
436  return *this;
437  }
438 
440  init_words(Bits, false);
441  return *this;
442  }
443 
444  BitVector &reset(unsigned Idx) {
445  Bits[Idx / BITWORD_SIZE] &= ~(BitWord(1) << (Idx % BITWORD_SIZE));
446  return *this;
447  }
448 
449  /// reset - Efficiently reset a range of bits in [I, E)
450  BitVector &reset(unsigned I, unsigned E) {
451  assert(I <= E && "Attempted to reset backwards range!");
452  assert(E <= size() && "Attempted to reset out-of-bounds range!");
453 
454  if (I == E) return *this;
455 
456  if (I / BITWORD_SIZE == E / BITWORD_SIZE) {
457  BitWord EMask = 1UL << (E % BITWORD_SIZE);
458  BitWord IMask = 1UL << (I % BITWORD_SIZE);
459  BitWord Mask = EMask - IMask;
460  Bits[I / BITWORD_SIZE] &= ~Mask;
461  return *this;
462  }
463 
464  BitWord PrefixMask = ~0UL << (I % BITWORD_SIZE);
465  Bits[I / BITWORD_SIZE] &= ~PrefixMask;
466  I = alignTo(I, BITWORD_SIZE);
467 
468  for (; I + BITWORD_SIZE <= E; I += BITWORD_SIZE)
469  Bits[I / BITWORD_SIZE] = 0UL;
470 
471  BitWord PostfixMask = (1UL << (E % BITWORD_SIZE)) - 1;
472  if (I < E)
473  Bits[I / BITWORD_SIZE] &= ~PostfixMask;
474 
475  return *this;
476  }
477 
479  for (unsigned i = 0; i < NumBitWords(size()); ++i)
480  Bits[i] = ~Bits[i];
481  clear_unused_bits();
482  return *this;
483  }
484 
485  BitVector &flip(unsigned Idx) {
486  Bits[Idx / BITWORD_SIZE] ^= BitWord(1) << (Idx % BITWORD_SIZE);
487  return *this;
488  }
489 
490  // Indexing.
491  reference operator[](unsigned Idx) {
492  assert (Idx < Size && "Out-of-bounds Bit access.");
493  return reference(*this, Idx);
494  }
495 
496  bool operator[](unsigned Idx) const {
497  assert (Idx < Size && "Out-of-bounds Bit access.");
498  BitWord Mask = BitWord(1) << (Idx % BITWORD_SIZE);
499  return (Bits[Idx / BITWORD_SIZE] & Mask) != 0;
500  }
501 
502  bool test(unsigned Idx) const {
503  return (*this)[Idx];
504  }
505 
506  // Push single bit to end of vector.
507  void push_back(bool Val) {
508  unsigned OldSize = Size;
509  unsigned NewSize = Size + 1;
510 
511  // Resize, which will insert zeros.
512  // If we already fit then the unused bits will be already zero.
513  if (NewSize > getBitCapacity())
514  resize(NewSize, false);
515  else
516  Size = NewSize;
517 
518  // If true, set single bit.
519  if (Val)
520  set(OldSize);
521  }
522 
523  /// Test if any common bits are set.
524  bool anyCommon(const BitVector &RHS) const {
525  unsigned ThisWords = NumBitWords(size());
526  unsigned RHSWords = NumBitWords(RHS.size());
527  for (unsigned i = 0, e = std::min(ThisWords, RHSWords); i != e; ++i)
528  if (Bits[i] & RHS.Bits[i])
529  return true;
530  return false;
531  }
532 
533  // Comparison operators.
534  bool operator==(const BitVector &RHS) const {
535  unsigned ThisWords = NumBitWords(size());
536  unsigned RHSWords = NumBitWords(RHS.size());
537  unsigned i;
538  for (i = 0; i != std::min(ThisWords, RHSWords); ++i)
539  if (Bits[i] != RHS.Bits[i])
540  return false;
541 
542  // Verify that any extra words are all zeros.
543  if (i != ThisWords) {
544  for (; i != ThisWords; ++i)
545  if (Bits[i])
546  return false;
547  } else if (i != RHSWords) {
548  for (; i != RHSWords; ++i)
549  if (RHS.Bits[i])
550  return false;
551  }
552  return true;
553  }
554 
555  bool operator!=(const BitVector &RHS) const {
556  return !(*this == RHS);
557  }
558 
559  /// Intersection, union, disjoint union.
561  unsigned ThisWords = NumBitWords(size());
562  unsigned RHSWords = NumBitWords(RHS.size());
563  unsigned i;
564  for (i = 0; i != std::min(ThisWords, RHSWords); ++i)
565  Bits[i] &= RHS.Bits[i];
566 
567  // Any bits that are just in this bitvector become zero, because they aren't
568  // in the RHS bit vector. Any words only in RHS are ignored because they
569  // are already zero in the LHS.
570  for (; i != ThisWords; ++i)
571  Bits[i] = 0;
572 
573  return *this;
574  }
575 
576  /// reset - Reset bits that are set in RHS. Same as *this &= ~RHS.
577  BitVector &reset(const BitVector &RHS) {
578  unsigned ThisWords = NumBitWords(size());
579  unsigned RHSWords = NumBitWords(RHS.size());
580  unsigned i;
581  for (i = 0; i != std::min(ThisWords, RHSWords); ++i)
582  Bits[i] &= ~RHS.Bits[i];
583  return *this;
584  }
585 
586  /// test - Check if (This - RHS) is zero.
587  /// This is the same as reset(RHS) and any().
588  bool test(const BitVector &RHS) const {
589  unsigned ThisWords = NumBitWords(size());
590  unsigned RHSWords = NumBitWords(RHS.size());
591  unsigned i;
592  for (i = 0; i != std::min(ThisWords, RHSWords); ++i)
593  if ((Bits[i] & ~RHS.Bits[i]) != 0)
594  return true;
595 
596  for (; i != ThisWords ; ++i)
597  if (Bits[i] != 0)
598  return true;
599 
600  return false;
601  }
602 
604  if (size() < RHS.size())
605  resize(RHS.size());
606  for (size_t i = 0, e = NumBitWords(RHS.size()); i != e; ++i)
607  Bits[i] |= RHS.Bits[i];
608  return *this;
609  }
610 
612  if (size() < RHS.size())
613  resize(RHS.size());
614  for (size_t i = 0, e = NumBitWords(RHS.size()); i != e; ++i)
615  Bits[i] ^= RHS.Bits[i];
616  return *this;
617  }
618 
619  BitVector &operator>>=(unsigned N) {
620  assert(N <= Size);
621  if (LLVM_UNLIKELY(empty() || N == 0))
622  return *this;
623 
624  unsigned NumWords = NumBitWords(Size);
625  assert(NumWords >= 1);
626 
627  wordShr(N / BITWORD_SIZE);
628 
629  unsigned BitDistance = N % BITWORD_SIZE;
630  if (BitDistance == 0)
631  return *this;
632 
633  // When the shift size is not a multiple of the word size, then we have
634  // a tricky situation where each word in succession needs to extract some
635  // of the bits from the next word and or them into this word while
636  // shifting this word to make room for the new bits. This has to be done
637  // for every word in the array.
638 
639  // Since we're shifting each word right, some bits will fall off the end
640  // of each word to the right, and empty space will be created on the left.
641  // The final word in the array will lose bits permanently, so starting at
642  // the beginning, work forwards shifting each word to the right, and
643  // OR'ing in the bits from the end of the next word to the beginning of
644  // the current word.
645 
646  // Example:
647  // Starting with {0xAABBCCDD, 0xEEFF0011, 0x22334455} and shifting right
648  // by 4 bits.
649  // Step 1: Word[0] >>= 4 ; 0x0ABBCCDD
650  // Step 2: Word[0] |= 0x10000000 ; 0x1ABBCCDD
651  // Step 3: Word[1] >>= 4 ; 0x0EEFF001
652  // Step 4: Word[1] |= 0x50000000 ; 0x5EEFF001
653  // Step 5: Word[2] >>= 4 ; 0x02334455
654  // Result: { 0x1ABBCCDD, 0x5EEFF001, 0x02334455 }
655  const BitWord Mask = maskTrailingOnes<BitWord>(BitDistance);
656  const unsigned LSH = BITWORD_SIZE - BitDistance;
657 
658  for (unsigned I = 0; I < NumWords - 1; ++I) {
659  Bits[I] >>= BitDistance;
660  Bits[I] |= (Bits[I + 1] & Mask) << LSH;
661  }
662 
663  Bits[NumWords - 1] >>= BitDistance;
664 
665  return *this;
666  }
667 
668  BitVector &operator<<=(unsigned N) {
669  assert(N <= Size);
670  if (LLVM_UNLIKELY(empty() || N == 0))
671  return *this;
672 
673  unsigned NumWords = NumBitWords(Size);
674  assert(NumWords >= 1);
675 
676  wordShl(N / BITWORD_SIZE);
677 
678  unsigned BitDistance = N % BITWORD_SIZE;
679  if (BitDistance == 0)
680  return *this;
681 
682  // When the shift size is not a multiple of the word size, then we have
683  // a tricky situation where each word in succession needs to extract some
684  // of the bits from the previous word and or them into this word while
685  // shifting this word to make room for the new bits. This has to be done
686  // for every word in the array. This is similar to the algorithm outlined
687  // in operator>>=, but backwards.
688 
689  // Since we're shifting each word left, some bits will fall off the end
690  // of each word to the left, and empty space will be created on the right.
691  // The first word in the array will lose bits permanently, so starting at
692  // the end, work backwards shifting each word to the left, and OR'ing
693  // in the bits from the end of the next word to the beginning of the
694  // current word.
695 
696  // Example:
697  // Starting with {0xAABBCCDD, 0xEEFF0011, 0x22334455} and shifting left
698  // by 4 bits.
699  // Step 1: Word[2] <<= 4 ; 0x23344550
700  // Step 2: Word[2] |= 0x0000000E ; 0x2334455E
701  // Step 3: Word[1] <<= 4 ; 0xEFF00110
702  // Step 4: Word[1] |= 0x0000000A ; 0xEFF0011A
703  // Step 5: Word[0] <<= 4 ; 0xABBCCDD0
704  // Result: { 0xABBCCDD0, 0xEFF0011A, 0x2334455E }
705  const BitWord Mask = maskLeadingOnes<BitWord>(BitDistance);
706  const unsigned RSH = BITWORD_SIZE - BitDistance;
707 
708  for (int I = NumWords - 1; I > 0; --I) {
709  Bits[I] <<= BitDistance;
710  Bits[I] |= (Bits[I - 1] & Mask) >> RSH;
711  }
712  Bits[0] <<= BitDistance;
713  clear_unused_bits();
714 
715  return *this;
716  }
717 
718  // Assignment operator.
719  const BitVector &operator=(const BitVector &RHS) {
720  if (this == &RHS) return *this;
721 
722  Size = RHS.size();
723  unsigned RHSWords = NumBitWords(Size);
724  if (Size <= getBitCapacity()) {
725  if (Size)
726  std::memcpy(Bits.data(), RHS.Bits.data(), RHSWords * sizeof(BitWord));
727  clear_unused_bits();
728  return *this;
729  }
730 
731  // Grow the bitvector to have enough elements.
732  unsigned NewCapacity = RHSWords;
733  assert(NewCapacity > 0 && "negative capacity?");
734  auto NewBits = allocate(NewCapacity);
735  std::memcpy(NewBits.data(), RHS.Bits.data(), NewCapacity * sizeof(BitWord));
736 
737  // Destroy the old bits.
738  std::free(Bits.data());
739  Bits = NewBits;
740 
741  return *this;
742  }
743 
744  const BitVector &operator=(BitVector &&RHS) {
745  if (this == &RHS) return *this;
746 
747  std::free(Bits.data());
748  Bits = RHS.Bits;
749  Size = RHS.Size;
750 
751  RHS.Bits = MutableArrayRef<BitWord>();
752  RHS.Size = 0;
753 
754  return *this;
755  }
756 
757  void swap(BitVector &RHS) {
758  std::swap(Bits, RHS.Bits);
759  std::swap(Size, RHS.Size);
760  }
761 
762  //===--------------------------------------------------------------------===//
763  // Portable bit mask operations.
764  //===--------------------------------------------------------------------===//
765  //
766  // These methods all operate on arrays of uint32_t, each holding 32 bits. The
767  // fixed word size makes it easier to work with literal bit vector constants
768  // in portable code.
769  //
770  // The LSB in each word is the lowest numbered bit. The size of a portable
771  // bit mask is always a whole multiple of 32 bits. If no bit mask size is
772  // given, the bit mask is assumed to cover the entire BitVector.
773 
774  /// setBitsInMask - Add '1' bits from Mask to this vector. Don't resize.
775  /// This computes "*this |= Mask".
776  void setBitsInMask(const uint32_t *Mask, unsigned MaskWords = ~0u) {
777  applyMask<true, false>(Mask, MaskWords);
778  }
779 
780  /// clearBitsInMask - Clear any bits in this vector that are set in Mask.
781  /// Don't resize. This computes "*this &= ~Mask".
782  void clearBitsInMask(const uint32_t *Mask, unsigned MaskWords = ~0u) {
783  applyMask<false, false>(Mask, MaskWords);
784  }
785 
786  /// setBitsNotInMask - Add a bit to this vector for every '0' bit in Mask.
787  /// Don't resize. This computes "*this |= ~Mask".
788  void setBitsNotInMask(const uint32_t *Mask, unsigned MaskWords = ~0u) {
789  applyMask<true, true>(Mask, MaskWords);
790  }
791 
792  /// clearBitsNotInMask - Clear a bit in this vector for every '0' bit in Mask.
793  /// Don't resize. This computes "*this &= Mask".
794  void clearBitsNotInMask(const uint32_t *Mask, unsigned MaskWords = ~0u) {
795  applyMask<false, true>(Mask, MaskWords);
796  }
797 
798 private:
799  /// Perform a logical left shift of \p Count words by moving everything
800  /// \p Count words to the right in memory.
801  ///
802  /// While confusing, words are stored from least significant at Bits[0] to
803  /// most significant at Bits[NumWords-1]. A logical shift left, however,
804  /// moves the current least significant bit to a higher logical index, and
805  /// fills the previous least significant bits with 0. Thus, we actually
806  /// need to move the bytes of the memory to the right, not to the left.
807  /// Example:
808  /// Words = [0xBBBBAAAA, 0xDDDDFFFF, 0x00000000, 0xDDDD0000]
809  /// represents a BitVector where 0xBBBBAAAA contain the least significant
810  /// bits. So if we want to shift the BitVector left by 2 words, we need to
811  /// turn this into 0x00000000 0x00000000 0xBBBBAAAA 0xDDDDFFFF by using a
812  /// memmove which moves right, not left.
813  void wordShl(uint32_t Count) {
814  if (Count == 0)
815  return;
816 
817  uint32_t NumWords = NumBitWords(Size);
818 
819  auto Src = Bits.take_front(NumWords).drop_back(Count);
820  auto Dest = Bits.take_front(NumWords).drop_front(Count);
821 
822  // Since we always move Word-sized chunks of data with src and dest both
823  // aligned to a word-boundary, we don't need to worry about endianness
824  // here.
825  std::memmove(Dest.begin(), Src.begin(), Dest.size() * sizeof(BitWord));
826  std::memset(Bits.data(), 0, Count * sizeof(BitWord));
827  clear_unused_bits();
828  }
829 
830  /// Perform a logical right shift of \p Count words by moving those
831  /// words to the left in memory. See wordShl for more information.
832  ///
833  void wordShr(uint32_t Count) {
834  if (Count == 0)
835  return;
836 
837  uint32_t NumWords = NumBitWords(Size);
838 
839  auto Src = Bits.take_front(NumWords).drop_front(Count);
840  auto Dest = Bits.take_front(NumWords).drop_back(Count);
841  assert(Dest.size() == Src.size());
842 
843  std::memmove(Dest.begin(), Src.begin(), Dest.size() * sizeof(BitWord));
844  std::memset(Dest.end(), 0, Count * sizeof(BitWord));
845  }
846 
847  MutableArrayRef<BitWord> allocate(size_t NumWords) {
848  BitWord *RawBits = static_cast<BitWord *>(
849  safe_malloc(NumWords * sizeof(BitWord)));
850  return MutableArrayRef<BitWord>(RawBits, NumWords);
851  }
852 
853  int next_unset_in_word(int WordIndex, BitWord Word) const {
854  unsigned Result = WordIndex * BITWORD_SIZE + countTrailingOnes(Word);
855  return Result < size() ? Result : -1;
856  }
857 
858  unsigned NumBitWords(unsigned S) const {
859  return (S + BITWORD_SIZE-1) / BITWORD_SIZE;
860  }
861 
862  // Set the unused bits in the high words.
863  void set_unused_bits(bool t = true) {
864  // Set high words first.
865  unsigned UsedWords = NumBitWords(Size);
866  if (Bits.size() > UsedWords)
867  init_words(Bits.drop_front(UsedWords), t);
868 
869  // Then set any stray high bits of the last used word.
870  unsigned ExtraBits = Size % BITWORD_SIZE;
871  if (ExtraBits) {
872  BitWord ExtraBitMask = ~0UL << ExtraBits;
873  if (t)
874  Bits[UsedWords-1] |= ExtraBitMask;
875  else
876  Bits[UsedWords-1] &= ~ExtraBitMask;
877  }
878  }
879 
880  // Clear the unused bits in the high words.
881  void clear_unused_bits() {
882  set_unused_bits(false);
883  }
884 
885  void grow(unsigned NewSize) {
886  size_t NewCapacity = std::max<size_t>(NumBitWords(NewSize), Bits.size() * 2);
887  assert(NewCapacity > 0 && "realloc-ing zero space");
888  BitWord *NewBits = static_cast<BitWord *>(
889  safe_realloc(Bits.data(), NewCapacity * sizeof(BitWord)));
890  Bits = MutableArrayRef<BitWord>(NewBits, NewCapacity);
891  clear_unused_bits();
892  }
893 
894  void init_words(MutableArrayRef<BitWord> B, bool t) {
895  if (B.size() > 0)
896  memset(B.data(), 0 - (int)t, B.size() * sizeof(BitWord));
897  }
898 
899  template<bool AddBits, bool InvertMask>
900  void applyMask(const uint32_t *Mask, unsigned MaskWords) {
901  static_assert(BITWORD_SIZE % 32 == 0, "Unsupported BitWord size.");
902  MaskWords = std::min(MaskWords, (size() + 31) / 32);
903  const unsigned Scale = BITWORD_SIZE / 32;
904  unsigned i;
905  for (i = 0; MaskWords >= Scale; ++i, MaskWords -= Scale) {
906  BitWord BW = Bits[i];
907  // This inner loop should unroll completely when BITWORD_SIZE > 32.
908  for (unsigned b = 0; b != BITWORD_SIZE; b += 32) {
909  uint32_t M = *Mask++;
910  if (InvertMask) M = ~M;
911  if (AddBits) BW |= BitWord(M) << b;
912  else BW &= ~(BitWord(M) << b);
913  }
914  Bits[i] = BW;
915  }
916  for (unsigned b = 0; MaskWords; b += 32, --MaskWords) {
917  uint32_t M = *Mask++;
918  if (InvertMask) M = ~M;
919  if (AddBits) Bits[i] |= BitWord(M) << b;
920  else Bits[i] &= ~(BitWord(M) << b);
921  }
922  if (AddBits)
923  clear_unused_bits();
924  }
925 
926 public:
927  /// Return the size (in bytes) of the bit vector.
928  size_t getMemorySize() const { return Bits.size() * sizeof(BitWord); }
929  size_t getBitCapacity() const { return Bits.size() * BITWORD_SIZE; }
930 };
931 
932 inline size_t capacity_in_bytes(const BitVector &X) {
933  return X.getMemorySize();
934 }
935 
936 } // end namespace llvm
937 
938 namespace std {
939  /// Implement std::swap in terms of BitVector swap.
940  inline void
942  LHS.swap(RHS);
943  }
944 } // end namespace std
945 
946 #endif // LLVM_ADT_BITVECTOR_H
BitVector & reset(const BitVector &RHS)
reset - Reset bits that are set in RHS. Same as *this &= ~RHS.
Definition: BitVector.h:577
void resize(unsigned N, bool t=false)
resize - Grow or shrink the bitvector.
Definition: BitVector.h:372
void clearBitsInMask(const uint32_t *Mask, unsigned MaskWords=~0u)
clearBitsInMask - Clear any bits in this vector that are set in Mask.
Definition: BitVector.h:782
void reserve(unsigned N)
Definition: BitVector.h:392
static GCMetadataPrinterRegistry::Add< ErlangGCPrinter > X("erlang", "erlang-compatible garbage collector")
int find_last_unset() const
find_last_unset - Returns the index of the last unset bit, -1 if all of the bits are set...
Definition: BitVector.h:358
This class represents lattice values for constants.
Definition: AllocatorList.h:24
bool empty() const
empty - Tests whether there are no bits in this bitvector.
Definition: BitVector.h:167
const_set_bits_iterator set_bits_end() const
Definition: BitVector.h:127
int find_last() const
find_last - Returns the index of the last set bit, -1 if none of the bits are set.
Definition: BitVector.h:336
This provides a very simple, boring adaptor for a begin and end iterator into a range type...
unsigned size_type
Definition: BitVector.h:86
bool all() const
all - Returns true if all bits are set.
Definition: BitVector.h:189
bool test(unsigned Idx) const
Definition: BitVector.h:502
const_set_bits_iterator_impl operator++(int)
Definition: BitVector.h:48
BitVector(const BitVector &RHS)
BitVector copy ctor.
Definition: BitVector.h:148
void setBitsNotInMask(const uint32_t *Mask, unsigned MaskWords=~0u)
setBitsNotInMask - Add a bit to this vector for every &#39;0&#39; bit in Mask.
Definition: BitVector.h:788
bool operator[](unsigned Idx) const
Definition: BitVector.h:496
uint64_t alignTo(uint64_t Value, uint64_t Align, uint64_t Skew=0)
Returns the next integer (mod 2**64) that is greater than or equal to Value and is a multiple of Alig...
Definition: MathExtras.h:685
int find_next_unset(unsigned Prev) const
find_next_unset - Returns the index of the next unset bit following the "Prev" bit.
Definition: BitVector.h:352
BitVector & operator>>=(unsigned N)
Definition: BitVector.h:619
std::size_t countLeadingZeros(T Val, ZeroBehavior ZB=ZB_Width)
Count number of 0&#39;s from the most significant bit to the least stopping at the first 1...
Definition: MathExtras.h:189
#define LLVM_UNLIKELY(EXPR)
Definition: Compiler.h:192
Definition: BitVector.h:938
BitVector & operator<<=(unsigned N)
Definition: BitVector.h:668
void clear()
clear - Removes all bits from the bitvector. Does not change capacity.
Definition: BitVector.h:367
size_t getMemorySize() const
Return the size (in bytes) of the bit vector.
Definition: BitVector.h:928
int find_prev_unset(unsigned PriorTo)
find_prev_unset - Returns the index of the first unset bit that precedes the bit at PriorTo...
Definition: BitVector.h:362
bool operator==(const const_set_bits_iterator_impl &Other) const
Definition: BitVector.h:61
std::size_t countTrailingOnes(T Value, ZeroBehavior ZB=ZB_Width)
Count the number of ones from the least significant bit to the first zero bit.
Definition: MathExtras.h:478
int find_first() const
find_first - Returns the index of the first set bit, -1 if none of the bits are set.
Definition: BitVector.h:332
size_t capacity_in_bytes(const BitVector &X)
Definition: BitVector.h:932
support::ulittle32_t Word
Definition: IRSymtab.h:51
void swap(BitVector &RHS)
Definition: BitVector.h:757
int find_next(unsigned Prev) const
find_next - Returns the index of the next set bit following the "Prev" bit.
Definition: BitVector.h:340
reference(BitVector &b, unsigned Idx)
Definition: BitVector.h:95
const_set_bits_iterator_impl(const BitVectorT &Parent, int Current)
Definition: BitVector.h:42
MutableArrayRef< T > drop_front(size_t N=1) const
Drop the first N elements of the array.
Definition: ArrayRef.h:362
BitVector & operator|=(const BitVector &RHS)
Definition: BitVector.h:603
int find_first_unset() const
find_first_unset - Returns the index of the first unset bit, -1 if all of the bits are set...
Definition: BitVector.h:348
LLVM_ATTRIBUTE_RETURNS_NONNULL void * safe_realloc(void *Ptr, size_t Sz)
Definition: MemAlloc.h:41
int find_first_unset_in(unsigned Begin, unsigned End) const
find_first_unset_in - Returns the index of the first unset bit in the range [Begin, End).
Definition: BitVector.h:268
BitVector()
BitVector default ctor - Creates an empty bitvector.
Definition: BitVector.h:135
BitVector & flip(unsigned Idx)
Definition: BitVector.h:485
const_set_bits_iterator_impl & operator++()
Definition: BitVector.h:54
void clearBitsNotInMask(const uint32_t *Mask, unsigned MaskWords=~0u)
clearBitsNotInMask - Clear a bit in this vector for every &#39;0&#39; bit in Mask.
Definition: BitVector.h:794
static GCRegistry::Add< OcamlGC > B("ocaml", "ocaml 3.10-compatible GC")
std::size_t countTrailingZeros(T Val, ZeroBehavior ZB=ZB_Width)
Count number of 0&#39;s from the least significant bit to the most stopping at the first 1...
Definition: MathExtras.h:120
bool anyCommon(const BitVector &RHS) const
Test if any common bits are set.
Definition: BitVector.h:524
int find_prev(unsigned PriorTo) const
find_prev - Returns the index of the first set bit that precedes the the bit at PriorTo.
Definition: BitVector.h:344
size_t getBitCapacity() const
Definition: BitVector.h:929
size_t size() const
size - Get the array size.
Definition: ArrayRef.h:149
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
bool any() const
any - Returns true if any bit is set.
Definition: BitVector.h:181
BitVector & operator^=(const BitVector &RHS)
Definition: BitVector.h:611
BitVector(unsigned s, bool t=false)
BitVector ctor - Creates a bitvector of specified number of bits.
Definition: BitVector.h:139
BitVector & reset()
Definition: BitVector.h:439
const_set_bits_iterator set_iterator
Definition: BitVector.h:122
const_set_bits_iterator set_bits_begin() const
Definition: BitVector.h:124
ForwardIterator for the bits that are set.
Definition: BitVector.h:32
BitVector(BitVector &&RHS)
Definition: BitVector.h:159
bool operator==(const BitVector &RHS) const
Definition: BitVector.h:534
BitVector & reset(unsigned I, unsigned E)
reset - Efficiently reset a range of bits in [I, E)
Definition: BitVector.h:450
MutableArrayRef< T > drop_back(size_t N=1) const
Definition: ArrayRef.h:367
void push_back(bool Val)
Definition: BitVector.h:507
constexpr bool empty(const T &RangeOrContainer)
Test whether RangeOrContainer is empty. Similar to C++17 std::empty.
Definition: STLExtras.h:204
const BitVector & operator=(const BitVector &RHS)
Definition: BitVector.h:719
iterator_range< T > make_range(T x, T y)
Convenience function for iterating over sub-ranges.
LLVM_ATTRIBUTE_RETURNS_NONNULL void * safe_malloc(size_t Sz)
Definition: MemAlloc.h:26
unsigned countPopulation(T Value)
Count the number of set bits in a value.
Definition: MathExtras.h:520
const_set_bits_iterator_impl(const BitVectorT &Parent)
Definition: BitVector.h:44
auto size(R &&Range, typename std::enable_if< std::is_same< typename std::iterator_traits< decltype(Range.begin())>::iterator_category, std::random_access_iterator_tag >::value, void >::type *=nullptr) -> decltype(std::distance(Range.begin(), Range.end()))
Get the size of a range.
Definition: STLExtras.h:1161
int find_last_in(unsigned Begin, unsigned End) const
find_last_in - Returns the index of the last set bit in the range [Begin, End).
Definition: BitVector.h:237
size_type count() const
count - Returns the number of bits which are set.
Definition: BitVector.h:173
reference operator[](unsigned Idx)
Definition: BitVector.h:491
BitVector & flip()
Definition: BitVector.h:478
void swap(llvm::BitVector &LHS, llvm::BitVector &RHS)
Implement std::swap in terms of BitVector swap.
Definition: BitVector.h:941
A range adaptor for a pair of iterators.
bool none() const
none - Returns true if none of the bits are set.
Definition: BitVector.h:202
MutableArrayRef< T > take_front(size_t N=1) const
Return a copy of *this with only the first N elements.
Definition: ArrayRef.h:387
reference & operator=(bool t)
Definition: BitVector.h:108
int find_first_in(unsigned Begin, unsigned End) const
find_first_in - Returns the index of the first set bit in the range [Begin, End). ...
Definition: BitVector.h:208
#define I(x, y, z)
Definition: MD5.cpp:58
#define N
reference & operator=(reference t)
Definition: BitVector.h:103
size_type size() const
size - Returns the number of bits in this bitvector.
Definition: BitVector.h:170
uint32_t Size
Definition: Profile.cpp:47
const_set_bits_iterator_impl< BitVector > const_set_bits_iterator
Definition: BitVector.h:121
T * data() const
Definition: ArrayRef.h:329
bool operator!=(const const_set_bits_iterator_impl &Other) const
Definition: BitVector.h:67
BitVector & reset(unsigned Idx)
Definition: BitVector.h:444
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
iterator_range< const_set_bits_iterator > set_bits() const
Definition: BitVector.h:130
E & operator &=(E &LHS, E RHS)
Definition: BitmaskEnum.h:134
std::underlying_type< E >::type Mask()
Get a bitmask with 1s in all places up to the high-order bit of E&#39;s largest value.
Definition: BitmaskEnum.h:81
bool test(const BitVector &RHS) const
test - Check if (This - RHS) is zero.
Definition: BitVector.h:588
int find_last_unset_in(unsigned Begin, unsigned End) const
find_last_unset_in - Returns the index of the last unset bit in the range [Begin, End)...
Definition: BitVector.h:299
for(unsigned i=Desc.getNumOperands(), e=OldMI.getNumOperands();i !=e;++i)
bool operator!=(const BitVector &RHS) const
Definition: BitVector.h:555
std::size_t countLeadingOnes(T Value, ZeroBehavior ZB=ZB_Width)
Count the number of ones from the most significant bit to the first zero bit.
Definition: MathExtras.h:462
void setBitsInMask(const uint32_t *Mask, unsigned MaskWords=~0u)
setBitsInMask - Add &#39;1&#39; bits from Mask to this vector.
Definition: BitVector.h:776
const BitVector & operator=(BitVector &&RHS)
Definition: BitVector.h:744