diff options
author | Dimitry Andric <dim@FreeBSD.org> | 2012-12-02 13:10:19 +0000 |
---|---|---|
committer | Dimitry Andric <dim@FreeBSD.org> | 2012-12-02 13:10:19 +0000 |
commit | 522600a229b950314b5f4af84eba4f3e8a0ffea1 (patch) | |
tree | 32b4679ab4b8f28e5228daafc65e9dc436935353 /include/llvm/ADT/BitVector.h | |
parent | 902a7b529820e6a0aa85f98f21afaeb1805a22f8 (diff) |
Diffstat (limited to 'include/llvm/ADT/BitVector.h')
-rw-r--r-- | include/llvm/ADT/BitVector.h | 86 |
1 files changed, 81 insertions, 5 deletions
diff --git a/include/llvm/ADT/BitVector.h b/include/llvm/ADT/BitVector.h index 3e2e5f230a3a..9d6388f7ee61 100644 --- a/include/llvm/ADT/BitVector.h +++ b/include/llvm/ADT/BitVector.h @@ -172,7 +172,7 @@ public: unsigned BitPos = Prev % BITWORD_SIZE; BitWord Copy = Bits[WordPos]; // Mask off previous bits. - Copy &= ~0L << BitPos; + Copy &= ~0UL << BitPos; if (Copy != 0) { if (sizeof(BitWord) == 4) @@ -237,6 +237,34 @@ public: 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 = 1UL << (E % BITWORD_SIZE); + BitWord IMask = 1UL << (I % BITWORD_SIZE); + BitWord Mask = EMask - IMask; + Bits[I / BITWORD_SIZE] |= Mask; + return *this; + } + + BitWord PrefixMask = ~0UL << (I % BITWORD_SIZE); + Bits[I / BITWORD_SIZE] |= PrefixMask; + I = RoundUpToAlignment(I, BITWORD_SIZE); + + for (; I + BITWORD_SIZE <= E; I += BITWORD_SIZE) + Bits[I / BITWORD_SIZE] = ~0UL; + + BitWord PostfixMask = (1UL << (E % BITWORD_SIZE)) - 1; + Bits[I / BITWORD_SIZE] |= PostfixMask; + + return *this; + } + BitVector &reset() { init_words(Bits, Capacity, false); return *this; @@ -247,6 +275,34 @@ public: 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 = 1UL << (E % BITWORD_SIZE); + BitWord IMask = 1UL << (I % BITWORD_SIZE); + BitWord Mask = EMask - IMask; + Bits[I / BITWORD_SIZE] &= ~Mask; + return *this; + } + + BitWord PrefixMask = ~0UL << (I % BITWORD_SIZE); + Bits[I / BITWORD_SIZE] &= ~PrefixMask; + I = RoundUpToAlignment(I, BITWORD_SIZE); + + for (; I + BITWORD_SIZE <= E; I += BITWORD_SIZE) + Bits[I / BITWORD_SIZE] = 0UL; + + BitWord PostfixMask = (1UL << (E % BITWORD_SIZE)) - 1; + Bits[I / BITWORD_SIZE] &= ~PostfixMask; + + return *this; + } + BitVector &flip() { for (unsigned i = 0; i < NumBitWords(size()); ++i) Bits[i] = ~Bits[i]; @@ -311,7 +367,7 @@ public: return !(*this == RHS); } - // Intersection, union, disjoint union. + /// Intersection, union, disjoint union. BitVector &operator&=(const BitVector &RHS) { unsigned ThisWords = NumBitWords(size()); unsigned RHSWords = NumBitWords(RHS.size()); @@ -328,7 +384,7 @@ public: return *this; } - // reset - Reset bits that are set in RHS. Same as *this &= ~RHS. + /// reset - Reset bits that are set in RHS. Same as *this &= ~RHS. BitVector &reset(const BitVector &RHS) { unsigned ThisWords = NumBitWords(size()); unsigned RHSWords = NumBitWords(RHS.size()); @@ -338,6 +394,23 @@ public: 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 = NumBitWords(size()); + unsigned RHSWords = NumBitWords(RHS.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; + } + BitVector &operator|=(const BitVector &RHS) { if (size() < RHS.size()) resize(RHS.size()); @@ -451,8 +524,11 @@ private: // 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; + BitWord ExtraBitMask = ~0UL << ExtraBits; + if (t) + Bits[UsedWords-1] |= ExtraBitMask; + else + Bits[UsedWords-1] &= ~ExtraBitMask; } } |