diff options
Diffstat (limited to 'include/llvm/ADT/APInt.h')
| -rw-r--r-- | include/llvm/ADT/APInt.h | 35 |
1 files changed, 30 insertions, 5 deletions
diff --git a/include/llvm/ADT/APInt.h b/include/llvm/ADT/APInt.h index d494ad2..aa3c3f6 100644 --- a/include/llvm/ADT/APInt.h +++ b/include/llvm/ADT/APInt.h @@ -284,12 +284,10 @@ public: initSlowCase(that); } -#if LLVM_HAS_RVALUE_REFERENCES /// \brief Move Constructor. APInt(APInt &&that) : BitWidth(that.BitWidth), VAL(that.VAL) { that.BitWidth = 0; } -#endif /// \brief Destructor. ~APInt() { @@ -656,7 +654,6 @@ public: return AssignSlowCase(RHS); } -#if LLVM_HAS_RVALUE_REFERENCES /// @brief Move assignment operator. APInt &operator=(APInt &&that) { if (!isSingleWord()) @@ -669,7 +666,6 @@ public: return *this; } -#endif /// \brief Assignment operator. /// @@ -1265,7 +1261,7 @@ public: /// \returns the number of words to hold the integer value with a given bit /// width. static unsigned getNumWords(unsigned BitWidth) { - return (BitWidth + APINT_BITS_PER_WORD - 1) / APINT_BITS_PER_WORD; + return ((uint64_t)BitWidth + APINT_BITS_PER_WORD - 1) / APINT_BITS_PER_WORD; } /// \brief Compute the number of active bits in the value @@ -1504,6 +1500,35 @@ public: return BitWidth - (*this - 1).countLeadingZeros(); } + /// \returns the nearest log base 2 of this APInt. Ties round up. + /// + /// NOTE: When we have a BitWidth of 1, we define: + /// + /// log2(0) = UINT32_MAX + /// log2(1) = 0 + /// + /// to get around any mathematical concerns resulting from + /// referencing 2 in a space where 2 does no exist. + unsigned nearestLogBase2() const { + // Special case when we have a bitwidth of 1. If VAL is 1, then we + // get 0. If VAL is 0, we get UINT64_MAX which gets truncated to + // UINT32_MAX. + if (BitWidth == 1) + return VAL - 1; + + // Handle the zero case. + if (!getBoolValue()) + return UINT32_MAX; + + // The non-zero case is handled by computing: + // + // nearestLogBase2(x) = logBase2(x) + x[logBase2(x)-1]. + // + // where x[i] is referring to the value of the ith bit of x. + unsigned lg = logBase2(); + return lg + unsigned((*this)[lg - 1]); + } + /// \returns the log base 2 of this APInt if its an exact power of two, -1 /// otherwise int32_t exactLogBase2() const { |