Class: BitUtil

Inherits:
Object
  • Object
show all
Defined in:
lib/visitor/numbering_visitor.rb

Instance Method Summary collapse

Constructor Details

#initialize ⇒ BitUtil

Returns a new instance of BitUtil.



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# File 'lib/visitor/numbering_visitor.rb', line 27

def initialize
  @masks = [ 0xffff, 0xff ]
  @rightTable = [ 0 ]
  @leftTable = [ 0 ]

  (1..255).each do |val|
    @rightTable << rightOneBit(val)
    @leftTable << leftOneBit(val)
  end
end

Instance Method Details

#bitGreaterThanOrEqualTo(startOffset, v1, v2) ⇒ Object 



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# File 'lib/visitor/numbering_visitor.rb', line 48

def bitGreaterThanOrEqualTo(startOffset, v1, v2)
  map = (1 << (startOffset - 1))
  while (startOffset < 64) do
    if (((v1 & map) != 0) && ((v2 & map) != 0)) then
      return startOffset
    else
      startOffset += 1
      map = map << 1
    end
  end
end

#leftBit(n) ⇒ Object 



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# File 'lib/visitor/numbering_visitor.rb', line 43

def leftBit(n)
  shiftCount, n = shiftToByteLeft(n)
  @leftTable[n & 0xff] + shiftCount
end

#leftMostBitToRightOf(bitNumber, n) ⇒ Object 



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# File 'lib/visitor/numbering_visitor.rb', line 60

def leftMostBitToRightOf(bitNumber, n)
  mask = getMask(bitNumber + 1)
  return leftBit(n & mask)
end

#rightBit(n) ⇒ Object 



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# File 'lib/visitor/numbering_visitor.rb', line 38

def rightBit(n)
  shiftCount, n = shiftToByteRight(n)
  @rightTable[n & 0xff] + shiftCount
end