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5278
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"{ Package: 'stx:libbasic2' }"
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"{ NameSpace: Smalltalk }"
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LimitedPrecisionReal variableByteSubclass:#IEEEFloat
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instanceVariableNames:'exponentSize'
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classVariableNames:''
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poolDictionaries:''
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category:'Magnitude-Numbers'
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!
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!IEEEFloat class methodsFor:'documentation'!
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documentation
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"
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Unfinished, ongoing work
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soft float emulation for arbitrary IEEE float formats.
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This is very very slow and should only be used when importing
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funny sized floating point numbers (such as float24 or float8) from
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external sources, or to simulate computations on otherwise unsupported floating pnt numbers.
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"
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! !
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!IEEEFloat class methodsFor:'instance creation'!
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size:numBits exponentSize:exponentSize
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^ (self basicNew:(numBits // 8)) exponentSize:exponentSize
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"
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self size:256 exponentSize:19
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"
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!
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size:numBits exponentSize:exponentSize fromFloat:aFloat
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^ ((self basicNew:(numBits // 8)) exponentSize:exponentSize) setValueFromFloat:aFloat
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"
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self size:256 exponentSize:19 fromFloat:1.0
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self size:256 exponentSize:19 fromFloat:2.0
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"
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!
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size:numBits exponentSize:exponentSize fromInteger:anInteger
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^ ((self basicNew:(numBits // 8)) exponentSize:exponentSize) setValueFromInteger:anInteger
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"
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self size:256 exponentSize:19 fromInteger:1
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self size:256 exponentSize:19 fromInteger:2
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"
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! !
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!IEEEFloat class methodsFor:'queries'!
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isAbstract
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"Return if this class is an abstract class.
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True is returned here for myself only; false for subclasses.
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Abstract subclasses must redefine this again."
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^ self == IEEEFloat.
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! !
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!IEEEFloat methodsFor:'accessing'!
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exponentSize
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^ exponentSize
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!
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exponentSize:something
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exponentSize := something.
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!
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setValueFromInteger:intValue
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"/ how many bits are there, in this int
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|absValue myNumBits numBitsInNumber shift|
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absValue := intValue abs.
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numBitsInNumber := absValue highBit.
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myNumBits := (self basicSize * 8) - 1 "sign" - exponentSize.
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shift := myNumBits - numBitsInNumber.
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numBitsInNumber > myNumBits ifTrue:[
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self halt.
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] ifFalse:[
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"/ number:
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"/ 1xxxxxxx...xxxxx
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"/ myRep:
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"/ seee...eeexxxxxxxxxx
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absValue digitLength to:1 by:-1 do:[:byteIndex |
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].
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].
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"/ cut off some bits
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"Float numBitsInExponent
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self size:16 exponentSize:4 fromInteger:1
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self size:32 exponentSize:11 fromInteger:1
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self size:256 exponentSize:19 fromInteger:1
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self size:256 exponentSize:19 fromInteger:2
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"
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! !
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!IEEEFloat class methodsFor:'documentation'!
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version_CVS
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^ '$Header$'
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! !
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