[Vm-dev] VM Maker: VMMaker.oscog-eem.240.mcz

Nicolas Cellier nicolas.cellier.aka.nice at gmail.com
Thu Dec 20 23:30:45 UTC 2012


By the way, value should be declared unsigned too in #signed32BitIntegerFor:

Nicolas

2012/12/21 Nicolas Cellier <nicolas.cellier.aka.nice at gmail.com>:
> 2012/12/20  <commits at source.squeak.org>:
>>
>> Eliot Miranda uploaded a new version of VMMaker to project VM Maker:
>> http://source.squeak.org/VMMaker/VMMaker.oscog-eem.240.mcz
>>
>> ==================== Summary ====================
>>
>> Name: VMMaker.oscog-eem.240
>> Author: eem
>> Time: 20 December 2012, 12:21:03.98 pm
>> UUID: f72e2cd1-8b0e-45af-acd7-06ba9bbc2a50
>> Ancestors: VMMaker.oscog-eem.239
>>
>
>>
>> Remove obsolete use of cCode: 'magnitude >> 32' in the integer
>> conversion routines signed64BitIntegerFor: et al now that Slang
>> generates the correct cases for right-shift.
>>
>
> Hi Eliot, did you see code at http://code.google.com/p/cog/issues/detail?id=92 ?
> My version of signed64BitIntegerFor: is much simpler
>
> 1) define magnitude as unsigned
>         <var: 'magnitude' type: 'usqLong'>,
>
> 2) handle SmallInteger positive and negative value during the sign test
>         integerValue < 0
>                 ifTrue:[        integerValue >= 16r-40000000 ifTrue: [^self
> integerObjectOf: integerValue].
>                                 largeClass := self classLargeNegativeInteger.
>                                 magnitude := 0 - integerValue]
>                 ifFalse:[       integerValue <= 16r3FFFFFFF ifTrue: [^self
> integerObjectOf: integerValue].
>                                 largeClass := self classLargePositiveInteger.
>                                 magnitude := integerValue].
>
> I think the 3rd change maybe is not worth, it replaces
>                         (highWord := highWord >> 8) = 0 ifFalse:[sz := sz + 1].
>                         (highWord := highWord >> 8) = 0 ifFalse:[sz := sz + 1].
>                         (highWord := highWord >> 8) = 0 ifFalse:[sz := sz + 1]].
> with:
>                         (highWord >> 16) = 0 ifFalse:
>                                 [highWord := highWord >> 16.
>                                 sz := sz + 2].
>                         (highWord >> 8) = 0 ifFalse:[sz := sz + 1].
>
> Nicolas


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