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

[Nicolas Cellier]

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