[Vm-dev] VM Maker: VMMaker.oscog-nice.1843.mcz
Esteban Lorenzano
estebanlm at gmail.com
Mon Apr 25 19:47:19 UTC 2016
and I confirm it works :)
Esteban
> On 25 Apr 2016, at 21:41, Nicolas Cellier <nicolas.cellier.aka.nice at gmail.com> wrote:
>
> And thanks to Esteban for pointing me to the bug.
>
>
> 2016-04-25 21:22 GMT+02:00 <commits at source.squeak.org <mailto:commits at source.squeak.org>>:
>
> Nicolas Cellier uploaded a new version of VMMaker to project VM Maker:
> http://source.squeak.org/VMMaker/VMMaker.oscog-nice.1843.mcz <http://source.squeak.org/VMMaker/VMMaker.oscog-nice.1843.mcz>
>
> ==================== Summary ====================
>
> Name: VMMaker.oscog-nice.1843
> Author: nice
> Time: 25 April 2016, 8:24:03.731 pm
> UUID: 9ef5d374-ae5e-437a-9116-cde9d708c0d7
> Ancestors: VMMaker.oscog-cb.1842
>
> Fix my recent bug for signed 32bit long access (introduced beginning of April).
>
> One symptom is:
> (Alien newGC: 4)
> signedLongAt: 1 put: -16r7287E552;
> signedLongAt: 1
>
> I incorrecly used the signed value (integerValue) in one branch, and the magnitude (value) in the other branch...
> This is an incorrect copy/paste from maybeInlinePositive32BitIntegerFor: in my ultimate #if SPURVM refactoring.
>
> While at it, avoid the confusion by using a better variable name (magnitude), and eliminate UB related to computing opposite of INT_MIN by explicitely using unsigned type.
>
> =============== Diff against VMMaker.oscog-cb.1842 ===============
>
> Item was changed:
> ----- Method: StackInterpreter>>noInlineSigned32BitIntegerFor: (in category 'primitive support') -----
> noInlineSigned32BitIntegerFor: integerValue
> "Answer a full 32 bit integer object for the given integer value."
> <notOption: #Spur64BitMemoryManager>
> + | newLargeInteger magnitude largeClass |
> - | newLargeInteger value largeClass |
> <inline: false>
> + <var: 'magnitude' type: 'unsigned int'>
> (objectMemory isIntegerValue: integerValue) ifTrue:
> [^objectMemory integerObjectOf: integerValue].
> self deny: objectMemory hasSixtyFourBitImmediates.
> integerValue < 0
> ifTrue: [largeClass := ClassLargeNegativeIntegerCompactIndex.
> + magnitude := 0 asUnsignedInteger - integerValue]
> - value := 0 - integerValue]
> ifFalse: [largeClass := ClassLargePositiveIntegerCompactIndex.
> + magnitude := integerValue].
> - value := integerValue].
> newLargeInteger := objectMemory
> eeInstantiateSmallClassIndex: largeClass
> format: (objectMemory byteFormatForNumBytes: 4)
> numSlots: 1.
> self cppIf: SPURVM
> ifTrue:
> ["Memory is 8 byte aligned in Spur, make sure that oversized bytes are set to zero"
> + objectMemory storeLong32: 0 ofObject: newLargeInteger withValue: (objectMemory byteSwapped32IfBigEndian: magnitude).
> - objectMemory storeLong32: 0 ofObject: newLargeInteger withValue: (objectMemory byteSwapped32IfBigEndian: integerValue).
> objectMemory storeLong32: 1 ofObject: newLargeInteger withValue: 0]
> ifFalse:
> + [objectMemory storeLong32: 0 ofObject: newLargeInteger withValue: (objectMemory byteSwapped32IfBigEndian: magnitude)].
> - [objectMemory storeLong32: 0 ofObject: newLargeInteger withValue: (objectMemory byteSwapped32IfBigEndian: value)].
> ^newLargeInteger!
>
>
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