Re: [Vm-dev] VM Maker: VMMaker.oscog-nice.1843.mcz

And thanks to Esteban for pointing me to the bug.

2016-04-25 21:22 GMT+02:00 commits@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

==================== 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!