Eliot Miranda uploaded a new version of VMMaker to project VM Maker:
http://source.squeak.org/VMMaker/VMMaker.oscog-eem.2832.mcz
==================== Summary ====================
Name: VMMaker.oscog-eem.2832
Author: eem
Time: 30 September 2020, 8:11:43.302713 pm
UUID: bc601167-a7f8-41d3-8621-eb8313bbc4ad
Ancestors: VMMaker.oscog-eem.2831
Comment an interesting policy choice in externalInstVar:ofContext:.
Fix a slip in the new IA32ABI copy into primitive
=============== Diff against VMMaker.oscog-eem.2831 ===============
Item was changed:
----- Method: CoInterpreter>>externalInstVar:ofContext: (in category 'frame access') -----
externalInstVar: offset ofContext: aContext
"Fetch an instance variable from a maybe married context.
If the context is still married compute the value of the
relevant inst var from the spouse frame's state.
If the context is single but has a negative instruction pointer
recognise that the instruction pointer is actually into machine
code and convert it to the corresponding bytecode pc."
<inline: false>
| value |
self assert: (objectMemory isContext: aContext).
self assert: offset <= (ReceiverIndex + (self checkStackPointerForMaybeMarriedContext: aContext)).
"method, closureOrNil & receiver need no special handling; only
sender, pc & stackp have to be computed for married contexts."
(self isReadMediatedContextInstVarIndex: offset) ifFalse:
[^objectMemory fetchPointer: offset ofObject: aContext].
self externalWriteBackHeadFramePointers.
(self isStillMarriedContext: aContext) ifTrue:
[^self fetchPointer: offset ofMarriedContext: aContext].
value := objectMemory fetchPointer: offset ofObject: aContext.
+ "Why not update the slot to refer to the mapped pc? We're damned if we do, and damned if
+ we don't. If it is and the context is live and is returned to, then the pc will be mapped back
+ to machine code. If we don't then the mapping will be repeated on every access. What we
+ need are stats that show whether or not a read here predicts one or other outcome with any
+ certainty. For now, we keep it as it has been for a long time and do not update the slot."
(offset = InstructionPointerIndex
and: [(objectMemory isIntegerObject: value)
and: [value signedIntFromLong < 0]]) ifTrue:
[^self mustMapMachineCodePC: (objectMemory integerValueOf: value) context: aContext].
^value!
Item was changed:
----- Method: IA32ABIPlugin>>primAlienCopyInto (in category 'primitives-accessing') -----
primAlienCopyInto
"Copy some number of bytes from the receiver starting at the first index into some destination
object starting at the second index. The destination may be an Aliens or a bit-indexable object.
The primitive will have the following signature:
<Alien>
primCopyFrom: start <Integer>
to: stop <Integer>
into: destination <Alien | indexableByteSubclass et al>
startingAt: destStart <Integer> ^<self>
<primitive: 'primitiveAlienReplace' error: errorCode module: 'IA32ABI'>
"
<export: true>
| alien start stop dest destStart src totalLength destAddr myLength |
alien := interpreterProxy stackValue: 4. "Unchecked!!"
start := interpreterProxy stackIntegerValue: 3.
stop := interpreterProxy stackIntegerValue: 2.
dest := interpreterProxy stackValue: 1.
destStart := interpreterProxy stackIntegerValue: 0.
(interpreterProxy failed
or: [(interpreterProxy isWordsOrBytes: dest) not]) ifTrue:
[^interpreterProxy primitiveFailFor: PrimErrBadArgument].
myLength := self sizeField: alien.
src := (self startOfData: alien withSize: myLength) + start - 1.
(self isAlien: dest)
ifTrue:
[totalLength := self sizeField: dest.
+ destAddr := (self startOfData: dest withSize: totalLength) + destStart - 1.
- destAddr := (self startOfData: dest withSize: totalLength) + start - 1.
totalLength = 0 "no bounds checks for zero-sized (pointer) Aliens"
ifTrue: [totalLength := stop]
ifFalse: [totalLength := totalLength abs]]
ifFalse:
[totalLength := interpreterProxy byteSizeOf: dest.
+ destAddr := (self startOfByteData: dest) + destStart - 1].
- destAddr := (self startOfByteData: dest) + start - 1].
((start >= 1 and: [start - 1 <= stop and: [stop <= myLength abs]])
and: [stop - start + 1 <= totalLength]) ifFalse:
[^interpreterProxy primitiveFailFor: PrimErrBadIndex].
(interpreterProxy isOopImmutable: dest) ifTrue:
[^interpreterProxy primitiveFailFor: PrimErrNoModification].
"Use memmove to allow source and desition to overlap"
self memmove: destAddr asVoidPointer _: src asVoidPointer _: stop - start + 1.
interpreterProxy methodReturnReceiver!
