[Vm-dev] VM Maker: VMMaker.oscog-eem.299.mcz
commits at source.squeak.org
commits at source.squeak.org
Fri Jun 14 23:49:39 UTC 2013
Eliot Miranda uploaded a new version of VMMaker to project VM Maker:
http://source.squeak.org/VMMaker/VMMaker.oscog-eem.299.mcz
==================== Summary ====================
Name: VMMaker.oscog-eem.299
Author: eem
Time: 14 June 2013, 4:47:32.815 pm
UUID: e51057f5-4de2-4c2b-82ce-844d130e2f33
Ancestors: VMMaker.oscog-eem.298
Fix bad performance regression that on certain platforms (linux)
results in all send misses causing a discarded PIC creation followed
by a slow hash lookup.
=============== Diff against VMMaker.oscog-eem.298 ===============
Item was changed:
----- Method: Cogit>>ceSICMiss: (in category 'in-line cacheing') -----
ceSICMiss: receiver
"An in-line cache check in a method has failed. The failing entry check has jumped
to the ceMethodAbort abort call at the start of the method which has called this routine.
If possible allocate a closed PIC for the current and existing classes.
The stack looks like:
receiver
args
sender return address
sp=> ceMethodAbort call return address
So we can find the method that did the failing entry check at
ceMethodAbort call return address - missOffset
and we can find the send site from the outer return address."
<api>
| pic innerReturn outerReturn entryPoint targetMethod newTargetMethodOrNil errorSelectorOrNil cacheTag extent result |
<var: #pic type: #'CogMethod *'>
<var: #targetMethod type: #'CogMethod *'>
"Whether we can relink to a PIC or not we need to pop off the inner return and identify the target method."
innerReturn := coInterpreter popStack.
targetMethod := self cCoerceSimple: innerReturn - missOffset to: #'CogMethod *'.
outerReturn := coInterpreter stackTop.
self assert: (outerReturn between: methodZoneBase and: methodZone freeStart).
entryPoint := backEnd callTargetFromReturnAddress: outerReturn.
self assert: targetMethod selector ~= objectMemory nilObject.
self cppIf: NewspeakVM ifTrue:
[self assert: (targetMethod asInteger + cmEntryOffset = entryPoint
or: [targetMethod asInteger + cmDynSuperEntryOffset = entryPoint]).
"Avoid the effort of implementing PICs for the relatively low dynamic frequency
dynamic super send and simply rebind the send site."
targetMethod asInteger + cmDynSuperEntryOffset = entryPoint ifTrue:
[^coInterpreter
ceDynamicSuperSend: targetMethod selector
to: receiver
numArgs: targetMethod cmNumArgs]].
self assert: targetMethod asInteger + cmEntryOffset = entryPoint.
self lookup: targetMethod selector
for: receiver
methodAndErrorSelectorInto:
[:method :errsel|
newTargetMethodOrNil := method.
errorSelectorOrNil := errsel].
"We assume lookupAndCog:for: will *not* reclaim the method zone"
self assert: outerReturn = coInterpreter stackTop.
cacheTag := objectRepresentation inlineCacheTagForInstance: receiver.
((errorSelectorOrNil notNil and: [errorSelectorOrNil ~= SelectorDoesNotUnderstand])
or: [(objectRepresentation inlineCacheTagIsYoung: cacheTag)
or: [newTargetMethodOrNil isNil
or: [objectMemory isYoung: newTargetMethodOrNil]]]) ifTrue:
[result := self patchToOpenPICFor: targetMethod selector
numArgs: targetMethod cmNumArgs
receiver: receiver.
self assert: result not. "If patchToOpenPICFor:.. returns we're out of code memory"
^coInterpreter ceSendFromInLineCacheMiss: targetMethod].
"See if an Open PIC is already available."
pic := methodZone openPICWithSelector: targetMethod selector.
pic isNil ifTrue:
["otherwise attempt to create a closed PIC for the two cases."
pic := self cogPICSelector: targetMethod selector
numArgs: targetMethod cmNumArgs
Case0Method: targetMethod
Case1Method: newTargetMethodOrNil
tag: cacheTag
isMNUCase: errorSelectorOrNil = SelectorDoesNotUnderstand.
+ (pic asInteger between: MaxNegativeErrorCode and: -1) ifTrue:
- pic asInteger < 0 ifTrue:
["For some reason the PIC couldn't be generated, most likely a lack of code memory.
Continue as if this is an unlinked send."
pic asInteger = InsufficientCodeSpace ifTrue:
[coInterpreter callForCogCompiledCodeCompaction].
^coInterpreter ceSendFromInLineCacheMiss: targetMethod].
processor flushICacheFrom: pic asInteger to: pic asInteger + closedPICSize].
"Relink the send site to the pic."
extent := backEnd
rewriteCallAt: outerReturn
target: pic asInteger + cmEntryOffset.
processor flushICacheFrom: outerReturn - 1 - extent to: outerReturn - 1.
"Jump back into the pic at its entry in case this is an MNU (newTargetMethodOrNil is nil)"
coInterpreter
executeCogMethodFromLinkedSend: pic
withReceiver: receiver
andCacheTag: (backEnd inlineCacheTagAt: outerReturn).
"NOTREACHED"
^nil!
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