[Vm-dev] VM Maker: VMMaker.oscog-cb.2016.mcz

commits at source.squeak.org commits at source.squeak.org
Thu Dec 1 09:33:41 UTC 2016

ClementBera uploaded a new version of VMMaker to project VM Maker:

==================== Summary ====================

Name: VMMaker.oscog-cb.2016
Author: cb
Time: 1 December 2016, 10:33:24.307114 am
UUID: 00547c08-bf88-4160-9dd8-baf1f367a96e
Ancestors: VMMaker.oscog-EstebanLorenzano.2015

Added a setting so that subclasses of cogit can choose to refuse early openPIC promotion.

This leads to much, much, *much* better type information on PICs in the Sista VM. No changes in the normal VM.

=============== Diff against VMMaker.oscog-EstebanLorenzano.2015 ===============

Item was added:
+ ----- Method: Cogit>>allowEarlyOpenPICPromotion (in category 'in-line cacheing') -----
+ allowEarlyOpenPICPromotion
+ 	<inline: true>
+ 	^ true!

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:
  			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."
  	| 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 asUnsignedInteger.
  	targetMethod := self cCoerceSimple: innerReturn - missOffset to: #'CogMethod *'.
  	(objectMemory isOopForwarded: receiver) ifTrue:
  		[^coInterpreter ceSendFromInLineCacheMiss: targetMethod].
  	outerReturn := coInterpreter stackTop asUnsignedInteger.
  	self assert: (outerReturn between: methodZoneBase and: methodZone freeStart).
  	entryPoint := backEnd callTargetFromReturnAddress: outerReturn.
  	self assert: targetMethod selector ~= objectMemory nilObject.
  	self assert: targetMethod asInteger + cmEntryOffset = entryPoint.
  	self lookup: targetMethod selector
  		for: receiver
  			[: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: [(backEnd inlineCacheTagAt: outerReturn) = self picAbortDiscriminatorValue
  	 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 or: [self allowEarlyOpenPICPromotion not]) ifTrue:
- 	pic ifNil:
  		["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:
  			["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 asUnsignedInteger to: pic asUnsignedInteger + closedPICSize].
  	"Relink the send site to the pic.  If to an open PIC then reset the cache tag to the selector,
  	 for the benefit of the cacheTag assert check in checkIfValidOopRef:pc:cogMethod: et al."
  	extent := pic cmType = CMOpenPIC
  						rewriteInlineCacheAt: outerReturn
  						tag: (self inlineCacheValueForSelector: targetMethod selector
  								  in: coInterpreter mframeHomeMethodExport
  								  at: outerReturn)
  						target: pic asInteger + cmEntryOffset]
  						rewriteCallAt: outerReturn
  						target: pic asInteger + cmEntryOffset].
  	processor flushICacheFrom: outerReturn asUnsignedInteger - extent to: outerReturn asUnsignedInteger.
  	"Jump back into the pic at its entry in case this is an MNU (newTargetMethodOrNil is nil)"
  		executeCogPIC: pic
  		fromLinkedSendWithReceiver: receiver
  		andCacheTag: (backEnd inlineCacheTagAt: outerReturn).

Item was added:
+ ----- Method: SistaCogit>>allowEarlyOpenPICPromotion (in category 'in-line cacheing') -----
+ allowEarlyOpenPICPromotion
+ 	<inline: true>
+ 	^ false!

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