[Vm-dev] VM Maker: VMMaker.oscog-cb.1919.mcz

commits at source.squeak.org commits at source.squeak.org
Wed Aug 17 14:12:47 UTC 2016

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

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

Name: VMMaker.oscog-cb.1919
Author: cb
Time: 17 August 2016, 4:10:53.445475 pm
UUID: 00a8dd2a-bc8d-4552-b400-be781c8aabec
Ancestors: VMMaker.oscog-cb.1918

fixed bug in scanner related to twoPath methods

=============== Diff against VMMaker.oscog-cb.1918 ===============

Item was changed:
  ----- Method: StackToRegisterMappingCogit>>compileFrameBuild (in category 'compile abstract instructions') -----
  	"Build a frame for a CogMethod activation.  See CoInterpreter class>>initializeFrameIndices.
  	 Override to push the register receiver and register arguments, if any."
  	self cppIf: IMMUTABILITY ifTrue: 
  		[useTwoPaths ifTrue: 
  			[self compileTwoPathFrameBuild.
  	needsFrame ifFalse:
  		[useTwoPaths ifTrue: 
  			[self compileTwoPathFramelessInit].
  		 self initSimStackForFramelessMethod: initialPC.
+ 	self deny: useTwoPaths.
  	self genPushRegisterArgs.
  	super compileFrameBuild.
  	self initSimStackForFramefulMethod: initialPC!

Item was changed:
  ----- Method: StackToRegisterMappingCogit>>scanMethod (in category 'compile abstract instructions') -----
  	"Scan the method (and all embedded blocks) to determine
  		- what the last bytecode is; extra bytes at the end of a method are used to encode things like source pointers or temp names
  		- if the method needs a frame or not
  		- what are the targets of any backward branches.
  		- how many blocks it creates
  	 Answer the block count or on error a negative error code"
  	| latestContinuation nExts descriptor pc numBlocks distance targetPC framelessStackDelta seenInstVarStore |
  	<var: #descriptor type: #'BytecodeDescriptor *'>
  	needsFrame := useTwoPaths := seenInstVarStore := false.
  	self maybeInitNumFixups.
  	self maybeInitNumCounters.
  	prevBCDescriptor := nil.
  	NewspeakVM ifTrue:
  		[numIRCs := 0].
  	(primitiveIndex > 0
  	 and: [coInterpreter isQuickPrimitiveIndex: primitiveIndex]) ifTrue:
  	pc := latestContinuation := initialPC.
  	numBlocks := framelessStackDelta := nExts := extA := extB := 0.
  	[pc <= endPC] whileTrue:
  		[byte0 := (objectMemory fetchByte: pc ofObject: methodObj) + bytecodeSetOffset.
  		 descriptor := self generatorAt: byte0.
  		 descriptor isExtension ifTrue:
  			[descriptor opcode = Nop ifTrue: "unknown bytecode tag; see Cogit class>>#generatorTableFrom:"
  			 self loadSubsequentBytesForDescriptor: descriptor at: pc.
  			 self perform: descriptor generator].
  		 (descriptor isReturn
  		  and: [pc >= latestContinuation]) ifTrue:
  			[endPC := pc].
  		  needsFrame ifFalse:
  			[(descriptor needsFrameFunction isNil
  			  or: [self perform: descriptor needsFrameFunction with: framelessStackDelta])
  						["With immutability we win simply by avoiding a frame build if the receiver is young and not immutable."
  						 self cppIf: IMMUTABILITY
  							ifTrue: [descriptor is1ByteInstVarStore
  									ifTrue: [useTwoPaths := true]
  									ifFalse: [needsFrame := true. useTwoPaths := false]]
+ 							ifFalse: [needsFrame := true. useTwoPaths := false]]
- 							ifFalse: [needsFrame := true]]
  						[framelessStackDelta := framelessStackDelta + descriptor stackDelta.
  						 "Without immutability we win if there are two or more stores and the receiver is new."
  						 self cppIf: IMMUTABILITY
  							ifTrue: []
  								[descriptor is1ByteInstVarStore ifTrue:
  										ifTrue: [useTwoPaths := true]
  										ifFalse: [seenInstVarStore := true]]]]].
  		 descriptor isBranch ifTrue:
  			[distance := self spanFor: descriptor at: pc exts: nExts in: methodObj.
  			 targetPC := pc + descriptor numBytes + distance.
  			 (self isBackwardBranch: descriptor at: pc exts: nExts in: methodObj)
  				ifTrue: [self initializeFixupAt: targetPC - initialPC]
  					[latestContinuation := latestContinuation max: targetPC.
  					 self maybeCountFixup.
  					 self maybeCountCounter]].
  		 descriptor isBlockCreation ifTrue:
  			[numBlocks := numBlocks + 1.
  			 distance := self spanFor: descriptor at: pc exts: nExts in: methodObj.
  			 targetPC := pc + descriptor numBytes + distance.
  			 latestContinuation := latestContinuation max: targetPC.
  			 self maybeCountFixup].
  		 NewspeakVM ifTrue:
  			[descriptor hasIRC ifTrue:
  				[numIRCs := numIRCs + 1]].
  		 pc := pc + descriptor numBytes.
  		 descriptor isExtension
  			ifTrue: [nExts := nExts + 1]
  			ifFalse: [nExts := extA := extB := 0].
  		 prevBCDescriptor := descriptor].

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