[Vm-dev] VM Maker: VMMaker.oscog-eem.757.mcz

[commits at source.squeak.org]

Eliot Miranda uploaded a new version of VMMaker to project VM Maker:
http://source.squeak.org/VMMaker/VMMaker.oscog-eem.757.mcz

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

Name: VMMaker.oscog-eem.757
Author: eem
Time: 5 June 2014, 10:38:06.398 am
UUID: c4908baa-712c-4cb6-a606-5bde992e9582
Ancestors: VMMaker.oscog-eem.756

Fix a stupid slip in genSpecialSelectorEqualsEquals.
The constant evaluation must remember to pop the simulation
stack before it pushes the boolean result.

=============== Diff against VMMaker.oscog-eem.756 ===============

Item was changed:
  ----- Method: StackToRegisterMappingCogit>>genSpecialSelectorEqualsEquals (in category 'bytecode generators') -----
  genSpecialSelectorEqualsEquals
  	| nextPC postBranchPC targetBytecodePC primDescriptor branchDescriptor nExts
+ 	  unforwardArg unforwardRcvr jumpEqual jumpNotEqual rcvrReg argReg result |
- 	  unforwardArg unforwardRcvr jumpEqual jumpNotEqual rcvrReg argReg |
  	<var: #jumpEqual type: #'AbstractInstruction *'>
  	<var: #jumpNotEqual type: #'AbstractInstruction *'>
  	<var: #primDescriptor type: #'BytecodeDescriptor *'>
  	<var: #branchDescriptor type: #'BytecodeDescriptor *'>
  	primDescriptor := self generatorAt: byte0.
  	"forwarders have been followed in cog:selector:"
  	(self ssTop type = SSConstant
  	 and: [(self ssValue: 1) type = SSConstant]) ifTrue:
  		[self assert: primDescriptor isMapped not.
+ 		 result := self ssTop constant = (self ssValue: 1) constant
- 		 ^self ssPushConstant: (self ssTop constant = (self ssValue: 1) constant
  									ifTrue: [objectMemory trueObject]
+ 									ifFalse: [objectMemory falseObject].
+ 		 self ssPop: 2.
+ 		 ^self ssPushConstant: result].
- 									ifFalse: [objectMemory falseObject])].
  
  	nextPC := bytecodePC + primDescriptor numBytes.
  	nExts := 0.
  	[branchDescriptor := self generatorAt: (objectMemory fetchByte: nextPC ofObject: methodObj) + (byte0 bitAnd: 256).
  	 branchDescriptor isExtension] whileTrue:
  		[nExts := nExts + 1.
  		 nextPC := nextPC + branchDescriptor numBytes].
  	"If branching the stack must be flushed for the merge"
  	(branchDescriptor isBranchTrue or: [branchDescriptor isBranchFalse]) ifTrue:
  		[self ssFlushTo: simStackPtr - 2].
  
  	unforwardRcvr := (self ssValue: 1) type ~= SSConstant
  						or: [objectRepresentation shouldAnnotateObjectReference: (self ssValue: 1) constant].
  	unforwardArg := self ssTop type ~= SSConstant
  						or: [objectRepresentation shouldAnnotateObjectReference: self ssTop constant].
  
  	"Don't use ReceiverResultReg for receiver to keep ReceiverResultReg live.
  	 Optimize e.g. rcvr == nil, the common case for ifNil: et al."
  	needsFrame
  		ifTrue: 
  			[unforwardArg ifTrue:
  				[self ssAllocateRequiredReg: (argReg := Arg0Reg) upThrough: simStackPtr - 1].
  			 self ssAllocateRequiredReg: (rcvrReg := Arg1Reg) upThrough: simStackPtr - 2]
  		ifFalse:
  			[unforwardArg ifTrue:
  				[argReg := self ssAllocatePreferredReg: ClassReg].
  			 rcvrReg := self ssAllocatePreferredReg: SendNumArgsReg].
  	unforwardArg
  		ifTrue:
  			[self ssTop popToReg: argReg.
  			 objectRepresentation genEnsureOopInRegNotForwarded: argReg scratchReg: TempReg.
  			 (self ssValue: 1) popToReg: rcvrReg.
  			 unforwardRcvr ifTrue:
  				[objectRepresentation genEnsureOopInRegNotForwarded: rcvrReg scratchReg: TempReg].
  			 self CmpR: argReg R: rcvrReg]
  		ifFalse:
  			[(self ssValue: 1) popToReg: rcvrReg.
  			 unforwardRcvr ifTrue:
  				[objectRepresentation genEnsureOopInRegNotForwarded: rcvrReg scratchReg: TempReg].
  			 self CmpCq: self ssTop constant R: rcvrReg].
  	self ssPop: 2.
  
  	"If not followed by a branch, resolve to true or false."
  	(branchDescriptor isBranchTrue or: [branchDescriptor isBranchFalse]) ifFalse:
  		[jumpNotEqual := self JumpNonZero: 0.
  		 self annotate: (self MoveCw: objectMemory trueObject R: rcvrReg)
  			objRef: objectMemory trueObject.
  		 jumpEqual := self Jump: 0.
  		 jumpNotEqual jmpTarget: (self annotate: (self MoveCw: objectMemory falseObject R: rcvrReg)
  										objRef: objectMemory falseObject).
  		 jumpEqual jmpTarget: self Label.
  		 self ssPushRegister: rcvrReg.
  		 ^0].
  
  	"Further since there is a following conditional jump bytecode, define
  	 non-merge fixups and leave the cond bytecode to set the mergeness."
  	targetBytecodePC := nextPC
  							+ branchDescriptor numBytes
  							+ (self spanFor: branchDescriptor at: nextPC exts: nExts in: methodObj).
  	postBranchPC := nextPC + branchDescriptor numBytes.
  	(self fixupAt: nextPC - initialPC) targetInstruction = 0
  		ifTrue: "The next instruction is dead.  we can skip it."
  			[deadCode := true.
  		 	 self ensureFixupAt: targetBytecodePC - initialPC.
  			 self ensureFixupAt: postBranchPC - initialPC]
  		ifFalse:
  			[self ssPushConstant: objectMemory trueObject]. "dummy value"
  	self gen: (branchDescriptor isBranchTrue ifTrue: [JumpZero] ifFalse: [JumpNonZero])
  		operand: (self ensureNonMergeFixupAt: targetBytecodePC - initialPC) asUnsignedInteger.
  	self Jump: (self ensureNonMergeFixupAt: postBranchPC - initialPC).
  	^0!