VM Maker: Cog-eem.410.mcz

 
Eliot Miranda uploaded a new version of Cog to project VM Maker:
http://source.squeak.org/VMMaker/Cog-eem.410.mcz

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

Name: Cog-eem.410
Author: eem
Time: 15 September 2020, 1:41:52.361982 pm
UUID: 74aea94d-a83d-4b8a-a3e7-9744bddb8476
Ancestors: Cog-eem.409

Get the MIPS simulator not to inctement the pc when faulting.  Fix a typo.

=============== Diff against Cog-eem.409 ===============

Item was changed:
  ----- Method: MIPSELSimulator>>executeFault: (in category 'memory') -----
  executeFault: address
  | jumpInstruction type |
  self assert: inDelaySlot not.
+ fault := #call. "default"
  jumpInstruction := MIPSInstruction new value: (self fetchInstruction: jumpingPC).
+ jumpInstruction opcode = J
+ ifTrue: [type := #jump]
+ ifFalse:
+ [jumpInstruction opcode = SPECIAL ifTrue:
+ [jumpInstruction function = JR ifTrue:
+ [fault := jumpInstruction rs = RA
+ ifTrue: [#return]
+ ifFalse: [#jump]]]].
- jumpInstruction opcode = J ifTrue: [type := #jump].
- jumpInstruction opcode = JAL ifTrue: [type := #call].
- jumpInstruction opcode = SPECIAL ifTrue:
- [jumpInstruction function = JR ifTrue:
- [jumpInstruction rs = RA
- ifTrue: [type := #return]
- ifFalse: [type := #jump]].
- jumpInstruction function = JALR ifTrue:
- [type := #call]].
- self assert: type ~~ nil.
 
  ^(ProcessorSimulationTrap
+ pc: jumpingPC
+ nextpc: address
- pc: nil
- nextpc: nil
  address: address
+ type: fault
- type: type
  accessor: nil)
  signal!

Item was changed:
  ----- Method: MIPSELSimulator>>fetchInstruction: (in category 'memory') -----
  fetchInstruction: address
+ address < executableBase ifTrue: [self executeFault: address].
+ address > executableLimit ifTrue: [self executeFault: address].
- address < exectuableBase ifTrue: [self executeFault: address].
- address > exectuableLimit ifTrue: [self executeFault: address].
  (address bitAnd: 3) = 0 ifFalse: [self error: 'Unaligned read'].
  ^memory unsignedLongAt: address + 1 bigEndian: false!

Item was changed:
  ----- Method: MIPSELSimulator>>readFault: (in category 'memory') -----
  readFault: address
  | destReg |
  self assert: inDelaySlot not. "Or we have to store nextPC somewhere."
  destReg := (MIPSInstruction new value: (self fetchInstruction: pc)) rt.
 
  ^(ProcessorSimulationTrap
  pc: pc
  nextpc: pc + 4
  address: address
+ type: (fault := #read)
- type: #read
  accessor: (self setterForRegister: destReg))
  signal
  !

Item was changed:
  ----- Method: MIPSELSimulator>>writeFault: (in category 'memory') -----
  writeFault: address
  | srcReg |
  self assert: inDelaySlot not. "Or we have to store nextPC somewhere."
  srcReg := (MIPSInstruction new value: (self fetchInstruction: pc)) rt.
 
  ^(ProcessorSimulationTrap
  pc: pc
  nextpc: pc + 4
  address: address
+ type: (fault := #write)
- type: #write
  accessor: (self getterForRegister: srcReg))
  signal
  !

Item was changed:
  Object subclass: #MIPSSimulator
+ instanceVariableNames: 'memory registers pc instructionCount inDelaySlot readableBase writableBase readableLimit writableLimit jumpingPC hi lo executableBase executableLimit fault'
- instanceVariableNames: 'memory registers pc instructionCount inDelaySlot readableBase writableBase exectuableBase readableLimit writableLimit exectuableLimit jumpingPC hi lo'
  classVariableNames: 'EndSimulationPC'
  poolDictionaries: 'MIPSConstants'
  category: 'Cog-Processors'!
 
  !MIPSSimulator commentStamp: 'rmacnak 11/11/2015 20:33:00' prior: 0!
  Simulator for 32-bit MIPS, without implementation of memory access.!

Item was changed:
  ----- Method: MIPSSimulator>>attemptJumpTo:type: (in category 'instructions - control') -----
  attemptJumpTo: nextPC type: trapType
+ (nextPC between: readableBase and: executableLimit) ifFalse:
- (nextPC between: readableBase and: exectuableLimit) ifFalse:
  [^(ProcessorSimulationTrap
  pc: pc
  nextpc: pc + OneInstruction
  address: nextPC
+ type: (fault := trapType))
- type: trapType)
  signal].
  pc := nextPC - OneInstruction "Account for general increment"!

Item was changed:
  ----- Method: MIPSSimulator>>initializeWithMemory: (in category 'as yet unclassified') -----
  initializeWithMemory: aByteArray
  memory := aByteArray.
  readableBase := 0.
  writableBase := 0.
+ executableBase := 0.
- exectuableBase := 0.
  readableLimit := memory size.
  writableLimit := memory size.
+ executableLimit := memory size.!
- exectuableLimit := memory size.!

Item was changed:
  ----- Method: MIPSSimulator>>runInMemory:minimumAddress:readOnlyBelow: (in category 'processor api') -----
  runInMemory: aMemory minimumAddress: minimumAddress readOnlyBelow: minimumWritableAddress
  "Note that minimumWritableAddress is both the minimum writeable address AND the maximum executable address"
  memory := aMemory.
  readableBase := minimumAddress.
  writableBase := minimumWritableAddress.
+ executableBase := minimumAddress.
- exectuableBase := minimumAddress.
  readableLimit := aMemory byteSize.
  writableLimit := aMemory byteSize.
+ executableLimit := minimumWritableAddress.
- exectuableLimit := minimumWritableAddress.
  self execute.!

Item was changed:
  ----- Method: MIPSSimulator>>step (in category 'as yet unclassified') -----
  step
  "If the next instruction is a branch, its delay slot will also be executed."
  | instruction |
  "Transcript print: instructionCount; nextPutAll: ' X '; nextPutAll: self currentInstruction; flush"
+ fault := nil.
  instruction := MIPSInstruction new value: (self fetchInstruction: pc).
  instruction decodeFor: self.
+ fault
+ ifNotNil: [fault := nil]
+ ifNil: [pc := pc + OneInstruction].
+ instructionCount := instructionCount + 1!
- pc := pc + OneInstruction.
- instructionCount := instructionCount + 1.!