"{ Package: 'jv:dragonfly/asm' }"

"{ NameSpace: Smalltalk }"

AJRegister subclass:#AJx86GPRegister

	instanceVariableNames:''

	classVariableNames:''

	poolDictionaries:'AJx86Registers'

	category:'AsmJit-x86-Operands'

!

AJx86GPRegister comment:'A general purpose x86 & x64 registers'

!

!AJx86GPRegister methodsFor:'accessing'!

descriptionOn: s

    s nextPutAll: 'A '; print: self size * 8; nextPutAll: 'bit general purpose register'.

!

registerName 

    ^ name asString.

!

stackSize

    ^ self size

! !

!AJx86GPRegister methodsFor:'converting'!

as16

    ^ self isHighByte

        ifTrue: [ self asLowByte as16 ]

        ifFalse: [ 

            AJx86Registers

                generalPurposeWithIndex: self index

                size: 2

                requiresRex: self index > 7

                prohibitsRex: false ]

!

as32

    ^ self isHighByte

        ifTrue: [ self asLowByte as32 ]

        ifFalse: [ 

            AJx86Registers

                generalPurposeWithIndex: self index

                size: 4

                requiresRex: self index > 7

                prohibitsRex: false ]

!

as64

    ^ self isHighByte

        ifTrue: [ self asLowByte as64 ]

        ifFalse: [ 

            AJx86Registers

                generalPurposeWithIndex: self index

                size: 8

                requiresRex: self index > 7

                prohibitsRex: false ]

!

as8

    "8-bit low-byte registers require REX if they have a high index (>7), or if they are one of BPL, SIL, DIL, SPL (indices 4-7).

    The only way to get AH, BH, CH, or DH out of this method is to send it to one of those registers."

    ^ self is8

        ifTrue: [ self ]

        ifFalse: [ 

            AJx86Registers

                generalPurposeWithIndex: self index

                size: 1

                requiresRex: self index > 3

                prohibitsRex: false ]

!

asHighByte

    self isHighByte

        ifTrue: [ ^ self ].

    self isLowByte

        ifFalse: [ Error signal: 'Can only convert AH, BH, CH, or DH to high byte' ].

    ^ AJx86Registers

        generalPurposeWithIndex: self index + 2r100

        size: 1

        requiresRex: false

        prohibitsRex: true

!

asLowByte

    self isLowByte

        ifTrue: [ ^ self ].

    self isHighByte

        ifFalse: [ Error signal: 'Can only convert high byte 8bit register to low byte' ].

    ^ AJx86Registers

        generalPurposeWithIndex: self index - 2r100

        size: 1

        requiresRex: false

        prohibitsRex: false

!

ptr

    "turn receiver into a memory operand with receiver as base"

    ^ AJMem new base: self

! !

!AJx86GPRegister methodsFor:'emitting'!

emitModRM: emitter code: rCode immSize: immSize

    "Receiver is register, hence mod = 3 

    immSize is ignored"

    ^ emitter emitMod: 3 reg: rCode rm: self code

! !

!AJx86GPRegister methodsFor:'printing'!

printAsMemBaseOn: aStream

    aStream nextPutAll: self registerName 

!

printOn: aStream

    aStream nextPutAll: self registerName 

! !

!AJx86GPRegister methodsFor:'testing'!

isGeneralPurpose

    ^ true

!

isHighByte

    "return true for 8bit high-byte registers (AH - DH)"

    ^ self prohibitsRex

!

isLowByte

    "return true for 8bit low-byte register (AL - DL)"

    "Note that this does *not* answer true for all byte registers -- send #is8 for that."

    ^ self code <= 3

! !