[Vm-dev] Access to arguments in the stack vm

[Hernan Wilkinson]

Thanks Clément! it worked perfectly!
I did not know about the externalize/internalize stuff, I saw them
everywhere but I did not understand it :-)
I there documentation or something to read about those kind of things?

Thanks!
Hernan

On Mon, Oct 8, 2018 at 4:12 PM Clément Béra <bera.clement at gmail.com> wrote:

>
> Hi,
>
> I think the general idea is that only the methods inlined in interpret can
> use localSP/localFP which are mapped to registers but only in the interpret
> method to make the interpreter quicker. In the rest of the code you need to
> used framePointer/stackPointer. Getting out of inlining in the interpreter
> requires a call to a method such as externalizeFPandSP which moves from the
> registers the value to variables, and internalizeIPandSP does the other way
> around.
>
> So in your case you need to see if for interpreter performance you want
> your code to be inlined if the main interpreter loop, if so, then use
> localSP, else, use stackPointer.
>
> Hope this helps!
>
> Best!
>
>
> On Mon, Oct 8, 2018 at 8:51 PM Hernan Wilkinson <
> hernan.wilkinson at 10pines.com> wrote:
>
>>
>> Hi,
>>  In the implementation of the dynamically typed vm I'm doing (to give it
>> a name) I need to get the parameters when a method gets activated.
>>  To do it I implemented a not-inlined method that sends the message
>> #internalStackValue:
>>  The problem is that the code for that method is not generated. The
>> method gets removed from the methods to generate code because it access
>> "localSP" although not directly but due to inlining #internalStackValue:
>>
>>  How should I access the arguments then? Why I can not use "localSP"?
>>
>>  The method source is:
>> keepArgumentTypes
>>
>> <inline: false>
>> | additionalMethodState tempVarsTypes |
>> additionalMethodState := self additionalMethodStateOf: newMethod.
>> additionalMethodState = objectMemory nilObject ifTrue: [ ^self ].
>> tempVarsTypes := objectMemory followObjField: 2 ofObject:
>> additionalMethodState.
>> tempVarsTypes = objectMemory nilObject ifTrue: [ ^self ].
>> 0 to: argumentCount-1 do: [ :argIndex |
>> self keepTypeInformationIn: tempVarsTypes at: argIndex for: (self
>> internalStackValue: argIndex) ].
>>  I manage to solve the problem passing localSP as parameter and doing the
>> following, but I should not be doing that:
>> keepArgumentTypes: sp
>>
>> <inline: false>
>> | additionalMethodState tempVarsTypes |
>> additionalMethodState := self additionalMethodStateOf: newMethod.
>> additionalMethodState = objectMemory nilObject ifTrue: [ ^self ].
>> tempVarsTypes := objectMemory followObjField: 2 ofObject:
>> additionalMethodState.
>> tempVarsTypes = objectMemory nilObject ifTrue: [ ^self ].
>> 0 to: argumentCount-1 do: [ :argIndex |
>> self keepTypeInformationIn: tempVarsTypes at: argIndex for: (stackPages
>> longAtPointer: sp + (argIndex * objectMemory bytesPerOop)) ].
>>
>> --
>>
>> *Hernán WilkinsonAgile Software Development, Teaching & Coaching*
>> *Phone: +54-011*-4893-2057
>> *Twitter: @HernanWilkinson*
>> *site: http://www.10Pines.com <http://www.10pines.com/>*
>> Address: Alem 896, Floor 6, Buenos Aires, Argentina
>>
>
>
> --
> Clément Béra
> https://clementbera.github.io/
> https://clementbera.wordpress.com/
>


-- 

*Hernán WilkinsonAgile Software Development, Teaching & Coaching*
*Phone: +54-011*-4893-2057
*Twitter: @HernanWilkinson*
*site: http://www.10Pines.com <http://www.10pines.com/>*
Address: Alem 896, Floor 6, Buenos Aires, Argentina
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