[LLVMdev] Garbage collection: Multiple copies of a root

[Mattias Holm]

Another open question is who is responsible for inserting calls to the  
collector routine (or signaling a collector thread)?

My impression is that this has to be done in the front-end for now  
since there is no support for doing this at the safe points at the  
moment.

Is this correct?


Regards,
Mattias

On 20 Mar 2009, at 13:09, Gordon Henriksen wrote:

> On 2009-03-20, at 05:09, Harmen van der Spek wrote:
>
>> The problem is that we want to implement some sort of copying
>> garbage collector. In this case, the roots on the stack must be
>> updated. However, if this root is also stored in an IR register,
>> then this pointer should be updated as well. Is there support for
>> identifying and updating such references in the GC framework, or
>> should we generate code ourselves to reload the updated references
>> from the stack.
>
> You should generate code to reload the registers from the stack for
> now. We'd ultimately like to move to a model where LLVM automatically
> inserts the reloads, only as necessary, but are not there yet.
>
> — Gordon
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