[llvm-dev] question: access IR class Instruction from DAG SDValue

[UE US via llvm-dev]

Look at the Metadata classes (MDNode for bitcode, SDNodes have their own
type).   They're pretty easy to extend and preserve down to the code
lowering phase if I'm remembering correctly.

https://llvm.org/docs/TypeMetadata.html


Cheers,

GNOMETOYS

On Wed, Nov 29, 2017 at 7:21 AM, Jonathan via llvm-dev <
llvm-dev at lists.llvm.org> wrote:

> Seems llvm cannot pass metadata to MachineInstr, or setting operand
> description in class Instruction and pass to class MachineInstr.
> Is it a good idea to extend llvm kernel structure to having this feature?
>
> Jonathan
>
>
> On Nov 27, 2017, at 9:01 PM, Jatin Bhateja <jatin.bhateja at gmail.com>
> wrote:
>
> SelectionDAGBuilder contained within SelectionDAGISel has a map (NodeMap)
> b/w Value (Instruction) and corrosponding dag value (SDValue).
>
> Isn't that usable for your purpose.
>
> Thanks,
> Jatin
>
> On 27 Nov 2017 18:21, "Jonathan via llvm-dev" <llvm-dev at lists.llvm.org>
> wrote:
>
>> I am working on llvm gpu backend. The instruction metadata can only get
>> in IR (class instruction). In DAG stage, the instructions are reordered, so
>> I cannot map the metadata to correct instruction if I cannot access
>> instruction from DAG or MachineInstr structure.
>>
>>
>> On Nov 26, 2017, at 11:02 PM, Ryan Taylor <ryta1203 at gmail.com> wrote:
>>
>> It might be a more useful to know what it is you need from the IR in the
>> DAG or what it is you r trying to do?
>>
>>
>>
>> On Nov 25, 2017 7:59 PM, "Jonathan via llvm-dev" <llvm-dev at lists.llvm.org>
>> wrote:
>>
>>> The llvm backend uses class Instruction in IR handle stage, create
>>> SDVaule and DAG in DAG translation stage and class MachineInstr in Machine
>>> instruction translation stage.
>>> Can I access class Instruction from DAG structure or stage, or access
>>> DAG and Instruction from MachineInstr structure or stage?
>>>
>>> Jonathan
>>> _______________________________________________
>>> LLVM Developers mailing list
>>> llvm-dev at lists.llvm.org
>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>>
>>
>>
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>>
>
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