[LLVMdev] understanding DAG: node creation

[Dmitri Kovalenko]

Sam, thanks for your answer.
That's a great suggestion.

And excuse me for maybe dilettante question:
To hard-code use of the global register means to hard-code it in the 'asm
string' argument of the instruction definition in the .td file?


2014-09-01 0:44 GMT+04:00 Sam Parker <S.Parker3 at lboro.ac.uk>:

> Hi Dmitri,
>
> If you have such a simple intrinsic which operates on a single register,
>  just lower the intrinsic to a target specific node which is only
> implemented by a single instruction. Like you were doing before and by
> using a chain operand. Hard code the instruction to use and define the
> global register and only pass the instruction the actual variable argument.
>
> Hope that helps,
> Sam
>
> Sam Parker
> Research Student
> Electronic Systems Design Group
> School of Electronic, Electrical and Systems Engineering
> Loughborough University
>
> ----- Reply message -----
> From: "Dmitri Kovalenko" <dmitri.a.kovalenko at gmail.com>
> To: <llvmdev at cs.uiuc.edu>
> Subject: [LLVMdev] understanding DAG: node creation
> Date: Sat, Aug 30, 2014 22:18
>
> I have an intrinsic and it must be lowered to instruction, which works
> with fixed register.
> So, it takes contents of this register and another argument as input.
> After execution, the result of the instruction is placed into that same
> fixed register.
>
> What should I do in SelectionDAGBuilder::visitIntrinicCall to describe
> such behaviour for a SDNode?
>
> Thank you for the ideas and insights.
> --
> Sincerely,
> Dmitri Kovalenko
>



-- 
Sincerely,
Dmitri Kovalenko
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