llvm dev - Feb 2013 - [LLVMdev] OperandWithDefaultOps question

Is it possible to use this operand class in an instruction that has a
pattern defined? If so, can you write it with anything besides a
ComplexPattern in the instruction's pattern DAG, to set it to a value?
Can you refer to it at all? Or would it be added to the MachineInstr
with the default value such that you could modify it later in the
backend?

If there is a non-ComplexPattern way to write this, can you provide an example?

Thanks,
Joe

On Fri, Feb 01, 2013 at 04:58:29PM -0800, Joe Matarazzo
wrote:
> Is it possible to use this operand class in an instruction that has a
> pattern defined? If so, can you write it with anything besides a
> ComplexPattern in the instruction's pattern DAG, to set it to a value?
> Can you refer to it at all? Or would it be added to the MachineInstr
> with the default value such that you could modify it later in the
> backend?
>
You can use OperandWithDefaultOps in an instruction with a pattern.
Take a look at the R600 target it has a lot of instructions that use
this operand class.

It's been a while since I looked at this, but I don't think you can
reference a member of this operand class in the pattern, but you
should try it out to be sure.

-Tom

> If there is a non-ComplexPattern way to write this, can you provide an
example?
> 
> Thanks,
> Joe
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev

Thanks for the reply Tom. I saw the InOperandList references to this
op class (like negate / "NEG", for example), but I could see any cases
where you referred to it in the pattern. That's why I was curious.
Hope someone can clarify.

On Fri, Feb 1, 2013 at 5:20 PM, Tom Stellard <tom at stellard.net>
wrote:
> On Fri, Feb 01, 2013 at 04:58:29PM -0800, Joe Matarazzo wrote:
>> Is it possible to use this operand class in an instruction that has a
>> pattern defined? If so, can you write it with anything besides a
>> ComplexPattern in the instruction's pattern DAG, to set it to a
value?
>> Can you refer to it at all? Or would it be added to the MachineInstr
>> with the default value such that you could modify it later in the
>> backend?
>>
>
> You can use OperandWithDefaultOps in an instruction with a pattern.
> Take a look at the R600 target it has a lot of instructions that use
> this operand class.
>
> It's been a while since I looked at this, but I don't think you can
> reference a member of this operand class in the pattern, but you
> should try it out to be sure.
>
> -Tom
>
>
>> If there is a non-ComplexPattern way to write this, can you provide an
example?
>>
>> Thanks,
>> Joe
>> _______________________________________________
>> LLVM Developers mailing list
>> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev