llvm dev - Oct 2012 - [LLVMdev] Any plan to add MIN/MAX isd node?

Hello,

 

      Do you have any plan to add MIN/MAX in ISD node?

Atomic operations have Min/Max operator already. This should

be easy to add Min/Max node in ISD list. Because after

converting control flow into Min/Max operator, it will 

result in better optimization because associative attribute

and can be moved around. 

     Could you give some opinions on this issue?

 

Thanks,

 

                                   Yin 

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Hi Yin,
>        Do you have any plan to add MIN/MAX in ISD node?
>
> Atomic operations have Min/Max operator already. This should
>
> be easy to add Min/Max node in ISD list. Because after
>
> converting control flow into Min/Max operator, it will
>
> result in better optimization because associative attribute
>
> and can be moved around.
>
>       Could you give some opinions on this issue?
what are the advantages over using "select" (or one of its codegen
variants)?

Ciao, Duncan.

Hi Duncan,

    To use select, usually, there is a compare before select.
Presence of comparison will disable some opportunities to 
optimize some code. Select and Compare is not associative
neither.

Thanks,

                       Yin 

-----Original Message-----
From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] On
Behalf Of Duncan Sands
Sent: Tuesday, October 30, 2012 12:38 AM
To: llvmdev at cs.uiuc.edu
Subject: Re: [LLVMdev] Any plan to add MIN/MAX isd node?

Hi Yin,
>        Do you have any plan to add MIN/MAX in ISD node?
>
> Atomic operations have Min/Max operator already. This should
>
> be easy to add Min/Max node in ISD list. Because after
>
> converting control flow into Min/Max operator, it will
>
> result in better optimization because associative attribute
>
> and can be moved around.
>
>       Could you give some opinions on this issue?
what are the advantages over using "select" (or one of its codegen
variants)?

Ciao, Duncan.

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