[LLVMdev] Any plan to add MIN/MAX isd node?

Yin Ma
Tue, 30 Oct 2012 18:53:33 -0000

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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