llvm dev - Jun 2018 - [VPlan] Dead instructions are invariant to VFs when build vplan

Hi,

I noticed that the dead instructions collected when build vplan are invariant to
different ranges of VFs since the original loop is not changed. Maybe
DeadInstructions should be treated as a data member of LoopVectorizationPlanner
and initialized by collectTriviallyDeadInstructions() in plan()?

Cheers,

Shixiong (Jason) Xu

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Hi

On 01/06/2018 10:56, Shixiong Xu via llvm-dev wrote:
> Hi,
> 
> I noticed that the dead instructions collected when build vplan are 
> invariant to different ranges of VFs since the original loop is not 
> changed. Maybe DeadInstructions should be treated as a data member of 
> LoopVectorizationPlanner and initialized by 
> collectTriviallyDeadInstructions() in plan()?
> 
Yep you are right. There's a patch under review, which also addresses 
that:  https://reviews.llvm.org/D47477

Thanks,
Florian

Thanks. I didn't notice the patch. 😊

Shixiong
-----Original Message-----
From: Florian Hahn <florian.hahn at arm.com> 
Sent: Friday, June 01, 2018 11:21 AM
To: Shixiong Xu <shixiong at cadence.com>; llvm-dev at lists.llvm.org
Cc: Caballero, Diego <diego.caballero at intel.com>; nd <nd at
arm.com>
Subject: Re: [llvm-dev] [VPlan] Dead instructions are invariant to VFs when
build vplan

EXTERNAL MAIL


Hi

On 01/06/2018 10:56, Shixiong Xu via llvm-dev wrote:
> Hi,
> 
> I noticed that the dead instructions collected when build vplan are 
> invariant to different ranges of VFs since the original loop is not 
> changed. Maybe DeadInstructions should be treated as a data member of 
> LoopVectorizationPlanner and initialized by
> collectTriviallyDeadInstructions() in plan()?
> 
Yep you are right. There's a patch under review, which also addresses 
that: 
https://urldefense.proofpoint.com/v2/url?u=https-3A__reviews.llvm.org_D47477&d=DwIC-g&c=aUq983L2pue2FqKFoP6PGHMJQyoJ7kl3s3GZ-_haXqY&r=FZEW1cDCyCU3ZbRFatG9st_R0bbu9fLOaIEKyKAe7wg&m=1H53Xvb7phmsnD0jJKQxe1-wa0mbdewKcT8B8DbRzYk&s=GtJno4-QfCaG0-yzw_SCrQ65uTZXwWVuWUL72Y_ySGc&e
Thanks,
Florian