[LLVMdev] Proposal for ""llvm.mem.vectorize.safelen"

Tian, Xinmin xinmin.tian at intel.com
Mon Sep 29 08:42:51 PDT 2014


Renato, I think Hal meant to ensure partial ordering, e.g. not to convert lexical forward data dep to lexical backward data dep due to statement ordering if any. 
'
Xinmin 

-----Original Message-----
From: Renato Golin [mailto:renato.golin at linaro.org] 
Sent: Monday, September 29, 2014 1:06 AM
To: Hal Finkel
Cc: Tian, Xinmin; Jonathan Humphreys; Robison, Arch; LLVM Dev
Subject: Re: [LLVMdev] Proposal for ""llvm.mem.vectorize.safelen"

On 28 September 2014 22:09, Hal Finkel <hfinkel at anl.gov> wrote:
> Thanks Xinmin!
>
> So we'll need a method to ensure the correct (partial) ordering.

I thought that the idea was to avoid computing loop dependencies when safelen is specified, at least at that level. We might do it to a greater length, but we should assume it to be safe for distances < VL.

We still need the method, I agree, for everything else, though.

cheers,
--renato




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