[PATCH] Use AA in LoopVectorize

[Nadav Rotem]

> On Jul 20, 2014, at 9:53 PM, Hal Finkel <hfinkel at anl.gov> wrote:
> 
> ----- Original Message -----
>> From: "Nadav Rotem" <nrotem at apple.com>
>> To: hfinkel at anl.gov, aschwaighofer at apple.com, nrotem at apple.com
>> Cc: llvm-commits at cs.uiuc.edu
>> Sent: Sunday, July 20, 2014 9:51:36 PM
>> Subject: Re: [PATCH] Use AA in LoopVectorize
>> 
>> Hi Hal,
>> 
>> Sorry for the delay in response.  The motivation for this change is
>> clear and the direction makes sense. Quick question: did you measure
>> the effect of this change on the mailing list? Were there any
>> performance wins or losses?
> 
> You mean in the test suite? I saw nothing significant either way. 
> 
> Performance wise, things should be strictly better than before. I have a number of internal benchmarks that improved for two reasons:
> 
> 1. Loops accessing many different arrays, some of different types, now require fewer checks (and thus now vectorize when they didn't before).
> 2. The loop being vectorized was an inner loop that, at runtime, had a relatively small trip count; the elimination of the unnecessary dependency checks was significant.
> 
This sounds excellent. Thank you! I really appreciate your help.

> Thanks again,
> Hal
> 
>> 
>> Thanks,
>> Nadav
>> 
>> http://reviews.llvm.org/D4599
>> 
>> 
>> 
> 
> -- 
> Hal Finkel
> Assistant Computational Scientist
> Leadership Computing Facility
> Argonne National Laboratory