[LLVMdev] Trip count and Loop Vectorizer

[Murali, Sriram]

Hey Arnold,
I have run into this situation many times while benchmarking.
I think it is best if this is addressed using a simple heuristic. For that, we need to identify the loop cost and decide if it makes sense to completely unroll the loop, or partially unroll. I am unsure of the optimal way to implement this though.

I want to run it by the list to get any ideas floating around :)
Thanks
Sriram

-----Original Message-----
From: Arnold Schwaighofer [mailto:aschwaighofer at apple.com] 
Sent: Friday, September 27, 2013 1:54 PM
To: Murali, Sriram
Cc: llvmdev at cs.uiuc.edu
Subject: Re: [LLVMdev] Trip count and Loop Vectorizer


On Sep 27, 2013, at 12:47 PM, Arnold Schwaighofer <aschwaighofer at apple.com> wrote:

>  so you could infer that n must be smaller than 8 (because you know the range of the other dimension). The question is how often does such an example occur, where this is possible, to make such an effort justifiable?
smaller equal, of course ;)