[PATCH] Optimize insertqi when we copy all the lower 64 bits.

[Nadav Rotem]

Hi Filipe, 

Why is this an IR-level transform? Could you implement this in SelectionDAG ?

Thanks,
Nadav

On Apr 15, 2014, at 10:48 AM, Jim Grosbach <grosbach at apple.com> wrote:

> +Nadav
> 
> Hi Filipe,
> 
> I like the idea of this transform. Nadav will have a better idea than I about whether this is the right place to go about it.
> 
> -Jim
> 
> On Apr 14, 2014, at 7:52 PM, Filipe Cabecinhas <filcab+llvm.phabricator at gmail.com> wrote:
> 
>> Updated the patch to add range merging, generating fewer insertqi when possible.
>> 
>> This also allows us to find more places to do the first opt.
>> 
>> Hi grosbach,
>> 
>> http://reviews.llvm.org/D3357
>> 
>> CHANGE SINCE LAST DIFF
>> http://reviews.llvm.org/D3357?vs=8482&id=8521#toc
>> 
>> Files:
>> lib/Transforms/InstCombine/InstCombineCalls.cpp
>> test/Transforms/InstCombine/vec_demanded_elts.ll
>> <D3357.2.patch>
>