[llvm] r220138 - [InstCombine] Do an about-face on how LLVM canonicalizes (cast (load

[Hans Wennborg]

On Tue, Nov 25, 2014 at 2:13 AM, Chandler Carruth <chandlerc at gmail.com> wrote:
>
> On Thu, Nov 20, 2014 at 11:19 AM, Hans Wennborg <hans at chromium.org> wrote:
>>
>> > The only fallout I've found so far from this change was SROA and I have
>> > fixed it to not be impeded by the different type of load. If you find
>> > more places where this change causes optimizations not to fire, those
>> > too are likely bugs where we are assuming that the type of pointers is
>> > "significant" for optimization purposes.
>>
>> This caused a 97 k binary size regression in Chromium. I'll try to
>> produce some diffs of how the code changed.
>
>
> What ever came of this? I know you were side-tracked on LVI, but I don't
> want to miss this.

Hopefully that side track is done now :)

> I've also landed the other half of this in r222748. This may have (sadly)
> papered over the issue, or exacerbated the issue, depending on the nature of
> the problem. Feel free to hit me up with examples of IR diff...

I'll try to figure out what the status is today.