[llvm] r321556 - AMDGPU: Remove mayLoad/hasSideEffects from MIMG stores

[Marek Olšák via llvm-commits]

On Wed, Jan 3, 2018 at 5:18 PM, Michel Dänzer via llvm-commits
<llvm-commits at lists.llvm.org> wrote:
>
> Hi Matt,
>
>
> On 2017-12-29 06:18 PM, Matt Arsenault via llvm-commits wrote:
>> Author: arsenm
>> Date: Fri Dec 29 09:18:18 2017
>> New Revision: 321556
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=321556&view=rev
>> Log:
>> AMDGPU: Remove mayLoad/hasSideEffects from MIMG stores
>>
>> Atomics still have hasSideEffects set on them because
>> of the mess that is the memory properties.
>
> This change broke the piglit test
> "spec at arb_shader_image_load_store@restrict at no qualifier image aliasing
> test" for me on Tonga.
>
> I'm attaching the pre-optimization LLVM IR and the good and bad disassembly.

It looks like the image stores are re-ordered. Perhaps LLVM needs to
know that the image stores write to volatile memory.

Marek