[llvm] r319894 - [InstSimplify] Fold insertelement into undef if index is out of bounds

[Michel Dänzer via llvm-commits]

On 2017-12-09 12:40 AM, Philip Reames wrote:
> FYI, Igor is out of office for the weekend.  Feel free to revert if needed.

I guess it's possible that this change just exposed an issue in the
AMDGPU backend. Matt / Nicolai, can you take a look?

Anyway, if there's no solution available soon, it would be nice to
revert this at least temporarily until there is, because it triggered
worse issues (GPU hangs) with real-world apps, at least
https://bugs.freedesktop.org/104192 but probably more, e.g.
https://bugs.freedesktop.org/104159 .

I don't feel like the right person to make the call (or the revert).


> On 12/08/2017 08:51 AM, Michel Dänzer via llvm-commits wrote:
>> Hi Igor,
>>
>>
>> On 2017-12-06 03:04 PM, Igor Laevsky via llvm-commits wrote:
>>> Author: igor.laevsky
>>> Date: Wed Dec  6 06:04:45 2017
>>> New Revision: 319894
>>>
>>> URL: http://llvm.org/viewvc/llvm-project?rev=319894&view=rev
>>> Log:
>>> [InstSimplify] Fold insertelement into undef if index is out of bounds
>> This change broke a bunch of piglit OpenGL tests with AMD GPUs using the
>> Mesa radeonsi driver. I'm attaching the LLVM IR and disassembly of the
>> generated code for the good and bad case of one test.
>>
>>
>>
>>
>> _______________________________________________
>> llvm-commits mailing list
>> llvm-commits at lists.llvm.org
>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits
> 


-- 
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer