[Mesa-dev] [PATCH 2/2] ac, radeonsi: reduce optimizations for complex compute shaders on older APUs

[Marek Olšák]

On Fri, Jul 20, 2018 at 12:53 AM, Dave Airlie <airlied at gmail.com> wrote:
> On 20 July 2018 at 13:12, Marek Olšák <maraeo at gmail.com> wrote:
>> From: Marek Olšák <marek.olsak at amd.com>
>>
>> To make dEQP-GLES31.functional.ssbo.layout.random.all_shared_buffer.23
>> finish sooner on the older CPUs. (otherwise it gets killed and we fail
>> the test)
>
> I think this is possibly a bad idea, since it's clear LLVM has some pathalogical
> behaviour the AMDGPU backend for this shader and we are just papering over it.
>
> A quick dig into LLVM shows horrible misuse of a SmallVector data structure
> for what ends up having 2000 entries in it.
>
> I'm not going to out right NAK this, but it would be nice to have it accompanied
> by a pointer to an llvm bug against the amdgpu backend for the
> pathalogical case.

Even if I comment out the push_back call in LLVM, it's still too slow.
(the dEQP test times out and fails) LLVMCodeGenLevelLess is faster,
but I don't know yet if it's enough for the test.

Marek