Bug 111039 - [radv] - Persona 5 in RPCS3 emulator has glitches when using hardware fp16 (LLVM 9)
Summary: [radv] - Persona 5 in RPCS3 emulator has glitches when using hardware fp16 (L...
Alias: None
Product: Mesa
Classification: Unclassified
Component: Drivers/Vulkan/radeon (show other bugs)
Version: git
Hardware: x86-64 (AMD64) Linux (All)
: medium normal
Assignee: mesa-dev
QA Contact: mesa-dev
Depends on:
Reported: 2019-07-02 01:49 UTC by Andrew Sheldon
Modified: 2019-09-18 20:07 UTC (History)
0 users

See Also:
i915 platform:
i915 features:

Renderdoc capture (45.71 MB, application/x-7z-compressed)
2019-07-09 02:08 UTC, Andrew Sheldon

Description Andrew Sheldon 2019-07-02 01:49:29 UTC
Since RPCS3 added support for native 16-bit float support, Persona 5 is exhibiting graphical glitches when using its Vulkan renderer:

With hardware fp16:

With hardware fp16 disabled (correct rendering):

Gentoo AMD64
Mesa git (RADV)
LLVM 9 git
RPCS3 git
Vega 56

Here's a link to the corresponding RPCS3 report: https://github.com/RPCS3/rpcs3/issues/6150

They suggest the problem may be with LLVM code generation. I should note that AMDVLK also has the same bug, which supports this conclusion. LLVM 8 can't be tested since it causes a black screen with RPCS3 (https://bugs.freedesktop.org/show_bug.cgi?id=110970).

Also of note, bug doesn't occur with an RX-550 (on RADV or AMDVLK) and the bug doesn't occur at all on Windows. So it looks to be a Vega specific bug, and only on Linux.
Comment 1 Andrew Sheldon 2019-07-09 02:08:58 UTC
Created attachment 144730 [details]
Renderdoc capture

Renderdoc capture. I'm not sure how helpful it will be since I can't reproduce the bug when renderdoc is running, but maybe it will help see what the game/emulator is doing.
Comment 2 Andrew Sheldon 2019-07-09 02:09:31 UTC
I should add that the bug doesn't occur with the ACO compiler.
Comment 3 Andrew Sheldon 2019-07-09 02:21:42 UTC
I've been informed that ACO doesn't support this feature yet, so it doesn't actually "work" with that compiler, it's just falling back to the non-native form.
Comment 4 GitLab Migration User 2019-09-18 20:07:48 UTC
-- GitLab Migration Automatic Message --

This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity.

You can subscribe and participate further through the new bug through this link to our GitLab instance: https://gitlab.freedesktop.org/mesa/mesa/issues/865.

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