Bug 111039

Summary:	[radv] - Persona 5 in RPCS3 emulator has glitches when using hardware fp16 (LLVM 9)
Product:	Mesa	Reporter:	Andrew Sheldon <asheldon55>
Component:	Drivers/Vulkan/radeon	Assignee:	mesa-dev
Status:	RESOLVED MOVED	QA Contact:	mesa-dev
Severity:	normal
Priority:	medium
Version:	git
Hardware:	x86-64 (AMD64)
OS:	Linux (All)
Whiteboard:
i915 platform:		i915 features:
Attachments:	Renderdoc capture

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:
https://i.imgur.com/NOyfaN7.jpg

With hardware fp16 disabled (correct rendering):
https://i.imgur.com/7oYKdBi.jpg

System:
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.

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