Bug 66731

Summary:	texture issues in xonotic with llvm+sb and offset mapping
Product:	Mesa	Reporter:	Stefano Teso <stefano.teso>
Component:	Drivers/Gallium/r600	Assignee:	Default DRI bug account <dri-devel>
Status:	RESOLVED MOVED	QA Contact:
Severity:	minor
Priority:	medium
Version:	git
Hardware:	x86-64 (AMD64)
OS:	Linux (All)
Whiteboard:
i915 platform:		i915 features:
Attachments:	shader dump

Description Stefano Teso 2013-07-09 11:02:23 UTC

To reproduce, use:

 - xonotic 0.7.0 at lowest detail, with only offset mapping turned on.

 - r600g from git, with SB backend and LLVM both turned on. Turning off either makes the bug disappear (although there are other issues, rensambling z fighting, when only llvm is enabled; not sure if they are related to offset mapping, I'll check later.)

The issue is clearly visible by running any of the demos that come with xonotic. FWIW, other apps (glxgears, gnome-shell, etc.) work just fine.

$gitgl glxinfo | grep str
server glx vendor string: SGI
server glx version string: 1.4
client glx vendor string: Mesa Project and SGI
client glx version string: 1.4
OpenGL vendor string: X.Org
OpenGL renderer string: Gallium 0.4 on AMD CEDAR
OpenGL version string: 2.1 Mesa 9.2.0-devel (git-2923685)
OpenGL shading language version string: 1.30

$ llvm-config --version
3.3

Tested with both stock 3.10 kernel from arch linux and the recent dpm-wip5 branch.

Nothing suspicious in dmesg.

May be related to #50230, which was closed as fixed.

Comment 1 Vadim Girlin 2013-07-09 22:56:38 UTC

Created attachment 82247 [details]
shader dump

Looks like it's llvm backend's issue, I'm attaching the dump of the failing shader.

As far as I know, SET_GRADIENTS_x instructions should be in the same TEX clause with SAMPLE_G instructions that use corresponding gradients. SB ignores SET_GRADIENTS_x instructions in separate clauses and this makes the problem more noticeable.

IIRC there was also piglit test failing due to this problem with llvm backend.

Comment 2 Stefano Teso 2013-07-11 10:16:57 UTC

Thanks for the quick response.

I just wanted to note that the glitch is still there with llvm 3.4 trunk.

Comment 3 GitLab Migration User 2019-09-18 19:04:16 UTC

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