Created attachment 128065 [details]
Glitched car windows

The game Life Is Strange has various rendering glitches with current mesa
master.

I have recorded an apitrace of the game:
 http://constexpr.org/tmp/LifeIsStrange-radeonsi.trace.xz (124 MiB)

The trace contains garbage geometry that is not there in the game (probably due
to persistent coherent mappings - the game crashes with
MESA_EXTENSION_OVERRIDE=-GL_ARB_buffer_storage), but the glitched car windows
seen in the screenshot are visible. I've tracked the origin of the glitches to
e.g. draw call 4741838.

All of the glitches go away when reverting commit 74e39de "radeonsi: set
IF_THRESHOLD to 3" while https://patchwork.freedesktop.org/patch/122101/ does
not help, so this is likely related to bug #98761.

GPU: R9 380X (tonga)
Kernel: 4.8.7-gentoo
Mesa: git-0c85d2f
LLVM: r287273