https://bugs.freedesktop.org/show_bug.cgi?id=94091
Bug ID: 94091 Summary: Tonga unreal elemental segfault since radeonsi: put image, fmask, and sampler descriptors into one array Product: Mesa Version: git Hardware: x86-64 (AMD64) OS: Linux (All) Status: NEW Severity: normal Priority: medium Component: Drivers/Gallium/radeonsi Assignee: dri-devel@lists.freedesktop.org Reporter: adf.lists@gmail.com QA Contact: dri-devel@lists.freedesktop.org
Created attachment 121675 --> https://bugs.freedesktop.org/attachment.cgi?id=121675&action=edit gdb bt
R9285 since mesa commit below Unreal ElementalDemo quits at start with a segfault.
gdb from demo generated core attached
commit 7aedbbacae6d3ec3d06735fff2eb662964773ad2 Author: Marek Olšák marek.olsak@amd.com Date: Sat Feb 6 22:09:45 2016 +0100
radeonsi: put image, fmask, and sampler descriptors into one array
The texture slot is expanded to 16 dwords containing 2 descriptors. Those can be: - Image and fmask, or - Image and sampler state
By carefully choosing the locations, we can put all three into one slot, with the fmask and sampler state being mutually exclusive.
This improves shaders in 2 ways: - 2 user SGPRs are unused, shaders can use them as temporary registers now - each pair of descriptors is always on the same cache line
v2: cosmetic changes: add back v8i32, don't load a sampler state & fmask at the same time