https://bugs.freedesktop.org/show_bug.cgi?id=98777
--- Comment #2 from Daniel Scharrer daniel@constexpr.org --- Reverting LLVM r286766 "AMDGPU: Implement SGPR spilling with scalar stores" (while not reverting anything in Mesa) fixes the glitches and lockup - so this is likely related to bug #98776 and bug #98761 after all.