Comment # 3 on bug 93475 from iive@yahoo.com

Could you try `export R600_DEBUG=nosb`?

This disables Shader Backend that optimizes the assembler code.
If this workarounds the problem, it would be useful to provide an
apitrace of the game that could reproduce your problem.

These may be related:
https://bugs.freedesktop.org/show_bug.cgi?id=86720
https://bugs.freedesktop.org/show_bug.cgi?id=94900