From a quick debugging session the error is coming from here https://github.com/mesa3d/mesa/blob/a5e1c9f1d5b6063f0a92634967475a05362c0d31/src/gallium/drivers/r600/r600_asm.c#L603 Don't have time ATM to look closer, but commenting here in case anybody have ideas, including what to look at.