Hi Evan, > Only rr forms of ADD*_DB are commutable. one of the dragonegg self-host buildbots was unhappy, saying: LLVM ERROR: Don't know how to commute: %reg16399<def> = ADD32ri8_DB %reg16398, 4, %EFLAGS<imp-def,dead>; GR32:%reg16399,16398 Hopefully this fixes it - thanks a lot! Ciao, Duncan.