(^4 because I unwittingly submitted the same patch a while back.) Ping for H.J.'s patch to avoid using dwarf extension codes for simple CFA addresses based on arg_pointer_rtx and frame_pointer_rtx in cases where Pmode is wider than the DWARF address size:
http://gcc.gnu.org/ml/gcc-patches/2012-04/msg01815.html Using extension codes for an internal rtx like frame_pointer_rtx (as opposed to hard_frame_pointer_rtx) can't work in general, because there's no associated DWARF register number. Even on targets that provide arg_pointer_rtx, I expect debuggers would expect the normal CFA-like addresses for arg_pointer_rtx-based expressions. I've had to use this locally for a few months now. Without it mipsisa64-elf doesn't build. Richard