http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17994
--- Comment #9 from Richard Henderson <rth at gcc dot gnu.org> 2011-02-16 18:04:08 UTC --- > Going by the internals document, INCOMING_FRAME_SP_OFFSET is already defined > but it is not used anywhere (in my patch). Certainly it's going to be used by the generic code in dwarf2out_frame_init, and if that's wrong everything that follows will be off as well. > INCOMING_RETURN_ADDR_RTX per se is not using POST_DEC. But once they are > defined to some values, during the libgcc build, an ICE is hit in > dwarf2out_frame_debug_expr(). If POST_DEC mode is defined, ICE disappears. I > am > yet to understand the relation between the POST_DEC and ICE and why it appears > when only CFI is being emitted. Ah, I see. Nothing to do with the initial frame setup, but the rest of the unwind info, since AVR uses POST_DEC for pushes. See http://gcc.gnu.org/ml/gcc-patches/2011-02/msg01059.html for my proposed patch for this. Note that the message contains both gas and gcc patches.
