On Oct 5, 2015, at 9:46 AM, Steve Ellcey <sell...@imgtec.com> wrote: > One example of an issue I have run into is with the DWARF unwind > generation and 'Rule 16' in dwarf2cfi.c. It assumes the AND instruction > has an integer constant argument but MIPS can't do an AND with a > constant like -16 so it has to put it in a register first and do the AND > with the register.
If you are using any detail about the architecture to imagine limitations with dwarf generation, then I think you’re missing that fact that the validity of the dwarf can be uncoupled from target considerations. See dwarf_pattern on frv for example, or more generally REG_FRAME_RELATED_EXPR on all the ports. When _must_ one use this? Whenever the generated dwarf is other than trivial. If trivial, it will usually just work. You didn’t include a lot of detail in your email, so I’m just extrapolating that I think you did and what you saw.
