William Tambe <tambewilliam@xxxxxxxxx> writes: > Could the answer be to define the macro CALL_USED_REGISTERS with all > bits set to 1 ? Yeah, that should do it. Thanks, Richard > On Wed, Aug 7, 2019 at 11:57 AM Segher Boessenkool > <segher@xxxxxxxxxxxxxxxxxxx> wrote: >> >> [ top-post not please do ] >> >> On Wed, Aug 07, 2019 at 10:48:58AM -0500, William Tambe wrote: >> > To expand on my previous reply, I would like to configure GCC so that >> > a callee does not need to save and restore registers that it is using >> > other than the frame-pointer and return-pointer registers. >> > The callee would not need to save and restore registers that it is >> > using because it would be assumed that the caller has saved all >> > registers that it is using. >> >> Then you need to define a new ABI for your target, and implement that >> in your target's GCC backend. >> >> >> Segher