"Paulo J. Matos" <pa...@matos-sorge.com> writes: > My question is, should added_clobbers_hard_reg_p take FLAGS_REGNUM > into consideration and allow it in a clobber, just as it allows a > scratch?
There is no middle-end concept of FLAGS_REGNUM (barring reg-stack.c which is really a target-specific pass). Some targets have several different flags registers, of which some are caller-saved and callee-saved. So what you are suggesting would seem to be a large conceptual change to the middle-end. One approach would be to use a pseudo-register which you eliminate to the flag register. I really don't know how well that would work. The function added_clobbers_hard_reg_p is a generated function. So another approach would be some sort of attribute which directs the generator (genemit) to ignore certain hard registers. And another approach would be a new target hook. I haven't thought enough about it to know whether any of these is a good idea. Ian
