On 03/03/2011 11:49 AM, DJ Delorie wrote: >> which never needs the pair of spill insns. Something to consider... > > Does gcc provide a flag that says "your $sp will be unspecified at the > end of this function" that's valid during reload and for prologue and > epilogue generation? I could push $pc onto the stack just after > setting $fp, so it's always where I can get to it in the epilogue. > > Most of the time, $sp happems to have the original value anyway, so no > registers are used and it just works.
See current_function_sp_is_unchanging. Also have a look at how that value is used in i386 epilogue expansion. Why would you push $pc? Or push anything for that matter... r~
