On Fri, 12 Apr 2019, Jeff Law wrote: > We've been through the "who owns the argument slots, caller or callee" > discussion a few times and I don't think we've ever reached any kind of > conclusion in the general case.
Callee must own the slots for tail calls to be possible. > I think this case side-steps the general case. > > We've got an argument slot for a const/pure call. Because of the > const/pure designation the caller can assume the callee doesn't modify > the argument slot. That may in turn allow the caller to place a > REG_EQUIV note on the store to the slot. I don't think this follows. Imagine a pure foo tailcalling a pure bar. To make the tailcall, foo may need to change some of its argument slots to pass new arguments to bar. Alexander
