https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113533
--- Comment #5 from Oleg Endo <olegendo at gcc dot gnu.org> --- (In reply to Andrew Pinski from comment #3) > That seems to make the cost of a load/store if just an index, the same as the > cost > as the index. Which definitely seems wrong. It should be the cost of the > load/store > and the cost of the address formation. Yep, that doesn't seem to be accurate. > The way aarch64 implements its _rtx_costs is that it cases SET and if the LHS > is a > mem, then it is the cost of the store there and returns true (though you > might need > to take into RHS if it can be more than just a register like). And then MEM > includes the cost of the load. That's what I'd also do intuitively. > i386 does something similar too. If every backend does that same thing, isn't it better to do it as a default for everybody? I can imagine the minimalist backends (like RX) will regress on this case as well. (Haven't checked it though)
