https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113533
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to Oleg Endo from comment #2) > (In reply to Andrew Pinski from comment #1) > > This is most likely a cost model issue on sh3. > > You mean this one (sh.cc, sh_rtx_costs)? > > /* The cost of a mem access is mainly the cost of the address mode. */ > case MEM: > *total = sh_address_cost (XEXP (x, 0), GET_MODE (x), MEM_ADDR_SPACE > (x), > true); > return true; 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. 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.
