http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52941
--- Comment #1 from Kazumoto Kojima <kkojima at gcc dot gnu.org> 2012-04-12 01:18:42 UTC --- (In reply to comment #0) > Other than that, should we add another option '-mhard-atomic' (which would > enable the movco/movli atomics on SH4A and disable all atomic insns for > non-SH4A)? I think so. > Actually, I think the options should be '-msp-atomic' and '-mmp-atomic', where > '-msp-atomic' would be the current '-msoft-atomic'. I don't think that -msp/mmp-atomic are good naming here. SP/MP notion is not directory connected with the soft/hard implementation of atomics, even if soft atomics are impossible for real MP system. Hard atomics should work with both SP and MP. I guess that the point is the necessity of kernel (i.e. software) services. If the atomics require kernel services, they are "soft" atomics even some of them utilize the LL/SC-like insns. If they don't require any kernel services, they are "hard" atomics. Using -msp-atomic for "soft" atomics looks a bit misleading, from this point of view. Perhaps an unsupprising way would be enable movco/movli on SH4A with both -msoft-atomic/-mhard-atomic if we can.
