On Wed, 2005-03-09 at 12:44 -0500, Bagalkote, Sreenivas wrote: > >> > > >> >> . And since this is compile time > >> >> system-wide property, I kept it as driver global. > >> > > >> >that step I don't understand... why is it a global > >*VARIABLE* if it's > >> >compile time system-wide property... > >> > > >> > >> I see your point! Are you saying I should use > >if(sizeof(dma_addr_t)==8) > >> instead of the shortcut if(is_dma64)? > >yep > >well you can use a preprocessor define of something to make it slightly > >more readable (eg shortcut) if you want, but that's what I mean yeah.. > > > >gcc will optimize the entire unused code away this way, including the > >actual conditional jump, so for performance and bloat-ness > >point of view > >it's nice.... and of course generic design beauty ;) > > > > Great. Thanks! I will change it. If I understand you correctly, I should > #define IS_DMA64 (sizeof(dma_addr_t)==8).
that's one way to do it yeah. > > Is this better than declaring is_dma64 global variable const? (Excuse the > oxymoron). in C yes; in C "const" doesn't quite mean what you want it to mean with this and as a result gcc I think can't optimize this the way it can with the define. - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
