On Tuesday 30 May 2006 23:47, Daniel Jacobowitz wrote: > On Tue, May 30, 2006 at 09:03:54PM +0100, Paul Brook wrote: > > > I found arm.md and the moveqi insns, but because of the different > > > addressing modes of strb and swpb, its not easy to make the > > > change. And there must be a compiler option for this, too. > > > > > > Could somebody please tell me how to implement this change? > > > > Short answer is probably not. > > > > There are a couple of complications that spring to mind. The > > different addressing modes and the fact that swp clobbers a > > register are the most immediate ones. > > > > You'll need to modify at least the movqi insn patterns, memory > > constraints and the legitimate address stuff. I'm not sure about > > the clobber, that might need additional reload-related machinery. > > I suspect it would be better to make GCC do halfword stores instead > (read/modify/write).
Hmmm... I have thought about that. But how do the compiler know if the byte address is even or odd? Every time testing the LSB of the address and making conditional statements is no joke... regards Wolfgang -- We're back to the times when men were men and wrote their own device drivers. (Linus Torvalds)
