Le 21/12/2010 13:35, Alexander Holler a écrit : > Hmm, is there actual somethinbg which should forbid the compiler to > generate such code which rereads something? It might not be nice, but I > don't think that it is forbidden for a compiler to do so. So the proper > way to handle such, might be to use asm to avoid that the compiler > touches that register.
Yes there is something that should prevent a compiler from inserting reads: these accesses are to hardware, not memory, and may cause side effects even on read (these could be acknowledges, for instance; I've seen instances of that myself on some HW). Another way to look at it is that the semantics of " *ptr = value " is a pure write and should not result in a write-then-read. > Regards, > > Alexander Amicalement, -- Albert. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
