On Thursday 13 January 2011 06:44 PM, Albert ARIBAUD wrote: > Le 13/01/2011 13:05, Aneesh V a écrit : > >>>> What I need is something like below: >>>> >>>> #define get_bit_field(nr, start, mask)\ >>>> (((nr) & (mask)) >> (start)) >>>> >>>> #define set_bit_field(nr, start, mask, val)\ >>>> (nr) = ((nr) & ~(mask)) | (((val) << (start)) & (mask)) >>>> >>>> Can these go in a generic header? If so, can I add them to >>>> "include/linux/bitops.h" >>> >>> After some more thought, I am wondering if a *generic* field setting and >>> getting macro is really useful. So far everyone is fine with at most >>> defining field-specific macros. >> >> Is it going to be easy if you have many fields to deal with? > > I don't see how the generic macros ease anything. Instead of defining say > > #define get_field_F(x) ((x >> F_start) & F_mask) > #define set_field_F(x,v) { x = (x ~ F_mask ) | (v << F_start) } > > You'd have > > #define get_field_F(x) get_bit_field(x, F_start, F_mask) > #define set_field_F(x,v) set_bit_field(x, F_start, F_mask, v); > > Which does not seem to bring any simplicity to me.
I wouldn't define get_field_F. Instead I would just use set_bit_field(x, F_start, F_mask, v) directly in the code and I have F_start and F_mask defined in the header files (automatically generated) Even if it was manual isn't it easier to define just F_start and F_mask per field than defining a get_field_F per field? Perhaps my requirement is different. If this scheme is not used by many, I shall put these macros in OMAP specific headers. best regards, Aneesh _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot