roll macro's in bitops.h

G'day people,

I was looking at bitops.h and noticed there were a couple of inline roll functions to operate on 32bit variables. (left and right)

I think that is a little bit dumb as they are constant width (only 32bits) due to it being an inline function, and was wondering if anyone thought it would be useful to have some (variable sized) roll macros instead.

I whipped these twp up as examples, but have not tested them yet.

#define RollRight(Data, Distance) \

({      typeof(Data) __a = Data;   \
        typeof(Distance) __b = Distance%(sizeof(__a) * 8); \
	__a = ((__a>>__b) | (__a<<((sizeof(__a) * 8) - __b))) \
	__a; \
})

#define RollLeft(Data, Distance) \

({      typeof(Data) __a = Data;   \
        typeof(Distance) __b = Distance%(sizeof(__a) * 8); \
	__a = ((__a<<__b) | (__a>>((sizeof(__a) * 8) - __b))) \
	__a; \
})

Also if these are useful I was wondering how to handle the existing functions ? #define them out for the time being ?

#define rol32(a, b) RollLeft(a, b)
#define ror32(a, b) RollRight(a, b)

Darren Jenkins

_______________________________________________
Kernel-janitors mailing list
[email protected]
https://lists.osdl.org/mailman/listinfo/kernel-janitors