On Monday 20 June 2011, NamJae Jeon wrote: > I found compile warning while compiling module when using -Wsign-compare option. > > include/linux/bitops.h: In function 'hweight_long': > include/linux/bitops.h:49: warning: signed and unsigned type in > conditional expression > > I found the reason of this problem that the default return value of > the below macro is signed. > > #define __const_hweight8(w) \ > ( (!!((w) & (1ULL << 0))) + \ > (!!((w) & (1ULL << 1))) + \ > (!!((w) & (1ULL << 2))) + \ > (!!((w) & (1ULL << 3))) + \ > (!!((w) & (1ULL << 4))) + \ > (!!((w) & (1ULL << 5))) + \ > (!!((w) & (1ULL << 6))) + \ > (!!((w) & (1ULL << 7))) ) > > So, I try to add (unsigned long) in __const_hweight8 like this. > > #define __const_hweight8(w) (unsigned long ) \ > ( (!!((w) & (1ULL << 0))) + \ > (!!((w) & (1ULL << 1))) + \ > (!!((w) & (1ULL << 2))) + \ > (!!((w) & (1ULL << 3))) + \ > (!!((w) & (1ULL << 4))) + \ > (!!((w) & (1ULL << 5))) + \ > (!!((w) & (1ULL << 6))) + \ > (!!((w) & (1ULL << 7))) ) > > so, I can't see compile warning after fixing it, Would you plz check this ? Yes, this looks correct to me. Could you send the change as a proper patch with your Signed-off-by:? Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
