On Fri, 29 Jan 2010 09:28:04 GMT tip-bot for Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> wrote: > +#define 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))) ) > + > +#define HWEIGHT16(w) (HWEIGHT8(w) + HWEIGHT8(w >> 8)) > +#define HWEIGHT32(w) (HWEIGHT16(w) + HWEIGHT16(w >> 16)) > +#define HWEIGHT64(w) (HWEIGHT32(w) + HWEIGHT32(w >> 32)) Would be nice if it had a comment explaining why it exists. If people accidentally use this with non-constant arguments, the generated code will be pretty ghastly. Or add some barf-if-not-__constant_p() thing, perhaps. -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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