On 5 April 2013 09:43, Peter Crosthwaite <peter.crosthwa...@xilinx.com> wrote: > Little macro that just gives you N ones (justified to LSB). > > Signed-off-by: Peter Crosthwaite <peter.crosthwa...@xilinx.com> > --- > > include/qemu/bitops.h | 2 ++ > 1 files changed, 2 insertions(+), 0 deletions(-) > > diff --git a/include/qemu/bitops.h b/include/qemu/bitops.h > index affcc96..da47fc8 100644 > --- a/include/qemu/bitops.h > +++ b/include/qemu/bitops.h > @@ -273,4 +273,6 @@ static inline uint64_t deposit64(uint64_t value, int > start, int length, > return (value & ~mask) | ((fieldval << start) & mask); > } > > +#define ONES(num) ((num) == 64 ? ~0ull : (1ull << (num)) - 1)
You can avoid the ?: here (assuming you're happy to say that ONES(0) is a silly thing to ask for): #define ONES(num) (~0ULL >> (64 - (num))) Needs a documentation comment, anyway. thanks -- PMM
