On 26 June 2012 19:25, Blue Swirl <blauwir...@gmail.com> wrote: > On Tue, Jun 26, 2012 at 6:11 PM, Peter Maydell <peter.mayd...@linaro.org> > wrote: >> On 26 June 2012 18:58, Blue Swirl <blauwir...@gmail.com> wrote: >>> On Mon, Jun 25, 2012 at 7:38 PM, Peter Maydell <peter.mayd...@linaro.org> >>> wrote: >>>> +static inline uint64_t field64(uint64_t value, int start, int length) >>> >>> start and length could be unsigned. >> >> They could be, but is there any reason why they should be? >> set_bit(), clear_bit() etc use 'int' for bit numbers, so this >> is consistent with that. > > Negative shifts don't work, the line with assert() would get shorter > and simpler and I like unsigned values.
I don't like using unsigned for numbers that merely happen to always be positive (as opposed to actually requiring unsigned arithmetic)[*], so I think I'll stick with being consistent with the existing bitops functions, thanks :-) [*] the classic example of where that kind of thing can trip you up is the way it complicates the termination condition on a "for (i = N; i >= 0; i--)" decreasing loop. -- PMM