[ovs-dev] [PATCH]: Use ctz64() instead of rightmost_1bit_idx() with 64 bit arg

[Kyle Upton]

Looks good to me.  Cleaner and more general.

Thanks,
-Kyle

On 09/18/2015 06:26 PM, Ben Pfaff wrote:
> On Wed, Sep 16, 2015 at 01:08:48PM -0400, Kyle Upton wrote:
>> Applied a patch which changed value of OFPACT_SET_QUEUE to be greater
>> than 32.  Tracked down a subsequent autotest failure to invocation of
>> rightmost_1bit_idx() with 64-bit argument 'opfacts_bitmap'.
>> rightmost_1bit_idx() only works with 32-bit integers.
>>
>> Changed this and other occurrences where rightmost_1bit_idx() is
>> invoked with a 64-bit argument to use ctz64() instead.
>>
>> Tested by running 'make check'.
>>
>> Signed-off-by: Kyle Upton <kupton at baymicrosystems.com>
>
> After looking through the OVS code, I don't think that any of the users
> of rightmost_1bit_idx() or leftmost_1bit_idx() rely on the case where
> all of the bits are zero.  That means that we can just change them to be
> alternate names for ctz64() or log_2_floor().  Arguably we could get rid
> of them entirely but personally I think the names are useful to make it
> clear how the user is thinking of the function.
>
> So, anyway, I sent an alternative patch:
>         http://openvswitch.org/pipermail/dev/2015-September/060257.html
> What do you think?
>
> Thanks,
>
> Ben.
>

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