I noticed it because, without it, making murmurhash the default hash
function caused unit test failures in e.g. "row hashing (scalars)".
We really have a remarkably paranoid testsuite in some ways.
On Tue, Jan 15, 2013 at 01:21:37PM -0800, Ethan Jackson wrote:
> How did you notice this problem? Did the hash unit tests catch it? If
> not, could we extend them in some way so that they would?
>
> Acked-by: Ethan Jackson <et...@nicira.com>
>
>
> On Fri, Dec 14, 2012 at 4:33 PM, Ben Pfaff <b...@nicira.com> wrote:
> > With rotates instead of shifts, the upper and lower 16 bits of the returned
> > hash are always the same.
> >
> > Signed-off-by: Ben Pfaff <b...@nicira.com>
> > ---
> > lib/hash.h | 6 +++---
> > 1 files changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/lib/hash.h b/lib/hash.h
> > index 701e686..96866c4 100644
> > --- a/lib/hash.h
> > +++ b/lib/hash.h
> > @@ -152,11 +152,11 @@ static inline uint32_t mhash_add(uint32_t hash,
> > uint32_t data)
> > static inline uint32_t mhash_finish(uint32_t hash, size_t n)
> > {
> > hash ^= n * 4;
> > - hash ^= hash_rot(hash, 16);
> > + hash ^= hash >> 16;
> > hash *= 0x85ebca6b;
> > - hash ^= hash_rot(hash, 13);
> > + hash ^= hash >> 13;
> > hash *= 0xc2b2ae35;
> > - hash ^= hash_rot(hash, 16);
> > + hash ^= hash >> 16;
> > return hash;
> > }
> >
> > --
> > 1.7.2.5
> >
> > _______________________________________________
> > dev mailing list
> > dev@openvswitch.org
> > http://openvswitch.org/mailman/listinfo/dev
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