...
> > ptr = (u64 *)(buff - offset);
> > shift = offset * 8;
> >
> > /*
> > * Head: zero out any excess leading bytes. Shifting back by the same
> > * amount should be at least as fast as any other way of handling the
> > * odd/even alignment, and means we can ignore it until the very end.
> > */
> > data = *ptr++;
> > #ifdef __LITTLE_ENDIAN
> > data = (data >> shift) << shift;
> > #else
> > data = (data << shift) >> shift;
> > #endif
I suspect that
#ifdef __LITTLE_ENDIAN
data &= ~0ull << shift;
#else
data &= ~0ull >> shift;
#endif
is likely to be better.
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT,
UK
Registration No: 1397386 (Wales)
