Yonghong Song <yhs@xxxxxxxx> wrote: > On 5/9/23 11:08 AM, Dave Thaler wrote: > > From: Dave Thaler <dthaler@xxxxxxxxxxxxx> > > > > Update the documentation regarding shift operations to explain the use > > of a mask, since otherwise shifting by a value out of range (like > > negative) is undefined. > > > > Signed-off-by: Dave Thaler <dthaler@xxxxxxxxxxxxx> > > LGTM with a few nit below. > > Acked-by: Yonghong Song <yhs@xxxxxx> [...] > > -BPF_ARSH 0xc0 sign extending shift right > > +BPF_ARSH 0xc0 sign extending dst >>= (src & mask) > > dst s>>= (src & mask) > ? I had thought about that, but based on Jose's LSF/MM/BPF presentation yesterday there are multiple such syntaxes. ">>=" vs "s>>=" is only one of several. There's ">>" vs ">>>", there's assembly-like, etc. So I thought that it would take more text to define "s>>" as meaning signing extending right shift, than just saying sign extending ">>=" here. And I didn't want to just assume the reader knows what "s>>" means without defining it since neither the C standard nor gcc use "s>>". Thanks for the Ack. Dave
