On 01/03/2013 02:31:30 PM, Alexander Graf wrote:
Am 03.01.2013 um 21:07 schrieb Scott Wood <scottw...@freescale.com>:
> On 01/03/2013 12:53:13 PM, Alexander Graf wrote:
>> On 22.12.2012, at 03:15, Scott Wood wrote:
>> > Search the queue more efficiently by first looking for a
non-zero word,
>> > and then using the common bit-searching function to find the bit
within
>> > the word. It would be even nicer if bitops_ffsl() could be
hooked up
>> > to the compiler intrinsic so that bit-searching instructions
could be
>> > used, but that's another matter.
>> >
>> > Signed-off-by: Scott Wood <scottw...@freescale.com>
>> What we really want is a bitmap wide ffs() bipops helper function
that returns the first set bit in a bitmap and can optimize the hell
out of that operation inside of itself. I don't think this belongs to
the OpenPIC code.
>
> Well, we do have find_next_bit() in bitops.c, but it looks
comparitively complicated in order to be generic and simply return a
value rather than perform an action on each bit set. I suspect that
the code in this patch would be faster, and avoids the need for me to
follow all the twists and turns of find_next_bit() to figure out
whether the undocumented interface is actually exactly what I guess
it to be (e.g. what does it return when no bit is found?).
I would just call it bit_ffs and follow the same semantics.
I'm not sure how that's an answer to what I wrote...
-Scott
