Messages in this thread | | | From | Alexey Brodkin <> | Subject | Re: [PATCH] __div64_32: implement division by multiplication for 32-bit arches | Date | Fri, 30 Oct 2015 15:54:02 +0000 |
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Hi Nicolas,
On Fri, 2015-10-30 at 11:17 -0400, Nicolas Pitre wrote: > On Fri, 30 Oct 2015, Måns Rullgård wrote: > > > Nicolas Pitre <nicolas.pitre@linaro.org> writes: > > > > > OK... I was intrigued, so I adapted my ARM code to the generic case, > > > including the overflow avoidance optimizations. Please have look and > > > tell me how this works for you. > > > > > > If this patch is accepted upstream, then it could be possible to > > > abstract only the actual multiplication part with some architecture > > > specific assembly. > > > > Good idea. > > Could you please provide a reviewed-by or acked-by tag?
Sure!
Acked-by: Alexey Brodkin <abrodkin@synopsys.com>
BTW I thought about that optimization a bit more and now I think we may even skip addition of arch-specific assembly insertions.
That's because that kind of division as discussed many times should be used as limited as possible, in other words there should be just a very few usages of it especially in very frequently used code paths. And in that case there might be not much of benefit having do_div() even faster and smaller than the one we're about to get with your change.
-Alexey | |