[FFmpeg-devel] [PATCH][WIP] lavc/cbrt_tablegen: speed up tablegen

Ganesh Ajjanagadde gajjanagadde at gmail.com
Fri Jan 1 17:10:00 CET 2016


On Fri, Jan 1, 2016 at 7:56 AM, Ronald S. Bultje <rsbultje at gmail.com> wrote:
> Hi,
>
> On Fri, Jan 1, 2016 at 10:52 AM, Ganesh Ajjanagadde <gajjanagadde at gmail.com>
> wrote:
>>
>> On Fri, Jan 1, 2016 at 7:51 AM, Ronald S. Bultje <rsbultje at gmail.com>
>> wrote:
>> > Hi,
>> >
>> > On Fri, Jan 1, 2016 at 10:46 AM, Ganesh Ajjanagadde
>> > <gajjanagadde at gmail.com>
>> > wrote:
>> >>
>> >> On Fri, Jan 1, 2016 at 7:43 AM, Ronald S. Bultje <rsbultje at gmail.com>
>> >> wrote:
>> >> > Hi,
>> >> >
>> >> > On Fri, Jan 1, 2016 at 10:40 AM, Ganesh Ajjanagadde
>> >> > <gajjanagadde at gmail.com>
>> >> > wrote:
>> >> >>
>> >> >> On Fri, Jan 1, 2016 at 6:54 AM, Ronald S. Bultje
>> >> >> <rsbultje at gmail.com>
>> >> >> wrote:
>> >> >> > Hi,
>> >> >> >
>> >> >> > On Thu, Dec 31, 2015 at 9:55 PM, Ganesh Ajjanagadde
>> >> >> > <gajjanagadde at gmail.com>
>> >> >> > wrote:
>> >> >> >>
>> >> >> >> This exploits an approach based on the sieve of Eratosthenes, a
>> >> >> >> popular
>> >> >> >> method for generating prime numbers.
>> >> >> >>
>> >> >> >> Tables are identical to previous ones.
>> >> >> >>
>> >> >> >> Tested with FATE. Does not work yet with
>> >> >> >> --enable-hardcoded-tables
>> >> >> >> due
>> >> >> >> to the union and lack of proper WRITE_ARRAY for it. Want to get
>> >> >> >> feedback
>> >> >> >> on this; if we always dynamically init it this won't need
>> >> >> >> addressing.
>> >> >> >
>> >> >> >
>> >> >> > I think you're getting ahead of yourself here. Assume for now that
>> >> >> > the
>> >> >> > hardcoded-tables feature will continue to exist for a while.
>> >> >>
>> >> >> I was referring to just this one, not to the question in general.
>> >> >
>> >> >
>> >> > I was also referring to this case specifically. Assume, for now, that
>> >> > hardcoded tables for this specific case, will continue to exist.
>> >>
>> >> Then defend it technically please. For instance, you have not
>> >> addressed the fundamental amortization of table init cost.
>> >
>> >
>> > No. It is the status quo, and remains that until it changes. That's why
>> > it's
>> > called the status quo. I've encouraged you several times to have this
>> > debate
>> > in the open, but you keep jumping away when that comes up.
>>
>> What is this if not "open"? Where does this "jumping away" come from?
>
>
> Open is an identifiable thread where people interested in that subject can
> participate. "[PATCH] cbrt: improve" is barely anything like that. Call it
> "[RFC] Disable compile-time tablegen if total cyclecount < $threshold".

You did not address the second question and your baseless attack. You
also never did "several times" define what you mean by "open" until
just now.

All that being said, thread created, with a modified subject line as
your proposed subject line is more general than the specific question
I am raising.

>
> Ronald


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