linux-kernel - Re: [PATCH v2 1/6] math.h: Add macros for rounding to the closest value

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Message-ID: <Zsy-8xXQ01-JhL0m@smile.fi.intel.com>
Date: Mon, 26 Aug 2024 20:44:19 +0300
From: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To: Devarsh Thakkar <devarsht@...com>
Cc: mchehab@...nel.org, hverkuil-cisco@...all.nl,
	linux-media@...r.kernel.org, linux-kernel@...r.kernel.org,
	sebastian.fricke@...labora.com, linux-doc@...r.kernel.org,
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	r-donadkar@...com, b-brnich@...com, detheridge@...com,
	p-mantena@...com, vijayp@...com, andi.shyti@...ux.intel.com,
	nicolas@...fresne.ca, jirislaby@...nel.org, davidgow@...gle.com,
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	jani.nikula@...el.com, rdunlap@...radead.org, nik.borisov@...e.com,
	Dave.Martin@....com
Subject: Re: [PATCH v2 1/6] math.h: Add macros for rounding to the closest
 value

On Mon, Aug 26, 2024 at 08:38:17PM +0530, Devarsh Thakkar wrote:
> Add below rounding related macros:
> 
> round_closest_up(x, y) : Rounds x to the closest multiple of y where y is a
> power of 2, with a preference to round up in case two nearest values are
> possible.
> 
> round_closest_down(x, y) : Rounds x to the closest multiple of y where y is
> a power of 2, with a preference to round down in case two nearest values
> are possible.
> 
> roundclosest(x, y) : Rounds x to the closest multiple of y, this macro
> should generally be used only when y is not multiple of 2 as otherwise
> round_closest* macros should be used which are much faster.

I understand the point, but if you need to send a v3, please explain
the equivalency between roundclosest() and one (or both?) of the
round_closest_*() in case the argument is power-of-2.

Because from the above I don't see what I'll get in such a case.

-- 
With Best Regards,
Andy Shevchenko