From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: Dipendra Khadka <kdipendra88@gmail.com>
Cc: lee@kernel.org, pavel@ucw.cz, linux-leds@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] leds: bcm6328: Replace divide condition with comparison for shift value
Date: Sat, 23 Nov 2024 21:55:46 +0200 [thread overview]
Message-ID: <Z0IzQlsP6OMCcXRB@surfacebook.localdomain> (raw)
In-Reply-To: <20241019073302.35499-1-kdipendra88@gmail.com>
Sat, Oct 19, 2024 at 07:33:01AM +0000, Dipendra Khadka kirjoitti:
> Fixes the following Smatch warnings:
> drivers/leds/leds-bcm6328.c:116 bcm6328_led_mode() warn: replace divide condition 'shift / 16' with 'shift >= 16'
> drivers/leds/leds-bcm6328.c:360 bcm6328_led() warn: replace divide condition 'shift / 16' with 'shift >= 16'
As discussed with Dan (author of smatch), these warnings make no much sense as
"division" by power-of-two numbers in modern world (ISAs, compilers, etc) most
unlikely become a real division instruction with all bad consequences. Even
though, some ISAs can optimize cases where foo / 16; foo % 16 goes together and
this change may break that.
So, please, consider not to send such changes in the future because at least
they are just noise, at most might add a (micro-)rgressions.
https://lore.kernel.org/linux-gpio/20241112201659.16785-1-surajsonawane0215@gmail.com/
https://lore.kernel.org/all/20241121105838.4073659-4-andriy.shevchenko@linux.intel.com/
--
With Best Regards,
Andy Shevchenko
prev parent reply other threads:[~2024-11-23 19:55 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-19 7:33 [PATCH v2] leds: bcm6328: Replace divide condition with comparison for shift value Dipendra Khadka
2024-10-31 16:10 ` (subset) " Lee Jones
2024-11-23 19:55 ` Andy Shevchenko [this message]
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