From: Al Viro <viro@ZenIV.linux.org.uk>
To: Jakub Kicinski <kubakici@wp.pl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC][PATCH] new byteorder primitives - ..._{replace,get}_bits()
Date: Wed, 13 Dec 2017 00:36:59 +0000 [thread overview]
Message-ID: <20171213003659.GA21978@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20171212155933.03c88eab@cakuba.netronome.com>
On Tue, Dec 12, 2017 at 03:59:33PM -0800, Jakub Kicinski wrote:
> > +static __always_inline __##type type##_replace_bits(__##type old, \
> > + base val, base mask) \
> > +{ \
> > + __##type m = to(mask); \
> > + if (__builtin_constant_p(val) && \
>
> Is the lack of a __builtin_constant_p(mask) test intentional? Sometimes
> the bitfield is a packed array and people may have a helper to which
> only the mask is passed as non-constant and the value is implied by the
> helper, thus constant.
If the mask in non-constant, we probably shouldn't be using that at all;
could you show a real-world example where that would be the case?
next prev parent reply other threads:[~2017-12-13 0:37 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-10 4:53 [RFC][PATCH] apparent big-endian bugs in dwc-xlgmac Al Viro
2017-12-11 4:33 ` Jie Deng
2017-12-11 5:05 ` Al Viro
2017-12-11 5:38 ` Al Viro
2017-12-11 6:46 ` Jie Deng
2017-12-11 15:54 ` [RFC][PATCH] new byteorder primitives - ..._{replace,get}_bits() Al Viro
2017-12-12 4:02 ` Jakub Kicinski
2017-12-12 6:20 ` Al Viro
2017-12-12 19:45 ` Al Viro
2017-12-12 20:04 ` Jakub Kicinski
2017-12-12 23:48 ` Al Viro
2017-12-12 23:59 ` Jakub Kicinski
2017-12-13 0:36 ` Al Viro [this message]
2017-12-13 1:04 ` Jakub Kicinski
2017-12-13 1:30 ` Al Viro
2017-12-13 1:35 ` Jakub Kicinski
2017-12-13 1:51 ` Al Viro
2017-12-13 2:44 ` Jakub Kicinski
2017-12-13 14:22 ` Al Viro
2017-12-13 17:45 ` Al Viro
2017-12-15 2:33 ` [RFC][PATCH] Add primitives for manipulating bitfields both in host- and fixed-endian Al Viro
2017-12-15 5:07 ` Jakub Kicinski
2017-12-15 5:34 ` Al Viro
2017-12-15 16:48 ` [RFC][PATCH v2] " Al Viro
2017-12-13 19:04 ` [RFC][PATCH] new byteorder primitives - ..._{replace,get}_bits() Jakub Kicinski
2017-12-11 6:18 ` [RFC][PATCH] apparent big-endian bugs in dwc-xlgmac Jie Deng
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20171213003659.GA21978@ZenIV.linux.org.uk \
--to=viro@zeniv.linux.org.uk \
--cc=kubakici@wp.pl \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.