From: Tyler Retzlaff <roretzla@linux.microsoft.com>
To: Bruce Richardson <bruce.richardson@intel.com>
Cc: "Stephen Hemminger" <stephen@networkplumber.org>,
"Thomas Monjalon" <thomas@monjalon.net>,
"Morten Brørup" <mb@smartsharesystems.com>,
dev@dpdk.org, david.marchand@redhat.com
Subject: Re: [PATCH v2 1/2] eal: provide leading and trailing zero bit count abstraction
Date: Fri, 6 Jan 2023 10:47:06 -0800 [thread overview]
Message-ID: <20230106184706.GA20685@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net> (raw)
In-Reply-To: <Y7gKgZoMOcHVZ+NQ@bricha3-MOBL.ger.corp.intel.com>
On Fri, Jan 06, 2023 at 11:48:17AM +0000, Bruce Richardson wrote:
> On Thu, Jan 05, 2023 at 04:32:40PM -0800, Stephen Hemminger wrote:
> > On Thu, 5 Jan 2023 09:21:18 -0800
> > Tyler Retzlaff <roretzla@linux.microsoft.com> wrote:
> >
> > > On Thu, Jan 05, 2023 at 10:01:31AM +0100, Thomas Monjalon wrote:
> > > > 05/01/2023 08:09, Morten Brørup:
> > > > > > From: Tyler Retzlaff [mailto:roretzla@linux.microsoft.com]
> > > > > > +/**
> > > > > > + * @warning
> > > > > > + * @b EXPERIMENTAL: this API may change, or be removed, without prior
> > > > > > notice
> > > > > > + *
> > > > > > + * Get the count of leading 0-bits in v.
> > > > > > + *
> > > > > > + * @param v
> > > > > > + * The value.
> > > > > > + * @return
> > > > > > + * The count of leading zero bits.
> > > > > > + */
> > > > > > +__rte_experimental
> > > > > > +static inline unsigned int
> > > > > > +rte_clzl(unsigned long v)
> > > > >
> > > > > Don't use l (long) and ll (long long) for names (and types), use explicit bit lengths, 32 and 64.
> > > > >
> > > > > E.g.: rte_clz32(uint32_t v)
> > > >
> > > > I agree on using numbers.
> > > >
> > >
> > > love the idea, fewer functions too.
> > >
> > > though it is a shame we cannot adopt C11 standard because we could just
> > > do away with the bit suffixes entirely.
> >
> > We could but the project needs to support older RHEL releases
> > which have older tool sets. Though probably this is moot point given
> > how much meson seems to change.
>
> True, though meson tends to be a bit easier to update than GCC on a system
> - no "pip3 install --upgrade gcc", sadly :-)
* on linux. :)
>
> If we can't go all the way to C11 support, how about at least going to C99
> support? As far as I know DPDK has never updated its minimum C-standard
> version, and it might be a good idea to start the process of doing so, even
> if it is a baby step.
the thing that blurs the line a bit is how the gcc version that is
holding us back does actually allow the use of some C99 optional
features. for example we use the C99 fixed width integer types so
technically some of the code already requires C99.
i also notice at least one driver is explicitly specifying -std=gnu99 so
maybe that driver just isn't being built when the old gcc is detected?
anyway, i think we are stuck pre-c99 so long as we have RHEL 7 to
contend with. the rationale is if we could use a compiler conforming to
the new standard we could just directly use those features, but so long
as we have to support non conforming compiler at a particular level we
have to introduce an abstraction and that is where all the extra work
comes from.
a prominent example is atomics from C11, but for other reasons in our
code base that i won't go into even if we required C11 we would still
need to abstract atomics. fwiw i'm working on this patch series now and
hope to provide a first draft in the next week or two.
finally, i do think it would be good to document a minimum C compiler
conformance level rather than specific gcc versions. though i admit we
also have a hard dependency on gcc right now. my goal is to improve
portability to a level where we could just state "you need a C<N>
compliant compiler" (or as close to it as possible).
ty
next prev parent reply other threads:[~2023-01-06 18:47 UTC|newest]
Thread overview: 81+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-23 22:14 [PATCH 0/2] eal: provide leading and trailing zero bit count Tyler Retzlaff
2022-11-23 22:14 ` [PATCH 1/2] eal: provide leading and trailing zero bit count abstraction Tyler Retzlaff
2023-04-03 21:46 ` Mattias Rönnblom
2022-11-23 22:14 ` [PATCH 2/2] test/bitcount: add bitcount tests Tyler Retzlaff
2022-11-23 23:43 ` [PATCH v2 0/2] eal: provide leading and trailing zero bit count Tyler Retzlaff
2022-11-23 23:43 ` [PATCH v2 1/2] eal: provide leading and trailing zero bit count abstraction Tyler Retzlaff
2022-11-24 10:17 ` Morten Brørup
2022-11-28 17:13 ` Tyler Retzlaff
2022-11-28 17:22 ` Morten Brørup
2022-11-28 17:27 ` Tyler Retzlaff
2023-01-05 9:04 ` Thomas Monjalon
2023-01-05 17:23 ` Tyler Retzlaff
2023-01-05 17:27 ` Tyler Retzlaff
2023-01-05 20:57 ` Tyler Retzlaff
2023-01-05 21:34 ` Morten Brørup
2023-01-05 22:06 ` Tyler Retzlaff
2023-01-05 23:10 ` Morten Brørup
2023-01-06 1:04 ` Tyler Retzlaff
2023-01-06 10:09 ` Thomas Monjalon
2023-01-06 10:00 ` Thomas Monjalon
2023-01-05 7:09 ` Morten Brørup
2023-01-05 9:01 ` Thomas Monjalon
2023-01-05 17:21 ` Tyler Retzlaff
2023-01-06 0:32 ` Stephen Hemminger
2023-01-06 11:48 ` Bruce Richardson
2023-01-06 12:41 ` Morten Brørup
2023-01-06 13:40 ` Thomas Monjalon
2023-01-06 18:58 ` Tyler Retzlaff
2023-01-06 20:51 ` Thomas Monjalon
2023-01-10 9:18 ` Ferruh Yigit
2023-01-06 18:47 ` Tyler Retzlaff [this message]
2023-01-09 8:50 ` Bruce Richardson
2023-04-04 21:23 ` Tyler Retzlaff
2023-04-05 8:44 ` Bruce Richardson
2023-04-05 15:22 ` Tyler Retzlaff
2023-04-05 15:51 ` Bruce Richardson
2023-04-05 17:25 ` Tyler Retzlaff
2022-11-23 23:43 ` [PATCH v2 2/2] test/bitcount: add bitcount tests Tyler Retzlaff
2023-01-04 23:46 ` [PATCH v2 0/2] eal: provide leading and trailing zero bit count Tyler Retzlaff
2023-01-09 17:36 ` [PATCH v4 0/2] eal: provide leading and trailing zero bit count abstraction Tyler Retzlaff
2023-01-09 17:36 ` [PATCH v4 1/2] eal: move bit operation functions from common to bitops header Tyler Retzlaff
2023-01-10 13:56 ` Ferruh Yigit
2023-01-09 17:36 ` [PATCH v4 2/2] eal: provide leading and trailing zero bit count abstraction Tyler Retzlaff
2023-01-10 13:55 ` Ferruh Yigit
2023-01-10 17:34 ` Tyler Retzlaff
2023-01-10 18:37 ` Tyler Retzlaff
2023-01-10 13:56 ` [PATCH v4 0/2] " Ferruh Yigit
2023-01-06 22:01 ` [PATCH v3 0/3] eal: provide leading and trailing zero bit count Tyler Retzlaff
2023-01-06 22:01 ` [PATCH v3 1/3] eal: move bit functions from common to bitops header Tyler Retzlaff
2023-01-06 22:01 ` [PATCH v3 2/3] eal: provide leading and trailing zero bit count abstraction Tyler Retzlaff
2023-01-06 22:01 ` [PATCH v3 3/3] test/bitcount: add bitcount tests Tyler Retzlaff
2023-01-07 8:15 ` Thomas Monjalon
2023-01-09 16:57 ` Tyler Retzlaff
2023-01-09 17:26 ` Tyler Retzlaff
2023-01-07 13:40 ` Morten Brørup
2023-01-09 8:51 ` [PATCH v3 0/3] eal: provide leading and trailing zero bit count Bruce Richardson
2023-01-10 19:38 ` [PATCH v5 0/2] eal: provide leading and trailing zero bit count abstraction Tyler Retzlaff
2023-01-10 19:38 ` [PATCH v5 1/2] eal: move bit operation common to bitops header Tyler Retzlaff
2023-01-10 19:38 ` [PATCH v5 2/2] eal: provide leading and trailing zero bit count abstraction Tyler Retzlaff
2023-01-10 19:46 ` [PATCH v6 0/2] " Tyler Retzlaff
2023-01-10 19:46 ` [PATCH v6 1/2] eal: move bit operation common to bitops header Tyler Retzlaff
2023-01-10 19:46 ` [PATCH v6 2/2] eal: provide leading and trailing zero bit count abstraction Tyler Retzlaff
2023-01-20 22:14 ` [PATCH v6 0/2] " Tyler Retzlaff
2023-02-02 9:14 ` David Marchand
2023-02-02 10:56 ` David Marchand
2023-02-02 15:57 ` Tyler Retzlaff
2023-02-03 9:14 ` David Marchand
2023-02-02 15:56 ` Tyler Retzlaff
2023-02-03 9:21 ` David Marchand
2023-04-01 0:45 ` [PATCH v7 0/4] eal: provide abstracted bit counting functions Tyler Retzlaff
2023-04-01 0:45 ` [PATCH v7 1/4] eal: move bit count functions to bitops header Tyler Retzlaff
2023-04-01 0:45 ` [PATCH v7 2/4] eal: provide abstracted bit count functions Tyler Retzlaff
2023-04-01 0:45 ` [PATCH v7 3/4] pipeline: add include of bitops Tyler Retzlaff
2023-04-01 0:45 ` [PATCH v7 4/4] maintainers: add bitcount test under EAL API and common code Tyler Retzlaff
2023-04-01 7:08 ` [PATCH v7 0/4] eal: provide abstracted bit counting functions Morten Brørup
2023-04-04 0:11 ` [PATCH v8 0/3] " Tyler Retzlaff
2023-04-04 0:11 ` [PATCH v8 1/3] eal: move bit count functions to bitops header Tyler Retzlaff
2023-04-04 0:11 ` [PATCH v8 2/3] eal: provide abstracted bit count functions Tyler Retzlaff
2023-04-04 0:11 ` [PATCH v8 3/3] maintainers: add bitcount test under EAL API and common code Tyler Retzlaff
2023-04-04 8:27 ` [PATCH v8 0/3] eal: provide abstracted bit counting functions Bruce Richardson
2023-08-25 8:41 ` David Marchand
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=20230106184706.GA20685@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net \
--to=roretzla@linux.microsoft.com \
--cc=bruce.richardson@intel.com \
--cc=david.marchand@redhat.com \
--cc=dev@dpdk.org \
--cc=mb@smartsharesystems.com \
--cc=stephen@networkplumber.org \
--cc=thomas@monjalon.net \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).