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From: "Mattias Rönnblom" <hofors@lysator.liu.se>
To: "Stephen Hemminger" <stephen@networkplumber.org>,
	"Mattias Rönnblom" <mattias.ronnblom@ericsson.com>
Cc: dev@dpdk.org, David Marchand <david.marchand@redhat.com>
Subject: Re: [PATCH 2/2] devtools: forbid the use of ffs compiler builtins
Date: Thu, 17 Oct 2024 07:50:06 +0200	[thread overview]
Message-ID: <c8ceb855-4c12-4562-a6d7-7e1917838ba2@lysator.liu.se> (raw)
In-Reply-To: <20241016080424.3f614ac2@hermes.local>

On 2024-10-16 17:04, Stephen Hemminger wrote:
> On Wed, 16 Oct 2024 15:54:11 +0200
> Mattias Rönnblom <mattias.ronnblom@ericsson.com> wrote:
> 
>> Extend checkpatches.sh to detect the use of __builtin_(ffs|ffsll).
>>
>> These intrinsics are not available in MSVC, and there are perfectly
>> serviceable alternatives in <rte_bitops.h>.
>>
>> Signed-off-by: Mattias Rönnblom <mattias.ronnblom@ericsson.com>
>> Suggested-by: David Marchand <david.marchand@redhat.com>
> 
> Shouldn't this apply to all _builtin_ functions.
> 

Aren̈́'t GCC builtins pretty much standard? So any driver not targeting 
Windows should be fine, although it would be better to use a DPDK wrapper.

> There are a lot of drivers still doing this.

I would suggest we fix this when someone has taken the time to 
improve/modernize/extend <rte_bitops.h> further (e.g., with _Generic 
versions of all bit fiddling and count functions and "all" __builtins 
are covered).

I guess other APIs also may need to be extended (for non-bitops builtins).


  parent reply	other threads:[~2024-10-17  5:50 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-10-16 13:54 [PATCH 1/2] bitset: discontinue the use of GCC builtin Mattias Rönnblom
2024-10-16 13:54 ` [PATCH 2/2] devtools: forbid the use of ffs compiler builtins Mattias Rönnblom
2024-10-16 15:04   ` Stephen Hemminger
2024-10-16 15:32     ` David Marchand
2024-10-16 15:39       ` Stephen Hemminger
2024-10-16 20:55         ` David Marchand
2024-10-17  5:50     ` Mattias Rönnblom [this message]
2024-10-16 15:19 ` [PATCH 1/2] bitset: discontinue the use of GCC builtin David Marchand
2024-10-16 20:55 ` David Marchand

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