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From: Stephen Hemminger <stephen@networkplumber.org>
To: Adrien Mazarguil <adrien.mazarguil@6wind.com>
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH 0/5] remove usage of register keyword in C
Date: Tue, 31 Jul 2018 11:07:37 -0700	[thread overview]
Message-ID: <20180731110737.38555f02@xeon-e3> (raw)
In-Reply-To: <20180731164840.GD5211@6wind.com>

On Tue, 31 Jul 2018 18:48:40 +0200
Adrien Mazarguil <adrien.mazarguil@6wind.com> wrote:

> On Tue, Jul 31, 2018 at 09:30:54AM -0700, Stephen Hemminger wrote:
> > Declaring variables as register in C is a leftover from an earlier
> > era (like cassette tape decks in cars).  
> 
> I don't agree here. It's a hint for compilers and developers that the
> address of such variables won't be needed (and cannot be taken) to enable
> whatever optimizations are possible knowing this.
> 
> Somewhat like inline functions, it's not a forced optimization, just a
> useful hint that shouldn't hurt if used wisely.
> 
> Besides, cassette decks are not dead yet :)

If you look at the code, that is not how register is being used (ie. don't take
address of this). It seems like an attempt at optimization.

  reply	other threads:[~2018-07-31 18:07 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-07-31 16:30 Stephen Hemminger
2018-07-31 16:30 ` [dpdk-dev] [PATCH 1/5] qat: remove redundant C register keyword Stephen Hemminger
2018-09-05 10:23   ` Jozwiak, TomaszX
2018-07-31 16:30 ` [dpdk-dev] [PATCH 2/5] qede: remove register from declaraitons Stephen Hemminger
2018-07-31 16:30 ` [dpdk-dev] [PATCH 3/5] ark: remove register keyword Stephen Hemminger
2018-07-31 16:30 ` [dpdk-dev] [PATCH 4/5] mlx5: no need for " Stephen Hemminger
2018-07-31 16:30 ` [dpdk-dev] [PATCH 5/5] mlx4: remove redunant " Stephen Hemminger
2018-07-31 16:48 ` [dpdk-dev] [PATCH 0/5] remove usage of register keyword in C Adrien Mazarguil
2018-07-31 18:07   ` Stephen Hemminger [this message]
2018-08-01 18:03     ` Yongseok Koh
2018-08-01 21:03       ` Stephen Hemminger
2018-08-23 13:07         ` Ferruh Yigit
2018-10-09  9:19           ` Ferruh Yigit
2019-01-31  8:02             ` Tom Barbette
2019-01-31  9:11               ` Bruce Richardson
2019-01-31  9:39                 ` Tom Barbette
2019-01-31 17:34                 ` Wiles, Keith
2018-08-01 10:18 ` Matan Azrad

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