From mboxrd@z Thu Jan 1 00:00:00 1970 From: SF Markus Elfring Subject: Re: InfiniBand-ocrdma: Delete unnecessary variable initialisations in 11 functions Date: Fri, 15 Jan 2016 16:26:36 +0100 Message-ID: <56990FAC.6000506@users.sourceforge.net> References: <566ABCD9.1060404@users.sourceforge.net> <567EDED5.4040201@users.sourceforge.net> <5697D865.5010507@users.sourceforge.net> <5697DE31.9040309@users.sourceforge.net> <20160115132014.GC30615@leon.nu> <56990733.7000506@users.sourceforge.net> <20160115150935.GA32346@leon.nu> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20160115150935.GA32346-2ukJVAZIZ/Y@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Leon Romanovsky Cc: Devesh Sharma , Doug Ledford , Hal Rosenstock , Mitesh Ahuja , Sean Hefty , Selvin Xavier , LKML , kernel-janitors-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Julia Lawall List-Id: linux-rdma@vger.kernel.org >> Would you like to clarify any measurable effects around the implementation >> detail when various variables will only be initialised immediately >> before they will be read again? > > Compiler will drop this variable initialization by itself because > there are no reads between this variable initialization and write. Which compiler variants would you to take into account for such an use case? > I recommend you to take a look on the assembly code and ensure it > by yourself. Will any configuration parameters and command arguments become relevant to improve also a corresponding software comparison? > The proposed change won't affect performance at all. Will unneeded variable assignments be really optimised away by default? By the way: Will a small source code reduction matter also a bit here? Regards, Markus -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html