From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Gunthorpe Subject: Re: [PATCH rdma-core 1/5] Pull uninitialized_var into util/compiler.h Date: Tue, 11 Oct 2016 12:05:17 -0600 Message-ID: <20161011180517.GA17866@obsidianresearch.com> References: <1475879772-29458-1-git-send-email-jgunthorpe@obsidianresearch.com> <1475879772-29458-2-git-send-email-jgunthorpe@obsidianresearch.com> <20161009054601.GB9282@leon.nu> <20161009230150.GB12551@obsidianresearch.com> <20161010040930.GF9282@leon.nu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20161010040930.GF9282-2ukJVAZIZ/Y@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Leon Romanovsky Cc: Doug Ledford , linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rdma@vger.kernel.org On Mon, Oct 10, 2016 at 07:09:30AM +0300, Leon Romanovsky wrote: > > I think people would complain about the extra stores. gcc 6 will > > eliminate them, but older compilers will not. > > This unintialized_var(x) adds extra store too (... x = x ...). I have confirmed that the unintialized_var macro does not impact code generation on the old gccs while the =0 approach does. So no extra store. Jason -- 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