From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 9349 invoked by alias); 3 Dec 2014 13:47:36 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 9340 invoked by uid 89); 3 Dec 2014 13:47:35 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.3 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=ham version=3.3.2 X-HELO: mail-oi0-f54.google.com Received: from mail-oi0-f54.google.com (HELO mail-oi0-f54.google.com) (209.85.218.54) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES128-SHA encrypted) ESMTPS; Wed, 03 Dec 2014 13:47:34 +0000 Received: by mail-oi0-f54.google.com with SMTP id u20so10807028oif.27 for ; Wed, 03 Dec 2014 05:47:32 -0800 (PST) MIME-Version: 1.0 X-Received: by 10.60.219.7 with SMTP id pk7mr3270347oec.0.1417614452505; Wed, 03 Dec 2014 05:47:32 -0800 (PST) Received: by 10.76.185.7 with HTTP; Wed, 3 Dec 2014 05:47:32 -0800 (PST) In-Reply-To: References: Date: Wed, 03 Dec 2014 13:47:00 -0000 Message-ID: Subject: Re: [PATCH x86_64] Optimize access to globals in "-fpie -pie" builds with copy relocations From: "H.J. Lu" To: Uros Bizjak Cc: "gcc-patches@gcc.gnu.org" , Sriraman Tallam , Jakub Jelinek Content-Type: text/plain; charset=UTF-8 X-IsSubscribed: yes X-SW-Source: 2014-12/txt/msg00269.txt.bz2 On Tue, Dec 2, 2014 at 12:01 PM, Uros Bizjak wrote: > On Tue, Dec 2, 2014 at 8:40 PM, H.J. Lu wrote: >> On Tue, Dec 2, 2014 at 11:19 AM, Uros Bizjak wrote: >>> Hello! >>> >>>> Ping. >>>>> Ping. >>>>>> Ping. >>>>>>> Ping. >>> >>> It would probably help reviewers if you pointed to actual path >>> submission [1], which unfortunately contains the explanation in the >>> patch itself [2], which further explains that this functionality is >>> currently only supported with gold, patched with [3]. >>> >>> [1] https://gcc.gnu.org/ml/gcc-patches/2014-09/msg00645.html >>> [2] https://gcc.gnu.org/ml/gcc-patches/2014-09/txt2CHtu81P1O.txt >>> [3] https://sourceware.org/ml/binutils/2014-05/msg00092.html >>> >>> After a bit of the above detective work, I think that new gcc option >>> is not necessary. The configure should detect if new functionality is >>> supported in the linker, and auto-configure gcc to use it when >>> appropriate. >> >> I think GCC option is needed since one can use -fuse-ld= to >> change linker. > > IMO, nobody will use this highly special x86_64-only option. It would > be best for gnu-ld to reach feature parity with gold as far as this > functionality is concerned. In this case, the optimization would be > auto-configured, and would fire automatically, without any user > intervention. > Let's do it. I implemented the same feature in bfd linker on both master and 2.25 branch. -- H.J.