From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 23027 invoked by alias); 20 Nov 2013 10:40:44 -0000 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org Received: (qmail 22967 invoked by uid 48); 20 Nov 2013 10:40:41 -0000 From: "rguenth at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/59209] builtin memcpy in inlined function is not optimized away if count is derived from src pointer difference Date: Wed, 20 Nov 2013 10:40:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: tree-optimization X-Bugzilla-Version: 4.9.0 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: rguenth at gcc dot gnu.org X-Bugzilla-Status: RESOLVED X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_status resolution Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-SW-Source: 2013-11/txt/msg01980.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59209 Richard Biener changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution|--- |DUPLICATE --- Comment #2 from Richard Biener --- We simply are not able to optimize x + 1 - x to 1. See also PR58742 for which I think this is a dup. _2 = x_1(D) + 1; src_end.1_8 = (long int) _2; src_start.2_9 = (long int) x_1(D); _10 = src_end.1_8 - src_start.2_9; _11 = (long unsigned int) _10; __builtin_memcpy (&r, x_1(D), _11); later on RTL we optimize the size argument to 1 but that's too late. *** This bug has been marked as a duplicate of bug 58742 ***