From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 25542 invoked by alias); 6 Aug 2012 00:58:38 -0000 Received: (qmail 25528 invoked by uid 22791); 6 Aug 2012 00:58:37 -0000 X-SWARE-Spam-Status: No, hits=-4.3 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00,KHOP_THREADED X-Spam-Check-By: sourceware.org Received: from localhost (HELO gcc.gnu.org) (127.0.0.1) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Mon, 06 Aug 2012 00:58:24 +0000 From: "chip at pobox dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug middle-end/28831] [4.6/4.7/4.8 Regression] Aggregate copy not elided when using a return value as a pass-by-value parameter Date: Mon, 06 Aug 2012 00:58:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: middle-end X-Bugzilla-Keywords: missed-optimization X-Bugzilla-Severity: normal X-Bugzilla-Who: chip at pobox dot com X-Bugzilla-Status: NEW X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: 4.6.4 X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 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 X-SW-Source: 2012-08/txt/msg00287.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28831 --- Comment #16 from Chip Salzenberg 2012-08-06 00:57:13 UTC --- Addendum: In cut down test cases where I only pass by value or only return by value, but not both, I find no extra stores, which is good; but I still find a lot of unnecessary frame allocation (either $24 or $40, depending), and tail call is still missing.