From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 27463 invoked by alias); 11 Mar 2011 21:28:02 -0000 Received: (qmail 27452 invoked by uid 22791); 11 Mar 2011 21:27:59 -0000 X-SWARE-Spam-Status: No, hits=-2.8 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 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; Fri, 11 Mar 2011 21:27:56 +0000 From: "wschmidt at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/48077] [Code Improvement] Poor expansion of multiply on powerpc64-linux X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: target X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: wschmidt at gcc dot gnu.org X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- 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 Date: Fri, 11 Mar 2011 21:28:00 -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 X-SW-Source: 2011-03/txt/msg01184.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48077 --- Comment #5 from William J. Schmidt 2011-03-11 21:27:25 UTC --- BTW, I mis-entered the optimization level before. The code generation was at -O2 when the mulhw was expanded into shifts/adds with the default P6 tuning. At -O3 and up, the mulhw is intact. This is all explained by the default tuning model in place during testing, since Power6 had a poorer performing integer multiply than the other machine models.