From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 10811 invoked by alias); 10 May 2014 13:49:45 -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 10720 invoked by uid 48); 10 May 2014 13:49:41 -0000 From: "olegendo at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/52628] SH Target: Inefficient shift by T bit result Date: Sat, 10 May 2014 13:49:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: target X-Bugzilla-Version: 4.8.0 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: olegendo 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-Flags: X-Bugzilla-Changed-Fields: 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: 2014-05/txt/msg00907.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52628 --- Comment #1 from Oleg Endo --- If conditional execution is implemented via zero-displacement branches ( PR 54762 ) then I'd expect this to work automatically. However, on SH variants that do not have dynamic shifts (SH1, SH2) it should be always better to jump around a constant shift than invoking the dynamic shift library function.