From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 16776 invoked by alias); 3 Jan 2014 14:44:05 -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 16721 invoked by uid 48); 3 Jan 2014 14:44:01 -0000 From: "rearnsha at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug rtl-optimization/59535] [4.9 regression] -Os code size regressions for Thumb1/Thumb2 with LRA Date: Fri, 03 Jan 2014 14:44:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: rtl-optimization X-Bugzilla-Version: 4.9.0 X-Bugzilla-Keywords: missed-optimization, ra X-Bugzilla-Severity: normal X-Bugzilla-Who: rearnsha at gcc dot gnu.org X-Bugzilla-Status: NEW X-Bugzilla-Priority: P1 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: 4.9.0 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: 2014-01/txt/msg00137.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59535 --- Comment #15 from Richard Earnshaw --- Another testcase where the thumb1 code is poor is gcc.c-torture/execute/pr28982b.c With LRA we often get sequences such as: mov r3, sp ldr r2, .L8+16 add r3, r3, r2 // r2 dead. str r0, [r3] Instead of: ldr r2, .L8+16 add r2, r2, sp str r0, [r2] Which is both shorter and needs fewer registers.