From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 29706 invoked by alias); 14 Nov 2014 09:37:00 -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 Received: (qmail 29413 invoked by uid 48); 14 Nov 2014 09:36:56 -0000 From: "jiwang at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/62173] [5.0 regression] [AArch64] Performance regression due to r213488 Date: Fri, 14 Nov 2014 09:37:00 -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: 5.0 X-Bugzilla-Keywords: missed-optimization X-Bugzilla-Severity: normal X-Bugzilla-Who: jiwang at gcc dot gnu.org X-Bugzilla-Status: NEW X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: jiwang 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: 2014-11/txt/msg01203.txt.bz2 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62173 --- Comment #5 from Jiong Wang --- The root cause is AArch64's TARGET_LEGITIMIZE_ADDRESS are not doing well when the input is ((reg + reg) + offset). looks like currently we have considered reg + non_normal_offset, and trying to split non_normal_offset to base + offset. while for ((reg1 + reg2) + offset), if reg + offset is valid, then we should legitimize it to reg3 = reg1 + offset return reg3 + reg2 will send out the patch after pass tests and benchmarking.