From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 1402 invoked by alias); 19 Jul 2005 19:53:22 -0000 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org Received: (qmail 1061 invoked by uid 48); 19 Jul 2005 19:53:18 -0000 Date: Tue, 19 Jul 2005 19:57:00 -0000 Message-ID: <20050719195318.1060.qmail@sourceware.org> From: "pinskia at gcc dot gnu dot org" To: gcc-bugs@gcc.gnu.org In-Reply-To: <20050719191302.22563.danalis@cis.udel.edu> References: <20050719191302.22563.danalis@cis.udel.edu> Reply-To: gcc-bugzilla@gcc.gnu.org Subject: [Bug rtl-optimization/22563] [3.4/4.0/4.1 Regression] performance regression for gcc newer than 2.95 X-Bugzilla-Reason: CC X-SW-Source: 2005-07/txt/msg02346.txt.bz2 List-Id: ------- Additional Comments From pinskia at gcc dot gnu dot org 2005-07-19 19:53 ------- There are a couple problems here, first we don't move the store to b_rec out side of the loop. Doing that on the mainline, we remove the loop as it is now unswitchable and really just empty. In fact that will not really be what you wantted but hey fast empty loops :). The other issue is that we don't constant prop the constants as we have a BIT_FIELD_REF which is most likely the cause of the orginal regression in the first place though BIT_FIELD_REF was there in 2.95.3. We can reduce your testcase down to stores really but that might not help the orginal code (except for the fact this is just a benchmark which is really useless). -- What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Ever Confirmed| |1 Keywords| |missed-optimization Known to fail| |3.3.3 3.0.4 3.2.3 3.4.0 Known to work| |2.95.3 Last reconfirmed|0000-00-00 00:00:00 |2005-07-19 19:53:16 date| | Summary|performance regression for |[3.4/4.0/4.1 Regression] |gcc newer than 2.95 |performance regression for | |gcc newer than 2.95 Target Milestone|--- |3.4.5 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22563