From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 1734 invoked by alias); 6 Jan 2007 10:17:10 -0000 Received: (qmail 1712 invoked by uid 48); 6 Jan 2007 10:17:02 -0000 Date: Sat, 06 Jan 2007 10:17:00 -0000 Message-ID: <20070106101702.1711.qmail@sourceware.org> X-Bugzilla-Reason: CC References: Subject: [Bug fortran/30388] gfortran42 is slower than g77 3.4 about 10% In-Reply-To: Reply-To: gcc-bugzilla@gcc.gnu.org To: gcc-bugs@gcc.gnu.org From: "rguenth at gcc dot gnu dot org" 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: 2007-01/txt/msg00374.txt.bz2 ------- Comment #10 from rguenth at gcc dot gnu dot org 2007-01-06 10:17 ------- Well, it all boils down to differences in induction variable choices. The choice made by 3.4 (for i686) doesn't look too good to me compared to 4.1.2 here. 4.1: MFLOPS: 990.4130 time(s): 28.10176 3.4: MFLOPS: 449.016235 time(s): 59.8477402 (-O2 -ffast-math -funroll-loops -fomit-frame-pointer) The predcomm branch should be able to do a lot better here. With SSE math I get 4.1: MFLOPS: 954.2382 time(s): 31.46597 3.4: MFLOPS: 467.92215 time(s): 59.1876984 -- rguenth at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |rakdver at gcc dot gnu dot | |org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30388