From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 18189 invoked by alias); 21 Jun 2010 17:00:42 -0000 Received: (qmail 18052 invoked by uid 48); 21 Jun 2010 17:00:12 -0000 Date: Mon, 21 Jun 2010 17:00:00 -0000 Message-ID: <20100621170012.18051.qmail@sourceware.org> X-Bugzilla-Reason: CC References: Subject: [Bug fortran/41137] inefficient zeroing of an array In-Reply-To: Reply-To: gcc-bugzilla@gcc.gnu.org To: gcc-bugs@gcc.gnu.org From: "burnus 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: 2010-06/txt/msg02081.txt.bz2 ------- Comment #10 from burnus at gcc dot gnu dot org 2010-06-21 17:00 ------- (In reply to comment #9) > (In reply to comment #7) > > I cannot reproduce the factor of 10 results, however. > Here this still is the case (so might depend on the precise architecture): OK, I was using -fwhole-file out of habit - thus the difference is that small (all optimization levels, including -O0). Otherwise, I also get the same factor-of-10 difference. If one splits it in two files, one needs to use "-O3 -flto" to get a fast program. For comparison, using two files, ifort also shows a factor of 2 to 5 difference (and is at -O0 ten times slower than gfortran; at -O2 it is twice as fast as gfortran). -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41137