From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 19250 invoked by alias); 1 Jan 2004 04:11:40 -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 19236 invoked by uid 48); 1 Jan 2004 04:11:36 -0000 Date: Thu, 01 Jan 2004 04:11:00 -0000 Message-ID: <20040101041136.19235.qmail@sources.redhat.com> From: "pinskia at gcc dot gnu dot org" To: gcc-bugs@gcc.gnu.org In-Reply-To: <20021002075601.8126.o.lauffenburger@topsolid.com> References: <20021002075601.8126.o.lauffenburger@topsolid.com> Reply-To: gcc-bugzilla@gcc.gnu.org Subject: [Bug optimization/8126] [3.3/3.4 regression] Floating point computation far slower in 3.2 than in 2.95 X-Bugzilla-Reason: CC X-SW-Source: 2004-01/txt/msg00027.txt.bz2 List-Id: ------- Additional Comments From pinskia at gcc dot gnu dot org 2004-01-01 04:11 ------- What is weird is that -march=i386 is faster than -march=i686 on a pentium3: grendel:~/src/gnu/gcctest>gcc -O3 -ffast-math -fomit-frame-pointer pr8126.c -march=i386 grendel:~/src/gnu/gcctest>time ./a.out Start? Stop! Result = 0.000000, 0.000000, 1.000000 2.726u 0.000s 0:02.74 99.2% 0+0k 0+0io 2pf+0w grendel:~/src/gnu/gcctest>time ./a.out Start? Stop! Result = 0.000000, 0.000000, 1.000000 2.710u 0.000s 0:02.74 98.9% 0+0k 0+0io 0pf+0w grendel:~/src/gnu/gcctest>gcc -O3 -ffast-math -fomit-frame-pointer pr8126.c -march=i686 grendel:~/src/gnu/gcctest>time ./a.out Start? Stop! Result = 0.000000, 0.000000, 1.000000 2.843u 0.007s 0:02.87 98.9% 0+0k 0+0io 2pf+0w grendel:~/src/gnu/gcctest>gcc -O3 -ffast-math -fomit-frame-pointer pr8126.c -march=i586 grendel:~/src/gnu/gcctest>time ./a.out Start? Stop! Result = 0.000000, 0.000000, 1.000000 2.703u 0.000s 0:02.72 99.2% 0+0k 0+0io 2pf+0w grendel:~/src/gnu/gcctest>gcc -O3 -ffast-math -fomit-frame-pointer pr8126.c -march= pentium3 grendel:~/src/gnu/gcctest>time ./a.out Start? Stop! Result = 0.000000, 0.000000, 1.000000 2.843u 0.007s 0:02.87 98.9% 0+0k 0+0io 2pf+0w Is it looks like a choosing the wrong instruction for pentium3. (pentium4 is different and does not matter that mcuh). -- What |Removed |Added ---------------------------------------------------------------------------- Last reconfirmed|0000-00-00 00:00:00 |2004-01-01 04:11:34 date| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=8126