On Thu, Mar 19, 2009 at 05:22:11PM +1100, Erik de Castro Lopo wrote: > > The following test case shows the failure when compiling with -ffast-math > gives a different result than when compiling with out it. > > More explanation in the comments at the top of the file. > > Cheers, > Erik > > /* > ** This file is in the Public Domain. > ** > ** This program demonstrates a bug in the -ffast-math option of the gcc > ** armel compiler : gcc version 4.3.2 (Debian 4.3.2-1.1) > ** > ** This works as expected: > ** > ** > gcc -Wall -O3 gcc-test.c -o gcc-test && ./gcc-test > ** min : 0.0000 max : 0.0000 > ** > ** Compile with -ffast-math and things goes screwy. > ** > ** > gcc -Wall -O3 -ffast-math gcc-test.c -o gcc-test && ./gcc-test > ** min : 99999.0000 max : 0.0000 > */
I get the following results: (sid)kroe...@agricola:~$ gcc -O1 -ffinite-math-only tst.c -o tst (sid)kroe...@agricola:~$ ./tst min : 99999.0000 max : -99999.0000 (sid)kroe...@agricola:~$ gcc -O3 -ffinite-math-only tst.c -o tst (sid)kroe...@agricola:~$ ./tst min : 99999.0000 max : 0.0000 With gcc version 4.3.3 (Debian 4.3.3-5) agricola is an armel running on a Thecus N2100: Processor : XScale-80219 rev 0 (v5l) BogoMIPS : 593.10 Features : swp half thumb fastmult edsp CPU implementer : 0x69 CPU architecture: 5TE CPU variant : 0x0 CPU part : 0x2e3 CPU revision : 0 I've also tried this on ia64, hppa, mips, mipsel and arm, they all gave the expected output. I will clone this bug to gcc and file a bug upstream. Kurt -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
