Re: numerical results differ after irrelevant code change

2011-05-08 Thread Robert Dewar
On 5/8/2011 12:48 PM, Michael D. Berger wrote: I made the changes you suggest. While I was previously getting -1.16e-16 and -1.03e-16 depending presence of an "extra" class member, I now get 1.11e-16 (sic not -). But it is now independent of the extra class member, which is excellent. Hopeful

RE: numerical results differ after irrelevant code change

2011-05-08 Thread Michael D. Berger
-- Michael D. Berger m.d.ber...@ieee.org http://www.rosemike.net/ > -Original Message- > From: gcc-ow...@gcc.gnu.org [mailto:gcc-ow...@gcc.gnu.org] On > Behalf Of Tim Prince > Sent: Sunday, May 08, 2011 11:38 > To: gcc@gcc.gnu.org > Subject: Re: numerical re

RE: numerical results differ after irrelevant code change

2011-05-08 Thread Joern Rennecke
Quoting "Michael D. Berger" : How does the extra precision lead to the variable result? Also, is there a way to prevent it? It is a pain in regression testing. Please read: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=323

Re: numerical results differ after irrelevant code change

2011-05-08 Thread Tim Prince
On 5/8/2011 8:25 AM, Michael D. Berger wrote: -Original Message- From: Robert Dewar [mailto:de...@adacore.com] Sent: Sunday, May 08, 2011 11:13 To: Michael D. Berger Cc: gcc@gcc.gnu.org Subject: Re: numerical results differ after irrelevant code change [...] This kind of result is

RE: numerical results differ after irrelevant code change

2011-05-08 Thread Michael D. Berger
> -Original Message- > From: Robert Dewar [mailto:de...@adacore.com] > Sent: Sunday, May 08, 2011 11:13 > To: Michael D. Berger > Cc: gcc@gcc.gnu.org > Subject: Re: numerical results differ after irrelevant code change > [...] > > This kind of result is qui

Re: numerical results differ after irrelevant code change

2011-05-08 Thread Robert Dewar
On 5/8/2011 10:54 AM, Michael D. Berger wrote: On a CentOS box with: # uname -a Linux xx 2.6.18-194.32.1.el5 #1 SMP Wed Jan 5 17:53:09 EST 2011 i686 i686 i386 GNU/Linux # gcc --version gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2-48) and using: Template Numerical Toolkit (TNT). as well as num