Re: c/8395: gcc 2.95.4 and 3.2 generate wrong code for double onintel

[Bruce Allen <ballen at gravity dot phys dot uwm dot edu>]

The following reply was made to PR c/8395; it has been noted by GNATS.

From: Bruce Allen <ballen@gravity.phys.uwm.edu>
To: Marco Bernardo <bernardo@sti.uniurb.it>
Cc: Tim Prince <tprince@computer.org>, Bruce Allen <ballen@aei.mpg.de>,
       gcc-gnats@gcc.gnu.org, gcc-prs@gcc.gnu.org, gcc-bugs@gcc.gnu.org,
       nobody@gcc.gnu.org
Subject: Re: c/8395: gcc 2.95.4 and 3.2 generate wrong code for double on
 intel
Date: Sun, 3 Nov 2002 00:19:45 -0600 (CST)

 Marco, Tim is also completely correct.
 
 Bruce
 
 On Sat, 2 Nov 2002, Tim Prince wrote:
 
 > On Saturday 02 November 2002 07:42, Marco Bernardo wrote:
 > 
 > > Let me conclude by saying that my intention is not to be polemic.
 > > My point of view is that of a university professor who wants to teach
 > > to his students that there is a great alternative to Microsoft,
 > > which is Linux and the free software world.
 > > You would then understand that it is very difficult for me to support gcc
 > > and to teach my students how to use gcc in the presence of such a strange
 > > behavior, which is not justifiable at all on a scientific basis.
 > >
 > >
 > From a professorial point of view, you should be encouraging your students to 
 > consult expert references on floating point numerics, even if you don't care 
 > to do so yourself.  Before you start arguing about IEEE standards and 
 > scientific bases, you should be reading up on them, and the technical reasons 
 > for including the extended precision option.
 > If you are teaching at this level of detail, you could show your students how 
 > to set 53-bit rounding mode in order to duplicate the fpu settings of 
 > Microsoft compilers, how to use fpu mode settings to test code reliability, 
 > and how to break the Microsoft compiler by putting the fpu in standard 
 > default mode.  As standard C does not define a function for this purpose, the 
 > C committee must not have considered it to be as large an issue as you.
 > -- 
 > Tim Prince
 >