Patch for Quad.cc compile error on Sun/GCC

[John W. Eaton]

On  5-May-2009, Carsten Clark wrote:

| 2009/5/4 John W. Eaton <jwe at octave.org>:
| >
| > I checked in the change, but what about
| >
| >  quad (@(x) x, single (0), single (2))
| >
| > ?  Are you using the Sun Fortran compiler?  My guess is that it will
| > work, and that GCC and the Sun Fortran compiler will handle floats in
| > a compatible way, unlike for doubles.
| 
| I was using g77 from GCC 4.  This works:
| 
| $ octave -qf
| octave:1> quad ( @(x) x, 0, 2 )
| ans =  2
| octave:2> quad ( @(x) x, single(0), single(2) )
| ans =  2.0000
| 
| I rebuilt using g++4 and this Sun Studio Fortran compiler:
| 
| $ /opt/SunStudioExpress/bin/f77 -V
| NOTICE: Invoking /opt/SunStudioExpress/bin/f90 -f77 -ftrap=%none -V
| f90: Sun Ceres Fortran 95 8.3 SunOS_i386 2008/10/22
| 
| and that works, too (your guess is right!):
| 
| octave:1> quad ( @(x) x, 0, 2 )
| ans =  2
| octave:2> quad ( @(x) x, single(0), single(2) )
| ans =  2
| 
| Actually, the GCC manual
| (http://gcc.gnu.org/onlinedocs/gcc-4.3.3/gcc/Interoperation.html)
| states that the compatibility problem that access_double() solves only
| occurs on SPARC systems.  I'm on an Intel PC.  Changing the #ifdefs in
| Quad.cc and sun-utils.h to __sparc, as in the attached patch, I can
| still run the above test code successfully, with both g77 and Sun
| Studio f77.  (I verified that __sparc is not defined for me and the
| access_double() lines are not compiled.)
| 
| I've checked a SPARC system at work, and it does define __sparc and
| sparc.  The Sun Studio 12 User's Guide
| (http://docs.sun.com/app/docs/doc/819-5267/6n7c46edt) also lists these
| symbols as defined on SPARC only.  However, I don't have GCC 4 on that
| system, so probably can't try building Octave.
| 
| At any rate, access_double() and assign_double() aren't necessary on
| my system, and it looks like this should be true of Solaris/Intel
| systems in general, unless I'm a fluke for some reason.

I applied the patch.

In the future, can you submit Mercurial changesets instead of plain
context diffs?

Thanks,

jwe