[R] linux compile options (64-bit)

[Göran Broström]

On Tue, Aug 02, 2005 at 09:33:45AM +0100, Prof Brian Ripley wrote:
> On Tue, 2 Aug 2005, Göran Broström wrote:
[...]

> >Incidentally, I have just tried building R on a Fujitsu Amilo amd64 with
> >debian-amd64 (unstable) and ATLAS. Both 'make' and 'make check' worked
> >without complaints with gcc-3.4.5,
> 
> There is no gcc 3.4.5!  There are versions 3.3.5 and 3.4.4.

I apologize for the incomplete description; gcc -v gives:

gcc version 3.4.5 20050706 (prerelease) (Debian 3.4.4-5)

> >but when I tried gcc-4.0.1, 'make check' failed with a segmentation 
> >error after
> 
> I have seen this on FC3.  Note that ZAXPY is a BLAS routine, and you are 
> using ATLAS: was that also built with gcc-4.0.1?  

Probably not; I just 'apt-get install'ed atlas3-base etc. I'll build atlas
from source and try again. 

> On FC3 I get the failure 
> if I use its BLAS, and not if I configure R with --without-blas.  (I did 
> not see the problem using the gcc4 RPM from FC3 update, and I gather 
> others have managed to use gcc4 from FC4.)
> 
> We do not recommend gcc-4.0.x as yet: we have yet to see any performance 
> gains (only losses) from it, and this is one of a number of known 
> nuisances.  More serious are places where it apparently generates 
> incorrect code and so gives incorrect answers.

OK. An additional advantage with gfortran(-4.x) will be the possibility to
use fortan95 code, n'est ce pas?

Göran