[Rd] make check of R-alpha_2006-04-08_r37675 fails: qbeta

[Prof Brian Ripley]

Uwe Ligges had the same problem with gcc 3.3.1 on SuSE 9.0.  So I 
installed gcc 3.3.5 from the sources on an i386 box, and was able to 
reproduce it.

It is an optimization bug.  The crucial code is

 	xtrunc = tx;	/* this prevents trouble with excess FPU */
 				/* precision on some machines. */
 	if (xtrunc == xinbta)
 	    goto L_converged;

and both xtrunc and xinbta are volatile.  Seems that is being ignored in 
3.3.5/1, and so the loop never terminates.

Using an explicit check is safer and faster. I'll put mine in once I have 
finished testing.


On Mon, 10 Apr 2006, Dirk Eddelbuettel wrote:

>
> On 10 April 2006 at 14:31, Bjørn-Helge Mevik wrote:
> | Dirk Eddelbuettel wrote:
> |
> | > Fair point, especially as you have to insist on using gcc 3.3.* on Debian:
> | > -- 3.3.6 is the current 3.3.* one whereas Bjørn-Helge used 3.3.5
> | > -- 3.4.5 is the latest 3.* one supplanting 3.3.(5,6)
> | > -- 4.0.3 is the current default
> | > -- 4.1.0 is available too
>
> [...]
> | Hmmm... I don't `see' all those versions.  After an `aptitude update':
>
> (That didn't show version numbers...)
>
> | My /etc/apt/sources.list is:
> |
> | deb http://ftp.no.debian.org/debian/ sarge main non-free contrib
> | deb-src http://ftp.no.debian.org/debian/ sarge main non-free contrib
> | deb http://ftp.no.debian.org/debian-non-US sarge/non-US main contrib non-free
> | deb-src http://ftp.no.debian.org/debian-non-US sarge/non-US main contrib non-free
> | deb http://security.debian.org/ sarge/updates main contrib non-free
> |
> | Why am I seeing older versions than you?
>
> Because you point to 'sarge' which was frozen and released a year ago.
> If you want something newer than Debian stable, you have to point to it.
>
> This is all off-topic here. Please consider (subscribing and) posting to
> r-sig-debian for R/Debian related matters, or debian-help for generic Debian
> questions.
>
> Hope this helps, Dirk
>
>

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595