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

[Peter Dalgaard]

Prof Brian Ripley <ripley at stats.ox.ac.uk> writes:

> 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.

However, if the compiler is disobeying "volatile", it is buggy and it
might be safer not to use that compiler at all. There's no telling
what else might break for the same reason.
 
> 
> 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______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel

-- 
   O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
  c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
 (*) \(*) -- University of Copenhagen   Denmark          Ph:  (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)                  FAX: (+45) 35327907