modreg buggy: uninitialized variable in sinerp.f (PR#302)

Prof Brian D Ripley ripley@stats.ox.ac.uk
Sat, 30 Oct 1999 19:00:05 +0100 (BST)


On Sat, 30 Oct 1999 thoffman@zappa.sax.de wrote:

> I had some strange problems with modreg: sometimes functions
> hang in an infinite loop, consuming 100% CPU time. Especially
> when update()ing models (as in example(ppr)) with sm.method="gcv"
> I found that if I repeated the call after I did interrupt the hang,
> it ran to completion.
> 
> After some lengthy debugging I could track down this problem:
> 
> sinerp.f, line 22--24 read:
> 
>       wjm3(1)=0d0
>       wjm3(2)=0d0
>       wjm3(1)=0d0
> 
> This leaves wjm3(3) uninitialized. So after changing these lines to
> 
>       wjm3(1)=0d0
>       wjm3(2)=0d0
>       wjm3(3)=0d0
> 
> the bug was gone.

Thank you very much!  We were aware of occasional problems (but only on
gcc), but had not managed to track them down. In all cases using
-ffloat-store had solved the problem.

I have committed this change for the next release.

-- 
Brian D. Ripley,                  ripley@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 272860 (secr)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

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