🚀 go-pugleaf

This sounds like a real bug.  However, we really can't work on
something without a way to reproduce the behavior ourselves.  So if
you do come up with a small test program, at the very least we'll
included it in our test suite, to remind us that the bug is there.

Gabriel Zachmann <zach@cs.uni-bonn.de> writes:

> I have a funny problem with gdb (GNU gdb Red Hat Linux (5.1-1)):
> 
> In a C++ program I have the following two lines:
> 
>     float v = -numeric_limits<float>::max();
>     fprintf(stderr,"v=%f\n", v );
> 
> When I run the program I always get the output
> 
>     v=-340282346638528859811704183484516925440.000000
> 
> However, when I run the program in gdb I sometimes get this
> 
>     375     float v = -numeric_limits<float>::max();
>     (gdb) 
>     376     fprintf(stderr,"v=%f\n", v );
>     (gdb) 
>     v=nan
> 
>       ^^^
> 
> Unfortunately, I seem to be unable to produce a small example program
> exhibiting this behavior.
> 
> I compile the program with g++ 3.0.4 using these options:
> 
>     -march=i686 -ansi -fno-default-inline -ffor-scope
>     -g3 -ggdb3 -Wall -W -Wpointer-arith
>     -Wcast-qual -Wcast-align -Wconversion -Woverloaded-virtual -Wsign-compare
>     -Wnon-virtual-dtor -Woverloaded-virtual -Wfloat-equal -Wmissing-prototypes
>     -Wunreachable-code -Wno-reorder -D_GNU_SOURCE 
> 
> Does anybody have any idea what might cause this differing behavior?
> 
> Thanks a lot in advance,
> Gabriel.
> 
> 
> -- 
> /---------------------------------------------------------------------\
> | The mind -- what is it?                                             |
> | It is the sound of the breeze                                       |
> | Blowing through the pines in the picture.        (Ikkyu)            |
> |                                                                     |
> | zach@cs.uni-bonn.de                 __@/'  Gabriel.Zachmann@gmx.net |
> | web.informatik.uni-bonn.de/~zach    __@/'   www.gabrielzachmann.org |
> \---------------------------------------------------------------------/

>  In a C++ program I have the following two lines:
>  
>      float v = -numeric_limits<float>::max();
>      fprintf(stderr,"v=%f\n", v );

Sorry I forgot to mention that this happened under RedHat 7.2
with the gdb version that comes with RedHat 7.2.

The good news is that it seems to have gone away with gdb 5.2 -
I compiled gdb5.2 myself, and so far I have not been able to reproduce the
bug - gdb always prints $5 = -3.40282347e+38, just as expected.

Thanks a lot for your quick responses!
Gab.

-- 
/---------------------------------------------------------------------\
| The mind -- what is it?                                             |
| It is the sound of the breeze                                       |
| Blowing through the pines in the picture.        (Ikkyu)            |
|                                                                     |
| zach@cs.uni-bonn.de                 __@/'  Gabriel.Zachmann@gmx.net |
| web.informatik.uni-bonn.de/~zach    __@/'   www.gabrielzachmann.org |
\---------------------------------------------------------------------/