numeric_limits<float>::max

[Gabriel Zachmann]

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.


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