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Re: Floating point exception in strtod()




On Sat, Apr 07, 2018 at 04:56:13PM -0400, Eliot Moss wrote:
> On 4/7/2018 1:40 PM, Ken Brown wrote:
> > $ cat strtod_test.c
> > #include <stdio.h>
> > #include <stdlib.h>
> > #include <fenv.h>
> >
> > int
> > main ()
> > {
> >    /* The following number comes from /usr/share/asymptote/ode.asy.  */
> >    const char *str = "121645100408832000.0";
> >    char *ptr;
> >
> >    feenableexcept (FE_INVALID);
> >    strtod (str, &ptr);
> >
> >    /* If there was an exception, the following will not get executed.  */
> >    printf ("No exception.\n");
> > }
>
> If I do the same thing WITHOUT the feenableexcept, it works fine.
> Perhaps strtod catches an exception and then applies a different
> method in some cases, or perhaps it wants exceptions off and
> deals with things its own way.
>
> If I include the feenableexcept, I get the same behavior you
> reported (in 32-bit; I did not test 64-bit).
>
> Regards - Eliot Moss
>
I tried in 64-bit with the same result as Eliot: works fine w/out
feenableexcept, no o/p with feenableexcept.

Cheers ... Duncan.

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