Fwd: exp sets the errno to ERANGE error .

Fwd: exp sets the errno to ERANGE error .

[Umesh Kalappa]

Hi everyone ,

we have situations ,where the following program sets the errno to
34(range error) in the version 2.28

$cat test.c
int main() {
printf("errno %d\n", errno);
printf("%f\n", exp(-1421.0));
printf("errno %d\n", errno);
}

according the C11 standard the exp should not set the errno to ERANGE
when it underflow to zero .

so we think that  glibc (atleast 2.28) is not consistent with the C
standard and any comments regrading the same .

Thank you  and looking forward for any suggestions / comments.
~Umesh

Re: Fwd: exp sets the errno to ERANGE error .

[Florian Weimer]

* Umesh Kalappa:

> Hi everyone ,
>
> we have situations ,where the following program sets the errno to
> 34(range error) in the version 2.28
>
> $cat test.c
> int main() {
> printf("errno %d\n", errno);
> printf("%f\n", exp(-1421.0));
> printf("errno %d\n", errno);
> }
>
> according the C11 standard the exp should not set the errno to ERANGE
> when it underflow to zero .
>
> so we think that  glibc (atleast 2.28) is not consistent with the C
> standard and any comments regrading the same .
>
> Thank you  and looking forward for any suggestions / comments.
> ~Umesh

There's a thread covering this on libc-alpha already.

Thanks,
Florian