Re: Problem with log function - Intel fortran compiler under Linux

On 4 okt, 15:35, Arjen Markus <arjen.mar...@xxxxxxxxxx> wrote:
Hello,

we are experiencing a rather nasty problem with the Intel Fortran
compiler under Linux
(version 9.0). The program is big and so far we have not been able to
trim the code
so that a moderately sized program displays the problem too.

The point is this:

The first application of the log function on double precision reals
causes
an NaN (while the argument is a perfectly acceptable value of about
0.6).

If we add a dummy statement like:

aa =log(r)

as one of the first statements, the value of aa becomes NaN and some
later computations
succeed. (NaNs occur at a different positions).

Here is some more information:

Intel Fortran: 9.0
Linux: Red Hat Enterprise Linux, ES release 4.

Has anyone encounter similar problems? Does anyone know how to solve
this problem?

Regards,

Arjen

Hm, things are brightening a bit:
- My original posting reflected the situation with all
sources compiled with debugging on
- I then tried with debugging on and array bound checking
- no error message about possible array bound violation
but the first NaN appears later on
- Without any options (so only the defaults) the first
NaN appears earlier on.

Especially this latter observation means that I have
a lot less code to worry about :)

Regards,

Arjen

.

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