[MITgcm-support] problems on alpha machine

[Martin Losch]

Hezi,

looks like the iteration in carbon_chem, S/R CALC_PCO2 fails and 
results in inf for 'x' which then becomes htotal and 
phlocal=10**(htotal)? Maybe the authors of this piece of the code could 
say something about their experience with this iteration?

Your compiler seems to be very particular (o:

Martin
On Dec 6, 2005, at 8:04 PM, Hezi Gildor wrote:

>
> Dear Ed and Martin,
>
> Thanks for trying to help.
>
> I have tried all the -fpeX options as well as reducing the 
> optimization level but it didn't help.
>
> It seems that phlocal=-Infinity at certain location after 2 iteration 
> and then the code try to execute 10**(-Infinity). Still didn't find 
> when and why phlocal gets this value.
>
>
> as for the other problem, in diagnostics_main_init.F :
>
> i tried to define a separate character variable and assign 
> rUnit2c//'^2/s^2' to it but it didn't help. same when trying ' m' 
> instead of 'm '
>
> Thanks again..., hezi.
>
>
>
> Ed Hill wrote:
>
>> On Sun, 2005-12-04 at 12:03 +0100, Martin Losch wrote:
>>
>>> Hezi,
>>>
>>> has someone answered you, yet?
>>>
>>> The first problem looks like perfect F77 syntax to me, so I have no 
>>> clue why your compiler doesn't take it. Can it compile 
>>> rUnit2c//'^2'? Maybe one has to define a separate character 
>>> variable, assign rUnit2c//'^2/s^2' to it and then pass it to 
>>> diags_mk_units? This is really stupid but have you tried to set 
>>> rUnit2c = ' m' instead of 'm '?
>>>
>>
>> Hi Hezi,
>>
>> I think Martin is right and that it is valid syntax.  I'm sorry your
>> compiler doesn't like it.  Perhaps there is a compiler option that 
>> will
>> help?
>>
>>
>>> Maybe you can try reducing your optimization level. Again I don't 
>>> know your compiler, but -O5 sounds like aggressive optimization.
>>>
>>
>> Some compilers for the alpha architecture have options that will allow
>> you to turn off some or all floating-point exceptions (or make them 
>> only
>> issue warnings instead of stopping your program).  The options are
>> usually called "-fpeX" where X is a number in the range 0--4.  So 
>> please
>> take a look at your compiler documentation and see if there are any
>> options that can help.
>>
>> Ed
>>
>> ps - As a last resort, one can extend the recently-added signal     
>> handler code (MITgcm/eesupp/src/sigreg.c) to trap and ignore     any 
>> signals caused by floating point exceptions.  [This is
>>     what the "-fpe" options do.]
>>
>>
> _______________________________________________
> MITgcm-support mailing list
> MITgcm-support at mitgcm.org
> http://mitgcm.org/mailman/listinfo/mitgcm-support