[MITgcm-devel] [MITgcm-cvs] MITgcm/tools/build_options CVS Commit

[Menemenlis, Dimitris (3248)]

Has anyone actually tested that "-fp-model precise -ftz" breaks the restart?
I thought that "-mp" implies "-ftz" and that is why EVP code runs fine with "-mp".
If noone has tested restarts with "-fp-model precise -ftz", I can put it on my todo list.
Dimitris

On Apr 26, 2010, at 8:41 AM, Constantinos Evangelinos wrote:

> On Saturday 24 April 2010 07:42:55 pm Jean-Michel Campin wrote:
>> Hi Dimitris,
>> 
>> I think that if your modified optfile degrade the results of
>> the 2+2 test, it's better to go back and leave the new option
>> commented: the reason is that it's quiet nice to be able
>> to restart exactly, and if it's no longer the case, it could
>> disturb other users. I personally don't run the 2+2 test very
>> often (apart from the standard verification tests), and it might
>> take them some time to realize that they lost this capability.
> 
> So essentially we have an option (-mp) that works but is not going to be there 
> in the Intel 12.0 compilers while its suggested equivalent option (-fp-model 
> precise) is producing underflows in the EVP solver slowing it down immensely 
> and at the same time a modification to -fp-model precise to avoid the 
> underflows (-ftz) breaks the restart... What a mess. 
> 
> Constantinos