[MITgcm-support] ifort optimization puzzle

[Constantinos Evangelinos]

On Wednesday 09 March 2005 02:40 am, Martin Losch wrote:

> So, what do I do now? I have recompile find_rho with -O0 (the rest with
> -O1) and everything looks OK, but maybe I can find out what type of
> statement produces the problem and replace it by something more stable.
> Does anyone know offhand the compiler directives for ifort that make
> the compile vectorize or not vectorize specifice loops?

Even -O3 will not do any vectorization of loops without a -axW/N flag. So the 
issue is not vectorization but some rather innocuous (but in this case 
deadly) optimization that the compiler does.

Constantinos
-- 
Dr. Constantinos Evangelinos
Department of Earth, Atmospheric and Planetary Sciences
Massachusetts Institute of Technology