Intel Fortran Compiler "-parallel" Not Working

I have a serial Fortran code that works fine. Once I compile the same code using ifort -parallel and run it, it gives wrong results and overflow. I would expect that with "-parallel" flag, the Intel compiler is capable of selecting the loops that are safe to parallelize and I should 开发者_如何学Goget the exact same results as for the serial code, which did not happen. The even more strange behaviour is that I went ahead and closed all the do loops parallelization in my code using !DEC$ NOPARALLEL, compiled the code using ifort -parallel to make sure that non of the loops was parallelized and then run. Surprisingly, I got the same wrong results and overflow, although the latter action should be exactly equivalent to a serial code.

Is there any one capable of explaining this behaviour or is it just an Intel compiler deficiency.

Greetings.

Sorry to say this, but it's unlikely to be an Intel compiler problem it's a pretty good compiler (no, I don't work for Intel ! but I do use their compilers).

Yes I am capable of explaining this sort of behaviour, but without sight of your program anything I suggest will be wrong.

Answers were given to this identical question on the Intel Fortran Forum: http://software.intel.com/en-us/forums/topic/269743

EDIT: I revised the link, since as stated in the comment, the original link is now dead.