parallelizing options

[A Ramakrishna Rao]

           Can you provide me with some of the compiler options used for 
optimization of code (also through parallelization).

          We need this to benchmark the systems in our lab. We 've used 
linpack. We want to tune the performance  using some compiler options to 
enhance performance.

           IBM rs6000   (os: AIX 4.3)
           Compaq proliant 8000  ( redhat linux)
           origin 3400    ( IRIX 6.3)

  etc,,                                      
                                            Thank you.                   
                              Ramakrishna