-qtune

The -qtune argument specifies the type of processor for which the program should be tuned to produce the best performance. Tuning for a processor involves instruction selection, scheduling, taking advantage of cache sizes and setting up pipelining to take advantage of the specified processor's hardware. Unlike the -qarch option, this option does not produce processor specific code. A code that is compiled with a -qtune argument designated for one type of processor will run correctly on any other POWER or POWERPC processor, although its performance may be worse than it would be if it were compiled with the appropriate -qtune argument.

The recommended value for this argument is

      -qtune=auto

The -qtune=auto option tells the compiler to produce a program tuned for the processor on which it is compiled.