HP 3000 Manuals

HP C Programmer's Guide

Removing Compilation Time Limits When Optimizing on HP-UX 

You can remove optimization time restrictions at the second, third, or
fourth optimization levels by using the +Onolimit option as follows:

     cc +O2 +Onolimit sourcefile.c 

or:

     cc +O3 +Onolimit sourcefile.c 

or:

     cc +O4 +Onolimit sourcefile.c 

By default, the optimizer limits the amount of time spent optimizing
large programs at levels 2, 3, and 4.  Use this option if longer compile
times are acceptable because you want additional optimizations to be
performed.

MPE/iX 5.0 Documentation