Defaults

The default is no optimization. However, this is only possible if you do not specify an optimization level. If you specify an optimization level, there is no option for turning optimization off.

If you are trying to avoid setting an optimization level, be sure not to specify any option that implies an optimization level. For example, -fast is a macro option that sets optimization at -xO5. All other options that imply an optimization level give a warning message that optimization has been set. The only way to compile without any optimization is to delete all options from the command line or make file that specify an optimization level.