Tuning for your system architecture
You can instruct the compiler to generate code for optimal execution on a given microprocessor or architecture family. By selecting appropriate target machine options, you can optimize to suit the broadest possible selection of target processors, a range of processors within a given family of processor architectures, or a specific processor.
The following table lists the optimization options that affect individual aspects of the target machine. Using a predefined optimization level sets default values for these individual options.
| Option | Behavior |
|---|---|
| -mcpu | Selects a family of processor architectures for which instruction code should be generated. This option restricts the instruction set generated to a subset of that for the PowerPC® architecture. See Getting the most out of target machine options for more information about this option. |
| -mtune | Biases optimization toward execution on a given microprocessor, without implying anything about the instruction set architecture to be used as a target. See Getting the most out of target machine options for more information about this option. |
| -qcache | Defines a specific cache or memory geometry. The defaults are determined through the setting of -mtune. See Getting the most out of target machine options for more information about this option. |
