tune

Option Type	Default Value	#pragma options	C	C++
-qoption	See below.	TUNE=suboption	x	x

Syntax

    -qtune=suboption 
    TUNE=suboption

Purpose Specifies the architecture system for which the executable program is optimized.

NotesAllowable values for suboption are:

`auto`	Automatically detects the specific architecture of the compiling machine. Use this suboption only if the execution environment is the same as the compilation environment.
`403`	Produces object code optimized for the PowerPC 403 processor.
`601`	Produces object code optimized for the PowerPC 601 processor.
`603`	Produces object code optimized for the PowerPC 603 processor.
`604`	Produces object code optimized for the PowerPC 604 processor.
`p2sc`	Produces object code optimized for the PowerPC P2SC processor.
`pwr`	Produces object code optimized for the POWER hardware platforms.
`pwr2`	Produces object code optimized for the POWER2 hardware platforms.
`pwr2s`	Produces object code optimized for the POWER2 hardware platforms, avoiding certain quadruple-precision instructions that would slow program performance.
`pwrx`	Produces object code optimized for the POWER2 hardware platforms (same as -qtune=pwr2).
rs64a	Produces object code optimized for the RS64A processor.
rs64b	Produces object code optimized for the RS64B processor.

If -qtune is specified without -qarch=suboption, the compiler uses -qarch=com.

You can use -qtune=suboption with -qarch=suboption.

-qarch=suboption specifies the architecture for which the instructions are to be generated, and,
-qtune=suboption specifies the target platform for which the code is optimized.

Default The default setting of the -qtune= option depends on the setting of the -qarch= option.

If -qtune is specified without -qarch, the compiler uses -qarch=com.
If -qarch is specified without -qtune=, the compiler uses the default tuning option for the specified architecture. Listings will show only:
```
    TUNE=DEFAULT
```

To find the actual default -qtune setting for a given -qarch setting, refer to the Acceptable Compiler Mode and Processor Architecture Combinations table.

Example To specify that the executable program testing compiled from myprogram.c is to be optimized for a POWER hardware platform, enter:

xlC -o testing myprogram.c -qtune=pwr