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.

Notes
Allowable values for suboption are:

auto Produces object code optimized for the hardware platfom on which it is compiled.
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.
pwr3 Produces object code optimized for the POWER3 hardware platforms.
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.
rs64c Produces object code optimized for the RS64C processor.

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

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

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

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


Specifying Compiler Options for Architecture-Specific, 32- or 64-bit Compilation


Acceptable Compiler Mode and Processor Architecture Combinations
List of Batch Compiler Options and Their Defaults
Options that Define the Compiler Object Code Produced
Equivalent Batch Compile-Link and Incremental Build Options