tune

Applies to C Applies to C++

Purpose

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

Syntax

                 .-ppc970-.
>>- -q--tune--=--+-auto---+------------------------------------><
 
 

where architecture suboptions are:


auto Produces object code optimized for the platfom on which it is compiled.
ppc970 Produces object code optimized for the PowerPC 970 processor.

See also #pragma options.

Default

The default setting of the -qtune option depends on the setting of the -qarch option. It should also be noted that -q64 affects the default for -qarch, and therefore also affects the default for -qtune.

Default -qtune settings for specific -qarch settings are described in Acceptable compiler mode and processor architecture combinations.

Notes

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

Example

To specify that the executable program testing compiled from myprogram.C is to be optimized for a PowerPC 970 hardware platform, enter:

xlc++ -o testing myprogram.C -qtune=ppc970

Related references

IBM Copyright 2003