Specifies the architecture system for which the executable program is optimized.
.-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.
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.
You can use -qtune=suboption with -qarch=suboption.
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