Performance Advisor determines how your executables are compiled by looking for XL compiler transformation reports and the build output from builds launched from within the IDE.
If this information gets out of sync, for example because a build was run manually on the remote machine, or in a shell or terminal window, or because the -qlistfmt=xml=all option was removed but the existing transformation reports were not, Performance Advisor can give incorrect recommendations about compiler options.
If you suspect this is the case: