C++ User's Guide

Defaults

If the -R option is not present, the library search path that is that is recorded in the output object and passed to the runtime linker depends upon the target architecture instruction specified by the -xarch option (when -xarch is not present, -xarch=generic is assumed).

-xarch Value

Default Library Search Path 

v9 or v9a

install_dir/SUNWspro/lib/v9

All other values 

install_dir/SUNWspro/lib

With a standard install, install-path is /opt.