Sun Studio 12: C++ User's Guide

A.2.112 -xcg[89|92]

(SPARC) Obsolete, do not use this option. Current Solaris operating system software no longer support SPARC V7 architecture. Compiling with this option generates code that runs slower on current SPARC platforms. Use -O instead and take advantage of compiler defaults for -xarch, -xchip, and -xcache.