The /Gq option is provided to maintain functional compatibility with earlier versions of the /GW option. It generates entry/exit code for real-mode Windows functions not explicitly marked __export. The /Gq option affects an entire compilation module; use the /Gw option (described later in this chapter) instead of the /Gq option if a module contains functions marked as __export.
The entry/exit code that the /Gq option generates does not save the calling function's data segment (DS). Use the new /GW option (which does save DS) if DS might change during the time a function is on the call stack. The /GW option is described later in this chapter.