The compiler has many options to improve your source code and the generated files. Click on Options, then on Compiler options to show them. In the dialog box, click on the desired options to select them.
You can also add another command when calling the compiler. If you want to get more help about each commands, launch the help file gcc.hlp located in the Help directory.
When you selected your options, click on OK to save them. You can press Cancel to quit the dialog without saving or on Default to reset the default compiler options.