Hi Chandra, > My requirement is not generate two executable outputs. It is not relevant whether the output is executable, object code, shared library, or archive library, or even pre-processor (-E). What is relevant is producing more-than-one output, such as two objects files, with different -f and/or -D compiler switches. > I want do the following under a new command line option to gcc (new option is needed because it is unusual producing two object files in single compilation) The problem remains the same as in my previous email. The problem being the one where you are trying to reduce compilation time. No compilation time reduction is possible in the scenario you describe. Sincerely, --Eljay