The Intel® C++ Compiler and gcc* support the following predefined macros:
You can specify the -no-gcc option to undefine these macros. If you need gcc interoperability (-cxxlib-gcc), do not use the -no-gcc compiler option.
Not defining these macros results in different paths through system header files. These alternate paths may be poorly tested or otherwise incompatible.
See also Predefined Macros and GNU Environment Variables.