gcc-you can use this code to learn something about gcc, and inquire further into linux,

				// Skip if not target: alpha*-*-*				// Special g++ Options: -Wno-deprecated								// This test verifies that return type promotion is working correctly.  				// The Alpha ABI specifies that 32-bit return values have bit 31 propagated,				// i.e. the value is sign-extended even if the unpromoted type is unsigned.								unsigned int f(unsigned int x) return y(x) { }								extern "C" void abort ();								int main()				{				  typedef long (*long_func)(long);				  long_func g = reinterpret_cast(f);								  if (g(-1L) != -1L)				    abort ();				  return 0;				}