Sorry the error is: mulhtest2.c:33: error: syntax error before ':' token mulhtest2.c:42: error: syntax error before string constant mulhtest2.c:42:51: macro "MULH_ASM" requires 4 arguments, but only 2 given mulhtest2.c:42: error: conflicting types for 'printf' mulhtest2.c:42: note: a parameter list with an ellipsis can't match an empty par ameter name list declaration mulhtest2.c:42: error: conflicting types for 'printf' mulhtest2.c:42: note: a parameter list with an ellipsis can't match an empty par ameter name list declaration mulhtest2.c:42: warning: data definition has no type or storage class I compiled wrong source.