An operator definition file 102 and the like included in a source program 101 and a compiler 100 that translates the source program 101 into a machine language program 105 are provided. The operator definition file 102 includes definitions of various fixed point type operators by class definitions. The compiler 100 can generate effectively advanced and specific instructions that a processor executes and make improvements through expanding functions and the like without repeating frequently upgrading of the version of the compiler itself. The compiler 100 is made up of an intermediate code generation unit 121 that generates intermediate codes, a machine language instruction substitution unit 122 that substitutes the intermediate codes referring to classes defined by the operator definition file 102 with machine language instructions and an optimization unit 130 that performs optimization targeting the intermediate codes including the substituted machine language instructions.