1. A compiler for compiling a first computer program written in a first computer programming language into a second computer program, the compiler comprises a code generator to generate the second computer program by generating tables and machine language code, the generated tables and the generated machine language code together forming the second computer program, the generated machine language code referencing the tables, wherein the compiler is configured to identify an arithmetic or logical expression in the first computer program, the expression depending on at least one variable, and the code generator is configured to generate one or more tables representing pre-computed results of the identified expression for multiple values of the variable and to generate machine language code to implement the identified expression in the second computer program by accessing the generated one or more tables representing pre-computed results, and wherein the machine language code generated to implement the identified expression does not contain arithmetic or logic machine instructions, and/or does not contain conditional machine instructions.