Compilers: Principles and Practice

B.1 Assembly Languages

There are five major advantages of assembly language, as compared to machine language:

1. It uses mnemonic op-codes, we do not need to remember actual bit-patterns of the op-code. For example, referring to 8085 microprocessor, we can write ‘ADD A’ instead of ‘87’ in hex.
2. Addresses can be given as symbolic addresses instead of numeric values. The assembler keeps track of the symbolic addresses by building a Symbol Table.
3. It is more human readable.
4. It makes available certain auxiliary operations like defining data and storage areas, setting the origin of a program segment, etc.
5. It may provide address arithmetic, macros, scoping of identifier names, conditional assembly, ready-made macros or subroutine library for input/output, ...