The most Important topics are
Parsers and parsing tables:
Top-down parsers : recursive descent parser, LL(1) parser {here most important thing is First() and Follow()}
How to check a given grammar is LL(1) grammar or not.
Bottom-Up parsers : LR(0) parser, SLR(1) parser, LALR(1) parser, CLR(1) parser and their respective parsing tables.
Here, most important thing is Action() and Goto()
How to check given grammar is LR(0) grammar, SLR(1) grammar, LALR(1) grammar, CLR(1) grammar.
Syntax Directed Translation:
How to construct SDT and how to evaluate it.
Intermediate Code Generator:
3-address code and control flow graph, postfix notation, syntax tree, Directed Acyclic Graph(DAG) here DAG is most important.
Data flow analyses:
Constant propagation, liveness analysis, common subexpression elimination.
Run time environment
and some small concepts like :checking for ambiguous grammar, left factoring, left recursion. Lexical analyzer etc.
